• 제목/요약/키워드: spatial reduction

검색결과 719건 처리시간 0.024초

도시단위 건축물 CO2 저감을 위한 데이터 통합 활용 기반기술에 관한 연구 (A Study on Integrated Utilization of Urban Spatial Data and Building Data for CO2 Reduction)

  • 최혜미;박창한;김주형;김재준
    • 한국BIM학회 논문집
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    • 제5권3호
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    • pp.1-10
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    • 2015
  • We have researched a character of BIM(Building Information Modeling) and GIS(Geographic Information System) data for integrated utilization of urban spatial data and building data for $CO_2$ reduction. We consider literature on integrated utilization of BIM and GIS and measure method of $CO_2$ in urban spatial unit. Among them without distortion of standard data structure, derive method how to install between BIM and GIS standard data. Rhino & Grasshopper is utilization tools of DB platform. The compatibility with existing BIM and GIS data format, graphic and numeric results can be output at the same time. And using the existing ARCHSIM, it can be easily combined for building energy analysis program. Based on BIM and GIS data to run an energy analysis target on Majang-dong, it could be poly synthetically derived the value information and graphic information.

Generalized Quadrature Spatial Modulation Scheme Using Antenna Grouping

  • Castillo-Soria, Francisco Ruben;Cortez-Gonzalez, Joaquin;Ramirez-Gutierrez, Raymundo;Maciel-Barboza, Fermin Marcelo;Soriano-Equigua, Leonel
    • ETRI Journal
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    • 제39권5호
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    • pp.707-717
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    • 2017
  • This paper presents a novel generalized quadrature spatial modulation (GQSM) transmission scheme using antenna grouping. The proposed GQSM scheme combines QSM and conventional spatial multiplexing (SMux) techniques in order to improve the spectral efficiency (SE) of the system. Analytical and simulation results show that the proposed transmission scheme has minimal losses in terms of the average bit error probability along with the advantage of an increased SE compared with previous SM and QSM schemes. For the case studies, this advantage represents a reduction of up to 81% in terms of the number of required transmit antennas compared with QSM. In addition, a detection architecture based on the ordered successive interference cancellation scheme and the QR decomposition is presented. The proposed QRD-M adaptive algorithm showed a near-maximum-likelihood performance with a complexity reduction of approximately 90%.

공간 계층적 구조 기반 지역 기술자 활용 얼굴인식 기술 (Using Spatial Pyramid Based Local Descriptor for Face Recognition)

  • 김경태;최재영
    • 한국멀티미디어학회논문지
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    • 제20권5호
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    • pp.758-768
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    • 2017
  • In this paper, we present a novel method to extract face representation based on multi-resolution spatial pyramid. In our method, a face is subdivided into increasingly finer sub-regions (local regions) and represented at multiple levels of histogram representations. To cope with misaligned problem, patch-based local descriptor extraction has been also developed in a novel way. To preserve multiple levels of detail in local characteristics and also encode holistic spatial configuration, histograms from all levels of spatial pyramid are integrated by using dimensionality reduction and feature combination, leading to our spatial-pyramid face feature representation. We incorporate our proposed face features into general face recognition pipeline and achieve state-of-the-art results on challenging face recognition problems.

Modal-based model reduction and vibration control for uncertain piezoelectric flexible structures

  • Yalan, Xu;Jianjun, Chen
    • Structural Engineering and Mechanics
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    • 제29권5호
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    • pp.489-504
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    • 2008
  • In piezoelectric flexible structures, the contribution of vibration modes to the dynamic response of system may change with the location of piezoelectric actuator patches, which means that the ability of actuators to control vibration modes should be taken into account in the development of modal reduction model. The spatial $H_2$ norm of modes, which serves as a measure of the intensity of modes to system dynamical response, is used to pick up the modes included in the reduction model. Based on the reduction model, the paper develops the state-space representation for uncertain flexible tructures with piezoelectric material as non-collocated actuators/sensors in the modal space, taking into account uncertainties due to modal parameters variation and unmodeled residual modes. In order to suppress the vibration of the structure, a dynamic output feedback control law is designed by imultaneously considering the conflicting performance specifications, such as robust stability, transient response requirement, disturbance rejection, actuator saturation constraints. Based on linear matrix inequality, the vibration control design is converted into a linear convex optimization problem. The simulation results show how the influence of vibration modes on the dynamical response of structure varies with the location of piezoelectric actuators, why the uncertainties should be considered in the reductiom model to avoid exciting high-frequency modes in the non-collcated vibration control, and the possiblity that the conflicting performance specifications are dealt with simultaneously.

