ppxscal/embedding_network huggingface dataset:
A full-scale solution to the rectilinear obstacle-avoiding Steiner problem
Authors: Tom Tong Jing, Yu Hu, Zhe Feng, Xian-Long Hong, Xiaodong Hu, Guiying Yan
Venue: Integration, the VLSI Journal (2008)

Routing is one of the important steps in very/ultra large-scale integration (VLSI/ULSI) physical design. Rectilinear Steiner minimal tree (RSMT) construction is an essential part of routing. Macro cells, IP blocks, and pre-routed nets are often regarded as obstacles in the routing phase. Obstacle-avoiding RSMT (OARSMT) algorithms are useful for practical routing applications. However, OARSMT algorithms for multi-terminal net routing still cannot meet the requirements of practical applications. This paper focuses on the OARSMT problem and gives a solution to full-scale nets based on two algorithms, namely An-OARSMan and FORSTer. (1) Based on ant colony optimization (ACO), An-OARSMan can be used for common scale nets with less than 100 terminals in a circuit. An heuristic, greedy obstacle penalty distance (OP-distance), is used in the algorithm and performed on the track graph. (2) FORSTer is a three-step heuristic used for large-scale nets with more than 100 terminals in a circuit. In Step 1, it first partitions all terminals into some subsets in the presence of obstacles. In Step 2, it then connects terminals in each connected graph with one or more trees, respectively. In Step 3, it finally connects the forest consisting of trees constructed in Step 2 into a complete Steiner tree spanning all terminals while avoiding all obstacles. (3) These two graph-based algorithms have been implemented and tested on different kinds of cases. Experimental results show that An-OARSMan can handle both convex and concave polygon obstacles with short wire length. It achieves the optimal solution in the cases with no more than seven terminals. The experimental results also show that FORSTer has short running time, which is suitable for routing large-scale nets among obstacles, even for routing a net with one thousand terminals in the presence of 100 rectangular obstacles.
A dynamically reconfigurable cache for multithreaded processors
Authors: Alex Settle, Dan Connors, Enric Gibert, Antonio González
Venue: Journal of Embedded Computing (2006)

Chip multi-processors (CMP) are rapidly emerging as an important design paradigm for both high performance and embedded processors. These machines provide an important performance alternative to increasing the clock frequency. In spite of the increase in potential performance, several issues related to resource sharing on the chip can negatively impact the performance of embedded applications. In particular, the shared on-chip caches make each job's memory access times dependent on the behavior of the other jobs sharing the cache. If not adequately managed, this can lead to problems in meeting hard real-time scheduling constraints. This work explores adaptable caching strategies which balance the resource demands of each application and in turn lead to improvements in throughput for the collective workload. Experimental results demonstrate speedups of up to 1.47X for workloads of two co-scheduled applications compared against a fully-shared two-level cache hierarchy. Additionally, the adaptable caching scheme is shown to achieve an average speedup of 1.10X over the leading cache partitioning model. By dynamically managing cache storage for multiple application threads at runtime, sizable performance levels are achieved, which provides chip designers the opportunity to maintain high performance as cache size and power budgets become a concern in the CMP design space.
The concave integral over large spaces
Authors: Ehud Lehrer, Roee Teper
Venue: Fuzzy Sets and Systems (2008)

This paper investigates the concave integral for capacities defined over large spaces. We characterize when the integral with respect to capacity v can be represented as the infimum over all integrals with respect to additive measures that are greater than or equal to v. We introduce the notion of loose extendability and study its relation to the concave integral. A non-additive version for the Levi theorem and the Fatou lemma are proven. Finally, we provide several convergence theorems for capacities with large cores.
Games, stories, or something more traditional: the types of assignments college students prefer
Authors: Daniel C. Cliburn, Susan Miller
Venue: Proceedings of the 39th SIGCSE technical symposium on Computer science education (2008)

In this paper, we describe a study designed to examine the types of projects college students prefer in an introductory programming course. For three assignments in a course, students were given a choice among three project types: a game, a "choose your own adventure" story, and a more traditional project (such as a problem from the text book). During the semester, 35 of 49 projects submitted by students were the game option (71.4%), with only two projects submitted that were stories. A statistical analysis revealed that student choices on assignments did not appear to be related to their overall performance in the course. On an end of term survey, students commented that they often chose projects that had all requirements clearly explained, and avoided assignments that were open-ended in nature.
How could ULS systems achieve architecture benefits?
Authors: Amir Azim Sharifloo, Mehdi Mirakhorli, Fereidoon Shams
Venue: Proceedings of the 2nd international workshop on Ultra-large-scale software-intensive systems (2008)

