VLDB 2026 Research / reviewers in the wild / expert
Sarvapali D. Ramchurn
dblp:81/1719 · also Sarvapali Dyanand Ramchurn
· DBLP profile ↗
91ranked-venue papers
10as first author
20since 2021 · last 2025
0000-0001-9686-4302ORCID · verified
Domains — the database's venue-derived domains; a paper can count in several
Artificial intelligence and machine learning · 56 · 7 first-author · 14 since 2021Graphics, computer vision, multimedia, augmented reality and games · 30 · 1 first-author · 4 since 2021Human-computer interaction and ubiquitous computing · 23 · 1 first-author · 5 since 2021Applied, interdisciplinary, general and emerging computing · 9 · 1 first-author · 2 since 2021Databases, data management, data science and information retrieval · 7 · 1 first-author · 2 since 2021Systems, architecture and hardware · 4 · 3 since 2021Computer networks · 2 · 1 since 2021Theory of computation · 2 · 1 since 2021
| Year | Publication | Venue | Position |
|---|---|---|---|
| 2025 | Optimising Spatial Teamwork Under UncertaintyabstractWe introduce a novel method for assessing agent teamwork based on their spatial coordination. Our approach models the influence of spatial proximity on team formation and sustained spatial dominance over adversaries using a Multi-agent Markov Decision Process. We develop an algorithm to derive efficient teamwork strategies by combining Monte Carlo Tree Search and linear programming. When applied to team defence in football (soccer) using real-world data, our approach reduces opponent threat by 21%, outperforming optimised individual behaviour by 6%. Additionally, our model enhances the predictive accuracy of future attack locations and provides deeper insights compared to existing teamwork models that do not explicitly consider the spatial dynamics of teamwork. Gregory Everett, Ryan Beal, Tim Matthews, Timothy J. Norman, Sarvapali D. Ramchurn |
AAAI | 5 |
| 2025 | Evaluating Defensive Influence in Multi-Agent Systems Using Graph Attention NetworksabstractEvaluating individual contributions from team members is a critical challenge across many domains, such as security and team sports. While progress has been made in valuing contributions, such as target defence in security or on-ball performance in football (soccer), many aspects of performance, such as off-ball football actions, remain difficult to quantify. We introduce GAPP, a Graph Attention Network model that predicts football pass reception probabilities and provides interpretable insights into off-ball defending. Using attention mechanisms, GAPP captures player interactions and introduces two new metrics to quantify defender contributions. We tested GAPP on 306 English Premier League matches, and showed it reduces binary cross-entropy loss by 6.4 percent compared to multiple baselines for pass reception prediction, while offering unique insights for off-ball defender evaluation for coaches, scouts and teams. This work shows the potential of graph attention networks for analysing complex multi-agent systems like football. Gregory Everett, Ryan Beal, Tim Matthews, Timothy J. Norman, Sarvapali D. Ramchurn |
DSAA | 5 |
| 2025 | Serious Games for Ethical Preference Elicitation
Jayati Deshmukh, Zijie Liang, Vahid Yazdanpanah, Sebastian Stein 0001, Sarvapali D. Ramchurn |
AAMAS | 5 |
| 2025 | Safe Pruning LoRA: Robust Distance-Guided Pruning for Safety Alignment in Adaptation of LLMsabstractAbstract Fine-tuning Large Language Models (LLMs) with Low-Rank Adaptation (LoRA) enhances adaptability while reducing computational costs. However, fine-tuning can compromise safety alignment, even with benign data, increasing susceptibility to harmful outputs. Existing safety alignment methods struggle to capture complex parameter shifts, leading to suboptimal safety-utility trade-offs. To address this issue, we propose Safe Pruning LoRA (SPLoRA), a novel pruning-based approach that selectively removes LoRA layers that weaken safety alignment, improving safety while preserving performance. At its core, we introduce Empirical-DIEM (E-DIEM), a dimension-insensitive similarity metric that effectively detects safety misalignment in LoRA-adapted models. We conduct extensive experiments on LLMs fine-tuned with mixed of benign and malicious data, and purely benign datasets, evaluating SPLoRA across utility, safety, and reliability metrics. Results demonstrate that SPLoRA outperforms state-of-the-art safety alignment techniques, significantly reducing safety risks while maintaining or improving model performance and reliability. Additionally, SPLoRA reduces inference overhead, making it a scalable and efficient solution for deploying safer and more reliable LLMs. The code is available at https://github.com/AoShuang92/SPLoRA. Shuang Ao, Yi Dong 0002, Jinwei Hu 0001, Sarvapali D. Ramchurn |
Trans. Assoc. Comput. Linguistics | 4 |
| 2025 | A User Study Evaluation of Predictive Formal Modelling at Runtime in Human-Swarm InteractionabstractFormal Modelling is often used as part of the design and testing process of software development to ensure that components operate within suitable bounds even in unexpected circumstances. We conducted a user study evaluation of predictive formal modelling (PFM) at runtime in a human-swarm mission to determine the benefit of PFM on performance and human-swarm interaction. A total of 180 participants were recruited to perform the role of aerial swarm operators delivering parcels to target locations in a simulation environment. The PFM model was integrated into the simulation software to inform the operator of the estimated mission completion time given the current number of drones deployed. The operator could increase the number of parcels delivered in any timestep by adding drones, which also increased costs, thus requiring the use of the minimum number of drones necessary to complete the task in the given time. We collected user feedback using standard survey questionnaires and measured performance using data obtained from the Human and Robot Interactive Swarm (HARIS) simulator. Our results show that PFM increased the performance of the human swarm team without significantly increasing the operators’ workload or affecting the system’s usability. Ayodeji Opeyemi Abioye, William Hunt, Eike Schneiders, Mohammad Naiseh, Blair Archibald, Michele Sevegnani, Sarvapali D. Ramchurn, Joel E. Fischer, Mohammad Divband Soorati |
ACM Trans. Hum. Robot Interact. | 8 |
| 2024 | Learning to Imitate Spatial Organization in Multi-robot SystemsabstractUnderstanding collective behavior and how it evolves is important to ensure that robot swarms can be trusted in a shared environment. One way to understand the behavior of the swarm is through collective behavior reconstruction using prior demonstrations. Existing approaches often require access to the swarm controller which may not be available. We reconstruct collective behaviors in distinct swarm scenarios involving shared environments without using swarm controller information. We achieve this by transforming prior demonstrations into features that describe multi-agent interactions before behavior reconstruction with multi-agent generative adversarial imitation learning (MA-GAIL). We show that our approach outperforms existing algorithms in spatial organization, and can be used to observe and reconstruct a swarm’s behavior for further analysis and testing, which might be impractical or undesirable on the original robot swarm. Ayomide O. Agunloye, Sarvapali D. Ramchurn, Mohammad Divband Soorati |
IROS | 2 |
| 2023 | The Effect of Data Visualisation Quality and Task Density on Human-Swarm InteractionabstractDespite the advantages of having robot swarms, human supervision is required for real-world applications. The performance of the human-swarm system depends on several factors including the data availability for the human operators. In this paper, we study the human factors aspect of the human-swarm interaction and investigate how having access to high-quality data can affect the performance of the human-swarm system— the number of tasks completed and the human trust level in operation. We designed an experiment where a human operator is tasked to operate a swarm to identify casualties in an area within a given time period. One group of operators had the option to request high-quality pictures while the other group had to base their decision on the available low-quality images. We performed a user study with 120 participants and recorded their success rate (directly logged via the simulation platform) as well as their workload and trust level (measured through a questionnaire after completing a human-swarm scenario). The findings from our study indicated that the group granted access to high-quality data exhibited an increased workload and placed greater trust in the swarm, thus confirming our initial hypothesis. However, we also found that the number of accurately identified casualties did not significantly vary between the two groups, suggesting that data quality had no impact on the successful completion of tasks Ayodeji Opeyemi Abioye, Mohammad Naiseh, William Hunt, Jed Clark, Sarvapali D. Ramchurn, Mohammad Divband Soorati |
RO-MAN | 5 |
| 2023 | Trustworthy UAV Relationships: Applying the Schema Action World Taxonomy to UAVs and UAV Swarm OperationsabstractHuman Factors play a significant role in the development and integration of avionic systems to ensure that they are trusted and can be used effectively. As Unoccupied Aerial Vehicle (UAV) technology becomes increasingly important to the aviation domain this holds true. This study aims to gain an understanding of UAV operators’ trust requirements when piloting UAVs by utilising a popular aviation interview methodology (Schema World Action Research Method), in combination with key questions on trust identified from the literature. Interviews were conducted with six UAV operators, with a range of experience. This identified the importance of past experience to trust and the expectations that operators hold. Recommendations are made that target training to inform experience, in addition to the equipment, procedures and organisational standards that can aid in developing trustworthy systems. The methodology that was developed shows promise for capturing trust within human-automation interactions. Katie J. Parnell, Joel E. Fischer, Jed Clark, Adrian Bodenmann, Maria Jose Galvez Trigo, Mario Brito, Mohammad Divband Soorati, Katherine L. Plant, Sarvapali D. Ramchurn |
Int. J. Hum. Comput. Interact. | 9 |
| 2022 | Revisiting Deep Fisher Vectors: Using Fisher Information to Improve Object Classification
Sarah Ahmed, Tayyaba Azim, Joseph Early, Sarvapali D. Ramchurn |
BMVC | 4 |
| 2022 | Trustworthy Autonomous Systems (TAS): Engaging TAS experts in curriculum designabstractRecent advances in artificial intelligence, specifically machine learning, contributed positively to enhancing the autonomous systems industry, along with introducing social, technical, legal and ethical challenges to make them trustworthy. Although Trustworthy Autonomous Systems (TAS) is an established and growing research direction that has been discussed in multiple disciplines, e.g., Artificial Intelligence, Human-Computer Interaction, Law, and Psychology. The impact of TAS on education curricula and required skills for future TAS engineers has rarely been discussed in the literature. This study brings together the collective insights from a number of TAS leading experts to highlight significant challenges for curriculum design and potential TAS required skills posed by the rapid emergence of TAS. Our analysis is of interest not only to the TAS education community but also to other researchers, as it offers ways to guide future research toward operationalising TAS education. Mohammad Naiseh, Caitlin M. Bentley, Sarvapali D. Ramchurn |
