• Journal of the Korea Computer Graphics Society
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• v.17 no.4
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• pp.31-40
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• 2011

Projector-based visual systems are widely used for VR and experience display applications. But the illumination irregularity on the screen surface due to the screen material and its light reflection properties sometimes deteriorates the user experience. This phenomenon is particularly troublesome when the participants of the head tracking VR system such as CAVE or the motion generation experience system continually move around the system. One of reason to illumination irregularity is projector-screen specular reflection component to participant's eye's position and it's analysis needs high computation complexity. Similar to calculate specular lighting term using GPU's programmable shader, Our research adjusts every pixel's brightness in runtime with given 3D screen space model to reduce illumination irregularity. For doing that, Angle-based brightness compensate function are considered for specific screen installation and modified it for GPU-friendly compute and access. Two aspects are implemented, One is function access transformation from angular form to product and the other is piecewise linear interpolate approximation.

• Journal of the Economic Geographical Society of Korea
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• v.19 no.1
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• pp.122-142
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• 2016

This paper examines the implications of North Korea's Special Economic Zone (SEZ) strategy since the early 1990s in terms of the shifts in both North Korea's economic system and geopolitical order on the Korean peninsula. Specifically, it analyzes the shifts in North Korea's SEZ policy in three different aspects-North Korea's unique territorial logic, stress on decentralization, and comparison with Chinese reform and opening-up. Based upon this analysis, this paper criticizes a linear approach to understand North Korea's economic transformation from isolation to opening-up, and explores the dynamics of North Korea SEZ strategy in various dimensions. It contends that North Korea's SEZ strategy is neither an inevitable choice from economic difficulty nor an adoption of Chinese model of reform and opening up. Rather this paper focuses on the geopolitical logic and local development imperatives underlying SEZ strategy.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.4 no.1
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• pp.34-44
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• 1992

A numerical model using Hybrid Element Method(HEM) is presented for the prediction of wave agitations in a harbor which are induced by the intrusion and transformation of incident short-period waves. A linear mild-slope equation including bottom friction is used as the governing equation and a partial absorbing boundary condition is used on solid boundaries. Functional derived in the present paper is based on the Chen and Mei(1974)'s concept which uses finite element net in the inner region and analytical solution of Helmholtz equation in the outer region. Final simultaneous equations are solved using the Gaussian Elimination Method. The model appears to be reasonably good from the comparison of numerical calculation with hydraulic experimental results of short-wave diffraction through a breakwater gap(Pos and Kilner, 1987). The problem of requring large computational memory could be overcome using 8-noded isoparametric elements.

• Korean Journal of Applied Biomechanics
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• v.15 no.2
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• pp.129-138
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• 2005

The purpose of this study was to investigate the techniques used by long jumpers who recorded over 8meters in 2002 Busan Asian Game and 2003 Daegu Universiade. The kinematic characteristics from the last three stride to takeoff at the takeoff board were analyzed such as velocities, heights and angles. The real-life three-dimensional coordinates of 20 body landmarks during each trial were collected using a Direct Linear Transformation procedure. The conclusion were as follows; 1. The height variation who recorded over 8 meters of center of gravity of the jumpers at the last stride was under 8cm. In order to record over 8meters the national long jumpers should have under 10cm height variation. 2. In the approach phase the horizontal velocity of the jumpers should reach to 10.5m/s in last three strides and 9.79m/s in touch down at take off board. 3. The horizontal velocity at take off board must have over 8.51m/s and the vertical velocity must have 3.75m/s simultaneously in order to record 8meters. 4. The forward body lean angle should have over 20degrees with pushing the take off board in forwarding movement. The appropriate body variation range ratio between take off and touch down should be 1.2 vs 1 and the trunk angle at touch down on the board should be close to the erect posture for higher body flight.

• Korean Journal of Applied Biomechanics
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• v.13 no.3
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• pp.199-215
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• 2003

The purpose of this study was to attempt new starting motion and supply present starting motion in the 500M short track speed skating according to the center of gravity position. The center of gravity position ratio was divided starting motion into five(type A : front 80%-back 20%, type B front 70%-back 30%, type C : front 50%-back 50%, type D : front 30%-back 70%, type E : front 20%-back 80%). The three dimension motion analysis with DLT(direct linear transformation) method was executed using two video cameras. The following conclusion was that It was appear that reaction and execution time in starting motion was the most short in type B. It was characteristic that step of skaters was shorten and center of gravity position ratio was not effect to change of the step in each event. It was appear that the displacement of type D and type E were longer than that type A and type B during the starting motion. It was appear that skill types of center of gravity position ratio to the front were lower than that to the back and contract a posture. Observing the above, it was conclusion that skill type B of center of gravity position ratio to the tent was more effect than that to the back. But it is important that these skill type was most used to the competition and estimate the result.

