• Title/Summary/Keyword: processes optimization

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Highly Efficient Thermal Plasma Scrubber Technology for the Treatment of Perfluorocompounds (PFCs) (과불화합물(PFCs) 가스 처리를 위한 고효율 열플라즈마 스크러버 기술 개발 동향)

  • Park, Hyun-Woo;Cha, Woo Byoung;Uhm, Sunghyun
    • Applied Chemistry for Engineering
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    • v.29 no.1
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    • pp.10-17
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    • 2018
  • POU (point of use) scrubbers were applied for the treatment of waste gases including PFCs (perfluorocompounds) exhausted from the CVD (chemical vapor deposition), etching, and cleaning processes of semiconductor and display manufacturing plant. The GWP (global warming potential) and atmosphere lifetime of PFCs are known to be a few thousands higher than that of $CO_2$, and extremely high temperature more than 3,000 K is required to thermally decompose PFCs. Therefore, POU gas scrubbers based on the thermal plasma technology were developed for the effective control of PFCs and industrial application of the technology. The thermal plasma technology encompasses the generation of powerful plasma via the optimization of the plasma torch, a highly stable power supply, and the matching technique between two components. In addition, the effective mixture of the high temperature plasma and waste gases was also necessary for the highly efficient abatement of PFCs. The purpose of this paper was to provide not only a useful technical information of the post-treatment process for the waste gas scrubbing but also a short perspective on R&D of POU plasma gas scrubbers.

Bayesian Image Restoration Using a Continuation Method (연속방법을 사용한 Bayesian 영상복원)

  • Lee, Soo-Jin
    • The Journal of Engineering Research
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    • v.3 no.1
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    • pp.65-73
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    • 1998
  • One approach to improved image restoration methods has been the incorporation of additional source information via Gibbs priors that assume a source that is piecewise smooth. A natural Gibbs prior for expressing such constraints is an energy function defined on binary valued line processes as well as source intensities. However, the estimation of both continuous variables and binary variables is known to be a difficult problem. In this work, we consider the application of the deterministic annealing method. Unlike other methods, the deterministic annealing method offers a principled and efficient means of handling the problems associated with mixed continuous and binary variable objectives. The application of the deterministic annealing method results in a sequence of objective functions (defined only on the continuous variables) whose sequence of solutions approaches that of the original mixed variable objective function. The sequence is indexed by a control parameter (the temperature). The energy functions at high temperatures are smooth approximations of the energy functions at lower temperatures. Consequently, it is easier to minimize the energy functions at high temperatures and then track the minimum through the variation of the temperature. This is the essence of a continuation method. We show experimental results, which demonstrate the efficacy of the continuation method applied to a Bayesian restoration model.

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Operation Status of Chinese Security Service Industry and Institutional Settlement Methods (중국 보안서비스산업의 운영실태 및 제도정착 방안)

  • Lee, Sangchul
    • Journal of the Society of Disaster Information
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    • v.10 no.4
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    • pp.536-547
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    • 2014
  • With the changing safety services and social order systems accompanied by the economic development and changing public security environment since the Chinese economic reform, the security service industry in China is growing daily and related problems are increasing. For the Chinese security service market to be activated, the monopoly of security services by the public security agencies must be removed. In addition, the research and development, expansion, and applications of safety and crime prevention technologies regarding the safety and protection of exhibition, sales, culture, sports, commerce activities, combinations of safety technologies and crime prevention processes, the provision of relevant technical operations, and the expansion of security service areas are required. Furthermore, the administration rights, property rights, and business management rights of security companies must be separated, the security headquarters must be integrated and coordinated for optimization of various resources solely by market needs, and their rights and affiliation relations must be clear. Besides, the competitiveness of security companies in the security service market must be enhanced by unifying the business management, and optimizing and sharing their resources. The security service ordinances of China that have been implemented now must be applied realistically, methods to activate the true market economy for security services must be researched, and various ordinances related to security services must be realigned in line with the characteristics of security services. Finally, for the mutual cooperation system between public and private security services, the public security agencies must acknowledge the importance of private security services and the status of security service providers in crime prevention and social order maintenance. They must establish partnership relations with each other beyond the unilateral direction and management system for security services and drive with positive attitudes the security service industry which is still in its infancy.

