• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.13-18
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• 2007

The construction by the ministry of health and welfare support of the first special hospital for only children in busan and gyeong-nam is under building with YPNUH(Yangsan Pusan National University Hospital) for the best medical treatment town and is to improve the productivity and efficiency by eliminating unproductive and inefficient fact through the construction management, systemic and scientific management technique. So in this study we would like to suggest the generated effect to apply project management technique to all stage such as from pre-design phase, turn-key enterprise choice, construction, design VE(Value Engineering), PMIS (Project Management Information System) construction to maintenance phase and cost and schedule reduction effect through basic, execution design VE by using engineer of field.

• Journal of the Korea Institute of Military Science and Technology
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• v.25 no.2
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• pp.144-150
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• 2022

The on-board processor of satellite synthetic aperture radar(SAR) generates transmission signal by digital signal processing, converts it into an analog signal. At this time, the transmission signal generated from the baseband requires the frequency modulation to convert it to the high-frequency band in order to improve the stability. General frequency modulation method using local oscillator(LO) causes IQ imbalance due to phase error/magnitude error and these error reduce performance of SAR. To generate transmission signal without phase/magnitude error, this paper suggests design method of the frequency modulation method using digital to analog converter(DAC) at on-board SAR. For design, this paper analyzes the characteristic of DAC mode and uses pre-compensation filter. To analyze the proposed method performance, performance index are compared with IQ imbalance signals. This method is suitable for on-board SAR using fast sampling DAC and has the advantage of being able to solve IQ imbalances.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.301-306
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• 2003

PID controller is applied mostly to two-order system. In third-order or higher- system, it's impossible to get high response quality because of having more zero point than the number of zero point being in the PID controller. To solve those, Jung & Dorf suggested a new type of PIDA controller and solved problen of a third-order system. But, as the result of getting step response using PIDA controller, rising time is very quickly but wide overshoot is happened. Beside designing PIDA controller with using CDM(Coefficient Diagram Method) suggested by shunji manabe. But, In Performance standard, CDM decreases overshoot to desired but rising time is very slow. Therefore this paper suggest a PD-PIDA controller for low overshoot with PD type Pre-compensator. This paper applied designed PD-PIDA controller to position control of 3-Phase induction motor.

• Journal of Power Electronics
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• v.4 no.4
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• pp.197-204
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• 2004

Two-stage Power-Factor-Correction (PFC) converters are the most common circuits for drawing sinusoidal and in phase current waveforms from an ac source with a good regulated output voltage. The first stage is a boost PFC converter with average-current-mode control for achieving the near-unity power factor and the second stage is a forward converter with voltage-mode control to regulate the output voltage. Stability analysis and design methods of two-stage PFC converters have previously been discussed using linear models. Recently, new nonlinear phenomena have been detected in pre-regulator boost PFC circuits and a new nonlinear model has been proposed for pre-regulated PFC converters. Therefore, investigation of two-stage PFC converters from the nonlinear viewpoint becomes important because the second stage DC/DC converter adds more complexity to the circuit. So, this paper introduces a study of the stability of two-stage PFC converters. A novel nonlinear model of two-stage PFC converters is proposed. Then, a stability analysis is made based upon this nonlinear model. The high correspondence between the simulated and experimental results confirms our analysis.

• Proceedings of the KIPE Conference
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• 2017.07a
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• pp.212-213
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• 2017

In this paper is presented a pre-charging sequence for single-phase cascaded neutal-point-clamped(NPC) converters for capacitors voltage balancing. capacitor imbalance problem in pre-charge sequence is caused in cascaded NPC converter by its topology. the DC link voltage at each NPC converter module can be balanced by the proposed switching method. the design and performance of the proposed sequence are verified by simulation and experimental results using prototype.

