ppxscal/embedding_network huggingface dataset:
Online Education in Computer and Digital Forensics: A Case Study
Authors: Gary C. Kessler
Venue: Proceedings of the 40th Annual Hawaii International Conference on System Sciences (2007)

Computer forensics is a relatively new, but growing, field of study at the undergraduate college and university level. This paper describes some of the course design aspects of teaching computer forensics in an online environment. The learning theories and pedagogies that provide the guiding principles for course design are presented, along with specific issues related to adult education. The paper then presents a detailed description of the design of an introductory computer forensics course, with particular attention to the issue of hands-on assignments in the online environment. Finally, a small study about the efficacy of the online courses is presented.
A hybrid numerical-asymptotic boundary integral method for high-frequency acoustic scattering
Authors: V. Dom&#x00ed;nguez, I. G. Graham, V. P. Smyshlyaev
Venue: Numerische Mathematik (2007)

We propose a new robust method for the computation of scattering of high-frequency acoustic plane waves by smooth convex objects in 2D. We formulate this problem by the direct boundary integral method, using the classical combined potential approach. By exploiting the known asymptotics of the solution, we devise particular expansions, valid in various zones of the boundary, which express the solution of the integral equation as a product of explicit oscillatory functions and more slowly varying unknown amplitudes. The amplitudes are approximated by polynomials (of minimum degree d) in each zone using a Galerkin scheme. We prove that the underlying bilinear form is continuous in L 2, with a continuity constant that grows mildly in the wavenumber k. We also show that the bilinear form is uniformly L 2-coercive, independent of k, for all k sufficiently large. (The latter result depends on rather delicate Fourier analysis and is restricted in 2D to circular domains, but it also applies to spheres in higher dimensions.) Using these results and the asymptotic expansion of the solution, we prove superalgebraic convergence of our numerical method as d &#x2192; &#x221e; for fixed k. We also prove that, as k &#x2192; &#x221e;, d has to increase only very modestly to maintain a fixed error bound (d &#x223c; k 1/9 is a typical behaviour). Numerical experiments show that the method suffers minimal loss of accuracy as k &#x2192;&#x221e;, for a fixed number of degrees of freedom. Numerical solutions with a relative error of about 10&#x2212;5 are obtained on domains of size $$\mathcal{O}(1)$$ for k up to 800 using about 60 degrees of freedom.
Quantitative Evaluation of Feature Extractors for Visual SLAM
Authors: Jonathan, Hong Zhang
Venue: Proceedings of the Fourth Canadian Conference on Computer and Robot Vision (2007)

We present a performance evaluation framework for visual feature extraction and matching in the visual simultaneous localization and mapping (SLAM) context. Although feature extraction is a crucial component, no qualitative study comparing different techniques from the visual SLAM perspective exists. We extend previous image pair evaluationmethods to handle non-planar scenes and the multiple image sequence requirements of our application, and compare three popular feature extractors used in visual SLAM: the Harris corner detector, the Kanade-Lucas-Tomasi tracker (KLT), and the Scale-Invariant Feature Transform (SIFT). We present results from a typical indoor environment in the form of recall/precision curves, and also investigate the effect of increasing distance between image viewpoints on extractor performance. Our results show that all methods can be made to perform well, although it is possible to distinguish between the three. We conclude by presenting guidelines for selecting a feature extractor for visual SLAM based on our experiments.
Supporting representation construction in sensemaking
Authors: George W. Furnas
Venue:  (2006)

This study investigates how people construct representations in sensemaking tasks and explores the design space of systems supporting representation construction. Russell et al (1993) defined sensemaking as a process that searches for appropriate representation to answer task-specific questions. Their approach brought representation into the center of sensemaking research. My research follows this representational approach, narrowing it down to the construction of external and explicit representations in the sensemaking process because these representations provide a medium for people and computer systems to access and interact with the sensemaking process.The research approach is to interlace theoretical analyses and behavioral studies with system design and development in a spiraling process towards greater understanding of and effective support for sensemaking activities. The research starts with the examination of existing sensemaking theories, which lead to the development of a pilot sensemaking supporting system. Using this pilot system, a behavioral study was conducted to investigate representation construction in the early stage of sensemaking. Design implications were drawn from this experiment. Then a preliminary design space of systems supporting structure finding and exploration on the web was laid out. A system framework was proposed and a prototype was implemented. The system prototype provides a platform for further explorations in the design space and for further behavioral studies.This study finds that people not only get ideas for structuring representation from their existing knowledge, but also from the outside information world. Representation construction and information seeking are closely coupled in the process. The findings suggest important revisions of previous sensemaking theories and new opportunities for system design. A system framework is then proposed to help people locate and explore websites with high probabilities of containing useful structures. Many theoretic and design problems are identified for future exploration.
Password-Based Authentication: Preventing Dictionary Attacks
Authors: Saikat Chakrabarti, Mukesh Singhal
Venue: Computer (2007)

