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Tensile Force Estimation of Externally Prestressed Tendon Using SI technique Based on Differential Evolutionary Algorithm (차분 진화 알고리즘 기반의 SI기법을 이용한 외부 긴장된 텐던의 장력추정)

  • Noh, Myung-Hyun;Jang, Han-Taek;Lee, Sang-Youl;Park, Taehyo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.29 no.1A
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    • pp.9-18
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    • 2009
  • This paper introduces the application of DE (Differential Evolutionary) method for the estimation of tensile force of the externally prestressed tendon. The proposed technique, a SI (System Identification) method using the DE algorithm, can make global solution search possible as opposed to classical gradient-based optimization techniques. The numerical tests show that the proposed technique employing DE algorithm is a useful method which can detect the effective nominal diameters as well as estimate the exact tensile forces of the externally prestressed tendon with an estimation error less than 1% although there is no a priori information about the identification variables. In addition, the validity of the proposed technique is experimentally proved using a scale-down model test considering the serviceability state condition without and with the loss of the prestressed force. The test results prove that the technique is a feasible and effective method that can not only estimate the exact tensile forces and detect the effective nominal diameters but also inspect the damping properties of test model irrespective of the loss of the prestressed force. The 2% error of the estimated effective nominal diameter is due to the difference between the real tendon diameter with a wired section and the FE model diameter with a full-section. Finally, The accuracy and superiority of the proposed technique using the DE algorithm are verified through the comparative study with the existing theories.

A Comparative Study on the Awareness of between Students and Teachers on the Actual Condition of career Guidance at Vocational High Schools (전문계 고교 진로지도 실태에 대한 학생과 교원의 인식 비교 연구)

  • Lee, Byung-Wook;Jung, Hyun-Ok;Lee, Chan-Joo
    • 대한공업교육학회지
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    • v.37 no.1
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    • pp.87-106
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    • 2012
  • The purpose of this research is to provide basic materials in developing an efficient career guidance method of Vocational High Schools on the basis of analyzing awareness differences in students, teachers and between students and teachers as well as awareness differences according to a position of teachers in terms of the actual condition of career guidance and improvements with the target of students and teachers at Vocational High Schools. The survey was carried out by targeting students and teachers at Vocational High Schools in the Seoul Metropolis. The results of this research are as follows. First, it appeared that the awareness of students on the career guidance level of Vocational High Schools is insufficient, and students answered that employment guidance is more insufficient compared to educational guidance. In addition, the awareness of students on the career guidance conditions appeared to be generally insufficient. Second, in case of awareness of teachers on the career guidance conditions of Vocational High Schools, teachers answered that arrangement of teachers in full charge of career guidance, career counselling room, securing and utilization of latest career information and information search systems capable of using the internet for career guidance are sufficient, whereas they answered that time for career guidance, operating budget of a career counselling room and linkage with external institutions are insufficient. Third, they answered that career guidance conditions are generally sufficient in the order of a principal, vice-principal and teachers. The principal is cognizing that career guidance conditions are sufficient all question items, and the vice-principal answered that career guidance conditions are insufficient in only operating budget of a career counselling room and linkage with external institutions. Teachers answered that career guidance conditions are insufficient in only time for career guidance, operating budget of a career counselling room and linkage with external institutions. In addition, compared to teachers, the principal was cognizing that career guidance conditions are sufficient except operating budget of the career counselling room through analysis of awareness difference among principle, vice-principle and teachers. Fourth, students answered that career guidance conditions are insufficient in all question items, but teachers cognized that career guidance conditions are sufficient in all question items excluding time for career guidance. Among them, what showed a difference of the biggest awareness was analyzed as information search systems capable of using the Internet.

Reviews of Radiation Protection and Shielding for Computed Tomography in Foreign Countries (외국의 컴퓨터 단층촬영 장치의 방어시설 문헌 조사)

