• Explosives and Blasting
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• v.32 no.2
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• pp.1-8
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• 2014

In this study, 16 test blastings had been carried out with different spacings, burdens, drilling lengths, and charges per delay for investigating the characteristics of ground vibration propagation, which depends on the delay time. From the tests, it was possible to derive a ground vibration equation. Using the equation, the characteristics of ground vibration could be investigated by analyzing the nomogram and predicting the Peak Particle Velocity (PPV), which are influenced by the delay time and the priming location. The trend of ground vibration change depending on the delay time was analyzed for the standards charges of 0.5, 1.6, 5, and 15 kg, which were suggested in "Blasting design and construction guidelines to road construction" by the Ministry of Land, Infrastructure and Transport. From the study, it would be possible to suggest a favorable vibration control method, which depends on the charge.

• Journal of Korean Ophthalmic Optics Society
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• v.14 no.4
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• pp.77-81
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• 2009

Purpose: To study the change of fixation disparity and accommodation as fusion contrast is deteriorated. Methods: 16 subjects who had above 20/20 and stereopsis took part. Monocular and binocular refraction were done with Zeiss Polatest Classic whereas the critical angle for stereopsis was done with TNO. A computer programmed with Random-Dot stereogram and vernier test managed a precise change of the fusion contrast and exposure time. Results: The fixation disparity was influenced by reduction of fusion contrast and had tendancy to exophoria (p=0.0004), especially it is considerably higher when uncrossed disparity was shown to exophoric subjects. Although accommodation was not influenced by a change of fusion contrast (p=0.803), vernier acuity was influenced (p=0.0000). Conclusions: Exophoric trend arose as the fusion contrast was reduced, nevertheless there was no accommadative change.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.41 no.6
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• pp.9-18
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• 2004

This paper proposes a new and simple stereo matching algorithm using the disparity space image (DSI) technique. First of all, we detect some salient feature points on each scan-line of the image pair and set the matching area using those points and define a simple cost matrix. And we take advantage of matching by pixel-by-pixel instead of using the matching window. While the pixel-by-pixel method boost up the speed of matching, because of no using neighbor information, the correctness of the matching may not be better. To cover this point, we expand the matching path using character of disparity-space-image for using neighbor information. In addition, we devise the compensated matching module using the volume of the disparity space image in order to improve the accuracy of the match. Consequently, we can reduce mismatches at the disparity discontinuities and can obtain the more detailed and correct disparity map.

• Journal of Korea Water Resources Association
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• v.33 no.1
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• pp.51-59
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• 2000

A dynamic model, which combined time series model with distributed-lag model, is applied to understand the relationship between rainfall and groundwater level. In the model, rainfall with distribution lags and past groundwater level as a dependent variables were used to estimate present groundwater level. The distribution of the lagged rainfall effects for groundwater levels was modeled by Almon polynomials. The model was applied to Banglim and Tanbu groundwater stations in Pyungchang river and Bocheong stream watershed which are representative basins for International Hydrological Program (IHP). The dynamic model represents observed groundwater levels very well and can be used to predict the levels. The model parameters reflect hydraulic characteristics of aquifer. In addition, from the parameters it appears that the increase in groundwater level due to rainfall takes place significantly within first two days of the rainfall event. The rainfall of the order of 18mm/day and 30mm/day at Banglim and Tanbu, respectively, had no significant effect on the groundwater levels.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.2C
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• pp.166-174
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• 2006

In this paper, a new stereo object tracking system using the disparity motion vector is proposed. In the proposed method, the time-sequential disparity motion vector can be estimated from the disparity vectors which are extracted from the sequence of the stereo input image pair and then using these disparity motion vectors, the area where the target object is located and its location coordinate are detected from the input stereo image. Being based on this location data of the target object, the pan/tilt embedded in the stereo camera system can be controlled and as a result, stereo tracking of the target object can be possible. From some experiments with the 2 frames of the stereo image pairs having 256$\times$256 pixels, it is shown that the proposed stereo tracking system can adaptively track the target object with a low error ratio of about 3.05$\%$ on average between the detected and actual location coordinates of the target object.

