ppxscal/embedding_network huggingface dataset:
On the Performance of V-BLAST Detectors in MIMO MT-CDMA Uplink over Multipath Fading Channel
Authors: Wei Yang, Yang Wei
Venue: Proceedings of the Sixth International Conference on Networking (2007)

In this paper, an asynchronous multiple-input multiple-output multitone code division multiple access (MIMO MT-CDMA) scheme for the uplink of the mobile communication in a frequency selective fading channel is analyzed. Maximum ratio combining (MRC) and linear Zero-forcing (ZF) V-BLAST detectors are applied at the receiver. The average bit error rate (BER) expression for uniform multipath power profile is derived when the number of receive antennas is greater than that of transmit antennas. Numerical results verify the BER expression and show that the number of transmit and receive antennas has a significant effect on the BER performance. Space diversity and path diversity have different abilities to improve the performance. The average BER performance of the proposed system is also compared with that of a conventional MT-CDMA system.
Designing Domain-Specific Software Architecture (DSSA): Towards a New Approach
Authors: Eduardo Santana de Almeida, Alexandre Alvaro, Vinicius Cardoso Garcia, Leandro Nascimento, Silvio Lemos Meira, Daniel Lucredio
Venue: Proceedings of the Sixth Working IEEE/IFIP Conference on Software Architecture (2007)

Since the first works involving software reuse, domain engineering is considered a key process to develop reusable and flexible software. However, the results have shown that there is still much to do before the vision of domain engineering is completely achieved. Among the reasons for this problem, we may highlight the lack of a process to support the design of domain-specific software architectures. This paper presents such an approach, based on a well defined set of principles, guidelines and metrics.
Circularity of objects in images
Authors: M. J. Bottema
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 2000. on IEEE International Conference - Volume 04 (2000)

The most commonly used measure of circularity of objects in images is shown to give incorrect results. An alternative measure of circularity based on the distance between a set and a discrete disk is described. The alternative measure gives circularity zero (distance zero) for discrete disks and values in the range (0,1) for discrete sets which are not disks.
Data-driven time-frequency classification techniques applied to tool-wear monitoring
Authors: B. W. Gillespie
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 2000. on IEEE International Conference - Volume 02 (2000)

In many pattern recognition applications features are traditionally extracted from standard time-frequency representations (e.g. the spectrogram) and input to a classifier. This assumes that the implicit smoothing of, say, a spectrogram is appropriate for the classification task. It is better to begin with no implicit smoothing assumptions and optimize the time-frequency representation for each specific classification task. Here we describe two different approaches to data-driven time-frequency classification techniques, one supervised and one unsupervised. We show that a certain class of quadratic time-frequency representations will always provide best classification performance. Using our techniques we explore the wear process of milling cutters. Our initial experiments give strong evidence to the nonlinear nature of the wear process and the importance of capturing nonstationary information about each flute-strike to accurately understand the wear process.
DMFS: a data migration file system for NetBSD
Authors: William Studenmund
Venue: Proceedings of the annual conference on USENIX Annual Technical Conference (2000)

I have recently developed DMFS, a Data Migration File System, for NetBSD[1]. This file system provides kernel support for the data migration system being developed by my research group at NASA/Ames. The file system utilizes an underlying file store to provide the file backing, and coordinates user and system access to the files. It stores its internal metadata in a flat file, which resides on a separate file system. This paper will first describe our data migration system to provide a context for DMFS, then it will describe DMFS. I also will describe the changes to NetBSD needed to make DMFS work. Then I will give an overview of the file archival and restoration procedures, and describe how some typical user actions are modified by DMFS. Lastly, I will present simple performance measurements which indicate that there is little performance loss due to the use of the DMFS layer.
Using Contextual Knowledge to Improve Parallel Spoken Language Understanding
Authors: Sang-Hwa Chung, Dan I. Moldovan
Venue: Proceedings of the 1994 International Conference on Parallel Processing - Volume 03 (1994)

This paper presents a parallel approach for utilizing contextual knowledge to improve spoken language understanding. The method emphasizes a hierarchically-structured knowledge base and a memory-based parsing technique. Within this paradigm, several levels of knowledge sources including contextual knowledge arc efficiently combined. An ambiguity resolution scheme utilizing the preceding discourse context and the situational context was implemented on a parallel computer using a marker-passing scheme. The experiments on the parallel computer for an Air Traffic Control (ATC) domain show an 86% sentence recognition accuracy with about 6% improvement compared with the system not utilizing the contextual knowledge.
A Digitally Testable Capacitance-Insensitive Mixed-Signal Filter
Authors: Erik Schuler, Marcelo Negreiros, Pascal Nouet, Luigi Carro
Venue: Proceedings of the 12th IEEE European Test Symposium (2007)

