ppxscal/embedding_network huggingface dataset:
Twenty-five years of end-user searching, Part 1: Research findings
Authors: Karen Markey
Venue: Journal of the American Society for Information Science and Technology (2007)

This is the first part of a two-part article that reviews 25 years of published research findings on end-user searching in online information retrieval (IR) systems. In Part 1 [Markey, 2007], the author seeks to answer the following questions: What characterizes the queries that end users submit to online IR systems? What search features do people use? What features would enable them to improve on the retrievals they have in hand? What features are hardly ever used? What do end users do in response to the system's retrievals? Are end users satisfied with their online searches? Summarizing searches of online IR systems by the search features people use everyday makes information retrieval appear to be a very simplistic one-stop event. In Part 2, the author examines current models of the information retrieval process, demonstrating that information retrieval is much more complex and involves changes in cognition, feelings, and&sol;or events during the information seeking process. She poses a host of new research questions that will further our understanding about end-user searching of online IR systems. &copy; 2007 Wiley Periodicals, Inc.
When is service really denied?: a user-centric dos metric
Authors: Jelena Mirkovic, Alefiya Hussain, Brett Willson, Sonia Fahmy, Wei-Min Yao, Peter Reiher, Stephen Schwab, Roshan Thomas
Venue: Proceedings of the 2007 ACM SIGMETRICS international conference on Measurement and modeling of computer systems (2007)

Denial-of-service (DoS) research community lacks accurate metrics to evaluate an attack's impact on network services, its severity and the effectiveness of a potential defense. We propose several DoS impact metrics that measure the quality of service experienced by end users during an attack, and compare these measurements to application-specific thresholds. Our metrics are ideal for testbed experimentation, since necessary traffic parameters are extracted from packet traces gathered during an experiment.
Evaluating the importance of collaborative learning in ALN's
Authors: S. R. Hiltz
Venue: Proceedings of the Frontiers in Education Conference,1997. on 27th Annual Conference. Teaching and Learning in an Era of Change. - Volume 01 (1997)

Asynchronous learning networks (ALNs) represent a new paradigm for teaching and learning. A basic premise of the authors' research efforts has been that collaborative or group learning, which can be facilitated by anytime/anywhere access to the group communication and work space, is key to achieving superior learning outcomes in this medium. This paper describes some of the major evaluation procedures and results for a recently completed three year project that produced and delivered 26 courses in computer and information science using ALN, to over 1000 students. It focuses on some of the methodological problems and inconsistencies in results that occur in trying to assess the process and outcomes of teaching and learning in ALNs.
A Static Load-Balancing Scheme for Parallel XML Parsing on Multicore CPUs
Authors: Yinfei Pan, Wei Lu, Ying Zhang, Kenneth Chiu
Venue: Proceedings of the Seventh IEEE International Symposium on Cluster Computing and the Grid (2007)

A number of techniques to improve the parsing performance of XML have been developed. Generally, however, these techniques have limited impact on the construction of a DOM tree, which can be a significant bottleneck. Meanwhile, the trend in hardware technology is toward an increasing number of cores per CPU. As we have shown in previous work, these cores can be used to parse XML in parallel, resulting in significant speedups. In this paper, we introduce a new static partitioning and load-balancing mechanism. By using a static, global approach, we reduce synchronization and load-balancing overhead, thus improving performance over dynamic schemes for a large class of XML documents. Our approach leverages libxml2 without modification, which reduces development effort and shows that our approach is applicable to real-world, production parsers. Our scheme works well with Sun's Niagara class of CMT architectures, and shows that multiple hardware threads can be effectively used for XML parsing.
Facilitating access point selection in IEEE 802.11 wireless networks
Authors: S. Vasudevan, K. Papagiannaki, C. Diot, J. Kurose, D. Towsley
Venue: Proceedings of the 5th ACM SIGCOMM conference on Internet Measurement (2005)

The performance experienced by wireless clients in IEEE 802.11 wireless networks heavily depends on the clients' ability to identify the Access Point (AP) that will offer the best service. The current AP affiliation mechanism implemented in most wireless clients is based on signal strength measurements received by the client from all the APs in its neighborhood. The client then affiliates with the AP from which it receives the strongest signal. It is well-known that such an algorithm can lead to sub-optimal performance, due to its ignorance of the load at different APs. In this work, we consider the problem of AP selection. We identify potential bandwidth as the metric based on which hosts should make affiliation decisions, and define it as the (MAC-layer) bandwidth that the client is likely to receive after affiliating with a particular AP. We further limit ourselves to the use of passive measurements that do not require an end-host to affiliate with the AP, thus allowing the end-host to simultaneously evaluate the potential bandwidth to multiple APs in range. This can also facilitate more informed roaming decisions. We propose a methodology for the estimation of potential upstream and downstream bandwidth between a client and an AP based on measurements of delay incurred by 802.11 Beacon frames from the AP. Preliminary experiments conducted in a controlled environment demonstrate that the proposed methodology looks promising, yielding fairly accurate results under varying conditions.
Benchmark Generation Using Domain Specific Modeling
Authors: Ngoc Bao Bui, Liming Zhu, Ian Gorton, Yan Liu
Venue: Proceedings of the 2007 Australian Software Engineering Conference (2007)

