Accurate traffic flow prediction remains a fundamental challenge in intelligent transportation systems, particularly in cross-domain, data-scarce scenarios where limited historical data hinders model training and generalisation. The complex spatio-temporal dependencies and nonlinear dynamics of urban mobility networks further complicate few-shot learning across different cities. This paper proposes MCPST, a novel Multi-phase Consensus Spatio-Temporal framework for few-shot traffic forecasting that reconceptualises traffic prediction as a multi-phase consensus learning problem. Our framework introduces three core innovations: (1) a multi-phase engine that models traffic dynamics through diffusion, synchronisation, and spectral embeddings for comprehensive dynamic characterisation; (2) an adaptive consensus mechanism that dynamically fuses phase-specific predictions while enforcing consistency; and (3) a structured meta-learning strategy for rapid adaptation to new cities with minimal data. We establish extensive theoretical guarantees, including representation theorems with bounded approximation errors and generalisation bounds for few-shot adaptation. Through experiments on four real-world datasets, MCPST achieves competitive performance against twenty-one (21) state-of-the-art methods in spatio-temporal graph learning, dynamic graph transfer learning, prompt-based spatio-temporal prediction, and cross-domain few-shot settings. Our framework delivers strong average prediction accuracy while requiring up to 90% less training data, and performs on par with the leading baselines in statistically significant comparisons. The implementation code is available at https://github.com/afofanah/MCPST.

Accurate traffic flow prediction is essential for intelligent transportation systems and urban planning. Traditional approaches that combine Transformer models with Graph Convolutional Networks (GCNs) or Convolutional Neural Networks (CNNs) often struggle to effectively integrate features with varying degrees of connectivity. As a result, graph-based problems do not fully utilise the capabilities of GCNs, while time-series problems fail to entirely leverage CNNs. To overcome these challenges, we introduce the Dual Heterogeneous Three-Stage Coupling and Multivariate Feature-Aware Learning Network (CHAMFormer). This architecture comprises three main components, each focusing on a distinct innovation: capturing fine-grained, short-range traffic patterns to manage immediate interactions and local bottlenecks; integrating mid-range spatial and temporal features to understand broader traffic interactions and ripple effects; and analysing complex, long-term traffic dynamics to anticipate and manage large-scale events and network behaviours across the entire system. These modules enhance GCN performance, enabling them to function more effectively alongside Transformers and Graph Neural Networks (GNNs). The CHAMFormer model incorporates a three-stage self-attention mechanism with a Skip-Connection method to improve the capture of detailed information without significantly increasing computational costs. By connecting low-level, intermediate-level, and high-level feature extractions, this model adapts well to changing traffic patterns, thereby enhancing multi-feature awareness and prediction accuracy. Extensive experiments using seven public datasets, both with and without predefined graph structures, and in multivariate and univariate scenarios demonstrate that CHAMFormer improves prediction accuracy by at least 10%–15%. To validate our proposed model, we also tested CHAMFormer in the energy domain, where it effectively handles time-series problems. Additionally, a sensitivity analysis confirms the model's predictability and interpretability, providing valuable insights for transportation policy and infrastructure development.

Significant challenges arise when Graph Neural Networks (GNNs) try to deal with uneven data. Specifically in signed and weighted graph structures. This makes classification tasks less effective. Within the GNN context, researchers have found traditional solutions like resampling, reweighting, and synthetic sample generation to be inadequate. GATE-GNN, a novel architecture designed specifically for imbalanced datasets, overcomes these limitations. GATE-GNN integrates an ensemble of network modules that harness the spatial features of graph networks and effectively utilise embedding information from earlier layers. This unique approach not only bolsters generalisation by reducing volatility. It also refines the optimisation algorithm, resulting in more accurate and stable classification outcomes. We rigorously tested the effectiveness of GATE-GNN on four widely recognised datasets: Cora, NELL, Citeseer, and PubMed. We performed a comparative analysis against established methods such as Graph Convolutional Networks (GCN), Graph Sample and Aggregate (GraphSAGE), Propagation Multilayer Perceptron PMLP), Imbalanced Node Sampling GNN (INS-GNN), GNN-Curriculum Learning (GNN-CL) and Graph Attention Networks (GAT). Empirical results demonstrate that GATE-GNN significantly outperforms these existing models, achieving an average improvement in classification accuracy of approximately 5%–10% over the previous best results. Additionally, GATE-GNN presents a marked reduction in training time. This underscores its efficiency and suitability for practical applications in imbalanced graph data scenarios. Implementation of the proposed GATE-GNN can be accessed here https://github.com/afofanah/GATE-GNN.

