• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2022년도 춘계학술대회
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• pp.6-8
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• 2022

웹 로그 분석은 서비스 개선에 있어 필수적인 절차 중 하나이다. ScienceON은 다양한 과학기술 문헌과 정보를 서비스하는 대표적인 정보 서비스이며, 우리는 지속적인 개선을 위해 웹 로그를 분석하고 있다. 본 연구는 2020년 5월과 2021년 5월 생성된 ScienceON 웹 로그에 대해 인간과 웹 크롤러로 구분하여 심층적인 분석을 하는 데 목표를 두고 있다. 먼저 S(검색), V(상세보기), D(다운로드) 타입에 해당하는 웹 로그만 추출하여 각 시기에 대해 658,407와 8,727,042 레코드로 정규화하였다. 그리고, 파이썬 'user_agents' 라이브러리를 이용하여 인간과 웹 크롤러로 로그를 분리하였으며, 각 로그에 대해 60초를 기준으로 세션 크기를 설정하고 분석하였다. 인간과 달리 웹 크롤러는 세션 당 평균 행위 패턴(Average Behaviors per Session)의 길이가 상대적으로 길고, 행위 패턴이 V 중심으로 이루어짐으로 확인하였다. 향후 웹 크롤러를 쉽게 탐지하고 대응하며, 인간 사용자의 행위 패턴에 대응할 수 있도록 서비스를 개선할 예정이다.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2002년도 proceedings of the second asia international conference on tribology
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• pp.445-446
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• 2002

The purpose of this study was to investigate the effect of micro holes, pattern structure and elastic modulus of pads on the polishing behavior such as the removal rate and WIWNU (within wafer non-uniformity) during CMP. The regular holes on the pad act as the superior abrasive particle's reservoir and regular distributor at the bulk pad, respectively. The superior CMP performance was observed at the laser processed bulk pad with holes. Also, th ε groove pattern shape was very important for the effective polishing. Wave grooved pad showed higher removal rates than K-grooved pad. The removal rate was linearly increased as the top pad's elastic modulus increased.

• 한국소음진동공학회논문집
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• 제11권8호
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• pp.331-337
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• 2001

The purpose of this study is to analyze the principal causes of vibration problem and find out the method of vibration reduction in a chip-mount system. The principal causes are investigated through measurements of vibration spectrum and model parameters. Modal parameters are obtained by using an experimental model test. Based on the model parameters from experiments. a model of finite element method is formulated. The model presents effective redesign of increasing the natural frequencies in order to reduce the vibration of a chip-mount system. Further, through computer simulation for the behavior of head to be main vibration source, the best acceleration pattern of head movement can be verified to achieve effective head-positioning and reduce the vibration due to head movement.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1995년도 추계학술대회 논문집
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• pp.388-392
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• 1995

The Electronic Speckle Pattern Interferometry(ESPI) has been applied to many technical problems such as deformation and displacement measurement, strain visualization and surface roughness monitoring. Composite materials have various complicated characteristics depending on the ply materials,ply orientations,ply stacking sequences and boundary conditions. Therefore, it is difficult to analyze composite material. For efficient use of composit materials in engineering applications, the dynamic behavior such as, natural frequencies and modal patterns should be identified. This studying presents FEM results for the free vibration of symmetrically laminated composite as [30/-30/90] $_{s}$. The natural frequencies of laminated composite rectangular plates having the boundary condition(:2-edge clamped) are experimentally obtained. In order to demonstrate the validity of the experiment,FEM analysis using ANSYS was performed and natural frequencies experimentally obtained is compared with calculated by FEM analysis. The results obtained from both experiment and FEM analysis show a good agreement.t.

• 경영과학
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• 제23권3호
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• pp.63-75
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• 2006

There are many kinds of research on web graph, most of them are focus on the hyperlinked structure of the web graph. Well known results on the web graph are rich-get-richer phenomenon, small-world phenomenon, scale-free network, etc. In this paper, we define 3 new directed web graph, so called the Web Usage Pattern Graph (WUPG), that nodes represent web sites arid arcs between nodes represent a movement between two sites by users' browsing behavior. The data to constructing the WUPG, approximately 56,000 records, are gathered from some users' PCs. The results analysing the data summarized as follows : (i) extremely rich-get-richer phenomenon (ii) average path length between sites is significantly less than the previous one (iii) less external hyperlinks, more internal hyperlinks.

