• Advances in aircraft and spacecraft science
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• v.5 no.2
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• pp.239-249
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• 2018

Physical tests are performed at various stages of the development cycle of a product, from prototype validation to product qualification. Although costly, there are growing demands for qualification tests like endurance vibration testing to be more representative of the real world. At the same time there are growing demands to assess the durability of these items based on FEA simulation. In this paper, we will explain how to set up a CAE-based test and how to correlate the results with some physical measurements. Specific assumptions will be explained and some advantages of using virtual tests will be highlighted such as the reduction of the number of prototypes needed, investigations on failures, evaluation of the level of reliability via sensitivity analysis, evaluation of the margins are at the end of a successful test. This presentation will therefore focus on explaining and showing how virtual tests can enrich the exploitation of physical tests.

• 한국신재생에너지학회:학술대회논문집
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• 2005.06a
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• pp.160-163
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• 2005

This paper proposes a simple MPPT control scheme of a Current-Control-Loop Error system Based that can be obtains a lot of advantage to compare with another digital control method, P&O and IncCond algorithm, that is applied mostly a PV system. An existent method is needed an expensive processor such as DSP that calculated to change the measure power of a using current and voltage sensor at the once. Therefore, it is applied a small home power generation system that required many expenses. But, a proposed method is easy to solve the cost reduction and power unbalance problems that it is used by control scheme to limit error of a current control of common sensor. This proposed algorithm had verified through a simulation and an experiment on battery charger using PIC that is the microprocessor of a low price.

• 한국신재생에너지학회:학술대회논문집
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• 2005.11a
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• pp.680-683
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• 2005

This paper proposes a simple MPPT control scheme of a Current-Control-Loop Error system Based that can be obtains a lot of advantage to compare with another digital control method, P&O and IncCond algorithm that is applied mostly a PV system. An existent method is needed an expensive processor such as DSP that calculated to change the measure power of a using current and voltage sensor at the once. Therefore, it is applied a small home power generation system that required many expenses. But, a proposed method is easy to solve the cost reduction and power unbalance problems that it is used by control scheme to limit error of a current control of common sensor. This proposed algorithm had verified through a simulation and an experiment on battery charger using PIC that is the microprocessor of a low price.

• Proceedings of the IEEK Conference
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• 1999.11a
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• pp.228-231
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• 1999

This paper describes the design and implementation of an application specific instruction-set processor developed for embedded DSP applications. The instruction-set has an uniform size of 16 bits, and supports 3 types of instructions: Primitive, Complex, and Specific. To reduce code size and cycle count we introduce complex instructions that can be selected according to the application under consideration, which leads to 50% code size reduction maximally. The processor has two independent data memories to double the data throughput and the address space. The processor is synthesized by 0.6$\mu$m single-poly double-metal technology. Critical path simulation shows that the maximum frequency is 110MHz and total gate count is 132, 000.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.623-628
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• 2009

Desiccant based air conditioning system offers a promising alternative to conventional one using vapour compression refrigeration for energy saving and greenhouse gas reduction. It is a heat driven cycle which has high potential for the use of low grade heat source such as the waste heat from the cogeneration plant or the solar thermal energy. In this study, the cooling performance of a desiccant cooling system incorporating a regenerative evaporative cooler was characterized in various operation conditions through numerical simulation. The cooling capacity and COP were evaluated at various outdoor conditions, regeneration temperatures, and supply flow rates. Based on the performance characteristics, the optimal control scheme was discussed to minimize the cooling cost at part load condition.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.16 no.3
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• pp.208-215
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• 2016

The lithography hotspot detection process is crucial for semiconductor design development process. But, the lithography hotspot detection using optical simulation method takes much time and it slowdown the layout design development cycle. Though the geometry based approach is introduced as an alternative, it still revealed low detection performance and sophisticated framework. To solve this problem, we introduce a deep convolutional neural network based hotspot detection method. Our method made better results in ICCCAD 2012 dataset. To reach this score, we used lots of technical effort to improve the result in addition to just utilizing the nature of convolutional neural network. Inspection region reduction, data augmentation, DBSCAN clustering helped our work more stable and faster.

