• 제목/요약/키워드: Two-opt

검색결과 59건 처리시간 0.021초

하이브리드 유전자알고리즘을 이용한 엄격한 시간제약 차량경로문제 (A Vehicle Routing Problem Which Considers Hard Time Window By Using Hybrid Genetic Algorithm)

  • 백정구;전건욱
    • 한국국방경영분석학회지
    • /
    • 제33권2호
    • /
    • pp.31-47
    • /
    • 2007
  • 본 연구는 엄격한 시간제약 차량경로문제에 대하여 유전자알고리즘과 휴리스틱 기법을 이용하여 최적해를 산출하는 것이다. 문제해결을 위해 수리적 모형을 구성하고, ILOG-CPLEX를 이용하여 최적해를 산출하였다. 임의 생성방법과 세이빙 휴리스틱을 적용한 초기해 생성, 실행불가능해의 교정과 유전자 알고리즘 종료 후 2-opt, Or-opt 등 해교정 및 해개선을 위한 과정이 추가된 하이브리드 유전자 알고리즘을 구축하여 엄격한 시간제약이 있는 차량경로 문제에 적용하여 솔로몬 예제와 비교하고, 제안한 알고리즘의 해공간탐색능력, 수렴성, 휴리스틱 기법의 효과를 확인하였다.

구호흡자(口呼吸者)의 Head posture에 관(關)한 연구(硏究) (A STUDY ON THE HEAD POSTURES OF MOUTH BREATHERS)

  • 안재현;차경석
    • 대한치과교정학회지
    • /
    • 제21권3호
    • /
    • pp.581-590
    • /
    • 1991
  • This study was carried out for the comparison of the head postures between mouth breathers and normal nasal breathers. For this purpose, a test group of 28 mouth breathers, between the ages of 8 to 12 years old and a control group of 25 nasal breathers were used. Following results were obtained after comparing the craniofacial and craniocervical angulations to the True Vertical line. 1. In the comparisions relating to the True Vertical Line, results were obtained using four items; NSL/VER, FH/VER, NL/VER, PMV/VER. Variations were observed in all the items and the craniofacial angulations in the mouth breathers group showed more superior position compared to the control group. 2. In the comparisions relating to the craniocervical angulations, results were obtained using four items; NSL/OPT, FH/OPT, NL/OPT, PMV/OPT. Variations between the two groups were observed only in the PMV/OPT item and the mouth breather group showed more craniocervical angulations compared to the control group.

  • PDF

A Study on the Opt-in Marketing

  • OH, Won-Kyo;LEE, Won-Jun
    • 산경연구논집
    • /
    • 제11권2호
    • /
    • pp.49-59
    • /
    • 2020
  • Purpose: Online and social media and mobile shopping are increasing and companies are required to provide personal information in order to supplement the non-invasive characteristics of the channels. With the increased provision of personal information, consumers' personal and social concerns about the prevention of personal information infringement are also increasing, and in response, personal or opt-in marketing has emerged to compensate for reckless information abuse. Despite the background of this emergence, the existing prior studies are limited to ignoring the negative feelings of consumers in the real world, including only the net function and positive effect of the opt-in mail. Research design, data and methodology: The research framework was intended to utilize the impact of human marketing activities on consumer attitudes combined with positive and negative factors. Factors that positively affect attitudes toward permation marketing were presented, such as informality, and perceived risks were presented as negative impact factors. Also, based on previous prior research, the prior factors of opt-in marketing were to present the effect on purchase intent through the medium of attitude toward opt-in marketing. Results: In this study, we used the framework of a two factor theory to address positive and negative factors as a leading factor in the customer attitude toward opt-in mail advertising, and as a result, functionality and personalization have a positive effect on customer attitude and perceived risk have a negative impact on customer attitude. In addition, it was confirmed that the customer attitude formed this way affects the intention to purchase again. Conclusions: This study suggests that we have demonstrated that marketing, an opt-in marketing that has been recognized as part of marketing that is deployed after obtaining customer consent, has been applied without any other marketing methodology. E-mail advertising at this point also provides practical implications that the system safeguards are in place under an opt-in protocol or system, and that even if an e-mail advertisement is carried out, customers will need to look at the level of awareness about the risks, and suggests that they need to consider the customer's journey that could lead to purchase at the content level.

