• Title/Summary/Keyword: Regulating Control

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Recovery of Ecosystem Service Functions through Ecological Restoration Practice: A Case Study of Coal Mine Spoils, Samcheok, Central Eastern Korea (훼손된 생태계의 복원을 통한 생태계 서비스의 회복: 채탄쓰레기 매립지 복원지의 사례)

  • Oh, Woo Seok;Lee, Chang Seok
    • Korean Journal of Environmental Biology
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    • v.32 no.2
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    • pp.102-111
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    • 2014
  • Ecological restoration is regarded as a major strategy for preventing biodiversity loss and thereby enhancing ecosystem service. This study was performed to evaluate ecosystem service value that the restored ecosystem provides. Ecosystem service was evaluated for provisioning and regulating services. The former service was evaluated by comparing similarities in a viewpoint of floristic composition to the reference site between the restored and the unrestored sites. Species composition of the restored site was found to be more similar to the reference site than that of the unrestored site and thereby restoration practice contributed for enhancing the provisioning service. Regulating service was evaluated based on microclimate control, soil amelioration, and improvement of water holding capacity. The value of ecosystem services in terms of microclimate control, soil amelioration, and improvement of water holding capacity was higher in the restored site than in the unrestored site. In consequence, ecological restoration of coal mine spoils contributed for enhancing the ecosystem service value of the corresponding site and thereby is rewarding the cost invested for restoration.

General Digital Fuzzy Logic Controller Design For Resonant Inverter (공진형 인버터를 위한 범용 퍼지 논리 제어기 설계)

  • 김태언;김남수;임영도
    • Journal of the Institute of Convergence Signal Processing
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    • v.5 no.1
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    • pp.60-65
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    • 2004
  • Induction heating system is time varying system around curie point. So, it has many troubles which are system shut down and change the load impedance. In this paper has been designed the parallel resonant inverter which controlling the constant power and tracking the load resonant frequency with PLL is possible, in order to minimize switching losses and solve it's many troubles. The current full-bridge type parallel resonant inverter of an induction heating system was composed of IGBT in switching device. For regulating the output power of an induction heating system, the Fuzzy logic controller is used. The Fuzzy controller makes the control signal for a stable power regulating control and when reference is changed, it is superior to adaptability. It has been evaluated a stable behavior for a noise with switching and a load disturbance.

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Functional Conservation and Divergence of FVE Genes that Control Flowering Time and Cold Response in Rice and Arabidopsis

  • Baek, Il-Sun;Park, Hyo-Young;You, Min Kyoung;Lee, Jeong Hwan;Kim, Jeong-Kook
    • Molecules and Cells
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    • v.26 no.4
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    • pp.368-372
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    • 2008
  • Recent molecular and genetic studies in rice, a short-day plant, have elucidated both conservation and divergence of photoperiod pathway genes and their regulators. However, the biological roles of rice genes that act within the autonomous pathway are still largely unknown. In order to better understand the function of the autonomous pathway genes in rice, we conducted molecular genetic analyses of OsFVE, a rice gene homologous to Arabidopsis FVE. OsFVE was found to be ubiquitously expressed in vegetative and reproductive organs. Overexpression of OsFVE could rescue the flowering time phenotype of the Arabidopsis fve mutants by up-regulating expression of the SUPPRESSOR OF OVEREXPRESSION OF CO1 (SOC1) and down-regulating FLOWERING LOCUS C (FLC) expression. These results suggest that there may be a conserved function between OsFVE and FVE in the control of flowering time. However, OsFVE overexpression in the fve mutants did not rescue the flowering time phenotype in in relation to the response to intermittent cold treatment.

Robust Position Control of a Single-Link Flexible Manipulator Using Sliding Mode and Piezofilm Actuator (슬라이딩모드와 압전필름 작동기를 이용한 단일링크 유연 머니퓰레이터의 강건위치제어)

  • 최승복
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.19 no.6
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    • pp.1371-1381
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    • 1995
  • A novel hybrid control scheme to actively control the endpoint position of a very flexible single-link manipulator is proposed. The control scheme consists of a motor mounted at the beam hub and a piezofilm actuator bonded to the surface of the flexible link. The control torque of the motor to produce a desired motion is firstly determined by employing the sliding mode control theory on the equation of motion of the rigid link having the same mass as that of the proposed flexible link. The torque is then applied to the flexible manipulator in order to activate the commanded motion. During the motion, undesirable oscillation is actively suppressed by applying a feedback control voltage to the piezofilm actuator. Consequently, the imposed desired position is accomplished. In order to demonstrate high control performances accrued from the proposed method, computer simulations are undertaken by treating both regulating and tracking control problems.

