• Title/Summary/Keyword: 공간 복잡도

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The Algorithm For Spatial XQuery2SQL Converter (Spatial XQuery2SQL Converter를 위한 알고리즘)

  • Choi, Young Nn;Seo, Hyun-Ho
    • Proceedings of the Korea Contents Association Conference
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    • 2004.11a
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    • pp.442-447
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    • 2004
  • XML is normalized text form that is designed to transmit structured document in web as that propose in W3C (World Wide Web Consortium) in 1996. Function that this can overcome HTML's limit that use in existing in Internet and user define new tag to HTML by way to solve SGML's complexity added. There is many efforts to use storing this XML document in RDBMS but to relation style DB because XML document is tree structure structurally data SQL and perfect disaster caused by things that is language to ask a question accomplish XQuery that so it is W3C's XML standard query appear. After store XML informations including space information to RDBMS in this paper, Spatial XQuery through converter that is Sqatial XQuery2SQL through Spatial operator, Spatial function SQL of by Sqatial XQuery2SQL conversion algorithm that draw information in RDBMS after change embody wish to.

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32×32 Full-Rate Massive MIMO Using Quasi-Orthogonal Space-Time Block Code (QOSTBC) (준직교 공간시간 블록부호를 적용한 32×32 전율 대규모 MIMO 시스템)

  • Winn, Khin Zar Chi;Chung, Yeon-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.19 no.3
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    • pp.507-513
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    • 2015
  • In this paper, we present the bit-error rate (BER) performance of quasi-orthogonal space-time block code (QOSTBC) massive multiple-input multiple-output (MIMO) system employing up to 32 transmit and receive antennas. The QOSTBC, due to its advantages in transmission rate and decoding complexity, is an important transmit diversity scheme for more than 2 transmit antennas. As massive MIMO implies very large number of antennas, practically at least more than 15 antennas, a different number of transmit and receive antennas (i.e. $2{\times}2$, $4{\times}4$, $8{\times}8$, $16{\times}16$ and $32{\times}32$) using QOSTBC for the massive MIMO system are considered. The BER performance of the massive MIMO with antennas up to $32{\times}32$ using BPSK modulation scheme is analyzed. Simulation results show that the full-rate massive MIMO systems with QOSTBC give a significant performance improvement due to increasing diversity effect, compared with previously considered massive MIMO systems.

Numerical modelling of electromagnetic waveguide effects on crosshole radar measurements (시추공간 레이다 측정에서 전자기 도파관 효과의 수치모델링)

  • Jang, Han-Nu-Ree;Park, Mi-Kyung;Kim, Hee-Joon
    • Geophysics and Geophysical Exploration
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    • v.10 no.1
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    • pp.69-76
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    • 2007
  • High-frequency electromagnetic (EM) wave propagation associated with borehole ground-penetrating radar (GPR) is a complicated phenomenon. To improve the understanding of the governing physical processes, we employ a finite-difference time-domain solution of Maxwell's equations in cylindrical coordinates. This approach allows us to model the full EM wavefield associated with crosshole GPR surveys. Furthermore, the use of cylindrical coordinates is computationally efficient, correctly emulates the three-dimensional geometrical spreading characteristics of the wavefield, and is an effective way to discretise explicitly small-diameter boreholes. Numerical experiments show that the existence of a water-filled borehole can give rise to a strong waveguide effect which affects the transmitted waveform, and that excitation of this waveguide effect depends on the diameter of the borehole and the length of the antenna.

Displacement Control Technique of Pre-stressable Cable Structures by Force Method (하중법을 이용한 케이블 구조물의 변위제어기법에 관한 연구)

  • Shon, Su-Deok;Kwan, Alan S.K.;Lee, Seung-Jae
    • Journal of Korean Association for Spatial Structures
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    • v.11 no.2
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    • pp.139-149
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    • 2011
  • A cable structures have the advantage that cover a large space without column but it is very sensitive to deal with shape control because of its flexibility. Especially, location of control member and needed elongation of member are important things. Therefore, the purpose of this paper is studied on displacement control technique for pre-stressed cable structures by force method considering order of control. The layout of this paper is as follows. Firstly, in section 2, the control technique by force method for cable structures is given. Secondly, section 3 briefly introduces simple cable net in order to apply control technique considering ordering of actuator. Finally, more complex example for effective member and the conclusion are in section 4 and 5, respectively.

Color matching between monitor and mobile display device using improved S-curve model and RGB color LUT (개선된 S-curve 모델과 RGB 칼라 LUT를 이용한 모니터와 모바일 디스플레이 장치간 색 정합)

  • 박기현;이명영;이철희;하영호
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.41 no.6
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    • pp.33-41
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    • 2004
  • This paper proposes a color matching 3D look-up table simplifying the complex color matching procedure between a monitor and a mobile display device. In other to perform color matching, it is necessary to process color of image in the device independent color space like CIEXYZ or CIELAB. To obtain the data of the device independent color space from that of the device dependent RGB color space, we must perform display characterizations. LCD characterization error using S-curve model is larger than tolerance error since LCD is more nonlinear than CRT. This paper improves the S-curve model to have smaller characterization error than tolerance error using the electro-optical transfer functions of X, Y, and Z value. We obtained images having higher color fidelity on mobile display devices through color matching experiments between monitor and mobile display devices. As a result of this experiments, we concluded that the color matching look-up table with 64(4${\times}$4${\times}$4) is the smallest size allowing characterization error to be acceptable.

