• Title/Summary/Keyword: time representation

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A design of discrete-time integral controllers under skewed sampling

  • Ishihara, Tadashi;Guo, Hai-Jiao;Taketa-Hiroshi
    • 제어로봇시스템학회:학술대회논문집
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    • 1993.10b
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    • pp.428-433
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    • 1993
  • First, we propose a transparent and efficient design of discrete-time integral controllers accounting sampling skew. Based on the proposed controller, we derive a state-space representation of doubly coprime factorization including integral action. The representation is then used to obtain a convenient state-space parametrization of discrete-time two-degree-of-freedom integral controllers acconting sampling skew.

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Literary Representation of the Holocaust in Martin Amis's Time's Arrow (홀로코스트 문학의 재현방식 -마틴 에이미스의 『시간의 화살』)

  • Hong, Dauk-Suhn
    • Journal of English Language & Literature
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    • v.58 no.2
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    • pp.347-378
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    • 2012
  • Holocaust fiction has always raised the moral and aesthetic questions about the nature of mimesis and the literary representation of atrocity. The Holocaust, defying any representation of it, has been considered as unspeakable, unknowable, and incomprehensible. This essay aims to explore Martin Amis's narrative strategies in Time's Arrow to conduct the difficult tasks of re-creating the primal scene and of discovering a moral reality behind the Holocaust. One of the major narrative experiments in Time's Arrow is the time reversal: the story moves from the present of phony innocence to the past of unrelieved horror. Reversing the temporal order of events reverses causality and generates the revision of the morality, ultimately creating the epistemological and ontological uncertainties. Amis's novel is also narrated from the perspective of a double persona of the protagonist who, as a Nazi doctor, participated in the massacre in Auschwitz and then fled to the United States following the war. As almost a self-conscious storyteller, the narrator shares a sense of retrospective guilt with the reader who finally realizes that the Holocaust was a world turned upside down morally. Amis's postmodern narrative strategies are unusual enough to warrant a new way of representing the Holocaust.

Topology Representation for the Voronoi Diagram of 3D Spheres

  • Cho, Young-Song;Kim, Dong-Uk;Kim, Deok-Soo
    • International Journal of CAD/CAM
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    • v.5 no.1
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    • pp.59-68
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    • 2005
  • Euclidean Voronoi diagram of spheres in 3-dimensional space has not been explored as much as it deserves even though it has significant potential impacts on diverse applications in both science and engineering. In addition, studies on the data structure for its topology have not been reported yet. Presented in this, paper is the topological representation for Euclidean Voronoi diagram of spheres which is a typical non-manifold model. The proposed representation is a variation of radial edge data structure capable of dealing with the topological characteristics of Euclidean Voronoi diagram of spheres distinguished from those of a general non-manifold model and Euclidean Voronoi diagram of points. Various topological queries for the spatial reasoning on the representation are also presented as a sequence of adjacency relationships among topological entities. The time and storage complexities of the proposed representation are analyzed.

An Analysis of the Momentum Effect by the Representation Patterns of Science Concepts (과학 개념의 표현 양식별 학습 지속 효과)

  • Kim, Jun-Tae;Kwon, Jae-Sool
    • Journal of The Korean Association For Science Education
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    • v.14 no.2
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    • pp.111-122
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    • 1994
  • This study tried to find the effect to the representation patterns of science concepts upon the momentum effect. The previous studies showed that the momentum effect is influenced by students' cognitive levels and the abstractness of test items. The representation patterns of science concepts are divided into 4 different types: quantitative and qualitative, verbal and image. The research method used in this study is time series design. The period is 50 days. The period is divided into "pre-lest", "intervention-test", "post-test". Pre-test period is 5 days and in this period class instruction does not exist. Intervention-lest period is 30 days and in this period class instruction exist. Post-test period is 15 days and in this period class instruction does not exist. The results showed longer momentum effect on the image-qualitative representation pattern than the other representation patterns. Qualitative concepts is formed better than quantitative. Momentum effects is not artifact but the essential characteristics of science study.

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Modeling in System Engineering: Conceptual Time Representation

  • Al-Fedaghi, Sabah
    • International Journal of Computer Science & Network Security
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    • v.21 no.3
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    • pp.153-164
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    • 2021
  • The increasing importance of such fields as embedded systems, pervasive computing, and hybrid systems control is increasing attention to the time-dependent aspects of system modeling. In this paper, we focus on modeling conceptual time. Conceptual time is time represented in conceptual modeling, where the notion of time does not always play a major role. Time modeling in computing is far from exhibiting a unified and comprehensive framework, and is often handled in an ad hoc manner. This paper contributes to the establishment of a broader understanding of time in conceptual modeling based on a software and system engineering model denoted thinging machine (TM). TM modeling is founded on a one-category ontology called a thimac (thing/machine) that is used to elaborate the design and analysis of ontological presumptions. The issue under study is a sample of abstract modeling domains as exemplified by time. The goal is to provide better understanding of the TM model by supplementing it with a conceptualization of time aspects. The results reveal new characteristics of time and related notions such as space, events, and system behavior.

