ppxscal/embedding_network huggingface dataset:
An Adaptive Beacon Scheduling Mechanism Using Power Control in Cluster-Tree WPANs
Authors: Jaejoon Cho, Sunshin An
Venue: Wireless Personal Communications: An International Journal (2009)

This paper presents an adaptive beacon scheduling mechanism using power control in cluster-tree network. We consider the emerging low-rate wireless personal area networks (LR-WPANs) technology as specified in the IEEE 802.15.4 standard that can support environmental monitoring applications. Node clustering is a useful topology management approach to reduce channel contention and improve the network lifetime in wireless sensor networks. A cluster-tree network conforming to the IEEE 802.15.4 standard is formed by several coordinators that periodically send beacon frames to the nodes of their cluster. However, if these periodic beacon frames are sent without any particular scheduling, they will collide with each other and those nodes that wait for them will lose synchronization with their coordinators. The purpose of this paper is to overcome this problem by proposing an adaptive beacon scheduling mechanism using power control, cluster grouping, and the group identifier (GID) in cluster-tree WPANs. This mechanism is designed such that all of the sensing devices send the measured received power level back to their cluster heads (CHs), thus enabling them to adjust their transmission power level after the construction of the topology. Following this, the PAN coordinator divides all of the CHs into several cluster groups (CGs) in order to transmit their beacon frames simultaneously without encountering any direct or indirect beacon frame collision problems. The PAN coordinator selects the group heads (GHs) and assigns the GID for each cluster group. In addition, the PAN coordinator controls the beacon transmission time of all of the CHs and GHs in the CGs using the GID information located in the beacon frame of the PAN coordinator in order to avoid beacon frame collisions. Accordingly, the overall lifetime of the network in cluster-tree WPANs is prolonged by solving the problem of beacon frame collisions. We evaluated the performance of our scheme through a mathematical analysis and a series of simulations using the Network Simulator 2 (NS-2).
HOLMES: Effective statistical debugging via efficient path profiling
Authors: Trishul M. Chilimbi, Ben Liblit, Krishna Mehra, Aditya V. Nori, Kapil Vaswani
Venue: Proceedings of the 2009 IEEE 31st International Conference on Software Engineering (2009)

Statistical debugging aims to automate the process of isolating bugs by profiling several runs of the program and using statistical analysis to pinpoint the likely causes of failure. In this paper, we investigate the impact of using richer program profiles such as path profiles on the effectiveness of bug isolation. We describe a statistical debugging tool called HOLMES that isolates bugs by finding paths that correlate with failure. We also present an adaptive version of HOLMES that uses iterative, bug-directed profiling to lower execution time and space overheads. We evaluate HOLMES using programs from the SIR benchmark suite and some large, real-world applications. Our results indicate that path profiles can help isolate bugs more precisely by providing more information about the context in which bugs occur. Moreover, bug-directed profiling can efficiently isolate bugs with low overheads, providing a scalable and accurate alternative to sparse random sampling.
Words Fail Them
Authors: Stan Kelly-Bootle
Venue: Queue (2009)

Dedesignating and other linguistic hazards
What/when causal expectation modelling applied to audio signals
Authors: Amaury Hazan, Ricard Marxer, Paul Brossier, Hendrik Purwins, Perfecto Herrera, Xavier Serra
Venue: Connection Science (2009)

A causal system to represent a stream of music into musical events, and to generate further expected events, is presented. Starting from an auditory front-end that extracts low-level (i.e. MFCC) and mid-level features such as onsets and beats, an unsupervised clustering process builds and maintains a set of symbols aimed at representing musical stream events using both timbre and time descriptions. The time events are represented using inter-onset intervals relative to the beats. These symbols are then processed by an expectation module using Predictive Partial Match, a multiscale technique based on N-grams. To characterise the ability of the system to generate an expectation that matches both ground truth and system transcription, we introduce several measures that take into account the uncertainty associated with the unsupervised encoding of the musical sequence. The system is evaluated using a subset of the ENST-drums database of annotated drum recordings. We compare three approaches to combine timing (when) and timbre (what) expectation. In our experiments, we show that the induced representation is useful for generating expectation patterns in a causal way.
Test Planning for Core-based Systems-on-chip: A Reuse-based Approach
Authors: Erika Cota
Venue:  (2009)

