• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2011.11a
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• pp.537-540
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• 2011

중요 목조문화재를 산불이나 인접 건축물의 화재로부터 보호하기 위한 방안으로 수막노즐을 제시하였다. 바닥으로부터 일정압력 이상으로 상승하는 물줄기로 수막을 형성하여 복사열을 차단함으로써 $200^{\circ}C{\sim}250^{\circ}C$에서 발생하는 목재의 열분해를 막기 위한 것으로 기존에 설치되어 있는 강원도 낙산사와 전라남도 무위사의 수막노즐의 설치상태를 확인해 보았고 이를 보완 개량하기 위한 방안으로 평상시 덮개에 덮인 노즐을 설치하여 경관을 손상시키지 않게 하였고 사용 시 수직상승하여 물을 분사할 수 있는 상하승강식 노즐봉과 이를 효과적으로 설치하는 방법에 대하여 연구되었다.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.1446-1452
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• 2009

This study is designed to examine the current status of the performance warranty systems for asphalt pavements implemented in Europe, USA, and Japan, and to review the feasibility and possibility of introducing this system into the Korean environment. For such objectives, the concept and necessity of performance warranty and the status of Korean contracting systems and overseas performance warranty systems were evaluated. In particular, the bidding systems, performance guarantee systems, and maintenance work inclusion status in the projects and warranty specifications of Europe, USA and Japan were comparatively evaluated. And methods of introducing the performance warranty system by utilizing defects liability system and design-build contracts of Korea were suggested.

• Journal of Biomedical Engineering Research
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• v.30 no.1
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• pp.66-78
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• 2009

A mobile ultrasound scanner developed for use in point-of-care applications is introduced, which can not only provide ultrasound images but can also measure various bio-signals. The mobile ultrasound scanner is also designed to meet the demanding requirements for point-of-care diagnosis, such as battery-powered operation, portability in terms of size and weigh, and real-time wireless communications capability for remote diagnosis. To meet these requirements, an efficient beamforming method for high resolution imaging with a small number of active elements, a hardware efficient beamformer architecture, and echo processing algorithms with greatly reduced computational complexity have been developed. Experimental results show that the prototype mobile ultrasound scanner is fully functional and satisfies most of the design requirements.

• Journal of Biomedical Engineering Research
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• v.30 no.1
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• pp.79-88
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• 2009

A harmonic quadrature demodulation method to extract the second harmonic component from focused ultrasound signals after a single transmit-receive event is proposed. In the proposed method, the focused ultrasound signal is converted into baseband inphase and quadrature components by multiplying with sine and cosine signals both having twice the center frequency of the transmitted signal and filtering the two modulated signals. The quadrature component is then passed through a Hilbert filter to be added to the inphase component, which leaves only the envelope of the second harmonic component. A novel phase estimation technique is employed in the proposed method to avoid the phase mismatch between the focused signal and the two modulating signals. The proposed method is verified through both theoretical analysis and computer simulations. It is shown that compared to the pulse inversion scheme the proposed method provides almost the same results for stationary targets and significantly improved harmonic to fundamental ratio for moving targets.

• Journal of the Korean Institute of Landscape Architecture
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• v.27 no.4
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• pp.101-107
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• 1999

In 1994, Songbuk-gu Office of Seoul held a design competition for Miarigogae-Park, Miarigogae has a special sense of place. It was a place where bararians had crossed the boundary to this country during the Manchu war of 1636. It was a public cemetery where only Koreans had been buried under the rule of Japanese imperialism. It was a place where national patriots had been kidnapped to the North during the Korean War. It's sorrows have been sung in the name of song-'Danjangeui-Miarigogae'(one of the most popular song in Korea). It's sense of place has been kept in every Korean people's mind in the form on 'non-physical image'. Even though, the site itself was a small space - only 1000㎡, the meaning of park-making was very significant. It meant that it would create a physical 'setting' to express the sense of place which has been existed only in our mind as a form of 'non-physical image'. In the winning scheme proposed by the author, the sense of place of Miarigogae was expressed in the form of 'castle walls' which could be easily come into everyone's mind as an image of war. The scope of work also included a crossing bridge and symbolic features. It was meaningful that a landscape architect won the competition including on those items which were not usually handled in pure landscape architectural offices. The purpose of this paper was to articulate the concept of the winning entry in detail and to describe how the concept actualized in reality.

