ppxscal/embedding_network huggingface dataset:
Seeing our signals: combining location traces and web-based models for personal discovery
Authors: E. Agapie, G. Chen, D. Houston, E. Howard, J. Kim, M. Y. Mun, A. Mondschein, S. Reddy, R. Rosario, J. Ryder, A. Steiner, J. Burke, E. Estrin, M. Hansen, M. Rahimi
Venue: Proceedings of the 9th workshop on Mobile computing systems and applications (2008)

Each of us has a complex and reciprocal relationship with our environment. Based on limited knowledge of this interwoven set of influences and consequences, we constantly make choices: where to live, how to go to work, what brands to buy, what to do with our leisure time. These choices evolve into patterns, and these patterns become driving functions of our relationship with the world around us. With increasing ease, devices we carry can sense, process, and transmit data on these patterns for our own use or to share, carefully, with others. In particular, here we will focus on location time series, gathered from GPS-enabled personal mobile devices. From this capacity emerges a new class of hybrid mobile-web applications that, first, enable personal exploration of our own patterns and, second, use the same data to index our life into other available datasets about the world around us. Such applications, revealing the previously unobservable about our own lives, offer an opportunity to employ mobile technology to illuminate the ramifications of our choices on others and the effects of the "microenvironments" we move through on us [1, 10].
Towards agents participating in realistic multi-unit sealed-bid auctions
Authors: loannis A. Vetsikas, Nicholas R. Jennings
Venue: Proceedings of the 7th international joint conference on Autonomous agents and multiagent systems - Volume 3 (2008)

When autonomous agents decide on their bidding strategies in real world auctions, they have a number of concerns that go beyond the models that are normally analyzed in traditional auction theory. Oftentimes, the agents have budget constraints and the auctions have a reserve price, both of which restrict the bids the agents can place. In addition, their attitude need not be risk-neutral and they may have uncertainty about the value of the goods they are buying. Some of these issues have been examined individually for single-unit sealed-bid auctions. However, here, we work towards extending this analysis to the multi-unit case, and also analyzing the multi-unit sealed-bid auctions in which a combination of these issues are present. In this paper, we present the initial results of this work. More specifically, we present the equilibria that exist in multi-unit sealed-bid auctions, when either the agents can have any risk attitude, or the auction has a reserve price.
A First Attempt to Express KAOS Refinement Patterns with Event B
Authors: Abderrahman Matoussi, Frédéric Gervais, Régine Laleau
Venue: Proceedings of the 1st international conference on Abstract State Machines, B and Z (2008)

It is now recognised that goals play an important role in requirements engineering process, and consequently in systems development process.Whereas specifications allow us to answer the question"WHAT the system does", goals allow us to address the "WHY, WHO, WHEN" questions [1]. Up to now, the development process associated with formal methods, including Event B, begins at the specification level. Our objective is to include requirements analysis within this process, and more precisely KAOS[2] which is a methodology to implement goal-based reasoning. Existing work [3,4] that combine KAOS with formal methods generate a formal specification model from a KAOS requirements model.We aim at expressing KAOS goal models with a formal language (Event B), hence staying at the same abstraction level. Our work is based on a constructive approach in which Event B models are built incrementally from KAOS goal models, driven by goal refinement patterns [1]. Since a KAOS goal means that a property must be established, the main idea is to represent each goal as a B event and the property as the post-condition of this B event. Up to now, we consider refinement patterns defined with first-order logic. Patterns with LTL temporal logic will be studied in further work.
A Novel Approach to Decentralized Workflow Enactment
Authors: Daniel Martin, Daniel Wutke, Frank Leymann
Venue: Proceedings of the 2008 12th International IEEE Enterprise Distributed Object Computing Conference (2008)

