ppxscal/embedding_network huggingface dataset:
A New Contention Access Method for Collision Avoidance in Wireless Sensor Networks
Authors: H.-C. Le, H. Guyennet, N. Zerhouni
Venue: Proceedings of the Sixth International Conference on Networking (2007)

In this paper, we present a new contention access method for scalable wireless sensor networks. In these networks, the traffic levels are often variants, particularly in monitoring applications. Sensors do not regularly have much data to send. However, when an event occurs, every sensor in a given area will send its alert to the access point simultaneously. Hence, this network suffers a huge number of communications at the same time. In fact, at an instant, only one transmission is permitted among interfering nodes. If there are more than two transmissions at the same time, there will be a collision. Therefore, this variant communication of wireless sensor networks leads to an increase in collision and energy consumption. Traditional wireless network uses an exponential back-off scheme to react to collision. However, this scheme is designed for traditional wireless networks and is not well adapted to wireless sensor networks. Our proposal uses a dynamical change of channel access probability which can reduce the number of contention times and collisions. Moreover, it can be applied in any existing MAC protocol of wireless sensor network.
Networks of Sensors in Public Spaces: Combining Technology with Art
Authors: Sameer Pai, Philip Kuryloski, Henry Yip, Srikant Yennamandra, Stephen Wicker, Kirsten Boehner, Geri Gay
Venue: Proceedings of the 21st International Conference on Advanced Information Networking and Applications Workshops - Volume 02 (2007)

This paper presents ongoing work with a wireless sensor network application at the Herbert Johnson Art Museum. We discuss the design and deployment of networked motes for the purpose of collecting information about museum visitors including number, density and tempo of group movement within the space. We also address the use of the collected data for dynamic real-time artistically-rendered feedback to those interacting with the system. In particular, the paper focuses on practical aspects of secure communication protocol design, mote application programming, network setup, gateway and server considerations, data processing and output of the system designed to accomplish these tasks. A discussion of major privacy concerns for uses of sensor networks in public spaces, such as a museum space, is introduced and methods of user-privacy protection are discussed. Finally, the paper introduces possible future deployments and upgrades to the system as well as enhanced privacy protections for museum visitors.
Markov chain Monte Carlo data association for target tracking
Authors: N. Bergman
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 2000. on IEEE International Conference - Volume 02 (2000)

We consider the estimation of the state of a discrete-time Markov process using observations which are sets of measurements from a finite number of known linear models. The measurement to model association is unknown and false measurements that do not yield any information about the Markov process are contained in the measurement set. The objective is to perform data association between the detected measurements and the models and determine optimal estimates of the state of the Markov process. The application of this problem is found in over the horizon target tracking. We derive iterative deterministic and stochastic algorithms based on Gibbs sampling. Rao-Blackwellisation allows us to solve the problem efficiently, yielding methods with computational complexity linear in the number of received data sets. Contrary to recent approaches based on the EM algorithm, the novel procedures we propose do not require an introduction of a missing data set and consequently their range of applicability is wider. A simulation study shows that the new algorithms are superior to previously proposed methods.
Removing the memory limitations of sensor networks with flash-based virtual memory
Authors: Andreas Lachenmann, Pedro José Marrón, Matthias Gauger, Daniel Minder, Olga Saukh, Kurt Rothermel
Venue: ACM SIGOPS Operating Systems Review (2007)

Virtual memory has been successfully used in different domains to extend the amount of memory available to applications. We have adapted this mechanism to sensor networks, where, traditionally, RAM is a severely constrained resource. In this paper we show that the overhead of virtual memory can be significantly reduced with compile-time optimizations to make it usable in practice, even with the resource limitations present in sensor networks. Our approach, ViMem, creates an efficient memory layout based on variable access traces obtained from simulation tools. This layout is optimized to the memory access patterns of the application and to the specific properties of the sensor network hardware. Our implementation is based on TinyOS. It includes a pre-compiler for nesC code that translates virtual memory accesses into calls of ViMem's runtime component. ViMem uses flash memory as secondary storage. In order to evaluate our system we have modified nontrivial existing applications to make use of virtual memory. We show that its runtime overhead is small even for large data sizes.
Visualizing Web Navigation Data with Polygon Graphs
Authors: Jiyang Chen, Tong Zheng, William Thorne, Daniel Huntley, Osmar R. Zayane, Randy Goebel
Venue: Proceedings of the 11th International Conference Information Visualization (2007)

