• 제목/요약/키워드: basis pursuit

검색결과 108건 처리시간 0.029초

공간적인 알리아싱을 포함한 탄성파 트레이스의 내삽을 위한 요소파 기반의 Matching Pursuit 기법 (Wavelet Based Matching Pursuit Method for Interpolation of Seismic Trace with Spatial Aliasing)

  • 최지훈;변중무;설순지
    • 지구물리와물리탐사
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    • 제17권2호
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    • pp.88-94
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    • 2014
  • 탄성파 탐사자료의 획득 시, 기계적인 결함이나 지형적인 접근성 등으로 인하여 자료를 부분적으로 획득하지 못하거나, 해상 탐사의 경우 스트리머의 간격으로 인하여 공간적인 알리아싱(aliasing)이 발생할 수 있다. 이러한 불규칙하고 공간적인 알리아싱이 존재하는 자료는 추후 탄성파 자료처리과정에서 문제를 일으키게 된다. 만약, 정확하고 효율적인 내삽(interpolation) 기법을 보유하고 있다면, 이러한 문제를 해결할 수 있으며, 나아가 탐사를 수행할 때 송신원 또는 수신기의 수를 줄일 수 있으므로 탐사의 시간 및 비용이 줄어들게 된다. 여러 내삽 방법들 중 Matching Pursuit 기법을 이용한 내삽 방법은 고르기(sampling)의 형태와 상관없이 적용이 가능하다는 장점을 가지고 있다. 그러나 정현파 함수(sinusoidal function)을 기저함수로 이용하는 경우, 공간적인 알리아싱이 존재하는 탄성파자료에 적용시 정확한 내삽이 불가능하다는 한계를 지니고 있다. 따라서 본 연구에서는 공간적인 알리아싱의 문제를 해결하기 위하여, 정현파 함수가 아닌 요소파(wavelet)를 기저함수로 이용하는 요소파 기반의 Matching Pursuit 기법을 개발하였다. 또한, L-2 norm을 이용한 기존의 방법과 달리, 내적을 이용하여 내삽의 수행속도를 향상시켰다.

시간차 보정을 적용한 Matching Pursuit 내삽 기법 연구 (A Study on Matching Pursuit Interpolation with Moveout Correction)

  • 이재강;변중무;설순지;김영창
    • 지구물리와물리탐사
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    • 제21권2호
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    • pp.103-111
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    • 2018
  • 탄성파 내삽 기법의 최근 연구방향은 공간적 알리아싱이 존재하는 자료에서의 내삽을 효과적으로 수행하는 것이다. 다양한 내삽 기법 중 기저함수를 정의하여 트레이스를 가장 잘 복원할 수 있는 기저함수의 조합을 찾아내는 Matching Pursuit 내삽 기법이 개발된 바 있다. 그러나 이 방법은 공간적 알리아싱 문제를 해결하지 못하는데 이를 해결하기 위해 다성분 Matching Pursuit 방법이 제안되었고 또한 시간차 보정(moveout correction) 방법도 소개된 바 있다. 다성분을 이용한 방법은 P파만을 갖는 다성분 자료가 획득되어야 하는데 해저면에서 다성분을 측정하는 OBC (Ocean Bottom Cable) 자료의 경우에는 P파 성분만을 분리하는 작업이 어려워 현장자료 적용이 힘들게 된다. 따라서 이 연구에서는 P파와 S파가 혼재하고 공간적 알리아싱이 존재하는 OBC 탐사 자료에서의 효과적인 단일성분 Matching Pursuit 내삽 기법을 다룬다. 이를 위해 시간차 보정을 포함하는 리커 요소파 기반의 단일성분 Matching Pursuit 내삽 기법 작업흐름도를 제안하고 그 효과를 체계적으로 살펴보았다. 이 작업흐름도는 내삽을 적용하기 전에 시간차 보정을 적용하고 다시 역 시간차 보정을 적용하여 공간적 알리아싱 문제를 해결하였다. 제안한 작업흐름도를 OBC 측정을 가정한 합성탄성파탐사 자료에 적용하여 그 효과를 검증하였고 현장자료에 적용함으로써 공간적 알리아싱이 심한 경우에도 내삽이 가능함을 확인하였다.

