• 제목/요약/키워드: control strategies

검색결과 2,451건 처리시간 0.033초

Optimization of Staphylokinase Production in Bacillus subtilis Using Inducible and Constitutive Promoters

  • Kim, June-Hyung;Wong, Sui-Lam;Kim, Byung-Gee
    • Biotechnology and Bioprocess Engineering:BBE
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    • 제6권3호
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    • pp.167-172
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    • 2001
  • Staphylokinase (SAK) was produced in B. subtilis using two different promoter systems, i.e. the P43 and sacB promoters. To maximize SAK expression in B. subtilis, fermentation control strategies for each promoter were examined. SAK, under P43, a vegetative promoter transcribed mainly by $\sigma$(sup)B containing RNA polymerase, was overexpressed at low dissolved oxygen (D.O.) levels, suggesting that the sigB operon is somewhat affected by the energy charge of the cells. The expression of SAK at the 10% D.O. level was three times higher than that at the 50% D.O. level. In the case of sacB, a sucrose-inducible promoter, sucrose feeding was used to control the induction period and induction strength. Since sucrose is hydrolyzed by two sucrose hydrolyzing enzymes in the cell and culture broth, the control strategy was based on replenishing the loss of sucrose in the culture. With continuous feeding of sucrose, WB700 (pSAKBQ), which contains the SAK gene under sacB promoter, yielded ca. 35% more SAK than the batch culture. These results present efficient promoter-dependent control strategies in B. subtilis host system for foreign protein expression.

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편타 손상 후 소극적 대처 전략이 통증 및 기능에 미치는 영향 (The Effects of Passive Coping Strategies in Pain and Function After Whiplash Injury)

  • 조현표;김영민
    • 대한물리의학회지
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    • 제10권1호
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    • pp.45-52
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    • 2015
  • PURPOSE: The purpose of this study was to observe the effect of pain and function according to the high and low manual passive coping strategies after whiplash injury. METHODS: The study was tested with 30 patients with neck pain. Coping was measured at after 10 days using the Pain Management Inventory. Group was divided into high passive(experimental) and low passive(control) group. All patients were equally treated with the ordinary therapy. Patients attended physical therapy for 3 times a week, for 6 weeks. Visual analogue scale (VAS) for pain, Pain Disability Index (PDI), neck disability index (NDI), were recorded both before and after the intervention. RESULTS: Each coping strategy group were evaluated after 6 weeks. VAS has been significantly reduced in both groups (p <.05). PDI and NDI was significantly decreased after the experiment before. In the experimental group (p <.001), the control group showed no significant difference. In the comparison between groups VAS was significantly reduced compared with the control group (p <.05), PDI and NDI was significantly reduced compared with the control group (p <.001). CONCLUSION: Low passive coping strategy predicts neck pain and disability recovery. It may be beneficial to assess and improve coping strategy early in whiplash injury.

연료전지 하이브리드 자동차의 최적 제어 (Optimal Control of Fuel Cell Hybrid Vehicles)

  • 정춘화;박영일;임원식;차석원
    • 한국자동차공학회논문집
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    • 제20권2호
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    • pp.135-140
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    • 2012
  • Fuel Cell Hybrid Vehicles (FCHVs) have already become the subject of major interest among automotive industry as well as power management strategies of FCHVs, as the fuel economy of FCHVs depends on them. There are several types of power management strategies of FCHVs that have been developed to improve the fuel economy of FCHVs. Among them, optimal control theory is applied to this study. A problem is defined and its objective is to minimize the energy consumption of an FCHV and to find the optimal trajectories of powertrain parameters during driving. Necessary conditions for the optimal control are introduced and the simulation results of constant costate are compared to that of variable costate in order to prove that the variable costate can be replaced with the constant costate.

캡슐형 빙축열시스템에 대한 운전 시뮬레이션 및 에너지비용 분석 (Simulation and Energy Cost Calculation of Encapsulated Ice Storage System)

  • 이경호;주용진;최병윤;김상준
    • 태양에너지
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    • 제19권3호
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    • pp.63-73
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    • 1999
  • Ice storage systems are used to shift the peak load in day time into night time in summer. This paper describes a system simulation of partial ice storage system composed of an encapsulated ice storage tank, a screw compressor chiller, a heat exchanger, and a brine pump. For the system simulation, a one-dimensional model of ice storage tank is developed and validated by comparison with the performance data from measurements of an ice storage tank installed at a building. The control strategies considered in this study are chiller priority and storage priority being used commercially. The system is simulated with design cooling load of 600 RT peak load in design day and with off-design day cooling load, and the electric energy costs of the two control strategies for the same system size are compared. As a result of calculation, the energy consumption in a week for storage priority is higher than that for chiller priority control. However due to lower cost of night electric charge rate, energy cost for storage priority control is lower than chiller priority.

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솔잎혹파리의 생태와 방제전략 (The Eclogy of the Pine Needle Gall Midge (Thecodiplosis japonensis Uchida et Inouye) ana Its Control Strategies)

  • 현재선
    • 한국응용곤충학회지
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    • 제21권3호
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    • pp.163-166
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    • 1982
  • The pine needle gall midge, Therodiplosis japonensis Uchida et Inouye, is the most important insect pest. It requires two different habitats for the development; on trees and under the ground. The habitat specific mortality rates ere $30\~40\%,\;and\;50\~60\%$ for the respective habitats. The key developmental stage is the prepupa, and the key mortality factor is the moisture contents of the soil and its variability. Since the insect is an exotic, the population status is the periphery and in the source of infestation are considerably different. Such a difference in habitats and the population status of the insect should be considered in relation to suppression of the insect. The control strategies should be directional and rational based on the reality of the pest status. There have been substantial information on the control methods of the pine needle gall midge, and each control method has an important place, but none has always provided a satisfactory solution to the many problems associated by this insect. These methods should be applied to a system based on the ecology of the insect. There should be continued support for directed effort on the development of operational management systems for the insect: specifically, estmation of the critical economic injury level, and of the absolute density of the insect.

