• Communications for Statistical Applications and Methods
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• 제17권1호
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• pp.39-45
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• 2010

환경가치가 높아짐에 따라 하천 수질에 대한 관심의 증대로 수질측정망 연구가 최근 활발히 진행되고 있으나 입지환경의 지리적 특성이나 유입량, 유출량, 유량, 유속과 같은 하천 특성 중심 연구이다. 본 연구에서는 상대적으로 연구가 미미한 관측지점의 수질 유사성을 측정하는 방법으로 수질의 시계열 패턴을 고려할 수 있는 상관계수행렬 방법을 제안하고 기존의 주성분점수를 이용한 방법과 비교하였다. 용담댐에서 2년간 조사된 수질관련 데이터를 이용하여 두 방법에 대한 실증분석을 실시하여 관측지점의 지리적 특성에 의해 분류된 결과와 본 연구에서 제안된 방법에 의해 관측지점 유사성을 측정하여 얻은 군집결과가 더 일치함을 보였다.

• 한국산업정보학회논문지
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• 제17권1호
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• pp.95-104
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• 2012

컴퓨터관련 교육기관들은 시대의 변천에 따라 다양한 프로그래밍 언어들을 교육시켜 왔으나 많은 학생들은 컴퓨터 활용의 측면에서는 능숙하지만 프로그래밍은 배우기 어려운 분야로 인식되고 있다. 프로그래밍에 대한 거부감은 컴퓨터관련 전공에 대한 기피현상으로 이어졌고, 전 세계적으로 프로그래머 인력의 부족 문제가 대두되고 있는 설정이다. 본 연구는 프로그래밍 언어들에 대해서 프로그래머들이 지각하고 있는 언어들 간의 유사성올 조사함으로써 각 언어의 상대적인 위치를 파악하고, 좌표평면 상에 나타내어 각 차원이 의미하는 바를 추정하고 규명하였다.

• 대한인간공학회지
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• 제23권4호
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• pp.23-34
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• 2004

The importance of the industrial safety has been growing gradually as well as the prevention activities on industrial accidents. Industrial accident rates have been decreasing by the prevention activities. However, the fatal industrial accidents such as the death tend to increase and risk per accident has increased. The previous studies on the industrial accidents focus on the entire accidents. However, these studies are lacking for the fatal industrial accidents such as the death. The purpose of this paper is to analyze the characteristics and trend of death which occurred by industrial accident, based on the real data of deaths collected last 5 years from 1999 to 2003 in korea. This paper suggests a analysis method using MDS(MultiDimensional Scaling) that considers accidents variables and properties simultaneously. We evaluate MDPREF (Multidimensional Analysis of Preference Data), one of the MDS analysis, to know the relations between the type of industry and region as well as the type of industry and occupation. This paper finds the type of industry which has high possibilities of death by regional groups. In addition, we find the type of occupation which has high possibilities of death by the type of industry. These findings indicate that industrial classification should be differently controled according to type of occupation and region.

• 한국수산과학회지
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• 제43권5호
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• pp.510-520
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• 2010

This study investigated the community structure and seasonal variation of the fish assemblages on Jangbong tidal flat, Incheon, Korea. Fish were collected monthly using a small otter trawl from November 1999 to January 2001. Thirty-six fish species were recorded, with a mean density of 185 individuals and biomass of 2,594.3 gWWt. The most abundant species by number were Johnius grypotus (23.7%), Acanthogobius hasta (17.8%), and Cynoglossus joyneri (10.7%), while the dominant species by catch weight were Acanthogobius hasta (21.2%), Sebastes schlegeli (16.2%), J. grypotus (14.0%), and C. joyneri (10.8%). Cluster analysis and non-metric multi-dimensional scaling (nMDS) were applied to assess the seasonal fluctuation in the fish assemblages. Based on the result of the cluster analysis and nMDS ordination, the faunal group could be divided into cold- and warm-water specialist groups. The cold-water specialists included A. hasta, Acanthogobius luridus, Triaenopogon barbatus, Tridentiger trigonocephalus, and Liza haematocheila. The warm-water specialists were J. grypotus, C. joyneri, S. schlegeli, and Hexagrammos otakii. In conclusion, the community structure showed a distinct seasonal trend, which seemed to be related to the seasonal fluctuations in water temperature.

• 한국수산과학회지
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• 제43권3호
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• pp.254-261
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• 2010

The feeding habits of six shark species, Scyliorhinus torazame, Mustelus manazo, Squalus megalops, Isurus oxyrinchus, Alopias pelagicus, and Carcharhinus plumbeus were studied using the stomach contents of 463 specimens collected between January and February 2007 in the southern sea of Korea. They consumed different prey items. S. torazame preyed mainly crustaceans, and M. manazo on crustaceans and fishes. S. megalops, I. oxyrinchus, A. pelagicus, and C. plumbeus consumed predominately fishes. Non-metric multi-dimensional scaling (NMDS) ordination plots emphasized that dietary similarities separated thesix shark species into three trophic groups based on similarities in percentage Index of Relative Importance (%IRI): Group I (crustacean feeders), Group II (fish and crustacean feeders), and Group III (fish feeders).