A FUZZY PID Control of Supply Duct Outlet Air Temperature for PEM (FUZZY PID 방법을 이용한 개별 공조시스템의 급기온도 제어)

  • 장영준;박영철;정광섭;한화택;이정재
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.14 no.4
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    • pp.278-284
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    • 2002
  • The work presented here provides a control of the supply duct outlet air temperature in PEM (personal environment module) using fuzzy PID controller. In previous work, PID control systems were used, but the result shows that the outlet air temperature and electric heater regulating voltage were oscillated. Fuzzy PID control systems are designed to improve the system response obtained using PID control and implemented experimentally Also, PID controller and fuzzy controller without PID logic are provided to compare the result with that of the fuzzy PID controller. Data obtained shows that the fuzzy PID control system satisfies the design criteria and works proper1y in controlling the supply air temperature. Also it has bettor performance than the previous result obtained using PID control.

Precise temperature control by modern control method on the refrigerator and air conditioner (현대제어 이론을 이용한 냉동공조기의 정밀 온도제어)

  • 한정만;유휘룡;김상봉
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10b
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    • pp.1213-1216
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    • 1996
  • This paper describes a precise temperature control method for refrigerating and air conditioning systems. The control technique is based on the optimal servo control design method and the control algorithm is implemented on a personal computer. To control the precise temperature, two actuators such as an inverter for the compressor speed control and a stepping motor for regulating the expansion valve are used. The superheat and evaporator temperatures are chosen as the system output. So a multivariable system which has two inputs and two outputs to be controlled. The complicative model is identified by using an ARX(Auto Regressive eXogenous) model and the controller is designed by using the Matlab software.

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Advanced Load Follow Operation Mode for Korean Standardized Nuclear Power Plants (한국 표준 원전의 부하추종을 위한 운전 기법)

  • Park, Jung-In;Oh, Soo-Youl;Song, In-Ho;Hah, Yung-Joon;Kuh, Jung-Eui;Lee, Un-Chul
    • Nuclear Engineering and Technology
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    • v.24 no.2
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    • pp.183-192
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    • 1992
  • An advanced load-follow operation mode, Mode K, is presented for the Korean Standardized Nuclear Power Plants. The Mode K utilizes a heavy worth bank dedicated to axial shape control independent of the existing regulating banks. In Mode K, the heavy bank provides a wide range of axial shape control and a monotonic relationship between its motion and the axial shape change, which makes it easy to automate axial shape control. The achievement of full automatic reactor power control both for the reactivity and power shape would reduce the burden due to load-follow operation on the operator. Also, it can accommodate the frequen-cy control, which requires the plant to respond to the unexpected demand. The Mode K design concepts were tested using simulation responses of Yonggwang Units 3&4, the reference plants for the Korean Standardized Nuclear Power Plants. The results illustrate that the Mode K is an adequate operation mode to provide practical load-follow capabilities for the Korean Standardized Nuclear Power Plants.

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Hypoglycemic Action of Red Ginseng Components (II). Investigation of the Effect of Fat Soluble Fraction from Red Ginseng on Enzymes Related to Glucose Metabolism in Cultured Rat Hapatocytes (홍삼 성분의 혈당강하작용 연구 (ll) :쥐의 배양 간세포의 당대사 관련 효소 활성에 미치는 홍삼 지용성 분획의 영향 조사)