As the volume of digitally accessible information grows, there is increasing pressure on the development of data visualization methods to enable humans to interpret that data. We provide a description of our WebViz system, as a tool to visualize both the structure and usage of web sites. We illustrate the use of our visualization paradigm by introducing polygonal graphs layered on top of our adaptation of radial disk trees. In our system, the structure of a web segment is rendered as a radial tree, and usage data can be extracted and layered as polygonal graphs. By interactively creating and adjusting these layers, a user can develop real time insight into the data. We present the system, show the idea of interactive visual operators, and provide some examples that help show the value of the specific visualization techniques, as well as the interactive use of those techniques.
Conditional maximum likelihood timing recovery
Authors: J. Riba
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 1999. on 1999 IEEE International Conference - Volume 04 (1999)

The conditional maximum likelihood (CML) principle, well known in the context of sensor array processing, is applied to the problem of timing recovery. A new self-noise free CML-based timing error detector is derived. Additionally, a new (conditional) Cramer-Rao bound (CRB) for timing estimation is obtained, which is more accurate than the extensively used modified CRB (MCRB).
Enhancing Adaptive Random Testing through Partitioning by Edge and Centre
Authors: Tsong Yueh Chen, Fei-Ching Kuo, Huai Liu
Venue: Proceedings of the 2007 Australian Software Engineering Conference (2007)

Random Testing (RT) is a simple but widely used software testing method. Recently, an approach namely Adaptive Random Testing (ART) was proposed to enhance the fault-detection effectiveness of RT. The basic principle of ART is to enforce random test cases as evenly spread over the input domain as possible. A variety of ART methods have been proposed, and some research has been conducted to compare them. It was found that some ART methods have a preference of selecting test cases from edges of the input domain over from the centre. As a result, these methods may not perform very well under some situations. In this paper, we propose an approach to alleviating the edge preference. We also conducted some simulations and the results confirm that our new approach can improve the effectiveness of these ART methods.
In the News
Authors: Sara Reese Hedberg
Venue: IEEE Intelligent Systems (2007)

"Bridging the Gap between Neuroscience and AI" looks at Jeff Hawkins' Hierarchical Temporal Memory theory and at efforts at the University of Southern California to create an implantable "brain chip" that mimics neuronal function.
A Tcl/Tk-based video annotation engine
Authors: M. Carrer, L. Ligresti, T. D. C. Little
Venue: Proceedings of the 5th conference on Annual Tcl/Tk Workshop 1997 - Volume 5 (1997)

The population of a video database requires tools for manipulation and annotation of raw video data. Characteristic of this requirement is the need to satisfy many disparate video-based application domains. In this extended abstract we describe the design and development of a video annotation engine called Vane (Fig. 1), intended to address the issue of domain-independent video annotation. Rather than relying on a single, general data model and application interface, we developed a dynamic interface and data model using the Tcl/Tk environment and SGML document type definitions (DTDs). This approach allowed us to implement an intuitive graphical user interface application that is easily portable to different systems. The outcome of our work is a multipurpose, domain-independent video annotation application that has been developed taking advantage of Tcl/Tk features for easy construction and reconfiguring of GUI widgets at execution time. Thereby offering a novel application model appropriate for the domain.
Improved matrix pair undecidability results
Authors: Vesa Halava, Mika Hirvensalo
Venue: Acta Informatica (2007)

