• Title/Summary/Keyword: Least-square method

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More Efficient Method for Determination of Match Quality in Adaptive Least Square Matching Algorithms

  • Lee, Hae-Yeoun;Kim, Tae-Jung;Lee, Heung-Kyu
    • Proceedings of the KSRS Conference
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    • 1998.09a
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    • pp.274-279
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    • 1998
  • For the accurate generation of DEMs, the determination of match quality in adaptive least square matching algorithm is significantly important. Traditionally, only the degree of convergence of a solution matrix in least squares estimation has been considered for the determination of match quality. It is, however, not enough to determine the true match quality. This paper reports two approaches of match quality determination based on adaptive least square correlation : the conventional if-then logic approaches with scene geometry and correlation as additional quality measures; and, the fuzzy logic approaches. Through these, accurate decision of match quality will minimize the number of blunder and maximize the number of exact match. The proposed methods have been tested on JERS and SPOT images and the results show good performance.

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Comparison of Active Sonar Target Positioning Performance and Optimal Sensor Arrangement (능동 소나 위치 추정 성능 비교 및 최적 수신망 배치)

  • 박치현;홍우영;고한석;김인익
    • The Journal of the Acoustical Society of Korea
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    • v.22 no.3
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    • pp.224-232
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    • 2003
  • In this paper, efficient deployment method of sensors and target positioning performance with respect to measurement error are dealt with. Active sonar can be categorized into Monostatic, Bistatic, Multistatic sonar, and characteristics of respective sonar are different. Assuming that each sensor can receive range and angular information, we compare the performance of Monostatic, Bistatic, and Multistatic systems. And we suggest Weighted least square (WLS) which gives the weight to former case, LS. In particular. adopting suggested method we investigate the target positioning performance according to number of sensor, distance from transmitter to receiver, and propose efficient arrangement rule for Multistatic sonar configurations. According to the experimental results, RMSE of Multistatic sonar is found to be superior to Monostatic and Bistatic by 35.98%. 37.45% respectively, and WLS is superior to LS approximately by 7.4% in average. Furthermore, as the difference of respective sensor's variance is large, it is observed that the improvement ratio of target positioning performance is increased.

Motion Adaptive Temporal Noise Reduction Filtering Based on Iterative Least-Square Training (반복적 최적 자승 학습에 기반을 둔 움직임 적응적 시간영역 잡음 제거 필터링)

  • Kim, Sung-Deuk;Lim, Kyoung-Won
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.47 no.5
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    • pp.127-135
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    • 2010
  • In motion adaptive temporal noise reduction filtering used for reducing video noises, the strength of motion adaptive temporal filtering should be carefully controlled according to temporal movement. This paper presents a motion adaptive temporal filtering scheme based on least-square training. Each pixel is classified to a specific class code according to temporal movement, and then, an iterative least-square training method is applied for each class code to find optimal filtering coefficients. The iterative least-square training is an off-line procedure, and the trained filter coefficients are stored in a lookup table (LUT). In actual noise reduction filtering operation, after each pixel is classified by temporal movement, simple filtering operation is applied with the filter coefficients stored in the LUT according to the class code. Experiment results show that the proposed method efficiently reduces video noises without introducing blurring.

On-line Compensation Method for Magnetic Position Sensor using Recursive Least Square Method (재귀형 최소 자승법을 이용한 자기 위치 센서의 실시간 보상 방법)

  • Kim, Ji-Won;Moon, Seok-Hwan;Lee, Ji-Young;Chang, Jung-Hwan;Kim, Jang-Mok
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.60 no.12
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    • pp.2246-2253
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    • 2011
  • This paper presents the error correction method of magnetic position sensor using recursive least square method (RLSM) with forgetting factor. Magnetic position sensor is proposed for linear position detection of the linear motor which has tooth shape stator, consists of permanent magnet, iron core and linear hall sensor, and generates sine and cosine waveforms according to the movement of the mover of the linear motor. From the output of magnetic position sensor, the position of the linear motor can be detected using arc-tan function. But the variation of the air gap between magnetic position sensor and the stator and the error in manufacturing process can cause the variation in offset, phase and amplitude of the generated waveforms when the linear motor moves. These variations in sine and cosine waveforms are changed according to the current linear motor position, and it is very difficult to compensate the errors using constant value. In this paper, the generated sine and cosine waveforms from the magnetic position sensor are compensated on-line using the RLSM with forgetting factor. And the speed observer is introduced to reduce the effect of uncompensated harmonic component. The approaches are verified by some simulations and experiments.

Non-uniform Weighted Vibration Target Positioning Algorithm Based on Sensor Reliability

  • Yanli Chu;Yuyao He;Junfeng Chen;Qiwu Wu
    • Journal of Information Processing Systems
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    • v.19 no.4
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    • pp.527-539
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    • 2023
  • In the positioning algorithm of two-dimensional planar sensor array, the estimation error of time difference-ofarrival (TDOA) algorithm is difficult to avoid. Thus, how to achieve accurate positioning is a key problem of the positioning technology based on planar array. In this paper, a method of sensor reliability discrimination is proposed, which is the foundation for selecting positioning sensors with small error and excellent performance, simplifying algorithm, and improving positioning accuracy. Then, a positioning model is established. The estimation characteristics of the least square method are fully utilized to calculate and fuse the positioning results, and the non-uniform weighting method is used to correct the weighting factors. It effectively handles the decreased positioning accuracy due to measurement errors, and ensures that the algorithm performance is improved significantly. Finally, the characteristics of the improved algorithm are compared with those of other algorithms. The experiment data demonstrate that the algorithm is better than the standard least square method and can improve the positioning accuracy effectively, which is suitable for vibration detection with large noise interference.

