This study investigates the optimization of sectional shape with two dimensions on the rubber gasket of electric vehicle battery in order to maintain the airtightness and watertightness. For the section optimization, the shape of protruding section was analyzed as design variables and the design point was composed by the design of experiment(DOE) for the selected protruding shape. The uniaxial tensile test was carried out for the analysis of rubber gasket and five parameters of Mooney-Rivlin hyperelastic model were derived from the test data in order to construct the strain energy function for nonlinear behavior. The rubber gasket compression analysis was performed by using ANSYS of a commercial software and the performance of optimal shape was verified by performing the tests of watertightness and airtightness on the 3D rubber gasket with the derived section.

In this study, we have investigated the optimal control method and the energy saving possibility when the dimming control for lighting and the suspended particles display(SPD) glass for window were applied to reduce the lighting load and the cooling load in office buildings. Simulations were carried out during from 8:00 am to 7:00 pm of typical one day on summer, winter and intermediate season. Simulation results showed that the cooling and lighting energy usage was reduced to 21.2% compared to the baseline model. Therefore, it was possible to predict the optimum control method of the suspended particles display(SPD) window to control the transmittance for energy saving and the dimming control for lighting during summer season.

본 연구는 시판 김치에 대한 소비자 인식을 통해 재료의 비율을 최적화하여 최적의 김치양념장을 개발하기 위한 연구이다. 189명의 20대이상 여성을 대상으로 조사를 실시하여 김치양념 재료 중 액젓, 젓갈, 물의 비율을 반응최적화 도구을 통해 최적 김치양념장 레시피를 선정하였다. 조사 대상 중 30대가 41.3%로 가장 많았고, 직업은 주부, 기타 직업, 학생순으로 조사되었다. 시판되는 김치를 구매하고 싶은 이유로 가정에서 김치를 만들기 번거로운 면과 경제 적인 면을 많이 꼽았으며, 나이가 어릴수록 김치를 만드는 방법을 모르기 때문이라는 답변이 많았다. 또한 가족 구성원 수가 적을수록 김치를 적게 먹어서 시판김치를 구매하는 경향이 있었다. 시판김치를 구매하지 않고 싶은 이유로 재료에 대한 믿음과 비싼 가격에 대한 이유가 높게 나타났고, 수입이 많을수록 인공조미료 사용 때문에 시판김치를 구매하지 않는다는 의견이 많았다. 김치에 대한 선호 맛은 감칠맛, 매운맛, 젓갈맛, 짠맛, 단맛 순이었으며, 나이가 어릴수록 짠맛을 선호하고, 41세 이상은 젓갈맛을 선호하는 것으로 조사되었다. 사전 조사 및 설문조사를 통해 김치 양념장제조시 조정 해야 할 재료를 멸치액젓, 물, 새우젓으로 선정하여 배합 비율을 조정하여 기호도에 대한 최적화를 잡은 결과 ‘–11.00A + 4.30B + 1.70C + 31.37AB + 33.56AC – 7.35BC’ (A: 멸치 액젓, B: 물, C: 새우젓)의 회귀식을 나타냈고, 멸치 액젓, 물, 새우젓의 최적 비율은 27.12 : 62.88 : 10.00 (w/w)이었다. 이 같은 연구 결과는 김치 양념 의 최적화를 통해 보다 좋은 맛과 품질의 김치를 개발할 데이터로 활용 가능하며, 고객 맞춤형 김치 양념장 개발에도 사용가능 할 것으로 보인다.

본 논문에서는 보의 대변형 및 비틀림 변형을 고려한 인간동력항공기 주익 main spar 질량 최적화 과정을 소개한다. 순차적 이차 프로그래밍 기법(sequential quadratic programming)을 최적화 기법으로 선정해 구조 최적설계에 적절한 최적화 알고리즘을 수행하였다. Main spar 내부 직경, 적층 두께 등을 설계변수로 설정하였다. 목적함수에는 질량 최소화, 굽힘 변형 변위 일정, 그리고 비틀림 변형 각도 일정 등의 요소를 포함하였다. 굽힘과 비틀림 변형 계산엔 대변형 해석에 적합한 기하학적 정밀 보 모델을 도입하였으며, 기하학적 정밀 보 모델에 필요한 단면 물성은 Variational Asymptotic Beam Sectional Analysis(VABS) 단면 해석프로그램를 통해 계산하였다. 그 결과 main spar의 굽힘 변형 및 비틀림 변형을 최대 1.45% 이내로 유지한 채로 7.88%의 질량 감소를 이루는 최적설계를 도출하였다, 이후 응력복원 및 변형률 복원을 통해 최적설계의 구조적 안정성과 최적화 과정의 타당성을 검증하였다.

