• Journal for History of Mathematics
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• v.19 no.1
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• pp.65-78
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• 2006

The law of refraction, which is called Snell's law in physics, has a significant meaning in mathematics history. After Snell empirically discovered the refraction law $\frac{v_1}{sin{\theta}_1}=\frac{v_2}{sin{\theta}_2$ through countless observations, many mathematicians endeavored to deduce it from the least time principle, and the need to surmount these difficulties was one of the driving forces behind the early development of calculus by Leibniz. Fermat solved it far advance of others by inventing a method that eventually led to the differential calculus. Historically, mathematics has developed in close connection with physics. Physics needs mathematics as an auxiliary discipline, but physics can also belong to the lived-through reality from which mathematics is provided with subject matters and suggestions. The refraction law is a suggestive example of interrelations between mathematical and physical theories. Freudenthal said that a purpose of mathematics education is to learn how to apply mathematics as well as to learn ready-made mathematics. I think that the refraction law could be a relevant content for this purpose. It is pedagogically sound to start in high school with a quasi-empirical approach to refraction. In college, mathematics and physics majors can study diverse mathematical proof including Fermat's original method in the context of discussing the phenomenon of refraction of light. This would be a ideal environment for such pursuit.

• Journal of Nutrition and Health
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• v.45 no.6
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• pp.588-599
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• 2012

There is a limitation to estimate vitamin $B_{12}$ intake due to the lack of data on vitamin $B_{12}$ content of Korean commercial foods. In this study, vitamin $B_{12}$ content was determined in favorite Korean restaurant foods, convenient or instant foods, fast foods and bakery products through a modified microbioassay using Lactobacillus delbrueckii ATCC 7830. Bulgogi and seafood & green pepper griddle had high vitamin $B_{12}$ content, 3.50 and $2.96{\mu}g$/100 g, respectively. Pork suyook, pork griddle and pollack griddle had 0.48, 0.31 and $0.32{\mu}g$/100 g of vitamin $B_{12}$, respectively. In stew, soft-tofu stew with seafood and doenjang stew with seafood had relatively high vitamin $B_{12}$ content, 1.93 and $1.44{\mu}g$/100 g, respectively. Bibimbap and 4 different types of rice porridge, beef & mushroom, chicken & ginseng, seafood or abalone, had 0.36, 0.08, 0.09, 1.64 and $0.13{\mu}g$/100 g of vitamin $B_{12}$, respectively. One serving of haejanggguk, yookejang, chuotang and galbitang had 5.97, 2.04, 2.63 and $1.91{\mu}g$ of vitamin $B_{12}$, respectively. One serving of samgetang and sulongtang had $2.89{\mu}g$ and $6.64{\mu}g$ of vitamin $B_{12}$. In noodles, one serving of cram noodle soup, bibim-nangmyeon, and mul-nangmyeon had 18.8, 1.21 and $0.38{\mu}g$ of vitamin $B_{12}$, respectively. One regular gimbap and one triangle gimbap contained 1.09-2.53 and $0.54-1.11{\mu}g$ of vitamin $B_{12}$, respectively. One cheese-burger, chicken-burger and bulgogi-burger had 0.76, 0.62 and $0.54{\mu}g$ of vitamin $B_{12}$, respectively. A plain bagel and a waffle contained 0.13 and $0.17{\mu}g$/100 g of vitamin $B_{12}$, respectively. Ready-made tomato sauce or cream sauce for spaghetti in a retort pouch contained only a trace of vitamin $B_{12}$. In conclusion, these results should contribute to improving the present food vitamin $B_{12}$ content database, most of which were cited from foreign data, thereby it could be helpful to estimate the vitamin $B_{12}$ intake of Koreans more accurately than before. It will also provide new information for dietary education related to vitamin $B_{12}$ and health.

• The Journal of the Korea Contents Association
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• v.17 no.8
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• pp.121-129
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• 2017

The evolution of biotechnology is no longer strange to the hypothetical scenario of cloning human genes to make cloned human beings. The characters of are cloned humans made in the laboratory by the 100-year-old life planning. They are cohabited in a school called Hailsham, where they are secretly reared. The purpose of this project is to provide healthy organs to real human patients with incurable diseases. The main characters Cathy, Tommy, and Ruth experience the growth of body and consciousness here during adolescence, and they also know the secret of identity as a clone. As adults, they move to a second residence, Cottage and are ready to begin organ donation. The second stage is also part of a program to provide more genuine-like organs to real patients. Even though they know all the plans that humans have built, they do not resist them and fatefully accept their situation. However, their non-responsiveness is not a declaration of renunciation of life, but a self-sacrificing life extension for another future that is the extension of life through their organ donation. The film emphasizes the fraternity and sacrificial attitudes of the cloned human beings and shows that it is necessary to continue the discussions on cloned human beings from a bio-ethical point of view supported by philosophical reasons.

