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Analysis of Surplus Solar Energy in Venlo Type Greenhouse (벤로형 온실의 잉여 태양에너지 분석)

  • Choi, Man Kwon;Shin, Yik Soo;Yun, Sung Wook;Kim, Hyeon Tae;Yoon, Yong Cheol
    • Journal of Bio-Environment Control
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    • v.22 no.2
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    • pp.91-99
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    • 2013
  • This research analyzed surplus solar energy in Venlo-type greenhouse using acquired typical meteorological year (TMY) data for designing a heat storage system for the surplus solar energy generated in the greenhouse during the day. In the case of paprika, the region-dependent heating loads for Jeju, Jinju, and Daegwanryong area were approximately 1,107.8 GJ, 1,010.0 GJ, and 3,118.5 GJ, respectively. The surplus solar energy measured in Jeju area was 1,845.4 GJ, Jinju area 1,881.8 GJ, and Daegwanryong area 2,061.8 GJ, with the Daegwanryong area showing 11.7% and 9.6% higher than the Jeju region and Jinju region respectively. In the case of chrysanthemums, regional heating loads were determined as 1,202.5 GJ for the Jeju region, 1,042.0 GJ for the Jinju region, and 3,288.6 GJ for the Daegwanryong region; the regional differences were similar to those for paprika. The recorded surplus solar energy was 1,435.2 GJ, 1,536.2 GJ, and 1,734.6 GJ for Jeju, Jinju, and Daegwanryong region, respectively. The Daegwanryong region recorded heating loads 20.9% and 12.9% higher than in the Jeju and Jinju region, respectively. From the above, it can be said that cultivating paprika, compared to cultivating chrysanthemums, requires less heating energy regardless of the region and tends to yield more surplus solar energy. Moreover, if the Daekwan Pass region is excluded, the surplus solar energy exceeds the energy required for heating. Although the required heating energy differs according to regions and crops, cucumbers were found to require the highest amount, followed by chrysanthemum and paprika. The amount of surplus solar energy was the highest in the case of paprika, followed by cucumber and chrysanthemum.

Effect of the Nematode Sterilization of Nursery Medium using QRD Microwave in the Plant Factory (QRD 마이크로파를 이용한 식물공장용 배지의 멸균 효과)

  • Kim, Jin Hyun;Kim, Tae Wook;Lee, Keun Woo;Ha, Yu Shin;Lee, Jae Hyun;Kim, Kyung Min
    • Journal of Bio-Environment Control
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    • v.22 no.2
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    • pp.100-107
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    • 2013
  • Unlike general microwave, QRD (Quadratic Residue Diffusor) Microwave used in this study is known as a new technology that enhances the sterilization effect with low power because it is possible to induce the average sterilization by changing wavelength phase difference. Therefore, basic research was conducted on the function that could sterilize culture media for plant factory by using environmentally friendly and low energy consuming QRD Microwave. The results are as follows: It was confirmed that there was no external deformation in the polyurethane foam and rock wool medium when changing the microwave level between 2 and 8 kW in different water content of culture media. However, PDA solid media at 2 kW were not dissolved in 60 and 180 seconds. All of the media were dissolved in other processing. There was little difference in the microwave irradiation level and surface temperature of the strain according to the processing time between Bacillus sp. and Burkholderia sp. In the sterility test according to the microwave irradiation level and processing time, it was confirmed that both Bacillus sp. and Burkholderia sp. grew in the microwave level 2 kW regardless of time. In the microwave level 6 kW, all experimental groups except the processing of Burkholderia sp. for 60 seconds were sterilized, and all of Bacillus sp. was killed in the all experimental groups. In the microwave level 8 kW, it was confirmed that both Bacillus sp. and Burkholderia sp. were sterilized regardless of time. The temperature in microwave-processed media after contaminating strains to each medium was maintained at more than 100 in polyurethane foam and rock wool medium after 60 seconds. In general, it was shown that it was possible to sterilize after 60 seconds. Therefore, it is considered that Bacillus sp. and Burkholderia sp. which are the biggest problems in the plant factory can be adequately sterilized by QRD Microwave used in this study.

