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A study on the constitution of S box and G function in SEED-type cipher (SEED 형식 암호에서 S 박스와 G 함수 구성에 관한 연구)

  • 송홍복;조경연
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.27 no.4A
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    • pp.291-300
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    • 2002
  • In this paper, a way of constituting optimized S box and G function was suggested in the block cipher whose structure is similar to SEED, which is KOREA standard of 128-bit block cipher. S box can be formed with nonlinear function and an affine transform. Nonlinear function must be strong with differential attack and linear attack, and it consists of an inverse number over GF(2$\^$8/) which has neither a fixed point, whose input and output are the same except 0 and 1, nor an opposite flexed number, whose output is one's complement of the input. Affine transform can be constituted so that the input/output correlation can be the lowest and there can be no fixed point or opposite fixed point. G function undergoes diffusive linear transform with 4 S-box outputs using the matrix of 4$\times$4 over GF(2$\^$8/). G function can be constituted so that MDS(Maximum Distance Separable) code can be formed, SAC(Strict Avalanche Criterion) can be met, there can be no weak input, where a fried point, an opposite fried point, and output can be two's complement of input, and the construction of hardware can be made easy. The S box and G function suggested in this paper can be used as a constituent of the block cipher with high security, in that they are strong with differential attack and linear attack with no weak input and they are excellent at diffusion.

Software development for the visualization of brain fiber tract by using 24-bit color coding in diffusion tensor image

  • Oh, Jung-Su;Song, In-Chan;Ik hwan Cho;Kim, Jong-Hyo;Chang, Kee-Hyun;Park, Kwang-Suk
    • Proceedings of the KSMRM Conference
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    • 2002.11a
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    • pp.133-133
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    • 2002
  • Purpose: The purpose of paper is to implement software to visualize brain fiber tract using a 24-bit color coding scheme and to test its feasibility. Materials and Methods: MR imaging was performed on GE 1.5 T Signa scanner. For diffusion tensor image, we used a single shot spin-echo EPI sequence with 7 non-colinear pulsed-field gradient directions: (x, y, z):(1,1,0),(-1,1,0),(1,0,1),(-1,0,1),(0,1,1),(0,1,-1) and without diffusion gradient. B-factor was 500 sec/$\textrm{mm}^2$. Acquisition parameters are as follows: TUTE=10000ms/99ms, FOV=240mm, matrix=128${\times}$128, slice thickness/gap=6mm/0mm, total slice number=30. Subjects consisted of 10 normal young volunteers (age:21∼26 yrs, 5 men, 5 women). All DTI images were smoothed with Gaussian kernel with the FWHM of 2 pixels. Color coding schemes for visualization of directional information was as follows. HSV(Hue, Saturation, Value) color system is appropriate for assigning RGB(Red, Green, and Blue) value for every different directions because of its volumetric directional expression. Each of HSV are assigned due to (r,$\theta$,${\Phi}$) in spherical coordinate. HSV calculated by this way can be transformed into RGB color system by general HSV to RGB conversion formula. Symmetry schemes: It is natural to code the antipodal direction to be same color(antipodal symmetry). So even with no symmetry scheme, the antipodal symmetry must be included. With no symmetry scheme, we can assign every different colors for every different orientation.(H =${\Phi}$, S=2$\theta$/$\pi$, V=λw, where λw is anisotropy). But that may assign very discontinuous color even between adjacent yokels. On the other hand, Full symmetry or absolute value scheme includes symmetry for 180$^{\circ}$ rotation about xy-plane of color coordinate (rotational symmetry) and for both hemisphere (mirror symmetry). In absolute value scheme, each of RGB value can be expressed as follows. R=λw|Vx|, G=λw|Vy|, B=λw|Vz|, where (Vx, Vy, Vz) is eigenvector corresponding to the largest eigenvalue of diffusion tensor. With applying full symmetry or absolute value scheme, we can get more continuous color coding at the expense of coding same color for symmetric direction. For better visualization of fiber tract directions, Gamma and brightness correction had done. All of these implementations were done on the IDL 5.4 platform.

