ppxscal/embedding_network huggingface dataset:
A Fast Vessel Centerline Extraction Algorithm for Catheter Simulation
Authors: Jan Egger, Zvonimir Mostarkic, Stefan Grosskopf, Bernd Freisleben
Venue: Proceedings of the Twentieth IEEE International Symposium on Computer-Based Medical Systems (2007)

In this paper, we present a fast and robust algorithm for centerline extraction in blood vessels. The algorithm is suitable for catheter simulation in CT data of blood vessels. It creates an initial centerline based on two user-defined points (start- and endpoint). For curved vessel structures, this initial centerline is computed by Dijkstra's shortest path algorithm. For linear vessel structures, the algorithm directly connects the start- and the endpoint to get the initial centerline. Thereafter, this initial path will be aligned in the blood vessel, resulting in the vessels centerline (i.e. an optimal catheter simulation path). The alignment is done by an active contour model combined with polyhedra placed along it. Results of the proposed centerline algorithm are demonstrated for CTA with variations in anatomy and location of pathology.
RB-T2 Path Planning Robot
Authors: Oscar J. Flores Villa, Gabriela Guerra Galan, Kathya J. Alvarado Montejo, Joaquin Loaiza Martinez, Raul I. Fernandez Mulia
Venue: Proceedings of the 17th International Conference on Electronics, Communications and Computers (2007)

In this paper the design and construction of a mobile robot for path planning is described. This robot is able to reach a specific point by processing the information of an image taken by an eye in the sky-like camera. The path is generated by a computer program that determines the shortest path considering the obstacle-free space from the start point to the goal. This information is encoded into commands for the motors in the robot and transmitted to the vehicle via RF. For future projects the computer algorithm should provide feedback in real time so moving obstacles can be avoided.
Making system configuration more declarative
Authors: John DeTreville
Venue: Proceedings of the 10th conference on Hot Topics in Operating Systems - Volume 10 (2005)

System administration can be difficult and painstaking work, yet individual users must typically administer their own personal systems. These personal systems are therefore likely to be misconfigured, undependable, brittle, and insecure, which restricts their wider adoption. Because updating the configuration of today's systems involve imperative updates in place, a system's correctness ultimately depends on the correctness of every install and uninstall it has ever performed; because these updates are local in scope, there is no easy way to specify or check desired properties for the whole system. We present a more checkable declarative approach to system configuration that should improve system integrity and make systems more dependable. As in the earlier Vesta system, we define a system model as a function that we can apply to a collection of system parameters to produce a statically typed, fully configured system instance; models can reference and thereby incorporate submodels, including submodels exported by each program in the system. We further check each system instance against established system policies that can express a variety of additional ad hoc rules defining which system instances are acceptable. Some system policies are expressible using additional type rules, while others must operate outside the type system. A preliminary design and implementation of this approach are under way for the Singularity OS, and we hope to specify and check a number of ad hoc system properties for Singularity-based personal systems.
Fast implementation of two-dimensional APES and CAPON spectral estimators
Authors: E. G. Larsson
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 2001. on IEEE International Conference - Volume 05 (2001)

The matched-filterbank spectral estimators APES and CAPON have received considerable attention in a number of applications. Unfortunately, their computational complexity tends to limit their usage in several cases-a problem that has previously been addressed by different authors. In this paper, we introduce a novel method to the computation of the 1D and 2D APES and CAPON spectra, which is considerably faster than all existing techniques. Numerical examples are provided to demonstrate the application of APES to synthetic aperture radar (SAR) imaging, and to illustrate the reduction in computational complexity provided by our implementation.
Modular and efficient resource management in the exedra media server
Authors: Stergios V. Anastasiadis, Kenneth C. Sevcik, Michael Stumm
Venue: Proceedings of the 3rd conference on USENIX Symposium on Internet Technologies and Systems - Volume 3 (2001)

Explosive growth in online services has recently renewed the interest for building modular and efficient network server systems. System design complications coupled with excessive expectations from technological progress previously discouraged the development of media servers efficiently supporting video streams with variable bit rates. In this paper, we describe the design of a distributed media server architecture, and the implementation details of a prototype. Native support is provided for variable bit rate streams, by considering their special features in the resource management policies. We identify several problems, and propose new approaches for scheduling the playback requests, organizing the memory buffers, allocating the storage space, and structuring the disk metadata. We justify several of our decisions with comparative performance measurements using both synthetic benchmarks and actual experiments with variable bit rate MPEG-2 streams over SCSI disks.
Distinctive feature detection using support vector machines
Authors: P. Niyogi
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 1999. on 1999 IEEE International Conference - Volume 01 (1999)

