• The Transactions of the Korean Institute of Power Electronics
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• v.12 no.4
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• pp.332-338
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• 2007

In this paper, the three modified space vector modulation methods are suggested in order to control effectively the shoot-through time at Z-source inverter. Both the switching patterns of three modulation methods and the modulation signals with a variation of shoot-through time are analyzed. The optimum modified space vector modulation method is determined by both the control range of the shoot-through time and the symmetry of the switching pattern and modulation signal. The performances of modulation methods are verified with the simulation results with 32-bit DSP.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.29 no.6
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• pp.449-456
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• 2018

Herein, several multibeam forming methods that can be applied to microwave wireless power transmission are presented. Because the conventional multibeam forming methods do not consider an active element pattern(AEP), an intended beam shape will contain a steering angle error when applied to an actual system. To solve this problem, a method of considering the average of the AEP and a method of considering all the AEPs by the modified Fourier series method have been proposed. We confirmed that the proposed method reduces the error with the intended beam shape in the multibeam formation. In addition, for the side lobe level(SLL) and null control, a method of multibeam forming by applying the superposition principle to the Dolph-Tschebyscheff method is proposed. We also confirmed that SLL control can be simultaneously achieved with the multibeam formation.

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.10
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• pp.1197-1205
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• 2014

Recently signal transmission of ultra high-definition(4K-UHD) video system is transferred as uncompressed high speed data. However, this has a limit to compose the system because EMI between separate cables of high speed interface section and skew bring distortion of the video signal and jitter. In this paper we applied V-by-One HS interface technique to transfer uncompressed high speed data. We analyzed HSD(High Speed Differential) transmission line signal integrity. Also we applied RF transmission technique instead of UHD video pattern control interface PCB design. When we measured V-by-One HS video signal of designed 4K-UHD class signal generator, We found that the transmission performance has been signal standard.

• Journal of Digital Contents Society
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• v.16 no.2
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• pp.235-244
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• 2015

This study proposes a leaf modeling method that uses feature-based warping for efficient generation of various digital leaves. The proposed method uses warping method, one of image processing application techniques that can control various shapes of leaves in an easy, intuitive way, and generate natural patterns of veins efficiently. First, information on approximated contour is detected from a leaf blade image to identify the shape of a blade. Based on this, control line is automatically calculated to be used for feature-based warping. Then, control line-based warping is conducted to modify forms of leaf blade images in an intuitive way, automatically generating leaves of various shapes. And natural vein patterns are generated by applying a contour-based venation growth algorithm from contour information of the modified leaf blade images. This study performs experiments to verify whether various shape of leaves that comprise plants can be efficiently generated using a sample binary image of a blade. Also, we demonstrate that express the natural growth of leaves by applying warping to the growth of the leaf blade.

• The KIPS Transactions:PartD
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• v.17D no.5
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• pp.359-370
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• 2010

As web 2.0 becomes one of the important architecture styles, more web applications adopt single page structure instead of multiple web pages and navigations between pages. A single page web application client, called a mashup client in this paper, interfaces more than one services and allows users to navigate in the page. A mashup client page includes complicated functions and has to handle various styles of services and user requirements, and therefore is usually developed manually. In this paper, we propose a model driven code generation approach for in-page navigations. We propose a page model and view navigation design approach, applying REST service architecture patterns. Then, we consider type conditions for each view to have service calls or navigation controls. Also, we developed an XForms page code generation system to demonstrate the efficiency of the proposed method. The developed system generates mashup client pages including navigation controls between services and views. This system can generate ready to use codes from service specifications, so this can help to reduce the development overhead. Moreover, our approach is based on formal model and navigation patterns so the generated result code is simple and easy to understand, and includes only the necessary controls. Therefore, the proposed approach can be more effective for the case of a large number of services.

