• 한국환경과학회지
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• 제27권10호
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• pp.831-844
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• 2018

Riverbank Filtration (RBF) is a kind of indirect artificial recharge method and is useful in obtaining higher-quality source water than surface water when procuring municipal water. This study evaluated optimal riverbank filtered water and the productivity of the radial collector wells on Ttansum Island in the area downstream of the Nakdong River, where Gimhae City is constructing a municipal water plant for the purpose of acquiring high-quality water. The RBF wells are planned to provide water to the citizens of Gimhae City through municipal water works. Groundwater flow modeling was performed with the following four scenarios: (a) 9 radial collector wells, (b) 10 radial collector wells, (c) 10 radial collector wells and two additional vertical wells, and (d) 12 radial collector wells. This study can be useful in determineing the optimum production rate of bank filtrated water not only in this study area but also in other places in Korea.

• 한국환경과학회지
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• 제21권6호
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• pp.695-704
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• 2012

The application of disinfection models on the plasma process was investigated. Nine empirical models were used to find an optimum model. The variation of parameters in model according to the operating conditions (first voltage, second voltage, air flow rate, pH) were investigated in order to explain the disinfection model. In this experiment, the DBD (dielectric barrier discharge) plasma reactor was used to inactivate Ralstonia Solanacearum which cause wilt in tomato plantation. Optimum disinfection models were chosen among the nine models by the application of statistical SSE (sum of squared error), RMSE (root mean sum of squared error), $r^2$ values on the experimental data using the GInaFiT software in Microsoft Excel. The optimum model was shown as Weibull+talil model followed by Log-linear+ Shoulder+Tail model. Two models were applied to the experimental data according to the variation of the operating conditions. In Weibull+talil model, Log10($N_o$), Log10($N_{res}$), ${\delta}$ and p values were examined. And in Log-linear+Shoulder+Tail model, the Log10($N_o$), Log10($N_{res}$), $k_{max}$, Sl values were calculated and examined.

• 대한원격탐사학회지
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• 제34권1호
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• pp.151-166
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• 2018

This paper compares the four selections of performance used in the application of genetic algorithms (GAs) to automatically optimize multispectral pixel cluster for unsupervised classification from KOMPSAT-3 data, since the selection among three main types of operators including crossover and mutation is the driving force to determine the overall operations in the clustering GAs. Experimental results demonstrate that the tournament selection obtains a better performance than the other selections, especially for both the number of generation and the convergence rate. However, it is computationally more expensive than the elitism selection with the slowest convergence rate in the comparison, which has less probability of getting optimum cluster centers than the other selections. Both the ranked-based selection and the proportional roulette wheel selection show similar performance in the average Euclidean distance using the pixel clustering, even the ranked-based is computationally much more expensive than the proportional roulette. With respect to finding global optimum, the tournament selection has higher potential to reach the global optimum prior to the ranked-based selection which spends a lot of computational time in fitness smoothing. The tournament selection-based clustering GA is used to successfully classify the KOMPSAT-3 multispectral data achieving the sufficient the matic accuracy assessment (namely, the achieved Kappa coefficient value of 0.923).

• 설비공학논문집
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• 제17권9호
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• pp.824-829
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• 2005

MHR(Metal Hydride Refrigerator) powered by MGT exhaust gas is investigated to find out the optimum conditions corresponding to MGT operating powers. There are many factors to affect cooling capacity of MHR. In this study, the effect of switching time, flow rate of brine on cooling temperature and capacity is investigated. The present results show (1) hydrogen reaction is saturated with 25 min switching time at 25 kW MGT power, (2) cooling power shows maximum phenomenon with increasing switching time, (3) optimum switching times are 20 minutes for 15kW MGT power and 15 minutes for 20, 25kW MGT power, (4) according to increasing brine flow rate, cooling capacity shows decrease at 15 kW MGT power and changes little at above 20 kW MGT power.

• Plant Resources
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• 제6권2호
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• pp.102-107
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• 2003

To find out the optimum fertilizer level for high yielding variety, Velox, experiment was conducted with 15 compositions of fertilizer levels at the experiment field of forage crop in Sunchon National University from Mar. 2000 to Aug. 2000. The effects of nitrogen fertilizer on plant growth were significant but increasing rate of application in potassium and phosphate fertilizers above 6 kg/a had negligible effects on plant growth. The optimum nitrogen application level of fertilizers turned out to be 16-6-6 kg/l0a of N-P$_2$O$_{5}$-K$_{5}$O. Content of crude protein was highest and that of crude fiber such as NDF, ADF, cellulose and lignin were lowest at this rate of fertilizer application. Furthermore, IVDMD was high and dry matter yield were highest at the optimum raterate

• 한국미생물·생명공학회지
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• 제5권1호
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• pp.5-12
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• 1977

As a basic study for the application of the spore-tearing lactic acid bacteria to foods, the effects of the sporulating conditions on the growth and sporogenesis were studied were observed. The results obtained are as follow. 1. All carbohydrates added to sporulation media except dextrin decreased the sporulation rate and the thermal resistance of spores. Dextrin stimulated the growth, however, there in no effect on the thermal resistance. 2. As nitrogen source, the protein hydrolysates such as peptone, casamino acid were effective to obtain were spores of the increased thermal resistance. 3. Ca$\^$＋＋/, Mn$\^$＋＋/ of the metal ions added to casamino acid containing medium validly increased the total growth, sporulation rate and thermal resistance. Its optimum concentration was 40 ppm each. 4. Biotin of vitamines had an effect on the total growth, sporulation and thermal resistance of spores. Its optimum concentration was 30${\gamma}$/ml. 5. The resistant spores required the adequate maturation period, more than 36 hours, sufficient aeration. and optimum temperature, 37∼45$^{\circ}C$.