We improve the undecidability bounds for problems involving two integer matrices by showing that Scalar Reachability, Zero in the Right Upper Corner, Vector Reachability, and Zero in the Left Upper Corner are undecidable for dimensions of 9, 10, 11, and 13, respectively. Problems Scalar Reachability, Zero in the Right Upper Corner, and Vector Reachability were previously known undecidable for dimensions 18, 18, and 16, respectively.
Boxscript: a language for teaching component-oriented programming
Authors: H. Conrad Cunningham
Venue:  (2005)

As component-oriented approaches become more commonly applied to the development of complex software systems, it becomes increasingly important to introduce computing science and software engineering students to appropriate programming concepts, languages, and techniques. This dissertation presents the design for a new language BoxScript, which seeks to address this need. BoxScript is a Java-based, component-oriented programming language. The components in BoxScript, called boxes, are blackbox entities that are strongly encapsulated and only expose their provided and required interfaces. BoxScript supports two key properties of component-oriented programming: compositionality and flexibility. It introduces a composition strategy and the compound box construct to support compositionality and introduces a box type structure consisting of abstract and concrete boxes, box variants, and an interface satisfaction policy to support flexibility. The syntactic structure of BoxScript is based on Java, a language with which most students are familiar. This dissertation presents the BoxScript language and associated design methods and demonstrates and evaluates their usage. It specifies the syntax of the BoxScript notation and describes preliminary formal specification techniques for BoxScript components and their compositions. It presents a methodology, from a software engineering perspective, for building a component software system and applies the methodology and the language to a case study---KeyWord In Context (KWIC). It also illustrates the design of the language's compiler BoxCompiler and its deployment tool BoxShipper, both of which are implemented in BoxScript itself. The dissertation evaluates the BoxScript language design by comparing it systematically with several other component-oriented programming languages and evaluates the language usage by analyzing the feedback from the test users. Some possible future work is identified that should improve and enhance BoxScript.
An Open Tracing System for P2P File Sharing Systems
Authors: Danny Hughes, James Walkerdine, Kevin Lee
Venue: Proceedings of the Second International Conference on Internet and Web Applications and Services (2007)

This paper describes the Open P2P tracing system which aims to improve the research community's understanding of P2P file sharing systems by providing continuous and up-to-date traffic data which is anonymized and made freely accessible to all interested parties. It is our hope that this open data set will grow over time into a resource capable of exposing trends in P2P network usage and promote research into the socio-technical factors that drive user behaviour on P2P file sharing systems.
Delay/Phase Regeneration Circuits
Authors: Crescenzo D'Alessandro, Andrey Mokhov, Alex Bystrov, Alex Yakovlev
Venue: Proceedings of the 13th IEEE International Symposium on Asynchronous Circuits and Systems (2007)

Designs which require a phase relationship between two signals to be maintained along a link benefit from the use of repeaters which actively regenerate this relationship. This paper discusses some implementations of phaseregeneration circuits and attempts to introduce the reader to the issues encountered in the design of such circuitry. The paper proposes various design solutions for the dual-rail case, extending the work to the multiple-rail case. A novel device which is able to reconstruct a sequence of events is also presented, the Transition Sequence Encoder. Simulation results are provided with discussion on the relative performance.
Overcoming glitches and dissipation timing skews in design of DPA-resistant cryptographic hardware
Authors: Kuan Jen Lin, Shan Chien Fan, Shih Hsien Yang, Cheng Chia Lo
Venue: Proceedings of the conference on Design, automation and test in Europe (2007)

