• Journal of Advanced Navigation Technology
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• v.19 no.1
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• pp.48-52
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• 2015

In this paper, we propose a differential fault analysis on SSB having same structure in encryption and decryption proposed in 2011. The target algorithm was designed using advanced encryption standard and has advantage about hardware implementations. The differential fault analysis is one of side channel attacks, combination of the fault injection attacks with the differential cryptanalysis. Because SSB is suitable for hardware, it must be secure for the differential fault analysis. However, using proposed differential fault attack in this paper, we can recover the 128 bit secret key of SSB through only one random byte fault injection and an exhausted search of $2^8$. This is the first cryptanalytic result on SSB having same structure in encryption and decryption.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.12A
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• pp.1122-1127
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• 2010

In this paper, we propose a relay-based DF cooperative communication scheme using repetitive transmission algorithm for wireless LAN environments on D-STBC. Additional transmission diversity gain can be obtained by repetitive transmission algorithm. However, in comparison with conventional schemes, data rate is decreased in half. We consider data modulation constellation twice higher than conventional schemes. Further, system complexity is decreased and performance degradation is minimized because repetitive transmission algorithm is adapted between source and relay node. We show the uncoded BER performance of the proposed algorithm over HiperLAN/2 Rayleigh fading channel.

• Journal of the Korean Society for Precision Engineering
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• v.24 no.5
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• pp.82-88
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• 2007

This work is to fabricate a precise optical fiber array using polymer composite for optical interconnection. Optical fiber array has to satisfy low optical loss requirement less than 0.4 dB according to temperature change. For this purpose, design criteria for an optical fiber array was derived. The coefficient of thermal expansion of silica particulate epoxy composites was affected by volume fraction of silica particles. And also, elastic modulus of silica particulate epoxy composites was affected by volume fraction of silica particles. To obtain the coefficients of thermal expansion below $10{\times}10E-6/^{\circ}C$ and elastic modulus more than 20 GPa , we chose the volume fraction more than 76%. Using silica particulate epoxy composites with the volume fraction 76%, 8-channel optical fiber array with dimensional tolerances below $1\;{\mu}m$ was manufactured by transfer molding technique using dies with the uniquely-designed core pin and precisely-machined zirconia ceramic V block. These optical fiber arrays showed optical loss variations within 0.4 dB under thermal cycling test and high temperature test.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.1
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• pp.128-136
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• 2013

This study presents the development of Gateway Control Module using SAE J1939 protocol for the commercial vehicles. Presently, the load rate of CAN bus is increased by the single network composition and addition of new ECUs for development of intelligent vehicles. Because the embedded system of the integrated network control function has the errors of the CAN bus caused by the increase of ECU, it is needed for development of commercial vehicles. Also, this study presents the development of smart functions that can diagnosis CAN bus errors, fault diagnosis of ECU and basic function that arbitrates CAN bus between ECUs of commercial vehicle. GCM was designed for 4channel separation about Gateway function as solution of load rate decrease and smart functions. HILS(Hardware in the loop simulation)system that can achieve simulation about CAN Messages of all systems on vehicle was applied to evaluate performance and verification of all functions and performance. The load rate on CAN bus was decreased at using functions what was delivery, block and process of GCM. Through this, it was enabled to organize systematic architecture for gateway.

• Journal of the Korea Society of Computer and Information
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• v.11 no.2 s.40
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• pp.201-211
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• 2006

The standardization of third Generation Partnership Project(3GPP) has been performed in of order to support interactive multimedia services under mobile environments. In this 3GPP, transmit diversity solutions are applied to increase the available diversity effectively using 2 or more antennas. In this paper, we analyzer the performances on STTD(Space Time Transmit Diversity) technique and its modified techniques such as STTD-OTD, CL-STTD, and 4TX-STTD out of open loop transmit diversities that the standardization of 3GPP has released. We also propose the open loop transmitter and receiver diversities to add the receiver diversity. We analyze and discuss the performance of the proposed techniques and using the Matlab simulation under the flat fading channel environment.

