ppxscal/embedding_network huggingface dataset:
Queueing-model based analysis of assembly lines with finite buffers and general service times
Authors: Michael Manitz
Venue: Computers and Operations Research (2008)

In this paper, we study the production process on multi-stage assembly lines. These production systems comprise simple processing as well as assembly stations. At the latter, workpieces from two or more input stations have to be merged to form a new one for further processing. As the flow of material is asynchronous with stochastic processing times at each station, queueing effects arise as long as buffers provide waiting room. We consider finite buffer capacities and generally distributed processing times. Processing is a service operation to customer items in the sense of a queueing system. The arrival stream of customer items is generated by processing parts at a predecessor station. This paper describes an approximation procedure for determining the throughput of such an assembly line. Exact solutions are not available in this case. For performance evaluation, a decomposition approach is used. The two-station subsystems are analyzed by G/G/1/N stopped-arrival queueing models. In this heuristic approach, the virtual arrival and service rates, and the squared coefficients of variation of these subsystems are determined. A system of decomposition equations which are solved iteratively is presented. Any solution to this system of equations indicates estimated values for the subsystems' unknown parameters. The quality of the presented approximation procedure is tested against the results of various simulation experiments. Scope and purpose: We consider assembly lines, i.e. flow production systems with a convergent flow of material and synchronization constraints. By considering assembly operations, our paper generalizes the work of Buzacott, Liu and Shanthikumar [Multistage flow line analysis with the stopped arrival queue model. IIE Transactions 1995;27:444-55], in which flow lines as series production systems are analyzed. It also extends the work of Helber [Performance analysis of flow lines with non-linear flow of material, Lecture notes in economics and mathematical systems, vol. 473, Berlin, Heidelberg, New York: Springer; 1999] and Jeong and Kim [Performance analysis of assembly/disassembly systems with unreliable machines and random processing times. IIE Transactions 1998; 30(1):41-53], who analyze assembly systems, by considering general service times. Station failures can be incorporated with the completion time concept proposed by Gaver [A waiting line with interrupted service, including priorities. Journal of the Royal Statistical Society 1962;24(2):73-90. [47]]. The comparison to various simulation results shows that the queueing-model based approach presented in this paper yields quite good approximations of the throughput.
Adaptive methodology for meshless finite point method
Authors: F. Perazzo, R. Löhner, L. Perez-Pozo
Venue: Advances in Engineering Software (2008)

In this work, a posteriori error estimator and an adaptive refinement process for the meshless finite point method (FPM), which is based on point collocation, are presented. The error indicator is formulated by the least-squares functional evaluation, used in the shape function development. New degrees of freedom or additional points can be incorporated without difficulty, in zones where the error estimator presents a high value, by means of h-p refinement processes. The validity of the proposed error estimator can be demonstrated by developments of numerical problems in mechanics of solids, using an adaptive refinement process of the solution.
Formalising Design Patterns in Predicate Logic
Authors: Ian Bayley
Venue: Proceedings of the Fifth IEEE International Conference on Software Engineering and Formal Methods (2007)

Design patterns are traditionally outlined in an informal manner. If they could be formalised, we could derive tools that automatically recognise design patterns and refactor designs and code. Our approach is to deploy predicate logic to specify conditions on the class diagrams that describe design patterns. The structure of class diagrams is itself described with a novel meta-notation that can be used for defining any graphical modelling language. As a result, the constraints, while based on UML, are highly readable and have much expressive power. This enables us not only to recognise design patterns in legacy code, but also to reason about them at the design stage, such as showing one pattern to be a special case of another. The paper discusses our specification of the original 23 design patterns and presents a representative sample of some of them.
A novel simplified channel tracking method for MIMO-OFDM systems with null sub-carriers
Authors: Hyoung-Goo Jeon, Erchin Serpedin
Venue: Signal Processing (2008)

