• Proceedings of the Korea Water Resources Association Conference
• /
• 2009.05a
• /
• pp.1658-1662
• /
• 2009

최근 들어 기후 변화로 인한 이상 강우 현상과 기록적인 집중 강우로 탁수 발생의 빈도와 강도가 증가하고, 탁수의 장기간 하류 방류로 인해 경제적인 피해가 발생할 뿐만 아니라 환경적으로도 중요한 문제로 대두되고 있다. 저수지로 유입된 탁수의 시공간적 분포 예측 결과의 신뢰도는 탁수 밀도류 해석의 정확도에 가장 큰 영향을 받으므로 유입 하천수의 밀도 거동에 대한 정확한 해석이 필요하다. 따라서 탁수의 거동해석은 수리 및 수질의 연동 모의(Coupled modeling)가 필수적이다. 본 연구의 목적은 수리 및 수질의 연동 해석이 가능한 2차원 횡 방향 평균 모형(CE-QUAL-W2)을 소양호에 구축하고, 기록적인 강우 사상을 보인 2006년 수문조건에서의 모형의 적용성과 한계점을 평가하는데 있다. 구축한 소양호 탁수 예측 모델을 2006년 탁수사상에 적용한 결과, 홍수 사상으로 이중 첨두 유량이 발생한 후 저수지 내에서 중층 밀도류와 바닥밀도류의 두 가지 밀도류 형태가 혼재하여 진행되는 현상이 적절히 모의되었다. 하지만, 저수지내에서 측정한 탁수 수괴(plume)의 시공간적 수직분포(profiles)는 모의결과와 다소 편차를 보였으며, 특히 저수지 바닥 인근에서 모델은 실측값을 과대평가 하였다. 오차의 원인은 모델 입력 자료의 불확실성과 수치모델의 불확실성으로 판단된다. 따라서 향후 탁수 거동 모델링과정의 불확실성을 최소화하고 모의결과의 신뢰도를 개선하기 위해서 극한탁수 사상에서 발생하는 수리학적 현상과 SS 입자 동력학에 대한 이론적 연구와 입력 자료의 정확한 산정을 위한 현장 실험이 필요하다.

• The KIPS Transactions:PartC
• /
• v.13C no.7 s.110
• /
• pp.865-872
• /
• 2006

Cooperative communications (CC) have received a great deal of attention recently as an efficient way to obtain the spatial diversity without physical arrays. Thus, space-time block codes (STBC) which are well-known for use in co-located multi-antenna systems can be still utilized for single-antenna users in a distributed fashion. In this paper, we propose a cooperative signaling structure using the $\frac{3}{4}$-rate STBC and derive closed-form BER expression which takes the effect of network geometry and transmit power constraint into account. A variety of simulated and numerical results demonstrated the cooperation considerably outperforms the direct transmission when partners are located in appropriate positions.

• Journal of the Economic Geographical Society of Korea
• /
• v.22 no.4
• /
• pp.592-609
• /
• 2019

This study attempts to expand the leverage cycle theory using the subprime real estate investors. The leverage cycle theory has demonstrated asset price fluctuations irrelevant to changes in fundamentals through the restructuring of transaction composition centered on optimistic buyers. However, it needs to understand how this theory works in the depressed housing market with low-income residential regions to explain the geographic origins of the financial crisis. In the depressed housing market, the subprime real estate investors focused on low-income residential regions. Through this spatial focus, the low-income residential regions solely have real estate investor-oriented composition of new purchase transactions in the depressed housing market. The discovery of the subprime real estate investors as new actors lays the foundation for applying the leverage cycle theory to the depressed housing market which has been a underserved area for capital investment. This attempt illustrates how the geographical reinterpretation of an economic theory reestablishes spatio-temporal context of economic phenomena.

• Proceeding of EDISON Challenge
• /
• 2017.03a
• /
• pp.110-117
• /
• 2017

Multiscale Simulation은 sub-nano scale의 전자 구조에서부터 macro scale의 multibody system에 이르기까지 다양한 시간/공간 스케일을 관통하는 시뮬레이션 기법이다. 즉, 전자수준에서의 변화로 인한 분자 전체의 구조 변화와 그에 따른 기능의 변화를 알 수 있는 simulation 방법으로 다양한 스케일에서 분자의 정보를 얻을 수 있다는 점에서 최근 중요하게 여겨지는 시뮬레이션 방법 중 하나이다. 따라서 본 연구에서는 몇 가지의 EDISON_CHEM 솔버들을 조합하여 Multiscale Simulation의 가능성을 제시하고자 한다. 또한, 세부적으로 양자계산 시에 어떤 이론을 선택하여 계산하면 더 정확한지, basis set 선택 시 발생하는 basis set superposition error(BSSE)로 인한 분자 수준의 물성의 오차는 어느정도 인지 알아보고자 했다. 본 연구에서는 비교적 간단하지만 온실 가스이자 에너지원으로 각광받고 있는 메탄을 대상으로 하였다. 다양한 시공간 스케일을 다루는 에디슨 솔버들 중에 양자 수준의 계산을 할 수 있는 솔버로는 "GAMESS"를 이용했고, 이 결과를 통해 분자 수준의 물성을 알아보기 위한 솔버로는 "사용자 지정 역장을 사용한 일반 분자동력학(general_MD)"과 "두가지 서로 다른 종류의 LJ입자에 대한 분자동력 시뮬레이션 프로그램(sejong_lj))"을 이용했다. 메탄의 상 전이 과정에 대한 연구 결과 Hartree fock (HF) self-consistent theory를 통해 얻은 force field 보다는 Second-order Møller-Plesset (MP2) perturbation theory로 얻은 force field가 더 정확한 상 전이 온도를 예측한다는 것을 메탄의 coarse-grained simulation을 통해 알 수 있었다. 또한, MP2 이론으로 구한 force field에서 BSSE를 보정해주면 실험적으로 구한 메탄의 상 전이 온도와 더 근사한 값의 시뮬레이션 결과를 얻을 수 있었다. 이를 통해 전자 간의 상호작용을 더 정교하게 계산하는 MP2 이론으로 force field를 구해서 BSSE를 보정해주면 계산의 결과가 정확해진다는 것을 알 수 있었으며 이것이 EDISON_CHEM의 솔버들로 가능하다는 것을 제시하였다.

