• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2012.06a
• /
• pp.210-210
• /
• 2012

레저보트의 경우 초기 설계단계에서 소비자의 요구사항과 그에 기반 한 외형 디자인이 매우 중요한 설계 요소 중 하나이다. 운용컨셉 정의, 스타일링 등 초기설계 결과는 구조 및 외형에 이르는 선체, 의장설계 뿐만 아니라 향후 제조, 판매에 이르기까지 개발과정 전반에 걸쳐 큰 영향을 미치게 된다. 해외의 경우 이러한 점을 고려한 3차원 모델 기반 통합설계 시스템에 대한 기술개발이 활발하게 이뤄지고 있으며, 더 나아가서 통합설계 데이터를 생산에 활용하는 단계에 이르고 있다. 본 연구에서는 3차원 형상모델을 중심으로 레저보트 기본설계 프로세스를 통합하기 위한 연구를 수행하였으며, 50피트 급 크루즈보트 설계 사례연구를 통해 그 효용성을 보였다.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.4 no.3
• /
• pp.29-37
• /
• 2000

Because the previous design procedure for the composite wind turbine blade structure using trial and error method takes long time, a improved design procedure by using the program based on classical laminate theory was proposed to reduce the inefficient element. According to the improved design procedure, limitation of strains, stresses and displacements specified by international standard specification IEC1400-1 for the composite wind turbine blade were applied to sizing the structural configuration by using the rule of mixture and the principal stress design technique with a simplified turbine blade. Structural safety for strength and buckling stability was confirmed by the developed analysis program based on the laminate theory to minimize the design procedure. After modifying the preliminary design result with additional structural components such as skin, foam sandwich and mounting joints, stresses, strains, displacements, natural frequency, buckling load and fatigue life were analyzed by the finite element method. Finally these results were confirmed by comparing with IEC1400-1 specification.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.22 no.2
• /
• pp.270-275
• /
• 2018

Method for improving the image quality are divided into a tone mapping method and a retinex theory based method. Typical example of the image quality enhancement method using tone mapping method is one using image characteristics like histogram. In this paper, we propose a hardware design of real-time wide dynamic range algorithm based on tone mapping method for image quality enhancement. The proposed method divides the image into the luminance and chroma components and then improves the chroma region based on the variation of the luminance component. Adding to that, it is designed to be compatible with the existing 8-bit signal, using high quality image with 12-bit extended signal according to the desired flow. As a result of simulation, it is confirmed that the image quality is improved, and the hardware design is confirmed that the real-time operations is possible at the maximum frequency at 138.26MHz.

• Journal of Korean Society of Steel Construction
• /
• v.14 no.1
• /
• pp.13-21
• /
• 2002

In this paper, 3-D frame design using refined plastic-hinge analysis accounting for local buckling is developed. This analysis accounts for material and geometric nonlinearities of the structural system and its component members. Moreover, the problem associated with conventional refined plastic-hinge analyses, which do not consider the degradation of the flexural strength caused by local buckling, is overcome. Efficient ways of assessing steel frame behavior including gradual yielding associated with residual stresses and flexure, second-order effect, and geometric imperfections are presented. In this study, a model consisting of the width-thickness ratio is used to account for local buckling. The proposed analysis is verified by the comparison of the LRFD results. A case study shows that local buckling is a very crucial element to be considered in second-order plastic-hinge analysis. The proposed analysis is shown to be an efficient, reliable tool ready to be implemented into design practice.

• Journal of the Korean GEO-environmental Society
• /
• v.5 no.3
• /
• pp.5-15
• /
• 2004

SIP has been widely used as a low noise and vibration piling method in Korea. But the quality control of SIP was not properly settled down and field workers did not fully understand the principle of SIP method. So not a less troubles were raised at construction site and bearing capacity was not fully mobilized. To settle these problems, Korea National Housing Corporation amended the construction and load test criteria of SIP in 2002. After load tests on the SIPs installed in field according to the new criteria, we found that the bearing capacity in field vs the design load ratio increased and bearing characteristics was enhanced than that installed by the former criteria. To consider the enhanced bearing characteristics in the pile design and determine the adequate design criteria, this paper analyzed the accuracy of design criterion which were commonly used in Korea comparing with the load test results. Analysis result shows that Meyerhof criteria(1976) properly simulates the bearing capacity of SIP installed by the new construction and load test criteria.