Analysing software log files has become a challenging task due to the diversity in file structure and the nonstandardisation of log syntax. During the process of extracting log data, it is required to manually decode the log syntax and interpret data semantics, which can become tedious and is often error-prone if not performed carefully. Contemporary log analysis software tools do exist in the market and most of them offer numerous options to analyse log files, however, their sheer focus is on providing log management solutions instead of log analysis capabilities. In particular, none of them offers a generic parsing and extracting solution that can discover hidden data structures, a critical and effortful task in log analysis. We thereby devise such a solution that is able to automatically identify hidden patterns in a given log file and extract useful information by generalising the patterns. The solution is implemented as an intelligent Web-based system known as iLSE (intelligent Log Structuring and Extraction) whose users are not required to possess fluent programming skills. This paper presents a reference architecture for the system as well as a comparison study on how the system performs against contemporary log analysis systems.

Engineering real-time communication protocols is a complex task, particularly in the safety-critical domain. Current protocols exhibit a strong tradeoff between flexibility and the ability to detect and handle faults in a deterministic way. Model-driven engineering promises a high level design of verifiable and directly runnable implementations. Arrangements of logic-labelled finite-state machines (LLFSMs) allow the implementation of complex system behaviours at a high level through a subsumption architecture with clear execution semantics. Here, we show that the ability of LLFSMs to handle elaborate hierarchical module interactions can be utilised towards the implementation of testable, safety-critical real-time communication protocols. We present an efficient implementation and evaluation of INCUS, a time-triggered protocol for safety-critical real-time communication that transcends the rigidity imposed by existing real-time communication systems through the use of a high-level subs umption architecture.

Globalization leads to an efficient new business paradigm generally known as Collaborative Virtual Enterprise (CVE) which demands flexible service orchestration and robust workflow execution. As two major service orchestration strategies, OWL-S and BPEL have their own strength and deficiencies. To meet the challenge in CVE, in this paper, we propose a Workflow Execution System (WES) that takes advantage of the complementary strengths of these two technologies. On the one hand, having semantic support, OWL-S is used in dynamic service discovery and composition at high level. On the other hand, at the concrete level, industry-based BPEL is exploited in service execution. The description of each Semantic Web service is enhanced with rule-based modeling of the essential business logic behind the service interface. In order to realize interoperability in OWL-S and BPEL without loss of semantic information, we further proposed an OWLS2BPEL Mapper to facilitate the workflow robustness and support rule evaluation to increase responsiveness to customers. A concrete scenario in PC manufacturing Collaborative Virtual Enterprise is analyzed to demonstrate the effectiveness of our workflow execution system.

With an increasing complexity of business processes, self-healing capability is becoming an important issue in order to support robust service flow execution. In this paper, a dynamic self-healing mechanism is proposed, which can dynamically identify suitable alternatives and replace faulty services such that a service flow can be performed successfully despite of unexpected exceptions. This mechanism explicitly utilizes semantic Web services for service matching and selection of a composite service in business service flow, and Semantic Web services are equipped with rich business rules in a domain-dependent manner. We explore the self-healing mechanism for supporting self-healable service flow execution which is modeled in BPEL4WS. A demo system of self-healing capable service flow execution is built to validate its effectiveness by a concrete scenario, PC manufacturing application.

