• 대한기계학회논문집A
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• 제24권6호
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• pp.1529-1539
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• 2000

A newly developed optimization method which uses the genetic algorithm combined with the sensitivity analysis is presented in this paper. The genetic algorithm is a probabilistic method, searching the optimum at several points simultaneously, requiring only the values of the object and constraint functions. It has therefore more chances to find global solution and can be applied various problems. Nevertheless, it has such shortcomings that even it approaches the optimum rapidly in the early stage, it slows down afterward and it can't consider the constraints explicitly. It is only because it can't search the local area near the current points. The traditional method, on the other hand, using sensitivity analysis is of great advantage in searching the near optimum. Thus the combination of the two techniques makes use of the individual advantages, that is, the superiority both in global searching by the genetic algorithm and in local searching by the sensitivity analysis. Application of the method to the several test functions verifies that the method suggested is very efficient and powerful to find the global solutions, and that the constraints can be considered properly.

• 한국디지털건축인테리어학회논문집
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• 제11권3호
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• pp.43-51
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• 2011

Currently the locations of Unpleasant Facilities, especially surrounding the site selections, have been causing conflicts among the national government, many local governments and local residents. These Unpleasant Facilities must be necessary facilities for people's modern cultural lives, but there is no obvious solution that will make us all pleasant for the locations of them until now. In this study, we'll focused on applying the Floating architecture, one of the variety of marine structures, as an alternative location of Public service facilities accommodating Unpleasant Facilities which are classified as public service facilities. Of course, there should be beforehand studies in which we can define Unpleasant Facilities and analyse the conflicts surrounding the locations of them, and we can suggest that applying the Floating architecture should be the very solution to solve all these problems together. And as our main study, we should research and develop the structure and construction, maintenance and management of the Floating architecture which will be applied to the Unpleasant Facilities, together with the environmental considerations of their emergence on the waters. In future, to secure Unpleasant Facilities sites will become more and more difficult, and so Various kinds of public service facilities will have to be the subject to the floating construction.

• 한국측량학회지
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• 제34권2호
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• pp.161-169
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• 2016

This paper is intended to propose a novel approach to select an optimal site for a small-scaled artificial recharge system installation using TOPSIS (Technique for Order Preference by Similarity to Ideal Solution) with geospatial data. TOPSIS is a MCDM (Multi-Criteria Decision Making) method to choose the preferred one of derived alternatives by calculating the relative closeness to an ideal solution. For applying TOPSIS, in the first, the topographic shape representing optimal recovery efficiency is defined based on a hydraulic model experiment, and then an appropriate surface slope is determined for the security of a self-purification capability with DEM (Digital Elevation Model). In the second phase, the candidate areas are extracted from an alluvial map through a morphology operation, because local alluvium with a lengthy and narrow shape could be satisfied with a primary condition for the optimal site. Thirdly, a shape file over all candidate areas was generated and criteria and their values were assigned according to hydrogeologic attributes. Finally, TOPSIS algorithm was applied to a shape file to place the order preference of candidate sites.

• 소음진동
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• 제10권5호
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• pp.783-791
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• 2000

This describes a study on the support location optimizations of the beams using the genetic algorithm and the sensitivity analysis. The genetic algorithm is a probabilistic method searching the optimum at several points simultaneously and requiring only the values of the object and constraint functions. It has therefore more chances to find the global solution and can be applied to the various problems. Nevertheless, it has such a shortcoming that it takes too many calculations, because it is ineffective in local search. While the traditional method using sensitivity analysis is of great advantage in searching the near optimum. thus the combination of the two techniques will make use of the individual advantages, that is, the superiority in global searching form the genetic algorithm and that in local searching form the sensitivity analysis. In this thesis, for the practical applications, the analysis is conducted by FEB ; and as the shapes of structures are taken as the design variation, it requires re-meshing for every analysis. So if it is not properly controlled, the result of the analysis is affected and the optimized solution amy not be the real one. the method is efficiently applied to the problems which the traditional methods are not working properly.

• Macromolecular Research
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• 제12권5호
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• pp.507-511
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• 2004

We have developed an injectable thermosensitive hydrogel for local drug delivery to treat cancers clinically. We selected chitosan as a polymer matrix because of its biocompatibility and biodegradability. Glycerol 2-phosphate disodium salt hydrate (${\beta}$-GP) was used to neutralize the chitosan solution to physiological pH. The chitosan solution displayed a sol-gel phase transition in a pH-and temperature-dependent manner and formed an endothermic hydrogel after subcutaneous injection into mouse in the presence of ${\beta}$-GP. Additionally, we evaluated the biodegradation of chitosan hydrogel in mice by measuring the volume of injected chitosan hydrogel after subcutaneous injection. The injected chitosan hydrogel in mice was sected and stained with hematoxylin-eosin reagent for histological observation to confirm biodegradation of the hydrogel by the infiltrated cells. Chitosan hydrogel systems that possess biocompatibility and biodegradability could be promising thermosensitive injectable materials useful as depot systems for local anti-cancer drug delivery.