• Journal of the Korea Concrete Institute
• /
• v.19 no.4
• /
• pp.491-497
• /
• 2007

In the current research, the scheme of displacement-based seismic design for seismic retrofit of concrete structures using FRP composite materials has been proposed. An algorithm of the nonlinear flexural analysis of FRP composite concrete members has been presented under multiaxial constitutive laws of concrete and composite materials. An algorithm for performance-based seismic retrofit design of reinforced concrete columns with FRP jacket has been newly introduced to modify the displacement coefficient method used in reinforced concrete structures. From applications of retrofit design, the method are easy to apply in the practice of retrofit design and give practical prediction of nonlinear seismic performance evaluation of retrofitted structures.

• Korean Architects
• /
• no.4 s.217
• /
• pp.48-57
• /
• 1987

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.37 no.9
• /
• pp.863-871
• /
• 2013

Flow characteristics of velocity-control trim in a valve is investigated numerically with high pressure drop. A basic trim widely used for a valve in domestic powerplants is selected and designed for a baseline of velocity-control trim. The numerical analysis is focused on flow rate and cavitation with the basic trim. For a condition of high-pressure drop, pressure drop between inlet and outlet and fluid temperature are selected to be 18.1 MPa and $160^{\circ}C$, respectively, which are typical ones considering operating conditions adopted in powerplants. With this baseline model and condition, design changes are made for improvement of flow rate and cavitation phenomenon. For re-design, trim is divided into three zones in radial direction and design parameters of flow area, stage, and flow direction are considered in each zone. With these combined parameters applied to each zone, 4 models with design changes are proposed and their flow rates and cavitation areas are investigated. From comparison with those in the baseline model of a basic trim, proposed models show better performance in both flow rate and cavitation.

• Proceedings of the Safety Management and Science Conference
• /
• 2012.11a
• /
• pp.473-485
• /
• 2012

최근 현대사회는 자동차, 철도 및 항공 등 대형 복합 시스템의 체계 속에서 지내고 있으며, 고장 및 사고로 인한 시스템의 안전 설계에 대한 고려와 안전에 대한 인식이 증가하고 있다. 따라서 기존의 시스템공학 프로세스에서 다루는 시스템 설계에 대한 단계별 안전 활동의 강화의 필요성 역시 강조되고 있다. 그 중에서도 시스템 설계의 최종 활동에 해당하는 검증 단계 활동이 제대로 수행되어야만 초기에 의도한 시스템 설계의 안전도 향상을 바라볼 수 있을 것이다. 본 논문에서는 안전 활동을 고려한 시스템공학 프로세스의 검증 단계의 개선사항 도출과 모델링을 통해 안전중시 시스템인 철도 차량 운전실 시스템을 대상으로 적용 및 조정 구축에 대한 내용을 기술하고 있다. 본 연구의 결과를 토대로 향후 품질 향상 및 비용 절감과 데이터의 관리 및 추적기능을 개선함으로써 안전사고 발생 가능성을 줄일 수 있을 것으로 기대된다.

• Journal of Digital Convergence
• /
• v.11 no.2
• /
• pp.193-203
• /
• 2013

In our thesis we introduce case study for qualifying university graduates system for efficient maintenance. First, we find out factors to make maintenance difficult and present solution for them. Second, we convert system architecture from algorithm-oriented to driving-engine-based, design DB schema, develop algorithms for important components of proposed system, and implement them. Through results of system operation, we show that our system can reduce maintenance cost fairly.