• International Journal of Concrete Structures and Materials
• /
• v.6 no.3
• /
• pp.155-163
• /
• 2012

In order to predict the neutralization of concrete which is the reaction of carbonation dioxide from the outside and cement hydration product, such as calcium hydroxide and C-S-H, it was studied the numerical analysis method considering change of the pore structure and relative humidity during the neutralization reaction. Diffusion-reaction neutralization model was developed to predict the neutralization depth of concrete with coating finishing material. In order to build numerical analysis models considering outdoor environment and finishing materials, the adaption of proposed model was shown the results of existing outdoor exposure test results and accelerated carbonation test.

• Environmental Analysis Health and Toxicology
• /
• v.4 no.1_2
• /
• pp.55-65
• /
• 1989

Nevertheless the serious environmental pollution in Korea has been discussed in concern with health effect, the significant effect are not determined easily. Toxicological method has been used to establish safe levels of exposure for environmental pollutants to have threshold health effect below which significant effects are unlikely to occur. However the conventional method cannot to establish safe levels of exposure for non-threshold pollutants have been used to express comprehensive pollution degree, not in detailed toxic effects. Acceptable exposure or risk levels are decides by policymakers who consider descriptions and estimates of risks together with social and economic benefits. This paper focuses on the concept development of risk assessment and describes some risks of environmental pollution based on the surveyed date in Korea. The current concepts of risk assessment in policy descisions can be explored and areas for possible improvement, given current scientific knowledge are identified. The experience of foreign countries can provide a realistic basis for evaluating the existing data of environmental pollutants. To improve the environmental quality, risk regulation should be managed as soon as possible in Korea.

• Clinical and Experimental Pediatrics
• /
• v.64 no.1
• /
• pp.3-11
• /
• 2021

There is a growing body of literature on the adverse health effects of ambient air pollution. Children are more adversely affected by air pollution due to their biological susceptibility and exposure patterns. This review summarized the accumulated epidemiologic evidence with emphasis on studies conducted in Korea and heterogeneity in the literature. Based on systematic reviews and meta-analyses, there is consistent evidence on the association between exposure to ambient air pollution and children's health, especially respiratory health and adverse birth outcomes, and growing evidence on neurodevelopmental outcomes. Despite these existing studies, the mechanism of the adverse health effects of air pollution and the critical window of susceptibility remain unclear. There is also a need to identify causes of heterogeneity between studies in terms of measurement of exposure/outcome, study design, and the differential characteristics of air pollutants and population.

• Journal of radiological science and technology
• /
• v.27 no.4
• /
• pp.37-41
• /
• 2004

Purpose : Raise ability cultivation in presence at a sicked business by performance management estimation of device through measurement. Also Learn a technology that measure exact tube voltage, exposure time, output dose. And it is to grasp photofluorography X-ray generator existing circumstances using at hospital. Material & Method : Investigated Photofluorography X-ray generator(inside, outside each 10) of 10 university hospitals using tube voltage, exposure time, output dose measuring instrument. Result : Photofluorography device that tube voltage correctness is incongruent by examination PAE decision came out 3, and at exposure time correctness examination 2 incongruent, Also 3 that calculate coefficient of variation about exposure in repeatability examination of exposure were incongruent. Inappropriate photofluorography device is 5 outside hospital(mobile unit) and the thing in hospital was 3 in 3 kind of efficiency test. It appeared high that photofluorography device outside hospital is more incongruent than thing in hospital. Conclusion : May ready situation that can offer patient medical service of good quality by radiation exposure reduction, image quality administration, retake decrease etc. by keeping performance of Photofluorography device. Therefore, is considered that need on-time efficiency test.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.13 no.1
• /
• pp.29-36
• /
• 2009

In this paper, we proposed auto exposure(AE) algorithm and hardware implementation for apply to mobile phone camera. AE is a function that control camera exposure automatically for appropriate to object. Existing AE is using micro controller unit and there are some problems about high expense and slow processing speed. For improve these problems, we proposed AE algorithm for hardware implementation without micro controller unit therefor we can expect improvement about the content of a production and operation speed. We proposed the algorithm that is considered efficiency of hardware resource and the results of hardware implementation of proposed AE algorithm apply to mobile phone camera sensor, we verified proposed AE function.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.5 no.11
• /
• pp.2160-2174
• /
• 2011

In this paper, a new technique for color reproduction based on color variation characteristics of digital camera under a dim light condition is proposed. Generally, photographers should adjust a camera exposure properly for obtaining an image with real color tone of subjects. Thus, in case of taking a picture under a dim light condition, the exposure time of a camera has to be relatively longer than the one under a bright light condition. Although images with real color tone of the subject are obtained, the images may get blurred due to the shaky hands of photographer holding the camera. In order to avoid the blur effect, an input image is captured from a camera set as a short exposure time under a dim light condition. Then we propose a method to reproduce color tone of the dim input image. To this end, color variation characteristics which represent color variations of a digital camera are first extracted by analyzing the Macbeth color checker images taken under various exposure values. Then, a color reproduction is performed by an estimation based on the color variation characteristics. Experimental results have shown that the proposed method has achieved better performance of color reproduction, compared with existing methods.

