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Recent Progress in Air Conditioning and Refrigeration Research - A Review of Papers Published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2002 and 2003 - (공기조화, 냉동 분야의 최근 연구 동향 -2002년 및 2003년 학회지 논문에 대한 종합적 고찰 -)

  • Chung Kwang-Seop;Kim Min Soo;Kim Yongchan;Park Kyoung Kuhn;Park Byung-Yoon;Cho Keumnam
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.16 no.12
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    • pp.1234-1268
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    • 2004
  • A review on the papers published in the Korean Journal of Air-Conditioning and Refrigerating Engineering in 2002 and 2003 has been carried out. Focus has been put on current status of research in the aspect of heating, cooling, air-conditioning, ventilation, sanitation and building environment/design. The conclusions are as follows. (1) Most of fundamental studies on fluid flow were related with heat transportation in diverse facilities. Drop formation and rivulet flow on solid surfaces were interesting topics related with condensation augmentation. Research on micro environment considering flow, heat transfer, humidity was also interesting to promote comfortable living environment. It can be extended considering biological aspects. Development of fans and blowers of high performance and low noise were continuing research topics. Well developed CFD technologies were widely applied for analysis and design of various facilities and their systems. (2) Heat transfer characteristics of enhanced finned tube heat exchangers and heat sinks were extensively investigated. Experimental studies on the boiling heat transfer, vortex generators, fluidized bed heat exchangers, and frosting and defrosting characteristics were also conducted. In addition, the numerical simulations on various heat exchangers were performed and reported to show heat transfer characteristics and performance of the heat exchanger. (3) A review of the recent studies shows that the performance analysis of heat pump have been made by various simulations and experiments. Progresses have been made specifically on the multi-type heat pump systems and other heat pump systems in which exhaust energy is utilized. The performance characteristics of heat pipe have been studied numerically and experimentally, which proves the validity of the developed simulation programs. The effect of various factors on the heat pipe performance has also been examined. Studies of the ice storage system have been focused on the operational characteristics of the system and on the basics of thermal storage materials. Researches into the phase change have been carried out steadily. Several papers deal with the cycle analysis of a few thermodynamic systems which are very useful in the field of air-conditioning and refrigeration. (4) Recent studies on refrigeration and air-conditioning systems have focused on the system performance and efficiency enhancement when new alternative refrigerants are applied. Heat transfer characteristics during evaporation and condensation are investigated for several tube shapes and new alternative refrigerants including natural refrigerants. Efficiency of various compressors and performance of new expansion devices are also dealt with for better design of refrigeration/air conditioning system. In addition to the studies related with thermophysical properties of refrigerant mixtures, studies on new refrigerants are also carried out. It should be noted that the researches on two-phase flow are constantly carried out. (5) A review of the recent studies on absorption refrigeration system indicates that heat and mass transfer enhancement is the key factor in improving the system performance. Various experiments have been carried out and diverse simulation models have been presented. Study on the small scale absorption refrigeration system draws a new attention. Cooling tower was also the research object in the respect of enhancement its efficiency, and performance analysis and optimization was carried out. (6) Based on a review of recent studies on indoor thermal environment and building service systems, it is noticed that research issues have mainly focused on several innovative systems such as personal environmental modules, air-barrier type perimeterless system with UFAC, radiant floor cooling system, etc. New approaches are highlighted for improving indoor environmental conditions and minimizing energy consumption, various activities of building energy management and cost-benefit analysis for economic evaluation.

