• 대한원격탐사학회지
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• 제34권1호
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• pp.151-166
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• 2018

This paper compares the four selections of performance used in the application of genetic algorithms (GAs) to automatically optimize multispectral pixel cluster for unsupervised classification from KOMPSAT-3 data, since the selection among three main types of operators including crossover and mutation is the driving force to determine the overall operations in the clustering GAs. Experimental results demonstrate that the tournament selection obtains a better performance than the other selections, especially for both the number of generation and the convergence rate. However, it is computationally more expensive than the elitism selection with the slowest convergence rate in the comparison, which has less probability of getting optimum cluster centers than the other selections. Both the ranked-based selection and the proportional roulette wheel selection show similar performance in the average Euclidean distance using the pixel clustering, even the ranked-based is computationally much more expensive than the proportional roulette. With respect to finding global optimum, the tournament selection has higher potential to reach the global optimum prior to the ranked-based selection which spends a lot of computational time in fitness smoothing. The tournament selection-based clustering GA is used to successfully classify the KOMPSAT-3 multispectral data achieving the sufficient the matic accuracy assessment (namely, the achieved Kappa coefficient value of 0.923).

• 한국통신학회논문지
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• 제34권7B호
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• pp.721-727
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• 2009

무선 센서 네트워크(WSN)에서는 저가 및 저 전력 센서를 활용하기 때문에 센서의 업무를 성공적으로 수행하면서 적은 에너지를 소모하는 것이 중요한 문제로 부각 된다. 기존의 계층척 WSN 알고리즘들에서 나타나는 제한점은 데이터 진행방향에 대한 역방향 전송이 이루어 질수 있다는 것이다. 본 논문은 데이터 방향성을 고려한 DDACM(Data Direction Aware Clustering Method) 방법을 제안한다. 데이터 역방향 전송 방지를 위해 클러스터헤더는 데이터 전송 방향에서 싱크노드와 가장 가까운 노드가 먼저 임명되고, 에너지 레벨이 일정량 이하 시 클러스터 헤더를 교체하는 방법융 제안한다. 실험을 통하여 LEACH(Low Energy Adaptive Clustering Hierarchy)방식과 비교하여 데이터 역방향 전송올 최소화하여 에너지 소모를 줄일 수 있음을 확인하였다.

• 한국의류산업학회지
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• 제1권2호
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• pp.137-147
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• 1999

The purpose of this study was to classify female students' somatotypes, to investigate the relationship between five somatotypes obtained from anthropometric measurements and to examine the relationship between the spinal deformity and somatotypes. The subjects for anthropometric measurements were 844 female middle and high school students. The data were analyzed by cluster analysis, correspondence analysis, Duncan test, and T-test. The results were as follows. Cluster analysis on the factors extracted from directly measured items classified subjects into five types (middle height and a little slim type (39.6%), low height and a little slim type (13.1%), middle height and a little fat type (18.0%), tall and very fat type (7.7%), and very tall and standard type (21.6%). In examining the relationship between the normal people and those of the spinal deformity, the normal showed higher mean value in almost all the items of the girth, the depth, and the length. High school students had more spinal deformity in number than middle school students. The degree of deformity was higher in the right spinal deformity than in the left spinal deformity as the age increased. In terms of the distribution of the spinal deformity classified by the somatotype, Type 1 (middle height and a little slim type) and Type 5 (very tall and standard type) appeared the highest.

• Journal of Power Electronics
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• 제17권4호
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• pp.1088-1096
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• 2017

Load variations on a distribution line result in voltage fluctuations at the point of common coupling (PCC). In order to keep the magnitude of the PCC voltage constant at its rated value and obtain zero voltage regulation (ZVR), a D-STATCOM is installed for voltage correction. Moreover, the ZVR mode of a D-STATCOM can also be used to balance the source current during unbalanced loading. For medium voltage and high power applications, a D-STATCOM is realized by the cascaded H-bridge topology. In the ZVR mode, the D-STATCOM may draw unbalanced current and in this process is required to handle different phase powers leading to deviations in the cluster voltages. Zero sequence voltage needs to be injected for ZVR mode, which creates circulating power among the phases of the D-STATCOM. The computed zero sequence voltage and the individual DC capacitor balancing controller help the DC cluster voltage follow the reference voltage. The effectiveness of the control scheme is verified by modeling the system in MATLAB/SIMULINK. The obtained simulations are further validated by the experimental results using a dSPACE DS1106 and five-level D-STATCOM experimental set up.

