• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.27 no.3
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• pp.162-166
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• 2014

We propose an analysis method of an autostereoscopic display system with lenticular lens array using finite ray-tracing method that is verified by the geometrical optics. In the present work, we adopt the cylinder equation for the mathematical expression of the lenticular lens. For the calculation of the direction cosine of the transmitted ray, we first calculate the refracting point at bottom of the lens and the direction cosine of the incident ray that propagating through the lens by the Snell's law, and then apply to finite ray-tracing method. Finally, we obtain the simulation results for the intensity distribution of the ray at optimal viewing distance. From these results, we confirm the realization of 3D image that exists separately according to the viewing position at an optimal viewing distance.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.52 no.9
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• pp.434-441
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• 2003

This paper deals with the temperature characteristics according to the cooling medium and the duct size in model transformers. For the analysis and the temperature-rise tests, two 400kVA model transformers have been manufactured. One has been filled with the alpha oil as the cooling medium and constructed the duct sizes of $3\textrm{mm}$ and $5\textrm{mm}$ in the low-voltage and high-voltage windings respectively. The other has been filled the beta oil and the duct sizes were $4\textrm{mm}$ and $6\textrm{mm}$. The temperature-rise tests have been performed by the back-to-back method and the load factor has been controlled the range of 90%∼130%. The temperature values have been measured by the thermocouple and from the sixteen points in each transformer. A commercial CFD program "FLUENT" has been used for the analysis of temperature distribution. The geometry of transformer has been modeled to 3-dimensional by using the hybrid calculation mesh including the radiator. And also, the natural convection velocity has been measured at the oil top position, and compared with the calculated results.

• Journal of the Korean Society of Industry Convergence
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• v.21 no.6
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• pp.309-316
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• 2018

The high-resolution satellite images provided by Kompsat-3A, a multipurpose satellite, have various applications such as digital map generation, 3D image generation, and DEM generation. In order to utilize high-resolution satellite images, the user must create an orthoimage in order to use the image in a suitable manner. The position and the number of the ground reference points affect the accuracy of the orthoimage. In particular, the Kompsat-3A satellite image has a high resolution of about 0.5m, so the difficulty in selecting the ground control points and the accuracy of the selected point will have a great influence on the subsequent application process. Therefore, in this study, we analyzed the influence of the number of ground reference points on the accuracy of the terrestrial satellite images.

• The Korean Journal of Physiology
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• v.1 no.1
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• pp.77-82
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• 1967

The normal lung volumes were determined and subdivided under sitting position in 48 middle school girls, 49 high school girls and 44 house wives. All subjects were free of pulmonary and vascular diseases. The vital capacity was measured by Mckessons spirometer and the residual volume was determined by Rahn's three breathing method. 1. The lung volumes (BTPS) of middle school girls determined were: $RV\;0.59{\pm}0.11l\;FRC\;1.45{\pm}2.22l\;VC\;2.68{\pm}0.29l$ 2. The lung volumes (BTPS) of high school girls determined were: $RV\;0.83{\pm}0.19l\;FRC\;1.9{\pm}0.25l\;VC\;3.15{\pm}0.24l$ 3. The lung volumes (BTPS) of house wives determind were: $RV\;0.95{\pm}0.61{\ell}\;FRC\;2.1{\pm}0.25{\ell}\;VC\;3.06{\pm}0.29l$ 4. The calculated residual ratio $(RV/TLC{\times}100)$ were: $17.7{\pm}2.57%$ in middle school girls and $20.6{\pm}3.65%$ in high school girls and $24.0{\pm}2.31%$ in house wives 5. The functional residual ratio $(FRC/TLC{\times}100)$ were: $43.7{\pm}5.98%$ in middle school girls and $48.8{\pm}4.41%4 in high school girls and $52.6{\pm}5.38%$ in house wives. 6. The correlation coefficients between vital capacity and total lung capacity were r=0.96 in middle school girls and r=0.986 in high school girls and r=0.856 in house wives. 7. The regression equations were obtained follows: $TLC(l) =1.105{\times}VC+0.304$ (in middle school girls) $TLC(l) =1.551{\times}VC-0.902$ (in high school girls) $TLC(l) =0.999{\times}VC+0.954$ (in house wives)

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.26 no.2
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• pp.103-110
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• 2008

General lens, widely using in Photogrammetry, has narrow view, and have to adjust "Image-Registration Method" after obtain images and it need cost; economic, period of time. Recent days, there is various study that use wide-angle lens, usually for robotics field, put to practical use in photogrammetry instead of general lens. In this studies, distortion tendency of wide-angle lens and utilize the correction techniques suitable to wide-angle lens by the existing photographic survey methods. After carrying out the calibration of the wide-angle lens, we calculated the correction parameters, and then developed the method that convert the original image-point to new image-point correcting distortion. For authorization the developed algorithm, we had inspection about shape and position; there are approximately 2D RMSE of 3 pixel, cx = 2, and cy = 3 different.

