• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.24 no.4
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• pp.348-356
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• 2014

To understand the relationship between road-traffic noise and urban components such as population, building, road-traffic and land-use, the city of Cheongju that already has road-traffic noise maps of daytime and nighttime was selected for this study. The whole area of the city is divided into square cells of a uniform size and for each cell, the urban components are estimated. A spatial representative noise level for each cell is determined by averaging out population-weighted facade noise levels for noise exposure population within the cell during nighttime. The relationship between the representative noise level and the urban components is statistically modeled at the cell level. Specially, we introduce a spatial auto regressive model and a spatial error model that turns out to explain above 85 % of the noise level. These findings and modeling methods can be used as a preliminary tool for environmental planning and urban design in modern cities in consideration of noise exposure.

• Journal of Preventive Medicine and Public Health
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• v.25 no.2 s.38
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• pp.162-171
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• 1992

The hematologic effect by low-concentration and repeated exposure to mixed organic solvent remains obscure. This study was performed to evaluate the hematologic effect by mixed organic solvent exposure, especially on the type of anemia by mean corpuscular volume(MCV) and red blood cell distribution width(RDW). The subject were 64 organic solvent workers(male 4, female 60) and 78 general workers(male 18, female 60) who showed anemic tendency in worker's health examination which carried out by Pusan Paik Hospital from January to December, 1988. The author gained some hematologic findings(hemoglobin, hematocrit, RBC, WBC, MCV, MCHC, platelet count, ESR, RDW) from auto-analysis method by coulter counter S plus IV, and compared the type of anemia by MCV and RDW. In the pilot study for estimating the prevalence of anemia according to the type of b, the prevalence rate was higher in organic solvent workers than in public officials as 10.9% and 4.1% respectively. There were statistical significance in the value of hemoglobin, hematocrit, MCV, MCHC, platelet count, ESR, RDW between the two study groups with more severe anemic tendency in organic solvent workers. The type of anemia in organic solvent workers was microcytic and anisocytic with the mean value of $68.28{\pm}8.3fL$ of MCV and $19.1{\pm}4.0%$ of RDW.

• Journal of Astronomy and Space Sciences
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• v.30 no.4
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• pp.327-334
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• 2013

The purpose of this study is to develop an observation program for obtaining effective flat images that are necessary for photometric observation. The development of the program was achieved by improving the existing method for obtaining twilight flat images. The existing method for obtaining twilight flat images acquires flat images by observing the sky light after sunset or light before sunrise. The decision of when to observe flat images at each night is solely dependent on the judgment of an observer, and thus the obtained flat images for particular nights may not be clean. Especially, in the case of the observatories where an automated observation system is in operation, there is a difficulty that an observer should pay attention during sunrise and sunset in order to obtain flat images. In this study, a computer program is developed to improve this inconvenience and to efficiently perform photometric observation in the observatories where an automated observation system is applied. This program can obtain flat images by calculating the time for obtaining flat images automatically and the exposure time using a numerically calculated function. When obtaining twilight flat images at dusk and at dawn, the developed program performs automated observation and provides effective flat images by acquiring appropriate exposure time considering the sunrise and sunset times that vary depending on the day of observation. The code for performing this task was added to Obs Tool II (Yoon et al. 2006), which is the automated observation system of the Chungbuk National University Observatory, and the usefulness of the developed program was examined by performing an actual automated observation. If this program is applied to other observatories where automated observation is in operation, it is expected that stable and high-quality flat images could be obtained, which can be used for the pre-processing of photometric observation data.

