• YAKHAK HOEJI
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• v.25 no.3
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• pp.89-99
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• 1981

This study was performed to investigate the contamination level of heavy metals in freshwater flshes. The samples of 92 cases were collected at 7 areas located on HanRiver from November to December in 1980. Contents of heavy metals: cadmium, lead, copper, chromium and zinc were analyzed by atomic absorption spectrophotometry. The results were as follows: 1. Generally mean value of the heavy metal contents of fishes collected on lower parts of Han River were higher than those of upper parts. 2. In the cadmium contents, the highest value was $20.52{\pm}5.10$ ppb in Carassius auratus, and the values at Hannam and Noryangjin area were higher than those at other parts on Han River. 3. In the lead contents, the highest was $0.29{\pm}0.03ppm$ in Carassius auratus and that in Parasilurus asotus was the lowest $0.12{\pm}0.02ppm$ Mean contents of lead in the samples of Hannam and Haengjue area were higher than those of other area 4. In the copper contents, the highest value was $3.13{\pm}0.34ppm$ in Carassius auratus and the contents of fishes of Haengjue area was higher than those of any other area. It was significant among the species, but not among the collecting areas in copper contents. 5. In the chromium contents, the highest was $1.16{\pm}0.12ppm$ in Carassius auratus and that in Parasilurus asotus was the lowest $0.21{\pm}0.01ppm$ The contents of samples of Hannam and Noryangjin area were also higher than those of other area. 6. In the zinc contents, that in Arassius auratus was the highest value with $14.06{\pm}1.13ppm$ and that in Parasilurus asotus was the lowest $4.79{\pm}0.53ppm$. On the other hand, it was significant among the species and collecting areas. 7. Accumulation of heavy metals in freshwater fishes is tended to increase with growth.

• Journal of Environmental Health Sciences
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• v.45 no.2
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• pp.126-133
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• 2019

Objectives: In this study, a nine-stage cascade impactor was used to collect dust, and the concentration of $PM_{2.1}$ & $PM_{10}$ and alveolar deposition ratio were investigated. Methods: This study was conducted at Kunsan National University from May to June 2016. A nine-stage Cascade Impactor was used to analyze the concentrations of fine and ultrafine dust and to estimate the alveolar deposition rate by particle size of atmospheric dust particles. The pore size of each stage of the collector used in this study gradually increased from F to 0, with the F-stage as the last stage. Results: The mass fraction of PM showed a bimodal distribution divided into $PM_{2.1}$ & $PM_{10}$ based on $2.1-3.1{\mu}m$. The average mass fraction of particulate matter in the range of $2.1-3.1{\mu}m$ was 44%, and the area occupied by $PM_{2.1}$ was similar. Therefore, the Gunsan area is considered to be a region where there are similar effects from anthropogenic and natural sources. Conclusion: Dust collecting efficiency increased with the stage of collecting fine dust, and the efficiency of collection was very low at the stage of collecting ultra-fine dust. The seasonal overall efficiency of the Cascade Impactor was 44% in spring and 37.4% in summer, and the average overall efficiency was 40.7%. The alveolar deposition rate of $PM_{2.1}/PM_{10}$ during the sampling period was estimated to be about 75% deposited in the alveoli.

• Journal of Korean Society for Atmospheric Environment
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• v.31 no.6
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• pp.530-537
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• 2015

The wet electrostatic precipitator (wet ESP) is an effective control device which removes submicron particles reentrained in a collection plate and water soluble gas. However, its collection efficiency decreases, as its operation is subject to water-induced distortion of the collection electrode. In order to make up for the limitation, we modified the wet ESP system by installing electrosprayed discharge electrodes. The modified wet ESP system can wash both the collection plate and discharge electrode. As a result, we were able to fabricate a compact wet ESP with a small specific collecting area ($0.18m^2(m^3/min)$) that can accomplish a high collection efficiency of fine particles (97.1%). In addition, the device obtained a relatively low specific corona power of approximately $10W/(m^3/min)$.

• Journal of Radiation Protection and Research
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• v.16 no.2
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• pp.17-26
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• 1991

Beta ray $(^{90}Sr+^{90}Y)$ absorbed dose at tissue surface was measured from the distance of 30cm by use of extrapolation chamber. In the measurement, following factors were considered: effective area of collecting electrode, polarity effect, ion recombination and window attenuation. The measured absorbed dose rate at tissue surface was $1.493{\mu}Gy/sec$ with ${\pm}2.9%$.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2003.11a
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• pp.173-179
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• 2003

This study analyzes the problems, which the residential inner area has, and proposes systematic and gradual progressing improvement plan for the residential environment in the inner area. Also, planning instruction is proposed through the case study of parcel·jointed complex housing. This study can be concluded as below: (1) Improvement plans sub-divided into promoting districts and inducing districts of the residential inner area are proposed. (2) Necessity for construction of streets is proposed in order to compensate existing problems in sites. (3) Necessity of complex housings is proposed fur roadsides of household unit or small-sized annexation of parcel. (4) Collecting design examples and existing literatures, the planning guideline for jointed parcel complex housing is proposed based on the established relation with a whole surface of streets, formation and distribution of purposes and increased role of exterior space.

