• Journal of the Institute of Electronics Engineers of Korea CI
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• v.38 no.5
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• pp.27-36
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• 2001

This paper proposes new design algorithms based on stochastic relaxation (SR) for an on-line vector quantizer (VQ) design. These proposed SR methods solve the local entrapment problems of the conventional Kohonen learning algorithm (KLA). These SR methods cover two different types depending upon the use of simulated annealing (SA) : the one that uses SA is called the OLVQ SA and the other the OLVQ SR. These methods arc combined with the KLA and therefore preserve the its convergence properties. Experimental results for Gauss Markov sources, real speech and image demonstrate that the proposed algorithms can consistently provide better codebooks than the KLA.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.5 no.6
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• pp.1166-1191
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• 2011

This paper presents an adaptive active tracking system with sector based scanning for a single PTZ camera. Dividing sectors on an image reduces the search space to shorten selection time so that the system can cover many targets. Upon the selection of a target, the system estimates the target trajectory to predict the zooming location with a finite amount of time for camera movement. Advanced estimation techniques using probabilistic reason suffer from the unknown object dynamics and the inaccurate estimation compromises the zooming level to prevent tracking failure. The proposed system uses the simple piecewise estimation with a few frames to cope with fast moving objects and/or slow camera movements. The target is tracked in multiple steps and the zooming time for each step is determined by maximizing the zooming level within the expected variation of object velocity and detection. The number of zooming steps is adaptively determined according to target speed. In addition, the iterative estimation of a zooming location with camera movement time compensates for the target prediction error due to the difference between speeds of a target and a camera. The effectiveness of the proposed method is validated by simulations and real time experiments.

• Journal of Korea Multimedia Society
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• v.13 no.3
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• pp.392-399
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• 2010

The Automobile has developed and changed through the years from the invention and increased human-being's scope of activity. Junction Box, one of the part of automobile, is inspected by human eyes which caused mistakes and slow progress. To achieve the speed and accuracy the system was compensated by vision system which is inspecting automatically. This paper is automatic inspection of fuse and relay which is inserted in the junction box by checking the color and pattern of the cover. After checking the performance of the system by using the junction box, the result was 100 percent perception and open the possibility to inspect junction box fast and easy and accurate if it is applied to the industry.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.322-322
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• 2011

지표에서의 토양수분은 작은 구성비를 가짐에도 불구하고 여러 수문 현상을 연계하는 매우 중요한 인자로써 최근 연구가 활발하게 진행되고 있다. 토양수분은 침투나 침루를 통하여 강우와 지하수를 연결하는 기능을 함과 동시에 강우사상에 따른 유출특성에 직접적인 영향을 미치며 증발산을 통하여 에너지 순환을 연결하는 기능을 하는 인자로 기후변화와 인간의 활동에 의해 영향을 받는다. 지난 수십 년간 산림개간과 도시화는 토지이용의 변화를 초래하여 토지피복의 변화를 초래하였다. 도시화는 불투수층을 증가시켰고, 산림개간으로 산림이 농장으로 변하여 침투율을 감소시켜 유출률의 증가를 초래하였다. 이처럼 토지피복의 변화는 토양수분의 변화에 직접적인 영향을 미친다. 본 연구에서는 토지피복 분류를 위해 구름의 영향이 적은 Landsat TM 영상을 사용하여 청미천 유역의 토지피복을 분류하여 토지피복도를 작성하였다. 청미천 유역은 현재 국제수문관측사업(IHP)의 일환으로 체계적인 수문관측이 진행되고 있는 지점으로, 추후 인공위성 영상을 통해 산정한 토양수분 자료를 비교할 수 있는 유역이다. Landsat TM 영상은 2009년 5월 23일에 관측된 115-34(path row) 영상으로 구름이 거의 없는 날의 자료를 사용하였다. 다중 스펙트럴 위성영상인 Landsat TM 영상은 30m 공간해상도로써 토지피복분류와 식생 등의 정보를 추출하는데 적합한 것으로 알려져 있다. 청미천 유역의 위성영상에 대하여 영상의 전처리 과정을 거쳐 무감독분류와 감독분류기법을 적용하여 토지피복을 분류하였다. 분류한 토지피복도는 국토해양부에서 국가수자원관리 종합정보시스템(WAMIS) 을 통하여 제공되는 토지피복도와 비교하였다.

