• 한국태양에너지학회:학술대회논문집
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• 2011.04a
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• pp.48-53
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• 2011

In this study, it is to verify the applicability for a simplified model(IEC61400-2, Design Require-ments for Small Wind Turbines, 2006-03) is the international standard is used to the structural design. In the design process of a wind turbine, the safety of a designed wind turbine is one of the most important factors. The simplified model can be used to determine the design load for small wind turbines. So, this paper has been re-evaluated a small wind turbine design loads that produced already. As a result, the material characteristic value(Rchar) of Blade, Rotor shaft and the tower are $90E6[N/m^2]$, $441E6[N/m^2]$ and $94E6[N/m^2]$. Therefore, the value of the applied safety factor to each part of the survival probability of 95% are satisfied.

• Journal of Energy Engineering
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• v.12 no.3
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• pp.177-183
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• 2003

The purpose of this paper is to verify that the design stress value of fuel rod for the irradiation test satisfies the structural design requirement. In this structural safety analysis thermal effect is the most severe element for the safety. The thermal effects are very complicated problem to be analyzed for the structural safety in short hand. By the application of theoretical analysis, the design margin of stress which was used in this fuel rod design was verified in the conservative point of view. In the future design of fuel rod, this analysis can be used as the theoretical method for the verification of safe design.

• Journal of Ocean Engineering and Technology
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• v.25 no.1
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• pp.27-31
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• 2011

The previously developed method of estimating the propulsion performance of a UUV was applied to the high speed UUV, which is propelled by commercial thrusters. The thrusters were selected with an overdesign mentality; in other words, their capacities were excessive. At that point, the designer's concern was focused on a question regarding at what rpm the UUV could reach the design speed. Because the developed method required thrust coefficient curve data, the researchers asked for the POW data of the thrusters from the manufacturer. From the data, the researchers extracted the thrust coefficient and estimated the rpm value of design speed for the UUV. Finally, the researchers compared the estimated value and the result from a self-propulsion test using a VPMM (Vertical planar motion mechanism) test at a towing tank in MOERI.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.28 no.5
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• pp.292-302
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• 2016

In this study, shallow-water design waves are estimated for various return periods based on statistical analysis of extreme waves observed 13 years at four stations on the Korean east coast (Sokcho, Mukho, Hupo, Jinha). These values are compared with the results from SWAN simulation by using the deep water design waves conventionally used in Korea (KORDI, 2005). It was found that the simulated values of the shallow-water design waves are comparatively smaller than the values from the extreme value analysis, expecially below 30 years frequency, which implies possible under-estimation of the deep-water design waves on the Korean east coast.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2002.09a
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• pp.189-196
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• 2002

The capacity of CFS piers has not been used to a practical design, because there is no guide of a seismic design for CFS piers. Therefore, the guide of a seismic design value is derived from tests of CFS piers in order to apply it to a practical seismic design. Steel piers and concrete-filled steel piers are tested with constant axial load using quasi-static cyclic lateral load to check ductile capacity and using the real Kobe ground motion of pseudo-dynamic test to verify seismic performance. The results prove that CFS piers have more satisfactory ductility and strength than steel piers and relatively large hysteretic damping in dynamic behaviors. The seismic performance of steel and CFS piers is quantified on the basis of the test results. These results are evaluated through comparison of both the response modification factor method by elastic response spectrum and the performance-based design method by capacity spectrum and demand spectrum using effective viscous damping. The response modification factor of CFS piers is presented to apply in seismic design on a basis of this evaluation for a seismic performance.

• Journal of the Korea Society for Simulation
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• v.10 no.2
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• pp.1-14
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• 2001

The layout design of component plays an important role in the design and usability of many engineering products. The Engineering artifacts of today are becoming increasingly complicated. The simulated annealing method has been applied effectively to the layout and packing problems of wafer. The main characteristics of simulated annealing method is that an optimum can be obtained from the many local optimums by controlling the temperature and introducing the statistic flickering. The objective of this study is to suggest a method to apply the simulated annealing method to the three dimensional layout design of submergible boat which has multiple constraint conditions and evaluation criteria. We describe an approach to define cost function, constraints and generate layouts using a computer. In this research three dimensional LAYout Design Optimization Program(LAYDOP ver.2) has been developed. The layout result(the total value of evaluation criteria) designed by a human layout expert has been improved by 31.0% using this program.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.24 no.2
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• pp.186-191
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• 2015

Presently, rapidly changing and unstable global economic environments demand engineers. Products should be designed to increase profits by lowering costs and provide distinguished performance compared with competitors. This study aims to optimize the design of the power-transmission drive shaft. The mass is reduced as an objective function, and the stress is constrained under a constant value. To reduce the number of experiments, CCD (central composite design) and D-Optimal are used for the experimental design. RSM (response surface methodology) is employed to construct a regression model for the objective functions and constraint function. In this problem, there is only one objective function for the mass. The other objective function gives 1; thus, NSGA-II is used.

• Current Photovoltaic Research
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• v.11 no.1
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• pp.34-37
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• 2023

Solar energy had become the main energy industry of renewable energy along with hydroelectric power generation. One of the technologies that contributed to the popularization of photovoltaic power and the decrease in the unit price of photovoltaic modules was the large-area solar cell. However, as the area increased, the light receiving area increased and the current value increased accordingly. Since power loss occurs when the current value was large, the number of busbar was increased to increase the current collection rate, and a technology to lower the current value through half-cutting was developed. The bus bar of the solar cell served as a passage through which the generated current was transmitted. This was because when the number of busbar decreases, the moving distance of electrons increased, so the amount of power generation decreases and when it increases, shadows occured. An important aspect of the electrode design was the optimal balance of these busbars and number of fingers. Therefore, in this study, the characteristics of the solar cell according to the number of front bus bars of the large-area solar cell were simulated using Griddler 2,5 pro. After selecting the number of busbar with the best characteristics, the difference was compared by varying the number of fingers and a better direction for the number of cutting was presented.

• 기술발표회
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• s.2006
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• pp.311-319
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• 2006

Artesian Pressure exists in Hwa Jeon Project Site of Nakdong Delta Area. Maxium value of the pressure ranges between 06 tonf/m2 and 1 3 tonf/m2 in the design site. This paper presents a design case study considering the Artesian Pressure to calculate the consolidation settlement of the deep marine clay.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.45 no.3
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• pp.131-138
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• 2022

The demand for chiller equipment that keeps each machine at a constant temperature to maintain the best possible condition is growing rapidly. PID (Proportional Integral Derivation) control is a popular temperature control method. The error, which is the difference between the desired target value and the current system output value, is calculated and used as an input to the system using a proportional, integrator, and differentiator. Through such a closed-loop configuration, a desired final output value of the system can be reached using only the target value and the feedback signal. Furthermore, various temperature control methods have been devised as the control performance of various high-performance equipment becomes important. Therefore, it is necessary to design for accurate data-driven temperature control for chiller equipment. In this research, support vector regression is applied to the classic PID control for accurate temperature control. Simulated annealing is applied to find optimal PID parameters. The results of the proposed control method show fast and effective control performance for chiller equipment.