ppxscal/embedding_network huggingface dataset:
Visualizing Graphs - A Generalized View
Authors: Hans-Jorg Schulz, Heidrun Schumann
Venue: Proceedings of the conference on Information Visualization (2006)

The visualization of graphs has proven to be very useful for exploring structures in different application domains. However, in certain fields of computer science, graph visualization is understood and focused quite differently. While "graph drawing" focuses on optimized layouts for nodelink- representations of networks, "information visualization" prefers to work on hierarchies focusing on very large structures, different views and interactivity. This paper gives a systematic view of the problem of graph visualization by combining both approaches. We will introduce a general view of different visualization methods as well as describe occurring problems and discuss basic constraints. These will be used to propose a visualization framework for graphs, whose development motivated this paper.
Real-Time Detection of Camera Tampering
Authors: Evan Ribnick, Stefan Atev, Osama Masoud, Nikolaos Papanikolopoulos, Richard Voyles
Venue: Proceedings of the IEEE International Conference on Video and Signal Based Surveillance (2006)

This paper presents a novel technique for camera tampering detection. It is implemented in real-time and was developed for use in surveillance and security applications. This method identifies camera tampering by detecting large differences between older frames of video and more recent frames. A buffer of incoming video frames is kept and three different measures of image dissimilarity are used to compare the frames. After normalization, a set of conditions is tested to decide if camera tampering has occurred. The effects of adjusting the internal parameters of the algorithm are examined. The performance of this method is shown to be extremely favorable in real-world settings.
New op-amp-RC to Gm-C transformation method
Authors: Rania F. Ahmed, Inas A. Awad, Ahmed M. Soliman
Venue: Analog Integrated Circuits and Signal Processing (2006)

A new transformation method is proposed and used to transform op-amp-RC circuits to G m -C ones with only grounded capacitors. The proposed method enables the generation of high-performance G m -C filters that benefit from the advantages of good and well-known op-amp-RC structures and at the same time feature electronic tunability, high frequency capability and monolithic integration ability. An attractive feature of the proposed method is that it results in G m -C structures with only grounded capacitors in spite of the presence of floating capacitors in the original op-amp-RC circuits.
Object Recognition Using a Generalized Robust Invariant Feature and Gestalt's Law of Proximity and Similarity
Authors: Sungho Kim, Kuk-Jin Yoon, In So Kweon
Venue: Proceedings of the 2006 Conference on Computer Vision and Pattern Recognition Workshop (2006)

In this paper, we propose a new context-based method for object recognition. We first introduce a neurophysiologically motivated visual part detector. We found that the optimal form of the visual part detector is a combination of a radial symmetry detector and a corner-like structure detector. A general context descriptor, named GRIF (Generalized-Robust Invariant Feature), is then proposed, which encodes edge orientation, edge density and hue information in a unified form. Finally, a context-based voting scheme is proposed. This proposed method is inspired by the function of the human visual system, called figure-ground discrimination. We use the proximity and similarity between features to support each other. The contextual feature descriptor and contextual voting method, which use contextual information, enhance the recognition performance enormously in severely cluttered environments.
A Concept-based Enhancement of Didactical Goals and Learning Needs with a Dynamic Background Library: Semantics vs. Pragmatics
Authors: Victor Manuel Garcia-Barrios
Venue: Proceedings of the Sixth IEEE International Conference on Advanced Learning Technologies (2006)

At present, the success and tenet of modern adaptive e-learning systems is seen in the efficient semantic enrichment of courseware and in advanced personalization techniques. Automatic adaptation steps, though, lead often to personalized navigational elements in learning assets, which in turn may not fulfill a learner need, because this need changes after delivering the asset. Thus, semantic descriptors should also enable different pragmatic viewpoints in order to solve the conflicts between an assumed didactical recommendation and the sum of possible 'sudden' personal learning needs. Regarding that context, this paper shows experiences gained from the utilization and evaluation of a Dynamic Background Library (DBL) in e-learning systems, and focuses on the usage of Concept Molecules for an enhanced DBL version.
A test chip for automatic MOSFET mismatch characterization
Authors: H. Klimach, M. C. Schneider, C. Galup-Montoro
Venue: Proceedings of the 19th annual symposium on Integrated circuits and systems design (2006)

