• 농촌계획
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• 제23권1호
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• pp.157-164
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• 2017

Roadside native vegetation provides important habitat for plants and animals, and provides visual amenity and beauty for drivers and rural areas. In particular, native wildflowers create and maintain attractive landscaping and scenic vistas while help protect and restore the natural environment. However, it is lacking in government policies and guidelines about using native wildflowers for roadside vegetation and alien invasive plants are a major threat to our environment. The purpose of this study is to review the regulations and programs for roadside vegetation, especially native wildflowers in USA in order to learn lessons about developing wildflower policies in Korea. A summary of results follows: (1) the goals of roadside vegetation have been shifted from beautification for pleasant driving experience to sustainable and economical maintenance. (2) Various funds and laws by federal and local government are essential for native wildflower planting and roadside enhancement. (3) Ongoing projects on seed collection and seed banking of native plants are conducted by wildflower research centers to conserve and propagate endangered plants. (4) Recognizing that wildflower viewing holds tremendous potential, increasing local governments try to grow wildflower tourism for economic benefits. In conclusion, we should establish a long-range plan and regulations on roadside wildflowers planting in order to create safe and sustainable transportation corridors in Korea. In addition, more research on wildflower habitat and propagation should be warranted and landscape architects should play a definitive role in providing pleasant driving experiences and promoting wildflower tourism.

• 한국압력기기공학회 논문집
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• 제10권1호
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• pp.7-14
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• 2014

There has been extensive experience associated with the operation of SGs wherein it was believed, based on NDE, that throughwall tube indications were present within the tubesheet. The installation of the SG tubes usually involves the development of a short interference fit, referred to as the tack expansion, at the bottom of the tubesheet. The tack expansion was usually effected by a hard rolling process and thereafter, in most instance, by the expansion of a urethane plug inserted into the tube end and compressed in the axial direction. The rolling process by its very nature is considered to be intensive with regard to metalworking at the inside surface of the tube and would be expected to lead to higher residual surface stresses. Alternate repair criteria(ARC) in the tack expansion area have been developed and applied to nuclear power plants in USA, however domestic nuclear power plants have not applied ARC for tubes in tubeheet area yet. In consideration of the degradation characteristics of tubes in the Steam Generator tubesheet, this paper suggests ARC application for tubes in the steam generator tubesheet of the domestic nuclear power plants in order to assure life time of the steam generator as well as nuclear power plants.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회B
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• pp.2664-2669
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• 2008

Feedwater heaters of many nuclear power plants have recently experienced severe wall thinning damange, which will increase as operating time progresses. Several nuclear power plants in Korea have experienced wall thinning damage in the area around the impingement baffle-installed downstream of the high pressure turbine extraction stream line- inside number 5A and 5B feedwater heaters. At that point, the extracted steam from the high pressure turbine is two phase fluid at high temperature, high pressure, and high speed. Since it flows in reverse direction after impinging the impingement baffle, the shell wall of the number 5 high pressure feedwater heater may be affected by flow-accelerated corrosion. This paper describes operation of experience and numerical analysis composed similar condition with real high pressure feedwater heater. This study applied squared, curved and new type impingement baffle plates to feedwater heater same as previous study. In addition, it shows difference of pressure distribution and value between single phase and two phase based on experience and numerical analysis.

• 설비공학논문집
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• 제21권9호
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• pp.483-495
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• 2009

Feedwater heaters of many nuclear power plants have recently experienced severe wall thinning damange, which will increase as operating time progresses. Several nuclear power plants in Korea have experienced wall thinning damage in the area around the impingement baffle-installed downstream of the high pressure turbine extraction stream line-inside number 5A and 5B feedwater heaters. At that point, the extracted steam from the high pressure turbine is two phase fluid at high temperature, high pressure, and high speed. Since it flows in reverse direction after impinging the impingement baffle, the shell wall of the number 5 high pressure feedwater heater may be affected by flow-accelerated corrosion. This paper describes operation of experience and numerical analysis composed similar condition with real high pressure feedwater heater. This study applied squared, curved and new type impingement baffle plates to feedwater heater same as previous study. In addition, it shows difference of pressure distribution and value between single phase and two phase based on experience and numerical analysis.

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2019년도 춘계학술논문요약집
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• pp.359-360
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• 2019

• 한국환경과학회지
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• 제19권5호
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• pp.655-663
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• 2010

Today, the importance of environmental education is a matter we are all concerned about. The environment surrounding us, such as the air we breathe, the water we drink, and the soil plants grow in, is critical for our survival. Currently there is a lot of interest in environmental education at the elementary, middle, and high school levels. This is a result of the deep recognition of the importance of the environment. However the environmental education being conducted in schools is not yet at a satisfactory level. The practical issues, including an entrance exam-oriented atmosphere, student' and parents' lack of understanding, and teachers' lack of expertise in environmental education, interfere with the stability of environmental curriculum in the schools. Accordingly, we need to devise an alternative environmental curriculum due to the fact that it hasn't been included as a regular subject in the curriculum of many national schools. This study, carried out from April to December 2009, was an examination of the effect of volunteer work at the place of ecology experience on the environmental sensitivity & state-trait anxiety of the 61 Gifted Students. The students were divided into two groups. The test group consisted of 30 gifted students who did volunteer work at the place of ecology experience run by Ulsan Science High School, in Ulsan Metropolitan City. The control group consisted of the rest of the students. The following are the study results: First, the volunteer work at the place of ecology experience was influential in increasing the environmental sensitivity of the gifted students. Second, the volunteer work at the place of ecology experience was influential in decreasing the state anxiety of in gifted students. Third, the volunteer work at the place of ecology experience was influential in decreasing the trait anxiety of in gifted students. Fourth, the volunteer work at the place of ecology experience positively influenced not only the gifted students' view of environmental education, but also their overall character.

