Earticle

반도체 소자의 크기가 작아지고 소재가 다양해지면서 식각 공정의 정밀도, 소재 종류에 따른 선택성, 공 정 신뢰성이 더욱 중요해지고 있습니다. 포토리소그래피는 반도체 공정에서 정밀한 패턴을 구현하는 데 핵심 공정 이며, 이는 고밀도 반도체 소자를 가능하게 합니다. 고밀도 반도체 소자는 기능과 성능이 향상되며, 고밀도 반도체 소자 공정은 공정 신뢰성 확보가 중요합니다. 본 연구는 반도체 소자의 목표 임계 치수와 웨이퍼 공정 신뢰성을 고려하여, 광식각 공정의 노출 시간과 현상 시간을 최적화하는 방법을 제시합니다. 이러한 최적화 기술은 에칭 및 증착과 같은 다른 반도체 공정에도 적용되어 전체 공정 효율성과 신뢰성을 향상시킬 수 있습니다.

Photolithography is essential in semiconductor manufacturing for defining intricate patterns with high precision, enabling densely packed integrated circuits crucial for modern electronics. Its high resolution ensures the functionality and performance of components, while its repeatability and scalability make it cost-efficient for mass production. This study presents a method to optimize exposure and development times in photolithography, considering target critical dimension and wafer reliability. These optimization techniques can also be applied to other semiconductor processes like etching and deposition, enhancing overall manufacturing efficiency and reliability.

Optimization is important for processes in all parts of our lives. By modeling existing processes, it can help optimize existing processes. We specifically modeled the library book lending process in the university. It was modeled using ARIS express, a free modeling tool for business process analysis and management and we measured the time and automation of the book lending process before and after modeling. Due to the introduction of the automation system, the level of automation generally increased, while the alternation of application systems has decreased. All these courses were conducted with the advice of staff and students at the University of Graz in Austria.

The current domestic policy flow towards nuclear decommissioning have difficult maintaining existing nuclear technologies and capabilities. Knowledge management has become an important project management execution process. The decommissioning research department of the Korea Atomic Energy Research Institute, which conducts decommissioning research and technology development, also attempted to develop a decommissioning project management information system using this knowledge management method. The decommissioning project management information system consisted of scope management, configuration management, organization and manpower management, schedule management, cost management, risk management, and stakeholder management. In this paper, we developed a document management system to perform the decommissioning of nuclear power plants in the process of constructing a project management system for dismantling nuclear facilities. The decommissioning project management system will be completed in stages by linking the history management platform and the process optimization platform based on the document management system.

Mechanisms can provide useful strategy guide for most emergency coping activities to improve the efficiency of modern emergency management. In this paper, the two major aspects of fundamental mechanism of modern emergency management are introduced firstly. The process optimization mechanism is proposed with a detailed discussion and description of the principle and logic secondly. A circle of procedures for dynamic decision making to optimize the emergency disposal process based on Bayesian approach is developed thirdly. Lastly, a case study is given to demonstrate the effectiveness and feasibility of the mechanism.

Mechanisms can provide useful strategy guide for most emergency coping activities to improve the efficiency of modern emergency management. In this paper, the two major aspects of fundamental mechanism of modern emergency management are introduced firstly. The process optimization mechanism is proposed with a detailed discussion and description of the principle and logic secondly. A circle of procedures for dynamic decision making to optimize the emergency disposal process based on Bayesian approach is developed thirdly. Lastly, a case study is given to demonstrate the effectiveness and feasibility of the mechanism.

Atomic layer deposition (ALD) process optimization of Al2O3-doped ZnO (AZO) interlayer (IL) inserted between channel and electrodes was held to improve electrical contact properties of amorphous In-Ga-Zn-O (a-IGZO) thin film transistors (TFTs). In particular, the modulation of the ALD supercycle duty and variations in Al₂O₃ injection cycles were investigated and optimized for their effects on contact properties during the deposition of the AZO IL. The use of alloy-AZO2 IL effectively improves overall device performance.