• 한국포장학회지
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• 제24권3호
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• pp.141-148
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• 2018

Photo-oxidation is one of the main causes of food deterioration of great variety of foods, such as dairy products, nuts, meat products, and wine. It causes a loss of both nutritional value and sensorial quality of products and may even leads to the formation of toxic compounds. Active packaging for food and beverages has been investigated and developed with embedding light absorbers or blocking materials into the plastics. In recent years, several novel light barrier materials have been proposed as an alternative option for different applications. This article reviews the up-to-date technology in light absorber and blocking material with special emphasis on chemical compound and mechanism. Inorganic, organic, hybrid organic-inorganic, and natural light absorbers were scoped. The challenges and future perspectives of light barrier materials are also discussed.

• 한국정보시스템학회지:정보시스템연구
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• 제28권3호
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• pp.105-121
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• 2019

Purpose One of the reasons for the expansion of information systems in the enterprise is the increased efficiency of data analysis. In particular, the rapidly increasing data types which are complex and unstructured such as video, voice, images, and conversations in and out of social networks. The purpose of this study is the customer needs analysis from customer voices, ie, text data, in the web environment.. Design/methodology/approach As previous study results, the word frequency of the sentence is extracted as a word that interprets the sentence has better affects than frequency analysis. In this study, we applied the TF-IDF method, which extracts important keywords in real sentences, not the TF method, which is a word extraction technique that expresses sentences with simple frequency only, in Korean language research. We visualized the two techniques by cluster analysis and describe the difference. Findings TF technique and TF-IDF technique are applied for Korean natural language processing, the research showed the value from frequency analysis technique to semantic analysis and it is expected to change the technique by Korean language processing researcher.

• 한국보육지원학회지
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• 제17권6호
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• pp.53-72
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• 2021

Objective: This study aimed to reveal early childhood teachers' perceptions of teacher competency for ESD using concept mapping and demonstrating its importance. Methods: 16 early childhood teachers in charge of 3-5 year olds conducted statement writing, and then the importance of selected statements were rated by 160 early childhood teachers in charge of 3-5 year olds. Selected statements were analyzed through multidimensional scaling and hierarchical cluster analysis. Results: Early childhood teachers perceived teacher competency for ESD in early childhood as concept mapping with two-dimensions and six clusters. The following six clusters were established (1) ethics for sustainable development, (2) willingness to participate in ESD, (3) development and operation of a sustainable development curriculum, (4) recognition and practice of environmental issues, (5) realization of value for sustainable development, and (6) practical thinking for ESD. And then among the six clusters, the most important cluster was recognized as 'ethics for sustainable development', and among the statements 'having an open mind to understand multiculturalism and the disabled' was considered relatively important Conclusion/Implications: Based on these results, we discussed the importance of teacher competency for ESD in early childhood, development of teacher competency scale, and preparation of a teacher education plans for each competency.

• 한국해양바이오학회지
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• 제14권2호
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• pp.124-132
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• 2022

By-products from fisheries produced in Korea are of the same industrial material as imported raw materials and are valuable resources for marine bioindustries. Securing raw materials for the mass production of functional materials is one of the main objectives for marine bioindustrial development. The use of fishery by-products as raw materials is anticipated to increase rapidly as the biomarket is growing into a promising industry. In this study, data were acquired from an open-source environment to perform exploratory data analysis, and various visualization methods were used to compare fishery production to the production of marine processed products in the year 2020. This study suggested that the amount of seafood processing, types of processing items, and areas where fishery processing residue is generated, should be able to secure hygienic raw material supply in large quantities. Thus far, it has been found that the Gyeonggi-do and Busan province, where HACCP-certified processing facilities are concentrated, and the local government Seafood Cluster and the Smart Aquaculture Cluster are at the forefront of stable, mass production of raw materials.

