• Journal of Korea Multimedia Society
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• v.7 no.2
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• pp.173-186
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• 2004

This paper proposed the content-based retrieval system as a method for performing image retrieval through the effective feature extraction of the object of significant meaning based on the characteristics of man's visual system. To allow the object region of interest to be primarily detected, the region, being comparatively large size, greatly different from the background color and located in the middle of the image, was judged as the major object with a meaning. To get the original features of the image, the cumulative sum of tile declination difference vector the segment of the object contour had and the signature of the bipartite object were extracted and used in the form of being applied to the rotation of the object and the change of the size after partition of the total length of the object contour of the image into the normalized segment. Starting with this form feature, it was possible to make a retrieval robust to any change in translation, rotation and scaling by combining information on the texture sample, color and eccentricity and measuring the degree of similarity. It responded less sensitively to the phenomenon of distortion of the object feature due to the partial change or damage of the region. Also, the method of imposing a different weight of similarity on the image feature based on the relationship of complexity between measured objects using the fractal dimension by the Boxing-Counting Dimension minimized the wrong retrieval and showed more efficient retrieval rate.

• Journal of KIISE:Software and Applications
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• v.35 no.10
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• pp.600-607
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• 2008

This paper proposes a robust human detection method irrespective of their pose variation using the multiple oriented 2D elliptical filters (MO2DEFs). The MO2DEFs can detect the humans regardless of their poses unlike existing object oriented scale adaptive filter (OOSAF). To overcome OOSAF's limitation, we introduce the MO2DEFs whose shapes look like the oriented ellipses. We perform human detection by applying four different 2D elliptical filters with specific orientations to the 2D spatial-depth histogram and then by taking the thresholds over the filtered histograms. In addition, we determine the human pose by using convolution results which are computed by using the MO2DEFs. We verify the human candidates by either detecting the face or matching head-shoulder shapes over the estimated rotation. The experimental results showed that the accuracy of pose angle estimation was about 88%, the human detection using the MO2DEFs outperformed that of using the OOSAF by $15{\sim}20%$ especially in case of the posed human.

• Journal of the Korean Chemical Society
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• v.61 no.3
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• pp.112-121
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• 2017

The purpose of the study was to investigate the effect of explanation in conjunction with gravity and density on students' alternative conceptions for floating and sinking phenomena. The subjects were 140 students of 11th grade in 4 classes of a high school located in Gangwon Province. We divided them in two groups; comparison and experiment. The students of experiment group learned explanation in confection with gravity and density. The students of comparison group learned explanation of pressure as represented in physics textbook. ANCOVAs (analysis of covariance) were conducted using the pretest as a covariance. In items related to characters of matter, 2 items are not significant and only 1 item has significant small effect size (Hedges' g=0.327). In the change of alternative conceptions, there is no meaningful gap between two group. However, in items related to relative weights between object and water, the all items have significant effect sizes (0.286~0.502). In addition, frequency of experiment group's alternative conceptions related to pressure decreases considerably, but comparison group does not. Therefore, the explanation in conjunction with gravity and density suggested in this study can decrease students' alternative conceptions related to floating and sinking phenomena and increase scientific conceptions.

• Korean Journal of Optics and Photonics
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• v.18 no.4
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• pp.246-255
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• 2007

The floating image system (FIS) is a device to display input source in the space between fast surface of the display and an observer and it provides pseudo 3D depth to an observer when input source as real object or 2D image was displayed through the optical lens system in the FIS. The Advanced floating image system (AFIS) was designed to give more effective 3D depth than existing FIS by adding front and rear depth cues to the displayed stereogram, which it was used as input source. The magnitude of disparity and size of stereogram were strongly related each other and they have been optimized for presenting 3D depths in a non-optical lens systems. Thus, if they were used in optical lens system, they will have reduced or magnified parameters, leading to problem such as providing incorrect 3D depth cues to an observer. Although the size of stereogram and disparity were demagnified by total magnifying power of optical system, the viewing distance (VD) from the display to an observer and base distance (BD) for the gap between the eyes were fixed. For this reason, the quantity of disparity in displayed stereogram through the existing FIS has not kept the magnifying power to the total optical system. Therefore, we proposed the methods to provide correct 3D depth to an observer by compensating quantity of disparity in stereogram which was satisfied to keep total magnifying power of optical lenses system by AFIS. Consequently, the AFIS provides a good floating depth (pseudo 3D) with correct front and rear 3D depth cues to an observer.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.16 no.4
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• pp.108-116
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• 2002

This paper presents the measurements and evaluation of voltage waveforms due to human electrostatic discharge(ESD). The principle of operation and design rule of a new device for measuring the ESD fast transient voltages with very fast rise time were described. Peak values and rise time of ESD voltages derived from a charged human body under a variety of experimental conditions were examined. The frequency bandwidth of the proposed voltage measuring system ranges from DC to 400[㎒]. The ESD voltage waveform is nearly equal to the ESD current waveform and the peak amplitude of ESD current waveform is roughly proportional to the ESD voltage in each experimental conditions. A rapid approach results in a discharge voltage with a faster initial rise time than for a slow approach. The voltages caused by direct finger ESDs have an initial slope with a relatively long, 10∼30[ns] rise time, but the amplitude is small. On the other hand, the voltages caused by direct hand/metal ESDs have a steep initial s1ope with 1 ∼3[ns] rise time, but an initial spike is very big. As a consequence, it was found that the ESD voltage and current waveforms strongly depend on the approach speed and material of intruder. These measurement results would be useful to design the ESD protective devices.

