ppxscal/embedding_network huggingface dataset:
Performance Comparison of Web Services Security: Kerberos Token Profile Against X.509 Token Profile
Authors: A. Moralis, V. Pouli, M. Grammatikou, S. Papavassiliou, V. Maglaris
Venue: Proceedings of the Third International Conference on Networking and Services (2007)

Web Services (WS) Security is the set of standards that provides means for applying security to WS. In this paper we present the performance of the WS Security Kerberos Token profile in contrast to the X.509 Token Profile. The measurements are based on the Apache wss4j library for the X.509 Token Profile and the extensions we have made on the same library in order to support the Kerberos Token Profile. The Kerberos Token profile is based exclusively on symmetric cryptography, whereas the X.509 profile uses Public Key Cryptography for encrypting the symmetric encryption key used for deciphering the message. These differences in the nature of cryptography are reflected and quantified on the measurements we have performed. The performance evaluation and numerical results, demonstrated that Kerberos Token profile has up to 28% packet throughput improvement over the X.509 Token profile, under full CPU load on the server.
Theoretical Approaches to Information Systems Research
Authors: Scott Schneberger, Mike Wade
Venue: Proceedings of the 40th Annual Hawaii International Conference on System Sciences (2007)

This is the inaugural appearance of the Theoretical Approaches to Information Systems Research mini-track at HICSS. The purpose of the track is to explore how theory can be developed, extended, and used within the context of information systems (IS) research. IS research draws heavily on theory from a variety of disciplines. It has developed or appropriated theories to examine central disciplinary themes such as IS development, adoption, implementation, training, application, as well as strategic, social and political factors. Some theories have originated within the IS field, while others have been drawn from complementary disciplines such as psychology, sociology, management, economics, and mathematics.
Linux Kernel hash table behavior: analysis and improvements
Authors: Chuck Lever
Venue: Proceedings of the 4th annual Linux Showcase & Conference - Volume 4 (2000)

The Linux kernel stores high-usage data objects such as pages, buffers, and inodes in data structures known as hash tables. In this report we analyze existing static hash tables to study the benefits of dynamically sized hash tables. We find significant performance boosts with careful analysis and tuning of these critical kernel data structures.
Relaxations of semiring constraint satisfaction problems
Authors: Louise Leenen, Thomas Meyer, Aditya Ghose
Venue: Information Processing Letters (2007)

The Semiring Constraint Satisfaction Problem (SCSP) framework is a popular approach for the representation of partial constraint satisfaction problems. In this framework preferences can be associated with tuples of values of the variable domains. Bistarelli et al. [S. Bistarelli, U. Montanari, F. Rossi, Semiring-based constraint solving and optimization, Journal of the ACM 44 (2) (1997) 201-236] defines a maximal solution to a SCSP as the best set of solution tuples for the variables in the problem. Sometimes this maximal solution may not be good enough, and in this case we want to change the constraints so that we solve a problem that is slightly different from the original problem but has an acceptable solution. We propose a relaxation of a SCSP, and use a semiring to give a measure of the difference between the original SCSP and the relaxed SCSP. We introduce a relaxation scheme but do not address the computational aspects.
Design and implementation of a transaction-based filesystem on freeBSD
Authors: Jason Evans
Venue: Proceedings of the annual conference on USENIX Annual Technical Conference (1999)

Transactional database management systems (DBMS's) have special data integrity requirements that standard filesystems such as the Berkeley Fast Filesystem do not address. This paper briefly describes the requirements a transactional DBMS makes of a transaction-based filesystem, then goes on to describe the design and implementation of such a filesystem, referred to as a block repository, which is part of the SQRL DBMS project. The implementation of SQRL's block repository is different than most traditional filesystems in that it is purposely implemented in user-land using raw devices and threads. Its performance is more tunable to the needs of transaction processing than would be the case if it were integrated into the kernel.
Analytical exploration of power efficient data-reuse transformations on multimedia applications
Authors: S. Kougia
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 200. on IEEE International Conference - Volume 02 (2001)

Power savings that can be achieved by data-reuse decisions targeting at a custom memory hierarchy for multimedia applications executing on embedded cores are examined in this paper. Exploiting the temporal locality of memory accesses in data-intensive applications a set of data-reuse transformations on a typical motion estimation algorithm is determined. The aim is to reduce data related power consumption by moving background memory accesses to smaller foreground memories, which are less power costly. The impact of these transformations on power, performance and area is evaluated both for application specific circuits and general purpose processors. The number of data and instruction memory accesses is analytically calculated, enabling a fast exploration of the design space by varying algorithmic parameters.
Taming the memory hogs: using compiler-inserted releases to manage physical memory intelligently
Authors: Angela Demke Brown, Todd C. Mowry
Venue: Proceedings of the 4th conference on Symposium on Operating System Design & Implementation - Volume 4 (2000)

