• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2006년도 하계종합학술대회
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• pp.17-18
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• 2006

In this paper, we propose a robust detection scheme of OSTBCs with channel estimation errors over time-selective fading channels. Channel estimation errors are inevitable over time-selective fading channels and even small channel estimation errors dramatically degrade the performance of space-time block coding schemes. Therefore, it is desired to investigate the effect of channel estimation errors on the performance of the proposed detection scheme compared with the existing detection scheme. The proposed detection scheme minimizes noise enhancement and impact of channel estimation errors which occur in an existing detection scheme. It is shown by simulations that the proposed detection scheme performs better than the existing detection scheme over time-selective fading channels.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권9호
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• pp.3384-3400
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• 2021

With the advent of the data era, people pay much more attention to data corruption. Aiming at the problem that the majority of existing schemes do not support corruption detection of ciphertext data stored in cloud environment, this paper proposes a data corruption detection scheme based on ciphertexts in cloud environment (DCDC). The scheme is based on the anomaly detection method of Gaussian model. Combined with related statistics knowledge and cryptography knowledge, the encrypted detection index for data corruption and corruption detection threshold for each type of data are constructed in the scheme according to the data labels; moreover, the detection token for data corruption is generated for the data to be detected according to the data labels, and the corruption detection of ciphertext data in cloud storage is realized through corresponding tokens. Security analysis shows that the algorithms in the scheme are semantically secure. Efficiency analysis and simulation results reveal that the scheme shows low computational cost and good application prospect.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1995년도 Proceedings of the Korea Automation Control Conference, 10th (KACC); Seoul, Korea; 23-25 Oct. 1995
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• pp.496-499
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• 1995

In this paper, a new detection scheme, the detectable maneuver set (DMS) scheme, is proposed by incorporating the trade-off property between target maneuver magnitude and detection time delay. With this new detection scheme, small maneuvers can be effectively detected without enlarging window size. Simulation results show that the proposed DMS scheme gives better tracking performance.

• 제어로봇시스템학회논문지
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• 제18권8호
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• pp.719-724
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• 2012

A traffic detection system is a device that collects traffic information around an intersection. Most existing traffic detection systems provide very limited traffic information for signal control due to the restriction of vehicle detection area. A signal control scheme determines the transition among signal phases and the time that a phase lasts for. However, the existing signal control scheme do not resolve the traffic congestion effectively since they use restricted traffic information. In this paper, a new traffic detection system with a zone division signal control scheme is proposed to provide correct and detail traffic information and decrease the vehicle's waiting time at the intersection. The traffic detection system obtains traffic information in a way of vehicle-to-roadside communication between vehicles and sensor network. A new signal control scheme is built to exploit the sufficient traffic information provided by the proposed traffic detection system efficiently. Simulation results show that the proposed signal control scheme has 121 % and 56 % lower waiting time and delay time of vehicles at an intersection than other fuzzy signal control scheme.

• 한국통신학회논문지
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• 제21권2호
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• pp.383-393
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• 1996

This paper considers the evaluation of the ecquistion performance for an accesschannel preamble based on a random access procedure of direct sequence code division multiple access(DS/CDMA) reverse link. The parallel acquistion technique that employs the single-well detection scheme and the multiple-dwell(double-dwell) detection scheme is mentioned. The acquisition performance for two detection schemes is compared in therms of the acquisition probability and the acquisition time. The parallel acquisition is done by a bank of N parallel I/Q noncoherent correlators. Expressions on the detection, false alarm, and miss probabilities of the single-dwell and multiple-dwell(double-well) detection schemes are derived for multiple H$_{1}$ cells and multipath Rayleight fading channel. comparing the single-dwell detection scheme with the multiple-dwell(double-dwell) detection scheme in the case of employing the parallel acquisition technique in the reverse link,the numerical results show that the single-dwell detection scheme deomonstrates a better performance.

• 전기학회논문지
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• 제56권2호
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• pp.407-414
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• 2007

A sensor fault detection scheme(SFDS) for a class of nonlinear systems that can be represented by Takagi-Sugeno fuzzy model is proposed. Basically, the SFDS may be considered as a multiple observer scheme(MOS) in which the bank of state observers and the detection & isolation logic are included. However, the proposed scheme has two great differences from the conventional MOSs. First, the proposed scheme includes fuzzy fault detection observers(FFDO) that are constructed based on the T-S fuzzy model that provides very good approximation to nonlinear dynamic systems. Secondly, unlike the conventional MOS, the FFDOS are driven not parallelly but sequentially according to the predetermined sequence to avoid the massive computational burden, which is known to be the biggest obstacle to the practical application of the multiple observer based FDI schemes. During the operating time, each FFDO generates the residuals carrying the information of a specified fault, and the corresponding fault detection logic unit performs the logical operations to detect and isolate the fault of interest. The proposed scheme is applied to an inverted pendulum control system for sensor fault detection/isolation. Simulation study shows the practical feasibility of the proposed scheme.