EDUCON | 3 |
| 2022 | Model Agnostic Interpretability for Multiple Instance Learning
Joseph Early, Christine Evers, Sarvapali D. Ramchurn |
ICLR | 3 |
| 2022 | Collective Decision Making in Communication-Constrained EnvironmentsabstractOne of the main tasks for autonomous robot swarms is to collectively decide on the best available option. Achieving that requires a high quality communication between the agents that may not always be available in a real world environment. In this paper we introduce the communication-constrained collective decision-making problem where some areas of the environment limit the agents' ability to communicate, either by reducing success rate or blocking the communication channels. We propose a decentralised algorithm for mapping environmental features for robot swarms as well as improving collective decision making in communication-limited environments without prior knowledge of the communication landscape. Our results show that making a collective aware of the communication environment can improve the speed of convergence in the presence of communication limitations, at least 3 times faster, without sacrificing accuracy. Thomas G. Kelly, Mohammad Divband Soorati, Klaus-Peter Zauner, Sarvapali D. Ramchurn, Danesh Tarapore |
IROS | 4 |
| 2022 | Non-Markovian Reward Modelling from Trajectory Labels via Interpretable Multiple Instance LearningabstractWe generalise the problem of reward modelling (RM) for reinforcement learning (RL) to handle non-Markovian rewards. Existing work assumes that human evaluators observe each step in a trajectory independently when providing feedback on agent behaviour. In this work, we remove this assumption, extending RM to capture temporal dependencies in human assessment of trajectories. We show how RM can be approached as a multiple instance learning (MIL) problem, where trajectories are treated as bags with return labels, and steps within the trajectories are instances with unseen reward labels. We go on to develop new MIL models that are able to capture the time dependencies in labelled trajectories. We demonstrate on a range of RL tasks that our novel MIL models can reconstruct reward functions to a high level of accuracy, and can be used to train high-performing agent policies. Joseph Early, Tom Bewley, Christine Evers, Sarvapali D. Ramchurn |
NeurIPS | 4 |
| 2021 | Combining Machine Learning and Human Experts to Predict Match Outcomes in Football: A Baseline ModelabstractIn this paper, we present a new application-focused benchmark dataset and results from a set of baseline Natural Language Processing and Machine Learning models for prediction of match outcomes for games of football (soccer). By doing so we give a baseline for the prediction accuracy that can be achieved exploiting both statistical match data and contextual articles from human sports journalists. Our dataset is focuses on a representative time-period over 6 seasons of the English Premier League, and includes newspaper match previews from The Guardian. The models presented in this paper achieve an accuracy of 63.18% showing a 6.9% boost on the traditional statistical methods. Ryan Beal, Stuart E. Middleton, Timothy J. Norman, Sarvapali D. Ramchurn |
AAAI | 4 |
| 2021 | BOSS: A Bi-directional Search Technique for Optimal Coalition Structure Generation with Minimal Overlapping (Student Abstract)abstractIn this paper, we focus on the Coalition Structure Generation (CSG) problem, which involves finding exhaustive and disjoint partitions of agents such that the efficiency of the entire system is optimized. We propose an efficient hybrid algorithm for optimal coalition structure generation called BOSS. When compared to the state-of-the-art, BOSS is shown to perform better by up to 33.63% on benchmark inputs. The maximum time gain by BOSS is 3392 seconds for 27 agents. Narayan Changder, Samir Aknine, Sarvapali D. Ramchurn, Animesh Dutta |
AAAI | 3 |
| 2021 | Large-Scale, Dynamic and Distributed Coalition Formation with Spatial and Temporal Constraints
Luca Capezzuto, Danesh Tarapore, Sarvapali D. Ramchurn |
EUMAS | 3 |
| 2021 | What Happened Next? Using Deep Learning to Value Defensive Actions in Football Event-DataabstractObjectively quantifying the value of player actions in football (soccer) is a challenging problem. To date, studies in football analytics have mainly focused on the attacking side of the game, while there has been less work on event-driven metrics for valuing defensive actions (e.g., tackles and interceptions). Therefore in this paper, we use deep learning techniques to define a novel metric that values such defensive actions by studying the threat of passages of play that preceded them. By doing so, we are able to value defensive actions based on what they prevented from happening in the game. Our Defensive Action Expected Threat (DAxT) model has been validated using real-world event-data from the 2017/2018 and 2018/2019 English Premier League seasons, and we combine our model outputs with additional features to derive an overall rating of defensive ability for players. Overall, we find that our model is able to predict the impact of defensive actions allowing us to better value defenders using event-data. Charbel Merhej, Ryan Beal, Tim Matthews, Sarvapali D. Ramchurn |
KDD | 4 |
| 2021 | Partner selection in self-organised wireless sensor networks for opportunistic energy negotiation: A multi-armed bandit based approach
Andre P. Ortega, Sarvapali D. Ramchurn, Long Tran-Thanh, Geoff V. Merrett |
Ad Hoc Networks | 2 |
| 2021 | In-the-loop or on-the-loop? Interactional arrangements to support team coordination with a planning agentabstractSummary In this paper, we present the study of interactional arrangements that support the collaboration of headquarters (HQ), field responders, and a computational planning agent in a time‐critical task setting created by a mixed‐reality game. Interactional arrangements define the extent to which control is distributed between the collaborative parties. We provide 2 field trials, one to study an “on‐the‐loop” arrangement in which HQ monitors and intervenes in agent instructions to field players on demand and the other, to study a version that places HQ more tightly “in‐the‐loop.” The studies provide an understanding of the sociotechnical collaboration between players and the agent in these interactional arrangements by conducting interaction analysis of video recordings and game log data. The first field trial focuses on the collaboration of field responders with the planning agent. Findings highlight how players negotiate the agent guidance within the social interaction of the collocated teams. The second field trial focuses on the collaboration between the automated planning agent and the HQ. We find that the human coordinator and the agent can successfully work together in most cases, with human coordinators inspecting and “correcting” the agent‐proposed plans. Through this field trial‐driven development process, we generalise interaction design implications of automated planning agents around the themes of supporting common ground and mixed‐initiative planning. Joel E. Fischer, Christopher Greenhalgh, Wenchao Jiang, Sarvapali D. Ramchurn, Feng Wu 0001, Tom Rodden |
Concurr. Comput. Pract. Exp. | 4 |
| 2021 | Seeing (Movement) is Believing: The Effect of Motion on Perception of Automatic Systems PerformanceabstractIn this article, we report on one lab study and seven follow-up studies on a crowdsourcing platform designed to investigate the potential of animation cues to influence users’ perception of two smart systems: a handwriting recognition and a part-of-speech tagging system. Results from the first three studies indicate that animation cues can influence a participant’s perception of both systems’ performance. The subsequent three studies, designed to try and identify an explanation for this effect, suggest that this effect is related to the participants’ mental model of the smart system. The last two studies were designed to characterize the effect more in detail, and they revealed that different amounts of animation do not seem to create substantial differences and that the effect persists even when the system’s performance decreases, but only when the difference in performance level between the systems being compared is small. Pedro Garcia Garcia, Enrico Costanza, Jhim Kiel M. Verame, Diana Nowacka, Sarvapali D. Ramchurn |
Hum. Comput. Interact. | 5 |
| 2020 | Learning the Value of Teamwork to Form Efficient TeamsabstractIn this paper we describe a novel approach to team formation based on the value of inter-agent interactions. Specifically, we propose a model of teamwork that considers outcomes from chains of interactions between agents. Based on our model, we devise a number of network metrics to capture the contribution of interactions between agents. This is then used to learn the value of teamwork from historical team performance data. We apply our model to predict team performance and validate our approach using real-world team performance data from the 2018 FIFA World Cup. Our model is shown to better predict the real-world performance of teams by up to 46% compared to models that ignore inter-agent interactions. Ryan Beal, Narayan Changder, Timothy J. Norman, Sarvapali D. Ramchurn |
AAAI | 4 |
| 2020 | ODSS: Efficient Hybridization for Optimal Coalition Structure GenerationabstractCoalition Structure Generation (CSG) is an NP-complete problem that remains difficult to solve on account of its complexity. In this paper, we propose an efficient hybrid algorithm for optimal coalition structure generation called ODSS. ODSS is a hybrid version of two previously established algorithms IDP (Rahwan and Jennings 2008) and IP (Rahwan et al. 2009). ODSS minimizes the overlapping between IDP and IP by dividing the whole search space of CSG into two disjoint sets of subspaces and proposes a novel subspace shrinking technique to reduce the size of the subspace searched by IP with the help of IDP. When compared to the state-of-the-art against a wide variety of value distributions, ODSS is shown to perform better by up to 54.15% on benchmark inputs. Narayan Changder, Samir Aknine, Sarvapali D. Ramchurn, Animesh Dutta |
AAAI | 3 |
| 2020 | Monte-Carlo Tree Search for Scalable Coalition FormationabstractWe propose a novel algorithm based on Monte-Carlo tree search for the problem of coalition structure generation (CSG). Specifically, we find the optimal solution by sampling the coalition structure graph and incrementally expanding a search tree, which represents the partial space that has been searched. We prove that our algorithm is complete and converges to the optimal given sufficient number of iterations. Moreover, it is anytime and can scale to large CSG problems with many agents. Experimental results on six common CSG benchmark problems and a disaster response domain confirm the advantages of our approach comparing to the state-of-the-art methods. Feng Wu 0001, Sarvapali D. Ramchurn |
