• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.10
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• pp.3911-3916
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• 2010

In this paper we describe contents and results on running test for ATP on-board equipment, which has propelled as one of the research projects, so called, "Reliability assessment and operation technology development for Korean-type tilting trains" in order to ensure the safety and operation efficiency of tilting trains. We developed tilting trains for the speed-up of conventional lines and for the passenger service improvement where the KTX is not available. And we made progress the operation trial test in the 120,000 km distance with the use of ATS equipment, used in existing lines, for the purpose of the reliability assessment of the developed tilting trains. We decided to accelerate the speed for more than 200km/h with respect to the 6 existing lines including Jungang-line and Chungbuk-line where KTX has not operated. According to this decision, Train control system is to be changed from ATS to ATP. We should have installed an ATP on-board unit in tilting trains and verified the operational suitability, therefore we installed the same ATP on-board unit on tilting trains as that used in the ATP construction project on Gyeongbu-line and Honam-line, and verified that the function and performance of the installed ATP on-board unit conformed to the tilting trains operation.

• Journal of the Korean Society of Marine Environment & Safety
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• v.16 no.4
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• pp.401-406
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• 2010

Vessel Operator has been navigating with subjective sate distance in accordance with night & daytime, fore & aft, port & stbd abeam and visibility situation. This sate distances may different depending on inside & outside harbor limit, current, wind and visibility situation. By now, the concept of proper sate distance between navigating vessels has been adopted in Korea, using the early 1980's foreign data. And the safe distance is being used with the same value without any consideration of inside & outside harbor and the kind of vessel. So it is necessary to evaluate or search proper distance concept based on different sate consciousness of Korean manners. This paper aims to develop the basic model for marine traffic evaluation and the new model of marine traffic congestion. Also this paper proposes the basic control guideline of vessel traffic service center. The result of this study showed that minimum sate distance should be 4.4L forward, 3.1L aft and 26L abeam in case of good visibility in daytime, considering various parameters such as visibility, day and night. Some differences Here found between the existing minimum sate distance and the new minimum sate distance derived from the result of this study.

• Information Systems Review
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• v.12 no.3
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• pp.75-88
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• 2010

Business models in open market systems targeting smart phone users are determined by several important factors. First, by providing developers efficient technical platforms, it contains a setting for developers to learn, apply and improve the skills relating to the product category easily while they stay beyond a corporate boundary. Second, by the first condition, a huge population of talented developers becomes to join a specific open market where will invite more customers to use their applications. Hence it will attract more and more developer participants who will finally give a rise to a persistent market growth. Third, the evaluation system between platform providers and application producers, and one between application producers and application users may underlie the trust relationships between them. The research conducted a multiple embedded case study to test the success factors of open market based business models. It focused on smart phone game communities that have installed user evaluation, and feedback systems. The user innovation empowerment model within the social game networks has highlighted the theories on the roles and characteristics of lead users, and lead user network behaviors for future NPD participations.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.355-358
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• 2002

Since the 1960s, though there were brisk supply in apartment housing, there were no preparation in standard for to extend the life(durability) of apartment housing by maintaining the $social{\cdot}physical$ aspect of apartment housing, and in standard maintenance system. So problem such as facilities safety and residence environment has occurred. Like the condition written above, efficient usage of housing resource by the maintenance of apartment housings in a state of great urgency. In service aspect of apartment housing, establishment of accurate long term repair plan and estimate of repair appropriation fund can prevent housing's fast-deterioration. But to the performers of the maintenance, like house managers and the tenants at the subject building has little awareness of necessity in establishment of accurate long term repair plan and accumulation of repair appropriation fund. Unestablishment of long term repair plan arises problem such as approval of repair appropriation fund's unreasonable accumulation. Hence, for the utmost performance of apartment housing and to extend the economic life of a building, the method of establishment of long term repair plan and estimate of repair appropriation fund on reliable basis is to be proposed.