A Least Squares Iterative Method For Solving Nonlinear Programming Problems With Equality Constraints

  • Sok Yong U.
    • Journal of the military operations research society of Korea
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    • v.13 no.1
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    • pp.91-100
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    • 1987
  • This paper deals with an algorithm for solving nonlinear programming problems with equality constraints. Nonlinear programming problems are transformed into a square sums of nonlinear functions by the Lagrangian multiplier method. And an iteration method minimizing this square sums is suggested and then an algorithm is proposed. Also theoretical basis of the algorithm is presented.

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A Study on Measurement of Blood Pressure by Partial Least Square Method (부분최소자승법을 이용한 혈압 측정에 관한 연구)

  • Kim, Yong-Joo;Nam, Eun-Hye;Choi, Chang-Hyun;Kim, Jong-Deok
    • Journal of Biosystems Engineering
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    • v.33 no.6
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    • pp.438-445
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    • 2008
  • The purpose of this study was to develop a measurement model based on PLS (Partial least square) method for blood pressures. Measurement system for blood pressure signals consisted of pressure sensor, va interface and embedded module. A mercury sphygmomanometer was connected with the measurement system through 3-way stopcock and used as reference of blood pressures. The blood pressure signals of 20 subjects were measured and tests were repeated 5 times per each subject. Total of 100 data were divided into a calibration set and a prediction set. The PLS models were developed to determine the systolic and the diastolic blood pressures. The PLS models were evaluated by the standard methods of the British Hypertension Society (BHS) protocol and the American Association for the Advancement of Medical Instrumentation (AAMI). The results of the PLS models were compared with those of MAA (maximum amplitude algorithm). The measured blood pressures with PLS method were highly correlated to those with a mercury sphygmomanometer in the systolic ($R^2=0.85$) and the diastolic blood pressure ($R^2=0.84$). The results showed that the PLS models were the effective tools for blood pressure measurements with high accuracy, and satisfied the standards of the BHS protocol and the AAMI.

The Detection of Ellipse by Using Modified Least Square Method in Image (영상에서 변형된 최소자승법을 이용한 타원 검출)

  • Jang, Yung-Chul;Oh, Moo-Song
    • The Transactions of the Korea Information Processing Society
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    • v.4 no.12
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    • pp.3200-3210
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    • 1997
  • In image processing we encounter some tasks to detect ellipse or to discriminate the curves. LSM is well used to fit curves to ellipse but it can fail to fit correctly when fitting to defected one. To overcome this problem, we propose Modified LSM. Only 2-parameters among 5-paramaters are to be determined by LSM, while 3-parameters are to be calculated by the constrain that the curve must pass 3 given points. Those 3 points are selected by operator so as to have elliptic feature. Such proposed MLSM shows better result than genunal LSM in case when the ellipse is severely defected. and is proved to be good method for determing the human dentition.

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A Compensated Current Acqaisition Device for CT Saturation (왜곡 전류 보상형 전류 취득 장치)

  • Ryu, Ki-Chan;Gang, Soo-Young;Kang, Sang-Hee
    • Proceedings of the KIEE Conference
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    • 2005.07a
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    • pp.96-98
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    • 2005
  • In this paper, an algorithm to compensate the distorted signals due to Current Transformer(CT) saturation is suggested, First, DWT which can be easily realized by filter banks in real-time applications is used to detect a start point and an end point of the saturation. Secondly, For enough Datas those need to use the least-square curve fitting method, the distorted current signal is compensated by the AR(autoregressive) model using the data during the previous healthy section until pick point of Saturation. Thirdly, the least-square curve fitting method is used to restore the distorted section of the secondary current. Finaly, this algorithm had a Hadware test using DSP board(TMS320C32) with Doble test device. DWT has superior detection accuracy and the proposed compensation algorithm which shows very stable features under various levels of remanent flux in the CT core is also satisfactory. And this algorithm is more correct than a previous algorithm which is only using the LSQ fitting method. Also it can be used as a MU involving the compensation function that acquires the second data from CT and PT.

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A Study on the 3D Representation of 2D Projection Data using Epipolar Geometry (Epipolar 기하학을 이용한 2차원 투영 데이터의 3차원 표현에 관한 연구)

  • Yu, Seon-Guk;Wang, Ge;Kim, Nam-Hyeon;Kim,Yong-Uk;Kim, Hui-Jung
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.51 no.5
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    • pp.212-219
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    • 2002
  • In this paper, the epipolar geometry, genera17y used as a pin-hole camera model, is newly adapted to our proposed method that enables the affine reconstruction of the 3D object from two projected views. The proposed method models the projective projection of inherent X-ray imaging system, obviates the need to attach artifirially constructed material on the body, and requires none of the prior-knowledge regarding to intrinsic and extrinsic parameters of two X-ray imaging systems. The optimum numerical solution is obtained by applying the least mean square estimator to corresponding points on two projected X-ray planes. The performance of this proposed method is Quantitatively analyzed using computer synthesized model of Cochlear implantation electrodes. In simulated experiments, the propnsed method is insensitive to the added random noise, the scaling factor change, the center point change, and rotational angular change between two projection planes, as well as enables the stable 3D reconstruction in least square sense even in worst testing cases.