• Journal of Ecology and Environment
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• 제30권2호
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• pp.201-207
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• 2007

Researchers have used a variety of methods to measure patterns of animal movement, including the use of spatial data (mapping the position of a moving animal at specified intervals) and direct estimation of travel path length by pacing under a moving animal or group. I collected movement data from five groups of siamangs (Symphalangus syndactylus) using two different methods concurrently to estimate the effects of the method of data collection on estimates of daily path length (DPL). Estimates of DPL produced from spatial data collected at 15-minute intervals were 12% lower than estimates of DPL produced by pacing under the traveling animal. The actual magnitude of the difference was correlated with the travel distance, but there was no correlation between the proportional difference and the travel distance. While the collection of spatial data is generally preferable, as spatial data permit additional analyses of patterns of movements in two or three dimensions, the relatively small difference between the DPL's produced using different methods suggests that pacing is an acceptable substitute where the collection of spatial data is impractical. I also subsampled the spatial data at increasing time intervals to assess the effect of sampling interval on the calculation of daily path lengths. Longer sampling intervals produced significantly shorter estimates of travel paths than shorter sampling intervals. These results suggest that spatial data should be collected at short time intervals wherever possible, and that sampling intervals should not exceed 30 minutes. Researchers should be cautious when comparing data generated using different methods.

• KSBB Journal
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• 제26권2호
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• pp.131-138
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• 2011

Some computational approaches are needed for clarifying RNAi sequences, because it takes much time and endeavor that almost of RNAi sequences are verified by experimental data. Incorrectness of RNAi mechanism and other unaware factors in organism system are frequently faced with questions regarding potential use of RNAi as therapeutic applications. Our massive parallelized pair alignment scoring between dsRNA in Genebank and expressed sequence tags (ESTs) in Caenorhabditis elegans Genome Sequencing Projects revealed that this provides a useful tool for the prediction of RNAi induced cosuppression details for practical use. This pair alignment scoring method using high performance computing exhibited some possibility that numerous unwanted gene silencing and cosuppression exist even at high matching scores each other. The classifying the relative higher matching score of them based on GO (Gene Ontology) system could present mapping dsRNA of C. elegans and functional roles in an applied system. Our prediction also exhibited that more than 78% of the predicted co-suppressible genes are located in the ribosomal spot of C. elegans.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 추계학술대회논문집 II
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• pp.799-804
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• 2001

Nonlinear normal mode (NNM) vibration, in a nonlinear dual mass Hamiltonian system, which has 6th order homogeneous polynomial as a nonlinear term, is studied in this paper. The existence, bifurcation, and the orbital stability of periodic motions are to be studied in the phase space. In order to find the analytic expression of the invariant curves in the Poincare Map, which is a mapping of a phase trajectory onto 2 dimensional surface in 4 dimensional phase space, Whittaker's Adelphic Integral, instead of the direct integration of the equations of motion or the Birkhotf-Gustavson (B-G) canonical transformation, is derived for small value of energy. It is revealed that the integral of motion by Adelphic Integral is essentially consistent with the one obtained from the B-G transformation method. The resulting expression of the invariant curves can be used for analyzing the behavior of NNM vibration in the Poincare Map.

• 한국광물학회지
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• 제32권1호
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• pp.63-69
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• 2019

광물 구조에 분포하는 철의 산화수 정보는 유 무기적 퇴적광물형성 시 산화환원 조건 등 과거 퇴적 환경에 대한 정보를 제공한다. 특히, 생광물화작용에서 미생물의 역할을 규명하기 위해서는 고분해능 투과 전자현미경(HRTEM) 및 전자에너지 손실 분광기(EELS)를 활용한 나노스케일 분석이 필요하다. HRTEM-EELS를 이용한 광물구조 내 철의 산화수 및 탄소 결합 구조 분석, Fe(II)/Fe(III) 및 탄소 기원 분포영상으로부터 광물생성의 생물학적 요소를 판별할 수 있다. 이와 같은 나노스케일 분석을 통하여 지질미생물학자들은 미생물-광물작용의 증거를 직접적으로 얻을 수 있다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2021년도 학술발표회
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• pp.139-139
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• 2021