This paper proposes an efficient scheme to track the time variant channel induced by multi-path Rayleigh fading in mobile wireless multiple input multiple output-orthogonal frequency division multiplexing (MIMO-OFDM) systems with null sub-carriers. In the proposed method, a blind channel response predictor is designed to cope with the time variant channel. The proposed channel tracking scheme consists of a frequency domain estimation approach that is coupled with a minimum mean square error (MMSE) time domain estimation method, and does not require any matrix inverse calculation during each OFDM symbol. The main attributes of the proposed scheme are its reduced computational complexity and good tracking performance of channel variations. The simulation results show that the proposed method exhibits superior performance than the conventional channel tracking method [Y.G. Li, N. Seshadri, S. Ariyavisitakul, Channel estimation for OFDM systems with transmitter diversity in mobile wireless channels, IEEE J. Sel. Areas Commun. 17 (March 1999) 461-471] in time varying channel environments. At a Doppler frequency of 100Hz and bit error rates (BER) of 10^-^4, signal-to-noise power ratio (E"b/N"0) gains of about 2.5dB are achieved relative to the conventional channel tracking method [Y.G. Li, N. Seshadri, S. Ariyavisitakul, Channel estimation for OFDM systems with transmitter diversity in mobile wireless channels, IEEE J. Sel. Areas Commun. 17 (March 1999) 461-471]. At a Doppler frequency of 200Hz, the performance difference between the proposed method and conventional one becomes much larger.
An Integrated Model and Algorithm for Facility Location under Uncertainty
Authors: Ming_ming Ren, Chao Yang, Bo He
Venue: Proceedings of the Third International Conference on Natural Computation - Volume 01 (2007)

In this paper, we present an integrated approach for simultaneous optimization of the facility location and capacity level of selected facilities under uncertainty. Existing approaches for facility location are usually restricted to only single determining capacity for alternative facilities, and we extend it to several alternative level of capacity for each potential facility so as to avoid the output surplus or scarcity in the future. For this issue, we propose a deterministic formulation and a two-stage stochastic programming model under uncertain environment. In addition, we design two Benders decomposition algorithms for our problems and implement them in matlab7.0. We report on a set of experiments, and conclude that the computational performance of the proposed algorithms is quite satisfactory.
Efficient Second-Order Iterative Methods for IR Drop Analysis in Power Grid
Authors: Yu Zhong, Martin D. F. Wong
Venue: Proceedings of the 2007 Asia and South Pacific Design Automation Conference (2007)

Due to the extremely large sizes of power grids, IR drop analysis has become a computationally challenging problem both in terms of runtime and memory usage. It has been shown in [5] that first-order iterative algorithms based on node-by-node and row-by-row traversals of the power grid have both accuracy and runtime advantages over the well-known Random-Walk method. In this paper, we propose second-order iterative algorithms that can significantly reduce the runtime. The new algorithms are extremely fast, and we prove that they guarantee converge to the exact solutions. Experimental results show that our algorithms outperform the Random-Walk algorithm in [2] and algorithms in [5]. For a 25-million node problem, while the Random-Walk algorithm takes 2 days with maximum error of 6.1 mV, the fastest algorithm in [5] takes 50 minutes, and our second-order row-based algorithm takes 32 minutes to get an exact solution. Moreover, we can get a solution with maximum error 2 mV in 10 minutes.
Cooperative forensics sharing
Authors: Fareed Zaffar, Gershon Kedem
Venue: Proceedings of the 1st international conference on Bio inspired models of network, information and computing systems (2006)

Having timely and credible security information is becoming critical to network and security management. Most current sources of threat information and detection techniques suffer from having a limited view of the global threat scenario. In this paper, we present Foresight, an internet scale threat analysis, indication, early warning and response architecture. We describe the design of an incentive based cooperation scheme to create a global trusted community which is more accountable and hence less vulnerable to attacks and abuse. Foresight utilizes this infrastructure to share a global threat view in order to detect unknown threats and isolate them. We describe a novel behavioral signature scheme to extract a generalized footprint for multi-modal threats. System performance analysis through trace-based simulations show significant benefits for sharing forensics across cooperating domains.
A hybrid fuzzy adaptive sampling - Run rules for Shewhart control charts
Authors: M.H. Fazel Zarandi, A. Alaeddini, I. B. Turksen
Venue: Information Sciences: an International Journal (2008)