• 한국표면공학회지
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• 제40권6호
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• pp.262-270
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• 2007

Recently, there has been a new appreciation of aluminum alloys as materials that are capable of reducing the environment load. This is because aluminum alloys are lightweight, easy to recycle, permit miniaturization, and have environmental friendly properties. In this study, we investigated the mechanical and electrochemical properties of 5083F aluminum alloys using slow strain rate test(SSRT) and potentiostatic tests under various potential conditions. In the potentiostatic tests, the current density in the potential range from -0.7 to -1.4V after 1,200 s was low. After considering the results of the potentiostatic tests, maximum tensile strength, yield strength, elongation, time-to-fracture, observation of fractured specimen and fractography analysis, the optimum protection potential range was between -1.3 and -0.7V(Ag/AgCl).

• 한국환경과학회지
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• 제11권2호
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• pp.93-102
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• 2002

Using a simple continuous optical technique, coupled with measurements of zeta potential, the flocculation characteristics of kaoline suspensions of different content(15, 35 and 55 NTU) by several cationic polyelectrolytes, has been examined. The optimum mixing is obtained under a constant stirring of 200 rpm, differently from a general flocculation test. The charge density of a polyelectrolyte is important in determining the optimum dosage and in the removal of kaoline particles. The optimum dosage is less for the polyelectrolyte of higher charge density and is the same regardless of kaoline content. At the dosage, the removal of kaoline particles is higher for the polyelectrolyte of higher charge density and zeta potential of kaoline particles reaches to near zero. The rate of adsorption and flocculation rate have been found to be affected by charge density and molecular weight of a polyelelctrolyte and the content of kaoline particles.

• 분석과학
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• 제13권1호
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• pp.41-48
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• 2000

돼지의 소장조직을 탄소반죽에 혼입시켜 과산화수소 정량 바이오센서를 제작하고, 기질농도와 pH변화가 전극의 효소반응속도에 미치는 영향을 관찰하였다. 수학적 취급이 용이하도록 매개체는 첨가하지 않았다. 관찰된 현상들을 정량적으로 처리하여 전극반응에 관련된 효소의 전기화학적 특성과 최대 반응속도를 구하였다. 또, pH에 따른 Michaelis 상수의 변화로부터 여러 가지 열역학적 파라미터를 얻고, 이를 이용하여 효소활동의 최적 pH를 구하는 방법을 고안하였다.

• 한국양식학회지
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• 제21권4호
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• pp.244-251
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• 2008

본 연구는 여름철에 넙치 치어 배합사료의 적정 지질함량 및 적정 사료공급량을 규명하는데 그 목적이 있다. 적정 지질함량 실험에서 실험사료는 사료내 단백질함량은 52로 동일하게 맞추고 지질함량은 6, 8, 10, 12, 14%가 되도록 설계 하였다. 평균 무게 $18.4{\pm}0.11\;g$ ($mean{\pm}SD$)인 넙치 치어를 300 L 사각수조에 30마리씩 수용하여 각 실험구당 3반복으로 6주간 실시하였으며, 실험기간 동안 평균 수온은 $21{\sim}25^{\circ}C$였다. 실험결과, 증중률, 일간성장률, 사료효율 및 단백질전환효율은 사료내 지질함량이 사료내 지질 함량이 8%(L8)및 10%(L10)인 실험구가 6, 14%인 실험구보다 유의적으로 높았으며(P<0.05), 사료내 지질 함량이 12%인 실험구와는 유의적인 차이가 나타나지 않았다. Broken line model분석을 통한 최대 성장을 위한 여름철 넙치치어 배합사료의 적정 지질 함량은 $9.08{\pm}0.37%$로 사료된다. 적정 공급량 실험에서는 적정 지질함량 실험에서 성장결과가 가장 우수했던 L10을 사용하여 사료공급량을 어체 중 당 2.0, 2.5, 3.0, 3.5% 그리고 만복공급으로 구분으로 6주간 실험하였다. 실험어는 평균무게 $13.4{\pm}0.1\;g$ ($mean{\pm}SD$)인 넙치 치어를 300 L 사각수조에 각각 30마리씩 수용하여 각 실험구당 3반복으로 실시하였으며, 실험기간 동안 평균 수온은 $21{\sim}25^{\circ}C$였다. 적정 사료공급량 실험결과, 증중률, 일간성장률은 사료공급량이 증가할수록 유의적으로 높게 나타났지만(P<0.05),사료공급량이 어체중 당 3.5%와 만복 실험구(어체중 당 4.0% 수준)는 유의적인 차이가 나타나지 않았다(Table 6). Broken line model 분석을 통한 최대 성장을 위한 여름철 단백질 52%,지질 10% (P/E ratio; 108mg protein/kcal)를 함유한 넙치치어 배합사료의 적정 사료공급량은 어체중 당 $3.56{\pm}0.06$로 사료된다. 따라서, 본 연구를 통하여 여름철 넙치치어($10{\sim}50\;g$)배합사료의 적정지질 함량은 $9{\sim}10%$ (Energy: 4,774 kcal, P/E ratio; 108 mg protein/kcal)내외, 이에 대한 적정사료 공급량은 어체중 당 3.5% 내외가 될 것으로 사료된다.