ppxscal/embedding_network huggingface dataset:
Study on the application of an AMR speech codec to VoIP
Authors: B. Liu
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 2001. on IEEE International Conference - Volume 03 (2001)

Degradation of speech quality caused by packet loss of voice traffic is still one of critical technical barriers of the VoIP system. We propose a new VoIP system that can adapt transmission bit rate flexibly to network conditions to reduce packet loss. In order to determine the transmission bit rate depending upon the network conditions on a frame basis, we use the time-stamp parameter in the RTP of the H.323 protocol. Experimental results demonstrate that the proposed system is very promising to reduce packet loss that leads to improvement of speech quality. 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
Global optimization in stabilizing controller design
Authors: Youngjung Chang, Nikolaos V. Sahinidis
Venue: Journal of Global Optimization (2007)

In this paper, we develop a global optimization methodology to solve stabilization problems. We first formulate stabilization problems as bilevel programming problems. By invoking the Hurwitz stability conditions, we reformulate these bilevel programs to equivalent single-level nonconvex optimization programs. The branch-and-reduce global optimization algorithm is finally applied to these problems. Using the proposed methodology, we report improved solutions for two feedback stabilization problems from the literature. In addition, we improve the lower bound of the stabilizability parameter of the Belgian chocolate problem from the previous best known 0.96 to 0.973974.
Bringing the Mobile Workforce to Business: A Case Study in a Field Service Organization
Authors: Dennis, Chongyun Yang
Venue: Proceedings of the International Conference on the Management of Mobile Business (2007)

The purpose of this research is to examine how businesses are using mobile computing technologies to improve their workforce efficiency, increase productivity, and to justify this investment. The study addresses questions such as: What benefits do businesses expect to justify their investment in mobile technologies? Once implemented, do mobile technologies match the expectations of the business? Are projected returns on investment positive? What are the key barriers to the m-workforce? How are these barriers being addressed? These questions are addressed through a case study in Alpha, a field service organization that implemented a mobile job dispatch application in 2002. The findings indicate that Alpha has received both monetary (e.g., reduced operating costs) and non-monetary (e.g., reduced abandoned calls) benefits. Additionally some of the drawbacks of mobilizing a workforce found in the literature (e.g., reduced contact between field staff and the organization) were verified and are being addressed.
Flexible qos-managed status dissemination middleware framework for the electric power grid
Authors: David E. Bakken
Venue:  (2006)

Electric power grids are complex interconnected systems that in North America can span more than a thousand miles. They must be operated such that the dynamic balance between supply and demand is maintained. Grids exhibit many power dynamics that are global over the entire grid, yet their control mechanisms and almost all of their operational data on the current dynamics and configuration of the grid status data are local in nature, typically limited to a single substation. The reason for this is that the communication system that is used to coordinate and monitor utility operations was designed largely in response to the 1965 blackout in the US Northeast. However, since then network and related technologies have improved dramatically. Status dissemination middleware is a new specialization of the publish-subscribe model that takes advantage of the semantics of status data. This dissertation presents a status dissemination middleware framework named GridStat for the electric power grid and other critical infrastructures. It takes advantage of the semantics of status data to optimize delivery and to manage its subscriptions for quality of service. In doing so, GridStat allows status information to be disseminated over a wide-area. The architecture, design, and implementation of this framework are described, along with its baseline mechanisms to improve efficiency and resilience. In addition, the rationale, design, and implementation of four mechanisms are presented. These mechanisms are limited flooding mechanisms, operating modes mechanism, filtering with multicast mechanism, and condensation function mechanism. This dissertation also presents an experimental evaluation of the GridStat framework.
Characterizing Document Types to Evaluate Web Cache Replacement Policies
Authors: F. J. Gonzalez-Canete, E. Casilari, Alicia Trivino-Cabrera
Venue: Proceedings of the Fourth European Conference on Universal Multiservice Networks (2007)

In this paper, a study of the performance of six replacement policies has been developed Three of them are classical caching algorithms (LRU, LFU and LFU-DA) while the other three are caching schemes specifically developed for Web documents (GD-SIZE, GDSF and GD*). This study has been divided by the main content-types observed in Web traffic (Application, Audio, Images, Text and Video). Using a trace log of a real proxy cache, a characterization of the main properties of the documents has been performed, such as size characteristics, popularity and temporal locality. Finally, a trace driven simulation study of the performance of the replacement policies has been developed for the traffic generated by each considered content-type.
On the use of orthogonal GMM in speaker recognition
Authors: L. Liu
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 1999. on 1999 IEEE International Conference - Volume 02 (1999)