A Case Study of BIM-based Framework on Constructability Tasks (BIM기반 골조공사의 시공성분석 업무 적용사례에 관한 연구)

  • Lee, Seung-Il;Kwon, Nam-Ha;Cho, Young-Sang
    • Journal of the Korea Institute of Building Construction
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    • v.10 no.5
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    • pp.45-54
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    • 2010
  • Recently more and more construction projects have become high-rise, complex and intelligent. Accordingly, such projects require an integrated management system for tasks, with a lean approach to construction with work processes for management and productivity. In particular, Construction Information Technology (CIT) fields are concerned with Building Information Modeling (BIM), which represents the process of generating and managing building data during its life cycle. Constructability research has progressed for the project goal which is a cost-time-quality of optimization by integrated construction knowledge and experience. However, the current constructability process has not been performed efficiently, as the existing 2D drawings and papers lack consistent and accurate information, it is difficult to share the contents of work, and the use of information is inefficient. This study proposes that the reformation and enhancement of BIM-based constructability work process can lead to brilliant performance in the framework of the construction phase through achieving collaboration between the design team and the workers at the site.

Working partial pressure of $CO_2$ gas in aqueous solution

  • Kim Dong-Su
    • Resources Recycling
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    • v.14 no.4 s.66
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    • pp.47-52
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    • 2005
  • Carbonate species in aqueous solution play an important role in the determination of chemical properties of water in relation with alkalinity, buffer capacity, biological productivity, and so on. These compounds also have reactive characteristics such as interphasal reactions between solid, liquid, and gas phases. In the absence of solid materials, the total amount and relative abundance of each carbonate species are directly influenced by the partial pressure of $CO_2$ gas in the atmosphere, which in turn significantly affects the properties of aquatic system. In the water/wastewater treatment process along with the wastes treatment and recycling process which occurring in aquatic environment, it is essential to figure out its characteristics for their optimization and one of its most influential features upon these processes is determined by carbonate species. To understand the fundamental aspect of the relationship between the partial pressure of $CO_2$ gas and chemical features of water, especially pH, the working partial pressure of pure $CO_2$ gas that produced by contacting the dry ice with water has been estimated based on equilibrium calculation. The equilibrium constants for the dissociation ot carbonic acid were determined using van't Hoff equation and the distribution diagram of carbonate species according to the pH has been constructed to substantiate the results of equilibrium calculation. The estimated working partial pressure of pure $CO_2$ gas was found to be a function of the concentration of carbonates in solution, which suggesting that Prior evaluation of the working partial pressure of gas is essential for a better understanding of aquatic interactions.

Optimization of Z-R relationship in the summer of 2014 using a micro genetic algorithm (마이크로 유전알고리즘을 이용한 2014년 여름철 Z-R 관계식 최적화)

  • Lee, Yong Hee;Nam, Ji-Eun;Joo, Sangwon
    • Journal of the Korean Institute of Intelligent Systems
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    • v.26 no.1
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    • pp.1-8
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    • 2016
  • The Korea Meteorological Administration has operated the Automatic Weather Stations, of the average 13 km horizontal resolution, to observe rainfall. However, an additional RADAR network also has been operated in all-weather conditions, because AWS network could not observed rainfall over the sea. In general, the rain rate is obtained by estimating the relationship between the radar reflectivity (Z) and the rainfall (R). But this empirical relationship needs to be optimized on the rainfall over the Korean peninsula. This study was carried out to optimize the Z-R relationship in the summer of 2014 using a parallel Micro Genetic Algorithm. The optimized Z-R relationship, $Z=120R^{1.56}$, using a micro genetic algorithm was different from the various Z-R relationships that have been previously used. However, the landscape of the fitness function found in this study looked like a flat plateau. So there was a limit to the fine estimation including the complex development and decay processes of precipitation between the ground and an altitude of 1.5km.

A Study on the Variation of Rn-222 Concentration in Groundwater at Busan-Geumjeong area (부산 금정구지역의 지하수에 포함된 라돈농도 변화 연구)

  • Cho, Jungg-Sook;Lee, Hyo-Min;Kim, Sun-Woong;Kim, Jin-Seop
    • Journal of Radiation Protection and Research
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    • v.37 no.3
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    • pp.149-158
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    • 2012
  • In this paper, we measured the variations of radon concentrations in groundwater using low-level Liquid Scintillation Counter (LSC), an instrument for analyzing the alpha and beta radionuclides at its 10 sites around the Kumjung-Gu, north-western of Busan. Optimization of Pulse Shape Analyzer (PSA) to determinate the highest value of figure of merit (FM) was decided using Quantulus 1200 LSC with radium-226 source, the optimal PSA level was shown in the range of 100 to 110. The results show that the Minimum Detectable Activity (MDA) of radon concentrations is 0.61 $Bq{\cdot}L^{-1}$ for 20 minutes in PSA level. We find that the average radon concentration in groundwater is high in granitic rock area and low in volcanic rock area. (Biotite granite : 191.39 $Bq{\cdot}L^{-1}$, Micro graphic granite : 141.88 $Bq{\cdot}L^{-1}$, Adamellite : 92.94 $Bq{\cdot}L^{-1}$, Andesite (volcanic) : 35.35 $Bq{\cdot}L^{-1}$). No significant seasonal variation pattern is observed from the long-term variation analysis from 10 selected sites. We have not seen the significant correlation of radon concentration to groundwater temperature, atmospheric temperature, atmospheric pressure and rainfall. The concentration variation is probably caused by more complex factors and processes.

