• Title/Summary/Keyword: Line Moment

Search Result 287, Processing Time 0.03 seconds

Theory and Experiment of the Cylindrical Edge-Slot Antenna with Coaxial Line Feed (동축선로로 급전된 원통형 에지-슬롯 안테나의 이론 및 실험)

  • 유상기;홍재표;조영기
    • Journal of the Korean Institute of Telematics and Electronics A
    • /
    • v.31A no.2
    • /
    • pp.39-44
    • /
    • 1994
  • A theoretical method has been considered for the analysis of a cylindrical edge-slot antenna which belongs to a class of circumferential slot antennas that are suitable for conformal mounting on conducting bodies of revolution. A coupled integral equation is formulated for unknown magnetic currents of both the coaxial aperture and the edge slot, and solved by the moment method. Theoretical values for reflection coefficient obtained based upon the method are compared with our experimental values and other author's results available. There arre good agreement between them.

  • PDF

Crank Angles Design to Reduce the Excitation Forces in 4-stroke Diesel Engine (4행정 기관의 기진력 감소를 위한 크랭크 각 설계)

  • 서영수;박정근;정의봉
    • Proceedings of the Korean Society of Marine Engineers Conference
    • /
    • 2000.11a
    • /
    • pp.108-114
    • /
    • 2000
  • The excitation forces from the periodical firing pressure in cylinder and the rotating crank mechanism cause lots of vibration problems in diesel engine. In this paper, the theoretical formulas for excitation forces are introduced and computational program for the optimization of crank angle is also developed to reduce the free moments in diesel engine. The computational results of 4-stroke in-line engine are applied to verify the reliability of the program.

  • PDF

Membrane Introduction Mass Spectrometry (MIMS) for Online, Real Time Analysis of Organic Substances

  • 박현채
    • Proceedings of the Membrane Society of Korea Conference
    • /
    • 1994.04a
    • /
    • pp.29-32
    • /
    • 1994
  • The increasing environmental risks exert strong demands for the knowledge of environmentally significant compounds and the reduction of such compounds on the earth. The risk reduction can, in principle, be most effectively achieved by minimizing the formation of environmental pollutants, by-products in many cases, during processes in factories, power plants and other sources. This can be done by on-line, real time monitoring the formation of pollutants at the moment when they are formed, and thereby through the feed-back control of the process.

  • PDF

Using play-back image sequence to detect a vehicle cutting in a line automatically (역방향 영상재생을 이용한 끼어들기 차량 자동추적)

  • Rheu, Jee-Hyung;Kim, Young-Mo
    • Journal of the Institute of Electronics and Information Engineers
    • /
    • v.51 no.2
    • /
    • pp.95-101
    • /
    • 2014
  • This paper explains effective tracking method for a vehicle cutting in a line on the road automatically. The method employs KLT based on optical flow using play-back image sequence. Main contribution of this paper is play-back image sequence that is in order image frames for rewind direction from a reference point in time. The moment when recognizing camera can read a license plate very well can usually be the reference point in time. The biggest images of object traced can usually be obtained at this moment also. When optic flow is applied, the bigger image of the object traced can be obtained, the more feature points can be obtained. More many feature points bring good result of tracking object. After the recognizing cameras read a license plate on the vehicle suspected of cut-in-line violation, and then the system extracts the play-back image sequence from the tracking cameras for watching wide range. This paper compares using play-back image sequence as normal method for tracking to using play-forward image sequence as suggested method on the results of the experiment and also shows the suggested algorithm has a good performance that can be applied to the unmanned system for watching cut-in-line violation.

On UFR Settings Considering Wind Power Fluctuation In Jeju Island (제주도 풍력발전기 출력변동성을 고려한 적정 UFR 차단방식 연구)

  • Park, Min-Su;Chun, Yeong-Han;Byun, Sung-Hyun;Yang, Jeong-Jae
    • The Transactions of The Korean Institute of Electrical Engineers
    • /
    • v.63 no.4
    • /
    • pp.445-450
    • /
    • 2014
  • Jeju power system is connected to the mainland power system through HVDC, and receives about half of required electricity through the HVDC lines. Jeju power system already experienced black out when a generator tripped at the moment of the HVDC line faults. But, UFR operated as was expected when HVDC line fault occurred at that time. As the penetration level of wind turbines increases, it is required to set UFR again considering intermittent wind turbin outputs. In this paper, we address a new way of UFR setting through computer simulation.

