• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.18 no.5
• /
• pp.1110-1115
• /
• 2014

The matrix-star and the transposition graphs are considered as star graph variants that have various merits in graph theory such as node symmetry, fault tolerance, recursive scalability, etc. This paper describes an one-to-one mapping algorithm from a matrix-star graph to a transposition graph using adjacent properties in graph theory. The result show that a matrix-star graph $MS_{2,n}$ can be embedded in a transposition graph $T_{2n}$ with dilation n or less and average dilation 2 or less.

• Journal of Multimedia Information System
• /
• v.4 no.3
• /
• pp.107-114
• /
• 2017

As to talk about computer aided 3D modeling, it can be conformed to the popular aesthetics based theory of heightening the organizing useful visual information. This thesis heightens the formativeness of the 3D modeling from the angle of the Gestalt psychology and attempts a finding of a method as also explains among the grouping laws of Gestalt. They are the definitions and the special features of 'The Law of Proximity', 'The Law of Similarity', 'The Law of Closure', 'The Law of Continuity', etc. And, through a logical, theoretical analysis, the relationships between such laws are found out. And the case examples of the uses of such laws in the 3D animation character designs and the situation in which such laws are applied to the things in the actual lives are analyzed. If it is intended to improve the formativeness of the 3D model forms, the rules of the simplicity, the safety, and the symmetry must be pursued according to the visual recognitions of the human beings. Because the actual objects are seen and touched, other than the visual pursuits by the human beings, the functionalities and the practicalities of the objects must be considered.

• Proceedings of the Acoustical Society of Korea Conference
• /
• autumn
• /
• pp.119-122
• /
• 2004

G.723.1은 저 전송률 환경에서 고 음질을 제공하여 주고 있으나 CELP형 부호화기가 갖는 합성에 의한 분석(Analysis by Synthesis)방식의 구조로 인해 많은 처리 시간과 계산량을 요구하게 된다. 본 논문에서는 G.723.1에 대해 NAMDF함수를 적용하여 델타 피치 검색과정의 계산량을 줄여 부호화기의 전체 계산량을 감소시키는 방법을 제안하였다. 기존의 피치 검출 알고리즘에서 피치 검출을 위해 사용하고 있는 자기상관함수는 곱셈 연산에서 발생하는 bit의 dynamic range가 커서 나눗셈 연산에서도 과도한 연산량을 필요로 한다. 따라서, 이러한 계산량의 감소를 위해 기존의 자기상관함수 대신 계산량을 감소하기 위하여 NAMDF 방법을 적용하였고 추가된 skipping 기법을 사용하였다. 계산량 감소율 측면에서는 약 $64\%$의 감소율을 보였고 기존의 방법과 제안한 방법간의 피치 pitch contour은 원음성의 피치 contour와 유사하였고, 음질 평가에서도 기존의 G.723.1 부호화기 합성음과 유사한 길과를 얻을 수 있었다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2003.05a
• /
• pp.255-258
• /
• 2003

Recently, Digital Watermarking is used to authenticate data and to determine whether the data are distorted or not in medical images which is digitalized. The Fourier Mellin method using the Fourier Transform and the Log-Polar coordinate transform gets an invariant feature for RST distortion in images. But there are several problems in the real materialization. Interpolation of the image value should be considered according to the pixel position and so a watermark loss, original image distortion, numerical approximation is happened. Therefore there should be solved to realization of the Fourier Mellin method. Using the Look up table, there reduce the data loss caused by the conversion between Rectangular and Polar coordinate. After diagnose, medical images are transformed the Polar coordinate and taken the Discrete Fourier transform in the center of ROI region. Maintaining the symmetry in Fourier magnitude coefficient, the gaussian distributed random vectors and binary images are embedded in medical images.

