• Title/Summary/Keyword: Projection pursuit

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Efficient Score Estimation and Adaptive Rank and M-estimators from Left-Truncated and Right-Censored Data

  • Chul-Ki Kim
    • Communications for Statistical Applications and Methods
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    • v.3 no.3
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    • pp.113-123
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    • 1996
  • Data-dependent (adaptive) choice of asymptotically efficient score functions for rank estimators and M-estimators of regression parameters in a linear regression model with left-truncated and right-censored data are developed herein. The locally adaptive smoothing techniques of Muller and Wang (1990) and Uzunogullari and Wang (1992) provide good estimates of the hazard function h and its derivative h' from left-truncated and right-censored data. However, since we need to estimate h'/h for the asymptotically optimal choice of score functions, the naive estimator, which is just a ratio of estimated h' and h, turns out to have a few drawbacks. An altermative method to overcome these shortcomings and also to speed up the algorithms is developed. In particular, we use a subroutine of the PPR (Projection Pursuit Regression) method coded by Friedman and Stuetzle (1981) to find the nonparametric derivative of log(h) for the problem of estimating h'/h.

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Building Regression Models for Tire Design Factors (타이어 설계 인자들에 대한 회귀모형의 수립)

  • Park, Jeong-soo;Hwang, Hyun-sik;Cho, Wan Hyun
    • Journal of Korean Society for Quality Management
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    • v.24 no.3
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    • pp.94-110
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    • 1996
  • Two regression models for explaining the tire performances (especially conering coefficients) by tire design and experimental factors are built. One is the ordinary regression model, and the explaining variables in the model are selected by a stepwise method. The other model is built by a modern nonparametric regression technique, called projection pursuit regression. Then two models are compared and combined, so that the relationship between the tire performances and design factors are well figured out. The optimal experimental design issue and future research ideas are also discussed.

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LMS and LTS-type Alternatives to Classical Principal Component Analysis

  • Huh, Myung-Hoe;Lee, Yong-Goo
    • Communications for Statistical Applications and Methods
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    • v.13 no.2
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    • pp.233-241
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    • 2006
  • Classical principal component analysis (PCA) can be formulated as finding the linear subspace that best accommodates multidimensional data points in the sense that the sum of squared residual distances is minimized. As alternatives to such LS (least squares) fitting approach, we produce LMS (least median of squares) and LTS (least trimmed squares)-type PCA by minimizing the median of squared residual distances and the trimmed sum of squares, in a similar fashion to Rousseeuw (1984)'s alternative approaches to LS linear regression. Proposed methods adopt the data-driven optimization algorithm of Croux and Ruiz-Gazen (1996, 2005) that is conceptually simple and computationally practical. Numerical examples are given.

Physical Interactive Game on the Digital Desk (디지털 데스크상의 체감형 게임 구현)

  • Chung, Jee-Hoon;Yun, Tae-Soo;Lee, Dong-Hoon;Yang, Hwang-Kyu
    • Journal of Korea Game Society
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    • v.5 no.1
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    • pp.11-18
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    • 2005
  • Recently, as one method of the game manipulation, physical interactive game is increasing, which controls the program by direct human movement. Tangible interface for physical interactive game implementation can control virtual model directly through real world object. A digital desk, one of the tangible interface, offers the interface that human can manipulate virtual object directly, by making projection screen on real world desk as computer display device. In this paper, we implement "Battle Region" game in the form of tangible interface, which can offer game users an efficient and amusing experiences by the use of physical interactive game. Traditional game cannot pursuit the diversity of game background contents but our game can do it through Map image projection. From this, game provider can supply the diversity of choice and users ran set up the difficulty of game. Therefore, our implemented game can offer users an efficient and amusing experiences by making game user's challenge and satisfaction maximum.

