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Effect of Concentration of Nutrient Solution on Water and Nutrient Uptake of Tomato Cultivars in Hydroponics (배양액 농도가 수경재배 토마토의 품종별 생육과 양수분 흡수특성에 미치는 영향)

  • Choi, Gyeong Lee;Yeo, Kyung Hwan;Choi, Su Hyun;Jeong, Ho Jeong;Kang, Nam Jun
    • Journal of agriculture & life science
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    • v.53 no.1
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    • pp.13-21
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    • 2019
  • This study was carried out to acquire basic data for a long-term hydroponic culture through investigating water and inorganic ion uptake characteristics at different EC level of nutrient solution of three tomato varieties. Three different tomato varieties, the European type(cv. Daphnis), the Asian type(cv. Super Doterang) and cherry type(cv. Minichal), were used for the investigation. Also, the deep flow technique(DFT) was applied. The three different electrical conductivity(EC) level(1.0, 2.0, 3.0, and 4.0 dS·m-1) of hydroponic nutrient solution were used as variable. At a high EC level of nutrient solution, the leaf area and fresh weight decreased in the early stage, and its growth(plant height, leaf number, leaf area, fresh-weight) was poor with salt stress. Result showed that the higher the EC level of the nutrient solution, the lesser was water uptake. The water uptake was not significantly different from varieties in the first survey, but In the second survey, the 'Daphnis' did not show a significant decrease in water uptake in the EC level higher than 2.0 dS·m-1., on the other hand, 'Super Doterang' presented very low water uptake. At a low EC level, N, P, and K, were absorbed more than the concentration of the irrigation water, while Ca, Mg, S uptake were low. At a high EC level, almost ions absorbed less than 50% of the initial concentration of irrigation water. Thus, imbalance among ions was severe at low EC level compared to high EC level. 'Daphnis' was a variety that effectively utilize nutrients under nutrient stress, showing high absorption at low concentration condition and low absorption at high concentration condition. However, 'Daphnis' suffered most seriously by absorbing nutrients excessively.

A Research on Actual Conditions of Juvenile Labor and Labor Rights Consciousness (청소년 노동의 실태와 노동인권 의식에 관한 연구)

  • Park, Sang-Jin
    • The Journal of the Convergence on Culture Technology
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    • v.7 no.1
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    • pp.264-271
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    • 2021
  • In this paper, we intended to find the labor situations and labor rights consciousness of local juveniles and also to identify how they are treated and respond to those treatments they encounter. At the same time, another purpose of this research is to collect basic data to give the youth proper education about labor rights when they are faced with unfair labor practice. The research results are as follows: First, 262 students (50.5%) have work experience. Second, 133 students(24.9%) took the education about labor rights, which means relatively small number of students were educated about labor rights. Third, it is reported that 54.2% of those students considered 'payment' top priority, and 67.7% of them got the work through their parents, friends, and acquaintances, and 60.2% had their jobs at restaurants. Average working hours are 7 hours a day and 20 hours a week, which shows that they worked quite long hours. Fourth, 28.9% of respondents reported they wrote employment contracts, and 82.1% said their main purpose of work was 'to make money'. Fifth, 24.7% of the students reported the experience of unfair treatment while working, and the most common case was 'jobs other than expected work'(17.9%). When they were asked how they coped with the unfair treatments, the largest percentage(30.3%) of them answered they 'quit the job'. Last, when the respondants were asked to list improvements for juvenile part-time jobs, the answers were minimum wage and payment with weekly vacation allowance(25.1%), enhancing social awareness(14.3%), increasing good job opportunity(12.8%), and etc.. This demonstrates that social awareness of juvenile labor jobs is to improve urgently in local community.