  • Jahng, Geon-Ho;Yang, Dal-Mo;Sung, Dong-Wook;Lee, Kwang-Yong;Kim, Hyeog-Ju
    • Progress in Medical Physics
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    • v.19 no.4
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    • pp.276-284
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    • 2008
  • A computed tomography (CT) is a powerful system for the effectively fast and accurate diagnosis. The CT system, therefore, has used substantially and developed for improving the performance over the past decade, resulting in growing concerns over the radiation dose from the CT. Advanced CT techniques, such as a multidetector row CT scanner and dual energy or dual source CT, have led to new clinical applications that could result in further increases of radiation does for both patients and workers. The objective of this study was to review the international guidelines of the shielding requirements for a CT facility required for a new installation or when modifying an existing one. We used Google Search Engine to search the following keywords: computed tomography, CT regulation or shield or protection, dual energy or dual source CT, multidetector CT, CT radiation protection, and regulatory or legislation or regulation CT. In addition, we searched some special websites, that were provided for sources of radiation protection, shielding, and regulation, RSNA, AAPM, FDA, NIH, RCR, ICRP, IRPA, ICRP, IAEA, WHO (See in Table 1 for full explanations of the abbreviations). We finally summarized results of the investigated materials for each country. The shielding requirement of the CT room design was very well documented in the countries of Canada, United States of America, and United Kingdom. The wall thickness of the CT room could be obtained by the iso-exposure contour or the point source method. Most of documents provided by international organizations were explained in importance of radiation reduction in patients and workers. However, there were no directly-related documents of shielding and patient exposure dose for the dual energy CT system. Based international guidelines, the guideline of the CT room shielding and radiation reduction in patients and workers should be specified for all kinds of CT systems, included in the dual energy CT. We proposed some possible strategies in this paper.

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A study on 'audience participation' of contemporary theatre in 'Sleep No More" of Punchdrunk (동시대 공연에 나타나는 '관객 참여'방식 연구 - 런던 펀치드렁크(Punchdrunk)극단의 를 중심으로)

  • Jeon, Yunkyung
    • (The) Research of the performance art and culture
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    • no.32
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    • pp.651-700
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    • 2016
  • The keyword of contemporary art in 21st is audience participation. London has emphasized the importance of audience participation since 2000. The National Theater of London is trying a new method, which is live performance to search new audiences. Also, they are trying to cross the boundaries between 'stage' and 'spectator'. This leads the other theaters to search new audiences and try new genre of performance. Therefore, they establish a new form of performance, which is that audience actively moves and find a new story in a theater. For example, "environmental theater" is the one. This theater escapes from the traditional stage, but it is based on "site-specific performance." Lots of new forms of theater have emerged. In this study, I focused on one of these new forms of theater, which is "Punchdrunk." "Punchdrunk" was founded by few students graduated from London University's Laban Center in 1999. They started at an empty stage in small school with only three audiences. 7 years after, it became one of major theaters in London. 10 years after, it showed their performances in the United state. Since then, their performances in New York have never been stopped. More strikingly, for last decades, this theater has been always full. In this study, I reasoned that the key of "Punchdrunk" success is audience participation. Therefore, I investigated the features of Punchdrunk theater and how they engage their audience in this performance. In this study, I focused on one of their performances, . Also, I categorized the audiences in three different ways: narrative visitor, walking visitor, and engaging visitor with mask. Three-part transition of Disney Theme Park from Louis Marin was applied to study "narrative visitor." For "walking visitor", Normadism from Gilles Deleuze was applied. For "engaging visitor with mask", Voyeurism was applied.

Digital Archives of Cultural Archetype Contents: Its Problems and Direction (디지털 아카이브즈의 문제점과 방향 - 문화원형 콘텐츠를 중심으로 -)

  • Hahm, Han-Hee;Park, Soon-Cheol
    • Journal of the Korean BIBLIA Society for library and Information Science
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    • v.17 no.2
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    • pp.23-42
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    • 2006
  • This is a study of the digital archives of Culturecontent.com where 'Cultural Archetype Contents' are currently in service. One of the major purposes of our study is to point out problems in the current system and eventually propose improvements to the digital archives. The government launched a four-year project for developing the cultural archetype content sources and establishing its related business with the hope of enhancing the nation's competitiveness. More specifically, the project focuses on the production of source materials of cultural archetype contents in the subjects of Korea's history. tradition, everyday life. arts and general geographical books. In addition, through this project, the government also intends to establish a proper distribution system of digitalized culture contents and to control copyright issues. This paper analyzes the digital archives system that stores the culture content data that have been produced from 2002 to 2005 and evaluates the current system's weaknesses and strengths. The summary of our findings is as follows. First. the digital archives system does not contain a semantic search engine and therefore its full function is 1agged. Second, similar data is not classified into the same categories but into the different ones, thereby confusing and inconveniencing users. Users who want to find source materials could be disappointed by the current distributive system. Our paper suggests a better system of digital archives with text mining technology which consists of five significant intelligent process-keyword searches, summarization, clustering, classification and topic tracking. Our paper endeavors to develop the best technical environment for preserving and using culture contents data. With the new digitalized upgraded settings, users of culture contents data will discover a world of new knowledge. The technology we introduce in this paper will lead to the highest achievable digital intelligence through a new framework.