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Characteristics of Hybrid Expression in Fashion Illustration (패션 일러스트레이션의 혼성적 표현 특성에 관한 연구)

  • Kim, Soon-Ja
    • Journal of the Korea Fashion and Costume Design Association
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    • v.15 no.1
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    • pp.59-74
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    • 2013
  • Post-modern society leads us to accept diversity and variability instead of pursuit of the absolute truth, beauty or classical value systems, thus leading to hybrid phenomena. The purpose of this study is to analyze characteristics and expressive effects of hybrid expressions through which to provide conceptual bases for interpreting expanded meanings of fashion illustrations that express aesthetic concepts of hybrid culture. Hybrid refers to a condition on which diverse elements are mixed with each other, so any one element can not dominate others. It is often used to create something unique and new by a combination of unprecedented things. Hybrid can be classified into four categories: temporal hybrid, spatial hybrid, morphological hybrid and hybrid of different genres. Temporal hybrid from a combination of past and present in fashion illustration includes temporal blending by repetition and juxtaposition. Spatial hybrid shows itself in the form of inter-penetration and interrelationship by means of projection, overlapping, juxtaposition and multiple space. Morphological hybrid expresses itself through combination of heterogenous forms and restructuring of deformed forms. Hybrid of different genres in fashion illustration applies various graphic elements or photos within the space, and represents blending of arts and daily living. Such hybrid expressions in fashion illustrations reflect the phenomena of diversity and variability of post-modern society. Hybrid expressions in fashion illustrations predict endless possibility of expressing new images through combining various forms or casual elements and can develop toward a new creative technique.

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Guaranteed Sparse Recovery Using Oblique Iterative Hard Thresholding Algorithm in Compressive Sensing (Oblique Iterative Hard Thresholding 알고리즘을 이용한 압축 센싱의 보장된 Sparse 복원)

  • Nguyen, Thu L.N.;Jung, Honggyu;Shin, Yoan
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.39A no.12
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    • pp.739-745
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    • 2014
  • It has been shown in compressive sensing that every s-sparse $x{\in}R^N$ can be recovered from the measurement vector y=Ax or the noisy vector y=Ax+e via ${\ell}_1$-minimization as soon as the 3s-restricted isometry constant of the sensing matrix A is smaller than 1/2 or smaller than $1/\sqrt{3}$ by applying the Iterative Hard Thresholding (IHT) algorithm. However, recovery can be guaranteed by practical algorithms for some certain assumptions of acquisition schemes. One of the key assumption is that the sensing matrix must satisfy the Restricted Isometry Property (RIP), which is often violated in the setting of many practical applications. In this paper, we studied a generalization of RIP, called Restricted Biorthogonality Property (RBOP) for anisotropic cases, and the new recovery algorithms called oblique pursuits. Then, we provide an analysis on the success of sparse recovery in terms of restricted biorthogonality constant for the IHT algorithms.

A Study on Automatic Learning of Weight Decay Neural Network (가중치감소 신경망의 자동학습에 관한 연구)

  • Hwang, Chang-Ha;Na, Eun-Young;Seok, Kyung-Ha
    • Journal of the Korean Data and Information Science Society
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    • v.12 no.2
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    • pp.1-10
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    • 2001
  • Neural networks we increasingly being seen as an addition to the statistics toolkit which should be considered alongside both classical and modern statistical methods. Neural networks are usually useful for classification and function estimation. In this paper we concentrate on function estimation using neural networks with weight decay factor The use of weight decay seems both to help the optimization process and to avoid overfitting. In this type of neural networks, the problem to decide the number of hidden nodes, weight decay parameter and iteration number of learning is very important. It is called the optimization of weight decay neural networks. In this paper we propose a automatic optimization based on genetic algorithms. Moreover, we compare the weight decay neural network automatically learned according to automatic optimization with ordinary neural network, projection pursuit regression and support vector machines.

