• Journal of Radiation Protection and Research
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• v.16 no.2
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• pp.41-54
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• 1991

This paper aimed to analyse dose sensitivity to the controllable parameters of indoor radon $(^{222}Rn)$ and its decay products (Rn-D) by applying the input~output linear system theory. Physical behaviors of $^{222}Rn\;&\;Rn-D$ were analyzed in terms of $(^{222}Rn)$ gas -generation, -migation and -infiltration to indoor environments, and the performance output-function, i. e. mean dose equivalent to Tracho-Bronchial (TB) lung region, was assessed to the following extented ranges of the controllable paramenters; a) the ventilation rate $constant({\lambda}_v)\;:\;0{\sim}50[h^{-l}].\;b)$ the attachment rate $constant({\lambda}_a)\;:\;0{\sim}500[h^{-l}].\;c)$ the unattached-deposition rate constant (${\lambda}^u_d)\;:\;0-50[h-l]$. A linear input-output model was reconstructed from the original models in literatures, as follows, which was modified into the matrices consisting of 111 nodal equations; a) indoor $^{222}Rn\;&\;Rn-D$ Behaviour; Jacobi-Porstendoerfer-Bruno model.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2006.05a
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• pp.187-192
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• 2006

도시의 과밀화로 인해 건물들은 고층화, 대형화되고 복잡한 형태를 이루고 있어 건물 이용자들에게 2차원의 정보뿐만 아니라 3차원 공간정보의 필요성이 증가하고 있으며 이를 해결하기 위해 3차원 GIS 모델의 활용이 요구되고 있다. 그러나 현재까지 연구되거나 응용되어 온 3차원 모델은 주로 건물 외부형태의 시각화를 위한 것으로 3차원 공간분석에 응용되기에는 한계가 존재해 왔다. 이에 본 연구에서는 3차원 모델을 공간분석에 적용하는 하나의 방안으로서 건물의 내부공간에서 경로탐색을 구현하기 위한 방법을 제시하였다. 이를 위해 건물 내부의 각 실들과 연결통로 및 기타 시설들을 각각 오브젝트로 분리하여 3차원으로 모델링하였다. 2차원 GIS데이터와 3차원 모델에 각각 벡터기반의 네트워크 모델을 생성하고 DB를 이용하여 두 모델을 연동함으로써 3차원 모델에서 네트워크기반의 경로분석과 탐지기능을 가능하게 하였다.

• Journal of Korea Spatial Information System Society
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• v.11 no.3
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• pp.50-54
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• 2009

Recently, many researches have been conducted to develop 3D Indoor/Outdoor Spatial Data Models. The 3D data created based on these data models have complex data structures. In order to manage these data efficiently, it is better to use a DBMS. There have been many researches to maintain the 3D data in Geo-DBMS, such that Oosterom (2002) and Arens (2005) developed a method to store 3D Building model, geometric and topological data of coverage in DBMSa. In this study, we propose a method to store the CityGML data into the RDBMS, Oracle Spatial 11g.

• Spatial Information Research
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• v.18 no.5
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• pp.133-142
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• 2010

Many pedestrian or fire evacuation models have been studied last decades for modeling evacuation behaviors or analysing building structures under emergency situations. However, currently developed models do not consider the differences of visibility of pedestrians by obstacles such as furniture, wall, etc. The visibility of pedestrians is considered one of the important factors that affect the evacuation behavior, leading to making simulation results more realistic. In order to incorporate pedestrian's visibility into evacuation simulation, we should be able to give different walking speeds according to differences of visibility. We improved the existing floor field model based on cellular automata in order to implement the visibility. Using the space syntax theory, we showed how we split the indoor spaces depending on the different visibilities created by different levels of structural depths. Then, we improved the algorithm such that pedestrians have different speeds instead of simultaneous movement to other cells. Also, in order for developing a real time simulation system integrated w ith indoor sensors later, we present a process to build a 3D simulator using a spatial DBMS. The proposed algorithm is tested using a campus building.

• Journal of Computational Design and Engineering
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• v.3 no.3
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• pp.250-265
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• 2016

Owing to our rapidly aging society, accessibility evaluation to enhance the ease and safety of access to indoor and outdoor environments for the elderly and disabled is increasing in importance. Accessibility must be assessed not only from the general standard aspect but also in terms of physical and cognitive friendliness for users of different ages, genders, and abilities. Meanwhile, human behavior simulation has been progressing in the areas of crowd behavior analysis and emergency evacuation planning. However, in human behavior simulation, environment models represent only "as-planned" situations. In addition, a pedestrian model cannot generate the detailed articulated movements of various people of different ages and genders in the simulation. Therefore, the final goal of this research was to develop a virtual accessibility evaluation by combining realistic human behavior simulation using a digital human model (DHM) with "as-is" environment models. To achieve this goal, we developed an algorithm for generating human-like DHM walking motions, adapting its strides, turning angles, and footprints to laser-scanned 3D as-is environments including slopes and stairs. The DHM motion was generated based only on a motion-capture (MoCap) data for flat walking. Our implementation constructed as-is 3D environment models from laser-scanned point clouds of real environments and enabled a DHM to walk autonomously in various environment models. The difference in joint angles between the DHM and MoCap data was evaluated. Demonstrations of our environment modeling and walking simulation in indoor and outdoor environments including corridors, slopes, and stairs are illustrated in this study.

