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A new computer algorithm for simultaneous test construction of two-stage and multistage testing

JOURNAL OF EDUCATIONAL AND BEHAVIORAL STATISTICS 2001年第2期26卷 180-198页

作者： Wu, IL Natl Chung Cheng Univ Dept Informat Management Chiayi 621 Taiwan

This paper discusses the simultaneous approach for test generation of two-stage and multistage tests from an item batik. However, most previous test generation problems involved binary programming models, and the efficiency of available solution algorithms is the major concern for these problems. Therefore, this study considers two important concepts on the solution process, i.e., alternative ways to formulate mathematical models and alternative solution algorithms. Based on these two concepts, this paper is two-fold. First, two binary programming models with a special network structure that would be explored computationally are presented for modeling these problems. The first model maximizes test information function at one specified ability point and the second model matches the target test information function at several specified ability points as closely as possible. Second, an efficient special-purpose network algorithm is then used to solve these two models. Hence, the test construction process tends to be improved in terms of both. computational efforts and quality of tests. An empirical study shows the results in line with the above two criteria.

关键词： two-stage and multistage testing binary programming network algorithm item response theory item bank test construction

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A New IP Video Delivery System for Heterogeneous networks using HTML5

A New IP Video Delivery System for Heterogeneous Networks us...

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IEEE International Conference on Communications (ICC)

作者： Lopez-Herreros, Andres Canovas, Alejandro Jimenez, Jose M. Lloret, Jaime Univ Politecn Valencia Inst Invest Gest Integrada Zonas Costeras E-46022 Valencia Spain

ISBN: (纸本)9781467364324

Currently, one of the main problems facing the video broadcast on the Internet is the limitation of the available bandwidth. The media elements contain a large number of multiplexed data and its encoding is necessary for a smooth issuance through the new Application Programming Interface (API) in HTML5 or through third-party plugins. Internet offers a wide compatibility with many formats and video codecs, but its emission focuses specifically on the three main ones: MPEG-4, Ogg and WEBM. In this paper, we study different encodings of a video depending on the bitrate and the encoding time. This study will allow us to know the characteristics of each one of these three video formats. Then, we use this information to design an algorithm, which will run in a server, in order to send the appropriate video type according to the studied characteristics.

关键词： video transmission video delivery video codec network algorithm

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Causality Tracking Trade-offs for Distributed Storage 19

Causality Tracking Trade-offs for Distributed Storage

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IEEE 19th International Symposium on network Computing and Applications (NCA)

作者： Guerreiro, Hugo Rodrigues, Luis Preguica, Nuno Quental, Nivia Univ Lisbon Inst Super Tecn INESC ID Lisbon Portugal Univ Nova Lisboa Fac Ciencias & Tecnol NOVA LINCS Lisbon Portugal INESC ID Lisbon Portugal

ISBN: (纸本)9781728183268

After the seminal paper by L. Lamport, which introduced (scalar) logical clocks, several other data structures for keeping track of causality in distributed systems have been proposed, including vector and matrix clocks. These are able to capture causal dependencies with more detail but, unfortunately, also consume a substantially larger amount of network bandwidth and storage space than Lamport clocks. This raises the question of whether the benefits of these more complex structures are worth their cost. We address this question in the context of partially replicated systems. We show that for some workloads the use of more expensive clocks does bring significant benefits and that for other workloads no visible benefits can be observed. The paper provides a characterization of the scenarios where each type of clock is more beneficial, helping designers to develop more efficient distributed storage systems.

关键词： Distributed Computing methodologies Distributed Storage network algorithm causal Consistency

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Methods For MetaâAnalyses Of Rare Events, Sparse Data, And Heterogeneity

Methods For Metaâ€“Analyses Of Rare Events, Sparse Data, ...

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作者： Brinley Zabriskie Utah State University

学位级别：博士

The vast and complex wealth of information available to researchers often leads to a systematic review, which involves a detailed and comprehensive plan and search strategy with the goal of identifying, appraising, and synthesizing all relevant studies on a particular topic. A metaâanalysis, conducted ideally as part of a comprehensive systematic review, statistically synthesizes evidence from multiple independent studies to produce one overall conclusion. The increasingly widespread use of metaâanalysis has led to growing interest in metaâanalytic methods for rare events and sparse data. Conventional approaches tend to perform very poorly in such settings. Recent work in this area has provided options for sparse data, but these are still often hampered when heterogeneity across the available studies differs based on treatment group. Heterogeneity arises when participants in a study are more correlated than participants across studies, often stemming from differences in the administration of the treatment, study design, or measurement of the outcome. We propose several new exact methods that accommodate this common contingency, providing more reliable statistical tests when such patterns on heterogeneity are observed. First, we develop a permutationâbased approach that can also be used as a basis for computing exact confidence intervals when estimating the effect size. Second, we extend the permutationâbased approach to the network metaâanalysis setting. Third, we develop a new exact confidence distribution approach for effect size estimation. We show these new methods perform markedly better than traditional methods when events are rare, and heterogeneity is present.

