ppxscal/embedding_network huggingface dataset:
Improving GMM-UBM speaker verification using discriminative feedback adaptation
Authors: Yi-Hsiang Chao, Wei-Ho Tsai, Hsin-Min Wang
Venue: Computer Speech and Language (2009)

The Gaussian mixture model - Universal background model (GMM-UBM) system is one of the predominant approaches for text-independent speaker verification, because both the target speaker model and the impostor model (UBM) have generalization ability to handle ''unseen'' acoustic patterns. However, since GMM-UBM uses a common anti-model, namely UBM, for all target speakers, it tends to be weak in rejecting impostors' voices that are similar to the target speaker's voice. To overcome this limitation, we propose a discriminative feedback adaptation (DFA) framework that reinforces the discriminability between the target speaker model and the anti-model, while preserving the generalization ability of the GMM-UBM approach. This is achieved by adapting the UBM to a target speaker dependent anti-model based on a minimum verification squared-error criterion, rather than estimating the model from scratch by applying the conventional discriminative training schemes. The results of experiments conducted on the NIST2001-SRE database show that DFA substantially improves the performance of the conventional GMM-UBM approach.
Improving reliability of cooperative concurrent systems with exception flow analysis
Authors: Fernando Castor Filho, Alexander Romanovsky, Cecília Mary F. Rubira
Venue: Journal of Systems and Software (2009)

Developers of fault-tolerant distributed systems need to guarantee that fault tolerance mechanisms they build are in themselves reliable. Otherwise, these mechanisms might in the end negatively affect overall system dependability, thus defeating the purpose of introducing fault tolerance into the system. To achieve the desired levels of reliability, mechanisms for detecting and handling errors should be developed rigorously or formally. We present an approach to modeling and verifying fault-tolerant distributed systems that use exception handling as the main fault tolerance mechanism. In the proposed approach, a formal model is employed to specify the structure of a system in terms of cooperating participants that handle exceptions in a coordinated manner, and coordinated atomic actions serve as representatives of mechanisms for exception handling in concurrent systems. We validate the approach through two case studies: (i) a system responsible for managing a production cell, and (ii) a medical control system. In both systems, the proposed approach has helped us to uncover design faults in the form of implicit assumptions and omissions in the original specifications.
Preparation and characterization of Si-doped barium titanate nanopowders and ceramics
Authors: Sanxiong Xiao, Xianping Yan
Venue: Microelectronic Engineering (2009)

Si-doped barium titanate nanopowders and ceramics were prepared through the sol-gel process. The powders and ceramics were characterized by methods of XRD, SEM and TEM. The dielectric properties of the ceramics were also determined. The results indicated that the powders were nanopowders and they were all cubic BaTiO"3 phase with the concentration of Si =
Central vs. distributed dynamic thermal management for multi-core processors: which one is better?
Authors: Michael Kadin, Sherief Reda, Augustus Uht
Venue: Proceedings of the 19th ACM Great Lakes symposium on VLSI (2009)

In this paper we investigate and contrast two techniques to maximize the performance of multi-core processors under thermal constraints. The first technique is a distributed dynamic thermal management system that maximizes the total performance without exceeding given thermal constraints. In our scheme, each core adjusts its operating parameters, i.e., frequency and voltage, according to its temperature which is measured using integrated thermal sensors. We propose a novel controller that dynamically adapts the system to simultaneously avoid timing errors and thermal violations. For comparison purposes, we implement a second technique based on a runtime centralized, optimal system that uses combinatorial optimization techniques to calculate the optimal frequencies and voltages for the different cores to maximize the total throughput under thermal constraints. To empirically validate our techniques, we put together an extensive tool chain that incorporates thermal and power consumption simulators to characterize the performance of multi-core processors for a number of configurations ranging from 2 cores at 90 nm to 16 cores at 32 nm. Our results show that both investigated techniques are capable of delivering significant improvements (about 40% for 16 cores) over standard frequency and voltage planning techniques. From the results, we outline the main advantages and disadvantages of both techniques.
Note: Note on the m-step competition numbers of paths and cycles
Authors: Yongqiang Zhao, Gerard J. Chang
Venue: Discrete Applied Mathematics (2009)

Since Cohen introduced the competition graph in 1968, the competition graph has been studied widely and many variations of it have been discussed. In 2000, Cho, Kim and Nam defined and studied the m-step competition graph and computed the 2-step competition numbers of paths and cycles. Recently, Ho gave bounds for the m-step competition numbers of paths and cycles. In this paper we continue to study the m-step competition numbers of paths and cycles, partially improve the results of Ho on the upper bounds of the m-step competition numbers of paths and cycles, and show that a conjecture posed by Ho is not true.
A separation theorem for nonlinear systems
Authors: Sinan Kilicaslan, Stephen P. Banks
Venue: Automatica (Journal of IFAC) (2009)

