• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.11
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• pp.5637-5645
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• 2012

To enhance the reutilization of waste skate skin for the functional food resources, the investigations of extraction characteristics, antioxidative activity of skate skin water extracts on the oxidation of three cooking oils were carried out, and rheological properties, storage safety and sensory evaluation of collagen gel from skate skin were performed. Aromatic and phenolic compounds contents of $50^{\circ}C$ extracts were higher by 49.4% and 32.7%, respectively, than those of $25^{\circ}C$ extracts. Reducing power of extract at $50^{\circ}C$ was higher by 52.74% than that of $25^{\circ}C$ extract, but was 14.9% of ascorbic acid and 27.8% of BHT. Electron donating ability was corresponded to reducing power and phenolic compounds contents. Antioxidative effect of extracts on cooking oil was higher at $50^{\circ}C$ extract than $25^{\circ}C$ extract, and its order was on corn seed oil, soybean oil and olive oil. Antioxidative effect of $50^{\circ}C$ extract showed 38.27~96.83% and 49.53~75.31% of those of ascorbic acid and BHT, respectively, over three cooking oil. The optimum extraction condition for collagen gellation was $100^{\circ}C$, 2 hours extraction under 2.5 folds hydrolysis, and gel strength was lowered above 50% by 10% seasoning.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.6
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• pp.103-108
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• 2020

Generally, the cargo tank of LPG carriers corresponds to an independent tank Type A defined by the International Maritime Organization (IMO). The outside of the tank is insulated by polyurethane foam, and the tank is made of expensive low temperature steel that can withstand temperatures as low as -50℃. The cargo tank is composed of outer shell plates, bulkheads, stiffeners, web frames, and stringers. Among them, the outer shell plates, bulkheads, and stiffeners can be designed without structural analysis by the Classification Rules and are constructed easily through optimal design. On the other hand, optimal design, including numerous structural analysis, is not performed because web frames and stringers should be designed and approved through structural analysis. Only adequate design, which determines the design dimensions through several dozen structural analysis, is performed. In this study, for finite element analysis, eight loading conditions were applied, and the deformation of the entire ship for each loading condition was considered. The minimum weight design was performed for the web frames of cargo tanks in the 82,000 ㎥ LNG carrier through the gradient-based optimization technique, and the weight was reduced by approximately 108 tons per ship.

• Journal of the Korean Association of Geographic Information Studies
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• v.13 no.4
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• pp.67-77
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• 2010

Growth of oil and chemical industries has been remarkable during recent years. Hazardous materials (Hazmat) make frequent use in the wide range of industries. It increases the frequency of Hazmat transport and it leads to increase the number of accidents. Optimal Hazmat routes can reduce damage. Thus, the objective of this study is to minimize the areas impacted by Hazmat accidents by adopting experts' opinion in planning the route. We calculated weights using AHP (Analytic Hierarchy Process) and deduced the best route by applying this weights. Results showed that in the case of shortest route versus weighted route, the percentage of population damage has been decreased by 33.4% in the comparison between shortest route and optimally weighted route. And the percentage of environmental damage also has been decreased by 21.8%. Social damage has been decreased by 1521.7%. In the case of none weighted route versus weighted route, the percentage of population damage has been decreased by 2.6% when we adopted weighted route. Consequently, the recommended route with weighted risk assessment avoids densely populated area comparing with none weighted route. Further research needs to be carried out in order to figure out the specific cost-effectiveness analysis applying the equal cost unit for each factor.

• Journal of the Earthquake Engineering Society of Korea
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• v.8 no.4
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• pp.51-62
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• 2004

Fuzzy supervisory control technique for the seismic response control of cable-stayed bridges subject to earthquakes is studied. The proposed technique is a hybrid control method, which adopts a hierarchical structure consisting of several sub-controllers and a fuzzy supervisor. Sub-controllers are independently designed to reduced the responses to be controlled of a cable-stayed bridge, and a fuzzy supervisor achieves improved seismic control performance by tuning the pre-designed sub-controllers. It is realized by converting static gains of the sub-controllers into time-varying dynamic gains through the fuzzy inference mechanism. To evaluate the feasibility of the proposed technique, the benchmark control problem of cable-stayed bridge proposed by Dyke et al. is adopted. The control variables for the seismic response control of the cable-stayed bridge are determined to be t도 shear forces and bending moments at the base of the towers, the longitudinal displacements at the top of the towers, the relative displacements between the deck and the tower, and the tensions in the stay cables. Comparative results between the fuzzy supervisory controller and LQG controller demonstrate the effectiveness of the proposed control technique.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.3 no.1 s.4
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• pp.31-44
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• 2004

