• 한국대기환경학회지
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• 제16권2호
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• pp.165-178
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• 2000

In this study the effects of block distance have been investigated on the particle deposition efficiency in the collecting cell of two-stage electrostatic precipitator by numerical analysis. Particle trajectories have been changed by the electrostatic and inertial force of particle with the inlet velocity electrostatic number and particle diameter. The total deposition efficiency has a minimum value by the interaction between the effect of particle inertial force and electrostatic force in the collecting cell. The increase of block distance makes the total deposition efficiency decrease under the range of the particle size which has the minimum deposition efficiency. However beyond the range of particle size which has minimum deposition efficiency total deposition efficiency has no trend with the variation of block distance.

• Journal of Power Electronics
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• 제14권4호
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• pp.764-777
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• 2014

This study analyzes the mathematical relationship between DC-link voltage and system parameters for shunt active power filters (APFs). Analysis and mathematical deduction are used to determine the required minimum DC-link voltage for APF. A novel adaptive DC-link voltage controller for the three-phase four-wire shunt APF is then proposed. In this controller, the DC-link voltage reference value will be maintained at the required minimum voltage level. Therefore, power consumption and switching loss will effectively decrease. The DC-link voltage can also adaptively yield different DC-link voltage levels based on different harmonic currents and grid voltage levels and thus avoid the effects of harmonic current and grid voltage fluctuation on compensation performance. Finally, representative simulation and experimental results in a three-phase four-wire center-split shunt APF are presented to verify the validity and effectiveness of the minimum DC-link voltage design and the proposed adaptive DC-link voltage controller.

• 한국환경과학회지
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• 제14권1호
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• pp.33-40
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• 2005

The size of minimum order stream has a very sensitive effect on runoff analysis model using the divergence characteristic of stream. Therefore, in this study, the threshold area of minimum order stream has been examined the change characteristic of topographical parameters. The subject basin of the research was the upper basin of the Kumho water gage station which is located in the middle of the Kumho river. The 1:25,000 numerical geography which was constructed $10{\times}10m$ mesh was used. The range of investigation of topographical parameters are number of stream order, length, area, slope, basin relief, sinuosity ratio, drainage density and total stream length etc. It was found from the result of analysis that the threshold value of minimum order stream has a very big effect on topographical parameters of basin. It was found that the threshold area of minimum ord er stream revealed under $0.10km^{2}.$ Furthermore, the parameters showed a serious change except for over $0.10km^{2}.$

• 한국가구학회지
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• 제28권4호
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• pp.355-361
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• 2017

Indoor noise environment is an important factor when it comes to occupants comfort, especially in cafe. Results of the survey, 33.9% of occupants were feel unpleasant and sensitive about noise environment. Noise in cafe fluctuate depending on the finishing of both wall and ceiling, volume of the room, and the number of occupants in the room. Therefore, the noise meter device was used for measurement of various under conditions. Also, the subjective assessment of occupant noise was conducted through questionnaires. When the interior finish was exposed concrete, the maximum value of the noise measurement was 66.6 dB and the minimum value was 63 dB, respectively. Also, the result of subjective assessment of unpleasant noise were 5.43 and 4.96 point of 10 point of noise and echo, respectively. Otherwise, the interior finish was gypsum board, the maximum value of the noise measurement was 73.8 dB and the minimum value was 60.4 dB, respectively. Also, the result of subjective assessment of unpleasant noise were 3.88 and 3.95 point of 10 point of noise and echo, respectively. The results of the study showed that the noises and echoes in the cafes were lower than when did not.