An important aspect of distinctive feature based approaches to automatic speech recognition is the formulation of a framework for robust detection of these features. We discuss the application of the support vector machines (SVM) that arise when the structural risk minimization principle is applied to such feature detection problems. In particular, we describe the problem of detecting stop consonants in continuous speech and discuss an SVM framework for detecting these sounds. In this paper we use both linear and nonlinear SVMs for stop detection and present experimental results to show that they perform better than a cepstral features based hidden Markov model (HMM) system, on the same task.
Application of time-frequency analysis for optimum non-equidistant sampling of automotive signals captured at knock
Authors: D. Konig
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 1996. on Conference Proceedings., 1996 IEEE International Conference - Volume 05 (1996)

The optimization of modern car engines includes knock control. Knocking combustions are characterized by high frequency resonances of the burnt gas in the combustion chamber. Knock detection is usually based on the estimated resonance energies of pressure or vibration signals. Unfortunately, the resonance frequencies vary with the crank angle. Optimum estimation of resonance energies can therefore be achieved by time varying filtering. Alternatively, optimized non-equidistant sampling leads to resonances with approximately constant frequencies in the discrete time domain. This paper addresses the second approach. A parametric model for the frequency modulation is used and the paper describes a method based on Wigner-Ville analysis to obtain parameter estimates for optimum non-equidistant sampling. Real data experiments demonstrate the usefulness of this approach.
Low-complexity linear group-SIC detectors: Research Articles
Authors: A. Bentrcia, A. Zerguine, A. U. Sheikh
Venue: Wireless Communications Mobile Computing (2007)

In this paper, we consider a linear group polynomial expansion successive interference cancellation (GPE-SIC) detector in a synchronous CDMA system. It is a hybrid detector, which combines parallel and successive cancellation techniques in order to extract the advantages of both schemes. We use the fact that even if the cross-correlation matrix of the system is not diagonal dominant, the sub-matrices corresponding to different groups can be forced to be diagonal dominant by suitable grouping of users to approximate the decorrelator&#x002F;MMSE detector by a low-complexity polynomial expansion detector. The latter is computationally very efficient if the cross-correlation matrix of users within the same group is diagonal dominant. Simulation results showed that the (GPE-SIC) detector has the same performance as the linear group decorrelator successive interference cancellation (GDEC-SIC) detector but with low-computational complexity. Copyright &copy; 2006 John Wiley & Sons, Ltd.
Power Aware Scheduling of Bag-of-Tasks Applications with Deadline Constraints on DVS-enabled Clusters
Authors: Kyong Hoon Kim, Rajkumar Buyya, Jong Kim
Venue: Proceedings of the Seventh IEEE International Symposium on Cluster Computing and the Grid (2007)

Power-aware scheduling problem has been a recent issue in cluster systems not only for operational cost due to electricity cost, but also for system reliability. As recent commodity processors support multiple operating points under various supply voltage levels, Dynamic Voltage Scaling (DVS) scheduling algorithms can reduce power consumption by controlling appropriate voltage levels. In this paper, we provide power-aware scheduling algorithms for bagof- tasks applications with deadline constraints on DVSenabled cluster systems in order to minimize power consumption as well as to meet the deadlines specified by application users. A bag-of-tasks application should finish all the sub-tasks before the deadline, so that the DVS scheduling scheme should consider the deadline as well. We provide the DVS scheduling algorithms for both time-shared and space-shared resource sharing policies. The simulation results show that the proposed algorithms reduce much power consumption compared to static voltage schemes.
Computing Properties of Materials Based on the Ginzburg-Landau Equation
Authors: Ehsan Nedaaee Oskoee
Venue: Computing in Science and Engineering (2007)

The Ginzburg-Landau equation has many applications, but it has no analytical solution, and thus must be solved numerically. When combined with other equations to model very complex phenomena, the solution requires advanced computational techniques.
Voiceless speech recognition using dynamic visual speech features
Authors: Wai Chee Yau, Dinesh Kant Kumar, Sridhar Poosapadi Arjunan
Venue: Proceedings of the HCSNet workshop on Use of vision in human-computer interaction - Volume 56 (2006)

This paper describes a voiceless speech recognition technique that utilizes dynamic visual features to represent the facial movements during phonation. The dynamic features extracted from the mouth video are used to classify utterances without using the acoustic data. The audio signals of consonants are more confusing than vowels and the facial movements involved in pronunciation of consonants are more discernible. Thus, this paper focuses on identifying consonants using visual information. This paper adopts a visual speech model that categorizes utterances into sequences of smallest visually distinguishable units known as visemes. The viseme model used is based on the viseme model of Moving Picture Experts Group 4 (MPEG-4) standard. The facial movements are segmented from the video data using motion history images (MHI). MHI is a spatio-temporal template (grayscale image) generated from the video data using accumulative image subtraction technique. The proposed approach combines discrete stationary wavelet transform (SWT) and Zernike moments to extract rotation invariant features from the MHI. A feed forward multilayer perceptron (MLP) neural network is used to classify the features based on the patterns of visible facial movements. The preliminary experimental results indicate that the proposed technique is suitable for recognition of English consonants.
A Privacy Enhancing Service Architecture for Ticket-based Mobile Applications
Authors: Oliver Jorns, Oliver Jung, Gerald Quirchmayr
Venue: Proceedings of the The Second International Conference on Availability, Reliability and Security (2007)

