ppxscal/embedding_network huggingface dataset:
Genesis: a scalable distributed system for large-scale parallel network simulation
Authors: Yu Liu, Boleslaw K. Szymanski, Adnan Saifee
Venue: Computer Networks: The International Journal of Computer and Telecommunications Networking (2006)

The complexity and dynamics of the Internet is driving the demand for scalable and efficient network simulation. In this paper, we describe a novel approach to scalability and efficiency of parallel network simulations. This approach is based on partitioning of a network into domains and of the simulation time into intervals. Each domain is simulated independently of and concurrently with the others over the same simulation time interval. At the end of each interval, traffic statistics data, including per flow average packet delays and packet drop rates, are exchanged between domain simulators. The simulators iterate over the same time interval until the exchanged information converges, that is until the certain metric of a difference between the information exchanged in two subsequent iterations is smaller than a prescribed precision. After convergence, all simulators progress to the next time interval. This approach allows the parallelization with infrequent synchronization, and achieves significant simulation speedups.Large memory size required by simulation software hinders the simulation of large-scale networks. To overcome this problem, our system supports distribution of network information by assigning to each participating simulator only data related to the part of the network that it simulates. Such a solution supports simulations of large-scale networks on machines with modest memory size.
Optimum: minimax estimation of quadratic functionals for quadratically constrained signal classes
Authors: N. I. Wijeyesekera, R. G. Shenoy
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 1995. on International Conference - Volume 02 (1995)

A new procedure for the minimax estimation of quadratic functionals of signals is described. The estimates are optimum when the signals satisfy a quadratic constraint, a common assumption made for estimation of linear functionals. The method will, for example, provide best minimax estimates of signal energy in a time-window and of pointwise evaluations of Fourier transform magnitude, in contrast to earlier methods, which first obtain optimum minimax estimates of linear functionals, and subsequently form a suboptimum quadratic estimate by evaluating a weighted sum of the squared linear estimates.
Learning at the nanoscale: research questions that the rapidly evolving interdisciplinarity of science poses for the learning sciences
Authors: Sherry Hsi, Nora Sabelli, Joseph Krajcik, Robert Tinker, Kirsten Ellenbogen
Venue: Proceedings of the 7th international conference on Learning sciences (2006)

Recent interdisciplinary discoveries in the sciences and engineering at the nanoscale, specifically in our ability to manipulate, molecules at atomic scales, suggests a need for the education community to reconsider the ways in which disciplinary-based sciences and mathematics are being taught in schools, as well as how the public might engage with nanoscale phenomena. This session will discuss key learning questions and their importance in helping to advance both conceptual reasoning from the macro, micro, nano, and atomic levels, as well as their implications for curricular restructuring, public programming, and teacher professional development. The timeliness and broader importance of this research derives in part from two NSF-sponsored workshops on nanoscale education held in 2005, the National Nanotechnology Initiative, and two multi-institutional NSF awards: a National Center for Learning and Teaching and the Nanoscale Informal Science Education Network. This session will discuss research implications for the learning sciences and education community.
Occlusion detection of real objects using contour based stereo matching
Authors: Kenichi Hayashi, Hirokazu Kato, Shogo Nishida
Venue: Proceedings of the 2005 international conference on Augmented tele-existence (2005)

In Augmented Reality, the occlusion between virtual and real objects has to be managed correctly, so that users can look at the natural scene. In order to overcome this problem, the depth of the real world from the user's viewpoint is employed. However, if the system is used in an environment including moving or deformable objects, the depth has to be measured in real-time. In this paper, we propose a method for real-time stereo matching using a contour based approach to acquire the accurate depth of the boundary of real objects.
Dark current characteristics of thermally treated contacts on GaN-based ultraviolet photodetectors
Authors: Y. C. Lee, Z. Hassan, M. J. Abdullah, M. R. Hashim, K. Ibrahim
Venue: Microelectronic Engineering (2005)

The III-V nitrides (GaN and AlGaN) are being actively investigated recently for its potential as ultraviolet (UV) photodetector materials. One of the most important considerations in fabricating a photodetector is achieving a low dark current condition, which is critical in producing UV photodetectors with a high signal-to-noise ratio. For this purpose, thermal treatment has been proven to be a useful method in reducing the leakage current in a Schottky contact, as well as reducing the dark current in a Schottky contact based metal-semiconductor-metal (MSM) photodetector. In this work, GaN based MSM photodetectors (photodiodes) with nickel (Ni) Schottky contacts were fabricated and characterized. The application of thermal treatment to the contacts at various annealing temperatures (400-700^oC) was investigated. Cryogenic cooling after heat treatment was also performed to determine the effects of this treatment on the electrical characteristics of the devices. Electrical and morphological characterization was performed by current-voltage (I-V) and atomic force microscopy (AFM) measurements, respectively.
An Enhanced Data-aware Scheduling Algorithm for Batch-mode Dataintensive Jobs on Data Grid
Authors: Jianhua Jiang, Gaochao Xu, Xiaohui Wei
Venue: Proceedings of the 2006 International Conference on Hybrid Information Technology - Volume 01 (2006)

