• 지적과 국토정보
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• 제46권2호
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• pp.225-237
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• 2016

최근 들어 공간정보를 비롯하여 다양한 정보와 관련된 정책 동향은 개방과 공유로 변화하고 있다. 이러한 정책 동향에 맞춰서 개별 시스템에서 관리하는 공간정보를 체계적으로 공유하기 위해서는 공간정보표준을 반드시 준수해야 한다. 공간정보표준을 준수할 경우, 정보에 대한 접근성과 가독성, 정보처리 및 시스템 간의 상호운용성을 향상시킬 수 있다. 하지만 이러한 표준의 이점에도 불구하고, 공간정보표준에 대한 체계적인 관리가 이루어지지 않아 공간정보사업자들은 표준 적용에 많은 어려움을 겪고 있다. 따라서 본 연구에서는 국내외 표준 제정 현황을 조사하고, 국내 공간정보표준이 갖는 표준의 중복성, 버전 간 불일치, 유사 표준 제정 등의 문제점을 다각적으로 분석하여 이러한 문제점을 개선하기 위한 정책 방안을 제시하였다. 본 연구의 결과는 향후 국가공간정보체계에서 공간정보표준의 관리 운영, 조직 구성, 법제도 개선 등을 위한 기초 연구 자료로 활용될 수 있을 것으로 판단된다.

• 한국지역지리학회지
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• 제12권5호
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• pp.614-630
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• 2006

자연 및 기술재해에 빠르고 효과적으로 대응하기 위해서는 그 재해지역 내에 있는 인구수를 정확히 추정할 필요가 있다. 그러나 센서스 구역과 재해지역의 공간적 불일치 문제 때문에, 재해지역 내에 있는 인구수를 정확하게 추정할 때에는 구역단위 인구자료를 공간적으로 세분화할 필요가 있다. 본 논문은 센서스 블럭그룹 내의 인구를 개개의 화소로 세분화하기 위한 밀도 구분적 표면모델을 구현하고, 그 표면기반 공간적 세분화 모델의 성능을 통계적 및 가시적으로 평가한다. 표면기반 공간적 세분화 모델은 밀도 구분적 내삽법과 위성영상으르부터 추출된 토지이용 및 피복자료를 사용하며 지리정보시스템에서 구현되었다. 토지이용 및 피복자료는 밀도 구분적 내삽법에서 인구의 지리적 분포에 관한 추가정보를 제공했고, 토지이용 및 피복자료의 퍼센트에 기반을 둔 경험적 표본추출법과 지역가중법은 각 화소에 대한 밀도 구분적 가중치를 객관적으로 결정하기 위해서 사용되었다. 표면기반 공간적 세분화 모델은 애틀란타 대도시권의 밀도 구분적 인구표면을 만드는데 적용되었다. 그 밀도 구분적 인구표변의 정확도는 센서스 수치와의 비교를 통해서 RMSE와 수정 RMSE를 사용하면서 검증되었다. 또한, 각 센서스 트랙과 블럭그룹별 오차들은 퍼센트 오차지도들에 의해서 가시화 되었다. 분석결과에 따르면, 밀도 구분적 인구표면은 인구수의 정확한 추정치를 제시할 뿐만 아니라, 센서스 블록그룹 내의 인구의 상세한 공간분포를 보여 준다. 또한, 인구표면은 대개 교외 및 산림지역 그리고 도심지역에서 인구를 과소평가하거나 과대평가하는 경향이 있다는 것을 밝혀냈다.

• 한국실내디자인학회논문집
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• 제20권6호
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• pp.88-96
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• 2011

In contemporary urban space, the identify is absent because of the object-oriented plans that ignore the context of urban space, and the ignorance of the regional characteristics and the historicity of places. Due to this reason, urban space lost its unique characteristics and becomes a mismatch with its surroundings. To solve these problems, the ideological trend of post-modernism emerged and new spatial paradigm rose based on the contextual concept to go with this trend. This contextual concept should be considered more importantly in the public space with discontinuous many and unspecified behavioral patterns. The components of space do not exist independently with individual identity. They should be considered based on a holistic view formed by the relations among elements and the establishment of those relations, and through this, correct identity can be established. Thus, this paper aims to analyze the context of spatial components through new contextual views on public spaces and study the expressional characteristics unveiled between these relations.