The study of Estimation model for the short-term travel time prediction. There is a different solution which has predicted the link travel time to solve this problem. By using this solution, the link travel time is predicted based on link conditions from time to time. The predicated link travel time is used to search the shortest path. Before providing a dynamic shortest path finding, the prediction model should be verified. To verify the prediction model, three models such as Kalman filtering, Stochastic Process, ARIMA. The ARIMA model should adjust optimal parameters according to the traffic conditions. It requires a frequent adjustment process of finding optimal parameters. As a result of these characteristics, It is difficult to use the ARIMA model as a prediction. Kalman Filtering model has a distinguished prediction capability. It is due to the modification of travel time predictive errors in the gaining matrix. As a result of these characteristics, the Kalman Filtering model is likely to have a non-accumulative errors in prediction. Stochastic Process model uses the historical patterns of travel time conditions on links. It if favorably comparable with the other models in the sense of the recurrent travel time condition prediction. As a result, for the travel time estimation, Kalman filtering model is the better estimation model for the short-term estimation, stochastic process is the better for the long-term estimation.

• Korean Journal of Food Science and Technology
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• v.51 no.6
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• pp.531-536
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• 2019

In this study, the optimization of the manufacturing process for the oil-in-water emulsification of rice bran oil was performed by response surface methodology (RSM) using varying amounts of the emulsifier (0.05-0.25%), varying rotation speeds of the homomixer (4,000-8,000 rpm), and varying water to oil ratios (0.8-1.6%) as independent variables, and the emulsion stability index (ESI) as the dependent variable. The optimization conditions predicted by the RSM model were 0.2%g of the total amount of the rice bran oil emulsion, emulsified at the homomixer rotation speed of 6,700 rpm using a water to oil ratio of 1:3. The ESI of the rice bran oil emulsion prepared under the optimized conditions was 95.7%, which was similar to the predicted value of 94.4% obtained by the RSM model. The transmission stability and the backscattering values were found to agree with each other over time and the turbiscan stability index was less than 0.7, indicating that the aggregation and upper floatation were less while the dispersion stability was maintained.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2017.04a
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• pp.164-164
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• 2017

스마트 돈사 환경의 복지 및 생산성 향상을 위하여 정량 분석법을 기반으로 한 모돈 관리의 중요성이 증가하고 있다. 모돈은 교배, 임신, 분만, 포유, 이유를 순환적 반복하여 이루어지는데 모돈의 관리는 돈사 농장의 생산성 및 경제성과 직결된다. 모돈 관리에 필요한 환경 및 계측정보를 획득하고 이 정보로부터 모돈의 개체관리를 극대화시키고 최적의 방안을 찾고자 지속적으로 계측이 가능한 모돈의 돈사 모니터링 시스템이 필요하다. 모돈의 행동특성 계측이 가능한 시스템이 필요한 이유는 모돈의 행동 특성(섭식 및 지제불량 등)에 상응하는 대사 불량, 질병 및 발정 징후 등을 조기에 발견할 수 있기 때문이다. 돈사 내에서 정지 상태로 판별이 되는 모돈의 지제상태(기립상태, 누운 상태, 앉은 상태)와 다르게 연속적인 움직임으로부터 판별되는 모돈의 섭식상태를 분석하기 위해서는 계측 시스템과 이를 분석해주는 시스템간의 시간적 차이를 최소화 할 수 있는 실시간 신호 처리 기술이 필수적이다. 모돈의 섭식을 정량적으로 지수화하기 위한 센서의 최소 SPS(sample per second)는 600 Hz($100Hz{\times}6$개)로서 최소 6개 ADC 채널과 최소 1,200 Hz 이상으로 샘플링 할 수 있는 마이크로 컨트롤러가 필요하다. 또한 16 비트의 분해능으로 1분 동안 연속 계측을 수행할 경우 필요한 정보량은 153,600 KByte ($1,200sample/s{\times}16bit/sample{\times}8Byte/bit$)으로 실시간 처리를 수행하기에 매우 큰 정보량이라 판단할 수 있다. 수행하고자 하는 정보처리 기법에 따라 다소 상이할 수 있으나, 1분을 주기로 모돈의 섭식 분석을 수행하고자 할 경우 최도 150 MByte의 정보량을 처리하기 위한 최소의 클럭수는 단순 대입의 경우 2.5 Mhz (clock/second) ($=1clock/Byte{\times}150MByte/60seconds$) 이며 덧셈(4 clock)의 경우 10 Mhz, 곱셈(16 clock)의 경우 40 Mhz의 클럭이 필요하다. 또한 정보의 저장 및 도시를 위해 필요한 부가적인 회로(LCD, SD메모리) 구동을 위해 필요한 클럭을 고려할 경우 추가적인 클럭이 필요하다. 이를 종합적으로 고려하여 120 Mhz ($= 40Mhz{\times}3$) 이상의 클럭이 필요하다고 판단할 수 있다. 또한 센서 계측 주기의 시간 분해능을 균등하게 유지하기 위해선 계측->도시->저장의 과정을 교차적으로 수행해야 한다. 이러한 과정을 거처 최종적으로 선정한 마이크로 프로세서는 ARM Cortex-M4이며 168 MHz로 연산 수행이 가능하여 목표하고자 하는 신호처리를 수행 할 수 있다. 현장 예비 실험을 통해 기대 성능을 만족하였으며, 시간 복잡도가 높은 연산을 대비하여 최적 시분할 스케쥴링 기법에 대한 보완이 필요하다고 판단되었다.

