• Title/Summary/Keyword: practical analysis

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Shape Scheme and Size Discrete Optimum Design of Plane Steel Trusses Using Improved Genetic Algorithm (개선된 유전자 알고리즘을 이용한 평면 철골트러스의 형상계획 및 단면 이산화 최적설계)

  • Kim, Soo-Won;Yuh, Baeg-Youh;Park, Choon-Wok;Kang, Moon-Myung
    • Journal of Korean Association for Spatial Structures
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    • v.4 no.2 s.12
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    • pp.89-97
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    • 2004
  • The objective of this study is the development of a scheme and discrete optimum design algorithm, which is based on the genetic algorithm. The algorithm can perform both scheme and size optimum designs of plane trusses. The developed Scheme genetic algorithm was implemented in a computer program. For the optimum design, the objective function is the weight of structures and the constraints are limits on loads and serviceability. The basic search method for the optimum design is the genetic algorithm. The algorithm is known to be very efficient for the discrete optimization. However, its application to the complicated structures has been limited because of the extreme time need for a number of structural analyses. This study solves the problem by introducing the size & scheme genetic algorithm operators into the genetic algorithm. The genetic process virtually takes no time. However, the evolutionary process requires a tremendous amount of time for a number of structural analyses. Therefore, the application of the genetic algorithm to the complicated structures is extremely difficult, if not impossible. The scheme genetic algorithm operators was introduced to overcome the problem and to complement the evolutionary process. It is very efficient in the approximate analyses and scheme and size optimization of plane trusses structures and considerably reduces structural analysis time. Scheme and size discrete optimum combined into the genetic algorithm is what makes the practical discrete optimum design of plane fusses structures possible. The efficiency and validity of the developed discrete optimum design algorithm was verified by applying the algorithm to various optimum design examples: plane pratt, howe and warren truss.

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CARIES PREDICTION MODEL USING LASER FLUORESCENCE (레이저 형광법을 이용한 우식유발 예측모형)

  • Lee, Sang-Ho;Lee, Chang-Seop;Jeong, Yeon-Hwa
    • Journal of the korean academy of Pediatric Dentistry
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    • v.28 no.1
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    • pp.16-24
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    • 2001
  • The purpose of this study was to evaluate the specificity, sensitivity, and diagnostic power of caries activity test using laser fluorescence. The subjects of this study were 50 children of $7\sim9$ years old. Fluorescence from initial carious lesion of teeth illuminated by an argon laser(480nm) was observed and photographed with barrier filter. Visual examination for the dDfFtT rate and Streptococcus mutans colony counting was done to evaluate correlation with caries activity test using laser fluorescence. Data analysis was accomplished by Axelsson's method. The results from the present study can be summarized as follows: 1. There was positive correlation $(\gamma=0.48)$ between laser fluorescence test and Streptococcus mutans count. And also positive correlation $(\gamma=0.39)$ exists between laser fluorescence test and dDfFtT rate (P<0.01). 2. Positive correlation $(\gamma=0.27)$ between Streptococcus mutans colony count and dDfFtT rate was found(P<0.05). 3. When dDfFtT rate was defined to standard testing method, the specificity, senstivity, and diagnostic power of laser fluorescence test were 44.4%, 85.7%, and 87.8%. 4. When dDfFtT rate was defined to standard testing method, the specificity, senstivity, and diagnostic power of S. mutans colony counting were 77.8%, 92.9%, 84.8%. 5. When S. mutans colony counting was defined to standard testing method, sensitivity, specificity and diagnostic power of laser fluorescence test were 40.0%, 84.8%, 95.1%. In regard to above results, laser fluorescence test considered to be accurate and reliable method for determining caries activity because of it's close relationship with caries susceptibility test and caries experience measurements. And it was also considered to be practical because it would be simple, inexpensive, and time saving method.