  • 이현아;심희선
    • Journal of Ginseng Research
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    • v.22 no.1
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    • pp.51-59
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    • 1998
  • In this study, rat hepatocytes known to have active glucose metabolism were obtained to investigate the hypoglycemic action of fat soluble fraction of red ginseng by using the liver perfusion technique and incubated in two different media-one containing insulin and glucagon (control group), and the other containing glucagon only The activities of main regulating enzymes, such as glucokinase, glucose 6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenate, and glucose 6-phosphatase, related to metabolic pathways of glucose in these two kinds of hepatocytes were compared between these two groups and the effects of addition of fat soluble fraction ($10^1$~$10^4$%) from red ginseng to these two groups on these enzymes were also detected. The results were as follows. The specific activity of enzymes such as glucokinase, flucorse 6-phosphate dehydrogenase, and 6-phosphogluconate dehydrogenase related to glucose-consuming pathways of insulin-deficient group was much less than control one. However, their decreased activity was recovered after the addition of fat-soluble fraction at all range of concentrations. The specific activity of these enzymes after the addition of ginseng components to the control group was also increased. On the other hand, the specific activity of glucose 6-phosphatase related to glucose-producing pathway of insulin-deficient group was much higher than control one, but their increased activity was decreased obviously after the addition of fat soluble fraction at all range of concentrations. The same results were observed after the addition of fat-soluble fraction to the control group. These results suggest that the red ginseng saponin components might be effective on diabetic hyperglycemia by regulating the activity of enzymes related to glucose metabolism directly and/or indirectly. The effects of fat-soluble fraction ($10^2$%) and ginsenosides (mixture, $Rb_1$ and $Rg_1$, $10^4$%) on hypoglycemic action were compared. As a result, they showed considerable effect on hyperglycemia, but the best eff ect on the activities of glucokinase and glucose 6-phosphate dehydrogenase was appeared by ginsenoside $Rb_1$ and that of 6-phosphogluconate dehydrogenase and glucose 6-phosphatase was by ginsenoside mixture.

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Growth and Quality Characteristics in Response to Elevated Temperature during the Growing Season of Korean Bread Wheat

  • Chuloh Cho;Han-Yong Jeong;Yulim Kim;Jinhee Park;Chon-Sik Kang;Jong-Min Ko;Ji-Young Shon
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2022.10a
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    • pp.124-124
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    • 2022
  • Wheat (Triticum aestivum L.) is the major staple foods and is in increasing demand in the world. The elevated temperature due to changes in climate and environmental conditions is a major factor affecting wheat development and grain quality. The optimal temperature range for winter wheat is between 15~25℃, it is necessary to study the physiological characteristic of wheat according to the elevated temperature. This study presents the effect of elevated temperature on the yield and quality of two Korean bread wheat (Baekkang and Jokyoung) in a temperature gradient tunnel (TGT). Two bread wheat cultivars were grown in TGT at four different temperature conditions, i.e. TO control (near ambient temperature), T1 control+1℃, T2 control+2℃, T3 control+3℃. The period from sowing to heading stage has accelerated, while the growth properties including culm length, spike length and number of spike, have not changed by elevated temperature. On the contrary, the number of grains per spike and grain yield was reduced under T3 condition compared with that of control condition. In addition, the. The grain filling rate and grain maturity also accelerated by elevated temperature (T3). The elevating temperature has led to increasing protein and gluten contents, whereas causing reduction of total starch contents. These results are consistent with reduced expression of starch synthesis genes and increased gliadin synthesis or gluten metabolism genes during late grain filling period. Taken together, our results suggest that the elevated temperature (T3) leads to reduction in grain yield regulating number of grains/spike, whereas increasing the gluten content by regulating the expression of starch and gliadin-related genes or gluten metabolism process genes expression. Our results should be provide a useful physiological information for the heat stress response of wheat.

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Adaptive digital control system of flow rates for an OTEC plant

  • Nakamura, Masatoshi;Uehara, Haruo
    • 제어로봇시스템학회:학술대회논문집
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    • 1987.10a
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    • pp.753-758
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    • 1987
  • The purpose of ocean thermal energy conversion (OTEC) plant control is to provide stable power efficiently by appropriately regulating the seawater flow rates and the working fluid flow rate under conditions of continually changing seawater temperatures. This paper describes digital control of working fluid flow rate based on an adaptive control theory for the "Imari 2" OTEC plant at Saga University. Provisions have been made for linkage between the software of the adaptive control theory and the hardware of the OTEC plant. In implementing the working fluid flow rate control, if persistency of excitation conditions are lost, the algorithm of identification often exhibits bursting phenomena. To avoid this difficulty, the stopping-and-starting rule for identification was derived and was used for the working fluid flow rate control. Satisfactory control performance was then obtained by using this digital control system.ol system.

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