미세먼지 집진을 위한 직접 하전 방식 정전분무의 최적 동작 조건에 관한 연구

최수기,김성환,정해영 한국전기전자재료학회 2023 전기전자재료학회논문지 Vol.36 No.5

This paper is an experimental study on the optimal operating conditions of direct charging type electrospray for particulate matter collection. To perform the research, a direct charging type electrospray visualization system was configured to photograph the spray shape of microdroplets, and experiments were performed with varying electrode distance, flow rate, and applied voltage, which are the main factors affecting the particulate matter collection efficacy. Through image processing, the total number of microdroplets according to each condition was analyzed, and the number of microdroplets with a diameter of 1.5 mm or less was confirmed. In addition, by calculating the number of microdroplets per power consumption according to the applied voltage, the optimal operating conditions were derived in terms of energy consumption efficacy, and the microdroplet size distribution was analyzed under the optimal operating conditions. As a result of the experiment, it was confirmed that the optimal operating condition was at a flow rate of 10 mL/min and a voltage of -20 kV in case of 5 mm electrode distance, and at a flow rate of 15 mL/min and a voltage of -30 kV in case of 100 mm electrode distance.

Optimization of Culture Conditions for the Production of Pleuromutilin from Pleurotus Mutilus Using a Hybrid Method Based on Central Composite Design, Neural Network, and Particle Swarm Optimization

Latifa Khaouane,Chérif Si-Moussa,Salah Hanini,Othmane Benkortbi 한국생물공학회 2012 Biotechnology and Bioprocess Engineering Vol.17 No.5

This study aims at optimizing the culture conditions (agitation speed, temperature and pH) of the Pleuromutilin production by Pleurotus mutilus. A hybrid methodology including a central composite design (CCD),an artificial neural network (ANN), and a particle swarm optimization algorithm (PSO) was used. Specifically, the CCD and ANN were used for conducting experiments and modeling the non-linear process, respectively. The PSO was used for two purposes: Replacing the standard back propagation in training the ANN (PSONN) and optimizing the process. In comparison to the response surface methodology (RSM) and to the Bayesian regularization neural network (BRNN), PSONN model has shown the highest modeling ability. Under this hybrid approach (PSONN-PSO), the optimum levels of culture conditions were: 242 rpm agitation speed; temperature 26.88 and pH 6.06. A production of 10,074 ± 500 μg/g, which was in very good agreement with the prediction (10,149 μg/g),was observed in verification experiment. The hybrid PSONN-PSO gave a yield of 27.5% greater than that obtained by the hybrid BRNN-PSO. This work shows that the combination of PSONN with the generic PSO algorithm has a good predictability and a good accuracy for bio-process optimization. This hybrid approach is sufficiently general and thus can be helpful for modeling and optimization of other industrial bio-processes.

Optimal conditions for endpoint constrained optimal control

김경응 대한수학회 2008 대한수학회보 Vol.45 No.3

We deduce the necessary conditions for the optimality of endpoint constrained optimal control problem. These conditions comprise the adjoint equation, the maximum principle and the transversality condition. We assume that the cost function is merely differentiable. Therefore the technique under Lipschitz continuity hypothesis is not directly applicable. We introduce Fermat's rule and value function technique to obtain the results.

Optimization of Cultivation and Extraction Conditions of Pupae-Cordyceps for Cordycepin Production

Ayman Turk,Beom Seok Kim,Sung Min Ko,연상원,류세환,Young-Guk Kim,황방연,이미경 한국생약학회 2021 Natural Product Sciences Vol.27 No.3

Cordycepin is a characteristic bioactive compound of Cordyceps militaris with various beneficial effects. Cordyceps grows on both grains and insects, and the content of cordycepin varies depending on the cultivation conditions. In this study, the effect of culture conditions on the cordycepin content was analyzed and the extraction conditions were optimized. Analysis of cordycepin content in Pupae-Cordyceps found that it was highly affected by temperature in culture conditions. In the case of mycelium, it grows well at 20 and 25 oC, but not at 30 oC. However, the content of cordycepin was highest at 30°C and less at 20 oC. The fruiting body also showed a similar tendency: growth was 20 oC > 25 oC > 30 oC, but the cordycepin content was 30 oC > 25 oC > 20 oC. The content of cordycepin decreased after the fruiting bodies were produced. Next, extraction conditions such as solvent and time were optimized for maximum cordycepin content using response surface methodology (RSM). There was a large difference in the content of cordycepin according to the content of ethanol and the extraction temperature. Through RSM, it was confirmed that the optimum condition for extraction of cordycepin was 48.9 oC using 49.0% ethanol, and 160.9 mg/g extract could be obtained under this condition. In conclusion, this study suggested the optimized conditions for the cultivation and extraction of Pupae-Cordyceps for maximizing the content of cordycepin, and this may be applied to the discovery of materials using cordycepin.

