• 한국지반환경공학회 논문집
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• 제11권11호
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• pp.5-18
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• 2010

본 연구에서는 지간 15m 이하의 지중파형강판 박스구조물의 3차원 해석 시 적용 가능한 3차원 보강판 모델을 제안하고 검증하였다. 3차원 보강판 모델은 실제 파형강판의 단면계수와 종방향과 길이방향의 단면특성을 고려하여 지중강판 박스구조물을 모델링함으로써, 3차원 해석 시 모델링을 간편하게 하고 해석시간을 단축할 수 있는 유용한 해석 모델이다. 이 모델을 검증하기 위해 3단계의 시공과정(정점부까지의 뒷채움, 토피고까지의 뒷채움, 활하중재하)에 따른 거동분석으로부터 최대 변위와 최대모멘트를 유발하는 재하상태를 도출하였고, 제안된 단면을 통해 파형강판의 거동을 분석하였다. 분석 결과를 3차원 등가판 모델, 2차원 모델, 실제파형강판 구조물과 동일하게 모델링한 3차원 Corrugated 판 모델과 비교 검증하였다. 해석결과 2차원 모델과 3차원 등가판 모델은 활하중 조건에서 3차원 Corrugated 판 모델과 큰 차이를 나타내었으나, 3차원 보강판 모델은 모든 해석 결과에서 3차원 Corrugated 판 모델과 일치하는 결과를 나타내었다.

• 한국실내디자인학회논문집
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• 제8호
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• pp.44-57
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• 1996

Now interior designers have to meet this challenge by rising to the occasion and taking advantage of opportunities while strengthening their skills which have not kept pace with the increasing emphasis on design. furthermore, they are hampered by the lack of a general working design methodology. Interior designers in Korea have been slow to recognize the need for developing a specification methodology manual which could be adapted to meet varying requirements and modified to reflect designers experiences. The design process in Korean interior design often involves utilizing drawing document methods based on architectural prototypes rather than upon drawing methods developed by design firms as a result of work experience s and unique needs. However, these unique nees are nearly always limited by traditional working drawing methods. This has led to confusion and inaccuracies due to the lack of a single starndardized and universally acceptable working drawing methodology which is capable of reflecting the needs of all parties involved , partiality those of interior designers. This thesis is an attmepted to establish the necessity for developing a better working drawing methodogoy or technical mans of satisfying the information sorting and processing need s of interior design professionals, a five step suggestion for developing such a methodology follows. First, arrange pertinent design research information by means of a process which can be employed throughout the design process, from inception through to working drawing stage. The end result should be an interior architectural design process culminating in a pattern skillfully blending architecture, vision and product with environment . The design process should be manifested into a series of definable steps and yet sufficiently flexible and variable in order to provide the most apropos design solution. Secondly , motify the design methodology systematically according to site conditions and prevailing construction technology and manifest the design process in a booklet form so that it reflects a desired pattern. Thirdly, this methodology should incorporate a stand-ardized and functional process capable of being utilized to impact clear design concepts and objectives with preci-sion and efficiency in a manual form.

• 환경영향평가
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• 제19권2호
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• pp.127-140
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• 2010

This study investigates the relation between the location of a habitat and the ecological connections according to the habitat type in the riparian zone at the Nonsan Stream and Yanghwa Stream. Stream habitat is classified into nine types for the aquatic insects and fish. For vegetation and birds, habitat is classified into two types of medium-scale streams, including both physical and chemical streams are analyzed accordingly. Nowadays, The fundamental goal of the river environment restoration enterprise is the rehabilitation or the restoration of the characteristic the river scenic or environment. For instance, The Channel habitats which has physical nature environment such as flat, speedy rapids, or closed-channel wetland, pool are constructed by artificial, Consequently, make them autogenesis smoothy eco-environment. However, the river environment are controlled not only physical environment, but it also need reasonable the quality of the water to compose smoothly. Finally, understanding what influence are effecting on physical habitat environment which are made by natural factors to water quality are very important factor for the river environment restoration enterprise Therefore, In this research, we are targeting to a basin to investigate the environment of the physical channel habitat and evaluate the changing of the water quality. This results will be a important characteristic that can judge the physical habitat and reciprocality connected to the water quality or adequacy of restoration technology. Therefore in this study, as a step to quantify functions and values of habitats and definite factors to perform habitat, we selected a representative stream of sand-stream, gravel-stream to classify habitat characteristics and quantified the physical, chemical, biological characteristics.

