ppxscal/embedding_network huggingface dataset:
VPC prediction: reducing the cost of indirect branches via hardware-based dynamic devirtualization
Authors: Hyesoon Kim, José A. Joao, Onur Mutlu, Chang Joo Lee, Yale N. Patt, Robert Cohn
Venue: Proceedings of the 34th annual international symposium on Computer architecture (2007)

Indirect branches have become increasingly common in modular programs written in modern object-oriented languages and virtual machine based runtime systems. Unfortunately, the prediction accuracy of indirect branches has not improved as much as that of conditional branches. Furthermore, previously proposed indirect branch predictors usually require a significant amount of extra hardware storage and complexity, which makes them less attractive to implement. This paper proposes a new technique for handling indirect branches, called Virtual Program Counter (VPC) prediction. The key idea of VPC prediction is to treat a single indirect branch as multiple virtual conditional branches in hardware for prediction purposes. Our technique predicts each of the virtual conditional branches using the existing conditional branch prediction hardware. Thus, no separate storage structure is required for predicting indirect branch targets. Our evaluation shows that VPC prediction improves average performance by 26.7% compared to a commonly-used branch target buffer based predictor on 12 indirect branch intensive applications. VPC prediction achieves the performance improvement provided by at least a 12KB (and usually a 192KB) tagged target cache predictor on half of the examined applications. We show that VPC prediction can be used with any existing conditional branch prediction mechanism and that the accuracy of VPC prediction improves when a more accurate conditional branch predictor is used.
Approximating and exploiting the residual redundancies-applications to efficient reconstruction of speech over noisy channels
Authors: F. Lahouti
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 200. on IEEE International Conference - Volume 02 (2001)

Exploiting the residual redundancy in a source coder output stream during the decoding process has been proven to be a bandwidth efficient way to combat the noisy channel degradations. We consider soft reconstruction of LSF parameters in the IS-641 CELP coder transmitted over a noisy channel. We propose two schemes. The first scheme attempts to exploit the interframe residual redundancies in the sequence of received parameters. The second approach exploits both interframe and intraframe residual redundancies. Simulation results are provided which demonstrates the efficiency of the algorithms. Another issue addressed here, is a methodology to efficiently approximate and store the residual redundancies or the a priori transition probabilities. For quantizers with high rates calculating these probabilities require a huge number of source samples, and storing them also require a large amount of memory. These issues can well make the decoder design process an impractical task. The proposed method is based on the classification of the signal domain. The presented schemes provide high quality error concealment solutions for CELP coders.
Waveform encoding of binary signals using a wavelet and its Hilbert transform
Authors: E. Ozturk
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 2000. on IEEE International Conference - Volume 05 (2000)

Orthogonal wavelets have been applied to communications since the early 90s. We prove that the Hilbert transform of a wavelet is orthogonal to its time shifts and it is also orthogonal to the corresponding wavelet and its time shifts. On the other hand, since the Hilbert transform only shifts the phase of the wavelet function by 90-degree, the magnitude spectrums of the wavelet and its transform are the same. Therefore they are located on the same frequency band. In order to utilize the above properties, we propose to use the wavelet and its Hilbert transform for waveform encoding of data bits. With this, we are able to double the bit rate without increasing the bandwidth or affecting the bit error rate (BER). Daubechies (1992) wavelets are used in the analyses of the proposed system.
A Group-Based Dynamic Key Management Scheme in Wireless Sensor Networks
Authors: Guorui Li, Jingsha He, Yingfang Fu
Venue: Proceedings of the 21st International Conference on Advanced Information Networking and Applications Workshops - Volume 02 (2007)

Sensor networks are widely used in a variety of commercial and military applications. As a fundamental requirement for providing security functionality in sensor networks, key management plays an essential role in authentication and encryption. In this paper, we propose a group-based dynamic key management scheme in wireless sensor networks. In our scheme, there is no requirement for such infrastructure as base stations and cluster heads and the dynamic key update feature ensures the security of the network without tampering the compromised sensor nodes. We also analyze the connectivity and security of the proposed scheme.
Configurable Error Control Scheme for NoC Signal Integrity
Authors: Daniele Rossi, Paolo Angelini, Cecilia Metra
Venue: Proceedings of the 13th IEEE International On-Line Testing Symposium (2007)

In this paper we propose a novel error control scheme to cope with errors affecting the communication links of a NoC. Our scheme can be configured in Correction Mode, Detection Mode, and Mixed Mode, depending on the particular application, thus allowing to meet different Quality of Service (QoS) levels in terms of error control. For each configuration mode, we propose different error control policies and we consider SEC Hamming codes, SEC/DED Hsiao codes, and Symbol Error Correcting codes. We evaluate advantages and drawbacks of each approach, in terms of signal integrity, area overhead and impact on performance.
A Capstone Design Experience in Architectural Engineering Technology
Authors: D. Davis
Venue: Proceedings of the Frontiers in Education Conference, 2001. 31st Annual - Volume 02 (2001)