다양한 활용용수 생산을 위한 막 소재 및 막여과 공정개발이 고도화됨에 따라 점차적으로 유지관리 측면의 연구개발 필요성이 부각되고 있다. 그 중에서 유지관리 측면의 막 손상 검지와 수명예측은 제도적으로 정립이 미흡한 실정이며, 막여과 공정 운영에서 경제성과 안정성을 고려한 막 손상 검지 기술개발은 막 특성 및 시설규모에 따른 오차보상이 불가피하게 수반되어야 하는 연구이다. 따라서 분리막의 물리/화학적 노출강도에 따른 특성 변화를 관찰하여 내구년한 산정 및 수명예측 알고리즘을 구축하고자 한다. 또한 분리막의 특성과 모듈의 배열에 따라 최적화된 막 손상 검지를 위한 기체-액체 치환율을 기반으로 물리적 한계도출과 병행하여 이를 극복하기 위한 센싱융합 기술을 소개하고자 한다.

In order to solve the limitation of the long span arch structures, a numerical analysis was carried out to investigate the effects of embedded trench installation technique to the earth pressure of an underground arch-rib shaped structure. For the arch-rib shape, the parabolic curve and the circular shape were analyzed according to the span-rise ratio varying from 0.1 to 0.5. The finite element analysis program, ABAQUS (2016), was used to consider the soil - structure interaction. The results from the analysis was verified through comparison with the existing Geofoam application technique.

Recently, interest in the development of alternative water resources has been increasing rapidly due to environmental pollution and depletion of water resources. In particular, seawater desalination has been attracting the most attention as alternative water resources. As seawater desalination consumes a large amount of energy due to high operating pressure, many researches have been conducted to improve energy efficiency such as energy recovery device (ERD). Consequently, this study aims to compare the energy efficiency of RO process according to ERD of isobaric type which is applied in scientific control pilot plant process of each 100 m3/day scale based on actual RO product water. As a result, it was confirmed that efficiency, mixing rate, and permeate conductivity were different depending on the size of the apparatus even though the same principle of the ERD was applied. It is believed that this is caused by the difference in cross-sectional area of the contacted portion for pressure transfer inside the ERD. Therefore, further study is needed to confirm the optimum conditions what is applicable to the actual process considering the correlation with other factors as well as the factors obtained from the previous experiments.

PURPOSES : The objective of this research is establishing system components and optimizing operational procedures in order to systematically manage road cave-ins in urban areas.METHODS: Based on the literature review and alternative comparison, optimization methods is suggested.RESULTS : Throughout the study, location referencing system, database structure, and operation strategy(procedure) were clarified, and the optimization methods for each item were suggested.CONCLUSIONS: Road cave-in management should be focused on user safety rather than focusing on economic aspects. The occurrence of road cave-in should be addressed thoroughly by road management system(location referencing system, database structure, and operation strategy(procedure), and the optimization methods), since they are closely related to road users' safety.

In recent years there have been large increases in the hydraulic loading rates used to design dissolved air flotation (DAF) facilities for drinking water applications. High rate DAF processes are now available at loading rates of 20 to 40 m3/m2·h. This research evaluated dissolved air flotation as a separation method for algae and organic compounds from water treatment plants. During the service period of 2016. 5. to 2017. 6., DAF pilot plants (500 m3/day) process has shown a constantly sound performance for the treatment of raw water, yielding a significantly low level of turbidity (DAF treated water, 0.21～1.56 NTU). As a result of analyzing the algae cell counts in the influent source, it was expressed at 100-120 cells/mL. In DAF treated water, the removal efficient of alge cell counts was found to be upto 90%. The stable turbidity and algae removal were confirmed by operating the high rate DAF process under the condition of the surface loading rate of 30 m3/m2·hr.

