Proteins are complex biological information granules that play a crucial role in various cellular processes within living organisms. Processing 3D protein structures, which are the most informative from the biological point of view, is both intricate and time-consuming. In particular, performing 3D protein structure searches against large protein datasets involves identifying similarities and conducting structural alignments across numerous molecules (granules). This task demands advanced methods for matching identical and similar regions within protein structures and substantial computational resources to handle large collections of macromolecular data efficiently. In this paper, we present our parallel implementation of scalable 3D structural alignment on the Apache Spark big data platform. We describe a customized approach that leverages Spark data transformations within the data processing pipeline for the alignment process. Our experimental results demonstrate that this solution, tightly integrated with the Spark processing model, is both efficient and scalable, even with the increasing volume of protein structure data.

Detection and prediction of failures in Automated Guided Vehicles (AGV) are essential for the uninterrupted operation of production plants. Anomaly detection is usually achieved by comparing expected measurement values with actual observations. Thus, it is crucial to predict telemetry signals properly. In this paper, we research the prediction of energy consumption using state-of-the-art Artificial Neural Networks architectures (SCINet) compared with other Recurrent Neural Network (RNN) approaches on the data streams acquired from CoBotAGV. We especially focus on the possibility of applying feature weighting. We show that it can improve prediction capabilities. We also investigate resource utilization in terms of time to fit the embedded AGV environment.

In today’s world, smart factories are a coexisting element of smarticizing cities. Smart manufacturing of today relies on the automation of many component tasks of the production process. Automated guided vehicles (AGVs) that transport materials on the production lines are important elements of this automation. Appropriate management of a fleet of AGVs requires avoiding collisions. However, prediction and early detection of approaching collision points on the transportation routes not only prevent collisions but also enables adjusting the AGV operation and improving its flow. In this paper, we demonstrate the use of fuzzy sets and linguistic variables in collision prevention by processing AGV data streams with Apache Kafka. We extend the capabilities of Apache Kafka and ksqlDB towards fuzzy stream processing and use fuzzy KSQL queries to predict collisions. Our experiments prove that fuzzy querying against AGV data streams does not consume much time and computational resources, and we can successfully avoid collisions by predicting future positions of the AGV for various densities of data streams and widths of time windows.

Reverse k-nearest neighbor (RkNN) queries are prevalent in location-based services to find those locations that have the query point as one of their k nearest neighbors. However, such query requires users to disclose the location of the query point to a service provider who might be untrustworthy. Previous attempts to preserve the privacy of RkNN queries are either based on weaker notions of privacy such as location cloaking or not efficient when k > 1. In this paper, we propose novel solutions based on the private information retrieval (PIR) mechanism to preserve the privacy of RkNN query points. Our solutions include server-side data indexing and client-side query processing methods to facilitate PIR which is an inherently expensive data retrieval mechanism. We experimentally evaluate our approach using real-world datasets and show that it preserves the location privacy of queries with reasonable computation and storage overhead.

Extracting patterns and deriving insights from spatio-temporal data finds many target applications in various domains, such as in urban planning and computational sustainability. Due to their inherent capability of simultaneously modeling the spatial and temporal aspects of multiple instances, tensors have been successfully used to analyze such spatio-temporal data. However, standard tensor factorization approaches often result in components that are highly overlapping, which hinders the practitioner's ability to interpret them without advanced domain knowledge. In this work, we tackle this challenge by proposing a tensor factorization framework, called CP-ORTHO, to discover distinct and easily-interpretable patterns from multi-modal, spatio-temporal data. We evaluate our approach on real data reflecting taxi drop-off activity. CP-ORTHO provides more distinct and interpretable patterns than prior art, as measured via relevant quantitative metrics, without compromising the solution's accuracy. We observe that CP-ORTHO is fast, in that it achieves this result in 5x less time than the most accurate competing approach.

One of the greatest challenges in spatial crowdsourcing is determining the veracity of reports from multiple users about a particular event or phenomenon. In this paper, we address the difficulties of truth discovery in spatio-temporal tasks and present a new method based on recursive Bayesian estimation (BE) from multiple reports of users. Our method incorporates a reliability model for users, which improves as more reports arrive while increasing the accuracy of the model in labeling the state of the event. The model is further improved by Kalman estimation (BE+KE) that models the spatio-temporal correlations of the events and predicts the next state of an event and is corrected when new reports arrive. The methods are tested in a simulated environment, as well as using real-world data. Experimental results show that our methods are adaptable to the available data, can incorporate previous beliefs, and outperform existing truth discovery methods of spatio-temporal events.