Flooding events often result from extreme precipitations driven by various climate mechanisms, which are often disregarded in flood risk assessments. To bridge this gap, we propose a climate-mechanism-based flood frequency analysis that accommodates the direct linkage between the dominant climate processes and risk management decisions. Several statistical methods have been utilized in this approach including the Markov Chain analysis, K-nearest neighbor (KNN) resampling approach, and Z-score-based jittering method. After that, the impacts of climate change are associated with the modification of the transition matrix (TM) and the application of the quantile mapping approach. For this study, we have selected the Nam River Basin, South Korea, to consider the heterogeneous impacts of the two climate mechanisms, including the Tropical Cyclone (TC) and non-TCs. Based on our results, while both climate mechanisms have significant impacts on future flood extremes, TCs have been observed to bring more significant and immediate impacts on the flood extremes. The results in this study have proven that the proposed approach can lead to a new insights into future flooding management.

• Educational Technology International
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• 제15권2호
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• pp.117-141
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• 2014

This qualitative study investigated different interaction patterns in an online discussion. The data was collected from asynchronous discussion occurred in a graduate course. The data analysis methods include inductive analysis and mapping strategy. The results of the study suggest three layers of interaction: response sequences, interaction amongst participants, and concept map of messages. The visualization of response sequences enabled the researcher to discover complex and dynamic interaction patterns amongst participants. The many-to-many communication feature of online discussion does not always enable direct one-on-one interaction between two participants. Rather, one message contributed to multiple threads in the stream of conversation. In terms of interaction amongst participants, the interaction amongst participants, as indicated in the data, the messages also bind each participant and consequently a group(s) of participants together. It appears that the contribution of one message may not only enable a response to one participant, but also connect many participants to each other. The concept map of messages proposes that response sequences and interaction amongst participants can also be viewed between concepts within messages in the discussion. On the surface, the messages posted by individuals are linked by the system in a linear fashion as they are posted. However, the interaction extends to collaborative conversation amongst participants. Ultimately, a conceptual network of interrelated ideas including multiple perspectives is built in asynchronous discussion.

• 한국압력기기공학회 논문집
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• 제19권2호
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• pp.93-101
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• 2023

In this study, a deep learning algorithm was used to diagnose electric potential signals obtained through CIPS and DCVG, used indirect inspection methods to confirm the soundness of buried pipes. The deep learning algorithm consisted of CNN(Convolutional Neural Network) model for diagnosing the electric potential signal and Grad CAM(Gradient-weighted Class Activation Mapping) for showing the flaw prediction point. The CNN model for diagnosing electric potential signals classifies input data as normal/abnormal according to the presence or absence of flaw in the buried pipe, and for abnormal data, Grad CAM generates a heat map that visualizes the flaw prediction part of the buried pipe. The CIPS/DCVG signal and piping layout obtained from the 3D finite element model were used as input data for learning the CNN. The trained CNN classified the normal/abnormal data with 93% accuracy, and the Grad-CAM predicted flaws point with an average error of 2m. As a result, it confirmed that the electric potential signal of buried pipe can be diagnosed using a CNN-based deep learning algorithm.

• 천문학회지
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• 제47권6호
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• pp.235-253
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• 2014

Intensity interferometry, based on the Hanbury Brown-Twiss effect, is a simple and inexpensive method for optical interferometry at microarcsecond angular resolutions; its use in astronomy was abandoned in the 1970s because of low sensitivity. Motivated by recent technical developments, we argue that the sensitivity of large modern intensity interferometers can be improved by factors up to approximately 25 000, corresponding to 11 photometric magnitudes, compared to the pioneering Narrabri Stellar Interferometer. This is made possible by (i) using avalanche photodiodes (APD) as light detectors, (ii) distributing the light received from the source over multiple independent spectral channels, and (iii) use of arrays composed of multiple large light collectors. Our approach permits the construction of large (with baselines ranging from few kilometers to intercontinental distances) optical interferometers at the cost of (very) long-baseline radio interferometers. Realistic intensity interferometer designs are able to achieve limiting R-band magnitudes as good as $m_R{\approx}14$, sufficient for spatially resolved observations of main-sequence O-type stars in the Magellanic Clouds. Multi-channel intensity interferometers can address a wide variety of science cases: (i) linear radii, effective temperatures, and luminosities of stars, via direct measurements of stellar angular sizes; (ii) mass-radius relationships of compact stellar remnants, via direct measurements of the angular sizes of white dwarfs; (iii) stellar rotation, via observations of rotation flattening and surface gravity darkening; (iv) stellar convection and the interaction of stellar photospheres and magnetic fields, via observations of dark and bright starspots; (v) the structure and evolution of multiple stars, via mapping of the companion stars and of accretion flows in interacting binaries; (vi) direct measurements of interstellar distances, derived from angular diameters of stars or via the interferometric Baade-Wesselink method; (vii) the physics of gas accretion onto supermassive black holes, via resolved observations of the central engines of luminous active galactic nuclei; and (viii) calibration of amplitude interferometers by providing a sample of calibrator stars.