Corporate Bond Rating Using Various Multiclass Support Vector Machines (다양한 다분류 SVM을 적용한 기업채권평가)

  • Ahn, Hyun-Chul;Kim, Kyoung-Jae
    • Asia pacific journal of information systems
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    • v.19 no.2
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    • pp.157-178
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    • 2009
  • Corporate credit rating is a very important factor in the market for corporate debt. Information concerning corporate operations is often disseminated to market participants through the changes in credit ratings that are published by professional rating agencies, such as Standard and Poor's (S&P) and Moody's Investor Service. Since these agencies generally require a large fee for the service, and the periodically provided ratings sometimes do not reflect the default risk of the company at the time, it may be advantageous for bond-market participants to be able to classify credit ratings before the agencies actually publish them. As a result, it is very important for companies (especially, financial companies) to develop a proper model of credit rating. From a technical perspective, the credit rating constitutes a typical, multiclass, classification problem because rating agencies generally have ten or more categories of ratings. For example, S&P's ratings range from AAA for the highest-quality bonds to D for the lowest-quality bonds. The professional rating agencies emphasize the importance of analysts' subjective judgments in the determination of credit ratings. However, in practice, a mathematical model that uses the financial variables of companies plays an important role in determining credit ratings, since it is convenient to apply and cost efficient. These financial variables include the ratios that represent a company's leverage status, liquidity status, and profitability status. Several statistical and artificial intelligence (AI) techniques have been applied as tools for predicting credit ratings. Among them, artificial neural networks are most prevalent in the area of finance because of their broad applicability to many business problems and their preeminent ability to adapt. However, artificial neural networks also have many defects, including the difficulty in determining the values of the control parameters and the number of processing elements in the layer as well as the risk of over-fitting. Of late, because of their robustness and high accuracy, support vector machines (SVMs) have become popular as a solution for problems with generating accurate prediction. An SVM's solution may be globally optimal because SVMs seek to minimize structural risk. On the other hand, artificial neural network models may tend to find locally optimal solutions because they seek to minimize empirical risk. In addition, no parameters need to be tuned in SVMs, barring the upper bound for non-separable cases in linear SVMs. Since SVMs were originally devised for binary classification, however they are not intrinsically geared for multiclass classifications as in credit ratings. Thus, researchers have tried to extend the original SVM to multiclass classification. Hitherto, a variety of techniques to extend standard SVMs to multiclass SVMs (MSVMs) has been proposed in the literature Only a few types of MSVM are, however, tested using prior studies that apply MSVMs to credit ratings studies. In this study, we examined six different techniques of MSVMs: (1) One-Against-One, (2) One-Against-AIL (3) DAGSVM, (4) ECOC, (5) Method of Weston and Watkins, and (6) Method of Crammer and Singer. In addition, we examined the prediction accuracy of some modified version of conventional MSVM techniques. To find the most appropriate technique of MSVMs for corporate bond rating, we applied all the techniques of MSVMs to a real-world case of credit rating in Korea. The best application is in corporate bond rating, which is the most frequently studied area of credit rating for specific debt issues or other financial obligations. For our study the research data were collected from National Information and Credit Evaluation, Inc., a major bond-rating company in Korea. The data set is comprised of the bond-ratings for the year 2002 and various financial variables for 1,295 companies from the manufacturing industry in Korea. We compared the results of these techniques with one another, and with those of traditional methods for credit ratings, such as multiple discriminant analysis (MDA), multinomial logistic regression (MLOGIT), and artificial neural networks (ANNs). As a result, we found that DAGSVM with an ordered list was the best approach for the prediction of bond rating. In addition, we found that the modified version of ECOC approach can yield higher prediction accuracy for the cases showing clear patterns.

Optimal Incentives for Customer Satisfaction in Multi-channel Setting (멀티채널에서의 고객만족제고 인센티브 연구)

  • Kim, Hyun-Sik
    • Journal of Distribution Research
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    • v.15 no.1
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    • pp.25-47
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    • 2010
  • CS is one of the major concerns of managers in the world because it is well known to be a key medium construct for firms' superior outcome. One of the major agents for CS management is retailers. Firms try to manage not only employees but also retailers to promote CS behaviors. And so diverse incentives are used to promote their CS behaviors under diverse channel setting such as multi-channel. However in spite of the rising needs there has been scarce studies on the optimal incentive structure for a manufacturer to offer competing retailers at the multi-channel. In this paper, we try to find better way for a manufacturer to promote the competing retailers' CS behaviors. We investigated how to promote the retailers' CS behavior via game-theoretic modeling. Especially, we focus on the possible incentive, CS bonus type reward introduced in the studies of Hauser, Simester, and Wernerfelt(1994) and Chu and Desai(1995). We build up a multi stage complete information game and derive a subgame perfect equilibrium using backward induction. Stages of the game are as following. (Stage 1) Manufacturer sets wholesale price(w) and CS bonus($\eta$). (Stage 2) Both retailers in competition set CS effort level($e_i$) and retail price($p_i$) simultaneously. (Stage 3) Consumers make purchasing decisions based on the manufacturer's initial reputation and retailers' CS efforts.