Resonant Analysis of Load Commutated Current Source Inverter System (부하(負荷) 전류식(轉流式) 전류형(電流形) 인버터 시스템의 공진(共振) 해석(解析))

  • Sim, Cheon-Bo;Jeong, Seung-Gi
    • Proceedings of the KIEE Conference
    • /
    • 1991.11a
    • /
    • pp.156-159
    • /
    • 1991
  • At LCCSI system, output capacitor of inverter and inductor of load motor raise mutuality operation. This parallel resonant increase equivalent impedance of inverter load and give wrong effect at LCCSI system. This paper carried out resonant analysis of LCCSI system. The result of analysis, particular resonant point of two was discovered that a resonant of S=0 vicinity and $\beta$ resonant of S=1 vicinity. In addition to, the case of harmonics resonant not come from $\alpha$ resonant but come from $\beta$ resonant. A moment of working of LCCSI system, resonant line must not suddenly variation. Accordingly, resonant line is a necessity for doing $f{\alpha}$ vicinity by properly capacitor value selection.

  • PDF

Nonlinear Feedback Linearization-H\ulcorner/Sliding Mode Controller Design for Improving Transient Stability in a Power System

  • Lee, Sang-Seung;Park, Jong-Keun
    • Journal of Electrical Engineering and information Science
    • /
    • v.3 no.2
    • /
    • pp.193-201
    • /
    • 1998
  • In this paper, the standard Dole, Glover, Khargoneker, and Francis (abbr. : DGKF 1989) H\ulcorner controller (H\ulcornerC) is extended to the nonlinear feedback linearization-H\ulcorner/sliding mode controller (NFL-H\ulcorner/SMC), to tackle the problem of the unmeasurable state variables as in the conventional SMC, to obtain smooth control as the linearized controller in a linear system, and to improve the time-domain performance under a worst scenario. The proposed controller is obtained by combining the H\ulcorner estimator with the nonlinear feedback linearization-sliding mode controller (NFL-SMC) and it does not need to measure all the state variables as in the traditional SMC. The proposed controller is applied as a nonlinear power system stabilizer (PSS) for the improvement of the power system damping characteristics of an single machine infinite bus system (SMIBS) connected through a double circuit line. The effectiveness of the proposed controller is verified by nonlinear time-domain simulation in case of a 3-cycle line-to-ground fault and in case of the parameter variations for the AVR gain K\ulcorner and for the inertia moment M.

  • PDF

Container Identifier Recognition System for GATE automation (GATE 자동화를 위한 컨테이너 식별자 인식 시스템)

  • 유영달;하성욱;강대성
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
    • /
    • 1998.10a
    • /
    • pp.137-141
    • /
    • 1998
  • Todays the efficient management of container has not been realized in container terminal, because of the excessive quantity of container transported and manual system. For the efficient and automated management of container in terminal, the automated container identifier recognition system in terminal is a significant problem. However, the identifier recognition rate is decreased owing to the difficulty of image preprocessing caused the refraction of container surface, the change of weather and the damaged identifier characters. Therefore, this paper proposes more accurate system for container identifier recognition as suggestion of Line-Scan Proper Region Detect for stronger preprocessing against external noisy element and Moment Back-Propagation Neural Network to recognize identifier.

  • PDF

Modal Analysis on SPL of the Periodic Structure depend on Unsymmetrical Beam Space (비대칭형 보강재 간격에 따른 주기구조물의 SPL모드 해석)

  • 김택현;김종태
    • Transactions of the Korean Society of Machine Tool Engineers
    • /
    • v.11 no.1
    • /
    • pp.52-60
    • /
    • 2002
  • The purpose of this research is to study the vibration and acoustic pressure radiation from a thin isotropic flat plate stiffened by a rectangular array of beams, and excited by a time harmonic point force. These constructions on aircraft and ship structures are often subjected to fiequency dependent pressure fluctuations and forces. Forces from the these excitations induce structural vibrations in a wide range of fiequencies, which may cause such things as acoustic fatigue and internal cabin noise in the aircraft. It is thus important that the response characteristics and vibration modes of such periodic structures be horn. From this theoretical model, the sound pressure levels(SPL) in a semi-infinite fluid(water) bounded by the plate with the variation in the locations of an external time harmonic point farce on the plate can be calculated efficiently using three numerical tools such as the Gauss-jordan method the LU decomposition method md the IMSL numerical package.

Active Vibration Control of a Plate Using the Distributed Modal Sensitivity (분포모달감도를 이용한 평판의 능동진동제어)

  • 송철기;박재상;이장무;황진권;최종호
    • Proceedings of the Korean Society of Precision Engineering Conference
    • /
    • 1995.04b
    • /
    • pp.320-325
    • /
    • 1995
  • This study deals with the active vibration control system for an all-clamped rectangular plate with piezoceramic actuators and sensors. A line nonent algorithm (LMA) with the distributed modal sensitivity(DMS) is proposed to reduce the structural vibrations effectively and to select the optimal locations and the optimal directions (skewed angles) of uniform piezoelectric actuators or sensors. Experimental results show that eachmode can attenuated byabout 10 .approx. 13 dB in case a piezoelectric actuator generate the psuedo-random disturbances that excite the plate modes.

  • PDF