• 한국생산제조학회지
• /
• 제24권1호
• /
• pp.7-14
• /
• 2015

The machine tools builders are trying to improve the efficiency and performance of the machine tools. The electro-mechanical driven broaching machine has many advantages such as lower noisy operating, higher energy efficiency, and smaller space of installation. This paper presents the structural and mechanical development of an electro-mechanical driven broaching machine that is replaced for traditional hydraulic one. The servo motor, ball screw and roller linear guide are used instead of hydraulic cylinder and translation frictional sliding guides. The simulation method based on FEM was applied to analyze the stress, deformation of the machine for static analysis. The dynamic analysis was carried out for verifying and assessing the mechanical behavior of the developed broaching machine. This work helps broaching machine developer make a better product at the early design stage with lower cost and development time.

• 인터넷정보학회논문지
• /
• 제19권1호
• /
• pp.123-130
• /
• 2018

With the emergence of a new paradigm called Open Science and Big Data, the need for data sharing and collaboration is also emerging in the computational science field. This paper, we analyzed data-driven research cases for computational science by field; material design, bioinformatics, high energy physics. We also studied the characteristics of the computational science data and the data management issues. To manage computational science data effectively it is required to have data quality management, increased data reliability, flexibility to support a variety of data types, and tools for analysis and linkage to the computing infrastructure. In addition, we analyzed trends of platform technology for efficient sharing and management of computational science data. The main contribution of this paper is to review the various computational science data repositories and related platform technologies to analyze the characteristics of computational science data and the problems of data management, and to present design considerations for building a future computational science data platform.

• Asia pacific journal of information systems
• /
• 제9권1호
• /
• pp.115-142
• /
• 1999

Legacy applications are valuable assets that should be integrated into next generation business systems. To gain this advantage, progressive companies can reverse engineer the legacy business operations. This paper presents a form-driven object-oriented reverse engineering(FORE) methodology by the use of business forms to recover semantics of legacy applications. They retain the user-oriented contents of business and thus are easily understandable. Our form driven object-oriented reverse engineering methodology consists of five phases: form and usage analysis, form object slicing, object structure modeling, scenario design, and model integration. Knowledge about form structure and user interaction with legacy applications is used to capture the design semantics. An object model, which consists of an object structure model and scenario results from such form knowledge. The resulting object model is more likely to help reverse engineers understand and reuse legacy systems.

• Journal of Mechanical Science and Technology
• /
• 제20권2호
• /
• pp.278-285
• /
• 2006

The present study has been conducted to simulate dynamics of a gas engine-driven heat pump (GHP) for design of control algorithm. The dynamics modeling of a GHP was based on conservation laws of mass and energy. For automatic control of refrigerant pressures, actuators such as engine speed, outdoor fans, coolant three-way valves and liquid injection valves were PI or P controlled. The simulation results were found to be realistic enough to apply for control algorithm design. The model can be applied to build a virtual real-time GHP system so that it interfaces with a real controller in purpose of prototyping control algorithm.

• 한국분무공학회지
• /
• 제21권3호
• /
• pp.121-129
• /
• 2016

The advantages of the common rail fuel injection system architecture have been recognized since the development of the diesel engine. In common rail systems, a high-pressure pump stores a reservoir of fuel at high pressure up to and above 2000 bar. And solenoid or piezoelectric valves make possible fine electronic control over the fuel injection time and quantity, and the higher pressure that the common rail technology makes available provides better fuel atomization. In this study, the direct needle-driven piezo injector was investigated for accomplishing injection pressure of 1800 bar by optimal design by simplification of component and changing number of springs and plates of DPI. It was found that a direct needle-driven piezo injection system features the prototype DPI for passenger vehicle to operate at 1800 bar of injection pressure.

• 디지털융복합연구
• /
• 제10권7호
• /
• pp.179-184
• /
• 2012

도시의 궁극적인 목적은 '도시의 삶의 질 향상'이다. 이를 이루기 위하여 지역사회 합의,평가와 지역공동체의 비젼과 목표의 공유는 물론 지역 및 커뮤니티의 컨텐츠 생산 및 유통 소비의 최적화가 요구된다. U-City에서 서비스의 내용인 콘텐츠의 공유에 대한 요구와 필요성이 증가하고 있다. 온톨로지는 공유를 전제로 의미적 관계를 설정하기 위한 도구로서 이러한 변화에 대응하는 온톨로지 기반 U-Service 모델 설계가 필요하다. 본 연구는 유비쿼터스 환경에서 온톨로지 위치기반 콘텐츠를 최대한 표현할 수 있도록 하는 지도의 생성 및 서비스 구현의 가능성을 밝혀보았다.