본 연구는 바이오디젤 제조를 위한 원료로서 커피찌꺼기(spent coffee grounds, SCG)를 이용하여 바이오디젤로 전환 하기 위한 반응 조건을 최적화하고자 한다. SCG에서 추출한 오일은 3.3%의 높은 유리지방산(free fatty acid, FFA)을 함 량하고, 이를 낮추기 위한 방법으로 산 촉매와 알칼리 촉매 전처리를 비교하였다. 산 촉매는 알칼리 촉매보다 효과적이고, 반응 후 오일의 수율은 98%이다. 산 촉매 전처리에 관련된 주요 인자를 반응표면분석법으로 최적화한 결과, 최적반응조 건은 0.87% H2SO4, 21.2% methanol, 74.7oC이고, 이 조건에서 예상되는 산가(Acid value, AV)는 1.40 mgKOH/g (FFA 0.7%)이다. 전처리된 SCG 오일을 바이오디젤로 전환하는 촉매로 KOH는 가장 효율적이다. 최적반응조건인 methanol 몰 비 6:1, 1.25% KOH, 65oC에서 생성된 fatty acid methyl ester 함량을 정량한 결과 97 ~ 98% 전환율을 보였다.

This study used spent coffee grounds (SCG) for producing biodiesel and was aimed at optimizing reaction conditions for converting to biodiesel. Two pretreatment methods using acid and alkali catalysts were examined to reduce high free fatty acid (FFA) content of 3.3% in the oil extracted from SCG. It was ascertained that acid catalyst was effective compared with alkali, showing the yield of 98%. And then the factors related in acid-catalyzed esterification were optimized using response surface methodology. The optimal reaction conditions were 0.87% sulfuric acid, 21.2% methanol, and a temperature of 74.7oC. Under these conditions, the expected FFA content was 0.7%. Alkali-catalyzed transesterification using KOH efficiently converts pretreated SCG oil to biodiesel. At the experimental optimal conditions (methanol to oil molar ratio of 6:1, 1.25% KOH, and 65oC), a conversion ratio of 97-98% was confirmed based on the generated fatty acid methyl ester.

제조업에 있어 효율적인 제조공정을 위해 기업의 생산성 향상 및 원가절감은 현 제조기업의 절실한 과제 이다. 효율적인 제조공정 설계와 생산성향상을 위해 동작분석 및 가상현실기반의 테스트베드 연계시스템을 활용하 여 불필요한 요소제거를 통해 효율적인 제조공정 방법을 연구한다. 가상의 사전 공정배치 시뮬레이션을 통한 최적 화 검증 후 작업라인을 구축할 경우 추가적인 공정 수정 또는 보완에 소요되는 비용을 절감하고, 이는 결과적으로 기업의 제조경쟁력 향상이라는 실질적 효과를 도출할 수 있다. 본 연구를 통해 설계기간 단축, 설비개선, 자동화, 인간공학 실현, 프로세스 개선 등을 하여 생산성 향상, 품질 향상, 비용절감뿐만 아니라 안전 및 건강에 대한 직원 만족을 달성할 수 있다.

For manufacturing industry to achieve efficient manufacturing process, improving a company’s productivity and reducing cost is a required task of the current manufacturing companies. For design of efficient manufacturing process and improvement of productivity, efficient manufacturing process method is studied through removal of unnecessary elements analyzing motions and using test-bed linkage system based on virtual reality. When building process line after verifying optimization through virtual process arrangement simulation in advance, it is available to save additional cost for process modification or supplement to result in practical effects of improving a company’s manufacturing competition. Reducing design period, improving equipment, making automation, realizing ergonomics, and improving process through this study, it will be available to achieve improvement of productivity, enhancement of quality, cost reduction as well as employees’ satisfaction for safety and health.

The properties of the conductor-mechanical, thermal, and electrical-are the key information in the design and optimization of superconducting coils. Particularly, in devices using second generation (2G) high temperature superconductors (HTS), whose base materials (for example, the substrate or stabilizer) and dimensions are adjustable, a design process for conductor optimization is one of the most important factors to enhance the electrical and thermal performance of the superconducting system while reducing the cost of the conductor. Recently, we developed a numerical program that can be used for 2G HTS conductor optimization. Focusing on the five major properties, viz. the electrical resistivity, heat capacity, thermal conductivity, Z-value, and enthalpy, the program includes an electronic database of the major base materials and calculates the equivalent properties of the 2G HTS conductors using the dimensions of the base materials as the input values. In this study, the developed program is introduced and its validity is verified by comparing the experimental and simulated results obtained with several 2G HTS conductors.