Predictive range queries retrieve objects in a certain spatial region at a (future) prediction time. Processing predictive range queries on large moving object databases is expensive. Thus effective pruning is important, especially for long-term predictive queries since accurately predicting long-term future behaviors of moving objects is challenging and expensive. In this work, we propose a pruning method that effectively reduces the candidate set for predictive range queries based on (high-order) Markov chain models learned from historical trajectories. The key to our method is to devise compressed representations for sparse multi-dimensional matrices, and leverage efficient algorithms for matrix computations. Experimental evaluations show that our approach significantly outperforms other pruning methods in terms of efficiency and precision.

The rapid development of positioning techniques has enabled information to be widely collected on continuously moving objects, such as vehicles and mobile device users. Database systems supporting massive updates and predictive spatio-temporal queries on the moving objects are essential for modern location-based services. On the other hand, information (e.g. Location and velocity) that describes the motion of millions of moving objects can be accommodated in main memory with modern computing machines. Thus, in-memory indexing techniques are gaining popularity among moving object databases. Recent works indicate that a simple uniform grid is one of the best choices for indexing moving objects in main memory. However, to the best of our knowledge, relevant works in the literature consider only grids in the location space but disregard the velocity information of the moving objects, which we believe can be exploited to further improve query performance. In this paper, we propose D-Grid, an in-memory dual space grid index for moving objects. Specifically, it indexes moving objects using grid structures in both location and velocity spaces, which improves query performance by almost an order of magnitude. We also propose a lazy deletion and garbage cleaning mechanism that can be applied to both our dual space and existing location space uniform grid based indexes and further improve update performance. Extensive experiments demonstrate that our approach significantly outperforms existing uniform grid based in-memory indexes.

We propose to demonstrate STAC, a tool for spatial task assignment with cloaked locations in crowd sensing applications. The need for systems such as STAC becomes critical when participants of crowd sensing applications hesitate to share their locations due to privacy concerns. In such applications, STAC enables effective task assignment capabilities without compromising the location privacy of workers and volunteers. STAC implements novel algorithms that handle uncertain task assignment, which is a challenging problem involving uncertain locations of participants as a result of location cloaking. We will demonstrate, from both synthetic and real data, that our methods achieve high sensing coverage with low cost using cloaked participant locations. We will also demonstrate a location-based mobile Q&A application that utilizes STAC for task assignment.

Indexing moving objects has been extensively studied in the past decades. In most real world applications, the moving objects exhibit particular patterns on their velocities. For example, velocities of vehicles in city road networks usually show patterns on both directions and values. Velocity-based partitioning techniques have been proved effective in improving query performances of moving object indexes. This demo presents VPIndexer, a toolkit for visualizing comparison of three velocity-based partitioning algorithms: VMBR-based partitioning, DVA-based partitioning and our recently proposed speed-based partitioning techniques. VPIndexer uses the Bx-tree and the TPR*-tree as the baseline approaches.

Distributed mobile crowd sensing is becoming a valuable paradigm, enabling a variety of novel applications built on mobile networks and smart devices. However, this trend brings several challenges, including the need for crowd sourcing platforms to manage interactions between applications and the crowd (participants or workers). One of the key functions of such platforms is spatial task assignment which assigns sensing tasks to participants based on their locations. Task assignment becomes critical when participants are hesitant to share their locations due to privacy concerns. In this paper, we examine the problem of spatial task assignment in crowd sensing when participants utilize spatial cloaking to obfuscate their locations. We investigate methods for assigning sensing tasks to participants, efficiently managing location uncertainty and resource constraints. We propose a novel two-stage optimization approach which consists of global optimization using cloaked locations followed by a local optimization using participants' precise locations without breaching privacy. Experimental results using both synthetic and real data show that our methods achieve high sensing coverage with low cost using cloaked locations.

Monitoring web browsing behavior has benefited many data mining applications, such as top-K discovery and anomaly detection. However, releasing private user data to the greater public would concern web users about their privacy, especially after the incident of AOL search log release where anonymization was not correctly done. In this paper, we adopt differential privacy, a strong, provable privacy definition, and show that differentially private aggregates of web browsing activities can be released in real-time while preserving the utility of shared data. Our proposed algorithms utilize the rich correlation of the time series of aggregated data and adopt a state-space approach to estimate the underlying, true aggregates from the perturbed values by the differential privacy mechanism. We evaluate our algorithms with real-world web browsing data. Utility evaluations with three metrics demonstrate that the quality of the private, released data by our solutions closely resembles that of the original, unperturbed aggregates.

Sharing aggregate statistics of private data can be of great value when data mining can be performed in real-time to understand important phenomena such as influenza outbreaks or traffic congestion. However, to this date there have been no tools for releasing real-time aggregated data with differential privacy, a strong and provable privacy guarantee. We propose FAST, a real-time system that allows differentially private aggregate sharing and time-series analytics. FAST employs a set of novel, adaptive strategies to improve the utility of shared/released data while guaranteeing the user-specified level of differential privacy. We will demonstrate the challenges and our solutions in the context of prepared data sets as well as live participation data dynamically collected among the SIGMOD'13 attendees.