Compressive sensing-based two-dimensional scattering-center extraction for incomplete RCS data

  • Bae, Ji-Hoon;Kim, Kyung-Tae
    • ETRI Journal
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    • 제42권6호
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    • pp.815-826
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    • 2020
  • We propose a two-dimensional (2D) scattering-center-extraction (SCE) method using sparse recovery based on the compressive-sensing theory, even with data missing from the received radar cross-section (RCS) dataset. First, using the proposed method, we generate a 2D grid via adaptive discretization that has a considerably smaller size than a fully sampled fine grid. Subsequently, the coarse estimation of 2D scattering centers is performed using both the method of iteratively reweighted least square and a general peak-finding algorithm. Finally, the fine estimation of 2D scattering centers is performed using the orthogonal matching pursuit (OMP) procedure from an adaptively sampled Fourier dictionary. The measured RCS data, as well as simulation data using the point-scatterer model, are used to evaluate the 2D SCE accuracy of the proposed method. The results indicate that the proposed method can achieve higher SCE accuracy for an incomplete RCS dataset with missing data than that achieved by the conventional OMP, basis pursuit, smoothed L0, and existing discrete spectral estimation techniques.

문화기술 융합적 관점으로 본 수원 화성 건축공간의 존재론적 의미 연구 (A Study on the Ontological Meaning of Architectural Space of Suwon Hwaseong from the Viewpoint of Culture-Technology Convergence)

  • 김지은;박은수
    • 한국실내디자인학회논문집
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    • 제23권3호
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    • pp.100-107
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    • 2014
  • Traditional architectural space, which is a historical cultural heritage must be connected mutually as a organic flow of various elements such as the environment of the time, political background and values, rather than approaching with fragmentary point of view. The Silhak Philosophy, the basis of late Chosun society developed equity thoughts on the basis of ideology of humanism, and it asserted the promotion of technology and industry as a measure to realize the pursuit of truth which is practically useful. Thus, we could verify the possibility of convergent interpretation of cultural technology of Hwaseong architectural space through the humanistic viewpoint of pioneer spirit of Silhak Philosophy which regards human as a main agent of desire of life, and the pursuit of truth which is useful for reality, and the realization of ethical value by aesthetic practicalism. Based on this, the ontological meaning and value of Suwon Hwaseong by the viewpoint of convergence of culture and technology have been drawn as the construction of planned new town by the practice of filial duty, the plan of city space based on rational values, the realization of a metropolis where self-sufficient economic activities are possible, the introduction of thorough construction management system, the introduction of advanced culture and its creative application, and the application of scientifical knowledges and cutting-edge technology.

단일 포식자-희생자 환경에서 포식자 추격 에너지 모델 (A Model of Pursuing Energy of Predator in Single Predator-Prey Environment)

  • 이재문;권영미
    • 한국게임학회 논문지
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    • 제13권1호
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    • pp.41-48
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    • 2013
  • 일반적으로 생태계에서 포식자-희생자 모델은 생존 경쟁의 연구모델로서 많이 연구되어 왔다. 기존의 논문이 포식자-희생자의 개체 수 변화량에 초점을 맞추고 있는 반면, 본 논문은 포식자-희생자 모델에서 포식자가 희생자를 추격하기에 필요한 에너지 제어에 관한 연구를 하였다. 문제를 간단히 하기 위하여 한 마리의 포식자와 한 마리의 희생자가 있다고 가정하였고, 이를 기반으로 일정한 거리에 있는 포식자가 희생자를 추격하여 성공하기에 필요 에너지를 물리적 이론을 근거로 제시하였고, 시뮬레이션에 기반하여 소비 에너지 모델을 제안하였다. 실험을 통하여 제안된 두 에너지 모델이 자연스러운 추격하기에 올바르게 적용될 수 있음을 보였다.

웰빙식생활 추구 정도에 따른 조미료(MSG)에 대한 인식과 기호도 조사 (A Survey of Awareness and Preference for MSG according to the Pursuit of Well-being in Diet)

  • 길가영;진소연
    • 한국식생활문화학회지
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    • 제30권5호
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    • pp.481-490
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    • 2015
  • This research was conducted to examine the awareness and preference levels related to MSG (monosodium glutamate) according to well-being dietary life pursuit attitude factors as well as to improve opportunities to meet value conscious consumption of well-being-oriented customers. According to well-being dietary life pursuit attitude factors, respondents were divided to three clusters, indifference type, well-being-oriented type, and active health action type. Sensory evaluations were carried out on soybean paste soup (Doenjang-guk) and seasoned spinach with different levels of MSG. In the results, 74.4% of all respondents preferred Doenjang soup with 2% MSG, 65.4% preferred seasoned spinach with the same ratio of MSG, and 35.9% preferred seasoned spinach with 0.5% MSG. Regarding the acceptance level of MSG, addition of MSG to improve taste was acceptable to the indifference type (cluster 1). On the contrary, active health action type did not prefer MSG, wanted natural seasonings despite high prices, and preferred to dine at restaurants that serve MSG-free foods. Based on this study, restaurant companies should segment their customers on the basis of MSG usage and establish their positioning strategies according to their concepts.