이 논문은 다목적 최적화 알고리듬을 이용하여 오일샌드 저류층에서 생산성이 높으면서도 최적의 에너지효 율을 갖는 SAGD(Steam Assisted Gravity Drainage) 공법의 운영조건을 선정하는 기법을 제안한다. 기존의 SAGD 공 법 최적화 연구들은 경제성인자가 고정된 단목적 최적화에 집중하였다. 이 연구에서는 회수율 최대화와 누적증기오 일비 최소화 관점에서 비지배관계에 놓이는 최적 생산운영 시나리오를 선정하였다. 이를 통하여 특정 목적함수에 편 향된 하나의 최종해만을 도출하는 기존 방법의 한계를 개선하였다. 제안한 방법으로 선정된 최적운영 시나리오들은 기존 방법과 달리 유가상황 및 비용 변화에 따라 추가적인 최적화 작업 없이 광구운영 의사결정에 유용하게 활용할 수 있다.

This paper proposes multi-objective optimization of the Steam Assisted Gravity Drainage (SAGD) process for improving the energy efficiency and recovery factor of oil sand reservoirs. Previous studies conducted on optimizing the SAGD process have focused on single-objective optimization with fixed economic factors. In this study, multiple trade-off operating scenarios were selected by applying a multi-objective optimization algorithm that aims at maximizing the recovery factor and minimizing the cumulative steam-oil ratio for efficiently addressing volatile market conditions. Thus, the proposed method can overcome the limitations of conventional optimization methods that not only yield a single solution based on a particular objective function but also are hard to adapt to fluctuating oil prices. Furthermore, the proposed method can provide optimum trade-off operating scenarios, and hence can aid in planning operating (i.e., marketing) strategies according to the variation in oil prices and operating costs, without the need for an additional optimization process.

제강분진(Electric Arc Furnace Dusts)은 유해폐기물로 지정되어있는 유해한 환경오염물질이다. 이 분진은 철강산 업의 부산물로써 철, 아연, 니켈, 구리 등 많은 유가금속을 포함하고 있어 적절한 처리를 거치면 폐기물이 아닌 자원으로 재활용이 가능하다. 본 연구에서는 국내 전기로에서 발생하는 제강분진을 대상으로 가장 높은 함유량을 가진 아연의 회수를 위한 최적조건을 도출하기 위해 습식침출법을 적용하였다. 분진과 황산의 고액비, 침출시간, MnO2 투입량 등의 조건을 종합하여 실험을 진행하여 최적 아연회수조건을 도출하였다. 황산농도 3 M, 고액비 1 : 2, 철 제거를 위한 폭기 1.8 L/min 강도로 2시간에서 95%의 아연 회수율이 관찰되었다. 그러나, 현장 적용의 현실성을 고 려한 다른 최적의 조건은 저농도 황산과 MnO2 3.5 g을 투입했을 경우 약 80 %의 아연 회수율을 나타내었다.

EAFD (Electric Arc Furnace Dust) is considered as pernicious pollutant, assigned hazardous waste. Since this dust is a by- product of industry, it contains valuable metals such as Fe, Zn, Ni, Cu which can be turned into resources by recycling process. In this study, hydrometallurgical process was applied to recover Zn from Electric Arc Furnace Dusts. The result showed 95% Zn recovery at 3M H2SO4, Solids/Liquid ratio 1 : 2 and aeration of 1.8L/min for 2hr. However there was 80% Zn recovery at lower H2SO4 concentration apply for pilot scale plant.

폐자동차 범퍼 파쇄물 재활용을 위하여 색채선별법을 도입하였다. 색채선별법은 기존의 비중, 입도 차이에 의한 선별이 어려운물질을 색상 차이를 이용한 카메라와 영상 분석기법으로 분리하는 선별법이다. 본 연구에서는 반응표면법 중 BBD (Box-Behnken Design)를 적용하여 실험을 계획하고 최적 조건을 도출하였다. 색채민감도, 피드투입량 및 입자크기의 영향을 분석하였으며, 회귀분석과 통계적인 방법에 기초하여 2차 반응 모델을 획득하였다. R 2 및 p-value는 각각 99.56%, < 0.001로 타당하였으며, 추정된 최적조건은 색채민감도 32%, 피드투입 200 kg/h, 입자크기 33 mm 조건에서 94.1%의 회수율이 나올 것으로 예측하였다. 실제 실험을통한 회수율은 93.8%로 나타나 해당 모델이 적절함을 확인하였다.

