• 제목/요약/키워드: transformation algorithm

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An Effective Algorithm of Power Transformation: Box-Cox Transformation

  • Lee, Seung-Woo;Cha, Kyung-Joon
    • 한국수학사학회지
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    • 제11권2호
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    • pp.63-76
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    • 1998
  • When teaching the linear regression analysis in the class, the power transformation must be introduced to fit the linear regression model for nonlinear data. Box and Cox (1964) proposed the attractive power transformation technique which is so called Box-Cox transformation. In this paper, an effective algorithm selecting an appropriate value for Box-Cox transformation is developed which is considered to find a value minimizing error sum of squares. When the proposed algorithm is used to find a value for transformation, the number of iterations needs to be considered. Thus, the number of iterations is examined through simulation study. Since SAS is one of most widely used packages and does not provide the procedure that performs iterative Box-Cox transformation, a SAS program automatically choosing the value for transformation is developed. Hence, the students could learn how the Box-Cox transformation works, moreover, researchers can use this for analysis of data.

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Simultaneous optimization method of feature transformation and weighting for artificial neural networks using genetic algorithm : Application to Korean stock market

  • Kim, Kyoung-jae;Ingoo Han
    • 한국지능정보시스템학회:학술대회논문집
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    • 한국지능정보시스템학회 1999년도 추계학술대회-지능형 정보기술과 미래조직 Information Technology and Future Organization
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    • pp.323-335
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    • 1999
  • In this paper, we propose a new hybrid model of artificial neural networks(ANNs) and genetic algorithm (GA) to optimal feature transformation and feature weighting. Previous research proposed several variants of hybrid ANNs and GA models including feature weighting, feature subset selection and network structure optimization. Among the vast majority of these studies, however, ANNs did not learn the patterns of data well, because they employed GA for simple use. In this study, we incorporate GA in a simultaneous manner to improve the learning and generalization ability of ANNs. In this study, GA plays role to optimize feature weighting and feature transformation simultaneously. Globally optimized feature weighting overcome the well-known limitations of gradient descent algorithm and globally optimized feature transformation also reduce the dimensionality of the feature space and eliminate irrelevant factors in modeling ANNs. By this procedure, we can improve the performance and enhance the generalisability of ANNs.

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스테레오 영상처리를 이용한 바퀴달린 6족 로봇의 형태변형 알고리즘 구현 (Implementation of Transformation Algorithm for a Leg-wheel Hexapod Robot Using Stereo Vision)

  • 이상훈;김진걸
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2006년 학술대회 논문집 정보 및 제어부문
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    • pp.202-204
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    • 2006
  • In this paper, the detection scheme of the spatial coordinates based on stereo camera for a Transformation algorithm of an Leg-wheel Hexapod Robot is proposed. Robot designed as can have advantages that do transfer possibility fast mobility in flat topography and uneven topography through walk that use wheel drive. In the proposed system, using the disparity data obtained from the left and right images captured by the stereo camera system and the perspective transformation between a 3-D scene and an image plane, depth information can be detected. Robot uses construed environmental data and transformation algorithm, decide wheel drive and leg waik, and can calculate width of street and regulate width of robot.

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스트랩다운 관성항법시스템의 가속도 변환 알고리즘 (An acceleration transformation algorithm for strapdown inertial navigation system)

  • 김광진;김정환;백양식
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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    • pp.1671-1674
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    • 1997
  • In tihs paper, an acceleratiion transformation algorithm which compensates the sculling error is proposed for strapdown inertial navigation system. The algorithm utilize the corss-product of the acceleromenter outputs and gyro outputs to keep the accuracy of the vehicle velocity under high frequency dynamic motion. From the error analysis of the algorithm, it is shown that the magnitude of estimation error is reduced by four orders.

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복수의 거리영상 간의 변환계수의 추출 (Registration multiple range views)

  • 정도현;윤일동;이상욱
    • 전자공학회논문지S
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    • 제34S권2호
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    • pp.52-62
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    • 1997
  • To reconstruct the complete 3-D shape of an object, seveal range images form different viewpoints should be merged into a single model. The process of extraction of the transformation parameters between multiple range views is calle dregistration. In this paper, we propose a new algorithm to find the transformation parameters between multiple range views. Th eproposed algorithm consists of two step: initial estimation and iteratively update the transformation. To guess the initial transformation, we modify the principal axes by considering the projection effect, due to the difference fo viewpoints. Then, the following process is iterated: in order to extract the exact transformation parameters between the range views: For every point of the common region, find the nearest point among the neighborhood of the current corresponding point whose correspondency is defined by the reverse calibration of the range finder. Then, update the transformation to satisfy the new correspondencies. In order to evaluate the performance the proposed registration algorithm, some experiments are performed on real range data, acquired by space encoding range finder. The experimental results show that the proposed initial estimation accelerate the following iterative registration step.