Electronic applications are currently developed under the reuse-based paradigm. This design methodology presents several advantages for the reduction of the design complexity, but brings new challenges for the test of the final circuit. In this manuscript, the main problems of the test of core-based systems are firstly identified and the current solutions are discussed. Then, two power-aware test planning approaches are proposed aiming at reducing the test costs of a core-based system by means of hardware reuse and integration of the test planning into the design flow. The first approach considers systems whose cores are connected through a functional bus or using a point-to-point model. The second approach considers the systems built upon a network-on-chip (NoC) and proposes the reuse of the NoC infrastructure to test the embedded cores. This book can be useful to students, researchers, DFT practitioners, and VLSI designers that want an overview of the testing of core-based systems and that want to know the basics of the reuse of a network-on-chip as test access mechanism.
Graph Cut Optimization for the Piecewise Constant Level Set Method Applied to Multiphase Image Segmentation
Authors: Egil Bae, Xue-Cheng Tai
Venue: Proceedings of the Second International Conference on Scale Space and Variational Methods in Computer Vision (2009)

The piecewise constant level set method (PCLSM) has recently emerged as a variant of the level set method for variational interphase problems. Traditionally, the Euler-Lagrange equations are solved by some iterative numerical method for PDEs. Normally the speed is slow. In this work, we focus on the piecewise constant level set method (PCLSM) applied to the multiphase Mumford-Shah model for image segmentation. Instead of solving the Euler-Lagrange equations of the resulting minimization problem, we propose an efficient combinatorial optimization technique, based on graph cuts. Because of a simplification of the length term in the energy induced by the PCLSM, the minimization problem is not NP hard. Numerical experiments on image segmentation demonstrate that the new approach is very superior in terms of efficiency, while maintaining the same quality.
Debugging, Object and State Management with OpenGL 1.x and 2.x
Authors: Jarosław Konrad Lipowski
Venue: Proceedings of the International Conference on Computer Vision and Graphics: Revised Papers (2008)

In this paper we present solutions to most important deficiencies of the current version of OpenGL library which are connected to the lack of proper debugging facilities, state management inefficiency and bind-to-change object management scheme. Our solutions differ from the ones that have surfaced earlier in that, they are relatively lightweight, low-level and portable.
The professor on your PC: a virtual CS1 course
Authors: Judith Gal-Ezer, Tamar Vilner, Ela Zur
Venue: Proceedings of the 14th annual ACM SIGCSE conference on Innovation and technology in computer science education (2009)

The Open University of Israel, a distance education institution with open admissions, offers a study system that was primarily based on written material. When we designed the new CS1 course in 2005, shifting from C++ to Java, we also switched from a course based on written material, to one based on videotaped lectures, which the students watch on PCs. Shifting to Java is an enormous challenge, however, we were also concerned about the new study method. Therefore, we conducted a study to determine how the students respond to the new and different environment, in terms of both learning and technical operation. The findings show that this method of study is at least as efficient as the previous one. The students' attitude to the new study method was positive and supportive of the new approach.
Implementation of ASK transceiver system-on-package (SoP) module for 60 GHz wireless communication applications
Authors: Young Chul Lee, Tae-Wan Kim, Azzemi Ariffin
Venue: Proceedings of the 8th Wseas international conference on Telecommunications and informatics (2009)