At the University of Hartford, we have developed a "Capstone Design Experience" in an effort to improve our Architectural Engineering Technology curriculum. By increasing the awareness of the interrelationships between different areas of study, we are attempting to strike a new balance. We have integrated the following into a single year-long design project: research, programming, planning, history and theory, design, model making, drawing, CAD (computer aided design), structures, environmental systems, presentations and writing. Our capstone program provides opportunities for exploration, questioning, testing, and criticism. It requires the students to use experience and knowledge gained in other courses and forces them to play an active role in their own learning. It demands personal accountability for decisions, and commitment to ideas and proposals that are scrutinized publicly. We believe that we have developed a model that other disciplines on campus could well profit from observing.
Multiple hypothesis testing for time-varying nonlinear system identification
Authors: M. Green
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 2000. on IEEE International Conference - Volume 01 (2000)

In this paper we consider the identification of a time-varying quadratic Volterra model. In the model, a set of known basis sequences are used to approximate the time-variation of the true system to enable identification. To reduce the number of parameters in the model we wish to determine which sequences can be considered significant in this approximation. The Bonferroni multiple hypothesis testing procedure is used for the selection of individual basis sequences to include in the model. This is compared with treating the multiple hypotheses separately. Not only does the Bonferroni procedure allow strong control over the false alarm but has more power when selecting the true model in low noise.
Understanding Instant Messaging Traffic Characteristics
Authors: Zhen Xiao, Lei Guo, John Tracey
Venue: Proceedings of the 27th International Conference on Distributed Computing Systems (2007)

Instant messaging (IM) has become increasingly popular due to its quick response time, its ease of use, and possibility of multitasking. It is estimated that there are several millions of instant messaging users who use IM for various purposes: simple requests and responses, scheduling face to face meetings, or just to check the availability of colleagues and friends. Despite its popularity and user base, little has been done to characterize IM traffic. One reason might be its relatively small traffic volume, although this is changing as more users start using video or voice chats and file attachments. Moreover, all major instant messaging systems route text messages through central servers. While this facilitates firewall traversal and gives instant messaging companies more control, it creates a potential bottleneck at the instant messaging servers. This is especially so for large instant messaging operators with tens of millions of users and during flash crowd events. Another reason for the lack of previous studies is the difficulty in getting access to instant messaging traces due to privacy concerns. In this paper, we analyze the traffic of two popular instant messaging systems, AOL Instant Messenger (AIM) and MSN/Windows Live Messenger, from thousands of employees in a large enterprise. We found that most instant messaging traffic is due to presence, hints, or other extraneous traffic. Chat messages constitute only a small percentage of the total IM traffic. This means, during overload, IM servers can protect the instantaneous nature of the communication by dropping extraneous traffic. We also found that the social network of IM users does not follow a power law distribution. It can be characterized by a Weibull distribution. Our analysis sheds light on instant messaging system design and optimization and provides a scientific basis for instant messaging workload generation.
Congestion Management in MINs through Marked and Validated Packets
Authors: Joan-LLuis Ferrer, Elvira Baydal, Antonio Robles, Pedro Lopez, Jose Duato
Venue: Proceedings of the 15th Euromicro International Conference on Parallel, Distributed and Network-Based Processing (2007)

Congestion management is a very critical problem tackled in interconnection networks for years but not solved yet. Although several mechanisms have been recently proposed for lossless Multistage Interconnection Networks (MINs), they either have drawbacks or are partial solutions. Some of them introduce penalty over packets not really addressed to the hot-spots, whereas others can cope only with congestion situations that last a short time. In this paper, we propose an effective and efficient congestion management mechanism for lossless interconnection networks based on explicit congestion notification. The mechanism uses two different flags in ACK packets, a Marking Bit (MB) and a Validation Bit (VB), to detect congestion and warn the origin hosts. In this way, packets belonging to "cold flows" but stopped because of head-of-line (HOL) blocking can be distinguished from "hot flow" packets which are really causing congestion. In response, origin hosts can apply corrective actions only to the "hot flows", minimizing the negative impact on "cold flows" performance. Evaluation results show that the proposed congestion management strategy is able to avoid the degradation of network performance, regardless of traffic load and the location of the congestion in the network.
A 3-query PCP over integers
Authors: Venkatesan Guruswami, Prasad Raghavendra
Venue: Proceedings of the thirty-ninth annual ACM symposium on Theory of computing (2007)

