• New & Renewable Energy
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• v.16 no.4
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• pp.49-64
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• 2020

Photovoltaic and Thermal collector (PV/T) systems are renewable energy devices that can produce electricity and heat energy simultaneously using solar panels and heat exchangers. Since PV/T systems are exposed to the outdoors, their reliability is affected by various environmental factors. This paper presents a reliability test for a PV/T system and evaluates the test results. The reliability assessment entails performance, environment, safety, and life tests. The factor that had the greatest influence on the life of the system was the hydraulic pressure applied to the heat exchanger. A test was conducted by repeatedly applying pressure to the PV/T system, and a reliability analysis was conducted based on the test results. As a result, the shape parameter (β) value of 5.6658 and the B10life 308,577 cycles at the lower 95% confidence interval were obtained.

• Proceedings of KOSOMES biannual meeting
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• 2018.06a
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• pp.35-35
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• 2018

• Proceedings of KOSOMES biannual meeting
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• 2018.06a
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• pp.141-141
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• 2018

• Proceedings of KOSOMES biannual meeting
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• 2017.04a
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• pp.51-51
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• 2017

• Journal of the Korean Association of Geographic Information Studies
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• v.19 no.1
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• pp.1-11
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• 2016

Climate change is the issue that attracts the most attention in the field of environment, as well as the most challenging task faced by the human race. There are various ways to resolve this issue. South Korea has established the primary and secondary national climate change adaptation plans at the national level, and is making it compulsory for each local government (lower and municipal-level) to establish climate change adaptation plans. Climate change vulnerability assessment plays an essential role in establishing climate change adaptation action plans. However, vulnerability assessment has a difficulty performing individual assessments since the results are produced through complex calculations of multiple impact factors. Accordingly, this study developed a web-based supporting tool(VESTAP) for climate change vulnerability assesment that can be used by lower and municipal-level local governments. The VESTAP consists of impact DB and vulnerability assessment and display tool. The index DB includes total 455 impacts of future climate data simulated with RCP (Representative Concentration Pathways) 4.5 and 8.5, atmospheric environment data, other humanities and social statistics, and metadata. The display tool has maximized convenience by providing various analytical functions such as spatial distribution, bias and schematization of each vulnerability assessment result. A pilot test of health vulnerability assessment by particulate matters in Sejong Metropolitan Autonomous City was performed using the VESTAP, and Bukang-myeon showed the highest vulnerability. By using the developed tool, each local government is expected to be able to establish climate change adaptation action plans more easily and conveniently based on scientific evidence.

• Progress in Medical Physics
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• v.5 no.1
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• pp.75-85
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• 1994

As we enter the 2000s, there are four nuclear power units of the pressurized heavy water reactor-type in the commercial operation at the Wolsung Nuclear Power Plant(NPP) site where a larger amount of tritium ($\^$3/H) is released inevitably to the site environment. This radioctive nuclide is easily distributed throghout our environment because of its ubiquitous form as tritiated water (HTO) and its persistence in the environment. Tritum has certain characterisitics that present unique challenges for beta radiation dosimety and health risk assesment. In this paper, therefore, a variety of matters on tritium are considered and reviewed in terms of its characteristics and sources, metabolism and dosimetry, microdosimetry, radiobiology, risk assessment, and transport and cycling in the environment, etc.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.21 no.1
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• pp.55-61
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• 2011

Cyclonite is a white powder and is very explosive. It can cause seizures (a problem of the nervous system) in human and animals when large amounts are inhaled or eaten. Research papers for workers exposure assesment of the cyclonite are very a few in the world. A field study was conducted at explosive compounds and bomb manufacturing companies to evaluate workers exposure to cyclonite. The airborne average concentration of cyclonite in explosive compounds manufacturing company was $4.10{\mu}g/m^3$(range: ND - $59.92{\mu}g/m^3$), and that of cyclonite in bomb manufacturing company was $31.49{\mu}g/m^3$(range: ND - $291.41{\mu}g/m^3$). Package process and assembly process in both companies were considered the high potential of exposure to cyclonite. Even though all airborne concentrations of cyclonite were lower than occupational exposure standard (MOEL: $500{\mu}g/m^3$), exposure to cyclonite can also occur through dermal contact during manufacture, handling, and clean-up of cyclonite. So control measures for protecting skin absorption of cyclonite were needed for preventing adverse health effect by cyclonite exposure.

• Aerospace Engineering and Technology
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• v.5 no.2
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• pp.67-76
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• 2006

This paper describes the analysis method to define the system specification for conducted EMI environment and verification method to evaluate the conducted EMI performance. Conducted EMI environment is characterized by the electrical power subsystem which is mainly issued by the switching circuit noise, common ground impedance coupling. To define and control these EMI problems, EMI assesment through system analysis are preceded at the early design phase and then EMI reduction methods are applied during the unit/system development phase. System EMC should be carefully controlled and designed in the consideration of EMC safety margin and its performance is fully evaluated at the whole development period.

• Ocean and Polar Research
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• v.28 no.4
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• pp.459-465
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• 2006

Ambient noise as a background noise in the ocean has been well known for its the various and irregular signal characteristics. Generally, these signals we treated as noise and they are analyzed through stochastical level if they don't include definite sinusoidal signals. This study is to see how ocean ambient noise can be analyzed by the chaotic analysis technique. The chaotic analysis is carried out with underwater ambient noise obtained in areas near the Korean Peninsula. The calculated physical parameters of time series signal are as follows: histogram, self-correlation coefficient, delay time, frequency spectrum, sonogram, return map, embedding dimension, correlation dimension, Lyapunov exponent, etc. We investigate the chaotic pattern of noises from these parameters. From the embedding dimensions of underwater noises, the assesment of underwater noise by chaotic analysis shows similar results if they don't include a definite sinusoidal signal. However, the values of Lyapunov exponent (divergence exponent) are smaller than that of random noise signal. As a result we confirm the possibility of classification of underwater noise using Lyapunov analysis.

• Proceedings of KOSOMES biannual meeting
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• 2006.05a
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• pp.201-206
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• 2006

As the seriousness of the global environment is gaining increasing our attention recently, studies on application of LCA(Life Cycle Assesment) to ship are being carried dynamically in various industry fields. This study examined general outline about local and international application cf LCA to ship. First of all, international background for the appearance of LCA and its general meaning are introduced. The state-of-the-art for its application to ship will be also explained. Finally, domestic study methodology for application of LCA to ship were suggested.