• Journal of the KSME
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• v.21 no.1
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• pp.21-31
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• 1981

원자력발전소의 원자로냉각재 압력경계의 건전성과 안정성을 확보하기 위하여 법적 요구조건을 설정함에 있어 파괴역학이 어떻게 적용되었는 가를 설명하였다. 이를 요약하면 다음과 같다. 1) 압력경계에 사용되는 재료의 $RT_{NDT}$를 정의하였다. 이는 무연성천이온도와 같은 개 념의 것으로, 앞으로 재료의 파괴인성은 이 $RT_{NDT}$에 대한 상대온도의 함수로 주어진다. 2)비연성파괴를 방지하기 위한 설계조건으로서 선형탄성 파괴역학에 근거한 조건식을 인용하였다. 여기서 조건식이란 능력확대계수의 합계가 어떠한 조건에서도 이러한 조건식을 만족한다는 것을 해석적으로 확인하고 규제당국의 승인을 받아야 한다. 3) 가동중검사에 발견된 결함으로 합격수준을 초과하는 것은 파괴역학적으로 해석하여 구조적 으로 안전하다는 것은 파괴역학적으로 해석하여 구조적으로 안전하다는 것을 입증하여야 한다. 이때 결함은 원자로의 가동과 더불어 성장하므로 수명기간중 피로파괴에 이를 것인지의 여부도 평가하여야 한다. 이때의 대조균열성장률은 Paris의 power law에 따른다. 4) 고속중성자 (E>1. 0MeV)에 의한 조사취화를 감시하기 위하여 감시시험계획을 사전에 수립 하고 이에 따라 감시시험을 수행하여 조사에 수립하고 이에 따라 감시시험을 수행하여 조사에 의한 원자로용기 재료의 파괴인성의 저하를 평가하여 이를 고려한 충분한 안전여유를 갖는 운 전조건 즉, 압력-온도 한계곡선을 산출하여야 한다. 이때의 취화 정도는 DELTA. $RT_{NDT}$ 와 Upper Shelf Energy의 감소로 나타낸다. 또한, 압력-온도 한계곡선은 선형관성 파괴역학에 입각한 조건식을 이용하여 해당 온도에서의 압력을 산출한다. System을 개발 사용하기 위하여 기존 전자계산소를 이용하는 방법이 바람직하며 System의 도입은 자체운영을 결정하기 전에 경제적인 여건 등 여러가지 문제를 검토하여야 한다. 특히 Turn Key Base로 System를 도입할 경우에는 System의 도입목 적과 사용빈도, 앞으로의 확장성 현재 설계및 생산 과정과의 마찰가능성, 유지보수문제 등을 신 중히 검토하여야 한다. 이제 기계공업도 전자계산기를 이해하고 사용하므로 서 발전할 수 있는 단계가 되었다. 예로부터 좋은 공구를 개발하여 적절히 사용하는 것이 기계공업 발전의 첩경이 었다. 전자계산기는 현대 기술이 개발한 가장 강력하고 사용하기 좋은 공구이다.점에서 피로구열의 안정성장을 논하고, 과거 10여년간의 피로 crack문제에 대한 연구방법, 실험방법 등을 소개하는 방향으로 고 를 진행시켜 나가겠다.에 그 효과가 증대됨을 알 수 있었다.적용한 임상실험이 수행되어야 할 것이다. 또한 위치결정에서 획득한 좌표값의 정확성을 알아보기 위해서 팬톰을 이용한 방사선조사 실험이 추후에 실행되어져야 할 것이다. 그리고 제작된 프레임에 Rotating X선 시스템과 내부 장기의 움직임을 계량화하고 PTV에서의 최적 여유폭을 설정함으로써 정위 방사선수술 및 3 차원 업체 방사선치료에 대한 병소 위치측정과 환자의 자세에 대한 setup 오차측정 결정에 도움이 될 수 있을 것이라고 사료된다. 상대적으로 우수한 것으로 나타났으며, 혼합충전재는 암모니아의 경우 코코넛과 펄라이트의 비율이 7：3인 혼합 재료 3번과 소나무수피와 펄라이트의 비율이 7：3인 혼합 재료 6번에서 다른 혼합 재료에 비하여 우수한 것으로 나타났다. 4. 코코넛과 소나무수피의 경우 암모니아 가스에 대한 흡착 능력은 거의 비슷한 것으로 사료되며,

• Journal of Elementary Mathematics Education in Korea
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• v.24 no.2
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• pp.187-205
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• 2020