    Structure of the Model We investigated four issues about the topic as following: (1) How much total incentive is adequate for a firm of a specific level of reputation to promote retailers' CS behavior under multi-channel setting ?, (2) How much total incentive is adequate under diverse level of complimentary externalities between the retailers' CS efforts to promote retailers' CS behavior?, (3) How much total incentive is adequate under diverse level of cost to make CS efforts to promote retailers' CS behavior?, (4) How much total incentive is adequate under diverse level of competition between retailers to promote retailers' CS behavior? Our findings are as following. (1) The higher reputation has the manufacturer, the higher incentives for retailers at multi-channel are required in the equilibrium.
    shows the increasing pattern of optimal incentive level along the manufacturer's reputation level(a) under some parameter conditions(b=1/2;c=0;$\beta$=1/2). (2) The bigger complimentary externalities exists between the retailers' CS efforts, the higher incentives are required in the equilibrium.
    shows the increasing pattern of optimal incentive level along the complimentary externalities level($\beta$) under some parameter conditions(a=1;b=1/2;c=0). (3) The higher is the retailers' cost, the lower incentives are required in the equilibrium.
    shows the decreasing pattern of optimal incentive level along the cost level(c) under some parameter conditions(a=1;b=1/2;$\beta$=1/2). (4) The more competitive gets those two retailers, the higher incentives for retailers at multi-channel are required in the equilibrium.
    shows the increasing pattern of optimal incentive level along the competition level(b) under some parameter conditions(c=0;a=1;$\beta$=1/2). One of the major contribution points of this study is the fact that this study is the first to investigate the optimal CS incentive system under multi-channel setting.

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The Importance-Performance Analysis of Bakery Cafe Choice Attributes Perceived by Customers in Seoul (베이커리카페 선택속성의 중요도 및 수행도 분석: 서울지역을 중심으로)

  • Choi, Mi-Kyung;Jung, Jae-Chan
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.35 no.4
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    • pp.456-463
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    • 2006
  • The purposes of this study were to extract choice attributes of bakery cafe customers and to conduct important- performance analysis (IPA) of choice attributes perceived by bakery cafe customers. The questionnaire was developed through literature review and focus group interview, and modified after pilot test. The questionnaires for main survey were distributed to 320 males and females aged 20 and over in Seoul. A total of 275 questionnaires were used for analysis (85.9%) and the statistical analyses were conducted using SPSS Win (12.0) for descriptive analyses, exploratory factor analysis, reliability analysis, and correlation analyses. The main results were as follows. 'Products', 'convenience to use', 'services and price', 'interior environments' 'brand' and 'location' dimensions were extracted as choice attributes dimensions of bakery cafe customers and customers of bakery cafe regarded 'sanitation and cleanness', 'kindness of employees', 'quality of products', 'comfortable and pleasant facilities' and 'taste of bakery products' as more important than other attributes. In addition, the results of IPA showed that marketing managers of bakery cafes should focused on the dimension of 'services and price' in the reason that this dimension was low at performance although customers regarded it very important. Overall, researchers and managers of bakery cafes should understand unique choice attributes of bakery cafe customers, and make efforts to establish marketing strategies that meet bakery cafe customers' needs.

Effects of Vitexin from Mung Bean on 3T3-L1 Adipocyte Differentiation and Regulation According to Adipocytokine Secretion (녹두의 Vitexin이 비만전구세포에서 세포분화 및 아디포사이토카인 분비능에 미치는 영향)

  • Wi, Hae-Ri;Choi, Mun-Ji;Choi, Se-Lim;Kim, Ae-Jung;Lee, Myoung-Sook
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.41 no.8
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    • pp.1079-1085
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    • 2012
  • Obesity is an important issue worldwide as it may associated with increased prevalence of metabolic diseases. Mung bean is known as a functional food for decreasing the glycemic index and lipid profile of plasma. The purpose of this study was to investigate the anti-obesity effects of vitexin from mung bean on the regulation of adipocyte differentiation and adipocytokine secretion. When 3T3-L1 adipocytes were treated with vitexin from days 0 to 14 at various levels of 25, 50, 100, and $200{\mu}M$, there was no change in cell viability. Vitexin treatment at 50, 100, and $200{\mu}M$ decreased triacylglycerol levels in cells, but only $100{\mu}M$ vitexin induced lipolysis. At $200{\mu}M$ of vitexin, phosphorylation of p38 and ERK, which causes secretion of inflammatory adipocytokines, was depressed, whereas there was an increase in expression of $PPAR{\gamma}$, the key regulator of adipocyte differentiation. Phosphorylation of AMPK increased at $100{\mu}M$ vitexin. TNF-${\alpha}$ and aP2 mRNA expression increased at $25{\mu}M$ vitexin, whereas only TNF-${\alpha}$ mRNA expression increased at $200{\mu}M$ vitexin. Further, the mRNA levels of TNF-${\alpha}$ and aP2 decreased at other concentrations in a dose-dependent manner. Since we observed that mRNA expression of C/EBP, SREBP1, and $PPAR{\gamma}$ did not change upon vitexin treatment, our future studies will investigate other genes such as mTOR, which is related with apoptosis signaling, or SIRT1, which is associated with inhibition of adipogenesis. Our results indicate that vitexin at concentrations between 100 and $200{\mu}M$ is suitable in vivo for the development of mung bean as an anti-obesity therapy or functional food.