Comparison on Patterns of Conflicts in the South China Sea and the East China Sea through Analysis on Mechanism of Chinese Gray Zone Strategy (중국의 회색지대전략 메커니즘 분석을 통한 남중국해 및 동중국해 분쟁 양상 비교: 시계열 데이터에 근거한 경험적 연구를 중심으로)

  • Cho, Yongsu
    • Maritime Security
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    • v.1 no.1
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    • pp.273-310
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    • 2020
  • This study aims at empirically analyzing the overall mechanism of the "Gray Zone Strategy", which has begun to be used as one of Chinese major maritime security strategies in maritime conflicts surrounding the South China Sea and East China Sea since early 2010, and comparing the resulting conflict patterns in those reg ions. To this end, I made the following two hypotheses about Chinese gray zone strategy. The hypotheses that I have argued in this study are the first, "The marine gray zone strategy used by China shows different structures of implementation in the South China Sea and the East China Sea, which are major conflict areas.", the second, "Therefore, the patterns of disputes in the South China Sea and the East China Sea also show a difference." In order to examine this, I will classify Chinese gray zone strategy mechanisms multi-dimensionally in large order, 1) conflict trends and frequency of strategy execution, 2) types and strengths of strategy, 3) actors of strategy execution, and 4) response methods of counterparts. So, I tried to collect data related to this based on quantitative modeling to test these. After that, about 10 years of data pertaining to this topic were processed, and a research model was designed with a new categorization and operational definition of gray zone strategies. Based on this, I was able to successfully test all the hypotheses by successfully comparing the comprehensive mechanisms of the gray zone strategy used by China and the conflict patterns between the South China Sea and the East China Sea. In the conclusion, the verified results were rementioned with emphasizing the need to overcome the security vulnerabilities in East Asia that could be caused by China's marine gray zone strategy. This study, which has never been attempted so far, is of great significance in that it clarified the intrinsic structure in which China's gray zone strategy was implemented using empirical case studies, and the correlation between this and maritime conflict patterns was investigated.

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Regeneration of a defective Railroad Surface for defect detection with Deep Convolution Neural Networks (Deep Convolution Neural Networks 이용하여 결함 검출을 위한 결함이 있는 철도선로표면 디지털영상 재 생성)

  • Kim, Hyeonho;Han, Seokmin
    • Journal of Internet Computing and Services
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    • v.21 no.6
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    • pp.23-31
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    • 2020
  • This study was carried out to generate various images of railroad surfaces with random defects as training data to be better at the detection of defects. Defects on the surface of railroads are caused by various factors such as friction between track binding devices and adjacent tracks and can cause accidents such as broken rails, so railroad maintenance for defects is necessary. Therefore, various researches on defect detection and inspection using image processing or machine learning on railway surface images have been conducted to automate railroad inspection and to reduce railroad maintenance costs. In general, the performance of the image processing analysis method and machine learning technology is affected by the quantity and quality of data. For this reason, some researches require specific devices or vehicles to acquire images of the track surface at regular intervals to obtain a database of various railway surface images. On the contrary, in this study, in order to reduce and improve the operating cost of image acquisition, we constructed the 'Defective Railroad Surface Regeneration Model' by applying the methods presented in the related studies of the Generative Adversarial Network (GAN). Thus, we aimed to detect defects on railroad surface even without a dedicated database. This constructed model is designed to learn to generate the railroad surface combining the different railroad surface textures and the original surface, considering the ground truth of the railroad defects. The generated images of the railroad surface were used as training data in defect detection network, which is based on Fully Convolutional Network (FCN). To validate its performance, we clustered and divided the railroad data into three subsets, one subset as original railroad texture images and the remaining two subsets as another railroad surface texture images. In the first experiment, we used only original texture images for training sets in the defect detection model. And in the second experiment, we trained the generated images that were generated by combining the original images with a few railroad textures of the other images. Each defect detection model was evaluated in terms of 'intersection of union(IoU)' and F1-score measures with ground truths. As a result, the scores increased by about 10~15% when the generated images were used, compared to the case that only the original images were used. This proves that it is possible to detect defects by using the existing data and a few different texture images, even for the railroad surface images in which dedicated training database is not constructed.

