• Title/Summary/Keyword: Unconstrained

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A High Order Product Approximation Method based on the Minimization of Upper Bound of a Bayes Error Rate and Its Application to the Combination of Numeral Recognizers (베이스 에러율의 상위 경계 최소화에 기반한 고차 곱 근사 방법과 숫자 인식기 결합에의 적용)

  • Kang, Hee-Joong
    • Journal of KIISE:Software and Applications
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    • v.28 no.9
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    • pp.681-687
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    • 2001
  • In order to raise a class discrimination power by combining multiple classifiers under the Bayesian decision theory, the upper bound of a Bayes error rate bounded by the conditional entropy of a class variable and decision variables obtained from training data samples should be minimized. Wang and Wong proposed a tree dependence first-order approximation scheme of a high order probability distribution composed of the class and multiple feature pattern variables for minimizing the upper bound of the Bayes error rate. This paper presents an extended high order product approximation scheme dealing with higher order dependency more than the first-order tree dependence, based on the minimization of the upper bound of the Bayes error rate. Multiple recognizers for unconstrained handwritten numerals from CENPARMI were combined by the proposed approximation scheme using the Bayesian formalism, and the high recognition rates were obtained by them.

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The configuration Optimization of Truss Structure (트러스 구조물의 형상최적화에 관한 연구)

  • Lim, Youn Su;Choi, Byoung Han;Lee, Gyu Won
    • Journal of Korean Society of Steel Construction
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    • v.16 no.1 s.68
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    • pp.123-134
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    • 2004
  • In this research, a multilevel decomposition technique to enhance the efficiency of the configuration optimization of truss structures was proposed. On the first level, the nonlinear programming problem was formulated considering cross-sectional areas as design variables, weight, or volume as objective function and behavior under multiloading condition as design constraint. Said nonlinear programming problem was transformed into a sequential linear programming problem. which was effective in calculation through the approximation of member forces using behavior space approach. Such approach has proven to be efficient in sensitivity analysis and different form existing shape optimization studies. The modified method of feasible direction (MMFD) was used for the optimization process. On the second level, by treating only shape design variables, the optimum problem was transformed into and unconstrained optimal design problem. A unidirectional search technique was used. As numerical examples, some truss structures were applied to illustrate the applicability. and validity of the formulated algorithm.

Analysis of Helicopter Maneuvering Flight Using the Indirect Method - Part I. Optimal Control Formulation and Numerical Methods (Indirect Method를 이용한 헬리콥터 기동비행 해석 - Part I. 최적제어 문제의 정식화와 수치해법)

  • Kim, Chang-Joo;Yang, Chang-Deok;Kim, Seung-Ho;Hwang, Chang-Jeon
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.36 no.1
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    • pp.22-30
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    • 2008
  • This paper deals with the nonlinear optimal control approach to helicopter maneuver problems using the indirect method. We apply a penalty function to the deviation from a prescribed trajectory to convert the system optimality to an unconstrained optimal control problem. The resultant two-point boundary value problem has been solved by using the multiple-shooting method. This paper focuses on the effect of the number of shooting nodes and initialization methods on the numerical solution in order to define the minimum number of shooting nodes required for numerical convergence and to provide a method increasing convergence radius of the indirect method. The results of this study can provide an approach to improve numerical stability and convergence of the indirect method when we solve the optimal control problems of an inherently unstable helicopter system.

The Analysis of Helicopter Maneuvering Flight Using the Indirect Method - Part II. Applicability of High Fidelity Helicopter Models (Indirect Method를 이용한 헬리콥터 기동비행 해석 - Part II. High Fidelity 헬리콥터 모델링의 사용 가능성)

  • Kim, Chang-Joo;Yang, Chang-Deok;Kim, Seung-Ho;Hwang, Chang-Jeon
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.36 no.1
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    • pp.31-38
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    • 2008
  • This paper deals with the nonlinear optimal control approach to helicopter maneuver problems using the indirect method. We apply a penalty function to the integral deviation from a prescribed trajectory to convert the system optimality to an unconstrained optimal control problem. The resultant two-point boundary value problem has been solved by using a multiple-shooting method. This paper focuses on the model selection strategies to resolve the problem of numerical instability and high wait time when a high fidelity model with rotor dynamics is applied. Four different types of helicopter models are identified, two of which are linear models with or without rotor models, as well as two models which include the nonlinear mathematical model for rotor in its formulation. The relative computation time and the number of function calls for each model are compared in order to provide a guideline for the selection of helicopter model.