One of the main problems when developing analog filters in VLSI is to achieve high accuracy regarding the cutoff frequency. This is mainly due to the difficulty in obtaining accurate time constants. Testing of such filters is also challenging, in the sense that special equipment is required. Small deviations in the resistor or capacitor values may lead to a very high mismatch between the expected and the achieved cutoff frequency. Although switched-capacitor or active-transistor techniques may produce good results, the cost to use such approaches becomes another limiting factor, and only increases the tester needs. In this work, we present the development of an analog FIR filter, which does not use passive components to tune the cutoff frequency or the quality factor. Instead, the filter coefficients and the input signal are represented in a bit stream fashion, and are digitally processed, thus avoiding the use of expensive analog-to-digital converters. The impact of this filter architecture on test cost and possible design-for-test techniques are discussed in this paper.
Fault-tolerant network computation of individuals in genetic algorithms
Authors: A. Hamilton-Wright, D. Stacey
Venue: Proceedings of the Evolutionary Computation on 2002. CEC '02. Proceedings of the 2002 Congress - Volume 02 (2002)

Many genetic algorithms have complex fitness functions which can easily be calculated in parallel, given the tools to do so. This paper explores the use of a tool to gather spare computing cycles from a variable set of machines to allow convergence of GAs of this type. A modification to the steady-state model for GAs allows us to use the fault-prone behavior of an underlying thin networked computation system as noise within the GA itself. This "real" noise is incorporated into the GA, maintaining the drive towards convergence in the case of the heavily noisy network environment.
Data management for internet-scale single-sign-on
Authors: Sharon E. Perl, Margo Seltzer
Venue: Proceedings of the 3rd conference on USENIX Workshop on Real, Large Distributed Systems - Volume 3 (2006)

Google offers a variety of Internet services that require user authentication. These services rely on a single-sign-on service, called Google Accounts, that has been in active deployment since 2002. As of 2006, Google has tens of applications with millions of user accounts worldwide. We describe the data management requirements and architecture for this service, the problems we encountered, and the experience we've had running it. In doing so we provide perspective on "where theory meets practice." The success of the system comes from combining good algorithms with practical engineering tradeoffs.
Recovery of 3D Pose of Bones in Single 2D X-ray Images
Authors: Piyush Kanti Bhunre, Wee Kheng Leow, Tet Sen Howe
Venue: Proceedings of the Eighth IEEE Workshop on Applications of Computer Vision (2007)

Estimation of the 3D pose of bones in 2D images plays an important role in computer-assisted diagnosis and surgery. Existing work has focused on registering a 3D model of the bone to the images of the same bone. This approach incurs a high health care cost on the patients, and are prescribed only for certain procedures. Such computer assistance is not routinely available to diagnostic and surgical procedures that involve only x-ray images, limiting the precision of the procedures. This paper proposes a method for recovering 3D pose by registering a generic 3D model of a bone to single x-ray images of different patients. It can perform 3D-2D registration with unknown correspondence automatically. Comprehensive test results show that the method is accurate and robust in recovering the pose of femurs in the x-ray images of different patients.
An interactive tool for bit error rate analysis of speech coding algorithms
Authors: H. C. Bhagatwala
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 1999. on 1999 IEEE International Conference - Volume 04 (1999)

A GUI-based software tool that provides a framework for evaluation of different speech coding algorithms is presented. The tool is designed to measure the susceptibility of speech coding algorithms to errors added on the encoded bit-stream during transmission. In particular, the errors can be added individually to the parameters that comprise the encoded bit-stream. This enables a designer of a speech codec to evaluate its performance under adverse or impaired channel conditions. The tool is universally applicable to different speech coding algorithms, by means of a user-defined bit-stream definition file. In fact, the tool has been used in the past to evaluate a number of standardized speech coding algorithms. This paper describes the features of the software. In addition, the paper presents sample results generated by this tool during a study of the ETSI GSM Enhanced Full Rate algorithm.
A fast Gabor spectrogram
Authors: Shie Qian
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 2000. on IEEE International Conference - Volume 02 (2000)

The Gabor expansion based spectrogram (commonly known as the Gabor spectrogram or the time-frequency distribution series) has previously been applied in many areas. In many applications, such as biomedical engineering, radar image processing, and seismology, it has been found to be a good alternative for the STFT-based spectrogram and Wigner-Ville distribution. Although the idea of the Gabor spectrogram is rather straightforward, the implementation has been quite involved. In this paper, we present a new algorithm for computing the Gabor spectrogram. The method presented is not only simple, but also fast. According to this new approach, the Gabor spectrogram is nothing more than separated two-dimensional interpolation filters. Consequently, it could be efficiently computed in the Fourier transform domain or implemented in off-the-shelf chips.
FPGA implementation of a nonlinear two dimensional fuzzy filter
Authors: J. G. R. Delva
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 1999. on 1999 IEEE International Conference - Volume 04 (1999)