외판원 문제의 확장된 k-opt 알고리즘 (The Extended k-opt Algorithm for Traveling Salesman Problem)

  • 이상운
    • 한국컴퓨터정보학회논문지
    • /
    • 제17권10호
    • /
    • pp.155-165
    • /
    • 2012
  • 본 논문은 지금까지 해결하지 못한 NP-Hard 문제들 중의 하나인 외판원 문제를 해결할 수 있는 알고리즘을 제안한다. 제안된 알고리즘은 간선교환 방법을 적용한 발견적 알고리즘이다. 초기해를 구하는 전형적인 방법은 첫 번째 노드부터 가장 인접한 노드를 방문하여 외판원의 경로를 결정하는 방법이다. 본 논문에서는 각 노드의 최소 간선을 선택하여 선택된 간선들 중 최소값을 가진 노드부터 출발하는 Min-Min 방법과 최대값을 가진 노드부터 출발하는 Min-Max 방법을 적용하고 두 방법 중 최소 경로길이를 가진 방법을 초기해로 결정하였다. 초기해로부터 최적해를 구하는 과정은 기존의 2-간선 교환 방법 (2-opt)을 기본적으로 적용하고, 추가로 확장된 3-opt와 4-opt를 제안하였다. 이와 같은 방법을 7개의 실제 데이터들에 적용한 결과 지금까지 알려진 최적해를 빠르고 정확히 구하는데 성공하였다.

비대칭 외판원문제에서 3-Opt를 이용한 효율적인 국지탐색 알고리즘 (An Efficient Local Search Algorithm for the Asymmetric Traveling Salesman Problem Using 3-Opt)

  • 김경구;권상호;강맹규
    • 산업경영시스템학회지
    • /
    • 제23권59호
    • /
    • pp.1-10
    • /
    • 2000
  • The traveling salesman problem is a representative NP-Complete problem. It needs lots of time to get a solution as the number of city increase. So, we need an efficient heuristic algorithm that gets good solution in a short time. Almost edges that participate in optimal path have somewhat low value cost. This paper discusses the property of nearest neighbor and 3-opt. This paper uses nearest neighbor's property to select candidate edge. Candidate edge is a set of edge that has high probability to improve cycle path. We insert edge that is one of candidate edge into intial cycle path. As two cities are connected. It does not satisfy hamiltonian cycle's rule that every city must be visited and departed only one time. This paper uses 3-opt's method to sustain hamiltonian cycle while inserting edge into cycle path. This paper presents a highly efficient heuristic algorithm verified by numerous experiments.

  • PDF

변수화된 통신모델에서의 최적의 멀티캐스트 알고리즘 및 컴퓨터 구조에 따른 튜닝 (Optimal Multicast Algorithm and Architecture-Dependent Tuning on the Parameterized Communication Model)

  • 이주영
    • 한국정보처리학회논문지
    • /
    • 제6권9호
    • /
    • pp.2332-2342
    • /
    • 1999
  • 멀티캐스트는 중요한 시스템 레벨의 그룹 프로세스들을 수반하는 통신 서비스의 한 클래스이다. 소프트웨어 멀티캐스트 알고리즘을 설계하는데 있어서의 주된 문제는 성능과 이식성 사이의 교환조건(trade-off)을 고려하는 것이다. 본 논문에서 제안하는 변수화 된 통신 모델은 LogP 모델의 확장으로 병렬 플랫폼의 통신 네트워크를 더 정확하게 특성화 할 수 있다. 이 변수화 된 모델에서, 컴퓨터 구조에 의존적이지 않고 이식성 있는 OPT-tree라는 최적의 멀티캐스트를 형성하는 알고리즘을 제안한다. 실제 여러 네트워크에 구현했을 때 진정한 최적의 수행을 달성하기 위해서 OPT-tree로 생성된 트리에서의 네트워크 위상에 따른 튜닝(tuning)에 대해 연구한다. 특히 웜홀 스위치를 사용하는 메쉬(mesh) 네트워크에서 변수화 된 멀티캐스트 알고리즘의 최적화 한 버전인 OPT-mesh 알고리즘을 개발하여 다른 알고리즘들과 비교하여 그 우수성을 검증한다.