• Journal of Korea Water Resources Association
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• v.41 no.7
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• pp.725-735
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• 2008

Due to recent climate change, flood damages have been increased, but it is difficult to construct large hydraulic structure for flood control such as dam because of environmental, economical and political problems. For this reason, several researches and studies have tried to use washland as an alternative of hydraulic facility. Because sizes of washlands are usually smaller than those of dams or reservoirs, there can be many available locations for washlands in a basin and proper combination of these locations can reduce flood disasters efficiently. However, in case there are many available locations for washland and many combinations to consider, it is very difficult to determine the optimal combination which yields to provide the maximum benefit. For the more, hydraulic approach that used in previous studies to calculate flood reduction effect needs a lot of time for calculation and sometimes can not give the final result. In this study, the flood reduction effect of washland is calculated by hydrologic approach and decision making model for optimal location of washland using genetic algorithm for determination of optimal solution is developed. The developed model has been applied to the Ansung River basin in order to examine the applicability and the application result shows that developed model can be used as decision making model for washland.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.9
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• pp.825-830
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• 2009

Pharmaceutical compounds enter the water environment through the diverse pathways. Because their concentration in the water environment was frequently detected in the level of ppt to ppb, the monitoring system should be optimized as much as possible for finding appropriate management policies and technical solutions. One Factor At a Time (OFAT) approach approximating the response with a single variable has been preferred for the optimization of LC-MS/MS operational conditions. However, it is common that variables in analytical instruments are interdependent. Therefore, the best condition could be found by using the statistical optimization method changing multiple variables at a time. In this research, response surface analysis (RSA) was applied to the LC-MS/MS analysis of emerging antibiotic compound, sulfamethoxazole, for the best sensitivity. In the screening test, fragmentation energy and collision voltage were selected as independent variables. They were changed simultaneously for the statistical optimization and a polynomial equation was fit to the data set. The correlation coefficient, $R^2$ valuerepresented 0.9947 and the error between the predicted and observed value showed only 3.41% at the random condition, fragmentation energy of 60 and collision voltage of 17 eV. Therefore, it was concluded that the model derived by RSA successfully predict the response. The optimal conditions identified by the model were fragmentation energy of 116.6 and collision voltage of 10.9 eV. This RSA can be extensively utilized for optimizing conditions of solid-phase extraction and liquid chromatography.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.2
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• pp.167-174
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• 1995

This experiment was carried out to investigate the major characters affecting the popping volume of popcorn. Tuygimok 1 (Kp1 ${\times}$ Kp2) and 8 popcorn hybrids' agronomic characters were tested to evaluate a certain extent how much they affect on the popping volume. Moisture con-tent was considered as the most important factor, but failed to evaluate the optimum moisture con-tent level in this experiment moisture range (12.2-14.4%) because popping volume increased as moisture content of kernels increased. The maximum popping volume was obtained at 55-60kg of kernel hardness, 80-90,um of pericarp thickness and 45-50% of S/H (Soft/Hard starch). But the Em/En(Embryo/Endosperm) ratio was negatively associated with the popping volume. Therefore the minimum popping volume was observed at the 10-11 % of Em/En ratio. Moisture content, hardness, pericarp thickness, Em/En and S/H ratio were selected as the appropriate variables for the maxi-mum popping volume using the stepwise forward regression method and the expecting popping volume was estimated by the multiple linear regression formular. The mean popping volume of ninepopcorn hybrids was about 29.2cm3/g.