• 약학회지
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• 제34권5호
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• pp.302-310
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• 1990

A study has been made of the Korean bentonite aqueous suspension contrast with American bentonite by means of XRD IR swelling, gel formation and rheogram at various conditions such as concentration, temperature and pH. The Korean bentonite was identified as montmorillonite clay containig a small proprotion of crystoballite and mordenite, and its swelling power were acceptable for requirements of Korean pharmacopeia regulations though its values were not satisfied. Korean bentonite swelled to 10 times and American one did to 15 times compared to its bulkiness of powder. The rheogram of Korean bentonite suspension reveals bulged pseudoplatic flow with yield value at higher concentration and pseudoplastic flow without yield value at lower concentration. The higher the concentration, the greater were the apparent viscosity and hysteresis loop. Korean bentonite suspension showed insignificant temperature dependence on both apparent viscosity and hysteresis loop and it was more temperature dependent on viscosity but less on hysteresis loop than those of American sample. The pH dependence was so high on viscosity that apparent minimum value was near pH 7 and maximum value at pH 3 or 7. The hysteresis loop appeared minimum over the pH range 5-7 and maximum near pH 3 or 11. The Korean bentonite was inferior to the American bentonite in swelling volume, gel formation, thioxotropy, however, it would be possible to improve the quality of Korean bentonite by developing the method of purification for bentonite clay.

• 동의신경정신과학회지
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• 제33권2호
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• pp.143-156
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• 2022

Objectives: The purpose of this study was to evaluate the quality of reporting for case reports published in Journal of Oriental Neuropsychiatry from year 2018 to 2021 compared with year 2013 to 2017 in order to recommend ways to improve the quality of case reports published in the future. Methods: To evaluate the quality of case reports identified by electronic searching in Oriental medicine Advanced Searching Integrated System (OASIS) and by hand searching from archives on peer review system of Journal of Oriental Neuropsychiatry using CAse REport (CARE) guideline. The researcher assessed the quality of reporting based on the CARE guideline as 'Sufficient', 'Not-Sufficient', 'Not-Applicable', and 'Not-Reported' for case reports published from 2018 to 2021 in Journal of Oriental Neuropsychiatry. In addition, it was compared with previous case reports published from 2013 to 2017. Results: Finally, 17 case reports were included for the assessment. General quality of reporting for case reports published from year 2018 to 2021 was improved compared with that of previous case reports published in 2018. The maximum value (46.4%→60.7%, 14.3% increase), the minimum value (22.2%→32.1%, 9.9% increase), and the median value (39.3%→50.0%, 10.7% increase) of the report rate evaluated as 'Sufficient' were generally improved. The maximum value (53.6%→50.0%, 3.6% decrease), minimum value (25.9%→21.4%, 4.5% decrease), and median value (35.7%→32.1%, 3.6% decrease) of the report rate evaluated as 'Not-Sufficient', the maximum value of the report rate evaluated as 'Not-reported' (40.7%→25.9%, 14.8% decrease), the minimum value (14.7%→10.7% decrease), and the intermediate value (14.7% decrease) were also generally improved. Four items (8b, 8d, 10c, and 13) were evaluated as 'Not-Reported'. These items seem to be items that need urgent improvement along with 8c, which showed a significant decrease in reporting rate. Conclusions: There are needs to improve the quality of case reports in Journal of Oriental Neuropsychiatry by comparing case reports published from year 2013 to 2017 with case reports published from year 2018 to 2021. To improve the quality of case reporting, sufficient education at the academic level should be provided on thesis preparation methods. It is also necessary to develop a tool for evaluating the quality of case reporting that reflects characteristics of Korean Medicine.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2004년도 총회 및 춘계학술발표회
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• pp.455-458
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• 2004

This study uses time series analyses to evaluate fluctuation of water levels in a geothermal water well due to pumping, in relation to rainfall at Dongrae hot-spring site on the southeastern coast of tile Korean peninsula. The volume of water pumped from the public study wells ranges from 542 to 993 m$^3$/month, and the minimum water level ranged from 35 to 144.7 m during the measured period. Autocorrelation analysis was conducted for the withdrawal rate at the public wells, water levels and rainfall. The autocorrelation of the withdrawal rate shows distinct periodicity with 3 months of lag time, the autocorrelation of rainfall shows weak linearity and short memory with 1 months of lag time, and the autocorrelation of water levels shows weak linearity and short memory with 2 months of lag time. The cross-correlation between the pumping volume and the minimum water level shows a maximum value 1 at a delayed time of 34 months. The cross-correlation between rainfall and the minimum water level shows a maximum value of 0.39 at a delayed time of 32 months.

