• Journal of the Korea institute for structural maintenance and inspection
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• v.11 no.5
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• pp.81-88
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• 2007

Among deteriorations of concrete due to environmental exposure, carbonation problems of concrete structures have increased in urban and underground structures. But conventional carbonation-prediction equations that were proposed by foreign references, can not be applied directly to the prediction of carbonation for domestic concrete structures. The purpose of this study is to propose a prediction equation of carbonation depth by considering domestic exposure conditions of concrete structures. For the derivation of the equation, conventional carbonation-prediction equations are analyzed. Through considering the relationship between results of prediction equation and those of various domestic field survey data, the so-called correction factors for different domestic exposure condition of concrete structures are derived. Finally, a carbonation-prediction equation of concrete structures under domestic exposure conditions is proposed with consideration for concrete strength in core and correction factors.

• Toxicological Research
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• v.13 no.1_2
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• pp.49-54
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• 1997

PCBs are classified as B2 (Probable human carcinogen) based on the induction of hepatocellular carcinomas in rats and mice from IRIS (Integrated Risk Information System). About 20 years ago, PCBs were phased out for electrical use in Korea, but PCBs were continuously used in the other field. Lately, there has been increasing concern on possible effects of contaminated soil to the other environment and human health. The purpose of this study is to determine PCBs level in soil at some site and to assess the human exposure doses according to exposure routes for people living within sites which expected to be exposed to PCBs. Pollution level of PCBs on the site was monitored using gas liquid chromatography. To assess the transport of PCBs in soil to plant and to air, various transfer factors(diffusion coefficient, bioconcentration factor etc.) were considered in simple calculations. To calculate the residential exposure doses by routes, some equations were considered using assumption value, which define inhalation, ingestion (soil, plant) and derreal uptake pathway. Computated results will be used as risk assessment information for human health evaluation on contaminated soil.

• Journal of Radiation Protection and Research
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• v.46 no.4
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• pp.213-217
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• 2021

Background: Radiation exposure can occur as a result of occupational activities utilizing sources of radiation. The average level of occupational exposure is generally similar to the global average, but some workers receive more than this. In this study, the occupational exposure data for workers in Korea to check the recent trend of radiation exposure. Materials and Methods: The data collection and analysis are carried out by two separate periods based on the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) survey. One is the year 2003 to 2014 for a recent survey, and the other is 2015 to 2019. All available data were collected by annual reports from radiation dose registry organizations. Results and Discussion: The annual dose over the record level to the total workers did not change much compared with the total increasing number of workers in this period. The dose to the nuclear fuel cycle field has a tendency to decrease. It resulted from the efforts of radiation dose reduction with high technology introduced to this area. Also, it is important result that the radiation dose to the workers in radiography is remarkably reduced. Conclusion: The number of radiation workers and average doses were analyzed for occupational categories in Korea. It still needs cooperative efforts between the dose registry organizations for the efficient dose management of Korean radiation workers.

• Korean Journal of English Language and Linguistics
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• v.1 no.1
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• pp.119-143
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• 2001

The main goal of this paper is to examine the current English education practices in Korea in the broad context of research and academia. Furthermore, it attempts to uncover why English education has not been well established as a field of science in English-related departments and consequently what has been neglected and what issues should be dealt with to increase understanding and to create a more interactive relationship between the university and society. First, the author deals with the influence of ‘folk science’ views in the field of English education by touching on some widely held perceptions and issues. Second, by dealing with the alienation of English education and examining the phenomenon of seeing English education as a secondary field of science in English related departments, an attempt was made to reveal underlying epistemological dualism rooted in Asian cultures. Third, the paper deals with a critical issue related to English education: Exposure and Time. By reviewing and reinterpreting some of basic and fundamental literature with respect to language learning, exposure, and time, the author raises a new issue in English education and proposes new interpretation and an alternative more relativistic viewpoint; he also investigates what should be done to improve English education on the basis of research and science in order to deal with the needs and problems of society.

• Journal of electromagnetic engineering and science
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• v.15 no.3
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• pp.134-141
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• 2015

The effect of a 60 Hz time-varying electric field was studied using a facing-electrode device (FED) and a coplanar-electrode device (CED) for further investigation of the genotoxicity of 60 Hz time-varying magnetic field (MF) from preceding research. Neither a single 30-minute exposure to the CED or to the FED had any obvious biological effects such as DNA double strand break (DSB) and apoptosis in cancerous SCC25, and HeLa cells, normal primary fibroblast IMR90 cells, while exposures of 60 Hz time-varying MF led to DNA damage with induced electric fields much smaller than those used in this experiment. Nor did repetitive exposures of three days or a continuous exposure of up to 144 hours with the CED induce any DNA damage or apoptosis in either HeLa or IMR90 cells. These results imply that the solitary electric field produced by time-varying MF is not a major cause of DSBs or apoptosis in cancer or normal cells.

