• Water for future
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• v.28 no.5
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• pp.151-162
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• 1995

A two-dimensional stream tube dispersion model is developed to simulate accurately transverse dispersion processes of pollutants in natural channels. Two distinct features of the stream tube dispersion model derived herein are that it employs the transverse cumulative discharge as an independent variable replacing the transverse distance and that it is developed in a natural coordinate system which follows the general direction of the channel flow. In the model studied, Eulerian-Lagrangian method is used to solve the stream tube dispersion equation. The stream tube dispersion equation is decoupled into two components by the operator-splitting approach; one is governing advection and the other is governing dispersion. The advection equation has been solved using the method of characteristics and the results are interpolated onto Eulerian grid on which the dispersion equation is solved by centered difference method. In solving the advection equation, cubic spline interpolating polynomials is used. In the present study, the results of the application of this model to a natural channel are compared with a steady-state flow measurements. Simulation results are in good accordance with measured data.

• Health Policy and Management
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• v.1 no.1
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• pp.95-108
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• 1991

The World Health Organization and its member states, in 1978, declared that primary health care is a key to attain the goal of Health for All by the goal of Health for All by the yeas 2000. As a member state of WHO, the Republic of Korea has participated in the declaration of ALMA-ATA and committed to put national efforts for devedoping and implementing primary health care approach with the spirit and content of this Declaration. Since 1978, to translate the spirit of the Declaration into realization, Korean goverment has developed a new category of health manpower such as Community Health Practitioners serving people living in remote rural areas and Village Health Workers serving voluntarily their own village, strengthened the function of Health Centers and Health Subcenters through their reorientation and improved the infrastructure by their new construction or renovation. While primary health care is viewed as an essential health care in Korea, there are some circles who follow a narrow definition in referring to the health care at the periphey of a health system, which is erroneous. Considering the PHC is accepted as the best alternative approach to health care to solve problems that modern health systems are facing, we propose the followings as desirable health policy directions that modern health systems are facing, we propose the followings as desirable health policy directions which might translate the persopective into action at the national level after reviewing past and current PHC approach in Korea : 1. To improve the equity through the reduction of gaps between those who have access to health care and those who have not. 2. To reinforce multisectoral approach and intersectoral coordination through the re- establishment of the National Health Council or establishment of equivalent organization at the central level. 3. To stengthen community participation through lacal people's empowerment by leadership training, changing planning process from the top-down approach to bottom-up and giving the priority to human resources rater than technology, 4. To reinforce the Ministries of Health and Social Affairs through upgrading its role and function to Coordinate Ministries which involve human welfare policies, and creating a Division which is in charge of PHC in the Ministry.

• Journal of the Korea Computer Graphics Society
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• v.17 no.2
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• pp.27-36
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• 2011

The Dual Contouring method has an advantage over the primal polygonization methods like the Marching Cube method in terms of better expression of sharp features. In this paper, the Dual Contouring method is implemented in Spherical coordinates, not the Cartesian ones to examine some characteristics. For this purpose, our octree is defined in Spherical coordinates, which is called "S-Octree". Among some characteristics, the proposed Dual Contouring method in the S-Octree tends to produce less vertices at the same octree level. In particular, for any surface models close to surface sphere, the generated mesh surfaces are smoother and more detailed than those of the Cartesian Dual Contouring approach for specific applications including mesh compression where available geometric information is quite limited.

• Science of Emotion and Sensibility
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• v.6 no.2
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• pp.1-7
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• 2003

The objectives of this study is to develop an adaptable digital wall model whose color can be changed dynamically according to the identified emotional state of a user. This study addresses how to capture a specific user's emotion through the web and use it for modifying VR model mainly for color adaptation. This adaptation process of a VR model consists of three phases: 1) identification of the user's emotional state projected onto the list of emotional keywords 2) translation of those captured emotional keywords into a pertinent set of color coordinations, and finally, 3) automated color adaptation process for the given model. This process derives an on-line viewer's emotional state, which can be utilized to find a new color scheme reflecting the identified emotion.