This paper describes a test circuit for intensive characterization of MOS transistors mismatch. It aggregates analog switches, a shift register and a reference circuit, as well as the matrix of 1296 transistors to be tested. This circuit was integrated in a 0.35 mm bulk technology, and was designed to give experimental support for our MOSFET mismatch model. The test chip was characterized over a wide range of operation conditions, from weak to strong inversion, from linear to saturation region, allowing the analysis of MOSFET mismatch from bias, process and geometric parameters.
A perceptually based spectral model for isotropic textures
Authors: Danny Holten, Jarke J. Van Wijk, Jean-Bernard Martens
Venue: ACM Transactions on Applied Perception (TAP) (2006)

Color is routinely used to visualize interval and ordinal data, while texture is not. For color, a variety of perceptually based models is available, which can be used to convey data via straightforward mapping. The dimensionality of texture is less well understood and there are almost no perceptually based and validated models available to generate textures on demand. We present a perceptually based texture synthesis model for isotropic textures. The model uses additive synthesis of band-limited noise in the spectral domain, comparable to the RGB (red, green, blue) model for color. Via user experiments, we have derived a three-dimensional model to control the amplitudes per band in a perceptually intuitive way, comparable to the HSV (hue, saturation, value) model for color. The three dimensions used are contrast, spatial frequency, and spectral purity. Besides a mapping to the amplitudes, we have derived a mapping to a perceptually equidistant space. We show how such textures can be combined with color; applications are presented.
A multi-step strategy for approximate similarity search in image databases
Authors: Paul W. H. Kwan, Junbin Gao
Venue: Proceedings of the 17th Australasian Database Conference - Volume 49 (2006)

Many strategies for similarity search in image databases assume a metric and quadratic form-based similarity model where an optimal lower bounding distance function exists for filtering. These strategies are mainly two-step, with the inital "filter" step based on a spatial or metric access method followed by a "refine" step employing expensive computation. Recent research on robust matching methods for computer vision has discovered that similarity models behind human visual judgment are inherently non-metric. When applying such models to similarity search in image databases, one has to address the problem of nonmetric distance functions that might to have an optimal lower bound for filtering. Here, we propose a novel three-step "prune-filter-refine" strategy for approximate similarity search on these models. First, the "prune" step adopts a spatial access method to roughly eliminate improbable matches via an adjustable distance threshold. Second, the "filter" step uses a quasi lower-bounding distance derived from the non-metric distance function of the similarity model. Third, the "refine" stage compares the query with the remaining candidates by a robust matching method for final ranking. Experimental results confirmed that the proposed strategy achieves more filtering than a two-step approach with close to no false drops in the final result.
An Empirical Evaluation ofWork Stealing with Parallelism Feedback
Authors: Kunal Agrawal, Yuxiong He, Charles E. Leiserson
Venue: Proceedings of the 26th IEEE International Conference on Distributed Computing Systems (2006)

