• Journal of Positioning, Navigation, and Timing
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• 제2권1호
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• pp.67-74
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• 2013

In this study, a remote controller was designed using localization technique. The designed remote controller system consists of infrared transmit/receive module for time synchronization, ultrasonic transmit/receive module for measuring the TOA value, and micro-controller for processing the measured data value. For the position estimation method of remote controller, the Savarese method was used which does not have a problem of diverging solution depending on initial value. The noise included in the measured value was removed by separating the signal and noise with the use of EMD method which is the non-stationary signal analysis technique. The designed system was tested by constructing a simulation environment, and the improvement of accuracy and precision for the application of EMD method was examined.

• Earthquakes and Structures
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• 제2권1호
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• pp.65-88
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• 2011

A new method for the seismic design of plane steel moment resisting frames is developed. This method determines the design base shear of a plane steel frame through modal synthesis and spectrum analysis utilizing different values of the strength reduction (behavior) factor for the modes considered instead of a single common value of that factor for all these modes as it is the case with current seismic codes. The values of these modal strength reduction factors are derived with the aid of a) design equations that provide equivalent linear modal damping ratios for steel moment resisting frames as functions of period, allowable interstorey drift and damage levels and b) the damping reduction factor that modifies elastic acceleration spectra for high levels of damping. Thus, a new performance-based design method is established. The direct dependence of the modal strength reduction factor on desired interstorey drift and damage levels permits the control of deformations without their determination and secures that deformations will not exceed these levels. By means of certain seismic design examples presented herein, it is demonstrated that the use of different values for the strength reduction factor per mode instead of a single common value for all modes, leads to more accurate results in a more rational way than the code-based ones.

• 대한산업공학회지
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• 제38권3호
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• pp.198-207
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• 2012

In product or process parameter design, the case of multiple performance characteristics appears more commonly than that of a single characteristic. Numerous methods have been developed to deal with such multi-characteristic parameter design (MCPD) problems. Among these, this paper considers three representative methods, which are respectively based on the desirability function (DF), grey relational analysis (GRA), and principal component analysis (PCA). These three methods are then used to solve the MCPD problems in ten case studies reported in the literature. The performance of each method is evaluated for various combinations of its algorithmic parameters and alternatives. Relative performances of the three methods are then compared in terms of the significance of a design parameter and the overall performance value corresponding to the compromise optimal design condition identified by each method. Although no method is significantly inferior to others for the data sets considered, the GRA-based and PCA-based methods perform slightly better than the DF-based method. Besides, for the PCA-based method, the compromise optimal design condition depends much on which alternative is adopted while, for the GRA-based method, it is almost independent of the algorithmic parameter, and therefore, the difficulty involved in selecting an appropriate algorithmic parameter value can be alleviated.

• 산업경영시스템학회지
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• 제45권4호
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• pp.99-108
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• 2022

Today, as technology advances and market competition for products intensifies, the product design to improve customer satisfaction by accurately identifying customer needs is emerging as a very important issue for company. Accordingly, the customer-oriented or customer-centered design that maximizes customer satisfaction by grasping and analyzing customer requirements is in the spotlight as an important design theory. In this study, the customer-oriented design is defined as finding the optimal value of design variable with the maximum overall customer satisfaction while minimizing the difference in individual customer satisfaction responded to various customers from multiple product quality characteristics from the perspective of robust design. Therefore, this study presents a new method for modeling the customer preference structure as the different sets of desirability functions for multiple quality characteristics and proposes a new customer-oriented design approach by applying the desirability functions to Taguchi's robust design process to deal with multi-characteristic design problem. Finally, the proposed method is illustrated with the Kansei engineering design problem of wine glass.

• Journal of Power Electronics
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• 제12권4호
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• pp.559-566
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• 2012

A new design method for the LCL filters of three-phase voltage source PWM rectifiers is presented in this paper. Based on the single-phase harmonic equivalent model, the harmonic voltage of the rectifier side is calculated to design the LCL filter parameters by an iterative algorithm, in which the resonance frequency $f_{res}$ and the ratio r between the grid-side inductance and the rectifier-side inductance are selected as known constants. The design criteria and process are introduced and the influence on the design result by the value of the resonance frequency $f_{res}$, ratio r is analyzed. Finally an example (600V, 500kW) is tested by simulation and experiment to verify the validity of the new design method.

