• Title/Summary/Keyword: direct updating method

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Calibration transfer between miniature NIR spectrometers used in the assessment of intact peach and melon soluble solids content

  • Greensill, Colin.V.;Walsh, Kerry.B.
    • Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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    • 2001.06a
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    • pp.1127-1127
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    • 2001
  • The transfer of predictive models using various chemometric techniques has been reported for FTNIR and scanning-grating based NIR instruments with respect relatively dry samples (<10% water). Some of the currently used transfer techniques include slope and bias correction (SBC), direct standardization (DS), piecewise direct standardization (PDS), orthogonal signal correction (OSC), finite impulse transform (FIR) and wavelet transform (WT) and application of neural networks. In a previous study (Greensill et at., 2001) on calibration transfer for wet samples (intact melons) across silicon diode array instrumentation, we reported on the performance of various techniques (SBC, DS, PDS, double window PDS (DWPDS), OSC, FIR, WT, a simple photometric response correction and wavelength interpolative method and a model updating method) in terms of RMSEP and Fearns criterion for comparison of RMSEP. In the current study, we compare these melon transfer results to a similar study employing pairs of spectrometers for non-invasive prediction of soluble solid content of peaches.

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Comparative Performance Study of Various Algorithms Computing the Closest Voltage Collapse Point (최단 전압붕괴 임계점을 계산하는 알고리즘의 특성 비교)

  • Song, Chung-Gi;Nam, Hae-Kon
    • Proceedings of the KIEE Conference
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    • 1997.07c
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    • pp.1078-1082
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    • 1997
  • The distance in load parameter space to the closest voltage collapse point provides the worst case power margin and the left eigenvector identifies the most effective direction to steer the system to maximize voltage stability under contingency. This paper presents the results of the comparative performance study of the algorithms, which are applicable to a large scale power system, for computing the closest saddle node bifurcation (CSNB) point. Dobson's iterative method converges with robustness. However the slow process of updating the load increasing direction makes the algorithm less efficient. The direct method converges very quickly. But it diverges if the initial guess is not very close to CSNB. Zeng's method of estimating the approximate critical point in the pre-determined direction is attractive in the sense that it uses only using load flow equations. However, the method is found to be less efficient than Dobson's iterative method. It may be concluded from the above observation that the direct method with the initial values obtained by carrying out the iterative method twice is most efficient at this time and more efficient algorithms are needed for on-line application.

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A study of building DB for BTO system (주문 적응형 생산시스템의 DB 구성 방안에 관한 연구)

  • 임기수;박경호
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2002.10a
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    • pp.89-92
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    • 2002
  • As the use of Internet being generalized, ordering system can be easily achieved on the Web so that the direct sailing system is replaced the various types of Built-To-Order system. It is important to give the up-to-date information to the end-user in order to build the Built-To-Order system. Recently, the way of providing information is updating the product related information continuously. In this study, we provide the method that can be streamlined Product Data Management System which manages a creation and update for product information into the direct BTO system in order to achieve the newest information. This methodology is not only transferring the information but also processing the information in an appropriate form. So this paper is going to cover the various point of view of information processing.

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An iterative method for damage identification of skeletal structures utilizing biconjugate gradient method and reduction of search space

  • Sotoudehnia, Ebrahim;Shahabian, Farzad;Sani, Ahmad Aftabi
    • Smart Structures and Systems
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    • v.23 no.1
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    • pp.45-60
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    • 2019
  • This paper is devoted to proposing a new approach for damage detection of structures. In this technique, the biconjugate gradient method (BCG) is employed. To remedy the noise effects, a new preconditioning algorithm is applied. The proposed preconditioner matrix significantly reduces the condition number of the system. Moreover, based on the characteristics of the damage vector, a new direct search algorithm is employed to increase the efficiency of the suggested damage detection scheme by reducing the number of unknowns. To corroborate the high efficiency and capability of the presented strategy, it is applied for estimating the severity and location of damage in the well-known 31-member and 52-member trusses. For damage detection of these trusses, the time history responses are measured by a limited number of sensors. The results of numerical examples reveal high accuracy and robustness of the proposed method.

Indoor Semantic Data Dection and Indoor Spatial Data Update through Artificial Intelligence and Augmented Reality Technology

  • Kwon, Sun
    • International conference on construction engineering and project management
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    • 2022.06a
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    • pp.1170-1178
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    • 2022
  • Indoor POI data, an essential component of indoor spatial data, has attribute information of a specific place in the room and is the most critical information necessary for the user. Currently, indoor POI data is manually updated by direct investigation, which is expensive and time-consuming. Recently, research on updating POI using the attribute information of indoor photographs has been advanced to overcome these problems. However, the range of use, such as using only photographs with text information, is limited. Therefore, in this study, and to improvement this, I proposed a new method to update indoor POI data using a smartphone camera. In the proposed method, the POI name is obtained by classifying the indoor scene's photograph into artificial intelligence technology CNN and matching the location criteria to indoor spatial data through AR technology. As a result of creating and experimenting with a prototype application to evaluate the proposed method, it was possible to update POI data that reflects the real world with high accuracy. Therefore, the results of this study can be used as a complement or substitute for the existing methodologies that have been advanced mainly by direct research.