• 산업경영시스템학회지
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• 제24권63호
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• pp.13-21
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• 2001

The present study compared the two experimental methods on inquiring the image structure of odors: Presenting a stimulus is one, and not presenting a stimulus is the other. For experiment one, five odors were presented, and the subjects were instructed to evaluate the odors on 7-point scale for each of the 25 adjectives. For experiment two, no odor was presented, and the subjects were instructed to perform the pair-wise comparisons for the each pair of two adjectives on their similarities on 7-point scale. The data from the two experiments were analysed and compared using MDS(Multi-Dimensional Scaling), Correlation, Cluster Analysis. The results showed that there was no structural differences between two experimental methods in term of the Image structure of odors. But, minor disparity was found between two methods in terms of density of distribution of the adjectives. It was construed that the difference came from the difference of the memory that was used for each of the experiments; that is, short term memory for experiment one and long-term memory for experiment two.

• 대한산업공학회지
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• 제29권4호
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• pp.259-270
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• 2003

In order to properly design warning sounds that are affectively suitable to computer users, warning sounds used in Windows operating system were analyzed in terms of their sound properties; frequency band, spectral characteristics and physical intensity. A total of 36 warning sounds (3*4*3) were generated and tested with respect to three experimental variables. Among 178 collected affective adjectives that are related to hearing and sounds, seven representative affective adjectives were abstracted by statistical grouping techniques. In the experiment, subjective preference tests were performed for the 36 warning sounds according to the seven affective factors. From the result, the affective factors were again grouped into three major factors and the 60dB boost-type warning sounds at the low frequency band were, in general, the most preferred. followed by the 70dB cut-type sounds at the middle frequency band. These warning sounds have a characteristic of boost power spectrum below 1000Hz frequency band and received good scores on simplicity, clarity and accurateness.

• 한국조경학회지
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• 제26권3호
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• pp.134-142
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• 1998

THe purpose of this study is to suggest the major determinants of visual preference in the outdoor spaces of urban office buildings. For this, the spatial image was analyzed by the factor analysis algorithm. The level of visual preferences was measured by a slide simulation test, and these data were analyzed by the multiple regressioni. The result of this study can be summarized as follows; Factors covering the spatial image were found to be 'mystery','changeability','coherence' and 'legibility'. T.V. was obtained as 58.4%. Outdoor spaces of urban office buildings were classified into four groups by the multi dimensional scaling method. As for the analysis of imageability in each spatial type, the factor scores of measuring high values were different for all types. Type II, IV obtained higher rank of visual preference and type III, I obtained lower. For all types, the factors of visual preference were found to be 'mystery','changeability','coherence' and 'legibility'. The visual preference determinants of urban setting focused on outdoor spaces of urban office buildings may be the major factors which must be considered in planning and designing as the functional basis for the quantitative analysis.

• Nuclear Engineering and Technology
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• 제53권12호
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• pp.3892-3901
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• 2021

The pressure drop of a moisture separator in a steam generator is the important design parameter to ensure the successful performance of a nuclear power plant. The moisture separators have a wide range of operating conditions based on the arrangement of them. The prediction of the pressure drop in a moisture separator is challenging due to the complexity of the multi-dimensional two-phase vortex flow. In this study, the moisture separator test facility using the air/water two-phase flow was used to predict the pressure drop of a moisture separator in a Korean OPR-1000 reactor. The prototypical steam/water two-phase flow conditions in a steam generator were simulated as air/water two-phase flow conditions by preserving the centrifugal force and vapor quality. A series of experiments were carried out to investigate the effect of hydraulic characteristics such as the quality and liquid mass flux on the two-phase pressure drop. A new prediction model based on the scaling law was suggested and validated experimentally using the full and half scale of separators. The suggested prediction model showed good agreement with the steam/water experimental results, and it can be extended to predict the steam/water two-phase pressure drop for moisture separators.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권3호
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• pp.1418-1433
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• 2019

In computer graphics, 3D mesh segmentation is a challenging research field. This paper presents a 3D mesh model segmentation algorithm that focuses on removing exterior salient parts from the original 3D mesh model based on prominent feature points and marching plane. To begin with, the proposed approach uses multi-dimensional scaling to extract prominent feature points that reside on the tips of each exterior salient part of a given mesh. Subsequently, a set of planes intersect the 3D mesh; one is the marching plane, which start marching from prominent feature points. Through the marching process, local cross sections between marching plane and 3D mesh are extracted, subsequently, its corresponding area are calculated to represent local volumes of the 3D mesh model. As the boundary region of an exterior salient part generally lies on the location at which the local volume suddenly changes greatly, we can simply cut this location with the marching plane to separate this part from the mesh. We evaluated our algorithm on the Princeton Segmentation Benchmark, and the evaluation results show that our algorithm works well for some categories.