• Title/Summary/Keyword: 공간-시간

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Low-area Bit-parallel Systolic Array for Multiplication and Square over Finite Fields

  • Kim, Keewon
    • Journal of the Korea Society of Computer and Information
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    • v.25 no.2
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    • pp.41-48
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    • 2020
  • In this paper, we derive a common computational part in an algorithm that can simultaneously perform multiplication and square over finite fields, and propose a low-area bit-parallel systolic array that reduces hardware through sequential processing. The proposed systolic array has less space and area-time (AT) complexity than the existing related arrays. In detail, the proposed systolic array saves about 48% and 44% of Choi-Lee and Kim-Kim's systolic arrays in terms of area complexity, and about 74% and 44% in AT complexity. Therefore, the proposed systolic array is suitable for VLSI implementation and can be applied as a basic component in hardware constrained environment such as IoT.

사이버대학, 교실의 해체가 아닌 교실의 확대이다

  • Han, Il-Hwan
    • 정보화사회
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    • s.138
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    • pp.44-47
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    • 2000
  • 사이버교육의 가장 큰 매력은 시간과 공간의 제약을 받지 않는다는 것과 학습자(수요자) 중심의 학습이 가능하다는 것이다. 사이버교육은 인터넷이 접속 가능한 환경에서는 언제 어디서나 자신의 필요에 따라 (on-demand), 적시에(just-in-time)교육을 받을 수 있기 때문에 접근성이 높다. 특정 시간에 특정 강의실을 찾아야 하는 전통 교육 방식과 비교했을 때, 시간과 비용의 불필요한 낭비를 제거하고, 교육 기회를 넓혀 준다.

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Diffusion Characteristics Based on the Gas Leakage Direction and Air Change per Hour in a Enclosed Space on Board a Ship (밀폐된 선내 공간에서 가스 누출방향과 환기횟수에 따른 확산특성)

  • Seong Min Lee;Ha Young Kim;Byeol Kim;Kwang Il Hwang
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.30 no.2
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    • pp.165-175
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    • 2024
  • Hydrogen is being touted as one of the energy sources to combat the climate change crisis. However, hydrogen can leak into enclosed spaces, rise to the ceiling, accumulate, and cause fires and explosions if it encounters an ignition source. In particular, ships that transport hydrogen or use it as a fuel comprise multiple enclosed spaces. Therefore, the dif usion characteristics within these spaces must be understood to ensure the safe use of hydrogen. The purpose of this study is to experimentally determine the diffusion characteristics of helium, which has similar properties to hydrogen, in a closed space on board a ship, and to determine the change in the oxygen concentration along the leakage direction as the air change per hour(ACH) increases to 25, 30, 35, 40, and 45 through CFD simulation. The study, results revealed that the oxygen concentration reduction rate was 2% for leakage in the -z direction and 1% for leakage in the +x and +z directions, and the ventilation time was 15 min 30 s for leakage in the -z direction, 7 min for leakage in the +x direction, and 9 min for leakage in the +z direction, showing that differences existed in the oxygen concentration and ventilation time depending on the leakage direction. In addition, no significant difference was observed in the rate of oxygen concentration reduction and ventilation time in all leakage directions from the ACH of 35 and above in the experimental space. Therefore, because the oxygen concentration and ventilation time were not improved by increasing the ACH, 35 was noted as the optimal ACH in this experimental environment.

Research on the Spatial Expression Characteristics of illustration in Picture Books (스토리형 그림책 속의 삽화 디자인의 시간적 표현 연구)

  • Han, YongGang;Kim, KieSu
    • The Journal of the Korea Contents Association
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    • v.21 no.7
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    • pp.59-70
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    • 2021
  • This paper studies and analyzes the effect of illustrations in picture books on time representation with fictional picture books as the study scope. In this paper, the time type of picture books can be divided into time point, timeline and time rhythm, referring to case analysis from time symbolic elements, picture layout and picture sequence respectively. First of all, time symbolic elements are referred to the time point and time rhythm. The materialized time symbolic element is things that can directly represent time and trigger associations with time; the color symbolic element means the color changes in the real world within a certain time; the contrast of light and shadow corresponds to the changes in a day. Fast-moving objects will be presented with dashed or blurred lines, while static, stable and slow objects will be depicted with solid lines. Secondly, the picture layout of illustrations in picture books is suitable for representing the content of the timeline and describing the sequence or causality of events. Finally, the picture sequence can represent the timeline, time rhythm and "synchronicity". It will make use of visual logic to win readers' trust in time information expressed in pictures, and then follow and connect viewpoints on the basis of adapting to reading habits. The essence of time representation in picture books is to express time by space, and use different combinations of elements in space and visual guidance to convey time information.

