• Proceedings of the IEEK Conference
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• 2004.08c
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• pp.600-607
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• 2004

The paper describes the implementation of the video conferencing system using public key infrastructure which is used for user authentication and media stream encryption. Using public key infrastructure, we are able to reinforce the authentication for conference participant and block several malicious hacking while protecting conference control information. The paper shows the implementation of the transportation layer secure protocol in conformity with Korea public key authentication algorithm standard and symmetric key encryption algorithm (RC2, SEED, DES and 3DES) for media stream encryption. The feature of the paper is transportation layer secure protocol that is implemented for protection of information on a user authentication and video conference and the media streaming encryption algorithm also can be envisioned with another block encryption algorithm. The key for media streaming encryption may be safely distributed by the transportation layer secure protocol.

• Proceedings of the Society of Korea Industrial and System Engineering Conference
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• 2002.05a
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• pp.467-472
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• 2002

Presented in this paper is an algorithm to compute the Voronoi diagram of a circle set from the Voronoi diagram of a point set. The circles are located in Euclidean plane, the radii of the circles are non-negative and not necessarily equal, and the circles are allowed to intersect each other. The idea of the algorithm is to use the topology of the point set Voronoi diagram as a seed so that the correct topology of the circle set Voronoi diagram can be obtained through a number of edge flipping operations. Then, the geometries of the Voronoi edges of the circle set Voronoi diagram are computed. The main advantages of the proposed algorithm are in its robustness, speed, and the simplicity in its concept as well as implementation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.7A
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• pp.1076-1083
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• 2000

Vehicle license plate recognition identifies vehicle as a unique, and have many applications in traffic monitoring field. In this paper, a vertical edge based algorithm to extract license plate within input gray-scale image is proposed. A size-and-shape filter based on seed-filling algorithm is applied to remove the edges that are impossible to be the vertical edges of license plate. Then the remaining edges are matched with each other according to some restricted conditions so as to locate license plate in input image. After license plate is extracted. normalized and segmented, the characters on it are recognized by template matching method. Experimental results show that the proposed algorithm can deal with license plates in normal shape effectively, as well as the license plates that are out of shape due to the angle of view.

• Journal of Biomedical Engineering Research
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• v.31 no.6
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• pp.427-433
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• 2010

Although tracking methods are efficient and popular for vessel segmentation, they require a seed to initiate an instance of tracking. In this paper, a new method to detect new seeds for tracking of arterial segments from CT angiography (CTA) and to construct a vascular structure is proposed. The proposed algorithm is based on shape analysis of connected components in a volume of interest around a vessel segment which was already extracted by tracking. The eigenvalues of the covariance matrix are used as the shape features for detection. The experimental results on actual clinical data showed that the results totally revealed the arterial tree not hindered by bone or veins. In visual comparison to a method which combines registration and subtraction of both pre-contrast and post-contrast CT volumes, the proposed method produced comparable results to the reference method and were confirmed of its feasibility for clinical use of reducing the cost and burden of patients.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.37 no.2
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• pp.1-14
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• 2000

The rosette-scan seeker, mounted on the infrared guided missile, is a device that tracks the target It can acquire the 2D image of the target by scanning a space about target in rosette pattern with a single detector Since the detected image is changed according to the position of the object in the field of view and the number of the object is not fixed, the unsupervised methods are employed in clustering it The conventional ISODATA method clusters the objects by using the distance between the seed points and pixels So, the clustering result varies in accordance with the shape of the object or the values of the merging and splitting parameters In this paper, we propose an Array Linkage Clustering Algorithm (ALCA) as a new clustering algorithm improving the conventional method The ALCA has no need for the initial seed points and the merging and splitting parameters since it clusters the object using the connectivity of the array number of the memory stored the pixel Therefore, the ALCA can cluster the object regardless of its shape With the clustering results using the conventional method and the proposed one, we confirm that our method is better than the conventional one in terms of the clustering performance We simulate the rosette scanning infrared seeker (RSIS) using the proposed ALCA as an infrared counter countermeasure The simulation results show that the RSIS using our method is better than the conventional one in terms of the tracking performance.

• Korean Journal of Computational Design and Engineering
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• v.6 no.1
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• pp.24-30
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• 2001

An efficient and robust algorithm to compute the exact Voronoi diagram of a circle set is presented. The circles are located in a two dimensional Euclidean space, the radii of the circles are non-negative and not necessarily equal, and the circles are allowed to intersect each other. The idea of the algorithm is to use the topology of the point set Voronoi diagram as a seed so that the correct topology of the circle set Voronoi diagram can be obtained through a number of edge flipping operations. Then, the geometries of the Voronoi edges of the circle set Voronoi diagram are computed. In particular, this paper discusses the topological aspect of the algorithm, and the following paper discusses the geometrical aspect. The main advantages of the proposed algorithm are in its robustness, speed, and the simplicity in its concept as well as implementation. Since the algorithm is based on the result of the point set Voronoi diagram and the flipping operation is the only topological operation, the algorithm is always as stable as the Voronoi diagram construction algorithm of a point set.

• Proceedings of the Korea Contents Association Conference
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• 2009.05a
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• pp.510-514
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• 2009

This program was developed in Visual C + +, the Windows operating system has security features within the files and directories. File and directory security, encryption / decryption operations yirueojimyeo file security can be round, to know the value of the key and security password I need to know the directory is designed to be decrypted. In addition, ECB, CBC algorithm and 3DES, SEED algorithms and methods, and encryption. De0 can not run that created the file extension, as has been developed to allow for double security.

• Proceedings of the Korean Society of Computer Information Conference
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• 2016.01a
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• pp.317-320
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• 2016

본 논문에서는 PC가 사용자를 구분하지 못하여 발생하는 보안 문제점과 개인이 PC를 관리하는 시간이 증가함에 따라 관리자가 미처 신경 쓰지 못하게 되는 보안 문제를 해결하고자 USB 저장 장치와 스마트폰을 이용한 사용자 PC인증 및 PC환경에서의 물리적 외부 접근 차단, 기업 차원이 아닌 개인 차원에서의 저 비용 보안 기술을 적용한 시스템을 구현하였다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.2
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• pp.344-352
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• 2006

We developed the facsimile encryption system that could send/receive the cipher text and plain text automatically. This facsimile encryption system is adopting the 128bits SEED encryption algorithm, 1024bits modular and 256bits exponential Diffie-Hellman key exchange method. We can reduce the cipher text transmitting time by developing the Dual Facsimile Server, it can make the real time encryption communication. Key is safely exchanged by the exchanging the listed serial numbers when the Diffie-Hellman key exchanging.

• Proceedings of the Korea Information Processing Society Conference
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• 2012.11a
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• pp.973-976
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• 2012

IT기기의 발전으로 다량의 개인정보들이 생성되고 이동하고 사라진다. 이에 따라 개인정보 보호의 중요성이 커지며 기존의 단순한 파일 숨김 또는 파일 잠금 형태의 보호 시스템이 아닌 데이터를 암호화하여 보안성을 높이는 시스템이 필요하다. 우리가 개발한 시스템은 윈도우즈에서는 물론 안드로이드 기기에서도 사용할 수 있으며, 윈도우즈 PC와 안드로이드 스마트폰이 통신하며 암 복호화를 가능하게 하여 활용성을 높이려 노력하였고, PC버전의 경우 대용량데이터 암 복호화 및 파일 안전 삭제 기능을 추가 하여 구현 하여 PC의 특수성도 별도로 고려하였다.