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An improved association rule mining algorithm for large data

JOURNAL OF INTELLIGENT SYSTEMS 2021年第1期30卷 750-762页

作者： Zhao, Zhenyi Jian, Zhou Gaba, Gurjot Singh Alroobaea, Roobaea Masud, Mehedi Rubaiee, Saeed Taif Univ Coll Comp & Informat Technol Dept Comp Sci At Taif Saudi Arabia Wenzhou Vocat Coll Sci & Technol Wenzhou 325000 Peoples R China Lovely Profess Univ Sch Elect & Elect Engn Phagwara 144411 India Univ Jeddah Coll Engn Dept Ind & Syst Engn Jeddah Saudi Arabia

The data with the advancement of information technology are increasing on daily basis. The data mining technique has been applied to various fields. The complexity and execution time are the major factors viewed in existing data mining techniques. With the rapid development of database technology, many data storage increases, and data mining technology has become more and more important and expanded to various fields in recent years. Association rule mining is the most active research technique of data mining. Data mining technology is used for potentially useful information extraction and knowledge from big data sets. The results demonstrate that the precision ratio of the presented technique is high comparable to other existing techniques with the same recall rate, i.e., the R-tree algorithm. The proposed technique by the mining effectively controls the noise data, and the precision rate is also kept very high, which indicates the highest accuracy of the technique. This article makes a systematic and detailed analysis of data mining technology by using the Apriori algorithm.

关键词： rule mining Apriori algorithm frequent item sets R-tree algorithm dynamic algorithm precision ratio accuracy

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Saturated fully leafed tree-like polyforms and polycubes

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JOURNAL OF DISCRETE algorithmS 2018年 52-53卷 38-54页

作者： Masse, Alexandre Blondin De Carufel, Julien Goupil, Alain

We present recursive formulas giving the maximal number of leaves in tree-like polyforms living in two-dimensional regular lattices and in tree-like polycubes in the three-dimensional cubic lattice. We call these tree-like polyforms and polycubes fully leafed. The proof relies on a combinatorial algorithm that enumerates rooted directed trees that we call abundant. In the last part, we concentrate on the particular case of polyforms and polycubes, that we call saturated, which is the family of fully leafed structures that maximize the ratio (number of leaves)/(number of cells). In the polyomino case, we present a bijection between the set of saturated tree-like polyominoes of size 4k + 1 and the set of tree-like polyominoes of size k. We exhibit a similar bijection between the set of saturated tree-like polycubes of size 41k + 28 and a family of polycubes, called 4-trees, of size 3k + 2. (C) 2018 Elsevier B.V. All rights reserved.

关键词： Polyomino dynamic algorithm Combinatorics Fully leafed Lattice Polyform Polycube Graph theory

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Transmissions in a network with capacities and delays

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NETWORKS 1999年第3期33卷 167-174页

作者： Kagaris, D Pantziou, GE Tragoudas, S Zaroliagis, CD Univ Patras Inst Comp Technol Patras 26110 Greece Technol & Educ Inst Athens GR-12210 Aigaleo Greece So Illinois Univ Dept Elect Engn Carbondale IL 62901 USA Univ Arizona Dept Elect & Comp Engn Tucson AZ 85740 USA Kings Coll London Dept Comp Sci London WC2R 2LS England

We examine the problem of transmitting in minimum time a given amount of data between a source and a destination in a network with finite channel capacities and nonzero propagation delays. In the absence of delays, the problem has been shown to be solvable in polynomial time. In this paper, we show that the general problem is NP-complete. In addition, we examine transmissions along a single path, called the quickest path, and present algorithms for general and special classes of networks that improve upon previous approaches. The first dynamic algorithm for the quickest path problem is also given. (C) 1999 John Wiley & Sons, Inc.

关键词： data transmission sparse network transmission time quickest path dynamic algorithm

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Fully dynamic Randomized algorithms for Graph Spanners

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ACM TRANSACTIONS ON algorithmS 2012年第4期8卷 35-35页

作者： Baswana, Surender Khurana, Sumeet Sarkar, Soumojit Indian Inst Technol Dept Comp Sci & Engn Kanpur 208016 Uttar Pradesh India Max Planck Inst Comp Sci D-66123 Saarbrucken Germany

Spanner of an undirected graph G = (V, E) is a subgraph that is sparse and yet preserves all-pairs distances approximately. More formally, a spanner with stretch t is an element of N is a subgraph (V, E-S), E-S subset of E such that the distance between any two vertices in the subgraph is at most t times their distance in G. Though G is trivially a t-spanner of itself, the research as well as applications of spanners invariably deal with a t-spanner that has as small number of edges as possible. We present fully dynamic algorithms for maintaining spanners in centralized as well as synchronized distributed environments. These algorithms are designed for undirected unweighted graphs and use randomization in a crucial manner. Our algorithms significantly improve the existing fully dynamic algorithms for graph spanners. The expected size (number of edges) of a t-spanner maintained at each stage by our algorithms matches, up to a polylogarithmic factor, the worst case optimal size of a t-spanner. The expected amortized time (or messages communicated in distributed environment) to process a single insertion/deletion of an edge by our algorithms is close to optimal.