Constraints allow users to declare relationships among objects and let the constraint systems maintain and satisfy these relationships. Formulas have been adopted to express constraints in a wide variety of single-user applications, because of their simplicity, efficiency and manageability. The needs and benefits of supporting formula-defined constraints in collaborative environments have long been recognized. However, maintaining both constraints and consistency in the presence of concurrency in collaborative systems is a challenge. In these systems, users may concurrently define formulas, which could result in that different formulas are defined to express the same object attribute at different sites. In this article, we discuss the issues and techniques in maintaining formula-defined constraints in collaborative systems. In particular, we also proposed a method that is able to maintain both constraints and system consistency in concurrent environments based on the existing consistency maintenance approaches. This method extends the application of these approaches from collaborative systems without constraint to systems that support formulas. The proposed method has been applied to implement a collaborative Visio system, called CoVisio, which leverages single-user Microsoft Visio for multi-user collaboration. Specific issues related to CoVisio are also discussed in detail.

Recent advancements in collaboration technology have shown that it is possible to convert existing single-user applications into real-time collaborative applications without modifying the source codes of the single-user applications. Such conversion relies on the API (Application Programming Interface) provided by the single-user applications. Poorly designed APIs make such conversion difficult, inefficient, or even impossible. Until now, it is not well understood what features APIs should provide to facilitate conversion of single-user applications into collaborative applications. This paper presents recommendations of the features single-user application APIs should provide to facilitate conversion. The results are based on what we have learnt from converting Microsoft Visio, into real-time collaborative Visio (CoVisio), and our previous experience in building CoWord and CoPowerPoint.

Constraints are very useful in real-time collaborative editing systems. They are able to automatically enforce semantic rules and properties. A specific type of constraint is dataflow constraint. Any property that can be expressed as an equation can be represented as a dataflow constraint. However, ensuring multi-way dataflow constraint satisfaction and consistency maintenance in a replicated collaborative environment is a challenge. This paper presents a novel method for computing multi-way dataflow constraint propagation for real-time collaborative editing systems. This method produces convergent result that is consistent with syntax level effect, irrespective of the operation execution order. This method is generic and is applied to enforce object placement and label name consistency in a realtime collaborative CASE system

Single-user interactive computer applications are pervasive in our daily lives and work. Leveraging single-user applications for supporting multi-user collaboration has the potential to significantly increase the availability and improve the usability of collaborative applications. In this article, we report an innovative Transparent Adaptation (TA) approach and associated supporting techniques that can be used to convert existing and new single-user applications into collaborative ones, without changing the source code of the original application. The cornerstone of the TA approach is the operational transformation (OT) technique and the method of adapting the single-user application programming interface to the data and operation models of OT. This approach and supporting techniques were developed and tested in the process of transparently converting two commercial off-the-shelf single-user applications (Microsoft Word and PowerPoint) into real-time collaborative applications, called CoWord and CoPowerPoint, respectively. CoWord and CoPowerPoint not only retain the functionalities and “look-and-feel” of their single-user counterparts, but also provide advanced multi-user collaboration capabilities for supporting multiple interaction paradigms, ranging from concurrent and free interaction to sequential and synchronized interaction, and for supporting detailed workspace awareness, including multi-user telepointers and radar views. The TA approach and generic collaboration engine software component developed from this work are potentially applicable and reusable in adapting a wide range of single-user applications.

Multi-way dataflow constraints are very useful in the development of collaborative applications, such as collaborative CAD and CASE systems, but satisfying multi-way dataflow constraints in the presence of concurrency in collaborative systems is difficult. In this article, we discuss the issues and techniques in maintaining multi-way dataflow constraints in concurrent environments. In particular, we also proposed a novel strategy that is able to reconstruct computation flows to satisfy multi-way dataflow constraints according to concurrent user operations in collaborative systems. Our strategy ensures both constraint satisfaction and system consistency, which is independent of the execution orders of concurrent operations.

Effective interaction among participants is crucial to the success of a presentation. The workspace of a presentation, which is the presentation slides, is a natural and effective medium of interactions among presentation participants. However, due to the insufficient support from existing collaborative presentation systems, workspace-mediated interaction is inconvenient in presentations, especially in collaborative presentations. In this paper, we explore typical workspace-mediated interaction forms and analyze their characteristics. Based on this analysis, we present a series of approaches to supporting workspace-mediated interaction in the context of the CoPowerPoint system.