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공대생들의 창의적 문제해결유형별 셀프리더십과 통제소재 (Creative Problem Solving Style, Self-leadership and Locus of Control in the Korean Engineering College Students)

  • 안정호;임지영
    • 공학교육연구
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    • 제13권4호
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    • pp.122-129
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    • 2010
  • 본 연구는 공대생들을 대상으로 창의적 문제해결유형별로 셀프리더십과 통제소재의 특성을 파악함으로써 문제해결능력과 과제수행을 증진시키고 효과적인 팀을 구성, 관리하는데 도움을 주기 위해 수행되었다. 창의적 문제해결유형의 3가지 차원(변화에 대한 지향, 일처리 방식, 의사결정의 중심)에 대해 각 차원을 구성하는 2가지 유형(혁신-개량, 외적처리-내적처리, 사람중심-과제중심)에 속하는 학생들을 분류하고, 문제해결유형과 성별에 따른 셀프리더십과 통제소재에 차이가 있는지를 알아보기 위해 이원분산분석을 실시했다. 문제해결유형의 주효과는 각 차원별로 다르게 나타났고, 성별의 주효과 및 성별과 문제해결 유형의 상호작용효과는 모든 척도에서 나타나지 않았다. 마지막으로 본 연구의 제한점과 후속연구를 위한 제언이 논의되었다.

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인공신경망 모델을 이용한 냉동기 및 공조기 최적 기동/정지 제어 (Artificial Neural Network Models for Optimal Start and Stop of Chiller and AHU)

  • 박성호;안기언;황승호;최선규;박철수
    • 대한건축학회논문집:구조계
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    • 제35권2호
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    • pp.45-52
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    • 2019
  • BEMS(Building Energy Management Systems) have been applied to office buildings and collect relevant building energy data, e.g. temperatures, mass flow rates and energy consumptions of building mechanical systems and indoor spaces. The aforementioned measured data can be beneficially utilized for developing data-driven machine learning models which can be then used as part of MPC(Model Predictive Control) and/or optimal control strategies. In this study, the authors developed ANN(Artificial Neural Network) models of an AHU (Air Handling Unit) and a chiller for a real-life office building using BEMS data. Based on the ANN models, the authors developed optimal control strategies, e.g. daily operation schedule with regard to optimal start and stop of the AHU and the chiller (500 RT). It was found that due to the optimal start and stop of the AHU and the chiller, 4.5% and 16.4% of operation hours of the AHU and the chiller could be saved, compared to an existing operation.

Traffic-induced vibrations at the wet joint during the widening of concrete bridges and non-interruption traffic control strategies

  • Junyong Zhou;Zunian Zhou;Liwen Zhang;Junping Zhang;Xuefei Shi
    • Computers and Concrete
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    • 제32권4호
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    • pp.411-423
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    • 2023
  • The rapid development of road transport has increased the number of bridges that require widening. A critical issue in the construction of bridge widening is the influence of vibrations of the old bridge on the casting of wet joint concrete between the old and new bridges owing to the running traffic. Typically, the bridge is closed to traffic during the pouring of wet joint concrete, which negatively affects the existing transportation network. In this study, a newly developed microscopic traffic load modeling approach and the vehicle-bridge interaction theory are incorporated to develop a refined numerical framework for the analysis of random traffic-bridge coupled dynamics. This framework was used to investigate traffic-induced vibrations at the wet joint of a widened bridge. Based on an experimental study on the vibration resistance of wet joint concrete, traffic control strategies were proposed to ensure the construction performance of cast-in-site wet joint concrete under random traffic without interruption. The results show that the vibration displacement and frequency of the old bridge, estimated by the proposed framework, were comparable with those obtained from field measurements. Based on the target peak particle velocity and vibration amplitude of the wet joint concrete, it was found that traffic control measures, such as limiting vehicle gross weight and limiting traffic volume by closing an additional traffic lane, could ensure the construction performance of the wet joint concrete.

단상 PWM 컨버터에 적용한 공간 벡터 PWM (Adaptation of Space Vector Modulation to Single-Phase High Power PWM Converters)

  • 이희면;이동명
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2011년도 전력전자학술대회
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    • pp.442-443
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    • 2011
  • In this paper, a voltage control method based on DQ transformation and Space Vector Pulse Width Modulation (SVPWM) for a single phase three-level converter is proposed. This control method is designed to use DC values instead of using instantaneous values of current which are usually used in single-phase application, so that it results in a fast and robust voltage control response. Simulation results demonstrate the validity of the control strategies.

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Q-learning for intersection traffic flow Control based on agents

  • 주선;정길도
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2009년도 정보 및 제어 심포지움 논문집
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    • pp.94-96
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    • 2009
  • In this paper, we present the Q-learning method for adaptive traffic signal control on the basis of multi-agent technology. The structure is composed of sixphase agents and one intersection agent. Wireless communication network provides the possibility of the cooperation of agents. As one kind of reinforcement learning, Q-learning is adopted as the algorithm of the control mechanism, which can acquire optical control strategies from delayed reward; furthermore, we adopt dynamic learning method instead of static method, which is more practical. Simulation result indicates that it is more effective than traditional signal system.

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