• Nuclear Engineering and Technology
• /
• v.52 no.6
• /
• pp.1231-1242
• /
• 2020

The Kori Unit 1 will be decommissioned after a permanent shutdown in June 2017. South Korea has a 0.1 mSv/yr exposure limit standard for limited or unlimited site release. This is South Korea's first commercial NPP; therefore, if the containment building is reused as a memorial hall, it will contribute to the improvement of public understanding and enhance the public's acceptance of NPPs. Also, existing Kori Unit 1 nuclear power plant manpower resources can be reused after decommissioning and resident staff and memorial hall visitors can activate nearby commercial areas. Therefore, such a reuse scenario may also prevent an economic recession. The exposure dose was calculated using the following scenarios: worker in the containment building, visitor in the containment building, and worker in buildings other than the containment building. The exposure dose in the buildings was calculated by the RESRAD-BUILD developed by the Argonne National Laboratory (ANL). The preliminary exposure dose and derived concentration guideline level (DCGL) were derived.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.45 no.2
• /
• pp.126-137
• /
• 2003

The feasibility study of UV-disinfection system was performed for disinfection of effluent from wastewater treatment plant. Three low-pressure UV lamps of 17, 25, and 41 W were examined with various flow rates. Low-pressure UV lamps of 17W were examined with various turbidity, DOM (dissolved organic matter), and SS (suspended solid). The pilot plant was a flow-through type UV-disinfection system, and the range of exposure time varied from 5 to 40 seconds, turbidity from 0 to 40 NTU, DOM from 0 to 30 mg/L, and SS from 10 to 40 mg/L. The 41W lamp demonstrated complete disinfection showing no survival ratio in all the experimental conditions, and generally 17W and 25W lamps also showed high removal ratio over 97%. For the same UV dose (UV intensity times exposure time), high intensity-short exposure conditions showed better disinfection efficiency than low intensity-long exposure conditions. While the effects of turbidity and DOM were not apparent, the effects of SS was significant on the disinfection efficiency which indicates that SS control before UV-disinfection appears to be necessary to increase removal efficiency. Considering characteristics of effluent from existing wastewater treatment plants, cost-effectiveness, stable performance, and minimum maintenance, the flow-through type UV-disinfection system with high intensity and low-pressure lamps was thought to be a competitive disinfection system for wastewater reclamation.

• Journal of Environmental Health Sciences
• /
• v.37 no.3
• /
• pp.193-200
• /
• 2011

Objective: The purpose of this study is to compare and analyze the level of exposure to volatile organic compounds for different kinds of households in apartments or houses and analyze the relation between atopy-related symptoms and concentration of volatile organic compounds in order to improve indoor air quality and start to build a process to prevent environmental diseases. Method: From July 2010 to November 2010, TVOC concentration levels were measured and analyzed in 402 general households and 236 weak households, totalling 638 households. Residents were asked to fill out a survey on environmental disease. All resources were analyzed using SPSS 12.0 program. Result: In comparing the differences in concentration levels of volatile organic compounds for different types of households, including existing apartments and houses, the type of housing did not affect the concentration level of volatile organic compounds, but the relevance with skin trouble, diagnosed atopy, and atopy systems all had statistical similarities. Moreover, above-limit volatile organic compounds showed statistical relevance with amount of ventilation, time of construction, skin trouble, diagnosed atopy and atopy symptoms. Conclusion: The study concludes that as the time of construction recedes further into the past and as the amount of ventilation is higher, the exposure level to volatile organic compounds was lower and the group that were suffering from atopy symptoms had higher exposure to volatile organic compounds.

• Nuclear Engineering and Technology
• /
• v.29 no.1
• /
• pp.78-84
• /
• 1997

The specific purpose of this study is to develop the numerical guide for the cost-benefit analysis of ORE ($/person-Sv reduction) to meet the criterion of ALARA in the design stage of the KNGR. In deriving the guide, the risk factor which is defined by the risk to unit collective radiation exposure dose (deaths/person-Sv) and the monetary value of human life ($/death) are required. The risk factor has been estimated from various clinical data accumulated for a number of years and continuously modified. And the monetary value of human life is usually quantified using the human capital approach. In this study, the risk to radiation exposure perceived by a group of people is investigated through an extensive poll survey conducted among university students in order to modify the existing risk factor for radiation exposure. And in evaluating the monetary value of human life, the QOL factor is introduced in order to incorporate the degree of public welfare or quality of life. As a result of study, a value within the range of 151, 000~172, 000 dollars per person-Sv reduction is recommended as the appropriate interim numerical guide for cost-benefit analysis of ORE to meet the criterion of ALARA in the design stage of the KNGR. A poll survey was also conducted in order to see whether the public acceptance cost of nuclear power should be incorporated in developing the guide, and the result of study shooed that such a cost does not need to be considered.