• Journal of the Korean Institute of Landscape Architecture
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• v.32 no.5
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• pp.119-128
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• 2004

In 2004, the Incheon Urban Development Corporation held a design competition for the Song-Do apartment complex development. Several projects that won the prize in the recent design competitions were reviewed to look around the current design tendency, and current conditions of the site were surveyed. The authors tried to combine digital and environment-friendly factors, considering the site condition. Because the site is on reclaimed land and is located at the center of the information-technology industrial area, these two factors inform the main concept of this project. The site was divided into two different zones : the Ocean Zone and the Digital Zone. The 'community spaces'(community street, community plaza and so on) were designed for the various activities of the residents. The Patios, 'private' community spaces, included many facilities for play, appreciation, rest, exercise, refreshment and gathering. To avoid common landscape styles in the patios, simple and minimal forms were designed. The environmental sculptures were carefully planned, allocated and shaped with digital technology, based on the 'Present and Future of Song-Do'. The authors also tried to introduce environment-friendly factors, such as the green roof system, wall planting, and the water recycling system. This project is following the M.A. (Master Architect) process, and is still being modified to make the hi-tech and environment-friendly apartment complex.

• Proceedings of the Korean Geotechical Society Conference
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• 1999.03a
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• pp.167-174
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• 1999

A Land slide in Granitic Gneiss weathered soil was stabilized successfully with soil nailing using 929mm steel bar. To understand the behavior of load transfer between soil and nail, in-situ pdl-out tests were carried out. The strains of steel bars were measured using strain gauges during pull-out tests. Forces-strain data from laboratory tension tests on steel bar and grouted steel bar were examined to compare with those of the pull-out tests. Comparisons were made between the pull-out test results and laboratory test result to understand load transfer mechanism.

• Proceedings of the KIPE Conference
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• 2011.07a
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• pp.512-513
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• 2011

본 논문에서는 PMSG(Permanent Magnet Synchronous Generator)의 가변속-고정피치(Variable-Speed Fixed-Pitch) 풍력발전시스템을 위한 FLC를 기반으로 하는 최대 전력점제어(MPPT) 알고리즘을 제시한다. 최근에는 풍속변화에 대응하여 최대전력을 발생할 수 있는 가변속 풍력발전 시스템에 대한 연구가 활발히 진행 중이다. 국내의 지형적 조건에 따른 바람의 영향으로 풍력발전 시스템의 MPPT제어가 반드시 필요하다. 종래의 풍력발전 MPPT 제어는 응답속도 등에 대한 문제점이 나타난다. 따라서 본 논문에서는 이러한 문제점을 해결하기 위해 파라미터 변동에 강인한 FLC를 기반으로 하는 최대 전력점 제어(MPPT)를 제시한다. 또한 본 논문에서 제시한 알고리즘은 시뮬레이션 결과를 통해 타당성을 입증한다.

• Proceedings of the KIPE Conference
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• 2011.07a
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• pp.514-515
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• 2011

본 논문은 풍력발전 시스템을 위한 종래의 HCS MPPT 알고리즘의 문제점을 위한 새로운 방법을 제시한다. 종래의 HCS MPPT 알고리즘은 스텝크기에 따른 효율변화와 바람의 변화 조건에서 잘못된 최대전력점 추종 결과를 나타낸다. 이러한 문제점을 해결하기 위해 바람이 변화되는 조건에서 최대전력점 추종을 위한 스텝크기를 지능적으로 변화시킨다. 이를 위해 새로운 최대전력점 검출 능력은 바람의 변화조건에 강인하게 동작될 수 있도록 설계한다. 제시한 알고리즘은 시뮬레이션 결과를 통해 타당성을 입증한다.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.8
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• pp.71-78
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• 2012

Recently, it is increased to apply sensorless drive for BLDC (Brushless DC) motor to maximize operating efficiency and fuel efficiency to an electrical component of (H)EV. Especially, Electric vehicle component promotes a fuel efficiency enhancement by the carbon dioxide emissions regulation of a vehicle becoming the principal of the environmental pollution globally, the oil price hike that continued increasingly. We suggested the air compressor which applied BLDC motor for electric vehicle component and compared suggested BLDC motor with the conventional DC motor. The experimental results show that the driving efficiency was increased and was inproved compressive force by suggested BLDC motor.