ppxscal/embedding_network huggingface dataset:
Mixed excitation linear prediction coding of wideband speech at 8 kbps
Authors: Weiran Lin
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 2000. on IEEE International Conference - Volume 02 (2000)

This paper presents our study on the feasibility and effectiveness of using the MELP (mixed excitation linear prediction) model for coding wideband (7 kHz) speech signals at a transmission bit rate of 8 kbps. In order to achieve a reasonably good subjective quality for the decoded speech while maintaining a low operating bit rate at the same time, modifications to the pitch estimation, LP analysis/synthesis and post filtering stages of the original MELP model are discussed. Informal listening tests show that the subjective quality of the decoded speech of the proposed coder is rated to be slightly better than the MPEG-4 CELP coder operating at 14.4 kbps for both male and female utterances. The subjective quality of the decoded female utterances from the proposed coder operating at 8.4 kbps is rated to be comparable to that produced by the ITU G.722 coder operating at 48 kbps.
Non-deterministic semantics for logics with a consistency operator
Authors: Arnon Avron
Venue: International Journal of Approximate Reasoning (2007)

In order to handle inconsistent knowledge bases in a reasonable way, one needs a logic which allows nontrivial inconsistent theories. Logics of this sort are called paraconsistent. One of the oldest and best known approaches to the problem of designing useful paraconsistent logics is da Costa's approach, which seeks to allow the use of classical logic whenever it is safe to do so, but behaves completely differently when contradictions are involved. da Costa's approach has led to the family of logics of formal (in)consistency (LFIs). In this paper we provide in a modular way simple non-deterministic semantics for 64 of the most important logics from this family. Our semantics is three-valued for some of the systems, and infinite-valued for the others. We prove that these results cannot be improved: neither of the systems with a three-valued non-deterministic semantics has either a finite characteristic ordinary matrix or a two-valued characteristic non-deterministic matrix, and neither of the other systems we investigate has a finite characteristic non-deterministic matrix. Still, our semantics provides decision procedures for all the systems investigated, as well as easy proofs of important proof-theoretical properties of them.
A semantic anchoring infrastructure for model-integrated computing
Authors: Janos Sztipanovits
Venue:  (2006)

Model-Integrated Computing (MIC) is an approach for model-based design of embedded software and systems. MIC places strong emphasis on the use of domain-specific modeling languages (DSMLs) and model transformation techniques in design flows. Metamodeling facilitates the rapid, inexpensive development of DSMLs. However, the semantics specification for DSMLs is still a hard problem. In this thesis, we propose a semantic anchoring infrastructure including a set of reusable "semantic units" that provide reference semantics for basic behavioral categories using the Abstract State Machine framework. A tool suite for the semantic anchoring methodology is developed to facilitate the transformational specification of DSML semantics. If the semantics of a DSML can be directly mapped onto one of the basic behavioral categories, its semantics can be defined by simply specifying the semantic anchoring rules between the DSML and a semantic unit. However, in heterogeneous systems, the semantics is not always fully captured by a predefined semantic unit. If the semantics is specified from scratch it is not only expensive but we lose the advantages of anchoring the semantics to a set of common and well-established semantic units. Therefore, we extend the semantic anchoring framework to heterogeneous behaviors by developing an approach for the composition of semantic units. The compositional semantics specification approach reduces the required effort from DSML designers and improves the quality of the specification. This thesis also includes three case studies for different purposes. The FSM domain in Ptolemy is used as a case study to explain the semantic anchoring methodology and to illustrate how the semantic anchoring tool suite is applied to design DSMLs. The Timed Automata Semantic Unit is defined as an example to illustrate how to specify semantic units. An industrial-strength modeling language, EFSM, is employed as a case study to explain the compositional semantics specification approach.
Performance evaluation of spherical parallel platforms for humanoid robots
Authors: Roque J. Saltaren, Jose M. Sabater, Eugenio Yime, Jose M. Azorin, Rafael Aracil, Nicolas Garcia
Venue: Robotica (2007)

This paper presents a simple methodology for the quantitative and qualitative analysis of the performance of spherical parallel platforms. The quaternion formulation is used to represent the possible rotations, showing the workspace as a three-dimensional (3-D) solid object. The singularities of the platform intersect graphically with its workspace, allowing a graphical study of the mechanism kinematics. The performance criterion considered here has been the local dexterity of the manipulator. This methodology has been used to study and analyze three known orientation parallel platforms: 3-<underline>R</underline>RR, 3-U<underline>P</underline>U-wrist, and 2-U<underline>P</underline>S-1-<underline>R</underline>U. The objective of this study is to analyze the ability of these platforms to be utilized as mechanisms for the neck and shoulders of humanoid robots. Finally, the forces on actuators in some typical motions for neck and shoulder are plotted.
Applicability of internet video in distance education for engineering
Authors: J. M. Pullen
Venue: Proceedings of the Frontiers in Education Conference, 2001. on 31st Annual - Volume 01 (2001)