Modern Enterprise & ESG Management philosophy of Gaeseong Ginseng Merchant (개성 인삼상인의 근대기업화와 ESG 경영이념)

  • Ock, Soon Jong
    • Journal of Ginseng Culture
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    • v.3
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    • pp.90-118
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    • 2021
  • Gaeseong fostered the conditions necessary for modern capitalism, as huge capital was accumulated through the cultivation and trade of ginseng, which were activities that flourished in the 18th century. During the Japanese colonial era, ginseng merchants were not simply limited to acquiring landowner capital from ginseng trade but actively converted such resource to productive and financial capital, thereby becoming modern entrepreneurs. Ginseng merchants led the joint management and investment of Gaeseong Electric Co., Ltd., Daehan Cheonil Bank, Gaeseong Brewing Co., Ltd., and Songgo Textile Company, founded in the early 20th century. They pursued corporate profits and, as leading individuals of society, spearheaded regional development by supporting educational and cultural projects in Gaeseong. These projects included the establishment of the Gaeseong Commercial School, the publication of Goryeo Times, and the operation of the Gaeseong Jwa Theater. Although liberal economics prioritized shareholder interest, the 21st century witnessed an emphasis on social responsibility among stakeholders asthe major purpose of enterprises. A trend that emerged was ESG (environment, social, governance) management, in which non-financial factors are valued more highly than financial performance. A successful business, which was denoted only by high profits in the past, is now defined by whether a company fulfills its social responsibility. In the early 20th century, the corporate activities of ginseng merchants in Gaeseong reflected entrepreneurship and stakeholder-centered ESG management, which later emerged as essential elements of modern business management. The modern management philosophy ahead of its times stemmed from the regionality of Gaeseong. The political discrimination against Gaeseong residents in the Joseon Dynasty precluded them from becoming government officers, and under a strict social hierarchy, yangban ("noblemen"), the intellectuals of the Joseon Dynasty, were forced to serve as merchants. Son Bong-sang and Kong Seong-hak, aside from being representative ginseng merchants, were both Confucian scholars and writers. The second and third generations of ginseng merchant families who had received higher education abroad returned to Gaeseong to carry on with their family businesses, then established modern companies with capital accrued from the ginseng industry. An analysis of the commercial activities of ginseng merchants in the early 20th century confirmed that these individuals were pioneering entrepreneurs who adopted the ESG management philosophy. In ginseng merchants, one sees a dimension of capitalism with a human face, as with ginseng thatsaves human life.

A Study on the trend of change in the number of elementary school students in Kyeonggi-do (경기도 초등학교 학생수 변화 경향에 대한 조사 연구)

  • Yoon, Yong-Gi;Choi, Ki-Seok
    • The Journal of Sustainable Design and Educational Environment Research
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    • v.20 no.1
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    • pp.43-54
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    • 2021
  • The results of the research and analysis are as follows: First, from the existing 57 types, 51 types were additionally discovered through the Gyeonggi-do research and analysis, and a total of 108 types could be subdivided. Second, as a result of the survey and analysis of Gyeonggi-do, 17 new unique types and the causes were found Third, out of 7 less than 10 years old schools, the Ns1 and Ns2 types were accounting for almost all of them. Of the 19 mid-term new schools, the Nm7 type accounted for 32.3%, and of the 41 long-term new schools, the most occupied type was Nl13 (33.5%). Among the 20 long-term rising types of 20 to 30 years old schools, the Ai19 type accounted for 22.6%, and the Ai8 type accounted for 19.4%. Among the 21 long-term decline types in existing schools, 17.0% was for the Ad5 type, 16.1% for the Ad15 type, 15.2% for the Ad10 type, 10.0% for the Ad7 type, and 8.1% for the Ad8 type.

