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최적 부하절체 알고리듬을 적용한 연속조류계산의 향상 (Improvement of Continuation Power Flow System Applying the Optimal Load Shedding Algorithm)

  • 송화창;이병준;권세혁
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1998년도 하계학술대회 논문집 C
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    • pp.899-901
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    • 1998
  • Continuation power flow is a tool that can trace the path of the solution from the base stable solution. However, the base stable solution cannot be calculated when the initial system load is too large to operate at a stable operating point. This case is called as unsolvable case. This paper presents implementation of the optimal load shedding algorithm on continuation power flow. It performs steady-state analysis of power systems at unsolvable case that can occur in contingency analysis. Numerical simulation on 20-bus test system demonstrates that the continuation power flow applying the optimal load shedding algorithm is robust at solvable and unsolvable cases.

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Stable Isotope Chemistry of Bone Collagen and Carbonate Assessed by Bone Density Fractionation

  • Shin, Ji-Young
    • Bulletin of the Korean Chemical Society
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    • 제32권10호
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    • pp.3618-3623
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    • 2011
  • This paper presents a stable isotope chemistry of bone collagen and carbonate. Bone carbonate has the potential to provide additional isotopic information. However, it remains controversial as to whether archaeological bone carbonate retains its original biogenic signature. I used a novel application of bone density fractionation and checked the integrity of ${\delta}^{13}C_{apa}$ values using radiocarbon dating. Diagenesis in archaeological bone carbonate still remains to be resolved in extracting biogenic information. The combined use of bone density fractionation and differential dissolution method shows a large shift in the ${\delta}^{13}C_{apa}$ values. Although ${\delta}^{13}C_{apa}$ values are improved in lighter density fractions, a large percentage of contamination in bone carbonate was reported via $^{14}C$ dating compared to that noted with bone collagen.

Stable Isotope Labeled Cytochrome $c_3$ from Desulfovibrio vulgaris on a Defined Medium as Sole Nitrogen Source

  • Kim, Andre;Shim, Yoon-Bo;Kang, Shin-Won;Park, Jang-Su
    • BMB Reports
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    • 제33권6호
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    • pp.506-509
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    • 2000
  • To obtain Cytochrome $c_3$ labeled with a stable isotope, the conditions of cultivation and the composition of medium for DvMF were examined. The growth of DvMF was steady and reproducible under purging with $N_2$ and under pH control. DvMF was able to go on a defined medium without natural products. The composition of the medium containing a small amount of $NH_4Cl$ as sole nitrogen source was established. Then, uniformly $^{15}N-labeled$ Cytochrome $c_3$ was obtained during the culture of DvMF in a defined medium with $^{15}NH_4Cl$; it was confirmed by $^{1}H-^{15}N$ HMQC.

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다공질 내부의 연소현상에 대한 실험적 연구 (An Experimental Study on the Combustion Phenomena in Porous Media)

  • 이용일;신현동
    • 대한기계학회논문집B
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    • 제20권1호
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    • pp.321-327
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    • 1996
  • Experiments were performed on the laminar premixed flame stabilized in a porous medium to know whether the flame downstream of the combustor exists or not. In previous theoretical studies, a stable flame has been predicted in the downstream region of the combustor, but it has never been observed in experiments. In this study, a stable downstream flame could be obtained for the lower burning velocity through circumferential heating by a blue flame positioned outside the periphery of the specially devised combustor. The existence of the stable downstream flame was confirmed by a direct photography of soot line, and temperature measurements. The effect of combustor diameter to flame stability was also considered. As the diameter of the combustor increases, the lean flammability limit was extended.

홈노즐을 이용한 정전분무 확산 연소 시스템 개발 및 특성 연구 (Characteristics of the Electrospraying Combustion Using Grooved Nozzle)

  • 김우진;김경태;김상수
    • 대한기계학회논문집B
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    • 제31권12호
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    • pp.979-985
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    • 2007
  • Spray combustion characteristics of the conducting fuel electrospray has been studied for clean combustion technology. The electrospraying multiplexed system which can maintain the characteristics of the cone-jet mode is able to obtain charged micro droplets with high flow rate. In addition, they have monodisperse distribution during operating the electrospray in the cone-jet mode. The multiplexed grooved nozzle system with the extractor was applied to this experimental device set up. The stable grooved mode can be generated by the grooved nozzle and this electrospray system was applied to the diffusion combustion. It is the first step to discover the diffusion combustion characteristics of the electrospray, In case of the single grooved nozzle electrospray the diffusion flames are occurred at each Jet of grooved mode and they are quite stable. The exhaust gas analysis was indicated that there is the critical point which can make very stable diffusion combustion

기존도시철도의 CBTC도입에 따른 병행운전방안 도출연구 (The Study for Mixed Operation of CBTC Train and Non-CBTC Ones)