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존슨변환을 이용한 공정능력분석 알고리즘 개발 (Process Capability Analysis Algorithm Using Johnson Transformation)

  • 김종걸;박은하;정연승
    • 대한안전경영과학회:학술대회논문집
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    • 대한안전경영과학회 2000년도 춘계학술대회
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    • pp.249-263
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    • 2000
  • This paper considers an algorithm using Johnson transformation to calculate process capability index for non-normal distribution. Johnson transformation is well known as one of methods transforming the data with non-normal distribution to normal data.

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A Study on Split Variable Selection Using Transformation of Variables in Decision Trees

  • Chung, Sung-S.;Lee, Ki-H.;Lee, Seung-S.
    • Journal of the Korean Data and Information Science Society
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    • 제16권2호
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    • pp.195-205
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    • 2005
  • In decision tree analysis, C4.5 and CART algorithm have some problems of computational complexity and bias on variable selection. But QUEST algorithm solves these problems by dividing the step of variable selection and split point selection. When input variables are continuous, QUEST algorithm uses ANOVA F-test under the assumption of normality and homogeneity of variances. In this paper, we investigate the influence of violation of normality assumption and effect of the transformation of variables in the QUEST algorithm. In the simulation study, we obtained the empirical powers of variable selection and the empirical bias of variable selection after transformation of variables having various type of underlying distributions.

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XML의 개념적 모델로부터 논리적 모델로의 변환 기법 (Transformation Methodology to Logical Model from Conceptual Model of XML)

  • 김영웅
    • 한국인터넷방송통신학회논문지
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    • 제16권6호
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    • pp.305-310
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    • 2016
  • 오늘날 데이터를 표현하고 교환하는 표준 언어로 XML을 사용하고 있다. XML의 개념적 모델을 정의하기 위해서는 XML이 가지는 다양한 요소들을 다이어그램으로 표현하는 표현 규칙과 생성된 다이어그램을 논리적 모델인 XML로 변환하는 변환 알고리즘을 정의해야 한다. 본 논문은 XML의 개념적 모델로부터 논리적 모델을 생성하기 위한 변환 기법을 제안한다. 본 논문에서 사용하는 개념적 모델로는 CMXML을 이용하고, 논리적 모델로 XML 스키마를 생성한다. 이를 위해 다이어그램으로 표현되는 CMXML을 정의하고, 이 다이어그램으로부터 XML 스키마를 생성하기 위한 자료구조를 정의하고 생성규칙을 정의하고, 변환 알고리즘을 제시한다.

Aliasing 감소를 위한 two-pass 영상회전변환 (An anti-aliasing two-pass image rotation)

  • 정덕진;이택주
    • 전자공학회논문지S
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    • 제34S권12호
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    • pp.98-105
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    • 1997
  • Image transformation ahs been widely used in compuater graphics, computer vision, robot vision, and image processing. Image rotation is one of important part of image transformation. In image rotation, a two-pass algorithm has many advantages over a one-pass algorithm in high speed computation. This paper presents a new two-pass algorithm that overcomes the limitations of previously reported effect of interpolation. A brief comparison of existent techniques and the twp-pass algorithm newly suggeste is presented. This paper also present the hardware structure for the two-pass algorithm suggested.

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A COMPLEXITY-REDUCED INTERPOLATION ALGORITHM FOR SOFT-DECISION DECODING OF REED-SOLOMON CODES

  • Lee, Kwankyu
    • Journal of applied mathematics & informatics
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    • 제31권5_6호
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    • pp.785-794
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    • 2013
  • Soon after Lee and O'Sullivan proposed a new interpolation algorithm for algebraic soft-decision decoding of Reed-Solomon codes, there have been some attempts to apply a coordinate transformation technique to the new algorithm, with a remarkable complexity reducing effect. In this paper, a conceptually simple way of applying the transformation technique to the interpolation algorithm is proposed.