• Title/Summary/Keyword: position prediction

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Predictive motion estimation algorithm using spatio-temporal correlation of motion vector (움직임 벡터의 시공간적인 상관성을 이용한 예측 움직임 추정 기법)

  • 김영춘;정원식;김중곤;이건일
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.33B no.6
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    • pp.64-72
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    • 1996
  • In this paper, we propose predictive motion estimatin algorithm which can predict motion without additional side information considering spatio-tempral correlatio of motion vector. This method performs motion prediction of current block using correlation of the motion vector for two spatially adjacent blocks and a temporally adjacent block. Form predicted motion, the position of searhc area is determined. Then in this searhc area, we estimate motion vector of current block using block matching algoirthm. Considering spatial an temporal correlation of motion vector, the proposed method can predict motion precisely much more. Especially when the motion of objects is rapid, this method can estimate motion more precisely without reducing block size or increasing search area. Futhrmore, the proposed method has computation time the same as conventional block matching algorithm. And as it predicts motion from adjacent blocks, it does not require additional side information for adjacent block. Computer simulation results show that motion estimation of proposed method is more precise than that of conventioanl method.

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Prediction of Ultimate Strength of Concrete Deep Beams with an Opening Using Strut-and-Tie Model (스트럿-타이 모델에 의한 개구부를 갖는 깊은 보의 극한강도 예측)

  • 지호석;송하원;변근주
    • Proceedings of the Korea Concrete Institute Conference
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    • 2001.05a
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    • pp.189-194
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    • 2001
  • In this study, ultimate strength of concrete deep beams with an opening is predicted by using Strut-and-Tie Model with a new effective compressive strength. First crack occurs around an opening by stress concentration due to geometric discontinuity. This results in decreasing ultimate strength of deep beams with an opening compared with general deep beams. With fundamental notion that ultimate strength of deep beam with an opening decreases as a result of reduction in effective compressive strength of a concrete strut, an equivalent effective compressive strength formula is proposed in order to reflect ultimate strength reduction due to an opening located in a concrete strut. An equivalent effective compressive strength formula which can reflect opening size and position is added to a testified algorithm of predicting ultimate strength of concrete deep beams. Therefore, ultimate strength of concrete deep beam with an opening is predicted by using a simple and rational STM algorithm including an equivalent effective compressive strength formula, not by finite element analysis or a former complex Strut-and-Tie Model

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Orbit Determination Accuracy Improvement for Geostationary Satellite with Single Station Antenna Tracking Data

  • Hwang, Yoo-La;Lee, Byoung-Sun;Kim, Hae-Yeon;Kim, Hae-Dong;Kim, Jae-Hoon
    • ETRI Journal
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    • v.30 no.6
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    • pp.774-782
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    • 2008
  • An operational orbit determination (OD) and prediction system for the geostationary Communication, Ocean, and Meteorological Satellite (COMS) mission requires accurate satellite positioning knowledge to accomplish image navigation registration on the ground. Ranging and tracking data from a single ground station is used for COMS OD in normal operation. However, the orbital longitude of the COMS is so close to that of satellite tracking sites that geometric singularity affects observability. A method to solve the azimuth bias of a single station in singularity is to periodically apply an estimated azimuth bias using the ranging and tracking data of two stations. Velocity increments of a wheel off-loading maneuver which is performed twice a day are fixed by planned values without considering maneuver efficiency during OD. Using only single-station data with the correction of the azimuth bias, OD can achieve three-sigma position accuracy on the order of 1.5 km root-sum-square.

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A Study on the Wear of Milling Tool and Relativity of Acoustic Emission in Cutting Process (절삭중 밀링공구의 마멸과 음향방출의 관련성에 관한 연구)

  • 윤종학;김동성
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.4 no.2
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    • pp.31-37
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    • 1995
  • This study is focused on the prediction of appropriate tool life by clarifying the correlation between progressive tool wear and AE signal. when rcutting SM45C by End mill in machining center. First of all, end mill have a problem that position of sensor sticking because it is revolution tool, but I think that it can be bained specific character according to sticking Sensor in the Vise. Consequently, the following results have been obtained; 1. Each cutting speed of feed rate over 0.1mm had a tendency to increase linearly according to the RMSAE 2. The level of AE signal at the same cutting area was more sensitive to depth of cut tharn the variation of feed rate 3. In the range of cutting duringqr about 75minqr atqr cutting speed 27m/min flankqr wear turns up aboutqr 0.21mm, aboutqr 0.29mm in the caseqr of about 65minqr at 33/min, qr hereby RMSAE increased rapidly at 0.2mm flank wear, also AE-HIT and CUM-CNTS.