Performance benchmarks are domain specific applications that are specialized to a certain set of technologies and platforms. The development of a benchmark application requires mapping the performance specific domain concepts to an implementation and producing complex technology and platform specific code. Domain Specific Modeling (DSM) promises to bridge the gap between application domains and implementations by allowing designers to specify solutions in domain-specific abstractions and semantics through Domain Specific Languages (DSL). This allows generation of a final implementation automatically from high level models. The modeling and task automation benefits obtained from this approach usually justify the upfront cost involved. This paper employs a DSM based approach to invent a new DSL, DSLBench, for benchmark generation. DSLBench and its associated code generation facilities allow the design and generation of a completely deployable benchmark application for performance testing from a high level model. DSLBench is implemented using Microsoft Domain Specific Language toolkit. It is integrated with the Visual Studio 2005 Team Suite as a plug-in to provide extra modeling capabilities for performance testing. We illustrate the approach using a case study based on .Net and C#.
Grid-based PSE for Engineering of Materials (GPEM)
Authors: Mohamed Salahuddin, Terence Hung, Harold Soh, Endang Sulaiman, Ong Yew Soon, Lee Bu Sung, Ren Yunxia
Venue: Proceedings of the Seventh IEEE International Symposium on Cluster Computing and the Grid (2007)

The design and engineering of complex materials and products often requires intricate interactions between domain experts in science, material and engineering as well as the utilization of diverse software systems for discovery and optimization. If left as it is, design engineers would most likely be at a loss on how to engage the entire entourage of the multidisciplinary processes as well as the compute-intensive and data-intensive nature of the activities involved. This paper describes a possible solution through the development of a Grid-based Problem Solving Environment for Engineering of Materials (GPEM). The GPEM aims to provide a one-stop platform where engineers will perform material discovery, design optimization and material characterization, with grid computing as the enabling technology. Upon describing the details of the process workflow and the adopted architecture design, the paper will present the current implementation of GPEM, in the design optimization of fractal structures.
The pebble component-based operating system
Authors: Eran Gabber, Christopher Small, John Bruno, José Brustoloni, Avi Silberschatz
Venue: Proceedings of the annual conference on USENIX Annual Technical Conference (1999)

Pebble is a new operating system designed with the goals of flexibility, safety, and performance. Its architecture combines a set of features heretofore not found in a single system, including (a) a minimal privileged mode nucleus, responsible for switching between protection domains, (b) implementation of all system services by replaceable user-level components with minimal privileges (including the scheduler and all device drivers) that run in separate protection domains enforced by hardware memory protection, and (c) generation of code specialized for each possible cross-domain transfer. The combination of these techniques results in a system with extremely inexpensive cross-domain calls that makes it well-suited for both efficiently specializing the operating system on a per-application basis and supporting modern component-based applications.
Speech enhancement by linear transformation and constrained optimization
Authors: Michael Scordilis
Venue:  (2006)

The effective enhancement of noise-degraded speech is one of the most challenging problems in speech processing. The difficulty results from the fact that current methods tend to introduce audible distortion and artifacts in the processed signal. In this dissertation, three speech enhancement algorithms are proposed and evaluated. The objective is to enhance single channel speech degraded by additive noise. All of the three enhancement methods apply linear transformations to the noisy speech, enhancement is performed in the transformed domain by constrained optimization. Method one uses linear prediction (LP) analysis to transform the noisy speech to the LP residual domain. The distortion of clean speech residual is minimized subject to the constraints imposed on the power of noise residual. A common feature of both method two and three is that they apply short time Fourier Transforms to map the noisy speech from the time to the frequency domain, where a spectral weighting function is derived by constrained optimization. Algorithm two is perceptually motivated. The constraints are specified as both the speech distortion and residual noise be suppressed below the masking thresholds, which incorporate both temporal and simultaneous masking effects. Method three enhances the harmonics of voiced speech by incorporating harmonic structure into the constraints. Noise-flooring parameter is included in the spectral gain for enhancement of harmonics and control of residual noise level. The performances of the proposed algorithms are evaluated in terms of modified bark spectral distortion (MBSD) measures and ITU PESQ scores. Experimental results indicate that the proposed algorithms effectively improve speech quality for both white Gaussian and real world colored noise.
Arabian Gulf Development Internet and Innovation Dynamics
Authors: Sadiq Hussain, Zain Tahboob
Venue: Proceedings of the First Asia International Conference on Modelling & Simulation (2007)

