• Title/Summary/Keyword: Constraint satisfaction

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A Conflict Detection Method Based on Constraint Satisfaction in Collaborative Design

  • Yang, Kangkang;Wu, Shijing;Zhao, Wenqiang;Zhou, Lu
    • Journal of Computing Science and Engineering
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    • v.9 no.2
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    • pp.98-107
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    • 2015
  • Hierarchical constraints and constraint satisfaction were analyzed in order to solve the problem of conflict detection in collaborative design. The constraints were divided into two sets: one set consisted of known constraints and the other of unknown constraints. The constraints of the two sets were detected with corresponding methods. The set of the known constraints was detected using an interval propagation algorithm, a back propagation (BP) neural network was proposed to detect the set with the unknown constraints. An immune algorithm (IA) was utilized to optimize the weights and the thresholds of the BP neural network, and the steps were designed for the optimization process. The results of the simulation indicated that the BP neural network that was optimized by IA has a better performance in terms of convergent speed and global searching ability than a genetic algorithm. The constraints were described using the eXtensible Markup Language (XML) for computers to be able to automatically recognize and establish the constraint network. The implementation of the conflict detection system was designed based on constraint satisfaction. A wind planetary gear train is taken as an example of collaborative design with a conflict detection system.

Factors Influencing Leisure Satisfaction Among Elderly with Economic Burden and Health Problems: Focusing on Leisure Activities (경제적 부담과 건강 문제를 겪는 노인들의 여가만족 요인에 관한 연구: 여가활동을 중심으로)

  • Hong, Seokho
    • 한국노년학
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    • v.40 no.1
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    • pp.197-216
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    • 2020
  • This study aimed to suggest leisure activities and policy-level support in the light of the characteristics and needs among the elderly by examining constraint factors of leisure activities among the elderly. Data of 3887 elderly with the age of 65 and above with economic burden and health problems from the 6th Korean Retirement and Income study were used for the statistical analyses. Hierarchical linear models were tested by entering factors stepswise; demographic factors(age, gender, marriage status, single household, region, living expenses, health status) in the first step, leisure factors(leisure time, leisure motivation) in the second step, and lastly leisure activity factors(desired leisure activities, undesired leisure activities) in the third step. The results were as follows: First, major factors that constrict leisure activities of the elderly were financial burden and health problems. Second, there were significant differences among three(financial constraint, health constraint, and financial and health constraint) groups. Financial constraint group was the highest in the level of leisure satisfaction but leisure time was the shortest. The major reason to do leisure activities of the financial constraint group was to keep relationships with families and friends. In terms of desired leisure activities, health constraint group wanted resting, financial constraint group wanted hobbies and entertainment, and the financial-and-health constraint group wanted social activities. Third, financial constraint group demonstrated higher levels of leisure activity satisfaction when they wanted to take care of pets or gardens; however, they showed lower levels of leisure activity satisfaction when they wanted to domestic trips for desired leisure activities. In case of health constraint group, they demonstrated lower levels of leisure activity satisfaction whether or not they wanted resting like watching TV or listening to the radio. And, the showed higher levels of leisure activity satisfaction when they wanted social activities such as participation in religion or social gathering organizations. For the financial-and-health constraint group, whereas they showed lower levels of leisure activity satisfaction when they wanted walking around or watching TV, and domestic trips for desired leisure activities, they demonstrated higher levels of leisure activity satisfaction when they wanted entertainment doing the game of go, or chess, and hobbies like hiking and social activities. Practice and policy level suggestions to offer leisure activities that meet the needs of the elderly were made based on the study results.

Job Shop Scheduling by Tabu Search Combined with Constraint Satisfaction Technique (Tabu Search와 Constraint Satisfaction Technique를 이용한 Job Shop 일정계획)

  • 윤종준;이화기
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.25 no.2
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    • pp.92-101
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    • 2002
  • The Job Shop Scheduling Problem(JSSP) is concerned with schedule of m different machines and n jobs where each job consists of a chain of operations, each of which needs to be processed during an uninterrupted time period of a given length on a given machine. The purpose of this paper is to develop the efficient heuristic method for solving the minimum makespan problem of the large scale job shop scheduling. The proposed heuristic method is based on a Tabu Search(TS) and on a Constraint Satisfaction Technique(CST). In this paper, ILOG libraries is used to embody the job shop model, and a CST is developed for this model to generate the increased solution. Then, TS is employed to overcome the increased search time of CST on the increased problem size md to refine the next-current solution. Also, this paper presents the new way of finding neighbourhood solution using TS. On applying TS, a new way of finding neighbourhood solution is presented. Computational experiments on well known sets of MT and LA problem instances show that, in several cases, our approach yields better results than the other heuristic procedures discussed In literature.

