• Title/Summary/Keyword: Weight Function Method

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Scene-based Nonuniformity Correction for Neural Network Complemented by Reducing Lense Vignetting Effect and Adaptive Learning rate

  • No, Gun-hyo;Hong, Yong-hee;Park, Jin-ho;Jhee, Ho-jin
    • Journal of the Korea Society of Computer and Information
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    • v.23 no.7
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    • pp.81-90
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    • 2018
  • In this paper, reducing lense Vignetting effect and adaptive learning rate method are proposed to complement Scribner's neural network for nuc algorithm which is the effective algorithm in statistic SBNUC algorithm. Proposed reducing vignetting effect method is updated weight and bias each differently using different cost function. Proposed adaptive learning rate for updating weight and bias is using sobel edge detection method, which has good result for boundary condition of image. The ordinary statistic SBNUC algorithm has problem to compensate lense vignetting effect, because statistic algorithm is updated weight and bias by using gradient descent method, so it should not be effective for global weight problem same like, lense vignetting effect. We employ the proposed methods to Scribner's neural network method(NNM) and Torres's reducing ghosting correction for neural network nuc algorithm(improved NNM), and apply it to real-infrared detector image stream. The result of proposed algorithm shows that it has 10dB higher PSNR and 1.5 times faster convergence speed then the improved NNM Algorithm.

Optimum Structural Design of D/H Tankers by using Pareto Optimal based Multi-objective function Method (Pareto 최적점 기반 다목적함수 기법에 의한 이중선각유조선의 최적 구조설계)

  • Na, Seung-Soo;Yum, Jae-Seon;Han, Sang-Min
    • Journal of the Society of Naval Architects of Korea
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    • v.42 no.3
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    • pp.284-289
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    • 2005
  • A structural design system is developed for the optimum design of double hull tankers based on the multi-objective function method. As a multi-objective function method, Pareto optimal based random search method is adopted to find the minimum structural weight and fabrication cost. The fabrication cost model is developed by considering the welding technique, welding poses and assembly stages to manage the fabrication man-hour and process. In this study, a new structural design is investigated due to the rapidly increased material cost. Several optimum structural designs on the basis of high material cost are carried out based on the Pareto optimal set obtained by the random search method. The design results are compared with existing ship, which is designed under low material cost.

Successful Removal of 15-year-old Pacemaker Leads by Weight and pulley method

  • Kim, Hyun-Woo;Shin, Ho-Cheol;Jin, Han-Young;Seo, Jeong-Sook;Jang, Jae-Sik;Yang, Tae-Hyun;Kim, Dae-Kyeong;Kim, Dong-Soo
    • Kosin Medical Journal
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    • v.33 no.3
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    • pp.396-401
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    • 2018
  • Extraction of old pacemaker leads remains a complex procedure owing to fibrotic encapsulation and lead adhesions. We report a case of extraction of 15-year-old pacemaker leads by weight and pulley method. A 81-year-old man presented with exposed pacemaker leads out of body with purulent discharge from a pacemaker insertion site. He inserted DDD (dual chamber pacing, dual chamber sensing dual function) pacemaker implantation 15 years ago for SSS. Previously pacemaker battery was removed 3 years ago due to recurrent infection of pacemaker scar site. We extracted the pacemaker leads by weight and pulley method successfully without any complications.

Topology Optimization of the Primary Mirror of a Multi-Spectral Camera (인공위성 카메라 주반사경의 위상최적화)

  • Park, Kang-Soo;Chang, Su-Young;Lee, Eung-Shik;Youn, Sung-Kie
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.26 no.6
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    • pp.1194-1202
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    • 2002
  • A study on the topology optimization of a multi-spectral camera for space-use is presented. The optimization is carried out under self-weight and polishing pressure loading. A multi-spectral camera for space-use experiences degradation of optical image in the space, which can not be detected on the optical test bench on the earth. An optical surface deformation of a primary mirror, which is a principal component of the camera system, is an important factor affecting the optical performance of the whole camera system. In this study, topology optimization of the primary mirror of the camera is presented. As an objective function, a measure of Strehl ratio is used. Total mass of the primary mirror is given as a constraint to the optimization problem. The sensitivities of the objective function and constraint are calculated by direct differentiation method. Optimization procedure is carried out by an optimality criteria method. For the light-weight primary mirror design, a three dimensional model is treated. As a preliminary example, topology optimization considering a self-weight loading is treated. In the second example, the polishing pressure is also included as a loading in the topology optimization of the mirror. Results of the optimized design topology for the mirror with various mass constraints are presented.