Keats 시(詩)의 구조(構造) (The dramatic structure in Keats' poetry)

  • 박찬조
    • 영어어문교육
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    • 제4호
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    • pp.229-247
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    • 1998
  • Keats is a poet who was in pursuit of 'the beautiful'. He tried to show various structures in his poetry to search for 'eternal pleasure'. These are explained in terms of 'metamorphosis', 'travel structure' and 'metamorphosis patterns', but put together, these can be expressed as simple terms of a dramatic structure. Especially We can assume this dramatic structure is the key to access his poetry on the basis of the fact that Keats always admired the world of drama and respected Shakespeare most. We can see Keats' dramatic structure in his poetry Ode to a Nightingale, Ode on a Grecian Urn. To Autumn and so on, and in these three poems, he was very successful in achieving unique poetic expression by inducing tension structure' through the dramatic structure of Introduction - development - crisis - climax - ending. In conclusion, his poetry achieved success in that he made clear his central theme, the pursuit of a beautiful and happy life through the application of a dramatic structure.

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Estimation of Hard-to-Measure Measurements in Anthropometric Surveys

  • Choi, Jong-Hoo;Kim, Ryu-Jin
    • Communications for Statistical Applications and Methods
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    • 제9권1호
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    • pp.213-220
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    • 2002
  • Anthropometric survey is important as a basis for human engineering fields. According to our experiences, there are difficulties in obtaining the measurements of some body parts because respondents are reluctant to expose. In order to overcome these difficulties, we propose a method for estimating such hard-to-measure measurements by using easy-to-measure measurements those are closely related to them. Multiple Regression Model, Feedforward Neural Network(FNN) Model and Projection Pursuit Regression(PPR) Model will be used as analytical tools for this purpose. The method we propose will be illustrated with real data from the 1992 Korea national anthropometric survey.

LQ기법을 이용한 수중 운동체의 마지막(terminal) 유도 알고리즘 설계 (Design of terminal guidance algorithm for underwater vehicles using LQ technique)

  • 김삼수;이갑래;이재명;전완수;박성희
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 22-24 Oct. 1991
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    • pp.620-628
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    • 1991
  • For a Stationary moving-target. the design technique of guidance system for underwater vehicle with a seeker of st type is developed. Using perturbation theory, a new method which linearizes the nonlinear intercept geometry is proposed. On the basis of the linearized system modeling, LQ and PID design technique is used to determine the structure and gain of the guidance system. Some simulation results applied underwater engagement are represented to show that the proposed guidance law is superior to the other guidance laws as pursuit, Bang-Beng, PN APN.

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미셸 푸코와 건축의 근대성(I): - 말과 사물, 말과 건축 - (Michel Foucault and Modern Architecture(I) - Words and Things, Words and Architecture -)

  • 배형민
    • 건축역사연구
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    • 제7권3호
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    • pp.87-105
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    • 1998
  • Surveying the literature of architecture since the nineteenth century, one can identify two dominant but problematic attitudes, among several, that pursue the task of defining what modern architecture is and should be. The first is the search for meaning and the second is the pursuit of form. This study, following Michel Foucault, asserts that the dual formation of meaning and form is a historical product of modernity and belies architecture's uncritical dependence on language since the nineteenth century. This study is a critique and historical analysis of this pernicious reliance, and constitutes a first step towards thinking of alternative relations between 'words and architecture' in the modern world. In reconstructing this problematic, the paper has called on Foucault's seminal The Order of Things. The study follows his construction of the Renaissance, the Classical and the Modern episteme, and in brief fashion, reconstructs the relation between language and architecture in each episteme. In analysing the Modern, the study focuses on Hegel's Lectures on Aesthetics. Hegel placed architecture in a genre hierarchy within which architecture, because of its material basis, was fundamentally limited in its ability to express the Spirit. For Hegel it was, among the arts, poetic language, and beyond art, the language of philosophy, through which the Absolute Spirit could be atttained. Much of post-nineteenth century architecture has remained within the shadow of Hegel, where architecture's materiality is perceived to be a burden, and in order to secure its relevance in modern society, architecture was deemed to pursue the role of language. As the most recent and sophisticated example of architecture's pursuit of form, the paper analyses the work of Peter Eisenman. Though Eisenman's theoretical writings are replete with post-Hegelian rhetoric, his architecture remains dependent upon the model of language, albeit a structuralist one. The paper concludes that ultimately, the pursuit of meaning and form is unable to face the crucial issue of value in modernity. While the former decides to easily what it is, the latter evades the issue itself. The second installment of this ongoing study will pursue a third possibility alluded to by Foucault, where language remains silent, pointing only to its 'ponderous' material existence.

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