• Korean Journal of Soil Science and Fertilizer
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• v.6 no.1
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• pp.27-28
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• 1973

The activities of peroxidase and polyphenoloxidase were investigated in the rice leaves(the upper halves) diseased with Akagare or Helminthosporium oryzae. The activity of polyphenoloxidase was slightly lower than that of peroxidase in the healthy leaves but it increased 56% in the diseased leaves while peroxidase decreased 35%. It was expected that polyphenoloxidase is dominant in the oxidation of polyphenols, and hydrogen peroxide may accumulate to harmful level due to the decrease of peroxidase activity resulting in non-enzymatic oxidation of polyphenols in the diseased leaves.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.sup1
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• pp.65-70
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• 2016

Background: In 2013, legislation in Vietnam regulated smoking in public areas. Included was a ban on indoor smoking at universities. Objective: Since awareness and attitude are moderators of the effectiveness of smoke-free policy, ou aim was to assess changes in students' knowledge and attitude tosecond hand smoke (SHS) and awareness and support of smoke-free legislation at four Vietnamese universities, one year after legislative changes. Methods: A two-phase cross sectional study of undergraduate students using self-administered questionnaires (based on the Global Adult Tobacco Survey and the Thrasher survey) was conducted at the introduction of the legislation and one year thereafter. Results: One-year post legislation there were significant increases in knowledge of smoke-free legislation and awareness of universities as smoke-free environments. There was a significant increase in knowledge of harmful effects of SHS on diseases such as examples in the heart and lung, including lung cancer, and miscarriage. Students expressed strong support of smoke-free environments in universities, hospitals, schools, workplaces, public transport, libraries, cinemas and theatres; support was also increased post legislation. Changes were seen in attitude to SHS, and rights of non-smokers and smokers. Conclusions: Positive changes have occurred in knowledge and attitude toward smoke-free environments and SHS in universities since enactment of Vietnamese tobacco control legislation.

• Journal of ILASS-Korea
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• v.21 no.2
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• pp.71-77
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• 2016

Air pollutants nitrogen oxides are inevitably generated in the combustion reaction. Its amount trend is steadily increasing because the rapid modern industrialization and population growth. For this reason, NOx is controlled to reducing the harmful components in the exhaust gas. So Marine Environment Protection Committee (MEPC) take effect 'Tier I', 'Tier II' of air pollution regulation in 2005 and 2011 respectively. According to NOx emissions are strictly regulated management of the vessel through them. In addition, since 2016 the regulation enter into force in the next step 'Tier III' was confirmed by MEPC 66th committee. It's 80% enhanced emissions limits than the 'Tier I' Alternatively these emission regulation, research is actively being carried out about exhaust gas after-treatment methods through the vessel application of Selective Catalytic Reduction(SCR). Therefore depending on the basic specification of cell density according to the Area velocity, Space velocity, Linear velocity is studied the effects of NOx removal efficiency

• Convergence Security Journal
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• v.8 no.1
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• pp.49-56
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• 2008

Recently, Phising attack uses trick of URL and sites, and technical concealment method which infiltrates sophisticated malicious code. However, sometimes Phising security technology cannot cover all of Phising methods. Consequently, this research proposes inspection to solve this problem. First, we can install Proxy server for a strong open information exchange of web environment between web servers and clients. Therefore, it compares and analyzes harmful site and Phising URL with White domain list, and filters them. Finally, designs for stable web based information so that we can block Phising with least regulation and active control. So the purpose of this paper is introducing this design system and structure, and inspect them.

• International Journal of Precision Engineering and Manufacturing
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• v.7 no.3
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• pp.24-29
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• 2006

Pressurized gas pipelines are subject to harmful effects from both the surrounding environment and the materials passing through them. Reliable assessment procedures, including fracture mechanics analyses, are required to maintain their integrity. Currently, integrity assessments are performed using conventional deterministic approaches, even though there are many uncertainties to hinder rational evaluations. Therefore, in this study, a probabilistic approach was considered for gas pipeline evaluations. The objectives were to estimate the failure probability of a corroded pipeline in the gas and oil industries and to propose limited operating conditions for different types of loadings. To achieve these objectives, a probabilistic assessment program was developed using a reliability index and simulation techniques, and applied to evaluate the failure probabilities of a corroded API-5L-X52 gas pipeline subjected to internal pressures, bending moments, and combined loadings. The results demonstrated the potential of the probabilistic integrity assessment program.

