• Title/Summary/Keyword: Regularization

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A Study on Control system design for Automated Cultivation of product (농작물 재배 자동화를 위한 제어시스템 설계에 관한 연구)

  • Cho, Young Seok
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.10 no.1
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    • pp.55-60
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    • 2014
  • Today, there is increasing the elderly population in rural community, and people of returning from the urban to the rural community are demand to be of high value-added agriculture. In this time, there are required to regularization, standardization, automation, for getting of production of high value crops. In this paper, we are study for automation cultivation control system design for produce high-value crops. this system were designed of two parts that one part is measure and control unit, another part is server part for database and server side control. the main controller for measurement and control is used MC9S08AW60, server for Database and server-side control was using MySQL with CentOS. The source code of control program was coding C and compile with GCC. the functions of measurement and control unit are digital input and output each 8channels and can be scan-able of 20 Bit with 2CH/Sec. Analog Output were designed that can be output of 4-20mA or 0-5V on 4channel. The Digital input and output part were designed 8-channel, and using the high speed photo coupler and relays. We showed that system is possible to measure a 20bit data width, 2Ch/sec as 8 channel analog signals.

Probabilistic penalized principal component analysis

  • Park, Chongsun;Wang, Morgan C.;Mo, Eun Bi
    • Communications for Statistical Applications and Methods
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    • v.24 no.2
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    • pp.143-154
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    • 2017
  • A variable selection method based on probabilistic principal component analysis (PCA) using penalized likelihood method is proposed. The proposed method is a two-step variable reduction method. The first step is based on the probabilistic principal component idea to identify principle components. The penalty function is used to identify important variables in each component. We then build a model on the original data space instead of building on the rotated data space through latent variables (principal components) because the proposed method achieves the goal of dimension reduction through identifying important observed variables. Consequently, the proposed method is of more practical use. The proposed estimators perform as the oracle procedure and are root-n consistent with a proper choice of regularization parameters. The proposed method can be successfully applied to high-dimensional PCA problems with a relatively large portion of irrelevant variables included in the data set. It is straightforward to extend our likelihood method in handling problems with missing observations using EM algorithms. Further, it could be effectively applied in cases where some data vectors exhibit one or more missing values at random.

Regularized iterative image resotoration by using method of conjugate gradient with constrain (구속 조건을 사용한 공액 경사법에 의한 정칙화 반복 복원 처리)

  • 김승묵;홍성용;이태홍
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.22 no.9
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    • pp.1985-1997
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    • 1997
  • This paper proposed a regularized iterative image restoration by using method of conjugate gradient. Compared with conventional iterative methods, method of conjugate gradient has a merit to converte toward a solution as a super-linear convergence speed. But because of those properties, there are several artifacts like ringing effects and the partial magnification of the noise in the course of restoring the images that are degraded by a defocusing blur and additive noise. So, we proposed the regularized method of conjugate gradient applying constraints. By applying the projectiong constraint and regularization parameter into that method, it is possible to suppress the magnification of the additive noise. As a experimental results, we showed the superior convergence ratio of the proposed mehtod compared with conventional iterative regularized methods.

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Spatially Adaptive CLS Based Image Restoration (CLS 기반 공간 적응적 영상복원)

  • 백준기;문준일;김상구
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.21 no.10
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    • pp.2541-2551
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    • 1996
  • Human visual systems are sensitive to noise on the flat intensity area. But it becomes less sensitive on the edge area. Recently, many types of spatially adaptive image restoration methods have been proposed, which employ the above mentioned huan visual characteristics. The present paper presents an adaptive image restoration method, which increases sharpness of the edge region, and smooths noise on the flat intensity area. For edge detection, the proposed method uses the visibility function based on the local variance on each pixel. And it adaptively changes the regularization parameter. More specifically, the image to be restored is divided into a number of steps from the flat area to the edge regio, and then restored by using the finite impulse response constrained least squares filter.

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A FRF-based algorithm for damage detection using experimentally collected data

  • Garcia-Palencia, Antonio;Santini-Bell, Erin;Gul, Mustafa;Catbas, Necati
    • Structural Monitoring and Maintenance
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    • v.2 no.4
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    • pp.399-418
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    • 2015
  • Automated damage detection through Structural Health Monitoring (SHM) techniques has become an active area of research in the bridge engineering community but widespread implementation on in-service infrastructure still presents some challenges. In the meantime, visual inspection remains as the most common method for condition assessment even though collected information is highly subjective and certain types of damage can be overlooked by the inspector. In this article, a Frequency Response Functions-based model updating algorithm is evaluated using experimentally collected data from the University of Central Florida (UCF)-Benchmark Structure. A protocol for measurement selection and a regularization technique are presented in this work in order to provide the most well-conditioned model updating scenario for the target structure. The proposed technique is composed of two main stages. First, the initial finite element model (FEM) is calibrated through model updating so that it captures the dynamic signature of the UCF Benchmark Structure in its healthy condition. Second, based upon collected data from the damaged condition, the updating process is repeated on the baseline (healthy) FEM. The difference between the updated parameters from subsequent stages revealed both location and extent of damage in a "blind" scenario, without any previous information about type and location of damage.