Optimal Roasting Conditions for Maximizing the Quality of Tea Leached from High Functional Perilla frutescens Leaves (고기능성 들깻잎을 이용한 침출차의 품질 극대화를 위한 최적 볶음조건 연구)

  • Yun, Ung-Jae;Yang, Sung-Yong;Lee, Hyun-Sun;Hong, Chung-Oui;Lee, Kwang-Won
    • Korean Journal of Food Science and Technology
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    • v.44 no.1
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    • pp.34-40
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    • 2012
  • This study was carried out to investigate the optimal roasting conditions for developing perilla leaf leached tea, which has high functional Perilla frutescens leaves. The roasting processes were carried out with variations in roasting temperature ($120-200^{\circ}C$) and roasting time (15-35 min), the response surface methodology was applied to monitor the changes in qualities of the roasted Perilla frutescens leaves. The antioxidant, bioactive substance in roasted Perilla frutescens leaves, and their extracts were the quality parameters. The total polyphenol and total flavonoid contents increased with time and temperature up to 25 min and $160^{\circ}C$. Antioxidative activities showed a positive correlation with the amount of phenolic compound. Caffeic acid and rosmarinic acid contents increased with time up to a mild temperature, $160^{\circ}C$, while they decreased at high temperatures over $160^{\circ}C$. The optimum roasting conditions selected for developing perilla leaf leached tea were thus $180^{\circ}C$ and 20 min, given the conditions in the above experiments.

Extraction Process Optimization of Poncirus trifoliata and Prunus mume for Antibacterial Activity against Vibrio parahaemolyticus (장염비브리오 항균활성을 위한 탱자와 매실의 추출조건 최적화)

  • Lee, Young-Guen;Choi, Young-Whan;Joo, Woo-Hong
    • Journal of Life Science
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    • v.16 no.4
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    • pp.640-646
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    • 2006
  • The present investigation was carried out particularly to optimize the extraction process of Poncirus trifoliata and Prunus mume to develop a functional foodstuff having antibacterial activity against Vibrio parahaemolyticus. The extracts were prepared from the fruits under various conditions, and then optimum extraction conditions were decided in case maximal antibacterial activity was obtained. In extraction process by using hot water, the best antibacterial activity of Poncirus trifoliata was achieved at $80{\sim}100^{\circ}C$ for 30 min, while that of Prunus mume was achieved at $100^{\circ}C$ for 30 min, as showing 14.8 and 16.6 mm of inhibition diameter, respectively. The extraction process with addition of NaOH increased the activity of Prunus mume, but addition of $K_2CO_3$ and $NaHCO_3$ drastically decreased the activity. In the processes at high temperature up to $120^{\circ}C$ by using pressure extractor and with various concentrations of NaOH, the maximum activity was observed in the extract of Prunus mume at $120^{\circ}C$ for 30 min with 0.05 N NaOH. The fermented ethanol extract of the fruits showed less activity than those of the extracts with water and NaOH solution.

On Developing The Intellingent contro System of a Robot Manupulator by Fussion of Fuzzy Logic and Neural Network (퍼지논리와 신경망 융합에 의한 로보트매니퓰레이터의 지능형제어 시스템 개발)

  • 김용호;전홍태
    • Journal of the Korean Institute of Intelligent Systems
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    • v.5 no.1
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    • pp.52-64
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    • 1995
  • Robot manipulator is a highly nonlinear-time varying system. Therefore, a lot of control theory has been applied to the system. Robot manipulator has two types of control; one is path planning, another is path tracking. In this paper, we select the path tracking, and for this purpose, propose the intelligent control¬ler which is combined with fuzzy logic and neural network. The fuzzy logic provides an inference morphorlogy that enables approximate human reasoning to apply to knowledge-based systems, and also provides a mathematical strength to capture the uncertainties associated with human cognitive processes like thinking and reasoning. Based on this fuzzy logic, the fuzzy logic controller(FLC) provides a means of converhng a linguistic control strategy based on expert knowledge into automahc control strategy. But the construction of rule-base for a nonlinear hme-varying system such as robot, becomes much more com¬plicated because of model uncertainty and parameter variations. To cope with these problems, a auto-tuning method of the fuzzy rule-base is required. In this paper, the GA-based Fuzzy-Neural control system combining Fuzzy-Neural control theory with the genetic algorithm(GA), that is known to be very effective in the optimization problem, will be proposed. The effectiveness of the proposed control system will be demonstrated by computer simulations using a two degree of freedom robot manipulator.

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