Factors Associated with Conversion from Conservative to Surgical Treatment in Single-Level Lumbar Spinal Stenosis Patients (보존적 치료 중인 단분절 요추관 협착증 환자에서 수술적 치료로 전환과 관련된 연관 인자)

  • Ahn, Young-Joon;Im, Se-Hyuk;Park, Byung-Kyu
    • Journal of Korean Society of Spine Surgery
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    • v.25 no.4
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    • pp.160-168
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    • 2018
  • Study Design: Retrospective study of prospectively-collected data. Objectives: To determine the factors associated with conversion from conservative to surgical treatment in single-level lumbar spinal stenosis patients. Summary of Literature Review: Various reports have presented clinical outcomes after the surgical and nonsurgical treatment of spinal stenosis. However, few reports have investigated factors predicting conversion to surgery during the course of conservative treatment. Materials and Methods: We analyzed 40 patients who visited our hospital from May 2010 to May 2015 and were traceable for at least 3 years after being advised to undergo surgery following 3 months of conservative treatment. Of these patients, 20 underwent surgery and 20 did not. We then investigated the factors associated with conversion to surgical treatment. Clinical assessments were conducted using a questionnaire, and the overall area of the spinal canal and the muscle area within the spinal canal were measured using magnetic resonance imaging. Results: The average area of the spinal canal was $81.40{\pm}53.61mm^2$ in the surgical group, compared to $127.75{\pm}82.55mm^2$ in the nonsurgical group (p=0.042). The muscle area in the spinal canal was $5.17{\pm}1.30cm^2$ in the surgical group, whereas it was $6.40{\pm}1.56cm^2$ in the nonsurgical group (p=0.010). The patients in the surgical group were more likely to have experienced repetitive strain and to have frequently visited health clubs (p=0.047, p=0.037, respectively). However, regular stretching was more common in the nonsurgical group (p=0.028). Conclusions: The factors associated with conversion to surgical treatment were a narrow spinal canal, a small muscle area within the spinal canal, visiting health clubs, repetitive sprain, and not stretching. A small muscle area within the spinal canal can be considered as a key factor related to surgical conversion.

Development and Complementation of Evaluation Area and Content Elements in Electrical, Electronics and Communications Subject (중등교사 임용후보자선정경쟁시험 표시과목인 전기·전자·통신의 평가영역 및 내용요소 개발·보완 연구)

  • Song, Youngjik;Kang, Yoonkook;Cho, Hanwook;Gim, Seongdeuk;Lim, Seunggak;Lee, Hyuksoo
    • 대한공업교육학회지
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    • v.44 no.1
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    • pp.52-71
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    • 2019
  • The quality of school education is a key element for national education development. An important factor that determines the quality of school education is qualities of teachers who are in responsible for school education in the field. Therefore, it is necessary to hire competent teachers in the teacher appointment exam for the secondary school. This necessity is evident especially for vocational high schools and Meister high schools with the introduction of 2015-revised curriculum based on NCS that separates each three subjects, "Electrical, Electronics Communication" resulting in the change of question mechanism, which requires new designing of assessment and content area. So, this study analyzes curriculum in college of education for "Electrical", "Electronics", "Communication", 2015-revised curriculum based on NCS and the development of standards for teacher qualifications and assessment area and evaluation of teaching ability in the subjects of the teacher appointment exam, "Electrical, Electronics Communication" Engineering" in 2009. The assessment area and content elements of "Electrical", "Electronics", "Communication are extracted from the analyzed results and they are verified by experts' consultation and presented as follows; First, the assessment area and content elements of the "Electrical" subject were designed to evaluate the NCS - based 2015 revised curriculum by presenting the NCS learning module to the evaluation area and content element in the basic subject "Electrical and Electronics Practice". Second, the section of "Electronics" presented the assessment area and content elements applying the Electronic Circuit, basic subject of the NCS and it also added "Electromagnetics", which is the basic part of Electronics in the Application of Electromagnetic waves that could be applied to the assessment. Third, the assessment area and content elements of "Communication" consist of the communication-related practice that is based on "Electrical" and "Electronic", considering the characteristics of "Communication Engineering". In particular, "Electrical and Electronics practice" which adds network construction practice and communication-related practice makes it to be able to evaluate the communication-related practical education.