An color sorting technique was introduced to recycle End-of-life automobile shredded bumpers. The color sorting is a innovate method of separating the differences in the color of materials which are difficult to separate in gravity and size classification by using a camera and an image process technique. Experiments were planned and optimal conditions were derived by applying BBD (Box-Behnken Design) in the reaction surface method. The effects of color sensitivity, feed rate and sample size were analyzed, and a second-order reaction model was obtained based on the analysis of regression and statistical methods and R 2 and p-value were 99.56% and < 0.001. Optimum recovery was 94.1% under the conditions of color sensitivity, feed rate and particle size of 32%, 200 kg/h, and 33 mm respectively. The recovery of actual experiment was 93.8%. The experimental data agreed well with the predicted value and confirmed that the model was appropriate.

다양한 환경영향을 하나의 단위로 나타낼 수 있는 전과정평가의 특성과 최적화 기법 가운데 하나인 simulated annealing을 이용하여 PCB(Printed Circuit Board) 생산공정에서 발생하는 폐수의 전기분해 공정을 환경적으로 최적화하였다. 전과정평가와 전기분해 도중 발생 가능한 반응의 제한을 통해 전기분해 중 각 물질의 변화량에 따른 환경영향 값의 정량화가 가능하였으며 전체 환경영향 변화량은 전력사용량, Cu, Cl2, NOx, SOx 등의 물질 변화량에 따른 함수로 나타낼 수 있었다. 하나의 변수를 가지는 조건 하에서는 최적화를 위해 그래프를 비교하는 방법을 사용할 수 있다. 정전압 8V의 전기분해에서 그래프를 비교하여 최적점을 찾아 보았을 때 반응시간 90분이 최적점인 것을 확인할 수 있었다. 전압과 반응시간의 두가지 변수를 가지는 문제의 최적화를 위해 simulated annealing을 이용하였을 때 최적점에 가까운 값을 빠른 시간 내에 찾아내는 것을 확인할 수 있었다. 전체 환경영향 값을 simulated annealing을 이용하여 최소화 시키는 방법은 특별한 이론적 모델링이 필요 없이 실험을 통하여 측정된 값을 바탕으로 최적화에 도달할 수 있으므로 많은 투입물과 배출물이 발생하는 복잡한 공정의 환경적 최적화에 있어서도 유용한 정보를 제공해 줄 수 있다.

LCA(Life Cycle Assessment), that unifies the scale of various environmental impacts, and simulated annealing are applied to optimizing electrolysis of wastewater from PCB(Printed Circuit Board) production. The changes of environmental impact can be quantified with LCA and the total changes of environmental impacts can be expressed as a function of power consumed, Cu recycled, Cl2, NOx and SOx discharged through restriction of feasible reactions. In a single-variate condition, the environmental optimum can be easily obtained through plotting and comparing each value. In 8V potentiostatic electrolysis, the lowest environmental impact can be achieved after 90 minutes. To optimize a multi-variate conditional system, simulated annealing can be applied and this can give the quick and near optimum in complex systems, where many input and output materials are involved, through experimentally measured values without a theoretical modeling.

