• Journal of Radiation Protection and Research
• /
• v.40 no.3
• /
• pp.124-131
• /
• 2015

Radiation exposure to humans can be caused by the gamma rays emitted from natural radioactive elements(such as uranium, thorium and potassium and any of their decay products) of Naturally Occurring Radioactive Materials(NORM) or Technologically Enhanced Naturally Occurring Radioactive Materials(TENORM) added consumer products. In this study, assume that activity of radioactive elements is $^{238}U$, $^{235}U$, $^{232}Th$ $1Bq{\cdot}g^{-1}$, $^{40}K$ $10Bq{\cdot}g^{-1}$ and the gamma rays emitted from these natural radioactive elements radioactive equilibrium state. In this study, reflected End-User circumstances and evaluated annual exposure dose for products based on ICRP reference voxel phantoms and ICRP Recommendation 103 using the Monte Carlo Method. The consumer products classified according to the adhere to the skin(bracelet, necklace, belt-wrist, belt-ankle, belt-knee, moxa stone) or not(gypsum board, anion wallpaper, anion paint), and Geometric Modeling was reflected in Republic of Korea "Residential Living Trend-distributions and Design Guidelines For Common Types of Household.", was designed the Room model($3m{\times}4m{\times}2.8m$, a closed room, conservatively) and the ICRP reference phantom's 3D segmentation and modeling. The end-user's usage time assume that "Development and Application of Korean Exposure Factors." or conservatively 24 hours; in case of unknown. In this study, the results of the effective dose were 0.00003 ~ 0.47636 mSv per year and were confirmed the meaning of necessary for geometric modeling to ICRP reference phantoms through the equivalent dose rate of belt products.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
• /
• v.15 no.1
• /
• pp.209-224
• /
• 2020

This study started from the question of whether the preference of corporate recruitment can be achieved without any difference between the start-up experiencer and the general job seekers. Therefore, the purpose of the study is to identify the factors related to start-ups that affect the preference of job seekers for companies, and to analyze the differences in the factors related to start-ups between general job seekers and job seekers with start-up experience. Third, it is to see the difference in the preference for employment between job seekers with start-up experiences and general job seekers. The independent variables of the research model were entrepreneurship, motivation for start-up (job search), and characteristics of the job seekers (founder). The dependent variables were job preference, and the moderating variables were presented as job seekers' classification (job seekers with start-up experience vs. general job seekers). The subjects of the study were personnel managers of 100 companies with more than 5 years of establishment and 100 new companies with less than 5 years of establishment. The questionnaire was distributed in two types, and 189 respondents, including 101 job seekers with start-up experiences and 88 general job seekers, were finally used for analysis. The results of the study were as follows. First, as a result of multiple regression analysis on both experienced start-up experiencers and general job seekers, only entrepreneurship had an effect on preference for recruitment. Second, the moderating effect of job seekers' classification was found only in the relationship between motivation for start-up and preference for employment. Third, the result of multiple regression analysis based on the start-up experiencers showed that the relationship between the motivation for start-up, the preference for recruitment, the characteristics of founders and the preference for recruitment was statistically significant. On the other hand, the characteristics of the founder and the preference for employment were rejected. Fourth, the results of the study based on general job seekers showed that the motivation for job search decreased the preference for employment. The study did not provide the results of differences in recognition between different industries, traditional enterprises and venture businesses due to the limitation of small examples. There is no clear definition of start-up experiencers either. However, it is meaningful to suggest the implications of what preparations should be made when the start-up experiencers close their start-ups and turn their career into employment and to help them to accurately recognize the importance of entrepreneurship. It also provides the preference of the general job seekers for the company, the preparation for successful employment, and the implications for the direction of the future start-up revitalization.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
• /
• v.15 no.2
• /
• pp.19-32
• /
• 2020