ULS systems have been introduced as a kind of future systems. They advent by increasing scale of systems from different dimensions. The scale causes essential differences between these systems and conventional software systems. Geographical distribution in development and deployment is one of them which bring problems in the growth of these systems. However these systems would become so complex and we have to encounter them. Today, software architecture is considered in developing large scale systems. It gives some benefits that are significant to overcome complexity effects. Since ULS systems are greater than large scale systems, considering their architecture could be more vital. In this position paper, we investigate how to architect ULS systems and also how to obtain their architecture.
Analytic Programming Powered by Distributed Self-Organizing Migrating Algorithm Application
Authors: Pavel Varacha, Ivan Zelinka
Venue: Proceedings of the 2008 7th Computer Information Systems and Industrial Management Applications (2008)

This paper presents an idea of new algorithm combining advantages of evolutionary algorithm and simple distributed computing to perform tasks which required many re-runs of the same program. Computing time is shorted due to elementary distribution within a number of common computers via the Internet. Progressive .NET Framework technology allowing this algorithm to run effectively and examples of possible usage are also described. The algorithm deals with a problem of synthesis of the artificial neural networks using the evolutional scanning method. The basic task to be solved is to create a symbolic regression algorithm on principles of analytic programming, which will be capable of performing a convenient neural network synthesis. The main motivation here is the computerization of such synthesis and discovering so far unknown solutions.
A Peer-To-Peer platform for simulating distributed virtual environments
Authors: Silvia Rueda, Pedro Morillo, Juan M. Orduna
Venue: Proceedings of the 13th International Conference on Parallel and Distributed Systems - Volume 02 (2007)

The current expansion of multi-player online games has promoted the growth of large scale distributed virtual environments (DVEs). In these systems, peer-to-peer architectures have been proved as an efficient scheme for supporting massively multi-player applications. In order to research on this type of architecture, stand-alone simulators do not take into account inconsistencies due to network latency, and it is necessary to develop a distributed tool that allows to simulate large-scale DVEs in an efficient way. In this paper, we propose a distributed platform for simulating the behavior of Peer-To-Peer DVEs. This simulator is implemented following a modular architecture. It is capable of providing the main performance metrics in distributed systems, and it contains all the elements involved in real DVE simulations like the awareness method and the graphic interface. As a result, this tool can be used in real simulations of Peer-to-Peer DVEs, becoming an invaluable tool for capturing the behavior of this kind of systems.
Technology innovations and architecture solutions for the next-generation optical access network
Authors: Ronald W. Heron, Thomas Pfeiffer, Doutje T. van Veen, Joe Smith, Sanjay S. Patel
Venue: Bell Labs Technical Journal (2008)

Although deployment of fiber to the home (FTTH) systems has been ongoing for over 5 years in certain markets, the industry is still in the early phases of what is expected to be a decades-long optical fiber&ndash;based access network build-out. Deployment so far has been largely opportunistic, as in greenfield deployment or copper rehab&semi; competitive, as competitive local exchange carriers (CLECs), utilities, and small multiple systems operators (MSOs) roll out solutions&semi; policy-driven, at the national or municipal level&semi; and strategic, in some isolated cases of a few large carriers. In the coming years as the appetite for bandwidth continues to grow, fiber-based networks will become the only acceptable solution. FTTH technologies have already undergone several stages of evolution, from asynchronous transfer mode passive optical network (APON) to broadband PON (BPON), Ethernet PON (EPON), and Gigabit PON (GPON)&mdash;and they will continue to do so in the future. Continuous innovations will allow for a long term increase in bandwidth, an improved cost structure, and greater reach. Starting from current FTTH architectures, including PON, point-to-point (PP), active Ethernet (AE), this paper will focus on the nextgeneration architectures and supporting technologies that will be used in the future including 10 Gbps PON (10GPON), multi-lambda GPON, coarse wavelength division multiplexing (CWDM) PON, and dense WDM (DWDM)-PON. It will show the relative merits of each architecture, the required supporting technologies, and the role of these solutions in the long term evolution of access networks. &copy; 2008 Alcatel-Lucent.
Evaluating remotely sensed rainfall estimates using nonlinear mixed models and geographically weighted regression
Authors: Y. Kamarianakis, H. Feidas, G. Kokolatos, N. Chrysoulakis, V. Karatzias
Venue: Environmental Modelling Software (2008)

This article evaluates an infrared-based satellite algorithm for rainfall estimation, the Convective Stratiform technique, over Mediterranean. Unlike a large number of works that evaluate remotely sensed estimates concentrating on global measures of accuracy, this work examines the relationship between ground truth and satellit0e derived data in a local scale. Hence, we examine the fit of ground truth and remotely sensed data on a widely adopted probability distribution for rainfall totals - the mixed lognormal distribution - per measurement location. Moreover, we test for spatial nonstationarity in the relationship between in situ observed and satellite-estimated rainfall totals. The former investigation takes place via using recent algorithms that estimate nonlinear mixed models whereas the latter uses geographically weighted regression.
Locally linear reconstruction for instance-based learning
Authors: Pilsung Kang, Sungzoon Cho
Venue: Pattern Recognition (2008)