A-STEAL is a provably good adaptive work-stealing thread scheduler that provides parallelism feedback to a multiprocessor job scheduler. A-STEAL uses a simple multiplicative-increase, multiplicative-decrease algorithm to provide continual parallelism feedback to the job scheduler in the form of processor requests. Although jobs scheduled by A-STEAL can be shown theoretically to complete in near-optimal time asymptotically while utilizing at least a constant fraction of the allotted processors, the constants in the analysis leave it open on whether A-STEAL works well in practice. This paper confirms with simulation studies that A-STEAL performs well when scheduling adaptively parallel work-stealing jobs on large-scale multiprocessors. Our studies monitored the behavior of A-STEAL on a simulated multiprocessor system using synthetic workloads. We measured the completion time and waste of A-STEAL on over 2300 job runs using a variety of processor availability profiles. Linear-regression analysis indicates that ASTEAL provides almost perfect linear speedup. In addition, A-STEAL typically wasted less than 20% of the processor cycles allotted to the job. We compared A-STEAL with the ABP algorithm, an adaptive work-stealing thread scheduler developed by Arora, Blumofe, and Plaxton which does not employ parallelism feedback. On moderately to heavily loaded large machines with predetermined availability profiles, A-STEAL typically completed jobs more than twice as quickly, despite being allotted the same or fewer processors on every step, while wasting only 10% of the processor cycles wasted by ABP. We compared the utilization of A-STEAL and ABP when many jobs with varying characteristics are using the same multiprocessor. These experiments provide evidence that A-STEAL consistently provides higher utilization than ABP for a variety of job mixes.
Measuring Arterial Diameters for Surgery Assistance, Patient Customized Endovascular Prosthesis Design and Post-Surgery Evaluation
Authors: Diego D. B. Carvalho, Thiago R. dos Santos, Aldo von Wangenheim
Venue: Proceedings of the 19th IEEE Symposium on Computer-Based Medical Systems (2006)

This paper presents a method for arterial diameter measurement for the patient customization of endovascular prosthesis and for the assistance in preoperative procedures. The use of three-dimensional reconstruction and organ representation through a traversable geometric representation, known as Doubly Linked Face List (DLFL), which guarantees some topological properties, allows the measurement of the diameter of the polygons formed by the intersection between any arbitrary plane and the organ to be performed in a very efficient way.
Multiple fidelity simulation optimization of hospital performance under high consequence event scenarios
Authors: Jason R Schenk, Deng Huang, Ning Zheng, Theodore T. Allen
Venue: Proceedings of the 37th conference on Winter simulation (2005)

In optimizing systems, experimental models are often available with different levels of cost and different levels of "fidelity" or trustworthiness, a fact that can be exploited. For example, a highly detailed model might be made for a few possible configurations, supplemented by a large number of rough models that are less expensive to construct. The purpose of this paper is to illustrate the application of a recently proposed Multiple Fidelity Sequential Kriging Optimization (MFSKO) method to derive the optimal resource allocation for disaster preparedness of a hospital. The system is evaluated via discrete event simulations of two sophistication levels. The MFSKO method integrates multiple fidelity data, including real-world data, in search for the global optima with less total evaluation cost. Kriging meta-models are generated as by-products of the optimization.
Broadcasting algorithms in radio networks with unknown topology
Authors: Artur Czumaj, Wojciech Rytter
Venue: Journal of Algorithms (2006)

In this paper we present new randomized and deterministic algorithms for the classical problem of broadcasting in radio networks with unknown topology. We consider directed n-node radio networks with specified eccentricity D (maximum distance from the source node to any other node). Bar-Yehuda et al. presented an algorithm that for any n-node radio network with eccentricity D completes the broadcasting in O(D log n + log2 n) time, with high probability. This result is almost optimal, since as it has been shown by Kushilevitz and Mansour and Alon et al., every randomized algorithm requires Ω (D log(n/D) + log2 n) expected time to complete broadcasting.Our first main result closes the gap between the lower and upper bound: we describe an optimal randomized broadcasting algorithm whose running time complexity is O(D log (n/D + log2 n), with high probability. In particular, we obtain a randomized algorithm that completes broadcasting in any n-node radio network in time O(n), with high probability.The main source of our improvement is a better "selecting sequence" used by the algorithm that brings some stronger property and improves the broadcasting time. Two types of "selecting sequences" are considered: randomized and deterministic ones. The algorithm with a randomized sequence is easier (more intuitive) to analyze but both randomized and deterministic sequences give algorithms of the same asymptotic complexity.
Computing Interval Enclosures for Definite Integrals by Application of Triple Adaptive Strategies
Authors: Chin-Yun Chen
Venue: Computing (2006)