• Journal of the Korean Society of Radiology
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• v.18 no.3
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• pp.257-265
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• 2024

In this study, we applied AEC(Auto Exposure Control), which is used in many chest examinations, to evaluate whether medical devices inserted into the body affect the dose and image quality of chest images. After attaching three HIMD(Human implantable medical devices) to the ion chamber, the Monte Carlo methodology-based program PCXMC(PC Program for X-ray Monte Carlo) 2.0 was applied to measure the effective dose by inputting the DAP(Dose Ares Product) value derived from the Pacemaker and CRT and Chemoport Additionally, to evaluate image quality, we set three regions of interest and one noise region on the chest and measured SNR and CNR. The final study results showed significant differences in DAP and Effective dose. There was a significant difference between Pacemaker and CRT when AEC was applied and not applied. (p<0.05) When applied, the dose increased by 37% for Pacemaekr and 52% for CRT. Chemoport showed a 10% increase in effective dose depending on whether AEC was applied, but there was no significant difference. (p>0.05) In the image quality evaluation, there was no significant difference in image quality between all HIMD insertions and AEC applied or not. (p>0.05) Therefore, when the HIMD was inserted into the chest during a chest x ray and overlapped with the ion chamber sensor, the effective dose increased, and there was no difference in image quality even at a low dose without AEC. Therefore, when performing a chest X-ray examination of a patient with a HIMD inserted, it is considered that performing the examination without applying AEC is a method that can be considered to reduce the patient's radiation exposure.

• Journal of Environmental Policy
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• v.1 no.1
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• pp.75-90
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• 2002

Methyl tertiary-butyl ether(MTBE) is used as an octane enhancer in gasoline. MTBE can enter the environment at any stage in the production, storage, and transport of undiluted MTBE or MTBE-blended gasoline. Although data on concentrations of MTBE in the environment are not available, modelling of fate of MTBE has provided predictions for concentrations of MTBE in the various media to which humans and other organisms may be exposed. Many individuals do not taste or smell MTBE at the $5{\mu}g/L$ level, and thus may be exposed to higher concentrations for a significant amount of time. MTBE exposure through inhalation is likely to be below health-threatening levels, except for occupational workers such as gasoline station attendants and auto mechanics. It should be stressed, however, that there are important data gaps in our understanding of the acute and chronic toxicity of MTBE. Little or no research concern including being conducted that directly addresses these issues. Rather than any immediate ban on MTBE, I recommend consideration of phasing out MTBE in USA and other countries. During the transition phase, a number of policies are suggested to reduce the risk of using MTBE. One of these policies is that the state should invest in a research program. Such research should, for example, examine effective alternatives for motor vehicle fuels, and detect concentrations of MTBE in ambient air, water, and other environmental media.

• Biomolecules & Therapeutics
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• v.1 no.1
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• pp.58-64
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• 1993

DNA addicts induced by putative chemical related to carcinogenesis were detected and determined by $^{32}$P-Postlabelling assay after exposure of 4 compounds comprising two auto dyes (amaranth, new coccine) and two flavonoid compounds (rutin, quercetin) to ICR mouse. DNA was isolated from mouse liver and digested enzymatically to deoxyribonucleoside 3'-monophosphate. The postincubation of DNA digests with nuclease Pl before $^{32}$P-labelling enhanced the technique's sensitivity. Nuclease Pl cleaves deoxyribonucleoside 3'-mono-phosphates of normal nucleotides to deoxyrihonucleosides which do not serve as substrates for polynucleotide kinase, while most of addicts were found to be totally or partially resistant to the 3'-dephosphorylating action of nuclease Pl. The adducted deoxyribonucleoside 3'-monophosphate was converted to 5'-$^{32}$P-labelled deoxynucleoside 3',5'-bisphosphate by T4 polynucleotide kinase. The nucleotides were separated by anion-exchange thin layer chromatography(TLC) on polyethyleneimine cellulose by 4-dimensional or 2-dimensional TLC then detected by autoradiography. The results show that DNA addicts were detected in liver DNA of ICR mouse after administration of amaranth and quercetin by 2-dimensional and/or 4-dimensional TLC.