Improved Kalman filter with unknown inputs based on data fusion of partial acceleration and displacement measurements

  • Liu, Lijun;Zhu, Jiajia;Su, Ying;Lei, Ying
    • Smart Structures and Systems
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    • v.17 no.6
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    • pp.903-915
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    • 2016
  • The classical Kalman filter (KF) provides a practical and efficient state estimation approach for structural identification and vibration control. However, the classical KF approach is applicable only when external inputs are assumed known. Over the years, some approaches based on Kalman filter with unknown inputs (KF-UI) have been presented. However, these approaches based solely on acceleration measurements are inherently unstable which leads poor tracking and so-called drifts in the estimated unknown inputs and structural displacement in the presence of measurement noises. Either on-line regularization schemes or post signal processing is required to treat the drifts in the identification results, which prohibits the real-time identification of joint structural state and unknown inputs. In this paper, it is aimed to extend the classical KF approach to circumvent the above limitation for real time joint estimation of structural states and the unknown inputs. Based on the scheme of the classical KF, analytical recursive solutions of an improved Kalman filter with unknown excitations (KF-UI) are derived and presented. Moreover, data fusion of partially measured displacement and acceleration responses is used to prevent in real time the so-called drifts in the estimated structural state vector and unknown external inputs. The effectiveness and performance of the proposed approach are demonstrated by some numerical examples.

Simultaneous identification of moving loads and structural damage by adjoint variable

  • Abbasnia, Reza;Mirzaee, Akbar;Shayanfar, Mohsenali
    • Structural Engineering and Mechanics
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    • v.56 no.5
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    • pp.871-897
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    • 2015
  • This paper presents a novel method based on sensitivity of structural response for identifying both the system parameters and input excitation force of a bridge. This method, referred to as "Adjoint Variable Method", is a sensitivity-based finite element model updating method. The computational cost of sensitivity analyses is the main concern associated with damage detection by these methods. The main advantage of proposed method is inclusion of an analytical method to augment the accuracy and speed of the solution. The reliable performance of the method to precisely indentify the location and intensity of all types of predetermined single, multiple and random damages over the whole domain of moving vehicle speed is shown. A comparison study is also carried out to demonstrate the relative effectiveness and upgraded performance of the proposed method in comparison to the similar ordinary sensitivity analysis methods. Moreover, various sources of error including the effects of noise and primary errors on the numerical stability of the proposed method are discussed.

Concrete fragmentation modeling using coupled finite element - meshfree formulations

  • Wu, Youcai;Choi, Hyung-Jin;Crawford, John E.
    • Interaction and multiscale mechanics
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    • v.6 no.2
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    • pp.173-195
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    • 2013
  • Meshfree methods are known to have the capability to overcome the strict regularization requirements and numerical instabilities that encumber the finite element method (FEM) in large deformation problems. They are also more naturally suited for problems involving material perforation and fragmentation. To take advantage of the high efficiency of FEM and high accuracy of meshfree methods, a coupled finite element (FE) and reproducing kernel (RK, one of the meshfree approximations) formulation is described in this paper. The coupling of FE and RK approximation is implemented in an evolutionary fashion, where the extent and location of the evolution is dependent on a triggering criteria provided by the material constitutive laws. To enhance computational efficiency, Gauss quadrature is applied to integrate both FE and RK domains so that no state variable transfer is required when mesh conversion is performed. To control the hourglassing that might occur with 1-point integrated hexahedral grids, viscous type hourglass control is implemented. Meanwhile, the FEM version of the K&C concrete (KCC) model was modified to make it applicable in both FE and RK formulations. Results using this code and the KCC model are shown for the modeling of concrete responses under quasi-static, blast and impact loadings. These analyses demonstrate that fragmentation phenomena of the sort commonly observed under blast and impact loadings of concrete structures was able to be realistically captured by the coupled formulation.

Support Vector Machine Algorithm for Imbalanced Data Learning (불균형 데이터 학습을 위한 지지벡터기계 알고리즘)

  • Kim, Kwang-Seong;Hwang, Doo-Sung
    • Journal of the Korea Society of Computer and Information
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    • v.15 no.7
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    • pp.11-17
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    • 2010
  • This paper proposes an improved SMO solving a quadratic optmization problem for class imbalanced learning. The SMO algorithm is aproporiate for solving the optimization problem of a support vector machine that assigns the different regularization values to the two classes, and the prosoposed SMO learning algorithm iterates the learning steps to find the current optimal solutions of only two Lagrange variables selected per class. The proposed algorithm is tested with the UCI benchmarking problems and compared to the experimental results of the SMO algorithm with the g-mean measure that considers class imbalanced distribution for gerneralization performance. In comparison to the SMO algorithm, the proposed algorithm is effective to improve the prediction rate of the minority class data and could shorthen the training time.

Weighted Edge Adaptive POCS Demosaicking Algorithm (Edge 가중치를 이용한 적응적인 POCS Demosaicking 알고리즘)

  • Park, Jong-Soo;Lee, Seong-Won
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.45 no.3
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    • pp.46-54
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    • 2008
  • Most commercial CCD/CMOS image sensors have CFA(Color Filter Array) where each pixel gathers light of a selective color to reduce the sensor size and cost. There are many algorithms proposed to reconstruct the original clolr image by adopting pettern recognition of regularization methods to name a few. However the resulting image still suffer from errors such as flase color, zipper effect. In this paper we propose an adaptive edge weight demosaicking algorithm that is based on POCS(Projection Onto Convex Sets) not only to improve the entire image's PSNR but also to reduce the edge region's errors that affect subjective image quality. As a result, the proposed algorithm reconstruct better quality images especially at the edge region.