The purpose of this study was to investigate the influence factors of the university level centering on the entrepreneurial performance of the university students and full-time faculties in the situation of increasing interest in entrepreneurial university. In order to achieve the purpose of the study, a panel data was established from 2015 to 2018 on the basis of the university notification data. The panel data included universities with data on the number of university students and full-time faculty founders for at least two years. Through this, four year data from 154 universities were used for analysis. As an analysis method, frequency analysis and descriptive statistics were conducted to understand the characteristics of the university. Since then, panel negative binomial regression analysis has been conducted in consideration of the longitudinal features and distribution of the data. Also, based on the Hausman test results, the results were interpreted based on random effect model. The results of this study are as follows. First, as a result of the analysis of the entrepreneurial performance and the change trend of the domestic university from 2015 to 2018, the entrepreneurial performance of the university has been steadily increasing in the last four years, and the increase in the number of university student entrepreneurs was relatively higher than the full-time faculties. Second, economic and educational approaches need to be combined to promote university students' start-ups. The university factors that promote the start-up of university students were found to be scholarships, start-up grants, startup lectures, and startup clubs. Third, the openness and regional characteristics of the univeristy can promote the establishment of university students. Fourth, the establishment of a research environment and support for start-ups for full-time faculty members can enhance their start-up performance. The university factors that promote the start-up of full-time faculty were research funds and staffes who support start-up. The conclusions drawn from these findings are as follows. First, overall efforts are needed to develop into an entrepreneurial university. Second, in order to change into an entrepreneurial university, direct support for entrepreneurship is needed. Third, as an entrepreneurial university, it is necessary to find a way to bridge the gap by university according to region and size. Fourth, it is necessary to reinforce the support for linking the research results of universities to start-ups. Fifth, it is necessary to improve the atmosphere for full-time faculty members to be entrepreneur.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
• /
• v.15 no.2
• /
• pp.47-65
• /
• 2020

With the era of the Fourth Industrial Revolution in sight, innovative business models utilizing new technologies are emerging, and startups are enjoying an abundance of opportunities based on the agility to respond to disruptive innovations and the opening to new technologies. However, what is most important in creating a sustainable start-up ecosystem is not the start-up itself, but the process of research-start-investment-investment-the leap to listing and big business-in order to build a virtuous circle of startups that leads to re-investment. To this end, the environment created in the hub area where start-ups were conducted is important, and these material and non-material environmental factors are described as being inclusive by the word "entrepreneurial ecosystem." This study aims to provide implications for Korea's entrepreneurial ecosystem through the study of the interaction of the elements that make up the start-up ecosystem and the relationship of ecosystem participants in Singapore. Singapore has been consistently mentioned as the top two Asian countries in assessing the start-up environment and business environment. In this process, six elements of the entrepreneurial ecosystem presented by Isenberg(2010)-policies, finance, culture, support, human resources, and market-are the best frameworks for analyzing entrepreneurial ecosystems in terms of well encompassing prior studies related to entrepreneurial ecosystem elements, and a model of regional transformation is formed focusing on some elements to suit Singapore, the target area of study. By considering that Singapore's political nature would inevitably have a huge impact on finance, Smart Nation policy was having an impact on university education related to entrepreneurship, and that the entrepreneurial networks and global connectivity formed within Singapore's start-up infrastructure had a significant impact on Singapore's start-up's performance, researches needed to look more at the factors of policy, culture and market. In addition, qualitative research of participants in the entrepreneurial ecosystem was essential to understand the internal interaction of the elements of the start-up ecosystem, so the semi-structured survey was conducted by visiting the site. As such, this study examined the status of the local entrepreneurial ecosystem based on qualitative research focused on policies, culture and market elements of Singapore's start-up ecosystem, and intended to provide implications for regulations related to start-ups, the role of universities and start-up infrastructure through comparison with Korea. This could contribute not only to the future research of the start-up ecosystem, but also to the creation of a start-up infrastructure, boosting the start-up ecosystem, and the establishment of the orientation of the start-up education in universities.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.24 no.6
• /
• pp.750-763
• /
• 2018

This study conducted 10 sampling sites survey 4 times to determine the trophic structure and energy flow of marine ecosystems for Uljin marine ranching area, Korean East Sea from March to October 2013. Based on the ecological characteristics of biological species, one used the non-Metric Multidimensional Scaling method based on the similarity of species. A total of 19 classified species groups formed categories including, top predators, seabirds, large pelagic fishes, small pelagic fishes, rockfishes, pleuronectiformes, benthic fishes, semi-benthic fishes, cephalopods, benthic feeders, epifauna, bivalves, abalone, Cnidaria, zooplankton, benthic algae, microalgae, phytoplankton and detritus. The biomass, production/biomass, consumption/biomass, diet composition data of each species groups to input data used in Ecopath mode estimated the trophic structure and energy flow of marine ecosystems in the Uljin marine ranching area. One estimated each species groups on the trophic level from 1 to 5.687. The sum of all consumption was estimated at $229.7t/km^2/yr$ and the sum of all exports was as estimated $3,432.4t/km^2/yr$. Total system throughput was at $6,796.2t/km^2/yr$, and the sum of all production was estimated at $3,613.1t/km^2/yr$. Net system production according to these results was estimated at $3,490.3t/km^2/yr$ and total biomass (excluding detritus) was estimated at $167.3t/km^2/yr$ in the Uljin marine ranching area.

