• Journal of the Korean Society of Manufacturing Process Engineers
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• v.17 no.1
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• pp.122-129
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• 2018

This study conducted a seismic qualification analysis of small savonius style vertical axis wind turbine(VAWT) using finite element method(FEM). The modal analysis was performed on the wind turbine structure to check the occurrence of resonance caused by the rotation of gearbox and windmill blades. Next, it conducted a seismic response spectrum analysis due to horizontal and vertical seismic load of required response spectrum of safe shutdown earthquake with 5 % damping(RRS/SSE 5%) of KS C IEC 61400 and conducted a static analysis due to deadweight and wind load. The total maximum stress of the VAWT structure was calculated by adding the maximum stresses due to each load case using the square root of the sum of the squares(SRSS) method. Finally, the structural safety of the VAWT structure was verified by comparing the total maximum stress and the allowable stress.

• Annual Conference on Human and Language Technology
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• 2008.10a
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• pp.79-84
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• 2008

많은 사용자들의 참여로 구축된 집단 지성을 이용한 지식 검색 서비스에서 사용자가 원하는 답변을 빨리 찾고자 하는 요구가 증가하고 있다. 기존의 연구에서 조회 수, 추천 수, 답변 수와 같은 비텍스트 정보가 답변을 평가하는데 좋은 자질임이 증명되었고, 신뢰도를 추정할 수 있는 여러 종류의 단어 사전을 이용하여 답변의 좋고 나쁨을 평가할 수 있는 연구도 진행되었다. 하지만, 조회 수, 추천 수, 답변 수와 같은 비텍스트 정보는 사용자 조작이 간단하여 지속적으로 관리를 해야 하며, 신뢰도를 추정할 수 있는 단어는 지속적으로 보강되어야 한다. 본 논문에서는 이러한 문제점을 해결하고자 동시출현 자질을 이용한 질문과 답변의 유사성을 활용하여 집단 지성에서 사용자의 활동을 분석하여 사용자의 명성을 평가하는 방법을 제안한다. 사용자의 명성을 계산할 수 있다면 조회 수와 추천 수가 많지 않은 답변의 신뢰도도 비교적 정확하게 추정할 수 있다. 이를 위해 우리는 PageRank 알고리즘을 수정하여 사용자 명성을 계산한다. 네이버 지식iN의 문서로 실험한 결과, 기존 정답 선택률을 보완할 수 있는 결과를 보였다.

• Animal cells and systems
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• v.12 no.4
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• pp.287-295
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• 2008

Variations of larval abundance and hatch timing of Dungeness crabs, Cancer magister Dana 1852, were investigated. Dungeness crab larvae were monthly collected at 16 stations arrayed in four transects, Upper Chatham, Icy Strait, Cross Sound, and Icy Point, in southeastern Alaska from May to September 1997-2004. Larval abundance at all transects was the highest in June except in the Icy Point transect. Larval abundance was the highest in the Icy Strait transect, moderate in the Upper Chatham and Cross Sound transects, and the lowest in the Icy Point transect. Zoeae I(ZI) was predominated in May; thereafter ZI decreased and late zoeal stages occurred. In May and June, small numbers of late stage larvae unusually co-occurred with ZI in three transects. These late stage larvae may have been transported from where hatching occurs earlier. The timing of ZI occurrence varied interannually and was related to degreedays during the egg incubation period of Dungeness crabs: later larval hatching in 1997 and 2002 when temperatures were colder, while earlier larval hatching in 1998 when temperatures were warmer. The distribution patterns of Dungeness crab larvae in southeastern Alaska were markedly different from those reported from other areas of the species distribution ranges: larvae occurring much later in the year, and late stage larvae occurring in inland waters.

• Ocean and Polar Research
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• v.32 no.3
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• pp.187-201
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• 2010

The purpose of this study was to investigate the temporal and spatial variability of taxonomic groups and major species of the mesozooplankton community in Lake Shihwa, Korea. Monthly collections were carried out at five stations in Lake Shihwa for a period of one year. The mesozooplankton community showed distinct seasonal variability with water temperature and salinity. Major mesozooplankton species in each seasonal community were derived from non-metric MDS and SIMPER as follows: winter community (Acartia hongi and Eurytemora pacifica), spring community (Acartia hudsonica and Polychaeta larvae), summer community (Acartia sinjiensis, Pavocalanus crassirostris, Evadne tergestina and Cirripedia nauplii) and fall community (Paracalanus indicus and Podon leuckarti). The succession of the seasonal species, A. hudsonica and A. sinjiensis, was the most remarkable event during the seasonal changes of the mesozooplankton community. The species response curve of these species fitted with the logistic regression in relation to water temperature and salinity. The curve also correctly represented the characteristics of the occurrence of A. hudsonica and A. sinjiensis in Lake Shihwa.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.49 no.2
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• pp.90-95
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• 2012

Remotely sensed data provide valuable information on land monitoring due to multi-temporal observation over large areas. Especially, high resolution imagery with 0.6~1.0 m spatial resolutions contain a wealth of information and therefore are very useful for thematic mapping and monitoring change in urban areas. Recently, remote sensing technology has been successfully utilized for natural disaster monitoring such as forest fire, earthquake, and floods. In this paper, an efficient change detection method based on texture differences observed from high resolution multi-temporal data sets is proposed for mapping disaster damage and extracting damage information. It is composed of two parts: feature extraction and detection process. Timely and accurate information on disaster damage can provide an effective decision making and response related to damage.

