• Journal of Satellite, Information and Communications
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• v.9 no.1
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• pp.57-64
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• 2014

Recently, many human-friendly communication methods have been studied for human-machine interface(HMI) without using any physical devices. One of them is the vision-based gesture recognition that this paper deals with. In this paper, we define some gestures for interaction with objects in a predefined virtual world, and propose an efficient method to recognize them. For preprocessing, we detect and track the both hands, and extract their silhouettes from the low-resolution hand images captured by a webcam. We modeled skin color by two Gaussian distributions in RGB color space and use blob-matching method to detect and track the hands. Applying the foodfill algorithm we extracted hand silhouettes and recognize the hand shapes of Thumb-Up, Palm and Cross by detecting and analyzing their modes. Then, with analyzing the context of hand movement, we recognized five predefined one-hand or both-hand gestures. Assuming that one main user shows up for accurate hand detection, the proposed gesture recognition method has been proved its efficiency and accuracy in many real-time demos.

• The Bulletin of The Korean Astronomical Society
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• v.43 no.1
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• pp.35.4-36
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• 2018

$Ly{\alpha}$ blobs are mysterious, giant (~100 kpc), glowing gas clouds in the distant universe. They occupy the dark matter halos that will evolve into the richest groups and clusters today. The blob's gas may be the proto-intracluster medium and their embedded galaxies are considered as the progenitors of massive cluster galaxies. Yet we do not know why $Ly{\alpha}$ blobs glow. There are evidences of kinematic measurements to exclude shocks and winds from AGN or starbursts as a power source, suggesting that photoionizing radiation or scattering of $Ly{\alpha}$ photons might be responsible. Polarization mapping can discriminate between these photo-ionization and scattering. Previous results of imaging polarimetry for $Ly{\alpha}$ nebulae are roughly consistent with scattering models. However the polarization morphologies in those of previous results are all different, motivating our polarimetric survey of $Ly{\alpha}$ nebulae for the statisticallymeaningful sample. As initial results of our survey, we present the total polarization map of the LABd05 which has the spatial offset between the peak of $Ly{\alpha}$ surface brightness and an obscured AGN. We detect the significant polarization in this target with the radially increasing polarization gradient, suggesting that scattering plays major role within this nebula. The polarization pattern is more aligned with the $Ly{\alpha}$ peak rather than the AGN (the potential energy source), indicating that the $Ly{\alpha}$ photons are originated from the region near the peak of $Ly{\alpha}$ intensity.

• Journal of Korea Multimedia Society
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• v.16 no.9
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• pp.1031-1043
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• 2013

Extracting hand region from images is the first part in the process to recognize hand posture and gesture interaction. Therefore, a good segmenting method is important because it determines the overall performance of hand recognition systems. Conventional hand segmentation researches were prone to changing illumination conditions or limited to the ability to detect multiple people. In this paper, we propose a robust technique based on the fusion of skin-color data and depth information for hand segmentation process. The proposed algorithm uses skin-color data to localize accurate seed location for region-growing from a complicated background. Based on the seed location, our algorithm adjusts each detected blob to fill up the hole region. A region-growing algorithm is applied to the adjusted blob boundary at the detected depth image to obtain a robust hand region against illumination effects. Also, the resulting hand region is used to train our skin-model adaptively which further reduces the effects of changing illumination. We conducted experiments to compare our results with conventional techniques which validates the robustness of the proposed algorithm and in addition we show our method works well even in a counter light condition.

• Journal of Broadcast Engineering
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• v.7 no.1
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• pp.2-9
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• 2002

Recently. VR( Virtual Reality) applications such as virtual studio and virtual character are wifely used In TV programs. and AR( Augmented Reality) applications are also belong taken an interest increasingly. This paper introduces a virtual screen system. which Is a new AR application for broadcasting. The virtual screen system is a real-time video augmentation system by tracking a chroma-patterned moving panel. We haute recently developed a virtual screen system.'K-vision'. Our system enables the user to hold and morse a simple panel on which live video, pictures of 3D graphics images can appear. All the Images seen on the panel change In the correct perspective, according to movements of the camera and the user holding the panel, in real-time. For the purpose of tracking janet. we use some computer vision techniques such as blob analysis and feature tracking. K-vision can work well with any type of camera. requiring no special add-ons. And no need for sensor attachments to the panel. no calibration procedures required. We are using K-vision in some TV programs such as election. documentary and entertainment.