• Korean Journal of Applied Biomechanics
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• v.13 no.3
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• pp.47-65
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• 2003

The purpose of this study was to investigate the differences of the kinematical and the kinetical factors that calculated from preflight to postflight of salto forward straight 3/2 turn motion between skitters and less-skitters. four S-VHS video cameras operating at 60Hz were used to record the performances. five elite male gymnasts were participated in this study as subjects. three-dimensional coordinates of 20 body landmarks during each trial were collected using a Direct Linear Transformation method. The digitized body landmarks were smoothed using a Butterworth second order with low pass digital filter and a cutoff frequency of 10Hz. 1. A skitter, got a high score for performance, showed shorter time and faster horizontal velocity than a less-skitter at the board contact. also, a skitter extended quickly his knee and hip joint after contacting board for preflight phase. 2. A skitter revealed faster time and horizontal velocity the vault from taking off board than a less-skiller. A skitter took a long time and high distance to get the vertical peak compared with a less-skiller. 3. For the second phase, a skitter, who executes the most optimal motions among the subjects, displayed a long flight time, a high height, and a far flight distance as well as maintaining consistent horizontal speed even at the peak of post flight. On the other side, a less-scorer displayed a slow vertical velocity, distance and a short time at the point of take-off from vault as well as low height at the peak of post flight.

• Korean Journal of Applied Biomechanics
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• v.13 no.3
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• pp.277-291
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• 2003

This study was designed to examine the kinematic factors in the phase during the marche fente motion. For this study, the subjects were 5 elite male fencing players. The direct linear transformation (DLT) method was used in calculating 3-D coordinate of the digitized body parts. The cubic spline function was used for smoothing and the kinematic data for displacement, velocity, angle variables were calculated for Kwon3d ver 2.1. And the following conclusions were drawn; 1. It show that the marche phase appeared to longer time than the pante phase In the performance time. For the fast attack, it showed that the subjects should be moving in a short stride width. 2. For a fast and stable movement posture in the marche phase, the vertical change of COG must be maintain the same position as possible, but all subjects appeared to decrease the COG because of a excessive the knee flection. 3. In the COG velocity change, all the subjects showed to the same change in both the marche and the fente phase. However in the attack extremity velocity, it increased velocity in order of upper arm, fore arm, and hand in the marche phase, but it showed different velocity among each subjects at the moment of stabbing. So that in order to do effective stabbing, they have to extend their upper extremity max and do faster the distal segment than the proximal segment. 4. It showed to take a fast and stable movement, because some subjects showed the big anteroposterior angle of the trunk flexed max shoulder angle and elbow angle of their attack arm and the other upper extremity.

• Korean Journal of Oriental Medicine
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• v.13 no.2 s.20
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• pp.59-63
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• 2007

The purpose of this study was to diagnosis that what patterns identification using the statistical method. Discriminant analysis using the medical specialist and resident pattern identification agree case in stroke patients within 1 month of onset. The agreement rate of dificiency of Gi(75%), heat-transformation(74%), dampphlegm syndrome(69%), deficiency of Eum(51%) and syndrome of blood stagnation(43%) are respectively 0.75, 0.74, 0.69, 0.51 and 0.43 in medical specialist and using linear discriminant function pattern identification are same. The study of inspection, pulse feeling and palpitation will be continued to evaluate concordance rate. Discrimination model will be make to get higher Accuracy and prediction, it means becomes the help in pattern identification diagnosis objectivity and scientific.

• Progress in Medical Physics
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• v.6 no.2
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• pp.35-40
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• 1995

Purpose: We have developed new film dosimetry algorithm for personal dosimetry and examined its characteristics. Materials and methods: Agfagaevart personal monitoring 2/10 films are used. Films which are in the film badges filtered with Cu 0.3mm, plastic 1.5mm, Aluminum 0.6mm and tin 0.8mm, were exposed by standard dosimetry laboratory. Irradiated energy categories are ANSI N13.1l Category III, and IV. Manual type film precessor and X-rite film densitometor was used. Filtered densities to energy relations and does to transformed densities relations can be obtained ofter transformation of H＆D curves to linear shape by polynomal fitting. Reults : Personal dose be determined within 25％ error for category m and 15％ for category IV. And we are able to evaluate the exposed energy. Conclusion : New algorithm developed in this study is good for personal dosimetry within 30％ error range for catergory III and IV. It is expectd to be complete personal dosimetry algorithm with further study for categrory, I, Dand II V.

• Journal of Korea Water Resources Association
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• v.30 no.3
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• pp.225-233
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• 1997

The nonlinear effects on the statistical properties of wave groups in terms of the average nomber of waves in a group and the mean number of waves in a high run is studied in this paper utilizing the complex envelope and total phase function, random variable transformation technique and perturbation method. It tures out that the phase distribution is modified significantly by nonlinearities and it show systematic excess of values near the mean phase and the corresponding symmetrical deficiency on both sides away from the mean. for the case of threshold crossing rate, it turns out that threshold crossing rate reaches its maxima just below the mean water level rather than zero and considerable amount of probability mass is shifted toward the larger values of water surface elevation as nonlinearity is getting profound. Furthermore, the mean waves in a high run associated with nonlinear wave are shown to have larger values than the linear counterpart. Similar trend can also be found in the average number of waves in a group.