• Journal of the Institute of Electronics Engineers of Korea SP
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• v.37 no.5
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• pp.54-63
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• 2000

We present a multi-resolution block matching algorithm (BMA) for fast motion estimation At the coarsest level, a motion vector (MV) having minimum matching error is chosen via a full search, and a MV with minimum matching error is concurrently found among the MVs of the spatially adjacent blocks Here, to examine the spatial MVs accurately, we propose an efficient method for searching full resolution MV s without MV quantization even at the coarsest level The chosen two MV s are used as the initial search centers at the middle level At the middle level, the local search is performed within much smaller search area around each search center If the method used at the coarsest level is adopted here, the local searches can be done at integer-pel accuracy A MV having minimum matching error is selected within the local search areas, and then the final level search is performed around this initial search center Since the local searches are performed at integer-pel accuracy at the middle level, the local search at the finest level does not take an effect on the overall performance So we can skip the final level search without performance degradation, thereby the search speed increases Simulation results show that in comparison with full search BMA, the proposed BMA without the final level search achieves a speed-up factor over 200 with minor PSNR degradation of 02dB at most, under a normal MPEG2 coding environment Furthermore, our scheme IS also suitable for hardware implementation due to regular data-flow.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.10A
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• pp.727-735
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• 2009

To alleviate positioning error using wireless ultra-wideband (UWB) is primary concern, and it has been studied how to reduce the positioning error effectively. Thanks to many repeated transmissions of UWB signals, we can have a variety of selections to point out the most precise positioning result. Towards this, scanning method has been preferred to be used due to its simplicity. This exhaustive method firstly fixes the candidate position, and calculates the sum of distances from observed positions. However, it has tremendous number of computations, and the complexity is more serious if the size of two-dimensional range is the larger. To mitigate the large number of computations, this paper proposes the technique employing genetic algorithm and block windowing. To exploit its superiority, simulations will be conducted to show the reduction of complexity, and the efficiency on positioning capability.

• The Journal of the Acoustical Society of Korea
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• v.18 no.2
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• pp.66-76
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• 1999

This paper proposes that can take at high speed the information of binocular disparity with moving translational and forward stereo camera to the extent that does not occur the problem of a correspondence point. It shows that in case of stereo vision with translational motion, can take the information of binocular disparity being devoid of error and putting high confidence in, and that in case of stereo vision with forward motion, can take the horizontal component which can not be detected in common stereo vision. Besides, the stereo vision can be done at high speed due to being bright and small a correspondence point comparing not to do, because a correspondence between right and left images is previously limited. But there are problem that a resonable information of binocular disparity can not be taken, if the vicinity of center of image is in accord with the region of occlusion in stereo vision with forward motion.

• Korean Journal of Remote Sensing
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• v.34 no.6_3
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• pp.1351-1367
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• 2018

Image registration is an essential process for image fusion, change detection and time series analysis using multi-sensor images. For this purpose, we need to detect accurately the difference of scale and rotation between the multi-sensor images with difference spatial resolution. In this paper, we propose a new feature matching method using variable circular template for image registration between multi-resolution images. The proposed method creates a circular template at the center of a feature point in a coarse scale image and also a variable circular template in a fine scale image, respectively. After changing the scale of the variable circular template, we rotate the variable circular template by each predefined angle and compute the mutual information between the two circular templates and then find the scale, the angle of rotation and the center location of the variable circular template, respectively, in fine scale image when the mutual information between the two circular templates is maximum. The proposed method was tested using Kompsat-2, Kompsat-3 and Kompsat-3A images with different spatial resolution. The experimental results showed that the error of scale factor, the error of rotation angle and the localization error of the control point were less than 0.004, $0.3^{\circ}$ and one pixel, respectively.

• Proceedings of the Korean Society for Quality Management Conference
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• 1998.11a
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• pp.580-593
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• 1998

The small composite design for second order response surface might be appropriate when experimentation is expensive, difficult, or time-consuming, especially when an independent estimate of experimental error is available. It is important that the small composite designs for response surface analysis would be rotatable and slope-rotatable. Therefore the small composite designs are studied from the viewpoint of rotatability and slope-rotatability, and the optimal values of a(the distance of axial points from the center) are investigated as k(the number of independent variables) and $n_0$(the number of center points) are changed.

• The Korean Journal of Applied Statistics
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• v.28 no.6
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• pp.1227-1234
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• 2015

Traditional criteria for optimum experimental designs depend on the specifications of the model; however, there will be a dilemma when we do not have perfect knowledge about the model. Box and Draper (1959) suggested one direction to minimize bias that may occur in this situation. We will demonstrate some examples with exact solutions that provide a no-bias design for polynomial regression. The most interesting finding is that a design that requires less bias should allocate design points away from the border of the design space.