• 한국컴퓨터그래픽스학회논문지
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• 제16권1호
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• pp.9-20
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• 2010

3차원 공간에 존재하는 반투명 물질을 물리 기반으로 렌더링하기 위해서 빛의 진행 경로를 작은 구간으로 나눈 후, 각 구간에 대하여 빛의 직접적인 영향, 산란으로 인한 영향, 반투명 물질안에서의 소멸 및 물질의 발광으로 인한 영향 등을 고려한 빛의 에너지를 계산하여 누적하는 방식을 사용한다. 이중 빛의 산란은 연속 공간에서 매우 복잡한 방식으로 작용하기 때문에 이의 시뮬레이션을 위해서 상당한 노력이 필요하다. 빛의 산란을 효과적으로 계산하기 위해 여러근사 방법들이 고안되었는데, 그중 볼륨 포톤매핑 기법은 빛이 간섭매체 내부에서 산란되는 효과를 단순화된 시뮬레이션으로 미리 계산하여두고 이를 검색해 효율적으로 렌더링 하는 방법을 사용한다. 이 방법은 주변에서 검색한 시뮬레이션 정보를 이용하기 위해서 밀도추정방법을 적용하는데, 시뮬레이션자료의분포에 따라서 검색에 따른 편차가 있을 수 있게된다. 또한 시뮬레이션된 자료만을 이용하여 산란효과를 반영하기 때문에 고밀도이지만 시뮬레이션이 충분하지 못한 위치에 대해서 방향성 있는 위상함수에 대한 특징을 잘 표현하지 못한다는 문제가있다. 이러한 문제를해결하고자 하는 노력의 일환으로, 본 논문에서는 입자형태로 시뮬레이션된 볼륨데이터에 대해 밀도추정방법의 하나인 커널스무딩을 이용하여 표현한 산란효과를 반투명물질 자료구조에 저장하고 이를 복원하는 방법을 제안하고, 실험결과 분석을 통하여 장단점을 분석한다.

• 한국HCI학회:학술대회논문집
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• 한국HCI학회 2008년도 학술대회 2부
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• pp.451-455
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• 2008

감성 디자인의 중요성은 정정 강조되는 반면, 제품의 전반적인 디자인 아이덴티티로부터 실질적인 오감만족을 제공하기 위해 사용자 요소들을 적절하게 통합하는 작업은 그리 체계적으로 이루어지지 않았다. 본 연구는 트렌드 분석에 따른 감성 어휘를 추출하고, 사용자 경험 요소를 매핑하여, 사용자 경험 요소를 통일성 있게 제품 디자인에 활용할 수 있도록 하기 위해 실시되었다. 본 연구에서 사용자 경험 요소는 칼라, 소재&마감, 사운드로 국한하였다. 이를 위해 각종 문헌 조사와 트렌드 분석 업체 및 사용자 경험 전문가들이 '08~'09 트렌드를 분석하고, 이를 가장 잘 반영할 수 있는 감성 형용사 31 개를 최종 추출하였다. 추출된 31 개의 어휘간 유사성 평정을 실시한 후, 다차원척도 분석을 통하여 2 차원의 감성축을 구성할 수 있었다. 트렌드 감성 어휘는 'human-centered' vs. 'techno-centered' 및 'warm vs. cool' 의 2 차원 공간에서 표현될 수 있었다. 다음으로 각 어휘에 따른 칼라, 소재&마감, 사운드 자극을 각각 제작한 후, 참가자들로 하여금 2 차원 감성 평면 위에서 직접 매핑시키는 실험을 통하여 이들간의 부합 정도를 검증해 보았다. 실험 결과를 토대로 가장 근접한 위치의 감성 어휘와 감성 요소들을 연결시키고, 디자이너들이 활용할 수 있도록 시스템화하였다. 추후 더욱 견고한 차원 구축 및 시스템화를 통해 실질적인 감성 디자인을 가이드 할 수 있을 것으로 기대된다.