Password-based authentication is susceptible to attack is used on insecure communication channels like the Internet. Researchers have engineered several protocols to prevent attacks, but we still nee formal models to analyze and aid in the effective design of acceptable password protocols geared to prevent dictionary attacks.
Partitioned Hybrid Encoding to Minimize On-Chip Energy Dissipation ofWide Microprocessor Buses
Authors: Sharath Jayaprakash, Nihar R. Mahapatra
Venue: Proceedings of the 20th International Conference on VLSI Design held jointly with 6th International Conference: Embedded Systems (2007)

Dynamic bus power dissipation, especially for long global signal buses, is becoming increasingly important with technology scaling due to several reasons: more pronounced interwire coupling effects, higher frequencies, greater traffic demands arising from higher levels of integration (e.g., as seen in system-on-chip and multi-core designs), and power density concerns, among others. While low-power dynamic bus encoding schemes, such as bus invert (BI) and odd-even bus invert (OEBI), have been proposed to reduce bus switching activities, they are not effective for wide microprocessor buses carrying correlated traffic found in typical workloads like SPEC CPU2000 benchmarks. To address this, we propose a partitioned hybrid bus encoding technique in which the bus is partitioned optimally and the most energy-efficient dynamic encoding scheme we consider bus invert (BI), odd/even bus invert (OEBI), and not encoding as the possible options, but any other collection of schemes can be considered - is independently applied to each partition depending upon traffic value characteristics to minimize total bus (wire self and interwire coupling) dynamic energy. While BI and OEBI provide average energy reductions of only 5.27%/1.58% and 0.98%/1.97% for data/instruction buses, respectively, for SPEC CPU2k benchmarks, our hybrid encoding technique yields average energy savings of 22.07%/27.40% for the same traffic and buses - these results take into account the energy consumed by control lines, too.
Skew Hadamard difference sets from the Ree--Tits slice symplectic spreads in PG(3,32h+1)
Authors: Cunsheng Ding, Zeying Wang, Qing Xiang
Venue: Journal of Combinatorial Theory Series A (2007)

Using a class of permutation polynomials of F"3"^"2"^"h"^"+"^"1 obtained from the Ree-Tits slice symplectic spreads in PG(3,3^2^h^+^1), we construct a family of skew Hadamard difference sets in the additive group of F"3"^"2"^"h"^"+"^"1. With the help of a computer, we show that these skew Hadamard difference sets are new when h=2 and h=3. We conjecture that they are always new when h>3. Furthermore, we present a variation of the classical construction of the twin prime power difference sets, and show that inequivalent skew Hadamard difference sets lead to inequivalent difference sets with twin prime power parameters.
Fundamental Solutions for Some Partial Differential Operators from Fluid Dynamics and Statistical Physics
Authors: Jorge Aara&tilde;o
Venue: SIAM Review (2007)

We present a method to find fundamental solutions for a class of partial differential equations that often arise in fluid dynamics and in transport problems. The method is elementary in the sense that it uses only linear algebra and ODEs.
Automatic design and layout of 3D user interfaces: Research Articles
Authors: Mark Green, Wai Leng Lee
Venue: Computer Animation and Virtual Worlds (2007)

The production of 3D user interfaces is complicated by the wide range of input and output devices used in 3D applications and the lack of software tools for their production. A 3D user interface that works well with one particular set of input and output devices could fail when another set of devices is used. To solve this problem the Grappl system automatically generates 3D user interfaces at run time. This paper presents the programmer interface to Grappl and some of the techniques used in its implementation. An important part of this process is placing user interface and application objects in 3D space. This is achieved by using policy techniques to automate the layout process. This paper presents some of the features and techniques that have been used in policy implementation, including relative position policy and grouping policy, with a few example applications. Copyright &copy; 2007 John Wiley & Sons, Ltd.
Force XXI Land Warrior: a systems approach to speech recognition
Authors: C. C. Broun
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 200. on IEEE International Conference - Volume 02 (2001)

Speech recognition is continually being realized as a user interface in new applications. As this technology progresses, it enables new ways for humans to interact with machines and information. The performance in many domains has approached users' expectations. Although there are still abundant technology challenges ahead, speech recognition has reached a maturity level that requires one to consider its deployment in complex systems and environments. It is in this vein that we discuss a systems approach to the successful execution of speech recognition within the Force XXI Land Warrior program. We discuss the system voice control component as it fits within the overall program. The requirements for robustness, recognition, and computational complexity issues are addressed. We explicitly cover the system aspects and how they influence the user interface and reveal the parameters for actual use. Finally, we consider the implementation of a polynomial-based classifier for speech recognition, and we provide the final system performance measures on a large domain specific database.
The auction manager: market middleware for large-scale electronic commerce
Authors: Tracy Mullen, Michael P. Wellman
Venue: Proceedings of the 3rd conference on USENIX Workshop on Electronic Commerce - Volume 3 (1998)

