Engineering design primarily focuses on product improvement through enhancing existing functionalities, integrating features, or adding new capabilities. In other words, it can be said that more design(adaptive design) changes to existing products based on benchmarking with competing products, differentiation strategies, changes in customer needs, etc. are actually performed rather than developing new products that did not exist before. Especially in the case of custom production, such as ships or buildings, a significant portion of actual design work involves modifying and adjusting past performance data according to the current customer's requirements. Therefore, design methods should be developed in a way that effectively supports these processes. Therefore, in this study, as QFD (Quality Function Deployment) ‘analysis of existing products’ and ‘creation of new alternatives’ is supported in Marine Concept Design with AHP (Analytic Hierarchy Process) techniques such as ‘Value Evaluation in Analysis Work’ and ‘Design Alternative Evaluation’, as a result, basic research was conducted on whether it could be used as a tool to effectively support the flow of the design process.

KEPCO KPS is the contractor for the full system decontamination (FSD) of Kori Unit 1 and under preparation such as modification, lay out for equipment installation, setting up tie-in/out point for chemical injection and way to pressurize the system, of its successful performance. In this research, KPS introduced how KPS has designed and prepared for the FSD project and how will the chemical decontamination process be implemented. As described in the previous research, chemical decontamination process is planned to be conducted for three cycles and each cycle is consisted of oxidation, reduction, decomposition, and purification. Oxidation and reduction process were conducted at 90°C. Chemical decomposition and purification process were conducted at 40°C due to the damage of IX by the heat. If the decontamination result does not meet the target DF and the dose rate, additional cycle can be conducted. Expected volume of process water for FSD is 200 m3. Three systems have been designated as decontamination targets: reactor coolant system (RCS), residual heat removal system (RHRS), chemical volume control system (CVCS). For the steady flow rate, existed plant equipment such as reactor coolant pump (RCP) will be operated and modifications on some components will be conducted. Due to the limited space for installation, decontamination equipment and other resources are distributed to three different places. KPS designed the layout of equipment installed inside the containment vessel. The layout contains the information of shielding for highly radiated equipment such as IX and filter skid.

The temperature of the spent fuel cladding is the basis for the evaluation of integrity. It is almost impossible to directly measure the temperature of spent nuclear fuel. Because spent nuclear fuel is dangerous. We are preparing a test to measure the cladding temperature with an equivalent fuel assembly by simulating the characteristics of spent nuclear fuel. PLUS7 was selected as the test target in consideration of the amount of generation, thermal water retention, residual moisture content, and manufacturability of domestic spent nuclear fuel. The nuclear fuel assembly is planned to be manufactured in two main ways. Except for the cladding tube that simulates decay heat, the structure will be manufactured by KEPCO Nuclear Fuel, and fuel rods and canisters will be manufactured by SUKEGAWA Electric in Japan. The same nuclear fuel assemblies as commercial skeleton will be applied. The temperature of the fuel cladding will be measured by attaching a thermocouple directly to the surface of the cladding tube. The canister is composed of a basket, a basket supporter, a heater and drain tube, a lead, and an observation window. The working fluid is water and helium, and the maximum pressure inside the canister is 1.1 MPa and the minimum pressure is 0.05 kPa. The maximum temperature of the surface of the cladding was designed to be 500°C, and the maximum temperature of the sealing to keep airtightness was designed to be 250°C. To satisfy this condition, we plan to evaluate the leak rate below 10−5 std.cm3·s−1, which is equivalent to helium tightness. The maximum heat of decay per fuel rod is 13 W, and one assembly is up to 3 kW. Production of the test equipment is expected to be completed in the first half of next year, and testing is scheduled to begin in the second half of next year. The test will evaluate all environments that the spent nuclear fuel may experience, such as dry normal conditions, abnormal conditions, wet conditions, and dry conditions. All data will be used for interpretation verification purposes.

The use of dampers is being considered a means to improve the seismic performance of buildings. It may take considerable time and effort to find an optimal design solution since repeated three-dimensional nonlinear time history analyses are required. Therefore, a preliminary design procedure for seismic retrofit using hysteretic dampers was proposed in this study. In the proposed procedure, the amount of retrofit (required number of dampers) is estimated from the capacity curve of the building before retrofit and allowable story drift of the building. In combining the capacity curves of the building and the dampers, the deformation demand for the dampers can be easily checked against their deformation capacity. The equations to transform the device displacement to roof displacement for the combination of capacity curves are developed. The proposed procedure was applied to the seismic retrofit design of sample buildings. The study found that the estimated capacity curve was very close to the actual capacity curve obtained from the pushover analysis, which can determine an appropriate configuration to meet the required seismic performance.