In crisp run control rules, usually it is stated that a process moves very sharply from in-control condition to out-of-control act. This causes an increase in both false-alarm rate and control chart sensitivity. Moreover, the classical run control rules are not implemented on an intelligent sampling strategy that changes control charts' parameters to reduce error probability when the process appears to have a shift in parameter values. This paper presents a new hybrid method based on a combination of fuzzified sensitivity criteria and fuzzy adaptive sampling rules, which make the control charts more sensitive and proactive while keeping false alarms rate acceptably low. The procedure is based on a simple strategy that includes varying control chart parameters (sample size and sample interval) based on current fuzzified state of the process and makes inference about the state of process based on fuzzified run rules. Furthermore, in this paper, the performance of the proposed method is examined and compared with both conventional run rules and adaptive sampling schemes.
Computer Slide Making in a Media Services Department
Authors: Norma Frye
Venue: IEEE Computer Graphics and Applications (1983)

No matter how sophisticated a slide-making system is, an artist's imagination and vision are still required to create a product of real value to a company. The ACM Portal is published by the Association for Computing Machinery. Copyright © 2010 ACM, Inc. Terms of Usage Privacy Policy Code of Ethics Contact Us Useful downloads: Adobe Acrobat QuickTime Windows Media Player Real Player
BioRoute: a network-flow based routing algorithm for digital microfluidic biochips
Authors: Ping-Hung Yuh, Chia-Lin Yang, Yao-Wen Chang
Venue: Proceedings of the 2007 IEEE/ACM international conference on Computer-aided design (2007)

Due to the recent advances in microfluidics, digital microfluidic biochips are expected to revolutionize laboratory procedures. One critical problem for biochip synthesis is the droplet routing problem. Unlike traditional VLSI routing problems, in addition to routing path selection, the biochip routing problem needs to address the issue of scheduling droplets under the practical constraints imposed by the fluidic property and the timing restriction of the synthesis result. In this paper, we present the first network-flow based routing algorithm that can concurrently route a set of non-interfering nets for the droplet routing problem on biochips. We adopt a two-stage technique of global routing followed by detailed routing. In global routing, we first identify a set of non-interfering nets and then adopt the network-flow approach to generate optimal global-routing paths for the nets. In detailed routing, we present the first polynomial-time algorithm for simultaneous routing and scheduling using the global-routing paths with a negotiation-based routing scheme. The experimental results show the robustness and efficiency of our algorithm.
Contract-Based ReusableWorst-Case Execution Time Estimate
Authors: Johan Fredriksson, Thomas Nolte, Mikael Nolin, Heinz Schmidt
Venue: Proceedings of the 13th IEEE International Conference on Embedded and Real-Time Computing Systems and Applications (2007)

We present a contract-based technique to achieve reuse of known worst-case execution times (WCET) in conjunction with reuse of software components. For resource constrained systems, or systems where high degree of predictability is needed, classical techniques for WCETestimation will result in unacceptable overestimation of the execution-time of reusable software components with rich behavior. Our technique allows different WCETs to be associated with subsets of the component behavior. The appropriate WCET for any usage context of the component is selected be means of component contracts over the input domain. In a case-study we illustrate our technique and demonstrate its potential in achieving tight WCETestimates for reusable components with rich behavior.
A Call for the Publishing of Blt-Stones
Authors: Tom DeFanti, Rick Frankel, Larry Leske, Maxine Brown
Venue: IEEE Computer Graphics and Applications (1987)