In addition to the well-known and widely-used adaptive strategies for region subdivision and the choice of local quadrature rules, there still exists a third possibility for doing numerical integration adaptively, when interval computation is considered. Based on the Peano's kernels theorem and interval arithmetic, we are able to estimate the truncation error of a quadrature rule by means of different derivatives of the integrand, where the available orders of the derivatives depend on the degree of smoothness of the integrand and the exactness degree of the underlying quadrature rule. We classify the methods as the adaptive orders strategies, if they make use of the derivatives of different orders to improve each single local error estimation. In this paper, alternatives for adaptive error estimation are discussed. Moreover, a practical way for realization of the optimal error estimation is suggested. Numerical results for integrands of different classes as well as numerical comparisons of different methods are given.
Finding a suitable system scale to optimize program performance on software DSM systems
Authors: Yi-Chang Zhuang, Jyh-Biau Chang, Tyng-Yeu Liang, Ce-Kuen Shieh, Laurence Tianruo Yang
Venue: Cluster Computing (2006)

Recently, software distributed shared memory systems have successfully provided an easy user interface to parallel user applications on distributed systems. In order to prompt program performance, most of DSM systems usually were greedy to utilize all of available processors in a computer network to execute user programs. However, using more processors to execute programs cannot necessarily guarantee to obtain better program performance. The overhead of paralleling programs is increased by the addition in the number of processors used for program execution. If the performance gain from program parallel cannot compensate for the overhead, increasing the number of execution processors will result in performance degradation and resource waste. In this paper, we proposed a mechanism to dynamically find a suitable system scale to optimize performance for DSM applications according to run-time information. The experimental results show that the proposed mechanism can precisely predict the processor number that will result in the best performance and then effectively optimize the performance of the test applications by adapting system scale according to the predicted result.
Guiding expeditions: the iterative, situated design of a learning environment for project-based science
Authors: Joseph Polman
Venue: Proceedings of the 1996 international conference on Learning sciences (1996)

In recent years, efforts to create learning environments that promote active engagement with science has led to a revival of interest in project-based pedagogy. The Learning Through Collaborative Visualization (CoVis) project based at Northwestern University brings this interest to high schools. CoVis includes a set of ideas and networked computer tools assembled by a group of university-based researchers, with the aid of high school teachers, and the support and funding of the National Science Foundation [Pea, 1993]. History has shown, however, that the creation of technologies and the ideas of academic researchers are inadequate to determine what happens in classrooms. Ultimately, teachers accomplish activity with their students daily in classrooms. Some critics might say that teachers do not accept ideas from the outside simply because they are stubborn or closedminded, but research has shown that teachers have good reasons for transforming outside ideas for their own classrooms. Above all, they are in a better position to understand the particular contexts in which they and their students are trying to work, and the individual personalities and needs of the students themselves.
Performance of Grid-Based PDE.Mart
Authors: Xiaobin Zhang, Mo Mu, Guoyong Mao, Wu Zhang
Venue: Proceedings of the Second IEEE International Conference on e-Science and Grid Computing (2006)

We study the performance of grid-based PDE.Mart. Several service protocols are investigated. The unsatisfactory performance is observed for grid-based PDE.Mart using the default RPC service protocol. To improve the efficiency, we present other approaches based on the protocol of message service with byte stream serialization and the protocol of RPC with SOAP attachment service. An adaptive hybrid approach is further proposed so that the system is also scalable with respect to the grid architecture, as well as capable of solving large scale problems.
Investigation on Human-Simulation Intelligent Control of the Touch Force in Remote Welding Teleteaching
Authors: L. J. Liu, H. M. Gao, G. G. Zhang, L. Wu
Venue: Proceedings of the First International Conference on Innovative Computing, Information and Control - Volume 1 (2006)