Nonlinear filtering has found many practical applications in digital signal and image processing. The computation complexity of these filtering algorithms make them difficult for real-time hardware implementation. One of these nonlinear filters, which is based on fuzzy classification of each pixel to subgroups of its neighboring pixels, is considered hen for hardware implementation. The criteria of this filter are based on the local context which form the basis of the fuzzy rule. The filtering algorithm is slightly modified for implementation into a Xilinx Virtex series of FPGA for real-time processing of image sequences. Implementation details and recommendations for further improvement are discussed. Result of a simulation example from the proposed hardware implementation is also presented.
Psychophysical investigation of facial expressions using computer animated faces
Authors: Rita T. Griesser, Douglas W. Cunningham, Christian Wallraven, Heinrich H. Bülthoff
Venue: Proceedings of the 4th symposium on Applied perception in graphics and visualization (2007)

The human face is capable of producing a large variety of facial expressions that supply important information for communication. As was shown in previous studies using unmanipulated video sequences, movements of single regions like mouth, eyes, and eyebrows as well as rigid head motion play a decisive role in the recognition of conversational facial expressions. Here, flexible but at the same time realistic computer animated faces were used to investigate the spatiotemporal coaction of facial movements systematically. For three psychophysical experiments, spatiotemporal properties were manipulated in a highly controlled manner. First, single regions (mouth, eyes, and eyebrows) of a computer animated face performing seven basic facial expressions were selected. These single regions, as well as combinations of these regions, were animated for each of the seven chosen facial expressions. Participants were then asked to recognize these animated expressions in the experiments. The findings show that the animated avatar in general is a useful tool for the investigation of facial expressions, although improvements have to be made to reach a higher recognition accuracy of certain expressions. Furthermore, the results shed light on the importance and interplay of individual facial regions for recognition. With this knowledge the perceptual quality of computer animations can be improved in order to reach a higher level of realism and effectiveness.
Trapeze/IP: TCP/IP at near-gigabit speeds
Authors: Andrew Gallatin, Jeff Chase, Ken Yocum
Venue: Proceedings of the annual conference on USENIX Annual Technical Conference (1999)

This paper presents experiences with high-speed TCP/IP networking on a gigabit-per-second Myrinet network, using a Myrinet messaging system called Trapeze. We explore the effects of common optimizations above and below the TCP/IP protocol stack, including zero-copy sockets, large packets with scatter/gather I/O, checksum offloading, message pipelining, and interrupt suppression. Our experiments use extended FreeBSD 4.0 kernels on a range of Intel and Compaq Alpha platforms. These experiments give a snapshot of the FreeBSD TCP/IP implementation running at bandwidths as high as 956 Mb/s. We also report some results using Gigabit Ethernet products from Alteon Networks, which yielded a TCP bandwidth of 988 Mb/s using zero-copy sockets on a 500 MHz Compaq Alpha 21264 workstation.
Proceedings of the 2nd ACM SIGOPS/EuroSys European Conference on Computer Systems 2007
Venue: European Conference on Computer Systems (2007)

Is there a "second conference" effect? After the success of EuroSys 2006 in Leuven I wondered how EuroSys 2007 might develop. Would we see a significant change in the number or distribution of submissions? The Call for Papers again emphasized the interest in systems papers without imposing restrictions on the specific area. EuroSys wants to establish itself as a premier systems conference that is open-minded with regard to subject area, and this year's program indicates that the conference is achieving this goal. There were 157 abstract submissions that turned into 131 papers. EuroSys 2007 used the same two-stage review process that is used by many high-quality conferences. The program committee, with the help of a small group of outside reviewers, produced 3 reviews for each paper in the first stage of the review process. Then, the committee selected 65 papers for the second stage and obtained an additional 2 -- 3 reviews. All papers were discussed at a full-day program committee meeting on Dec. 2nd in Zurich, Switzerland. (There were 7 submissions co-authored by members of the program committee, two of those are included in the program.) There were many high-quality submissions that could not be included in this year's conference. I am confident that revisions of these papers will appear in future conferences. 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
An inverse problem approach to robust regression
Authors: J.-J. Fuchs
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 1999. on 1999 IEEE International Conference - Volume 04 (1999)