• Journal of Korean Society of Steel Construction
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• v.10 no.4 s.37
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• pp.779-788
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• 1998

This paper presents the results of the experimental and analytical investigation for the fatigue strength of welded details frequently used in steel bridges, especially for the details with relatively lower fatigue strength. Considering the measured stress fatigue cracking initiated at toe of the transverse fillet weld joining the gusset plates to the web because of the stress concentration that developed as a result of the geometric conditions and the greater probability of microscopic discontinuities at the fillet weld toe A comparison was made of the stress calculated by considering geometric aspect of bead and measured at same position. They indicate that the geometric conditions of the weld toe result in similar stress concentration on both FEM models and test results. The test results were compared with the fatigue criteria of AASHTO, JSSC specifications. Specimens of 80 and 150mm gusset plate configuration tested either respectively equaled or exceeded the fatigue resistance provided by category D and E of the AASHTO specification. It also satisfied the category F and G of JSSC. Both WG1 and WG3 specimen tend to provide S-N curves with a store near -0.3 less than AASHTO and JSSC.

• Journal of Korea Multimedia Society
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• v.14 no.2
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• pp.171-181
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• 2011

A vision-based method for positioning and orienting of pallets is presented in this paper, which guides autonomous forklifts to engage pallets automatically. The method uses a single camera mounted on the fork carriage instead of two cameras for stereo vision that is conventionally used for positioning objects in 3D space. An image back-projection technique for determining the orient of a pallet without any fiducial marks is suggested in tins paper, which projects two feature lines on the front plane of the pallet backward onto a virtual plane that can be rotated around a given axis in 3D space. We show the fact that the rotation angle of the virtual plane on which the back-projected feature lines are parallel can be used to describe the orient of the pallet front plane. The position of the pallet is determined by using ratio of the distance between the back-projected feature lines and their real distance on the pallet front plane. Through a test on real pallet images, we found that the proposed method was applicable to real environment practically in real-time.

• Journal of the Korea Computer Graphics Society
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• v.18 no.1
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• pp.1-9
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• 2012

Video-based modeling / rendering developed to produce photo-realistic video contents have been one of the important research topics in computer graphics and computer visions. To smoothly combine original input video clips and 3D graphic models, geometrical information of light sources and cameras used to capture a scene in the real world is essentially required. In this paper, we present a simple technique to estimate the position and orientation of an optimal light source from the topology of objects and the silhouettes of shadows appeared in the original video clips. The technique supports functions to generate well matched shadows as well as to render the inserted models by applying the estimated light sources. Shadows are known as an important visual cue that empirically indicates the relative location of objects in the 3D space. Thus our method can enhance realism in the final composed videos through the proposed shadow generation and rendering algorithms in real-time.

• Advances in Computational Design
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• v.3 no.4
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• pp.319-338
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• 2018

High-performing architecture should be designed by taking into account the mutual dependency between the new building and the local context. The performative architecture plays an important role to avert any unforeseen failures after the building has been built; particularly ones related to the microclimate impacts that affect the human comfort. The use of the concept of solar envelopes helps designers to construct the developable mass of the building design considering the solar access and the site obstruction. However, the current analysis method using solar envelopes lack in terms of integrating the detailed information of the existing context during the simulation process. In architectural design, often the current site modelling not only absent in preserving the complex geometry but also information on the surface characteristics. Currently, the emerging applications of point clouds offer a great possibility to overcome these limitations, since they include the attribute information such as XYZ as the position information and RGB as the color information. This study particularly presents a comparative analysis between the manually built 3D models and the models generated from the point cloud data. The modelling comparisons focus on the relevant factors of solar radiation and a set of simulation to calculate the performance indicators regarding selected portions of the models. The experimental results emphasize an introduction of the design approach and the dataset visibility of the 3D existing environments. This paper ultimately aims at improving the current architectural decision of support environment means, by increasing the correspondence between the digital models for performance analysis and the real environments (context of design) during the conceptual design phase.

• Journal of Sasang Constitutional Medicine
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• v.19 no.1
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• pp.90-97
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• 2007

1. Objectives and Methods This study was done to investigate the relationships of Sound parameters between Liver Heat Symptom and Esophagus Symptom of Taeumin using PSSC(Phonetic System of Sasang Constitution) in a sentence. Experimental Participants were 20 Korean adult males including, each 10 Liver Heat Symptom and Esophagus Symptom of Taeumin. 2. Results In Pitch segment, APQ segment and Shimmer segment, there were no significant differences between Liver Heat Symptom and Esophagus Symptom of Taeumin. In Octave segment, there were significant differences in Octave 1, Octave 3, Octave 4, Octave 6 of Liver Heat Symptom of Taeumin were significantly high compared with Esophagus Symptom of Taeumin. In Energy segment, FreQ Domain Total Sum / cnt(0), 0k-2k Total Sum,0k-2k sum dev., 2k-4k Total Sum, 2k-4k sum dev., A# Tot E, B__TOT_E, C__TOT_E, C# Tot E, D__TOT_E, A sum dev., A# sum dev., B sum dev., C sum dev., C# sum dev., Dsum dev., D# sum dev., E sum dev., F sum dev., F# sum dev., G sum dev., G# sum dev. of Liver Heat Symptom of Taeumin were significantly high compared with Esophagus Symptom of Taeumin. In Voice Recording time segment, Total Voice Recording Time, Voice Recording Time, Divide By Time3, Divide By Energy10, Total Unit, Max Unit Position, U_0 TO 3 of Liver Heat Symptom of Taeumin were significantly high compared with Esophagus Symptom of Taeumin. 3. Conclusion From above result, there is the postbility of efficiency quide constitutional sx. of Taeumin by Voice characteristics. More Soeumin, Soyangin and Taeyangin Symptoms are needed to determine Sasang Constitution using PSSC and to make PSSC effective.