• Journal of the Korean Institute of Landscape Architecture
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• v.34 no.3 s.116
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• pp.120-138
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• 2006

A city evolves over time. It grows, transforms, and sometimes degrades. Chuncheon is at a turning point from a city souggling with regulations regarding clean water supply and a military encampment to a masterpiece city with a sustainable vision. The city is getting ready to restructure itself to become a world-famous culture and tourism complex expanding its physical boundary across the Camp Page site and absorbing Jungdo as a major tourist attraction. The landscape in the future blueprint of Chuncheon will play a great role in restructuring urban form. The regenerated in will have a new networked open space system as well as re-evaluated landscape resources. The hybrid theoretical practice called 'landscape urbanism' burgeoning in the fields between 'landscape architecture' and 'urbanism' can guide us in considering the terms of the relationship between a city and landscape when we design a future city Landscape urbanism is considered to be an effective framework by which we can diagnose the current status of a landscape in our contemporary urban design practice in Korea. This paper tries to provide a different perspective from the viewpoint of landscape urbanism to decipher the hidden implications of the social agreement on the role of landscape in urban structure by re-reading eight design proposals presented for the ChunCheon G5 international design competition based on the main principles of landscape urbanism. The G5 design competition is a great opportunity to test out new ideas on a city, demonstrating the relative values among various urban-design professional realms. First, this paper provides an overview of the main ideas of landscape urbanism based on the literature review and case studies. Second, framework categories are suggested in order to extract the explicit and implicit ideas on the landscape. Third, eight proposals are reviewed according to the suggested categories to situate the current landscape design of Korea within the mainstream of contemporary practice of landscape urbanism. Based on the review of eight proposals, the following diagnostic conclusions are made; first, the ideas of landscape urbanism have not been actively introduced in large-scaled urban landscape projects in Korea like Chuncheon G5. Second, it remains to be a big task for landscape professions to be able to participate in design consortiums on an equal footing. Third, In order to introduce and reify the ideas of landscape urbanism in Korea, it is inevitable and critical to test the ideas in both academic fields and professional practices to find the appropriately adjusted model of landscape urbanism.

• Fisheries and Aquatic Sciences
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• v.7 no.2
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• pp.64-69
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• 2004

A bacteriological survey for 20 large grocery stores (M 1 to M20) in Korea was investigated for one year. The average detection rate of Esherichia coli was $22\%$ (166/763) for 7 kinds of ready-to-eat food through the year, where each grocery store and each type of food showed different detection rates. Eleven grocery stores showed lower detection rates, while 9 grocery stores showed a higher than average rate. Especially, M3 showed a rate that was twice as high as the average and one which was 7 times higher than M14, which had the lowest rate of $6\%$ E. coli detection. The detection rate for each type of food was: $38\%$ (41/109) for Kimbop, $31\%$ (34/109) for vegetable salad, $19\%$ (21/109) for bean-curd, $18\%$ (20/109) for the cooked materials used in making Kimbop, $17\%$ (19/109) for Hoe (sliced raw fish) and Sushi (Japanese vinegared rice delicacies), and $11\%$ (12/109) for cooked pork hock. During the summer, the E. coli detection rate averaged $43\%$ (71/166), which was twice as high as other seasons. Most (89/100) of the food contacting surfaces contained more than the critical limit $(1.3\;log_{10}\;CFU/10cm^2)$ of aerobic viable cell counts (AVC). The $log_{10}$ AVC and $log_{10}$ coliform count (CC) of 218 meat samples (beef, pork, and chicken) ranged between 4.6-7.1 CFU/g and 1.9-6.4 CFU/g, except for 41 meat samples $(19\%)$ which were found to contain no coliform. There was a definite correlation between the $log_{10}$ AVC and $log_{10}$ CC, and the values of $log_{10}$ CC made a more accurate straight than the $log_{10}$ AVC, which are variable. From these results, it is suggested that a detection rating of less than 2.1 CFU/g of $log_{10}$ CC (correspond to 5.0 CFU/g of $log_{10}$ AVC) is the critical point of freshness, and a rating of more than 6.3 CFU/g of $log_{10}$ CC (correspond to 7.0 CFU/g of $log_{10}$ AVC) can be considered an initial spoilage point.