关键词： small samples network meta-analysis confidence distributions correlated data network algorithm Mathematics

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Two routers network architecture and scheduling algorithms under packet category classification constraint 2021

Two routers network architecture and scheduling algorithms u...

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The 5th International Conference on Future networks & Distributed Systems

作者： Akram Sarhan Mahdi Jemmali Abir Ben Hmida Department of Information systems College of Computing and information technology University of Jeddah Saudi Arabia Department of Computer Science and Information College of Science at Zulfi Majmaah University Saudi Arabia and University of Sousse MARS Laboratory University of Sousse Tunisia Department of Information systems College of Computing and Information Technology at Khulis University of Jeddah Saudi Arabia

ISBN: (纸本)9781450387347

The sending and exchanging of data have become essential in the current revolution of industry 4.0 and digital transformation and all aspects of life. Ensuring the security of transmitted data continues to be a critical issue due to the fast advancement in technology. The studied problem is proven to be NP-hard in the strong sense. The contribution of this paper is twofold. First, we propose a network architecture that enables multilevel data sharing through two routers based on a data category classification constraint. Second, we propose a set of heuristic algorithms for an NP-Hard problem. The constraint of the studied problem is described as follows. Two files belonging to the same category of confidential level should not be transmitted simultaneously through the routers. The proposed architecture involves a scheduler component responsible for finding a schedule that minimizes the maximum estimated transmission time respecting the data category classification constraint. An experimental result is carried out to show the performance of the proposed algorithms. Several indicators are used to measure the performance of algorithms. The best algorithm is the Modified decreasing estimated-transmission time algorithm in 91.6% of cases. The experimental results confirm the practicality of the proposed scheme in terms of two-machines scheduling problems.

关键词： Data security and privacy Data sharing Packet scheduling Heuristics network algorithm

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AIS explorer: Prioritization for watercraft inspections-A decision-support tool for aquatic invasive species management

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JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022年 314卷 115037页

作者： Kinsley, Amy C. Haight, Robert G. Snellgrove, Nicholas Muellner, Petra Muellner, Ulrich Duhr, Meg Phelps, Nicholas B. D. Univ Minnesota Dept Vet Populat Med St Paul MN USA Univ Minnesota Ctr Anim Hlth & Food Safety St Paul MN USA USDA Forest Serv Northern Res Stn St Paul MN USA Epi interact POB 15327 Wellington 6243 New Zealand Massey Univ Sch Vet Sci Palmerston North New Zealand Univ Minnesota Minnesota Aquat Invas Species Res Ctr Minneapolis MN USA Univ Minnesota Dept Fisheries Wildlife & Conservat Biol Minneapolis MN USA 1988 Fitch Ave St Paul MN 55108 USA

Invasions of aquatic invasive species have caused significant economic and ecological damage to global aquatic ecosystems. Once an invasive population has established in a new habitat, eradication can be financially and logistically impossible, motivating management strategies to rely heavily upon prevention measures to reduce the introduction and spread. To be productive, on-the-ground management of aquatic invasive species requires effective decision-making surrounding the allocation of limited resources. Watercraft inspections play an important role in managing aquatic invasive species by preventing the overland transport of invasive species between waterbodies and providing education to boaters. In this study, we developed and tested an interactive web-based decision-support tool, AIS Explorer: Prioritization for Watercraft Inspections, to guide AIS managers in developing efficient watercraft inspection plans. The decision-support tool is informed by a network-based algorithm that maximized the number of inspected watercraft that move from AIS infested to uninfested lakes within and between counties in Minnesota, USA. It was iteratively built with stakeholder feedback, including consultations with county managers, beta-testing of the web-based application, and workshops to educate and train end-users. The co-development and implementation of data-driven decision support tools demonstrate how interdisciplinary methods can be used to connect science and management to support decision-making. The AIS Explorer: Prioritization for Watercraft Inspections application makes optimized research outputs accessible in multiple dynamic forms that maintain pace with discovery of new infestations and local needs. In addition, the decision support tool has supported improved and closer communication between AIS managers and researchers on this topic.

关键词： Aquatic invasive species Decision-support tool Invasive species management Resource allocation network algorithm Aquatic resource management Stakeholder engagement

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A Novel Two-Routers Model Based on Category Constraints Secure Data-Dissemination-Aware Scheduling in Next-Generation Communication networks

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JOURNAL OF network AND SYSTEMS MANAGEMENT 2023年第3期31卷 59-59页

作者： Jemmali, Mahdi Ben Hmida, Abir Sarhan, Akram Y. Majmaah Univ Coll Sci Zulfi Dept Comp Sci & Informat Al Majmaah 11952 Saudi Arabia Univ Sousse MARS Lab Sousse Tunisia Univ Monastir Higher Inst Comp Sci & Math Dept Comp Sci Monastir 5000 Tunisia Univ Jeddah Coll Comp & Informat Technol Khulis Dept Informat Technol Jeddah Saudi Arabia