Network operators gradually open their interfaces to formerly hidden services. This fosters the development of a new class of mobile applications that take into account user's location and presence information. However, this development also raises problems especially the lack of protection of privacy in location-based services. This paper proposes a service architecture that is aimed at overcoming some of the shortages of currently existing context-aware applications that make use of network providers services as well as existing mobile payment systems. We therefore introduce the combination of tickets together with a novel privacy enhancing mechanism that is based on the notion of pseudonyms. Compared to other privacy enhancing solutions our pseudonym mechanism can also be implemented on mobile devices that have some restrictions regarding resources like memory or processing power. Due to their flexibility tickets can be used for many different kinds of applications. One important aspect in this respect is the highly postulated pay-as-you-go model. We give an example of a transport ticket application and explain the message interaction patterns for the basic functionalities of the systems, regarding aspects like data and privacy protection. This example further shows how 3rd party application providers can build meaningful mobile applications that are accepted by users.
A Practical Algorithm for Planar Straight-line Grid Drawings of General Trees with Linear Area and Arbitrary Aspect Ratio
Authors: Adrian Rusu, Confesor Santiago
Venue: Proceedings of the 11th International Conference Information Visualization (2007)

Trees are usually drawn using planar straight-line drawings. [2] presented an algorithm for constructing a planar straight-line grid drawing of a degree-d(general) tree with area O(n)and any pre-specified aspect ratio in the rangewhere 0 \le1is any constant, in O(logn)time. Unfortunately, the algorithm of [2] is not suitable for practical use. The main problem is that the constant hidden in the notation for area is quite large (for binary trees was 3900). In this paper, we have made several improvements to the algorithm, which make it suitable for practical use. We have also conducted an experiment on this newer version of the algorithm for randomly-generated general trees with up to 50,000 nodes. Our experiment shows that it constructs area-efficient drawings in practice, with area at most 19 times the number of nodes.
Designing voting machines for verification
Authors: Naveen Sastry, Tadayoshi Kohno, David Wagner
Venue: Proceedings of the 15th conference on USENIX Security Symposium - Volume 15 (2006)

We provide techniques to help vendors, independent testing agencies, and others verify critical security properties in direct recording electronic (DRE) voting machines. We rely on specific hardware functionality, isolation, and architectural decision to allow one to easily verify these critical security properties; we believe our techniques will help us verify other properties as well. Verification of these security properties is one step towards a fully verified voting machine, and helps the public gain confidence in a critical tool for democracy. We present a voting system design and discuss our experience building a prototype implementation based on the design in Java and C.
A User Friendly Toolkit for Building Robust Environmental Sensor Networks
Authors: John-Paul Arp, Bradford G. Nickerson
Venue: Proceedings of the Fifth Annual Conference on Communication Networks and Services Research (2007)

Wireless sensor network research is growing rapidly, but building and deploying real-world wireless sensor network applications still requires the assistance of technology experts. We present a user friendly toolkit that simplifies the process of building robust and extensible wireless sensor networks, with our first target application being long-term environmental sensor networks. This project includes a programing language called the Sensor Web Language (SWL), an Eclipse-based graphical user interface for writing SWL programs, and a compiler for generating a complete stack of deployable sensor network code. Currently we target Mica2 andMica2dotmotes,MDA300 sensor boards, Linuxbased servers for base stations, Java clients, and gateways using embedded Linux and cellular network modems.
Shadow Profiling: Hiding Instrumentation Costs with Parallelism
Authors: Tipp Moseley, Alex Shye, Vijay Janapa Reddi, Dirk Grunwald, Ramesh Peri
Venue: Proceedings of the International Symposium on Code Generation and Optimization (2007)