Configuration System through Vector Space Modeling In I-Commerce (전자상거래에서의 벡터 공간 모델링을 통한 Configuration 시스템)

  • 김세형;조근식
    • Journal of Intelligence and Information Systems
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    • v.7 no.1
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    • pp.149-159
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    • 2001
  • There have been lots of researches for providing a personalized service to a customer using one-to-one marketing and collaborative filtering techniques in E-Commerce. However, there are technical difficulties for providing the recommendation of products far users, which often involve high complexity of computation. In this paper, we have presented an integrated method of classification problem solving method and constraint based configuration techniques. This method can reduce a complexity of computation by classifying a solution domain space that has a higher complexity of composition. Thereafter, we have modeled customers constraints and the components of products to configure a complete system by passing it to constraint processing module in Constraint Satisfaction Problems. Constraint-based configuration uses the constraint propagation using the constraints of buyers and the constraints among PC components to configure a proper product for a customer. We have transformed and applied vector space modeling method in the field of information retrieval to consider a customer satisfaction in addition to the CSP. Finally, we have applied our system to test data fur evaluating a customers satisfaction and performance of the proposed system.

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The associations between marital satisfaction and life satisfaction among retirees in later life: a longitudinal comparison (은퇴 노인의 부부관계 만족도와 삶 만족도의 관계에 대한 종단적 비교)

  • Choi, Bomi;Jun, Hey Jung;Joo, Susanna
    • Journal of Family Relations
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    • v.21 no.2
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    • pp.77-96
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    • 2016
  • Objectives: The aims of this study are to examine the associations between marital satisfaction and life satisfaction among Korean retirees in later life and to test whether the degrees of associations increased over time. Method: Nationally representative Korean Longitudinal Study of Ageing data from wave 1 (in 2006) to wave 4 (in 2012) was utilized and retirees in later life (65-89 years old, N=402) were analyzed. Latent growth modeling (LGM) and model constraint were applied using Mplus 7.3. Age, sex, household income, subjective health, depressive symptoms and elapsed time after retirement were included as control variables. Results: Linear unconditional LGM fitted the data well and showed gradual decrease in life satisfaction. Conditional LGM revealed significant associations between marital satisfaction and life satisfaction from time 1 to time 4. According to model constraint test, the size of associations between marital satisfaction and life satisfaction did not change with time. Conclusions: To sum up these results, the associations between marital satisfaction and life satisfaction were significant and relatively stable over time among retirees in later life. This study suggests one's spouse is a fundamental component of social convoy among Korean retirees in later life. Therefore, intervention programs targeted toward enhancing marital relationships among retirees' couples will help them to live a better life.

Pedagogically-Driven Courseware Content Generation for Intelligent Tutoring Systems

  • Hadji, Hend Ben;Choi, Ho-Jin;Jemni, Mohamed
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.12 no.1
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    • pp.77-85
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    • 2012
  • This paper describes a novel approach to adaptive courseware generation. This approach adopts its structure from existing intelligent tutoring systems and introduces a new component called pedagogical scenario model to support pedagogical flexibility in the adaptation process of courseware generation system. The adaptation is carried out using Dynamic Constraint Satisfaction Problem framework, which is a variant of classical Constraint Satisfaction Problem, to deliver courseware tailored to individual learner. Such a framework provides a high level of expressiveness to deal with the particular characteristics of courseware generation problem. Further, it automatically designs a sound courseware satisfying the design constraints imposed by the domain, the pedagogical scenario and learner models.