최근 전 세계적으로 SNS, 매스컴 등을 통해 싱크홀(Sinkhole)이 사회적 이슈가 됐다. 특히, 포장도로 하부 동공으로 인해 발생하는 도로함몰은 도로이용자에게 직접적인 안전상의 위험이 되기 때문에 시민들의 불안이 확산되고 있다. 서울시(2014)는 도로함몰에 대한 시민들의 불안을 조기에 해소하고 보다 안전하게 통행할 수 있는 도로환경을 조성하고자 ‘도로함몰 특별관리 대책’을 수립하여 발표했다. 환경부(2015)는 노후관로 약 40,000km 구간을 대상으로 정밀조사를 실시했으며 ‘하수관로 정밀조사 매뉴얼’을 발간했다. 국토부는 2018년부터 예방형 재난피해 지하시설물 관리를 위한 ‘지하시설물의 안전관리에 대한 특별법’을 공포했다. 이는 도로함몰의 사후 대책, 하수관 및 지하시설물의 관리 법률 등의 개선이다. 그러나 각 기관의 이러한 노력에도 불구하고 도로함몰을 체계적으로 관리하고 운영하는 시스템은 미흡한 상태이다. 도로함몰은 도심에 대규모로 발생하는 경우 도시의 이미지를 실추하고 도로이용자에게 안전상의 직접적 위협과 물적 피해를 야기하기 때문에 도로함몰에 집중된 관리전략이 필요하다. 전략에는 도로함몰의 조사, 분석, 예측, 평가, 보수, 모니터링, feedback의 체계적인 운영 절차와 구성요소의 최적화가 필요하다. 따라서 본 연구의 목적은 도로함몰관리시스템을 구성하는 위치정보, DB, 운영전략, 운영절차의 정의와 최적화 방안을 정리하고 분석하는 것이다. 그림 1.은 본 연구에서 제시하는 도로함몰 관리 시스템의 Tracking Tool과 Analysis Tool 사이의 System Framework의 구성이다

지구 온난화, 석유고갈, 환경오염에 대한 해결 방안으로 수송부분에서 국제적으로 바이오연 료에 관한 연구가 활발하게 이루어지고 있다. 그 중 바이오디젤은 석유계 디젤과 비교해 이산화탄소 및 대기오염 물질 배출이 적고 세탄가가 높은 장점을 가지고 있다. 현재 국내 바이오디젤 수요는 지속적으로 증가하고 있으나 원료부족으로 인해 수입의존도가 커지고 있는 상황이다. 이러한 문제를 해결하기 위해 본 연구는 현재 사용되지 않는 음폐유(약 33 % 유리지방 산 함유)를 Amberlyst-15 촉매가 이용한 에스테르화 반응을 통해 바이오디젤 원료로서 활용가능성을 확인 하였다. 다양한 반응 조건의 영향을 조사하기 위한 실험을 수행한 결과 반응온도 383 K에서 97.62 %의 전환 율을 얻었으며, 반응속도는 353 K에서 373 K로 증가 할 때 최대 1.99 배까지 상승하였다. 또한 동역학 적 결과를 이용하여 29.75 kJ/mol의 활성화 에너지를 확인하여 선행연구에서 연구된 타 고체촉매에 비 해 에스테르화반응에 Amberlyst-15 더 적합함을 확인하였다. 그리고 메탄올 몰 비가 증가함에 따라 최 대 91.43 %의 반응 전환율을 확인하였고, 촉매량 영향의 경우 0 wt%에서 20 wt%까지 증가시킨 결과 반응 전환율이 43.78 %에서 94.62 %까지, 초기 반응 속도는 1.1∼1.4 배로 상승하는 것을 확인하였 다. 교반속도의 경우 100∼900 rpm의 조건에 따라 실험을 수행하였으나 반응 전환율에는 큰 영향을 주 지 않음을 확인하였고 반응 시간에 따른 영향의 경우 240 분 까지 산가 감소를 보이다가 300 분이 지 나면서부터 산가가 상승하는 결과를 가져왔다. 그리고 위 실험들을 통해 도출된 최적 조건을 적용하여 음폐유 에스테르화 반응에 적용하였고 그 결과 반응시간 60 분에서 음폐유와 모사 폐유지간의 13 %의 반응 전환율 차이를 보였으나 최종 240 분 반응 전환율은 모사 폐유지 98.12 %, 음폐유는 97.62 %로 거의 유사한 결과를 얻었다.

PURPOSES: Pavement Management System contains the data that describe the condition of the road. Under limited budget, the data can be utilized for efficient plans. The objective of this research is to develop a mixed integer program model that maximizes remaining durable years (or Lane-Kilometer-Years) in road maintenance planning. METHODS: An optimization model based on a mixed integer program is developed. The model selects a cluster of sectors that are adjacent to each other according to the road condition. The model also considers constraints required by the Seoul Metropolitan Facilities Management Corporation. They select two lanes at most not to block the traffic and limit the number of sectors for one-time construction to finish the work in given time. We incorporate variable cost constraints. As the model selects more sectors, the unit cost of the construction becomes smaller. The optimal choice of the number of sectors is implemented using piecewise linear constraints. RESULTS: Data (SPI) collected from Pavement Management System managed by Seoul Metropolitan City are fed into the model. Based on the data and the model, the optimal maintenance plans are established. Some of the optimal plans cannot be generated directly in existing heuristic approach or by human intuition. CONCLUSIONS: The mathematical model using actual data generates the optimal maintenance plans.