• 방송공학회논문지
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• 제13권2호
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• pp.236-244
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• 2008

본 논문에서는 칼라 세그멘테이션, 에지 정합, 지각적 그룹핑 등을 사용하여 Lidar 데이터와 광학 영상의 정보 융합에 의한 새로운 구조물 검출 및 복원 알고리듬을 제안한다. 제안하는 알고리듬은 두 가지 단계로 구성된다. 첫 번째로, 항공 Lidar 데이터로부터 초기 구조물 추출 결과와 영상의 칼라 세그멘테이션 결과를 사용하여 coarse building boundary를 추출한다. 두 번째로, coarse building boundary와 에지 정합 및 지각적 그룹핑에 의해 보다 정밀한 구조물 추출 결과인 precise building boundary를 추출한다. 본 논문에서 제안하는 알고리듬은 보다 신뢰성 있는 구조물 검출을 위해, 광학 영상으로부터 칼라 정보를 사용한다. 이를 통해, Lidar에 의해 획득된 붕괴된 형태의 구조물 외곽선을 보완한다. 또한, 인공지물의 특징으로서, 에지의 직선성 및 다면체 형태의 지붕모양을 반영함으로써 신뢰성 있는 구조물을 검출한다. 다중 센서 데이터에 대한 실험은 제안하는 알고리듬이 Lidar 단일 센서 결과에 비해 정밀하고 신뢰성 있는 결과를 보여준다.

• Journal of Power Electronics
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• 제17권3호
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• pp.821-834
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• 2017

This paper reports on a single-inductor multiple-output step-up converter with digital control. A systematic analog-to-digital-controller design is explained. The number of digital blocks in the feedback path of the proposed converter has been decreased. The simpler digital pulse-width modulation (DPWM) architecture is then utilized to reduce the power consumption. This architecture has several advantages because counters and a complex digital design are not required. An initially designed unit-delay cell is adopted recursively for the construction of coarse, intermediate, and fine delay blocks. A digital limiter is then designed to allow only useful code for the DPWM. The input voltage is 1.8 V, whereas output voltages are 2 V and 2.2 V. A co-simulation was also conducted utilizing PowerSim and Matlab/Simulink, whereby the 55 nm process was employed in the experimental results to evaluate the performance of the architecture.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.1079-1081
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• 2007

An L-band Linear Accelerator System for E-beam sterilization is under construction for bio-technology application. The klystron-modulator system as an RF microwave source has an important role as major components to offer the system reliability for long time steady-state operations. A PFN line type pulse generator with a peak power of 71.5-MW, $7\;{\mu}s$, 285 pps is required to drive a high-power klystron. The high power pulse transformer has a function of transferring pulse energy from a pulsed power source to a high power load. The pulse transformer producing a pulse with a peak voltage of 275 kV is required to produce 30-MW peak and 60 kW average RF output power at the frequency of 1.3-GHz. We have designed the high power pulse transformer with 1:13 step-up ratio. The peak and average power capability is 71.5-MW (275 kV, 260 A at load side with $7\;{\mu}s$ pulse width) and 130 kW, respectively. In this paper, we present measurements and its analysis on the design parameters, and an initial test result as well as a design concept on the high-power pulse transformer.

• Macromolecular Research
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• 제15권5호
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• pp.437-442
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• 2007

Poly(ethylene glycol) methyl ether (PEG)-poly(${\beta}$-amino ester) (PAE) block copolymers were synthesized using a Michael-type step polymerization, and the construction of pH-sensitive polymeric micelles (PM) investigated. The ${\beta}$-amino ester block of the block copolymers functioned as a pH-sensitive moiety as well as a hydrophobic block in relation to the ionization of PAE, while PEG acted as a hydrophilic block, regardless of ionization. The synthesized polymers were characterized using $^1H-NMR$, with their molecular weights measured using gel permeation chromatography. The $pK_b$ values of the pH-sensitive polymers were measured using a titration method. The pH-sensitivity and critical micelle concentration (CMC) of the block copolymers in PBS solution were estimated using fluorescence spectroscopy. The pH dependent micellization behaviors with various bisacrylate esters varied within a narrow pH range. The critical micelle concentration at pH 7.4 decreased from 0.032 to 0.004 mg/mL on increasing the number of methyl group in the bisacrylate from 4 to 10. Also, the particle size of the block copolymer micelles was determined using dynamic light scattering (DLS). The DLS results revealed the micelles had an average size below 100 nm. These pH-sensitive polymeric micelles may be good carriers for the delivery of an anticancer drug.

