• Title/Summary/Keyword: space-Time

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Coded Layered Space-Time Transmission with Signal Space Diversity in OFDM Systems (신호 공간 다이버시티 기법을 이용한 OFDM 기반의 부호화된 시공간 전송기법)

  • Kim, Ji-Hoon;Lee, In-Kyu
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.32 no.7C
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    • pp.644-651
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    • 2007
  • In multiple antenna systems, vertical Bell Labs Layered Space-Time (V-BLAST) systems enable very high throughput by nulling and cancelling at each layer detection. In this paper, we propose a V-BLAST system which combines with signal space diversity technique. The benefit of the signal space diversity is that we can obtain an additional gain without extra bandwidth and power expansion by applying inphase/quadrature interleaving and the constellation rotation. Through simulation results, it is shown that the performance of the proposed system is less than 0.5dB away from the ideal upper bound.

Close Looking at Gilles Deleuze's Any-Space-Whatever (무규정 공간 자세히 보기)

  • Kim, Jung-Ho;Kim, Jae Sung
    • The Journal of the Korea Contents Association
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    • v.21 no.12
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    • pp.765-790
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    • 2021
  • The affection-image is the close-up of the face with real connections in space-time, or with virtual conjunction, outside spatio-temporal co-ordinates. The close-up can carry its own space-time in background. with deframing and fragmentation, Space itself has left behind its own space-time connection and become any-space-whatever that is the affection-image. The elements of any-space-whatever are the shadows, lyrical abstraction, the colors, the disconnected parts, the empty space. Deleuze examines any-space-whatever through the close ups, fragmentation of space and de-framing in Dreyer and Bresson's cinema.

Gamma-Ray Burst Observation by SNIPE mission

  • Lee, Jae-Jin;Kim, Hong Joo;Nam, Uk-Won;Park, Won-Kee;Shon, Jongdae;Kim, Soon-Wook;Kim, Jeong-Sook;Kang, Yong-Woo;Uhm, Z. Lucas;Kang, Sinchul;Im, Sang Hyeok;Kim, Sunghwan
    • The Bulletin of The Korean Astronomical Society
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    • v.45 no.1
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    • pp.39.3-40
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    • 2020
  • For the space weather research, KASI (Korea Astronomy and Space Science Institute) is developing the SNIPE (Small-scale magNetospheric and Ionospheric Plasma Experiment) mission, which consists of four 6U CubeSats of ~10 kg. Besides of space weather research, the SNIPE mission has another astrophysical objective, detecting Gamma-Ray Bursts(GRB). By cross-correlating the light curves of the detected GRBs, the fleet shall be able to determine the time difference of the arriving signal between the satellites and thus determine the position of bright short bursts with an accuracy ~100'. To demonstrate the technology of the GRB observation, CSI gamma-ray detectors combined with GPS and IRIDIUM communication modules are placed on each SNIPE CubeSat. The time of each spacecraft is synchronized and when the GRB is detected, the light curve will be transferred to the Mission Operation Center (MOC) by IRIDIUM communication module. By measuring time difference of each GRB signals, the technology for localization of GRB will be proved. If the results show some possibilities, we can challenge the new astrophysical mission for investigating the origin of GRB.

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Time and Space through Minimum Units in Animation -Focus on Structural Linguistics- (애니메이션의 시간소와 공간소를 통한 시간성과 공간성 -구조주의 언어학을 중심으로-)

  • Kim, Ji-Hong
    • The Journal of the Korea Contents Association
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    • v.7 no.10
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    • pp.126-134
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    • 2007
  • It have been studied many researches for time and space in film, drama and even animation. This study, however, is for investigating a new methodology of time and space study base on the structural linguistics. It can not be detected any of previous study on this method, and it is the first time to try out for researching with the structural linguistics of time and space in animation with this concept. In order to study on the time and space by applying a new method of structural linguistics, it is identify the terminology and concept of the minimum unite of time and space and than analysis with paradigmatic and syntagmatic. Consequence of this study, it can suggest a new methodology of study in the ways of structural linguistics in animation. Further study is to apply this method on character design in animation.

An Optimal Space Time Coding Algorithm with Zero Forcing Method in Underwater Channel (수중통신에서 Zero Forcing기법을 이용한 최적의 시공간 부호화 알고리즘)

  • Kwon, Hae-Chan;Park, Tae-Doo;Chun, Seung-Yong;Lee, Sang-Kook;Jung, Ji-Won
    • Journal of Navigation and Port Research
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    • v.38 no.4
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    • pp.349-356
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    • 2014
  • In the underwater communication, the performance of system is reduced because of the inter-symbol interference occur by the multi-path. In the recent years, to deal with poor channel environment and improve the throughput, the efficient concatenated structure of equalization, channel codes and Space Time Codes has been studied as MIMO system in the underwater communication. Space Time Codes include Space Time Block Codes and Space Time Trellis Codes in underwater communication. Space Time Trellis Codes are optimum for equalization and channel codes among the Space Time Codes to apply in the MIMO environment. Therefore, in this paper, turbo pi codes are used for the outer code to efficiently transmit in the multi-path channel environment. The inner codes consist of Space Time Trellis Codes with transmission diversity and coding gain in the MIMO system. And Zero Forcing method is used to remove inter-symbol interference. Finally, the performance of this model is simulated in the underwater channel.