The Leisure Activity Pattern and Effects of Leisure Constraints on Leisure Satisfaction of Adolescents (청소년의 여가활동 특성과 여가장애에 따른 여가만족도 차이)

  • Lee Eun-Hee;Min Hyun-Sun
    • Journal of the Korean Home Economics Association
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    • v.42 no.12 s.202
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    • pp.231-251
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    • 2004
  • The purpose of this study us to determine the adolescents' leisure activity pattern, leisure constraints and leisure satisfaction and to identify the relevant variables. The subjects were middle and high school students. The data was collected by using the questionnaire and the final 741 cases were analyzed by SPSS Win 10.0 program. The major findings were as follows: 1. The adolescents' leisure activity hours were 2.27hours/day(weekday), 4.20hours/day(Saturday) and 5.35hours/day(Sunday). On weekdays, female students spent more time for leisure activity than male students. The most frequent activities were watching TV and playing computer. 2. The adolescents' leisure constraints were social-economic, psychological and situational. The degree of the adolescents' situational constraint was the highest. 3. The adolescents' leisure satisfactions were leisure use, leisure condition and leisure meaning. The adolescents' degree of leisure meaning satisfaction was relatively high. 4. The major related variable influencing the leisure satisfaction were psychological constraint, situational constraint and gender.

The effects of perceived father's rearing attitude on leisure satisfaction and leisure constraint in middle school students: the mediating effects of self-efficacy (중학생이 지각한 아버지의 애정-합리적 설명형 양육태도가 여가만족 및 여가제약에 미치는 영향 : 자기효능감의 매개효과를 중심으로)

  • Jung, In-Kyung;Kim, Jung-Hyun
    • Journal of Korean Home Economics Education Association
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    • v.27 no.2
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    • pp.77-93
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    • 2015
  • The purpose of this study was to investigate the mediating effects of self-efficacy on the relationship between perceived father's rearing attitude and leisure satisfaction/leisure constraint in junior high school students. A survey was conducted using a convenient sample drawn from 448 students from eleven junior high school in Seoul area. Data were analyzed using SPSS 20.0 program. The results showed that students who perceived their father's rearing attitude as affection-rational explanation performed more of out-door leisure activity with their family. Perceived father's rearing attitude and self-efficacy was positively related with leisure satisfaction but negatively related with leisure constraint. In addition, self-efficacy partially mediated the relationship between perceived father's rearing attitude and leisure satisfaction/leisure constraint. These results suggest the leisure activity could be increased by father's rearing attitude through improving self-efficacy. Therefore, to improve the leisure activity through increase of leisure satisfaction and decrease of leisure constraint, father should raise their children in love and help to grow their self-efficacy.

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Optimal Berth and Crane Scheduling Using Constraint Satisfaction Search and Heuristic Repair (제약만족 탐색과 휴리스틱 교정기법을 이용한 최적 선석 및 크레인 일정계획)

  • 류광렬;김갑환;백영수;황준하;박영만
    • Journal of Intelligence and Information Systems
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    • v.6 no.2
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    • pp.1-14
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    • 2000
  • The berth and crane scheduling problem in a container terminal encompasses the whole process of assigning berth to each ship, determining the duration of berthing, assigning container cranes to each ship, and determining the specific start and end time of each crane service, for all the ships scheduled to be arriving at the terminal during a certain scheduling horizon. This problem is basically a constraint satisfaction problem in which cranes and berths should be assigned in such a way that all the spatial and temporal constraints are satisfied without any interference. However, it is also an optimization problem because the requested arrival and departure time should be met for as many of the scheduled ships as possible, while the operation cost of the terminal should be minimized. In this paper, we present an effective and efficient approach to solving this type of problem, which combines constrain satisfaction search and heuristic repair. We first employ a constraint satisfaction search to find a feasib1e solution. Then, the feasible solution is modified to a more optimal one by iteratively applying our heuristic repair operations within the framework of constraint satisfaction search. Experimental results with a real data from Pusan East Container Terminal showed that our approach can derive a schedule of satisfactory quality in a very short time.

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Development and Application of Scheduling System in Cold Rolling Mills (냉연 일정계획 시스템의 개발과 적용)

  • Kim, Chang-Hyun;Park, Sang-Hyuck
    • IE interfaces
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    • v.16 no.2
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    • pp.201-210
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    • 2003
  • The purpose of this research is to develop a scheduling system for CAL (Continuous Annealing Line) in Cold Rolling Mill. Based on CSP (Constraint Satisfaction Problem) technique in artificial intelligence, appropriate algorithms to provide schedules satisfying all the constraints imposed on CAL are designed and developed. Performance tests show that the proposed scheduling system outperforms human operators in case of aggregating the same attributes and minimizing the thickness differences between two adjacent coils.