• Title/Summary/Keyword: Improved TSP

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A Case Study on the Characteristics of TSP Concentrations and Yellow Sand Phenomena in Seoul (서울 부유분진 농도와 황사 특성에 관한 사례 연구)

  • 김우규;전영신;이원환;김현미
    • Journal of Korean Society for Atmospheric Environment
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    • v.11 no.2
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    • pp.199-209
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    • 1995
  • The variations of TSP concentrations observed at Air Quality Monitoring Stations(AQMSs) in Seoul were analysed from 1986 to 1993. And those of Yellow Sand period were investigated to find out the characteristics between normal and Yellow Sand period. The TSP concentrations have begun lower than 150.mu.g/m$^{3}$ annual mean concentration at Gwanghwamun, Hannam-dong, and south river region since 1989, and air quality in Seoul was improved in 1991, but polluted again in Hannam-dong, and Seongsu-dong in 1992. Yellow sand phenomena of 1990 and 1993 were selected for case study. During the whole period in 1990, the TSP concentrations were exceeded over 300.mu.g/m$^{3}$, which is the upper limit of 24 hour concentration, at the center of city such as Mapo, Gileum-dong, sinseol-dong. But in 1993, the TSP concentrations got lower than 24 hour concentration, and air quality was highly improved.

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Improved Ant Colony System for the Traveling Salesman Problem (방문판매원 문제에 적용한 개선된 개미 군락 시스템)

  • Kim, In-Kyeom;Yun, Min-Young
    • The KIPS Transactions:PartB
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    • v.12B no.7 s.103
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    • pp.823-828
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    • 2005
  • Ant Colony System (ACS) applied to the traveling salesman problem (TSP) has demonstrated a good performance on the small TSP. However, in case of the large TSP. ACS does not yield the optimum solution. In order to overcome the drawback of the An for the large TSP, the present study employs the idea of subpath to give more irormation to ants by computing the distance of subpath with length u. in dealing with the large TSP, the experimental results indicate that the proposed algorithm gives the solution much closer to the optimal solution than does the original ACS. In comparison with the original ACS, the present algorithm has substantially improved the performance. By utilizing the proposed algorithm, the solution performance has been enhanced up to $70\%$ for some graphs and around at $30\%$ for averaging over all graphs.

Improved VRP & GA-TSP Model for Multi-Logistics Center (복수물류센터에 대한 VRP 및 GA-TSP의 개선모델개발)

  • Lee, Sang-Cheol;Yu, Jeong-Cheol
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.8 no.5
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    • pp.1279-1288
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    • 2007
  • A vehicle routing problem with time constraint is one of the must important problem in distribution and logistics. In practice, the service for a customer must start and finish within a given delivery time. This study is concerned about the development of a model to optimize vehicle routing problem under the multi-logistics center problem. And we used a two-step approach with an improved genetic algorithm. In step one, a sector clustering model is developed by transfer the multi-logistics center problem to a single logistics center problem which is more easy to be solved. In step two, we developed a GA-TSP model with an improved genetic algorithm which can search a optimize vehicle routing with given time constraints. As a result, we developed a Network VRP computer programs according to the proposed solution VRP used ActiveX and distributed object technology.

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타부탐색(Tabu Search)의 확장모델을 이용한 '외판원 문제(Traveling Salesman Problem)' 풀기

  • 고일상
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 1996.10a
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    • pp.135-138
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    • 1996
  • In solving the Travel Salesman Problem(TSP), we easily reach local optimal solutions with the existing methods such as TWO-OPT, THREE-OPT, and Lin-Kernighen. Tabu search, as a meta heuristic, is a good mechanism to get an optimal or a near optimal solution escaping from the local optimal. By utilizing AI concepts, tabu search continues to search for improved solutions. In this study, we focus on developing a new neighborhood structure that maintains the feasibility of the tours created by exchange operations in TSP. Intelligent methods are discussed, which keeps feasible tour routes even after exchanging several edges continuously. An extended tabu search model, performing cycle detection and diversification with memory structure, is applied to TSP. The model uses effectively the information gathered during the search process. Finally, the results of tabu search and simulated annealing are compared based on the TSP problems in the prior literatures.

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An Internal Touch Screen Panel Using Standard a-Si:H TFT LCD process

  • You, Bong-Hyun;Lee, Byoung-Jun;Lee, Ki-Chan;Han, Sang-Youn;Koh, Jai-Hyun;Takahashi, Seiki;Berkeley, Brian H.;Kim, Nam-Deog;Kim, Sang-Soo
    • 한국정보디스플레이학회:학술대회논문집
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    • 2008.10a
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    • pp.250-253
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    • 2008
  • A touch screen panel embedded 12.1-inch TFT LCD employing a standard a-Si:H TFT process has been successfully developed. Compared with conventional external touch screen panels, the new internal TSP exhibits a clearer image and improved touch feeling. Our new internal proposed TSP can be fabricated with low cost.

