• 제목/요약/키워드: time-space

검색결과 11,191건 처리시간 0.039초

On the Relationship Between the Performance Criteria of Unitary Space-Time Codes with Noncoherent and Coherent Decoding

  • Cheun, Kyung-Whoon;Kim, Jeong-Chang;Choi, Soong-Yoon
    • 한국통신학회논문지
    • /
    • 제35권12A호
    • /
    • pp.1145-1151
    • /
    • 2010
  • Hochwald et al. introduced unitary space-time codes for quasi-static Rayleigh fading channels which allows for noncoherent decoding when the channel response is not known at the receiver. However, when reliable information on the channel response is available, coherent decoding is preferable for improved performance. Here, we study the relationship between the performance criteria on the diversity and coding advantages provided by unitary space-time codes with noncoherent and coherent decoding. We show that when a unitary space-time code achieves full spatial diversity with noncoherent decoding, full spatial diversity is also guaranteed with coherent decoding.

근대 시각예술에서의 시-공간 운동성 표현에 관한 고찰 -구성주의 작품을 중심으로- (A Study on the Expression of Movement in the Space-Time of Modern Visual Art -Focused on the Constructivist Works-)

  • 이광인
    • 한국디지털건축인테리어학회논문집
    • /
    • 제7권1호
    • /
    • pp.15-20
    • /
    • 2007
  • This study is aimed to analyze the method of movement expression in the Space-Time of Modern Visual Art. According to the results of analysis. the following is obtained. (1) The still object is perceived by the sense or optical illusion, and its whole image is made through the information processing prodedure. The concept of Space-Time is integrated into the constructivist works by the composition of image through transforming the position of the fundamental geometry and projecting it. (2) The traditional notion that the work of art is still concept of is changed. The movement of observer is caused by inducing the direction and concept of time through the object in three dimensional space.

  • PDF

시각적 차원에 의한 건축 공간의 개념 형성에 관한 연구 (A Study on Formation of Concepts of Architectural Space based on the Optical Dimension)

  • 변대중
    • 한국실내디자인학회논문집
    • /
    • 제19권5호
    • /
    • pp.56-66
    • /
    • 2010
  • This study proposes a thesis of architectural concepts and visual dimension systems, and the comparison between steps of spatial formation and dimensional alteration. The second chapter, to form the basis of this study, explains the dimensional alterations and changes of fundamental notion of space. In the third chapter, history of space, architectural formations, and changes of the viewpoint are analyzed as objects of study. The forth chapter presents the interrelation between dimensional alteration and the transition in fundamental notion of space, demonstrating that modern architecture has been born from these cultural movements. Lastly, the fifth chapter suggests possibilities on further studies and the following conclusions: First, architectural spaces have been changed, in accordance with the changes of culture, art and the tools that regulate architectural design. Proportional regulations by two-dimensional tools and depth through three-dimensional drawings are created. Second, architectural spaces gained depth by recognizing movement and time that have induced formations to change, creating various aesthetic backgrounds and attempts. Third, the aesthetic background and cosmologic spatial concept have led the visualization and changes of architectural experience. It created the design tools and shapes originated in dynamism and vitality. Forth, diversification of fundamental spatial concepts has become palimpsest and complex, and been divided into four dimensions; expressional two-dimensional space, perspective three-dimensional space, forth-dimensional space of time and experience, and imagery space formed by body movement. Fifth, architecture has been influenced by the elevated viewpoint that understands the whole world as a space. It has evolved from the two-dimensional proportion principle, change of depth and vanishing point to multidimensional space of movement and time. Sixth, changes of fundamental notion of space have arisen from changes of visual dimensions in times. In other words, space has been developed from two-dimensional space to multidimensional space by accepting visual dimension, grasping distance, direction, depth, height, velocity, movement, gravity, power and structure.

시간지리학 응용을 위한 시공간데이터베이스 기반의 GIS 컴퓨팅 연구 (Geocomputation with Spatio-Temporal Database for Time Geography Application)