• Journal of the East Asian Society of Dietary Life
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• v.19 no.2
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• pp.157-168
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• 2009

The principal objective of this study was to provide basic data regarding health care services for middle-aged men, via an analysis of the relationships among stress level, food habits and well-being-related attitudes with social-demographic characteristics and health-related factors. The main findings of this study were as follows. The average age of the participants was $48.7{\pm}5.2$. With regard to health status, 18.8% of the participants were diagnosed with digestive diseases within the past year. Stress levels were higher in the participants with lower levels of educational attainment. Furthermore, participants who had become divorced or lived separately from their families, participants who did not have their own houses, and participants who reported low marital satisfaction also had high levels of stress. Our food habits scores revealed meaningful differences among the study subjects, and were shown to vary with marital satisfaction, occupation, and residence type. In terms of both the importance and practice level of well-being-associated food habits, the most frequent response in this study was 'Consume home-made food rather than processed or ready-to-eat food' ($4.30{\pm}0.86$, $3.68{\pm}1.04$). In terms of importance level, the factors most relevant to well-being in terms of food habits were education level, marital satisfaction, residence type, self-assessed health status, smoking, drinking, regular exercises and leisure activities. With regard to practice levels, the degree to which subjects engaged in food habits targeted toward well-being differed meaningfully depending on marital status, marital satisfaction, residence type, family type, self-assessed health status, smoking, drinking, nutritional supplement intake, regular exercises and leisure activities. After analyzing the correlation among stress level, food habit score and the attitude towards well-being-related dietary habits (importance and practice level), we observed a meaningful relationship between the four factors at the level of p<0.001. According to the above result, continuous attention to health, including the appropriate control of smoking and drinking, as well as, stress management, via regular exercises and appropriate food habits is expected to exert a positive influence on the prevention of disease, and is also expected to improve quality of life. For all well-being-associated items, the importance level was shown to be higher than the practice level. Thus, in order to foster health-oriented food habits, we recommend that a new plan be designed, targeted toward ease of active practice for middle-aged men.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.1261-1262
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• 2008

Laser-based crystallization techniques are ideally-suited for forming high-quality crystalline Si films on active-matrix display backplanes, because the highly-localized energy deposition allows for transformation of the as-deposited a-Si without damaging high-temperature-intolerant glass and plastic substrates. However, certain significant and non-trivial attributes must be satisfied for a particular method and implementation to be considered manufacturing-worthy. The crystallization process step must yield a Si microstructure that permits fabrication of thin-film transistors with sufficient uniformity and performance for the intended application and, the realization and implementation of the method must meet specific requirements of viability, robustness and economy in order to be accepted in mass production environments. In recent years, Low Temperature Polycrystalline Silicon (LTPS) has demonstrated its advantages through successful implementation in the application spaces that include highly-integrated active-matrix liquid-crystal displays (AMLCDs), cost competitive AMLCDs, and most recently, active-matrix organic light-emitting diode displays (AMOLEDs). In the mobile display market segment, LTPS continues to gain market share, as consumers demand mobile devices with higher display performance, longer battery life and reduced form factor. LTPS-based mobile displays have clearly demonstrated significant advantages in this regard. While the benefits of LTPS for mobile phones are well recognized, other mobile electronic applications such as portable multimedia players, tablet computers, ultra-mobile personal computers and notebook computers also stand to benefit from the performance and potential cost advantages offered by LTPS. Recently, significant efforts have been made to enable robust and cost-effective LTPS backplane manufacturing for AMOLED displays. The majority of the technical focus has been placed on ensuring the formation of extremely uniform poly-Si films. Although current commercially available AMOLED displays are aimed primarily at mobile applications, it is expected that continued development of the technology will soon lead to larger display sizes. Since LTPS backplanes are essentially required for AMOLED displays, LTPS manufacturing technology must be ready to scale the high degree of uniformity beyond the small and medium displays sizes. It is imperative for the manufacturers of LTPS crystallization equipment to ensure that the widespread adoption of the technology is not hindered by limitations of performance, uniformity or display size. In our presentation, we plan to present the state of the art in light sources and beam delivery systems used in high-volume manufacturing laser crystallization equipment. We will show that excimer-laser-based crystallization technologies are currently meeting the stringent requirements of AMOLED display fabrication, and are well positioned to meet the future demands for manufacturing these displays as well.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.32 no.3
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• pp.260-264
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• 2010