Cryptographic embedded systems are vulnerable to Differential Power Analysis (DPA) attacks. In this paper, we propose a logic design style, called as Precharge Masked Reed-Muller Logic (PMRML) to overcome the glitch and Dissipation Timing Skew (DTS) problems in design of DPA-resistant cryptographic hardware. Both problems can significantly reduce the DPA-resistance. To our knowledge, the DTS problem and its countermeasure have not been reported. The PMRML design can be fully realized using common CMOS standard cell libraries. Furthermore, it can be used to implement universal functions since any Boolean function can be represented as the Reed-Muller form. An AES encryption module was implemented with multi-stage PMRML. The results show the efficiency and effectiveness of the PMRML design methodology.
Introducing network programming into a CS1 course
Authors: Michael H. Goldwasser, David Letscher
Venue: ACM SIGCSE Bulletin (2007)

Incorporating advanced programming concepts into an introductory programming course has to be done carefully to avoid overwhelming the students. We describe our experiences doing network programming in a CS1 course taught in Python. The simplicity of the built-in libraries allowed a fair amount of networking to be introduced in a week-long module of the course. In this short time we had the students writing both multithreaded clients and servers.
Solving aerosol coagulation with size-binning methods
Authors: Edouard Debry, Bruno Sportisse
Venue: Applied Numerical Mathematics (2007)

The sectional approach is usually advocated for solving coagulation of atmospheric aerosols. This article aims at reviewing and benchmarking some widely used sectional methods. A rigorous framework is proposed and the focus is put on differences and similarities among the approaches. The sensitivity with respect to the computation of the partition coefficients is investigated. The dynamical behavior of coagulation is also studied.
Democratizing content publication with coral
Authors: Michael J. Freedman, Eric Freudenthal, David Mazières
Venue: Proceedings of the 1st conference on Symposium on Networked Systems Design and Implementation - Volume 1 (2004)

CoralCDN is a peer-to-peer content distribution network that allows a user to run a web site that offers high performance and meets huge demand, all for the price of a cheap broadband Internet connection. Volunteer sites that run CoralCDN automatically replicate content as a side effect of users accessing it. Publishing through CoralCDN is as simple as making a small change to the hostname in an object's URL; a peer-to-peer DNS layer transparently redirects browsers to nearby participating cache nodes, which in turn cooperate to minimize load on the origin web server. One of the system's key goals is to avoid creating hot spots that might dissuade volunteers and hurt performance. It achieves this through Coral, a latency-optimized hierarchical indexing infrastructure based on a novel abstraction called a distributed sloppy hash table, or DSHT.
The Duties, Skills, and Knowledge of Software Architects
Authors: Paul Clements, Rick Kazman, Mark Klein, Divya Devesh, Shivani Reddy, Prageti Verma
Venue: Proceedings of the Sixth Working IEEE/IFIP Conference on Software Architecture (2007)

This paper focuses on the human aspects of architecting software--in particular, the duties, skills, and knowledge of software architects. We present the results of a survey of approximately 200 public sources of information aimed at professional software architects that we conducted in the summer of 2006. We summarize what those sources have to say about the duties, skills, and knowledge that competent architects must perform and have.
E-teaching simply with e-mail
Authors: J. E. Sharp
Venue: Proceedings of the 30th Annual Frontiers in Education - Volume 02 (2000)

This paper describes e-mail as a simple, relatively low-tech, and effective way to enhance teaching. Focusing on the boon rather than the bane of e-mail, it presents practical methods for using e-mail as a teaching tool and for communicating with students more effectively. It reports results of a two-semester survey of engineering students in a technical communication course, updating the previous report of a one-semester survey. Items receiving the most responses from 59 participants indicate recommendations to faculty about communicating with e-mail in the following categories: format and organization, reminders and assignment information, usage, frequency, e-mail and the Web, and miscellaneous tips. The ACM Portal is published by the Association for Computing Machinery. Copyright © 2010 ACM, Inc. Terms of Usage Privacy Policy Code of Ethics Contact Us Useful downloads: Adobe Acrobat QuickTime Windows Media Player Real Player
Unified Software Method: An Engineering Approach to Software Engineering
Authors: Stephane Mercier, Michel Lavoie, Roger Champagne
Venue: Proceedings of the 30th Annual IEEE/NASA Software Engineering Workshop (2006)