A classic result due to Haastad~hastad established that for every constant ε > 0, given an overdetermined system of linear equations over a finite field Fq where each equation depends on exactly 3 variables and at least a fraction (1-ε) of the equations can be satisfied, it is NP-hard to satisfy even a fraction (1/q+ε) of the equations. In this work, we prove the analog of Håstad's result for equations over the integers (as well as the reals). Formally, we prove that for every ε,δ > 0, given a system of linear equations with integer coefficients where each equation is on 3 variables, it is NP-hard to distinguish between the following two cases: (i) There is an assignment of integer values to the variables that satisfies at least a fraction (1-ε) of the equations, and (ii) No assignmenteven of real values to the variables satisfies more than a fraction δ of the equations.
Proceedings of the 2nd workshop on Workflows in support of large-scale science
Venue: High Performance Distributed Computing (2007)

Welcome to the 2nd Workshop on Workflows in Support of Large-Scale Science (WORKS'07). Since the 1st WORKS workshop, there has been a growing interest in the workflow technologies and workflows are still considered a key technology to enable large-scale science applications. Workflows enable scientists to design complex applications that are composed of individual application components or services. Often times these components and services are designed, developed, and tested collaboratively. Because of the size of the data and the complexity of the analysis, large amounts of shared resources such as clusters and storage systems are being used to store the data sets and execute the workflows. The process of workflow design and execution in a distributed environment can be very complex and involve mapping high-level workflow descriptions onto the available resources, as well as monitoring and debugging of the subsequent execution. Because computations and data access operations are performed on shared resources, there is an increased interest in managing the fair allocation and management of those resources at the workflow level. Adequate workflow descriptions are needed to support the complex workflow management process that includes workflow creation, reuse, and modifications made to the workflow over time---for example modifications to the individual components. Additional annotations may provide guidelines and requirements for resource mapping and execution. Large-scale scientific applications impose requirements on the workflow systems. Besides the magnitude of data processed by the workflow components, the resulting and intermediate data need to be annotated with provenance information and any other information needed to evaluate the quality of the data and support the repeatability of the analysis. The Workshop on Workflows in Support of Large-Scale Science focuses on the entire workflow lifecycle including the workflow composition, mapping, and robust execution, as well as workflow applications. During the 2nd WORKS meeting, papers spanning a range of workflow topics will be presented. Among them are: real-time workflow systems, graphical workflow composition, distributed workflow caching in P2P environments, workflow automation, workflow-based applications and semantic authoring tools.
Discover knowledge from distribution maps using Bayesian networks
Authors: Norazwin Buang, Nianjun Liu, Terry Caelli, Rob Lesslie, Michael J. Hill
Venue: Proceedings of the fifth Australasian conference on Data mining and analystics - Volume 61 (2006)

This paper applies a Bayesian network to model multi criteria distribution maps and to discover knowledge contained in spatial data. The procedure consists of three steps: pre processing map data, training the Bayesian Network model using distribution maps of Australia and testing the generalization and diagnosis of the model using individual states' maps. The Bayesian network that we used in this study is known as na&iuml;ve Bayesian network. Results show that this environmental Bayesian network model can generalize the classification rules from training data for good prediction and diagnosis of a distribution map.
Java visual debugger
Authors: Ali Rafieymehr, Richard McKeever
Venue: ACM SIGCSE Bulletin (2007)

We have developed a visual debugger for Java programs (JVD) that makes use of smooth continuous graphical animation and runtime state history retention to display program state during execution, in order to consider the viability of this approach in the context of both software engineering and computer science education.
Proving thread termination
Authors: Byron Cook, Andreas Podelski, Andrey Rybalchenko
Venue: Proceedings of the 2007 ACM SIGPLAN conference on Programming language design and implementation (2007)

Concurrent programs are often designed such that certain functions executing within critical threads must terminate. Examples of such cases can be found in operating systems, web servers, e-mail clients, etc. Unfortunately, no known automatic program termination prover supports a practical method of proving the termination of threads. In this paper we describe such a procedure. The procedure's scalability is achieved through the use of environment models that abstract away the surrounding threads. The procedure's accuracy is due to a novel method of incrementally constructing environment abstractions. Our method finds the conditions that a thread requires of its environment in order to establish termination by looking at the conditions necessary to prove that certain paths through the thread represent well-founded relations if executed in isolation of the other threads. The paper gives a description of experimental results using an implementation of our procedureon Windows device drivers and adescription of a previously unknown bug found withthe tool.
Simultaneous Motion and Structure Estimation by Fusion of Inertial and Vision Data
Authors: Peter Gemeiner, Peter Einramhof, Markus Vincze
Venue: International Journal of Robotics Research (2007)