In profiling, a tradeoff exists between information and overhead. For example, hardware-sampling profilers incur negligible overhead, but the information they collect is consequently very coarse. Other profilers use instrumentation tools to gather temporal traces such as path profiles and hot memory streams, but they have high overhead. Runtime and feedback-directed compilation systems need detailed information to aggressively optimize, but the cost of gathering profiles can outweigh the benefits. Shadow profiling is a novel method for sampling long traces of instrumented code in parallel with normal execution, taking advantage of the trend of increasing numbers of cores. Each instrumented sample can be many millions of instructions in length. The primary goal is to incur negligible overhead, yet attain profile information that is nearly as accurate as a perfect profile. The profiler requires no modifications to the operating system or hardware, and is tunable to allow for greater coverage or lower overhead. We evaluate the performance and accuracy of this new profiling technique for two common types of instrumentation-based profiles: interprocedural path profiling and value profiling. Overall, profiles collected using the shadow profiling framework are 94% accurate versus perfect value profiles, while incurring less than 1% overhead. Consequently, this technique increases the viability of dynamic and continuous optimization systems by hiding the high overhead of instrumentation and enabling the online collection of many types of profiles that were previously too costly.
Number Jigsaw Puzzle: A Mathematical Puzzle Game for Facilitating Players' Problem-Solving Strategies
Authors: Owen W. S. Huang, Hercy N. H. Cheng, Tak-Wai Chan
Venue: Proceedings of the The First IEEE International Workshop on Digital Game and Intelligent Toy Enhanced Learning (2007)

Puzzles can be regarded as problem-solving games, in which players have to solve the obstacle they confront. Solving puzzles helps players to foster logical thinking and to facilitate problem-solving strategies. In this paper, we base on four puzzle games, Magic Square, Jigsaw Puzzle, Sudoku, and Kakuro, and then we design a number puzzle game, called Number Jigsaw Puzzle (NJP). In solving NJP, players could construct their problem-solving strategies according to their previous knowledge. A pilot study was conducted to investigate what strategies the players would use in solving NJP. The result shows that the five different strategies had been found in the pilot study.
Scheme for Reducing the Storage Requirements of FFT Twiddle Factors on FPGAs
Authors: T. Sansaloni, A. Pérez-Pascual, V. Torres, J. Valls
Venue: Journal of VLSI Signal Processing Systems (2007)

A scheme for reducing the hardware resources to implement on LUT-based FPGA devices the twiddle factors required in Fast Fourier Transform (FFT) processors is presented. The proposed scheme reduces the number of embedded block RAM for large FFTs and the number of slices for FFT lengths higher than 128 points. Results are given for Xilinx devices, but they can be generalized for other advanced LUT-based devices like ALTERA Stratix.
Decentralized, adaptive resource allocation for sensor networks
Authors: Geoffrey Mainland, David C. Parkes, Matt Welsh
Venue: Proceedings of the 2nd conference on Symposium on Networked Systems Design & Implementation - Volume 2 (2005)

This paper addresses the problem of resource allocation in sensor networks. We are concerned with how to allocate limited energy, radio bandwidth, and other resources to maximize the value of each node's contribution to the network. Sensor networks present a novel resource allocation challenge: given extremely limited resources, varying node capabilities, and changing network conditions, how can one achieve efficient global behavior? Currently, this is accomplished by carefully tuning the behavior of the low-level sensor program to accomplish some global task, such as distributed event detection or in-network data aggregation. This manual tuning is difficult, error-prone, and typically does not consider network dynamics such as energy depletion caused by bursty communication patterns. We present Self-Organizing Resource Allocation (SORA), a new approach for achieving efficient resource allocation in sensor networks. Rather than manually tuning sensor resource usage, SORA defines a virtual market in which nodes sell goods (such as sensor readings or data aggregates) in response to prices that are established by the programmer. Nodes take actions to maximize their profit, subject to energy budget constraints. Nodes individually adapt their operation over time in response to feedback from payments, using reinforcement learning. The behavior of the network is determined by the price for each good, rather than by directly specifying local node programs. SORA provides a useful set of primitives for controlling the aggregate behavior of sensor networks despite variance of individual nodes. We present the SORA paradigm and a sensor network vehicle tracking application based on this design, as well as an extensive evaluation demonstrating that SORA realizes an efficient allocation of network resources that adapts to changing network conditions.
Applying Location-Aware Linkcell-Based Data Management to Context-Aware Mobile Business Services
Authors: James E. Wyse
Venue: Proceedings of the International Conference on the Management of Mobile Business (2007)

Providing location-aware services to mobile users comes with an inherent service-degrading data management problem for which the location-aware linkcell-based data management method was developed as a solution. Context-aware services are often viewed as generalizations of location-aware services; thus, many context-aware application systems necessarily inherit the data management problems associated with any subsumed location-aware subsystems. Despite their potential to solve these problems, linkcell-based methods have not been previously examined for use in context-aware applications. This article explores how linkcell-based methods may be incorporated into context-aware applications to support the provision of context-aware services to mobile business users. The article begins by reviewing the essentials of linkcell-based data management. Next it decomposes a prototypical context-aware system into its essential components and then contemplates how the linkcell method may be reformulated to support the data management requirements associated with providing context-aware mobile business services.