Validation of Korean Diagnostic Scale of Multiple Intelligence (한국형 다중지능 진단도구의 타당화)

  • Moon, Yong-Lin;Yu, Gyeong-Jae
    • (The) Korean Journal of Educational Psychology
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    • v.23 no.3
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    • pp.645-663
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    • 2009
  • The purpose of this study is to develop and verify a Korean Diagnostic Scale of Multiple Intelligence(MI), which will be an alternative test to avoid problems with former Shearer's MI test and to adopt H. Gardner's suggestions to develop MI assessment. The test is developed 5 types; kindergartner, elementary lower grader, elementary upper grader, middle schooler, high schooler test. A form of test is diversified with 3 types; multiple-choice items for accomplishment, true or false items for ability, and self-reported items with likert scale for interest and ability. According to H. Gardner's suggestions, we have tried to reanalyze key component of MI, analyze an overlapping or hierarchical relationship between intelligences, develop intelligences-fair items, diversify form of item. We have developed a final standardized test through a primary, secondary preliminary-test analysis, and sampled 5,585 students by age, gender, and regional groups. As a result of this sampling test, we can get a norm score and compare individuals with other's score relatively. To verify this test, we analyzed behavior observation, mean, standard deviation, a percentage of correct answers, reliability of each test type, correlation between intelligence scales, Kruskal-Wallis test of mean rank of career choice by intelligences. As a result of correlation analysis between sub-intelligence scales, we can conclude that this MI test is satisfied with intelligence independent assumption. Besides, as non-parametric statistics test(Kruskal-Wallis) of career choice by intelligences, we can identify that MI is related with domain of career choice. This test is not a linguistic and logical-mathematical biased test but a intelligences-fair test. It makes us compare individual's potential with a norm score. Besides, it could be useful as a means of educational prescription or counsel in comparison with ability, interest, and accomplishment of individual. But this test is limited to do factor or correlation analysis between types of sub-test, because items are minimized for a time-constraint and a heavy burden of test receiver. But if it could be tested with increased items by two sessions, further research could be expected to get over this constraints and do a further validation analysis.

Comparison of food involvement scale (FIS) and use intention for block type sauce between US and Japanese consumers (미국과 일본 소비자의 음식관여도와 블록형 소스에 대한 이용의도 비교 분석)

  • Lee, Hojin;Kim, Su Jin;Lee, Min A
    • Journal of Nutrition and Health
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    • v.51 no.6
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    • pp.590-598
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    • 2018
  • Purpose: This study was conducted to compare the food involvement scale (FIS) of American and Japanese consumers. In addition, the effects of familiarity, likability, and expectations on willingness to use intentions for block type sauce by nationality were evaluated. Methods: A total of 149 and 112 American and Japanese consumers, respectively, completed the survey. Consumers were asked about familiarity, likability, expectation, willing to use intention, and usage frequency of block type sauce, food involvement scale (FIS), and demographic information. Results: There were differences in the using frequency of block type sauce according to nationality, with consumers in Japan showing significantly higher frequency of using block type sauce than those in the United States (US) (p < 0.001). According to the FIS, US consumers were more focused on how to provide food than food, such as cooking process, table setting, and food shopping, compared to Japanese consumers. In addition, 'expectation' and 'likability' among US consumers and 'expectation' and 'familiarity' among Japanese consumers were positive attributes for willing to use intention (p < 0.01). Conclusion: In the case of the US consumers, 'familiarity' was not significant because the using frequency of the block type sauce was lower than that of Japanese consumers. In the case of the Japanese consumers, 'likability' was not significant because they enjoy cooking itself according to the FIS. Therefore, it is necessary to recognize positive attributes as a key factor for block type sauce, as well as to search for ways to apply marketing strategies based on attributes by nationality.

