• Journal of Radiation Protection and Research
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• 제10권1호
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• pp.29-40
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• 1985

The objectives of present study is to investigate genetic damage of radiation in mammalian male germ cell and. to establish available screening method for determining genetic hazard by radiation. Several methods were employed to measure the genetic damage of radiation as follows: Sperm head counts, frequency occurrence of sperm with abnormal head shape, fertility, activity of LDH-X, and the induction of unscheduled DNA synthesis (U.D.S.) in male mouse were performed with the passing of time after irradiation by making use of the sequence of event that occurs during spermatogenesis. Sperm head counts and activity of LDH-X in testes were gradually reduced by increased radiation dose and with the passing of the time after irradiation. Frequency occurrence of sperm with abnormal head shape, sterile period, and the induction of unscheduled DNA synthesis were increased by increased radiation dose. It is suggested that since germ cell is a direct reflection of genetic complement, the use of male germ cell is rapid and convenient method for measuring genetic damage by radiation.

• 정보처리학회논문지C
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• 제14C권4호
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• pp.341-348
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• 2007

홈 네트워크에서 홈 디바이스에 저장되는 비밀 정보는 사용자의 안전에 직접적으로 관련이 있어 매우 신중과 안전을 요하지만, 디바이스에서의 비밀 정보의 보호를 위해서는 추가적인 하드웨어의 지원에 기댈 수밖에 없었다. 하지만 많은 홈 디바이스들이 이러한 준비 없이 사용되고 있으며 이러한 디바이스들에 대한 대비 또한 필요하다고 하겠다. 이 논문에서는 이러한 부분에 있어서, 추가적인 하드웨어의 지원 없이 기존의 홈 디바이스가 가지고 있는 네트워킹 기능을 사용하여 비밀 정보를 보호할 수 있는 두 가지 방법과 그 방법들을 동시에 사용하는 방안에 대해서 제안하고, 제안하는 기법에 대해서 보안적 측면과 비용적 측면에서 각각 살펴본다.

• 농촌계획
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• 제12권3호
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• pp.57-65
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• 2006

Stonewall in Jeju has been regarded as the one of the most esthetic landscape in rural regions. In addition, they have been played as a useful facility to protect houses or crops from strong winds, but also to indicate the boundary of ownership. In the recent research, stonewall has been appointed as the one of important components in rural landscape. Thus, stonewall in Jeju retains intrinsic and real value by many usages in rural regions. However, in spite of it's value, stonewall has been abandoned without any concerns and political measures. Now stonewall is urgently needed to be dealt by a certain political measure for protection. Therefore, the depth of concerns and systematic management measures for protection should be discussed and made, otherwise the destruction of these natural valuable structures will be continued. In this sense, the purpose of this paper, first of all, is to examine the status of stonewall in jeju. And then, with the result of this examination, political measures and suggestions to protect stonewall are proposed. Several areas such as Sungsan, Sinchon, and so on in Jeju are selected as the sample areas for this study, and examination are carried with a wide range of literature reviews and the GIS technology for data collection and analyses.

• Corrosion Science and Technology
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• 제16권3호
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• pp.109-114
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• 2017

Monitoring of corrosion is in most cases based on simulation of environmental conditions on a large and complex structure such as a buried pipeline using a small probe, and the measurement of thermodynamics and kinetics of corrosion processes occurring on the probe surface. This paper presents a hybrid corrosion monitoring probe designed for simulating deteriorating conditions wrought by disbonded coatings and for measuring current densities and distribution of such densities on a simulated pipeline surface. The concept of the probe was experimentally evaluated using immersion tests under cathodic protection (CP) in high resistivity aqueous solution. Underneath the disbonded area, anodic currents and cathodic currents were carefully measured. Anodic current densities were used to calculate metal loss according to Faraday's law. Calculated corrosion patterns were compared with corrosion damage observed at the surface of the probe after a series of stringent tests. The capability of the probe to measure anodic current densities under CP, without requiring interruption, was demonstrated in high resistivity aqueous solution. The pattern of calculated metal loss correlated well with corrosion products distribution observed at the array surface. Working principles of the probe are explained in terms of electrochemistry.

• Nuclear Engineering and Technology
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• 제52권8호
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• pp.1826-1833
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• 2020

Administration of stable iodine has been considered a best measure to protect the thyroid from internal irradiation by radioiodine intake, and its efficacy on thyroid protection has been quantitatively evaluated in several simulation studies on the basis of simple iodine biokinetic models (i.e., three-compartment model). However, the new iodine biokinetic model adopted by the International Commission on Radiological Protection interprets and expresses the thyroid blocking phenomenon differently. Therefore, in this study, the new model was analyzed in terms of thyroid blocking and implemented to reassess the protective effects and to produce dosimetric data. The biokinetic model calculation was performed using computation modules developed by authors, and the results were compared with those of experimental data and prior simulation studies. The new model predicted protective effects that were generally consistent with those of experimental data, except for those in the range of stable iodine administration -72 h before radioiodine exposure. Additionally, the dosimetric data calculated in this study demonstrates a critical limitation of the three-compartment model in predicting bioassay functions, and indicated that dose assessment 1 d after exposure would result in a similar dose estimate irrespective of the administration time of stable iodine.