• Proceedings of KOSOMES biannual meeting
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• 2007.11a
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• pp.91-95
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• 2007

It tries to develop a collect system for floating garbage flowed into the sea Based on the study on the characteristics of floating garbage in rainy season, it confirmed the structure and specification of each device and tested its performance on the sea It showed tint the collection device of this system could sweep more than 15 meters of sea area at a time when a ship moves with the efficiency of the spreading device. It means tint it is more efficient in collecting garbage than now in use garbage collecting ships. The water height of the net to which the garbage is finally input maintained more 50cm within the towing speed of 5kt. It indicates tint the garbage input performance is good The collect system of this research showed good performance collecting 200kg of garbage into the net for each test of collecting floating garbage.

• Environmental Engineering Research
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• v.18 no.4
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• pp.229-234
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• 2013

This study aimed to develop a new dust collecting system equipped with an activated carbon (A.C.) coated electrode. Before fabrication, pre-treatment of A.C. was performed to remove metal ions within the A.C. to enlarge its specific surface area. Then, pre-treated A.C., black carbon, polyvinyl acetate (PVAc), and methanol were mixed to make a gel compound, which was coated onto aluminum plates to fabricate electrodes. The optimal mixing ratio of A.C., black carbon, PVAc, and methanol was found to be 10 g: 2 g: 3 g: 20 mL. After fabrication, the electrodes were used in the batch-type experiment for $NH_3$ and $H_2S$ removal. The reduction rates of the gases were high at the beginning and slowly reduced with time. Dust collection experiments were conducted in continuous flow, with various voltages applied. Compared to 5 kV, dust removal efficiency was 1.5 times higher when 10 kV was applied. Increasing the number of electrodes applied also increased the collecting efficiency. The correlation coefficient between actual collecting efficiency and trend line was higher than 99%. Consequently, the novel dust collection system equipped with A.C. coated electrode appears to be a promising substitute for existing dust-control devices.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.10a
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• pp.513-516
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• 2013

In this paper, we present an information collecting system in medical information management domain. Our proposed system performs a systemized process, consisting of collection, transmission, and management, to develop intelligent medical information system and medical big data processing system. Our information collecting system consists of low-power biomedical sensors, biomedical information collecting devices, and storage systems. Currently, almost biomedical information of patients is collected manually by employees like nurses and medical doctors. Therefore, collected biometric data can be error-pronoun data. Since there is a lack to make big data of medical information, it is difficult to enhance the quality of medical services and researches. Accordingly, through our proposed system, we can overcome the problems like error-pronoun biometric data. In addition, we can extremely extend the area of collectable biometric data. Furthermore, using this system, we are able to make a real-time biomedical analysis system, like a real-time patient diagnosis system, and establish a strategy to against future medical markets changing rapidly.

• Journal of Korean Society for Atmospheric Environment
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• v.29 no.6
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• pp.773-779
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• 2013

This study was performed to provide the basic data for the function of BTEX removal for compact electrostatic precipitator which are applicable to indoor environment (or closed spaces). For this purpose, the adsorption equilibrium test was conducted for BTEX of activated carbon sheet (ACS) and activated carbon (AC), and the adsorption characteristics of AC and ACS were evaluated using the Langmuir constant which was obtained from the adsorption characteristics, adsorption capacity and regression calculation. The surface area and adsorption pore volume of ACS reduced by 70% and 86%, respectively, as compared to those of AC, and the adsorption capacities of BTEX also showed a similar level. Thus, it is considered that ACS applied electrostatic precipitator is able to remove dust and BTEX simultaneously.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.61-62
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• 2015

This study presents a movable USV (Unmanned Surface Vehicle) based on Micro Controller. Recently, Micro Controller has widely used in application programming such as industry and education application. In particular, Robot is capable of collecting Marine Debris in any sea area is needed so We propose USV used IP camera for automatic driving, distance detection to control movement of USV in order to prevent of collision based on Arduino. Also, Surrounding situation taken by IP camera can be transmitted to monitor and smartphone.