• 국제학술발표논문집
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• The 1th International Conference on Construction Engineering and Project Management
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• pp.621-626
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• 2005

Recent increases in construction costs on Korean public works projects, largely due to change orders caused by poorly elaborated design, become a motivation of applying VE process in Korean construction industry. The Seoul Toll Plaza project, recently value analyzed by four VE teams, demonstrates how value management helps save time, money and increase functional performance. The objective of this project is to upgrade and expand existing pay and ticket booths system on "Kyungboo Express Highway", the main artery for the Korean peninsula linking Seoul to Pusan. The value management study generated several innovate alternatives capable of saving up to 50% of project cost from the baseline project plan.

• Nuclear Engineering and Technology
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• 제48권4호
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• pp.1047-1057
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• 2016

Design engineering process for field programmable gate array (FPGA)-based reactor trip functions are developed in this work. The process discussed in this work is based on the systems engineering approach. The overall design process is effectively implemented by combining with design and implementation processes. It transforms its overall development process from traditional V-model to Y-model. This approach gives the benefit of concurrent engineering of design work with software implementation. As a result, it reduces development time and effort. The design engineering process consisted of five activities, which are performed and discussed: needs/systems analysis; requirement analysis; functional analysis; design synthesis; and design verification and validation. Those activities are used to develop FPGA-based reactor bistable trip functions that trigger reactor trip when the process input value exceeds the setpoint. To implement design synthesis effectively, a model-based design technique is implied. The finite-state machine with data path structural modeling technique together with very high speed integrated circuit hardware description language and the Aldec Active-HDL tool are used to design, model, and verify the reactor bistable trip functions for nuclear power plants.

• 한국건설관리학회논문집
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• 제12권3호
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• pp.42-52
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• 2011

최근 세계적으로 환경문제가 대두됨에 따라 모든 산업분야에서 환경부하를 감소시키기 위한 노력이 나타나고 있다. 특히 건축물이 환경에 미치는 양향은 절대적인 비중을 차지하고 있기 때문에 건축물의 전생애주기 동안에 에너지 절약과 생태환경보전을 위해 국가별로 친환경 건축물 인증제도를 운영하고 있다. 국내에서도 국토해양부와 환경부가 모든 시설물에 대한 친환경건축물 인증을 실시하고 있다. 특히 2010년부터 신축되는 모든 공공청사에 대해서 건물에너지효율 1등급의 취득을 의무화하고 있다. 효율적이고 체계적인 친환경건축물의 설계를 위해서는 설계 초기단계부터 친환경요소를 고려해야 하는 것이 필수적이다. 그러나 현재 친환경건축물 인증을 받기 위한 과정을 살펴보면, 실시설계가 거의 완료된 시점에서 친환경요소들을 고려함으로써 근본적인 친환경요소들을 설계에 적용하는데 어려움이 있다. 이러한 문제를 해결하기 위해, 기본 및 실시설계 Value Engineering에서 친환경적인 요소들을 고려하여 체계적인 친환경요소들을 고려한다면 효율적인 친환경건축물을 설계할 수 있을 것이다. 따라서 본 연구에서는 친환경건축물 인증기준과 기존의 VE 대상선정 기법을 분석하여 프로젝트에서 집중적으로 고려해야 하는 친환경적인 요소들을 선정하기 위한 Green VE 대상선정모델을 제안하고자 한다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2004년도 ICEIC The International Conference on Electronics Informations and Communications
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• pp.339-342
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• 2004

In this paper, we investigated methods to reduce SAR(Specific Absorption Rate) value with EMI(Electromagnetic Interference) paint distribution on front case of mobile handset. Simulations for several different EMI patterns were carried out. For the purpose of modeling, we used 3 dimensional CAD(Computer Aided Design) program, `Pro-engineering'. SAR simulation was done with SEMCAD, simulation platform for electromagnetic compatibility antenna design and dosimetry. In order to distinguish the individual pieces and to enable an assignment of the different material properties, each subfile was imported separately. In simulation, folding angle was set to $142^{\circ}.$ If we vary folding angle, different SAR value will be obtained. Among the tested EMI paint patterns, the hairpin pattern showed the best performance, i.e. the decrease efficiency of $16.5\%$ and horizontal-direction zigzag pattern showed the decrease efficiency of $12.2\%$ when we set the completely removed pattern as reference.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 A
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• pp.119-121
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• 1995

This paper is a study on inductive superconducting fault current limiter design.. We have created simulation for an imaginery power system with inductive superconducting fault current limiter. Then input variables for characteristic analysis and actual manufacturing, and output variables for design results was assigned. Using the results from these variables, the design criterion was determined which was fed into concept design arising from characteristic analysis to determine the inductance of limiting coil and normal state resistance value of triggering coil. These result was put back into design details to finally give out the design result for inductive superconducting fault current limiter.