• Journal of Information Technology Application
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• v.3 no.2
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• pp.133-147
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• 2001

This paper proposed a new algorithm for binarization and removal of noises in color images with characters and pictures. Binarization was performed by threshold which had computed with color-relationship relative to the number of pixel in background and character candidates and pre-threshold for dividing of background and character candidates in input images. The pre-threshold has been computed by the histogram of R, G, B In respect of the images, while background and character candidates of input images are divided by the above pre-threshold. As it is possible that threshold can be dynamically decided by the quantity of the noises, and the character images are maintained and the noises are removed to the maximum. And, in this study, we made the noise pattern table as a result of analysis in noise pattern included in the various color images aiming at removal of the noises from the Images. Noises included in the images can figure out Distribution by way of the noise pattern table and pattern matching itself. And then this Distribution classified difficulty of noises included in the images into the three categories. As removal of noises in the images is processed through different procedure according to the its classified difficulties, time required for process was reduced and efficiency of noise removal was improved. As a result of recognition experiments in respect of extracted characters in color images by way of the proposed algorithm, we conformed that the proposed algorithm is useful in a sense that it obtained the recognition rate in general documents without colors and pictures to the same level.

• Korean Journal of Ecology and Environment
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• v.34 no.3 s.95
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• pp.192-198
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• 2001

The Kyongan Stream and the inlet part of Paltang Reservoir are under significant influence of the effluent of sewage wastewater treatment plant (SWTP) and untreated domestic wastewater (DOW). The fertility of wastewater was evaluated through bioassay using natural phytoplankton population diluted in five levels. The concentrations of $NH_4$, SRP and SRSi were positively correlated with the biomass of phytoplankton. P concentration showed stronger correlation (r = 0.959, p<0.001)than other nutrients. Compared with the initial concentrations, $NH_4$ concentrations in samples from SWTP and DOW decreased 96% and 7%, respectively during the cultivation, and those of SRSi decreased 97% and 60%. However, $NO_3$ concentrations in samples neither showed any particular change nor any increase. Chl-a concentration ranged between $20\;{\mu}g/l$ and $125\;{\mu}g/l$, which maximum value increased up to 83 times. Estimated from the relationship between chl-a and SRP, the P concentration that can maintain the biomass of algae under mesotrophic state (<25\;{mu}g$\;chl-a/l$) was $83\;{mu}g\; P/l$. The volume of flow to maintain this level solely by natural dilution was about $16{\sim}25$ times of in flowing volume in the stream. However, it is not feasible to tap water of such quantity. Therefore, it is imperative to build an advanced sewage wastewater treatment facility that can reduce $NH_4$ and SRP concentrations that promote the growth of phytoplankton in discharged water.

• Journal of the Korean Institute of Gas
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• v.17 no.2
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• pp.59-69
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• 2013

This study presents development of the ANN simulator for well placement of infill drilling in gas fields. The input data of the ANN simulator includes the production time, well location, all inter well distances, boundary inter well distance, infill well position, productivity potential, functional links, reservoir pressure. The output data includes the bottomhole pressure in addition to the production rate. Thus, it is possible to calculate the productivity and bottomhole pressure during production period simultaneously, and it is expected that this model could replace conventional simulators. Training for the 20 well placement scenarios was conducted. As a result, it was found that accuracy of ANN simulator was high as the coefficient of correlation for production rate was 0.99 and the bottomhole pressure 0.98 respectively. From the resultes, the validity of the ANN simulator has been verified. The term, which could produce Maximum Daily Quantity (MDQ) at the gas field and the productivity according to the well location was analyzed. As a result, the MDQ could be maintained for a short time in scenario C-1, which has the three infill wells nearby aquifer boundary, and a long time in scenario A-1. In conclusion, it was found that scenario A maintained the MDQ up to 21% more than those of scenarios B and C which include parameters that might affect the productivity. Thus, the production rate can be maximized by selecting the location of production wells in comprehensive consideration of parameters that may affect the productivity. Also, because the developed ANN simulator could calculate both production rate and bottomhole pressure, respectively, it could be used as the forward simulator in a various inverse model.

• Journal of Radiation Protection and Research
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• v.36 no.1
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• pp.8-16
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• 2011

We manufactured the Vac-lok that can be applied to patient of special body shape and need to special set-up position and evaluated the usefulness in the radiation therapy. The manufacture Vac-lok, It was used EVA resin and biobeadform of a diameter 1.5 mm. carried out the test of functionality, structural and analyzed the relative reproducibility of phantoms and patients. During the total period of radiation therapy, Vacuum pressure bring variety to a very small amount in the test of functionality of the manufacture Vac-lok. But It was a negligible quantity. The manufacture Vac-lok improved the relative reproducibility of phantoms than the existing Vac-lok and tolerance has a confidence less than 4% error. Also, relative reproducibility of patient increased error than phantom in the antero-posterior and lateral plan. However, the maximum set-up error was less than ${\pm}\;2.3$ mm. In conclusion, If tolerance set-up error of radiotherapy is less than ${\pm}\;3$ mm, the manufacture Vac-lok was enough possible to use and improvement of reproducibility, considering supply with the Vac-lok made to measure of special patient that produced at a low price and without delay.