Web service orchestrations -- expressed in the Web Service Business Process Execution Language (WS-BPEL or BPEL for short) -- are a manifestation of the two-level-programming paradigm where services, i.e. the business functions used by the composite application, are composed through BPEL's control flow constructs. BPEL processes Web service orchestrations, business functions therefore can be transparently accessed remotely, allowing to build composite applications that integrate business functions provided by different partners on different locations. As of today, execution of BPEL processes, i.e. the evaluation of the processes' control flow, is performed by a central workflow engine. In certain scenarios, such as complex collaborative cross-partner interactions, this approach of centralized workflow enactment leads to "un-natural" process models; process models that are not driven by the processes' original business goal but by infrastructural or organizational reasons. In this paper, we propose an alternative approach to enacting BPEL process control flow in a distributed, decentralized manner. We present the overall process lifecycle and give a detailed description of the underlying process model.
Modular array structure for non-restoring square root circuit
Authors: S. Samavi, A. Sadrabadi, A. Fanian
Venue: Journal of Systems Architecture: the EUROMICRO Journal (2008)

Square root is an operation performed by the hardware in recent generations of processors. The hardware implementation of the square root operation is achieved by different means. One of the popular methods is the non-restoring algorithm. In this paper, the classical non-restoring array structure is improved in order to simplify the circuit. This reduction is done by eliminating a number of circuit elements without any loss in the precision of the square root or the remainder. For a 64-bit non-restoring circuit the area of the suggested circuit is about 44% smaller than that of a conventional non-restoring array circuit. Furthermore, in order to create an environment for modular design of the non-restoring square root circuit, a number of modules are suggested. Using these modules it is possible to construct any square root circuit with an arbitrary number of input bits. The suggested methodology results in an expandable design with reduced-area. Analytical and simulation results show that the delay of the proposed circuit, for a 64-bit radicand, is 80% less than that of a conventional non-restoring array circuit.
Using Semantic Web Technologies for Knowledge-Driven Querying of Biomedical Data
Authors: Martin O'Connor, Ravi Shankar, Samson Tu, Csongor Nyulas, Dave Parrish, Mark Musen, Amar Das
Venue: Proceedings of the 11th conference on Artificial Intelligence in Medicine (2007)

Software applications that work with biomedical data have significant knowledge-management requirements. Formal knowledge models and knowledge-based methods can be very useful in meeting these requirements. However, most biomedical data are stored in relational databases, a practice that will continue for the foreseeable future. Using these data in knowledge-driven applications requires approaches that can form a bridge between relational models and knowledge models. Accomplishing this task efficiently is a research challenge. To address this problem, we have developed an end-to-end knowledge-based system based on Semantic Web technologies. It permits formal design-time specification of the data requirements of a system and uses those requirements to drive knowledge-driven queries on operational relational data in a deployed system. We have implemented a dynamic OWL-to-relational mapping method and used SWRL, the Semantic Web Rule Language, as a high-level query language that uses these mappings. We have used these methods to support the development of a participant tracking application for clinical trials and in the development of a test bed for evaluating biosurveillance methods.
A contour dynamics algorithm for axisymmetric flow
Authors: Karim Shariff, Anthony Leonard, Joel H. Ferziger
Venue: Journal of Computational Physics (2008)

The method of contour dynamics, developed for two-dimensional vortex patches by Zabusky et al. [N.J. Zabusky, M.H. Hughes, K.V. Roberts, Contour dynamics for the Euler equations in two-dimensions, J. Comp. Phys. 30 (1979) 96-106] is extended to vortex rings in which the vorticity distribution varies linearly with normal distance from the symmetry axis. The method tracks the motion of the boundaries of the vorticity regions and hence reduces the dimensionality of the problem by one. We discuss the formulation and implementation of the scheme, verify its accuracy and convergence, and present illustrative examples.
2D shape deformation based on rigid square matching
Authors: Yanzhen Wang
Venue: Computer Animation and Virtual Worlds (2008)