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Activation plan for the edible insect industry by improving perception (인식개선을 통한 식용곤충 산업의 활성화 방안)

  • Hwang, Dooseon;Lim, Chae-Hwan;Lee, Seung Hun;Yun, Eun-Young
    • Food Science and Industry
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    • v.55 no.2
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    • pp.128-139
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    • 2022
  • Although edible insects are attracting attention as future alternative food because of their nutritional, eco-friendly, and economic advantages and functionality, consumption is low, so measures to promote consumption are needed. The problems in edible insect consumption were identified as the aversion to the edible insects, lack of publicity for edible insects newly registered in the Food Code, and difficulties in continuously supplying high-quality edible insects and selling products. To solve these problems, it is necessary to establish effective public relations plans for new edible insects and develop processing methods for improving their taste and flavor, education content about edible insects, and products interesting to the target age. In addition, it is necessary to establish a one-stop cluster that can perform quality control of harmful substances and nutrients, purchase raw materials, sell products, educate, and publicize.

Lightweight IPsec protocol for IoT communication environments (IoT 통신 환경을 위한 경량 IPsec 프로토콜 연구)

  • Song, In-A;Oh, Jeong-Hyeon;Lee, Doo-Won;Lee, Young-Seok
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.11 no.1
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    • pp.121-128
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    • 2018
  • Internet of Things architecture connected to the Internet is a technology. However, Many paper research for the lightweight Protocol of IoT Environment. In these Paper excluded secure problem about protocol. So Light weight Protocol has weakness of secure in IoT environment. All of IoT devices need encryption algorithm and authentication message code for certain level of security. However, IoT environment is difficult to using existing security technology. For this reason, Studies for Lightweight IPsec is essential in IoT environment. For Study of Lightweight IPsec, We analyze existing protocols such as IPsec, 6LoWPAN for IEEE 802.15.4 layer and Lightweight IPsec based 6LoWPAN. The result is to be obtained for the lightweight IPsec protocols for IoT environment. This protocol can compatible with Internet network.

Optimization of coding and PRML detection scheme for perpendicular magnetic recording systems (수직 자기기록 시스템을 위한 코딩 및 PRML 검출 방법의 최적화)

  • Lee Joo hyun;Lee Jae jin
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.30 no.3C
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    • pp.59-63
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    • 2005
  • We propose non-DC-free generalized PRML (GPRML) that are suppressed DC contents for matching to the response of perpendicular magnetic recording channel with a ring-head. In addition, DC-free encoding is considered to prevent low-frequency disturbances. The SNR performance is obtained by combining the various PRML channels with DC-free and non-DC-free codes during the normalized recording density increases from 2.5 to 3.5. The GPRML detections without using DC-free code get SNR gains more than 1dB compared to the conventional PRML systems at 10/sup -5/BER. We confirmed that the rate 127/136 DC-free coded GPRML systems show good performances compared with the 16/17 non-DC-free coded GPRML systems. In results, DC-free coded GPRML detections get gains about 1.4dB and 2.0dB at the density of 3.3 and 3.5, respectively.

A Numerical Analysis on the Shear and Hydraulic behavior of Single Rock Joint with Roughness (거칠기를 고려한 단일 절리의 전단, 수리적 거동에 대한 수치해석)

  • 이희석;이연규
    • Proceedings of the Korean Society for Rock Mechanics Conference
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    • 2000.09a
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    • pp.117-128
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    • 2000
  • The development of proper joint model, which can describe real phenomena exactly and still can be used easily, is one of the most important element for the analysis of the mechanical and hydraulic behavior of discontinuous rock mass. In this study, an elasto-plastic constitutive model of joint behavior considering asperity degradation was extended with the concept of first and second order asperities. The proposed model was implemented to numerical code with discrete finite joint element. The parametric study with the various asperity angles and degradation coefficients showed that the model can reproduce the shear behavior of typical rough joints well. Results of laboratory monotonic and cyclic shear tests were compared with those of numerical tests to validate the model. The hydraulic model considering the relations between gouge production and aperture was introduced to the mechanical model. In an attempt to examine the performance of the model, comparative numerical test was conducted. Permeability between joint surfaces increased rapidly at the first stage, but became nearly constant with increasing shear displacement due to gouge production and uniform variation of aperture distribution.