As the number and diversity of electronic commerce participants grows, the complexity of purchasing from a vast and dynamic array of goods and services needs to be hidden from the end user. Putting the complexity into the commerce system instead means providing flexible middleware for enabling commerce within different commercial communities. In this paper, we present one such commerce middleware component-an Auction Manager designed to simplify and automate both the creation of new markets and the matching of users to existing markets. The Auction Manager determines which markets are appropriate for a given buyer or seller using market-specific inference rules applied to the current market offerings. We also show how these same inference rules can be used by the Auction Manager to automatically compose and decompose market offerings to respond to changing conditions within the marketplace. Finally, we describe how the Auction Manager provides a focal point for expressing policy decisions such as how much to charge for starting and running auctions, as well as who and when to charge.
Speaker clustering and transformation for speaker adaptation in large-vocabulary speech recognition systems
Authors: M. Padmanabhan
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 1996. on Conference Proceedings., 1996 IEEE International Conference - Volume 02 (1996)

A speaker adaptation strategy is described that is based on finding a subset of speakers, from the training set, who are acoustically close to the test speaker, and using only the data from these speakers (rather than the complete training corpus) to re-estimate the system parameters. Further, a linear transformation is computed for every one of the selected training speakers to better map the training speaker's data to the test speaker's acoustic space. Finally, the system parameters (Gaussian means) are re-estimated specifically for the test speaker using the transformed data from the selected training speakers. Experiments showed that this scheme is capable of reducing the error rate by 10-15% with the use of as little as 3 sentences of adaptation data.
Emphasizing software quality in undergraduate programming laboratories
Authors: D. Gustafson
Venue: Proceedings of the 28th Annual Frontiers in Education - Volume 03 (1998)

Summary form only given. We have received funding from NSF's Division of Undergraduate Education under the Instrumentation and Laboratory Improvement Program to develop an approach to improving the software development skill of undergraduate computer science students, integrate that approach into our curriculum, and evaluate its benefits. Part of our work involves the development of an interactive web-site that governs the interaction of instructors and students in defining, completing and evaluating course assignments. We have implemented an initial version of this web-site and plan on demonstrating its capabilities. Our curriculum is designed to provide a solid foundation in the concepts and techniques needed by practicing computer scientists. The core courses in our curriculum involve a significant number of programming laboratory exercises. In these laboratories students are given a well defined problem which they are to solve by designing and writing a computer program. These exercises serve to develop problem-solving and design skills, provide a deep familiarity with the notations of the profession, and give concrete feedback to the student regarding their progress.
P-stable high-order super-implicit and Obrechkoff methods for periodic initial value problems
Authors: Beny Neta
Venue: Computers Mathematics with Applications (2007)

This paper discusses the numerical solution of periodic initial value problems. Two classes of methods are discussed, super-implicit and Obrechkoff. The advantage of Obrechkoff methods is that they are high-order one-step methods and thus will not require additional starting values. On the other hand they will require higher derivatives of the right-hand side. In cases when the right-hand side is very complex, we may prefer super-implicit methods. We develop a super-implicit P-stable method of order 12 and Obrechkoff method of order 18.
Techniques for the design of java operating systems
Authors: Godmar Back, Patrick Tullmann, Leigh Stoller, Wilson C. Hsieh, Jay Lepreau
Venue: Proceedings of the annual conference on USENIX Annual Technical Conference (2000)

Language-based extensible systems, such as Java Virtual Machines and SPIN, use type safety to provide memory safety in a single address space. By using software to provide safety, they can support more efficient IPC. Memory safety alone, however, is not sufficient to protect different applications from each other. Such systems need to support a process model that enables the control and management of computational resources. In particular, language-based extensible systems should support resource control mechanisms analogous to those in standard operating systems. They need to support the separation of processes and limit their use of resources, but still support safe and efficient IPC. We demonstrate how this challenge is being addressed in several Java-based systems. First, we lay out the design choices when implementing a process model in Java. Second, we compare the solutions that have been explored in several projects: Alta, K0, and the J-Kernel. Alta closely models the Fluke operating system; K0 is similar to a traditional monolithic kernel; and the J-Kernel resembles a microkernel-based system. We compare how these systems support resource control, and explore the tradeoffs between the various designs.
DB2 performance enhancements using Materialized Query Table for LUW
Authors: Shanmugam K. Satish, Mohan K. Saraswatipura, Suma C. Shastry
Venue: Proceedings of the Second International Conference on Systems (2007)