This paper analyzes the pros and cons of Internet video in delivery of synchronous distance education for engineering topics and presents the results of a recent experiment in adding video to a course that previously was delivered using Internet audiographics only. The author has extensive experience teaching a variety of courses that support regional students by reducing commuting and also allowing time-shifting of classes using online recordings of the synchronous sessions. His distance delivery had evolved away from video as a teaching medium in order to use limited capacity Internet modem links. With the recent availability of higher access rates using cable modem and DSL, video has become more practical as a teaching medium. This has led to experimentation with web-based video delivery. In this paper, he provides a detailed analysis of the advantages and disadvantages of video when used in this way, and supports the analysis with feedback provided by students in a controlled experiment where the same students attended classes with and without Internet video.
Secure data replication over untrusted hosts
Authors: Bogdan C. Popescu, Bruno Crispo, Andrew S. Tanenbaum
Venue: Proceedings of the 9th conference on Hot Topics in Operating Systems - Volume 9 (2003)

Data replication is a widely used technique for achieving fault tolerance and improved performance. With the advent of content delivery networks, it is becoming more and more frequent that data content is placed on hosts that are not directly controlled by the content owner, and because of this, security mechanisms to protect data integrity are necessary. In this paper we present a system architecture that allows arbitrary queries to be supported on data content replicated on untrusted servers. To prevent these servers from returning erroneous answers to client queries, we make use of a small number of trusted hosts that randomly check these answers and take corrective action whenever necessary. Additionally, our system employs an audit mechanism that guarantees that any untrusted server acting maliciously will eventually be detected and excluded from the system.
Efficient summarization-aware search for online news articles
Authors: Wisam Dakka, Luis Gravano
Venue: Proceedings of the 7th ACM/IEEE-CS joint conference on Digital libraries (2007)

News portals gather and organize news articles published daily on the Internet. Typically, news articles are clustered into 'events' and each cluster is displayed with a short description of its contents. A particularly interesting choice for describing the contents of a cluster is a machine-generated multi-document summary of the articles in the cluster. Such summaries are informative and help news readers to identify and explore only clusters of interest. Naturally, multi-document clusters and summaries are also valuable to help users navigate the results of keyword-search queries. Unfortunately, current document summarizers are still slow; as a result, search strategies that define document clusters and their multi-document summaries online, in a query-specific manner, are prohibitively expensive. In contrast, search strategies that only return offline, query-independent document clusters are efficient, but might return clusters whose (query-independent) summaries are of little relevance to the queries. In this paper, we present an efficient Hybrid search strategy to address the limitations of fully online and fully offline summarization-aware search approaches. Extensive experiments involving user relevance judgments and real news articles show that the quality of our Hybrid results is high, and that these results are computed in substantially less time than with the fully online strategy. We have implemented our strategy and made it available on the Newsblaster news summarization system, which crawls and summarizes news articles from a variety of web sources on a daily basis.
A comparison of large-scale software installation methods on NT and UNIX
Authors: Michail Gomberg, Rémy Evard, Craig Stacey
Venue: Proceedings of the 1998 Conference on Large Installation System Administration of Windows NT (1998)

Our computing environment consists of hundreds of UNIX and NT-based computers. We have a coherent UNIX software installation model that scales comfortably to hundreds of machines. We have spent a great deal of time in the last year learning to understand the software installation and support mechanisms for a similarly large NT infrastructure. In this paper, we examine the underlying requirements for large-scale software installation support, and compare and contrast the NT and UNIX environments, identifying strong points, weak points, and issues.
Performance analysis of DS-CDMA systems using improved Gaussian approximation method
Authors: Y. D. Li, T. T. Tjhung
Venue: Proceedings of the The 8th International Conference on Communication Systems - Volume 02 (2002)

We present an accurate bit error rate (BER) expression for direct sequence code division multiple access (DS-CDMA) communication systems over Nakagami multipath fading channels. This problem has been considered by Trabeisi and Yongacoglu (1995). However, the receiver of Trabeisi et al. only extracted the first path and regarded the other multipaths as interference. Our BER analysis in this paper use a RAKE receiver to exploit all the multipaths in a maximal ratio combiner. We adopt an improved Gaussian approximation (IGA) method proposed by Holtzman (1992), which takes into account the second moment effect of the multiple-access interference (MAI) variance, to derive the error performance expression. We show by Monte Carlo (MC) simulation that the derived formula gives a more accurate prediction of the error performance as compared with that obtained by using the standard Gaussian approximation (SGA) method.
Performance analysis and comparison of time-hopping and direct-sequence UWB-MIMO systems
Authors: W. Pam Siriwongpairat, Masoud Olfat, K. J. Ray Liu
Venue: EURASIP Journal on Applied Signal Processing (2005)