• Journal of Radiation Industry
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• v.11 no.3
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• pp.123-130
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• 2017

Concerns about high radiation exposure to the hands of radiation workers who may contact with radioactive contamination on surfaces in a nuclear power plant (NPP) had been raised, and the Korean regulatory body required the extremity dose estimation during contact tasks with radioactive materials. Korean NPPs conducted field tests to identify the incident radiation to the hands of radiation workers who may contact with radioactive contamination during maintenance periods. The results showed that the radiation fields for contact tasks are dominated by high energy photons. It was also found that the radiation doses to the hands of radiation workers in Korean NPPs were much less than the annual dose limits for extremities. This approach can be applicable to measure and estimate the extremity dose to the hands of medical workers who handle the radioactive materials in a hospital.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.10 no.2
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• pp.98-108
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• 2000

Controlling the over-exposure of welding fumes is not an easy problem because neither general nor local exhaust ventilation systems could be successfully applied. A jet air supplying welding mask was development to reduce the exposure level of welding fumes. The jet airs tream pushes the welding fumes away from the breathing zone by using the frictional characteristic of jet. Laboratory experiments were conducted to optimize the efficiency of controlling welding fumes. Thereafter, its performance was tested in a laboratory and an industrial field. The efficiencies of reducing the welding fume exposure were about 90% and 80% in a laboratory and an industrial field, respectively. Additionally, it resulted in elimination of heat inside the mask and enhancement of clear visuality.

• Journal of The Korean Society of Grassland and Forage Science
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• v.14 no.2
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• pp.93-98
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• 1994

This experiment was canied out to investigated the effect of slope exposure on winter hardiness of grasses in mountainous pastures of Taekwalyong area The results obtained were summarized as follows; 1. Plant vigour(PV) before wintering influenced on the growth of next spring, field survival rates and winter hardiness of grasses. 2. The dry weight of plant per relative tiller appearance rates(DW/RTAR) was significantly negative correlated with plant vigour(PV) before wintering, but the weight of plant per relative tiller appearance rates(DW1 RTAR) were significantly positive correlated with the number of tiller per plant before wintering($NT_O$), number of tillers per plant of 1st cutting(NT), dry weight of plant(DW), field survival rates(SR) and relative tiller appearance rate(RTAR). 3. There ranking order of high winter hardiness of grasses, it were west(W), north-north west(NNW), eastsoutheast( ESE) and south-southwest(SSW) exposure, respectively.

• Nuclear Engineering and Technology
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• v.7 no.4
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• pp.277-284
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• 1975

A result of measurement for the relative dose distribution of neutron gamma mixed radiation field in the biological irradiation facility installed at TRIGA Mark-III reactor is described. The relative dose distributions of neutron-gamma mixed radiation field in the biological exposure room have been experimentally determined using a thermoluminescent dosimeter. Presented herein in graphical forms are the experimental results obtained. It as observed that the region commonly having the characteristics of rather homogeneous horizontal and lateral dose distributions is confined to the area bounded by the two planes horizontally parallel to the beam direction with heights of about 40 cm and 130 cm, respectively, at distances beyond 100 cm from the segmentary surface of the aluminum pool liner projected into the the exposure room, while other areas show a steeper gradient in dosage, especially the places adjacent to the segment of the aluminum pool liner and near the inner po${\gamma}$lion of the concrete walls of the exposure room.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.9 no.5
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• pp.687-697
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• 1998

In spite of increasing public concern about the human exposure to electric and magnetic fields(EMFs), there is little information about the EMF levels in the vicinity of power facilities and of home appliances. To provide such information, a nationwide survey for EMFs near overhead transmission lines has been conducted. The median values of the electric fields and magnetic fields of 153 transmission lines were 0.47 kV/m and 11.6 mG, respectively. The maximum values were 3.16 kV/m and 125 mG. These were low values in comparison with any EMF guidelines or standards of advanced contries. Measurements of the magnetic fields of typical home appliances and daily human exposure records have been also conducted. These magnetic field values were comparable to those of the transmission lines.