• Journal of Food Hygiene and Safety
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• v.20 no.4
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• pp.237-243
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• 2005

Methanol, ether, ethylacetate and water extracts from flesh and peel of yuna (Citrus junos) were investigated to analyze their ability of electron donating, nitrite scavenging and nitrosodimethylamine (NDMA) formation in model system. The electron donating ability of ynza flesh extract, when it added at 10 mg/ml or over, were more an $50\%$, except ether extract. The high electron donating ability ($99.2{\pm}0.37\%$) was observed in the methanol extract and its effect was similar to BHA and ascorbic acid, when 40 mg/ml of methanol extract was added in reaction solution. Nitrite scavenging ability of all extracts ken yuza was increased in proportion to sample concentration and more than $40\%$ when 1 mg/ml sample was added, under pH 1.2. Also nitrite scavenging ability was higher in peel extracts than flesh extracts of yuza. Inhibition ratio of NDMA formation from flesh methanol extract of yuza was $31.7{\pm}1.25\%$, when 40 mg/ml added under pH 1.2. In all samples, inhibition effects were lower than $20\%$, at pH 4.2 and 6.0.

• Research in Community and Public Health Nursing
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• v.16 no.3
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• pp.341-350
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• 2005

Purpose: The purpose of this research was to find out factors affecting job stress and job satisfaction of nurses working at the welfare centers. Methods: This study was performed with 140 nurses who were working at or had retired within 1 year from general welfare centers in Seoul during the period from March 29 to February 29 2004. We used a questionnaire asking about general characteristics. work characteristics. stress factors and job satisfaction. We analysed 103 subjects who replied to the questionnaires. Results: The mean job stress level was 2.84 out of 5 and. as for the sub-factors of job stress. income was 4.19, career development 3.69, service environment 3.26 and support system 1.90. The mean job satisfaction level was 3.32 out of 5 and. as for the sub-factors of job satisfaction, job control was 3.58, efficiency of organization 3.27, job burden and responsibility 2.92 and role ambiguity 2.25. When the nurses' job stress was compared according to their general and work characteristics. stress level was significantly high in nurses who had a short experience. were working at the department of senior welfare center. or were the only staff at their workplace (p <0.05). In addition. satisfaction level was significantly high in nurses who were working at the department of senior welfare center and medical welfare team. were the only staff at their workplace or had a heavy work load (p<0.05). According to the results of multiple regression analysis. job stress level was influenced by age ($R^2$=0.212. p<0.01). and job satisfaction level by the number of staffs and work' load ($R^2$=0.272. p<0.1). Conclusions: The results of the study suggest that good atmosphere should be made up to communicate between the departments at the workplace in order to lessen job stress and enhance job satisfaction of nurses working at welfare centers. In addition. role division and job duties among special staffs should be reviewed in order to achieve high efficiency in performing job duties.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.11 no.1
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• pp.100-106
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• 2018

Since the concept of virtual currency called Bitcoin was announced in 2008, the blockchain technology, which is the basis of Bitcoin, is attracting attention as an important platform technology in the era of the 4th industrial revolution that can change our society in the future. Although Existing electronic financial transactions store and manage all transaction history at a reliable central organization such as government and bank, blockchain-based electronic financial transactions are composed of a distributed structure in which all participants participating in the transaction store and manage the transaction history, it is possible to secure transaction transparency while reducing system construction and operation costs. Besides the virtual currency that started with bit coins, the technology of these blockchains has been extended in various fields such as smart contracts and document management. The key technology area of this blockchain is security based on proven cryptographic technology to make it difficult to forge and hack, but there are security risks such as security vulnerabilities in the virtual currency trading service, We will discuss security risks in using virtual currency and discuss countermeasures. Especially security accidents of virtual currency exchanges are occurring frequently recently, the damage of users who trade the virtual currency is also increasing, we propose security threats and security countermeasures against virtual currency exchanges.

