• 한국전산구조공학회:학술대회논문집
• /
• 한국전산구조공학회 2004년도 가을 학술발표회 논문집
• /
• pp.3-10
• /
• 2004

The earthquake-resistant structural systems have to ensure the sufficient stiffness and ductility for the stability. For those purposes, recently, the performance design concept to increase the degree of absorbed energy level of structures has been proposed. One practical way of the performance design in the spatial structures is to apply the isolation system to boundary parts of roof system and sub-structure to obtain the target performance. So, it is necessary to examine the characteristics of dynamic behavior of spatial structures governed by higher modes rather than lower modes different from the cases of high rise buildings. The objectives of this paper are to develop the equivalent lumped mass model to simplify the analytical processes and to investigate the dynamic behavior of roof system according to the mass and the stiffness of sub-structures as a fundamental study of performance design for the spatial structures.

• International Journal of Quality Innovation
• /
• 제8권2호
• /
• pp.115-131
• /
• 2007

The vehicle development process (VDP) is iterative in nature with numerous interactions and information flows between design groups and between development phases. The VDP has been changed from a sequential-functional development to a concurrent-team based approach. Concurrent execution of design activities may reduce the development lead-time, but it increases the managerial complexity in the VDP. A system dynamics model was developed to understand the transient behavior of parallel, overlap, and sequential processes in the VDP and to determine the optimal level of overlapping considering the development lead-time and total number of reworks. The simulation results showed that different execution processes should be used, depending upon the intensity of reworks.

• 한국생산제조학회지
• /
• 제26권3호
• /
• pp.299-305
• /
• 2017

Gate-lifting devices in small- to mid-sized sluice gates mostly employ the mechanical roller rack pinion (RRP) system. This RRP system, which consists of a rack-bar and a pinion, transforms a rotation motion into a linear one. The rack-bar has a series of roller trains that mesh with the pinion. In this study, we adopt an exact involute-trochoid tooth profile of the pinion to obtain a higher contact fatigue strength using the profile modification coefficient. Further, we determine the contact forces and investigate Hertz contact stresses to predict the pitting life of the pinion according to varying the shape design parameters. The results indicate that the design fatigue life of an RRP system for sluice gate can be achieved only when the design value of the profile modification coefficient reaches or exceeds a certain level.

• 항공우주시스템공학회지
• /
• 제1권4호
• /
• pp.22-27
• /
• 2007

The 150 gal Ion EFT(External Fuel Tank) used to enlarge the aircraft operation range was adopted an import equipment in T-50 FSD phase. But in Production phase the EFT was planed to develop for the stable ILS(Integrated Logistics Support) and technical ability improvement by using the composite materials. The design for configuration and fuel system is intended to maintain compatibility with aircraft systems and the development test is performed on component, assembly and aircraft. This study is conducted to provide the technology of design and test for the 150 gallon composite EFT in LRU level. The test results show that the composite EFT is satisfied with structural, functional and environment requirements which are described in specification.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2004년도 추계학술대회논문집
• /
• pp.751-754
• /
• 2004

This paper presents a design of the directional radiation pattern by using the structural-acoustic interaction. For this purpose, prediction of the pressure distribution of the field points and radiation pattern of the structural-acoustic coupling system is shown. In order to get a strong coupling, coupled system that has a finite space and a semi-infinite space separated by two flexible walls and an opening is selected. A volume interaction can be occurred in structure boundary and a pressure interaction can be happened in the opening boundary. The coupled system is maximized the radiation power on the main axis and minimized the side lobe level.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 1998년도 추계학술대회 논문집
• /
• pp.530-536
• /
• 1998

In the design of the light rail transit which is more reliable and economical, it is essential to develope a efficient third rail system. Especially, the analysis for the conductivity of conduct rail and the wear of collecting shoe is the first step of its development. In this paper, experiments for conductivity in conductor rail, wear in collecting shoe were performed respectively as different materials of conductor rail and current collector. Noise level and interruption, wear and contact resistance of collecting shoe were proposed as design parameters for the development of this system. Experimental equipment and methods of design parameter stated above were proposed, which is expected that analyzed results will be used as a basic data for the development of the system.