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Dehumidification and Temperature Control for Green Houses using Lithium Bromide Solution and Cooling Coil (리튬브로마이드(LiBr) 용액의 흡습성질과 냉각코일을 이용한 온실 습도 및 온도 제어)

  • Lee, Sang Yeol;Lee, Chung Geon;Euh, Seung Hee;Oh, Kwang Cheol;Oh, Jae Heun;Kim, Dea Hyun
    • Journal of Bio-Environment Control
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    • v.23 no.4
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    • pp.337-341
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    • 2014
  • Due to the nature of the ambient air temperature in summer in korea, the growth of crops in greenhouse normally requires cooling and dehumidification. Even though various cooling and dehumidification methods have been presented, there are many obstacles to figure out in practical application such as excessive energy use, cost, and performance. To overcome this problem, the lab scale experiments using lithium bromide(LiBr) solution and cooling coil for dehumidification and cooling in greenhouses were performed. In this study, preliminary experiment of dehumidification and cooling for the greenhouse was done using LiBr solution as the dehumidifying materials, and cooling coil separately and then combined system was tested as well. Hot and humid air was dehumidified from 85% to 70% by passing through a pad soaked with LiBr, and cooled from 308K to 299K through the cooling coil. computational Fluid Dynamics(CFD) analysis and analytical solution were done for the change of air temperature by heat transfer. Simulation results showed that the final air temperature was calculated 299.7K and 299.9K respectively with the deviation of 0.7K comparing the experimental value having good agreement. From this result, LiBr solution with cooling coil system could be applicable in the greenhouse.

A Study of Korean Costume in the Collection of Overseas Museums (해외 박물관 소장 한국 복식문화재에 관한 연구)

  • 윤은재;임영자
    • Journal of the Korean Society of Costume
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    • v.36
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    • pp.219-238
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    • 1998
  • For the purpose of this Study, the situation of Korean costume properties in the collection of overseas museums was investigated through correspondence, interviews with their curators and persons in charge and survey. As results were made about the situation of museum science (conservation) and practical utilization of costume properties. So, the study result were drawn as follows : Krean costume properties unexplaind of 'Korean cultural Properties' could be found in the Metropolitan Museum of Art of New York(135 pieces), the Brooklyn Museum of New York(20 pieces), the Newark Museum of New Jersey(15 pieces), and the Victoria Albert Museum of London(100 pieces). Korean costume properties in the collection of over-seas museums mostly fall under the rang of period between the 19th century and the early 20th century and are classified into everyday clothing, wedding costume and armors for the most part. In 1900s, museum in several countries began to collected Korean cultural properties through foreign missionaries or diplomats as well as merchants or travellers in who bought Korean objects. Recently, scholars, traditional Korean costume designerss and diplomatic and consular offices in overseas have donated our Korean costume to many foreign museums. Korean costume properties were largely on display in the dependent display of folklore museums or in a part of exhibition gallery for Asian culture and there were the separate exhibition rooms in museums in the United Kingdom, Germany, Denmark, Austria, Japan and the United States America. But the size and level of display room for Korean cultural properties is one third as large as that for chinese or Japanese cultual properties. It was found in this study that the traditional Korean costume in the collection of overseas museums was largely recorded only as general items rather than given their proper names. The typical example of misnaming included bridal's Kimono for Wonsam(원삼) in the Metropolitan Museum of Art, Yeonroksaek-bumunsajeokori for Dangeui(당의) and Jissan-gryongwonmunsadurumagi for Kongdali(동달이) in the Okura collection of the Tokyo National Museum, and so on. And the Victoria Albert Museum modified the way of wearing Daenim(대님) and the National Museum of Ethnology in Osaka seemed to misplace the ornament of Keanggi(댕기) on Mubok(무복) and Josunjuk(조선족: Chinese-Korean) Museum also misplace hansam(한삼). On the one hand, the Newark museum of New Jersey mixed Chinese armor with the Korean one and the Photohraph of King Kojong(고종) with Chinese one. It is corrected to publish and disseminate the book concering Korean costume in order to inform foreign museums of thed proper names and wearing method of our traditional costumed. The repair of costume before cleaning in the process of conservation treatment can prevent damage likely to occur as the properties of fiber itself are weakened in liquid. It is recommended that western 8-figure stitch and tacking stitch is added to Korean traditional stitching method. Museums in the U.S.A and the U.K are concerned about the aftermath of cleaning it-self, specially conservation treatment may exert on remains and predominantly use the vacuuming method to remove dust or bits of straw before the exhibition beings. But in case of Korea, the dry cleaning and wet cleaning method are used according to the nature and state of a sample costume. This comprehensive cleaning method is gradually developing scientifically but it is expected that those concerned will make a chemical analysis of the solvent to be used and also the more precise test of costume properties will be conducted before cleaning them. A partial study was made here because the scope of study was too broad and vast. It is expected that more studies will be conducted concerning our costume culture under the long-term plan and active support at the government level.