Object grouping is an effective means for managing the complexity in graphics editing. However, research on collaborative object grouping has not been adequate. In this paper, we contribute a novel collaborative object grouping technique, called CoGroup. CoGroup can achieve maximal combined effects among compatible operations and preserve all users' work in the face of conflict without the overhead of undoing and redoing conflict operations as in existing serialization approaches. CoGroup has been implemented in collaborative word processing (CoWord) and slide authoring (CoPowerPoint) systems and is generally applicable to a range of off-the-shelf commercial graphics applications, particularly CAD/CASE tools.

Telepointers are a real-time groupware interface feature to indicate where other users are pointing. None of existing telepointer techniques, however, is capable of tracking the reference object and preserving the relative position in the face of dynamic content and view changes in real-time collaborative document editing systems. In this paper, we report a novel object-associated telepointer (OAT) technique with the following features in the face of dynamic content and view changes: (1) relocating telepointers to track the reference object; (2) preserving the position relative to the reference object; and (3) providing feedback of the telepointer relocation to the local user with a virtual local cursor. The key technique for supporting OAT is to extend the operational transformation technique with a generic Refer operation to support adjusting the reference object position. The OAT technique has been implemented in the CoWord system based on the transparent adaptation approach so that it can provide the OAT support to a range of realtime collaborative applications.

Operational Transformation (OT) is a technique originally invented for supporting consistency maintenance in collaborative text editors. Word processors have much richer data types and more comprehensive operations than plain text editors. Among others, the capability of updating attributes of any types of object is an essential feature of all word processors. In this paper, we report an extension of OT for supporting a generic Update operation, in addition to Insert and Delete operations, for collaborative word processing. We focus on technical issues and solutions involved in transforming Updates for both consistency maintenance and group undo. A novel technique, called Multi-Version Single-Display (MVSD), has been devised to resolve conflict between concurrent Updates, and integrated into the framework of OT. This work has been motivated by and conducted in the CoWord project, which aims to convert MS Word into a real-time collaborative word processor without changing its source code. This OT extension is relevant not only to word processors but also to a range of interactive applications that can be modelled as editors.

Single-user interactive computer applications are pervasive in our daily lives and work. Leveraging single-user applications for multi-user collaboration has the potential to significantly increase the availability and improve the usability of collaborative applications. In this paper, we report an innovative transparent adaptation approach for this purpose. The basic idea is to adapt the single-user application programming interface to the data and operational models of the underlying collaboration supporting technique, namely Operational Transformation. Distinctive features of this approach include: (1) Application transparency: it does not require access to the source code of the single-user application; (2) Unconstrained collaboration: it supports concurrent and free interaction and collaboration among multiple users; and (3) Reusable collaborative software components: collaborative software components developed with this approach can be reused in adapting a wide range of single-user applications. This approach has been applied to transparently convert MS Word into a real-time collaborative word processor, called CoWord, which supports multiple users to view and edit any objects in the same Word document at the same time over the Internet. The generality of this approach has been tested by re-applying it to convert MS PowerPoint into CoPowerPoint.

An unfavorable phenomenon is observed: current electronic markets are fragmented and have formed a set of autonomously distributed product information islands. This leads to heterogeneity of product information between separated sources and makes difficult on product document interoperation. To resolve the issue and facilitate business document interoperation, this paper proposes a heterogeneous concept mapping approach. By this approach, heterogeneous product documents are transformed from one context to another context without losing any semantic information. This transformation process is supported by a heterogeneous concept transformation algorithm that includes five transformation steps: source-local context transformation, local-common context transformation, common-common context transformation, common-local context transformation and local-source context transformation.

Real-time collaborative graphics editing systems allow a group of users to view and edit the same graphics document at the same time from geographically dispersed sites connected by communication networks. Consistency maintenance in the face of concurrent accesses to shared objects is one of the core issues in the design of these types of systems. In this article, we propose an object-level multiversioning approach to consistency maintenance in real-time collaborative graphic editors. This approach is novel in achieving intention preservation and convergence, in preserving the work concurrently produced by multiple users in the face of conflict, and in minimizing the number of object versions for conflict resolution. Major technical contributions of this work include a formal specification of a unique combined effect for an arbitrary group of conflict and compatible operations, a distributed algorithm for incremental creation of multiple object versions, a consistent object identification scheme for multiple object versions, and a convergent layering scheme for overlapping objects. All algorithms and schemes presented in this article have been implemented in an Internet-based GRACE (graphics collaborative editing) system.