Betulin, a pentacyclic triterpenoid, abundantly accumulated in Inonotus obliquus (chaga mushroom), exhibits strong anti-inflammatory, antioxidant, anticancer, and wound-healing properties. However, its extraction remains challenging due to its poor solubility and thermal sensitivity. In this study, we optimized ultrasound-assisted extraction (UAE) using response surface methodology (RSM) to maximize simultaneous betulin and antioxidant compound recovery from I. obliquus. We evaluated three extraction variables (i.e., time, temperature, and ethanol concentration) using a three-factor, five-level design. All quadratic models were significant (p < 0.05), with R² values ranging from 0.83 to 0.93 and prediction errors remaining below 5 %, thereby confirming strong model reliability. Multi-response optimization using a superimposed response plot identified 92.08 % ethanol, 42.56 min, and 62.19 °C as a narrow optimal region, in which all responses simultaneously met the desired criteria. Under these conditions, extraction was predicted to yield high phenolic content (2.58 mg GAE/g DM), increased flavonoid levels (0.57 mg QE/ g DM), strong DPPH radical-scavenging activity (87.49 % DSA), and a betulin content of 2.00 mg/g DM. In contrast, low ethanol concentrations, excessive heating, or prolonged extraction times resulted in reduced yields due to the oxidative or thermal degradation of the bioactive constituents. Overall, the optimized extraction conditions emphasize the importance of controlling solvent polarity and balancing the temperature and time parameters to prevent thermolabile compound decomposition. These results provide a reproducible and eco-efficient framework for large-scale antioxidant constituent extraction from I. obliquus.

The background of this study is to establish a systematic development process for SSD(Solid State Drive) which is being watched as the next generation auxiliary memory device and to make stable production. In order to do so, we select the two products that have been developed and classify and analyze all defects generated in each product by type and process of defects. The root cause of the fault and its background were reflected in the contradiction matrix of TRIZ's technical contradiction, and the improvements suggested in the 40 inventive principles were reflected in the test case design methodology of each process. Finally, this study suggests a process optimization method for systematic development.

This study proposed TACT based optimization model for improving work continuity in apartment structural work. The model was developed by focusing on three key as follows; First, the proposed model allows work crews to effectively rotate tasks to maximize the labor productivity. Second, the proposed model makes a plan for an efficient way to repeatedly carry out the same tasks by standardizing smaller TACT processes. Third, The proposed model suggests a multi-dimensional way to look at a frame construction process to comprehensively reflect characteristics of the construction site such as the combination of work crew and labor productivity, the calculation of the number of workers and equipments that are suitable to carry repetitive works. Through case study, the proposed model showed productivity increase of 25%, non-working days and half-working days decrease of 5 and 4 days, respectively, compared to 6 day cycle. The proposed model would help contractors to achieve successful completion of projects by establishing practical plans with improved work continuity and productivity.

The objective of this study is to investigate the optimal condition for macerating enzymatic extraction process that leads to the highest yield and the largest extracted amount of bio-active contents from Rubus coreanus Miq. fruit. The optimal extraction conditions were found as the following: The initial amount of the water added to the fruit was 20 ~ 30%by weight. The mixing ratio used for the macerating enzyme was 4 : 1 : 2 (w : w : w) for cellulase:pectinase:amylogucosidase,and the amount of the macerating enzyme added was 2% by weight. The extraction process was done at a temperature of 45 ~ 50℃ for 10 hours. The extraction yields on Rubus coreanus Miq. fruit by macerating enzymatic extraction process was increased by 84.3% compared to that of hot-water extraction process. The amounts of organic acids and vitamin found in the extract were also higher. The amount of polyphenol and anthocyanin contents in the extract were 185% and 257% of those from hot-water extraction, respectively. These results suggest that macerating enzymatic extraction is an effective method to boost extraction yield and to increase the amount of extraction of bio-active contents from Rubus coreanus Miq. fruit.

본 논문에서는 클러스터링 알고리즘을 활용하여 과다 허용 방화벽 정책을 최적화 하는 방법을 제시 한다. 과다 허용 방화벽 정책의 트래픽 로그 데이터 1,698,420개를 클러스터링 알고리즘을 활용하여 효율적인 방화벽 정책을 도출하고 이를 시각화 및 성능 지표로 평가하였다. 이를 통해 특히 인력이 부 족한 네트워크 보안 관리 분야에서 적은 자원으로 보안 위험 감소에 기여할 수 있는 방안을 제시한다.

Forged part made of Cold heading quality wire materials are used for automotive brake systems. The cost reduction of forged products is a major issue because of the strict shape change. A series of studies were conducted to minimize the cost of EPB spindle process among brake parts. In order to reduce the material cost, heat treatment-abbreviated material was applied and the formability on the processes was verified by the ductile fracture theory. In addition, the causes of shape fixation and die life degradation were analyzed using the numerical simulation. The process cost has been minimized by re-designing process, changing the product shape, and the die material.