• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.10
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• pp.4405-4410
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• 2012

This research aims to do heat transfer analysis on multi-functional dough conditioner. The dough conditioner is a key bakery machine for the maturation of dough which is raw material of bakery and also it's amount of used has been increased. Solidworks which is one of automatic design programs is applied to design in order to manufacture the multi-functional dough conditioner, and ANSYS which is a three dimensional finite element analysis code is used for the heat transfer analysis. Inside temperatures and heat fluxes are obtained as the results of heat transfer analysis and the results are contributed significantly in manufacturing the multi-functional dough conditioner.

• Transactions of Materials Processing
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• v.14 no.4 s.76
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• pp.368-374
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• 2005

In the present study we used a diagrammatic analysis of 6 sigma quality control and Taguchi method for injection molding of monitor back-cover, evaluated the influence on the cycle time with part design, mold design, molding process and standardization activity involving design and molding, adopted analysis of sensitivity and effective factors of the part design and molding process conditions for productivity, identified main design molding factors. The contributing factors for the final cycle time could be enumerated as follows; the thickness of hot spot, main nominal part thickness, coolant inlet temperature, melt temperature and cooling line layout, etc.. As a first step, all the critical factors of design process applied to the current monitor housing were investigated through 6 sigma process. Thereafter, the optimal and better critical factors found in the first step were applied to new product design to prove that our process was correct. The Moldflow was used for injection molding simulation, and Minitab software for the statistical analysis, respectively. Finally, the productivity of new design was increased about 33 percents for our specific case.

• Journal of Ocean Engineering and Technology
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• v.25 no.2
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• pp.73-78
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• 2011

The purpose of this study was to investigate the natural frequency of filament-wound composite towers for large scale wind-turbines using the finite element method (FEM). To define the material properties, we used both the effective property method and the stacking properties method. The effective properties method assumes that a composite consists of one ply. The stacking properties method assumes that a composite consists of several stacked plies. First, a modal analysis of the tower, filament-wound with angles of $[{\pm}30]$, was carried out using the two methods for composite material properties, the stacking method and effective method. Then, an FE analysis was performed for composite towers using filament winding angles of $[{\pm}30]$, $[{\pm}45]$, and $[{\pm}60]$. The FE analysis results using the stacking properties of the composite were in good agreement with the results from the effective properties method. The difference between the FEM and material properties methods was approximately 0~0.6%

• Analytical Science and Technology
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• v.30 no.4
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• pp.167-173
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• 2017

In the era of the forth Industrial Revolution, open source code and open source hardware have gained much attention. In particular, 3D printing technology is expanding into the realms of classical science, technology and our daily lives. Relatedly, in the present study, we demonstrate the manufacture of a nano-LC MALDI spotter robot using 3D printing technology. The parts of the spotter robot were either made using a 3D printer or purchased as 3D printer parts from the 3D printer online market, so that anyone can make the robot without a deep knowledge of engineering or electronics, i.e., DIY (do-it-yourself) product. In the nano-LC MALDI spotter, the nano-LC eluent and MALDI matrix were mixed in a T-union and discharged from the capillary outlet. The eluent and matrix mixture could be spotted onto the movable MALDI plate. The MALDI plate was designed to translate in a two-dimensional space (xy plane), which was enabled by the movements of two stepper motors. In the paper, all computer-aided design (CAD) files for the parts and operation software are provided to help the reader manufacture their own spotter robot.

• 한국전산유체공학회:학술대회논문집
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• 2004.03a
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• pp.224-229
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• 2004

The objective of this work is not only to perform feasibility studies on the CFD (computational fluid dynamics) analysis for the capillary system design but also to provide an enhanced understanding of the autonomous capillary flow. The capillary flow is evaluated by means of the commercial CFD software of FLUENT, which includes the VOF (volume-of-fluid) model for multiphase flow analysis. The effect of wall adhesion at fluid interfaces in contact with rigid boundaries is considered in terms of static contact angle. Feasibility studies are first performed, including mesh-resolution influence on pressure profile, which has a sudden increase at the liquid/gas interface. Then we perform both 2D and 3D simulations and examine the transient nature of the capillary flow. Analytical solutions are also derived for simple cases and compared with numerical results. Through this work, essential information on the capillary system design is brought out. Our efforts and initial success in numerical description of the microfluidic capillary flows enhance the fundamental understanding of the autonomous capillary flow and will eventually pave the road for full-scale, computer-aided design of microfluidic networks.

• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.3
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• pp.109-121
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• 2004

This paper presents an optimal design method for structure-borne durability of a vehicle body structure. Structure-borne durability design requires a new design that can increase fatigue lives of critical areas in a structure and must prohibit transition phenomenon of critical areas that results from modification of the structure at the same time. Therefore, the optimization problem fur structure-borne durability design are consists of an objective function and design constraints of 2 types; type 1-constraint that increases fatigue lives of the critical areas to the required design limits and type 2-constraint that prohibits transition phenomenon of critical areas. The durability design problem is generally dynamic because a designer must consider the dynamic behavior such as fatigue analyses according to the structure modification during the optimal design process. This design scheme, however, requires such high computational cost that the design method cannot be applicable. For the purpose of efficiency of the durability design, we presents a method which carry out the equivalent static design problem instead of the dynamic one. In the proposed method, dynamic design constraints for fatigue life, are replaced to the equivalent static design constraints for stress/strain coefficients. The equivalent static design constraints are computed from static or eigen-value analyses. We carry out an optimal design for structure-borne durability of the newly developed bus and verify the effectiveness of the proposed method by examination of the result.

• Proceedings of the KIEE Conference
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• 2005.07d
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• pp.3022-3024
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• 2005

연성 PCB(flexible printed circuit board)는 현재 노트북 PC와 디지털 카메라등에 적용되며, 굴곡성이 강하고 소형화 및 조립에 용이하여 주로 기판 사이나주기판과 외부 커넥터사이에 데이터의 전송매체로써 널리 사용되는 핵심부품이다. 근래에 개발되는 PCB 기반의 고성능 신호처리회로들은 데이터 전송율이 수백 MHz에서 수 GHz에 이르고 있으며, 신호선과 유전체, 접지판의 구조적 특성에 따라서, 반사 효과와 같은 신호무결성 문제들이 파생되어 신호의 최대성능을 제한하게된다. 이에 따라 적절한 임피던스 제어를 통하여 고성능신호들의 왜곡을 상쇄시키는 기술이 중요하게 되었다. 본 논문에서는 연성 PCB 전송라인을 위한 임피던스 모델을 대상으로 각 모델의 주요 특징 및 정확성을 분석하였다. 연성 PCB의 전송라인은 보통 전통적인 마이크로스트립 라인의 특성 임피던스 모델에 비해 신호선의 너비가 크며, 이를 반영한 개선된 수학적 임피던스 모델들이 제안되어 있다. 따라서 본 논문은 기존의 마이크로스트립 전송라인과 연성 PCB 전송라인에 적합한 수학적 모델들을 이용하여 신호 무결성 문제를 모의할 수 있는 CAE(computer-aided engineering) 도구의 임피던스 측정 결과를 비교 및 분석하였다.

• Journal of the Korean Society for Railway
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• v.11 no.1
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• pp.101-106
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• 2008

Recently, Architecture Frameworks are used to develop Information Management System (IMS). This paper describes an operational architecture development method for railway system safety assessment. using DoDAF (Department of Defense Architecture framework). The need of IMS is increasing to perform safety assessment task effectively and efficiently as safety-critical system like railway System. It is necessary that operational architecture based IMS requirements generated fir safety assessment. ARP(Aerospace Recommended Practice)4761 are referred to develop safety assessment operational architecture applicable to railway system. Firstly, schema and template was developed to perform the operational architecture development process using a commercial CASysE(Computer-Aided Systems engineering) tool, CORE. Not only the operational architecture allows building flexible IMS, but also helps business process solving.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2004.05a
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• pp.269-272
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• 2004

The present study used a diagrammatic analysis of 6 sigma quality control and Taguchi method for injection molding process of monitor back-cover, evaluated the influence on the cycle time with part design, mold design, molding process and standardization activity involving design & molding, adopted analysis of sensitivity and effective factors of the part design and molding process conditions for productivity, identified main design molding factors, as critical ones influencing on the quality and productivity, of which is summarized as design guidance. The main contribution factors for cycle time can be sequentially enumerated as follows; hot spot, part thickness, coolant inlet temperature, melt temperature cooling line layout, etc.. As a first step critical factors of the design process of current monitor housing were investigated. And the optimal and better critical factors found in the first step were applied to a new product proving our process was correct. Moldflow software was used for injection molding simulation, and Minitab software for the statistical analysis. Finally, the productivity was increased by about 33 percents for our specific case.

• Journal of Drive and Control
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• v.16 no.4
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• pp.56-64
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• 2019

Recently, as the environmental regulation for earth moving equipment has been tightened, advanced systems using electronic control have been introduced for energy savings. An IMV(Independent Metering Valve), which consists of four 2-way valves, is one of the electro-hydraulic control systems that provides more flexible controllability and potential for energy savings in excavators, when compared to the conventional 4-way spool valve system. To fully realize an IMV, a two-stage bi-directional flow control valve which can regulate the large amount of flow in both directions, should be developed in advance. A simple design that allows proportional flow control to apply the pilot pressure from the current-controlled solenoid to the spring loaded flow control spool and thus valve displacement, is proportional to the solenoid current. However, this open-loop type valve is vulnerable to flow force which directly affects the valve displacement. Force feedback servo of which the position loop is closed by the feedback spring which interconnects the solenoid valve and flow control spool, could compensate for the flow force. In this study, linearity for the solenoid current input and robustness against load pressure disturbance is investigated by linear analysis of the static nonlinear equations for the IMV proportional flow control valve with feedback spring. Gains of the linear system confirm the performance improvement with the feedback spring design.