In this paper, a ASK transceiver system-on-package (SoP) compact module using a low-temperature co-fired ceramic (LTCC) multi-layer technology is presented for 60 GHz point-to-point (PTP) wireless communication applications. The transceiver module has been implemented in the six-layer LTCC dielectric. The eight MMICs for a transmitter (Tx) and receiver (Rx), one LPF for a detector of the Rx, and a high-isolation via fence are integrated into single LTCC substrate. The implemented transceiver SoP module is as small as 17.8 × 17.9 × 0.6 mm3. Its transmitter part shows output power of 12.8 dBm at 62.2405 GHz with a LO frequency of 62.24 GHz. Also, its receiver part reveals a dynamic range from -48 to -15dBm, a bit error rate of 10-12, and good eye pattern. The fabricated transceiver module archives 1.25Gbps data rate. Outdoor wireless link test using a received signal strength indicator (RSSI) value measurement shows that the transmission range of PTP system using the implemented transceivers is over 1 Km.
The Architecture of an Intelligent Agent in MAS
Authors: Nikola Ciprich, Marie Duží, Tomáš Frydrych, Ondřej Kohut, Michal Košinár
Venue: Proceeding of the 2009 conference on Information Modelling and Knowledge Bases XX (2009)

In the paper we propose a Brain Architecture which allows developers of a Multi-Agent System (MAS) to integrate various supporting tools. For the purpose of agents' communication and reasoning we make use of Transparent Intesional logic (TIL), or more exactly of its software variant the TIL-Script language. The proposed architecture makes it possible to utilise also the Prolog language as a reasoning tool. Rules and facts are stored in agent's internal knowledge base is designed in a way appropriate both for Prolog and TIL-Script languages. The architecture is an open one so that other tools of reasoning can be easily incorporated.
A distributed reinforcement learning approach to mission survivability in tactical MANETs
Authors: Marco Carvalho
Venue: Proceedings of the 5th Annual Workshop on Cyber Security and Information Intelligence Research: Cyber Security and Information Intelligence Challenges and Strategies (2009)

In this paper we present an ongoing research to develop a distributed reinforcement learning approach for mission survivability that combines two basic strategies for mission resilience: a) mission decomposition and distribution with replication of critical components, and b) differential task allocation based on estimated level of threat. Level of threat is estimated from a locally perceived attack, or the possibility of an attack, based on threat information that is shared between similar nodes.
Complex dynamics and stability of Hopfield neural networks with delays
Authors: S. J. Guo, J. B. Guan, Xinchu Fu
Venue: International Journal of Systems, Control and Communications (2009)

In this paper, by utilising the Lyapunov functional method, we analyse the global asymptotic stability of Hopfield neural networks with delays. We obtain some new sufficient conditions to ensure the global asymptotic stability of the model being independent of delays. By using the Lyapunov second method for special cases, we also get that the equilibrium of the system is locally asymptotically stable when the delay is under a critical value; and when the delay is equal to this value, Hopf bifurcation will occur and the equilibrium is unstable; and when the delay is above the critical value, the system will demonstrate complex dynamics. Finally, numerical simulations are presented to verify the analytical results.
A Planning-Based Knowledge Acquisition Methodology
Authors: Eder Mateus Nunes Gonçalves, Guilherme Bittencourt
Venue: Proceeding of the 2005 conference on Advances in Logic Based Intelligent Systems: Selected Papers of LAPTEC 2005 (2005)

In the development of complex distributed systems using a cognitive multi-agent approach, where each agent encapsulates an expert system, the knowledge acquisition process is known to be the most difficult task. This paper presents a methodology based on planning and on high level Petri nets to the knowledge acquisition process of such systems. This methodology was applied in the implementation of a robot soccer team for the Robocup simulator.
An Agent-based Approach to Assisting Learners to Dynamically Adjust Learning Processes
Authors: Weidong Pan
Venue: Proceeding of the 2005 conference on Artificial Intelligence in Education: Supporting Learning through Intelligent and Socially Informed Technology (2005)

This paper presents an approach to assisting learners to dynamically adjust learning processes by using software agents. Software agents are integrated into the online learning environment to help learners develop personalized preferred learning plans and dynamically adjust learning towards their learning goals.
TrustWalker: a random walk model for combining trust-based and item-based recommendation
Authors: Mohsen Jamali, Martin Ester
Venue: Proceedings of the 15th ACM SIGKDD international conference on Knowledge discovery and data mining (2009)