Automatic Building Extraction Using LIDAR and Aerial Image (LIDAR 데이터와 수치항공사진을 이용한 건물 자동추출)

  • Jeong, Jae-Wook;Jang, Hwi-Jeong;Kim, Yu-Seok;Cho, Woo-Sug
    • Journal of Korean Society for Geospatial Information Science
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    • v.13 no.3 s.33
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    • pp.59-67
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    • 2005
  • Building information is primary source in many applications such as mapping, telecommunication, car navigation and virtual city modeling. While aerial CCD images which are captured by passive sensor(digital camera) provide horizontal positioning in high accuracy, it is far difficult to process them in automatic fashion due to their inherent properties such as perspective projection and occlusion. On the other hand, LIDAR system offers 3D information about each surface rapidly and accurately in the form of irregularly distributed point clouds. Contrary to the optical images, it is much difficult to obtain semantic information such as building boundary and object segmentation. Photogrammetry and LIDAR have their own major advantages and drawbacks for reconstructing earth surfaces. The purpose of this investigation is to automatically obtain spatial information of 3D buildings by fusing LIDAR data with aerial CCD image. The experimental results show that most of the complex buildings are efficiently extracted by the proposed method and signalize that fusing LIDAR data and aerial CCD image improves feasibility of the automatic detection and extraction of buildings in automatic fashion.

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Implication to Ecosystem Assessment from Distribution Pattern of Subtidal Macrobenthic Communities in Nakdong River Estuary (낙동강 하구 조하대 저서동물 군집분포에 따른 생태계 평가 적용)

  • Yoon, Kon-Tak;Park, Heung-Sik;Chang, Man
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.16 no.4
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    • pp.246-253
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    • 2011
  • In this study, we investigated the effect of freshwater discharge on benthic community in Nakdong estuaries. The sediment was dominated by sand except few channels where heterogenetic sediment composition was observed. Sediment composition was rarely affected by freshwater discharge during the rainy season; however, organic content in the sediment slightly increased after the rainy season. Macrobenthic species composition differed spatially. For instance, species composition decreased after the rainy season near the barrage. Benthic community analysis revealed three groups, in which the first group was found between barrage and sand bars located at the mouth of estuary, the second group was observed outside the sand bars, and the last group was found in the channel. Opportunistic benthic species indicative of organic pollution, such as Sinocorophium sinensis, Magelona japonica, and Heteromastus filiformis, dominated areas close to the barrage. Organic pollution by freshwater discharge appears to be responsible for the emergence of opportunistic benthic species, and this influenced areas from the mouth of bay to sand bars. Outside the sand bars, freshwater discharge did not seem to have affected species composition.

Carrier Comparison PWM for Voltage Control of Vienna Rectifier (비엔나 정류기의 전압제어를 위한 반송파 비교 PWM)

  • Yoon, Byung-Chul;Kim, Hag-Wone;Cho, Kwan-Yuhl
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.10
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    • pp.4561-4568
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    • 2011
  • In this paper, carrier comparison PWM method for voltage control of Vienna rectifier is discussed. In general, in industrial and communications applications, the two-level rectifier is used. However, this two-level rectifier has the limit of high THD and low efficiency. So, the studies of three-level rectifier has been carried out so far, and the Vienna rectifier circuit is the representative. The space vector pulse width modulation(SVPWM) method is generally used for Vienna rectifier, in which voltage vectors and duration time are calculated from the voltage reference. However, this method require very sophisticated and complex calculations, so realizing this method by software is very difficult. To overcome this disadvantage, simple carrier comparison PWM method for Vienna rectifier is proposed which is modified from the carrier comparison method for 3 level inverter. Furthermore, to verify the usefulness of the Vienna rectifier carrier comparison PWM the simulation and experiment are carried out.

A Comprehensive Framework for Estimating Pedestrian OD Matrix Using Spatial Information and Integrated Smart Card Data (공간정보와 통합 스마트카드 자료를 활용한 도시철도 역사 보행 기종점 분석 기법 개발)

  • JEONG, Eunbi;YOU, Soyoung Iris;LEE, Jun;KIM, Kyoungtae
    • Journal of Korean Society of Transportation
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    • v.35 no.5
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    • pp.409-422
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    • 2017
  • TOD (Transit-Oriented Development) is one of the urban structure concentrated on the multifunctional space/district with public transportation system, which is introduced for maintaining sustainable future cities. With such trends, the project of building complex transferring centers located at a urban railway station has widely been spreaded and a comprehensive and systematic analytical framework is required to clarify and readily understand the complicated procedure of estimation with the large scale of the project. By doing so, this study is to develop a comprehensive analytical framework for estimating a pedestrian OD matrix using a spatial information and an integrated smart card data, which is so called a data depository and it has been applied to the Samseong station for the model validation. The proposed analytical framework contributes on providing a chance to possibly extend with digitalized and automated data collection technologies and a BigData mining methods.

Cultural Facility Design in Japan (일본의 문화시설 현황과 디자인 특징에 관한 연구 - 1990년대 신축시설을 중심으로 -)

  • 김선영
    • Archives of design research
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    • v.14 no.3
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    • pp.15-26
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    • 2001
  • The goal of this study is threefold. First, this study explores the historical origin and architectural characteristics of cultural facilities in Japan. For this purpose, I examine various cultural facilities in Japan such as theaters, multi-purpose halls, convertible spaces and cultural centers. Second, this study also sheds a new light on the meaning of the relationships between cultural activity and architecture design in Japan. For this, I primarily look at the various categories of cultural buildings in Japan and their main functions. Finally, I demonstrate how both traditional and modem design elements are embodied in Japanese cultural facilities.

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