The Gaussian mixture modeling (GMM) techniques are increasingly being used for both speaker identification and verification. Most of these models assume diagonal covariance matrices. Although empirically any distribution can be approximated with a diagonal GMM, a large number of mixture components are usually needed to obtain a good approximation. A consequence of using a large GMM is that its training is time consuming and its response speed is very slow. This paper proposes a modification to the standard diagonal GMM approach. The proposed scheme includes an orthogonal transformation: feature vectors are first transformed to the space spanned by the eigenvectors of the covariance matrix before applying to the diagonal GMM. Only a small computational load is introduced by this transformation, but results from both speaker identification and verification experiments indicated that the orthogonal transformation considerably improves the recognition performance. For a specific performance level, the GMM with orthogonal transform needs only one-fourth the number of Gaussian functions required by the standard GMM.
The election problem in asynchronous distributed systems with bounded faulty processes
Authors: Sung Hoon Park
Venue: The Journal of Supercomputing (2007)

Determining the "weakest" failure detectors is a central topic in solving many agreement problems such as Consensus, Non-Blocking Atomic Commit and Election in asynchronous distributed systems. So far, this has been studied extensively for several such fundamental problems. It is stated that Perfect Failure Detector P is the weakest failure detector to solve the Election problem with any number of faulty processes. In this paper, we introduce Modal failure detector M and show that to solve Election, M is the weakest failure detector to solve election when the number of faulty processes is less than ¿n/2¿. We also show that it is strictly weaker than P.
Fast codeword search for vector quantization using a multi-stage approach
Authors: T. K. Moon
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 2000. on IEEE International Conference - Volume 05 (2000)

Vector quantization (VQ) is widely used in many high-quality and high-rate data compression applications such as speech coding, audio coding, image coding and video coding. When the size of a VQ codebook is large, the computational complexity for the full codeword search method is a significant problem for many applications. A number of complexity reduction algorithms have been proposed and investigated using such properties of the codebook as the triangle inequality. This paper proposes a new fast VQ search algorithm that is based on a multi-stage structure for searching for the best codeword. Even using only two stages, a significant complexity reduction can be obtained without any loss of quality.
Efficient continuous skyline computation
Authors: M. Morse, J. M. Patel, W. I. Grosky
Venue: Information Sciences: an International Journal (2007)

In a number of emerging streaming applications, the data values that are produced have an associated time interval for which they are valid. A useful computation over such streaming data is to produce a continuous and valid skyline summary. Previous work on skyline algorithms have only focused on evaluating skylines over static data sets, and there are no known algorithms for skyline computation in the continuous setting. In this paper, we introduce the continuous time-interval skyline operator, which continuously computes the current skyline over a data stream. We present a new algorithm called LookOut for evaluating such queries efficiently, and empirically demonstrate the scalability of this algorithm. In addition, we also examine the effect of the underlying spatial index structure when evaluating skylines. Whereas previous work on skyline computations have only considered using the R^*-tree index structure, we show that for skyline computations using an underlying quadtree has significant performance benefits over an R^*-tree index.
A queueing analysis for the denial of service (DoS) attacks in computer networks
Authors: Yang Wang, Chuang Lin, Quan-Lin Li, Yuguang Fang
Venue: Computer Networks: The International Journal of Computer and Telecommunications Networking (2007)

In most network security analysis, researchers mainly focus on qualitative studies on security schemes and possible attacks, and there are few papers on quantitative analysis in the current literature. In this paper, we propose one queueing model for the evaluation of the denial of service (DoS) attacks in computer networks. The network under DoS attacks is characterized by a two-dimensional embedded Markov chain model. With this model, we can develop a memory-efficient algorithm for finding the stationary probability distribution which can be used to find other interesting performance metrics such as the connection loss probability and buffer occupancy percentages of half-open connections for regular traffic and attack traffic. Different from previous works in the literature, this paper gives a more general analytical approach to the study of security measures of a computer network under DoS attacks. We hope that our approach opens a new avenue to the quantitative evaluation of more complicated security schemes in computer networks.
Asset Valuation Technique for Network Management and Security
Authors: Luc Beaudoin, P. Eng
Venue: Proceedings of the Sixth IEEE International Conference on Data Mining - Workshops (2006)

One of the most difficult tasks for analysts working in Network Operation Centres is to evaluate the impact of the loss of a given asset. This paper proposes a new technique to evaluate such a value using a simple model and computation. The resulting value for each network asset represents its contribution to the value delivery chain. This value can be used to evaluate the impact of vulnerabilities, malicious and non-malicious incidents, and is a keystone to automating risk assessment.
Data Flow Attack Detection Mechanism for PARTY Protocol
Authors: Mounis KHATIB, Ghazi Al SUKKAR, Abdallah MHAMED
Venue: Proceedings of the Third International Conference on Networking and Services (2007)

