• Journal of Electrical Engineering and Technology
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• v.6 no.4
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• pp.493-504
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• 2011

The present paper presents a genetic algorithm (GA) to maximize social welfare and perform congestion management by optimally placing and sizing one Thyristor-Controlled Series Capacitor (TCSC) device in a double-sided auction market. Simulation results, with line flow constraints before and after the compensation, are compared through the Sequential Quadratic Programming SQP method, and are used to analyze the effect of TCSC on the congestion levels of modified IEEE 14-bus and 30-bus test systems. Quadratic, smooth and nonsmooth (with sine components due to valve point loading effect) generator cost curves, and quadratic smooth consumer benefit functions are considered. The main aims of the present study are the inclusion of customer benefit in the social welfare maximization and congestion management objective function, the consideration of nonsmooth generator characteristics, and the optimal locating and sizing of the TCSC using real code-based GA to guarantee fast convergence to the best solution.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.4
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• pp.1638-1654
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• 2018

The heterogeneous network (HetNet) has been one of the key technologies in Long Term Evolution-Advanced (LTE-A) with growing capacity and coverage demands. However, the introduction of femtocells has brought serious co-layer interference and cross-layer interference, which has been a major factor affecting system throughput. It is generally acknowledged that the resource allocation has significant impact on suppressing interference and improving the system performance. In this paper, we propose a hybrid-clustering algorithm based on the $Mat{\acute{e}}rn$ hard-core process (MHP) to restrain two kinds of co-channel interference in the HetNet. As the impracticality of the hexagonal grid model and the homogeneous Poisson point process model whose points distribute completely randomly to establish the system model. The HetNet model based on the MHP is adopted to satisfy the negative correlation distribution of base stations in this paper. Base on the system model, the spectrum sharing problem with restricted spectrum resources is further analyzed. On the basis of location information and the interference relation of base stations, a hybrid clustering method, which takes into accounts the fairness of two types of base stations is firstly proposed. Then, auction mechanism is discussed to achieve the spectrum sharing inside each cluster, avoiding the spectrum resource waste. Through combining the clustering theory and auction mechanism, the proposed novel algorithm can be applied to restrain the cross-layer interference and co-layer interference of HetNet, which has a high density of base stations. Simulation results show that spectral efficiency and system throughput increase to a certain degree.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 2002.06a
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• pp.156-160
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• 2002

본 논문에서는 사용자의 속성과 물품에 대한 속성을 이용한 효과적인 경매시스템의 알고리즘에 대하여 연구하였다. 사람이 경매를 하는 것과 유사한 척도를 가지고 물품에 대한 가격을 결정하고 입찰가를 제안할 수 있는 알고리즘을 제안하였다. 이것은 본 연구에서는 물품에 대한 다속성을 이용하여 다수의 입찰자들의 제한된 자율성을 가진 agent들이 경매를 참여할 수 있도록 하였다. 또한 입찰자가 물품에 대한 금액을 산정 하는데 보다 객관적으로 판단을 할 수 있도록 보조하여준다. 이러한 이유들로 인하여 본 논문에서 제안한 알고리즘이 사람과 유사한 경매를 할 수 있을 뿐만 아니라, 사람의 감성부분도 속성에 추가할 수 있는 특징이 있다.

• Proceedings of the Korea Information Processing Society Conference
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• 2000.04a
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• pp.1190-1195
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• 2000

상거래의 의미가 곧 전자상거래로 대변될 만큼 전자상거래의 전성기를 맞이하고 있으며 국내도 예외는 아니다. 전자상거래방식을 기초로 하는 인터넷 경매는 경매인과 입찰자의 상호의사표현을 통한 거래를 인터넷으로 하는 것을 말한다. 인터넷 경매에 있어서 에이전트는 입찰자, 경매인, 중개인의 경매 참여자를 대신하여 업무를 대행해주거나 결정을 도와주는 소프트웨어라고 정의할 수 있다. 기존 인터넷 경매에서의 에이전트는 단순한 검색기능과 광고만을 대행하고 있고, 경매인이 물품등록을 하고자 할 때, 주관적인 가치평가에 의해 경매시작가를 결정해야 한다. 이러한 경매인의 주관적인 경매시작가는 높은 경매시작가로 인해 유찰이 되거나 낮은 경매시작가로 낙찰가가 낮아 불이익을 가져온다. 따라서 본 논문은 경매인이 등록하고자 하는 물품에 대한 사례 경매 데이터베이스의 경매기록을 기초로 경매시작가를 분석된 정보를 제공하는 경매 정보 시스템(Auction Information System)을 제안하고자 한다.