Prediction of a hit drama with a pattern analysis on early viewing ratings (초기 시청시간 패턴 분석을 통한 대흥행 드라마 예측)

  • Nam, Kihwan;Seong, Nohyoon
    • Journal of Intelligence and Information Systems
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    • v.24 no.4
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    • pp.33-49
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    • 2018
  • The impact of TV Drama success on TV Rating and the channel promotion effectiveness is very high. The cultural and business impact has been also demonstrated through the Korean Wave. Therefore, the early prediction of the blockbuster success of TV Drama is very important from the strategic perspective of the media industry. Previous studies have tried to predict the audience ratings and success of drama based on various methods. However, most of the studies have made simple predictions using intuitive methods such as the main actor and time zone. These studies have limitations in predicting. In this study, we propose a model for predicting the popularity of drama by analyzing the customer's viewing pattern based on various theories. This is not only a theoretical contribution but also has a contribution from the practical point of view that can be used in actual broadcasting companies. In this study, we collected data of 280 TV mini-series dramas, broadcasted over the terrestrial channels for 10 years from 2003 to 2012. From the data, we selected the most highly ranked and the least highly ranked 45 TV drama and analyzed the viewing patterns of them by 11-step. The various assumptions and conditions for modeling are based on existing studies, or by the opinions of actual broadcasters and by data mining techniques. Then, we developed a prediction model by measuring the viewing-time distance (difference) using Euclidean and Correlation method, which is termed in our study similarity (the sum of distance). Through the similarity measure, we predicted the success of dramas from the viewer's initial viewing-time pattern distribution using 1~5 episodes. In order to confirm that the model is shaken according to the measurement method, various distance measurement methods were applied and the model was checked for its dryness. And when the model was established, we could make a more predictive model using a grid search. Furthermore, we classified the viewers who had watched TV drama more than 70% of the total airtime as the "passionate viewer" when a new drama is broadcasted. Then we compared the drama's passionate viewer percentage the most highly ranked and the least highly ranked dramas. So that we can determine the possibility of blockbuster TV mini-series. We find that the initial viewing-time pattern is the key factor for the prediction of blockbuster dramas. From our model, block-buster dramas were correctly classified with the 75.47% accuracy with the initial viewing-time pattern analysis. This paper shows high prediction rate while suggesting audience rating method different from existing ones. Currently, broadcasters rely heavily on some famous actors called so-called star systems, so they are in more severe competition than ever due to rising production costs of broadcasting programs, long-term recession, aggressive investment in comprehensive programming channels and large corporations. Everyone is in a financially difficult situation. The basic revenue model of these broadcasters is advertising, and the execution of advertising is based on audience rating as a basic index. In the drama, there is uncertainty in the drama market that it is difficult to forecast the demand due to the nature of the commodity, while the drama market has a high financial contribution in the success of various contents of the broadcasting company. Therefore, to minimize the risk of failure. Thus, by analyzing the distribution of the first-time viewing time, it can be a practical help to establish a response strategy (organization/ marketing/story change, etc.) of the related company. Also, in this paper, we found that the behavior of the audience is crucial to the success of the program. In this paper, we define TV viewing as a measure of how enthusiastically watching TV is watched. We can predict the success of the program successfully by calculating the loyalty of the customer with the hot blood. This way of calculating loyalty can also be used to calculate loyalty to various platforms. It can also be used for marketing programs such as highlights, script previews, making movies, characters, games, and other marketing projects.

Correlation of Quality Characteristics of Soybean Cultivars and Whole Soymilk Palatability (콩 품종별 품질특성과 전두유 식미의 상관관계)

