• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.16 no.6 s.111
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• pp.665-673
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• 2006

This paper proposes a RSM-based hybrid evolutionary Algorithm (RHEA) which combines the merits of the popular programs such as genetic algorithm (GA), tabu search method and response surface methodology (RSM). This algorithm, for improving the convergent speed that is thought to be the demerit of genetic algorithm, uses response surface methodology and simplex method. The mutation of GA offers random variety to finding the optimum solution. In this study, however, systematic variety can be secured through the use of tabu list. Efficiency of this method has been proven by applying traditional left functions and comparing the results to GA. It was also proved that the newly suggested algorithm is very effective to find the global optimum solution to minimize the weight for avoiding the resonance of fresh water tank that is placed in the after body area of ship. According to the study, GA's convergent speed in initial stages is improved by using RSM method. An optimized solution is calculated without the evaluation of additional actual objective function. In a summary, it is concluded that RHEA is a very powerful global optimization algorithm from the view point of convergent speed and global search ability.

• Korean Journal of Soil Science and Fertilizer
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• v.40 no.1
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• pp.43-50
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• 2007

Veterinary antibiotics have been widely used to increase feed efficiency, to prevent disease, and to promote growth as well as to control disease. The antibiotics administered can be excreted through the urine and feces. One of the major routes of veterinary antibiotics entering soil and water environment is via the application of animal manure to agricultural land as an organic fertilizer source. Since little is known about impacts of antibiotics on the environment, this study was conducted to prioritize the veterinary antibiotics based on the consumption and potential to reach the environment. Among 83 veterinary antibiotics consumed in Korea, ten antibiotics were used at the greater dose than 25 Mg in 2004. Potential to reach the environment was determined according to excretion rate after administered to animals and sorption affinity to soil solids after applied to agricultural land. Seventeen antibiotic active ingredients (Ais) were classified as 'High' priority in terms of the potential to reach the environment. An overall priority score was determined by combining priority score based on consumption with the degree of potential environment exposure. Twenty veterinary antibiotic AIs were classified as 'Very high' or 'High' priority requiring detailed assessment. The antibiotic AIs were identified four aminoglycosides, two macrolides, two penicillins, five sulfonamides, three tetracyclines, two quinolones, and two miscellaneous. Eight veterinary antibiotic AIs including amoxicillin, carbadox, chlortetracycline, neomycin, oxytetracycline, sulfamethazine, sulfathiazole, and tylosin were identified to have a greater priority of environmental risk in Korea.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.6
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• pp.898-904
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• 2021

This experimental study aims to investigate the use of a wet electrostatic precipitator as a post-treatment device to satisfy the strict emission regulations for sulfur oxides and particulate matter (PM). The inlet/outlet of a wet electrostatic precipitator was installed in a funnel using a marine four-stroke diesel engine (STX-MAN B&W) consuming marine heavy fuel oil (HFO) with a sulfur content of about 2.1%. Measurements were then obtained at the outlet of the wet electrostatic precipitator; an optical measuring instrument (OPA-102), and the weight concentration measurement method (Method 5 Isokinetic Train) were used for the PM measurements and the Fourier transform infrared (FT-IR; DX-4000) approach was used for the sulfur oxide measurements. The experimenst were conducted by varying the engine load from 50%, to 75% and 100%; it was noted that the PM reduction efficiency was a high at about 94 to 98% under all load conditions. Additionally, during the process of lowering the exhaust gas temperature in the quenching zone of the wet electrostatic precipitator, the sulfur dioxide (SO₂) values reduced because of the cleaning water, and the reduction rate was confirmed to be 55% to 81% depending on the engine load.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.55 no.3
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• pp.198-205
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• 2019

The small yellow croaker (Larimichthys polyactis) is one of the representative high-class fish species in Korea. The catch of small yellow croaker in adjacent water fisheries has been continuously decreasing from 59,226 tons in 2011 to 19,271 tons in 2016. The small yellow croaker is caught by gillnet, stow net and bottom trawl, among which about 55~65% is caught by gillnet. For the sustainable use of small yellow croaker, the fishing power of small yellow croaker drift gillnet is very important. Therefore, the change of fishing power index were analyzed to identify the development of the vessel and gear technology that may have improved the fishing efficiency of the small yellow croaker drift gillnet fishery from 1960s to 2010s. Gross tonnage and horse power per fishing vessel was increased annually. The mesh size was 75.0 mm in the 1960s, but reduced to 60.6 mm in the 1980s and to 51.0 mm in the 2000s. In the 1960s, it was hauled out by manpower. However, the net hauler were modernized and supply rate was also increased since 1970. Due to the mechanization of the net hauler, the number (length) of used net gradually increased from 1.5 km in the 1960s to 7.5 km in the mid-1980s and to 15 km in 2010. Colour fish finders and positioning system were introduced and utilized from the mid-1980s. Surveys on the supply and upgrading of fishing equipment utilized visiting research. Therefore, the relative fishing power index in the small yellow croaker drift gillnet fishery increased from 1.0 in 1980 to 0.8 in 1970, to 1.1 in 1990, to 1.6 in 2000 and to 1.9 in 2010. The results are expected to contribute to reasonable fisheries stock management of the small yellow croaker drift gillnet fishery.