A few works deal with the forwarding attacks in Self Organized Network, as most of research care for securing the routing process to minimize the effects of an attacker on the network stability. However, data packet forwarding behavior is a very important aspect that should be taken into account to achieve a high-quality performance in application and network stability. We propose in this paper an effective mechanism to detect forwarding-attacks in self organized networks, and we will deploy our mechanism to secure PARTY routing protocol. Within our approach, nodes are enabled to localize malicious node that start to drop or to duplicate packets. Our approach is scalable and can be implemented independently of routing protocol.
An Efficient Implementation of Adaptive Prefix Coding
Authors: Yakov Nekrich
Venue: Proceedings of the 2007 Data Compression Conference (2007)

The goal of the prefix coding is to assign codewords to elements of the input alphabet A, so that no codeword is a prefix of another one, and the total length of the encoded message S is minimized. In the case of static prefix coding, symbol frequencies are known in advance.
Multi-dispatch in the Java virtual machine: design and implementation
Authors: Christopher Dutchyn, Paul Lu, Duane Szafron, Steven Bromling, Wade Holst
Venue: Proceedings of the 6th conference on USENIX Conference on Object-Oriented Technologies and Systems - Volume 6 (2001)

Mainstream object-oriented languages, such as C++ and Java, provide only a restricted form of polymorphic methods, namely uni-receiver dispatch. In common programming situations, developers must work around this limitation. We describe how to extend the Java Virtual Machine to support multi-dispatch and examine the complications that Java imposes on multidispatch in practice. Our technique avoids changes to the Java programming language itself, maintains source code and library compatibility, and isolates the performance penalty and semantic changes of multimethod dispatch to the program sections which use it. We have micro-benchmark and application-level performance results for a dynamic Most Specific Applicable (MSA) dispatcher, a framework-based Single Receiver Projections (SRP) dispatcher, and a tuned SRP dispatcher. Our general-purpose technique provides smaller dispatch latency than programmer-written double-dispatch code with equivalent functionality.
Compositional pattern producing networks: A novel abstraction of development
Authors: Kenneth O. Stanley
Venue: Genetic Programming and Evolvable Machines (2007)

Natural DNA can encode complexity on an enormous scale. Researchers are attempting to achieve the same representational efficiency in computers by implementing developmental encodings, i.e. encodings that map the genotype to the phenotype through a process of growth from a small starting point to a mature form. A major challenge in in this effort is to find the right level of abstraction of biological development to capture its essential properties without introducing unnecessary inefficiencies. In this paper, a novel abstraction of natural development, called Compositional Pattern Producing Networks (CPPNs), is proposed. Unlike currently accepted abstractions such as iterative rewrite systems and cellular growth simulations, CPPNs map to the phenotype without local interaction, that is, each individual component of the phenotype is determined independently of every other component. Results produced with CPPNs through interactive evolution of two-dimensional images show that such an encoding can nevertheless produce structural motifs often attributed to more conventional developmental abstractions, suggesting that local interaction may not be essential to the desirable properties of natural encoding in the way that is usually assumed.
Attribute Aggregation and Federated Identity
Authors: N. Klingenstein
Venue: Proceedings of the 2007 International Symposium on Applications and the Internet Workshops (2007)

A principal sometimes needs to present a combination of attributes from multiple identities from distinct organizations to fully identify itself. This problem is rarely encountered in non-federated identity transactions because services operate within the context of a single identity domain. Federated identity allows for data about one entity to be scattered across multiple identities throughout the distributed system. These data must be unified through attribute aggregation to fully identify an entity. In order to do so, the identities must be associated in some fashion, the user must have a session with a service, and the service must have all the information it needs to process the attributes it receives.
Adaptive motion estimation using local measures of texture and similarity
Authors: S. L. Dockstader
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 2000. on IEEE International Conference - Volume 04 (2000)

Traditional approaches to the estimation of motion in video sequences have relied on the appropriate selection of various algorithm parameters. This dependence becomes a prohibitive drawback in applications where automation is desirable or necessary or in sequences where a single set of parameters can not achieve sufficiently accurate results. We investigate a number of techniques for locally adapting both the spatio-temporal filters and the hierarchical structure used in the estimation of optical flow. The surviving technique utilizes projected active contours and gradient-based Chamfer distance images to adapt the filters and a temporally-based Kolmogorov-Smirnov metric to locally adapt the hierarchical structure. The advantages of using these adaptive variations are demonstrated on articulated and self-occluding motion.
Aiming and clicking in young children's use of the computer mouse
Authors: Afke Donker, Pieter Reitsma
Venue: Computers in Human Behavior (2007)