• Journal of the Korean Society for Nondestructive Testing
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• v.22 no.3
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• pp.254-260
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• 2002

In this study, two types of mobile robotic systems using NDT (Non-destructive testing) method are developed for automatic diagnosis of the boiler tubes and large size pipelines. The developed mobile robots crawl the outer surface of the tubes or pipelines and detect in-pipe defects such as pinholes, cracks and thickness reduction by corrosion and/or erosion using EMAT (Electro-magnetic Acoustic Transducer). Automation of fault detection by means of mobile robotic systems for these large-scale structures helps to prevent significant troubles without danger of human beings under harmful environment.

• Korean Journal of Ecology and Environment
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• v.36 no.3 s.104
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• pp.375-380
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• 2003

For some decades eutrophication poses a great problem in water quality management in fresh-waters. To solve this problem, studies based on "bottom-up" hypothesis have been mostly carried out worldwidely unlike biomanipulation. This implies that not only fish but also fish stock playa key role down to other food web components in pelagic ecosystem. It is generally accepted that biomanipulation becomes a potent tool for eutrophication control. For a practical application of this, however, further development and understanding of the food web under the specific lake condition on a whole-lake scale are needed. The question is how can we maintain the positive effects resulted from biomanipulation (fortuitous or planned) for a long period.

• Journal of the Korea Safety Management & Science
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• v.11 no.2
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• pp.59-67
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• 2009

The goal of this study is to propose the effective method of investigating the injurious factors and making improved plans that prevents the workers against musculoskeletal disorders at an diesel engine manufacturing company and the same business field with similar working conditions and process. A questionnaire were adopted to analyze the symptoms of workers' musculoskeletal disorders, and an ergonomic assessment method such as RULA, OWAS were performed to find out harmful factors of workplace and working posture. Based on the result of the evaluation, to enhance the working environment, improvement of worktable, working space, tools, and outfit was suggested, and induction of mechanical system was also suggested. It can be concluded that the method and process described in this paper could be helpful for diagnosing the musculoskeletal disorders and making improvement plans to the diesel engine fuel injection system manufacturing company and the same business field with similar working conditions and process.

• 한국태양에너지학회:학술대회논문집
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• 2012.03a
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• pp.534-542
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• 2012

Vertical closed-loop ground source heat pump systems(GSHP) have been installed widely in Korea since it can extract moderate temperature level of geothermal heat in a small area. As a ground heat exchanger, a vertical closed-loop type with brine circulation is mostly preferred since it is simple and less harmful to ground environment. However, it requires a secondary heat exchange loop between the refrigerant in a heat pump and the brine. By adding a geothermal heat exchanger in the secondary heat exchange loop, circulation pumps should be attached and the temperature difference between refrigerant and ground is increased, which are important parts of performance degradation. In this paper, annual and seasonal performances of direct expansion(DX) geothermal heat pump were estimated mathematically as an alternative of classical indirect geothermal heat pump based on the annual performance evaluation. As a result, DX geothermal heat pump showed 43% higher annual performance than the classical U-tube geothermal heat pump.

• Journal of the Korean Solar Energy Society
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• v.32 no.3
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• pp.114-122
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• 2012

Vertical closed-loop ground source heat pump systems(GSHP) have been installed widely in Korea since it can extract moderate temperature level of geothermal heat in a small area. As a ground heat exchanger, a vertical closed -loop type with brine circulation is mostly preferred since it is simple and less harmful to ground environment. However, it requires a secondary heat exchange loop between the refrigerant in a heat pump and the brine. By adding a geothermal heat exchanger in the secondary heat exchange loop, circulation pumps should be attached and the temperature difference between refrigerant and ground is increased, which are important parts of performance degradation. In this paper, annual and seasonal performances of direct expansion(DX) geothermal heat pump were estimated mathematically as an alternative of classical indirect geothermal heat pump based on the annual performance evaluation. As results, DX geothermal heat pump showed 43% higher annual performance than the classical U-tube geothermal heat pump.