Out-of-core applications consume physical resources at a rapid rate, causing interactive applications sharing the same machine to exhibit poor response times. This behavior is the result of default resource management strategies in the OS that are inappropriate for memory-intensive applications. Using an approach that integrates compiler analysis with simple OS support and a run-time layer that adapts to dynamic conditions, we have shown that the impact of out-of-core applications on interactive ones can be greatly mitigated. A combination of prefetching pages that will soon be needed, and releasing pages no longer in use results in good throughput for the out-of-core task and good response time for the interactive one. Each class of application performs well according to the metric most important to it. In addition, the OS does not need to attempt to identify these application classes, or modify its default resource management policies in any way. We also observe that when an out-of-core application releases pages, it both improves the response time of interactive tasks, and also improves its own performance through better replacement decisions and reduced memory management overhead.
SPDW: A Software Development Process Performance Data Warehousing Environment
Authors: Karin Becker, Duncan D. Ruiz, Virginia S. Cunha, Taisa C. Novello, Franco Vieira e Souza
Venue: Proceedings of the 30th Annual IEEE/NASA Software Engineering Workshop (2006)

Metrics are essential in the assessment of the quality of software development processes (SDP). However, the adoption of a metrics program requires an information system for collecting, analyzing, and disseminating measures of software processes, products and services. This paper describes SPDW, an SPD Data Warehousing environment developed in the context of the metrics program of a leading software operation in Latin America, currently assessed as CMM Level 3. SDPW architecture encompasses: 1) automatic project data capturing, considering different types of heterogeneity present in the software development environment; 2) the representation of project metrics according to a standard organizational view; and 3) analytical functionality that supports process analysis. The paper also describes current implementations, and reports experiences on the use of SPDW by the organization.
Potentials of Social Networks for Knowledge Management with Regard to the Development of Stable Competences and Dynamic Capabilities--Conceptualization and Case Study Results
Authors: Harald F. O. VonKortzfleisch, Ines Mergel, Christian Proll
Venue: Proceedings of the 40th Annual Hawaii International Conference on System Sciences (2007)

In order to balance the tensions of the concepts of organizational core competencies and dynamic capability we introduce social knowledge networks as a strategic means from a knowledge management perspective. A facilitator for the development of the respective framework is the precise distinction between explicit and non-explicit knowledge. Social knowledge networks are informal with regard to their very character but offer the opportunity to enhance the advantages of stability and reliability of organizational core competences as well as flexibility and dynamics of dynamic capabilities. The results of a case study in the automotive and machine building industry confirm the viability of the new framework by looking at social network ties in the IT department on the basis of information sharing and problem-oriented advice. Overall point of reference is IT Governance, especially the ITIL standard.
Explaining "Noise" as Environmental Variations in Population Dynamics
Authors: Timothy R. Ginn, Frank J. Loge, Timothy D. Scheibe
Venue: Computing in Science and Engineering (2007)

By integrating a population dynamic model with models of contaminant/stressor fate and transport and biological organism movement, researchers can capture the impact of spatial and temporal heterogeneity on population dynamics, and ultimately develop and implement improved management decisions and policies.
Resolving hand over face occlusion
Authors: Paul Smith, Niels da Vitoria Lobo, Mubarak Shah
Venue: Image and Vision Computing (2007)

The ability to segment or track the hand is an important problem in computer vision. While various solutions have been proposed, many methods do not work against complex or cluttered backgrounds. Solving these cases is essential to solving many problems in the domain of computer vision such as, human-computer interaction (HCI), surveillance, and virtual reality (i.e., augmented desks). This paper presents a method to segment the hand over complex backgrounds, such as the face. The similar colors and texture of the hand and face make the problem particularly challenging. The method is not restricted to only segmenting hands across faces and uses no knowledge of hands. Our method is based on the underlying concept of an image force field. In this representation change is measured through how particles move through the field. Each individual image location consists of a vector value which is a nonlinear combination of the remaining pixels in the image. We introduce and develop a novel physics-based feature that is able to measure regional structure in the image thus avoiding the problem of local pixel-based analysis, which breaks down under our conditions. The regional image structure changes in the occluded region during occlusion, while elsewhere the regional structure remains relatively constant. We model the regional image structure at all image locations over time using a mixture of Gaussians (MoG) to detect the occluded region in the image. We have tested the method on a number of sequences demonstrating the versatility of the proposed approach.
A hybrid wavelet-based fingerprint matcher
Authors: Loris Nanni, Alessandra Lumini
Venue: Pattern Recognition (2007)