This paper aims to propose an enhanced dataaware scheduling algorithm for batch-mode dataintensive job on Gfarm Data Grid by using LSF plugin mechanism. The batch-mode data-intensive job is categorized into two types. These two types of batchmode jobs are analyzed in details and implemented by our scheduling algorithm. Finally, an example is given to evaluate this algorithm and some conclusions have been drawn by analysis.
H.264/AVC Video Encoder Implementation Based on TI TMS320DM642
Authors: Hong-Jun Wang, Yong-Jian Huang, Hua Li
Venue: Proceedings of the 2006 International Conference on Intelligent Information Hiding and Multimedia (2006)

Compared with the previous standards, the coding efficiency and coding performance of H.264/AVC are improved at the cost of higher computational complexity. It is a big challenge for us to develop the embedded real-time H.264/AVC video encoder with the limited on-chip memory space. This paper introduces the method to develop and optimize the H.264/AVC "baseline' encoder on the TMS320DM642 DSP hardware platform. The emphasis is put on the optimization methods of memory space allocation, the strategy of data transfer and pixel interpolation in motion compensation. Hereinto, ping-pong buffering technique was used to optimize the input interface of H.264/AVC encoder and the bi-linear interpolation method was used to replace the 6-tap filter which has been adopted in the "x264" source program. Experiments show that the coding performance of the optimized encoder is improved effectively with a little loss in PSNR and video sequences with QCIF resolution can be encoded in real time.
Improving image segmentation quality through effective region merging using a hierarchical social metaheuristic
Authors: Abraham Duarte, Ángel Sánchez, Felipe Fernández, Antonio S. Montemayor
Venue: Pattern Recognition Letters (2006)

This paper proposes a new evolutionary region merging method in order to efficiently improve segmentation quality results. Our approach starts from an oversegmented image, which is obtained by applying a standard morphological watershed transformation on the original image. Next, each resulting region is represented by its centroid. The oversegmented image is described by a simplified undirected weighted graph, where each node represents one region and weighted edges measure the dissimilarity between pairs of regions (adjacent and non-adjacent) according to their intensities, spatial locations and original sizes. Finally, the resulting graph is iteratively partitioned in a hierarchical fashion into two subgraphs, corresponding to the two most significant components of the actual image, until a termination condition is met. This graph-partitioning task is solved by a variant of the min-cut problem (normalized cut) using a hierarchical social (HS) metaheuristic. We have efficiently applied the proposed approach to brightness segmentation on different standard test images, with good visual and objective segmentation quality results.
fMRI Measures of Perceptual Filling-in in the Human Visual Cortex
Authors: J. D. Mendola, I. P. Conner, S. Sharma, A. Bahekar, S. Lemieux
Venue: Journal of Cognitive Neuroscience (2006)

Filling-in refers to the tendency of stabilized retinal stimuli to fade and become replaced by their background. This phenomenon is a good example of central brain mechanisms that can selectively add or delete information to/from the retinal input. Importantly, such cortical mechanisms may overlap with those that are used more generally in visual perception. In order to identify cortical areas that contribute to perceptual filling-in, we used functional magnetic resonance imaging to image activity in the visual cortex while subjects experienced filling-in. Nine subjects viewed an achromatic disc with slightly higher luminance than the background and indicated the presence or absence of filling-in by a keypress. The disc was placed in either the upper or lower left quadrant. Similar high-contrast stimuli were used to map out the retinotopic representation of the disc. Unexpectedly, the lower-field high-contrast stimulus produced more parietal cortex activation than the upper-field condition, indicating preferential representation of the lower field by attentional control mechanisms. During perceptual filling-in, we observed significant contralateral reductions in activation in lower-tier retinotopic areas V1 and V2. In contrast, increased activation was consistently observed in visual areas V3A and V4v, higher-level cortex in the intraparietal sulcus, posterior superior temporal sulcus, and the ventral occipital&ndash;temporal region, as well as the pulvinar. The filling-in activation pattern was remarkably similar for both the upper- and lower-field conditions. Behaviorally, filling-in was reported to be easier for the lower visual field, and filling-in periods were longer for the lower than the upper quadrant. We suggest this behavioral asymmetry may be partially due to the preferential parietal representation of the lower field. The results lead us to propose that perceptual filling-in recruits high-level control mechanisms to reconcile competing percepts, and alters the normal image-related signals at the first stages of cortical processing. Moreover, the overall pattern of activation during filling-in resembles that seen in other studies of perceptually bistable stimuli, including binocular rivalry, indicating common control mechanisms.
Using simulation to analyze R&D value creation
Authors: Douglas A. Bodner, William B. Rouse, Michael J. Pennock
Venue: Proceedings of the 37th conference on Winter simulation (2005)