关键词： algorithms Theory Graph algorithms dynamic algorithm graph spanner approximate shortest paths

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Investigation of a Real-Time dynamic Model for a PV Cooling System

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ENERGIES 2022年第5期15卷 1836页

作者： Manasrah, Ahmad Masoud, Mohammad Jaradat, Yousef Bevilacqua, Piero Al Zaytoonah Univ Jordan Mech Engn Dept Amman 11733 Jordan Al Zaytoonah Univ Jordan Elect Engn Dept Amman 11733 Jordan Univ Calabria Dept Mech Energet & Management Engn I-87036 Arcavacata Di Rende Italy

The cooling of PV models is an important process that enhances the generated electricity from these models, especially in hot areas. In this work, a new, active cooling algorithm is proposed based on active fan cooling and an artificial neural network, which is named the artificial dynamic neural network Fan cooling algorithm (DNNFC). The proposed system attaches five fans to the back of a PV model. Subsequently, only two fans work at any given time to circulate the air under the PV model in order to cool it down. Five different patterns of working fans have been experimented with in this work. To select the optimal pattern for any given time, a back propagation neural network model was trained. The algorithm is a dynamic algorithm since it re-trains the model with new recorded surface temperatures over time. In this way, the model automatically adapts to any weather and environmental conditions. The model was trained with an indoor dataset and tested with an outdoor dataset. An accuracy of more than 97% has been recorded, with a mean square error of approximately 0.02.

关键词： PV cooling neural network dynamic algorithm

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Channel assignment with separation in the Cartesian product of two cycles

Channel assignment with separation in the Cartesian product ...

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24th International Conference on Information Technology Interfaces (ITI 2002)

作者： Vesel, A Univ Maribor PEF Dept Math SI-2000 Maribor Slovenia

ISBN: (纸本)9539676959

The L(2,1)-coloring is an abstraction of assigning integer frequencies to radio transmitters such that transmitters that are one unit of distance apart receive frequencies that differ by at least two, and transmitters that are two units apart receive frequencies that differ by at least one. In particular, the L (2, I)-coloring in the two dimensional torus (the Cartesian product of two cycles) is considered. Me describe approximation and exact algorithms to search L(2, 1) colorings in the torus. The exact values 077 the L(2, l)-coloring of three infinite families of graphs: C(n)squareC(5), C(n)squareC(6) and C(n)squareC(7) are presented.

关键词： channel assignment wireless network dynamic algorithm algorithm antivoter Cartesian product

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Approximation algorithms for Large Scale Data Analysis 21

Approximation Algorithms for Large Scale Data Analysis

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40th ACM SIGMOD-SIGACT-SIGAI Symposium on Principles of Database Systems (PODS)

作者： Saha, Barna Univ Calif Berkeley Berkeley CA 94720 USA

ISBN: (纸本)9781450383813

One of the greatest successes of computational complexity theory is the classification of countless fundamental computational problems into polynomial-time and NP-hard ones, two classes that are often referred to as tractable and intractable, respectively. However, this crude distinction of algorithmic efficiency is clearly insufficient when handling today's large scale of data. We need a finer-grained design and analysis of algorithms that pinpoints the exact exponent of polynomial running time, and a better understanding of when a speed-up is not possible. Based on stronger complexity assumptions than P vs NP, like the Strong Exponential Time Hypothesis, recently conditional lower bounds for a variety of fundamental problems in P have been proposed. Unfortunately, these conditional lower bounds often break down when one may settle for a near-optimal solution. Indeed, approximation algorithms can play a significant role when designing fast algorithms not just for traditional NP Hard problems, but also for polynomial time problems. For some applications arising in machine learning, the time complexity of the underlying algorithms is not sufficient to ensure a fast solution. It is often needed to collect side information about the data to ensure high accuracy. This requires low query complexity. In this presentation, we will cover new facets of fast algorithm design for large scale data analysis that emphasizes on the role of developing approximation algorithms for better polynomial time/query complexity.

关键词： approximation algorithms fine-grained complexity dynamic algorithm interactive algorithms

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New algorithms and Hardness for Incremental Single-Source Shortest Paths in Directed Graphs 2020

New Algorithms and Hardness for Incremental Single-Source Sh...