The purpose of this study is to develop the elementary mathematics education program for the cultivation of humanistic imagination and characters through the link between mathematics and literature to find out its effectiveness. This study has verified the effectiveness of mathematics academic achievement, humanistic imagination and characters with the program development and preliminary program and application of this program for two years. After conducting classes on proportional expression and proportional distribution for 79 sixth-grade elementary school students (39 in the experimental class and 40 in the comparative class) in Seoul and Gyeonggi-do under this program, the researcher analyzed how the application of the program affects students' perception using pre- and post-examinations on mathematics academic achievement, humanistic imagination, and characters, including interviews with students, and analysis of outputs of the students. Studies have shown that the application of the elementary mathematics education program to foster humanities imagination and characters did not make any significant difference in mathematics academic achievement, and there were statistically significant differences in the subcategories of "reflection on life", "positive self-consciousness" and "humanistic imagination" categories, and there were no statistically significant differences in the "purpose of life" and "human relations" categories. However, the responses from the students' interviews showed that their perspectives of humans and the world has become wider and deeper. It also did not produce significant results for characters. As suggestions, the ministry should present the need to develop and distribute concerning materials for teachers, secure time for creative experience activities for convergence subjects, and operate practical and long-term training programs for teachers.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.11 no.1
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• pp.56-67
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• 1999

It is desired to use a domestically manufactured ocean data buoy for the long-term operational ocean monitoring. The ocean data buoy manufacturing technology was introduced through the research cooperation with the Qingkong University of Taiwan. The introduced ocean data buoy system was further expanded and improved for more efficient application for the marine environmental monitoring in Korea. The size of the ocean data buoy is 2.5 m in diameter, which is smaller compared to the NOAA's 3.0 m discus buoy to allow easy land transportation and ocean deployment as well. From the dynamic response test of the buoy carried out numerically, it was shown that the measurement of waves with period greater than 4 seconds is acceptable. The measurement and control system of the data buoy were improved to increase the number of measuring parameters, to reduce power consumption and to enhance better data analysis and management. Each component of the improved data buoy system was described in detail in this paper. Water quality sensors of water temperature, salinity, DO, pH and turbidity were added to the system in addition to the marine meteorological sensors of wind speed and direction, air temperature, humidity, air pressure and wave. Inmarsat satellite communication system is used for the real-time data telemetry from the buoy deployed offshore. A field performance test of the improved and domestically manufactured buoy was carried out for a month at the open sea off Pohang together with DatawelI's Wave-rider buoy to compare the wave data. The results of the test were satisfactory.

• Journal of the Korean Society for Marine Environment & Energy
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• v.7 no.2
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• pp.98-103
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• 2004

Recently, a New Great Harbour Bridge between Mokpo City and Koha Island is planned to be built across Mokpo Inner Harbour, and Namak New Town is under construction adjacent to Mokpo. Citizels' concorn of and participation in 「Campaign for Shaping Mokpo into Beautiful Seaport」 are necessary to match the view of Mokpo harbour with natural scenery beautifully and with marine environment harmoniously. Citizens'ㄹ levels of consciousness of coastal and marine environment were ascertained through questionnaire surveys of local citizenry attitudes and opinions, and citizenry action plans for the conservation of coastal and marine environments around Mokpo harbour are suggested on the basis of the results of questionnaire surveys. Citizens' voluntary participations in local policy for the control of marine wastes production and in a campaign for the collections of marine debris and wastes around beaches and coastal areas are required. The operation of municipal sewage treatment plants is to be performed effectively and efficiently, and to be monitored and evaluated periodically by the general public, the local federation for environmental movement or NGO. The development and performance of marine environmental education programs and an enlightenment campaign for environment preservation are to be incessantly done in cooperation with local residents. Only when local government of Mokpo collects the public opinions and continues to shape Mokpo into international beautiful seaport in the direction of a reflex of public opinion, coastal and marine environment around Mokpo harbour can be kept in good condition with citizens' positive participation in citizenry long-term practical action plans for environment conservation.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.24 no.2
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• pp.295-310
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• 2014

DCS (Distributed Control System), the main control system of power plants, is an automated system for enhancing operational efficiency by monitoring, tuning and real-time operation. DCS is becoming more intelligent and open systems as Information technology are evolving. In addition, there are a large amount of investment to enable proactive facility management, maintenance and risk management through the predictive diagnostics. However, new upcoming weaponized malware, such as Stuxnet designed for disrupting industrial control system(ICS), become new threat to the main control system of the power plant. Even though these systems are not connected with any other outside network. The main control systems used in the power plant usually have been used for more than 10 years. Also, this system requires the extremely high availability (rapid recovery and low failure frequency). Therefore, installing updates including security patches is not easy. Even more, in some cases, installing security updates can break the warranty by the vendor's policy. If DCS is exposed a potential vulnerability, serious concerns are to be expected. In this paper, we conduct the penetration test by using NESSUS, a general-purpose vulnerability scanner under the simulated environment configured with the Ovation version 1.5. From this result, we suggest a log analysis method to detect the security infringement and react the incident effectively.