Comparative analysis of RN-BSN Program in Korea and U. S. A. (간호학사 편입학제도의 교과과정 비교분석)

  • Lee Ok-Ja;Kim Hyun-Sil
    • The Journal of Korean Academic Society of Nursing Education
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    • v.3
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    • pp.99-116
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    • 1997
  • In response of the increasing demand for professional degree in nursing, some university in Korea offers RN-BSN program for R. N. from diploma in nursing. However, RN-BSN program in Korea is in formative period. Therefore, the purpose of this survey study is for the comparative analysis of RN-BSN curriculum in Korea and U.S.A. In this study, subjects consisted of 18 department of nursing in university and 5 RN-BSN programs in Korea and 18 department of nursing in university and 12 RN-BSN programs in U.S.A. For earn the degree of Bachelor of Science in Nursing, the student earns 134 of mean credits in U.S.A., whereas 150.3 of mean credits in Korea. The mean credit for clinical pratice is 30.1 in U.S.A., whereas 23.9 in Korea. Students are assigned to individually planned clinical experiences under the direction of a preceptor in U.S.A. In RN-BSN program, total mean credits through lecture and clinical practice for earn the degree of BSN is 35.5(lecture : 27.7, practice ; 7.8)in U.S.A., whereas,48.1 (lecture;42.1, practice;6.0) in Korea. RN-BSN program can be taken on a full-or-part time basis in U.S.A., whereas didn't in Korea. Especially, emphasis is place on the advanced nursing practicum that focus on the role of the professional nurse in providing health care to individuals, families, and groups in community setting in U.S.A. 27.7 of mean credits was earned through lecture in U.S.A., whereas 42.1 of mean credits in Korea. It means that RN-BSN program in Korea is the lesser development in teaching method and appraisal method than in U.S.A. Students of RN-BSN program in U.S.A. can earns credit through CLEP, NLN achievement test, portfolio review session etc as well as lecture. Therefore, the authors suggests some recommendations for the development of curriculum of RN-BSN program in Korea based on comparative analysis of RN-BSN curricula in U.S.A. and Korea. 1. The curriculum of RN-BSN Program in nursing was required to do some alterations. Nursing care, today, is complex and ever changing. According to change of public need, RN-BSN curriculum intensified primary care program in community setting, geriatric nursing, marketing skill, computer language. 2. The various and new methods of earning credit should be developed. That is, the students will earn credits through the transfer of previous nursing college credits, accredited examination of university, advanced placement examination, portfolio review session, case study, report, self-directed learning and so on. Flexible teaching place should ile offered. 3. Flexible teaching place should be offered. The RN-BSN curriculum should accommodate each RN student's geographical needs and school/work schedule. Therefore, the university should search a variety of teaching places and the RN students can obtain their degrees comfortably throughout the teaching place such as lecture room inside the health care agency and establishment of the branch school in each student's residence area. 4. The RN-BSN program should offer a long distance education to place-bound RN student in many parts of Korea. That is, from the main office of university, the RN-BSN courses are delivered to many areas by Internet, EdNet (satellite telecommunication) and other non-traditional methods. 5. For allowing RN student to take nursing courses, program length should be various, depending upon the student's study/work schedule. That is, the various term systems such as semester, three terms, quarter systems and the student's status like full time or part time should be considered. Therefore, the student can take advantage of the many other educational and professional opportunities, making them available during the school year.

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Analysis of Real State and Effect of Assistance Activity for Middle School Career Education by Gyeonggi-do Vocational High Schools (경기도 직업계고 제공 중학교 진로교육 지원 활동 실태 및 효과 분석)