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Influence of Motivational, Social, and Environmental Factors on the Learning of Hackers (동기적, 사회적, 그리고 환경적 요인이 해커의 기술 습득에 미치는 영향)

  • Jang, Jaeyoung;Kim, Beomsoo
    • Information Systems Review
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    • v.18 no.1
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    • pp.57-78
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    • 2016
  • Hacking has raised many critical issues in the modern world, particularly because the size and cost of the damages caused by this disruptive activity have steadily increased. Accordingly, many significant studies have been conducted by behavioral scientists to understand hackers and their practices. Nonetheless, only qualitative methods, such as interviews, meta-studies, and media studies, have been employed in such studies because of hacker sampling limitations. Existing studies have determined that intrinsic motivation was the dominant factor influencing hackers, and that their techniques were mainly acquired from online hacking communities. However, such results have yet to be causally proven. This study attempted to identify the causal factors influencing the motivational and environmental factors encouraging hackers to learn hacking skills. To this end, hacker community members using the theory of planned behavior were observed to identify the causal factors of their learning of hacking skills. We selected a group of students who were developing their hacking skills. The survey was conducted over a two-week period in May 2015 with a total of 227 students as respondents. After list-wise deletion, 215 of the responses were deemed usable (94.7 percent). In summary, the hackers were aware that hacking skills are considered socially unethical, and their attitudes toward the learning of hacking skills were affected by both intrinsic and extrinsic motivations. In addition, the characteristics of the online hacking community affected their perceived behavioral control. This study introduced new concepts in the process of conducting a causal relationship analysis on a hacker sample. Moreover, this research expanded the discussion on the causal direction of subjective norms in unethical research, and empirically confirmed that both intrinsic and extrinsic motivations affect the learning of hacking skills. This study also made a practical contribution by raising the educational and policy response issues for ethical hackers and demonstrating the necessity to intensify the punishment for hacking.

Context Prediction Using Right and Wrong Patterns to Improve Sequential Matching Performance for More Accurate Dynamic Context-Aware Recommendation (보다 정확한 동적 상황인식 추천을 위해 정확 및 오류 패턴을 활용하여 순차적 매칭 성능이 개선된 상황 예측 방법)