• 한국수학교육학회지시리즈A:수학교육
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• 제46권4호
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• pp.371-388
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• 2007

This is a case study trying to understand from the view of affordance which certain three middle school students perceive an activation of previous knowledge in the course of problem solving when they solve algebra word problems with a previous knowledge. The results of this study showed that at first, every subjects perceived the text as affordance which explaining superficial similarities, that is, a working(painting)situation rather than problem structure and then activated the related solution knowledge on the ground of the experience of previous problem solving which is similar to current situation. The subject's applying process for solving knowledge could be arranged largely into two types. The first type is a numeral information connected with the described problem situation or a symbolic representation of mathematical meaning which are the transformed solution applied process with a suitable solution formula to the current problem. This process achieved by constructing a virtual mental model that indicating mathematical situation about the problem when the solver read the problem integrating symbolized information from the described text. The second type is a case that those subjects symbolizing a formal mathematical concept which is not connected with the problem situation about the described numeral information from the applied problem or the text of mathematical meaning, which process is the case to perceive superficial phrases or words that described from the problem as affordance and then applied previously used algorithmatical formula as it was. In conclusion, on the ground of the results of this case study, it is guessed that many students put only algorithmatical knowledge in their memories through previous experiences of problem solving, and the memories are connected with the particular phrases described from the problems. And it is also recognizable when the reflection process which is the last step of problem solving carried out in the process of understanding the problem and making a plan showed the most successful in problem solving.

• 한국지진공학회논문집
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• 제7권4호
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• pp.31-37
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• 2003

본 논문에서는 오래된 원자력발전소의 내진검증과 관련한 USI A-46 문제의 해결에 사용될 수 있는 캐비닛의 내진보강방안에 대해 연구하였다. 캐비닛 구조물의 동적거동특성을 파악하기 위하여 3종류의 모델링을 수행하였고 그 결과를 비교하였다. 또한 ICRS(In Cabinet Reponse Spectrum)의 저감을 위하여 1) 보강프레임, 2)감쇠기 설치, 3) 동조질량감쇠기 등 세 가지 내진보강방안에 대하여 구조물의 응답을 산정하였다. 해석결과, 가새보강 및 감쇠기를 설치하는 보강방법에서는 보강전의 구조물보다 큰 ICRS가 얻어지는 경우가 발생해 보강시 많은 주의가 요구된다. 동조질량감쇠기의 사용은 좋은 제진효과를 보였으나 실구조물과 정확한 진동특성을 반영한 모델의 작성이 중요한 것으로 판단되었다.

• 한국산림과학회지
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• 제34권1호
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• pp.47-56
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• 1977

I have investigated and compared the morphology of vascular bundle shown in the section of culm wall of bamboo trees growing on Mt. Jiri which were classified by Grosser and Liese with their methods of morphological classification. The results obtained were as follows: 1. It was shown that there are no b.g.i. types of bamboo classified by Grosser and Liese among the bamboo trees on Mt. Jiri (Phyllostachys and Sasa). 2. As for the thickness of the culm wall in the culm, it was shown that the culm wall of the Phyllostachys becomes thinner in proportion to its nearness to the upper part of the tree, but no distinctive difference appeared in the Sasa. 3. The c, d, and e types of Sasa were the same as those of the Phyllostachys, but there was a vascular bundle type of the a' type, which was quite different from that of the Phyllostachys. 4. It was shown that the a', d, and e types of Sasa were distributed in a zone less than 500m above sea level, but no a' type was distributed in the high mountain area except for the c, d and e types which ranged from 600m to 1000m above sea level. Such facts mean that the vascular bundle sheath has changed in quantity because of the height of mountain. 5. In general, as compared with the Phyllostachys, the Sasa (types a, c, d and e which included a new type a) have fewer vascular bundles. 6. Considering the above results, it is thought that not by the current Sasa classification method based on observation of the the study of Sasa form the outside, but by a new method of classification based on the aspect of the physiological construction as seen from the inside wall is advanced. I believe this new method of classification to be a first step towards an epoch-making methodological advance and encourage the further study of it.