• Journal of Korean Society for Atmospheric Environment
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• v.19 no.E2
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• pp.51-61
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• 2003

The material exposure tests have been carried out since 1993 to evaluate the relationship between air pollution and material corrosion with the cooperation of the researchers in Japan, China, and Korea. The test pieces such as bronze, copper, marble, and carbon steel have been exposed under both unsheltered and rain-sheltered outdoor condition separately at 18 sampling sites in East Asia. At the same time, the concentration of SO$_2$ and NO$_2$ has been measured simultaneously with passive sampler. The meteorological data were collected from the AWS (Auto-mated weather station) In each country and chemical compositions of wet deposition were also analyzed by the bulk sampling of rainfall every month. As the results, it was found that the corrosion rates of test pieces in the ambient air were appeared to be in the order of carbon steel > marble > bronze copper. The corrosion rates of test pieces in the unsheltered outdoor condition were 2.34 to 5.88 times larger than those in rain-sheltered condition. It was also found that the corrosion rate in the heavy polluted area in China was the highest, and the corrosion rates of the metal pieces were generally proportional to SO$_2$ concentration. Between two sites in Korea, the test pieces at Daegu site showed higher corrosion rates that would be due to the higher SO$_2$ concentration.

• Journal of Preventive Medicine and Public Health
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• v.27 no.3 s.47
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• pp.557-567
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• 1994

This study was conducted to examine the effect of chronic low dose organic solvent exposures in the industries towards then neurobehavioral functions of workers. Subjective symptoms on neurobehavioral function as well as a visual reaction time test (Flicker test) were administered to 94 exposed and 162 unexposed workers in a oil refinery and some other auto-repair shops. The results obtained were as follows : 1. Symptom complaints were higher and Flicker test values were lower in exposed workers than in unexposed workers. 2. Flicker valus were Inversely correlated with urinary Hippuric acid concentration in exposed workers(r=-0.26, p<0.05). 3. Flicker valus were inversely co..elated with Subjective symptom score(r=-0.15, p<0.05). Low Flicker value were also related with some subjetive symptoms such as 'Dimmed vision', 'Nightmare', 'Weakness on extrimity' in workers as a whole. While symptoms of 'Dimmed vision ', 'Nightmare' only observed among exposed workers.

• Journal of the Korea Institute of Military Science and Technology
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• v.19 no.1
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• pp.119-126
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• 2016

The US Army used MARK-1 composed of atropine autoinjector and 2-PAM autoinjector as a medical countermeasure against nerve agent poisoning. Recently, it has been being replaced by the ATNAA(Antidote Treatment Nerve Agent AutoInjector) for improvement the convenience in use and rapid detoxification effect. ATNAA(FDA approval, NDA 21-175, 2002. 1. 17) is a multi-chambered autoinjector that sequentially delivers atropine and 2-PAM through a single needle to allow Warfighters to survive against lethal exposure to nerve agents. In this paper, our group investigated the case of FDA approval of ATNAA in a point of the various data required by FDA guideline, thereby making it easy to meet the KFDA guideline for the approval of the prototype our group has been developed. The purpose of this study is to provide a reference for efficient research activities to minimize time and cost. Additionally, the purpose of this study is to provide a reference for the planning for the development of similar drug.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.86-89
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• 2015

Quantitative Evaluation of Image Quality using Automatic Exposure Control This it leads, the relationship of control and image between of photographing condition, DR proper use method proposing. Chest phantom acquires Chest PA images which it follows in conditional change, Image evaluation factor (SNR (Signal to Noise Ratio), CNR (Contrast to Noise Ratio), PSNR (Peak Signal to Ratio), RMS (Root Mean Square)). It excepted RMS price, SNR, CNR, PSNR the case which uses AEC it came out being high The fact that the quality of image is better there was a case which does not use AEC. but Price it was slight. Image qualitative it was deficient in AEC use presence. Through this, the overall situation and most efficient use of radiation workers is better suited. But Passive AEC use would be appropriate for use rather than proactive AEC.