• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.5B no.4
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• pp.343-349
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• 2005

This paper proposes a novel zero-voltage-switching (ZVS) Push-pull DC-DC Converter for high input voltage and high power applications. This topology utilizes two switches in series to replace one switch in conventional push-pull converter, and two clamping diodes are introduced. The voltage stress of the switches is the input voltage, and the switches can realize ZVS with the use of the leakage inductance of the transformer. Furthermore, secondary full-wave rectifier with a clamping capacitor is used to eliminate the voltage oscillation and spike of the rectifier diodes due to the reverse recovery. Therefore, the electromagnetic interference is reduced effectively. The operation principle of the proposed converter is analyzed theoretically. The output characteristic, ZVS condition and design principle of the clamping capacitor are discussed. Experimental results obtained from a 270V input 2kW prototype with $95.8\%$ high efficiency confirms the design.

• Journal of the Korea Organic Resources Recycling Association
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• v.8 no.1
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• pp.60-68
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• 2000

Biofiltration is an environmentally-sound technology for elimination of VOCs and odorous compound from low-concentration, high-volume waste gas streams because of its simplicity and cost-effectiveness. It can be appled to the treatment of gases from publicly owned treatment works, composting facilities, landfill sites, and soil vapor extraction systems. The ability to design an effective biofilter system involves a combination of fundamental biofilter knowledge, practical experience, and bench- and pilot-scale testing. The objective of this paper was to review principle, design parameters, operational conditions, case studies, and economy of biofiltration through literature.

• Journal of architectural history
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• v.1 no.1 s.1
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• pp.240-254
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• 1992

The purpose of this paper is to suggest new direction to the historical research society of Korean architecture by epistemological discussion. Korean architectural history at present, without question of history for what, for whom, and how, is regarded as 'history for the past' only 'to describe past' or 'to collect correct data' However, history is beyond that; history ought to suggest a direction of present and near future. Moreover, architecture is not pure but applied knowledge, that is, focused to 'how to build'. Therefore, past historical knowledge by research should influence to present design. In order to do that, history of mere data collection should change direction to the history of meaning by interpretation, and then, of finding design principle. The principle used in architectural community becomes theory in scientific research community, and finally is unified to 'theory of practice'. Creative history should be substituted for retrospective history reusing historical reservoir, at the specific situation of Korea; tradition has been discontinued drastically and Western method imported to the point of being culturally-colonized. Some expmples of altanative history are suggested at the end of this paper as conclusion.

• Journal of the Korean housing association
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• v.22 no.2
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• pp.131-139
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• 2011

This study is to examine architectural designers' views on the correlations between components and contextual principle of the roadside building facade with the roadside building facade on the border of Asian Culture Center in Gwangju which is expected to undergo a great change by public policies. For setting direction of the roadside building management at the region examined, height of facade, advertisement/signboard, security of continuity through surface pattern management, nodes building, array of height by story, awning/arcade and locality of advertisement/signboard should be induced to design with locality and consideration of local characteristics with silhouette, window and external colors is needed for discrimination from other cities. Regarding the realization method important thing was found that the planning and implementation of architectural design guidelines, architectural aesthetics of the pre-hearing enhancement, active citizen participation, and then additional landscape screening system, incentive schemes, landscape designation of landscape zone was found to be a major realization system.

• Korean Institute of Interior Design Journal
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• v.15 no.6 s.59
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• pp.11-18
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• 2006

Ceaseless studies and efforts to verify today's Korean nature that has advanced into digital era of 21C are continued. At this point of time, it is required to look back our heritage in diverse points of view free from theoretical and formal studies on our traditional spaces. Phenomenology, which is rising as the important theme in recent modem Western philosophy, suggests interesting analyses from this standpoint. This study is intended to analyze Korea's traditional residents 'Dok Rak Dang' based on Marleau-Ponty's phenomenology, and explore phenomenological spatial principle and new point of view implied in it. Particularly, Marleau-Ponty's phenomenology is the philosophy that shows intersubjective and involved relations between space and human, and intended to accept coincidental incidents occurred by human's action truthfully as they are. With three spatial concepts of direction, depth, and movement in Ponty's phenomenology, and placement nature of the earth that intercombine with human's body who is subject of these three concepts as analyze tool, Korea's traditional residents, 'Dok Rak Dang' has been analyzed. More segmentalized analyses have been deduced, and principle of phenomenology, that perceptions such as direction, depth, movement, etc are working synthetically to be accepted as essence of experiences could also be found in Dok Rak Dang.