  • Kwon, Oh-Byung
    • Asia pacific journal of information systems
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    • v.19 no.3
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    • pp.51-67
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    • 2009
  • Developing an agile recommender system for nomadic users has been regarded as a promising application in mobile and ubiquitous settings. To increase the quality of personalized recommendation in terms of accuracy and elapsed time, estimating future context of the user in a correct way is highly crucial. Traditionally, time series analysis and Makovian process have been adopted for such forecasting. However, these methods are not adequate in predicting context data, only because most of context data are represented as nominal scale. To resolve these limitations, the alignment-prediction algorithm has been suggested for context prediction, especially for future context from the low-level context. Recently, an ontological approach has been proposed for guided context prediction without context history. However, due to variety of context information, acquiring sufficient context prediction knowledge a priori is not easy in most of service domains. Hence, the purpose of this paper is to propose a novel context prediction methodology, which does not require a priori knowledge, and to increase accuracy and decrease elapsed time for service response. To do so, we have newly developed pattern-based context prediction approach. First of ail, a set of individual rules is derived from each context attribute using context history. Then a pattern consisted of results from reasoning individual rules, is developed for pattern learning. If at least one context property matches, say R, then regard the pattern as right. If the pattern is new, add right pattern, set the value of mismatched properties = 0, freq = 1 and w(R, 1). Otherwise, increase the frequency of the matched right pattern by 1 and then set w(R,freq). After finishing training, if the frequency is greater than a threshold value, then save the right pattern in knowledge base. On the other hand, if at least one context property matches, say W, then regard the pattern as wrong. If the pattern is new, modify the result into wrong answer, add right pattern, and set frequency to 1 and w(W, 1). Or, increase the matched wrong pattern's frequency by 1 and then set w(W, freq). After finishing training, if the frequency value is greater than a threshold level, then save the wrong pattern on the knowledge basis. Then, context prediction is performed with combinatorial rules as follows: first, identify current context. Second, find matched patterns from right patterns. If there is no pattern matched, then find a matching pattern from wrong patterns. If a matching pattern is not found, then choose one context property whose predictability is higher than that of any other properties. To show the feasibility of the methodology proposed in this paper, we collected actual context history from the travelers who had visited the largest amusement park in Korea. As a result, 400 context records were collected in 2009. Then we randomly selected 70% of the records as training data. The rest were selected as testing data. To examine the performance of the methodology, prediction accuracy and elapsed time were chosen as measures. We compared the performance with case-based reasoning and voting methods. Through a simulation test, we conclude that our methodology is clearly better than CBR and voting methods in terms of accuracy and elapsed time. This shows that the methodology is relatively valid and scalable. As a second round of the experiment, we compared a full model to a partial model. A full model indicates that right and wrong patterns are used for reasoning the future context. On the other hand, a partial model means that the reasoning is performed only with right patterns, which is generally adopted in the legacy alignment-prediction method. It turned out that a full model is better than a partial model in terms of the accuracy while partial model is better when considering elapsed time. As a last experiment, we took into our consideration potential privacy problems that might arise among the users. To mediate such concern, we excluded such context properties as date of tour and user profiles such as gender and age. The outcome shows that preserving privacy is endurable. Contributions of this paper are as follows: First, academically, we have improved sequential matching methods to predict accuracy and service time by considering individual rules of each context property and learning from wrong patterns. Second, the proposed method is found to be quite effective for privacy preserving applications, which are frequently required by B2C context-aware services; the privacy preserving system applying the proposed method successfully can also decrease elapsed time. Hence, the method is very practical in establishing privacy preserving context-aware services. Our future research issues taking into account some limitations in this paper can be summarized as follows. First, user acceptance or usability will be tested with actual users in order to prove the value of the prototype system. Second, we will apply the proposed method to more general application domains as this paper focused on tourism in amusement park.

The Effects of Global Entrepreneurship and Social Capital Within Supply Chain on the Export Performance (글로벌 기업가정신과 공급사슬 내 사회적 자본이 수출성과에 미치는 영향)