• Management & Information Systems Review
• /
• v.37 no.2
• /
• pp.149-167
• /
• 2018

The purpose of this study is to analyze the performance of Virtual Desktop Infrastructure(VDI) adoption. VDI performance was measured by IS manager (system quality, security, and managerial operation) and business user (usability, access, and user satisfaction). The survey questionnaires were developed for measuring VDI performance. 84 data samples were collected from the companies that had adopted cloud-based VDI. This research model was verified by Smart-PLS and SPSS. The research findings were as follows: First, the companies using VDI experienced actual performance, but they did not attain their expectation. Second, as results of comparing between IS managers and business users, IS administrators had considerably higher performance than business users, which indicates that there were big differences in performance perception among users. Compared with prior research such as technical trend, system construction, and performance improvement, this study has the following implications. First, by comparing the expected performance with the actual performance of the companies that have implemented and operating VDI, it was suggested how a company that wants to adopt VDI can manage the expectation level of VDI and achieve higher actual performance. Second, because the perception of VDI performance differs between business users and system managers, it is meaningful that a fair evaluation of VDI performance requires a balanced consideration of business users and system managers.

• Korean Journal of Environment and Ecology
• /
• v.26 no.2
• /
• pp.273-282
• /
• 2012

This study has estimated Gyeongju National Park's natural environment and cultural relic value in the same way and then been performed to compare the size of the value. Representative method to measure environmental property is contingent valuation methods, CVM. The variables and estimated models adopted for the calculation were same and the respondents were asked by distinguishing between the amount which they would pay to preserve the natural environment and that which they were willing to pay to preserve the cultural relics. As the result, WTP(Willing to pay), the amount that they were willing to pay to preserve the natural environment of Gyeongju National Park was 17,838 won per person and that to preserve the cultural relics appeared to be 316,248 won per person. Based on this, it was estimated that the value of the natural environment with which Gyeongju National Park provided annual visitors was 47 billion won and that the annual value of the cultural relics was 845.7 billion. If the natural environment and the cultural relics value elements are united, it can be estimated that the natural environment and cultural relic value got at the time of people's first visit to Gyeongju National Park is 334,086 won and that the annual value is 893.4 billion won. In this study, the value of the cultural relics has been estimated 18 times higher than that of the natural environment. This reason was that visitors judged that a total of 66 cultural properties including 11 national treasures, 23 treasures, 13 historic places, one historic sites and scenic spot and 18 local cultural properties, etc. which were distributed in Gyeongju National Park were worth far more than the natural environment. Based on the result of this study, the operating management plan of Gyeongju National Park should include a differentiated operation strategy through consultation with relevant experts by taking into account characteristics of the physical components.

• Economic and Environmental Geology
• /
• v.38 no.5 s.174
• /
• pp.547-561
• /
• 2005