When recording data, large errors may occur occasionally. The corresponding abnormal data points, called outliers, can have drastic effects on the estimates. There are several ways to cope with outliers-detect and delete or adjust the erroneous data,-use a modified cost function. We propose a new approach that allows, by introducing additional variables, to model the outliers and to detect their presence. In the standard linear regression model this leads to a linear inverse problem that, associated with a criterion that ensures sparseness, is solved by a quadratic programming algorithm. The new approach (model+criterion) allows for extensions that cannot be handled by the usual robust regression methods.
A direction finding method under sensor gain and phase uncertainties
Authors: P. Charge
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 2000. on IEEE International Conference - Volume 05 (2000)

An original eigenstructure-based method for direction finding in presence of sensor gain and phase uncertainties is presented. The method has been developed in order to estimate the directions of arrival of non-circular radiating sources for any geometrical array configuration. The gain and phase of each sensor are also provided by this technique. We show that this method works even in the case where the number of sources is larger than the number of sensors. The proposed procedure gives very good results as we show through two demonstrative computer simulations.
Single-machine scheduling problems with the time-dependent learning effect
Authors: Wen-Hung Kuo, Dar-Li Yang
Venue: Computers Mathematics with Applications (2007)

In this paper, three single-machine scheduling problems with time-dependent learning effect model to minimize the sum of weighted completion times, the sum of the kth powers of completion times and the maximum lateness are investigated. We show that the shortest processing time first (SPT) rule is an optimal solution for the problem to minimize the sum of the kth powers of completion times. Some polynomial time solutions are provided for the other two problems under certain conditions, respectively.
Monte Carlo Minimization and Counting: One, Two, ..., Too Many
Authors: Isabel Beichl, Dianne P. O'Leary, Francis Sullivan
Venue: Computing in Science and Engineering (2007)

Monte Carlo methods use sampling to produce approximate solutions to problems for which other methods aren't practical. In this homework assignment, we study three uses of Monte Carlo methods: for function minimization, discrete optimization, and counting.
Gaining the middleground: a linux-based open source middleware initiative
Authors: Greg Wettstein, Johannes Grosen
Venue: Proceedings of the 4th annual Linux Showcase & Conference - Volume 4 (2000)

Central to the development of the Internet, and the resulting business paradigm shifts, has been the adoption of standards which have provided the necessary framework for computer systems to cooperate and exchange information. The next major step necessary to support the continuation of this process is the development of software protocols and tools which provide the ability to manage the delivery of services to users. This paper describes a Linux-based middleware initiative which has been deployed at North Dakota State University to support a Category of Service information delivery system for the North Dakota Higher Education Computing Network. The system was designed to support a computing model where the majority of the service infrastructure is supplied by Linux servers and which is extensible to the 11 state institutions comprising the HECN. The paper begins with a discussion of middleware and its importance in the development of next-generation information systems. Included in this discussion are the topics of identification, authentication and authorization and the requirement for them in a modern middleware solution. Central to this topic will be a discussion of the potential threat that proprietary middleware solutions pose to the continued penetration of Open Source efforts into the enterprise computing model. The paper then discusses in detail the design and architecture of the User Services Management System which implements the middleware solution at NDSU. The three fundamental components discussed will be the User Services DataBase, LDAP meta-directory services and the User Account Management System. Discussion of the system architecture will include details of how standard services have been modified to operate under middleware control. The paper will conclude with a discussion of the implications of this work. Also included is a discussion of the next generation of the system architecture.
Analysis of redundancy and application balance in the SPEC CPU2006 benchmark suite
Authors: Aashish Phansalkar, Ajay Joshi, Lizy K. John
Venue: Proceedings of the 34th annual international symposium on Computer architecture (2007)

The recently released SPEC CPU2006 benchmark suite is expected to be used by computer designers and computer architecture researchers for pre-silicon early design analysis. Partial use of benchmark suites by researchers, due to simulation time constraints, compiler difficulties, or library or system call issues is likely to happen; but a random subset can lead to misleading results. This paper analyzes the SPEC CPU2006 benchmarks using performance counter based experimentation from several state of the art systems, and uses statistical techniques such as principal component analysis and clustering to draw inferences on the similarity of the benchmarks and the redundancy in the suite and arrive at meaningful subsets. The SPEC CPU2006 benchmark suite contains several programs from areas such as artificial intelligence and includes none from the electronic design automation (EDA) application area. Hence there is a concern on the application balance in the suite. An analysis from the perspective of fundamental program characteristics shows that the included programs offer characteristics broader than the EDA programs' space. A subset of 6 integer programs and 8 floating point programs can yield most of the information from the entire suite.