• The Journal of the Acoustical Society of Korea
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• v.37 no.5
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• pp.323-330
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• 2018

This study investigated effects of absorbent gypsum board in the ceiling on low-frequency heavyweight floor impact sound through sound absorption coefficient and floor impact sound measurement. The sound absorption coefficients were measured with sound absorbent gypsum board, glass wool on gypsum board, and a double panel absorbent gypsum board (absorbent gypsum board + glass wool + absorbent gypsum board). Result showed that the absorbent gypsum board had sound absorption coefficient of 0.1 ~ 0.7 from 200 and 630 Hz octave band. The sound absorption coefficient was increased in all frequency range by adding glass wool. Additional absorbent gypsum board increased sound absorption coefficient up to 250 Hz octave band, but decreased over 250 Hz. Heavyweight floor impact sounds were measured in test building for three materials above, gypsum board, and bare slab. Result showed that glass wool on gypsum board and a double panel absorbent gypsum board reduced by 3 dB ~ 4 dB (single number quantity) heavyweight floor impact sound. Comparing with bare slab condition, floor impact sound reduction was mainly found from 125 Hz to 500 Hz octave band, and the maximum reduction was shown in the 250 Hz octave band.

• Journal of Energy Engineering
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• v.25 no.3
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• pp.73-82
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• 2016

The energy consumption efficiency in a variety of operational test mode was considered for domestic gas boiler below 70 kW. The energy efficiency test carried out in the experimental conditions similar to the actual operation status was analyzed and compared with the current Korean efficiency test method. Four types of test modes for each boiler(Non-condensing and condensing boiler) were carried out in the condition of laboratory mode(full load, steady state) and actual operating mode. Futhermore divided into two operational status for each of these, it was applied by maximum gas consumption and consumer sales conditions. Test equipment has the function referred to gas boiler standards, such as KS or European standard EN. The equipment should be continuously measured and record the measuring factors which are the flow volume of gas and water, laboratory temperature, water flow volume for heating, return water volume after heating and quantity of the exhaust gases(CO, NO, $NO_2$). The experimental results were found that non-condensing boiler efficiency of laboratory mode is about 10% higher than that of actual mode. In case of condensing boiler, the efficiency of laboratory condition is about 20% higher than that of the actual using conditions. I suggest that the government will gradually take the efficiency test method considering the actual conditions.

• Journal of The Korean Society of Grassland and Forage Science
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• v.35 no.1
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• pp.43-49
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• 2015

This experiment was conducted to evaluate the agronomic characteristics and forage productivity of Italian ryegrass cultivars in Yecheon, Kyeongbuk from 2011 to 2013. The experimental design was a randomized complete block design (RCBD) with three replications. Italian ryegrass cultivars were seeded on Sep. 26 in 2011 and Sep. 25 in 2012. The Italian ryegrass cultivars were harvested on the heading date of the variety. The cold-resistance of domestic cultivars was stronger than other foreign varieties. Among early-maturing cultivars, the dry matter (DM) yield of the "Kowinearly" was 10,031 kg/ha, which was significantly higher than that of other cultivars (p<0.05). In medium-maturing cultivars, the DM yield of the "Kowinmaster" and "Tam 90" were 10,484 and 8,191 kg/ha, respectively. Of the two, the former's DM yield was higher than the latter's (p<0.05). Among late-maturing cultivars, the DM yield of "Hwasan 104" was 10,641 kg/ha, which was similar to that of "Hwasan 101" and significantly higher than the other late-maturing cultivars (p<0.05). According to the results obtained from this study, an early-maturing variety with cold-tolerance and high productivity is required for the paddy field cultivation of an Italian ryegrass cultivar after rice harvest in the mid-northern region of Korea. A medium- or late-maturing variety is more advantageous for the field cultivation of the maximum quantity that is possible. In conclusion, to select which variety/ies to grow, the climate of the growing area, weather conditions, and the cropping system must all be considered.

