http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : 정근원(Jeong Keun Won) (검색결과 7 건)
- 무료
- 기관 내 무료
- 유료
-
강경인(Kang Kyeong In),김정일(Kim Jeong Il),정근원(Jeong Keun Won),이광배(Lee Kwang Bae),김현욱(Kim Hyen Ug) 한국정보처리학회 1997 정보처리학회논문지 Vol.4 No.3
In this paper, we propose a new algorithm to perform DCT(Discrete Cosine Transform) within the area reduced by predicting position of quantization coefficients to be zero. This proposed algorithm not only decreases the encoding time and the decoding time by reducing computation amount of FDCT(Forward DCT) and IDCT(Inverse DCT) but also increases compression ratio by performing each different horizontal-vertical zig-zag scan according to the classified block size for each block on the huffman coding. Traditional image coding method performs the same DCT computation and zig-zag scan over all blocks, however this proposed algorithm reduces FDCT computation time by setting to zero instead of computing DCT for quantization coefficients outside classified block size on the encoding. Also, the algorithm reduces IDCT computation time by performing IDCT for only dequantization coefficients within classified block size on the decoding. In addition, the algorithm reduces Run-Length by carrying out horizontal-vertical zig-zag scan appropriate to the classified block characteristics, thus providing the improvement of the compression ratio. On the other hand, this proposed algorithm can be applied to 16*16 block processing in which the compression ratio and the image resolution are optimal but encoding time and the decoding time take long. Also, the algorithm can be extended to motion image coding requiring real time processing.
-
-
박경배(Park Kyung Bae),정우석(Jung Woo Suk),김정일(Kim Jung Il),정근원(Jeong Keun Won),이광배(Lee Kwang Bae),김현욱(Kim Hyen Ug) 한국정보처리학회 1995 정보처리학회논문지 Vol.2 No.5
프랙탈을 이용한 대부분의 영상 부호화는 최적의 유사 변환점을 얻기 위해서 방대한 비교 연산이 필요하여 장시간의 부호화 시간이 요구되는 문제점이 있다. 이러한 문제는 블럭특성에 적합한 블럭 분류기를 설계함으로써 해결할 수 있다. 일반적으로 공간 영역에서 보다는 주파수 영역에서 좀더 정확하고 다양한 블럭의 형태를 예측할 수 있다. 본 논문에서는 DCT특성을 이용하여 블럭의 형태를 예측할 수 있는 블럭 분류기를 제안하였다. 이 분류기는 프랙탈 특징과 부합하여 부호화 시간을 줄임과 동시에 복원된 영상의 화질을 높이는 장점이 있다. 주파수 영역에서의 AC 계수의 크기는 다양한 블럭 형태를 예측 가능하게 함으로써 최적의 축소 변환점을 얻기 위한 도메인 블럭과 레인지 블럭간에 비교 연산을 줄일 수 있다. 특히 DCT 각 계수의 부호값은 프랙탈 적용을 위한 8가지 변환에 대해 불필요한 변환을 생략함으로써 2가지 변환만으로도 축소 변환점을 찾는 장점을 나타낸다. Most fractal image codings using fractal concept require long encoding time because a large amount of computation is needed to find an optimal affine transformation point. Such a problem can be solved by designing a block classifier fitted to characteristics of image blocks. In general, it is possible to predict more precise and various types of blocks in frequency domain than in spatial domain. In this paper, we propose a block classifier to predict the block type using characteristics of DCT(Discrete Cosine Transform). This classifier has merits to enhance the quality of decoded images as well as to reduce the encoding time by meeting fractal features. AC coefficient values in frequency domain make it possible to predict various types of blocks. As the results, the number of comparisons between a range block and the corresponding domain blocks to reach an optimal affine transformation point can be reduced. Specially, signs of DCT coefficients help to find the optimal affine transformation point with only two isometric transformations by eliminating unnecessary isometric transformations among eight isometric transformations used in traditional fractal codings.
-
한지훈(Han Ji Hoon),박경배(Park Gyong Bae),곽승욱(Kwak Seung Uk),김정일(Kim Jeong II),정근원(Jeong Keun Won),송인근(Song In Keun),이광배(Lee Kwang Bae),김현욱(Kim Hyen Uk) 한국정보처리학회 1999 정보처리학회논문지 Vol.6 No.1
Uses can share information and use resources effectively by using TCP/IP-based networks. So, a protocol to manage complex networks effectively is needed. For the management of the distributed networks, the SNMP(Simple Network Management Protocol) has been adopted as an international standard in 1989, and the SNMPv2 in which a security function was added was published in 1993. There are two encryption schemes in SNMPv2, the one is a DES using symmetric encryption scheme and the other is a MD5(Message Digest5) hash function for authentication. But the DES has demerits that a key length is a few short and the encryption and the authentication is executed respectively. In order to solve these problems, we use a RSA cryptography in this paper. In this paper, we examine the items related with SNMP. In addition to DES and MD5 proposed in SNMPv3, we enhance security functionality be adopting RSA, a public key algorithm executing the encryption and the authentication simultaneously. The proposed SNMPv3 security module is written in JAVA under Windows NT environment.
-
강기성,정근원 도립 강원전문대학 1998 道立 江原專門大學 論文集 Vol.1 No.1
In this paper, we propose a block classifier to predict the block type using characteristics of DCT(Discrete Cosine Transform) coefficient. AC coefficient values in frequency domain make possible to predict various types of blocks. As the results, the number of comparisons between a range block and the corresponding domain blocks to reach an optimal affine transformation point can be reduced. Specially, signs of DCT coefficients help to find the optimal affine transformation point with only two onto by eliminating unnecessary isometric transformations among eight isometric transformations used in traditional fractal codings.
-
박경배,임경묵,강경인,김정일,정근원,이광배,김현욱 명지대학교 대학원 1997 대학원논문집 Vol.1 No.-
As recently the need for electronic commerce and infra information system using Internet increases, several organizations have attempted to develop mutual authentication mechanism between Certification Authorities(CA's) as well as fundamental authentication mechanism, based on Public-key. In this paper, we propose a new efficient authentication protocol which is applicable to various servers. For the protocol, we complement Public-key certificate structure and authentication protocol defined in X.509 with self-arithmetic function and data security function of 1C card.
-
Lee, Kwang-Bae,Kim, Jeong-Il,Yoo, Choong-Yeol,Jeong, Keun-Won,Kim, Hyen-Ug 明知大學校 産業技術硏究所 1997 産業技術硏究所論文集 Vol.16 No.-
본 논문에서는 프랙탈 영상 부호화시 부호화 시간이 장시간 소요되는 단점을 보완하고, 압축율을 향상시키기 위한 프랙탈 영상 부호화 알고리즘을 제안한다. 기존의 프랙탈 영상부호화 방식은 원영상을 축소하여 비교될 영상으로 만들고, 축소된 영상에 대한 원영상의 축소변환의 고정점을 얻기 위해 축소된 영상의 전체 영역을 탐색하므로써 많은 부호화 시간이 소요되었다. 그러나, 제안한 알고리즘은 스케일링 방식과 탐색영역제한 방식을 이용하여 부호화 시간을 대폭 단축시킬 수 있었으며, 비트 플레인 영상을 구성하여 원영상으로 사용하므로서 압축율을 향상시킬 수 있었다.
ScienceON
KISS연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