• 대한안전경영과학회지
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• 제11권2호
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• pp.77-85
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• 2009

Considering heat insulation and beautiful sight of construction, making use of exterior panels is increasing. Recently the exterior panels now are weak very much, and so in consequence of the weakness fire spreads rapidly. Compared with internal fire, external vertical fire spread rate goes rapidly and it is extensive in spread range, therefore it is dangerous very much. Accordingly, under present condition of poor standard of exterior panels, it is required to take measure to meet the appropriate situation. In this study, by making use of FDS(Fire Dynamic Simulation) program about external vertical fire of high rise building, fire behavior is searched by computer. It is important that realizing by computer fire modeling about external vertical fire must be included certainly in procedure of fire performance design in the future. In modeling program, FDS version 5 is available, and aluminium composite panel is applied in external panels. In this study, for realizing of actual fire condition, FDS is applied by details of fire scenarios considering influence of wind.

• Journal of Radiation Protection and Research
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• 제9권2호
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• pp.112-117
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• 1984

A lot of radioisotopes are applied to medical fields. It's very important to measure the activities on airborne radioiodine discharged in air from $Na^{131}I$ solutions and from patients treated with radioiodine. Also surface decontamination is another one important problem to be completly solved in the isotope laboratory where there is always the possibility of radiation contamination. The Authors measured the activities on airborne radioiodine with RI collector and scintillation counter. 1. The mean accumulative activity of airborne radioiodine discharged into air from $Na^{131}I$ solution was measured as $1.3{\times}10^{-3}/hr$ rate, and the maximum value was $1.8{\times}10^{-3}/hr$. 2. Radioactivity rate per hour of airborne iodine discharged into air from patients treated with $Na^{131}I$ was measured as $6.2{\times}10^{-5}/hr$ at 8 hour after administration of radioiodine and decreased into $2{\times}10^{-6}/hr$ after 24 hour. 3. Metalic surfaces such as stainless steel or aluminum are decontaminated 5 to 6 times more rapidly than wood and concrete surfaces. 4. Decontamination with wet wiping with detergent was 9 to 10 times more rapidly than dry wiping method, but dry wiping was useful for the first step to prevent spreading and flowing from liquid radioactive materials.

• Earthquakes and Structures
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• 제11권6호
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• pp.1143-1164
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• 2016

Time Delay of Arrival (TDOA) estimation methods based on correlation function analysis play an important role in the micro-seismic event monitoring. It makes full use of the similarity in the recorded signals that are from the same source. However, those methods are subjected to the noise effect, particularly when the global similarity of the signals is low. This paper proposes a new approach for micro-seismic monitoring based on cross wavelet transform. The cross wavelet transform is utilized to analyse the measured signals under micro-seismic events, and the cross wavelet power spectrum is used to measure the similarity of two signals in a multi-scale dimension and subsequently identify TDOA. The offset time instant associated with the maximum cross wavelet transform spectrum power is identified as TDOA, and then the location of micro-seismic event can be identified. Individual and statistical identification tests are performed with measurement data from an in-field mine. Experimental studies demonstrate that the proposed approach significantly improves the robustness and accuracy of micro-seismic source locating in mines compared to several existing methods, such as the cross-correlation, multi-correlation, STA/LTA and Kurtosis methods.

• 한국기계가공학회지
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• 제11권2호
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• pp.47-54
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• 2012

An oxygen sensor installed in vehicle exhaust systems enables to measure the amount of oxygen in the exhaust gas, in which the measured data are collected and analyzed in ECU(Engine Control Unit). The oxygen sensor is exposed to the high speed exhaust gas at high temperature circumstance, so that protection caps are required not only to protect the susceptible measuring part, but also to provide the real time measurement without time delay. In this study, a new oxygen sensor with one protection cap was proposed, and the CFD analysis was carried out in order to compare the performance characteristics, such as flow speed and ratio of AOA(Age of Air), for the conventional and new oxygen sensor. The numerical results of CFD analysis provided the flow speed of 1.34m/s and the ratio of AOA of 3.43. The similar features obtained from the numerical results showed that the new oxygen sensor guarantees the same performance characteristics of the conventional ones.

• 한국의류학회지
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• 제22권5호
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• pp.646-653
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• 1998

Because there is a great concern' today about the damaging effect of chronic exposure to sunlight the use of sunscreen providing the photoprotection effect against ultraviolet (UV) was widely increased. As a result of common use of level of photosynthetic Vit. D3 in human skin decreased these days. In our experiment the animals covered with fabrics with 50% (fabric B) and 100% (fabric A) protection rate against ultraviolet B (UVB) were used to measure serum 25(OH)D3, ALP, total clacium and phosphorus. Vitamin D deficiency diet group had no effect on concentration of serum phosphorus. But the concentrations of serum 25(OH)D9 and total calcium were more decreased in vitamin D deficiency diet rats than in normal diet rats. Alkaline phosphatase activity in sunlight irradiated groups covered with 50% (fabric B) and 100% (fabric A) WB protection fabrics was more significantly decreased than vitamin D deficiency diet group. In conclusion, sunlight irradiateted groups were compared to effective to protect born disease due to the Vit. D deficeincy group.