• The Journal of the Korea Contents Association
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• v.12 no.2
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• pp.52-59
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• 2012

Recently, LEDs are used in various fields such as lightings, billboards, displays, and so on. In this paper, we tried to combine a costume with LEDs in a performance environment. To meet the environmental requirements, we propose a digital costume platform which consists of wireless network, an embedded system, a control jacket, a digital skin, and a pattern authoring tool. It is utilized for making a digital costume with LED lighting effects. The embedded system controls LED lighting according to the signals from a show control system through wireless networks. The control jacket can carry the embedded system and connect it with LEDs. The digital skin means a costume with LEDs. The LEDs were designed to fit in performance concept in point of aesthetic. The pattern authoring tool enables users to make timeline-based changing patterns of LED lighting. The proposed platform is a new lighting element in performances. It can expand stage representation techniques and be used as a special effect. It will play a role as a moving light in performances. We evaluated stable operations of our platform by employing it in live performances.

• Journal of the Korean Institute of Intelligent Systems
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• v.17 no.7
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• pp.930-938
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• 2007

Captions which appear in images include information that relates to the images. In order to obtain the information carried by captions, the methods for text extraction from images have been developed. However, most existing methods can be applied to captions with fixed height of stroke's width. We propose a method which can be applied to various caption size. Our method is based on connected components. And then the edge pixels are detected and grouped into connected components. We analyze the properties of connected components and build a neural network which discriminates connected components which include captions from ones which do not. Experimental data is collected from broadcast programs such as news, documentaries, and show programs which include various height caption. Experimental result is evaluated by two criteria : recall and precision. Recall is the ratio of the identified captions in all the captions in images and the precision is the ratio of the captions in the objects identified as captions. The experiment shows that the proposed method can efficiently extract captions various in size.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.1
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• pp.75-80
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• 2010

Noise handing is very important in voice recognition of vehicle environment. that has been studying about to hardware and software approach. hardware method that is noise filter circuit design, basically using Low-pass filter. it was shown a good result. and the side of software that has been developing about to algorithm for Noise canceler, NN(neural network), etc. in this paper we have analysis about to classified parameter pattern matting level for voice recognition on car noise environment that use of DTW(Dynamic Time Warping) which is applicable time series pattern recognition algorithm.

• Journal of the Korean Institute of Telematics and Electronics
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• v.26 no.2
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• pp.112-117
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• 1989

This paper describes to the unit rectangle EB direct writing lithography method using SEM. This method has the constant exposure time to any rectangle pattern. In order to change the EB current according to various rectangle size for the constant exposure time, the supply current of condenser lens in controlled by BITMAP-IV CAD system. By this method, the resizing procedure of density pattern area is not needed to pattern data conversion, and the through-put ofr exposure is increased about 172 times compared with the unit scan exposure method.

• Proceedings of the KOR-KST Conference
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• 1998.10b
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• pp.275-284
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• 1998

신호화 교차로는 한정된 시간 자원을 각 접근로별로 서로 다른 수요에 적절하게 효과적으로 배분함으로써 그 운영효율이 극대화될 수 있다. 현재 서울시 기존 전자신호시스템은 검지기체계를 갖추고 있으나 주로 시간대별 제어방식(TOD제어)을 사용하고 있다. 이에 대한 대안으로 실시간 교차로신호제어시스템인 이른바 첨단신호시스템이 개발되어 서울시 강남지역 61개소에서 시범운영중에 있다. 첨단신호시스템은 접근로별 수요에 따라 녹색시간을 배분하는 방식을 적용하고 있는데, 본 논문에서는 첨단신호시스템의 운영효율성을 평가하기 위하여 실제 교통수요와 운영녹색시간을 비교·분석하였다. 그 결과로 얻은 결론은 다음과 같다. 첫째, 방출차량에 의한 포화도의 비율을 고려하여 주기 및 녹색시간을 결정하는 첨단신호제어시스템의 알고리즘은 비포화시 직진이동류에 대한 녹색시간은 수요에 비해 과대산출운영되고 있다. 둘째, 좌회전의 경우 대기차량의 패턴이 불규칙할 때, 실시간 녹색시간제어기능이 미흡하다. 따라서, 향후에는 교통수요를 고려할 수 있는 알고리즘의 보다 심도있는 연구·개발이 요구되며, 또한 비포화 상황이 아닌 과포화 상황에도 적용될 수 있는 알고리즘의 개발이 이루어져야할 것으로 보인다.