• 한국압력기기공학회 논문집
• /
• 제9권1호
• /
• pp.15-19
• /
• 2013

The auxiliary feedwater is an important to remove the heat from the reactor core when the main feedwater system is unavailable. In most initiating events in Probabilistic Safety Assessment(PSA), the operaton of this system is required to mitigate the accidents. For one of domestic nuclear power plants, a design change of a turbine-driven auxiliary feedwater pump(TD-AFWP), pipe, and valves in the auxiliary system is implemented due to the aging related deterioration by long time operation. This change includes the replacement of the TD-AFWP, the relocation of some valves for improving the system availability, a new cross-tie line, and the installation of manual valves for maintenance. The design modification affects the PSA because the system is critical to mitigate the accidents. In this paper, the safety effect of the change of the auxiliary feedwater system is assessed with regard to the PSA view point. The results demonstrate that this change can supply the auxiliary feedwater from the TD-AFWP in the accident with the motor-driven auxiliary feedwater pump(MD-AFWP) unavailable due to test or maintenance. In addition, the change of MOV's normal position from "close" to "open" can deliver the water to steam generator in the loss of offsite power(LOOP) event. Therefore, it is confirmed that the design change of the auxiliary feedwater system reduces the total core damage frequency(CDF).

• 대한임베디드공학회논문지
• /
• 제8권4호
• /
• pp.195-204
• /
• 2013

The embedded software has been developed in the forms of various versions that provides similar service based on product family. For increase usefulness of product family, software must has well-structured and reusable properties. Software architecture is important to improve adaptability in model-based development of embedded software mounted onto product family. In this paper, we proposed a technique of ADD(Attribute-Driven Design)-based software architecture design for low power software development. This technique provides a chance to consider the power consumption issue in design phase of software, and makes possible to develop low power embedded software.

• 한국원자력학회:학술대회논문집
• /
• 한국원자력학회 1998년도 춘계학술발표회논문집(1)
• /
• pp.660-665
• /
• 1998

The feasibility study on conceptual design methodology for accelerator-driven sodium-cooled sub-critical transmutation reactors has been conducted to optimize the design parameters from the scale laws and validates reactor performance with the integrated code system. A 1000 MWth sodium-cooled sub-critical transmutation reactor has been scale and verified through the methodology in this paper, which is referred to advanced Liquid Metal Reactor (ALMR). a Pb-Bi target material and a partitioned fuel are the liquid phases, and they are cooled by the circulation of secondary Pb-Bi coolant and by primary sodium coolant, respectively. Overall key design parameters are generated from the scale laws and they are improved and validated by the intergrated code system. Intergrated Code System (ICS) consist of LAHET, HMCNP, ORIGEN2, and COMMIX codes and some files. Through ICS the target region, the core region, and thermal-hydraulic related are analyzed once-through. Results of conceptual design are attached in this paper.

• International Journal of Naval Architecture and Ocean Engineering
• /
• 제6권2호
• /
• pp.257-268
• /
• 2014

In this study, flow-driven rotor simulations with a given load are conducted to analyze the operational characteristics of a vertical-axis Darrieus turbine, specifically its self-starting capability and fluctuations in its torque as well as the RPM. These characteristics are typically observed in experiments, though they cannot be acquired in simulations with a given tip speed ratio (TSR). First, it is shown that a flow-driven rotor simulation with a two-dimensional (2D) turbine model obtains power coefficients with curves similar to those obtained in a simulation with a given TSR. 3D flow-driven rotor simulations with an optimal geometry then show that a helical-bladed turbine has the following prominent advantages over a straight-bladed turbine of the same size: an improvement of its self-starting capabilities and reduced fluctuations in its torque and RPM curves as well as an increase in its power coefficient from 33% to 42%. Therefore, it is clear that a flow-driven rotor simulation provides more information for the design of a Darrieus turbine than a simulation with a given TSR before experiments.