• 조명전기설비학회논문지
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• 제25권7호
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• pp.83-91
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• 2011

Even if smoke, fumes, mist or dust particles are removed by electrostatic precipitators (ESPs), the occurrence of ozone, which is harmful to human body, has to be severely restricted in the indoor environments of hospitals, offices, and workshops. Therefore, the two-stage ESP generating positive corona at the ionizer is typically used because it creates less ozone than the two-stage ESP generating negative corona at the ionizer. In order to predict the collection performance and the optimal design of the two-stage ESP applied to positive high-voltage, particle concentration is experimentally investigated in this paper. In addition, particle motion within the collector section is also numerically analyzed. The positive corona discharge current of the ionizer is found to be affected by the applied voltage in the collector section but less so by the particle concentration. Particle concentration shows a minimum near the high voltage electrode of the collector section. The minimum value of the collection efficiency is almost proportional to gas velocity. When the collector length decreases, the minimum value of the collection efficiency increases. Charged particles entering the collector region are linearly deflected towards the grounded plate by an electric field. From the above experimental and numerical results, two empirical equations on the concentration ratio and the collection efficiency are derived, and are in good agreement with the experimental data.

• Journal of Biosystems Engineering
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• 제19권3호
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• pp.211-221
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• 1994

In this study, to maximize the solar energy utilization for greenhouse heating during the winter season, solar energy-underground latent heat storage system was constructed, and the thermal performance of the system has been analyzed to obtain the basic data for realization of greenhouse solar heating system. The results are summarized as follows. 1. $Na_2SO_4{\cdot}10H_20$ was selected as a latent heat storage material, its physical properties were stabilized and the phase change temperature was controlled at $13{\sim}15^{\circ}C$. 2. Solar radiation of winter season was the lowest value in December, and Jinju area was the highest and the lowest value was shown in Jeju area. 3. The minimum inner air temperature of greenhouse with latent heat storage system(LHSS) was $7.0{\sim}7.5^{\circ}C$ higher than that of greenhouse without LHSS and was $7.0{\sim}11.2^{\circ}C$ higher than the minimum ambient air temperature. 4. Greenhouse heating effect of latent heat storage system was getting higher according to the increase of solar radiation and was not concerned with the variation of minimum ambient air temperature. 5. The relative humidity of greenhouse with latent heat storage system was varied from 50 to 85%, but that of greenhouse without LHSS was varied from 30 to 93%. 6. The heating cost of greenhouse with solar energy-latent heat storage system was about 24% of that with the kerosene heating system.

• Journal of Biosystems Engineering
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• 제30권5호
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• pp.268-273
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• 2005

This study was conducted to investigate the specificities of four fulcrum types for geo-statistical analysis of elevation within rice paddy field. In Korea, the spaces between inter-rows and between hills for rice transplanting are 30cm and 11cm to 14cm, respectively. So, the size and shape of fulcrum for field elevation measurement should be considered according to the inter-row and the hill spaces. Four kinds of fulcrum were chosen such as round-shape with 2.5cm diameter, circular-shape with 10cm diameter, 10cm (one third of inter-row space) by 24cm (double of hill space) rectangular-shape, and 20cm (two-thirds of inter-row space) by 24cm rectangular-shape. The resulting descriptive statistics couldn't determine the best fulcrum type to measure the rice paddy field elevation. But the results of geo-statistical analysis could determine the best fulcrum type. In the case of 10cm by 24cm rectangular-shape fulcrum, Nugget and range, meaning measurement error and/or noise, and limit of spatial connection, respectively, were minimum; Q value meaning weight of spatial structure and $r^2$ value were minimum, and residual sum of squares was minimum. It means that 10cm by 24 cm rectangular-shape fulcrum could best describe the rice paddy field elevation.