It is the purpose of this Invited-Paper to address issues in Arabian Gulf Development Internet and Innovation Dynamics. In the new Millennium, for biz strategy reasons as well as technological ones, we require a sound understanding of the dynamics of interaction between businesses, economies, and Internet & Web Technologies. The Paper also presents some original research case methods from the Arabian Gulf on innovative development Internet roles as well as the role of the internet as a catalyst for improving regional education, business, industry, and management.
Vision-based human-computer interface using hand gestures
Authors: Janez Zaletelj, Jernej Perhavc, Jurij F. Tasic
Venue: Proceedings of the Eight International Workshop on Image Analysis for Multimedia Interactive Services (2007)

The proliferation of interactive digital TV applications will depend on their complexity and ease of use. The investigation of simple, intuitive human-machine interfaces is therefore crucial for their success. While the operation of most home devices is today based on using remote control, in this paper we investigate an alternative solution using a visual input of the users's gestures. The proposed system recognises point and click gestures of the user's hand, which is enough to control simple iconic user interfaces of the interactive TV applications. Position of the user's hand is tracked using Kalman filtering, and shape analysis is performed to detect the pose of the forefinger. A finger bending gesture is recognized and transformed into a click action on the screen. Simulations show that the system performs well in uncontrolled home environment under different lighting conditions and cluttered backgrounds and thus could be used in future smart home devices.
Performance of an adaptive multicarrier CDMA system
Authors: T. M. Lok
Venue: Proceedings of the The 8th International Conference on Communication Systems - Volume 02 (2002)

An adaptive multicarrier CDMA system is considered. In this system, each user is given a number of codes. Each code essentially creates a different transmission channel for the corresponding user. Each user uses one of the code channels to transmit a data symbol in each symbol interval. At the receiver, the noise and interference level at each code channel is monitored. If the noise and interference level at an available code channel is lower than that in the current code channel, a procedure, called code handoff, would be executed at allowed instants, i.e., the user would switch to the better code channel. Only power control and code handoff, which can be readily implemented, are required in the system. Analysis shows that interference power can be significantly reduced. With suitable choices of the codes, the effects of fading can also be alleviated. Simulations also show that the proposed system performs better than ordinary multicarrier CDMA systems.
Achieving Discrete Relative Timing with Untimed Process Algebra
Authors: Anton Wijs
Venue: Proceedings of the 12th IEEE International Conference on Engineering Complex Computer Systems (2007)

For many systems, timing aspects are essential. Therefore, when modelling these systems, time should somehow be represented. In the past, many timed pro- cess algebras have been developed, using untimed pro- cess algebras as initial inspiration. In this paper, we take another approach, considering the possibility to model timing aspects with an untimed process algebra. The advantage is that the algebra itself does not need to be extended, and the available tools can be reused. In contrast to other work, where this approach has been looked at, we focus on ease of modelling, and single delay steps of varying sizes. We present the timing mechanism used, our approach, and some examples.
Santa Fe Trail for Artificial Ant with Analytic Programming and Three Evolutionary Algorithms
Authors: Zuzana Oplatkova, Ivan Zelinka
Venue: Proceedings of the First Asia International Conference on Modelling & Simulation (2007)

The paper deals with a novelty tool for symbolic regression -- Analytic Programming (AP) which is able to solve various problems from the symbolic regression domain. One of the tasks for it can be a setting an optimal trajectory for an artificial ant on Santa Fe trail which is the main application of Analytic Programming in this paper. In this contribution main principles of AP are described and explained. In the second part of the article how AP was used for a setting an optimal trajectory for the artificial ant according the user requirements is in detail described. An ability to create so called programs, as well as Genetic Programming (GP) or Grammatical Evolution (GE) do, is shown in that part. AP is a superstructure of evolutionary algorithms which are necessary to run AP. In this contribution 3 evolutionary algorithms were used -- Self Organizing Migrating Algorithm, Differential Evolution and Simulated Annealing. The results show that the first two used algorithms were more successful than not so robust Simulated Annealing.
BER sensitivity of OFDM systems to time synchronization error
Authors: C. R. N. Athaudage
Venue: Proceedings of the The 8th International Conference on Communication Systems - Volume 01 (2002)

This paper presents the details of a simulation based study performed to investigate the BER performance degradation (sensitivity) of OFDM systems due to time synchronization error at the demodulator. It is shown that an OFDM system incorporating a cyclic prefix (CP) has an asymmetric effect on the received constellation with synchronization error away from CP introducing intersymbol interference (ISI), while that towards the CP introducing only a phase error. We approximate the time synchronization error by a Gaussian distributed random variable, in order to evaluate the BER sensitivity of OFDM systems to timing error. The BER performance was evaluated for an AWGN channel and a multipath fading channel in terms of the synchronization error variance. The results of this investigation will be useful in developing time synchronization algorithms in OFDM systems to achieve a particular BER performance target for a given channel condition.
Modeling techniques for multiscale difference equation signal models
Authors: M. Ali
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 1996. on Conference Proceedings., 1996 IEEE International Conference - Volume 03 (1996)