IJCAI | 2 |
| 2020 | Solving the fair electric load shedding problem in developing countriesabstractAbstract Often because of limitations in generation capacity of power stations, many developing countries frequently resort to disconnecting large parts of the power grid from supply, a process termed load shedding. This leaves households in disconnected parts without electricity, causing them inconvenience and discomfort. Without fairness being taken into due consideration during load shedding, some households may suffer more than others. In this paper, we solve the fair load shedding problem (FLSP) by creating solutions which connect households to supply based on some fairness criteria (i.e., to fairly connect homes to supply in terms of duration, their electricity needs, and their demand), which we model as their utilities. First, we briefly describe some state-of-art household-level load shedding heuristics which meet the first criteria. Second, we model the FLSP as a resource allocation problem, which we formulate into two Mixed Integer Programming (MIP) problems based on the Multiple Knapsack Problem. In so doing, we use the utilitarian, egalitarian and envy-freeness social welfare metrics to develop objectives and constraints that ensure our FLSP solutions results in fair allocations that consider the utilities of agents. Then, we solve the FLSP and show that our MIP models maximize the groupwise and individual utilities of agents, and minimize the differences between their pairwise utilities under a number of experiments. When taken together, our endeavour establishes a set of benchmarks for fair load shedding schemes, and provide insights for designing fair allocation solutions for other scarce resources. Olabambo I. Oluwasuji, Obaid Malik, Jie Zhang 0008, Sarvapali D. Ramchurn |
Auton. Agents Multi Agent Syst. | 4 |
| 2020 | Offline and Online Electric Vehicle Charging Scheduling With V2V Energy TransferabstractWe propose offline and online scheduling algorithms for the charging of electric vehicles (EVs) in a single charging station (CS). The station has available cheaper, but limited, energy from renewable energy sources (RES). The EVs are capable of and willing to participate in vehicle-to-vehicle (V2V) energy transfers that are used to reduce the charging cost and increase the RES utilization. The algorithms are centralized and aim to minimize the total charging cost for the EVs. We formulate the problem as a mixed integer programming (MIP) one and we solve it optimally assuming full knowledge of the EV demand and energy generation. Later, we propose an online algorithm that iteratively calls the offline one and copes with unknown future interruptions by arriving the EVs and with the inability to predict accurately RES production. In addition, a novel technique called virtual demand is developed that increases the demand of already existing EVs, in order to store renewable energy and later transfer it via V2V to EVs that will arrive at the CS in the future. This technique is used for mitigating the inefficiency due to the uncertainty about future actions that real-time scheduling entails. In a setting with up to 150 EVs and using real data regarding the RES production, our algorithms are shown to have low execution times, while the use of virtual demand increases RES utilization by 12% and reduces cost by 3.3%. Alexandros Koufakis, Emmanouil Rigas, Nick Bassiliades, Sarvapali D. Ramchurn |
IEEE Trans. Intell. Transp. Syst. | 4 |
| 2019 | Tracking the Consumption of Home EssentialsabstractPredictions of people's behaviour increasingly drive interactions with a new generation of IoT services designed to support everyday life in the home, from shopping to heating. Based on the premise that such automation is difficult due to the contingent nature of people's practices, in this work we explore the nature of these contingencies in depth. We have designed and conducted a technology probe that made use of simple linear predictions as a provocation, and invited people to track the life of their household essentials over a two-month period. Through a mixed-method approach we demonstrate the challenges of simple predictions, and in turn identify eight categories of contingencies that influenced prediction accuracy. We discuss strategies for how designers of future predictive IoT systems may take the contingencies into account by removing, hiding, revealing, managing, or exploiting the system uncertainty at the core of the issue. Carolina Fuentes, Martin Porcheron, Joel E. Fischer, Enrico Costanza, Obaid Malik, Sarvapali D. Ramchurn |
CHI | 6 |
| 2019 | Model Checking Human-Agent Collectives for Responsible AIabstractHumans and agents often need to work together and agree on collective decisions. Ensuring that autonomous systems work responsibly is complex especially when encountering dilemmas. This paper proposes a novel, systematic model checking approach to responsible decision making by a human-agent collective to ensure it is safe, controllable and ethical. Our approach, which is based on the MCMAS model checker, verifies the permissibility of an agent's actions by checking the decision-making behaviour against the logical formulae specified for safety, controllability and ethical behaviour. The verification results through counterexamples and simulation results can provide a judgement, and an explanation to the AI engineer of the reasons actions are refused or allowed. Dhaminda B. Abeywickrama, Corina Cîrstea, Sarvapali D. Ramchurn |
RO-MAN | 3 |
| 2018 | Learning from the Veg Box: Designing Unpredictability in Agency DelegationabstractThe Internet of Things (IoT) promises to enable applications that foster a more efficient, sustainable, and healthy way of life. If end-users are to take full advantage of these developments we foresee the need for future IoT systems and services to include an element of autonomy and support the delegation of agency to software processes and connected devices. To inform the design of such future technology, we report on a breaching experiment designed to investigate how people integrate an unpredictable service, through the veg box scheme, in everyday life. Findings from our semi-structured interviews and a two-week diary study with 11 households reveal that agency delegation must be warranted, that it must be possible to incorporate delegated decisions into everyday activities, and that delegation is subject to constraint. We further discuss design implications on the need to support people's diverse values, and their coordinative and creative practices. Jhim Kiel M. Verame, Enrico Costanza, Joel E. Fischer, Andy Crabtree, Sarvapali D. Ramchurn, Tom Rodden, Nicholas R. Jennings |
CHI | 5 |
| 2018 | Algorithms for Fair Load Shedding in Developing CountriesabstractDue to the limited generation capacity of power stations, many developing countries frequently resort to disconnecting large parts of the power grid from supply, a process termed load shedding. During load shedding, many homes are left without electricity, causing them inconvenience and discomfort. In this paper, we present a number of optimization heuristics that focus on pairwise and groupwise fairness, such that households (i.e. agents) are fairly allocated electricity. We evaluate the heuristics against standard fairness metrics in terms of comfort delivered to homes, as well as the number of times they are disconnected from electricity supply. Thus, we establish new benchmarks for fair load shedding schemes. Olabambo I. Oluwasuji, Obaid Malik, Jie Zhang 0008, Sarvapali D. Ramchurn |
IJCAI | 4 |
| 2018 | A Decentralised Approach to Intersection Traffic ManagementabstractTraffic congestion has a significant impact on quality of life and the economy. This paper presents a decentralised traffic management mechanism for intersections using a distributed constraint optimisation approach (DCOP). Our solution outperforms the state of the art solution both for stable traffic conditions (about 60% reduced waiting time) and robustness to unpredictable events. Huan Vu, Samir Aknine, Sarvapali D. Ramchurn |
IJCAI | 3 |
| 2018 | Algorithms for electric vehicle scheduling in large-scale mobility-on-demand schemes
Emmanouil Rigas, Sarvapali D. Ramchurn, Nick Bassiliades |
Artif. Intell. | 2 |
| 2018 | Speeding Up GDL-Based Message Passing Algorithms for Large-Scale DCOPsabstractThis paper develops a new approach to speed up Generalized Distributive Law (GDL) based message passing algorithms that are used to solve large-scale Distributed Constraint Optimization Problems (DCOPs) in multi-agent systems. In particular, we significantly reduce computation and communication costs in terms of convergence time for algorithms such as Max-Sum, Bounded Max-Sum, Fast Max-Sum, Bounded Fast Max-Sum, BnB Max-Sum, BnB Fast Max-Sum and Generalized Fast Belief Propagation. This is important since it is often observed that the outcome obtained from such algorithms becomes outdated or unusable if the optimization process takes too much time. Specifically, the issue of taking too long to complete the internal operation of a DCOP algorithm is even more severe and commonplace in a system where the algorithm has to deal with a large number of agents, tasks and resources. This, in turn, limits the practical scalability of such algorithms. In other words, an optimization algorithm can be used in larger systems if the completion time can be reduced. However, it is challenging to maintain the solution quality while minimizing the completion time. Considering this trade-off, we propose a generic message passing protocol for GDL-based algorithms that combines clustering with domain pruning, as well as the use of a regression method to determine the appropriate number of clusters for a given scenario. We empirically evaluate the performance of our method in a number of settings and find that it brings down the completion time by around 37–85% (1.6–6.5 times faster) for 100–900 nodes, and by around 47–91% (1.9–11 times faster) for 3000–10 000 nodes compared to the current state-of-the-art. Md. Mosaddek Khan, Long Tran-Thanh, Sarvapali D. Ramchurn, Nicholas R. Jennings |
Comput. J. | 3 |
| 2018 | On the distinctiveness of the electricity load profile
Manuele Bicego, Alessandro Farinelli, Enrico Grosso, D. Paolini, Sarvapali D. Ramchurn |
Pattern Recognit. | 5 |
| 2017 | Distributed Negotiation for Collective Decision-MakingabstractCollective decision-making is a process in which participants make a collective choice from several alternatives. In this paper, we focus on collective decision contexts in which more than two selfish agents negotiate over multiple issues. We specifically consider a case of joint household energy purchase where the concerned households have to define a collective energy contract. The households involved may each be interested only in a subset of the issues at stake. We devise an effective protocol to regulate the interactions among the (household) agents and reduce their reasoning complexity. The mechanism we introduce is fully decentralized, it facilitates multi-lateral negotiation, and it reduces the complexity of the solution despite the inherent complexity of the problem. Ndeye Arame Diago, Samir Aknine, Sarvapali D. Ramchurn, Onn Shehory, Mbaye Sene |
ICTAI | 3 |