Numerical modeling of concrete conveying capacity of screw conveyor based on DEM

  • Yu, Wenda;Zhang, Ke;Li, Dong;Zou, Defang;Zhang, Shiying
    • Computers and Concrete
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    • v.29 no.6
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    • pp.361-374
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    • 2022
  • On the premise of ensuring that the automatic and quantitative discharging function of concrete conveyors is met, the accuracy of the weight forecast by the mathematical model of the screw conveying volume is improved, and the error of the weight of the concrete parts and the accumulation thickness is reduced. In this paper, the discrete element method (DEM) is used to simulate the macroscopic flow of concrete. Using the concrete discrete element model, the size of the screw conveyor is set, and establish the response model between the influencing factors (process and structure) and the concrete mass flow rate according to the design points of the screw discharging experiment. The nonlinear data fitting method is used to obtain the volumetric efficiency function under the influence of process and structural factors, and the traditional screw conveying volume model is improved. The mass flow rate of concrete predicted by the improved mathematical model of screw conveying volume is consistent with the test results. The model can accurately describe the conveying process of concrete and achieve the purpose of improving the accuracy of forecasting the weight of discharged concrete.

Ranking Decision on Assessment Indicator of Natural Resource Conservation Area Using Fuzzy Theory - Focused on Site Selection for the National Trust - (퍼지이론을 이용한 자연자원 보전지역의 평가지표 순위 결정 - 내셔널 트러스트 후보지 선정을 중심으로 -)

  • You Ju-Han;Jung Sung-Gwan;Park Kyung-Hun;Oh Jeong-Hak
    • Journal of the Korean Institute of Landscape Architecture
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    • v.33 no.4 s.111
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    • pp.97-107
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    • 2005
  • This study was carried out to construct accurate and scientific system of assessment indicators in selection of National Trust conservation areas, which was new concept of domestic environment movement and offer the raw data of new analytic method by introducing the fuzzy theory and weight for overcoming the uncertainty of ranking decision. To transform the Likert's scale granted to assessment indicators into the type of triangular fuzzy number(a, b, c), there was conversion to each minimum(a), median(b), and maximum(c) in applying membership function, and in using the center of gravity and eigenvalue, there was to decide the ranking. The rankings of converted values applied a mean importance and weight were confirmed that they were generally changed. Therefore, the ranking decision was better to accomplish objective and rational ranking decision by applying weight that was calculated in grouping of indicator than to judge the singular concept and to be useful in assessment of diverse National Trust site. In the future, because AHP, which was general method of calculating weight, was lacked, there was to understand the critical point to fix a pertinent weight, and to carry out the study applying engineering concept like fuzzy integral using $\lambda-measure$.

Management of small yellow croaker stock in Korean waters based on production value-per-recruit analysis (가입당 생산액 분석에 의한 한국 해역 참조기 Larimichthys polyactis 자원의 관리)

  • Zhang, Chang-Ik;Lee, Eun-Ji;Kang, Hee-Joong
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.50 no.4
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    • pp.467-475
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    • 2014
  • This study was performed to estimate optimum fishing mortality (F) and the age at first capture ($t_c$) for small yellow croaker in Korean waters. We first estimated optimum F and $t_c$ using traditional yield-per-recruit (YPR) analysis, and the results were 0.8/year and 2.5 years old, respectively. However, the individual fish price per unit weight of small yellow croaker in Korea increases dramatically by size. Thus, we developed an alternative method, which is called as production value-per-recruit (PPR) analysis. We developed two types of the PPR analysis, that is, the discrete function and the continuous function method. We estimated optimum F and $t_c$ using the two types of the PPR analysis and compared the results. The optimum F and $t_c$ from the discrete function method, were 0.3/year and 5.0 years old, respectively, while those from the continuous function method were 0.5/year and 3.5 years old, respectively. These PPR estimates were much more conservative for the stock management than the traditional YPR analysis, which can prevent the fish stock from the economic overfishing. As a result, the PPR analysis could be more proper approach for stock assessment in the case that the individual fish price per unit weight increases dramatically by size like small yellow croaker in Korea.

