ppxscal/embedding_network huggingface dataset:
A Viterbi based decoding algorithm for multiple description variable length codes
Authors: Huan Yao
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 2000. on IEEE International Conference - Volume 05 (2000)

In the presence of bit errors, variable length (VL) codes often suffer from a loss of synchronization, which leads to spans of symbol errors. It is of our interest to investigate whether the redundancy introduced by multiple description (MD) coding is useful for improving performance. We consider a sequence of i.i.d. source symbols of known length, first quantized, then coded using MD VL codes and transmitted over a binary symmetric channel (BSC). We propose a maximum a posteriori probability (MAP) decoder, in which the optimal sequence with the right number of symbols and bits is found using the Viterbi algorithm. We compare the MD VL code performance against a conventional single description (SD) VL entropy code, and against a single description (SD) parity code.
Adaptive synchronization and cell search algorithm for WCDMA systems
Authors: Chia-Horng Liu
Venue: Proceedings of the The 8th International Conference on Communication Systems - Volume 02 (2002)

The adaptive synchronization and cell search algorithm, which is the first step for a mobile station to access the communication network, for WCDMA systems is presented. A three-stage synchronization and cell search procedure is suggested by the 3GPP specifications. Based on this procedure, we propose an adaptive algorithm to detect synchronization codes according to the channel conditions, which is estimated by a power meter. Computer simulations are conducted to evaluate the performance of the adaptive synchronization and cell search algorithm in different channel conditions. It is shown that, using the proposed adaptive algorithm, the average computation complexity is reduced with little increased acquisition time at good channel conditions. 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
Simultaneous image formation and motion blur restoration via multiple capture
Authors: Xinqiao Liu
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 2001. on IEEE International Conference - Volume 03 (2001)

Advances in CMOS image sensors enable fast image capture, which makes it possible to capture multiple images within a normal exposure time. An algorithm that takes advantage of this capability by simultaneously constructing a high dynamic range image and performing motion blur restoration from multiple image captures is described. The algorithm comprises two main procedures-photocurrent estimation and motion/saturation detection. It operates completely locally-each pixel's final value is computed using only its captured values-and recursively, requiring the storage of only a constant number of values per pixel independent of the number of images captured. These modest computational and storage requirements make it feasible to integrate all needed memory and processing with the image sensor on a single CMOS chip. Simulation results demonstrate the enhanced SNR, dynamic range, and the motion blur restoration obtained using our algorithm.
A taxonomy of security vulnerabilities in scada protocols
Authors: Ronald D. Williams
Venue:  (2007)

Modern industrial facilities, such as oil refineries, chemical factories, electric power generation plants, and manufacturing facilities are large, distributed complexes. Plant operators must continuously monitor and control many different sections of the plant to ensure its proper operation. The development of networking technology has made this remote command and control feasible. The earliest control networks were simple point-to-point networks connecting a monitoring or command device to a remote sensor or actuator. These have since evolved into complex networks that support communication between a central control unit and multiple remote units on a common communication bus. The nodes on these networks are usually special purpose embedded computing devices such as sensors, actuators, and programmable logic controllers (PLCs). These industrial command and control networks are commonly called SCADA (Supervisory Control and Data Acquisition) networks. The increasing interconnectivity of SCADA (Supervisory Control and Data Acquisition) networks has exposed them to a wide range of network security problems. One of the important issues in securing SCADA networks is to identify vulnerabilities in the SCADA communication protocols. This dissertation addresses the problem of security assessment of SCADA communication protocols. The main contribution of this dissertation is the organization of information related to known vulnerabilities in SCADA protocols into a taxonomy that provides a systematic methodology for the security assessment of other SCADA protocols. Attack and vulnerability taxonomies have been generally accepted as a reliable method of using knowledge from past mistakes in predicting sources of vulnerabilities in new systems. The dissertation analyses existing qualitative security assessment guidelines and proposes a new framework for organizing information about known attacks and vulnerabilities to find unknown or similar vulnerabilities in new systems. There are no existing databases of vulnerabilities in SCADA protocols. In order to develop the framework for security assessment of SCADA protocols, this dissertation presents a comprehensive security assessment of one SCADA protocol. The protocol chosen for this work was the PROFIBUS protocol. The information gained from the results of this assessment is then mapped onto the general framework to develop a SCADA-protocol specific taxonomy of vulnerabilities. To demonstrate its usefulness, this new taxonomy is then used to identify vulnerabilities in the Foundation Fieldbus protocol.
Sub-state tying in tied mixture hidden Markov models
Authors: Liang Gu
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 2000. on IEEE International Conference - Volume 02 (2000)