• 대한공업교육학회지
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• v.32 no.1
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• pp.55-72
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• 2007

The purpose of this study is to improve specialized high school of electrical field-to-work transition by a SWOT Analysis. The subject analyzed the curricula of 12 special highschool and surveyed 192 vocational teachers of them. In this study, a SWOT matrix was filled to improve transition from electric special high school to work, and the results was gotten as follows: First, the government should offer the military service special case for students of electric special high school, strengthen the course of CEO for the school master, and make the system to expand job training. Second, the provincial office of education should aid a functional training with a administrative ability and financial support, offer a list of industry visiting teachers to specialized high school, and promote a modification of the department according to a growth industry of the area. Third, each school should present a school education goal agreed with the purpose of specialized department and intensify the counselling of job selection and the application of the approved textbook.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.3
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• pp.346-352
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• 2018

This study was conducted to investigate the quality of sleep of university students according to smoking behavior and to generate basic data for use in development of smoking prevention and smoking policies for university students and young adults in their 20s. The quality of sleep of 291 college students was measured based on smoking behavior and the Pittsburgh Sleep Quality Index (PSQI) questionnaire from May 29, 2017 to June 3, 2017. Multiple logistic regression analysis with step-wise analysis revealed that the quality of OR increased from 2.542 to 2.820 times as the grade increased, and that OR was 3.126 times higher than that of non-smokers and stop-smokers. The quality of sleep worsened with OR=12.388 times. Among general smokers, 72.4% of the students had poor sleep quality, but 82.6% of the students who did not have good sleep quality of electronic-cigarette or tobacco smokers had electronic-cigarette or tobacco worse than regular tobacco.Based on these findings, quitting smoking is essential to improve quality of sleep, but this can be difficult. Therefore, it is necessary to develop legal regulations and policies at the national level. Moreover, a system or service that can manage phased smoking cessation is needed.

• Journal of the Korean Institute of Landscape Architecture
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• v.18 no.2
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• pp.31-44
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• 1990

This study was carried out to investigate the changes of rural residential environmemts accompanied by the rural village improvement projects. The results of this study can be a guidoline for further betterment works of rural village envirnments. This sutdy is composed of the survey of two major parts, one Is the interview of the residents and the survey of existing conditions of residential environments, and the other is a questionnaire survey of the mental image, preference and satisfaction for each village residential environments. Based on preliminary investigation, five rural villages, located In Kyungsamgun., Kyungbuk province, were selected as sutdy sites. The major results are summarized as follows; 1. In socio-cultural enveronments, the ratio of compound and non - agricultural household are increased with the modernization of rural villages. On the ocher hand, the numbers of neighbor's association are considerably decreased. This means the traditional community of korean rural villages are diminishing. 2. In physical environments, the ratio of improved western type gouses are increased In modprnized villages. And the modernization is most remarkable in the palls of fences and gardens. 3. By the result of the analysis of residfnt's environmental image and preference, the image scores of urban, formal, mdoern, etc. are showed to be high. And the preference is also high in modernized villages. But in general, the Preference for the village environment is comparatively low in all villages. This means the improvememt work should be continuous and systematic. 4. By the result of stepwise regression analysis, the variables, affecting the preference of village environment. are regularity, familiarity, amount of greenery, beauty of surrounding scenery, convenience, cleanness, etc. The R2s of the perference models were 0.4486 ∼0.9395, Which are considered to be high. 5. In the satisfaction for each residences, the toilets are mostly dis - satisfying. With the modernization of vilelages, the needs for environmental quality by residents are increased. 6. In the satisfaction for village enveironments, the satisfaction level is most low in service facilities, such as public bath, barbershop. And the satisfaction for the scenic beauty, the amenity of surrondings, and the com munity of the traditional villages, are commparatively high in conventional villges. 7. The imporvement works, based on the characteristics of each rural villages, are recommended. And the tradition of Jung - ja tree spaces and harmony with surrounding landscape of traditional villages, must be conserved with good regards.