• 전자공학회논문지A
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• 제33A권2호
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• pp.196-204
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• 1996

This paper presents a new scheduling algorithm, which is the most improtant subtask in the high level synthesis. The proposed algorithm performs scheduling in consideration of resource sharing concept based on characteristics of conditionsla bransches in the intermediate data structure. CDFG (control data flow graph) generated by a VHDL analyzer. This algorithm constructs a conditon graph based on time frame of each operation using both the ASAP and the ALAP scheduling algorithm. The conditon priority is obtained from the condition graph constructed from each conditional brance. The determined condition priority implies the sequential order of transforming the CDFG with conditonal branches into the CDFG without conditional branches. To minimize resource cost, the CDFG with conditional branches are transformed into the CDFG without conditonal brancehs according to the condition priority. Considering the data dependency, the hardware constraints, and the data execution time constraints, each operation in the transformed CDFG is assigned ot control steps. Such assigning of unscheduled operations into contorl steps implies the performance of the scheduling in the consecutive movement of operations. The effectiveness of this algorithm is hsown by the experiment for the benchmark circuits.

• 한국정밀공학회지
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• 제19권4호
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• pp.109-116
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• 2002

The solution of the aircraft wing spar cross-section area optimization problem is obtained by the response surface method. The object function of the problem is wing total weight, design variables are spar cross-section areas, constraints are the conditions that the stresses at the each spar is less than the allowable stress. D-Optimal condition is utilized to obtain the experimental points to construct the response surfaces. D-Optimal experimental points are obtained by the commercial software "Deign-Expert". Response values for the object function and constraints for each experimental point are calculated by the NASTRAN. Response surfaces for object function and constraints are approximated from the response values by the least square method. The optimization solution is obtained by the DOT for the response surfaces of object function and constraints. The optimization results obtained from the response surface are compared with the results obtained by the NASTRAN SOL200.

• 가정과삶의질연구
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• 제22권2호
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• pp.97-107
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• 2004

The purposes of this study were compare the leisure attitudes, leisure activities, and leisure constraint among three different generations - teenagers, adults, and elderly adults. Data were obtained from a Questionnaire completed by both male and female lived metropolitan, and aged over 13. Using the factor analysis, this study classified the types of leisure attitudes. The leisure attitude was divided to 4 factors - reducing stress, self-realization, family activity, and surplus time. In order to compare the attitudes, activities, and constraints of leisure among three different generations, ANOVA was used The findings of this study are as follows: First, there were significant differences between teenager group and the others. The teenagers (n=107) recognized the leisure as a mechanism of reducing stress, or as just surplus time. They liked sports, computer games, travels, and reading books, but were not likely to like leisure activities shared with family members. Their leisure constraints were significantly larger than those of the other groups. Teenagers' constraints of time, money, and skills could be leisure barriers. Second, adults group (n=123) attached importance to the family leisure activities. They liked to spend time with their family members, but they seemed to be relatively passive in most types of leisure activities. They like to read newspapers and magazines, and to participate in religious activities. Third, elderly adults' (n=86) purpose of leisure activities was to improve the health condition, and to develop relationships with their friends. They liked sports such as swimming and aerobic dance, travels, religious activities and community service activities. Their good health condition and economic resources could decrease the leisure constraints.

• 한국도로학회논문집
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• 제19권3호
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• pp.65-70
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• 2017

PURPOSES : Pavement Management System contains the data that describe the condition of the road. Under limited budget, the data can be utilized for efficient plans. The objective of this research is to develop a mixed integer program model that maximizes remaining durable years (or Lane-Kilometer-Years) in road maintenance planning. METHODS : An optimization model based on a mixed integer program is developed. The model selects a cluster of sectors that are adjacent to each other according to the road condition. The model also considers constraints required by the Seoul Metropolitan Facilities Management Corporation. They select two lanes at most not to block the traffic and limit the number of sectors for one-time construction to finish the work in given time. We incorporate variable cost constraints. As the model selects more sectors, the unit cost of the construction becomes smaller. The optimal choice of the number of sectors is implemented using piecewise linear constraints. RESULTS : Data (SPI) collected from Pavement Management System managed by Seoul Metropolitan City are fed into the model. Based on the data and the model, the optimal maintenance plans are established. Some of the optimal plans cannot be generated directly in existing heuristic approach or by human intuition. CONCLUSIONS:The mathematical model using actual data generates the optimal maintenance plans.

• 한국정밀공학회지
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• 제23권4호
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• pp.75-82
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• 2006

In this paper, we propose an optimal trajectory for biped robots to move up-and-down stairs using a genetic algorithm and a computed-torque control for biped robots to be dynamically stable. First, a Real-Coded Genetic Algorithm (RCGA) which of operators are composed of reproduction, crossover and mutation is used to minimize the total energy. Constraints are divided into equalities and inequalities: Equality constraints consist of a position condition at the start and end of a step period and repeatability conditions related to each joint angle and angular velocity. Inequality constraints include collision avoidance conditions of a swing leg at the face and edge of a stair, knee joint conditions with respect to the avoidance of the kinematic singularity, and the zero moment point condition with respect to the stability into the going direction. In order to approximate a gait, each joint angle trajectory is defined as a 4-th order polynomial of which coefficients are chromosomes. The effectiveness of the proposed optimal trajectory is shown in computer simulations with a 6-dof biped robot that consists of seven links in the sagittal plane. The trajectory is more efficient than that generated by the modified GCIPM. And various trajectories generated by the proposed GA method are analyzed in a viewpoint of the consumption energy: walking on even ground, ascending stairs, and descending stairs.