In this paper we have obtained a nonlinear separation result for controlled stochastic systems. The result is based on a sequential technique, introduced by the second author, which has been applied with significant success for nonlinear deterministic systems.
Intersection-Aware Channel Assignment and Routing in Multi-Channel Multi-Hop Wireless Networks with a Single Transceiver
Authors: Huang Chuanhe, Cheng Yong, Yang Ling, Shi Wenming, Zhou Hao
Venue: International Journal of Distributed Sensor Networks (2009)

This article proposes an intersection-aware channel assignment and routing protocol for wireless ad hoc networks with a single transceiver. This protocol increases the network capacity of an IEEE 802.11 network by exploiting frequency diversity. Using the proposed protocol, multiple communications can simultaneously take place in a region without interfering with each other. However, it must avoid a multi-channel hidden terminal problem for designing channel assignment and routing protocol. This paper considers issues regarding multiple channels at the network layer, assuming a single channel MAC protocol such as IEEE 802.11 DCF. Also, the proposed protocol assumes that each node in the network is equipped with a single transceiver. This set of assumptions is very practical, because most devices have a single wireless card implementing the IEEE 802.11 DCF protocol. Each node uses modular exponentiation congruence to represent the channel schedule, which assures that each pair of nodes has common channels for communication in every cycle. Each node switches across channels in such a manner that each pair of nodes works on the same channel when they desire to communicate; otherwise they work on a different channel, and hence do not interfere with each other. However, for the intersecting node, there is no benefit in using single radio multiple channels since the capacity around the intersection node can at most be O (W), W is the link capacity, regardless of the number of channels. The protocol lets the intersecting node always work on the same channel whereas the nonintersecting node can work on different channels. The two states for every node in the network are the state of an intersecting node and the state of non-intersecting node. Using the proposed protocol, nodes discover multiple routes to the destination node; the node selects the path with most intersecting nodes to avoid more nodes become intersecting nodes when the number of flows increases greatly. Once a node becomes an intersecting node, it will work on the same channel in a cycle. Simulation results show that the proposed protocol significantly increases the aggregate end-to-end throughput and network capacity greatly over a single-channel protocol and some other channel assignment and routing protocols in several wireless networking scenarios.
Virtual labs with remote access to a real hardware equipment in the computer systems education
Authors: Orlin Tomov
Venue: Proceedings of the 9th International Conference on Computer Systems and Technologies and Workshop for PhD Students in Computing (2008)

The paper focuses on the need of virtual labs and more specific - the virtual labs based on real hardware equipment. Different architectures and approaches are overviewed. It is paid attention on the technologies for development and different approaches for realisation.
Modeling software evolution defects: a time series approach
Authors: Uzma Raja, David P. Hale, Joanne E. Hale
Venue: Journal of Software Maintenance and Evolution: Research and Practice (2009)

The Department of Information Systems, Statistics and Management Science, prediction of software defects and defect patterns is and will continue to be a critically important software evolution research topic. This study presents a time series analysis of multi-organizational multi-project defects reported during ongoing software evolution efforts. Using data from monthly defect reports for eight open source software projects over five years, this study builds and tests time series models for each sampled project. The resulting model accounts for the ripple effects of defect detection and correction by modeling the autocorrelation of code defect data. The autoregressive integrated moving average model (0,1,1) was found to hold for all sampled projects and thus provide a basis for both descriptive and predictive software defect analysis that is computationally efficient, comprehensible, and easy to apply. The model may be used to evaluate and compare the reliability of candidate software solutions, and to facilitate planning for software evolution budget and time allocation. Copyright &copy; 2008 John Wiley & Sons, Ltd.
Proactive attacker localization in wireless LAN
Authors: Chuan Han, Siyu Zhan, Yaling Yang
Venue: ACM SIGCOMM Computer Communication Review (2009)

This paper addresses the open problem of locating an attacker that intentionally hides or falsies its position using advanced radio technologies. A novel attacker localization mechanism, called Access Point Coordinated Localization (APCL), is proposed for IEEE 802.11 networks. APCL actively forces the attacker to reveal its position information by combining access point (AP) coordination with the traditional range-free localization. The optimal AP coordination process is calculated by modeling it as a finite horizon discrete Markov decision process, which is efficiently solved by an approximation algorithm. The performance advantages are veried through extensive simulations.
Steganalysis of JPEG Images with Joint Transform Features
Authors: Zohaib Khan, Atif Bin Mansoor
Venue: Proceedings of the 3rd Pacific Rim Symposium on Advances in Image and Video Technology (2009)