• Journal of Food Hygiene and Safety
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• v.28 no.2
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• pp.158-167
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• 2013

This study was carried out to assess the safety of cereals and their products (20 species, 205 samples) distributed in Gyeonggi province by analyzing contamination levels such as exposure frequency of Aflatoxins and Deoxynivalenol (DON). Aflatoxins were detected in 16 (8%) samples in total with a range of 0.01~27.88 ${\mu}g/kg$, including 3 of 9 bake flour (33%), 2 of 6 dried corn (33%), 3 of 12 frying flour (25%) and 2 of 11 sorghum (18%). DON was found in 56 (27%) samples including 11 of 13 adlay (85%), 6 of 8 wheat (75%), 6 of 10 processed corn for popcorn (60%), 6 of 11 sorghum (55%) and 7 of 16 barley (44%) with a range of 2.2~754.4 ${\mu}g/kg$. In particular, both Aflatoxins and DON were detected in 8 samples (2 millet, 2 wheat, 1 sorghum, 1 adlay, 1 dried corn, 1 bake flour) simultaneously. As a result of this study, we found that an adult is exposed to Aflatoxins of $0.80({\times})10^{-3}{\mu}g/kg$ b.w./day and DON of 0.18 ${\mu}g/kg$ b.w./day. The quantity of exposure to DON amounted to 18.5 percentage level compared with PMTDI 1 ${\mu}g/kg$ b.w./day suggested on JECFA, therefore we can assess that the possibility of health risks by intake cereals distributed in Gyeonggi province is low. However the concentration of Aflatoxins in one dried corn was 27.88 ${\mu}g/kg$ which was over the maximum residue limits (MRL) suggested on internal and external level, the monitoring about mycotoxin should be conducted on continuously.

• Korean Journal of Poultry Science
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• v.11 no.2
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• pp.115-125
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• 1984

The Waste Rice Straws (W.R.S.) after cultivation with the Pleurotas Ostreatus SACCARDO was substituted for wheat bran in the broiler ration. The results of the experiment 1 and 2 obtained were summerized as follows; 1. The content of C. protein in the W.R.S. showed 1.5% higher value than that in the rice straw. No change was detected in the content of C. fat. However the content of C. fiber and N.F.E in W.R.S. decreased in comparision with those of raw rice straw. 2. The treated groups were inclned to rapid gain of body weight, especially the 4% W.R.S. group had been showed significatly higher value of gain than the control and 6% treated groups (p＜0.05 ). 3. No significant differences were observed in the amount of feet intake among experimental groups, even if the treated groups showed slightly higher intake than control group. 4. The treated groups in W.R.S. were inferior to the control group in feed intake but there were no significant differences. 5. The methionine in W.R.S. was the only amino acid which contained similar quantity of wheat brans. 6. To extend the amount of W.R.S. in broiler ration the 6% of W.R.S. was substituted for wheat bran and methionine mixture was added. No significance differences had been showed in weight gain, feed intake and feed efficiency between control and treated groups. Even though the treated groups showed more feed intake and lower weight gain in comparision with control group. 7. The methionine added group showed adverse effect in economics of production (p＜0.01) because of high cost of the methionine mixture, Therefore less than. 6% of the WRS could be substituted for wheat bran. According to the results of the experiment 1 and 2 it could be concluded that maximum use of the W.R.R. as substitute for wheat bran was less than 4% of the ration.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.08a
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• pp.119-119
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• 2011

This study examined the synthesis of large area graphene and the change of its characteristics depending on the ratio of CH4/H2 by using the thermal CVD methods and performed the experiments to control the electron-hole conduction and Dirac-point of graphene by using chemical doping methods. Firstly, with regard to the characteristics of the large area graphene depending on the ratio of CH4/H2, hydrophobic characteristics of the graphene changed to hydrophilic characteristics as the ratio of CH4/H2 reduces. The angle of contact also increased to 78$^{\circ}$ from 58$^{\circ}$. According to the results of Raman spectroscopy showing the degree of defect, the ratio of I(D)/I(G) increases to 0.42% from 0.25% and the surface resistance also increased to 950 ${\Omega}$ from 750 ${\Omega}$/sq. As for the graphene synthesis at the high temperature of 1,000$^{\circ}$ by using CH4/H2 in a Cu-Foil, the possibility of graphene formation was determined as a function of the ratio of H2 included in the fixed quantity of CH4 as per specifications of every equipment. It was observed that the excessive amount of H2 prevented graphene from forming, as extra H-atoms and molecules activated the reaction to C-bond of graphene. Secondly, in the experiment for the electron-hole conduction and the Dirac-point of graphene using the chemical doping method, the shift of Dirac-point and the change in the electron-hole conduction were observed for both the N-type (PEI) and the P-type (Diazonium) dopings. The ID-VG results show that, for the N-type (PEI) doped graphene, Dirac-point shifted to the left (-voltage direction) by 90V at an hour and by 130 V at 2 hours respectively, compared to the pristine graphene. Carrier mobility was also reduced by 1,600 cm2/Vs (1 hour) and 1,100 cm2/Vs (2 hours), compared to the maximum hole mobility of the pristine graphene.