Blt-stones, pronounced "blit-stones" are a set of standard routines for interfacing application programs to graphics memories on personal computers. Blt stands for block transfer, and in computer graphics its most common use is combined with bit, as in bitbit. Blt-stones make color bitbits fast and easy to code. They provide both quantitative and qualitative information about graphics hardware performance, and they give insight into the architectures of graphics boards. They can be used to count the number of pixel-writes per secound, or to determine how many bytes of code are required to gain access to a board's memory. Blt-stones is a term coined by the authors to be a graphics analog to whetsones and dhrysones, performance measures for computer processing speeds.
An Analysis of Estimation of Distribution Algorithms with Finite Population Models
Authors: Yan Wu, Yuping Wang, Xiaoxiong Liu
Venue: Proceedings of the Third International Conference on Natural Computation - Volume 03 (2007)

The convergence of Estimation of Distribution Algorithms (EDAs) with finite population is analyzed in this paper. At first, the models of EDAs with finite population are designed by incorporating an error into expected distribution of parent population. Then the convergence of the EDAs is proved with finite population under three widely used selection schemes. The results show that EDAs converge to the optimal solutions within the range of error described in this paper.
A Novel Approach of Rough Set-Based Attribute Reduction Using Fuzzy Discernibility Matrix
Authors: Ming Yang, Songcan Chen, Xubing Yang
Venue: Proceedings of the Fourth International Conference on Fuzzy Systems and Knowledge Discovery - Volume 03 (2007)

Rough set approach is one of effective attribute reduction (also called a feature selection) methods that can preserve the meaning of the attributes(features). However, most of existing algorithms mainly aim at information systems or decision tables with discrete values. Therefore, in this pa- per, we introduce a novel rough set-based method followed by establishing a fuzzy discernibility matrix by using dis- tance preserving strategy for attribute reduction, and only choose fisher discriminant analysis with kernels as discrim- inant criteria for testing the effectiveness of selected at- tribute subsets with relatively higher fitness values, since the proposed method is independent of post-analysis algo- rithms (predictors).Experimental results show that the clas- sifiers developed using the selected attribute subsets have better or comparable performance on all eight UCI bench- mark datasets than those obtained by all attributes. Thus, our newly developed method can, in most cases, get effec- tive attribute subsets. In addition, this method can be di- rectly incorporated into other learning algorithms, such as PCA, SVM and etc. and can also be more easily applied to many real applications, such as Web Categorization, Image recognition and etc.
GridVine: An Infrastructure for Peer Information Management
Authors: Philippe Cudre-Mauroux, Suchit Agarwal, Karl Aberer
Venue: IEEE Internet Computing (2007)

GridVine is a semantic overlay infrastructure based on a peer-to-peer (P2P) access structure. Built following the principle of data independence, it separates a logical layer—in which data, schemas, and schema mappings are managed—from a physical layer consisting of a structured P2P network supporting decentralized indexing, key load-balancing, and efficient routing. The system is decentralized, yet fosters semantic interoperability through pair-wise schema mappings and query reformulation. GridVine's heterogeneous but semantically related information sources can be queried transparently using iterative query reformulation. The authors discuss a reference implementation of the system and several mechanisms for resolving queries collaboratively.
Evaluating MobySpace-based routing strategies in delay-tolerant networks: Research Articles
Authors: Jérémie Leguay_aff1n2, Timur Friedman, Vania Conan
Venue: Wireless Communications Mobile Computing (2007)

Because a delay-tolerant network (DTN) can often be partitioned, routing is a challenge. However, routing benefits considerably if one can take advantage of knowledge concerning node mobility. This paper addresses this problem with a generic algorithm based on the use of a high-dimensional Euclidean space, that we call MobySpace, constructed upon nodes' mobility patterns. We provide here an analysis and a large-scale evaluation of routing schemes using MobySpace by replaying real mobility traces. The specific MobySpace evaluated is based on the frequency of visits of nodes to each possible location. We present simulation results for single-copy and multi-copy routing strategies that use MobySpace as a means to route bundles or to control flooding. We show that routing based on MobySpace can achieve good performance compared to a number of common algorithms. Copyright &copy; 2007 John Wiley & Sons, Ltd.
Two storage inventory model in a mixed environment
Authors: Manas Kumar Maiti, Manoranjan Maiti
Venue: Fuzzy Optimization and Decision Making (2007)