As the front-end to product and system lifecycles, research and development activities serve as engines of value creation. By nature, though, R&D involves significant uncertainty. As such, it often is viewed as an investment problem, whereby funds are invested in ventures under risk, with the hope of achieving future value. This paper investigates the use of organizational simulation to analyze the R&D investment problem, focusing on ways to increase value created from R&D. Based on a process-focused model of R&D systems, initial results indicate that using a real options framework to valuate R&D outperforms traditional discounted cash flow (DCF) methods in total value created, but that DCF methods are preferred for return on R&D investment. To complement the process-focused R&D system model, a product-focused model of R&D is specified and integrated with the process-focused model.
A natural wayfinding exploiting photos in pedestrian navigation systems
Authors: Ashweeni Kumar Beeharee, Anthony Steed
Venue: Proceedings of the 8th conference on Human-computer interaction with mobile devices and services (2006)

The increasing power and ubiquity of mobile phones mean that a visitor to a city now carries with them a device capable of giving quite detailed guiding and routing information. Whilst there has been a lot of studies of text and map based guiding applications for mobile devices, in this paper we want to propose and give an initial exploratory study of a guiding system that utilises photographs. These photographs are not explicitly taken with the intention of using them subsequently for giving route directions; rather they are extracted from existing geo-tagged photo collections from mobile phones. A user of our system sees a route description as text and a map that refers to a series of photographs. The main contribution of this paper is in demonstrating this concept and testing it in an exploratory between-subjects experiment. The experiment shows that presenting the right photographs certainly can help with particular types of routing instruction for users not familiar with an area. For example, in unusual situation where the user has to walk through a specific gate or path, photographs provide information and reassurance about the navigation decision.
Utility-Based Cache Partitioning: A Low-Overhead, High-Performance, Runtime Mechanism to Partition Shared Caches
Authors: Moinuddin K. Qureshi, Yale N. Patt
Venue: Proceedings of the 39th Annual IEEE/ACM International Symposium on Microarchitecture (2006)

This paper investigates the problem of partitioning a shared cache between multiple concurrently executing applications. The commonly used LRU policy implicitly partitions a shared cache on a demand basis, giving more cache resources to the application that has a high demand and fewer cache resources to the application that has a low demand. However, a higher demand for cache resources does not always correlate with a higher performance from additional cache resources. It is beneficial for performance to invest cache resources in the application that benefits more from the cache resources rather than in the application that has more demand for the cache resources. This paper proposes utility-based cache partitioning (UCP), a low-overhead, runtime mechanism that partitions a shared cache between multiple applications depending on the reduction in cache misses that each application is likely to obtain for a given amount of cache resources. The proposed mechanism monitors each application at runtime using a novel, cost-effective, hardware circuit that requires less than 2kB of storage. The information collected by the monitoring circuits is used by a partitioning algorithm to decide the amount of cache resources allocated to each application. Our evaluation, with 20 multiprogrammed workloads, shows that UCP improves performance of a dual-core system by up to 23% and on average 11% over LRU-based cache partitioning.
Implementation of a discrete event simulator for biological self-assembly systems
Authors: Tiequan Zhang, Rori Rohlfs, Russell Schwartz
Venue: Proceedings of the 37th conference on Winter simulation (2005)

We have implemented a simulation tool for the study of computationally challenging biological self-assembly systems, particularly viral protein shells. The simulator implements a generic model of self-assembly based on simple local binding interactions to specify the behavior of complex self-assembly reactions. Recently developed discrete event methods allow for fast quantitative simulation of these systems. The new simulator uses the Java language to implement the model in a portable, interactive graphical tool. The Java libraries can also be used directly to build customized simulations. This paper discusses the simulator model, the theoretical basis for its efficient operation, and implementation issues in its design. It also discusses empirical validation of the simulator package and presents sample applications.
The importance of locality in the visualization of large datasets: Research Articles
Authors: J. M. Brooke, J. Marsh, S. Pettifer, L. S. Sastry
Venue: Concurrency and Computation: Practice Experience (2007)