General characteristics of groundwater contamination by As were reviewed with several recent researches, and its occurrence in groundwater of Korea was investigated based on a ffw previous studies and a groundwater quality survey in Nonsan and Geumsan areas. In Bangladesh, which has been known as the most serious arsenic calamity country, about $28\%$ of the shallow groundwaters exceeded the Bangladesh drinking water standard, $50{\mu}g/L$, and it was estimated that about 28 million people were exposed to concentrations greater than the standard. Groundwater was characterized by circum-neutral pH with a moderate to strong reducing conditions. Low concentrations of $SO_4^{2-}$ and $NO_3^-$, and high contents of dissolved organic carbon (DOC) and $NH_4^+$ were typical chemical characteristics. Total As concentrations were enriched in the Holocene alluvial aquifers with a dominance of As(III) species. It was generally agreed that reductive dissolution of Fe oxyhydroxides was the main mechanism for the release of As into groundwater coupling with the presence of organic matters and microbial activities as principal factors. A new model has also been suggested to explain how arsenic can naturally contaminate groundwaters far from the ultimate source with transport of As by active tectonic uplift and glaciatiion during Pleistocene, chemical weathering and deposition, and microbial reaction processes. In Korea, it has not been reported to be so serious As contamination, and from the national groundwater quality monitoring survey, only about $1\%$ of grounwaters have concentrations higher than $10{\mu}g/:L.$ However, it was revealed that $19.3\%$ of mineral waters, and $7\%$ of tube-well waters from Nonsan and Geumsan areas contained As concentrations above $10{\mu}g/:L.$. Also, percentages exceeding this value during detailed groundwater quality surveys were $36\%\;and\;22\%$ from Jeonnam and Ulsan areas, respectively, indicating As enrichment possibly by geological factors and local mineralization. Further systematic researches need to proceed in areas potential to As contamination such as mineralized, metasedimentary rock-based, alluvial, and acid sulfate soil areas. Prior to that, it is required to understand various geochemical and microbial processes, and groundwater flow characteristics affecting the behavior of As.

• Horticultural Science & Technology
• /
• v.33 no.4
• /
• pp.501-510
• /
• 2015

In this study, we investigated the onset and release of endo-dormancy under natural conditions by observing bud break characteristics in 'Fuji' apple trees using water cuttings. Through examinations of bud break rate and days to bud break, we found that the endo-dormancy of 'Fuji' apple tree continues for 70 d from 165 to 255 d after full bloom (DAFB), from late October to early January of the following year. In addition, within 20 d of first bud break, based on a final bud break rate of 60% or more, we able to identify the timing of the changeover from para-dormancy to endo-dormancy, and endo-dormancy to eco-dormancy. Analysis of the chilling requirement during the endo-dormancy period revealed that chilling accumulation up to 255 DAFB to release endo-dormancy amounted to 666 and 517 h based on the CH and Utah models, respectively. Observation of internal changes in the bud during endo-dormancy showed that flower bud differentiation begins from mid-July, and t ime of inflorescence o f the disk f lower is a vailable to f ind. The f lower buds subsequently developed slowly but steadily during endo-dormancy and in the following year in February, the developmental stage of each organ had progressed. Moreover, the flower buds of 'Fuji' apples were mostly healthy during the dormancy period, but some exhibited necrosis of flower primordium, due partial cell damage from the formation of ice crystals rather than a direct effect of the low temperature. Flower buds were formed in both the axillary buds of bourse shoots and terminal buds of spurs, but lower bud differentiation was observed for the terminal buds of spurs at rate of about 65% of total buds, which was directly related to the bud size and shoot diameter.

• Science of Emotion and Sensibility
• /
• v.13 no.1
• /
• pp.47-60
• /
• 2010

Most of the researches about classification usually have used kNN(k-Nearest Neighbor), SVM(Support Vector Machine), which are known as learn-based model, and Bayesian classifier, NNA(Neural Network Algorithm), which are known as statistics-based methods. However, there are some limitations of space and time when classifying so many web pages in recent internet. Moreover, most studies of classification are using uni-gram feature representation which is not good to represent real meaning of words. In case of Korean web page classification, there are some problems because of korean words property that the words have multiple meanings(polysemy). For these reasons, LSA(Latent Semantic Analysis) is proposed to classify well in these environment(large data set and words' polysemy). LSA uses SVD(Singular Value Decomposition) which decomposes the original term-document matrix to three different matrices and reduces their dimension. From this SVD's work, it is possible to create new low-level semantic space for representing vectors, which can make classification efficient and analyze latent meaning of words or document(or web pages). Although LSA is good at classification, it has some drawbacks in classification. As SVD reduces dimensions of matrix and creates new semantic space, it doesn't consider which dimensions discriminate vectors well but it does consider which dimensions represent vectors well. It is a reason why LSA doesn't improve performance of classification as expectation. In this paper, we propose new LSA which selects optimal dimensions to discriminate and represent vectors well as minimizing drawbacks and improving performance. This method that we propose shows better and more stable performance than other LSAs' in low-dimension space. In addition, we derive more improvement in classification as creating and selecting features by reducing stopwords and weighting specific values to them statistically.