• Journal of Practical Engineering Education
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• v.6 no.2
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• pp.119-126
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• 2014

The purpose of this study is to take a look at the cases on managing the senior human resources of business enterprises following the significant number of retirement of baby-boom generation and obligatory retirement age of 60 years of age and present the implication points in policies. With respect to the implication of the company, it would urgently require the introduction of programs with long-term point of view for career management strategy from the time of employment to the resignation, settlement of company leave system called chulhyang, expansion of wage peak system, full-time job transfer support center within the enterprise for retirement management, expansion of various consulting, conversion of paradigm on senior human resource management of top management in the enterprise level. In the government level, it is considered as required for systematic supplementation of the chulhyang system, improvement of support system for employment encouragement fund, expansion of national work capability standard-based senior employment field as well as task development, support for innovation of personnel management system, supply of management manual and implementation of job transfer education for life-time conversion period in the government level.

• Journal of Korean Society of Transportation
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• v.28 no.2
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• pp.135-150
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• 2010

This paper focuses on finding out which covenants are different among the concession agreements of Korean BTO projects and how these influenced IRR(Internal Rate of Return). That is, to figure out the political and economical determinants of IRR by analyzing the concession agreements which are the basic contract of implementing projects. As IRR is an index of profitability, so spread is an indicator of risk to collect debts. That's the reason why the analysis of spread is included. For the empirical analysis, the data of concession agreements for 75 projects and financial models are used. These 75 concession agreements are contracted from 1995 to 2008. The dependent variables are after tax nominal IRR and the spread of long term interest rates of 75 BTO projects. The independent variables are project's proceeding factors, the feasibility variables, the variables related to financial character and the variables related to covenants or the government's policy. The analysis shows that IRR has been influenced by the equity level of financial investors, the national government managed projects, the projects with minimum revenue guarantee (MRG), etc. And the equity level of financial investors, the national government managed projects and the implementation of supplementary project have an effect on spread also.

• Korean Journal of Ecology and Environment
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• v.49 no.4
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• pp.245-257
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• 2016

Although rivers cover only 0.5% of the total land area on the Earth, they are windows that show the integrated effects of watershed biogeochemistry. Studies on the loads and properties of riverine carbon have been conducted because they are directly linked with drinking water quality, and because regional or global net ecosystem production (NEP) can be overestimated, unless riverine carbon loads are subtracted. Globally, ${\sim}0.8-1.5Pg\;yr^{-1}$ and ${\sim}0.62-2.1Pg\;yr^{-1}$ of carbon are transported from terrestrial ecosystems to the ocean via rivers and from inland waters to the atmosphere, respectively. Concentrations, ${\delta}^{13}C$, and fluorescence spectra of riverine carbon have been investigated in South Korea to understand the spatiotemporal changes in the sources. Precipitation as well as land use/land cover can strongly influence the composition of riverine carbon, thus shifting the ratios among DIC, DOC, and POC, which could affect the concentrations, loads, and the degradability of adsorbed organic and inorganic toxic materials. A variety of analyses including $^{14}C$ and high resolution mass spectroscopy need to be employed to precisely define the sources and to quantify the degradability of riverine carbon. Long-term data on concentrations of major ions including alkalinity and daily discharge have been used to show direct evidence of ecosystem changes in the US. The current database managed by the Korean government could be improved further by integrating the data collected by individual researchers, and by adding the major components ions including DIC, DOC, and POC into the database.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.10
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• pp.458-470
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• 2016

The purpose of this study was to understand and describe nurses' recognition regarding successful aging of hospitalized elderly in long-term care hospitals. Data were collected using focus group interviews in 2016. Three focus group interviews were held in three long-term care hospitals, and a total of 14 nurses participated. All interviews were recorded and transcribed as they were spoken, and data were analyzed using qualitative content analysis. A total of 25 concepts were identified, 15 subcategories, and five major categories emerged from the analysis. The five categories of the nurses' recognition about successful aging of hospitalized elderly in long-term care hospitals were "adjusting themselves to a lifestyle of long-term care hospital," "living positively in each situation," "communicating with each other and making a relationship," "obtaining interest and support of their families," and "maintaining economic independence". Therefore, further qualitative study will be performed and compared with this study results on successful aging of hospitalized elderly in long-term care hospitals. Moreover, based on these study results, it is necessary to develop and apply programs for successful aging of hospitalized elderly in long-term care hospitals.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.10
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• pp.537-547
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• 2016

Deep Sea Water (DSW) has been exploited mainly by industry in a few countries including the U.S., Japan, Taiwan, and Korea. The development strategy of these states has pursued various goals based on their unique industrial environments and visions. Among them, Taiwan recently started their DSW industrialization, but has rapidly developed a variety of technologies and products. On the contrary, the Korean DSW industry has remained stagnant in the initial and growing stages for years, and now appears to need new plans and strategies for further development. The current literature lacks the strategy and policies required to foster the development of the domestic DSW industry. Relying upon the case of advanced foreign DSW industries, this study delineates the current status of the Korean DSW industry and discusses its future direction. Taiwan in particular has moved forward with policy development, financial and operation systems. This study attempts to provide a set of guidelines for the Korean DSW industry by focusing on the case of its Taiwanese equivalent. The Taiwanese strategical plans include premium drinkable water, government driven industrialization, diversification of DSW technologies and development of value-added products. This study provides a new direction for the DSW industry.