  • 김유호;이수환;유종천;김종기;백종현
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2003년도 추계학술대회 논문집(III)
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    • pp.151-156
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    • 2003
  • The Communication Based Train Control(CBTC) System generally used to improving existing lines in the world is efficient and stable for improvement. Also it is efficient for improvement because it does not cause any problems in operation of existing lines. We examined the mixed operation scheme for more efficient and stable improvement when improvement is implemented depending on aged equipment and the increased number of passengers in the Korean city railroad. The biggest point in the mixed operation is to implement a stable test without interfering with the operation of the existing lines. For this purpose, we deduced a method of installing the equipment, a method of testing depending on the installed equipment, and the types of mixed operation, and presented a scheme of execution of the methods depending on the mixed operation.

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Phase behaviors, lamellar structures, and physical properties of synthetic vitamin E ceramide (Tocomide) mixed with cholesterol and linoleic acid

  • Lee, Young-Jin;Kim, Do-Hoon;Park, Ho-Sik;Kang, Hyung-Seok;Kim, Joong-Soo;Kim, Han-Kon
    • 대한화장품학회:학술대회논문집
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    • 대한화장품학회 2003년도 IFSCC Conference Proceeding Book II
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    • pp.357-368
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    • 2003
  • II-A isotherms and phase behaviors of 'tocomide', a newly synthesized 1,3-bis(N-(2-hydroxyethyl)-tocopherol succinylamino)-2-hydroxypropane, mixed with cholesterol and linoleic acid, was studied for its monolayer miscibility and a stable delivery formulation for antioxidant applications. The monolayer of tocomide and cholesterol was formed in a homogeneously mixed state at air-water interface. The ternary mixtures with linoleic acid showed various bulk structures, including a stable and transparent solution of thermodynamically stable lamellar phase. The lamellar structure was confirmed by the X-ray diffraction (XRD) patterns and polarized microscopy such that pure tocomide formed a liquid crystal at room temperature with a lamellar periodicity of 36.7 $\AA$(2$\theta$=2.41$^{\circ}$).

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구조적 파라미터 불확실성을 갖는 안정한 선형계에 대한 강인 포화 제어기 (Robust Saturation Controller for the Stable LTI System with Structured Real Parameter Uncertainties)

  • 임채욱;박영진;문석준;박윤식
    • 제어로봇시스템학회논문지
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    • 제12권6호
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    • pp.517-523
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    • 2006
  • This paper is focused on a robust saturation controller for the stable linear time-invariant (LTI) system involving both actuator's saturation and structured real parameter uncertainties. Based on affine quadratic stability and multi-convexity concept, a robust saturation controller is newly proposed and the linear matrix inequality (LMI)-based sufficient existence conditions for this controller are presented. The controller suggested in this paper can analytically prescribe the lower and upper bounds of parameter uncertainties, and guarantee the closed-loop robust stability of the system in the presence of actuator's saturation. Through numerical simulations, it is confirmed that the proposed robust saturation controller is robustly stable with respect to parameter uncertainties over the prescribed range defined by the lower and upper bounds.

Dynamics and GA-Based Stable Control for a Class of Underactuated Mechanical Systems

  • Liu, Diantong;Guo, Weiping;Yi, Jianqiang
    • International Journal of Control, Automation, and Systems
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    • 제6권1호
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    • pp.35-43
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    • 2008
  • The control of underactuated mechanical system is very complex for the loss of its control inputs. The model of underactuated mechanical systems in a potential field is built with Lagrangian method and its structural properties are analyzed in detail. A genetic algorithm (GA)based stable control approach is proposed for the class of under actuated mechanical systems. The Lyapunov stability theory and system properties are utilized to guarantee the system stability to its equilibrium. The real-valued GA is used to adjust the controller parameters to improve the system performance. This approach is applied to the underactuated double-pendulum-type overhead crane and the simulation results illustrate the complex system dynamics and the validity of the proposed control algorithm.

시뮬레이션에 기반한 휴머노이드 로봇 두 대의 안정적인 물체 운반 및 제어 연구 (Simulation Based for Intelligent Control System of Multi - Humanoid Robots for Stable Load Carrying)

  • 김한근;김형진;박원만;김윤혁;김동한;안진웅
    • 제어로봇시스템학회논문지
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    • 제16권2호
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    • pp.120-125
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    • 2010
  • This paper proposes an intelligent PID/Fuzzy control system for two humanoid robots to transport objects stably. When a robot transports an object while walking, a whole body system of a robot may not be stable due to vibration or external factors from a different departure speed error and a body movement of walking robots. Therefore, it is necessary to measure the horizontal and vertical locations and speeds of object, then calibrate the difference of departure speed between robots with PID/Fuzzy control. The results of simulation with two robots indicated that a proposed controller makes robots to transport an object stably.