In remote welding teleteaching process (RWTP), some factors, such as the high-frequency interference ,the vibration of the robot arm, the change of the actual gravity center of welding tracing probe produced by the change of robot space posture ,and the roughness of the welding groove, etc. This may strongly interfere with the force signal, reduce the reliability of touch force signal transmission, distort the force telepresence of welding operator, and consequently influence remote welding teleteaching quality. The paper, by analyzing force error target track on the foundation of the PID control model, brings forward human-simulation intelligent control(HSIC) strategy based on the force guiding. Its characteristic algorithm is established ,including the characteristic model, characteristic identification, characteristic memory, multi-model control and multitarget decision-making. The experimental results show that the force error between fact phase track and idea phase track is lessened , the oscillating scope of touch force obviously reduced ,the stability time of RWTP shortened, the efficiency and playback precision of the RWTP improved by comparing HSIC with PID control.
Theoretical Analysis and Performance of NC-PRMA Protocol for Multichannel Wireless Networks
Authors: Jenn-Kaie Lain, Tain-Sao Chang, Yi-Show Chen, Jyh-Horng Wen
Venue: Wireless Personal Communications: An International Journal (2006)

In this paper, we analyze the effect of duplexing schemes on the throughput and the average packet dropping probability of a new multichannel wireless access protocol which allows for non-collision packet reservation multiple access with multiple channel (NC-PRMA/MC). N C equal-capacity, orthogonal, traffic channels are shared by M mobile users on the uplink. Transmission attempts on the uplink are made by using time-frequency signaling in every frame, which enables transmission attempts of mobile users to be conveyed to the base station without collisions. Two kinds of duplexing schemes, frequency division duplexing and shared time division duplexing, are considered in the performance analysis. Using a discrete-time Markov chain analysis, we derive the analytic expressions for the average per channel throughput and the average packet dropping probability. Computer simulation results verify the analysis. Analytical evaluation and computer simulation show that NC-PRMA/MC with shared time division duplexing improves the channel capacity, which approaches the theoretical upper bound.
The Key Knob
Authors: Alois Ferscha, Clemens Holzmann, Stefan Resmerita
Venue: Proceedings of the 26th IEEE International ConferenceWorkshops on Distributed Computing Systems (2006)

Locks are mechanical fastening devices used on various kinds of objects like doors and vehicles, and they can be released using a certain type of key. They have a long history, from wood-made Egyptian keys to electronic keys as they are common nowadays, and they are mostly restricted to the basic functionality of selecting one of two states (e.g. locked or unlocked). In many cases however, it would be useful to have the possibility of multistage or even continuous control also, as it is provided by omnipresent turning knobs. In this paper, we propose a novel concept of a handy knob to which we refer to as key knob, which automatically connects to dedicated devices in close proximity, and enables to control them in both discrete and continuous ways in the case of authorization. We present a prototype, point out its potentials with concrete application scenarios, and conclude with an outlook on further improvements of the key knob.
Optimum beamforming for a nearfield source in signal-correlated interferences
Authors: Monika Agrawal, Richard Abrahamsson, Per hgren
Venue: Signal Processing (2006)

In this paper, the problem of optimum beamforming using a uniform linear array is considered, for the purpose of avoiding target signal cancellation, which normally results when signal-correlated interferences are present in the environment. A convenient and direct characterization of the interference subspace in terms of its orthogonal complement is provided, leading to the estimation of a signal free covariance matrix directly from the observed data. This characterization enables us, not only to improve the performance of the farfield beamformers suggested by Bresler et al. [Optimum beamforming for coherent signal and interferences, IEEE Trans. Acoust. Speech Signal Process. ASSP-36(6) (1988) 833-843], but it also allows us to generalize the results of [Y. Bresler, et al. Optimum beamforming for coherent signal and interferences, IEEE Trans. Acoust. Speech Signal Process. ASSP-36(6) (1988) 833-843] to obtain the corresponding nearfield beamformers. The three beamformers proposed, work equally well even in scenarios where interferences are correlated with the signal of interest. Computer simulations are presented to validate the performance of these beamformers in the presence of correlated and uncorrelated interferences.