For mobile robotics, head gear in augmented reality (AR) applications or computer vision, it is essential to continuously estimate the egomotion and the structure of the environment. This paper presents the system developed in the SmartTracking project, which simultaneously integrates visual and inertial sensors in a combined estimation scheme. The sparse structure estimation is based on the detection of corner features in the environment. From a single known starting position, the system can move into an unknown environment. The vision and inertial data are fused, and the performance of both Unscented Kalman filter and Extended Kalman filter are compared for this task. The filters are designed to handle asynchronous input from visual and inertial sensors, which typically operate at different and possibly varying rates. Additionally, a bank of Extended Kalman filters, one per corner feature, is used to estimate the position and the quality of structure points and to include them into the structure estimation process. The system is demonstrated on a mobile robot executing known motions, such that the estimation of the egomotion in an unknown environment can be compared to ground truth.
A Kalman filter based approach for estimating nonstationary VAR models via pole tracking
Authors: M. Elling
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 2000. on IEEE International Conference - Volume 02 (2000)

A time-varying vector autoregressive (VAR) model is used for the modeling of time series with changing spectral content. Our approach focuses on the model's time-varying poles. We show the relationship between the deviations in these poles and deviations in the VAR coefficients, which leads to a reparameterization of the model. The performance characteristics of the model are investigated by using simulation.
Nsync: a constraint based Toolkit for multimedia
Authors: Brian Bailey, Joseph A. Konstan
Venue: Proceedings of the 5th conference on Annual Tcl/Tk Workshop 1997 - Volume 5 (1997)

Nsync (pronounced 'in-sync') is a declarative multimedia synchronization toolkit, implemented entirely in Tcl, designed to ease the complexity of designing innovative, interactive multimedia applications. Nsync does not represent a new multimedia synchronization model; rather, it provides a set of building blocks in the form of temporal and non-temporal constraints useful for specifying both the synchronization and interaction properties of an application. Nsync depends only on the logical time system provided by the Berkeley Continuous Media Toolkit, thus allowing any application using a similar notion of time to also benefit from the Nsync constraint mechanism. Nsync presents a new and powerful environment for rapid development of highly interactive multimedia applications.
Multidisciplinary undergraduate mechatronic experiments
Authors: J. Mariappan
Venue: Proceedings of the 26th Annual Frontiers in Education - Volume 01 (1996)

Mechatronics is a relatively new field that represents the integration of mechanical, electronics engineering and computer technology for the design of products. With the availability of microprocessors at low cost, more and more products are becoming mechatronic in nature. Engineers faced with the task of developing mechatronic products must understand the principles of mechatronic design, which requires multidisciplinary knowledge. Therefore, it is necessary to develop and teach multi- and interdisciplinary courses that provide students with cross-platform skills and expertise to meet the rapidly changing needs of industry. Towards this end, an undergraduate mechatronics course has been developed at GMI. This course is heavily laboratory and project oriented. Several laboratory experiments and projects that are mechatronic in nature have been developed for this course, and this paper presents various issues associated with this course, and the development of undergraduate student experiments and projects in mechatronics at GMI. These projects provide a true multidisciplinary experience by integrating core mechanical engineering disciplines, basic electrical engineering and electronics engineering and computers.
Mixed H/sup 2//H/sup /spl infin// optimal signal reconstruction in noisy filter banks
Authors: H. Vikalo
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 2000. on IEEE International Conference - Volume 01 (2000)

We study the design of synthesis filters in noisy filter bank systems using an H/sup /spl infin// estimation point of view. The H/sup /spl infin// approach is most promising in situations where the statistical properties of the disturbances (arising from quantization, compression, etc.) in each subband of the filter bank are unknown, or are too difficult to model and analyze. For arbitrary analysis polyphase matrices, standard state-space H/sup /spl infin// techniques can be employed to obtain numerical solutions. When the synthesis filters are restricted to being FIR, as is often the case in practice, the design can be cast as a finite-dimensional semi-definite program. In this case, we can effectively exploit the inherent non-uniqueness of the H/sup /spl infin// solution to optimize for an additional average performance and thus obtain mixed H/sup 2//H/sup /spl infin// optimal FIR synthesis filters.
HapStick: A High Fidelity Haptic Simulation for Billiards
Authors: Venkatraghavan Gourishankar, Govindarajan Srimathveeravalli, Thenkurussi Kesavadas
Venue: Proceedings of the Second Joint EuroHaptics Conference and Symposium on Haptic Interfaces for Virtual Environment and Teleoperator Systems (2007)

This paper presents the work in developing a high fidelity haptic device and virtual environment for playing billiards. The haptic device features a natural user interface to simulate realistic play of billiards. The paper also discusses the physics behind the virtual reality game, the kinematics and dynamics of the force feedback device and finally an implementation of a computed torque control for providing haptic feedback. Complete information about calibration and comparative performance measures for the device has also been provided. The paper also aims to serve as a template for anyone who is interested in building their own beginner level haptic interface. Information regarding the device and the necessary code and blueprints has been uploaded on the lab's research website to facilitate the same.