• Title/Summary/Keyword: Combinatorial

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A QEE-Oriented Fair Power Allocation for Two-tier Heterogeneous Networks

  • Ji, Shiyu;Tang, Liangrui;He, Yanhua;Li, Shuxian;Du, Shimo
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.12 no.5
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    • pp.1912-1931
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    • 2018
  • In future wireless network, user experience and energy efficiency will play more and more important roles in the communication systems compared to their roles at present. Quality of experience (QoE) and Energy Efficiency (EE) become the widely used metrics. In this paper, we study a combinatorial problem of QoE and EE and investigate a fair power allocation in heterogeneous networks. We first design a new metric, QoE-aware EE (QEE) to reflect the relationship of QoE and energy. Then, the concept of Utopia QEE is introduced, which is defined as the achievable maximum QEE in ideal conditions, for each user. Finally, we transform the power allocation process to an optimization of ratio of QEE and Utopia QEE and use invasive weed optimization (IWO) algorithm to solve the optimization problem. Numerical simulation results indicate that the proposed algorithm can get converged and efficiently improve the system energy efficiency and the QoE for each user.

Fuzzy Learning Method Using Genetic Algorithms

  • Choi, Sangho;Cho, Kyung-Dal;Park, Sa-Joon;Lee, Malrey;Kim, Kitae
    • Journal of Korea Multimedia Society
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    • v.7 no.6
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    • pp.841-850
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    • 2004
  • This paper proposes a GA and GDM-based method for removing unnecessary rules and generating relevant rules from the fuzzy rules corresponding to several fuzzy partitions. The aim of proposed method is to find a minimum set of fuzzy rules that can correctly classify all the training patterns. When the fine fuzzy partition is used with conventional methods, the number of fuzzy rules has been enormous and the performance of fuzzy inference system became low. This paper presents the application of GA as a means of finding optimal solutions over fuzzy partitions. In each rule, the antecedent part is made up the membership functions of a fuzzy set, and the consequent part is made up of a real number. The membership functions and the number of fuzzy inference rules are tuned by means of the GA, while the real numbers in the consequent parts of the rules are tuned by means of the gradient descent method. It is shown that the proposed method has improved than the performance of conventional method in formulating and solving a combinatorial optimization problem that has two objectives: to maximize the number of correctly classified patterns and to minimize the number of fuzzy rules.

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Dose-response assessment of the anti-cancer efficacy of soy isoflavones in dimethylhydrazine-treated rats fed 6% fructooligosaccharide

  • Sung, Rye-Young;Choi, Young-Sun
    • Nutrition Research and Practice
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    • v.2 no.2
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    • pp.55-61
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    • 2008
  • We investigated the combinatorial effects of different doses of dietary soy isoflavones (SI) and fructooligosaccharide (FOS) in a rat model of colon cancer. We hypothesized that increased bioavailability of SI metabolites due to dietary FOS may increase production of bioactive equol and affect colon carcinogenesis in a dose-dependent manner. Sprague-Dawley male rats were injected with 12-dimethylhydrazine (DMH) and were providec experimental diets that contained 0, 10, 50, 150, or 500 mg SI per kg of diet and 6% FOS for 12 weeks. The number of aberrant crypt foci (ACF) and the expression of cyclooxygenase-2 (COX-2) in colonic tissues were significantly decreased in the 6% FOS-fed groups compared to the control group. Gut transit time and fecal pH were significantly lower, and fecal concentrations of bifidobacteria were increased with 6% FOS. However, dietary SI supplementation in combination with 6% dietary FOS did not affect ACF formation or COX-2 expression. Plasma equol concentrations were dose-dependently increased by supplementation of SI up to 500 mg/kg of diet. In conclusion, SI supplementation up to 500 mg/kg of diet appeared to have no additive beneficial effects in rats with chemically-induced colon cancer that were fed 6% FOS, although plasma equol was dose-dependently increased.