  • Yoon, Heon-Deok;Kwak, Ki-Young;Seo, Ri-Bin
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.7 no.3
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    • pp.1-16
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    • 2012
  • Under the international business circumstance, global supply chain management is considered a vital strategic challenge to small and medium-sized enterprises(SMEs) suffering from deficient resources and capabilities to exploit overseas markets comparing with large corporations. That is because they can expand their business domains into overseas markets by establishing strategic alliances with global supply chain partners. Although a wide range of previous researches have emphasized the cooperative networks in the chain, most are ignoring the importance of developing relational characteristics such as trust and reciprocity with the partners. Besides, verifying the relational factors influencing firms' export performances, some studies proposed different and inconsistent factors. According to the social capital theory, which is the social quality and networks facilitating close cooperation of inter-individual and inter-organization, provides the integrated view to identify the relational characteristics in the aspects of network, trust and reciprocal norm. Meanwhile, a number of researchers shows that global entrepreneurship is the internal and intangible resource necessary to promote SMEs' internationalization. Upon closer examination, however, they cannot explain clearly its influencing mechanism in the inter-firm cooperative relationships. This study is to verify the effect of social capital accumulated within global supply chain on SMEs' qualitative and quantitative export performance. In addition, we shed new light on global entrepreneurship expected to be concerned with the formation of social capital and the enhancement of export performances. For this purpose, the questionnaires, developed through literature review, were collected from 192 Korean SMEs affiliated in Korean Medium Industries Association and Global Chief Executive Officer's Club focusing on their memberships' international business. As a result of multi-regression analysis, the social capital - network, trust and reciprocal norm shared with global supply chain partner - as well as global entrepreneurship - innovativeness, proactiveness and risk-taking - have positive effect on SMEs' export performances. Also global entrepreneurship affects positively social capital which has mediating effect partially in the relationship between global entrepreneurship and performances. These results means that there is a structural process - global entrepreneurship(input), social capital(output), and export performances(outcome). In other words, a firm should consistently invest in and develop the social capital with global supply chain partners in order to achieve common goals, establish strategic collaborations and obtain long-term export performances. Furthermore, it is required to foster the global entrepreneurship in an organization so as to build up the social capital. More detailed practical issues and discussion are made in the conclusion.

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A Study on the Relationship Between Entrepreneur Characteristics and the Performance of Small Firms (창업자 특성과 소기업 사업성과 간 관계에 관한 연구)

  • Kim, Wan-Jae;Chung, Hwa-Young
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.2 no.3
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    • pp.33-60
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    • 2007
  • This study alms to analyze the entrepreneur characteristics of founder on enterprise performance from the strategic viewpoint as well as features of founder of small firms such as background feature of founder, psychological features and management skill. As considered by Background features of founder include educational background of founder, his experience in business creation, consultation or course related to business creation. This study verified the effects of factor which business performance (financial, non financial) on small firms. Also, this study considered psychological features of founder include achievement desire, risk-free propensity, level of patience on vagueness and control position. And it analyzed that between such factors and performance of small firms were examined in related. In the mean time, management ability of founder, entrepreneur ability, technical and function ability were considered for management skill of founder and alalyzed effect of the factors on performance of small firm were examined. Effects of strategic intention of founder of small firm were analyzed by the strategic viewpoint. At this time, strategy of small firm was divided into product-service reform differentiation strategy, marketing differentiation strategy and cost leadership strategy. This study distributed questionnaire on CEO of small firms in Daejeon and Chungnam area for accomplish the study objective and it collected a total of 145 copies of questionnaires. As a result of analyzing collected questionnaire, this study deduced the following study results and suggestions. First, results different from those of existing studies were found Since sales, net income and profit rate of small firm were not high cause economic depression on the whole. Second, entrepreneur ability was found to be required for success of business creation. Entrepreneur ability of founder was the factor that affects both financial and non - financial performance of small firm. As such, entrepreneur ability can be regarded as the most important factor for success in business creation of small firm. Accordingly, entrepreneur ability is the most important source for success in business creation of small firm. Third, strategy of small firm was found to be the important factor that affects the non-financial performance even if it could not give significant effects on financial performance. Thus, product service reform differentiation strategy, marketing differentiation strategy and cost leadership strategy have significant effects on non - financial performance of small firm. Accordingly, it is required to operate small firm with strategic mind - set for small firm to achieve success. This study analyzed the effects of feature of founder and strategy of small firm on business performance of small firm through practical analysis on small firms in Daejeon and Chungnam area, and deduced meaningful results. However, Since this study collected data on small firms in Daejeon and Chungnam only, there is a limit in generalizing the results of this study to all small firms in Korea. Companies answering to this questionnaire process were mainly wholesale and retail service companies. In addition, there is a limit in that it failed to analyze feature of representative type of industry due to limit in number of sample, it is required to divide representative type of industry and to compare and analyze types of industry in future studies.

