• 제목/요약/키워드: local solution

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이산설계공간에서 직교배열표를 이용한 순차적 알고리듬의 국부해 (Local Solution of a Sequential Algorithm Using Orthogonal Arrays in a Discrete Design Space)

  • 이정욱;박경진
    • 대한기계학회논문집A
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    • 제28권9호
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    • pp.1399-1407
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    • 2004
  • Structural optimization has been carried out in continuous design space or in discrete design space. Generally, available designs are discrete in design practice. However, the methods for discrete variables are extremely expensive in computational cost. An iterative optimization algorithm is proposed for design in a discrete space, which is called a sequential algorithm using orthogonal arrays (SOA). We demonstrate verifying the fact that a local optimum solution can be obtained from the process with this algorithm. The local optimum solution is defined in a discrete design space. Then the search space, which is a set of candidate values of each design variables formed by the neighborhood of a current design point, is defined. It is verified that a local optimum solution can be found by sequentially moving the search space. The SOA algorithm has been applied to problems such as truss type structures. Then it is confirmed that a local solution can be obtained by using the SOA algorithm

이산설계공간에서 직교배열표를 이용한 순차적 알고리듬의 국부해 (Local Solution of Sequential Algorithm Using Orthogonal Arrays in Discrete Design Space)

  • 이정욱;박경진
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2004년도 춘계학술대회
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    • pp.1005-1010
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    • 2004
  • The structural optimization has been carried out in the continuous design space or in the discrete design space. Generally, available designs are discrete in design practice. But methods for discrete variables are extremely expensive in computational cost. In order to overcome this weakness, an iterative optimization algorithm was proposed for design in the discrete space, which is called as a sequential algorithm using orthogonal arrays (SOA). We focus to verify the fact that the local solution can be obtained throughout the optimization with this algorithm. The local solution is defined in discrete design space. Then the search space, which is the set of candidate values of each design variables formed by the neighborhood of current design point, is defined. It is verified that a local solution can be founded by moving sequentially the search space. The SOA algorithm has been applied to problems such as truss type structures. Then it is confirmed that a local solution can be obtained using the SOA algorithm

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Effect of warming local anesthesia solutions before intraoral administration in dentistry: a systematic review

  • Tirupathi, Sunny Priyatham;Rajasekhar, Srinitya
    • Journal of Dental Anesthesia and Pain Medicine
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    • 제20권4호
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    • pp.187-194
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    • 2020
  • Background: The aim of the present systematic review was to evaluate and compare the efficacy of warmed and unwarmed local anesthesia solutions in reduction of pain during intraoral injection administration. Methods: PubMed, Ovid SP, and Cochrane Central Register of Controlled Trials were searched from publication years 1990 to 2020 with relevant MeSH terms. Studies were screened by titles and abstracts, followed by full-texts evaluation of the included studies. Results: A total of four studies were included in the systematic review. Outcomes evaluated were subjective and objective pain during administration of the warmed local anesthesia solution in comparison with the unwarmed local anesthesia solution. Among the four studies that evaluated the self-reported pain score, three studies showed significantly lower pain scores associated with warmed local anesthesia. Only two studies evaluated the observed pain score, and both of them reported a significantly lower pain reaction with the warmed local anesthesia solution. Conclusion: Within the limits of this systematic review, warming the local anesthesia solution to body temperature (37℃) before administration seemed to reduce the discomfort during intraoral local anaesthesia administration, and more high-quality studies should be carried out to validate the same.

국소마취시 통증을 줄이기 위한 기기들 (Devices for reducing Pain during local anesthesia)

  • 박원서
    • 대한치과의사협회지
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    • 제56권1호
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    • pp.58-65
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    • 2018
  • Dental local anesthesia is important procedure for the elimination of pain during dental treatment. However, the pain during local anesthesia is one of the main source of fear to the patients. The cause of pain during dental local anesthesia includes soft tissue damage during penetration of the oral mucosa, pressure from the spread of the anesthetic solution, temperature of anesthetic solution, low pH of anesthetic solution, and the characteristics of the drug. Several concepts and devices introduced to date to reduce the pain during local anesthesia for dental treatment. In this report, devices that can reduce the pain during local anesthesia will be discussed.

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Localization and a Distributed Local Optimal Solution Algorithm for a Class of Multi-Agent Markov Decision Processes

  • Chang, Hyeong-Soo
    • International Journal of Control, Automation, and Systems
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    • 제1권3호
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    • pp.358-367
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    • 2003
  • We consider discrete-time factorial Markov Decision Processes (MDPs) in multiple decision-makers environment for infinite horizon average reward criterion with a general joint reward structure but a factorial joint state transition structure. We introduce the "localization" concept that a global MDP is localized for each agent such that each agent needs to consider a local MDP defined only with its own state and action spaces. Based on that, we present a gradient-ascent like iterative distributed algorithm that converges to a local optimal solution of the global MDP. The solution is an autonomous joint policy in that each agent's decision is based on only its local state.cal state.