An approach is proposed for partial tying of states of tied-mixture hidden Markov models. To facilitate tying at the sub-state level, the state emission probabilities are constructed in two stages, or equivalently, are viewed as a "mixture of mixtures of Gaussians." This paradigm allows, and is complemented with, an optimization technique to seek the best complexity-accuracy tradeoff solution, which jointly exploits Gaussian density sharing and sub-state tying. Experimental results on the E-set show that the classification error rate is reduced by over 20% compared to standard Gaussian sharing and whole-state tying. The approach is then embedded within the recently developed procedure of combined parameter training and reduction technique. Experiments with the overall technique show that the error rate is further reduced by 8%.
Concatenating syllables for response generation in spoken language applications
Authors: A. Arvaniti
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 2000. on IEEE International Conference - Volume 02 (2000)

We describe our approach in developing a speech synthesis technique for response generation in domain-specific spoken language applications. Our approach handles two Chinese dialects-Cantonese and Putonghua. We chose the foreign exchange domain, and worked with its constrained vocabulary and response expressions. The syllable is selected to be our basic unit for concatenation. Each unit label includes a two-digit appendix to encode the distinctive features of the left and right coarticulatory context. Our approach attempts to maximize intelligibility and naturalness of the responses within the application domain. Hence the synthesized outputs compare favorably with a domain-independent TD-PSOLA synthesizer.
Space-time and space-frequency diversity schemes for data rate enhancement in a Bluetooth system
Authors: R. Sriram, A. Nallanathan, H. K. Garg
Venue: Proceedings of the The 8th International Conference on Communication Systems - Volume 01 (2002)

In this paper, space-time (ST) and space-frequency (SF) diversity schemes are used to improve the performance of a Bluetooth system under Rayleigh and Rician fading chann transmit antennasels. We assume that the transmitter is equipped with two transmit antennas and the receiver with m (m =1, 2) receive antennas. The diversity schemes improve the bit error rate (BER) performance significantly without much increase in implementation complexity. A comparison in BER performance is also made between transmit and receive diversity schemes.
Restoration of error-diffused images using POCS
Authors: G. Bozkurt
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 1999. on 1999 IEEE International Conference - Volume 06 (1999)

Halftoning is a process that deliberately injects noise into the original image in order to obtain visually pleasing output images with a smaller number of bits per pixel for displaying or printing purposes. In this paper, a novel inverse halftoning method is proposed to restore a continuous tone image from the given halftone image. A set theoretic formulation is used where three sets are defined using the prior information about the problem. A new space domain projection is introduced assuming the halftoning is performed with error diffusion, and the error diffusion filter kernel is known. The space domain, frequency domain, and space-scale domain projections are used alternately to obtain a feasible solution for the inverse halftoning problem which does not have a unique solution.
An Account of the Use of Integrated Assessment for Students in the Area of Databases at Level 2
Authors: Andrea Gorra, Sanela Lazarevski, Jackie Campbell
Venue: Proceedings of the 24th British National Conference on Databases (2007)

The purpose of this paper is to share innovative teaching methods at Leeds Metropolitan University in the Innovation North Faculty of Information and Technology (INN Faculty). The paper provides an account of the use of integrated assessment with a focus on the area of database teaching at Level 2 in the INN Faculty. Integrated assessments are also known as synoptic assessments. This type of assessment helps students to make connections between modules and aims to raise the level of student engagement with the curriculum. An explorative study has been undertaken to provide an initial evaluation of the use of synoptic assessments within the Computing subject area. The analysis of the interviews indicates that students and also staff perceive the delivery pattern of block teaching and pairing of modules as beneficial. The paper concludes by offering an account of the benefits and issues to consider for those aiming implementing integrated assessments.
Problem Solving Environment for Medical Image Analysis
Authors: Ketan C. Maheshwari, Silvia D. Olabarriaga, Charl P. Botha, Jeroen G. Snel, Johan Alkemade, Adam Belloum
Venue: Proceedings of the Twentieth IEEE International Symposium on Computer-Based Medical Systems (2007)

The development of Medical Image Analysis (MIA) applications that can successfully be applied in clinical practice is difficult for several reasons, one of them being the large amount and variety of resources involved (people, data, methods, computing). The application goes through several phases (development, parameter optimization, evaluation and clinical deployment) usually supported by different systems. The lack of support for information flow from phase to phase puts extra logistics burden on the lifecycle of MIA applications. In this paper we describe our first efforts to develop a Problem Solving Environment (PSE) for MIA applications using the three systems available at the proof-of-concept environment of the Virtual Laboratory for e-Sciences project. The proposed PSE implements data provenance mechanisms that support information flow among systems, facilitating navigation across phases of the application lifecycle.
Probability of false alarm estimation in oversampled active sonar systems
Authors: D. A. Abraham
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 1999. on 1999 IEEE International Conference - Volume 05 (1999)