Neighborhood Park Design for Railroad Station in Uijeongbu City (의정부 역전 근린공원 설계)

  • Kwon, Jin-Wook
    • Journal of the Korean Institute of Landscape Architecture
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    • v.38 no.4
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    • pp.64-74
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    • 2010
  • The study is based on an urban park design that is designed in consideration of the characteristics of Uijeongbu City, applied with adequate functions for the environment and showcasing the unique scenery in relation to the relocation of the US Air Force Camp Falling Water. The bases of the design are: the reasonable convergence of the square and park in consideration of the site characteristics; the application of an urban context as the park is located near a station; and the realization of an eco-friendly space. This study is based on foundation research regarding a review of urban square patterns, particular items in planning in relation to modern urban parks and the adaptability of the park in the future. Regarding space usage, the design is applied with notable ideas that allow the space to make its own characteristics through voluntary user activity in conjunction with the environment that will allow the park to cope with changes in the future, as opposed to a space that users experience through pre-determined programs. Below are the focal points of the design. First, the park is designed as an empty space which may accommodate the urban structural context of and usage patterns for being a field of the city ecology that changes and develops, beyond a passively-created square pattern. Such open spaces have a continuity which allows it to adapt to the development of the city. In addition, the design facilitates spontaneous processes through changes in usage pattern and time. Second, the design includes the message that the park and the city, natural things and artificial things, must communicate and network with each other. Hence the park shall not be an isolated green island within the city, but is an open space accommodating the demands for open area from nearby commercial, public and residential facilities; the park shall include a field that can accommodate a variety of programs. Third, the park is designed to encourage the effect of direct and indirect practical education by reflecting a physical plan as well as interesting experience design methods to lower carbon emissions and to create and maintain an eco-friendly space, the basis of a zero-emissions city.

A Comparison of the Overall Satisfaction of the Tourist Attractions at the Terelj Tourist Area in Mongolia by Mongolian and Korean Travelers (몽골 테렐지 관광지 관광자원 매력에 관한 몽·한 관광객 만족도 비교 분석)

  • Kim, Dong-Chan;Byambajamts, Nasanjargal
    • Journal of the Korean Institute of Landscape Architecture
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    • v.41 no.6
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    • pp.96-106
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    • 2013
  • The aim of this study was to reveal the advantages and disadvantages of Terelj Mongolian National Park based on the impressions of foreign and domestic travelers, and subsequently suggest supporting ideas to make this tourist attraction more enjoyable for travelers. A statistical program(SPSS 20.0) and an IPA matrix method were used to reveal the impressions of travelers and the results showed the following ideas. First, we made the technical analyses to demonstrate the characteristics of the current natural scenery which travelers want to see and the results indicated that both Korean and Mongolian travelers overall were not satisfied and the Park was not as they had imagined. The second part of the research highlighted the differences between the impressions held by Mongolian and Korean travelers, which showed dissimilarities in cultural resources, food, variety of events, cultural functions and parking, all of which were shown as important criteria in sightseeing. The variations were found in scenes of nature, variety of programs, and food, areas which revealed and were very important in the overall satisfaction of travelers. Third, the IPA method was used for analyze the advantages and disadvantages of Terelj National Park. The Mongolian travelers nominated the width of the road, cleanliness, variety of events and parking are the most essential things to feel satisfied, but Koreans selected safety of travel, accommodation, the width of the road and cleanliness. Finally, we analyzed the feelings of the travelers at the end of their trip. The Mongolian travelers preferred the area resource and environment convenience to feel satisfaction. For Korean travelers, the area resource is the most important when choosing travelling sights. Based on these results, if we take responsibility to protect the beauty of nature, and create a sightseeing place using natural sources, while also making more comfortable accommodations and improving the services, it can be a more unique place than others and lead to greater overall satisfaction for travelers.

