• 한국산업정보학회:학술대회논문집
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• 한국산업정보학회 2001년도 춘계학술대회논문집:21세기 신지식정보의 창출
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• pp.129-133
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• 2001

Accelerated life test is a viable method for identifying failure modes, incorporating design changes on an on-going basis during the early stages of automotive development program. The information from tests at high stress levels is extrapolated to obtain estimate of life at normal stress levels. This paper presents a practical method for accelerated life test to achieve a specified accuracy in estimating life at a design stress. Recommended and optimum plan are presented and the plans are illustrated with a simulated test data for the automotive power element example.

• 한국농공학회지
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• 제42권
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• pp.31-37
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• 2000

Regulated Deficit Irrigation (RDI) is one of the most important measures for the water-saving and high yield of crops. RDI is based on the crop and water relations. The theories of RDI were analyzed using the experiment data in Shaanxi and Gansu Province. There are several problems of RDI in practical use, which include; the uncertainty of crop-water relations, the proper growth stages and water deficit degree of RDI applied, and the requirements of RDI to irrigation system and irrigation techniques.

• 산업경영시스템학회지
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• 제21권45호
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• pp.253-263
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• 1998

This study presents a method of realizing the theoretical results of Demyanov in practice on a computer in order to produce a kind of constructive evidence for his theory and a practical method of getting numerical results for quasi-differentiab1e optimization problems which may arise in industry and science. A practical result for a restricted nondifferentiable optimization problem is experimented with a simle example.

• Smart Structures and Systems
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• 제4권4호
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• pp.465-492
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• 2008

Proper pretest planning is a vital component of any successful vibration test on engineering structures. The most important issue in dynamic testing of many engineering structures is arriving at the number and optimal placement of sensors. The sensors must be placed on the structure in such a way that all the important dynamic behaviour of a structural system is captured during the course of the test with sufficient accuracy so that the information can be effectively utilised for structural parameter identification or health monitoring. Several optimal sensor placement (OSP) techniques are proposed in the literature and each of these methods have been evaluated with respect to a specific problem encountered in various engineering disciplines like aerospace, civil, mechanical engineering, etc. In the present work, we propose to perform a detailed characteristic evaluation of some selective popular OSP techniques with respect to their application to practical civil engineering problems. Numerical experiments carried out in the paper on various practical civil engineering structures indicate that effective independence (EFI) method is more consistent when compared to all other sensor placement techniques.

• 한국실천공학교육학회논문지
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• 제2권2호
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• pp.61-67
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• 2010

인터넷기반의 IT기기의 발달과 함께 다양한 디자인을 선호하는 소비자니즈에 따른 새로운 제품의 출시를 위해서 이에 필요한 생산도구인 금형제작에 있어서도 리드타임이 짧은 금형개발기술의 필요성이 절실히 요구되고 있는 것이 현실이다. 금형개발기간 단축을 위한 공정기술이 금형개발 산업체에서의 매우 중요한 실무교육 중 하나이고, 신제품에 대한 납기단축, 품질 및 원가 세 가지 요소가 고루 갖춰지지 않는다면 경쟁에서 힘들기 때문이다. 본 논문에서는 기존의 제품개발에 따른 금형개발 교육훈련 프로그램이 체계적이지 못하고, 그리고 현실성이 부족한 교육훈련과정을 개선하여 실질적으로 현장에서 이행될 수 있는 실무기술능력 향상과 금형개발기간 단축을 위한 공정기술개선으로 실무중심 교육훈련 프로그램을 적용한 모형으로 발전시켜보고자 한다.