| 2017 | A cooperative game-theoretic approach to the social ridesharing problem
Filippo Bistaffa, Alessandro Farinelli, Georgios Chalkiadakis, Sarvapali D. Ramchurn |
Artif. Intell. | 4 |
| 2017 | Coalition structure generation problems: optimization and parallelization of the IDP algorithm in multicore systemsabstractSummary The coalition structure generation problem is well known in the area of multi‐agent systems. Its goal is to establish coalitions between agents while maximizing the global welfare. Among the existing different algorithms designed to solve the coalition structure generation problem, DP and IDP are the ones with smaller temporal complexity. After analyzing the operation of the dynamic programming and improved dynamic programming algorithms, we have identified which are the most frequent operations and propose an optimized method. In addition, we study and implement a method for dividing the work into different threads. To describe incremental improvements of the algorithm design, we first compare performance of an improved single central processing unit core version where we obtain speedups ranging from 7 × to 11 × . Then, we describe the best resource use in a multi‐thread optimized version where we obtain an additional 7.5 × speedup running in a 12‐core machine. Francisco Cruz-Mencia, Antonio Espinosa 0001, Juan C. Moure, Jesús Cerquides, Juan A. Rodríguez-Aguilar, Kim Svensson, Sarvapali D. Ramchurn |
Concurr. Comput. Pract. Exp. | 7 |
| 2017 | A hierarchical clustering approach to large-scale near-optimal coalition formation with quality guarantees
Alessandro Farinelli, Manuele Bicego, Filippo Bistaffa, Sarvapali D. Ramchurn |
Eng. Appl. Artif. Intell. | 4 |
| 2017 | Algorithms for Graph-Constrained Coalition Formation in the Real WorldabstractCoalition formation typically involves the coming together of multiple, heterogeneous, agents to achieve both their individual and collective goals. In this article, we focus on a special case of coalition formation known as Graph-Constrained Coalition Formation (GCCF) whereby a network connecting the agents constrains the formation of coalitions. We focus on this type of problem given that in many real-world applications, agents may be connected by a communication network or only trust certain peers in their social network. We propose a novel representation of this problem based on the concept of edge contraction, which allows us to model the search space induced by the GCCF problem as a rooted tree. Then, we propose an anytime solution algorithm (Coalition Formation for Sparse Synergies (CFSS)), which is particularly efficient when applied to a general class of characteristic functions called m + a functions. Moreover, we show how CFSS can be efficiently parallelised to solve GCCF using a nonredundant partition of the search space. We benchmark CFSS on both synthetic and realistic scenarios, using a real-world dataset consisting of the energy consumption of a large number of households in the UK. Our results show that, in the best case, the serial version of CFSS is four orders of magnitude faster than the state of the art, while the parallel version is 9.44 times faster than the serial version on a 12-core machine. Moreover, CFSS is the first approach to provide anytime approximate solutions with quality guarantees for very large systems of agents (i.e., with more than 2,700 agents). Filippo Bistaffa, Alessandro Farinelli, Jesús Cerquides, Juan A. Rodríguez-Aguilar, Sarvapali D. Ramchurn |
ACM Trans. Intell. Syst. Technol. | 5 |
| 2016 | An Axiomatic Framework for Ex-Ante Dynamic Pricing Mechanisms in Smart GridabstractIn electricity markets, the choice of the right pricing regime is crucial for the utilities because the price they charge to their consumers, in anticipation of their demand in real-time, is a key determinant of their profits and ultimately their survival in competitive energy markets. Among the existing pricing regimes, in this paper, we consider ex-ante dynamic pricing schemes as (i) they help to address the peak demand problem (a crucial problem in smart grids), and (ii) they are transparent and fair to consumers as the cost of electricity can be calculated before the actual consumption. In particular, we propose an axiomatic framework that establishes the conceptual underpinnings of the class of ex-ante dynamic pricing schemes. We first propose five key axioms that reflect the criteria that are vital for energy utilities and their relationship with consumers. We then prove an impossibility theorem to show that there is no pricing regime that satisfies all the five axioms simultaneously. We also study multiple cost functions arising from various pricing regimes to examine the subset of axioms that they satisfy. We believe that our proposed framework in this paper is first of its kind to evaluate the class of ex-ante dynamic pricing schemes in a manner that can be operationalised by energy utilities. Sambaran Bandyopadhyay, Ramasuri Narayanam, Sarvapali D. Ramchurn, Vijay Arya, Iskandarbin Petra |
AAAI | 4 |
| 2016 | It is too Hot: An In-Situ Study of Three Designs for HeatingabstractSmart energy systems that leverage machine learning techniques are increasingly integrated in all aspects of our lives. To better understand how to design user interaction with such systems, we implemented three different smart thermostats that automate heating based on users' heating preferences and real-time price variations. We evaluated our designs through a field study, where 30 UK households used our thermostats to heat their homes over a month. Our findings through thematic analysis show that the participants formed different understandings and expectations of our smart thermostat, and used it in various ways to effectively respond to real-time prices while maintaining their thermal comfort. Based on the findings, we present a number of design and research implications, specifically for designing future smart thermostats that will assist us in controlling home heating with real-time pricing, and for future intelligent autonomous systems. Alper T. Alan, Mike Shann, Enrico Costanza, Sarvapali D. Ramchurn, Sven Seuken |
CHI | 4 |
| 2016 | "Just whack it on until it gets hot": Working with IoT Data in the HomeabstractThis paper presents findings from a co-design project that aims to augment the practices of professional energy advisors with environmental data from sensors deployed in clients' homes. Premised on prior ethnographic observations we prototyped a sensor platform to support the work of tailoring advice-giving to particular homes. We report on the deployment process and the findings to emerge, particularly the work involved in making sense of or accounting for the data in the course of advice-giving. Our ethnomethodological analysis focuses on the ways in which data is drawn upon as a resource in the home visit, and how understanding and advice-giving turns upon unpacking the indexical relationship of the data to the situated goings-on in the home. This insight, coupled with further design workshops with the advisors, shaped requirements for an interactive system that makes the sensor data available for visual inspection and annotation to support the situated sense-making that is key to giving energy advice. Joel E. Fischer, Andy Crabtree, Tom Rodden, James A. Colley, Enrico Costanza, Michael O. Jewell, Sarvapali D. Ramchurn |
CHI | 7 |
| 2016 | The Effect of Displaying System Confidence Information on the Usage of Autonomous Systems for Non-specialist Applications: A Lab StudyabstractAutonomous systems are designed to take actions on behalf of users, acting autonomously upon data from sensors or online sources. As such, the design of interaction mechanisms that enable users to understand the operation of autonomous systems and flexibly delegate or regain control is an open challenge for HCI. Against this background, in this paper we report on a lab study designed to investigate whether displaying the confidence of an autonomous system about the quality of its work, which we call its confidence information, can improve user acceptance and interaction with autonomous systems. The results demonstrate that confidence information encourages the usage of the autonomous system we tested, compared to a situation where such information is not available. Furthermore, an additional contribution of our work is the method we employ to study users' incentives to do work in collaboration with the autonomous system. In experiments comparing different incentive strategies, our results indicate that our translation of behavioural economics research methods to HCI can support the study of interactions with autonomous systems in the lab. Jhim Kiel M. Verame, Enrico Costanza, Sarvapali D. Ramchurn |
CHI | 3 |
| 2016 | Planning Search and Rescue Missions for UAV TeamsabstractThe coordination of multiple Unmanned Aerial Vehicles (UAVs) to carry out aerial surveys is a major challenge for emergency responders. In particular, UAVs have to fly over kilometre-scale areas while trying to discover casualties as quickly as possible. To aid in this process, it is desirable to exploit the increasing availability of data about a disaster from sources such as crowd reports, satellite remote sensing, or manned reconnaissance. In particular, such information can be a valuable resource to drive the planning of UAV flight paths over a space in order to discover people who are in danger. However challenges of computational tractability remain when planning over the very large action spaces that result. To overcome these, we introduce the survivor discovery problem and present as our solution, the first example of a continuous factored coordinated Monte Carlo tree search algorithm. Our evaluation against state of the art benchmarks show that our algorithm, Co-CMCTS, is able to localise more casualties faster than standard approaches by 7% or more on simulations with real-world data. Chris A. B. Baker, Sarvapali D. Ramchurn, W. T. Luke Teacy, Nicholas R. Jennings |
ECAI | 2 |
| 2016 | Managing Energy Markets in Future Smart Grids Using Bilateral ContractsabstractFuture smart grids will empower home owners to buy energy from real-time markets, coalesce into energy cooperatives, and sell energy they generate from their local renewable energy sources. Such interactions by large numbers of small prosumers (that both consume and produce) will engender potentially unpredictable fluctuations in energy prices which could be detrimental to all actors in the system. Hence, in this paper, we propose negotiation mechanisms to orchestrate such interactions as well as pricing mechanisms to help stabilise energy prices on multiple time scales. We then prove 1) that our solution guarantees that, while prices fluctuations can be constrained, 2) that it is individually rational for agents to join energy cooperatives and 3) that the negotiation mechanisms we employ result in pareto-optimal solutions. Romain Caillière, Samir Aknine, Antoine Nongaillard, Sarvapali D. Ramchurn |
ECAI | 4 |