We analyze the performance of ultra-wideband (UWB)multiple-inputmultiple-output (MIMO) systems employing various modulation and multiple access (MA) schemes including time-hopping (TH) binary pulse-position modulation (BPPM), TH binary phase-shift keying (BPSK), and direct-sequence (DS-) BPSK. We quantify the performance merits of UWB space-time (ST) systems regardless of specific coding scheme. For each modulation technique, we introduce a framework that enables us to compare UWB-MIMO systems with conventional UWB single-input single-output (SISO) systems in terms of diversity and coding gains. We show that the combination of ST coding and RAKE receiver is capable of exploiting spatial diversity as well as multipath diversity, richly inherent in UWB environments. In addition, we adopt the real orthogonal design (ROD) as the engine code for UWB-ST codes. We find the upper bound of the average pairwise error probability (PEP) under the hypothesis of quasistatic Nakagami-m frequency-selective fading channels. The performance comparison of ROD-ST codes with different rates is also addressed. Finally, simulation results are presented to support the theoretical analysis.
Estimation of link interference in static multi-hop wireless networks
Authors: Jitendra Padhye, Sharad Agarwal, Venkata N. Padmanabhan, Lili Qiu, Ananth Rao, Brian Zill
Venue: Proceedings of the 5th ACM SIGCOMM conference on Internet Measurement (2005)

We present a measurement-based study of interference among links in a static, IEEE 802.11, multi-hop wireless network. Interference is a key cause of performance degradation in such networks. To improve, or to even estimate the performance of these networks, one must have some knowledge of which links in the network interfere with one another, and to what extent. However, the problem of estimating the interference among links of a multi-hop wireless network is a challenging one. Accurate modeling of radio signal propagation is difficult since many environment and hardware-specific factors must be considered. Empirically testing every group of links is not practical: a network with n nodes can have O(n2) links, and even if we consider only pairwise interference, we may have to potentially test O(n4) pairs. Given these difficulties, much of the previous work on wireless networks has assumed that information about interference in the network is either known, or that it can be approximated using simple heuristics. We test these heuristics in our testbed and find them to be inaccurate. We then propose a simple, empirical estimation methodology that can predict pairwise interference using only O(n2) measurements. Our methodology is applicable to any wireless network that uses omni-directional antennas. The predictions made by our methodology match well with the observed pairwise interference among links in our 22 node, 802.11-based testbed.
Flexible and Manageable Delegation of Authority in RBAC
Authors: Tuan-Anh Nguyen, Linying Su, George Inman, David Chadwick
Venue: Proceedings of the 21st International Conference on Advanced Information Networking and Applications Workshops - Volume 02 (2007)

One of the most challenging problems in managing large networks is the complexity of security administration. Role based access control (RBAC) has become the predominant model for advanced access control. Flexibility and manageability are important requirements for any delegation system which is one of the most important access control management mechanisms in authorisation systems This paper proposes a delegation model that satisfies these requirements.
Manifold splines
Authors: Hong Qin, Xianfeng Gu
Venue:  (2006)

Real-world objects are oftentimes of complex geometry and arbitrary topology. One fundamental goal in computer graphics and geometric modeling is to seek accurate and effective techniques for the compact representation of smooth shapes. Towards this goal, spline surfaces have been extensively investigated during the past decades and have demonstrated their significance in geometric design, scientific computation, visualization, manufacturing, etc. Most popular examples include B&eacute;zier surfaces, tensor-product B-spline surfaces, and triangular B-spline surfaces. Essentially, all of them are piecewise polynomials defined over planar parametric domains for efficient evaluation. While these spline surfaces are ideal for modeling open surfaces with curved boundaries, they are cumbersome to represent smooth surfaces with complicated topology. It is a fundamental open problem to rigorously define spline surfaces on manifold of arbitrary topology.In this dissertation, we systematically study the planar spline, spherical spline, and then present a general theoretical and computational framework of manifold spline, in which in spline surfaces defined over planar domains can be extended to manifold domains of arbitrary topology. We prove that the existence of manifold spline is equivalent to the existence of a manifold's affine atlas. We also prove that given a closed manifold of genus g, a manifold spline can be constructed with |2g - 2| extraordinary points. Based on our theoretical breakthrough, we develop a set of practical algorithms to construct manifold splines for real-world applications. We generalize existing planar spline schemes, such as triangular B-splines, Powell-Sabin splines, tensor-product B-splines and T-splines to manifold domain of arbitrary topology. Our manifold splines inherit all the favorable properties of the above planar spline schemes and admit them as special cases. Through our experiments, we have demonstrated that manifold splines are both powerful and effective in modeling shapes of complicated geometry and arbitrary topology.
Optimised Motion Estimation for Robust Video Coding in Packet Loss Environment
Authors: Fuzheng Yang, Shuai Wan, Ebroul Izquierdo
Venue: Proceedings of the Eight International Workshop on Image Analysis for Multimedia Interactive Services (2007)