Instance-based learning (IBL), so called memory-based reasoning (MBR), is a commonly used non-parametric learning algorithm. k-nearest neighbor (k-NN) learning is the most popular realization of IBL. Due to its usability and adaptability, k-NN has been successfully applied to a wide range of applications. However, in practice, one has to set important model parameters only empirically: the number of neighbors (k) and weights to those neighbors. In this paper, we propose structured ways to set these parameters, based on locally linear reconstruction (LLR). We then employed sequential minimal optimization (SMO) for solving quadratic programming step involved in LLR for classification to reduce the computational complexity. Experimental results from 11 classification and eight regression tasks were promising enough to merit further investigation: not only did LLR outperform the conventional weight allocation methods without much additional computational cost, but also LLR was found to be robust to the change of k.
A modified EM alr-algorithm for replacing rounded zeros in compositional data sets
Authors: J. Palarea-Albaladejo, J. A. Martín-Fernández
Venue: Computers Geosciences (2008)

The presence of rounded zeros results in an important drawback for the statistical analysis of compositional data. Data analysis methodology based on log-ratios cannot be applied under these conditions. In this paper rounded zeros are considered as a special kind of missing data. Thus, an EM-type computational algorithm for replacing them is provided. The procedure is based on the additive logistic transformation and assumes an additive logistic normal model for the data. First, the alr transformation moves data from the constrained simplex space to the unconstrained real space. Next, missing transformed data are imputed by using modified EM steps. Last, imputed data are transformed back into the simplex space to obtain a compositional data set free of rounded zeros. Additionally, a sequential strategy is proposed for the case of rounded zeros in all the components of a composition. This work focuses on the algorithm's properties and on computational implementation details. Also, its effectiveness on simulated data sets with a range of detection limits is analyzed. Special attention is paid on the effects on the covariance structure of a compositional data set. Results confirm the good behavior of our proposal. Finally, MATLAB routines implementing the algorithm are made available to the reader.
A high-order tangential basis algorithm for electromagnetic scattering by curved surfaces
Authors: M. Ganesh, S. C. Hawkins
Venue: Journal of Computational Physics (2008)

We describe, analyze, and demonstrate a high-order spectrally accurate surface integral algorithm for simulating time-harmonic electromagnetic waves scattered by a class of deterministic and stochastic perfectly conducting three-dimensional obstacles. A key feature of our method is spectrally accurate approximation of the tangential surface current using a new set of tangential basis functions. The construction of spectrally accurate tangential basis functions allows a one-third reduction in the number of unknowns required compared with algorithms using non-tangential basis functions. The spectral accuracy of the algorithm leads to discretized systems with substantially fewer unknowns than required by many industrial standard algorithms, which use, for example, the method of moments combined with fast solvers based on the fast multipole method. We demonstrate our algorithm by simulating electromagnetic waves scattered by medium-sized obstacles (diameter up to 50 times the incident wavelength) using a direct solver (in a small parallel cluster computing environment). The ability to use a direct solver is a tremendous advantage for monostatic radar cross section computations, where thousands of linear systems, with one electromagnetic scattering matrix but many right hand sides (induced by many transmitters) must be solved.
A filtered polynomial approach to density estimation
Authors: Dominik Heinzmann
Venue: Computational Statistics (2008)

In this paper, a little known computational approach to density estimation based on filtered polynomial approximation is investigated. It is accompanied by the first online available density estimation computer program based on a filtered polynomial approach. The approximation yields the unknown distribution and density as the product of a monotonic increasing polynomial and a filter. The filter may be considered as a target distribution which gets fixed prior to the estimation. The filtered polynomial approach then provides coefficient estimates for (close) algebraic approximations to (a) the unknown density function and (b) the unknown cumulative distribution function as well as (c) a transformation (e.g., normalization) from the unknown data distribution to the filter. This approach provides a high degree of smoothness in its estimates for univariate as well as for multivariate settings. The nice properties as the high degree of smoothness and the ability to select from different target distributions are suited especially in MCMC simulations. Two applications in Sects. 1 and 7 will show the advantages of the filtered polynomial approach over the commonly used kernel estimation method.
Efficient bulk insertion into a distributed ordered table
Authors: Adam Silberstein, Brian F. Cooper, Utkarsh Srivastava, Erik Vee, Ramana Yerneni, Raghu Ramakrishnan
Venue: Proceedings of the 2008 ACM SIGMOD international conference on Management of data (2008)