PURPOSES : In Korea, asphalt overlay has been used as a typical alternative rehabilitation method for deteriorated pavements. However, asphalt overlay has problems due to poor bonding of the asphalt overlay and the old concrete. Recently, concrete overlays, which have advantages such as long-term durability and high structural capacity to carry heavy traffic, have been considered for rehabilitation construction. However, concrete overlays have limitations such as difficulty in opening to traffic and pavement noise. Recently, an appropriate fine-size exposed aggregate concrete pavement technique was reported to solve these problems. Therefore, this study aims to suggest an optimum mixture design of fine-size exposed aggregate concrete overlay (EACO) that can ensure low noise and early strength. METHODS : The optimum mixture design of fine-size EACO is determined to ensure adequate structural performance for early traffic opening and good functional performances such as low noise. Therefore, the optimum mixture proportion is determined based on the optimum design of aggregate content to produce a low-noise pavement texture by controlling the exposed aggregate number (EAN) and mean texture depth (MTD). RESULTS : The water-cement ratio and unit cement ratio were used to determine the mixture designs to achieve workability and adequate strength for early traffic opening. The texture was determined by selecting the maximum size of coarse aggregate smaller than 10 mm with an S/a ratio of less than 30% for low noise. With these mixture proportions, the EAN and MTD were 50±5 / 25cm2 and 1.0±0.2 mm. Respectively, which meet the criteria for EACO. CONCLUSIONS: In this study, an optimum mixture design of EACO for early traffic opening and low noise is suggested by using earlyhigh strength cement, and the pavement texture is implemented considering EAN and MTD. In addition, a pavement surface texture criterion is suggested for the quality control of EACO.

In this study, a design procedure for the practical application of the dampers to building structures under earthquake loads was presented by using earthquake response spectrum. Nonlinear time history results using a 10 story building structure installed with damper verified the effectiveness of the proposed procedure by showing that the structural response could be reduced to the target performance level for seismic loads. Since the proposed design procedures are based on response spectrum seismic analysis result of the original structure, the capacity, location and the number of damper and the consequent response reduction effects can be preliminarily determined without performing the nonlinear time history analysis.

This paper describes a development of design tool for knowledge based engineering(KBE) that covers structural, aerodynamic, and optical analysis of large-scale telescope structures. A module of the commercial program Adaptive Modeling Language(AML) was used to develop a knowledge-based design tool that reflects the design of parameters for rapid design change and analysis. Through this study, it is proposed a design tool with a knowledge based engineering and a function based design technique. The knowledge based engineering design is good at frequent design changes, and it is effective to extract a core design behavior from previous designs. It is concluded that the developed tool can bring fair effects in implementing a time and cost-effective design environment.

원자력발전소내 습식저장중인 사용후핵연료의 건식저장을 위해서는 캐니스터 내부에 사용후핵연료를 옮겨 담은 이후, 건 식저장 캐니스터 내장품이나 사용후핵연료 다발의 부식방지 및 피복관의 열화방지를 위해 모든 수분은 제거해야 한다. 캐 니스터 내부의 수분을 제거하는데 사용할 수 있는 기체강제순환 건조시스템 개발을 위한 연구개발이 진행중이다. 본 연구 에서는 기체강제순환 건조시스템 설계, 제작을 위한 예비설계를 수행하였다. 예비설계에는 캐니스터 내부 잔존수분 제거를 위한 건조사례조사, 건조관련 규격이나 표준, 건조합격기준, 건조장치구성, 현장요구분석, 습식저장중인 사용후핵연료 특성 을 포함하였다. 예비설계를 통하여 기체강제순환 건조시스템의 설계 개념도와 P&ID를 도출하였고, 이를 활용하여 건조시 스템 제작을 위한 상세설계를 수행할 것이다.

Flight dynamic simulation programs are useful to estimate dynamic performances of an aircraft and to develop flight control laws. Usually, simulation programs were developed by the causal programming method which required a distinct relationship between inputs and outputs. Recently, a new approach, acausal programming, has been developed and applied in many fields to deal with the disadvantages of causal simulation programs. The authors have developed a flight dynamic simulation program by using Modelica which is an acausal programming language. The developed program has been tested by several simulations for attitude and velocity hold control. It has been shown that servo systems for control surfaces can be designed by this program. The level of detail of models can be easily increased by using the library of Modelica. The simulation program can be used to develop unmanned aerial vehicles and rotor crafts.