펄트루젼 I형 단면 압축재의 국부좌굴계수 계산을 위한 근사식의 개발 (An Approximate Solution for the Local Buckling Coefficient of Pultruded I-Shape Compression Members)

  • 주형중;정재호;이승식;윤순종
    • 한국복합재료학회:학술대회논문집
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    • 한국복합재료학회 2004년도 춘계학술발표대회 논문집
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    • pp.223-227
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    • 2004
  • The pultruded structural shapes are usually composed of thin-walled plate elements. Because the composite material has relatively low elastic moduli, the design of pultruded compression members may not be governed by the material strength limit state but by the stability limit state such as the local buckling or the global buckling. Therefore, the stability limit state must be checked to design pultruded columns. In this research, the local buckling analysis of pultruded I-shape column was conducted for various composite materials using the closed-form solution. To establish the design guidelines for the local buckling of pultruded I-shape compression members, the simplified form of equation to find the local buckling coefficient of pultruded I-shape column was proposed as a function of mechanical properties and the width ratio of plate components using the results obtainde by the closed-form solution. In order to verify the validity of proposed solution, the results obtained by the proposed approximate solution were compared with those of the closed-form solution and the experimental results.

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외판원문제에서 국지해를 탈출하기 위한 비용완화법 (Cost Relaxation Method to Escape from a Local Optimum of the Traveling Salesman Problem)

  • 권상호;김성민;강맹규
    • 대한산업공학회지
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    • 제30권2호
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    • pp.120-129
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    • 2004
  • This paper provides a simple but effective method, cost relaxation to escape from a local optimum of the traveling salesman problem. We would find a better solution if we repeat a local search heuristic at a different initial solution. To find a different initial solution, we use the cost relaxation method relaxing the cost of arcs. We used the Lin-Kernighan algorithm as a local search heuristic. In experimental result, we tested large instances, 30 random instances and 34 real world instances. In real-world instances, we found average 0.17% better above the optimum solution than the Concorde known as the chained Lin-Kernighan. In clustered random instances, we found average 0.9% better above the optimum solution than the Concorde.

Rural Postman Problem 해법을 위한 Iterative Local Search 알고리즘 (An Iterative Local Search Algorithm for Rural Postman Problems)

  • 강명주
    • 한국컴퓨터정보학회논문지
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    • 제7권1호
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    • pp.48-53
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    • 2002
  • 본 논문에서는 Rural Postman Problem(RPP) 해법을 위한 Iterative Local Search(ILS) 알고리즘을 제안한다. ILS 알고리즘은 초기해를 여러 번 생성하여 탐색 시작점을 달리하는 방법으로, 초기해의 설정 방법에 따라 알고리즘의 성능이 크게 좌우되는 Local Search(LS) 알고리즘의 단점을 보완할 수 있다. 본 논문에서는 LS 알고리즘과 ILS 알고리즘을 18개의 RPP 문제에 적용하고 그 성능을 분석한다. 실험 결과에서는 ILS 알고리즘이 각각 다른 탐색 시작점에서 해 공간을 탐색함으로서 LS에 비해 좋은 해를 찾을 수 있음을 알 수 있었다.

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Buffered versus unbuffered local anesthesia for inferior alveolar nerve block injections in children: a systematic review

  • Tirupathi, Sunny Priyatham;Rajasekhar, Srinitya
    • Journal of Dental Anesthesia and Pain Medicine
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    • 제20권5호
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    • pp.271-279
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    • 2020
  • Background: The present study aimed to evaluate and compare the efficacy of buffered and unbuffered local anesthesia solutions during inferior alveolar nerve block (IANB) administration in children. Methods: PubMed, Ovid SP, and Cochrane databases were searched separately by two independent reviewers for potential papers published between 1980 and April 2020 using relevant MeSH terms and pre-specified inclusion and exclusion criteria. T Studies of IANB administration in children comparing buffered and unbuffered local anesthesia solutions were evaluated. The primary outcome evaluated was pain (perception and reaction), while the secondary outcome was the onset of anesthesia. Results: A total of five articles were included in a qualitative analysis; among them, four qualified for quantitative analysis of the primary outcome and three for quantitative analysis of the secondary outcome. A fixed-effects model was used to perform the meta-analysis. Pain perception (child-reported pain): Significantly lower pain scores were reported with buffered local anesthesia solution than with unbuffered solution (P = 0.006, MD: -0.32, 95% CI: -0.55 to -0.09). Pain reaction (observer-reported pain reaction in child): No significant difference was found between buffered and unbuffered solution in terms of observer-reported pain behavior in the child (P = 0.09, MD: -0.21, 95% CI: -0.46 to 0.04). Onset of anesthesia: A significantly lower duration of anesthesia onset was reported with buffered local anesthesia solution than with unbuffered solution (P = 0.00001, MD: -12.38, 95% CI: -17.64 to -7.13]. Conclusion: Buffering local anesthesia solution may reduce discomfort due to IANB injection administration and lower the initial onset time of anesthesia. More randomized control trials with adequate sample sizes should be carried out to validate the accuracy of these results.