• Journal of Radiation Protection and Research
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• v.26 no.2
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• pp.59-66
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• 2001

It is a hot issue to determine the spatial location and shape of tumor boundary in fractionated stereotactic radiotherapy (FSRT). We could get consecutive transaxial plane images from the phantom (paraffin) and 4 patients with brain tumor using helical computed tomography(HCT). K-means classification algorithm was adjusted to change raw data pixel value in CT images into classified average pixel value. The classified images consists of 5 regions that ate tumor region (TR), normal region (NR), combination region (CR), uncommitted region (UR) and artifact region (AR). The major concern was how to separate the normal region from tumor region in the combination area. Relative average deviation analysis was adjusted to alter average pixel values of 5 regions into 2 regions of normal and tumor region to define maximum point among average deviation pixel values. And then we drawn gross tumor volume (GTV) boundary by connecting maximum points in images using semi-automatic contour method by IDL(Interactive Data Language) program. The error limit of the ROI boundary in homogeneous phantom is estimated within ${\pm}1%$. In case of 4 patients, we could confirm that the tumor lesions described by physician and the lesions described automatically by the K-mean classification algorithm and relative average deviation analyses were similar. These methods can make uncertain boundary between normal and tumor region into clear boundary. Therefore it will be useful in the CT images-based treatment planning especially to use above procedure apply prescribed method when CT images intermittently fail to visualize tumor volume comparing to MRI images.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.18 no.12
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• pp.1828-1840
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• 1993

In this paper, a centralized protocol model for videoconference service over a wide-area-network is presented. the model is comprised of three distinct components : clients, server and mixer. The server handles all can management functions, and the mixer performs realtime traffic mixing. The control and data are separated, flowing over separated connections in the model. A set of new protocols are defined : call management protocol, media transport protocol, and multimedia synchronization protocol. This paper also presents the functional design of the mixer.

• Journal of ILASS-Korea
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• v.4 no.1
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• pp.13-18
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• 1999

It has been known that spray characteristics have an important effect on the mixture formation and directly influence the engine performances and the emissions. Up to now, the measurement of droplet size is well developed such as PDPA and PMAS though the behavior of small droplets during secondary atomization is not clear. Particle image velocimetry(PIV), a planar measuring technique, is a very efficient tool for studying complicated behavior and a fast and reliable method to track numerous droplets during injection. In this study, two-color scanning PIV is designed to obtain quasi-instantaneous two dimensional velocity data by using he-ion laser, rotating mirror and beam splitter. This PIV method which has high temporal and spatial resolution provides the information about the small complex droplet behavior.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.8
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• pp.1454-1463
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• 2008

Blind source separation by independent component analysis (ICA) has applied in signal processing, telecommunication, and image processing to recover unknown original source signals from mutually independent observation signals. Neural networks are learned to estimate the original signals by unsupervised learning algorithm. Because the outputs of the neural networks which yield original source signals are mutually independent, then mutual information is zero. This is equivalent to minimizing the Kullback-Leibler convergence between probability density function and the corresponding factorial distribution of the output in neural networks. In this paper, we present a learning algorithm using information theory and higher order statistics to solve problem of blind source separation. For computer simulation two deterministic signals and a Gaussian noise are used as original source signals. We also test the proposed algorithm by applying it to several discrete images.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2018.06a
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• pp.173-174
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• 2018

배경제거는 영상에서 움직이는 객체를 분리할 때 유용한 방법이며, 대표적인 예인 Mixture of Gaussian (MOG) 알고리즘은 픽셀 당 3-5 가우스 모델을 혼합해 배경과 움직이는 객체를 구분한다. 소형 표적을 추적하기 위해서는 화소 혹은 작은 블록 단위로 시/공간적 밝기 변화량을 이용하는 옵티컬 플로우 기법이 적절하다. 본 논문에서는 소형 표적의 강인한 객체 추적을 위해 MOG2와 옵티컬 플로우의 결합 방법을 소개한다. 제안된 방법은 MOG2를 사용하여 전경 영역을 획득하고 전경 영역에만 옵티컬 플로우를 적용한다. 실험 결과는 제안 방법이 잡음과 배경의 미세 변화가 있더라도 무인 비행체를 잘 추적할 수 있음을 보여준다.