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Error Prediction Considering the Measurement Direction in OMM System (OMM 시스템에서 측정방향을 고려한 가공물의 오차평가)

  • 최진필;이상조;권혁동
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2002.05a
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    • pp.632-635
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    • 2002
  • In this paper, a general procedure to determine machine tool errors from the on-machine measurement (OMM) data is described. First, a parameterized error model of a machine tool is illustrated by approximating error components as linear function of axis positions, and a modified error model is proposed which includes backlash effects. To determine the unknown model coefficient vectors of the forward and backward error model, an artifact with 8 cutes is made and calibrated on CMM. Then, lower-left and upper-right cube corners are measured with a touch-trigger probe mounted on the machine tool spindle. Measured error data are used to determine the coefficient vectors. The positioning errors in the XY plane at the fixed z position are simulated for the forward and backward error model.

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Prediction of Machine Tool's Energy Consumption during the Cutting Process (공작기계의 절삭공정 소비 에너지 예측기술)

  • Lee, Chan-Hong;Hwang, Jooho;Heo, Segon
    • Journal of the Korean Society for Precision Engineering
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    • v.32 no.4
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    • pp.329-337
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    • 2015
  • In this paper, a simulation based estimation method of energy consumption of the spindle and feed drives for the NC machine tool during the cutting process is proposed. To predict energy consumption of the feed drive system, position, velocity, acceleration and jerk of the table are analyzed based on NC data and then the power and energy are calculated considering friction force and mass of the stages. Energy consumption of the spindle is estimated based on models from acceleration motion of rotating parts, friction torque and power loss of motors. Moreover, simulation models of cutting power and energy for the material removal along the NC tool paths are proposed.

Prediction of Postoperative Pulmonary Function Following Thoracic Operations - Perfusion Lung Scanning Method - (폐관류스캔에 의한 폐절제술후 폐기능 예측)

  • Park, Guk-Yang;Yu, Hoe-Seong;Kim, Ju-Hyeon
    • Journal of Chest Surgery
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    • v.19 no.2
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    • pp.209-216
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    • 1986
  • The purpose of this study is to predict postoperative lung function by perfusion lung scanning method. 40 patients who underwent lobectomy or pneumonectomy between 1983-1985 were analyzed. Mean preoperative FEV1 was 2.36 L in lobectomy cases and 1.73 L in pneumonectomy cases. Preoperative and postoperative lung function were measured by routine spirometry in sitting position. Perfusion lung scanning was performed by 99mTc-MAA radioisotope. Postoperative FEV1 and VC were predicted by the formula; Postoperative FEV1 [VC]=Preoperative FEV1 [VC] x percent function of regions of lung not to be resected. In this study, I concluded that perfusion lung scanning is a simple and useful method to predict postoperative ventilatory function after pneumonectomy of lobectomy.

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Identifying the Location of a Mobile Object in Real-time using PID-controlled Moving Objects Spatio-Temporal Model

  • Zhi, Wang;Sung, Kil-Young;Lee, Kyou-Ho
    • Journal of information and communication convergence engineering
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    • v.9 no.5
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    • pp.545-550
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    • 2011
  • Trilateration is a typical method to locate an object, which requires inherently at least three prerecognized reference points. In some cases, owing to out of reachability to communication facilities the target node cannot be reachable always to three base stations. This paper presents a predictive method, which can identify the location of a moving target node in real time even though the target node could not get in touch with all three base stations. The method is based on the PIDcontrolled Moving Objects Spatio-Temporal Model Algorithm. Simulation results verify that this method can predict the moving direction of a moving target, and then combine with its past position information to judge accurately the location.

Numerical Evaluation of CO Gas Distribution in Underground Parking Lot (지하주차장 내부 일산화탄소 가스 분포의 전산 해석적 평가)

  • Kim Jae Won;Ham Kyoung-A
    • Journal of computational fluids engineering
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    • v.7 no.2
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    • pp.33-42
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    • 2002
  • Numerical estimation for concentration of mono-carbon oxygen (CO) gas inside an underground parking lot with auxiliary jet fans for enhancement of ventilation is carried out by using a commercial program. Main interest lies on the diagnosis of the present ventilation system including position and selection of auxiliarly fans in addition to main suppliers and exhausts. Details of both flows and concentration of CO gas that is most important component among car exhaust gases are illustrated in this investigation and those are presented for engineering construction of an underground parking pool. Prediction data of computational work is also validated by real measurements of concentration of CO gas.

Prediction of the Aerodynamic Characteristics of an Airship Hull (비행선 동체 공력 특성 예측)

  • Ok Honam
    • 한국전산유체공학회:학술대회논문집
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    • 2001.10a
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    • pp.76-83
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    • 2001
  • The incompressible Reynolds-averaged Navier-Stokes equations are solved to predict the aerodynamic characteristics of an airship hull. The concept of pseudo-compressibility is employed to couple the pressure field with the velocity field. The upwind differencing method for spatial discretization and a line relaxation scheme for time integration are used. The flowfield around the low drag airship hull of fineness ratio 4 is solved for two Reynolds numbers with a wide range of angle of attack. The effect of Reynolds number and transition position is briefly examined together with the change in aerodynamic coefficients due to a gondola attached to the hull, and the results will be used as basic data for the design of a low drag airship hull.

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