In this paper, we propose a fast and stable method for 2D shape deformation based on rigid square matching. Our method utilizes uniform quadrangular control meshes for 2D shapes and tries to maintain the rigidity of each square in the control mesh during user manipulation. A rigid shape matching method is performed to find an optimal pure rotational transformation for each square in the control mesh. An iterative solver is proposed to compute the final deformation result for the entire control mesh by minimizing the difference between the deformed vertices and their counterparts in the neighboring rigid square. The deformation result on the 2D shape is as rigid as possible and the details of the shape are preserved well. As extensions, we present a shape-aware splitting method to improve the deformation effect for coarse meshes and a simple sketch-based clustering method for skeletal deformation. Experiments with various 2D shapes show that our method is efficient and easy to use, and can provide physically plausible result for shapes of objects in real world. Therefore, our shape deformation method is especially suitable for applications in cartoon character animation. Copyright &copy; 2008 John Wiley & Sons, Ltd.
A Study of a Loosely-Coupled Groupware System for Supporting Collaboration and Coordination
Authors: Tiffany Y. Tang, Hareton K. Leung
Venue: Proceedings of the 8th Asia-Pacific conference on Computer-Human Interaction (2008)

A number of researches have focused on the usability aspect of groupware in supporting collaborative work. Unfortunately, our understandings on their impact on supporting collaborative learning are still limited due to a lack of attention on this issue. Furthermore, the majority of educators and designers in CSCL expect that interactions and collaborations would come naturally, as a result, we are too busy with how versatile the tools in educational groupware systems shall have in order to provide a wide variety of interaction opportunities for both learners and educators, and largely ignore whether or not these features are valuable from learners' as well as educators' perspective. To bridge this gap, in this paper, we describe our experiences with loosely-coupled collaborative software called GroupScribbles, in its potential of supporting cooperation and coordination among learners as well as its failures. Our study suggests that it is not the versatility of the tools in these educational groupware systems, but how they can provide a seamless and focused distributed learning environment determines the overall pedagogical appropriateness of the software in CSCL. That is, the learning environment, although distributed, and fragmented, should be capable of sticking learners, their activities and meta-cognitive problem solving skills cohesively so as to continuously construct a relatively compact learning space where coordination and collaborations can be made cheap, lightweight, effective and efficient.
Deterministic Rendezvous in Trees with Little Memory
Authors: Pierre Fraigniaud, Andrzej Pelc
Venue: Proceedings of the 22nd international symposium on Distributed Computing (2008)

We study the size of memory of mobile agents that permits to solve deterministically the rendezvous problem, i.e., the task of meeting at some node, for two identical agents moving from node to node along the edges of an unknown anonymous connected graph. The rendezvous problem is unsolvable in the class of arbitrary connected graphs, as witnessed by the example of the cycle. Hence we restrict attention to rendezvous in trees, where rendezvous is feasible if and only if the initial positions of the agents are not symmetric. We prove that the minimum memory size guaranteeing rendezvous in all trees of size at most n is ¿(logn) bits. The upper bound is provided by an algorithm for abstract state machines accomplishing rendezvous in all trees, and using O(logn) bits of memory in trees of size at most n. The lower bound is a consequence of the need to distinguish between up to n ¿ 1 links incident to a node. Thus, in the second part of the paper, we focus on the potential existence of pairs of finite agents (i.e., finite automata) capable of accomplishing rendezvous in all bounded degree trees. We show that, as opposed to what has been proved for the graph exploration problem, there are no finite agents capable of accomplishing rendezvous in all bounded degree trees.
Educational platform for developing high-performance sensor nodes around a DSP core
Authors: Maximilian Nicolae, Radu Dobrescu, Dan Popescu
Venue: Proceedings of the 9th WSEAS International Conference on International Conference on Automation and Information (2008)

The paper presents an architecture of a wireless sensor node on which students can develop high-performance applications for ubiquitous sensor networks. A digital signal processor (DSP) was used for signal processing, an audio codec for data acquisition and a 802.11g wireless access point for communication. The entire network was approached initially as a Voice over IP (VoIP) mobile network, yet the information exchanged wasn't voice but measures and commands with Quality of Service (QoS) inherited from VoIP. The usage of mature technologies of audio codecs and wireless LANs assured a high performance and cost efficient solution for mobile sensor networks. The platform's modularity and flexibility allow its usage for many applicative didactical activities and also in research, as logistic support for developing complex projects.
Episodes in Space: A Modeling Study of Hippocampal Place Representation
Authors: Balázs Ujfalussy, Péter Erős, Zoltán Somogyvári, Tamás Kiss
Venue: Proceedings of the 10th international conference on Simulation of Adaptive Behavior: From Animals to Animats (2008)

