• Title/Summary/Keyword: Concurrent

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The Effect of Factors in The Concurrent Engineering on the Efficiency of the Product Development Processes (동시공학의 제 요인들이 제품개발의 효율성에 미치는 영향)

  • 손달호
    • Journal of the Korean Operations Research and Management Science Society
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    • v.21 no.3
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    • pp.89-108
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    • 1996
  • During the whole product design and development processes, the concurrent engineering relies on strong and permanent interactions between the departmental functions. Concurrent or simultaneous engineering in new product development is a new concept which needs to be redefined. This paper deals with a concurrent engineering model which represents how concurrency, as an organizational process, is related to a interfunctional project team. Four dimensions shaping the sucess of the concurrent engineering are suggested with detailed meausrement instruments. Moreover, an empirical study on the effects of the four dimensions on the efficiency of the product development processes is carried out in the field of electronic industries.

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A Study on the Performance Analysis of Process Model with Resource Constraints in Concurrent Engineering Environment (동시공학 환경에서 자원제약이 있는 프로세스 모델의 성능분석에 관한 연구)

  • 강동진;이상용;유왕진;정용식
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.22 no.51
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    • pp.231-240
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    • 1999
  • A major concern in Concurrent Engineering is the control and management of workload in a period of process. As a general rule, leveling the peak of workload in certain period is difficult because concurrent processing is comprised of various processes, including overlapping, paralleling looping and so on. Therefore, the workload management with resource constraints is so beneficial that effective methods to analyze design process are momentous. This study presents the Timed Petri Nets approach of precedence logic networks, and provides an alternative for users to analyze constraint processes to resolve conflicts of resources. Another approach to Continuous Time Markov Chain using Stochastic Petri Nets is also proposed. These approaches are expected to facilitate resolving resource constrained scheduling problems more systematically in Concurrent Engineering environment.

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Drug Interactions of Ibuprofen and Prednisolone in Antiinflammatory and Antipyretic Effects (항염 및 해열효과에 미치는 Ibuprofen과 Prednisolone의 약 상호 작용)

  • 강영자;조윤성
    • YAKHAK HOEJI
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    • v.25 no.3
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    • pp.109-114
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    • 1981
  • The authors investigated drug interaction of ibuprofen and prednisolone in antiinflammatory and antipyretic activities. We have found significant differences of the antiinflammatory and antipyretic activities between single and concurrent administration of ibuprofen and prednisolone, using Sprague-Dawley Strain rats, carrageenin as a phlogistic agent and brewer's yeast as a fever inducing agent. 1) Ibuprofen(20mg/kg) was administered to the rats orally and resulted in significant reduction of (31.70 %) the swelling of rat paw induced by carrageenin, 2) prednisolone (9mg/kg) showed significant reduction of (45.76%) the swelling, 3) concurrent administration of ibuprofen (20mg/kg) and prednisolone (9mg/kg) also reduced (57.40%) the swelling. In ibuprofen (125mg/kg) administration, the inhibition rate of edema was 39.32% and in prednisolone (1mg/kg) administration, the rate was 39.04%. In concurrent administration of ibuprofen (125mg/kg) and prednisolone (1mg/kg), the inhibition rate of edema was 63.09%. Concurrent administration of ibuprofen and prednisolone showed more anti-inflammatory effects than single administration of ibuprofen and prednisolone respectively. Prednisolone itself did not show antipyretic effect, but concurrent administration of ibuprofen and prednisolone showed more antipyretic effects than ibuprofen single administratron.

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Automation of the Concurrent Real-Time Task Structuring in the modified CDOARTS Methodology (수정된 CODARTS 벙법론에서의 실시간 병렬 태스크 자동 구성)

  • 김규년;정민포;이종구
    • Journal of KIISE:Software and Applications
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    • v.26 no.1
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    • pp.106-106
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    • 1999
  • When we design real-time software target system is analyzed and then we structure sequential executive modules into concurrent tasks. As a result of the analysis, control flow and dataflow diagram based on the RTSA notation is produced. This diagram is structured into concurrenttasks under the condition that performance problem is not serious. The criteria structuring concurrenttasks are introduced as Concurrent Design Approach for Real-Time System(CODARTS) by Gomaa.But structuring concurrent tasks using the criteria of CODARTS is somewhat difficult because thecriteria are dependent on designer's experience. CODARTS is an wide-range and abstractmethodology. As a result, the design can be inconsistent and peoples can understand it differently Inthis paper, we restructure the CODARTS methodology, propose a revised CODARTS structure andrepresent the task structuring steps for this new framework to overcome the understanding andinconsistency problems. The revised CODARTS framework and task structuring steps can be used toautomate the design of real time concurrent software systems. Finally, we show an example of taskstructuring in revised CODARTS framework.

A Study on Validity of the Korean Version of the Subhealth Questionnaire (한국판 아건강 평가 설문지의 타당도 연구)

  • Ryu, Jae-Min;Park, Young-Bae;Park, Young-Jae
    • The Journal of the Society of Korean Medicine Diagnostics
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    • v.13 no.2
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    • pp.78-87
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    • 2009
  • Background and Objective: We previously developed questionnaire of subhealth status. Developed questionnaire was verified about reliability and validity, but there had a lack of concurrent validity study. On this study, we will verify concurrent Validity of the Korean Version of the Subhealth Questionnaire. Methods: Guibi-tang questionnaire, chalder questionnaire and subhealth questionnaire were applied to 113 college students. After then do correlation analysis, we calculate concurrent validity of that. Results and Conclusions: As a result, subhealth questionnaire between chalder questionnaire, and subhealth questionnaire between Guibi-tang questionnaire had a significant correlation respectively. The result of this study indicate that the developed questionnaire of subhealth status was verified about concurrent validity.