• 한국육종학회지
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• 제42권1호
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• pp.87-99
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• 2010

한국의 농업유전자원센터로부터 분양받은 한국 야생콩, 일본의 Biological Resource Center in Lotus and Glycine, Frontier Science Research Center, University of Miyazaki로부터 분양 받은 일본 야생콩, 그리고 중국 지린성에서 수집되어진 야생콩 의 유전적 다양성과 유연관계를 SSR마커로 분석하여 콩 육종의 유전적 변이 확대를 위한 기초자료로 이용하고자 수행한 연구결과를 요약하면 다음과 같다. 1. 한국 야생콩 67종, 일본 야생콩 71종 및 중국 지린성의 야생콩 46종을 포함한 총 184종을 23개의 SSR마커로 유전적 다양성과 유연관계를 분석한 결과, 총 964개의 대립인자가 확인되었고, 평균 41.9개의 대립인자가 확인되었다. SSR마커별로 대립인자 수는 최소 23개(Satt635)에서 최대 56개(Satt157)까지 확인되었으며, PIC 값의 범위는 0.880~0.968로 평균 0.945이었다. 2. 한국 야생콩은 대립인자의 수는 총 513개이었고 평균 22.3개 이었으며, 일본 야생콩은 대립인자의 수는 총 511개이었고 평균 22.2개이었으며, 중국 지린성 야생콩의 대립인자의 수는 총 312개 이었으며 평균 13.6개이었다. 평균 유전적 다양성(PIC 값)은 한국 야생콩이 0.905, 일본 야생콩이 0.897 및 중국 지린성의 야생콩이 0.850로서 큰 차이가 없었다. 3. 한국, 일본 및 중국 지린성의 야생콩들은 SSR마커를 이용한 유전적 거리에 따른 군집분석에서 3그룹으로 구분되었다. I그룹은 중국 지린성의 야생콩만이 분포하였고, II그룹은 대부분이 일본의 야생콩이 분포하였는데 한국의 야생콩 5종이 포함되었으며, III그룹은 대부분이 한국의 야생콩이 분포하였으며 일본의 야생콩 6종과 중국 지린성의 야생콩 1종이 포함되었다. I그룹은 동일그룹 내에서 다른 군이 형성되지 않았으나, II그룹과 III그룹은 동일그룹 내에서 각각 몇 개의 군으로 분류되었다. 4. SSR마커에 의한 유연관계는 한국과 일본의 야생콩 간의 유전적 거리가 한국과 중국 지린성 및 일본과 중국 지린성의 야생콩 간의 유전적 거리보다 더 가까웠다.

• 한국의류학회지
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• 제29권7호
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• pp.978-986
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• 2005

The color of apparel products have a close relationship with the face skin colors of consumers. In order to extract the favorable colors which flatter to consumer's face skin colors, this study was carried our to classify the face skin colors of Korean females. The criteria that select new subjects who have the classified face skin colors have to be decided. With color spectrometer, JX-777, face skin colors of subjects were measured and classified into three clusters that had similar hue, value and chroma with Munsell Color System. Sample size was 324 Korean females and other new 10 college girls. Data were analyzed by K-means cluster analysis, ANOVA, Duncan multiple range test, Stepwise discriminant analysis using SPSS Win. 12. Findings were as follows: 1. 324 subjects who have YR colors were clustered into 3 face skin color groups. 2. Discriminant variables of face skin colors were 5 variables : b value of cheek, V value of forehead, L value of cheek, C value of forehead and H value of cheek by the standardized canonical discriminant function coefficient 1. 3. Hit ratio of type 1 was $96.8\%$, of type 2 was $94.9\%$, of type 3 was $100.0\%$ and mean of hit ratio was $96.9\%$ by canonical discriminant function of 5 variables. 4. With the unstandardized canonical discriminant function coefficient and constant, canonical discriminant function equation 1 and 2 were calculated. And cutting score and range of score of the classified types were computed. The criteria that select the new subjects were decided.