• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.2
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• pp.163-171
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• 2016

In order to detect the exact position of high-speed train, it is necessary to obtain location information from the transponder tag installed along the track. In this paper, we proposed parallel descrambling scheme for high-speed railway transponder system, which aims for reducing the processing time required to decode telegram. Since a telegram is stored in a tag after information bits are scrambled by an encoder, decoding procedure includes descrambling of received telegram to recover the original information bits. By analyzing the structure of the descrambling shift register circuit, we proposed a parallel descrambling scheme for fast decoding of telegram. By comparing the required number of clocks, it is shown that the proposed scheme significantly outperforms the original one.

• KIPS Transactions on Computer and Communication Systems
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• v.1 no.3
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• pp.187-192
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• 2012

This paper describes efficient H.264/AVC video scrambling methods for digital rights management. The proposed scrambling methods are to scramble level and suffix in entropy encoding and MVD in motion estimation of the H.264 video compression process. Other scrambling methods have been proposed but they degrade the compression efficiency or make it difficult to achieve real-time processing due to the large amount of computational efforts. Since the proposed scrambling methods resolve the drawbacks of other approaches, they do not cause image distortion and the original compression efficiency is maintained. We verified our scrambling methods and evaluated the performance by conducting several experiments with H.264 reference program. Finally, we implemented video player system using USB dongle in order to apply the proposed scrambling/descrambling methods to H.264 video compression.

• Proceedings of the KIEE Conference
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• 1998.11b
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• pp.579-581
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• 1998

본 연구에서는 $11.7GHz{\sim}12.2GHz$ 주파수 대역의 무궁화 위성방송 송 수신기 정합표준 2.0과 디지털 위성방송 제한수신 정합 잠정표준을 만족하는 무궁화 위성방송 수신시스템 분야에 대한 연구를 수행하였다. 상위 표준에 의거하여 제한 수신모듈을 탑재한 디지털 위성방송 수신장치 개발에 따른 타당성과 신뢰성을 검증하고자 Subscribed and Per-Per-View 채널 디스크램블링 및 가입자 관리(Subscriber Management)에 필요한 데이터 ECM, EMM, RCM 등의 데이터 축출과 처리과정을 모델링하고 모의 실험 수신기(IRD : Integrated Receiver and Decoder)를 제작하여 한국 전자통신연구원에서 작성한 "제한 수신 시스템 신뢰성 검증시험절차서"에 따라 동작반응을 시험하였다.

• The Transactions of the Korea Information Processing Society
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• v.4 no.12
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• pp.3123-3132
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• 1997

In this paper, we describe access control system for protection of pay TV program in digital DBS(Direct Broadcast satellite) system. We also propose a possible access control system and operation scenario for scrambling and descrambling which are important in access control system. Transport stream structure and option, entitlement checking message and entitlement management message for access control on digital broadcasting system are described in this paper. Especially, the authentication based on Flat-Shamir and Gulllou-Quisquater schemes required for verification of proper subscriber as access control is oriented to smart card number and subscriber ID(Identity). It has less restriction than scheme oriented to descrambler number.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.10A
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• pp.1020-1030
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• 2006

As the Terrestrial DMB(T-DMB) has been launched, service providers are focusing on finding a business model as well as preparing the variety of data services. So, the need for development of the CAS(Conditional Access system) is urgently required and its domestic standardization is also in progress. This Paper proposes design and implementation methods of an Ensemble Re-multiplexer and receiver platform for its verification that can be used for the CAS system in T-DMB. And, with transmitting ensemble stream scrambled by the proposed Ensemble Re-multiplexer, we verified their performance by do-scrambling and decoding according to scramble mode at the receiver platform.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.11B
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• pp.1579-1587
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• 2010

In this paper, we design the PCS(Physical Coding Sublayer) transmitting and receiving module for 400/1000 Ethernet and verify the performance of it through logic simulation. In this work, we defined each function module and internal/external control signals and implemented them using HDL programming language. We also designed 64B/66B encoding/decoding, scrambling/descrambling including operation mode, detection of invalid frames, and multi-lane based distribution/arrangement. It was simulated using ModelSim and verified in terms of the operation and timing according to input data. The simulation result shows that all designed modules in 400/100G Ethernet are correctly performed.

• Journal of Korea Multimedia Society
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• v.14 no.3
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• pp.403-413
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• 2011

In this paper, we proposed a digital image watermarking technique using scrambled binary phase computer generated hologram in the discrete cosine transform(DCT) domain. For the embedding process of watermark. Using simulated annealing algorithm, we would generate a binary phase computer generated hologram(BPCGH) which can reconstruct hidden image perfectly instead of hidden image and encrypt it through the scramble operation. We multiply the encrypted watermark by the weight function and embed it into the DC coefficients in the DCT domain of host image and an inverse DCT is performed. For the extracting process of watermark, we compare the DC coefficients of watermarked image and original host image in the DCT domain and dividing it by the weight function and decrypt it using descramble operation. And we recover the hidden image by inverse Fourier transforming the decrypted watermark. Finally, we compute the correlation between the original hidden image and recovered hidden image to determine if a watermark exits in the host image. The proposed watermarking technique use the hologram information of hidden image which consist of binary values and scramble encryption technique so it is very secure and robust to the various external attacks such as compression, noises and cropping. We confirmed the advantages of the proposed watermarking technique through the computer simulations.

• 한국체육학회지인문사회과학편
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• v.58 no.6
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• pp.449-459
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• 2019

The purpose of this study is to identify how postural mechanics affects postural control on balance and stability by using frequency analysis technique from the kinematic data acquired during the one leg standing posture. For this purpose, the experimental group consisted of two groups, the normal group (n=6) and the national Gymnastics group (n=6). Displacement data of CoP were analyzed by frequency analysis of rambling (RM) and trembling (TR) by FFT signal processing. As a results, there was a significant difference in evaluating the stabilization index between the two groups with the eyes open and closed one leg stnading (p <.05). The cause of the difference was found to be the output of the maximum amplitude of RM (f1) and TR (f2) (p <.05). In particular, in the low frequency RM of 8-9 Hz, which is a natural frequency of signal wave involved in postural feedback feedback, the main frequency appeared to be performs the exercise mechanism of stable brain posture control. And in the high frequency TM of 120-135 Hz, it is considered that the adaptation of the reflective muscle response is minimized to minimize posture shaking. In conclusion, this study provides evidence for the intrinsic main frequencies according to the postural control ability which affects the CNS in one leg standing.