• Journal of Institute of Control, Robotics and Systems
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• v.13 no.7
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• pp.677-682
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• 2007

Concurrent competition for finite resources by multiple parts in flexible manufacturing systems(FMS's) and inappropriate initial marking or net structure of Petri net with share resources results in deadlock. This is an important issue to be addressed in the operation of the systems. Deadlock is a system state so that some working processes can never be finished. Deadlock situation is due to a wrong resource allocation policy. In fact, behind a deadlock problem there is a circular wait situation for a set of resources. Deadlock can disable an entire system and make automated operation impossible. Particularly, an unmanned system cannot recover from such a status and a set of jobs waits indefinitely for never-to-be-released resources. In this paper, we proposed a deadlock prevention method using siphon and trap of Petri net. It is based on potential deadlock which are siphon that eventually became empty. This method prevents the deadlock by the control of transition fire and initial marking in the Petri net. An given example of FMS is shown to illustrate our results with deadlock-free.

• 제어로봇시스템학회:학술대회논문집
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• 1989.10a
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• pp.733-743
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• 1989

This paper deals with the control of system with controlled jump Markov disturbances. A such formulation was used by Boukas to model the planning production and maintenance of a FMS with failure machines. The optimal control problem of systems with controlled jump Markov process is addressed. This problem describes the planning production and preventive maintenance of production systems. The optimality conditions in both cases finite and infinite horizon, are derived. A numerical example is presented to validate the proposed results.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1991.11a
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• pp.235-241
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• 1991

The FMS(flexible Manufacturing System) was introduced to the part manufacturing industry more than twenty years ago. Considering the vast capital investment and today's competitive environment, it is very important to effectively manage and control the FMS including the day to day disturbances while meeting customer requirements.(omitted)

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2001.10a
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• pp.407-412
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• 2001

국내외 자동화 및 생산시스템 관련 교육기관에서 생산시스템의 제어 및 운영을 위한 기자재로써 교육용 FMS(Flexible Manufacturing System)를 도입, 운영하고 있다. 하지만 상당수 교육기관에서 당초의 도입목표를 제대로 달성하지 못하고 있는 실정이다. 본 논문에서는 교육기관에서 생산시스템 교육을 위해 필요한 교육용 FMS의 주요 기능과 역할을 정의하고, FMS 운영소프트웨어인 시스템 컨트롤러의 구축을 통한 시스템통합과 생산시스템 제어 및 운영을 위한 교육방안을 제시하고자 한다.

• 제어로봇시스템학회:학술대회논문집
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• 1987.10b
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• pp.294-299
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• 1987

The concept of FMS (Flexible Manufacturing System) has been widely used in discrete parts manufacturing environment. But, it is very difficult to analyze enotrol FMS due to its complex and dynamic behaviour. This paper describes a Simulation program for performance evaluation of FMS. The program is written in FORTRAN and is capable of simulating different configurations.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.864-867
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• 1995

Presented in the paper is a structured approach to modeling automated manufacturing system (AMS) in the form of an event graph. The proposed two-phase procedure for formal modeling is 1) reference modeling by schematic supervisory control modeling and 2) event graph transformation from supervisory control model. Also described is a formal model for a small-sized FMS in the form of an event graph.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.43 no.1
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• pp.143-150
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• 2020

To enhance the effectiveness of the FMS (flexible manufacturing system), it is necessary for the manufacturing control system to be upgraded by integrating the cyber and the physical manufacturing systems. Using the CPPS (Cyber-Physical Production System) concept, this study proposes a 4-stage vertical integration and control framework for an aircraft parts manufacturing plant. In the proposed framework, the process controller prepares the operations schedule for processing work orders generated from the APS (advanced planning & scheduling) system. The scheduled operations and the related control commands are assigned to equipments by the dispatcher of the line controller. The line monitor is responsible for monitoring the overall status of the FMS including work orders and equipments. Finally the process monitor uses the simulation model to check the performance of the production plan using real time plant status data. The W-FMCS (Wing rib-Flexible Manufacturing Control & Simulation) are developed to implement the proposed 4-stage CPPS based FMS control architecture. The effectiveness of the proposed control architecture is examined by the real plant's operational data such as utilization and throughput. The performance improvement examined shows the usefulness of the framework in managing the smart factory's operation by providing a practical approach to integrate cyber and physical production systems.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10a
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• pp.488-492
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• 1991

This paper deals with modeling and scheduling for flexible manufacturing systems(FMS). In modeling extended Petri nets are used to describe various and complex properties. To resolve multiple conflict without predefined properties, such as part selection, machine selection, rule-based scheduling method is introduced. This structure have a capability of on-line scheduling with systematic modeling description.

• Physical Therapy Rehabilitation Science
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• v.6 no.3
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• pp.113-119
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• 2017

Objective: The objective of this study was to investigate the effects of Schroth's three-dimensional exercises in combination with respiratory muscle exercise (SERME) on Cobb's angle and functional movement screen (FMS). Design: Randomized controlled trial. Methods: Fifteen subjects with scoliosis were randomly assigned to two groups. Eight subjects were assigned to the experimental group and seven subjects were assigned to the control group. The experimental group underwent SERME using SpiroTiger (Idiag, Switzerland), while the control group performed only the Schroth's three-dimensional exercises (SE). Both groups performed exercises for one hour per day, three times a week for eight weeks. Cobb's angle, pulmonary function (forced vital capacity, forced expiratory volume at one second, and peak expiratory flow) and FMS were measured before and after the experiment. Results: After intervention, the SERME group showed a significant difference in Cobb's angle, FMS scores, and pulmonary function as compared to before intervention (p<0.05). In the SE group, there was a statistically significant difference in Cobb's angle, pulmonary function, and FMS scores compared to before intervention (p<0.05). The SERME group showed a significant difference in Cobb's angle and peak expiratory flow in pulmonary function compared to the SE group (p<0.05). Conclusions: The results suggest that SERME could be a more effective intervention for improvement of the Cobb's angle and pulmonary function for scoliosis patients.

• PNF and Movement
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• v.14 no.1
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• pp.23-32
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• 2016

Purpose: The purpose of this study was to determine the effects of a coordinative locomotor training program on the functional movement screen (FMS) scores of badminton players. Methods: The participants consisted of 31 badminton players who were randomly assigned to either an experimental group (n=15) or a control group (n=16), and engaged in exercise five times per week for six weeks. The experimental group engaged in coordinative locomotor training and the control group engaged in general exercise. An FMS kit (USA) was used to measure the following: FMS score, deep squat, hurdle step, in-line lunge, shoulder mobility, active straight leg raise, trunk stability push up, and rotary stability. Results: The FMS score, deep squat, hurdle step, in-line lunge, active straight leg raise, and trunk stability push up showed significant improvement in the experimental group (p<0.05). Conclusion: The coordinative locomotor training program was able to produce confirmation that functional movement screen scores change in the case of effective exercise interventions in badminton players.