  • Lee, Chan Joo;Hyun, Su;So, Jun young
    • 대한공업교육학회지
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    • v.44 no.1
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    • pp.72-93
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    • 2019
  • The purpose of this study was to provide basic data needed to establish a system of career education which can offer necessary information for middle school students to select vocational high schools suiting to their talent and aptitude. For this, the study formulated research questions: how middle school students in Gyeonggi-do could acquire information related with entering high school; their level of understanding about general high school and vocational high school and their level of information requirement; real state and effect (level of helping them choose future school) of assistance activity for career education as provided by vocational high schools. For the analysis, the study developed a questionnaire and conducted survey for 4,459 3rd graders from 627 middle schools at Gyeonggi-do. Findings were as follows. First, methods of middle school students getting information related with entering high school turned out in the order of internet search (42.0%), consultation with family and friends (25.5%), consultation with teachers (24.0%). While, their methods of getting information related with entering vocational high school turned out in the order of briefing session by vocational high schools (39.4%), field trip to vocational high schools (24.9%), consultation with teachers from vocational high schools (15.7%). Second, the level of understanding (five points full marks) of Gyeonggi-do middle school students about high school by the type they wished to enter, and the level of information requirement (five points full marks) turned out 3.65 and 3.67 respectively for students who wished to enter general high schools, with the difference being 0.02. On the other hand, the level of understanding and that of information requirement turned out 2.92 and 3.25 respectively with the difference being 0.33, for students who wished to enter vocational high schools. Third, looking at the real state of participation of Gyeonggi-do middle school students in assistance activities for career education provided by vocational high schools, 79.4% of all students were participating. Activity with high participation ratio out of these turned out to be in the order of PR and guide book (booklet, brochure, etc.) for vocational high schools at 90.3%, briefing session prepared by vocational high schools on visit at 87.8% and video of vocational high school PR and introduction at 85.9%. The level of how these activities helped middle school students choose their high school was 3.45, showing more effect by 0.13 on students wishing to enter vocational high schools compared to those wishing to enter general high schools.

A New Approach to Automatic Keyword Generation Using Inverse Vector Space Model (키워드 자동 생성에 대한 새로운 접근법: 역 벡터공간모델을 이용한 키워드 할당 방법)

  • Cho, Won-Chin;Rho, Sang-Kyu;Yun, Ji-Young Agnes;Park, Jin-Soo
    • Asia pacific journal of information systems
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    • v.21 no.1
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    • pp.103-122
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    • 2011
  • Recently, numerous documents have been made available electronically. Internet search engines and digital libraries commonly return query results containing hundreds or even thousands of documents. In this situation, it is virtually impossible for users to examine complete documents to determine whether they might be useful for them. For this reason, some on-line documents are accompanied by a list of keywords specified by the authors in an effort to guide the users by facilitating the filtering process. In this way, a set of keywords is often considered a condensed version of the whole document and therefore plays an important role for document retrieval, Web page retrieval, document clustering, summarization, text mining, and so on. Since many academic journals ask the authors to provide a list of five or six keywords on the first page of an article, keywords are most familiar in the context of journal articles. However, many other types of documents could not benefit from the use of keywords, including Web pages, email messages, news reports, magazine articles, and business papers. Although the potential benefit is large, the implementation itself is the obstacle; manually assigning keywords to all documents is a daunting task, or even impractical in that it is extremely tedious and time-consuming requiring a certain level of domain knowledge. Therefore, it is highly desirable to automate the keyword generation process. There are mainly two approaches to achieving this aim: keyword assignment approach and keyword extraction approach. Both approaches use machine learning methods and require, for training purposes, a set of documents with keywords already attached. In the former approach, there is a given set of vocabulary, and the aim is to match them to the texts. In other words, the keywords assignment approach seeks to select the words from a controlled vocabulary that best describes a document. Although this approach is domain dependent and is not easy to transfer and expand, it can generate implicit keywords that do not appear in a document. On the other hand, in the latter approach, the aim is to extract keywords with respect to their relevance in the text without prior vocabulary. In this approach, automatic keyword generation is treated as a classification task, and keywords are commonly extracted based on supervised learning techniques. Thus, keyword extraction algorithms classify candidate keywords in a document into positive or negative examples. Several systems such as Extractor and Kea were developed using keyword extraction approach. Most indicative words in a document are selected as keywords for that document and as a result, keywords extraction is limited to terms that appear in the document. Therefore, keywords extraction cannot generate implicit keywords that are not included in a document. According to the experiment results of Turney, about 64% to 90% of keywords assigned by the authors can be found in the full text of an article. Inversely, it also means that 10% to 36% of the keywords assigned by the authors do not appear in the article, which cannot be generated through keyword extraction algorithms. Our preliminary experiment result also shows that 37% of keywords assigned by the authors are not included in the full text. This is the reason why we have decided to adopt the keyword assignment approach. In this paper, we propose a new approach for automatic keyword assignment namely IVSM(Inverse Vector Space Model). The model is based on a vector space model. which is a conventional information retrieval model that represents documents and queries by vectors in a multidimensional space. IVSM generates an appropriate keyword set for a specific document by measuring the distance between the document and the keyword sets. The keyword assignment process of IVSM is as follows: (1) calculating the vector length of each keyword set based on each keyword weight; (2) preprocessing and parsing a target document that does not have keywords; (3) calculating the vector length of the target document based on the term frequency; (4) measuring the cosine similarity between each keyword set and the target document; and (5) generating keywords that have high similarity scores. Two keyword generation systems were implemented applying IVSM: IVSM system for Web-based community service and stand-alone IVSM system. Firstly, the IVSM system is implemented in a community service for sharing knowledge and opinions on current trends such as fashion, movies, social problems, and health information. The stand-alone IVSM system is dedicated to generating keywords for academic papers, and, indeed, it has been tested through a number of academic papers including those published by the Korean Association of Shipping and Logistics, the Korea Research Academy of Distribution Information, the Korea Logistics Society, the Korea Logistics Research Association, and the Korea Port Economic Association. We measured the performance of IVSM by the number of matches between the IVSM-generated keywords and the author-assigned keywords. According to our experiment, the precisions of IVSM applied to Web-based community service and academic journals were 0.75 and 0.71, respectively. The performance of both systems is much better than that of baseline systems that generate keywords based on simple probability. Also, IVSM shows comparable performance to Extractor that is a representative system of keyword extraction approach developed by Turney. As electronic documents increase, we expect that IVSM proposed in this paper can be applied to many electronic documents in Web-based community and digital library.