A Parallel Genetic Algorithm for Solving Deadlock Problem within Multi-Unit Resources Systems

  • Ahmed, Rabie;Saidani, Taoufik;Rababa, Malek
    • International Journal of Computer Science & Network Security
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    • v.21 no.12
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    • pp.175-182
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    • 2021
  • Deadlock is a situation in which two or more processes competing for resources are waiting for the others to finish, and neither ever does. There are two different forms of systems, multi-unit and single-unit resource systems. The difference is the number of instances (or units) of each type of resource. Deadlock problem can be modeled as a constrained combinatorial problem that seeks to find a possible scheduling for the processes through which the system can avoid entering a deadlock state. To solve deadlock problem, several algorithms and techniques have been introduced, but the use of metaheuristics is one of the powerful methods to solve it. Genetic algorithms have been effective in solving many optimization issues, including deadlock Problem. In this paper, an improved parallel framework of the genetic algorithm is introduced and adapted effectively and efficiently to deadlock problem. The proposed modified method is implemented in java and tested on a specific dataset. The experiment shows that proposed approach can produce optimal solutions in terms of burst time and the number of feasible solutions in each advanced generation. Further, the proposed approach enables all types of crossovers to work with high performance.

Effect of Citrus macroptera Fruit Pulp Juice on Alteration of Caspase Pathway Rendering Anti-Proliferative Activity against Ehrlich's Ascites Carcinoma in Mice

  • Hasan, Md. Mahmudul;Islam, Md. Shihabul;Hoque, Kazi Md. Faisal;Haque, Ariful;Reza, Md Abu
    • Toxicological Research
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    • v.35 no.3
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    • pp.271-277
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    • 2019
  • Citrus macroptera (Rutaceae) has long been used in folk medicine in Bangladesh. Considering the folkloric context, this study was aimed to scrutinize anti-proliferative activity of C. macroptera fruit pulp juice (CMFPJ) against Ehrlich's ascites carcinoma (EAC). The anti-proliferative capacity of CMFPJ was investigated and confirmed primarily using MTT assay. In vivo anti-proliferative aptitude of CMFPJ was investigated with 25, 50, and 100 mg/kg/day intraperitoneal (i.p.) treatment. Anti-proliferative efficacy of CMFPJ was assessed based on EAC growth inhibition. CMFPJ inhibited EAC growth in vitro in a dose-dependent manner. And the percentages of in vivo EAC growth inhibition were 19.53, 49.2, and 68.9% at 25, 50, and 100 mg/kg CMFPJ respectively. CMFPJ significantly induced expression of apoptosis regulatory genes caspase-8, caspase-9, cytochrome-c, and caspase-3. This considerable anti-cancer activity was perhaps due to combinatorial effect of lectin, polyphenols, and flavonoids present in CMFPJ.

STUDY OF THE ANNIHILATOR IDEAL GRAPH OF A SEMICOMMUTATIVE RING

  • Alibemani, Abolfazl;Hashemi, Ebrahim
    • Communications of the Korean Mathematical Society
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    • v.34 no.2
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    • pp.415-427
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    • 2019
  • Let R be an associative ring with nonzero identity. The annihilator ideal graph of R, denoted by ${\Gamma}_{Ann}(R)$, is a graph whose vertices are all nonzero proper left ideals and all nonzero proper right ideals of R, and two distinct vertices I and J are adjacent if $I{\cap}({\ell}_R(J){\cup}r_R(J)){\neq}0$ or $J{\cap}({\ell}_R(I){\cup}r_R(I)){\neq}0$, where ${\ell}_R(K)=\{b{\in}R|bK=0\}$ is the left annihilator of a nonempty subset $K{\subseteq}R$, and $r_R(K)=\{b{\in}R|Kb=0\}$ is the right annihilator of a nonempty subset $K{\subseteq}R$. In this paper, we assume that R is a semicommutative ring. We study the structure of ${\Gamma}_{Ann}(R)$. Also, we investigate the relations between the ring-theoretic properties of R and graph-theoretic properties of ${\Gamma}_{Ann}(R)$. Moreover, some combinatorial properties of ${\Gamma}_{Ann}(R)$, such as domination number and clique number, are studied.