Accuracy of implant digital scans with different intraoral scanbody shapes and library merging according to different oral exposure height (구내 스캔바디의 형태에 따른 임플란트의 디지털 스캔 정확도 및 구강 내 노출 높이에 따른 라이브러리 중첩 정확도 비교 연구)

  • Jeong, Byungjoon;Lee, Younghoo;Hong, Seoung-Jin;Paek, Janghyun;Noh, Kwantae;Pae, Ahran;Kim, Hyeong-Seob;Kwon, Kung-Rock
    • The Journal of Korean Academy of Prosthodontics
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    • v.59 no.1
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    • pp.27-35
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    • 2021
  • Purpose: The purpose of this study is to compare the accuracy of digital scans of implants according to different shapes of scanbodies, and to compare the accuracy of library merging according to different oral exposure height. Materials and methods: A master model with a single tooth edentulous site was prepared. For the first experiment, three types of intraoral scanbodies were prepared, divided into three groups, and the following experiments were conducted for each group: An internal hex implant was placed. The master model with the scanbody connected was scanned with a model scanner, and a master reference file (control group) was created. 10 files (experimental group) were created by performing 10 consecutive scans with an intraoral scanner. After superimposing the control and experimental groups, the following values were calculated: 1) Distance deviation of a designated point on the scanbody 2) Angle deviation of the major axis of the scanbody. For the second experiment, the scanbody scan data were prepared in 6 different heights. Library files were merged with each of the scan data. The distance and angular deviation were calculated using the 7 mm scan data as control group. Results: In the first experiment, there were no significant differences between A and B (P=.278), B and C (P=.568), and C and A (P=.711) in the distance deviations. There were no significant differences between A and B (P=.568), B and C (P=.546), and C and A (P=.112) in the angular deviations. Also, the scanbody showed significantly higher library merging accuracy in the groups with high oral exposure height (P<.5). Conclusion: There were no significant differences in scan accuracy according to the different shapes of scanbodies, and the accuracy of library merging increased according to exposure height of the scanbody in the oral cavity.

Comparative Analysis of Entrepreneurship Education and Entrepreneurship Programs in American Universities: Focusing on Major Entrepreneurship Centers in 7 Universities in the United States (미국 대학의 창업교육 및 창업프로그램 비교분석: 미국 7개 대학 주요 기업가정신센터를 중심으로)

  • Lee, Sung Ho;Nam, Jung Min
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.15 no.6
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    • pp.67-79
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    • 2020
  • This study analyzed the start-up education curriculum and start-up education programs of seven universities in the U.S. to find out what courses are provided, what various programs exist, and what the characteristics of start-up education in each university are. California State University, San Bernardino / University of California, Irvine / Drexel University / Oklahoma State University / Florida State University / San Diego State University / University of Southern California where entrepreneurship education based on the Entrepreneurship Degree Course is being established based on the Entrepreneurship Center of seven universities in the United States, which is not well introduced in Korea. This study examined how the start-up education courses and start-up support systems at seven universities in the U.S. are progressing at the undergraduate, MBA, master's and doctoral levels, and comparative levels. Through the case studies of the universities presented, the primary analysis was carried out to explore the various characteristics of American university start-up education. The implications of start-up education at American universities in this study are as follows. First, in order for universities to take the initiative in providing start-up education, they should be organized to suit the course of start-up education suitable for the characteristics of universities and introduce support programs. Second, it is necessary to establish an independent center within domestic universities to be operated autonomously. Third, the start-up education of universities should include building university-industry partnerships, operating entrepreneurship degree courses and collaboration between departments of universities. Fourth, the independent center should lead the active participation of alumni and local start-ups and start-up-related programs should be operated based on this. Fifth, Differentiated programs for each university's characteristics should be introduced and applied to universities. Although case studies have limitations that cannot be generalized, they can provide a useful framework. Therefore, it is necessary to design a systematic start-up education that reflects the correct design direction and characteristics of each university.