An Evaluation on the Operating of Fisheries Extension Services (어촌지도사업의 평가)

  • 최정윤
    • The Journal of Fisheries Business Administration
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    • v.17 no.2
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    • pp.65-106
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    • 1986
  • 1, The Purpose of Study This is a study on the Evaluation of the operating of Fisheries Extension Services of Korea, for performing the activities such as guiding fisheries technique as well as offering industrial information to the fishermen in fishing village. By doing so, the Fisheries Extension Sevices(FES) can materialize the continued growth of fisheries, the social and economic development of fishing village, and the increase in income by enhancing the knowledge level of Fishermen, etc. In performing fisheries policy, this activity plays a great role on the research and development activity, and it has become practical since 1976 in Korea. In order to meet immediately with the problem of fisheries technical innovation and rapid environmental changes surrounding the fisheries, the fishermen should not only enhance their scientific and comprehensive capacity in fisheries technique but abtain various effective information. Generally, as most of all the fishemen are poor in the managerial structure and scattered in fishing villages, they have little opportunity in the contact of information. As a result, it is nessessary for the FES to perform the fishing business by the extension service officials who has received special training and acquired fisheries know-how in these fields. And yet, FES is under the unfullfilled circumstance in such factors as manpower, technical know-how, equipment, and the service system etc., which is required in promoting the social, economic development of fishing village and in resolving the high technique demand of fisherman. This study on the fisheries extension services have been studied from those backgrounds. 2. Research Method The data of collecting methods which were necessary in carrying out this study was adopted by the questionaire research on the present extension service activity, through the subject of the extension services (driving agency of the work and the officials), the object(fishemen) and the 3rd observers to the extension services (the authorities concerned). The research sample was taken by the sampling extraction of total 1, 774 men from the above 3 groups. And the research was carried out from August, 1986 to October, 1986, supported from the Fisheries Extension Office (FEO) located in field during the research process. In this study, the levels of the extension operating were determined and estimated in accordance with the extension service method, morale of extension service officials and the extension service system, etc. through the collected data of the research questionaire paper. And based on this result, the essential conditions of the extension services were grasped, and also we tried to present the various activity plan necessary to promote the operating of the extension services. The questionaire research data was calculated by the computer center of National Fisheries University of Pusan, and the total result was again tried on the one demension analysis along with two dimension analysis to search out the relativity between the questionaire, and the statistical test was done $\chi$$^2$test in significance level of l~5%. 3. Contents of Study This study consists of 7 chapters and the contents are as follows : Chapter I : The object and method of the study Chapter II : The assessment and analysis of the extension services Chapter III : The contents and method of the extension services Chapter IV : Analysis of the essential conditions for the extension services Chapter V : The evaluation of activities of extension services Chapter Ⅵ : Conclusion.4. Results and RecommendationTherefore, the results of this study estimated by logical process and analysis are as follows : 1) Most of Korean fishing villages and coastal fishermen have shown much concerns about fisheries technique and social changes, thus many of them were confronted with new problems on how to adapt and to meet changes. 2) Majority of fishermen estimated FEO as an organization of specific technologies with all the thing concerning the fisheries technique in general. Therefore the fishermen wanted to utilize the FEO as an adaptable method for the modern fisheries techniques as well as the environmental changes. 3) In contrast with the fast changes of the fisheries technique, the complexity and variety of technical system and the broadness of fishing village and fishermen, it was revealed that the necessary factors such as the facilities, manpower, budget, and the level of applying techniques of the FEO located in field were highly insufficient. Accordingly, the guiding efficiency was low and the extension services did not provide full solution to the various request from fishermen. 4) It is possible to classify the activation factor for the extension service into two large dimension ; personal dimension relevant to guidance officials and work dimension relevant to the organization. And it was found that the activation level of the work dimension was far lower than the personal dimension between them. So, the activation should be done first in the dimesion to promote the activation of the extension services. 5) The extension services officials are now demoralized in general, thus it is necessary to take reality into consideration : the expense of activity, the adequate endowment of activity scope and the reasonable operation of the position class, etc to enhance its morale. However, in order to do the FES activation, first of all, the systems should be established which is lain unsettled stage until now. And there must be change in the understanding of government i.e. the fisheries extension services are the essential policy subject to build up the base of fisheries growth and modernize the fisheries management. And it should be driven positively with the recognition of the "lasting project".g project".uot;.