• Journal of Institute of Control, Robotics and Systems
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• v.21 no.7
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• pp.641-647
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• 2015

This paper proposes a new strategy for a quad-rotor to track a moving object efficiently by using image processing and an extended Kalman filter. The goal of path planning for the quad-rotor is to design an optimal path from the start point to the destination point. To lengthen the freight time of the quad-rotor, an optimal path is required to reduce the energy consumption. To track a moving object, the mark signed on the moving object has been detected by a camera mounted first on the quad-rotor. The center coordinates of the mark and its area are calculated through the blob analysis which is one type of image processing. The mark coordinates are utilized to obtain information on the motion direction and the area of the mark is utilized to recognize whether the object moves backward or forward from the camera on the quad-rotor. In addition, an extended Kalman filter has been applied to predict the direction and speed of the dynamically moving object. Through these schemes, it is aimed that the quad-rotor can track the dynamic object efficiently in terms of flight distance and time. Through the two different route freights of the quad-rotor, the performance of the proposed system has been demonstrated.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.10a
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• pp.204-207
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• 2011

본 논문에서는 경추 초음파 DICOM 영상에서 개선된 퍼지 시그마 기법을 이용하여 경부심굴곡근을 추출하고 두께를 측정하는 방법을 제안한다. 제안된 방법은 ROI 영역에서 Ends-In Search Stretching을 적용하여 명암 대비를 강조한다. Stretching된 ROI 영역에서 평균 이진화를 적용한 후, Blob 알고리즘을 적용하여 흉쇄유돌근과 경부심굴곡근의 후보 영역을 추출한다. 추출된 경부심굴곡근 후보 영역에서 경추의 위치 정보를 이용하여, 경추의 경계 영역을 검출한 후, Cubic Spline 보간법 알고리즘을 적용하여 스플라인 곡선을 추출한다. 스플라인 곡선 영상에서 상/하 탐색 알고리즘을 적용하여, 최대/최소 범위 영역을 설정한다. Stretching된 ROI 영역에서 최대/최소 범위에 해당하는 영역에 대해 개선된 퍼지 시그마 이진화를 적용한다. 적용된 영역을 Blob 알고리즘을 이용하여 잡음을 제거하고 Morphology 알고리즘을 이용하여 초음파 영상의 첫 번째 경추 기준점의 좌표 정보를 추출한다. 경추 기준점을 기준으로 두께 측정에 필요한 경부심굴곡근 후보 영역을 추출하고 개선된 퍼지 시그마 이진화 알고리즘을 적용한다. 개선된 퍼지 시그마 이진화 알고리즘이 적용된 영상에서 근막의 위치 정보를 이용하여 경부심굴곡근상단 경계선을 추출한다. 추출된 각 경추 객체에 DDA(Digital Differential Analyzer) 알고리즘과 Cubic Spline 보간법 알고리즘을 적용하여 경부심굴곡근의 하단 경계선을 추출한다. 추출된 경부심 굴곡근의 상/하단 경계선의 위치 정보를 이용하여, 측정에 필요한 경부심굴곡근을 추출한다. 제안된 방법을 경추 초음파 영상에 적용하여 경부심굴곡근을 추출한 결과, 기존의 경부심굴곡근추출 방법보다 효율적으로 경부심굴곡근을 추출하는 것을 확인할 수 있었다.

• Smart Media Journal
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• v.5 no.1
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• pp.114-121
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• 2016

Currently, different medical institutions have been carrying out the e-healthcare system project. The system includes electronic medical record and prescription delivery system, and, the Medical Treatment law permits electronic signature for medical record management, which reduced the relevant costs and enabled sharing medical record. And medical solution using online certificates is expanding its application. In that light, the role of certificates became more important than ever. However, in contrast to active effort made to manage personal certificates, certificates related to medical solutions and other types of work are not being managed properly. Most work-related certificates are saved in office computers, which makes them vulnerable to various security threats. Although certificate servers can be used as a solution to this problem, hospitals must build the server separately and, therefore, small and medium-size hospitals can be reluctant to bear the burden. This study proposed a way to design and implement an effective and secure certificate management system by save the certificate file as a BLOB, using existing resources without needing to build a separate certificate server, at minimized costs.