• 전자공학회논문지CI
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• 제42권6호
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• pp.47-54
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• 2005

본 연구에서는 점대점(point-to-point) 링크 상에서 각 스테이션 간의 안테나 빔의 스위트 스폿을 찾고 유지하는 방법을 제안 한다. 제안한 방식은 송수신 데이터에 안테나의 정보를 같이 실어 보내고 그 정보를 이용하여 변형된 유전자 알고리즘으로 스위트 스폿을 찾고 유지 한다. 변형된 유전자 알고리즘은 지역해(local solution)에 수렴하는 문제를 해결하여 전처리 과정으로 우수한 초기집단을 선택한 후 진화하는 방법이다. 제안한 방식의 유용성을 점대점 링크 상에서 잡음이 없는 경우와 잡음이 첨가된 경우에 대하여 시뮬레이션을 통하여 확인하였다.

• Bulletin of the Korean Chemical Society
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• 제22권7호
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• pp.703-708
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• 2001

K2NiF4-type organic-based perovskites of the (C4H9NH3)2FexPb1-xCl4 (x=0.00, 0.25, 0.50, and 0.75) system have been synthesized using a low-temperatu re solution method under a flowing argon gas. When stoichiometric butylamine, iron chloride, and lead chloride are mixed, a yellow solution are obtained from slow cooling of 90 to -10 $^{\circ}C.$ The final product is a plate-like yellow crystal. The X-ray crystallographic analysis has been carried out using XRD in the range of $5^{\circ}{\leq}$ 2${\theta}$ ${\leq}80^{\circ}.$ The local symmetry around the absorbing Pb atom of the samples has been determined by the EXAFS spectroscopic study. The crystals assign to orthorhombic system by the XRD analysis. The FT-IR spectra are analyzed in the range of 600 to 3300 cm-1 . DSC and TGA are measured to detect thermal stability between 30 and 300 $^{\circ}C.$ Two endothermic peaks are detected in all samples. The electrical conductivity has been measured using the four-probes technique for the (C4H9NH3)2FexPb1-xCl4 system in 300-460 K. Photoluminescence phenomenon was also investigated at room-temperature.

• 산업경영시스템학회지
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• 제42권1호
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• pp.8-20
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• 2019

The vehicle routing problem is one of the vibrant research problems for half a century. Many studies have extensively studied the vehicle routing problem in order to deal with practical decision-making issues in logistics. However, developments of new logistics strategies have inevitably required investigations on solution methods for solving the problem because of computational complexity and inherent constraints in the problem. For this reason, this paper suggests a simulated annealing (SA) algorithm for a variant of vehicle routing problem introduced by a previous study. The vehicle routing problem is a multi-depot and multi-trip vehicle routing problem with multiple heterogeneous vehicles restricted by the maximum permitted weight and the number of compartments. The SA algorithm generates an initial solution through a greedy-type algorithm and improves it using an enhanced SA procedure with three local search methods. A series of computational experiments are performed to evaluate the performance of the heuristic and several managerial findings are further discussed through scenario analyses. Experiment results show that the proposed SA algorithm can obtain good solutions within a reasonable computation time and scenario analyses show that a transportation system visiting non-dedicated factories shows better performance in truck management in terms of the numbers of vehicles used and trips for serving customer orders than another system visiting only dedicated factories.

• 한국산업융합학회 논문집
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• 제25권6_1호
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• pp.927-939
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• 2022

This study was conducted to develop a Web-GIS based monitoring module of smart city that can effectively respond, manage and improve situation in all stages of illegal dumping management on a city scale. First, five technologies were set for the core technical elements of the module configuration. Five core technical elements are as follows; video screening technology based on motion vector analysis, human behavior detection based on intelligent video analytics technology, mobile app for receiving civil complaints about illegal dumping, illegal dumping risk model and street cleanliness map, Web-GIS based situation monitoring technology. The development contents and results for each set of core technical elements were evaluated. Finally, a Web-GIS based 'illegal dumping monitoring module' was proposed. It is possible to collect and analyze city data at the local government level through operating the proposed module. Based on this, it is able to effectively detect illegal dumpers at relatively low cost and identify the tendency of illegal dumping by systematically managing habitual occurrence areas. In the future, it is expected to be developed in the form of an add-on module of the smart city integration platform operated by local governments to ensure interoperability and scalability.

• International Journal of Computer Science & Network Security
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• 제24권3호
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• pp.12-22
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• 2024

The travelling salesman problem is very famous and very difficult combinatorial optimization problem that has several applications in operations research, computer science and industrial engineering. As the problem is difficult, finding its optimal solution is computationally very difficult. Thus, several researchers have developed heuristic/metaheuristic algorithms for finding heuristic solutions to the problem instances. In this present study, a new hybrid genetic algorithm (HGA) is suggested to find heuristic solution to the problem. In our HGA we used comprehensive sequential constructive crossover, adaptive mutation, 2-opt search and a new local search algorithm along with a replacement method, then executed our HGA on some standard TSPLIB problem instances, and finally, we compared our HGA with simple genetic algorithm and an existing state-of-the-art method. The experimental studies show the effectiveness of our proposed HGA for the problem.