| 2016 | The potential of physical motion cues: changing people's perception of robots' performanceabstractAutonomous robotic systems can automatically perform actions on behalf of users in the domestic environment to help people in their daily activities. Such systems aim to reduce users' cognitive and physical workload, and improve well-being. While the benefits of these systems are clear, recent studies suggest that users may misconstrue their performance of tasks. We see an opportunity in designing interaction techniques that improve how users perceive the performance of such systems. We report two lab studies (N=16 each) designed to investigate whether showing physical motion, which is showing the process of a system through movement (that is intrinsic to the system's task), of an autonomous system as it completes its task, affects how users perceive its performance. To ensure our studies are ecologically valid and to motivate participants to provide thoughtful responses we adopted consensus-oriented financial incentives. Our results suggest that physical presence does yield higher performance ratings. Pedro Garcia Garcia, Enrico Costanza, Sarvapali D. Ramchurn, Jhim Kiel M. Verame |
UbiComp | 3 |
| 2016 | Interactive Scheduling of Appliance Usage in the Home
Ngoc Cuong Truong, Tim Baarslag, Sarvapali D. Ramchurn, Long Tran-Thanh |
IJCAI | 3 |
| 2016 | Coordinating Human-UAV Teams in Disaster Response
Feng Wu 0001, Sarvapali D. Ramchurn |
IJCAI | 2 |
| 2016 | Guest Editorial
Sarvapali D. Ramchurn, Avi Rosenfeld, Joel E. Fischer |
Auton. Agents Multi Agent Syst. | 1 |
| 2016 | Human-agent collaboration for disaster response
Sarvapali D. Ramchurn, Feng Wu 0001, Wenchao Jiang, Joel E. Fischer, Steven Reece, Stephen J. Roberts, Tom Rodden, Christopher Greenhalgh, Nicholas R. Jennings |
Auton. Agents Multi Agent Syst. | 1 |
| 2016 | A Disaster Response System based on Human-Agent Collectives
Sarvapali D. Ramchurn, Trung Dong Huynh, Feng Wu 0001, Yuki Ikuno, Jack Flann, Luc Moreau 0001, Joel E. Fischer, Wenchao Jiang, Tom Rodden, Edwin Simpson, Steven Reece, Stephen J. Roberts, Nicholas R. Jennings |
J. Artif. Intell. Res. | 1 |
| 2016 | Decentralized Patrolling Under Constraints in Dynamic EnvironmentsabstractWe investigate a decentralized patrolling problem for dynamic environments where information is distributed alongside threats. In this problem, agents obtain information at a location, but may suffer attacks from the threat at that location. In a decentralized fashion, each agent patrols in a designated area of the environment and interacts with a limited number of agents. Therefore, the goal of these agents is to coordinate to gather as much information as possible while limiting the damage incurred. Hence, we model this class of problem as a transition-decoupled partially observable Markov decision process with health constraints. Furthermore, we propose scalable decentralized online algorithms based on Monte Carlo tree search and a factored belief vector. We empirically evaluate our algorithms on decentralized patrolling problems and benchmark them against the state-of-the-art online planning solver. The results show that our approach outperforms the state-of-the-art by more than 56% for six agents patrolling problems and can scale up to 24 agents in reasonable time. Shaofei Chen, Feng Wu 0001, Lincheng Shen, Sarvapali D. Ramchurn |
IEEE Trans. Cybern. | 5 |
| 2016 | Tariff Agent: Interacting with a Future Smart Energy System at HomeabstractSmart systems are becoming increasingly ubiquitous and consequently transforming our lives. The level of system autonomy plays a vital role in the development of smart systems as it profoundly affects how people and these systems interact with each other. However, to date, there are very few studies on human interaction with such systems. This paper presents findings from two field studies where two different prototypes for automating energy tariff-switching were developed and evaluated in the wild. Both prototypes offer flexible autonomy by which users can shift the system's level of autonomy among three options: suggestion-only, semi-autonomy, and full autonomy, whenever they like. Our findings based on thematic analysis show that flexible autonomy is a promising way to sustain users' engagement with smart systems, despite their occasional mistakes. The findings also suggest that users take responsibility for the undesired outcomes of automated actions when delegation of autonomy can be adjusted flexibly. Alper T. Alan, Enrico Costanza, Sarvapali D. Ramchurn, Joel E. Fischer, Tom Rodden, Nicholas R. Jennings |
ACM Trans. Comput. Hum. Interact. | 3 |
| 2015 | Sharing Rides with Friends: A Coalition Formation Algorithm for RidesharingabstractWe consider the Social Ridesharing (SR) problem, where a set of commuters, connected through a social network, arrange one-time rides at short notice. In particular, we focus on the associated optimisation problem of forming cars to minimise the travel cost of the overall system modelling such problem as a graph constrained coalition formation (GCCF) problem, where the set of feasible coalitions is restricted by a graph (i.e., the social network). Moreover, we significantly extend the state of the art algorithm for GCCF, i.e., the CFSS algorithm, to solve our GCCF model of the SR problem. Our empirical evaluation uses a real dataset for both spatial (GeoLife) and social data (Twitter), to validate the applicability of our approach in a realistic application scenario. Empirical results show that our approach computes optimal solutions for systems of medium scale (up to 100 agents) providing significant cost reductions (up to -36.22%). Moreover, we can provide approximate solutions for very large systems (i.e., up to 2000 agents) and good quality guarantees (i.e., with an approximation ratio of 1.41 in the worst case) within minutes (i.e., 100 seconds). Filippo Bistaffa, Alessandro Farinelli, Sarvapali D. Ramchurn |
AAAI | 3 |
| 2015 | Crowdsourcing Complex Workflows under Budget ConstraintsabstractWe consider the problem of task allocation in crowdsourcing systems with multiple complex workflows, each of which consists of a set of inter-dependent micro-tasks.We propose Budgeteer, an algorithm to solve this problem under a budget constraint. In particular, our algorithm first calculates an efficient way to allocate budget to each workflow. It then determines the number of inter-dependent micro-tasks and the price to pay for each task within each workflow, given the corresponding budget constraints. We empirically evaluate it on a well-known crowdsourcing-based text correction workflow using Amazon Mechanical Turk, and show that Budgeteer can achieve similar levels of accuracy to current benchmarks, but is on average 45 % cheaper. Long Tran-Thanh, Trung Dong Huynh, Avi Rosenfeld, Sarvapali D. Ramchurn, Nicholas R. Jennings |
AAAI | 4 |
| 2015 | Balanced Trade Reduction for Dual-Role Exchange Markets
Dengji Zhao, Sarvapali D. Ramchurn, Enrico H. Gerding, Nicholas R. Jennings |
AAAI | 2 |
| 2015 | Building a Birds Eye View: Collaborative Work in Disaster ResponseabstractCommand and control environments ranging from transport control rooms to disaster response have long been of interest to HCI and CSCW as rich sites of interactive technology use embedded in work practice. Drawing on our engagement with disaster response teams, including ethnography of their training work, we unpack the ways in which situational uncertainty is managed while a shared operational 'picture' is constituted through various practices around tabletop work. Our analysis reveals how this picture is collaboratively assembled as a socially shared object and displayed by drawing on digital and physical resources. Accordingly, we provide a range of principles implicated by our study that guide the design of systems augmenting and enriching disaster response work practices. In turn, we propose the Augmented Bird Table to illustrate how our principles can be implemented to support tabletop work. Joel E. Fischer, Stuart Reeves, Tom Rodden, Steven Reece, Sarvapali D. Ramchurn |
CHI | 5 |
| 2015 | CrowdAR: Augmenting Live Video with a Real-Time CrowdabstractFinding and tracking targets and events in a live video feed is important for many commercial applications, from CCTV surveillance used by police and security firms, to the rapid mapping of events from aerial imagery. However, descriptions of targets are typically provided in natural language by the end users, and interpreting these in the context of a live video stream is a complex task. Due to current limitations in artificial intelligence, especially vision, this task cannot be automated and instead requires human supervision. Hence, in this paper, we consider the use of real-time crowdsourcing to identify and track targets given by a natural language description. In particular we present a novel method for augmenting live video with a real-time crowd. Elliot Salisbury, Sebastian Stein 0001, Sarvapali D. Ramchurn |
HCOMP | 3 |
| 2015 | A Scalable Interdependent Multi-Issue Negotiation Protocol for Energy Exchange
Muddasser Alam, Enrico H. Gerding, Alex Rogers, Sarvapali D. Ramchurn |
IJCAI | 4 |
| 2015 | A Study of Human-Agent Collaboration for Multi-UAV Task Allocation in Dynamic Environments
Sarvapali D. Ramchurn, Joel E. Fischer, Yuki Ikuno, Feng Wu 0001, Jack Flann, Antony Waldock |
IJCAI | 1 |
| 2015 | Agile Planning for Real-World Disaster Response
Feng Wu 0001, Sarvapali D. Ramchurn, Wenchao Jiang, Joel E. Fischer, Tom Rodden, Nicholas R. Jennings |
IJCAI | 2 |
| 2015 | Recommending Fair Payments for Large-Scale Social RidesharingabstractWe perform recommendations for the Social Ridesharing scenario, in which a set of commuters, connected through a social network, arrange one-time rides at short notice. In particular, we focus on how much one should pay for taking a ride with friends. More formally, we propose the first approach that can compute fair coalitional payments that are also stable according to the game-theoretic concept of the kernel for systems with thousands of agents in real-world scenarios. Our tests, based on real datasets for both spatial (GeoLife) and social data (Twitter), show that our approach is significantly faster than the state-of-the-art (up to 84 times), allowing us to compute stable payments for 2000 agents in 50 minutes. We also develop a parallel version of our approach, which achieves a near-optimal speed-up in the number of processors used. Finally, our empirical analysis reveals new insights into the relationship between payments incurred by a user by virtue of its position in its social network and its role (rider or driver). Filippo Bistaffa, Alessandro Farinelli, Georgios Chalkiadakis, Sarvapali D. Ramchurn |
RecSys | 4 |
| 2015 | Managing Electric Vehicles in the Smart Grid Using Artificial Intelligence: A SurveyabstractAlong with the development of smart grids, the wide adoption of electric vehicles (EVs) is seen as a catalyst to the reduction of CO2emissions and more intelligent transportation systems. In particular, EVs augment the grid with the ability to store energy at some points in the network and give it back at others and, therefore, help optimize the use of energy from intermittent renewable energy sources and let users refill their cars in a variety of locations. However, a number of challenges need to be addressed if such benefits are to be achieved. On the one hand, given their limited range and costs involved in charging EV batteries, it is important to design algorithms that will minimize costs and, at the same time, avoid users being stranded. On the other hand, collectives of EVs need to be organized in such a way as to avoid peaks on the grid that may result in high electricity prices and overload local distribution grids. In order to meet such challenges, a number of technological solutions have been proposed. In this paper, we focus on those that utilize artificial intelligence techniques to render EVs and the systems that manage collectives of EVs smarter. In particular, we provide a survey of the literature and identify the commonalities and key differences in the approaches. This allows us to develop a classification of key techniques and benchmarks that can be used to advance the state of the art in this space. Emmanouil Rigas, Sarvapali D. Ramchurn, Nick Bassiliades |