  • Lee, Ji Hae;Lee, Yu Young;Son, Yurim;Yeum, Kyung-Jin;Lee, Yoon-Mi;Lee, Byong Won;Woo, Koan Sik;Kim, Hyun-Joo;Han, Sangik;Lee, Byoung Kyu
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.63 no.4
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    • pp.322-330
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    • 2018
  • The correlation between the nutritional composition of soybeans and whole soymilk palatability was investigated using nine soybean cultivars (Teagwangkong, Daewonkong, Saedanback, Jinpung, Daechan, Miso, Cheongmiin, Cheongja 3, and Socheongja). Physicochemical analysis of soybeans, showed that the protein and lipid contents were 37.7-46.0 and 15.2-20.9%, respectively. Unsaturated fatty acids were 81.1-84.8% of total fatty acids, of which linoleic acids was 49.7-56.8%. Total tocopherol was $243.5-361.3{\mu}g/g$ of extract, of which ${\gamma}$-tocopherol was $67.14-86.49{\mu}g/g$. Total isoflavone contents varied within cultivars from $495.4-1,443.8{\mu}g/g$ of extract. Daidzin and genistin were 252.1-556.0 and $241.8-730.7{\mu}g/g$, respectively, which were major isoflavones in soybeans. For the sensory evaluation, whole soymilk was made from nine soybean cultivars and 20 panels investigate its palatability. The Daechan cultivar had the highest (9.1), and Cheongmiin the lowest (5.6), overall palatability score. Interestingly, sensory results were strongly correlated with linoleic acid (0.746) and stearic acid (-0.716) content. In summary, the fatty acid composition of soybeans is the key factor in determining the palatability of whole soymilk. This study could be applied to determine the suitability of cultivars for soybean products, including whole soymilk.

Reduction effects of N-acetyl-L-cysteine, L-glutathione, and indole-3-acetic acid on phytotoxicity generated by methyl bromide fumigation- in a model plant Arabidopsis thaliana (모델식물 애기장대에 대한 훈증제 메틸브로마이드의 약해발생 및 N-acetyl-L-cysteine, L-glutathione, indole-3-acetic acid의 약해억제 효과)

  • Kim, Kyeongnam;Kim, Chaeeun;Park, Jungeun;Yoo, Jinsung;Kim, Woosung;Jeon, Hwang-Ju;Kim, Jun-Ran;Lee, Sung-Eun
    • Korean Journal of Environmental Biology
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    • v.39 no.3
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    • pp.354-361
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    • 2021
  • Understanding the phytotoxic mechanism of methyl bromide (MB), an essential fumigant during the quarantine and pre-shipment process, is urgently needed to ensure its proper use and reduce international economic losses. In a previous study, two main MB-induced toxic mechanisms such as reactive oxygen species (ROS) and auxin distribution were selected by analyzing transcriptomic analysis. In the study, a 3-week-old A. thaliana was supplied with 1 mM ROS scavengers [N-acetyl-L-cysteine (NAC) or L-glutathione (GSH)] and 1µM indole-3-acetic acid(IAA) three times every 12 h, and visual and gene expression assessments were performed to evaluate the reduction in phytotoxicity by supplements. Phytotoxic effects on the MB-4h exposed group were decreased with GSH application compared to the other single supplements and a combination of supplements at 7 days post fumigation. Among these supplements, GSH at a concentration of 1, 2, and 5mM was suppled to A. thaliana with MB-fumigation. During a long-term observation of 2 weeks after the fumigation, 5 mM GSH application was the most effective in minimizing MB-induced phytotoxic effects with up-regulation of HSP70 expression and increase in main stem length. These results indicated that ROS was a main key factor of MB-induced phytotoxicity and that GSH can be used as a supplement to reduce the phytotoxicity of MB.

Soil Physical and Chemical Properties of Kaolinite Opencast Mines and Adjacent Red Pine Forests in Sancheong-gun (산청군 고령토(백토) 노천 광산 채굴지와 인접 소나무 임분의 토양 물리·화학적 성질)