Data breaches are a critical issue and have become one of the top widespread risks in today's data-driven digital environment. Hence, Secure data outsourcing is essential in today's digital communications. The current interconnected network lack many core features, including privacy and security, which make it vulnerable to data leakages when transmitting sensitive information during critical circumstances (e.g., natural and human disasters). In this paper, we propose a network model that can be employed as a future private network paradigm to promptly and securely transmit confidential data, hence minimizing the chances of breaches. Our schemes provide the following contributions: (1) design a private novel network architecture to disseminate multilevel confidential packets using two routers;(2) Develop several heuristics to reduce an NP-hard problem to find an optimal solution for the studied problem;(3) Employee a developed scheduler for selecting the best algorithm that schedule packets securely and timely through two routers such that critical data packets associated to the same confidential level are prohibited from being transmitted at the same time;(4) conduct an analysis study to compare the developed heuristics and to prove the practicality of the proposed solution. The experimental results show the performance of the proposed heuristics. The results showed that the best heuristic is IFP2 in 84.4% of cases.

关键词： Data sharing Data privacy Data dissemination Traffic modeling network algorithm Data classification

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A novel smart multilevel security approach for secure data outsourcing in crisis

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PEERJ COMPUTER SCIENCE 2023年 9卷 e1367页

作者： Sarhan, Akram Y. Univ Jeddah Coll Comp & Informat Technol Dept Informat Technol Jeddah Mecca Province Saudi Arabia

The Interconnected network or the Internet has revolutionized digital communi-cations. It has expanded worldwide over the past four decades due to numerous features such as connectivity, transparency, hierarchy, and openness. Several drawbacks, including mobility, scalability, controllability, security, etc., have been presented due to continuous developments. Although several network paradigms exist to address such drawbacks, many issues still persist. This research proposed a future network paradigm that addresses multilevel security shortcomings. It suggested the following: (i) a two -router network-based cyber security architecture for multilevel data sharing;(ii) using a scheduler to deal with the multilevel transmitted packets scheduling problem;(iii) five algorithms for the studied difficult problem;and (iv) providing an experimental result to show the optimal results obtained by the developed algorithms and comparing it with algorithms in the literature. The experimental result shows that the random-grouped classification with shortest scheduling algorithm (RGS) performed the best at 37.7% with a gap of 0.03. This result proves the practicality of our approach in terms of two -machine scheduling problems.

关键词： Future network Multilevel security cyber security Data sharing network algorithm Packet scheduling Heuristics Secure Data Sharing

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Fast Computation of Exact Confidence Limits for the Common Odds Ratio in a Series of 2 × 2 Tables

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Quarterly Publications of the American Statistical Association 1991年第414期86卷 404-409页

The odds ratio is widely used as a measure of association in epidemiologic studies and clinical trials. We consider calculation of exact confidence limits for the common odds ratio in a series of independent 2 × 2 tables and propose three modifications of the network algorithm of Mehta, Patel and Gray: (1) formulating and dealing with the problem in algebraic instead of graph theoretic terms, (2) performing convolutions on the natural scale instead of the logarithmic scale, and (3) using the secant method instead of binary search to compute roots of polynomial equations. Enhancement of computational efficiency, exceeding an order of magnitude, afforded by these modifications is empirically demonstrated. We also compare the modified method with one based on the fast Fourier transform (FFT). Further, we show that the FFT method can also result in considerable loss of numerical accuracy. The modifications proposed in this article yield an algorithm that is not only fast and accurate but that combines conceptual simplicity with ease of implementation. Anyone with a rudimentary knowledge of computer programming can implement it and quickly compute exact confidence intervals for relatively large data sets even on microcomputers. Thus it should help make exact analysis of the common odds ratio more common.

关键词： Convolution algorithm Exact inference Fast Fourier transform network algorithm

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Exact Inference for Contingency Tables With Ordered Categories

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Journal of the American Statistical Association 1990年第410期85卷 453-458页

作者： Agresti, Alan Mehta, Cyrus R. Patel, Nitin R. Department of Statistics University of Florida Gainesville FL 32611 Associate Professor Department of Biostatistics Harvard University School of Public Health Boston MA 02115 President Cytel Software Corporation Cambridge MA 02139 Visiting Professor Department of Biostatistics Harvard University School of Public Health Boston MA 02115

This article proposes an efficient numerical algorithm for small-sample exact inferences in contingency tables having ordinal classifications. The inferences, which apply conditional on the observed marginal totals, also provide an exact analysis for the log-linear model of linear-by-linear association for cell probabilities. An exact test of independence has a one-sided P value equal to the null probability that model-based maximum likelihood estimates of odds ratios are at least as large as the observed estimates. The conditional nonnull distribution yields confidence intervals for odds ratios having a linear-by-linear structure. The computations utilize an extension of the network algorithm proposed by Mehta and Patel (1983). [ABSTRACT FROM AUTHOR]

关键词： Linear-by-linear association Log-linear models Multiple hypergeometric distribution network algorithm Odds ratio Rank tests Score tests Uniform association

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