• Tunnel and Underground Space
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• v.24 no.1
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• pp.97-109
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• 2014

In order to identify the characteristics of the propagation depending on delay time (20, 25 ms) and priming location (top priming, middle priming, bottom priming), test blasts were carried out a total of 4 times using different spacing, burden, drilling length, charge per delay and was derived the formula to predict blast vibration. This study investigated the characteristics of vibration by analysis of the nomogram and prediction of Peak Particle Velocity (PPV) from delay time and priming location by the formula to predict ground vibration. And it analyzed the trends of vibration increase by standards charge 0.5, 1.6, 5, 15 kg. Standards charge is "Blasting design and construction guidelines to road construction" by the Ministry of Land, Infrastructure and Transport. Depending on the charge in favor of vibration control method is proposed. Thus, when the design was to be used as a variable.

• Explosives and Blasting
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• v.27 no.1
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• pp.7-20
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• 2009

In this study, 5 steps of different delay intervals are applied to a plasma rock-breaking machine that is driven by electric shocks in order to improve the workability of the traditional single-shot type plasma rock-breaking operation. The sequential steps use the electrolyte volume per delay of 1, 2, 3, 4, 5 kg and it has been analyzed to measure the delay time and level of the ground vibration and noise according to exploding. The delay time of the rock-breaking machine by an electric shock of 5 steps has used about 40~50ms at the electrolyte connected from 1 to 3 holes, about 70~80ms at the electrolyte connected from 4 to 5 holes. It is identified that the extents of the ground vibration is low to 1 over 3~6 compared with that of the emulsion explosives.

• The KIPS Transactions:PartB
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• v.10B no.5
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• pp.561-566
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• 2003

This paper proposes a new algorithm that generates smooth and realistic transition views from one viewpoint to another view point on the panorama based navigation system. The proposed algorithm is composed with two steps. One is prewarping that aligns the viewing direction in two panorama image, the other is bidirectional disparity morphing (BDM) that generates the intermediate scene from the aligned panorama images. For the prewarping, first of all, we compute the phase correlation between two images in order to get the information such as the displacement, rotation, and scale. Then we align the original images using these information. As soon as finishing the prewarping, we compute the block based disparity vectors (DVs) and smooth them using the two occluding patterns. As we apply these DVs to the BDM, we can get the elaborate intermediate scenes. We make an experiment on the proposed algorithm with real panoramic images and we can get the satisfactory results.

• Proceedings of the Korea Information Processing Society Conference
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• 2005.05a
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• pp.851-854
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• 2005

본 논문에서는 영상 내 객체들의 운동시차를 이용하여 실시간으로 2차원 영상을 입체 영상으로 변환하는 알고리즘을 제안하였다. 제안한 입체 영상 변환 알고리즘은 영상 내 객체 분할, 운동시차를 이용한 운동 객체 검출, 시차 처리를 이용하여 입체 영상으로 변환한다. 입체 영상 변환 알고리즘의 성능 평가를 위해 좌안과 우안 영상의 절대 차이 영상을 이용하여 기존의 MTD 방식과 시뮬레이션 결과를 비교, 분석하였다. 제안한 알고리즘은 영상의 운동 방향 및 속도에 상관없이 다양한 영상원에 대해 실시간 입체 영상 변환이 가능하다. 입체 영상 변환 장치는 VHDL로 설계하였으며, FPGA 테스트 보드 구현을 통해 성능 및 기능을 검증하였다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.26 no.9B
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• pp.1267-1276
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• 2001

본 논문은 스테레오 시차정보를 이용하여 스테레오 비젼 시스템에서 표적물체의 영역 및 위치를 구하고, 표적물체를 제외한 배경을 분리함으로써 표적물체 영역을 효과적으로 추출할 수 있는 새로운 알고리즘을 제시하였다. 즉, 제안한 알고리즘은 스테레오 비젼 시스템에서 얻어지는 양안시차 정보와 각 픽셀의 유사도를 이용하여 1차적으로 배경을 분리한 후 그 결과에 히스토그램을 적용하여 최종적으로 표적물체 영역을 추출하였다. 실험 결과 제안한 알고리즘은 스테레오 입력 영상에서 배경잡음과 관계없이 표적 물체영역을 추출할 수 있었고, 이의 구현으로 스테레오 원격작업 시스템이나 적응적인 스테레오 물체 추적기 등의 구현 가능성을 제시하였다.