Undo is a useful and widely supported feature which can be used to recover from erroneous operations, learn new system features, and explore alternative solutions. The ability to undo any operation at any time is especially important for collaborative editing systems because it can be used to support local or global undo and also multiple undo models. The Any Undo solution presented in this paper is able to undo any operation in collaborative graphics editing systems. The major challenge in designing the Any Undo solution is to produce the correct undo/redo effect when operations may be undone/redone in any order. The solution is divided into two parts. The first part focuses on how to produce the undo/redo effect on individual objects. Due to the use of multi-versioning concurrency control protocol, the second part of the solution focuses on producing the correct version and the correct number of versions. This Any Undo solution has been implemented in a collaborative graphics editing system called GRACE.

Real-time collaborative editing systems are distributed groupware systems that allow multiple users to edit the same document at the same time from multiple sites. A specific type of collaborative editing system is the object-based collaborative graphics editing system. Traditionally, locking has been used as the major concurrency control techniques in this type of system. This paper examines locking in a supporting role to the concurrency control technique of multi-versioning. Two types of locks are examined: object and region. Two optional and responsive locking schemes, instant locking and instant exclusive locking, are presented. Their advantages and disadvantages are discussed.

Groupware systems are a special class of distributed computing systems which support human-computer-human interaction. Real-time collaborative graphics editors allow a group of users to view and edit the same graphics document at the same time from geographically dispersed sites connected by communication networks. Resolving conflict access to shared objects is one of the core issues in the design of this type of system. This paper proposes a novel distributed multi-version approach to conflict resolution. This approach aims to preserve the work concurrently produced by multiple users in the face of conflicts, and to minimize the number of object versions for accommodating combined effects of conflicting and compatible operations. Major technical contributions of this work include a formal specification of a unique combined effect for any group of conflicting and compatible operations, a distributed algorithm for incremental creation of multiple object versions, and a consistent object identification scheme for multi-version and multireplica graphics editing systems. All algorithms and schemes preserved in this paper have been used in the GRACE (Graphics Collaborative Editing) system implemented in Java.

Object based collaborative graphics editing systems allow multiple users to edit the same graphics document at the same time from multiple sites. The paper examines the use of locking to prevent the generation of conflicting operations in this type of system. Two types of locks are examined: object and region. A locking scheme which preserves the intentions of all operations is proposed. Furthermore, the problems of lock ownership caused by concurrent operations are resolved.

Real-time collaborative editing systems are groupware systems that allow multiple users to edit the same document at the same time from multiple sites. A specific type of collaborative editing system is the object-based collaborative graphics editing system. One of the major challenge in building such systems is to solve the concurrency control problems. This paper addresses the concurrency control problem of how to preserve the intentions of concurrently generated operations whose effects are conflicting. An object replication strategy is proposed to preserve the intentions of all operations. The effects of conflicting operations are applied to different replicas of the same object, while non-conflicting operations are applied to the same object. An object identification scheme is proposed to uniquely and consistently identify non-replicated and replicated objects. Lastly, an object replication algorithm is proposed to produce consistent replication effects at all sites.

Real-time cooperative editing systems allow multiple users to view and edit the same text/graphic/image/multimedia document at the same time for multiple sites connected by communication networks. Consistency maintenance is one of the most significant challenges in designing and implementing real-time cooperative editing systems. In this article, a consistency model, with properties of convergence, causality preservation, and intention preservation, is proposed as a framework for consistency maintenance in real-time cooperative editing systems. Moreover, an integrated set of schemes and algorithms, which support the proposed consistency model, are devised and discussed in detail. In particular, we have contributed (1) a novel generic operation transformation control algorithm for achieving intention preservation in combination with schemes for achieving convergence and causality preservation and (2) a pair of reversible inclusion and exclusion transformation algorithms for stringwise operations for text editing. An Internet-based prototype system has been built to test the feasibility of the proposed schemes and algorithms