• Journal of KIISE:Information Networking
• /
• v.27 no.1
• /
• pp.12-21
• /
• 2000

Arrangement graph has desirable properties for design requirements of a multihop lightwave network, such as node and edge symmetry, low diameter, simple routing, etc. In this paper, arrangement lightwave network based on arrangement graph model is proposed as new logical topology of multihop lightwave network. In the proposed scheme, multistar and grouping of network are used for improving reusability of wavelength and scalability. Also, this paper shows that the proposed scheme is an alternative logical topology for application requiring more nodes with limited wavelengths by evaluating performance with related works.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.9 no.4
• /
• pp.170-178
• /
• 1984

For the reduction of the 12-channel TDM/FDM translation time the 14-point fast DCT algorithm is used and the polyphase network which translates the prototype filter into the channel filters required in each channel is designed. For the prototype filter the degree of the numerator is 168 and the coefficients have symmetry values, the degree of the numerator is 6. Such a prototype filter is consistant with the CCITT requirements. In this case the required multiplication rate is CCITT requirements. In this case the required multiplication rate is $0.12267{\times}10^2$ multiplications/sec. channel and reduces to about 15-40% of the rate required in the exising systems. The proposed 12-channel TDM/FDM translation system is simulated using a demodulation system with a computer (PRIME 750) and the results show that the proposed conversion method is valid.

• Journal of Korea Society of Industrial Information Systems
• /
• v.17 no.3
• /
• pp.9-17
• /
• 2012

In this paper, we propose a SPN 256 bit block cipher so called XSB(eXtended SPN Block cipher) which has a symmetric structure in encryption and decryption. The proposed XSB is composed of the even numbers of N rounds where the first half of them, 1 to N/2-1 round, applies a pre-function and the last half of them, N/2+1 to N round, employs a post-function. Each round consists of a round key addition layer, a substiution layer, a byte exchange layer and a diffusion layer. And a symmetry layer is located in between the pre-function layer and the post-function layer. The symmetric layer is composed with a multiple simple bit slice involution S-Boxes. The bit slice involution S-Box symmetric layer increases difficult to attack cipher by Square attack, Boomerang attack, Impossible differentials cryptanalysis etc.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.23 no.9A
• /
• pp.2365-2371
• /
• 1998

Discrete cosine transform (DCT) has wide applications in speech and image coding. In this paper, we propose a novel fast dCT scheme with the property of reduced multiplication stages and the smaller number of additions and multiplications. This exploits the symmetry property of the DCT kernel to decompose the N-point dCT to N/2 point, and can be generally applied recursively to $2^{m}$-point. The proposed algorithm has a structure that most of multiplications tend to be performed at final stage, and this reduces propagation of truncation error which could occur in the fixed-point computation. Also the minimization of the multiplication stages further decreases the error.

• Proceedings of the IEEK Conference
• /
• 2000.07a
• /
• pp.446-449
• /
• 2000

A direct RTI(Rotation and translation invariant) fingerprint identification is proposed using the GCMs(generalized complex moments) and Gabor filter-based features from the grey level fingerprint around core point. The core point is located as reference point for the translation invariant matching. And its symmetry axis is detected for the rotation invariant matching from its neighboring region centered at the core point. And then, fingerprint is divided into non-overlapping blocks with respect to the core point and, in contrast to minutiae-based method using various processing steps, features are directly extracted from the blocked grey level fingerprint using Gabor filter, which provides information contained in a particular orientation in the image. The Proposed fingerprint identification is based on the Euclidean distance of the corresponding Gabor features between the input and the template fingerprint. Experiments are conducted on 300 ${\times}$ 300 fingerprints obtained from the CMOS sensor with 500 dpi resolution, and the proposed method could obtain 97% identification rate.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.2 no.4
• /
• pp.37-44
• /
• 2009

Stroke patients are the most in the cause of death among Koreans. Therefore, an accurate diagnosis of stroke is very important. But, it is the only way to diagnose strokes that the doctors see the MRI image and detect the pathological pattern. In this paper, we proposed the new method to detect the pathological pattern of a suspected stroke. We used the quasibi-symmetry of the MRI brain image in our new method. we detected pathological pattern applied the proposed method, and show the result.