• Journal of Broadcast Engineering
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• v.17 no.4
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• pp.625-633
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• 2012

Extended Depth of Focus (EDF) algorithms for extracting three-dimensional (3D) information from a set of optical image slices are studied by many researches recently. Due to the limited depth of focus of the microscope, only a small portion of the image slices are in focus. Most of the EDF algorithms try to find the in-focus area to generate a single focused image and a 3D depth image. Inherent to most image processing algorithms, the EDF algorithms need parameters to be properly initialized to perform successfully. In this paper, we select three popular transform-based EDF algorithms which are each based on pyramid, wavelet transform, and complex wavelet transform, and study the performance of the algorithms according to the initialization of its parameters. The parameters we considered consist of the number of levels used in the transform, the selection of the lowest level image, the window size used in high frequency filter, the noise reduction method, etc. Through extended simulation, we find a good relationship between the initialization of the parameters and the properties of both the texture and 3D ground truth images. Typically, we find that a proper initialization of the parameters improve the algorithm performance 3dB ~ 19dB over a default initialization in recovering the 3D information.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.3 s.118
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• pp.273-281
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• 2007

This paper presented design for a dipole antenna operated at 900 MHz band RFID tag, and antenna performance varied by the sticked material was experimentally evaluated. When dipole antenna was sticked by the material having a difffrent electric characteristic such as dielectric material, fero-magnetic material and conductor, variations of antenna return loss and radiation pattern according to the sticked material kinds, size, and height between antenna and the sticked plate were experimentally observed and evaluated. When antenna was sticked by dielectric surface, the measured return loss and radiation pattern by affection of different dielectric permittivity ratio showed resonant frequency shift of about 40 MHz and relative attenuation of 1 dB to 3 dB. Even though frequency shift by size variation of the sticked plate was observed, the measured radiation pattern of dipole antenna located on the sticked plate was similar with one without backside plate. In the case of conductor or fero-magnetic material as the sticked ground plate, because of frequency shift and phase difference by distance between dipole antenna and the sticked ground plate, amplitude decrease of radiation pattern at 910 MHz was observed about 5 dB above.

• Journal of Korean Ophthalmic Optics Society
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• v.13 no.2
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• pp.17-22
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• 2008

To develop an imaging optical system for the 545 nm fluorescent plate of X-ray. Methods: We designed and manufactured a new imaging optical system for the 545 nm fluorescent plate of X-ray by Sigma 2000 program after deciding the design comparison standards referred to Canon CX2-70 model. Results: The characteristics of the new imaging optical system for the 545 nm fluorescent plate of X-ray have the magnification of -0.225x, the image field size of $90mm{\times}90mm$, and the 0.033 mm resolution line width at the 30% MTF value criterion. These mean that the new model has a capability of deciphering for the more large screen and the resolution of deciphering is superior to that of Canon CX2-70 model. Also the image side NA (-0.196) of the new model is about $\sqrt{2}$ times than that (-0.139) of CX2-70 and the object side NA (0.044) of the new model is about 2 times than that (0.022) of CX2-70. These mean that the sensitivity of the film in the new design model is able to be increased to about 4 times and there is the possibility of reducing the bombed time of X-ray to 1/4 times. Conclusions: We could design and manufacture the imaging optical system for the 545 nm fluorescent plate of X-ray having the possibility of reducing the bombed time of X-ray to 1/4 times in comparision to Canon CX2-70 model, the characteristics of which have the image field size of $90mm{\times}90mm$ and the MTF of 30% or more at 15 lines/mm criterion.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.2
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• pp.508-516
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• 2010

An autonomous and automatic home mess-cleanup robot is newly developed in this paper. Thus far, vacuum-cleaners have lightened the burden of household chores but the operational labor that vacuum-cleaners entail has been very severe. Recently, a cleaning robot was commercialized to solve but it also was not successful because it still had the problem of mess-cleanup, which pertained to the clean-up of large trash and the arrangement of newspapers, clothes, etc. Hence, we develop a new home mess-cleanup robot (McBot) to completely overcome this problem. The robot needs the capability for agile navigation and a novel manipulation system for mess-cleanup. The autonomous navigational system has to be controlled for the full scanning of the living room and for the precise tracking of the desired path. It must be also be able to recognize the absolute position and orientation of itself and to distinguish the messed object that is to be cleaned up from obstacles that should merely be avoided. The manipulator, which is not needed in a vacuum-cleaning robot, has the functions of distinguishing the large trash that is to be cleaned from the messed objects that are to be arranged. It needs to use its discretion with regard to the form of the messed objects and to properly carry these objects to the destination. In particular, in this paper, we describe our approach for achieving accurate localization using RFID for home mess-cleanup robots. Finally, the effectiveness of the developed McBot is confirmed through live tests of the mess-cleanup task.

• Journal of KIISE:Software and Applications
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• v.28 no.7
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• pp.501-510
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• 2001

Generally, it is essential to estimate exact disparity for the 3D modeling from stereo images. Because existing methods calculate disparities from a whole image, they require too much cimputational time and bring about the mismatching problem. In this article, using the characteristic that the disparity vectors in stereo images are distributed not equally in a whole image but only exist about the background and obhect, we do a wavelet transformation on stereo images and estimate coarse disparity fields from the reduced lowpass field using area-based method at first-step. From these coarse disparity vectors, we generate disparity histogram and then separate object from background area using it. Afterwards, we restore only object area to the original image and estimate dense and accurate disparity by our two-step pixel-based method which does not use pixel brightness but use second gradient. We also extract feature points from the separated object area and estimate depth information by applying disparity vectors and camera parameters. Finally, we generate 3D model using both feature points and their z coordinates. By using our proposed, we can considerably reduce the computation time and estimate the precise disparity through the additional pixel-based method using LOG filter. Furthermore, our proposed foreground/background method can solve the mismatching problem of existing Delaunay triangulation and generate accurate 3D model.