• Journal of Electrical Engineering and Technology
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• v.7 no.4
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• pp.501-512
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• 2012

Social welfare maximization in a double-sided auction market is performed by implementing an aggregation-based particle swarm optimization (CAPSO) algorithm for optimal placement and sizing of one Static Synchronous Series Compensator (SSSC) device. Dallied simulation results (without/with line flow constraints and without/with SSSC) are generated to demonstrate the impact of SSSC on the congestion levels of the modified IEEE 14-bus test system. The proposed CAPSO algorithm employs conventional quadratic smooth and augmented quadratic nonsmooth generator cost curves with sine components to improve the accurate of the model by incorporating the valve loading effects. CAPSO also employs quadratic smooth consumer benefit functions. The proposed approach relies on particle swarm optimization to capture the near-optimal GenCos and DisCos, as well as the location and rating of SSSC while the Newton based load flow solution minimizes the mismatch equations. Simulation results of the proposed CAPSO algorithm are compared to solutions obtained by sequential quadratic programming (SQP) and a recently implemented Fuzzy based genetic algorithm (Fuzzy-GA). The main contributions are inclusion of customer benefit in the congestion management objective function, consideration of nonsmooth generator characteristics and the utilization of a coordinated aggregation-based PSO for locating/sizing of SSSC.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.11
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• pp.4311-4330
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• 2015

Cloud computing has become a new paradigm by enabling on-demand provisioning of applications, platforms or computing resources for clients. Workflow scheduling has always been treated as one of the most challenging problems in clouds. Commercial clouds have been widely used in scientific research, such as biology, astronomy and weather forecasting. Certainly, it is very important for a cloud service provider to pursue the profits for the commercial essence of clouds. This is also significantly important for the case of providing services to workflow tasks. In this paper, we address the issues of workflow scheduling in commercial clouds. This work takes the communication into account, which has always been ignored. And then, a topology-based workflow-scheduling algorithm named Resource Auction Algorithm (REAL) is proposed in the objective of getting more profits. The algorithm gives a good performance on searching for the optimum schedule for a sample workflow. Also, we find that there exists a certain resource amount, which gets the most profits to help us get more enthusiasm for further developing the research. Experimental results demonstrate that the analysis of the strategies for most profits is reasonable, and REAL gives a good performance on efficiently getting an optimized scheme with low computing complexity.

• Journal of KIISE:Computer Systems and Theory
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• v.30 no.9
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• pp.477-486
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• 2003

In combinatorial auctions buyers nay bid for arbitrary combinations of goods. But determining the winners of combinatorial auctions who maximize the profit of a seller is known to be NP-complete. A branch-and-bound method can be one of practical algorithm for winner determination. However, bid selection heuristics play a very important role in the efficiency of a branch-and-bound method. In this paper, we designed and implemented an algorithm which used a branch-and-bound method and Linear Programming for winner determination in combinatorial auctions. We propose new bid selection heuristics which consider a branching bid and conflicting bids simultaneously to select a branching bid in the algorithm. In addition, upper bounds are reused to reduce the running time in specific cases. We evaluated the performance of the algorithm by experiments with five data distributions and compared our method with others. The algorithm using heuristics showed a superior efficiency in two data distributions and a similar efficiency in three distributions.

• Proceedings of the IEEK Conference
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• 2001.06b
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• pp.257-260
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• 2001

Routing region modeling methods for PCB auto-routing system in Shape based type(non-grid method) used region process type and the shape located in memory as a individual element, and this element consumed small memory due to unique data size. In this paper we design PCB(Printed Circuit Board) auto-routing system using the auction algorithm method that 1) Could be reached by solving the shortest path from single original point to various destination, and 2) Shaped based type without any memory dissipation with the best speed. Also, the auto-routing system developed by Visual C++ in Window environment, and can be used in IBM Pentium computer or in various individual PC system.

• Journal of Korea Society of Industrial Information Systems
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• v.8 no.4
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• pp.17-25
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• 2003

In the current bandwidth mechanism, ISPs provide guaranteed internet bandwidth within itself domains. Also transmission of data through the network can cause congestion. An inevitable consequence is partly responsible for the difficulties to ISPs and customers. In economic views, multiple demands for a scarce resource are mediated through a bandwidth market. Using the auction-based admission algorithm In price congestion, I propose a different pricing scheme for statistically guaranteed QoS.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2006.11a
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• pp.175-178
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• 2006

A numerical study for spray combustion of fluctuated fuel and oxidizer droplets injected into combustion chamber has been conducted for the analysis of spray combustion considering characteristics of injector. The 2 dimensional unsteady state flow fields have been calculated by using QUICK Scheme and SIMPLER Algorithm. As the spray model, DSF model and Euler-Lagrange Scheme have been used. The sine Auction has been used for droplet fluctuation model of fuel and oxidizer, while the coupling effects of the droplets between gas phase and evaporated vapor have been calculated by using PSIC model.