In this paper, we describe novel encoding and decoding methods for multiscale difference equation (MSDE) signal models. Recently, MSDE signal models have been introduced to exploit self-similarities in signals. The encoding process for MSDE models requires an adaptive signal representation from the dictionary of translations and dilations of the signal to be modeled. Here, we propose a new iterative technique that tries to select an 'active' set under the modeling constraints so that the portion of the signal representation due to the 'inactive' set has small or zero norm. Using methods similar to 'line searches and backtracking' used for global non-linear optimization, this method yields the global minima for exact representation. The decoding process involves an eigenvector analysis of a particular matrix. We provide a fast algorithm to obtain the required eigenvector in O(N/sup 2/ log N) operations. We also provide a perturbation analysis of MSDE models that gives a bound on the reconstruction error due to errors in the MSDE coefficients.
Team teaching: advanced materials design and manufacturing
Authors: R. Singh, A. A. Ogale, S. N. Amirkhanian, R. J. Diefendorf
Venue: Proceedings of the Frontiers in Education Conference, on 1995. Proceedings., 1995 - Volume 02 (1995)

The crossing of disciplinary boundaries is one of the main issues being addressed in this study which is directed towards the development of materials design and manufacturing courses by the team teaching approach. The proposed approach allows the pooling of resources from different academic units and also encourages students as well as faculty to transcend the disciplinary boundaries. This paper reports our experiences of team teaching a freshman-level materials design course. Four faculty members from ceramic, chemical, civil and electrical engineering participated in this experimental project. The concepts introduced in this project are equally applicable to manufacturing courses.
Visualization of pulse propagation phenomena with MATLAB and Wavefront software
Authors: W. J. Bishop
Venue: Proceedings of the 26th Annual Frontiers in Education - Volume 01 (1996)

Propagation of electromagnetic pulses in transmission lines, waveguides, and optical fibers is an important topic in the design of telecommunication, signal processing, and VLSl systems. Modern undergraduate and graduate programs in electrical and computer engineering often include this topic in their curricula. Static displays of scalar or vector fields are usually not sufficient to illustrate the complexity of the propagation process, particularly when dispersion and attenuation are considered. We describe use of the MATLAB and WAVEFRONT Data Visualizer software to provide a dynamic view of the pulse propagation process in a variety of situations. The propagation process itself is described by a cascade of linear filters that represent different mechanisms of signal distortion. The modeling and simulation of this process are performed using MATLAB. Data are then filtered and exported into WAVEFRONT. Libraries of signal waveforms and filters are provided for a variety of common configurations used in optical and microwave engineering. Extension of this work to cover nonlinear propagation effects is under investigation.
An explicit semidefinite characterization of satisfiability for Tseitin instances on toroidal grid graphs
Authors: Miguel F. Anjos
Venue: Annals of Mathematics and Artificial Intelligence (2006)

This paper is concerned with the application of semidefinite programming to the satisfiability problem, and in particular with using semidefinite liftings to efficiently obtain proofs of unsatisfiability. We focus on the Tseitin satisfiability instances which are known to be hard for many proof systems. For Tseitin instances based on toroidal grid graphs, we present an explicit semidefinite programming problem with dimension linear in the size of the Tseitin instance, and prove that it characterizes the satisfiability of these instances, thus providing an explicit certificate of satisfiability or unsatisfiability.
Modelling, Performance Analysis and Design of WPAN Systems
Authors: Ana García-Armada, Beatriz Bardón Rodríguez, Víctor P. Jiménez, Matilde Sánchez-Fernández
Venue: Wireless Personal Communications: An International Journal (2007)

This paper covers the main issues that must be solved in order to design and analyse the performance of Wireless Personal Area Networks (WPANs) with the aid of simulation tools. We review state-of-the-art channel models to account for small- and large-scale propagation conditions in waveform- and system-level simulations. When dealing with waveform simulations, we also look at Montecarlo and importance sampling techniques that allow efficient estimation of error probabilities. Additionally, discrete channel models are introduced to efficiently link both waveform- and system-level approaches and we point out some methods to obtain the model parameters that are suitable for the wireless environment. The discussion of these techniques is complemented with two application examples that show the use of the different simulation levels for system design and performance study. With the paradigm of Bluetooth piconets we illustrate the usefulness of discrete channel models and we consider the design of an OFDM-based WPAN system to exemplify simulation from a waveform-level point of view.