• International Journal of Automotive Technology
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• v.2 no.4
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• pp.135-145
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• 2001

DEUTZ AG, co-founded in 1864 by Nicolaus August Otto, the inventor of the four-stroke cycle engine, has developed the new 2013 engine for commercial vehicles on the basis of the tried and tested 1012 and 1013 series. With 4 and 6 cylinder models, the engine covers the power range between 100 and 190 kW. At the time of their introduction to the market, the engines will meet the exhaust emission legislation of EURO IV and incorporate the potential for EURO IV, Further engineering targets were. (Compactness, Favourable power/cost relation, Low weight, Low fuel consumption and Low noise level). All targets could be accomplished in a relatively short development period via the application of modem simulation tools and test methods. In this paper, the design configuration of the engines is described with particular emphasis on measures for noise emission reduction and the combustion system including injection and turbo charging. Furthermore, we demonstrate the engine's potential to fullfill the European emission legislation EU4, which comes into force in 2005.

• KIEAE Journal
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• v.11 no.4
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• pp.63-70
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• 2011

In respond to the global energy crisis and climate change, there have been many ongoing national efforts to develop a sustainable housing prototype followed by "2 million Green Home Project" in Korea. More than 50% of nation's population are currently living in apartment housing thus the country is seriously in need of developing green apartment prototype. In this research, we focused on energy-conservative green apartment design prototype that have both passive components and active systems explored in a systemic design approach. After selecting an existing basic apartment unit, we analyzed and compared statistical data with the simulated annual energy consumption to match these two data sets for validating simulation accuracy performed with TRNSYS package. We performed energy simulations with different passive design factors such as varied insulation thickness, window types and infiltration rates as well as the active design factors including boilers and lighting fixtures to analyze their impacts on the energy performance of the housing unit using TRNSYS software. As a result, we acquired significant energy reduction effect with explored design strategies but the life cycle cost analysis for the final design guidline would need to be performed. In this study, we focused on a systematic comparative energy analysis based on TRNSYS that can improve the design of a green apartment housing.

• International Journal of Aeronautical and Space Sciences
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• v.18 no.4
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• pp.651-661
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• 2017

A truss-braced wing (TBW) aircraft has recently received increasing attention due to higher aerodynamic efficiency compared to conventional cantilever wing aircraft. For conceptual TBW aircraft design, we developed a propulsion-and-airframe integrated design environment by replacing a semi-empirical turbofan engine model with a thermodynamic cycle-based one built upon the numerical propulsion system simulation (NPSS). The constructed NPSS model benefitted TBW aircraft design study, as it could handle engine installation effects influencing engine fuel efficiency. The NPSS model also contributed to broadening TBW aircraft design space, for it provided turbofan engine design variables involving a technology factor reflecting progress in propulsion technology. To effectively consolidate the NPSS propulsion model with the TBW airframe model, we devised a rapid, approximate substitute of the NPSS model by reduced-order modeling (ROM) to resolve difficulties in model integration. In addition, we formed an artificial neural network (ANN) that associates engine component attributes evaluated by object-oriented weight analysis of turbine engine (WATE++) with engine design variables to determine engine weight and size, both of which bring together the propulsion and airframe system models. Through propulsion-andairframe design space exploration, we optimized TBW aircraft design for fuel saving and revealed that a simple engine model neglecting engine installation effects may overestimate TBW aircraft performance.

• KIEAE Journal
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• v.15 no.3
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• pp.57-63
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• 2015

Purpose: Ground source heat pump system has been attracted in the horticulture industry for the reduction of energy costs and the increasing of farm income. Even though it has higher initial costs, if it uses in combination with heat storage, it is able to reduce the initial costs and operate efficiently. In order to have significant effect of heat storage type ground source heat pump system, it is required to design the capacity considering various conditions such as energy load pattern and operating schedule. Method: In this study, we have designed heat storage type ground source heat pump system in 5 cases by the operating schedule, and examined the system to find the most economic and having superb performance regarding the system COP(Coefficient of Performance) and energy consumption, using dynamic energy simulation, TRNSYS 17. Result: Conventional ground source heat pump system has lower energy consumption than heat storage type, but following the result of LCC(Life Cycle Cost) analysis, the heat storage type was more economic due to the initial costs. In addition, it has the most efficient performance and energy costs in the case of the smallest heat storage time.