IEEE Trans. Intell. Transp. Syst. | 2 |
| 2014 | Doing the laundry with agents: a field trial of a future smart energy system in the homeabstractFuture energy systems that rely on renewable energy may bring about a radical shift in how we use energy in our homes. We developed and prototyped a future scenario with highly variable, real-time electricity prices due to a grid that mainly relies on renewables. We designed and deployed an agent-based interactive system that enables users to effectively operate the washing machine in this scenario. The system is used to book timeslots of washing machine use so that the agent can help to minimize the cost of a wash by charging a battery at times when electricity is cheap. We carried out a deployment in 10 households in order to uncover the socio-technical challenges around integrating new technologies into everyday routines. The findings reveal tensions that arise when deploying a rationalistic system to manage contingently and socially organized domestic practices. We discuss the trade-offs between utility and convenience inherent in smart grid applications; and illustrate how certain design choices position applications along this spectrum. Enrico Costanza, Joel E. Fischer, James A. Colley, Tom Rodden, Sarvapali D. Ramchurn, Nicholas R. Jennings |
CHI | 5 |
| 2014 | Energy advisors at work: charity work practices to support people in fuel povertyabstractWe present an ethnographic study of energy advisors working for a charity that provides support, particularly to people in fuel poverty. Our fieldwork comprises detailed observations that reveal the collaborative, interactional work of energy advisors and clients during home visits, supplemented with interviews and a participatory design workshop with advisors. We identify opportunities for Ubicomp technologies that focus on supporting the work of the advisor, including complementing the collaborative advice giving in home visits, providing help remotely, and producing evidence in support of accounts of practices and building conditions useful for interactions with landlords, authorities and other third parties. We highlight six specific design challenges that relate the domestic fuel poverty setting to the wider Ubicomp literature. Our work echoes a shift in attention from energy use and the individual consumer, specifically to matters of advice work practices and the domestic fuel poverty setting, and to the discourse around inclusive Ubicomp technologies. Joel E. Fischer, Enrico Costanza, Sarvapali D. Ramchurn, James A. Colley, Tom Rodden |
UbiComp | 3 |
| 2014 | Behavioural Biometrics Using Electricity Load ProfilesabstractModelling behavioural biometric patterns is a key issue for modern user centric applications, aimed at better monitoring users' activities, understanding their habits and detecting their identity. Following this trend, this paper investigates whether the electrical energy consumption of a user can be a distinctive behavioural biometric trait. In particular we analyse daily and weekly load profiles showing that they are closely related to the identity of the users. Hence, we believe that this level of analysis can open interesting application scenarios in the field of energy management and it provides a good working framework for the continuous development of smart environments with demonstrable benefits on real-world implementations. Manuele Bicego, F. Recchia, Alessandro Farinelli, Sarvapali D. Ramchurn, Enrico Grosso |
ICPR | 4 |
| 2014 | A Tutorial on Optimization for Multi-Agent SystemsabstractResearch on optimization in multi-agent systems (MASs) has contributed with a wealth of techniques to solve many of the challenges arising in a wide range of multi-agent application domains. Multi-agent optimization focuses on casting MAS problems into optimization problems. The solving of those problems could possibly involve the active participation of the agents in a MAS. Research on multi-agent optimization has rapidly become a very technical, specialized field. Moreover, the contributions to the field in the literature are largely scattered. These two factors dramatically hinder access to a basic, general view of the foundations of the field. This tutorial is intended to ease such access by providing a gentle introduction to fundamental concepts and techniques on multi-agent optimization. Jesús Cerquides, Alessandro Farinelli, Pedro Meseguer, Sarvapali D. Ramchurn |
Comput. J. | 4 |
| 2014 | A Message-Passing Approach to Decentralized Parallel Machine SchedulingabstractThis paper tackles the problem of parallelizing heterogeneous computational tasks across a number of computational nodes (aka agents) where each agent may not be able to perform all the tasks and may have different computational speeds. An equivalent problem can be found in operations research, and it is known as scheduling tasks on unrelated parallel machines (also known as R∥Cmax). Given this equivalence observation, we present the spanning tree decentralized task distribution algorithm (ST-DTDA), the first decentralized solution to R∥Cmax. ST-DTDA achieves decomposition by means of the min–max algorithm, a member of the generalized distributive law family, that performs inference by message-passing along the edges of a graphical model (known as a junction tree). Specifically, ST-DTDA uses min–max to optimally solve an approximation of the original R∥Cmax problem that results from eliminating possible agent-task allocations until it is mapped into an acyclic structure. To eliminate those allocations that are least likely to have an impact on the solution quality, ST-DTDA uses a heuristic approach. Moreover, ST-DTDA provides a per-instance approximation ratio that guarantees that the makespan of its solution (optimal in the approximated R∥Cmax problem) is not more than a factor ρ times the makespan of the optimal of the original problem. In our empirical evaluation of ST-DTDA, we show that ST-DTDA, with a min-regret heuristic, converges to solutions that are between 78 and 95% optimal whilst providing approximation ratios lower than 3. Meritxell Vinyals, Kathryn S. Macarthur, Alessandro Farinelli, Sarvapali D. Ramchurn, Nicholas R. Jennings |
Comput. J. | 4 |
| 2013 | Interdependent Multi-Issue Negotiation for Energy Exchange in Remote Communities
Muddasser Alam, Alex Rogers, Sarvapali D. Ramchurn |
AAAI | 3 |
| 2013 | Interpretation of Crowdsourced Activities Using Provenance Network AnalysisabstractUnderstanding the dynamics of a crowdsourcing application and controlling the quality of the data it generates is challenging, partly due to the lack of tools to do so. Provenance is a domain-independent means to represent what happened in an application, which can help verify data and infer their quality. It can also reveal the processes that led to a data item and the interactions of contributors with it. Provenance patterns can manifest real-world phenomena such as a significant interest in a piece of content, providing an indication of its quality, or even issues such as undesirable interactions within a group of contributors. This paper presents an application-independent methodology for analyzing provenance graphs, constructed from provenance records, to learn about such patterns and to use them for assessing some key properties of crowdsourced data, such as their quality, in an automated manner. Validating this method on the provenance records of CollabMap, an online crowdsourcing mapping application, we demonstrated an accuracy level of over 95% for the trust classification of data generated by the crowd therein. Trung Dong Huynh, Mark Ebden, Matteo Venanzi, Sarvapali D. Ramchurn, Stephen J. Roberts, Luc Moreau 0001 |
HCOMP | 4 |
| 2013 | C-Link: A Hierarchical Clustering Approach to Large-scale Near-optimal Coalition Formation
Alessandro Farinelli, Manuele Bicego, Sarvapali D. Ramchurn, Mauro Zucchelli |
IJCAI | 3 |
| 2013 | Forecasting Multi-Appliance Usage for Smart Home Energy Management
Ngoc Cuong Truong, James McInerney, Long Tran-Thanh, Enrico Costanza, Sarvapali D. Ramchurn |
IJCAI | 5 |
| 2013 | Recommending energy tariffs and load shifting based on smart household usage profilingabstractWe present a system and study of personalized energy-related recommendation. AgentSwitch utilizes electricity usage data collected from users' households over a period of time to realize a range of smart energy-related recommendations on energy tariffs, load detection and usage shifting. The web service is driven by a third party real-time energy tariff API (uSwitch), an energy data store, a set of algorithms for usage prediction, and appliance-level load disaggregation. We present the system design and user evaluation consisting of interviews and interface walkthroughs. We recruited participants from a previous study during which three months of their household's energy use was recorded to evaluate personalized recommendations in AgentSwitch. Our contributions are a) a systems architecture for personalized energy services; and b) findings from the evaluation that reveal challenges in designing energy-related recommender systems. In response to the challenges we formulate design recommendations to mitigate barriers to switching tariffs, to incentivize load shifting, and to automate energy management. Joel E. Fischer, Sarvapali D. Ramchurn, Michael A. Osborne, Oliver Parson, Trung Dong Huynh, Muddasser Alam, Nadia Pantidi, Stuart Moran, Khaled Bachour, Steven Reece, Enrico Costanza, Tom Rodden, Nicholas R. Jennings |
IUI | 2 |
| 2012 | Competing with Humans at Fantasy Football: Team Formation in Large Partially-Observable DomainsabstractWe present the first real-world benchmark for sequentially-optimal team formation, working within the framework of a class of online football prediction games known as Fantasy Football. We model the problem as a Bayesian reinforcement learning one, where the action space is exponential in the number of players and where the decision maker's beliefs are over multiple characteristics of each footballer. We then exploit domain knowledge to construct computationally tractable solution techniques in order to build a competitive automated Fantasy Football manager. Thus, we are able to establish the baseline performance in this domain, even without complete information on footballers' performances (accessible to human managers), showing that our agent is able to rank at around the top percentile when pitched against 2.5M human players. Tim Matthews, Sarvapali D. Ramchurn, Georgios Chalkiadakis |
AAAI | 2 |