An improved motion estimation method for robust video coding is proposed. It is designed to enhance packet loss resilience in lossy environments. The proposed motion estimation is based on an end-to-end rate-distortion optimisation framework. Initially, the end-to-end reconstructed distortion is efficiently estimated considering the distortion caused by quantisation, error propagation, and error concealment. Then, the total bit rate for coding the residual is estimated using a quadratic rate-distortion model. The results are incorporated into the Lagrangian optimisation during motion estimation. Optimised motion vectors are selected in the sense of coding efficiency and robustness. A comparative evaluation with conventional robust video coding techniques was conducted. The experimental results demonstrate a superior performance of the proposed method.
Manage people, not Userids
Authors: Jon Finke
Venue: Proceedings of the 19th conference on Large Installation System Administration Conference - Volume 19 (2005)

Despite the title, this is not about managing people, but rather managing the enterprise data about the people, especially in defining the relationship between a person and the organisation and controlling functions based on that relationship, or what some people might refer to as identity management. Single sign-on is an attractive goal for many organisations. When you include parking gates and badge readers on building entrances, the problem gets even more interesting. As we expand our deployment of wireless access points and publically accessible network jacks, the need to require authentication for access to our virtual world grows stronger. With the need for authentication, so grows the demands on the systems that provide authentication and authorisation, especially in the area of managing who gets access and revoking that access at the appropriate time. Concurrently, with the rising interest in physical security of our facilities, the need for authentication and controlling access to our physical world is also growing. This also requires tools and systems to manage the people and their status and privileges. Both of these issues share many common attributes and can be well addressed by merging them into a single system to manage people information, and from that, access to the virtual (network) world as well as the physical world. By combining these projects, we are able to take advantage of the mandate (and administrative support) to identify all of the people on our campus to provide physical access control, and so, manage our virtual world. We will also attempt to define a somewhat generic or standard methodology for doing this with our particular business rules and requirements confined to a few limited and specific areas. While the technical issues are challenging, the more daunting task comes with negotiating the institutional politics and getting adequate "buy in" from the appropriate departments to provide the people and resources willing to operate and use the eventual technical solutions. This paper discusses both the social and technical aspects of those solutions.
Generalized variable dimensional set partitioning for embedded wavelet image compression
Authors: D. Mukherjee
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 1999. on 1999 IEEE International Conference - Volume 06 (1999)

A vector enhancement of Said and Pearlman's (1996) set partitioning in hierarchical trees (SPIHT) methodology, named VSPIHT, has recently been proposed for embedded wavelet image compression. While the VSPIHT algorithm works better than scalar SPIHT for most images, a common vector dimension to use for coding an entire image may not be optimal. Since statistics vary widely within an image, a greater efficiency can be achieved if different vector dimensions are used for coding the wavelet coefficients from different portions of the image. We present a generalized methodology for developing a variable dimensional set partitioning coder, where different parts of an image may be coded in different vectoring modes, with different scale factors, and up to different number of passes. A Lagrangian rate-distortion criterion is used to make the optimum coding choices. Coding passes are made jointly for the vectoring modes to produce an embedded bitstream.
Environmental Engineering Program in Brazil
Authors: C. da Rocha Brito
Venue: Proceedings of the Frontiers in Education Conference, 2001. 31st Annual - Volume 02 (2001)

In a country like Brazil, more than ever it is necessary to increase the number of researchers committed to the environment, principally because this country has an immense challenge: to promote development for the welfare of people without forgetting the human aspects involved in the relations-man, progress and nature. So it is imperative that the creation of alternatives for the qualification of scientific minds to make science and create technology. This project consists in a proposal of an Environmental Engineering Program, conceived by the Coordinating Team of Engineering School of Lusiada University Center. It is a five years program, having in its curriculum some new courses of modern sciences, besides the ones demanded by the Education Law of Brazil, for engineering programs. It is a modular education, developed in periods, called "theoretical modules" and "search modules". They last four months each and they are complimentary. At the end of the the student will be an engineer capable of promoting human welfare and contributing to decrease the grade of the impact of progress over nature and even over men.