• ETRI Journal
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• v.14 no.3
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• pp.1-15
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• 1992

Stand-slone 신호 중계 교환기인 SMX-1(Signalling Message eXchange No.1)은 통신망의 신경계인 공통선 신호망(Common Channel Signalling Network)의 하부 구조를 구성하는 시스팀이다. SMX-1에 총괄명 번역서비스를 수용하게 되면 통신망 사용자에게 통신망 내부의 구성 및 구성 요소의 변화에 구속되지 않고 지속적인 지능망 서비스를 제공할 수 있게 된다. 본 연구에서는 SMX-1의 설계 이념에 부합되도록 신호연결 제어부의 기능을 소프트웨어 및 하드웨어적으로 분산화하여 설계, 구현함으로써 SMX-1의 고신뢰성 및 신속성을 추구하였다. 소프트웨어적으로는 총괄명번역 서비스 제공을 위해 국제 전신 전화 자문 회의(CCITT)권고 Q.711-Q.714에서 정의하고 있는 신호연결 제어부(SCCP:Signalling Connection Control Part)의 기능을 관리 기능(SCMG : SCCP Management Part)과 루팅 제어 기능(SCRC : SCCP Routing Control Part)으로 분리하여 각각의 기능을 이중화하여 설계, 구현하였다. 하드웨어적으로는 관리 기능을 하나의 보드로 집중화하고 루팅 제어 기능을 여러개의 보드로 분산화하였다. 분산되어 있는 루팅 제어기능이 총괄명번역 서비스를 수행하기 위하여 사용하는 루팅 제어 데이터의 일치성을 유지하기 위하여, 관리 기능에 루팅 제어 데이터를 총괄적으로 관리하는 루팅 제어 데이터 관리 기능(RCDMFB : Routing Control Data Management Function Block)과 운용 관리 기능 (OMS : Operation and Management Subsystem)의 제원관리 지원기능을 구현하였다.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.42 no.10 s.340
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• pp.25-30
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• 2005

This paper generalizes the concept of the signal space detection to construct a fixed delay tree search (FDTS) detector which estimates a block of n channel symbols at a time. This technique is applicable to high speed implementation. Two approaches are discussed both of which are based on efficient signal space partitioning. In the first approach, symbol detection is performed based on a multi-class partitioning of the signal space. This approach is a generalization of binary symbol detection based on a two-class pattern classification. In the second approach, binary signal detection is combined with a look-ahead technique, resulting in a highly parallel detector architecture.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.41 no.10
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• pp.17-22
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• 2004

We developed a new ANGLED display driving method which used both amplitude and pulse width modulation. For pulse width modulation, we divided a picture frame time into S sub-frames. For amplitude modulation, we used three OLED luminance(or current) levels which were controlled by TFT's gate voltages. By combining these two modulation methods, we obtained 35(=243) grey levels. And we designed a new data electrode driving circuit block with two shift registers without using DAC's. To verify the feasibility, we simulated the key circuit components by HSpice with TFT parameters extracted from current-voltage characteristics of 6${\mu}{\textrm}{m}$ channel length polysilicon TFT's. From the simulation results, we found that 320${\times}$240, dual scan, 243 grey level AMOLED display can be designed with this method.

• JSTS:Journal of Semiconductor Technology and Science
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• v.16 no.4
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• pp.436-442
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• 2016

An electroencephalogram (EEG)-connectome processor to monitor and diagnose mental health is proposed. From 19-channel EEG signals, the proposed processor determines whether the mental state is healthy or unhealthy by extracting significant features from EEG signals and classifying them. Connectome approach is adopted for the best diagnosis accuracy, and synchronization likelihood (SL) is chosen as the connectome feature. Before computing SL, reconstruction optimizer (ReOpt) block compensates some parameters, resulting in improved accuracy. During SL calculation, a sparse matrix inscription (SMI) scheme is proposed to reduce the memory size to 1/24. From the calculated SL information, a small world feature extractor (SWFE) reduces the memory size to 1/29. Finally, using SLs or small word features, radial basis function (RBF) kernel-based support vector machine (SVM) diagnoses user's mental health condition. For RBF kernels, look-up-tables (LUTs) are used to replace the floating-point operations, decreasing the required operation by 54%. Consequently, The EEG-connectome processor improves the diagnosis accuracy from 89% to 95% in Alzheimer's disease case. The proposed processor occupies $3.8mm^2$ and consumes 1.71 mW with $0.18{\mu}m$ CMOS technology.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.7A
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• pp.629-634
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• 2002

The next generation of wireless communication system is expected to provide users with wireless multimedia services such as high speed internet access and wireless mobile computing. Depending on the Quality of Service(QoS) requirements and different applications per user, many wireless communication systems have been proposed. The simple decoding algorithm of space-time block coding is based on the assumption of flat fading channel, where no intersymbol interference exists. In this paper, we propose to combine space-time transmit diversity with adaptive equalizer. The proposed system effectively eliminates interference caused by multipath environment. Simulation results show that the proposed system provides improved bit error rate performance.