In this work we present a hybrid fingerprint matcher system based on the multi-resolution analysis of the fingerprint pattern and on minutiae-based registration module. Two fingerprints are first aligned using their minutiae, then the images are divided in sub-windows and each sub-window is decomposed into frequency sub-bands at different decomposition levels using a set of wavelet functions, finally a distinct classifier is trained on each sub-band to distinguish matching pairs of fingerprint from non-matching one (defining a two-class matching problem). The features extracted for the matching are the standard deviation of the image convolved with 16 Gabor filters. The selection among the pool of matchers, is performed by running Sequential Forward Floating Selection. The retained matchers are weighted by a novel localized quality measure and combined by a fusion rule. Extensive experiments conducted over the four FVC2002 fingerprint databases show the effectiveness of the proposed approach.
Throughput optimization and transmitter power saving (totps) algorithm and extended totps (etotps) algorithm for ieee 802.11 links
Authors: Charles Bostian
Venue:  (2006)

The IEEE 802.11 wireless local area network (WLAN) standard supports multiple transmission modes. However, the higher mandatory data rate mode does not necessarily yield higher throughput. This research started from the relationship between the link throughput and the channel's carrier-to-noise (C/N) ratio. Two algorithms are proposed, a throughput optimization and transmitter power saving (TOTPS) algorithm and an extended throughput optimization and transmitter power saving (ETOTPS) algorithm, based on the knowledge of the C/N ratio at the receiver. In particular, we take the approach of adjusting link parameters like transmitter power and transmission mode to achieve the maximum throughput at different C/N values. Since the TOTPS algorithm tends to reduce the transmitter power without degrading the link throughput, transmitter power can be saved. This not only prolongs battery life, which is critical in ad hoc wireless networks, but also reduces the potential interference to neighboring wireless network systems. The ETOTPS algorithm, on the other hand, aims for higher throughput by trading in more transmitter power. This is particularly desired for high-speed data transfer in an emergency situation. Both algorithms are developed to be applied to IEEE 802.11b, IEEE 802.11a and IEEE 802.11g links.
Semi-automated 3-D Building Extraction from Stereo Imagery
Authors: Sung Chun Lee, Keith Price, Ram Nevatia, Tom Heinze, John M. Irvine
Venue: Proceedings of the 35th Applied Imagery and Pattern Recognition Workshop (2006)

The production of geospatial information from overhead imagery is generally a labor-intensive process. Analysts must accurately delineate and extract important features, such as buildings, roads, and landcover from the imagery. Automated Feature Extraction (AFE) tools offer the prospect of reducing analyst's workload. This paper presents a new tool, called iMVS, for extracting buildings and discusses user testing conducted by the National Geospatial-Intelligence Agency (NGA). Using a semi-automated approach, iMVS processes two or more images to form a set of hypothesized 3-D buildings. When the user clicks on one of the building vertices, the system determines which hypothesis is the best fit and extracts the building. A set of powerful editing tools support rapid clean-up of the extraction, including extraction of complex buildings. User testing of iMVS provides an assessment of the benefits and identifies areas for system improvement.
Blind adaptive separation of wide-band sources
Authors: C. Serviere
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 1996. on Conference Proceedings., 1996 IEEE International Conference - Volume 05 (1996)

Conventional antenna array processing techniques are based on the use of second order statistics but rest on restrictive assumptions. Thus, when a priori information about the propagation or the geometry of the array is hardly available, the model is close to a blind source separation model. It supposes the statistical independence of the sources and their non-Gaussianity. We focus in this paper on the generalization of the source separation problem to convolutive mixtures of wide-band sources with no assumption on their probability densities. We propose a blind cost function, using a specific decomposition and parametrization of the complex gains of the convolutive filters. An adaptive gradient algorithm can be associated to the function and we prove that no local minima exist. Consequently, it assumes that the proposed algorithm converges towards the good solutions.
Reconfigurable Antenna for Future Wireless Communication Systems
Authors: E. Re, S. Morosi, D. Marabissi, L. Mucchi, L. Pierucci, L. S. Ronga
Venue: Wireless Personal Communications: An International Journal (2007)

This paper deals with the processing techniques which are known as reconfigurable antennas: these methods are foreseen to be a booster for the future high rate wireless communications, both for the benefits in terms of performance and for the capacity gains. In particular, adaptive digital signal processing can provide improved performance for the desired signal in terms of error probability or signal-to-noise ratio while the bandwidth efficiency can be increased linearly with the number of transmitting and receiving antennas. In this article, the main antenna processing techniques are reviewed and described, aiming at highlighting performance/complexity trade-offs and how they could be implemented in the future systems. The coexistence of all these different technologies in a wireless environment requires high efficiency and flexibility of the transceiver. Future transceiver implementations which are based on the Software Defined Radio technology are also reviewed and described.
An examination of the transition of the Arjuna distributed transaction processing software from research to products
Authors: M. C. Little, S. K. Shrivastava
Venue: Proceedings of the 2nd conference on Industrial Experiences with Systems Software - Volume 2 (2002)