  • PDF

안전한 항공기 운항을 위한 현업 전지구예보모델 기반 깊은 대류 예측 지수: Part 2. 계절별 최적화 및 사례 분석 (Aviation Convective Index for Deep Convective Area using the Global Unified Model of the Korean Meteorological Administration, Korea: Part 2. Seasonal Optimization and Case Studies)

  • 박이준;김정훈
    • 대기
    • /
    • 제33권5호
    • /
    • pp.531-548
    • /
    • 2023
  • We developed the Aviation Convective Index (ACI) for predicting deep convective area using the operational global Numerical Weather Prediction model of the Korea Meteorological Administration. Seasonally optimized ACI (ACISnOpt) was developed to consider seasonal variabilities on deep convections in Korea. Yearly optimized ACI (ACIYrOpt) in Part 1 showed that seasonally averaged values of Area Under the ROC Curve (AUC) and True Skill Statistics (TSS) were decreased by 0.420% and 5.797%, respectively, due to the significant degradation in winter season. In Part 2, we developed new membership function (MF) and weight combination of input variables in the ACI algorithm, which were optimized in each season. Finally, the seasonally optimized ACI (ACISnOpt) showed better performance skills with the significant improvements in AUC and TSS by 0.983% and 25.641% respectively, compared with those from the ACIYrOpt. To confirm the improvements in new algorithm, we also conducted two case studies in winter and spring with observed Convectively-Induced Turbulence (CIT) events from the aircraft data. In these cases, the ACISnOpt predicted a better spatial distribution and intensity of deep convection. Enhancements in the forecast fields from the ACIYrOpt to ACISnOpt in the selected cases explained well the changes in overall performance skills of the probability of detection for both "yes" and "no" occurrences of deep convection during 1-yr period of the data. These results imply that the ACI forecast should be optimized seasonally to take into account the variabilities in the background conditions for deep convections in Korea.

비대칭 마진 SVM 최적화 모델을 이용한 기업부실 예측모형의 범주 불균형 문제 해결 (Optimization of Uneven Margin SVM to Solve Class Imbalance in Bankruptcy Prediction)

  • 조성임;김명종
    • 경영정보학연구
    • /
    • 제24권4호
    • /
    • pp.23-40
    • /
    • 2022
  • Support Vector Machine(SVM)은 기업부실 예측문제 등 다양한 분야에서 성공적으로 활용되어 왔으나 범주 불균형 문제가 존재하는 경우 다수 범주의 경계영역은 확장되는 반면, 소수 범주의 경계영역은 축소되고 분류 경계선이 소수 범주로 편향되어 분류 성과에 부정적인 영향을 미치는 것으로 보고되고 있다. 본 연구는 범주 불균형 문제에 대한 대칭 마진 SVM(EMSVM)의 한계점을 개선하기 위하여 비대칭 마진 SVM(UMSVM)과 임계점 이동 기법을 결합한 최적화 비대칭 마진 SVM인 OPT-UMSVM을 제안한다. OPT-UMSVM은 소수 범주 방향으로 치우진 분류 경계선을 다수 범주로 재이동함으로써 소수 범주의 민감도를 개선하고 최적화된 분류 성과를 산출함으로써 SVM의 일반화 능력을 향상시키는 장점을 가진다. OPT-UMSVM의 성과 개선 효과를 검증하기 위하여 불균형 비율이 상이한 5개의 표본군을 구성하여 10-fold 교차타당성 검증을 수행한 결과는 다음과 같다. 첫째, 범주 불균형이 미미한 표본에서 UMSVM은 EMSVM의 성과 개선 효과가 미약한 반면, 범주 불균형이 심화된 표본에서 UMSVM은 EMSVM의 성과개선에 크게 공헌하고 있다. 둘째, OPT-UMSVM은 EMSVM 및 기존의 UMSVM과 비교하여 범주 균형 및 범주 불균형 표본 모두에서 보다 우수한 성과를 가지고 있으며, 특히 범주 불균형이 심화된 표본에서 유의적인 성과 차이를 보였다.