Multi-item inventory models with two storage facility and bulk release pattern are developed with linearly time dependent demand in a finite time horizon under crisp, stochastic and fuzzy-stochastic environments. Here different inventory parameters--holding costs, ordering costs, purchase costs, etc.--are assumed as probabilistic or fuzzy in nature. In particular cases stochastic and crisp models are derived. Models are formulated as profit maximization principle and three different approaches are proposed for solution. In the first approach, fuzzy extension principle is used to find membership function of the objective function and then it's Graded Mean Integration Value (GMIV) for different optimistic levels are taken as equivalent stochastic objectives. Then the stochastic model is transformed to a constraint multi-objective programming problem using Stochastic Non-linear Programming (SNLP) technique. The multi-objective problems are transferred to single objective problems using Interactive Fuzzy Satisfising (IFS) technique. Finally, a Region Reducing Genetic Algorithm (RRGA) based on entropy has been developed and implemented to solve the single objective problems. In the second approach, the above GMIV (which is stochastic in nature) is optimized with some degree of probability and using SNLP technique model is transferred to an equivalent single objective crisp problem and solved using RRGA. In the third approach, objective function is optimized with some degree of possibility/necessity and following this approach model is transformed to an equivalent constrained stochastic programming problem. Then it is transformed to an equivalent single objective crisp problem using SNLP technique and solved via RRGA. The models are illustrated with some numerical examples and some sensitivity analyses have been presented.
COMBI-operator - database support for data mining applications
Authors: Alexander Hinneburg, Dirk Habich, Wolfgang Lehner
Venue: Proceedings of the 29th international conference on Very large data bases - Volume 29 (2003)

Database support for data mining has become an important research topic. Especially for large high-dimensional data volumes, comprehensive support from the database side is necessary. In this paper we identify the data intensive subproblem of aggregating high-dimensional data in all possible low-dimensional projections (for instance estimating low-dimensional histograms), which occurs in several established data mining techniques. Second, we show that existing OLAP SQL-extensions are insufficient for high-dimensional data and propose a new SQL-operator, which seamlessly fits into the set of existing OLAP Group By operators. Third, we propose efficient implementations for the operator, which take the limited resources of main memory into account. We demonstrate on a number of real and synthetic data sets that for the identified subproblem our new implementations yield a large speedup (up to factor 10) over existing methods built in commercially available database systems.
Making p2p accountable without losing privacy
Authors: Mira Belenkiy, Melissa Chase, C. Chris Erway, John Jannotti, Alptekin Küpçü, Anna Lysyanskaya, Eric Rachlin
Venue: Proceedings of the 2007 ACM workshop on Privacy in electronic society (2007)

Peer-to-peer systems have been proposed for a wide variety of applications, including file-sharing, web caching, distributed computation, cooperative backup, and onion routing. An important motivation for such systems is self-scaling. That is, increased participation increases the capacity of the system. Unfortunately, this property is at risk from selfish participants. The decentralized nature of peer-to-peer systems makes accounting difficult. We show that e-cash can be a practical solution to the desire for accountability in peer-to-peer systems while maintaining their ability to self-scale. No less important, e-cash is a natural fit for peer-to-peer systems that attempt to provide (or preserve) privacy for their participants. We show that e-cash can be used to provide accountability without compromising the existing privacy goals of a peer-to-peer system. We show how e-cash can be practically applied to a file sharing application. Our approach includes a set of novel cryptographic protocols that mitigate the computational and communication costs of anonymous e-cash transactions, and system design choices that further reduce overhead and distribute load. We conclude that provably secure, anonymous, and scalable peer-to-peer systems are within reach.