Breaking Z-path : A Digital Comics Layout Strategy for Tablet PC (읽기 순서 바꾸기 : 타블렛PC 전자만화책의 레이아웃 연출)

  • Yoh, Mi-Ju;Shi, Chung-Kon
    • Cartoon and Animation Studies
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    • s.24
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    • pp.49-64
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    • 2011
  • Comics is sequential art. In comics, the story is developped by its sequential panels which have their own sizes and sites. Accordingly, comics is closer to 'space' art than text. The reading order in a page of comic book follows the human long-standing reading habit, and it is the same as that of textbook. When we read a korean comic book, our eyes run from left to right, and downward on the page. But some factors related to panels or comic structures can change the typical reading order. Meanwhile, breaking the typical reading order is easier in the "infinite canvas" by reason of unconstrained spatial composition. This paper introduces the factors that change the comic book readers' reading order and proposes a tablet PC comic book layout which includes an arbitrary reading path using interaction

Strategy for Improving the Resolution of Electrical-resistivity Inversions for Detecting Soft Ground at Shallow Depths (~ 10 m) (천부(약 10 m) 연약 지반 탐지를 위한 전기비저항 역산 해상도 향상 전략)

  • Jang, Hangilro;Song, Seo Young;Kim, Bitnarae;Nam, Myung Jin
    • The Journal of Engineering Geology
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    • v.28 no.3
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    • pp.367-377
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    • 2018
  • This study introduces a DC resistivity inversion method that incorporates structural and inequality constraints to enhance the resolution of resistivity inversions, and presents sample inversion results with these constraints. In the constrained inversions, a base model is constructed from a layered model through interpretation of other geophysical data. Inversion tests establish that both the structural and inequality constraints produce better resistivity models than the unconstrained inversion. However, the inequality inversion not only reproduces the exact layered structure of the background, it reproduces conductive anomalies at a depth of ~ 10 m when an inexact base model of electrical resistivity is used.

A Sensibility Evaluation Study on Interior Space of Exposed Concrete Finish - Focused on the Kim Ok Gil Memorial Hall Restaurant - (노출 콘크리트 마감의 실내 공간 감성평가 연구 - 김옥길 기념관 레스토랑을 중심으로 -)

  • Lee, Jisun;Jung, Hyun-Won;Lee, Hyunsoo
    • Korean Institute of Interior Design Journal
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    • v.25 no.5
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    • pp.121-129
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    • 2016
  • With the ingenious properties of unconstrained formativeness and frank expression of materiality the exposed concrete became popular with numerous architectures. The application of the exposed concrete has expanded to indoor environments such as commercial and residential spaces beyond the building exteriors with the uncompromising nature of its materiality. The purpose of this study is to conduct sensibility evaluation of the exposed concrete finish in interior spaces. The sensibility evaluation is conducted through a survey on a set of space models of the exposed concrete finish. The three rendered space models were evaluated by emotional vocabulary of 18 pairs of words. The result were as follows: First, the emotions derived from the exposed concrete finish are 'modern', 'cold', 'simple', 'restrained', 'rough', 'dark', 'new', 'chic', 'familiar' and 'eco-friendly'. Second, three sets of space models with alternative materials on walls and floors in exposed concrete interior space showed clear difference in sensibility. A space with the exposed concrete finish on the floor, the walls and the ceiling showed the results of 'cold', 'dark', 'rational' and 'masculine'. In the exposed concrete finish environment with wood flooring 'comfortable', 'warm', 'bright' senses and with white paint finish on the wall 'bright', 'practical', 'ordinary' and 'restrained' senses were obtained. Third, all three images achieved senses of 'chic', 'modern', 'new', 'pleasant', 'environment friendly' and 'satisfactory'. The modernity and stylish expressions of the exposed concrete finish were kept with the application of different material finishes as well as complementing its cold and rough expressions with warmth and brightness.