• Journal of the Korea Convergence Society
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• v.10 no.9
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• pp.69-74
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• 2019

The purpose of this study is to compare the efficiency of bacteria removal of three different types of hand washing methods. This study performed a convenient sampling of 30 volunteers in cross-over design. The study divided the 30 volunteers into three random groups. The three groups were asked to use antiseptic soap, alcohol-based hand disinfectant, and disposable wet wipes respectively. The result of the study showed that mean log reduction values after each had washing method were $-0.45({\pm}0.69)$ with antiseptic soap and water, $-1.19({\pm}0.52)$ with alcohol-based hand disinfectant and $-0.75({\pm}0.58)$ with disposable wet wipes. The difference was statistically significant when using alcohol-based hand disinfectant compared to the other two methods (p=0.000). According to this study, alcohol-based hand disinfectant was the most effective product based on bacteria removal for hand washing. Advantages of using alcohol-based hand disinfectant are that it is cost-effective and easy to buy, also eco-friendly. Therefore, to prevent infectious disease, providing alcohol-based hand disinfectant to every corner of the community will be very helpful.

• Journal of Korean Society of Disaster and Security
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• v.12 no.1
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• pp.57-66
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• 2019

One of the most serious problems with concrete small dams or barriers installed in small/median rivers is the deposit of sediments, especially, in Korea. An effective way to discharge such sediments to downstream is to construct a bypass pipe under the river bed. However, efficiency may become lowered if ripraps are entered into the bypass pipe. Therefore, in this study, we derived the threshold condition for the exclusion of ripraps from the bypass pipe using 3D numerical analysis. Upstream flow of the small dam was assumed to be stationary, and the energy concept was applied to the control volume containing the bypass pipe and its periphery. As a result, when the ratio of the water level difference between upstream and downstream to the diameter of the riprap was approximately equal to 1.2, the threshold condition for exclusion of the stones or riprap from the bypass pipe was affirmatively determined. If the characteristics of the adsorptive sediment adversely affecting the river environment in the future would be taken into account, results from this study are expected to put to practical use in the management of concrete small dam with bypass pipe system.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.22 no.5
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• pp.27-43
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• 2019

This study applied the LANDIS-II model to the forest vegetation of the study area in Yeongdong-gun, Korea to identify climate effects on ecosystems of forest vegetation. The main purpose of the study is to examine the long-term changes in forest aboveground biomass(AGB) under three different climate change scenarios; The baseline climate scenario is to maintain the current climate condition; the RCP 4.5 scenario is a stabilization scenario to employ of technologies and strategies for reducing greenhouse gas emissions; the RCP 8.5 scenario is increasing greenhouse gas emissions over time representative with 936ppm of $CO_2$ concentration by 2100. The vegetation survey and tree-ring analysis were conducted to work out the initial vegetation maps and data for operation of the LANDIS model. Six types of forest vegetation communities were found including Quercus mongolica - Pinus densiflora community, Quercus mongolica community, Pinus densiflora community, Quercus variabilis-Quercus acutissima community, Larix leptolepis afforestation and Pinus koraiensis afforestation. As for changes in total AGB under three climate change scenarios, it was found that RCP 4.5 scenario featured the highest rate of increase in AGB whereas RCP 8.5 scenario yielded the lowest rate of increase. These results suggest that moderately elevated temperatures and $CO_2$ concentrations helped the biomass flourish as photosynthesis and water use efficiency increased, but huge increase in temperature ($above+4.0^{\circ}C$) has resulted in the increased respiration with increasing temperature. Consequently, Species productivity(Biomass) of trees decrease as the temperature is elevated drastically. It has been confirmed that the dominant species in all scenarios was Quercus mongolica. Like the trends shown in the changes of total AGB, it revealed the biggest increase in the AGB of Quercus mongolica under the RCP 4.5 scenario. AGB of Quercus mongolica and Quercus variabilis decreased in the RCP 4.5 and RCP 8.5 scenarios after 2050 but have much higher growth rates of the AGB starting from 2050 under the baseline scenario. Under all scenarios, the AGB of coniferous species was eventually perished in 2100. In particular they were extinguished in early stages of the RCP 4.5 and RCP 8.5 scenarios. This is because of natural selection of communities by successions and the failure to adapt to climate change. The results of the study could be expected to be effectively utilized to predict changes of the forest ecosystems due to climate change and to be used as basic data for establishing strategies for adaptation climate changes and the management plans for forest vegetation restoration in ecological restoration fields.

