• The Journal of Korean Institute of Communications and Information Sciences
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• v.13 no.6
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• pp.490-500
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• 1988

In recent years the acquisition, processing and interpretation of three dimensional seisimic data, for the purpose of locating gas and reservoirs, have become practical. This paper exlores one way in which the volume data can be searched and visualized, which may aid the interpreter. The illusion of looking at a three dimensional volume can be obrained by fusing a stereoscopic pair of pictures. Each picture can be made by projecting each data point of the volume into a plane from a point where the eye is placed. The data valuse along any projection line can be summed to form the picture, or only a segment along the line can be selected. By selective projection, the volume can be searched and obscuring layers removed. The stereoscopic pictures show the physical models in there ture spatial positions. Projection of the envelope function of the seismic traces is shown to give improved depth perception compared with projection of the position amplitudes.

• Journal of KIISE:Software and Applications
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• v.30 no.12
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• pp.1239-1246
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• 2003

Registration is the process aligning the range data sets from different views in a common coordinate system. In order to achieve a complete 3D model, we need to refine the data sets after coarse registration. One of the most popular refinery techniques is the iterative closest point (ICP) algorithm, which starts with pre-estimated overlapping regions. This paper presents an improved ICP algorithm that can automatically register multiple 3D data sets from unknown viewpoints. The sensor projection that represents the mapping of the 3D data into its associated range image is used to determine the overlapping region of two range data sets. By combining ICP algorithm with the sensor projection constraint, we can make an automatic registration of multiple 3D sets without pre-procedures that are prone to errors and any mechanical positioning device or manual assistance. The experimental results showed better performance of the proposed method on a couple of 3D data sets than previous methods.

• Journal of radiological science and technology
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• v.32 no.3
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• pp.253-259
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• 2009

Purpose : The purpose of this study was to find out useful radiological projection of shoulder subluxation in patients with post-stroke hemiplegia. Methods : A total of 33 patients with post-stroke hemiplegia were included(20 men and 13 women, mean age 62.3 years) and having the subluxed shoulder over one finger breath. The shoulder subluxation was determined as the ratio of the radiographic vertical and horizontal distance. The vertical distance was determined by measuring the distance between the most inferolateral point of the acromion and the central point of the humeral head. The horizontal distance was determined by measuring the distance between the central point of the glenoid fossa and the central point of the humeral head. To measure of the shoulder subluxation, the shoulder AP, axial and transthoracic lateral projections were taken on both affected and unaffected shoulders. We analyzed the difference of subluxation distance by t-test. Results : When patients was in sitting position, the average time of being shoulder subluxation was 123 second. There was significant difference between supine($49.90{\pm}13.6\;mm$) and sitting position($60.72{\pm}16.3\;mm$) in the vertical distance of shoulder anterior-posterior projection. Also, there was significant difference on transthoracic lateral projections, Affected $35.92{\pm}6.2\;mm$, Unaffected $28.76{\pm}5.4\;mm$. But in case of shoulder axial projection(supine position), there was no significant difference (Unaffected and affected was $23.01{\pm}9.0\;mm$, $22.45{\pm}8.2\;mm$ each). Conclusion : Radiological projection of shoulder subluxation has diagnostic value when it goes after check out the process of subluxation through finger breadth test. For this, patients must be in sitting and shoulder neutral position about 2 minutes. In addition, Shoulder anterior-posterior and transthoracic projection were significant to diagnose subluxation. But in axial projection, there wasn't meaningful differences.

• Journal of KIISE:Databases
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• v.30 no.1
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• pp.52-63
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• 2003

Spatiotemporal moving objects are changing their Positions and/or shape over time in real world. As most of the indices of moving object are based on the R-tree. they have defects of the R-tree which are dead space and overlap. Some of the indices amplify the defects of the R-tree. In the paper, to solve the problems, we propose the MPR-tree(Moving Point R-tree) using Projection operation which has more effective search than existing moving point indices on time slice query and spatiotemporal range query. The MPR-tree connects positions of the same moving objects over time by using linked list, so it processes the combined query about trajectory effectively. The usefulness of the Projection operation is confirmed during processing moving object queries and in practical use of space from experimentation to compare MPR-tree with existing indices of moving objects. The proposed MPR-tree would be useful in the LBS, the car management using GPS, and the navigation system.

• Journal of the Korean Geotechnical Society
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• v.29 no.1
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• pp.171-181
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• 2013

The radial mapping rule in bounding surface model was experimentally investigated by analyzing the drained stress probe tests on Chicago clays. The experimental data obtained from 10 drained stress probe paths were analyzed to calculate the directions of the plastic strain increments. The anisotropic bounding surface model was adopted to represent a bounding yield surface which resides in the pre-consolidation yield stress of undisturbed clays. The projection origins were estimated by finding the interceptions of the straight lines passing through the current stress point and the imaginary yield stress point on the bounding surface. The results show that the projection origin is not fixed at a point but moves toward the direction of the stress probe path after it is established around the initial stress point.