| 2012 | Delivering the Smart Grid: Challenges for Autonomous Agents and Multi-Agent Systems ResearchabstractRestructuring electricity grids to meet the increased demand caused by the electrification of transport and heating, while making greater use of intermittent renewable energy sources, represents one of the greatest engineering challenges of our day. This modern electricity grid, in which both electricity and information flow in two directions between large numbers of widely distributed suppliers and generators — commonly termed the ‘smart grid’ — represents a radical reengineering of infrastructure which has changed little over the last hundred years. However, the autonomous behaviour expected of the smart grid, its distributed nature, and the existence of multiple stakeholders each with their own incentives and interests, challenges existing engineering approaches. In this challenge paper, we describe why we believe that artificial intelligence, and particularly, the fields of autonomous agents and multi-agent systems are essential for delivering the smart grid as it is envisioned. We present some recent work in this area and describe many of the challenges that still remain. Alex Rogers, Sarvapali D. Ramchurn, Nicholas R. Jennings |
AAAI | 2 |
| 2012 | Understanding domestic energy consumption through interactive visualisation: a field studyabstractMotivated by the need to better manage energy demand in the home, in this paper we advocate the integration into Ubicomp systems of interactive energy consumption visualisations, that allow users to engage with and understand their consumption data, relating it to concrete activities in their life. To this end, we present the design, implementation, and evaluation of FigureEnergy, a novel interactive visualisation that allows users to annotate and manipulate a graphical representation of their own electricity consumption data, and therefore make sense of their past energy usage and understand when, how, and to what end, some amount of energy was used. To validate our design, we deployed FigureEnergy "in the wild" -- 12 participants installed meters in their homes and used the system for a period of two weeks. The results suggest that the annotation approach is successful overall: by engaging with the data users started to relate energy consumption to activities rather than just to appliances. Moreover, they were able to discover that some appliances consume more than they expected, despite having had prior experience of using other electricity displays. Enrico Costanza, Sarvapali D. Ramchurn, Nicholas R. Jennings |
UbiComp | 2 |
| 2012 | Evaluating semi-automatic annotation of domestic energy consumption as a memory aidabstractFrequent feedback about energy consumption can help conservation, one of the current global challenges. Such feedback is most helpful if users can relate it to their own day-to-day activities. In earlier work we showed that manual annotation of domestic energy consumption logs aids users to make such connection and discover patterns they were not aware of. In this poster we report how we augmented manual annotation with machine learning classification techniques. We propose the design of a lab study to evaluate the system, extending methods used to evaluate context aware memory aids, and we present the results of a pilot with 5 participants. Darren P. Richardson, Enrico Costanza, Sarvapali D. Ramchurn |
UbiComp | 3 |
| 2011 | A Distributed Anytime Algorithm for Dynamic Task Allocation in Multi-Agent SystemsabstractWe introduce a novel distributed algorithm for multi-agent task allocation problems where the sets of tasks and agents constantly change over time. We build on an existing anytime algorithm (fast-max-sum), and give it significant new capa- bilities: namely, an online pruning procedure that simplifies the problem, and a branch-and-bound technique that reduces the search space. This allows us to scale to problems with hundreds of tasks and agents. We empirically evaluate our algorithm against established benchmarks and find that, even in such large environments, a solution is found up to 31% faster, and with up to 23% more utility, than state-of-the-art approximation algorithms. In addition, our algorithm sends up to 30% fewer messages than current approaches when the set of agents or tasks changes. Kathryn S. Macarthur, Ruben Stranders, Sarvapali D. Ramchurn, Nicholas R. Jennings |
AAAI | 3 |
| 2011 | Decentralised Control of Micro-Storage in the Smart GridabstractIn this paper, we propose a novel decentralised control mechanism to manage micro-storage in the smart grid. Our approach uses an adaptive pricing scheme that energy suppliers apply to home smart agents controlling micro-storage devices. In particular, we prove that the interaction between a supplier using our pricing scheme and the actions of selfish micro-storage agents forms a globally stable feedback loop that converges to an efficient equilibrium. We further propose a market strategy that allows the supplier to reduce wholesale purchasing costs without increasing the uncertainty and variance for its aggregate consumer demand. Moreover, we empirically evaluate our mechanism (based on the UK grid data) and show that it yields savings of up to 16% in energy cost for consumers using storage devices with average capacity 10 kWh. Furthermore, we show that it is robust against extreme system changes. Thomas Voice, Perukrishnen Vytelingum, Sarvapali D. Ramchurn, Alex Rogers, Nicholas R. Jennings |
AAAI | 3 |
| 2011 | Guest editorial: Special issue on optimisation in multi-agent systems
Sarvapali D. Ramchurn, Alessandro Farinelli, Juan A. Rodríguez-Aguilar |
Auton. Agents Multi Agent Syst. | 1 |
| 2011 | Theoretical and Practical Foundations of Large-Scale Agent-Based Micro-Storage in the Smart GridabstractIn this paper, we present a novel decentralised management technique that allows electricity micro-storage devices, deployed within individual homes as part of a smart electricity grid, to converge to profitable and efficient behaviours. Specifically, we propose the use of software agents, residing on the users' smart meters, to automate and optimise the charging cycle of micro-storage devices in the home to minimise its costs, and we present a study of both the theoretical underpinnings and the implications of a practical solution, of using software agents for such micro-storage management. First, by formalising the strategic choice each agent makes in deciding when to charge its battery, we develop a game-theoretic framework within which we can analyse the competitive equilibria of an electricity grid populated by such agents and hence predict the best consumption profile for that population given their battery properties and individual load profiles. Our framework also allows us to compute theoretical bounds on the amount of storage that will be adopted by the population. Second, to analyse the practical implications of micro-storage deployments in the grid, we present a novel algorithm that each agent can use to optimise its battery storage profile in order to minimise its owner's costs. This algorithm uses a learning strategy that allows it to adapt as the price of electricity changes in real-time, and we show that the adoption of these strategies results in the system converging to the theoretical equilibria. Finally, we empirically evaluate the adoption of our micro-storage management technique within a complex setting, based on the UK electricity market, where agents may have widely varying load profiles, battery types, and learning rates. In this case, our approach yields savings of up to 14% in energy cost for an average consumer using a storage device with a capacity of less than 4.5 kWh and up to a 7% reduction in carbon emissions resulting from electricity generation (with only domestic consumers adopting micro-storage and, commercial and industrial consumers not changing their demand). Moreover, corroborating our theoretical bound, an equilibrium is shown to exist where no more than 48% of households would wish to own storage devices and where social welfare would also be improved (yielding overall annual savings of nearly £1.5B). Perukrishnen Vytelingum, Thomas Voice, Sarvapali D. Ramchurn, Alex Rogers, Nicholas R. Jennings |
J. Artif. Intell. Res. | 3 |
| 2011 | Agent-based homeostatic control for green energy in the smart gridabstractWith dwindling nonrenewable energy reserves and the adverse effects of climate change, the development of the smart electricity grid is seen as key to solving global energy security issues and to reducing carbon emissions. In this respect, there is a growing need to integrate renewable (or green) energy sources in the grid. However, the intermittency of these energy sources requires that demand must also be made more responsive to changes in supply, and a number of smart grid technologies are being developed, such as high-capacity batteries and smart meters for the home, to enable consumers to be more responsive to conditions on the grid in real time. Traditional solutions based on these technologies, however, tend to ignore the fact that individual consumers will behave in such a way that best satisfies their own preferences to use or store energy (as opposed to that of the supplier or the grid operator). Hence, in practice, it is unclear how these solutions will cope with large numbers of consumers using their devices in this way. Against this background, in this article, we develop novel control mechanisms based on the use of autonomous agents to better incorporate consumer preferences in managing demand. These agents, residing on consumers' smart meters, can both communicate with the grid and optimize their owner's energy consumption to satisfy their preferences. More specifically, we provide a novel control mechanism that models and controls a system comprising of a green energy supplier operating within the grid and a number of individual homes (each possibly owning a storage device). This control mechanism is based on the concept of homeostasis whereby control signals are sent to individual components of a system, based on their continuous feedback, in order to change their state so that the system may reach a stable equilibrium. Thus, we define a new carbon-based pricing mechanism for this green energy supplier that takes advantage of carbon-intensity signals available on the Internet in order to provide real-time pricing. The pricing scheme is designed in such a way that it can be readily implemented using existing communication technologies and is easily understandable by consumers. Building upon this, we develop new control signals that the supplier can use to incentivize agents to shift demand (using their storage device) to times when green energy is available. Moreover, we show how these signals can be adapted according to changes in supply and to various degrees of penetration of storage in the system. We empirically evaluate our system and show that, when all homes are equipped with storage devices, the supplier can significantly reduce its reliance on other carbon-emitting power sources to cater for its own shortfalls. By so doing, the supplier reduces the carbon emission of the system by up to 25% while the consumer reduces its costs by up to 14.5%. Finally, we demonstrate that our homeostatic control mechanism is not sensitive to small prediction errors and the supplier is incentivized to accurately predict its green production to minimize costs. Sarvapali D. Ramchurn, Perukrishnen Vytelingum, Alex Rogers, Nicholas R. Jennings |