A computer model of learning and representing spatial locations is studied. The model builds on biological constraints and assumptions drawn from the anatomy and physiology of the hippocampal formation of the rat. The emphasis of the presented research is on the usability of a computer model originally proposed to describe episodic memory capabilities of the hippocampus in a spatial task. In the present model two modalities --- vision and path integration --- are contributing to the recognition of a given place. We study how place cell activity emerges due to Hebbian learning in the model hippocampus as a result of random exploration of the environment. The model is implemented in the Webots mobile robotics simulation software. Our results show that the location of the robot is well predictable from the activity of a population of model place cells, thus the model is suitable to be used as a basic building block of location-based navigation strategies. However, some properties of the stored memories strongly resembles that of episodic memories, which do not match special spatial requirements.
Validated Evaluation of Special Mathematical Functions
Authors: Franky Backeljauw, Stefan Becuwe, Annie Cuyt
Venue: Proceedings of the 9th AISC international conference, the 15th Calculemas symposium, and the 7th international MKM conference on Intelligent Computer Mathematics (2008)

Because of the importance of special functions, several books and a large collection of papers have been devoted to the numerical computation of these functions, the most well-known being the Abramowitz and Stegun handbook [1]. But up to this date, no environment offers routines for the provable correct evaluation of these special functions.We point out how series and limit-periodic continued fraction representations of the functions can be helpful in this respect. Our scalable precision technique is mainly based on the use of sharpened a priori truncation and round-off error upper bounds, in case of real arguments. The implementation is validated in the sense that it returns a sharp interval enclosure for the requested function evaluation, at the same cost as the evaluation.
Efficient Measurement of the Eye Blinking by Using Decision Function for Intelligent Vehicles
Authors: Ilkwon Park, Jung-Ho Ahn, Hyeran Byun
Venue: Proceedings of the 7th international conference on Computational Science, Part IV: ICCS 2007 (2007)

In this paper, we propose an efficient measurement of the eye blinking for drowsy driver detection system that is one of the driver safety systems for the intelligent vehicle. However, during the real driving in the daytime, driver's face is exposed to various illuminations. It makes too difficult to monitor driver's eye blinking. Therefore, we propose efficient formation of the cascaded form of Support Vector Machines (SVM) as eye verification to boost the accuracy of eye detection. Furthermore, for an efficient measurement of eye blinking, we newly define decision function that is based on the measure of eyelid movement and the weight generated by the eye classifier. In the experiments, we can show the reliable performance for our own test data acquired during a real driving in the various illumination conditions. Furthermore, through our proposed method, we use detected eye blinking for Drowsy Driver Detection System.
Voronoi Diagram of Polygonal Chains under the Discrete Fréchet Distance
Authors: Sergey Bereg, Kevin Buchin, Maike Buchin, Marina Gavrilova, Binhai Zhu
Venue: Proceedings of the 14th annual international conference on Computing and Combinatorics (2008)

Polygonal chains are fundamental objects in many applications like pattern recognition and protein structure alignment. A well-known measure to characterize the similarity of two polygonal chains is the (continuous/discrete) Fréchet distance. In this paper, for the first time, we consider the Voronoi diagram of polygonal chains in d-dimension under the discrete Fréchet distance. Given a set ${\cal C}$ of n polygonal chains in d-dimension, each with at most k vertices, we prove fundamental properties of such a Voronoi diagram VD F (${\cal C}$). Our main results are summarized as follows. The combinatorial complexity of VD $_F({\cal C})$ is at most O(n dk + ¿ ). The combinatorial complexity of VD $_F({\cal C})$ is at least ¿(n dk ) for dimension d = 1,2; and ¿(n d(k ¿ 1) + 2) for dimension d > 2.
Patterns in Internet Architecture
Authors: Arjan Durresi
Venue: Proceedings of the 2nd international conference on Network-Based Information Systems (2008)