• The Journal of Engineering Geology
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• v.11 no.2
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• pp.153-161
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• 2001

The quantitative evaluation of the stereo graphic projection, the limit equilibrium analysis, the finite difference analysis, the distinct element methocI is a analytical evaluation using many variables. Through the reliability analysis by the point estimation technique, uncertainty of other variables that have an effect on the stability of the rock slo~ was considered. The organized evaluation method of the approximate reasoning concept and using a fuzzy language was developed to confer and analysis the failure factors in planning and constructing the rock slope. Considering the result of the an- alysis, it was demonstrated that stability of entire sections can be evaluated through reliability analysis of point estimation technique. The results of stability evaluation by Fuzzy Approximate Reasoning is generally identical with the results of other existirw; analyses. As mentioned above, general and organized evaluation of special qualities of rock slope is possible using RMR Classification, Stereo Graphic Projection, Limit Equilibriwn Analysis, Finite Difference Analysis, Distinct Element Method, Point Estimation Technique, and Fuzzy Approximate Reasoning.

• The Journal of the Korea Contents Association
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• v.14 no.8
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• pp.1-12
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• 2014

The projection mapping technique is used in various ways in almost every genre of performance arts at the moment. Thus, artist from various areas are participated in contents productions using it. The diversification of projection mapping contents gave producers a clue to try fresher visual effects and it was connected to the change of point of time using the camera working which was never used in old projection mapping contents productions. It is analyzed that the use of camera workings in the projection mapping image maximizes the visual Tactility and helps audiences concentrate on the contents. This study performed the theoretical research on the 'camera working' which is a new visual expression of the projection mapping and analyzed cases of projection mapping works applying them. It is to reconstruct the camera working which has been applied only by images of movies and suggest a guideline to create the optimized visual effect.

• Archives of Plastic Surgery
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• v.43 no.4
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• pp.339-343
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• 2016

Background Numerous techniques have been used to achieve long-term projection of the nipple following nipple-areola reconstruction. However, the reconstructed nipple loses projection over time. We describe a technique that uses local flaps to improve the lost projection of reconstructed nipples. Methods Between November 2013 and March 2015, nine patients (11 nipples) underwent revisional nipple reconstruction for lost projection. Only C-H nipple reconstructions were included in this study. The medical history of each patient was reviewed and photographs were taken in front and lateral views. All patients attended routine follow-up visits. Deepithelialized triangular flaps were made on all four sides of the nipple and buried in the opposite corners in order to augment the volume of the nipple. Anchoring sutures were used to attach each triangular flap on the side opposite their point of origin, and the resulting defects were closed directly. Results This procedure was used successfully in nine patients (11 nipples). Adequate projection was achieved in all patients and no complications occurred. The average nipple height was 3 mm before operation, 7 mm one day after operation, 5 mm at the six-month follow-up, and 5 mm at the 12-month follow-up. The average nipple-areolar angle was $164^{\circ}$ before the operation, $111^{\circ}$ one day after the operation, $130^{\circ}$ at the six-month follow-up, and $133^{\circ}$ at the 12-month follow-up. Conclusions The method described provides a solution to the loss of projection in reconstructed nipples. We recommend this technique because it leads to better projection, greater volume, and a more natural shape.

• The KIPS Transactions:PartA
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• v.10A no.2
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• pp.165-172
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• 2003

In this paper, we constructed horizontal and vertical virtual spaces using the projection table and the projection wall. We then implemented a system that stereoscopically visualizes three-dimensional (3D) buildings in the virtual environments in accordance with the user's viewing point. The projection table, a kind of horizontal display equipment, is effectively used in reproducing operations on a table or desk as well as in areas that require bird-eye views because its viewing frustum allows to view things from above. On the other hand, the large projection wall, a kind of vertical display equipment, is effectively used in navigating virtual spaces because its viewing frustum allows to take a front view. In this paper, we provided quick interaction between the user and virtual objects by representing major objects as detail 3D models and a background as images. We also augmented the reality by properly integrating models and images with user's locations and viewpoint in different virtual environments.

• Proceedings of the IEEK Conference
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• 2001.09a
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• pp.535-538
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• 2001

In this paper, we present a novel method to solve the inevitable RGB beam mismatch problem in projection TV receivers. Conventional methods solve the mismatch problem by directly controlling the cathode ray tube (CRT) using the convergence yoke (CY). Unlike conventional methods, the proposed method is based on digital video processing using image warping techniques. Firstly RGB beam projection paths are mathematically modeled. Then based on the modeling, the input video signal to CRT is prewarped so that RGB beams are landed at the same point on the screen. Since the proposed method is based on a digital video processing instead of using CY, it can outperform the conventional method in terms of quality and cost. The experimental results with a real 60´projection TV demonstrate that the proposed method indeed produces converged images on the projection TV screen.