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A Literature Review and Classification of Recommender Systems on Academic Journals (추천시스템관련 학술논문 분석 및 분류)

  • Park, Deuk-Hee;Kim, Hyea-Kyeong;Choi, Il-Young;Kim, Jae-Kyeong
    • Journal of Intelligence and Information Systems
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    • v.17 no.1
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    • pp.139-152
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    • 2011
  • Recommender systems have become an important research field since the emergence of the first paper on collaborative filtering in the mid-1990s. In general, recommender systems are defined as the supporting systems which help users to find information, products, or services (such as books, movies, music, digital products, web sites, and TV programs) by aggregating and analyzing suggestions from other users, which mean reviews from various authorities, and user attributes. However, as academic researches on recommender systems have increased significantly over the last ten years, more researches are required to be applicable in the real world situation. Because research field on recommender systems is still wide and less mature than other research fields. Accordingly, the existing articles on recommender systems need to be reviewed toward the next generation of recommender systems. However, it would be not easy to confine the recommender system researches to specific disciplines, considering the nature of the recommender system researches. So, we reviewed all articles on recommender systems from 37 journals which were published from 2001 to 2010. The 37 journals are selected from top 125 journals of the MIS Journal Rankings. Also, the literature search was based on the descriptors "Recommender system", "Recommendation system", "Personalization system", "Collaborative filtering" and "Contents filtering". The full text of each article was reviewed to eliminate the article that was not actually related to recommender systems. Many of articles were excluded because the articles such as Conference papers, master's and doctoral dissertations, textbook, unpublished working papers, non-English publication papers and news were unfit for our research. We classified articles by year of publication, journals, recommendation fields, and data mining techniques. The recommendation fields and data mining techniques of 187 articles are reviewed and classified into eight recommendation fields (book, document, image, movie, music, shopping, TV program, and others) and eight data mining techniques (association rule, clustering, decision tree, k-nearest neighbor, link analysis, neural network, regression, and other heuristic methods). The results represented in this paper have several significant implications. First, based on previous publication rates, the interest in the recommender system related research will grow significantly in the future. Second, 49 articles are related to movie recommendation whereas image and TV program recommendation are identified in only 6 articles. This result has been caused by the easy use of MovieLens data set. So, it is necessary to prepare data set of other fields. Third, recently social network analysis has been used in the various applications. However studies on recommender systems using social network analysis are deficient. Henceforth, we expect that new recommendation approaches using social network analysis will be developed in the recommender systems. So, it will be an interesting and further research area to evaluate the recommendation system researches using social method analysis. This result provides trend of recommender system researches by examining the published literature, and provides practitioners and researchers with insight and future direction on recommender systems. We hope that this research helps anyone who is interested in recommender systems research to gain insight for future research.