• Journal of the Korea Institute of Building Construction
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• v.18 no.3
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• pp.277-283
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• 2018

This study is conducted to improve the manufacturing process of the modular construction method, which is a pre-fabricated construction method recognized for its advantage on the shortening of construction time. This study first identified the factors that result in shortening of pre-fabrication processes in the current module-processing factory. In addition, those identified factors were further considered for installing the M.E.P. system that is being outsourced on the main module in the production line. A manufacturing process of the construction modules, which considers installation of a M.E.P. system most suitable for shortening the time on the outsourcing of modular construction, is introduced throughout the research. Furthermore, this study suggests the factors in need of improvement during design phase of modular construction and improvement measures to consider the quality of unit modules by focusing on the module parts that are most exposed to defects.

• Human Ecology Research
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• v.61 no.3
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• pp.361-373
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• 2023

The purpose of this study is to develop and apply a teaching-learning plan of apartment house class to improve middle school students' empathy for home economics education and to verify its effect. The study was conducted in five stages: analysis, design, development, implementation, and evaluation using the ADDIE model. In the analysis phase, the study set learning objectives after analyzing how community housing is dealt with in the 2015 revised home economics curriculum and 12 current technology and home economics textbooks. In the design and development stage, in order to evaluate the validity of the experts and to improve the empathy ability, the study goal design, the composition of the learning elements, the development of the learning materials, and the pre and post-questionnaire for the students were developed. In the implementation stage, the empathic ability evaluation was carried out before and after the beginning of the first class by applying the teaching-learning process plan of the 8th class. In the evaluation stage, we examined whether the teaching-learning process developed in this study has a significant effect on empathy ability by evaluating the pre-post difference of empathy ability. As a result of examining the results of the pre - and post - evaluation of empathy ability for the results of this study, both cognitive and communicative factors were improved, and the apartment house class had a significant effect on the improvement of empathy ability.

• Korean Journal of Construction Engineering and Management
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• v.11 no.2
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• pp.74-82
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• 2010

A government agency has been announced to increase 23,663 hundred million wons by cost of design change which occurred in the pre-construction and construction phase. As design change is a phenomenon to occur by means of a characteristic of the building design that standardization is difficult, even if it is said that a perfect design is done in design phase, design change is prevented, and it is going to decrease, and there is a limit. Because there are some causes in all of the construction project, it is change order of client, relative system, unfit design and field condition, etc. In this study, we are suggested logic and basic model of the decision making support process model that it should selecting the optimal alternative through complex and quantitative analyzed: that is cost, performance and constructability as respect Owner or CMr is executing project under the CM delivery system construction project which it occurred design change.

• Journal of Power Electronics
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• v.9 no.1
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• pp.74-84
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• 2009

The design and implementation of a high performance PID (Proportional Integral & Differential) style controller with zero-phase error tracking property is considered in this article. Unlike a ball screw driven system, the controller in a direct drive system should provide a high level of tracking performance while avoiding the problems due to the absence of the gear system. The stiff mechanical element in a direct drive system allows high precise positioning capability, but relatively high tracking ability with minimal position error is required. In this work, a feasible position controller named 'Unified PID controller' is presented. It will be shown that the function of the closed position loop can be designed into unity gain system in continuous time domain to provide minimal position error. The focus of this work is in two areas. First, easy gain tunable PID position controller without speed control loop is designed in order to construct feasible high performance drive system. Second, a simple but powerful zero phase error tracking strategy using the pre-designed function of the main control loop is presented for minimal tracking error in all operating conditions. Experimental results with a s-curve based position pattern commonly used in industrial field demonstrate the feasibility and effective performance of the approach.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.864-867
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• 2007

Recent advancement in ICT and IT infrastructure drives the construction industry towards a IT-based industry. Accordingly, the importance of the planning phase of a project is significantly highlighted due to recent large-scale national development projects such as U-city and multifunctional administration city. various development and studies are conducted on the convergence of 3D CAD and GIS in order to support the decision making by simulation of each phase of construction prior to the actual construction of a building. However there has been limits to the implementation of the IT technology in the planning phase due to its characteristics such as high reliability on the experts knowledge and the compliance of the administration work. In this study, a trendy issue of the convergence of the GIS technology with the 3D CAD design data is suggested to improve the efficiency of a decision support in the planning phase.