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Effects of cyanocobalamin and its combination with morphine on neuropathic rats and the relationship between these effects and thrombospondin-4 expression

  • Duzenli, Neslihan;Ulker, Sibel;Sengul, Gulgun;Kayhan, Buse;Onal, Aytul
    • The Korean Journal of Pain
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    • v.35 no.1
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    • pp.66-77
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    • 2022
  • Background: Thrombospondin-4 (TSP4) upregulates in the spinal cord following peripheral nerve injury and contributes to the development of neuropathic pain (NP). We investigated the effects of cyanocobalamin alone or in combination with morphine on pain and the relationship between these effects and spinal TSP4 expression in neuropathic rats. Methods: NP was induced by chronic constriction injury (CCI) of the sciatic nerve. Cyanocobalamin (5 and 10 mg/kg/day) was administered 15 days before CCI and then for 4 and 14 postoperative days. Morphine (2.5 and 5 mg/kg/day) was administered only post-CCI. Combination treatment included cyanocobalamin and morphine, 10 and 5 mg/kg/day, respectively. All drugs were administered intraperitoneally. Nociceptive thresholds were detected by esthesiometer, analgesia meter, and plantar test, and TSP4 expression was assessed by western blotting and fluorescence immunohistochemistry. Results: CCI decreased nociceptive thresholds in all tests and induced TSP4 expression on the 4th postoperative day. The decrease in nociceptive thresholds persisted except for the plantar test, and the increased TSP4 expression reversed on the 14th postoperative day. Cyanocobalamin and low-dose morphine alone did not produce any antinociceptive effects. High-dose morphine improved the decreased nociceptive thresholds in the esthesiometer when administered alone but combined with cyanocobalamin in all tests. Cyanocobalamin and morphine significantly induced TSP4 expression when administered alone in both doses for 4 or 14 days. However, this increase was less when the two drugs are combined. Conclusions: The combination of cyanocobalamin and morphine is more effective in antinociception and partially decreased the induced TSP4 expression compared to the use of either drug alone.

Improvement of Ant Colony Optimization Algorithm to Solve Traveling Salesman Problem (순회 판매원 문제 해결을 위한 개미집단 최적화 알고리즘 개선)

  • Jang, Juyoung;Kim, Minje;Lee, Jonghwan
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.42 no.3
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    • pp.1-7
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    • 2019
  • It is one of the known methods to obtain the optimal solution using the Ant Colony Optimization Algorithm for the Traveling Salesman Problem (TSP), which is a combination optimization problem. In this paper, we solve the TSP problem by proposing an improved new ant colony optimization algorithm that combines genetic algorithm mutations in existing ant colony optimization algorithms to solve TSP problems in many cities. The new ant colony optimization algorithm provides the opportunity to move easily fall on the issue of developing local optimum values of the existing ant colony optimization algorithm to global optimum value through a new path through mutation. The new path will update the pheromone through an ant colony optimization algorithm. The renewed new pheromone serves to derive the global optimal value from what could have fallen to the local optimal value. Experimental results show that the existing algorithms and the new algorithms are superior to those of existing algorithms in the search for optimum values of newly improved algorithms.

Travelling Salesman Problem Based on Area Division and Connection Method (외판원 문제의 지역 분할-연결 기법)

  • Lee, Sang-Un
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.15 no.3
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    • pp.211-218
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    • 2015
  • This paper introduces a 'divide-and-conquer' algorithm to the travelling salesman problem (TSP). Top 10n are selected beforehand from a pool of n(n-1) data which are sorted in the ascending order of each vertex's distance. The proposed algorithm then firstly selects partial paths that are interconnected with the shortest distance $r_1=d\{v_i,v_j\}$ of each vertex $v_i$ and assigns them as individual regions. For $r_2$, it connects all inter-vertex edges within the region and inter-region edges are connected in accordance with the connection rule. Finally for $r_3$, it connects only inter-region edges until one whole Hamiltonian cycle is constructed. When tested on TSP-1(n=26) and TSP-2(n=42) of real cities and on a randomly constructed TSP-3(n=50) of the Euclidean plane, the algorithm has obtained optimal solutions for the first two and an improved one from that of Valenzuela and Jones for the third. In contrast to the brute-force search algorithm which runs in n!, the proposed algorithm runs at most 10n times, with the time complexity of $O(n^2)$.

Persulfate Wet Oxidation Method for the Determination of Total Phosphorus in Atmospheric Aerosols and Its Application for a Year-round Observation in Beijing

  • Okuda, Tomoaki;Gunji, Yuma;He, Kebin;Ma, Yongliang
    • Asian Journal of Atmospheric Environment
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    • v.7 no.3
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    • pp.169-175
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    • 2013
  • Measurement of the phosphorus concentration in aerosols in Beijing, which was a representative East Asian mega-city, was carried out. The optimum procedure for analyzing phosphorus in aerosols was found in this study. Recovery of phosphorus in environmental samples through the improved method was almost 100%. The concentration of phosphorus in TSP was $145{\pm}47\;ng/m^3$, with a seasonal variation showing high concentrations in winter and low concentrations in summer. The concentrations of phosphorus in $PM_{2.5}$ accounted for $35{\pm}6%$ of those in TSP, with no seasonal variations. The major source of phosphorus in aerosols in Beijing was soil dust, and additional sources of phosphorus in fine particles could be coal combustion and biomass burning.

An improved version of Minty's algorithm to solve TSP with penalty function

  • Moon, Geeju;Oh, Hyun-Seung;Yang, Jung-Mun;Kim, Jung-Ja
    • Korean Management Science Review
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    • v.13 no.3
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    • pp.187-198
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    • 1996
  • The traveling salesman problem has been studied for many years since the model can be used for various applications such as vehicle routing, job sequencing, clustering a data array, and so on. In this paper one of the typical exact algorithms for TSP, Minty's, will be modified to improve the performance of the algorithm on the applications without losing simplicity. The Little's algorithm gives good results, however, the simple and plain Minty's algorithm for solving shortest-route problems has the most intuitive appeal. The suggested Minty's modification is based on the creation of penalty-values on the matrix of a TSP. Computer experiments are made to verify the effectiveness of the modification.

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