In this paper, a universal steganalysis scheme for JPEG images based upon joint transform features is presented. We first analyzed two different transform domains (Discrete Cosine Transform and Discrete Wavelet Transform) separately, to extract features for steganalysis. Then a combination of these two feature sets is constructed and employed for steganalysis. A Fisher Linear Discriminant classifier is trained on features from both clean and steganographic images using all three feature sets and subsequently used for classification. Experiments performed on images embedded with two variants of F5 and Model based steganographic techniques reveal the effectiveness of proposed steganalysis approach by demonstrating improved detection for joint features.
Scalable don't-care-based logic optimization and resynthesis
Authors: Alan Mishchenko, Robert Brayton, Jie-Hong Roland Jiang, Stephen Jang
Venue: Proceeding of the ACM/SIGDA international symposium on Field programmable gate arrays (2009)

We describe an optimization method for combinational and sequential logic networks, with emphasis on scalability and the scope of optimization. The proposed resynthesis (a) is capable of substantial logic restructuring, (b) is customizable to solve a variety of optimization tasks, and (c) has reasonable runtime on industrial designs. The approach uses don't cares computed for a window surrounding a node and can take into account external don't cares (e.g. unreachable states). It uses a SAT solver and interpolation to find a new representation for a node. This representation can be in terms of inputs from other nodes in the window thus effecting Boolean re-substitution. Experimental results on 6-input LUT networks after high effort synthesis show substantial reductions in area and delay. When applied to 20 large academic benchmarks, the LUT count and logic level is reduced by 45.0% and 12.2%, respectively. The longest runtime for synthesis and mapping is about two minutes. When applied to a set of 14 industrial benchmarks ranging up to 83K 6-LUTs, the LUT count and logic level is reduced by 11.8% and 16.5%, respectively. Experimental results on 6-input LUT networks after high-effort synthesis show substantial reductions in area and delay. The longest runtime is about 30 minutes.
Merging element fuzzy cognitive maps
Authors: Xiangfeng Luo, Yi Du, Fangfang Liu, Zhian Yu, Weimin Xu
Venue: Proceedings of the 3rd International Conference on Ubiquitous Information Management and Communication (2009)

Importance degree and difference degree of keywords in different topics have been computed by the weights in Element Fuzzy Cognitive Maps (E-FCMs). Logic "and" operation is introduced to roughly evaluate the similarities between mass E-FCMs in order to form similar communities of E-FCMs. Based on the weights computing and the logic "and" operation, an E-FCMs-based knowledge merging algorithm is proposed to inspect the noisy and the redundancy information hidden in the original E-FCMs belonging to one similar community. Shannon entropy is employed as an indicator to measure the loss of textual information during the merging process of E-FCMs. The merging algorithm and the indicator provide a concise representation of text knowledge that can be used in understanding-based text automatic classification and clustering, as well as relevant knowledge aggregation and integration. The proposed algorithm has very good application prospects in the fields of e-Science knowledge gird and e-Learning.
Consistency in a Chaotic Spiking Oscillator
Authors: Tomohiro Inagaki, Toshimichi Saito
Venue: IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences (2008)

This letter studies response of a chaotic spiking oscillator to chaotic spike-train inputs. The circuit can exhibits a variety of synchronous/asynchronous phenomena and we show an interesting phenomenon “consistency”: the circuit can exhibit random response that is identical in steady steady state for various initial values. Presenting a simple test circuit, the consistency is confirmed experimentally.
Proceedings of the 2nd India software engineering conference
Venue: India Software Engineering Conference (2009)

Welcome to the 2nd India Software Engineering Conference (ISEC 2009). This conference series was started by the Special Interest Group on Software Engineering of the Computer Society of India, and is intended to be the flagship conference in Software Engineering out of India. The first ISEC was held in Hyderabad. The response to the ISEC has been tremendous both in terms of submissions (both times we received about 100 submissions), and in terms of participation (we had over 100 participants in ISEC 2008). In ISEC 2009, there were 120 submissions, with authors from 16 countries. Out of these we accepted 11 full papers, 6 experience reports and 10 posters. The accepted papers have authors from 10 countries. In ISEC2009, we will have one keynote from a world known Software Engineering researcher. We are proud to have Prof. David Rosenblum as this keynote speaker. We will also have one IT-industry leader from India as the second keynote speaker. We are proud to have Mr. Vijayakumar Ivaturi, CTO of Wipro, as this keynote speaker. Besides these keynotes, in partnership with SIGSOFT of ACM, ISEC2009 we also have two of the best papers from ICSE2008 and two from FSE2008 presented as invited talks. These papers won the "ACM-Sigsoft distinguished paper award" respectively, for ICSE2008 and FSE2008. The presence of these sessions will help ensure that top work in the field of software engineering is presented in ISEC. We have one day of workshops after the conference, and one day of tutorials before the conference. There was a huge response to "call for tutorials" as well, and we selected 4 half day tutorials, most of which are industry oriented. Overall, we believe that we have a very interesting program for the attendees. We sincerely hope that you will find the program enjoyable and exciting.
DDoS-shield: DDoS-resilient scheduling to counter application layer attacks
Authors: Supranamaya Ranjan, Ram Swaminathan, Mustafa Uysal, Antonio Nucci, Edward Knightly
Venue: IEEE/ACM Transactions on Networking (TON) (2009)