In this paper, we propose an engineering approach to software engineering called "Unified Software Method" (USM). The goal pursued through this work in progress is to offer complete traceability between software requirements and the resulting software application for any kind of application and as a result, establish accountability of a practitioner's work. This paper presents an introduction to USM and focuses mainly on how USM can apply traceability to maintain synchronization between a software application and the relevant documents such as requirements, architecture, design, code, test, and executable.
Variable-order N-gram generation by word-class splitting and consecutive word grouping
Authors: H. Masataki, Y. Sgisaka
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 1996. on Conference Proceedings., 1996 IEEE International Conference - Volume 01 (1996)

In this paper, a generation scheme for variable-order N-grams is proposed to attain reliable statistical constraints from a given language corpus. Starting from POS bigrams, the proposed scheme creates variable-order N-grams by splitting a POS into finer groups and by adding frequent consecutive word sequences as word-classes. This word-class splitting and consecutive word grouping are carried out incrementally by minimizing the total entropy. Experiments showed that the perplexity of the proposed model for the test corpus is lower than that for a conventional trigram and that this model requires a quite smaller number of statistical parameters. By applying this model to speech recognition, we get a better recognition rate than using conventional bigrams.
Managing prefetch memory for data-intensive online servers
Authors: Chuanpeng Li, Kai Shen
Venue: Proceedings of the 4th conference on USENIX Conference on File and Storage Technologies - Volume 4 (2005)

Data-intensive online servers may contain a significant amount of prefetched data in memory due to large-granularity I/O prefetching and high execution concurrency. Using a traditional access recency or frequency-based page reclamation policy, memory contention can cause a substantial number of prefetched pages to be prematurely evicted before being accessed. This paper presents a new memory management framework that handles prefetched (but not-yet-accessed) pages separately from the rest of the memory buffer cache. We examine three new heuristic policies when a victim page (among the prefetched pages) needs to be identified for eviction: 1) evict the last page of the longest prefetch stream; 2) evict the last page of the least recently accessed prefetch stream; and 3) evict the last page of the prefetch stream whose owner process has consumed the most amount of CPU since it last accessed the prefetch stream. These policies require no application changes or hints on their data access patterns. We have implemented the proposed techniques in the Linux 2.6.10 kernel and conducted experiments based on microbenchmarks and two real application workloads (a trace-driven index searching server and the Apache Web server hosting media clips). Compared with access history-based policies, our memory management scheme can improve the server throughput of real workloads by 11-64% at high concurrency levels. Further, the proposed approach is 10-32% below an approximated optimal page reclamation policy that uses application-provided I/O access hints. The space overhead of our implementation is about 0.4% of the physical memory size.
Detecting malicious java code using virtual machine auditing
Authors: Sunil Soman, Chandra Krintz, Giovanni Vigna
Venue: Proceedings of the 12th conference on USENIX Security Symposium - Volume 12 (2003)

The Java Virtual Machine (JVM) is evolving as an infrastructure for the efficient execution of large-scale, network-based applications. To enable secure execution in this environment, industrial and academic efforts have implemented extensive support for verification of type-safety, authentication, and access control. However, JVMs continue to lack intrinsic support for intrusion detection. Existing operating system auditing facilities and host-based intrusion detection systems operate at the process level, with the assumption that one application is mapped onto one process. However, in many cases, multiple Java applications are executed concurrently as threads within a single JVM process. As such, it is difficult to analyze the behavior of Java applications using the corresponding OS-level audit trail. In addition, the malicious actions of a single Java application may trigger a response that disables an entire execution environment. To overcome these limitations, we have developed a thread-level auditing facility for the Java Virtual Machine and an intrusion detection tool that uses audit data generated by this facility to detect attacks by malicious Java code. This paper describes the JVM auditing mechanisms, the intrusion detection tool, and the quantitative evaluation of their performance.