• 한국산업융합학회 논문집
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• 제7권2호
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• pp.193-198
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• 2004

This is the dissertation of the study of design characteristics about the practical flexible manufacturing system (PFMS). The basic ideas to analyze the manufacturing system which is the automatically operated is dependant on the various manufacturing procedures in factory. PFMS is the very useful equipment for students and trainee of production lines. This system is composed of hardware and software sub systems i.e. control and test unit and personal computer with software. The PFMS can be developed with design concepts and approved the capability of first article with functional tests. The PFMS module will be very useful for the manufacturing drill system in universities and practical fields. The flexible manufacturing systems have various subsystems appropriated for the final manufacturing products. Therefore the systems have the various kinds of hard wares as well as softwares. We study the software for the practical flexible manufacturing system designed in the Halla University and specially the design concept and using specification of the SCARA (Selective Compliance Assembly Robot Arm) robot which is used for the movement of the product is analyzed and introduced in this dissertation.

• 한국자동차공학회논문집
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• 제12권1호
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• pp.106-113
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• 2004

Most of mechanical structures are composed of many substructures connected to one another by various types of mechanical joints. In automotive engineering, it is important to study these connected structures under various dynamic forces for the evaluations of fatigue life and stress concentration exactly. In this study, the dynamic response of vehicle structure to external forces is classified an inverse problem involving strains from the experiment and the analysis. The practical dynamic forces are determined by the combination of the analytical and experimental method with analyzed strain by quasi-static finite element analysis under unit force and with measured strain by a strain gage under driving load, respectively. In a stressed body, inter-molecular chemical bonds are failed beyond the certain magnitude. The failure of molecular structure in material is considered as a time process of which rate is determined by mechanical stress. That is, the failure of inter-molecular chemical bonds is the fatigue lift of material. This kinetic concept is expressed as lethargy coefficient. And S-N curve is obtained with the lethargy coefficient from quasi-static tensile test. Equivalent practical dynamic force is obtained from the identification of practical dynamic force for one loading point. Using the practical dynamic force and S-N curve, fatigue life of a window pillar is analyzed with FEM under the identified force by the procedure of above mentioned.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.1136-1141
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• 2004

This paper presents a control method for time-delay systems and verifies the performance of the designed control system via real experiments. Specifically, the control method is applied to a flexible-link system with time delays. The method combines time- and frequency-domain controllers: linear quadratic optimal controller (or LQR) and lag compensator. The LQR is used to stabilize the system in optimal fashion, whereas the lag compensator is used to compensate time-delay effects by increasing the delay margin of the system. With this methodology, the maximum allowable time delay can be increased significantly. The proposed method is simple but quite practical for time-delay system control as it is based on the conventional loop-shaping method, which gives practical insights on delay-phase relationship. Simulation and experiment results show that the method presented in this paper is feasible and practical.

• Structural Engineering and Mechanics
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• 제46권3호
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• pp.433-445
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• 2013

Vibration-based structural identification has become an important tool for structural health monitoring and safety evaluation. However, various kinds of uncertainties (e.g., observation noise) involved in the field test data obstruct automation system identification for accurate and fast structural safety evaluation. A practical way including a data preprocessing procedure and a vector backward auto-regressive (VBAR) method has been investigated for practical bridge identification. The data preprocessing procedure serves to improve the data quality, which consists of multi-level uncertainty mitigation techniques. The VBAR method provides a determinative way to automatically distinguish structural modes from extraneous modes arising from uncertainty. Ambient test data of a cantilever beam is investigated to demonstrate how the proposed method automatically interprets vibration data for structural modal estimation. Especially, structural identification of a truss bridge using field test data is also performed to study the effectiveness of the proposed method for real bridge identification.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2001년도 춘계학술대회 논문집
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• pp.496-500
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• 2001

When we cut a key way on the axial or on the boss, we generally use a slotter or a broach. To do the key seating, turing operations have to be preceded and then the key on the axial or on the boss can be seated. For this reason, the production process of key way cutting becomes complicated. If is necessary to simplify the process and we have developed a small practical machine for key way cutting. The machine is located on the carriage of the lathe. Using this small and practical key way machine, after operation the turing, you do not have to remove the workpiece from the chuck of the lathe to carry on the key seating process. The developed machine will save cutting time and the cost.