  • 박기호;이양원;안재성
    • Spatial Information Research
    • /
    • 제13권3호
    • /
    • pp.221-237
    • /
    • 2005
  • 이 논문에서는 시간지리학 모형을 위한 객체관계형 시공간데이터베이스를 구현하고, 이를 통해 시공간경로, 시공간프리즘, 시공간접근성에 대한 질의 및 시각화를 수행하는 GIS 컴퓨팅을 연구한다. 이러한 GIS 컴퓨팅환경은 (i) 시공간데이터베이스의 자료원이 되는 개인통행자료를 수집하는 모바일 애플리케이션, (ii) 시간지리학 모형을 포함하는 객체관계형 시공간데이터베이스 서버, (iii) 시공간데이터베이스와 연동하여 시간지리학 모형에 대한 질의와 시각화를 수행하는 3D 클라이언트로 구성된다. 시공간 개인통행자료는 GPS-PDA 클라이언트를 통해 일정시간 간격으로 자동 수집되고, 시공간자료관리 미들웨어의 중개를 거쳐 좌표변환 및 DB전송이 이루어진다. 일반 DBMS를 확장하여 구현한 시공간데이터베이스는 시간지리학 응용을 위한 시공간 객체 및 시공간함수를 포함하며, 이를 이용하여 시공간 SQL을 구성할 수 있다. 질의 및 시각화 클라이언트는 시공간경로, 시공간프리즘, 시공간접근성에 대한 SQL 질의 결과를 X-Y 공간축과 T 시간축으로 이루어진 시공간입방체를 통해 표현한다. 이 논문에서는 시간지리학 모형을 위한 모바일 GIS와 DBMS의 연동 가능성을 확인하였으며, 시공간객체와 시공간함수를 포함하는 객체관계형 시공간데이터베이스의 구현을 통해 대용량 자료처리를 위한 데이터베이스 기반의 시간지리학 데이터베이스 모델을 수립하였다.

  • PDF

Heliocentric Potential (HCP) Prediction Model for Nowscast of Aviation Radiation Dose

  • Hwang, Junga;Kim, Kyung-Chan;Dokgo, Kyunghwan;Choi, Enjin;Kim, Hang-Pyo
    • Journal of Astronomy and Space Sciences
    • /
    • 제32권1호
    • /
    • pp.39-44
    • /
    • 2015
  • It is well known that the space radiation dose over the polar route should be carefully considered especially when the space weather shows sudden disturbances such as CME and flares. The National Meteorological Satellite Center (NMSC) and Korea Astronomy and Space Science Institute (KASI) recently established a basis for a space radiation service for the public by developing a space radiation prediction model and heliocentric potential (HCP) prediction model. The HCP value is used as a critical input value of the CARI-6 and CARI-6M programs, which estimate the aviation route dose. The CARI-6/6M is the most widely used and confidential program that is officially provided by the U.S. Federal Aviation Administration (FAA). The HCP value is given one month late in the FAA official webpage, making it difficult to obtain real-time information on the aviation route dose. In order to overcome this limitation regarding time delay, we developed a HCP prediction model based on the sunspot number variation. In this paper, we focus on the purpose and process of our HCP prediction model development. Finally, we find the highest correlation coefficient of 0.9 between the monthly sunspot number and the HCP value with an eight month time shift.

현상학 측면에서 본 한국 전통주거건축의 부분성에 관한 연구 (Study on the Characteristic of Partiality in Korean Traditional Residential Architecture in view of the Phenomenology)

  • 육옥수
    • 한국주거학회논문집
    • /
    • 제27권5호
    • /
    • pp.73-81
    • /
    • 2016
  • Focused on developing form of Western architecture, invisible elements covering actual human life has been dealt with separately and the time was turned away and disparaged. But now the phenomenology, arranging such a meeting of space and time, gives opportunity to look at the actual life in architecture. Recently, Guille Deleuze and Merleau-Ponty tried to recover the sense of touch segregated in skin from body keeping eyes for distance. And the activity can be happened by being connected to the body rather than to eye in the space. From the phase of recognition where the human body tries to identify the object in the space considering a time, it will be changed for the subject to the phase of space-time structure. If the tactility is to erase the distance different from the visuality in dichotomy, it will be occurred to having a tension and makes new relationship to work trying to move the subjective point of view in object. Like this evidence in analysis of architecture, it can be found these in the Korean traditional architecture rather than Western architecture in terms of emphasizing the time and space. And this study will be intensive to the side of the Phenomenology how it is being connected to the movement in the space and time for the subject and object.

Combination of Array Processing and Space-Time Coding In MC-CDMA System

  • Hung Nguyen Viet;Fernando W. A. C
    • 대한전자공학회:학술대회논문집
    • /
    • 대한전자공학회 2004년도 ICEIC The International Conference on Electronics Informations and Communications
    • /
    • pp.302-309
    • /
    • 2004
  • The transmission capacity of wireless communication systems may become dramatically high by employ multiple transmit and receive antennas with space-time coding techniques appropriate to multiple transmit antennas. For large number of transmit antennas and at high bandwidth efficiencies, the receiver may become too complex whenever correlation across transmit antennas is introduced. Reducing decoding complexity at receiver by combining array processing and space-time codes (STC) helps a communication system using STC to overcome the big obstacle that prevents it from achieving a desired high transmission rate. Multi-carrier CDMA (MC-CDMA) allows providing good performance in a channel with high inter-symbol interference. Antenna array, STC and MC-CDMA system have a similar characteristic that transmit-receive data streams are divided into sub-streams. Thus, there may be a noticeable reduction of receiver complexity when we combine them together. In this paper, the combination of array processing and STC in MC-CDMA system over slow selective-fading channel is investigated and compared with corresponding existing MC-CDMA system using STC. A refinement of this basic structure leads to a system design principle in which we have to make a trade off between transmission rate, decoding complexity, and length of spreading code to reach a given desired design goal.