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Antioxidant Activity and Quality Characteristics of Perilla leaves(Perilla frutescens var. japonica HARA) Cookies (들깻잎 쿠키의 항산화활성 및 품질특성)

  • Choi, Hae-Yeon;Oh, So-Yeon;Lee, Yang-Soon
    • Korean journal of food and cookery science
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    • v.25 no.5
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    • pp.521-530
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    • 2009
  • Perilla leaves powder was added to cookies to determine a practical use for the herb, which has been shown to have medical benefits and functionality. We examined the antioxidant activity and quality characteristics of cookies prepared with different amounts (as ratios of 0.5%, 1%, 3%, 5% to the total materials) of perilla leaves powder. The antioxidant activity was estimated by DPPH free radical scavenging activity and the total phenolic compound content in perilla leaves powder and cookies. The quality characteristics of the perilla leaves cookie were estimated in terms of the bulk density, pH of the dough, spread factor, loss rate, leavening rate, color, texture profile analysis, and sensory evaluations. While the bulk density and pH of the dough as well as total polyphenol contents and DPPH free radical scavenging activity of cookies significantly increased, the spread factor, loss rate, leavening rate and L value of the cookies decreased with increasing perilla leaves powder content(p<.05). The consumer acceptability scores for the $1{\sim}3%$ perilla leaves cookie groups ranked significantly(p<.05) higher than those of the other groups in appearance, taste, flavor, texture, and overall preference. This study suggests that perilla leaves powder is a good ingredient to increase the consumer acceptability and the functionality of cookies.

A Study on Relationship between Social Entrepreneurship and Organizational Performance - Focused on Moderating Effect of Government support - (사회적 기업가정신이 조직성과에 미치는 영향 - 정부지원 조절효과를 중심으로 -)

  • Lim, Jae-Woong;Chang, Sug-In
    • Management & Information Systems Review
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    • v.37 no.2
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    • pp.235-258
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    • 2018
  • This study is an empirical analysis on Moderating Effect of Government support on Relationship between Social Entrepreneurship and Organizational Performance. Previous studies have focused on case studies for specific companies and studies on Social entrepreneurship have been carried out in recent years. As the interest in social enterprises is increasing due to the problem of social polarization, it is necessary to study the causal relationship between social entrepreneurship and organizational performance deeply, and the government continues to provide government support for social enterprises. However, there is a lack of research on the effects of government support on social entrepreneurship and organizational performance. Therefore, this study analyzes the Proactiveness and Risk-taking of social entrepreneurship and examines the causal relationship between the organization's economic performance and social performance and the moderating effect of government support on the members of the social enterprise in Chungcheong area based on the previous research It is expected that the researcher will give academic and practical value to practitioners. As a result of this study, it is shown that the risk sensitivity of social entrepreneurship has a significant effect on the economic performance, and the Proactiveness of entrepreneurship and Risk-taking of social entrepreneurship all have a positive effect on the social performance, The results of the study show that government support has only a positive effect on the moderating effects of the variables of enterprising and social performance among the variables. The results of this study suggest that social entrepreneurship in social enterprises is an important factor affecting organizational performance. Therefore, if managers of social enterprises continue to educate and apply social entrepreneurship to their members, The social and economic performance of social enterprises will increase, which will help to enhance the competitiveness of enterprises. In addition, although the government has implemented various policies to support social enterprises, there is no expectation of government support for organizational performance because of the lack of support from the government after social enterprise certification. And to develop the government's fine - tuned upbringing policy that can improve organizational performance.