ACM Trans. Intell. Syst. Technol. | 1 |
| 2010 | Decentralized Coordination in RoboCup RescueabstractEmergency responders are faced with a number of significant challenges when managing major disasters. First, the number of rescue tasks posed is usually larger than the number of responders (or agents) and the resources available to them. Second, each task is likely to require a different level of effort in order to be completed by its deadline. Third, new tasks may continually appear or disappear from the environment, thus requiring the responders to quickly recompute their allocation of resources. Fourth, forming teams or coalitions of multiple agents from different agencies is vital since no single agency will have all the resources needed to save victims, unblock roads and extinguish the fires which might erupt in the disaster space. Given this, coalitions have to be efficiently selected and scheduled to work across the disaster space so as to maximize the number of lives and the portion of the infrastructure saved. In particular, it is important that the selection of such coalitions should be performed in a decentralized fashion in order to avoid a single point of failure in the system. Moreover, it is critical that responders communicate only locally given they are likely to have limited battery power or minimal access to long-range communication devices. Against this background, we provide a novel decentralized solution to the coalition formation process that pervades disaster management. More specifically, we model the emergency management scenario defined in the RoboCup Rescue disaster simulation platform as a coalition formation with spatial and temporal constraints (CFST) problem where agents form coalitions to complete tasks, each with different demands. To design a decentralized algorithm for CFST, we formulate it as a distributed constraint optimization problem and show how to solve it using the state-of-the-art Max-Sum algorithm that provides a completely decentralized message-passing solution. We then provide a novel algorithm (F-Max-Sum) that avoids sending redundant messages and efficiently adapts to changes in the environment. In empirical evaluations, our algorithm is shown to generate better solutions than other decentralized algorithms used for this problem. Sarvapali D. Ramchurn, Alessandro Farinelli, Kathryn S. Macarthur, Nicholas R. Jennings |
Comput. J. | 1 |
| 2009 | An Anytime Algorithm for Optimal Coalition Structure GenerationabstractCoalition formation is a fundamental type of interaction that involves the creation of coherent groupings of distinct, autonomous, agents in order to efficiently achieve their individual or collective goals. Forming effective coalitions is a major research challenge in the field of multi-agent systems. Central to this endeavour is the problem of determining which of the many possible coalitions to form in order to achieve some goal. This usually requires calculating a value for every possible coalition, known as the coalition value, which indicates how beneficial that coalition would be if it was formed. Once these values are calculated, the agents usually need to find a combination of coalitions, in which every agent belongs to exactly one coalition, and by which the overall outcome of the system is maximized. However, this coalition structure generation problem is extremely challenging due to the number of possible solutions that need to be examined, which grows exponentially with the number of agents involved. To date, therefore, many algorithms have been proposed to solve this problem using different techniques ranging from dynamic programming, to integer programming, to stochastic search all of which suffer from major limitations relating to execution time, solution quality, and memory requirements. With this in mind, we develop an anytime algorithm to solve the coalition structure generation problem. Specifically, the algorithm uses a novel representation of the search space, which partitions the space of possible solutions into sub-spaces such that it is possible to compute upper and lower bounds on the values of the best coalition structures in them. These bounds are then used to identify the sub-spaces that have no potential of containing the optimal solution so that they can be pruned. The algorithm, then, searches through the remaining sub-spaces very efficiently using a branch-and-bound technique to avoid examining all the solutions within the searched subspace(s). In this setting, we prove that our algorithm enumerates all coalition structures efficiently by avoiding redundant and invalid solutions automatically. Moreover, in order to effectively test our algorithm we develop a new type of input distribution which allows us to generate more reliable benchmarks compared to the input distributions previously used in the field. Given this new distribution, we show that for 27 agents our algorithm is able to find solutions that are optimal in 0.175% of the time required by the fastest available algorithm in the literature. The algorithm is anytime, and if interrupted before it would have normally terminated, it can still provide a solution that is guaranteed to be within a bound from the optimal one. Moreover, the guarantees we provide on the quality of the solution are significantly better than those provided by the previous state of the art algorithms designed for this purpose. For example, for the worst case distribution given 25 agents, our algorithm is able to find a 90% efficient solution in around 10% of time it takes to find the optimal solution. Talal Rahwan, Sarvapali D. Ramchurn, Nicholas R. Jennings, Andrea Giovannucci |
J. Artif. Intell. Res. | 2 |
| 2009 | Trust-Based Mechanisms for Robust and Efficient Task Allocation in the Presence of Execution UncertaintyabstractVickrey-Clarke-Groves (VCG) mechanisms are often used to allocate tasks to selfish and rational agents. VCG mechanisms are incentive compatible, direct mechanisms that are efficient (i.e., maximise social utility) and individually rational (i.e., agents prefer to join rather than opt out). However, an important assumption of these mechanisms is that the agents will "always" successfully complete their allocated tasks. Clearly, this assumption is unrealistic in many real-world applications, where agents can, and often do, fail in their endeavours. Moreover, whether an agent is deemed to have failed may be perceived differently by different agents. Such subjective perceptions about an agent's probability of succeeding at a given task are often captured and reasoned about using the notion of "trust". Given this background, in this paper we investigate the design of novel mechanisms that take into account the trust between agents when allocating tasks. Specifically, we develop a new class of mechanisms, called "trust-based mechanisms", that can take into account multiple subjective measures of the probability of an agent succeeding at a given task and produce allocations that maximise social utility, whilst ensuring that no agent obtains a negative utility. We then show that such mechanisms pose a challenging new combinatorial optimisation problem (that is NP-complete), devise a novel representation for solving the problem, and develop an effective integer programming solution (that can solve instances with about 2x10^5 possible allocations in 40 seconds). Sarvapali D. Ramchurn, Claudio Mezzetti, Andrea Giovannucci, Juan A. Rodríguez-Aguilar, Rajdeep K. Dash, Nicholas R. Jennings |
J. Artif. Intell. Res. | 1 |
| 2008 | Towards Real-Time Information Processing of Sensor Network Data Using Computationally Efficient Multi-output Gaussian ProcessesabstractIn this paper, we describe a novel, computationally efficient algorithm that facilitates the autonomous acquisition of readings from sensor networks (deciding when and which sensor to acquire readings from at any time), and which can, with minimal domain knowledge, perform a range of information processing tasks including modelling the accuracy of the sensor readings, predicting the value of missing sensor readings, and predicting how the monitored environmental variables will evolve into the future. Our motivating scenario is the need to provide situational awareness support to first responders at the scene of a large scale incident, and to this end, we describe a novel iterative formulation of a multi-output Gaussian process that can build and exploit a probabilistic model of the environmental variables being measured (including the correlations and delays that exist between them). We validate our approach using data collected from a network of weather sensors located on the south coast of England. Michael A. Osborne, Stephen J. Roberts, Alex Rogers, Sarvapali D. Ramchurn, Nicholas R. Jennings |
IPSN | 4 |
| 2008 | Information Agents for Pervasive Sensor NetworksabstractIn this paper, we describe an information agent, that resides on a mobile computer or personal digital assistant (PDA), that can autonomously acquire sensor readings from pervasive sensor networks (deciding when and which sensor to acquire readings from at any time). Moreover, it can perform a range of information processing tasks including modelling the accuracy of the sensor readings, predicting the value of missing sensor readings, and predicting how the monitored environmental parameters will evolve into the future. Our motivating scenario is the need to provide situational awareness support to first responders at the scene of a large scale incident, and we describe how we use an iterative formulation of a multi-output Gaussian process to build a probabilistic model of the environmental parameters being measured by local sensors, and the correlations and delays that exist between them. We validate our approach using data collected from a network of weather sensors located on the south coast of England. Alex Rogers, Mike Osborne, Sarvapali D. Ramchurn, Stephen J. Roberts, Nicholas R. Jennings |
PerCom | 3 |
| 2007 | Anytime Optimal Coalition Structure Generation
Talal Rahwan, Sarvapali D. Ramchurn, Viet Dung Dang, Andrea Giovannucci, Nicholas R. Jennings |
AAAI | 2 |
| 2007 | Near-Optimal Anytime Coalition Structure Generation
Talal Rahwan, Sarvapali D. Ramchurn, Viet Dung Dang, Nicholas R. Jennings |
IJCAI | 2 |
| 2007 | Negotiating using rewards
Sarvapali D. Ramchurn, Carles Sierra, Lluís Godo, Nicholas R. Jennings |
Artif. Intell. | 1 |
| 2007 | Coordinating team players within a noisy Iterated Prisoner's Dilemma tournament
Alex Rogers, Rajdeep K. Dash, Sarvapali D. Ramchurn, Perukrishnen Vytelingum, Nicholas R. Jennings |
Theor. Comput. Sci. | 3 |
| 2004 | Minimising Intrusiveness in Pervasive Computing Environments Using Multi-Agent NegotiationabstractThis paper highlights intrusiveness as a key issue in the field of pervasive computing environments and presents a multiagent approach to tackling it. Specifically, we discuss how interruptions can impact on individual and group tasks and how they can be managed by taking into account user and group preferences through negotiation between software agents. The system we develop is implemented on the Jabber platform and is deployed in the context of a meeting room scenario. Sarvapali D. Ramchurn, Benjamin Deitch, Mark Kenneth Thompson, David De Roure, Nicholas R. Jennings, Michael Luck |
MobiQuitous | 1 |