Estimation of Inflows to Jangchan Reservoir from Outside Watershed by Minimizing Reservoir Water Storage Errors (저수량 오차에 의한 장찬저수지의 유역외 유입량 추정)

  • Noh, Jae-Kyoung
    • Journal of The Korean Society of Agricultural Engineers
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    • v.52 no.5
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    • pp.61-68
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    • 2010
  • Jangchan reservoir is located in Okcheon county, Chungbuk province, of which watershed area is $29.4\;km^2$ from outside, and $5.1\;km^2$ from inside watershed, effective storage capacity is $392{\times}10^4\;m^3$, paddy area to be irrigated is 474 ha. To determine inflows from Keumcheon weir located in outside watershed on an optimum level, a repeated procedure which is composed of simulation of inflows to Keumcheon weir, setting of range of water taking at Keumcheon weir, simulation of inflows to Jangchan reservoir, estimation of paddy water from Jangchan reservoir, and simulation of water storages in Jangchan reservoir was selected. Parameters of DAWAST model for simulating inflows to Jangchan reservoir were determined to UMAX of 315 mm, LMAX of 21 mm, FC of 130 mm, CP of 0.018, and CE of 0.007 with absolute sum of errors in reservoir water storages minimized using unconstrained Simplex method because of no inflows data. Inflows to Keumcheon weir were simulated to $2,132{\times}10^4\;m^3$ on an annual average. Optimal range of water taking at Keumcheon weir to transfer to Jangchan reservoir were $0.81{\sim}50\;mm/km^2/d$, which were summed up to $1,397{\times}10^4\;m^3$ in 66% of total on an annual average. Inflows to Jangchan reservoir were simulated to $1,739{\times}10^4\;m^3$ on an annual average of which were 80 % from Keumcheon weir of outside watershed. Requirements to paddy water from Jangchan reservoir were estimated to $543{\times}10^4\;m^3$ on an annual average.

Recognition of Handwritten Numerals using Hybrid Features And Combined Classifier (복합 특징과 결합 인식기에 의한 필기체 숫자인식)

  • 박중조;송영기;김경민
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.5 no.1
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    • pp.14-22
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    • 2001
  • Off-line handwritten numeral recognition is a very difficult task and hard to achieve high recognition results using a single feature and a single classifier, since handwritten numerals contain many pattern variations which mostly depend upon individual writing styles. In this paper, we propose handwritten numeral recognition system using hybrid features and combined classifier. To improve recognition rate, we select mutually helpful features -directional features, crossing point feature and mesh features- and make throe new hybrid feature sets by using these features. These hybrid feature sets hold the local and global characteristics of input numeral images. And we implement combined classifier by combining three neural network classifiers to achieve high recognition rate, where fuzzy integral is used for multiple network fusion. In order to verify the performance of the proposed recognition system, experiments with the unconstrained handwritten numeral database of Concordia University, Canada were performed. As a result, our method has produced 97.85% of the recognition rate.

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Iris Detection at a Distance by Non-volunteer Method (비강압적 방법에 의한 원거리에서의 홍채 탐지 기법)

  • Park, Kwon-Do;Kim, Dong-Su;Kim, Jeong-Min;Song, Young-Ju;Koh, Seok-Joo
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2018.05a
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    • pp.705-708
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    • 2018
  • Among biometrics commercialized for security, iris recognition technology has the most excellent security for the probability of the match between individuals is the lowest. Current commercialized iris recognition technology has excellent recognition ability, but this technology has a fatal drawback. Without the user's active cooperation, it cannot recognize the iris correctly. To make up for this weakness, recent trend of iris recognition development mounts a non-volunteering, unconstrained method. According to this information, the objective of this research is developing a module that can identify people iris from a video acquired by high performance infrared camera in a range of 3m and in a involuntary way. For this, we import images from the video and find people's face and eye positions from the images using Haar classifier trained through Cascade training method. finally, we crop the iris by Hough circle transform and compare it with data from the database to identify people.

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