• Journal of Korean Philosophical Society
• /
• v.148
• /
• pp.157-181
• /
• 2018

The aim of this essay is to identify elements of methodologies to investigate the development of Newtonian dynamics. This methodology involves the transformation and synthesis of preceding theories. My essay attempts to confirm my assertion by analyzing historical case of Newton's discovery of his dynamics. While discovering his mechanistic theory, Newton reconstructed theoretical concepts and structures of intellectual predecessors, such as Aristotle, Descartes, Galileo, and Kepler. Newton's synthesis was possible only after carefully reconstructing the appropriate and useful ideas of previous natural philosophers' ideas. As a result, Newtonian dynamics are completed with these modified and integrated concepts incorporated into Newton's law of motion and space-time concepts. This study consists of two parts. First, Lakatos' research program has been applied in order to analyze the structure of Newtonian dynamics. Second, the aforementioned methodologies of discovery are distilled from the case study.

• Korean Association for Visual Culture
• /
• v.35
• /
• pp.5-33
• /
• 2019

This paper examines the problems of the concept of 'analogon' which occupies an important place in Jean-Paul Sartre's theory of imagination and his 'aesthetic of the unreal', focusing on Michel Dufrenne's objection to the concept. In the Imaginary (1940), Sartre offers a phenomenological account of the imaginative experience and his theory of imagination provides the basis for his account of experience of art. Sartre distinguishes the imagining consciousness from the realizing consciousness of perception. The work of art, for Sartre, is transformed into an irreal thing ("The work of art is irreality."), i.e. it appears only as aesthetic object, and only under the condition that the spectator's consciousness changes into an imagining consciousness. Some claim that Sartre underemphasizes the function of materiality in artworks. Mikel Dufrenne, in his The Phenomenology of Aesthetic Experience (1953), criticizes Sartre's thesis of irreality. Dufrenne argues that the aesthetic object is the work of art accomplished by aesthetic perception, the meaning of the aesthetic object is given as a whole in the sensuous and does not refer to something that lies outside the object as with imagination or irreality. An affective a priori is the condition of possibility for the occurrence of aesthetic experience.

• Journal of KIISE:Computer Systems and Theory
• /
• v.35 no.1
• /
• pp.44-52
• /
• 2008

In this paper we consider detecting collisions between characters whose motion is specified by motion capture data. Since we are targeting on massive crowd simulation, we only consider rough collisions, modeling the characters as a disk in the floor plane. To provide efficient collision detection, we introduce a hierarchical bounding volume, the Motion Oriented Bounding Box tree (MOBB tree). A MOBBtree stores space-time bounds of a motion clip. In crowd animation tests, MOBB trees performance improvements ranging between two and an order of magnitude.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2022.10a
• /
• pp.536-538
• /
• 2022

Since the invention of a novel diversity technique, namely a space-time line code (STLC), though the previous studies have theoretically analyzed the error rate and ergodic capacity, the outage probability has not been revealed yet. In this paper, we characterize the probability density function of the instantaneous signal-to-noise ratio, and mathematically derive the closed-form expression of the outage probability. Based on numerical simulations, furthermore, we validate the accuracy of the mathematical analysis, and present the insight into the system design and implementation.

• The Journal of the Korea Contents Association
• /
• v.9 no.12
• /
• pp.138-145
• /
• 2009

Humanism connotes dignity and esteem with the essential idea of human and more human. This paper has conducted a inquiry of the understanding about human and humanism represented by visual image of film. Especially, this study investigated the way to adhere to reflective attitude about human and society. It is based on theoretical discussion of formalism and auteurism and analyzed the way of constructing time-space structure of (by Lars von Trier) which is known the typical formalism film. According to the findings, appeared to appropriate the ocularcentrism aesthetic to film form and give the self-regulation to definite the idea of film art through picturesque imagination of dramatic stage. Such a result means that it converts the filmic time-space to the virtual things and practicalize the classification of the ethical doctrine of innate goodness and innate sin of human and the definition of humanism. Also it means formalism film overturns the existing institutional mode of representation.

• Cartoon and Animation Studies
• /
• s.49
• /
• pp.203-220
• /
• 2017

In the field of visual arts, the introduction of synthesis allowed us to express various expressions that were outside the constraints of time and space. Digital synthesis is constrained by realistic representation due to technical limitations. However, it is no exaggeration to say that after digital synthesis has been fully established, at least the limits of image representation through synthesis have almost disappeared. The existing research papers on composing are either technical studies on the production techniques, or the synthesis was mainly focused on the change of the space-time concept and meaning of the visual arts. I felt the need for research on. In addition, I felt the need to look back on the changes in my view of art. Therefore, in this paper, rather than dealing with the conceptual theory of the technical part or spatio-temporal extension, it is necessary to classify it as natural, heterogeneous, heterogeneous and natural according to the traits revealed in the artistic expression of art, And diversity.