Impact of the spatial orientation of the patient's head, metal artifact reduction, and tube current on cone-beam computed tomography artifact expression adjacent to a dental implant: A laboratory study using a simulated surgical guide

  • Matheus Barros-Costa;Julia Ramos Barros-Candido;Matheus Sampaio-Oliveira;Deborah Queiroz Freitas;Alexander Tadeu Sverzut;Matheus L Oliveira
    • Imaging Science in Dentistry
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    • 제54권2호
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    • pp.191-199
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    • 2024
  • Purpose: The aim of this study was to evaluate image artifacts in the vicinity of dental implants in cone-beam computed tomography (CBCT) scans obtained with different spatial orientations, tube current levels, and metal artifact reduction algorithm (MAR) conditions. Materials and Methods: One dental implant and 2 tubes filled with a radiopaque solution were placed in the posterior region of a mandible using a surgical guide to ensure parallel alignment. CBCT scans were acquired with the mandible in 2 spatial orientations in relation to the X-ray projection plane (standard and modified) at 3 tube current levels: 5, 8, and 11 mA. CBCT scans were repeated without the implant and were reconstructed with and without MAR. The mean voxel and noise values of each tube were obtained and compared using multi-way analysis of variance and the Tukey test(α=0.05). Results: Mean voxel values were significantly higher and noise values were significantly lower in the modified orientation than in the standard orientation (P<0.05). MAR activation and tube current levels did not show significant differences in most cases of the modified spatial orientation and in the absence of the dental implant (P>0.05). Conclusion: Modifying the spatial orientation of the head increased brightness and reduced spatial orientation noise in adjacent regions of a dental implant, with no influence from the tube current level and MAR.

A Spatial Analysis of the Causal Factors Influencing China's Air Pollution

  • Kim, Yoomi;Tanaka, Katsuya;Zhang, Xinxin
    • Asian Journal of Atmospheric Environment
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    • 제11권3호
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    • pp.194-201
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    • 2017
  • This study investigates the factors that affect China's air pollution using city-level panel data and spatial econometric models. We address three air pollutants ($PM_{10}$, $SO_2$, and $NO_2$) present in 30 cities in China between 2004-2012 using global OLS and spatial models. To develop the spatial econometric analysis, we create a spatial weights matrix to define spatial patterns based on two neighborhood criteria - the queen contiguity and k nearest neighbors. The results show that the estimated coefficients are relatively consistent across different spatial weight criteria. The OLS models indicate that the effect of green spaces is statistically significant in decreasing the concentrations of all air pollutants. In the $PM_{10}$ and $SO_2$ analyses, the OLS models find that the number of buses and population density are also positively related to a reduction in the concentration of air pollutants. In addition, an increase in the temperature and the presence of secondary industries increase $SO_2$ and $NO_2$ concentrations, respectively. All spatial models capture a positive and significant effect of green spaces on reducing the concentration of each air pollutant. Our results suggest that green spaces in cities should receive priority consideration in local planning aimed at sustainable development. Furthermore, policymakers need to be able to discern the differences among pollutants when establishing environmental policies.