• Advances in concrete construction
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• 제1권2호
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• pp.121-136
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• 2013

Tension tests were carried out to investigate the effect of the corrosion pattern on the ductility of tension bars extracted from a 26-year-old corroded reinforced concrete beam. The tensile behavior of corroded bars with different corrosion patterns was examined carefully, as were two non-corroded bars extracted from a 26-year-old control beam. The results show that corrosion leads to an increase in the ratio of the ultimate strength over the yield strength, but reduces the ultimate strain at maximum force of the reinforcement. Both the corrosion pattern and the corrosion intensity play an important role in the ductile properties. The asymmetrical distribution of the corrosion around the surface is a decisive factor, which can influence the ultimate strain at maximum force more seriously.

• 교육시설
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• 제11권6호
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• pp.13-21
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• 2004

The purpose of this study is to make planning factors for outdoor space in elementary school site, with analyzation focusing on a Japanese elementary school examples. We evaluated the planning factors which encourage the development of children’s behaviors from quality of space. And we can get the important points as planning factor for school site as follows: 1) The base point of zoning is school building, building entrance, entrance of site and track 2) The importance of linked space plan with inside of site and surrounding environment 3) Preservation linked system of space in school site for linked pattern of child’s behavior.

• 환경위생공학
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• 제13권2호
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• pp.66-75
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• 1998

The computer simulation model was used to forecast the concentrations of COD$_{cr}$, NH$_{4}$$^{+}$-N and NO$_{3}$$^{-}$-N in each reactors. In the biological wastewater treatment system, the computer simulation model was used to observe the behavior of pollutants especially. In this research, effect of SRT, feeding pattern and recirculation rate on UCT(University of Cape Town) process was evaluated by computer simulation model. T-N removal was affected to the SRT. SRT for effective T-N removal was 15 days or longer. Feeding pattern in UCT process was affected to the T-N removal. Feeding pattern which 100% loading to the first reactor was most effective for T-N removal. The effect of recirculation rate was clear for T-N removal. The recirculation from anoxic reactor to anaerobic reactor was not need but the recirculation from oxic reactor to anoxic reactor was need. In aspect of nitrogen removal efficiency, A/O process was higher than UCT process.

• International Journal of Naval Architecture and Ocean Engineering
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• 제8권1호
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• pp.22-37
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• 2016

This article investigates numerical modeling of surface piercing propeller (SPP) in unsteady open water condition using boundary element method. The home code based on BEM has been developed for the prediction of propeller performance, unsteady ventilation pattern and cross flow effect on partially submerged propellers. To achieve accurate results and correct behavior extraction of the ventilation zone, finely mesh has generated around the propeller and especially in the situation intersection of propeller with the free surface. Hydrodynamic coefficients and ventilation pattern on key blade of SPP are calculated in the different advance coefficients. The values obtained from this numerical simulation are plotted and the results are compared with experiments data and ventilation observations. The predicted ventilated open water performances of the SPP as well as ventilation pattern are in good agreement with experimental data. Finally, the results of the BEM code/experiment comparisons are discussed.

• KIEE International Transactions on Electrophysics and Applications
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• 제5C권2호
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• pp.81-85
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• 2005

This paper presents some interesting results regarding the harmonic performance on the photonic band-gap (PBG) structures formed by periodic conducting vias. Study on PBG structures has been one of the major topics in electromagnetics, microelectronics, and communications areas. In most of the studies, the band-gap filtering behavior was fulfilled by a periodic pattern of perforations on the ground planes of microstrip lines. Nevertheless, the PBG characteristics can also be realized using a periodic via-pattern along the transmission-line circuits. Hence, some of the via-typed PBG structures are studied and their frequency characteristics in terms of the scattering parameters are presented. It is found that by varying the length of vias with respect to the period pattern, different harmonic performances are observed.