A Study on the Enhancement of Detection Performance of Space Situational Awareness Radar System

  • Choi, Eun-Jung;Lee, Jonghyun;Cho, Sungki;Moon, Hyun-Wook;Yum, Jea-Myong;Yu, Jiwoong;Park, Jang-Hyun;Jo, Jung Hyun
    • Journal of Astronomy and Space Sciences
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    • v.35 no.4
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    • pp.279-286
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    • 2018
  • Radar sensors are used for space situational awareness (SSA) to determine collision risk and detect re-entry of space objects. The capability of SSA radar system includes radar sensitivity such as the detectable radar cross-section as a function of range and tracking capability to indicate tracking time and measurement errors. The time duration of the target staying in a range cell is short; therefore, the signal-to-noise ratio cannot be improved through the pulse integration method used in pulse-Doppler signal processing. In this study, a method of improving the signal-to-noise ratio during range migration is presented. The improved detection performance from signal processing gains realized in this study can be used as a basis for comprehensively designing an SSA radar system.

Statistical Inference for Space Time Series Model with Application to Mumps Data

  • Jeong, Ae-Ran;Kim, Sun-Woo;Lee, Sung-Duck
    • Journal of the Korean Data and Information Science Society
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    • v.17 no.2
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    • pp.475-486
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    • 2006
  • Space time series data can be viewed either as a set of time series collected simultaneously at a number of spatial locations or as sets of spatial data collected at a number of time points. The major purpose of this article is to formulate a class of space time autoregressive moving average (STARMA) model, to discuss some of the their statistical properties such as model identification approaches, some procedure for estimation and the predictions. For illustration, we apply this STARMA model to the mumps data. The data set of mumps cases consists of the number of cases of mumps reported from twelve states monthly over the years 1969-1988.

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Hybrid State Space Self-Tuning Fuzzy Controller with Dual-Rate Sampling

  • Kwon, Oh-Kook;Joo, Young-Hoon;Park, Jin-Bae;L. S. Shieh
    • 제어로봇시스템학회:학술대회논문집
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    • 1998.10a
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    • pp.244-249
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    • 1998
  • In this paper, the hybrid state space self-tuning control technique Is studied within the framework of fuzzy systems and dual-rate sampling control theory. We show that fuzzy modeling techniques can be used to formulate chaotic dynamical systems. Then, we develop the hybrid state space self-tuning fuzzy control techniques with dual-rate sampling for digital control of chaotic systems. An equivalent fast-rate discrete-time state-space model of the continuous-time system is constructed by using fuzzy inference systems. To obtain the continuous-time optimal state feedback gains, the constructed discrete-time fuzzy system is converted into a continuous-time system. The developed optimal continuous-time control law is then convened into an equivalent slow-rate digital control law using the proposed digital redesign method. The proposed technique enables us to systematically and effective]y carry out framework for modeling and control of chaotic systems. The proposed method has been successfully applied for controlling the chaotic trajectories of Chua's circuit.

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A Study on the Property of Visual Perception of Interior Space - By revising the observation time of the design element - (실내공간의 주시특성에 관한 연구 - 전회공간의 주시시간 보정을 통해 -)

  • Choi, Gae-Young;Kim, Jong-Ha;Lee, Jeong-Ho
    • Korean Institute of Interior Design Journal
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    • v.18 no.5
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    • pp.128-136
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    • 2009
  • This study analyzed and defines the property of visual perception throughout the revision of the observation time of the original space and the rotating space. The conclusions of this study are as fellows: First, based on the existing theory and experiment, the study obtained the basis which decides the sector data originating fixation-gaze after staring the specific sector over 300ms time. It will become the turning point hereafter for our research to fix the time in this way. Second, in analyzing the minute data, the study built a revision method of the observation time by analyzing the meanings and the reasons of the revision of the original data. Third, according to the difference of revision quantity, female testee have more increases in the amount of data than male testee from the original screen. On the other hand, the opposite tendency appears from the previous data. This shows there is a difference in the observation properly by sex. Last, we could grasp Information about the property of the observation time throughout eyeball fixations, and the revision and analysis of the 'controlled observation data'. These data can be used in design element arrangement of interior space, hereafter.

A Study on the Features of Visual-Information Acquirement Shown at Searching of Spatial Information - With the Experiment of Observing the Space of Hall in Subway Station - (공간정보의 탐색과정에 나타난 시각정보획득특성에 관한 연구 - 지하철 홀 공간의 주시실험을 대상으로 -)

  • Kim, Jong-Ha
    • Korean Institute of Interior Design Journal
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    • v.23 no.2
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    • pp.90-98
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    • 2014
  • This study has analyzed the meaning of observation time in the course of acquiring the information of subjects who observed the space of hall in subway stations to figure out the process of spatial information excluded and the features of intensive searching. The followings are the results from the analysis of searching process with the interpretation of the process for information acquirement through the interpretation of observation area and time. First, based on the general definition of observation time, the reason for analyzing the features of acquiring spatial information according to the subjects' observation time has been established. The feature of decreased analysis data reflected that of observation time in the process of perceiving and recognizing spatial information, which showed that the observation was focused on the enter of the space during the time spent in the process of observing the space and the spent time with considerable exclusion of bottom end (in particular, right bottom end). Second, while the subjects were observing the space of hall in subway stations, they focused on the top of the left center and the signs on the right exit the most, which was followed by the focus on the both side horizontally and the clock on the top. Third, the analysis of consecutive observation frequency enabled the comparison of the changes to the observation concentration by area. The difference of time by area produced the data with which the change to the contents of spatial searching in the process of searching space could be known. Fourth, as the observation frequency in the area of I changed [three times -> six times -> 9 times], the observation time included in the area increased, which showed the process for the change from perception to recognition of information with the concentration of attention through visual information. It makes it possible to understand that more time was spent on the information to be acquired with the exclusion of the unnecessary information around.