• 한국압력기기공학회 논문집
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• 제10권1호
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• pp.1-6
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• 2014

PID(Proportional, Integral, Derivative) controller is one of the most used process controllers in nuclear power plants. The optimized parameter setting of process controller contributes to the stable operation and efficiency in the operating nuclear power plants. PID parameter setting is tuned when new process control system is established or process control system is changed. It is a burdensome work for I&C(Instrument and Control) engineers to tune the PID controller because it requires a lot of experience and knowledge. When the plant is in operation, inadequate PID parameter setting can be the cause of the unstable process of the plant. Therefore the results of PID parameter setting should be compared, simulated, verified and finally optimized. The practical PID tuning methods used in process controller are tuning operation calculation(Ziegler-Nicholes, Minimum TIAE, Lambda, IMC), exclusive tuning program based on computer and Matlab application. This paper introduces the various tuning methods and suggests an optimized PID tuning process in the operating nuclear power plants.

• 한국화재소방학회논문지
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• 제24권4호
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• pp.116-122
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• 2010

원자력발전소는 심층화재방어 개념에 따라 화재 발생시 발전소 외부로 방사능의 누출을 억제하고, 발전소의 안전정지 기능이 유지될 수 있도록 설계, 건설, 운영되어야 한다. 해외의 원전건설 국가는 이러한 원자력발전소의 안전정지 기능의 목적을 달성하기 위하여 원자력발전소에 대한 통합된 화재방호 규제요건을 가지고 있으나, 우리나라의 경우, 원자력발전소의 화재방호계통을 적용하기 위한 강제 요건으로서 소방관계법과 원자력법을 동시에 적용하는 비합리적인 규제지침을 가지고 있다. 화재방호설비에 관하여 원자력발전소 운영에 오랜 경험을 가진 미국, 캐나다 및 일본의 기술적으로 단일화된 원자력발전소의 화재방호 규제체계를 제시하였고, 우리나라도 화재방호설비는 원자력법에 의한 화재하중에 따른 화재위험도분석 결과를 설계에 반영하여 소방관계법에서는 예외조항으로 인정받을 수 있어야 함을 제안하였다.

• 한국압력기기공학회 논문집
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• 제7권3호
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• pp.23-29
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• 2011

The renewed global interest in nuclear power has arisen from the need to reduce greenhouse gas emissions and to provide sufficient electricity for a growing global population before the accident at Fukushima Dai-ichi nuclear power plant in Japan. In spite of the safety issues of nuclear power plants raised by the ongoing Japanese nuclear crisis, many countries with nuclear power plants (NPPs) are still implementing license extensions of 10~20 years, and even consideration is being given to the concept of life-beyond-60, a further period of license extension from 60 to 80 years. To solving the materials aging problem is integral to its success. To evaluate the plant aging phenomena, a lot of background information such as materials and environment of the parts of the reactor and plant systems is needed by the experts. Information on degradation mechanisms is also used. In this paper, a materials degradation evaluation program called OnMDE-SYS (On-line Materials Degradation Evaluation System) is introduced. The developed program provides a variety of information on the materials and stressors as well as operational experience to the experts. It is also anticipated that the experts can perform materials degradation assessment on the web directly by referring to domestic and international information about the degradation of a nuclear power plants through OnMDE-SYS.

• 인간식물환경학회지
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• 제24권3호
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• pp.301-309
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• 2021

Background and objective: The purpose of this study is to analyze the case of healing experience for lifestyle and environmental diseases through life and activities in the forest from the perspecitive of critical realism, and how the causal power and mechanism of the healing experience relate to forest healing factors and programs. Methods: 93 video data of people who started living in the forest for disease treatment were analyzed using a qualitative content analysis method from the perspective of critical realism. Categories for analysis include general categories (age, duration, occupation, disease name), forest therapy categories (climate therapy, plant therapy, water therapy, diet therapy, kinesiotherapy, psychotherapy), and other categories (ecology, learning and management, life tools), etc., and the unit of analysis is the context unit. Results: 1) The diseases that motivated life in the forest were digestive system diseases, lung diseases, cardiovascular diseases, endocrine system diseases, and various lifestyle-related diseases and environmental diseases in similar proportions. This indicates that forest life does not have specificity to respond to specific diseases, but provides treatment and recovery for all lifestyle and environmental diseases. 2) Among the forest therapies, climate therapy and plant therapy are related to the climatic and residential environment in the forest where 'natural persons' live. And others such as water therapy, diet therapy, kinesiotherapy, psychotherapy indicate the change from the lifestyle that caused the disease to the lifestyle for treatment and recovery. Conclusion: Life and activities in the forest provide an environment for treatment and recovery in which the healing principles such as aromatherapy, nutritional and dietary therapy, kinesiotherapy, and emotional psychotherapy are integrated in the 'real world'.