The probability of false alarm (P/sub fa/) in active sonar systems is an important system performance measure. This measure is typically estimated by the proportion of alarms to opportunities over some finite window, essentially forming the sample exceedance distribution function (EDF). It is common for sonar systems to be 'over-sampled'; that is, to have a sampling rate higher than the minimum required for representing the bandwidth of the received signal, resulting in reverberation data that are correlated from sample to sample. The performance of the sample EDF in P/sub fa/ estimation under such conditions is of interest. It is easily shown that the estimator remains unbiased with correlated data. However, it is shown in this paper that the variance of the estimator may be reduced from that for independent data by oversampling. Further, the variance is seen to fall between the Cramer-Rao lower bound based on independent thresholded (binary) data and that based on the complex matched filter output data. 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
Grid Computing Infrastructures and their Value for Risk Management
Authors: Wolfgang Hackenbroch, Matthias Henneberger
Venue: Proceedings of the 40th Annual Hawaii International Conference on System Sciences (2007)

Risk/return management has evolved as one of the key success factors for enterprises especially in the financial services industry. It is highly demanding in terms of business requirements and technical resources, making it an almost ideal application for grid computing concepts. In this paper we analyze the value proposition of grid computing for risk/return management. We focus on a specific problem the estimation of covariance matrices and propose a model to quantify the benefits and cost of the corresponding calculations. Our model not only makes a contribution to understand the business value of grid computing in the domain of risk/return management, it also constitutes a building block for the development of economic resource allocation mechanisms.
Detecting targeted attacks using shadow honeypots
Authors: K. G. Anagnostakis, S. Sidiroglou, P. Akritidis, K. Xinidis, E. Markatos, A. D. Keromytis
Venue: Proceedings of the 14th conference on USENIX Security Symposium - Volume 14 (2005)

We present Shadow Honeypots, a novel hybrid architecture that combines the best features of honeypots and anomaly detection. At a high level, we use a variety of anomaly detectors to monitor all traffic to a protected network/service. Traffic that is considered anomalous is processed by a "shadow honeypot" to determine the accuracy of the anomaly prediction. The shadow is an instance of the protected software that shares all internal state with a regular ("production") instance of the application, and is instrumented to detect potential attacks. Attacks against the shadow are caught, and any incurred state changes are discarded. Legitimate traffic that was misclassified will be validated by the shadow and will be handled correctly by the system transparently to the end user. The outcome of processing a request by the shadow is used to filter future attack instances and could be used to update the anomaly detector. Our architecture allows system designers to fine-tune systems for performance, since false positives will be filtered by the shadow. Contrary to regular honeypots, our architecture can be used both for server and client applications. We demonstrate the feasibility of our approach in a proof-of-concept implementation of the Shadow Honeypot architecture for the Apache web server and the Mozilla Firefox browser. We show that despite a considerable overhead in the instrumentation of the shadow honeypot (up to 20% for Apache), the overall impact on the system is diminished by the ability to minimize the rate of false-positives.
Devil: an IDL for hardware programming
Authors: Fabrice Mérillon, Laurent Réveillère, Charles Consel, Renaud Marlet, Gilles Muller
Venue: Proceedings of the 4th conference on Symposium on Operating System Design & Implementation - Volume 4 (2000)

To keep up with the frantic pace at which devices come out, drivers need to be quickly developed, debugged and tested. Although a driver is a critical system component, the driver development process has made little (if any) progress. The situation is particularly disastrous when considering the hardware operating code (i.e., the layer interacting with the device). Writing this code often relies on inaccurate or incomplete device documentation and involves assembly-level operations. As a result, hard-ware operating code is tedious to write, prone to errors, and hard to debug and maintain. This paper presents a new approach to developing hardware operating code based on an Interface Definition Language (IDL) for hard-ware functionalities, named Devil. This IDL allows a high-level definition of the communication with a device. A compiler automatically checks the consistency of a Devil definition and generates efficient low-level code. Because the Devil compiler checks safety critical properties, the long-awaited notion of robustness for hardware operating code is made possible. Finally, the wide variety of devices that we have already specified (mouse, sound, DMA, interrupt, Ethernet, video, and IDE disk controllers) demonstrates the expressiveness of the Devil language.
Critera for direct blind deconvolution of MIMO FIR systems driven by white source signals
Authors: Y. Inouye
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 1999. on 1999 IEEE International Conference - Volume 05 (1999)