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Optimal Chip Rate of Power and Rate Adapted DS/CDMA Communication Systems in Nakagami Fading Channels (나카가미 페이딩 채널에서 전력 및 전송률 적응화 직접 대역확산 부호분할 다중접속 통신시스템을 위한 최적 칩률에 관한 연구)

  • Lee, Ye-Hoon
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.35 no.2A
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    • pp.128-133
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    • 2010
  • We investigate the optimal chip rate of power or rate adapted direct-sequence code division multiple access (DS/CDMA) communication systems in Nakagami fading channels. We find that the optimal chip rate that maximizes the spectral efficiency depends upon both the channel parameters, such as multipath intensity profile (MIP) and line-of-sight (LOS) component, and the adaptation scheme itself. With the rate adaptation, the optimal chip rate is less than $1/T_m$, irrespective of the channel parameters, where $1/T_m$ is multipath delay spread. This indicates that with the rate adaptation, correlation receiver achieves higher spectral efficiency than RAKE receiver. With the power adaptation, however, the optimal chip rate and the corresponding number of tabs in RAKE receiver are sensitive to MIP and LOS component.

ECG Data Compression Using Adaptive Fractal Interpolation (적응 프랙탈 보간을 이용한 심전도 데이터 압축)

  • 전영일;윤영로
    • Journal of Biomedical Engineering Research
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    • v.17 no.1
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    • pp.121-128
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    • 1996
  • This paper presents the ECG data compression method referred the adaptive fractal interpolation algorithm. In the previous piecewise fractal interpolation(PFI) algorithm, the size of range is fixed So, the reconstruction error of the PFI algorithm is nonuniformly distributed in the part of the original ECG signal. In order to improve this problem, the adaptive fractal interpolation(AEI) algorithm uses the variable range. If the predetermined tolerance was not satisfied, the range would be subdivided into two equal size blocks. large ranges are used for encoding the smooth waveform to yield high compression efficiency, and the smaller ranges are U for encoding rapidly varying parts of the signal to preserve the signal quality. The suggested algorithm was evaluated using MIT/BIH arrhythmia database. The AEI algorithm was found to yield a relatively low reconstruction error for a given compression ratio than the PFI algorithm. In applications where a PRD of about 7.13% was acceptable, the ASI algorithm yielded compression ratio as high as 10.51, without any entropy coding of the parameters of the fractal code.

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Performance Analysis of Modulator using Direct Digital Frequency Synthesizer of Initial Clock Accumulating Method (클록 초기치 누적방식의 직접 디지털 주파수 합성기를 이용한 변조기의 성능해석)

  • 최승덕;김경태
    • Journal of the Korean Institute of Telematics and Electronics T
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    • v.35T no.3
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    • pp.128-133
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    • 1998
  • This paper is study on performance analysis of modulator using direct digital frequency synthesizer of Initial Clock Accumulating Method. It has been generally used for PLL or digital frequency synthesizing method to be synthesizd randomly chosen frequency state. In order to improve disadvantage of two methods, we constructed modulator system using DDFS of Initial Clock Accumulating Method. We also confirmed the coherence frequency hopping state and possibility of phase control. The results obtained from the experiments are as follows; First, the synthesized output frequency is proportional to the sampling frequency, according to index, K. Second, the difference of the gain between the basic frequency and the harmonic frequencies was more than 50 [dB], that is, this means facts that is reduced the harmonic frequency factor. Third, coherence frequency hopping state is confirmed by PN code sequence. Here, we confirmed the proposed method cut switching time, this verify facts that is the best characteristic of the frequency hopping. We also verified the fact that the phase varies as the adder is operated set or reset.

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The Effect of QR Information Service on Medical Service Loyalty (의료서비스충성도에 대한 QR정보서비스의 효과)

  • Kim, Mi Ra;Hwang, Yoon Yong
    • Journal of Korea Society of Industrial Information Systems
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    • v.27 no.5
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    • pp.119-128
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    • 2022
  • This study investigated the influence relationship of information service using QR code on customer's service quality perception and loyalty behavior for medical service in the physical environment. As a result of the study, when medical institutions provide location information services about the physical environment by utilizing the usefulness and reliability of QR codes, the perceived quality of customers' QR information will be strengthened, and furthermore, loyalty behavior toward medical services will increase in the future. Considering the spread of smartphones as a popular digital medium today, marketers use QR codes to connect and provide four-dimensional information services without time and place restrictions, thereby strengthening the interactive experience with customers. And these efforts suggest that it can contribute to improving service image and strengthening loyalty beyond simply providing service information to companies.