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An Adaptive Partial Response Equalizer Using Branch Metrics of Viterbi Trellis for Optical Recording Systems (고밀도 광 기록 장치에서 비터비 트렐리스의 가지 메트릭을 이용한 부분 응답 적응 등화기)

  • Lee, Kyu-Suk;Lee, Joo-Hyun;Lee, Jae-Jin
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.30 no.9C
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    • pp.871-876
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    • 2005
  • In this paper, we propose an improved partial response maximum likelihood (PRML) detection scheme that has an adaptive equalizer and can be applied in the asymmetric optical recording system with high-density. We confirmed that the proposed PRML detector improves detection performance. In addition, we implemented the detector by Verilog HDL. The adaptive equalizer is composed of tap coefficient updating unit using LMS algorithn and FIR filter. FIR filter is implemented by the transposed direct form architecture for high speed operation. Viterbi detector is implemented by the register exchange method.

Running Inverse for Implementing Decorrelating Detectors in Synchronous DS/CDMA Systems

  • Joo, Jung-Suk;Lee, Yong-Hoon
    • Journal of IKEEE
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    • v.2 no.2 s.3
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    • pp.294-298
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    • 1998
  • We propose an efficient method for updating the inverse of the signature waveform cross-correlations (SWC) matrix when the number of users in the synchronous direct-sequence code-division multiple-access (DS/CDMA) system changes. It is shown that the computational complexity of the proposed method is $O(n^2)$ in which n represents the number of active users in the system.

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Damage detection of plate-like structures using intelligent surrogate model

  • Torkzadeh, Peyman;Fathnejat, Hamed;Ghiasi, Ramin
    • Smart Structures and Systems
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    • v.18 no.6
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    • pp.1233-1250
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    • 2016
  • Cracks in plate-like structures are some of the main reasons for destruction of the entire structure. In this study, a novel two-stage methodology is proposed for damage detection of flexural plates using an optimized artificial neural network. In the first stage, location of damages in plates is investigated using curvature-moment and curvature-moment derivative concepts. After detecting the damaged areas, the equations for damage severity detection are solved via Bat Algorithm (BA). In the second stage, in order to efficiently reduce the computational cost of model updating during the optimization process of damage severity detection, multiple damage location assurance criterion index based on the frequency change vector of structures are evaluated using properly trained cascade feed-forward neural network (CFNN) as a surrogate model. In order to achieve the most generalized neural network as a surrogate model, its structure is optimized using binary version of BA. To validate this proposed solution method, two examples are presented. The results indicate that after determining the damage location based on curvature-moment derivative concept, the proposed solution method for damage severity detection leads to significant reduction of computational time compared with direct finite element method. Furthermore, integrating BA with the efficient approximation mechanism of finite element model, maintains the acceptable accuracy of damage severity detection.

Compensatory cylindricity control of the C.N.C. turing process (컴퓨터 수치제어 선반에서의 진원통도 보상제어)

  • 강민식;이종원
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.12 no.4
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    • pp.694-704
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    • 1988
  • A recursive parameter estimation scheme utilizing the variance perturbation method is applied to the workpiece deflection model during CNC turning process, in order to improve the cylindricity of slender workpiece. It features that it is based on exponentially weighted recursive least squares method with post-process measurement of finish surfaces at two locations and it does not require a priori knowledge on the time varying deflection model parameter. The measurements of finish surfaces by using two proximity sensors mounted face to face enable one to identify the straightness, guide-way, run-out eccentricity errors. Preliminary cutting tests show that the straightness error of the finish surface due to workpiece deflection during cutting is most dominant. Identifying the errors and recursive updating the parameter, the off-line control is carried out to compensate the workpiece deflection error, through single pass cutting. Experimental results show that the proposed method is superior to the conventional multi-pass cutting and the direct compensation control in cutting accuracy and efficiency.

A Study on Interference Cancelling Receiver with Adaptive Blind CMA Array (적응 블라인드 CMA 어레이를 이용한 간섭 제거 수신기에 관한 연구)

  • 우대호;변윤식
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.27 no.4A
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    • pp.330-335
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    • 2002
  • In the direct sequence code division multiple access system, the problem of multiple access interference due to multiple access is generated. A interference cancelling receiver is used to solve this problem. The conventional interference cancelling receiver is structure of successive interference canceller using antenna array. In this structure, the difference of between method I and method II depends on updating weight vector. In this paper, the adaptive blind CMA array interference cancelling receiver using cost function of constant modulus algorithms is proposed to update weight vector at conventional structure. The simulation compared the proposed interference cancelling receiver with two conventional interference cancelling receivers by signal to interference ratio and bit error rate curve under additive white Gaussian noise environment. The simulation results show that the proposed receiver has about the gain of SIR of 1.5[dB] more than method I which is conventional receiver at SIR curve, and about the gain of SIR of 0.5(dB) more than method II. In BER curve, the proposed IC receiver about the gain of SNR of 2[dB] more than method I and about the gain of SNR of 0.5[dB] more than method If, Thus, the proposed interference cancelling receiver has the higher performance than conventional interference cancelling receivers.