• Steel and Composite Structures
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• v.18 no.5
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• pp.1197-1214
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• 2015

There is a great difference in mechanical behavior between design model one-time loading and step-by-step construction process. This paper presents practical computational methods for simulating the structural behavior of long-span rigid steel structures during construction processes. It introduces the positioning principle of node rectification for installation which is especially suitable for rigid long-span steel structures. Novel improved nonlinear analytical methods, known as element birth and death of node rectification, are introduced based on several calculating methods, as well as a forward iteration of node rectification method. These methods proposed in this paper can solve the problem of element's 'floating' and can be easily incorporated in commercial finite element software. These proposed methods were eventually implemented in the computer simulation and analysis of the main stadium for the Universiade Sports Center during the construction process. The optimum construction scheme of the structure is determined by the improved algorithm and the computational results matched well with the measured values in the project, thus indicating that the novel nonlinear time-varying analysis approach is effective construction simulation of complex rigid long-span steel structures and provides useful reference for future design and construction.

• Journal of the Society of Naval Architects of Korea
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• v.35 no.1
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• pp.46-53
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• 1998

In this paper, we studied to improve Inoue's[1] and Kijima's[2] model used to predict ship's manoeuvrability at initial design state. To perform this work, we carried out PMM(Planar motion Mechanism) test and rudder open water test for 12 models of low-speed blunt-ship which have horn type rudders and bulbs in afterbody. As we adopted MMG(Mathematical Modelling Group) model, we could analyze hydrodynamic and MMG experimental coefficients. The regression analyses by principle parameters were carried out for hydrodynamic and MMG experimental coefficients. The regression analyses by principle parameters were carried out for hydrodynamic and MMG experimental coefficients and the equations by regression analysis wee used to search sensitivities and to estimate ship's manoeuvrability. We had simulated ship's manoeuvrability to check revised MMG.

• Journal of Fashion Business
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• v.16 no.2
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• pp.124-137
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• 2012

This study aims to identify the meaning and formation cause of a style, and the essential elements of style formation, through psychobiological research as well as an analysis of the designs of Iris Van Herpen, a fashion designer, who in just 6 years has developed into a world-renowned new designer. As a result, it has been found that the psychobiological causes to form a style stem from the action of 'long-term memory', which is consolidated by 'selective attention', 'perceptional subjectivity', the principle of the 'neuron's connection specificity and invariance', and the principle of a 'neuronal signal's unilateral flow'. With such action, Herpen could develop her own original composition techniques. The formative shapes created by such composition techniques are characterized by enumeration, superposition, and hanging. The study has also found that the essential elements for a designer to be able to form his/her own style include 'aesthetic originality' in which the designer views the property of a thing from his/her inherent perspective, and finds the uniqueness from the thing that only he/she can express, 'technical differences' that are creative and original, and 'formative specificity' that is summarized into one property through an impressive shape.

• Journal of Drive and Control
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• v.11 no.3
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• pp.31-40
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• 2014

This paper proposes a multi absorbing wave energy converter design, in which a hydrostatic transmission is used to transfer wave energy to electric energy. The most important feature of this system is its combination of the pressure coupling principle with the use of a hydraulic accumulator to eliminate the effects of wave power fluctuation; this maintains a constant speed of the hydraulic motor. Tilt motion of a floating buoy was employed as the power take-off mechanism. Furthermore, a PID controller was designed to carry out the speed control of the hydraulic motor. The design offers some advantages such as extending the life of the hydraulic components, increasing the amount of energy harvested, and stabilizing the output speed.

• Journal of Power Electronics
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• v.19 no.3
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• pp.655-664
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• 2019

In order to analyze the nonlinear phenomena of the bifurcation and chaos caused by the switching of nonlinear switching devices in inductively coupled power transfer (ICPT) systems, a Jacobian matrix model, based on discrete mapping numerical modeling, is established to judge the system stability of the periodic closed orbit and to study the nonlinear behavior of Hopf bifurcation in a system under full resonance. The general flow of the parameter design, based on the stability principle for ICPT systems, is proposed to avoid the chaos and bifurcation phenomena caused by unreasonable parameter selection. Firstly, based on the state equation of SS-type compensation, a three-dimensional bifurcation diagram with the coupling coefficient as the bifurcation parameter is established with a numerical simulation to observe the nonlinear phenomena in the system. Then Filippov's method based on a Jacobian matrix model is adopted to deduce the boundary of stable operation and to judge the type of the bifurcation in the system. Then the general flow of the parameter design based on the stability principle for ICPT systems is proposed through the above analysis to realize stable operation under the conditions of weak coupling. Finally, an experimental platform is built to confirm the correctness of the numerical simulation and modeling.