OPTIMAL CONDITIONS FOR ENDPOINT CONSTRAINED OPTIMAL CONTROL

Kim, Kyung-Eung Korean Mathematical Society 2008 대한수학회보 Vol.45 No.3

We deduce the necessary conditions for the optimality of endpoint constrained optimal control problem. These conditions comprise the adjoint equation, the maximum principle and the transversality condition. We assume that the cost function is merely differentiable. Therefore the technique under Lipschitz continuity hypothesis is not directly applicable. We introduce Fermat's rule and value function technique to obtain the results.

StoSAG를 이용한 탄산염암 저류층의 유정 운영 최적화

오병건,김영주,이원석,장영호,민배현,정훈영 한국자원공학회 2021 한국자원공학회지 Vol.58 No.2

Well operating conditions can significantly affect the economic feasibility of developing an oil and gas field. The optimal operating conditions can be calculated using gradient-based optimization algorithms. However, using the finite difference method for this calculation is significantly costly under reservoir uncertainty and complex operating conditions. Thus, stochastic simplex approximate gradient (StoSAG), which is a calculation of the gradient by perturbing decision variables randomly, is an efficient application for optimization under uncertainty . In this study, StoSAG was applied to optimize the operating conditions in a real carbonate reservoir. Compared to the initial operating conditions, the optimized model shows a 10% increase in net present value (NPV ). The results can be utilized to determine cost-efficient operating conditions for complex reservoirs. 유가스전 개발에 있어 유정 운영 조건은 개발 경제성에 큰 영향을 미친다. 경사도 기반의 최적화 기법을 이용하여 최적 유정 운영 조건을 효율적으로 탐색할 수 있다. 그러나 저류층 불확실성이 높고많은 유정이 존재한다면 유한차분법을 이용하여 경사도를 계산하는 데 막대한 계산량이 요구된다. 최적화 변수의 미소 변화를 추계학적으로 생성하여 경사도를 계산하는 방법 중 하나인 Stochastic Simplex Approximate Gradient(StoSAG)를 이용하면 불확실성이 높고 많은 수의 유정을 가진 유정운영 최적화 문제를 풀 수 있다. 본 연구에서는 StoSAG를 이용하여 실제 탄산염암 저류층의 생산및 주입 조건을 최적화하였다. 최적화된 운영 조건은 초기 운영 조건에 비해 순현재가치가 약 10% 증가하였다. 본 연구결과는 불확실성이 높고 유정 개수가 많은 저류층의 유정 운영 최적화를 효율적으로 수행하는 데에 활용할 수 있다.

Topology Optimization of the Decking Unit in the Aluminum Bass Boat and Strength Verification using the FEM-program

Kwang-Cheol Seo,Jin Gwak,Joo-Shin Park 해양환경안전학회 2018 해양환경안전학회지 Vol.24 No.3

The objective of this paper is to optimize the cross-section of aluminum decking units used in the bass boats under operating conditions, and to verify the optimized model from the results via by ANSYS software. Aluminum decking unit is needed to endure specific loading while leisure activity and sailing. For a stiffer and more cost-neutral aluminum decking unit, optimization is often considered in the naval and marine industries. This optimization of the aluminum decking unit is performed using the ANSYS program, which is based on the topology optimization method. The generation of finite element models and stress evaluations are conducted using the ANSYS Multiphysics module, which is based on the Finite Element Method (FEM). Through such a series of studies, it was possible to determine the most suitable case for satisfying the structural strength found among the phase-optimized aluminum deck units in bass boats. From these optimization results, CASE 1 shows the best solution in comparison with the other cases for this optimization. By linking the topology optimization with the structural strength analysis, the optimal solution can be found in a relatively short amount of time, and these procedures are expected to be applicable to many fields of engineering.