• Nuclear Medicine and Molecular Imaging
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• 제42권2호
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• pp.172-180
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• 2008

PET/CT fused image with anatomical and functional information have improved medical diagnosis and interpretation. This fusion has resulted in more precise localization and characterization of sites of radio-tracer uptake. However, a motion during whole-body imaging has been recognized as a source of image quality degradation and reduced the quantitative accuracy of PET/CT study. The respiratory motion problem is more challenging in combined PET/CT imaging. In combined PET/CT, CT is used to localize tumors and to correct for attenuation in the PET images. An accurate spatial registration of PET and CT image sets is a prerequisite for accurate diagnosis and SUV measurement. Correcting for the spatial mismatch caused by motion represents a particular challenge for the requisite registration accuracy as a result of differences in PET/CT image. This paper provides a brief summary of the materials and methods involved in multiple investigations of the correction for respiratory motion in PET/CT imaging, with the goal of improving image quality and quantitative accuracy.

• 한국환경과학회지
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• 제29권1호
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• pp.15-23
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• 2020

The determination of soil characteristics is important in the simulation of rainfall runoff using a distributed FLO-2D model in catchment analysis. Digital maps acquired using remote sensing techniques have been widely used in modern hydrology. However, the determination of a representative parameter with spatial scaling mismatch is difficult. In this investigation, the FLO-2D rainfall-runoff model is utilized in the Yongdam catchment to test sensitivity based on three different methods (mosaic, arithmetic, and predominant) that describe soil surface characteristics in real systems. The results show that the mosaic method is costly, but provides a reasonably realistic description and exhibits superior performance compared to other methods in terms of both the amount and time to peak flow.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집C
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• pp.246-250
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• 2001

In resin transfer molding (RTM), resin is forced to flow through the fiber perform of inhomogeneous permeability. This inhomogeneity is responsible for the mismatch of resin velocity within and between the fiber tows. The capillary pressure of the fiber tows exacerbates the spatial variation of the resin velocity. The resulting microscopic perturbations of resin velocity at the flow front allow numerous air voids to form. In this study, a mathematical model was developed to predict the formation and migration of micro-voids during resin transfer molding. A transport equation was employed to account for the migration of voids between fiber tows. Incorporating the proposed model into a resin flow simulator, the volumetric content of micro-voids in the preform could be obtained during the simulation of resin impregnation.

• 대한교통학회지
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• 제13권3호
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• pp.5-17
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• 1995

One of interesting issues in urban land-use and transportation policy is about an unproven belief that imbalances between employment and residential sites strongly influence urban commuting patterns. The purpose of this study si to find how spatial distribution of jobs and housing affects commuting distances in Seoul Metropolitan Area using 1990 Census O-D Data. This study estimates cost-minimizing required commuting distance, given the actual distributions of jobs and housing , and compares required commuting distances with actual commuting distances. One of findings is that the standard urban economic theory explains only 1/3 of actual commuting in the case study area. The policy implication of this study is that jobs-housing balance policy will have only a minor effect on the actual commuting.

• Structural Engineering and Mechanics
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• 제37권5호
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• pp.529-542
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• 2011

Three dimensional solutions for free vibrations analysis of functionally graded fiber reinforced cylindrical panel are presented, using differential quadrature method (DQM). The orthotropic panel is simply supported at the edges and is assumed to have an arbitrary variation of reinforcement volume fraction in the radial direction. Suitable displacement functions that identically satisfy the simply supported boundary condition are used to reduce the equilibrium equations to a set of coupled ordinary differential equations with variable coefficients, which can be solved by differential quadrature method to obtain natural frequencies. The main contribution of this work is presenting useful results for continuous grading of fiber reinforcement in the thickness direction of a cylindrical panel and comparison with similar discrete laminate composite ones. Results indicate that significant improvement is found in natural frequency of a functionally graded fiber reinforced composite panel due to the reduction in spatial mismatch of material properties.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2000년도 춘계학술대회논문집
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• pp.1667-1674
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• 2000

A new method is proposed to measure the flow rate in a pipe by multiple measurements of acoustic pressure using a microphone array. It is based on the realization that variation in flow velocity affects the change in wave number. The method minimizes measurement random errors and sensor mismatch errors thereby providing practically realizable flow rate measurement. One of the advantages of the method is that it does not obstruct the flow field and can provide the time-spatial mean flow rate. Numerical simulations and experiments were conducted to verify the utility of this method.

• Steel and Composite Structures
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• 제10권4호
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• pp.349-360
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• 2010

Three dimensional free vibrations analysis of functionally graded fiber reinforced cylindrical shell is presented, using differential quadrature method (DQM). The cylindrical shell is assumed to have continuous grading of fiber volume fraction in the radial direction. Suitable displacement functions are used to reduce the equilibrium equations to a set of coupled ordinary differential equations with variable coefficients, which can be solved by differential quadrature method to obtain natural frequencies. The main contribution of this work is presenting useful results for continuous grading of fiber reinforcement in the thickness direction of a cylindrical shell and comparison with similar discrete laminate composite ones. Results indicate that significant improvement is found in natural frequency of a functionally graded fiber reinforced cylinder due to the reduction in spatial mismatch of material properties and natural frequency.