This paper addresses the blind deconvolution of multi-input-multi-output (MIMO) FIR systems driven by white non-Gaussian source signals. First, we present a weaker condition on source signals than the so-called i.i.d. condition so that blind deconvolution is possible. Then, under this condition, we provide a necessary and sufficient condition for blind deconvolution of MIMO FIR systems. Finally, based on this result, we propose two maximization criteria for blind deconvolution of MIMO FIR systems. These criteria are simple enough to be implemented by adaptive algorithms.
Building a Learning Organization: Three Phases of Communities of Practice in a Software Consulting Company
Authors: Aase Mestad, Rune Myrdal, Torgeir Dingsoyr, Tore Dyba
Venue: Proceedings of the 40th Annual Hawaii International Conference on System Sciences (2007)

Special interest groups or communities of practice are seen as important mechanisms for knowledge sharing in the knowledge management literature. However, there are few empirical studies of communities of practice in the software engineering field. This article presents an action research project in a small size software consulting company, where the organization of the learning activities went through three phases, where different models were tried out and evaluated. We discuss the models in relation to community of practice theory to explain the learning effect of the models. A flexible model for organizing knowledge-sharing seems to provide the greatest learning effect.
Loop-Level Profiling and Analysis of DoD Applications Using TAU
Authors: Shirley Moore, David Cronk, Sameer Shende, Allen Malony
Venue: Proceedings of the HPCMP Users Group Conference (2006)

Performance of computationally intensive applications often depends critically on the floating point and memory performance of nested loop structures. this paper describes extensions to the Tuning Analysis and Utilities (TAU) parallel performance system that implement automated of parallel C/C++ and Fortran programs to collect loop-level profile data. Link-time and run-time options for configuring the instrumented version of the code to perform various types of measurements, such as time and hardware counter based profiling are described. Finally, examples are given of collecting and analyzing loop-level profile data for several DoD applications.
Educating the next generation of information specialists, in collaboration with industry
Authors: D. K. Lidtke
Venue: Proceedings of the 26th Annual Frontiers in Education - Volume 01 (1996)

This is a bald, new effort to have industry and academia work together to define the curriculum to prepare the information specialists for tomorrow. The task force which is working to develop this curriculum is made of up an equal number of members of industry and academia In addition to a curriculum this work includes a plan for delivery. Not surprisingly, industry members are concerned that the graduates be able to adapt quickly to the environment of business and industry. Today all too many graduates lack skills in teamwork and communication. In most cases the employers are satisfied with the technical skills of graduates. This paper discusses the background that lead to this project, the early developments of the "Profile of the Graduate", the work on delivery of the curriculum, a brief description of the status of the curriculum and how this addresses the concerns of industry.
Embracing and Extending 20th-Century Instruction Set Architectures
Authors: Joe Gebis, David Patterson
Venue: Computer (2007)

A vector case study shows how new functionality can be added to extend the 80x86 and PowerPC architectures to support a full vector architecture, primarily by enhancing their multimedia extensions to provide a better model for compilers and an easier-to-understand model for programmers.
Talk Before You Type: Coordination in Wikipedia
Authors: Fernanda B. Viegas, Martin Wattenberg, Jesse Kriss, Frank van Ham
Venue: Proceedings of the 40th Annual Hawaii International Conference on System Sciences (2007)

Wikipedia, the online encyclopedia, has attracted attention both because of its popularity and its unconventional policy of letting anyone on the internet edit its articles. This paper describes the results of an empirical analysis of Wikipedia and discusses ways in which the Wikipedia community has evolved as it has grown. We contrast our findings with an earlier study [11] and present three main results. First, the community maintains a strong resilience to malicious editing, despite tremendous growth and high traffic. Second, the fastest growing areas of Wikipedia are devoted to coordination and organization. Finally, we focus on a particular set of pages used to coordinate work, the "Talk" pages. By manually coding the content of a subset of these pages, we find that these pages serve many purposes, notably supporting strategic planning of edits and enforcement of standard guidelines and conventions. Our results suggest that despite the potential for anarchy, the Wikipedia community places a strong emphasis on group coordination, policy, and process.
Automated Natural Deduction for Propositional Linear-Time Temporal Logic
Authors: Alexander Bolotov, Oleg Grigoriev, Vasilyi Shangin
Venue: Proceedings of the 14th International Symposium on Temporal Representation and Reasoning (2007)

We present a proof searching technique for the natural deduction calculus for the propositional linear-time temporal logic and prove its correctness. This opens the prospect to apply our technique as an automated reasoning tool in a number of emerging computer science applications and in a deliberative decision making framework across various AI applications.