Fast Channel Allocation for Ultra-dense D2D-enabled Cellular Network with Interference Constraint in Underlaying Mode

  • Dun, Hui;Ye, Fang;Jiao, Shuhong
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.15 no.6
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    • pp.2240-2254
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    • 2021
  • We investigate the channel allocation problem in an ultra-dense device-to-device (D2D) enabled cellular network in underlaying mode where multiple D2D users are forced to share the same channel. Two kinds of low complexity solutions, which just require partial channel state information (CSI) exchange, are devised to resolve the combinatorial optimization problem with the quality of service (QoS) guaranteeing. We begin by sorting the cellular users equipment (CUEs) links in sequence in a matric of interference tolerance for ensuring the SINR requirement. Moreover, the interference quota of CUEs is regarded as one kind of communication resource. Multiple D2D candidates compete for the interference quota to establish spectrum sharing links. Then base station calculates the occupation of interference quota by D2D users with partial CSI such as the interference channel gain of D2D users and the channel gain of D2D themselves, and carries out the channel allocation by setting different access priorities distribution. In this paper, we proposed two novel fast matching algorithms utilize partial information rather than global CSI exchanging, which reduce the computation complexity. Numerical results reveal that, our proposed algorithms achieve outstanding performance than the contrast algorithms including Hungarian algorithm in terms of throughput, fairness and access rate. Specifically, the performance of our proposed channel allocation algorithm is more superior in ultra-dense D2D scenarios.

A Study on Tracing-Threshold of Public-Key Traitor-Tracing Schemes (공개키 기반의 공모자 추적기법에서의 추적 임계치에 관한 연구)

  • 임정미;이병선;박창섭
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.13 no.6
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    • pp.121-127
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    • 2003
  • The threshold value of the traitor-tracing schemes means a maximum number of traitors whose identities can be uniquely exposed using the tracing scheme. In the traitor-tracing scheme based on an error-correcting code, which is focused at this paper, the threshold value is determined by the error-correcting capability of the underlying error-correcting code. Analyzed in terms of a combinatorial property of the tracing scheme is the resulting effect on the tracing scheme when the collusion size is over the threshold value, and a possibility of two disjoint groups of users making an identical unauthorized decryption key is shown.

Optimization Methods for Power Allocation and Interference Coordination Simultaneously with MIMO and Full Duplex for Multi-Robot Networks

  • Wang, Guisheng;Wang, Yequn;Dong, Shufu;Huang, Guoce;Sun, Qilu
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.15 no.1
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    • pp.216-239
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    • 2021
  • The present work addresses the challenging problem of coordinating power allocation with interference management in multi-robot networks by applying the promising expansion capabilities of multiple-input multiple-output (MIMO) and full duplex systems, which achieves it for maximizing the throughput of networks under the impacts of Doppler frequency shifts and external jamming. The proposed power allocation with interference coordination formulation accounts for three types of the interference, including cross-tier, co-tier, and mixed-tier interference signals with cluster head nodes operating in different full-duplex modes, and their signal-to-noise-ratios are respectively derived under the impacts of Doppler frequency shifts and external jamming. In addition, various optimization algorithms, including two centralized iterative optimization algorithms and three decentralized optimization algorithms, are applied for solving the complex and non-convex combinatorial optimization problem associated with the power allocation and interference coordination. Simulation results demonstrate that the overall network throughput increases gradually to some degree with increasing numbers of MIMO antennas. In addition, increasing the number of clusters to a certain extent increases the overall network throughput, although internal interference becomes a severe problem for further increases in the number of clusters. Accordingly, applications of multi-robot networks require that a balance should be preserved between robot deployment density and communication capacity.

Novel High-Throughput DNA Part Characterization Technique for Synthetic Biology

  • Bak, Seong-Kun;Seong, Wonjae;Rha, Eugene;Lee, Hyewon;Kim, Seong Keun;Kwon, Kil Koang;Kim, Haseong;Lee, Seung-Goo
    • Journal of Microbiology and Biotechnology
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    • v.32 no.8
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    • pp.1026-1033
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    • 2022
  • This study presents a novel DNA part characterization technique that increases throughput by combinatorial DNA part assembly, solid plate-based quantitative fluorescence assay for phenotyping, and barcode tagging-based long-read sequencing for genotyping. We confirmed that the fluorescence intensities of colonies on plates were comparable to fluorescence at the single-cell level from a high-end, flow-cytometry device and developed a high-throughput image analysis pipeline. The barcode tagging-based long-read sequencing technique enabled rapid identification of all DNA parts and their combinations with a single sequencing experiment. Using our techniques, forty-four DNA parts (21 promoters and 23 RBSs) were successfully characterized in 72 h without any automated equipment. We anticipate that this high-throughput and easy-to-use part characterization technique will contribute to increasing part diversity and be useful for building genetic circuits and metabolic pathways in synthetic biology.