Collaborative filtering is the most popular approach to build recommender systems and has been successfully employed in many applications. However, it cannot make recommendations for so-called cold start users that have rated only a very small number of items. In addition, these methods do not know how confident they are in their recommendations. Trust-based recommendation methods assume the additional knowledge of a trust network among users and can better deal with cold start users, since users only need to be simply connected to the trust network. On the other hand, the sparsity of the user item ratings forces the trust-based approach to consider ratings of indirect neighbors that are only weakly trusted, which may decrease its precision. In order to find a good trade-off, we propose a random walk model combining the trust-based and the collaborative filtering approach for recommendation. The random walk model allows us to define and to measure the confidence of a recommendation. We performed an evaluation on the Epinions dataset and compared our model with existing trust-based and collaborative filtering methods.
Surface ECG organization analysis to predict paroxysmal atrial fibrillation termination
Authors: R. Alcaraz, J. J. Rieta
Venue: Computers in Biology and Medicine (2009)

The aim of this work is to predict non-invasively if an AF episode terminates spontaneously or not by analyzing the increase of atrial activity organization prior to paroxysmal atrial fibrillation (PAF) termination. Sample entropy was selected as non-linear organization index. Synthetic PAF signals were used to evaluate the notable impact of noise in AA organization estimation. Three strategies to reduce noise, ventricular residues and enhance the atrial activity main features were proposed. The best prediction results were obtained through main atrial wave (MAW) organization estimation. The MAW can be considered as the fundamental waveform associated to the AA. The 92% of the terminating and non-terminating analyzed PAF episodes were correctly classified. Thereby, it can be concluded that the MAW non-linear analysis from the surface ECG is a reliable and useful tool to predict spontaneous PAF termination.
Unsupervised hierarchical modeling of locomotion styles
Authors: Wei Pan, Lorenzo Torresani
Venue: Proceedings of the 26th Annual International Conference on Machine Learning (2009)

This paper describes an unsupervised learning technique for modeling human locomotion styles, such as distinct related activities (e.g. running and striding) or variations of the same motion performed by different subjects. Modeling motion styles requires identifying the common structure in the motions and detecting style-specific characteristics. We propose an algorithm that learns a hierarchical model of styles from unlabeled motion capture data by exploiting the cyclic property of human locomotion. We assume that sequences with the same style contain locomotion cycles generated by noisy, temporally warped versions of a single latent cycle. We model these style-specific latent cycles as random variables drawn from a common "parent" cycle distribution, representing the structure shared by all motions. Given these hierarchical priors, the algorithm learns, in a completely unsupervised fashion, temporally aligned latent cycle distributions, each modeling a specific locomotion style, and computes for each example the style label posterior distribution, the segmentation into cycles, and the temporal warping with respect to the latent cycles. We demonstrate the flexibility of the model on several application problems such as style clustering, animation, style blending, and filling in of missing data.
Exceeding expectations and clustering uncertain data
Authors: Sudipto Guha, Kamesh Munagala
Venue: Proceedings of the twenty-eighth ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems (2009)

Database technology is playing an increasingly important role in understanding and solving large-scale and complex scientific and societal problems and phenomena, for instance, understanding biological networks, climate modeling, electronic markets, etc. In these settings, uncertainty or imprecise information is a pervasive issue that becomes a serious impediment to understanding and effectively utilizing such systems. Clustering is one of the key problems in this context. In this paper we focus on the problem of clustering, specifically the k-center problem. Since the problem is NP-Hard in deterministic setting, a natural avenue is to consider approximation algorithms with a bounded performance ratio. In an earlier paper Cormode and McGregor had considered certain variants of this problem, but failed to provide approximations that preserved the number of centers. In this paper we remedy the situation and provide true approximation algorithms for a wider class of these problems. However, the key aspect of this paper is to devise general techniques for optimization under uncertainty. We show that a particular formulation which uses the contribution of a random variable above its expectation is useful in this context. We believe these techniques will find wider applications in optimization under uncertainty.
Developing scientific applications using Generative Programming
Authors: Ritu Arora, Purushotham Bangalore, Marjan Mernik
Venue: Proceedings of the 2009 ICSE Workshop on Software Engineering for Computational Science and Engineering (2009)