개폐식 대공간 구조물의 효율적인 지진응답제어를 위한 TMD의 최적 설치 위치 분석 (Investigation Into Optimal Installation Position of TMD for Efficient Seismic Response Reduction of Retractable-Roof Spatial Structure)

  • 이영락;김현수;강주원
    • 한국공간구조학회논문집
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    • 제18권2호
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    • pp.43-50
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    • 2018
  • In this study, TMD(Tuned Mass Damper) is installed in a retractable-roof spatial structure in order to investigate dynamic response characteristics according to mass ratio and installed position of TMD on large spatial structures. The example analytical model is generated based on the Singapore sports hub stadium. Twenty eight analytical models are used to investigate optimal installation position of TMD for the example retractable-roof spatial structure using 4 to 16 TMDs. The mass of one TMD is set up 1% of total mass at the example analytical model. Displacement response ratio of model with TMD is compared with that of base model without TMD. It has been found from numerical simulation that it is more effective to install TMD at the edge of the spatial structure rather than to concentrate the TMD at the center of the spatial structure.

홍수터 관리 최적대안 결정을 위한 공간퍼지접근 (The Spatial Fuzzy Approach to Multi-Criteria Decision Analysis for Flood Management)

  • 임광섭;최시중
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2009년도 학술발표회 초록집
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    • pp.1647-1651
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    • 2009
  • The uncertainty or imprecision associated with vague parameters and weighting sets, reduces the ability to decide what alternative is better for a particular location. To efficiently reduce the effect of imprecision frequently arising in available information, fuzzy theory has been used to improve consideration of imprecision in a Multi-Criteria Decision Analysis (MCDA) problem. Fuzzy logic offers a way to represent and handle imprecision present in continuous real world applications. A GIS implementing fuzzy set theory, (referred to in this paper as the "Spatial Fuzzy Approach") enables decision makers to express imprecise concepts associated with geographic data and provides decision makers the ability to have even more definition and discrimination in terms of the best alternatives for a particular spatial location. This study is focused on addressing questions pertaining to the methodology of floodplain analysis using GIS and Spatial Fuzzy MCDA to evaluate flood damage reduction alternatives. The issues will be examined in a case study of the Suyoung River Basin in Pusan, Korea.

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Effects of Prenatal Cnidium officinale Makino Treatment on Spatial Memory and Neurogenesis in the Hippocampus of Rat Pups Born from Maternal Rats Exposed to Noise Stress during Pregnancy

  • Song, Yun-Kyung;Lim, Hyung-Ho;Hong, Seo-Young
    • 대한한의학회지
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    • 제27권4호
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    • pp.125-134
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    • 2006
  • During the prenatal period, the development of the individual is influenced by a host of environmental factors. Exposure to noise stress during pregnancy was determined to result in the retardation of growth, a reduction in neurogenesis, and an impairment of spatial learning ability in the rat pups. In the present study, we have attempted to characterize the effects of prenatal treatment with Cnidium officinale Makino on spatial memory and neurogenesis in the hippocampus of rat pups born from maternal rats exposed to noise stress during pregnancy. Prenatal treatment with Cnidium officinale Makino was shown to increase neurogenesis and enhanced spatial learning ability in rat pups born from maternal rats exposed to noise stress. In this study, we have determined that prenatal treatment with Cnidium officinale Makino can stimulate spatial development and neurogenesis in the brain of the fetuses exposed to prenatal stresses.

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공극 자속밀도의 공간 고조파 유입 방법을 통한 IPM type BLDC Motor의 성능 개선 (Performance Improvement of IPM-type BLDC Motor Using the Influx Method of Spatial Harmonic in Air-gap Flux Density)

  • 이광현;류진욱;허진
    • 전기학회논문지
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    • 제60권4호
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    • pp.739-745
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    • 2011
  • This paper proposes a method for reducing the negative spatial harmonics of the radial flux density of an interior-type permanent magnet (IPM) motor. The reliability of the motor is increased by minimizing its vibrations under dynamic eccentricity (DE) state and normal state due to reduction of a negative spatial harmonics component through the influx of a zero spatial harmonics component in the radial flux density. To minimize the vibrations, optimal notches corresponding to the distribution shape of the magnetic field are designed on the rotor pole face. The variations of vibration computation by finite element method (FEM) and the validity of the analysis and rotor shape design are confirmed by vibration and performance experiments.