• Computational Structural Engineering
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• v.3 no.3
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• pp.113-123
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• 1990

The paper is concerned with the elasto-plastic and geometrically nonlinear analysis of shell structures using an improved degenerated shell element. In the formulation of the element stiffness, the combined use of three different techniques was made. They are; 1) an enhanced interpolation of transverse shear strains in the natural coordinate system to overcome the shear locking problem ; 2) the reduced integration technique in in-plane strains to avoid the membrane locking behavior ; and 3) selective addition of the nonconforming displacement modes to improve the element performances. This element is free of serious shear/membrane locking problems and undesirable compatible/commutable spurious kinematic deformation modes. In the formulation for plastic deformation, the concept of a layered element model is used and the material is assumed von Mises yield criterion. An incremental total Lagrangian formulation is presented which allows the calculation of arbitrarily large displacements and rotations. The resulting non-linear equilibrium equations are solved by the Netwon-Raphson method combined with load or displacement increment. The versatility and accuracy of this improved degenerated shell element are demonstrated by solving several numerical examples.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.4 no.3
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• pp.174-181
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• 2011

A new registration method for IR image and EO image is proposed in this paper. IR sensor is applicable to many area because it absorbs thermal radiation energy unlike EO sensor does. However, IR sensor has difficulty to extract and match features due to low contrast compared to EO image. In order to register both images, we used modified SIFT(Scale Invariant Feature Transform) and block processing to increase feature distinctiveness. To remove outlier, we applied RANSAC(RANdom SAample Concensus) for each block. Finally, we unified matching features into single coordinate system and remove outlier again. We used 3~5um range IR image, and our experiment result showed good robustness in registration with IR image.

• Journal of KIISE
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• v.44 no.4
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• pp.392-398
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• 2017

The point-cloud representation of an object is performed by scanning a space through a laser scanner that is extracting a set of points, and the points are then integrated into the same coordinate system through a registration. The set of the completed registration-integrated point clouds is classified into meaningful regions, shapes, and noises through a mathematical analysis. In this paper, the aim is the matching of a curved area like a cylinder shape in 3D point-cloud data. The matching procedure is the attainment of the center and radius data through the extraction of the cylinder-shape candidates from the sphere that is fitted through the RANdom Sample Consensus (RANSAC) in the point cloud, and completion requires the matching of the curved region with the Catmull-Rom spline from the extracted center-point data using the Principal Component Analysis (PCA). Not only is the proposed method expected to derive a fast estimation result via linear and curved cylinder estimations after a center-axis estimation without constraint and segmentation, but it should also increase the work efficiency of reverse engineering.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.3 no.4
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• pp.867-873
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• 1999

Camera calibration is a procedure which calculates internal and external parameters of a camera with the Down world coordinates of the control points. Accurate camera calibration is required for achieving accurate visual measurements. In this paper, we propose a simple and flexible camera calibration using neural networks which doesn't require a special knowledge of 3D geometry and camera optics. There are some applications which are not in need of the values of the internal and external parameters. The proposed method is very useful to these applications. Also, the proposed camera calibration has advantage that resolves the ill-condition as object plane is near parallel image plane. The ill-condition is frequently met in product inspection. For little more accurate calibration, acquired image is divided into two regions according to radial distortion of lens and neural network is applied to each region. Experimental results and comparison with Tsai's algorithm prove the validity of the proposed camera calibration.

• Journal of KIISE:Software and Applications
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• v.31 no.1
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• pp.8-19
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• 2004

In this paper, we propose an efficient method for locating destination address block on both of machine-Printed and handwritten Korean mail piece images. The proposed method extracts connected components from the binary mail piece image, generates text lines by merging them, and then groups the text fines into nine clusters. The destination address block is determined by selecting some clusters. Considering the geometric characteristics of address information on Korean mail piece, we split a mail piece image into nine areas with an equal size. The nine clusters are initialized with the center coordinate of each area. A modified Manhattan distance function is used to compute the distance between text lines and clusters. We modified the distance function on which the aspect ratio of mail piece could be reflected. The experiment done with live Korean mail piece images has demonstrated the superiority of the Proposed method. The success rate for 1, 988 testing images was about 93.56%.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.26 no.6
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• pp.451-456
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• 2013

To study emission properties of white phosphorescent organic light emitting devices (PHOLEDs), we fabricated white PHOLEDs of ITO(150 nm) / NPB(30 nm) / TcTa(10 nm) / mCP(7.5 nm) / light-emitting layer(25 nm) / UGH3(5 nm) / Bphen(50 nm) / LiF(0.5 nm) / Al(200 nm) structure. The total thickness of light-emitting layer with co-doping and blue-doping/co-doping using a host-dopant system was 25 nm and the dopant of blue and red was FIrpic and $Bt_2Ir$(acac) in UGH3 as host, respectively. The OLED characteristics were changed with position and thickness of blue doping layer and co-doping layer as light-emitting layer and the best performance seemed in structure of blue-doping(5 nm)/co-doping(20 nm) layer. The white PHOLEDs showed the maximum current density of $34.5mA/cm^2$, maximum brightness of $5,731cd/m^2$, maximum current efficiency of 34.8 cd/A, maximum power efficiency of 21.6 lm/W, maximum quantum efficiency of 15.6%, and a Commission International de L'Eclairage (CIE) coordinate of (0.367, 0.436) at $1,000cd/m^2$.