• Journal of Korean Ophthalmic Optics Society
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• v.9 no.1
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• pp.19-27
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• 2004

The purpose of this study is to survey spectacle wearers's way of thinking through the questionaire and to investigate their wearing conditions through fitting conditions, the pantascopic angle, vertex distance, the coincidence of vertical and horizontal distance between optical center of the lens and pupillary distance of the eye in random selected 150 ametropic corrective wearers in the age of 17 to 19. The results are as follows : 1. The most popular causes of physical complaints in the ex-wearing spectacle are frame pressure(34.0%), slipping forward(30.0%) and most popular visual complaints are blur vision(30.0%) and asthenopia(20.0%). 2. The most common physical or visual complaints in the present wearing spectacle are slipping forward(30.0%), pressure (50.0%), color(10.0%). 3. Myopic glasses wearers accounted for 56.7% of the subjects, the others were compound myopic astigmatism. In 60% of the subjects' binocular diopter did not coincide. 4. In the pantascopic angle of the both eyes coincide in 66.7% of the subjects. The average of pantascopic angle is $10.07^{\circ}$. 5. In the vertex distance of the both eyes coincided in 65.3% of the subjects. the he average of vertex distance is 13.6 mm. 6. Among 150 eyes with monocular, the vertical distance between optical center of the lens and pupillary distance of the eye is within the RAL-RG 915 that is tolerance of ophthalmic dispensing in German Standards in 82 eyes (54.6%). 7. Among 150 eyes with monocular, the horizontal distance between optical center of the lens and pupillary distance of the eye is within the RAL-RG915 that is tolerance of ophthalmic dispensing in German Standards in 86 eyes(57.3 %).

• Fire Science and Engineering
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• v.33 no.1
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• pp.92-98
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• 2019

To determine if water-jet nozzle moves and water jetting are effective according to the location of the fire, this study examined the automatic fire-tracking water cannon system and aan indoor hydrant system, such as water jet centered directivity, water jet range maintainability and water jet shape uniformity. First, an examination to find the center of fire accurately from this system design showed that the water jet centered test was accurate. Second, the water jet range test results showed that when water is jetted at the maximum water jet radius, the water jet shows an inaccurate result but within the allowable tolerance range. Finally, the water-jet shape test result confirmed that there are no problems in setting the block from the algorithm design.

• Korean Journal of Remote Sensing
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• v.35 no.6_1
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• pp.907-917
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• 2019

Recently, the demand for high-resolution satellite images increases in many fields such as land monitoring and terrain analysis. Therefore, the need for geometric correction is increasing. As an automatic precision geometric correction method, there is a method of automatically extracting the GCP by matching between the GCP Chip and the satellite image. For automatic precision geometric correction, the success rate of matching GCP Chip and satellite image is important. Therefore, it is important to evaluate the matching performance of the manufactured GCP Chip. In order to evaluate the matching performance of GCP Chips, a total of 3,812 GCP Chips in South Korea were used as experimental data. The GCP Chip matching results of KOMPSAT-3A and Google Map showed similar matching results. Therefore, we determined that Google Map satellite imagery could replace high-resolution satellite imagery. Also, presented a method using center point and error radius of Google Map to reduce the time required to verify matching performance. As a result, it is best to set the optimum error radius to 8.5m. Evaluated the matching performance of GCP Chips in South Korea using Google Maps. And verified matching result using presented method. As a result, the GCP Chip s in South Korea had a matching success rate of about 94%. Also, the main matching failure factors were analyzed by matching failure GCP Chips. As a result, Except for GCP Chips that need to be remanufactured, the remaining GCP Chips can be used for the automatic geometric correction of satellite images.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.12
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• pp.1086-1092
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• 2012

It has been studied for DGPS/INS(Differential Global Positioning System/Inertial Navigation System) to offer the more precise and reliable navigation data with the aviation industry development. The flight performance evaluation of navigation system is very significant because the reliability of navigation data directly affect the safety of aircraft. Especially, the high-level navigation system, as DGPS/INS, need more precise flight performance evaluation method. The performance analysis is performed by comparing between the DGPS/INS navigation data and reference trajectory which is more precise than DGPS/INS. The GPS receiver, which is capable of post-processed CDGPS(Carrier-phase DGPS) method, can be used as reference system. Generally, the DGPS/INS is estimated the CG(Center of Gravity) point of aircraft while the reference system is output the position of GPS antenna which is mounted on the outside of aircraft. For this reason, estimated error between DGPS/INS and reference system will include the error due to lever arm. In order to more precise performance evaluation, it is needed to compensate the lever arm. This paper presents procedure and result of flight test which includes lever arm compensation in order to verify reliability and performance of DGPS/INS more precisely.