Countering distributed denial of service (DDoS) attacks is becoming ever more challenging with the vast resources and techniques increasingly available to attackers. In this paper, we consider sophisticated attacks that are protocol-compliant, non-intrusive, and utilize legitimate application-layer requests to overwhelm system resources. We characterize application-layer resource attacks as either request flooding, asymmetric, or repeated one-shot, on the basis of the application workload parameters that they exploit. To protect servers from these attacks, we propose a counter-mechanism namely DDoS Shield that consists of a suspicion assignment mechanism and a DDoS-resilient scheduler. In contrast to prior work, our suspicion mechanism assigns a continuous value as opposed to a binary measure to each client session, and the scheduler utilizes these values to determine if and when to schedule a session's requests. Using testbed experiments on a web application, we demonstrate the potency of these resource attacks and evaluate the efficacy of our counter-mechanism. For instance, we mount an asymmetric attack which overwhelms the server resources, increasing the response time of legitimate clients from 0.3 seconds to 40 seconds. Under the same attack scenario, DDoS Shield improves the victims' performance to 1.5 seconds.
Compiling Techniques for Coarse Grained Runtime Reconfigurable Architectures
Authors: Mythri Alle, Keshavan Varadarajan, Alexander Fell, S. K. Nandy, Ranjani Narayan
Venue: Proceedings of the 5th International Workshop on Reconfigurable Computing: Architectures, Tools and Applications (2009)

In this paper we develop compilation techniques for the realization of applications described in a High Level Language (HLL) onto a Runtime Reconfigurable Architecture. The compiler determines Hyper Operations (HyperOps) that are subgraphs of a data flow graph (of an application) and comprise elementary operations that have strong producer-consumer relationship. These HyperOps are hosted on computation structures that are provisioned on demand at runtime. We also report compiler optimizations that collectively reduce the overheads of data-driven computations in runtime reconfigurable architectures. On an average, HyperOps offer a 44% reduction in total execution time and a 18% reduction in management overheads as compared to using basic blocks as coarse grained operations. We show that HyperOps formed using our compiler are suitable to support data flow software pipelining.
Design of a hybrid adaptive CMAC with supervisory controller for a class of nonlinear system
Authors: Hung-Ching Lu, Chih-Ying Chuang, Ming-Feng Yeh
Venue: Neurocomputing (2009)

This paper attempts to propose a hybrid adaptive cerebellar model articulation controller (CMAC) sliding mode control (SMC; called HAC-SMC) with a supervisory controller for a class of nonlinear system, in which the HAC composed of a direct adaptive CMAC and an indirect adaptive CMAC control is performed as the SMC. There are two methods to design the switching control law of SMC. One is the sign switching controller. The other is the CMAC switching controller. Besides, a supervisory controller is appended to the HAC-SMC to guarantee the states staying in the boundary layer. The adaptive laws of the control system are derived in the sense of Lyapunov theorem so that the asymptotic stability of the system could be guaranteed. Simulation results show that the proposed control system has satisfactory performance on the inverted pendulum system and the Chua's chaotic circuit.
Simulation
Authors: Lance A. Leventhal
Venue: Proceedings of the May 19-22, 1980, national computer conference (1980)

Simulation is one of the oldest application areas for computers. Traditional users of simulation include the aerospace, military/defense, process control, industrial control, and energy industries. Newer users of simulation include corporate management, private and governmental planning agencies, and small businessmen. The NCC sessions describe advances in traditional areas such as process control as well as new applications such as the modeling of computer software, decision support systems for business management, futures planning, and small business decisionmaking. A particularly significant growth area is the use of simulation to explore the effects of decisions and alternative futures. This area is represented by sessions on decision support systems, cross-impact models, and small business applications. 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