A Study on the Design Guidelines of Healing Landscape in Housing Complexes (공동주택에서 치유조경계획을 위한 가이드라인 연구)

  • Chun, Hyunwoo;Lee, Shiyoung
    • Journal of the Korean Institute of Landscape Architecture
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    • v.44 no.5
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    • pp.26-37
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    • 2016
  • As activities and convenience of residents in outdoor spaces in apartment houses have been considered important, strategies for making outdoor spaces in apartment houses healing spaces have emerged as a major interest. The purpose of this study is to draw elements for planning healing to create healing spaces in collective housing areas and to present design guidelines. The findings of this study are as follows. Functional elements of a healing environment were classified into safe environment, therapeutic environment, ancillary environment, orientation-reinforcing environment, amenities, and social environment. Outdoor spaces in collective housing areas were divided into collective housing entrance areas, internal and external spread areas, outdoor activity areas, and areas by theme. First, collective housing entrance areas should be planned in such a manner that residents can feel the area is private and easy to recognize. Second, internal and external spread areas should be planned in such a manner that they are easy to access and communicate with neighbors. Third, outdoor activity areas should be divided into an open space, resting space, playing space, and sports space. Open spaces should be planned in such a manner that they can command a fine view and respect the privacy of nearby residents. Resting spaces should be equipped with a shelter that protects users from direct sunlight, rain, and snow as well as include a movable bench. Playing spaces should be built considering development of children's curiosity, adventurous spirit, character, stimulation, and physical health. Playing spaces should be designed in such a manner that roadways and sidewalks can be separated for safe traffic. Sport spaces should be planned in such a manner that they can be associated with a pavilion and trail that provide residents with an opportunity to communicate with each other and rest. Fourth, spaces by theme are classified into sense garden, therapeutic garden, experiential garden, and learning garden. Sense gardens are a small garden based on the five senses. Sense gardens should be designed in such a manner that they can improve users' mental and physical health through programs that stimulate the sense of sight, auditory sense, and olfactory sense. Therapeutic gardens should be designed in such a manner that they can provide a comfortable and relaxing space by minimizing noise. It is advisable for therapeutic gardens to be equipped with a medicinal herb garden, meditation garden, and sense garden. Experiential and learning gardens should be designed in such a manner that they can provide users with a space in which they can enjoy nature and leisure activities. It is advisable for experiential and learning gardens to be equipped with a tea garden, vegetable garden, and camping garden. Healing programs should be designed in such a manner that users can feel relaxed by providing a healing environment, making the most of the natural environment. Further research on evaluating whether the findings of this study are effective in healing in a qualitative and quantitative manner is needed.

Exploratory Study on the Phenomena of Entrepreneurship Education in Food and Agriculture Sectors Based on the Grounded Theory Approach (근거이론접근법에 기반한 농식품분야 창업교육현상에 관한 탐색적 연구)

  • Seol, Byung Moon
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.15 no.3
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    • pp.33-46
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    • 2020
  • This study analyzes the entrepreneurship education phenomena for agri-food entrepreneurs whose main business is the production of agricultural products and the sale of processed products, using the qualitative study Strauss & Corbin(1998)'s evidence theory approach. From the entrepreneur's point of view, I would like to summarize the phenomena that appear in education, and to prepare a theoretical basis for explaining the phenomena. The importance of entrepreneurship education is emphasized to cultivate the ability to develop and provide products tailored to customers. The necessity of education leads to an increase in demand according to the situational awareness of the founders, and the quantitative increase in entrepreneurship education in the agri-food sector is a clear trend. Inevitably, the need for various discussions on systematic and effective entrepreneurship education is raised. For the study, an interview was conducted with preliminary or entrepreneur who have experienced entrepreneurship education in the agri-food sector. As a research method, I use Strauss & Corbin(1998)'s approach and analyze qualitative data using QSR's NVIVO 12 program. Through this study, it was found that contextual and systematic entrepreneurship education in the agri-food sector has the effect of strengthening competitiveness and strengthening sales. There is a need for follow-up management of trainees. Strengthening the competitiveness of start-ups is based on training professional manpower through education and linking regions with cities. Strengthening sales is based on product planning and market development. This study explores entrepreneurship education in the agri-food sector, which has not been actively conducted in the past. Exploratory analysis on the experiences of the founders of agri-food sector as education demanders has an important meaning for understanding the phenomenon of start-up education.