The networking research community is working to design the Next Generation Internet, which will meet the needs of the twenty-first century. The Next Generation Internet has to be commerce friendly and secure. It should allow receivers to set policies for how and where they receive their information. The Next Generation Internet should be designed for mobile objects. Naming, addressing architecture, and routing have to be such that these objects can move and decide how and where they want to receive their Internet traffic with full rights of privacy of their location, if desired. Most of such capabilities turn out to be mostly a consequence of the network architecture. Therefore, it is adamant a better understanding of issues related to Internet architectures. In this talk, I will identify several architectural patterns that have emerged from the Internet evolution, from its beginning until now. Furthermore, we will discuss about lessons that could be learned from these patterns in network architecture.
Hand gesture recognition and tracking based on distributed locally linear embedding
Authors: S. S. Ge, Y. Yang, T. H. Lee
Venue: Image and Vision Computing (2008)

In this paper, we present a computer vision system for human gesture recognition and tracking based on a new nonlinear dimensionality reduction method. Due to the variation of posture appearance, the recognition and tracking of human hand gestures from one single camera remain a difficult problem. We present an unsupervised learning algorithm, distributed locally linear embedding (DLLE), to discover the intrinsic structure of the data, such as neighborhood relationships information. After the embedding of input images are represented in a lower dimensional space, probabilistic neural network (PNN) is employed and a database is set up for static gesture classification. For dynamic gesture tracking, the similarity among the images sequence are utilized. Hand gesture motion can be tracked and dynamically reconstructed according to the image's relative position in the corresponding motion database. The method is robust against the input sequence frames and bad image qualities. Experimental results show that our approach is able to successfully separate different hand postures and track the dynamic gesture.
A Study of Convergence Speed in Multi-objective Metaheuristics
Authors: Antonio Jesús Nebro, Juan José Durillo, Carlos A. Coello Coello, Francisco Luna, Enrique Alba
Venue: Proceedings of the 10th international conference on Parallel Problem Solving from Nature: PPSN X (2008)

An open issue in multi-objective optimization is designing metaheuristics that reach the Pareto front using a low number of function evaluations. In this paper, we adopt a benchmark composed of three well-known problem families (ZDT, DTLZ, and WFG) and analyze the behavior of six state-of-the-art multi-objective metaheuristics, namely, NSGA-II, SPEA2, PAES, OMOPSO, AbYSS, and MOCell, according to their convergence speed, i.e., the number of evaluations required to obtain an accurate Pareto front. By using the hypervolume as a quality indicator, we measure the algorithms converging faster, as well as their hit rate over 100 independent runs. Our study reveals that modern multi-objective metaheuristics such as MOCell, OMOPSO, and AbYSS provide the best overall performance, while NSGA-II and MOCell achieve the best hit rates.
Planning and Learning in Environments with Delayed Feedback
Authors: Thomas J. Walsh, Ali Nouri, Lihong Li, Michael L. Littman
Venue: Proceedings of the 18th European conference on Machine Learning (2007)

This work considers the problems of planning and learning in environments with constant observation and reward delays. We provide a hardness result for the general planning problem and positive results for several special cases with deterministic or otherwise constrained dynamics. We present an algorithm, Model Based Simulation, for planning in such environments and use model-based reinforcement learning to extend this approach to the learning setting in both finite and continuous environments. Empirical comparisons show this algorithm holds significant advantages over others for decision making in delayed environments.
High Performance Geocomputation - Preface
Authors: Yong Xue, Dingsheng Liu, Jianwen Ai, Wei Wan
Venue: Proceedings of the 8th international conference on Computational Science, Part II (2008)

This paper presents the introduction to Geocomputation workshop in ICCS2008. The Workshop on Geocomputation continues with the ICCS conferences held in Amsterdam (2002), St. Petersburg (2003), Krakow (2004), Atlanta (2005), Reading (2006), and Beijing (2007).