A Case Study on the Evaluation of Open Source Bulletin Board System with Multi-Function by the Analytical Hierarchy Process (AHP를 이용한 오픈소스 다기능 게시판의 평가 사례연구)

  • Sim, Min-Jae;Jang, Seong-Yong;Lee, Won-Young
    • Korean Management Science Review
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    • v.27 no.1
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    • pp.91-105
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    • 2010
  • We proposed and stratified a selection standard model on Open Source Functional Board which could be found in Web. So we could grasp the weight about Performance Evaluation from the viewpoints of planners, developers, and web disigner professional of views. We suggested applying diverse measurement types in case of item which could chart Evaluation Standards on chosen sample boards. In case of item which couldn't do that, we compared and analyzed it by using selective type of 9 point scaling method on professionalists in every sample board. As a result of weight on upper estimate section of evaluation model chart, the order of importance was convenience(0.334), performance(0.333), function(0.240) and design(0.093) respectively. It indicates that there is more weight on performance and convenience which are hard to be structurally modified than designs and functions that are directly shown to the users. Also, it was evident that opposite results came out when using 9-point scale survey and measurement with objective data such as function and performance. The reason is because the surveyed subject can have his or her own subjectivity and bias unlike objective data. However, objectivity of the administrator is also an important factor thus both two perspectives have to be all considered when selecting the bulletin board.

Weighted Latin Hypercube Sampling to Estimate Clearance-to-stop for Probabilistic Design of Seismically Isolated Structures in Nuclear Power Plants

  • Han, Minsoo;Hong, Kee-Jeung;Cho, Sung-Gook
    • Journal of the Earthquake Engineering Society of Korea
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    • v.22 no.2
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    • pp.63-75
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    • 2018
  • This paper proposes extension of Latin Hypercube Sampling (LHS) to avoid the necessity of using intervals with the same probability area where intervals with different probability areas are used. This method is called Weighted Latin Hypercube Sampling (WLHS). This paper describes equations and detail procedure necessary to apply weight function to WLHS. WLHS is verified through numerical examples by comparing the estimated distribution parameters with those from other methods such as Random Sampling and Latin Hypercube Sampling. WLHS provides more flexible way on selecting samples than LHS. Accuracy of WLHS estimation on distribution parameters is depending on the selection of weight function. The proposed WLHS is applied to seismically isolated structures in nuclear power plants. In this application, clearance-to-stops (CSs) calculated using LHS proposed by Huang et al. [1] and WLHS proposed in this paper, respectively, are compared to investigate the effect of choosing different sampling techniques.

Learning Behaviors of Stochastic Gradient Radial Basis Function Network Algorithms for Odor Sensing Systems

  • Kim, Nam-Yong;Byun, Hyung-Gi;Kwon, Ki-Hyeon
    • ETRI Journal
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    • v.28 no.1
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    • pp.59-66
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    • 2006
  • Learning behaviors of a radial basis function network (RBFN) using a singular value decomposition (SVD) and stochastic gradient (SG) algorithm, together named RBF-SVD-SG, for odor sensing systems are analyzed, and a fast training method is proposed. RBF input data is from a conducting polymer sensor array. It is revealed in this paper that the SG algorithm for the fine-tuning of centers and widths still shows ill-behaving learning results when a sufficiently small convergence coefficient is not used. Since the tuning of centers in RBFN plays a dominant role in the performance of RBFN odor sensing systems, our analysis is focused on the center-gradient variance of the RBFN-SVD-SG algorithm. We found analytically that the steadystate weight fluctuation and large values of a convergence coefficient can lead to an increase in variance of the center-gradient estimate. Based on this analysis, we propose to use the least mean square algorithm instead of SVD in adjusting the weight for stable steady-state weight behavior. Experimental results of the proposed algorithm have shown faster learning speed and better classification performance.

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