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A SYSTMATIC APPROACH FOR APPORTIONING CONCURRENT DELAY

  • Nie-Jia Yau;Chia-Chi Chang
    • International conference on construction engineering and project management
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    • 2007.03a
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    • pp.520-529
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    • 2007
  • Apportioning responsibilities of concurrent delay to the owner and the contractor is a difficult task, due to the sophisticate nature both in the schedule and in the factors that cause the delay. This research attempts to develop a simplified yet systematic approach that can be used for a fair apportionment of concurrent delay. A concurrent delay is defined herein as when the contractor and the owner have both caused independent critical path delays during the same approximate time period. Incorporating the concepts of windows analysis and critical path method (CPM), the developed approach has three "windowing of delay" steps to quickly apportion the delay in each of these windows, and a fourth step to sum up those apportioned delays to obtain each party's final responsibilities. This developed approach is found to be simple and effective at this stage; it will be tested against real cases in the near future.

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A CONCEPTUAL FRAMEWORK FOR CONCURRENT CONSTRUCTION PLANNING

  • Euysup Shim;Kenneth Reinschmidt
    • International conference on construction engineering and project management
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    • 2009.05a
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    • pp.440-448
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    • 2009
  • Concurrent construction (or overlapping) is an alternative project delivery process to reduce time-tomarket such that the owner can get higher profits; the increased profits due to shortened project duration would exceed the loss of profits from the increased cost, if any. For more effective concurrent construction, a new conceptual framework for concurrent construction planning is suggested. With multiple work methods available in each activity, the performance of overlapping between two activities in terms of cost is affected by the compatibility between work methods selected and the benefit to the project owner is determined by internal rate of return (RoR). The impact of the compatibility between work methods and the conceptual framework are explained by a hypothetical case study.

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Optimization for robot operations in cluster tools for concurrent manufacturing of multiple wafer types (복수 타입의 웨이퍼 혼류생산을 위한 클러스터 장비 로봇 운영 최적화)

  • Tae-Sun Yu;Jun-Ho Lee;Sung-Gil Ko
    • Journal of Industrial Technology
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    • v.43 no.1
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    • pp.49-55
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    • 2023
  • Cluster tools are extensively employed in various wafer fabrication processes within the semiconductor manufacturing industry, including photo lithography, etching, and chemical vapor deposition. Contemporary fabrication facilities encounter customer orders with technical specifications that are similar yet slightly varied. Consequently, modern fabrications concurrently manufacture two or three different wafer types using a cluster tool to maximize chamber utilization and streamline the flow of wafer lots between different process stages. In this review, we introduce two methods of concurrent processing of multiple wafer types: 1) concurrent processing of multiple wafer types with different job flows, 2) concurrent processing of multiple wafer types with identical job flows. We describe relevant research trends and achievements and discuss future research directions.

The Effects of the Angle of Ankle Joints and Direction of Isometric Contraction on Fatigue in the Contralateral Muscle (발목관절 각도와 등척성 수축방향이 반대측 근육 피로도에 미치는 영향)

  • Yoon, Doo-Sik;Kim, Tack-Hoon;Cynn, Heon-Seock;Roh, Jung-Suk
    • Physical Therapy Korea
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    • v.12 no.3
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    • pp.46-55
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    • 2005
  • The purpose of this study was to evaluate the effect of concurrent and reciprocal isometric contraction and angle of ankle joint on fatigue of concentrically contracting contralateral dorsiflexor and plantar flexor. Seventeen able-bodied subjects participated in the study. Concurrent and reciprocal isometric contraction were performed under three different ankle joint angles (dorsiflexion, neutral position, plantar flexion). During concurrent or reciprocal isometric contraction. fatigue of concentrically contracting contralateral tibialis anterior, gastrocnemius, and soleus was investigated and compared. There was no interaction between different ankle joint angles and direction of isometric contraction (p<.05). No significant differences were found among three different ankle joint angles (p<.05). Contralateral muscle fatigability was lower in reciprocal isometric contraction than that in concurrent isometric contraction (p<.05). Therefore, the findings of this study suggest that reciprocal isometric contraction is more beneficial than concurrent isometric contraction inducing less fatigability during contralateral concentric contraction.

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Development of Concurrent Engineering System for Design of Composite Structures (복합재 구조물의 설계를 위한 동시공학 시스템의 개발)

  • ;;;H.T.Hahn
    • Composites Research
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    • v.12 no.6
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    • pp.43-52
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    • 1999
  • This paper explains the development of a concurrent engineering system for the rlesign of composite structures. The concurrent engineering system is developed to meet the demand for the better quality products with lower production cost and time. In this study, to compose the architecture of concurrent engineering system, the commercial and noncommercial programs related to design and analysis of composite structures are surveyed and classified. The concurrent engineering system is including various design modules such as design/analysis of composite structures using CLPT and FEM, buckling and post bucking analysis, thermo-elastic analysis of carbon-carbon composite, and optimum design using expert system and genetic algorithm. For the integration and management of softwares, the concurrent engineering system is realized by Microsoft visual $C++{^\circledR}$ that provide multi-tasking and graphic user interface environment.

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