The present study investigated the abilities of young children to aim and click with a computer mouse. Young children have not yet fully developed their motor skills and they are therefore more likely than adults to click next to targets on the computer screen. Because in educational software incorrect clicks could result in incorrect answers, children may initiate a laborious aiming process that increases the risk of repetitive strain injuries. The present study evaluated some factors that could affect the difficulty of aiming and clicking for children from Kindergarten 2 and Grade 1. Adults participated to serve as a reference group. The results show that the accuracy of mouse clicks and aiming speed are related the size of targets. The shape of targets or a context of distracting objects did not affect accuracy or speed. This work recommends the use of targets of at least 1 centimeter wide and tall in the design of software for young children.
On the complexity of spill everywhere under SSA form
Authors: Florent Bouchez, Alain Darte, Fabrice Rastello
Venue: ACM SIGPLAN Notices (2007)

Compilation for embedded processors can be either aggressive (time consuming cross-compilation) or just in time (embedded and usually dynamic). The heuristics used in dynamic compilation are highly constrained by limited resources, time and memory in particular. Recent results on the SSA form open promising directions for the design of new register allocation heuristics for embedded systems and especially for embedded compilation. In particular, heuristics based on tree scan with two separated phases -- one for spilling, then one for coloring/coalescing -- seem good candidates for designing memory-friendly, fast, and competitive register allocators. Still, also because of the side effect on power consumption, the minimization of loads and stores overhead (spilling problem) is an important issue. This paper provides an exhaustive study of the complexity of the "spill everywhere" problem in the context of the SSA form. Unfortunately, conversely to our initial hopes, many of the questions we raised lead to NP-completeness results. We identify some polynomial cases but that are impractical in JIT context. Nevertheless, they can give hints to simplify formulations for the design of aggressive allocators.
Approximate parameterized matching
Authors: Carmit Hazay, Moshe Lewenstein, Dina Sokol
Venue: ACM Transactions on Algorithms (TALG) (2007)

Two equal length strings s and s&prime;, over alphabets &Sigma;s and &Sigma;s&prime;, parameterize match if there exists a bijection &pi; : &Sigma;s &rightarrow; &Sigma;s&prime; such that &pi; (s) &equals; s&prime;, where &pi; (s) is the renaming of each character of s via &pi;. Parameterized matching is the problem of finding all parameterized matches of a pattern string p in a text t, and approximate parameterized matching is the problem of finding at each location a bijection &pi; that maximizes the number of characters that are mapped from p to the appropriate &verbar;p&verbar;-length substring of t. Parameterized matching was introduced as a model for software duplication detection in software maintenance systems and also has applications in image processing and computational biology. For example, approximate parameterized matching models image searching with variable color maps in the presence of errors. We consider the problem for which an error threshold, k, is given, and the goal is to find all locations in t for which there exists a bijection &pi; which maps p into the appropriate &verbar;p&verbar;-length substring of t with at most k mismatched mapped elements. Our main result is an algorithm for this problem with O(nk1.5 &plus; mk log m) time complexity, where m &equals; &verbar;p&verbar; and n&equals;&verbar;t&verbar;. We also show that when &verbar;p&verbar; &equals; &verbar;t&verbar; &equals; m, the problem is equivalent to the maximum matching problem on graphs, yielding a O(m &plus; k1.5) solution.
Media-independent interfaces in a media-dependent world
Authors: Ken Arnold, Kee Hinckley, Eric Shienbrood
Venue: Proceedings of the USENIX Conference on Object-Oriented Technologies on USENIX Conference on Object-Oriented Technologies (COOTS) (1995)

Wildfire is a communications assistant that uses speech recognition to work over phone lines. At least that's what it is today. But in the future it wants to run on desktops, PDAs (like the Newton Message Pad), and who knows what all. To provide a level of media independence, we designed a subsystem to isolate the communications knowledge of the assistant from the mechanisms of prompt/response. This layer is called the MMUI. It provides abstractions of input and output that let the assistant ask questions and get responses without knowledge of the specifics of the communication channels involved. The specifics of speech recognition, as well as the degree of abstraction desired, make this an interesting case of presentation/semantic split using object polymorphism. This presentation will cover the design of the MMUI, its fundamental weaknesses, and furious handwaving over future directions to mend them.