Afterlife with Image: Life and Death in Portraiture (이미지 속에서 살아남다? 초상화에서의 삶과 죽음)

  • Shin, Seung-Chol
    • The Journal of Art Theory & Practice
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    • no.16
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    • pp.139-174
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    • 2013
  • Pliny the Elder said that multiple cultures agree that the painting began as a shadow trace. A daughter of Butades, the potter in Corinth, traced an outline around a man's shadow, and it was the very beginning of painting. In this anecdote, the profile, i. e. the portrait substitutes body of the absent lover. It makes the absent body present and replaces his place. In this context Hans Belting put the anthropological value to this visual practice. Human being made images to cope actively with the shock of death and the disappearing of body. With the aid of the representation of the bodily presence, the image struggles to resist the death. This paper is a study on the critical meaning of representation in the context of bodily survival by image. The representation is the paradoxical trick of consciousness, an ability to see something as 'there' and 'not there' at the same time. So the connection between image and the body would be suspicious. Although this relation was tight in the ancient shadow painting and the medieval effigies, the modern visual practice forsakes this connection and exposes the trick of representation. It insists that image was not real and even expels the medieval visual practice from the boundary of fine arts. The genealogy of the portraiture is formed by two different visual practices. The belief and the disbelief in the image are observed in the process of representation and anti-representation, and this ambivalence transforms the ontological meaning of portrait in the visual representation.

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State-Space Representation of Complementary Filter and Design of GPS/INS Vertical Channel Damping Loop (보완 필터의 상태 공간 표현식 유도 및 GPS/INS 수직채널 감쇄 루프 설계)

  • Park, Hae-Rhee
    • Journal of Institute of Control, Robotics and Systems
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    • v.14 no.8
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    • pp.727-732
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    • 2008
  • In this paper, the state-space representation of generalized complimentary filter is proposed. Complementary filter has the suitable structure to merge information from sensors whose frequency regions are complementary. First, the basic concept and structure of complementary filter is introduced. And then the structure of the generalized filter and its state-space representation are proposed. The state-space representation of complementary filter is able to design the complementary filter by applying modern filtering techniques like Kalman filter and $H_{\infty}$ filter. To show the usability of the proposed state-space representation, the design of Inertial Navigation System(INS) vertical channel damping loop using Global Positioning System(GPS) is described. The proposed GPS/INS damping loop lends the structure of Baro/INS(Barometer/INS) vertical channel damping loop that is an application of complementary filter. GPS altitude error has the non-stationary statistics although GPS offers navigation information which is insensitive to time and place. Therefore, $H_{\infty}$ filtering technique is selected for adding robustness to the loop. First, the state-space representation of GPS/INS damping loop is acquired. And next the weighted $H_{\infty}$ norm proposed in order to suitably consider characteristics of sensor errors is used for getting filter gains. Simulation results show that the proposed filter provides better performance than the conventional vertical channel loop design schemes even when error statistics are unknown.

A STUDY ON THE TIME-VARYING POWER SPECTRUM ESTIMATION ALGORITHM USING TIME-FREQUENCY REPRESENTATION (시주파수 표현에 의한 시변파워스펙트럼 추정 알고리즘에 관한 연구)

  • Lee, Jeong-Whan;Lee, Joon-Young;Lee, Dong-Joon;Kim, Han-Soo;Jeon, Woo-Chul;Lee, Myoung-Ho
    • Proceedings of the KIEE Conference
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    • 1999.07b
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    • pp.991-993
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    • 1999
  • This study proposed a new algorithm to assess autonomic function activity using Time-Frequency Representation(TFR). TFR is a way of describing the time-valiant energy of a signal. A discrete Wigner representation that is capable of filtering out any cross terms occuring in the Wigner-Ville Distribution(WVD) is used for time-variant energy distribution of heart rate variability(HRV) signals. And the marginal condition are evaluated to estimate power spectrum of HRV signals. The proposed algorithm showed that estimated power spectrum of HRV signals well describe the autonomic nerve system function and also showed the dynamics of autonomic nervous system response.

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Efficient Acquisition of High-Quality ISAR Images Using the Discrete Gabor Representation in an Oversampling Scheme (Oversampling 형태를 갖는 Discrete Gabor Representation을 이용한 고품질 표적 ISAR 영상의 효율적인 획득)

  • Park, Ji-Hoon;Yang, Woo-Yong;Bae, Jun-Woo;Kang, Seong-Cheol;Myung, Noh-Hoon
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.24 no.5
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    • pp.566-573
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    • 2013
  • Inverse synthetic aperture radar(ISAR) images have been widely used in non-cooperative target recognition(NCTR). One of the most important issues in ISAR imaging is the improvement of the image smeared by target motion. In this paper, we propose the discrete Gabor representation(DGR) in an oversampling scheme for efficient acquisition of high-quality ISAR images. The DGR compartmentally assigns the Gabor coefficients to unit cells of the time-frequency grid related to the given Gabor logons. Thus, it can show an excellent time-frequency concentration and effectively discriminates the Doppler components from point-scatterers. The simulation results demonstrated that the DGR not only obtained high-quality ISAR images but also retained computational efficiency.

Discrete Representation Method of Nonlinear Time-Delay System in Control

  • Park, Ji-Hyang;Chong, Kil-To
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.327-332
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    • 2003
  • A new discretization method for nonlinear system with time-delay is proposed. It is based on the well-known Taylor series expansion and the zero-order hold (ZOH) assumption. We know that a discretization of linear system can be obtained with the ZOH assumption and within the sampling interval. A similar line of thinking is available in nonlinear case. The mathematical structure of the new discretization method is explored and under the structure, the sampled-data representation of nonlinear system including time-delay is computed. Provided that the discrete form of the single input nonlinear system with time-delay is derived, this result is easily extended to nonlinear system with multi-input time-delay. For simplicity two inputs are considered in this study. It is enough to generalize that of multiple inputs. Finally, the time-discretization of non-affine nonlinear system with time-delay is investigated for apply all nonlinear system

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