The Arjuna transaction system began life in the mid 1980s as an academic project to examine the use of object-oriented techniques in the development of fault-tolerant systems; over 15 years later it is now a Hewlett-Packard product in its own right and is also embedded in several other offerings from HP. In addition, many of the original developers of Arjuna have accompanied the system on its journey and had first hand experience in taking this academic research vehicle into a commercial environment. At times the transition has been neither easy nor smooth but it has been interesting from many different perspectives. In this paper we shall attempt to give an overview of how this occurred and illustrate some of the lessons we have learned over the years.
Service Broker for Managing Feature Interactions in IP Multimedia Subsystem
Authors: Anahita Gouya, Noel Crespi
Venue: Proceedings of the Sixth International Conference on Networking (2007)

Since the vast deployment of telecommunication services, until the broad development of innovative 3G services, dealing with Feature Interaction issue has been constantly challenging. This issue results in the occurrence of incorrect or unexpected behaviours from the features and services that are invoked during an IP multimedia session. The purpose of this article is to include a flexible SIP-based Feature Interaction Detection and Resolution algorithm in the service invocation mechanism of IMS. Through several feature interaction examples, we confirm that our proposed algorithm covers a wide range of Feature Interactions and manages the conflicts that arise between various features.
Semi-Supervised Handwritten Word Segmentation Using Character Samples Similarity Maximization and Evolutionary Algorithm
Authors: Jerzy Sas, Urszula Markowska-Kaczmar
Venue: Proceedings of the 6th International Conference on Computer Information Systems and Industrial Management Applications (2007)

In this paper, the problem of semi-supervised handwriting segmentation into isolated character images is considered. Semi-supervised segmentation means here that the character sequence constituting a word presented on the image is known, but the character boundaries are not given and need to be automatically determined. The semi-supervised word segmentation can be useful in analytic writer-dependent approach to handwriting recognition, where the training set for personalized character classifier must be created for each writer from the text corpus consisting of text samples of an individual writer. The method described here over-segments the word images into sequences of graphemes in the first step. Then such grapheme sequences subdivision is sought, which results in the hypothetical character images sets maximizing average similarity in subsets corresponding to characters from the alphabet. It leads to the combinatorial optimization problem with enormously large search space. The suboptimal solution of this problem can be found using evolutionary algorithm. The sample character images extracted in this way can be used to train character classifiers. Some preliminary results of handwriting segmentation are presented in the paper and compared with fully supervised segmentation carried out by a human.
Performance-driven processor allocation
Authors: Julita Corbalán, Xavier Martorell, Jesús Labarta
Venue: Proceedings of the 4th conference on Symposium on Operating System Design & Implementation - Volume 4 (2000)

This work is focused on processor allocation in shared-memory multiprocessor systems, where no knowledge of the application is available when applications are submitted. We perform the processor allocation taking into account the characteristics of the application measured at run-time. We want to demonstrate the importance of an accurate performance analysis and the criteria used to distribute the processors. With this aim, we present the SelfAnalyzer, an approach to dynamically analyzing the performance of applications (speedup, efficiency and execution time), and the Performance-Driven Processor Allocation (PDPA), a new scheduling policy that distributes processors considering both the global conditions of the system and the particular characteristics of running applications. This work also defends the importance of the interaction between the medium-term and the long-term scheduler to control the multiprogramming level in the case of the clairvoyant scheduling pol-icies1. We have implemented our proposal in an SGI Origin2000 with 64 processors and we have compared its performance with that of some scheduling policies proposed so far and with the native IRIX scheduling policy. Results show that the combination of the SelfAnalyzer+PDPA with the medium/long-term scheduling interaction outperforms the rest of the scheduling policies evaluated. The evaluation shows that in workloads where a simple equipartition performs well, the PDPA also performs well, and in extreme workloads where all the applications have a bad performance, our proposal can achieve a speedup of 3.9 with respect to an equipartition and 11.8 with respect to the native IRIX scheduling policy.
Electric power transient disturbance classification using wavelet-based hidden Markov models
Authors: Jaehak Chung
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 2000. on IEEE International Conference - Volume 06 (2000)

We utilize wavelet-based hidden Markov models (HMM) to classify electric power transient disturbances associated with degradation of power quality. Since the wavelet transform extracts power transient disturbance characteristics very well, this wavelet-based HMM classifier illustrates high classification correctness rates. The power transient disturbance is decomposed into multi-resolution wavelet domains, and the wavelet coefficients are modeled by a HMM. Based on this modeling, the maximum likelihood classification is applied to classify actual power quality transient disturbance data recorded on a 7200 V distribution line, and the result is tuned by post-processing. Of 507 power quality events experimentally observed by an electrical utility, 95.5% are correctly classified.