Treatment of the mandibular fracture consists of reduction and fixation. The apparatus that is used to keep the jaws together during healing will often reduce the fracture as well. When the jaws are brought together and intermaxillary elastic rubber traction is placed, the occlusion of the teeth will help to orient the fractured parts into good position. Intermaxillary fixation, that is, fixation obtained by elastic bands between the upper & lower jaws to which suitable anchoring devices have been attached, will successfully treat most fractures of the mandible. Arch bars are perhaps the ideal method for intermaxillary fixation. Several types of ready-made arch bars are used. But, daily occupational life and oral hygiene is difficult to maintain during the period of longterm immobilized intermaxillary fixation (commonly 6-8 weeks), owing to malnutrition and emotional disorders in a position of the patient with mandibular fractures. Most mandibular fractures heal well enough to allow removal of fixation in about 6 weeks. Though there are many complications of mandibular fracture, such as infection, hemorrhage, trismus, paresthesia and nonunion, it is favorable to attain the short-term removable intermaxillary fixation care by use of an additive incision & drainage establishment on the oral lacerated wounds of adjacent mandibular compound fractures. The purpose of an additive incision & drainge establishment is the prevention of wound infection & nonunion by removing the hematoma & seroma in the fracture sites.

• Journal of Environmental Science International
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• v.27 no.5
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• pp.281-289
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• 2018

The Korean environmental impact assessment(EIA) system, and explored ways to improve it as a more efficient and viable institution relevant to the demand of our time and conditions in study. The first problem this study identified is found in the fact that the party to write up the assessment report is itself the business operator or the one who is planning to work out the business plan. This structure translates into placing an order with an agent for EIA report. The reporting job may br subcontracted to the agent at a cost far below the rate specified in the 'Standard for Estimate of Agency Fee for Environmental Impact Assessment.' This practice also causes the vicious circle of producing a report that is written to justify the project or business in question or it leads to rough-and ready and poor documentation to minimize the time required. Second, in order to achieve the goal of the plan or business, which is the target of EIA, the local residents tend to ve regarded as an obstacle. This means elimination of the local people from participating in the EIA or their opinion being frequently ignored. This is the seed of distrust and hostility that sometimes provoke disagreements or fierce conflicts. The first proposal to improve these problem is to improve the factors that cause poor documentation of the assessment report as well as improve the understanding of the EIA system. This study proposes the following measures for improvement. The agency cost for EIA should be paid by the business operator or a third party that can ensure faithful implementation of the payment. A system should be established to verify transparent estimation of the agency cost. In order to enhance the professional quality of EIA agents, there should be implementation of qualification test for industrial engineer of related engineers in addition to the current EIA Qualification Test. The second proposal for improvement is to improve the citizen participation process by instituting a legal framework to make clear the purpose of the briefing session for local residents, which is held as a procedure of EIA, and to ensure more positive publicity during the stage of listening to the opinion of the local community. For a smooth and rational communication process, a moderator and a communicator of opinion, as is the case in a public hearing, could be instituted to clearly get the purpose of the briefing session across to the residents and to help to carry out the explanation and Q & A sessions according to the categories of the opinion of the residents. At present, the notification of the public inspection of the draft of the assessment report and briefing session for the residents is made on the newspaper and internet network. But some people have difficulty with access to this method of announcement. A higher participation rate could be secured if a legal provision is added to specify putting up placards in specific places such as the entrance to the place for the briefing session for residents or the building of administrative agencies of the area concerned.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.9 no.2
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• pp.221-232
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• 2014

Many preliminary entrepreneurs are ready to start a business in every year. However, starting and preparing business have a lot of difficulties. Entrepreneurship is the most important factor for overcoming these difficulties. But, it is not easy to understand entrepreneurship to founders despite many research scholars. In this paper, we are focused on easy understanding of entrepreneurs. Instead of vague theories, we analyzed selected two companies in Korea. From the beginning until now, these companies have founders entrepreneurship and organization entrepreneurship. we studied these entrepreneurship factors with other Various causes. Analysis of two cases is summarized into three type. First, both companies had well-founded internal network system. Trained employees in internal network were flexible to meet the market conditions. Also, network effect made that employees can offer their idea and make discussions. Second, The company quickly recognized for organizational culture despite of most other companies recent awareness. This factor was the basic driving force for solving human resource management problem of small size companies. final factor is innovation capacity of these companies. Financial difficulties experienced of establishment is common to every company. However, two companies has continued to invest research and development despite of this financial problem. As a result, intellectual property management was accepted, as well as technology development. Clearly, these three factors are consistently applied since established and led to the company's continued growth and success.