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Winning Coalition, Expansion of Wealth, and Naval Power (승자연합과 부(富)의 확장, 그리고 해군력)

  • Park, Ju-Hyeon
    • Strategy21
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    • s.41
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    • pp.174-207
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    • 2017
  • Human history shows diverse strategies for survival and prosperity. This study introduces the concept of the expansion of wealth as a key to explain choice and behavior of political entities. American scholar, -Bruce Bueno de Mesquita-, offers theoretical grounds for this concept in that the cores of selectorate theory is settled. The political entity consists of two groups, -the winning coalition that has power to replace leader and non-winning coalition that has not. Leaders implement policies serving for the welfare of winning coalition in return for their loyalty. Both internal problems caused by demographic changes and external ones of climate changes, epidemic disease, or invasion compel leader and winning coalition to adopt policies of expansion that they believe may lead to the acquisition of wealth needed to counter those problems. The process starts by occupying one spot where other entities reside and then connecting it to its own. The line between spots functions as a foothold to form a new line to other spots. By repeating this process, a space is created in which new laws and orders are instated. In the early stage of expansion, war is hardly avoidable. Once finished successfully, the political circumstance tilts to encourage economic activities in order to generate national revenues to strengthen political power of winning coalition. However, as scale of economic activities grows, so does political power of civic classes in production and trade. To gain financial support required to run the political entity, delegation of power or bestowing autonomy to non-winning coalition is inevitable. Thus, expansion is not the ultimate solution, only to prolong the political survival if succeed. Maritime power came to attractive option when overland expansion had become obstructed. It offered much greater advantages in terms of political risks and financial burdens in exploring new regions of precious commodities than overland expansion. Each political entity around world have been, for the first time in human history, connected by maritime means since 15th century. It is worthy of noting that land conditions propelled people out to sea. Political and economic situations created opportunities to exploit geographical position in pursuit of wealth. In the 21st century, we witness the operation of international winning coalition that presides over the rules of expansion. Competing for market is synonymous to the expansion in this era, the cause and aim of it has not been changed though. Energy and dollars are key factors of expansion since the end of the 2nd world war. No matter what the forms and conditions change, naval power is still the most relevant means for expansion as it retains unique characters of maneuver, flexibility, continuity, display and projection of power. The strategy for using naval power should be in line with two different approaches for expansion: Approaches to the international winning coalition by making contribution to world order, and approaches to the non-international winning coalition by enhancing military diplomatic activities. The former will serve our share of winning coalition while the latter will open chances to acquire further prosperity.

A study on the beauty of space by overall arrangement and composition of a picture in Oriental painting (동양회화의 경영위치(經營位置)에 의한 여백(餘白)의 미(美) 연구(硏究))

  • Lee, Seung-Sook
    • Journal of Science of Art and Design
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    • v.11
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    • pp.201-220
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    • 2007
  • From two viewpoints the writer investigated the beauty of space by overall arrangement and composition of a picture in Oriental painting. In particular, she examined the expanded representation and significance of space use which had not properly been recognized in the field of a colored picture contrary to a painting in India ink. She studied that the boundary for the representation and appreciation of space was unlimited to one field of painting by studying and analyzing it in connection with other fields of art which had something in common with it in techniques or languages of representation. The writer considered the aspects of similar forms and spirits as the methods of understanding and representing the essence of an object in creating a work. She generally considered the aspect of perfecting knowledge by studying the principle of an actual thing for the representation of revealed forms corresponding to the aspect of similar forms, and tried to reach the stage of 'materialization' united with the spirit of the subject of creation for the formless forms corresponding to the aspect of representing an artist's inner world as well as the external shapes of things. She tried to reach the stage of spiritual cultivation in pursuit of the boundary between 'mental vanity' and 'sitting quietly and attaining the state of perfect selflessness', which were presented by Chuang-tzu, to express the spirituality internal to it. She recognized that the projection of the cultivation on a work could convey internal essence as well as external forms to a picture. It was because the image of the form represented in a picture was based on the aesthetic experience got from realty. In the concept of space and a method of representing it, she explored and analyzed the basic concept of space, arranged the concept of space shown in Oriental ideas dividing it into the concepts of space in Confucianism, Taoism and the Zen sect. What she felt acutely through this study was that she should establish the identity of her work by succeeding to, changing and re-creating tradition based on the historical heritage left by successive excellent painters and theorists. Putting together all these things showed that establishing the identity in the world of work pursued and oriented by her required searching the direction in future works by mixing tradition with modern times in a creative way, which is just the purpose of study in this thesis.

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