In this study, factors analysis is performed for reducing friction in elevation motion of a large television stand over 50 inch. The first study is for specification decision and volume compensation experiment as an apparatus for compensating of the volume of the cylinder is compressed as the volume of piston rod. The second study is for optimized piston structure development by comparison pipe orifice and labyrinth orifice. Consequently, the result of total consideration in stability problem and performance of volume compensation for specification decision and volume compensation experiment is determined the final speculation of hollow rod ∅8 x ∅4 and riveting system. and the labyrinth orifice is not founded that of the Ø0.4~0.6 orifice both tests on 300 mm intervals.

Abstract The increase of the superheat is one of several factors adversely affecting the efficiency of the refrigeration cycle. To this end, it is important to release the heat inside the compressor. Therefore, in this paper, we have increased the convective heat transfer coefficient inside the compressor by utilizing the vibration of the moving part of the compressor. The results show that reducing the gap between the shell and the moving part increases the flow velocity in the gap resulting in the increase of convective heat transfer coefficient.

As a result of frequent occurrence of serious industrial accidents due to chemical substances, Korea Occupational Safety & Health Agency has been implementing the PSM system (process safety management) since 1996, and the target sites are required to submit process safety reports. In the semiconductor business, which is becoming smaller and more integrated as the technology advances, many of these hazardous chemicals are used. Most of the semiconductor sites are PSM target sites, and many devices are included in the PSM target equipment. This study optimizes the introduction and setup process of new equipments in the semiconductor workplace using harmful hazardous materials, and conducted an empirical study on the improvement of the safety risk, focusing on the S group semiconductor business, and applied the common standard of work under the PSM system This is an example of improving the risk of leakage of toxic gas components and waste of rework by arranging functions and risks in the space centering method

As a preparation of a design standard regarding road facilities in terms of reliability based optimum design examples, such as cantilever columns for traffic lights, optimum design in deterministic and probabilistic ways for the foundation of traffic lights poles are proposed. Most of the previous study have focused on the foundation surrounded by cohesionless soil. However, the design would be governed by risky condition. Therefore the resistance by clay-soil is investigated compared with other design specifications. In deterministic optimization, GRG method is applied. It is found that both geometries of deep and shallow foundation provides optimum values. The resistance of cohesive soil is selected to represent the ultimate limit states, in terms of sliding, overturning and bearing pressures from super structures to the foundation under external loads. Example foundations with varying height of columns for traffic lights are optimized about 30% decreased embedded depth of foundation. The optimum coefficients of resistant and load factors may need to be developed with design load combinations in order to prepare design specifications as the next step.

This study was carried out to extract ginsenosides in by-products from honeyed red ginseng. Response surface methodology (RSM) was used to optimize the extraction conditions. Based on D-optimal design, independent variables were ethanol (extraction solvent) concentration (30-90%, v/v), extraction temperature (25-70oC), and extraction time (5-11 h). Extraction yield (Y1) and total ginsenosides (Y2) in the extract were analyzed as dependent variables. Results found that extraction yield increased with increasing extraction temperature and time, whereas it was decreased with increasing ethanol concentration. Similar trends were found for the content of ginsenosides in the extracts, except for ethanol concentration, which was increased with increasing ethanol concentration. Regression equations derived from RSM were suggested to coincide well with the results from the experiments. The optimal extraction conditions for extraction yield and total ginsenosides were an extraction temperature of 56.94oC, ethanol concentration of 57.90%, and extraction time of 11 h. Under these conditions, extraction yield and total ginsenoside contents were predicted to be 84.52% and 9.54 mg/g, respectively.

This study investigates the analysis algorithm for developing an optimum hull form with minimum wave resistance by using the practical application of one minus prismatic. In this algorithm the potential-based panel method was adopted to get the wave resistance coefficient as the objective function and SQP method was applied as an optimizer to get the optimum hull form. As an target ship, the series 60(CB=0.6) was taken into account and LBP(length between perpendiculars) of the ship was changed in the direction including a central parallel portion. To verity the validity of this study, the results of the numerical analyses were compared with experimental data.