Many scientific phenomena in large high-resolution datasets such as the U.K. Ocean Circulation and Advanced Modelling (OCCAM) ocean model are better discovered through visualization than by algorithmic analysis: it is often more straightforward to see a feature than it is to characterize it numerically. Using traditional rendering techniques, the size of modern datasets presents a challenge for even high-end graphical supercomputers, and the cost of such hardware limits its availability for day-to-day analysis. We present an architecture that brings visual analysis to the desktop by exploiting consumer-grade graphics hardware in order to provide initial interactive exploration and Web services to enable finer-grained analysis and interoperability with traditional visualization tools. Copyright &copy; 2006 John Wiley & Sons, Ltd.
Interactive Lecture using Cyber Assistant Professor: CAP
Authors: Hiroshi Matsuda, Yoshiaki Shindo
Venue: Proceedings of the Sixth IEEE International Conference on Advanced Learning Technologies (2006)

The 3D Computer Graphics (3D-CG) animation using a virtual actor's speaking is very effective as an educational medium. But it takes a long time to produce a 3D-CG animation. To reduce the cost of producing 3D-CG educational contents and improve the capability of the education system, we have developed a new education system using Virtual Actor. It includes 3D-CG stage, many kinds of stage parts (3D-CG shaped models, photographs or text panels) and Virtual Actor(s). Virtual Actor is a software robot of various shaped based on 3D-CG and speech synthesis. Virtual Actor speaks English/Japanese by voice synthesizer with facial expressions and body actions. We have developed an education system named Cyber Assistant Professor (CAP). CAP has been designed for an e-learning system, which enables interactive communication between Virtual Teacher and learner. We also have developed the exclusive scenario language to write a scenario of 3D-CG animation. It is a tag-based hypertext language like HTML. CAP converts this scenario to real-time interactive 3D-CG animations, which are not rendering movies. This paper describes the system architecture of CAP , details of scenario language and results of experimental lessons named Interactive Lecture in an elementary school.
Towards Interactive Fault Localization Using Test Information
Authors: Dan Hao, Lu Zhang, Hong Mei, Jiasu Sun
Venue: Proceedings of the XIII Asia Pacific Software Engineering Conference (2006)

Finding the location of a fault is a central task of debugging. Typically, a developer employs an interactive process for fault localization. To accelerate this task, several approaches have been proposed to automate fault localization. In practice, testing-based fault localization (TBFL), which uses test information to locate faults, has become a research focus. However, experimental results reported in the literature showed that current automation of fault localization can only serve as a means to confirming the search space and prioritizing search sequences, not a substitute of the interactive fault localization process. In this paper, we propose an approach based on test information to support the entire interactive fault localization process. During this process, the information gathered from previous interaction steps can be used to provide the ranking of suspicious statements for the current interaction step. As a feasibility study of our approach, we performed an experiment on applying our approach together with some other TBFL approaches on the Siemens programs, which have been used in the literature. Our experimental results show the effectiveness of our approach.
A factorial representation of permutations and its application to flow-shop scheduling
Authors: Kazunori Watase
Venue: Systems and Computers in Japan (2007)

The first objective of the current research was to incorporate the NEH search method, which is the classical heuristic algorithm for the flow-shop scheduling problem, into a genetic algorithm to improve search performance. To achieve this objective, the author used factorial numbers to represent permutations. Since chromosome representations according to factorial numbers have a one-to-one correspondence with permutations, there is no redundancy. Since no lethal gene is produced by crossover, uniform crossover can also be applied, not just one-point or two-point crossover. In addition, it was apparent that the NEH concept could be naturally introduced into the genetic algorithm search process by arranging n jobs in ascending order of total work times as the basic permutation that is used when associating permutations and factorial numbers. Factorial numbers can also be used to represent certain types of constraints. The second objective of the current research was to verify the effectiveness of the factorial number representation in order-constrained permutation searches. To accomplish this, the author performed numerical experiments and obtained superior results than were obtained by conventional methods. &copy; 2006 Wiley Periodicals, Inc. Syst Comp Jpn, 38(1): 73&ndash;86, 2007; Published online in Wiley InterScience (). DOI 10.1002&sol;scj.10348
Case libraries for middle school science instruction
Authors: N. Hari Narayanan, Cindy E. Hmelo, Douglas L. Holton, Janet L. Kolodner
Venue: Proceedings of the 1996 international conference on Learning sciences (1996)

Case Libraries: A case library is a computer-based multimedia database containing cases that describe real-world problems and how they have been solved (successfully or unsuccessfully). In an educational setting, students navigate a case library to find cases and stories that can help them solve problems. Cases suggest issues needing exploration, methods for solving problems, past solutions that may be applicable, and potential pitfalls. Cases are structured as graphic and textual overviews, lists of significant issues, and their elaborations in both general and specific terms. Cases are indexed according to situations in which they might be useful. We are building case libraries of both artifacts and experiments for use by middle school students. We will demonstrate a case library constructed to help students design an artificial lung, one of a set of problems that we have developed for our middle school project.