Short-term Power Load Forecasting using Time Pattern for u-City Application (u-City응용에서의 시간 패턴을 이용한 단기 전력 부하 예측)

  • Park, Seong-Seung;Shon, Ho-Sun;Lee, Dong-Gyu;Ji, Eun-Mi;Kim, Hi-Seok;Ryu, Keun-Ho
    • Journal of Korea Spatial Information System Society
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    • v.11 no.2
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    • pp.177-181
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    • 2009
  • Developing u-Public facilities for application u-City is to combine both the state-of-the art of the construction and ubiquitous computing and must be flexibly comprised of the facilities for the basic service of the building such as air conditioning, heating, lighting and electric equipments to materialize a new format of spatial planning and the public facilities inside or outside. Accordingly, in this paper we suggested the time pattern system for predicting the most basic power system loads for the basic service. To application the tim e pattern we applied SOM algorithm and k-means method and then clustered the data each weekday and each time respectively. The performance evaluation results of suggestion system showed that the forecasting system better the ARIMA model than the exponential smoothing method. It has been assumed that the plan for power supply depending on demand and system operation could be performed efficiently by means of using such power load forecasting.

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Cuts and Frames as the Segmented Formation of Time and Space : From Prehistory Picture to Hypertext (시간과 공간의 분절(分節)형식으로서의 칸과 틀 : 선사화(先史畵)에서 하이퍼텍스트까지)

  • Lee, Soon-Gu
    • Cartoon and Animation Studies
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    • s.9
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    • pp.1-17
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    • 2005
  • The image that reflects the lapse of time can only take the form of segmentation originally. All of the fixation status in an image is shown to us as the form of division(segmentation) whether it is the form of two dimensional paintings or three dimensional sculptures, but not the form of video monitors. This kind of method was extremely developed in the cartoon field. Therefore, the cartoon evolves the subjects of events and finds the worth and meaning through the arrangement of cuts. Also, Animation inquires into the principles of attaching the media continuously. The media is represented in the segmentation according to the lapse of time and I tend to analyze the origination of cartoon formation. Consequently, I tired to find the examples of the prehistoric cuts and forms, the divisions of fragmented cartoon stripes, and the cuts and forms which are composed of narrative and descriptive styles of arrangement, and finally can certify and validate them. In summary, the sections and divisions of the variable kinds of cuts and frames for the expression of the time were corroborated. The potentials of the space usage and the diversity of the cartoon formation were also founded and illustrated to suggest the broader stands of cartoon.

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CUDA Implementation for the Four-Russian Algorithm (4-러시안 알고리즘의 CUDA 구현)

  • Kim, Young Ho;Jeong, Ju-Hui;Kang, Dae Woong;Sim, Jeong Seop;Kim, Minho;Park, Soo-jun;Lim, Myungeun;Jung, Ho-Youl
    • Proceedings of the Korea Information Processing Society Conference
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    • 2012.04a
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    • pp.261-264
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    • 2012
  • 상수 크기의 알파벳 ${\Sigma}$에 대해 길이가 각각 m, n인 두 문자열 X와 Y의 편집거리는 X를 Y로 변환하기 위해 필요한 최소 편집연산의 수로 정의된다. 두 문자열의 편집거리는 잘 알려진 동적프로그래밍을 이용하여 O(mn) 시간과 공간에 계산할 수 있으며, 4-러시안 알고리즘을 이용해도 계산할 수 있다. 4-러시안 알고리즘은 블록 크기를 상수 t라 할 때, 전처리 단계에서 $O\((3{\mid}{\Sigma}{\mid})^{2t}t^2\)$ 시간과 $O\((3{\mid}{\Sigma}{\mid})^{2t}t^2\)$ 공간이 필요하며, 계산 단계에서 O(mn/t) 시간과 O(mn) 공간을 이용하여 편집거리를 계산하는 알고리즘이다. 본 논문에서는 4-러시안 알고리즘의 계산 단계를 CUDA를 이용하여 구현하고 실험을 통해 CPU 기반의 순차적인 수행시간과 GPU 기반의 병렬적인 수행시간의 비교결과를 제시한다. 본 논문의 병렬알고리즘은 m/t개의 쓰레드를 사용하여 O(m+n) 시간에 편집거리를 계산한다. GPU 기반의 알고리즘이 CPU 기반의 알고리즘 보다 t=1일 때 약 10배 빠르고, t=2일 때 약 3배 빠른 결과를 보였다.