• 드라이브 ㆍ 컨트롤
• /
• 제18권3호
• /
• pp.23-29
• /
• 2021

Hydrogen energy is the clean energy source of the future. Ultra-high-pressure hydrogen is used in hydrogen stations, with its parts being developed. On the other hand, ultra-high-pressure ball valve, which is one of its parts, depends on overseas, with the level of domestic research on this being only about 10% of advanced technology research on this abroad. In this study, the shape of an ultra-high-pressure ball valve for a hydrogen station was designed to improve its structural strength. The valve body was designed according to distance between both processed body holes along inlet and outlet ports. The designed vale body was then analyzed using ANSYS to check whether points with stress were concentrated. In addition, the valve with improved body was analyzed to confirm that the valve satisfied the design condition.

• 한국실내디자인학회논문집
• /
• 제23권6호
• /
• pp.133-141
• /
• 2014

Graduate education in general means nurturing scholars who are capable of research that adds to the 'body of knowledge' and educators in the higher education system. Therefore 'discovering' new knowledge has always been a major role of graduate schools. However, interior design is a special field that 'application' can also produce new knowledge and therefore a wider understanding of scholarship is needed especially in the graduate level education. The purpose of this paper is to understand Interior Design graduate education system in the United States in order to develop issues that need to be discusses and addressed in Korea. Therefore, this paper first examines meanings of graduate degrees in general and current situation of Interior degrees offered in Korea. Then investigates the different types of graduate degrees in the U.S. such as post-professional degrees, first-professional degrees, and differences in general degree(M.A., M.S.) and professional degrees (M.F.A., M.I.D.). The researcher has used websites of each school and information lists of degrees offered by KIID and IDEC that serves as the main educators council in each countries. The characteristics of graduate degrees in America can be described as a structured system based on variety, flexibility, and distinction. For instance, M.F.A means a professional degree that is focused on building theory based project abilities, longer period to study but counted as a terminal in the field. However, in Korea even though the title of the degrees may differ there is not much difference shown in the educational contents. Therefore issues such as developing a more universal and international degree system, flexible and selective educational road-map, mutual understanding and unified system between various organizations for better graduate education system are proposed. Moreover, hope to start a discourse on defining scholarship and professionalism in the field of Interior Design.

• 대한기계학회논문집A
• /
• 제27권12호
• /
• pp.2028-2038
• /
• 2003

High-speed feed drive systems have been widely used in the manufacturing and semiconductor industries. Specifications for high-speed systems require more advanced capabilities than conventional feed drive systems. It is necessary to devise special design concepts to achieve the level of performance for high-speed feed drive systems. In this paper, an integrated design method is proposed for high-speed feed drive systems in which the interactions between mechanical and electrical subsystems ought to be considered simultaneously during the design process. Based on the integrated design method, a nonlinear optimal design procedure of mechanical subsystems considering the Abbe and radius errors is accomplished through the design process of electrical subsystems satisfying the control stability and the saturation condition of actuators as well as the relative stability. Both mechanical and electrical parameters are considered as design variables. Simulations and numerical case studies show that the integrated design method of high-speed feed drive systems creates results satisfying the desired performances of mechatronic systems.

• International Journal of CAD/CAM
• /
• 제9권1호
• /
• pp.1-16
• /
• 2010

When Deterministic Design Optimization (DDO) methods are used, deterministic optimum designs are frequently pushed to the design constraint boundary, leaving little or no room for tolerances (or uncertainties) in design, manufacture, and operating processes. In the Reliability-Based Design Optimization (RBDO) model for robust system design, the mean values of uncertain system variables are usually used as design variables, and the cost is optimized subject to prescribed probabilistic constraints as defined by a nonlinear mathematical programming problem. Therefore, a RBDO solution that reduces the structural weight in uncritical regions does not only provide an improved design but also a higher level of confidence in the design. In this work, we seek to improve the quality of RBDO processes using efficient optimization techniques with object of improving the resulting objective function and satisfying the required constraints. Our recent RBDO developments show its efficiency and applicability in this context. So we present some recent structural engineering applications demonstrate the efficiency of these developed RBDO methods.