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52nd Annual ACM SIGACT Symposium on Theory of Computing (STOC)

作者： Gutenberg, Maximilian Probst Williams, Virginia Vassilevska Wein, Nicole Univ Copenhagen Copenhagen Denmark MIT Cambridge MA 02139 USA

ISBN: (纸本)9781450369794

In the dynamic Single-Source Shortest Paths (SSSP) problem, we are given a graph G = (V, E) subject to edge insertions and deletions and a source vertex s is an element of V, and the goal is to maintain the distance d(s, t) for all t is an element of V. Fine-grained complexity has provided strong lower bounds for exact partially dynamic SSSP and approximate fully dynamic SSSP [ESA'04, FOCS'14, STOC'15]. Thus much focus has been directed towards finding efficient partially dynamic (1 + epsilon)-approximate SSSP algorithms [STOC'14, ICALP'15, SODA'14, FOCS'14, STOC'16, SODA'17, ICALP'17, ICALP'19, STOC'19, SODA'20, SODA'20]. Despite this rich literature, for directed graphs there are no known deterministic algorithms for (1 +epsilon)-approximate dynamic SSSP that perform better than the classic ES-tree [JACM'81]. We present the first such algorithm. We present a deterministic data structure for incremental SSSP in weighted directed graphs with total update time (O) over tilde (n(2) log W /epsilon(O(1))) which is near-optimal for very dense graphs;here W is the ratio of the largest weight in the graph to the smallest. Our algorithm also improves over the best known partially dynamic randomized algorithm for directed SSSP by Henzinger et al. [STOC'14, ICALP'15] if m = omega(n(1.1)). Complementing our algorithm, we provide improved conditional lower bounds. Henzinger et al. [STOC'15] showed that under the OMv Hypothesis, the partially dynamic exact s-t Shortest Path problem in undirected graphs requires amortized update or query time m(1/2-o(1)), given polynomial preprocessing time. Under a new hypothesis about finding Cliques, we improve the update and query lower bound for algorithms with polynomial preprocessing time to m(0.626-o(1)). Further, under the k-Cycle hypothesis, we show that any partially dynamic SSSP algorithm with O(m(2-epsilon)) preprocessing time requires amortized update or query time m(1-o(1)), which is essentially optimal. All previous conditional lo

关键词： dynamic algorithm shortest path single source shortest path conditional lower bound

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Decremental Strongly-Connected Components and Single-Source Reachability in Near-Linear Time 2019

Decremental Strongly-Connected Components and Single-Source ...

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51st Annual ACM SIGACT Symposium on Theory of Computing (STOC)

作者： Bernstein, Aaron Probst, Maximilian Wulff-Nilsen, Christian Rutgers Univ New Brunswick Dept Comp Sci New Brunswick NJ USA Univ Copenhagen Copenhagen Denmark

ISBN: (纸本)9781450367059

Computing the Strongly-Connected Components (SCCs) in a graph G = (V, E) is known to take only O(m + n) time using an algorithm by Tarjan from 1972[SICOMP 72] where m = vertical bar E vertical bar, n = vertical bar V vertical bar. For fully-dynamic graphs, conditional lower bounds provide evidence that the update time cannot be improved by polynomial factors over recomputing the SCCs from scratch after every update. Nevertheless, substantial progress has been made to find algorithms with fast update time for decremental graphs, i.e. graphs that undergo edge deletions. In this paper, we present the first algorithm for general decremental graphs that maintains the SCCs in total update time (O) over tilde (m)(1), thus only a polylogarithmic factor from the optimal running time. Previously such a result was only known for the special case of planar graphs [Italiano et al, STOC 17]. Our result should be compared to the formerly best algorithm for general graphs achieving (O) over tilde (m root n) total update time by Chechik ***. [FOCS 16] which improved upon a breakthrough result leading to O(mn(0.9+o(1))) total update time by Henzinger, Krinninger and Nanongkai [STOC 14, ICALP 15];these results in turn improved upon the longstanding bound of O(mn) by Roditty and Zwick [STOC 04]. All of the above results also apply to the decremental Single-Source Reachability (SSR) problem, which can be reduced to decrementally maintaining SCCs. A bound of O(mn) total update time for decremental SSR was established already in 1981 by Even and Shiloach [JACM 81].

关键词： dynamic algorithm strongly connected components single source reachability

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Statistical and cognitive optimization of experimental designs in conjoint analysis

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EUROPEAN JOURNAL OF MANAGEMENT AND BUSINESS ECONOMICS 2016年第3期25卷 142-149页

作者： Huertas-Garcia, Ruben Nenez-Carballosa, Ana Miravitlles, Paloma Univ Barcelona Fac Econ & Empresa Dept Econ & Org Empresas Comercializac & Invest Mercados Barcelona Spain Univ Barcelona Fac Econ & Empresa Dept Econ & Org Empresas Org Empresas Barcelona Spain

Conjoint analysis has become the most used technique for measuring preferences for new products to be launched in the market. Experimental design models are key elements for its use in market research. Such models involve a matrix in which attributes and levels are combined, making product concepts that respondents then evaluate. Experimental design has emerged as a key element in conjoint analysis' success because its application generates statistical and reliability implications for part-worth factor estimations and for the type of heuristics followed by respondents. This paper proposes a conceptualization of both statistical and cognitive efficiency criteria for experimental designs. A review of the most used statistical optimization criteria is presented, as well as a methodology for optimizing cognitive efficiency. Finally, we suggest a dynamic algorithm for optimizing the objective function in a sequential manner. (c) 2015 AEDEM. Published by Elsevier Espana, S.L.U.

关键词： Optimal experimental design Cognitive ability Conjoint analysis Preference measurement dynamic algorithm

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