Design Optimization of Cooling Channels and Molding Conditions in Injection Molds for Minimizing Warpage of Automobile Door Locking Device Component

Man-Jun Yu(유만준),Jong-Cheon Park(박종천) 한국기계가공학회 2023 한국기계가공학회지 Vol.22 No.7

The objective of this study is to minimize warpage at the opening of an injection-molded component for automobile door locking mechanism by optimizing the cooling channel design and molding conditions. Experiments were initially conducted using Taguchis orthogonal array and the face-centered central composite design method, followed by statistical analysis to determine the optimal design conditions for the peripheral cooling channels and molding conditions. A simulation experiment was conducted to validate the predicted optimal design conditions, which yielded a warpage of 0.8319 mm. To further reduce the warpage, serial- and baffle-type cooling channels were installed between the head and opening of the product. A full factorial experiment was conducted to optimize the design variables for each channel type. The internal cooling channels significantly reduced the fluctuation of the mold surface temperature to maintain the allowable warpage limit of 0.7 mm. Comparisons of the warpage values confirmed that baffle-type internal cooling channels provided more uniform cooling and effectively reduced warpage compared with serial-type channels.

원통형 이차전지의 저항용접 품질 향상을 위한 공정 최적화

정지선,박순서,김지호,권혁무,홍성훈,이민구 한국품질경영학회 2020 품질경영학회지 Vol.48 No.1

Purpose: This study aims to determine the optimal conditions for the spot welding process that mechanically connects the case of a cylindrical secondary battery and the negative tab. Methods: We use 33 factorial design to derive the optimal conditions for the spot welding process. The pulling strength, the cross-sectional area of nugget, and the shock test life are selected as response variables, which can represent the resistance welding quality. The input variables are selected as the welding time, welding voltage, and pressure, which are the controllable factors in the spot welding process. Results: The main effects of welding time and welding voltage and the interaction effect of welding time and welding voltage are significant. Conclusion: The optimal conditions for the spot welding process to mechanically join the negative electrode tab of the cylindrical secondary battery and the battery case are developed. The result shows that the pulling strength is increased by 44% compared to before improvement under optimal conditions.

Statistical Optimization of Culture Media and Conditions for Production of Mannan by Saccharomyces cerevisiae

Hong-Zhi Liu,Qiang Wang,Yuan-Yuan Liu,Fang Fang 한국생물공학회 2009 Biotechnology and Bioprocess Engineering Vol.14 No.5

In view of the increase in Saccharomyces cerevisiae mannan content, the culture medium and condition for S.cerevisiae were optimized in this study. The influence of culture medium ingredients such as carbon and nitrogen sources, inorganic ion, and enzyme activator on mannan production were evaluated using factional design. The mathematical model was established by the quadratic rotary combination design through response surface analysis. The optimized concentrations of culture medium were determined as follows: 4.98 g/100 mL, sucrose; 4.39 g/100 mL, soybean peptone; 3.10 g/100 mL, yeast extract; and 2.21 g/100 mL, glycerol. The optimized culture medium increased mannan production from 82.7 ± 3.4 mg/100 mL to 162.53 ± 3.47 mg/100 mL. The influence of original pH, inoculum size, temperature, and media volume on mannan production was evaluated and confirmed by orthogonale experimental design, with the order of effect as follows: media volume > temperature > initial pH > inoculation size. The optimized culture condition was pH, 5; inoculum size, 5 ml; temperature, 32oC; and media volume, 40 mL. The maximum mannan production increased to 258.5 ± 9.1 mg/100 mL at the optimum culture condition.=It was evident that the mannan production was affected significantly by culture medium and condition optimization (é < 0.01). In view of the increase in Saccharomyces cerevisiae mannan content, the culture medium and condition for S.cerevisiae were optimized in this study. The influence of culture medium ingredients such as carbon and nitrogen sources, inorganic ion, and enzyme activator on mannan production were evaluated using factional design. The mathematical model was established by the quadratic rotary combination design through response surface analysis. The optimized concentrations of culture medium were determined as follows: 4.98 g/100 mL, sucrose; 4.39 g/100 mL, soybean peptone; 3.10 g/100 mL, yeast extract; and 2.21 g/100 mL, glycerol. The optimized culture medium increased mannan production from 82.7 ± 3.4 mg/100 mL to 162.53 ± 3.47 mg/100 mL. The influence of original pH, inoculum size, temperature, and media volume on mannan production was evaluated and confirmed by orthogonale experimental design, with the order of effect as follows: media volume > temperature > initial pH > inoculation size. The optimized culture condition was pH, 5; inoculum size, 5 ml; temperature, 32oC; and media volume, 40 mL. The maximum mannan production increased to 258.5 ± 9.1 mg/100 mL at the optimum culture condition.=It was evident that the mannan production was affected significantly by culture medium and condition optimization (é < 0.01).