• Spatial Information Research
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• v.11 no.2
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• pp.101-117
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• 2003

High resolution satellite image analysis has been recognized as an effective technique for monitoring local land-cover and atmospheric changes. In this study, a new high resolution map for land-cover was generated using both high-resolution IKONOS image and conventional land-use mapping. Fuzzy classification method was applied to classify land-cover, with minimum operator used as a tool for joint membership functions. In separateness analysis, the values were not great for all bands due to discrepancies in spectral reflectance by seasonal variation. The land-cover map generated in this study revealed that conifer forests and farm land in the ground and tidal flat and beach in the ocean were highly changeable. The kappa coefficient was 0.94% and the overall accuracy of classification was 95.0%, thus suggesting a overall high classification accuracy. Accuracy of classification in each class was generally over 90%, whereas low classification accuracy was obtained for classes of mixed forest, river and reservoir. This may be a result of the changes in classification, e.g. reclassification of paddy field as water area after water storage or mixed use of several classification class due to similar spectral patterns. Seasonal factors should be considered to achieve higher accuracy in classification class. In conclusion, firstly, IKONOS image are used to generated a new improved high resolution land-cover map. Secondly, IKONOS image could serve as useful complementary data for decision making when combined with GIS spatial data to produce land-use map.

• The Journal of the Korea Contents Association
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• v.12 no.3
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• pp.84-94
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• 2012

The year 2011 witnessed interactive communication media and digital instrument experience a substantial growth in popularity within developed nations as well as developing nations in part due to the ongoing development of internet and information technology. The development of interactive media and technology have contributed to the increased progress of not only digital contents but also to the development of diverse interactive arts. This study will demonstrate how the direction of interactive media moving images through interactive media by utilizing the use of interactive art directing modules which will aid by expressing the theme and the directing concept of the art. To aid in the understanding of interaction directing module, two examples of art works are used as samples cases - "Room Two"(Mixing Lab in a museum; Interactive media art & Experimental mixing, Seoul Art Center, 2006) and a RPG(Role-playing game) style Game. Through these cases, this study intends to enhance the yet insufficient reference for interactive media art and assist artists attempting interactive media moving images through interactive media.

• The KIPS Transactions:PartB
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• v.19B no.2
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• pp.107-112
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• 2012

An active object tracking algorithm using Pan and Tilt camera based in the stepwise application of region and color information from realtime image sequences is proposed. To reduce environment noises in input sequences, Gaussian filtering is performed first. An image is divided into background and objects by using the adaptive Gaussian mixture model. Once the target object is detected, an initial search window close to an object region is set up and color information is extracted from the region. We track moving objects in realtime by using the CAMShift algorithm which enables to trace objects in active camera with the color information. The proper tracking is accomplished by controlling the amount of pan and tilt to be placed the center position of object into the middle of field of view. The experimental results show that the proposed method is more effective than the hand-operated window method.

• Journal of the Korean Chemical Society
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• v.29 no.5
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• pp.503-509
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• 1985

Sixteen organochlorine pesticides extracted out from the crops and cleaned by solvent-solvent partitioning and Florisil column chromatography were determined by gas-liquid chromatography. The majority of the pesticides were well separated by being eluted through 5% QF-1 column and some of them through 3% OV-17 column and 2.596 DC-200/2.5% QF-1 column, and the eluted pesticides were detected by $^{63}Ni$ electron capture detector. The linear calibration curves were obtained for the most of pesticides while some curves were slightly deviated from the linearity. In the determination of 16 pesticides added to thirteen kinds of crops, the recoveries were showed over 85% for the most cases and the relative standard deviations of 5 analyses were less than 12.1%. The results were within the criteria of the AOAC method.

• Resources Recycling
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• v.15 no.6 s.74
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• pp.3-9
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• 2006

In this study, a machine vision system using a color recognition method has been designed and developed to automatically sort out specified materials from a mixture, especially Cu and other non-ferrous metal scraps from a mixture of iron scraps. The system consists of a CCD camera, light sources, a frame grabber, conveying devices and an air-nozzle ejector, and is program-controlled by a image processing algorithms. The ejectors designed to be operated by an I/O interface communication with a hardware controller. In the functional tests of the system, its efficiency in the separation of Cu scraps from its mixture with Fe ones reaches to 90% or more at a conveying speed of 15m/min, and thus the system is proven to be excellent in terms of the separating efficiency. Therefore, it is expected that the system can be commercialized in the industry of shredder makers if an automated sorting system of high speed is realized.