  • Kim, Kyung Tae;Baek, Gyeongwon;Choi, Byeonggil;Ha, Jiseok;Kim, Choonsig
    • Journal of Korean Society of Forest Science
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    • v.109 no.4
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    • pp.382-389
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    • 2020
  • Soil properties in opencast mines are a key factor in reclamation (revegetation) of mining areas. In this study we determined the soil physical and chemical properties of kaolinite tailings, reclaimed areas, and adjacent natural red pine (Pinus densiflora S. et Z.) forests in kaolinite opencast mines in Sancheong-gun, Gyeongsangnam-do. Six sites were chosen for collection of soil samples to determine soil physical and chemical properties at a soil depth of 10 cm. Soil bulk density was significantly higher (P < 0.05) in the kaolinite tailings (1.51 g·cm-3) than in the reclaimed areas (1.19 g·cm-3) and red pine forests (0.93 g·cm-3), whereas air phase in the kaolinite tailings (14.2%) was significantly lower than in the red pine forests (32.6%). Clay content in the red pine forests was significantly higher than in the reclaimed areas (18.7%) or kaolinite tailings (14.8%), whereas soil structural stability index was significantly lower in the reclaimed areas (1.61%) and kaolinite tailings (0.87%) than in the red pine forests (7.75%). Soil pH was significantly higher in the kaolinite tailings (pH 6.68) and reclaimed areas (pH 6.27) than in the red pine forests (pH 5.31). Soil organic carbon and total nitrogen were significantly higher in the red pine forests (C: 36.03 mg·g-1; N: 2.08 mg·g-1) than in the reclaimed areas (C: 5.00 mg·g-1; N: 0.31 mg·g-1) than in the kaolinite tailings (C: 2.12 mg·g-1; N: 0.07 mg g-1). The amount of available phosphorus was not significantly different among the three treatments. The concentration of exchangeable potassium was significantly lower in the kaolinite tailings (0.08 cmolc·kg-1) than in the reclaimed areas (0.21 cmolc·kg-1) and red pine forests (0.30 cmolc·kg-1). These results indicate that, because of high soil bulk density and low soil organic carbon, total nitrogen, available phosphorus, and exchangeable potassium in kaolinite tailings and reclaimed mining areas, soil nutrient management is needed in order to reclaim the vegetation in these type of areas.

A Study on the Selection of Evaluation Factors on Forest Carbon Cycle Community(F.C.C.C) using DHP Analysis Method (DHP분석을 이용한 산림탄소순환마을 대상지 평가기준 선발에 관한 연구)

  • Seo, Jeong-Weon;Kwak, Kyung-Ho;Jeong, Se-Myong;Kang, Sung-Pyo;An, Ki-Wan
    • Journal of Korean Society of Forest Science
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    • v.100 no.4
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    • pp.672-680
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    • 2011
  • The purpose of this study has been carried to develop a criterion for the selection of evaluation factors on Forest Carbon Cycle Community(F.C.C.C) based on the result of survey of 96 participants who were operation managers on mountain eco village(31), relevant experts(33), and officers of local government(32). For analysis of the results of survey, DHP(Delphi Hierarchy Process) method was used which is a combination of Delphi method and AHP(Analytic Hierarchy Process) method. The key factors on selection of a suitable area to launch F.C.C.C. project of Korea Forest Service was selected under three hierarchical classes. Class 1 comprises 3 indices(Physical resource index, Human resource index, Vision index), and Class 2 which contains 10 indices (Existing resource, Surroundings resource, Forest biomass resource, Humanities Social quality, Local resident participation, Leader's ability, External support, Planning of operation, Capability of operation, and Effect of operation). Class 3 is sub-level class of class which possess 38 indices. From the results of analysis, Consistency Index(C.I) of each index in the 3 classes was used as evaluation factor. In Class 1, index 'human resources' showed highest Consistency Index(0.454). In Class 2, index 'forest biomass resources' was the highest Consistency Index(0.376) in 'physical resources' of Class 1, index 'leader's ability' was the highest Consistency Index(0.326) in 'human resources' of Class 1, and index 'planning of operation' was the highest Consistency Index(0.346) in 'vision' of Class 1. In Class 3, relative importance of 38 index including 'Joint ownership land security(C.I.-0.266)' was evaluated. Based on the result of this study, a criterion for the selection of evaluation factors for F.C.C.C was developed and the evaluation criterion is expected to be use to select of a suitable area to launch F.C.C.C. project since 2011.