• 한국통신학회논문지
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• 제40권9호
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• pp.1722-1724
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• 2015

본 논문은 MIMO-OFDM 시스템에서 복잡도와 검출 성능의 관점에서 효율성을 위하여, QRD-M과 DFE 및 반복 검출을 통한 분할 검출 기법을 제안한다. 제안된 기법은 공간 스트림에 따라 다른 검출 방법을 사용하여 신호들을 검출한다. 제안된 기법에서 낮은 복잡도를 요구하는 공간 스트림에서는 높은 복잡도와 높은 검출 성능을 가지는 QRD-M을 사용하고 높은 복잡도를 요구하는 공간 스트림에서는 낮은 복잡도와 낮은 검출 성능을 가지는 DFE를 사용한다. 또한 DFE가 사용된 공간 스트림에 대해서는 신뢰성을 보장하기 위해 반복 검출을 수행한다. 시뮬레이션을 통하여, 제안된 기법은 비록 기존의 기법보다 증가된 복잡도를 가지지만, 검출 성능을 월등히 개선시키는 것을 확인하였다.

• Journal of Electrical Engineering and Technology
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• 제9권4호
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• pp.1401-1410
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• 2014

This paper presents a modified adaptive fading EKF (AFEKF) for sensor fault detection and isolation in the satellite. Also, the fault detection and isolation (FDI) scheme is developed in three phases. In the first phase, the AFEKF is modified to increase sensor fault detection performance. The sensor fault detection and sensor selection method are proposed. In the second phase, the IMM filer with scalar penalty is designed to detect wherever actuator faults occur. In the third phase of the FDI scheme, the sub-IMM filter is designed to identify the fault type which is either the total or partial fault. An important feature of the proposed FDI scheme can decrease the number of filters for detecting sensor fault. Also, the proposed scheme can classify fault detection and isolation as well as fault type identification.

• 방송공학회논문지
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• 제25권6호
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• pp.870-881
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• 2020

본 논문에서는 5G NR (new radio) 시스템에서 PSS/SSS (primary synchronization signal/secondary synchronization signal)를 이용한 cell ID (cell identity) 검출 방법들을 제시하고 성능을 평가한다. 시간 영역에서 PSS를 먼저 검출한 후 검출된 PSS 정보를 이용하여 채널 추정 및 SSS의 시퀀스 검출에 사용하는 2단계(2-stage) 검출 방법과 PSS와 SSS 시퀀스를 결합하여 동시에 검출하는 결합 검출(joint detection) 방법을 사용한다. 또한, 추정한 채널 이득을 이용하여 주어진 PSS 및 SSS의 전체 시퀀스 길이의 상관(correlation) 값을 계산하는 coherent 방법과 시퀀스의 전체 길이를 여러 개의 그룹으로 나누어 각 그룹 내에서는 coherent 상관을 계산하고, 이들을 결합하여 전체 그룹의 상관 값을 계산하는 non-coherent combining 방법을 제시한다. 본 논문에서 고려한 검출 방법들에 대해 전산 실험을 통하여 PSS 및 SSS의 개별 검출 에러율과 전체 cell ID 검출 에러율 성능을 비교한다. 전산 실험 결과는 가산 백색 가우시안 잡음환경과 고정 및 이동 환경에서 non-coherent combining 방법이 coherent 방법에 비해 우수한 검출 성능을 보이며, 결합 검출 방법은 2단계 검출 방법에 비해 우수한 성능을 보이나 계산 복잡도 측면에서는 2단계 검출 방법이 보다 낮은 복잡도를 갖는다는 것을 보여준다.

• 한국정보과학회논문지:소프트웨어및응용
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• 제26권1호
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• pp.80-80
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• 1999

As Temporal DataBase Systems(TDBSs) manages both the historical versions and the current version of each data item, a temporal transaction may access more data records than atransaction in traditional database systems. Hence, the concurrency control subsystem of temporaldatabase management system should be able to correctly and efficiently detect actual conflicts amongconcurrent temporal transactions while the cost of detecting conflicts is maintained in low levelwithout detecting false conflicts which cause severe degradation of system throughput.In this paper, Two-Level Conflict Detection(TLCD) scheme is proposed for efficient conflictdetection between concurrent temporal transactions in TDBs. In the proposed TLCD scheme, sincechecking conflict between concurrent temporal transactions is performed at two levels, i, e., logicallevel and physical level, conflicts between concurrent temporal transactions are efficiently and correctlydetected,Furthermore, we also evaluate the performance of the proposed TLCD scheme with those oftraditional conflict detection schemes, logical-level conflict detection scheme and physical-level conflictdetection scheme by simulation approach, The result of the simulation study shows that the proposedTLCD scheme outperforms the previous conflict detection schemes with respect to the averageresponse time.