• Korean Institute of Interior Design Journal
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• v.14 no.4 s.51
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• pp.19-26
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• 2005

Digital technology continually makes a space evolves. The real-time behavior design communicates the data with the situation of circumference of the space(visitors moving, interior and exterior situations). The space form was changed because it interfaces in real time. The purpose of this study was finding out the characteristics of real-time behavior space design through the analysis of space formative languages, sensorium, S-R and material. This study will be the one of basic references for the digital space design. The boundary of this study set limits to the works of digital space designer who applies the real-time exchanging data to their design among the digital space design works from 1996 to 2004. But it excepted from the real-time behavior space in virtual realty. Therefore, the objects of this study were the works of onl and NOX(paraSITE, Trans-port 2001, Muscle, MotormeCCa, Handdrawspace, Saltwater Pavilion, Son-O-House, H2O Expo). The method was the contents analysis of space formative languages(Greg Lynn's ten space formative languages; bleb, blob, branch, flower, fold, lattice, teeth, shred, skins and strand), sensorium, S-R and material. The results of the study are as follows: 1) The organizational elements; Space formative languages(bleb, blob, fold, shred, skins, strand), stimulation(Human Participation, Human Moving, Weather Conditions), and response(Spatial Moving, Sound Pattern, Lighting Pattern, color Pattern, Activating Particles, Moving Picture, Virtual Friend) 2) The material Use; Sound, lights, and network have been used in the space. Immaterial matter will be used the main material of space design in 21"'century, 3)The spatial types; formal changing of space, projecting immaterial elements, and changing the sound.

• Journal of The Korean Astronomical Society
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• v.54 no.2
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• pp.61-70
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• 2021

We investigate 20 post-coronal mass ejection (CME) blobs formed in the post-CME current sheet (CS) that were observed by K-Cor on 2017 September 10. By visual inspection of the trajectories and projected speed variations of each blob, we find that all blobs except one show irregular "zigzag" trajectories resembling transverse oscillatory motions along the CS, and have at least one oscillatory pattern in their instantaneous radial speeds. Their oscillation periods are ranging from 30 to 91 s and their speed amplitudes from 128 to 902 km s-1. Among 19 blobs, 10 blobs have experienced at least two cycles of radial speed oscillations with different speed amplitudes and periods, while 9 blobs undergo one oscillation cycle. To examine whether or not the apparent speed oscillations can be explained by vortex shedding, we estimate the quantitative parameter of vortex shedding, the Strouhal number, by using the observed lateral widths, linear speeds, and oscillation periods of the blobs. We then compare our estimates with theoretical and experimental results from MHD simulations and fluid dynamic experiments. We find that the observed Strouhal numbers range from 0.2 to 2.1, consistent with those (0.15-3.0) from fluid dynamic experiments of bluff spheres, while they are higher than those (0.15-0.25) from MHD simulations of cylindrical shapes. We thus find that blobs formed in a post-CME CS undergo kinematic oscillations caused by fluid dynamic vortex shedding. The vortex shedding is driven by the interaction of the outward-moving blob having a bluff spherical shape with the background plasma in the post-CME CS.

• Journal of Chest Surgery
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• v.40 no.5 s.274
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• pp.362-368
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• 2007

Background: Spontaneous pneumothorax patients with blebs or bullae are considered to be good candidates for operation, and various objective diagnostic modalities have been performed for detection of blebs and bullae. This study was performed to compare the efficacy of thoracoscopic examination with using a minimally invasive 2 mm thoracoscope with high-resolution computed tomography (HRCT) for treating primary spontaneous pneumothorax. Material and Method: From June 2001 to March 2002, 34 patients with spontaneous pneumothorax undewent study with 2 mm video-thoracoscopic examination and HRCT. We regarded a blob larger than 5 mm in diameter as significant. Standard thoracoscopic wedge resection was performed in 18 patients with significant blob via a 2 mm video-thoracoscopic examination. 1 patient incurred bleeding, and the remaining 15 patients were treated with pleural drainage. Result: Multiple or single blob lesions were detected by 2 mm video-thoracoscope in 52.9% (18/34) of the patients with primary pneumothorax. For a total of 19 patients who were operated on, the diagnostic accuracy of the 2 mm video-thoracoscopic examination for bullae and blob was 94.7% (18/19), which was superior to that of HRCT (73.7%, 14/19). At a mean follow-up of $30{\pm}3$ months, no recurrence occurred in both the operative group and the non-operative group. Conclusion: 2 mm video-thoracoscopic examination under local anesthesia has higher diagnostic accuracy than HRCT, and it is a useful alternative for determining the operative indications for spontaneous pneumothorax.