A Study on Investors Determinants Addressed by Startup Entrepreneurs : In the Center of Startups in Water Industry (창업기업관점에서 바라본 투자자의 투자결정요인에 관한 연구 : 물산업 창업기업을 중심으로)

  • Park, Dong Il;Yang, Young Seok;Kim, Myung Seuk
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.16 no.1
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    • pp.1-19
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    • 2021
  • The purpose of this research is to improve the investment success rate for startups in the water industry for the development of the entrepreneurial environment of the Korean water industry. In this research, we identified investment determinants through prior research and stratified them, and then surveyed the investor group at the beginning of the start-up using the FGI method, and determined the order of the investment determinants of investors. At the same time, we classified 41 start-ups related to the water industry into two groups: the group that received investment and the group that did not in the early stages of the start-up. Then we investigated the understanding of the investor's investment determinants, ranked them, and compared them by using the AHP technique. Through this, this research proposes five implications. First, it is important for start-ups in the early stages to receive seed investment to revitalize investment for startups in the water industry. For this, startups need to understand investors and prepare to attract investment with the perspective of angel investors rather than the perspective of VC investors. Second, Start-ups in the water sector should consider that the characteristics of the founder are important in order to receive seed investment, and also need to define their business at the industry and market level, and provide relevant rationale to meet the expectations of investors who value industry expertise and experience, and to increase the possibility of seed investment, which is important in the early stages of a startup. Third, institutions, such as K-water(Korea Water Resources Corporation), that support water industry startups need to conduct open innovation business opportunities discovery programs linked to startups so that startups currently participating in the startup support program could have business opportunities from the business infrastructure of platform-forming companies in the water industry. In particular, such institutions should help founders develop their industrial expertise and careers by supporting this type of start-up preparation process through the participation of in-house venture founders. Fourth, when K-water uses the government start-up support fund to discover and foster founders, it should increase initial contact with seed investors, conduct more thorough verification of business plans, and develop programs that use government start-up support funds to prepare a business suitable for seed angel investors. Fifth, K-water should support seed by connecting funds for initial investment among funds operated by itself. It is also necessary to develop a program that links the company receiving the seed investment with VC investment, not angel investment in cooperation with the VC fund operation entity participating as an LP so that companies that have attracted seed investment could attract follow-up VC investment.

GIS-based review of Goguryeo's defense system during the Gungnaeseong Period with the focus on the upper and middle reaches of the Amnok River and the mid-stream region of the Liohe River (GIS를 활용한 고구려 국내성 시기의 관방체계 검토 - 압록강 중상류~요하 중류를 중심으로 -)

  • Hong, Balgeum;Kang, Dongseok
    • Korean Journal of Heritage: History & Science
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    • v.54 no.1
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    • pp.260-279
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    • 2021
  • The Goguryeo kingdom established a unique defense system centered on a series of mountain fortresses. However, modern-day studies on its defense system have tended to focus on how they were positioned and generally consist of little more than individual surveys or introductions to the relevant materials, leaving much to be desired. This study attempts to extend the scope of studies about fortresses dating back to the Goguryeo period, taking into account the limitations of the available materials. As such, this study reviews the defense system of Goguryeo during the Gungnaeseong Period (i.e., the period when Gungnaeseong was the capital of Goguryeo) using the GIS system, with the focus on fortresses that are thought to have been built in the area extending from the middle and upper reaches of the Amnok River to the mid-stream region of the Liohe River, based on the aforementioned studies. The results of the study are as follows. First, the major roads built during the Gungnaeseong Period were as stated in the foregoing studies to some extent. Researchers believed that during the middle period of the dynasty, a major road ran along the Suzihe, Fuer and Xinkai rivers before finally reaching Jian. The study found that fortified walls and fortress strongholds were built along this road. Second, there were seven fortresses between the middle and upper reaches of the Amnokgang River and the midstream region of the Liaohe River. A primary defense line was closely established between the strongholds and the nearby walls, with secondary and tertiary defense lines established more loosely and encompassing a much wider area. Third, regarding the defense system along the major roads, the Choejinbosanseong, Goisanseong and Cheolbaesanseong fortresses served as strongholds along the 60-kilometer-long primary defense line, with 80-kilometer-long secondary and tertiary defense lines set up behind it. The final 120-kilometer-long defense line of the capital was established along with the Onyeosanseong Fortress, while a stumbling block was set up close to the capital as a defense system, rather than building a fortified wall. To summarize, a primary defense system was established centered on a series of fortresses, with each stronghold maintaining a closely-knit defense system in connection with other nearby strongholds to repel invaders.