Comparative Effects of Phytase Derived from Escherichia coli and Aspergillus niger in Sixty Eight-week-old Laying Hens Fed Corn-soy Diet

  • Yan, L.;Zhou, T.X.;Jang, H.D.;Hyun, Y.;Kim, H.S.;Kim, I.H.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • 제22권10호
    • /
    • pp.1391-1399
    • /
    • 2009
  • Two hundred and sixteen 68-week-old Hy-Line brown laying hens were used in a 6-week feeding trial to compare the efficacy of phytases Optiphos (OPT) and Natuphos (NAT), which were isolated from Escherichia coli and Aspergillus niger, respectively. Hens were randomly allotted into six treatments with six replications (six layers in three adjacent cages) per treatment according to their initial BW. The hens were then subjected to one of the following dietary treatments: i) Positive Control (PC; available phosphorus (AP) 0.4%); ii) Negative control (NC; AP 0.2%); iii) NAT1 (NC+250 FTU/kg NAT); iv) NAT2 (NC+500 FTU/kg NAT); v) OPT1 (NC+250 FTU/kg OPT); vi) OPT2 (NC+500 FTU/kg OPT). Feed intake, egg production, egg quality, apparent nutrient digestibility and serum P and Ca concentration were evaluated to compare the effect of the two phytases. Feed intake and eggshell thickness were not affected by the treatments. Superior effects (p<0.05) of OPT were only observed in egg production and egg weight compared with NAT. Characteristics such as eggshell breaking strength, apparent digestibility of N, Ca and P and serum P concentration were equally increased with the supplementation of both phytases (p<0.05), where no significant difference was observed in those characteristics between PC and phytase supplementation at 500 FTU/kg. Equally effective improvements (p<0.05) were also observed in egg production and DM digestibility, where no improvements were observed (p<0.05) between the PC group and the groups with phytase supplementation at 500 FTU/kg. Equal increases in the serum Ca level were observed when the groups with phytase supplementation were compared to the PC group. Overall, the results of this study suggest that NAT and OPT are equally effective at liberating phytate-bound complexes when included in 0.2% available phosphorus diets for 68-week laying hens; either source of phytase can be fed to commercial 68-week laying hens at 500 FTU/kg to correct the negative effects associated with a 0.2% available phosphorus diet. In conclusion, either source of phytase can be fed to commercial first cycle laying hens at 500 FTU/kg to effectively replace inorganic phosphorus when economically justified.

두부자세와 두개안면형태의 상관관계에 대한 두부방사선 계측학적 연구 (A ROENTGENOCEPHALOMETRIC STUDY ON THE RELATIONSHIP BETWEEN HEAD POSTURE AND CRANIOFACIAL MORPHOLOGY)

  • 한희성;남동석
    • 대한치과교정학회지
    • /
    • 제18권1호
    • /
    • pp.253-265
    • /
    • 1988
  • This study was designed to compare the normal head posture group with the extended head posture group in order to investigate the relatinship between head posture and craniofacial morphology. The subjects were devided into two groups; one included 80 children with normal head posture and occlusion, and the other 60 malocclusion patients with extended head posture. Their lateral cephalograms were traced and analysed based on 38 selected items. The following conclusion were reached. 1. The craniocervical angulations in normal group; OPT to SN, CVT to SN, OPT to FH and CVT to FH angles were $101.7^{\circ},\;104.8^{\circ},\;91.7^{\circ}\;and\;100.7^{\circ}$, respectively. 2. Compared with normal group, experimental group showed increase in mandibular plane angle, decrease in facial plane angle, airway space and posterior facial height but, there were insignificant differences in anterior facial height and tongue level between two groups. 3. Of the craniocervical angulations, OPT to FH angle was most highly correlated to the variables of the craniofacial morphology. 4. The effect of craniocervical angulation on craniofacial morphology in experimental group was different from that in comparison of normal group and experimental group.

  • PDF