• Proceedings of the KSRS Conference
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• 2007.10a
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• pp.286-289
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• 2007

This study is to develop a cloud detection algorit1un for COMS and it is currently tested by using MODIS level 2B and MTSAT-1R satellite radiance data. Unlike many existing cloud detection schemes which use a threshold method and traditional statistical methods, in this study a feed-forward neural network method with back-propagation algorit1un is used. MODIS level 2B products are matched with feature information of five-band MTSAT 1R image data to form the training dataset. The neural network is trained over the global region for the period of January to December in 2006 with 5 km spatial resolution. The main results show that this model is capable to detect complex cloud phenomena. And when it is applied to seasonal images, it shows reliable results to reflect seasonal characteristics except for snow cover of winter. The cloud detection by the neural network method shows 90% accuracy compared to the MODIS products.

• Atmosphere
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• v.28 no.3
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• pp.317-324
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• 2018

In this study, we review the ground-based whole-sky camera (WSC), which is developed to continuously capture day and night cloud images using the illumination data from a precision Lightmeter with a high temporal resolution. The WSC is combined with a precision Lightmeter developed in IYA (International Year of Astronomy) for analysis of an artificial light pollution at night and a DSLR camera equipped with a fish-eye lens widely applied in observational astronomy. The WSC is designed to adjust the shutter speed and ISO of the equipped camera according to illumination data in order to stably capture cloud images. And Raspberry Pi is applied to control automatically the related process of taking cloud and sky images every minute under various conditions depending on illumination data from Lightmeter for 24 hours. In addition, it is utilized to post-process and store the cloud images and to upload the data to web page in real time. Finally, we check the technical possibility of the method to observe the cloud distribution (cover, type, height) quantitatively and objectively by the optical system, through analysis of the captured cloud images from the developed device.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.17 no.4
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• pp.15-21
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• 2008

Secondary electron detectors used in scanning electron microscope accept secondary electrons emitted from the specimen and convert them to an electrical signal that, after amplification, is used to modulate the gray-level intensities on a cathode ray tube, producing an image of the specimen. In order to acquire images with good qualities, as many secondary electrons as possible should be reached to the detector. To realize this it is very important to select an appropriate mounting position and angle of the detector inside the chamber of scanning electron microscope. In this paper, a number of numerical simulations are performed to explore the relationships between detection rates of secondary electrons and the values of some parameters, such as distances between the detector and sample, relative mounting positions of scintillator positioned inside the detector with respect to detector cover, two types of mounting angles of the detector. The relationships between detection rates and applied voltages to corona ring and faraday cage, and energies of secondary electrons are investigated as well.

• Journal of Institute of Control, Robotics and Systems
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• v.15 no.5
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• pp.519-524
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• 2009

This paper describes a new sensor system for 3D environment perception using stereo structured infrared light sources and a camera. Environment and obstacle sensing is the key issue for mobile robot localization and navigation. Laser scanners and infrared scanners cover $180^{\circ}$ and are accurate but too expensive. Those sensors use rotating light beams so that the range measurements are constrained on a plane. 3D measurements are much more useful in many ways for obstacle detection, map building and localization. Stereo vision is very common way of getting the depth information of 3D environment. However, it requires that the correspondence should be clearly identified and it also heavily depends on the light condition of the environment. Instead of using stereo camera, monocular camera and two projected infrared light sources are used in order to reduce the effects of the ambient light while getting 3D depth map. Modeling of the projected light pattern enabled precise estimation of the range. Two successive captures of the image with left and right infrared light projection provide several benefits, which include wider area of depth measurement, higher spatial resolution and the visibility perception.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.20 no.2
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• pp.145-153
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• 2002

Reforming land is an important foundation for benefit of society as well as national development. A correct investigation and information acquirement as to land must go first to establish land management and plan. Land investigation by remote sensing is one of the most reasonable methods that doesn't need lots of time and manpower. In this study, Image classification on land use from Landsat data was carried out, which were respectively in 1980, 1985, 1990, 1995 and 2000, covering southern Han river and then land use changes were detected. In addition, an available information was reported, which could be used in the control of southern Han river. As a result, there is an obvious change in land use, especially the increase of water and decrease of forest and agriculture. Those are caused by the industrialization and the construction of dam.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.277-279
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• 2003

The study utilizes remote sensing as the main monitoring means. With different spatial high-resolution, multichannel ASTER remote sensing image as the main information in Beijing city zone; with regional border and statistical data as auxiliary factor a study between the thermal space distribution character and the underground medium is analyzed based on the GIS logical algorithm and synthetic analysis technology. Results show thermal forming mechanism and the rule of distribution is mainly related to the underground medium and the change of the city distribution. Different underground medium has different degree and intensity influence on the thermal space distribution. Furthermore, urban greenbelt and water areas can reduce the thermal effect and large-scale greenbelt creates green island effect. In addition, Road net, residential area, population density, heat resources and so on have some positive effect on the thermal distribution, which increase the local temperature and intensity on the other hand. It is important to study the thermal distribution and its related factors, which contributes to the plan, construction and development of the city.