• Journal of Korean Academy of Nursing
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• v.46 no.1
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• pp.50-58
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• 2016

Purpose: The purpose of this study was to identify the knowledge structure of cancer survivors. Methods: For data, 1099 articles were collected, with 365 keywords as a Noun phrase extracted from the articles and standardized for analyzing. Co-occurrence matrix were generated via a cosine similarity measure, and then the network analysis and visualization using PFNet and NodeXL were applied to visualize intellectual interchanges among keywords. Results: According to the result of the content analysis and the cluster analysis of author keywords from cancer survivors articles, keywords such as 'quality of life', 'breast neoplasms', 'cancer survivors', 'neoplasms', 'exercise' had a high degree centrality. The 9 most important research topics concerning cancer survivors were 'cancer-related symptoms and nursing', 'cancer treatment-related issues', 'late effects', 'psychosocial issues', 'healthy living managements', 'social supports', 'palliative cares', 'research methodology', and 'research participants'. Conclusion: Through this study, the knowledge structure of cancer survivors was identified. The 9 topics identified in this study can provide useful research direction for the development of nursing in cancer survivor research areas. The Network analysis used in this study will be useful for identifying the knowledge structure and identifying general views and current cancer survivor research trends.

• Journal of Ocean Engineering and Technology
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• v.29 no.6
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• pp.411-417
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• 2015

The shipping and shipbuilding industries have had business difficulties since the implementation of regulations on the CO₂ emissions from ships by IMO and the occurrence of the global financial crisis in 2008. Under this global recession, most shipping firms have started to operate their fleets at slow steaming rates with the goal of improving the profit ratio per transported unit. This study analyzed the resistance performance of a 6,800 TEU container ship corresponding to its trim variation with slow steaming, compared with that at its original design speed. Two different grid systems were used for the numerical calculation, one that considered the free surface allowing the capture of the dynamic trim and one that did not. This made it possible to clearly classify each resistance component to provide useful information to hull-form designers. In addition, a form factor assumption method using CFD was used for a reasonable effective power prediction in compliance with the 1978 ITTC performance prediction method. It was found that the total resistance of a 6,800 TEU container ship was reduced by 2.6% in the case of a 1-m trim at the bow at 18 kn.

• Journal of IKEEE
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• v.24 no.1
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• pp.254-259
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• 2020

This paper is the implementation of the conversion system from image to music based on intentional synesthesia. The input image based on color, texture, and shape was converted into melodies, harmonies and rhythms of music, respectively. Depending on the histogram of colors, the melody can be selected and obtained probabilistically to form the melody. The texture in the image expressed harmony and minor key with 7 characteristics of GLCM, a statistical texture feature extraction method. Finally, the shape of the image was extracted from the edge image, and using Hough Transform, a frequency component analysis, the line components were detected to produce music by selecting the rhythm according to the distribution of angles.

• ETRI Journal
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• v.38 no.1
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• pp.174-184
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• 2016

Information identification with image data by means of low-level visual features has evolved as a challenging research domain. Conventional text-based mapping of image data has been gradually replaced by content-based techniques of image identification. Feature extraction from image content plays a crucial role in facilitating content-based detection processes. In this paper, the authors have proposed four different techniques for multiview feature extraction from images. The efficiency of extracted feature vectors for content-based image classification and retrieval is evaluated by means of fusion-based and data standardization-based techniques. It is observed that the latter surpasses the former. The proposed methods outclass state-of-the-art techniques for content-based image identification and show an average increase in precision of 17.71% and 22.78% for classification and retrieval, respectively. Three public datasets - Wang; Oliva and Torralba (OT-Scene); and Corel - are used for verification purposes. The research findings are statistically validated by conducting a paired t-test.

• Korean Journal of Environment and Ecology
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• v.29 no.2
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• pp.228-235
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• 2015

Stream ecosystems are closely related to many human activities. Therefore, streams are affected by anthropogenic disturbances such as riverine development and gravel-mining as well as deterioration of water quality. The goal of this study was to elucidate the recolonization process of the macroinvertebrate community after a small-scale anthropogenic disturbance. Field studies were conducted at three sites in a natural stream. The number of recolonizing species tended to increase slightly over time, exceeding the total species number of the control. Ephemeroptera contributed the most to shaping the recolonizing pattern of the entire community. From the result of changes in dominant species, the early recolonizers of each site were the species that showed more frequent occurrence particulary at each sites. But the late recolonizers are Chironomidae at all the sites commonly. This result implies that the actual differences exist among the recolonizing trends of each benthic macroinvertebrate taxon. Collector-gatherers and scrapers comprised about 70% of the recolonizing species. These results indicate that the recolonizing process of an aquatic community after an artificial disturbance depends on the environmental conditions(particularly substratum composition or organic pollution) of the habitat.