Performance of an application has become the need of the hour. There have been lots of challenges in achieving the desired rate of throughput in terms of application tuning and database tuning. Materialized query table (MQT) is one such efficient tool used in enhancing the performance of OLTP/OLAP applications. This presentation is targeted to bring out the importance of MQT and its associated technologies used in DB2 UDB, an IBM Database Product.
2007 Special Issue: Predictive uncertainty in environmental modelling
Authors: Gavin C. Cawley, Gareth J. Janacek, Malcolm R. Haylock, Stephen R. Dorling
Venue: Neural Networks (2007)

Artificial neural networks have proved an attractive approach to non-linear regression problems arising in environmental modelling, such as statistical downscaling, short-term forecasting of atmospheric pollutant concentrations and rainfall run-off modelling. However, environmental datasets are frequently very noisy and characterized by a noise process that may be heteroscedastic (having input dependent variance) and/or non-Gaussian. The aim of this paper is to review existing methodologies for estimating predictive uncertainty in such situations and, more importantly, to illustrate how a model of the predictive distribution may be exploited in assessing the possible impacts of climate change and to improve current decision making processes. The results of the WCCI-2006 predictive uncertainty in environmental modelling challenge are also reviewed, suggesting a number of areas where further research may provide significant benefits.
Time-selective Access Control for Realtime Calls in a CDMA Common Trunk
Authors: Jae-Hoon Kim
Venue: Wireless Personal Communications: An International Journal (2007)

We address the problem of dynamically allocating radio resource to various call types over the single CDMA common trunk. Based on the estimation of queue waiting time (QWT) of non-realtime (NRT) calls, we decide the appropriate allocation method to each call between Time Divisional (TD) and Code Divisional (CD) type resource allocation. We perform queuing analysis to derive closed-form expressions for QWT, which enables the delay-guarantee of access control scheme easy to solve in realtime (RT) fashion. This quickness and simplicity of the proposed method to any traffic environment well manifests its potential to real-world implementations. Computational experience also reveals its effectiveness in utilizing resource over the static radio resource allocation schemes, implemented in the presently operative 3G CDMA systems.
PRESTO: feedback-driven data management in sensor networks
Authors: Ming Li, Deepak Ganesan, Prashant Shenoy
Venue: Proceedings of the 3rd conference on Networked Systems Design & Implementation - Volume 3 (2006)

This paper presents PRESTO, a novel two-tier sensor data management architecture comprising proxies and sensors that cooperate with one another for acquiring data and processing queries. PRESTO proxies construct time-series models of observed trends in the sensor data and transmit the parameters of the model to sensors. Sensors check sensed data with model-predicted values and transmit only deviations from the predictions back to the proxy. Such a model-driven push approach is energy-efficient, while ensuring that anomalous data trends are never missed. In addition to supporting queries on current data, PRESTO also supports queries on historical data using interpolation and local archival at sensors. PRESTO can adapt model and system parameters to data and query dynamics to further extract energy savings. We have implemented PRESTO on a sensor testbed comprising Intel Stargates and Telos Motes. Our experiments show that in a temperature monitoring application, PRESTO yields one to two orders of magnitude reduction in energy requirements over on-demand, proactive or model-driven pull approaches. PRESTO also results in an order of magnitude reduction in query latency in a 1% duty-cycled five hop sensor network over a system that forwards all queries to remote sensor nodes.
Thread-modular shape analysis
Authors: Alexey Gotsman, Josh Berdine, Byron Cook, Mooly Sagiv
Venue: ACM SIGPLAN Notices (2007)

We present the first shape analysis for multithreaded programs that avoids the explicit enumeration of execution-interleavings. Our approach is to automatically infer a resource invariant associated with each lock that describes the part of the heap protected by the lock. This allows us to use a sequential shape analysis on each thread. We show that resource invariants of a certain class can be characterized as least fixed points and computed via repeated applications of shape analysis only on each individual thread. Based on this approach, we have implemented a thread-modular shape analysis tool and applied it to concurrent heap-manipulating code from Windows device drivers.
Automatic 2D Shape Orientation by Example
Authors: Waqar Saleem, Danyi Wang, Alexander Belyaev, Hans-Peter Seidel
Venue: Proceedings of the IEEE International Conference on Shape Modeling and Applications 2007 (2007)

As large shape repositories become more common, the problem of automatically generating good views of shapes has recently gained prominence. However, very few of the proposed methods take into account the orientation of the shape in the resulting view, and none presents a satisfactory solution. In this paper, we present a simple, example based method to correct the orientation of a shape in a query image. Our method depends on the availability of a database of classified images containing correctly oriented shapes. In the first step, a candidate class for the query shape is identified, and in the second, the query shape is aligned with a target shape from the candidate class.