We study the problem of bulk-inserting records into tables in a system that horizontally range-partitions data over a large cluster of shared-nothing machines. Each table partition contains a contiguous portion of the table's key range, and must accept all records inserted into that range. Examples of such systems include BigTable[8] at Google, and PNUTS [15] at Yahoo! During bulk inserts into an existing table, if most of the inserted records end up going into a small number of data partitions, the obtained throughput may be very poor due to ineffective use of cluster parallelism. We propose a novel approach in which a planning phase is invoked before the actual insertions. By creating new partitions and intelligently distributing partitions across machines, the planning phase ensures that the insertion load will be well-balanced. Since there is a tradeoff between the cost of moving partitions and the resulting throughput gain, the planning phase must minimize the sum of partition movement time and insertion time. We show that this problem is a variation of NP-hard bin-packing, reduce it to a problem of packing vectors, and then give a solution with provable approximation guarantees. We evaluate our approach on a prototype system deployed on a cluster of 50 machines, and show that it yields significant improvements over more naïve techniques.
Chitosan Complexes Eliminate Chloroform and Carbon Tetrachloride in Drinking Water
Authors: Yuan Yihua, Jia Demin, Chen Xin, Pang Yulian
Venue: Proceedings of the 2008 International Conference on BioMedical Engineering and Informatics - Volume 01 (2008)

This paper introduced the preparation methods of chitosan and its complex. It focuses on drinking water treatment, eliminating products causing by chlorine disinfect (Chloroform, Carbon tetrachloride). The results showed that all the chitosan granule, chitosan- activated carbon complex and activated carbon had certain adsorption ability to the chloroform and carbon tetrachloride. Before 40 min, the adsorption rate was 80% or so, but at 60 min, the adsorption rate suffered a decline apparently, or even occurred the negative adsorption.
Accuracy and stability in mass-spring systems for sound synthesis
Authors: Don Morgan, Sanzheng Qiao
Venue: Proceedings of the 2008 C3S2E conference (2008)

This paper examines the stability and accuracy of mass-spring systems used in sound synthesis. We show that the standard method used in mass-spring systems has no numerical damping, but does have frequency warping and is unstable at frequencies above 1/&pi; times the sampling rate. We compare the standard method with two higher order numerical methods: the fourth order Runge-Kutta, and the VEFRL algorithm, a fourth order symplectic algorithm. We find that the VEFRL algorithm is much more accurate than the standard method, but that this increase in accuracy does not noticeably affect the quality of the sound produced by the mass-spring system when used to simulate a vibrating string. The increased accuracy of the VEFRL method may, however, be useful for mass-spring spring systems used in physics or engineering requiring high accuracy.
Hardware-software system for acceleration of image processing operations
Authors: Bogusław Cyganek
Venue: Machine Graphics Vision International Journal (2006)

The paper presents design and architecture of a hybrid software/hardware system for acceleration of image processing. The front end consists of a software interface that defines the basic data structures and exchange mechanisms for connecting to external software. The back end consists of a hardware board which is responsible for acceleration of image computations. Thus, the two main components follow the handle/body concept, which allows modifications to the implementation without changes in interfaces. This flexibility allows for better resource usage, and faster development, and facilitates system extensions. In this paper we present the design and implementation issues for the system, as well as discuss its run-time performance for the selected image operations.
Justification and numerical realization of the uniform method for finding point estimates of interval elicited scaling constants
Authors: Kiril Tenekedjiev, Natalia Nikolova
Venue: Fuzzy Optimization and Decision Making (2008)

The form of the utility function over multi-dimensional consequences depends on the point estimates of the scaling constants. Fuzzy rational decision makers elicit those in the form of uncertainty intervals. The paper proposes an analytical justification and a numerical realization of the uniform method that finds point estimates of interval scaling constants. The main assumption of the technique is that constants are uniformly distributed in their uncertainty intervals. The density of the constants' sum is constructed using preliminarily chosen knots. A new numerical procedure to calculate the I type error p value of a two-tail test for singularity of the constants' sum is proposed. All numerical procedures are embodied into program functions. The application of the method is demonstrated in examples. The connection between precision and time for analysis is investigated. Comparison of the analytical uniform method and an earlier proposed simulation realization is also conducted.
Teaching Grid Technologies to PhD Students, Part 1: Using Best Practices to Build the Course
Authors: Dana Petcu
Venue: IEEE Distributed Systems Online (2008)

Grid technologies serving large distributed systems can help address many application areas' computing and storage needs. Consequently, the scientific and large-scale information processing communities are increasingly interested in studying large-scale distributed systems, such as Grid-based ones. Unfortunately, there are relatively few reports on best practices in teaching Grid topics that teachers can follow when they start building a new Grid-related course. Part 1 of this two-part department surveys reported efforts. Most of these efforts concern training activities organized by research teams for Grid user communities, but some discuss semester-long courses for advanced computer science or computer engineering students.