  • PDF

카페공간에서 방문의도성과 대상체의 유무에 따른 관심영역 분석 (An Analyzed the Area of Interest based on the Visiting Intention and Existence of People in Cafe Space)

  • 김주연
    • 한국실내디자인학회논문집
    • /
    • 제25권5호
    • /
    • pp.130-139
    • /
    • 2016
  • To determine "how humans move in space, what they want, and through which visual information they act and choose," this study aims to define in which sense space is preferred in gaze. The ultimate goal is to extract data of human visual awareness and preference in space. This study analyzed the observation characteristics perceived through observation frequency and time depending on the purpose cafe customers to understand what intension of visiting the space has on the observation characteristics which are the results obtained as information through visual perception. This research methods are as follows. First, the areas of preference in $caf{\acute{e}}$ space gazed by visual concentration are analyzed by divided into 12 by 12 grid A and B images separated depends on existence of people. Second, eye-tracking visual path in conscious gaze is analyzed to examine. Third, though the higher section frequency is likely to have more observation time, the interest area of I(3sec/180), II(6sec/360) and III(9sec/540) had higher frequency of Intention. The followings are the results of this study. First, the time range for searching or wandering and the observation characteristics could be estimated by the meaning of observation time by grade with the time-range out of the distribution of sections. Second, at the time distribution by section, when there was intention, the observation time was found to have higher occupation. In conclusion, this study is to determine the correlation of human concentration gazing at space images. It is an exploratory research on research methodologies, and aims to develop methodologies and provide basic data to plan attractive spaces in light of the subconscious of consumers in the future by interpreting gaze data related to concentration.

동서양 건축에서의 공간과 시간 (Space and Time in the Architectures of the East and the West)

  • 김성우
    • 건축역사연구
    • /
    • 제13권3호
    • /
    • pp.97-117
    • /
    • 2004
  • The tradition of architecture in the East and the West are different in many ways. One of the basic cause of such difference, however, is the different ways of perception of space and time. This paper aims to identify the attitude of perception of space and time in the cultures of the East and the West, and its influence on architecture. Degrees of importance placed on either space or time, as well as the modes of perception of space and time are discussed in relation to architecture. Basically, the architecture of the West seems to be more spatially oriented than the East, and this have much to do with the fact that the tradition of Western architecture is visually oriented. On the other hand, East Asian architecture have been more conscious on bodily feeling and its movement in architecture. Spatial units of traditional Eastern architecture, are arranged in such a way in which man can experience the change of space that is supposed to be organized to form a sequential message. Thus, in the East, temporal dimension is more deliberately included in the course of architectural experience compared to the cases of the West. Although it is not easy to attempt any kind of value judgment on such aspects, it is necessary to understand how the different perception of space and time influenced architectural outcome, especially when one wants to understand the cultural cause that have made the architectures of the East and the West very different. Such understanding is particularly important in East Asia where their future of architecture depends much on how they harmonize the Eastern and Western background which are already built up as two cultural structure in their consciousness to be able to create more desirable architecture for themselves.

  • PDF

정기선 선복 확보를 위한 Space Chartering의 경제성에 관한 연구 (An Empirical Study on the Economic Benefit of Space Chartering)

  • 박두진;김현;남기찬
    • 한국항해항만학회지
    • /
    • 제30권8호
    • /
    • pp.663-668
    • /
    • 2006
  • 오늘날 세계 해운 시황의 호황에 따라 컨테이너 정기선 부분에서는 선복량의 부족 현상이 초래되고 있으며 선사는 신조선 발주와 중고선 구입 및 정기 용선을 통해 부족한 선복 문제를 해결하고 있다. 특히, 정기선사들은 신조선 발주시 TUE당 운송비용을 절감하기 위하여 컨테이너선의 대형화를 적극적으로 추진하고 있다. 이러한 대형 컨테이너선박의 발주를 통한 선복 확보 방안은 차후 선복 과잉 문제가 발생될 수 있음이 컨테이너선의 실증 분석을 통해 연구되었다. 본 논문에서는 2008년 이후 대형 컨테이너선이 대거 인도되는 시기에 선복량의 과잉공급으로 인한 해운시황의 변동에 따른 선사의 대응 전략 방안에 대해 연구한다. 즉, 경제성 분석을 바탕으로 한 초대형 컨테이너선의 Space Chartering 시점에 대한 선사의 전략 수립에 대해 논의한다.