• Journal of Radiation Protection and Research
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• v.47 no.1
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• pp.16-21
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• 2022

Background: Epidemiological observations such as mental retardation, physical deformities, etc., in children besides different types of cancer in the adult population of the Malwa region have been reported. The present study is designed to get insight into the role of naturally occurring radioactive material (NORM) in causing detrimental health effects observed in the general population of this region. Materials and Methods: Deep soil samples were collected from different locations in the Malwa region. Their activity concentrations were determined using low-level background gammaray spectrometry. High efficiency and high purity germanium detector capped in a lead-shielded chamber having a resolution of 1.8 keV at 1,173 keV and 2.0 keV at the 1,332 keV line of ⁶⁰Co was used in the present work. Data were evaluated with Genie-2000 software. Results and Discussion: Mean activity concentrations of ²³⁸U, ²³²Th, and ⁴⁰K in deep soil were found to be 101.3 Bq/kg, 65.8 Bq/kg, and 688.6 Bq/kg, respectively. The mean activity concentration of ²³⁸U was found to be three and half times higher than the global average prescribed by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). It was further observed that the activity concentration of ²³²Th and ⁴⁰K has a magnitude that is nearly one and half times higher than the global average prescribed by UNSCEAR. In addition, the radioisotope ¹³⁷Cs which is likely to have its origin in radiation fallout was also observed. It is postulated that the NORM present in high quantity in deep soil somehow get mobilized into the water aquifers used by the general population and thereby causing harmful health problems. Conclusion: It can be stated that the present work has been able to demonstrate the use of low background gamma-ray spectrometry to understand the role of NORM in causing health-related effects in a general population of the Malwa region of Punjab, India.

• Journal of Practical Agriculture & Fisheries Research
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• v.23 no.1
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• pp.59-66
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• 2021

This study aimed to a basic research for the development of dye-sensitized solar cells that the wavelength band required for crop growth is passed, and the wavelength band that is not necessary for crop growth can be used for the generation of electricity. The transmissivity according to the illuminance was about 10% higher in the Blue filter and the Green filter than in the Red filter, but the transmissivity according to the PPFD was about 10% higher in the Red filter and the Blue filter than in the Green filter. In addition, the greenhouse attached with 30% infrared blocking filter was predicted to have a lower air temperature than other greenhouses, but it was investigated that there was no significant difference. Therefore, it was investigated that the application of the infrared cut filter would not be appropriate in a greenhouse that controls the temperature by opening a window. As a result of investigating, it was found that the Green and Blue filter greenhouses had the severe overgrowth and the stems grew weaker. The fresh weight of paprika in the infrared blocking filter greenhouse was the highest at 678.9g, and the growth of Red filter and the control greenhouses was relatively poor. Photosynthetic rate, amount of transpiration, and stomatal conductivity were the infrared blocking filter and control greenhouse higher than others. On the other hand, the water use efficiency did not show a big difference.

• Journal of Applied Biological Chemistry
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• v.65 no.3
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• pp.173-181
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• 2022

This study was carried out to investigate the residual characteristics of flubendiamide in kale to establish pre-harvest residue limits (PHRL) and the removal efficiency according to the washing solvent and method. Field tests were conducted at two different greenhouses, field 1 (Anseong-si, Gyeonggi-do) and field 2 (Incheon-si, Gyeonggi-do). According to the safe use guidelines kale was sprayed with flubendiamide twice every 10 days and harvested 0 (after 2 h), 1, 2, 3, 5, 7 and 10 days after the final application. The biological half-live of flubendiamide in kale was calculated based on dissipation curves of the pesticide in samples analyzed by liquid chromatography coupled with tandem mass spectrometry. In the analysis, method limits of quantitation (MLOQ) were 0.01 mg/kg, and recoveries performed with two different fortification levels of 10 MLOQ and maximum residue limit (0.7 mg/kg) were 104.2±3.6 and 101.9±10.2%, respectively. The dissipation rate constant of flubendiamide in kales were 0.2437 at field 1 and 0.1981 at field 2. PHRL calculation equations obtained using the dissipation constants estimated as follows: if the residual concentration of flubendiamide in kale on 10 days before harvest is less than 8.0 mg/kg, the residual concentration on the harvest would be under MRL. The removal of flubendiamide from kale was the greatest when it was washed with vinegar (39.8%), followed by baking soda (31.7%), calcium powder (30.2%), neutral detergent (27.2%), and tap water (15.9%). The results of this study would be useful for both farmers and consumers to produce or consume safe agricultural products.