• 전산구조공학
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• 제9권3호
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• pp.179-186
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• 1996

본 연구에서는 구조체의 위상학적 최적화를 위한 비선형 formulation(NLP)가 개발, 검토되었다. 이 NLP는 multiple-loading하에서 임의의 오브젝티브 함수, 응력, 변위 제약조건들을 쉽게 다룰 수가 있다. 또한 이 NLP는 해석과 최적화 디자인을 동시에 실시함으로써 요소 사이즈가 영으로 접근함에 따른 강성 매트릭스의 singularity를 피할 수 있다. 즉, 평형 방정식을 등제약조건으로 치환함으로써 강성 매트릭스 그 자체나 그의 역매트릭스를 구할 필요도 없어진다. 이 NLP는 multiple-loading conditon하에서 테스트되었으며, 이를 통해 이 NLP가 다양한 제약조건하에서 강력하게 작용함이 입증되었다.

• 재활복지
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• 제21권1호
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• pp.253-277
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• 2017

이 연구는 지체장애인의 운동참여제약을 측정할 수 있는 운동참여제약 측정도구(Constraints in Physical Activity Scale for people with physical Disabilities: CPASD)를 개발하는 데에 목적이 있다. 이를 위해 이 연구에서는 Messick(1995)의 통합적 타당도, Benson(1998)의 강력한 구인타당도 프로그램 틀을 기반으로 한 다섯 가지 단계로 연구를 설계하였고, 지체장애인 264명을 대상으로 공통요인모형과 측정모형을 적용하여 CPASD의 타당도 증거를 체계적으로 제시하였다. 이 연구의 결과와 논의를 토대로 결론을 제시하면 다음과 같다. 첫째, CPASD는 구인타당도의 증거를 제시하였다. 요인구조의 해석가능성과 요인계수의 적합성을 통해 지도자 제약, 경제적 제약, 편견, 운동환경 제약으로 구성된 4요인, 17개 문항으로 개발되었다. 둘째, 개발된 CPASD의 요인구조(지도자제약, 경제적제약, 편견, 운동환경제약)는 통계적으로 구분됨과 동시에, 기존 운동참여제약 관련 이론을 안정적으로 반영하였다. 셋째, 개발된 CPASD는 준거관련타당도 증거를 제시하였다. 지도자제약, 편견은 긍정적 운동정서와 부적인 상관관계를, 지도자제약, 편견, 운동환경제약은 부정적 운동정서와 정적인 상관관계를 나타내었다. 따라서 후속 연구에서는 CPASD의 요인로 도출된 지도자제약, 경제적제약, 편견, 운동환경제약과 관련된 현재의 제도, 실태 등을 재평가할 필요성이 대두되고, 이를 위해 CPASD를 활용한 인과관계검증, IRT 이론을 적용한 현실 수준정도를 판단할 필요가 있다.

• 한국정밀공학회지
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• 제33권8호
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• pp.669-681
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• 2016

Mechanical designers often make mistakes that result in unwanted over-constraints, causing difficulty in assembly operations and residual stress due to interference among parts. This study is concerned with detection and elimination of over-constraints. Screw theory is a general method that is used for constraint analysis of an assembly and motion analysis of a mechanism. Mechanical assemblies with plane-plane, pin-hole, and pin-slot constraint pairs are analyzed using screw theory to illustrate its utility. As a real-world problem, a ball valve design is analyzed using the same method, and several unwanted over-constraints are detected. Elimination measures are proposed. Nominal dimensions of some parts are adjusted, and dimensions and tolerances of the pins and holes are modified using the virtual condition boundary concept. The revised design is free of over-constraints. General procedure for applying screw theory to constraint analysis is established and demonstrated; it will contribute to improving quality of assembly designs.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.176.5-176
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• 2001

This paper presents a fuzzy dynamic output feedback controller design method for Parallel Distributed Compensation (PDC)-type Takagi-Sugeno (T-S) model based fuzzy dynamic system with H$\infty$ performance and additional constraints on the closed pole placement. Design condition for these controller is obtained in terms of the linear matrix inequalities (LMIs). The proposed fuzzy controller satisfies the disturbance rejection performance and the desired transient response. The design method is verified by this method for an inverted pendulum with a cart using the proposed method.

• 국제학술발표논문집
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• The 2th International Conference on Construction Engineering and Project Management
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• pp.777-786
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• 2007

This paper presents a modified simulated annealing algorithm to optimize linear scheduling projects with multiple resource constraints and its effectiveness is verified with a proposed problem. A two-stage solution-finding procedure is used to model the problem. Then the simulated annealing and the modified simulated annealing are compared in the same condition. The comparison results and the reasons of improvement by the modified simulated annealing are presented at the end.