Scientific applications usually involve large number of distributed and dynamic resources and huge datasets. A mechanism like checkpointing is essential to make these applications resilient to failures. Using checkpointing as an example, this paper presents an approach for integrating the latest software engineering techniques with the development of scientific software. Generative programming is used in this research to achieve the goals of non-intrusive reengineering of existing applications to insert the checkpointing mechanism and to decouple the checkpointing-specifications from its actual implementation. The end-user specifies the checkpointing details at a higher level of abstraction, using which the necessary code is generated and woven into the application. The lessons learned and the implementation approach presented in this paper can be applied to the development of scientific applications in general. The paper also demonstrates that the generated code does not introduce any inaccuracies and its performance is comparable to the manually inserted code.
H∞ control by extended static output feedback
Authors: Addison Rios-Bolivar, Francklin Rivas-Echeverria, Gloria Mousalli-Kayat
Venue: Proceedings of the 9th WSEAS international conference on Robotics, control and manufacturing technology (2009)

This contribution tackles the problem about controller synthesis in H∞ for linear time invariant systems (LTI), by means of the extended static feedback of the output. The method consists of designing feedback gains for the injection of the output and its derivatives, which corresponds to the control signal. Conditions for the existence of such controllers are established. The stabilization problem is formulated in the context of linear matrix inequalities (LMI).
Join processing for flash SSDs: remembering past lessons
Authors: Jaeyoung Do, Jignesh M. Patel
Venue: Proceedings of the Fifth International Workshop on Data Management on New Hardware (2009)

Flash solid state drives (SSDs) provide an attractive alternative to traditional magnetic hard disk drives (HDDs) for DBMS applications. Naturally there is substantial interest in redesigning critical database internals, such as join algorithms, for flash SSDs. However, we must carefully consider the lessons that we have learnt from over three decades of designing and tuning algorithms for magnetic HDD-based systems, so that we continue to reuse techniques that worked for magnetic HDDs and also work with flash SSDs. The focus of this paper is on recalling some of these lessons in the context of ad hoc join algorithms. Based on an actual implementation of four common ad hoc join algorithms on both a magnetic HDD and a flash SSD, we show that many of the "surprising" results from magnetic HDD-based join methods also hold for flash SSDs. These results include the superiority of block nested loops join over sort-merge join and Grace hash join in many cases, and the benefits of blocked I/Os. In addition, we find that simply looking at the I/O costs when designing new flash SSD join algorithms can be problematic, as the CPU cost is often a bigger component of the total join cost with SSDs. We hope that these results provide insights and better starting points for researchers designing new join algorithms for flash SSDs.
Modelling Java requires state
Authors: Alexander J. Summers
Venue: Proceedings of the 11th International Workshop on Formal Techniques for Java-like Programs (2009)

Interesting questions concerning Java-like languages are often studied in the context of smaller programming calculi such as Featherweight Java. The simplicity of the syntax, and small number of features, and in particular the lack of state, make it possible to focus on the issues of interest. Although the programming languages are imperative, Featherweight Java and various similar calculi are functional. We argue that the study of the type system of Java 5.0 and beyond requires a calculus with state. For example, the treatment of wildcards in Java is tailored to preserve soundness in the presence of stateful computation, a feature that is not present in functional calculi. A stateful calculus is necessary before the potential pitfalls of an incorrect proposal can be seen. We illustrate this point by showing that a traditional treatment of existential types (based on that historically known for the Lambda Calculus) is unsound for Java but remains sound for Featherweight Java.