• Proceedings of the KIEE Conference
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• 1991.07a
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• pp.753-756
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• 1991

This paper aimed to analyse dose sensitivity to the controllable parameters of in-door radon $(^{222}Rn)$ and its decay products(Rn-D) by applying the input-output linear system theory. Physical behaviors of $^{222}Rn$ & Rn-D were analyzed in terms of $^{222}Rn$ gas generation, -migation and - infiltration to indoor environments, and the performance output-function(i.e. mean dose equivalent to Tracho-Bronchial(TB) lung region was assessed to the following ranges of the controllable parameters; a) the ventilation rate constant $({\lambda}_v)$ : $0{\sun}500[h^{-1}]$. b) the attachment rate constant$({\lambda}_a)$ : 0-500 $[h^{-1}]$. c) deposition rate constant $({\lambda}{_{d}^{u}})$: 0-50$[h^{-1}]$. A linear input-output model was reconstructed from the original models in literatures, as follows, which was modified into the matrices consisting of 111 nodal equations. a) indoor ${222}Rn$ & Rn-D Behaviour: jacobi- Porstendorfer- Bruno model. b) lung dosimerty : Jacobi-Eisfeld model. Some of the major findings, which identify the effectiveness of this model, were as follows. a) ${\lambda}_v$ is most effective, dominant controllable parameters in dose reduction, if mechanical ventilation is applied. b) ${\lambda}_v$, depending on the air particle-concentration, reduces the dose somewhat within ${\lambda}_v$<1 $h^{-1}R range. However, the dose increases conversely, ${\lambda}_v$>1 $h^{-1}R range range. c) ${\lambda}{_{d}^{4}}$ reduces the dose linearly as ${\lambda}_v$ dose. Such dose(z-axis) sentivities are shown with three-dimensional plots whoes x,y-axes are combined 2out the 3 parameter${\lambda}_v{\lambda}_s,\;{\lambda}_d^s$.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.43 no.4 s.310
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• pp.96-107
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• 2006

In this paper, a low bitrate video coding method based on new panoramic modeling is proposed for panning cameras. An input video frame from a panning camera is decomposed into a background image, rectangular moving object regions, and a residual image. In coding the background, we employ a panoramic model that can account for several image formation processes, such as perspective projection, lens distortion, vignetting and illumination effects. Moving objects aredetected, and their minimum bounding rectangular regions are coded with a JPEG-2000 coder. We have evaluated the effectiveness of the proposed algorithm with several indoor and outdoor sequences and found that the PSNR is improved by $1.3{\sim}4.4dB$ compared to that of JPEG-2000.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.23 no.4
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• pp.375-384
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• 2005

Three dimensional urban models are being increasingly applied for various purposes such as city planning, telecommunication cell planning, traffic analysis, environmental monitoring and disaster management. In recent years, technologies from CAD and GIS are being merged to find optimal solutions in three dimensional modeling of urban buildings. These solutions include modeling of the interior building space as well as its exterior shape visualization. Research and development effort in this area has been performed by scientists and engineers from Computer Graphics, CAD and GIS. Computer Graphics and CAD focussed on precise and efficient visualization, where as GIS emphasized on topology and spatial analysis. Complementary research effort is required for an effective model to serve both visualization and spatial analysis purposes. This study presents an efficient way of using the CAD plans included in the building register documents to reconstruct the internal space of buildings. Topological information was built in the geospatial database and merged with the geometric information of CAD plans. as well as other attributal data from the building register. The GIS network modeling method introduced in this study is expected to enable an effective 3 dimensional spatial analysis of building interior which is developing with increasing complexity and size.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.2
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• pp.1-6
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• 2010

Short-range wireless communication systems are expanding at rapid rate, finding application in offices and homes. Development of wireless local network is accompanied by steady increase in the demand for ever higher data rates. This in turn entails the necessity to develop communication systems which operate at higher frequencies. It can be expected that short-rage wireless communication networks will soon push towards the THz frequency range. We use a 3D ray-launching for analysis of propagation environments at the indoor fixtures. We extended the approach from the modeling of the reflectivity of optically thick, smooth building materials at THz frequencies to materials with a rough surface. The simulation result of propagation environment is similar to average received power of reference paper. The RMS delay spread was calculated to be 9.11 ns in a room size of $6m(L){\times}5m(W){\times}2.5m(H)$ for the concrete plaster.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.45 no.6
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• pp.26-34
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• 2008

The information of traversability and path planning is essential for UGV(Unmanned Ground Vehicle) navigation. Such information can be obtained by analyzing 3D terrain. In this paper, we present the method of 3D terrain modeling with color information from a camera, precise distance information from a 2D Laser Range Finder(LRF) and wheel encoder information from mobile robot with less data. And also we present the method of 3B terrain modeling with the information from GPS/IMU and 2D LRF with less data. To fuse the color information from camera and distance information from 2D LRF, we obtain extrinsic parameters between a camera and LRF using planar pattern. We set up such a fused system on a mobile robot and make an experiment on indoor environment. And we make an experiment on outdoor environment to reconstruction 3D terrain with 2D LRF and GPS/IMU(Inertial Measurement Unit). The obtained 3D terrain model is based on points and requires large amount of data. To reduce the amount of data, we use cubic grid-based model instead of point-based model.