• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -1
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• pp.152-155
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• 2002

In this paper, a new approach is proposed for the error detection dedicated to MPEG-4 video coding by using the digital watermarking. In the process of encoding, the proposed scheme abstracts the macroblock features of headers, motion vectors, and Discrete Cosine Transform (DCT) coefficients, which are embedded in the quantized DCT coefficients as the digital watermarks. The decoder performs the accurate error detection through the watermark extraction. Simulation results demonstrate that the error detection ability of the proposed approach can be significantly enhanced, and that digital watermark embedding incurs little degradation to the picture quality.

• ETRI Journal
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• 제45권6호
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• pp.929-938
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• 2023

The detection of all the symbols transmitted simultaneously in multiuser systems using limited wireless resources is challenging. Traditional model-based methods show high performance with perfect channel state information (CSI); however, severe performance degradation will occur if perfect CSI cannot be acquired. In contrast, data-driven methods perform slightly worse than model-based methods in terms of symbol error ratio performance in perfect CSI states; however, they are also able to overcome extreme performance degradation in imperfect CSI states. This study proposes a novel deep learning-based method by improving a state-of-the-art data-driven technique called deep soft interference cancellation (DSIC). The enhanced DSIC (EDSIC) method detects multiuser symbols in a fully sequential manner and uses an efficient neural network structure to ensure high performance. Additionally, error-propagation mitigation techniques are used to ensure robustness against channel uncertainty. The EDSIC guarantees a performance that is very close to the optimal performance of the existing model-based methods in perfect CSI environments and the best performance in imperfect CSI environments.

• 대한기계학회논문집A
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• 제38권11호
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• pp.1299-1307
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• 2014

본 논문은 감도가 낮고 정밀한 족적센서의 특성에 대하여 연구한 논문이다. 이를 위하여 센서의 형상 변수 조절 범위를 낮게 선정하였다. 센서의 감도 해석으로 2차원 해석 모델을 사용할 경우 실험값과 비교한 결과 오차가 많이 나는 것을 확인하였다. 따라서 이 오차를 개선하기 위하여 3D 기반의 새로운 해석 모델을 적용시켜 재해석 하였고, 이를 실험값과 비교한 결과 오차가 개선되었음을 확인할 수 있었다.

• 전기전자학회논문지
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• 제21권2호
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• pp.130-135
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• 2017

Normally, in data transmission, extra parity bits are added to the input message which were derived from its input and a pre-defined algorithm. The same algorithm is used by the receiver to check the consistency of the delivered information, to determine if it is corrupted or not. It recovers and compares the received information, to provide matching and correcting the corrupted transmitted bits if there is any. This paper aims the following objectives: to use an alternative error detection-correction method, to lessens both the fixed number of the required redundancy bits 'r' in cyclic redundancy checking (CRC) because of the required polynomial generator and the overhead of interspersing the r in Hamming code. The experimental results were synthesized using Xilinx Virtex-5 FPGA and showed a significant increase in both the transmission rate and detection of random errors. Moreover, this proposal can be a better option for detecting and correcting errors.

• IEIE Transactions on Smart Processing and Computing
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• 제3권2호
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• pp.83-87
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• 2014

This paper introduces a refined opportunistic interference alignment (OIA) technique that uses minimum mean square error (MMSE) detection at the receivers in multiple-input multiple-output multi-cell uplink networks. In the OIA scheme under consideration, each user performs the optimal transmit beamforming and power control to minimize the level of interference generated to the other-cell base stations, as in the conventional energy-efficient OIA. The result showed that owing to the enhanced receiver structure, the OIA scheme shows much higher sum-rates than those of the conventional OIA with zero-forcing detection for all signal-to-noise ratio regions.

• 한국항공운항학회지
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• 제17권2호
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• pp.62-67
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• 2009

LOSA is a flight safety program that analyses human errors in normal operations. Trained pilot observers monitor the normal flights at the observer seat. LOSA is a proactive non jeopardy data collection tool using threat and error management(TEM) as a framework. With the analysis of crew behaviors through LOSA with The LOSA collaborative(TLC), the airlines can identify the behaviors of the crew during normal operations. The major objective of LOSA is to measure how the crew manage threats, errors and undesired aircraft deviations in the cockpit on day to day operations. The airlines are able to set up effective TEM training with practical six generation Crew recourse management(CRM) with data of error from LOSA instead of theoretical CRM courses. The Airlines can use TEM as an integral part of a Safety Management System(SMS) and uses monitoring and cross-checking skills in the flight operations to manage threats and errors effectively when we know the errors we make in the cockpit on daily operation. The result of LOSA indicates that the error detection rate should be enhanced since around the half of the errors went undetected. The areas which should be focused for enhancing the error detection are monitor, cross-check, the management of workload, automation and taxiway/ runway to manage errors effectively.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.101.2-101
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• 2001

This paper proposes a novel face recognition algorithm to recognize human face robustly under various conditions, such as changes of pose, illumination, and expression, etc. at indoor environments. A conventional automatic face recognition system consists of the detection and the recognition part. Generally, the detection part is dominant over the other part in the estimating whole recognition rate. So, in this paper, we suggest the view-specific eigenface method as preprocessor to estimate various poses of the face in the input image. Then, we apply the Enhanced FLD Models (EFM) to the result of it, twice. Because, the EFM recognizes human face, and reduces the error of standardization effectively. To deal with view-varying problem, we build one basis vector set for each view individually. Finally, the dimensionalities of ...

• 한국통신학회논문지
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• 제31권3A호
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• pp.232-239
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• 2006

본 논문에서는 Wireless PAN(WPAN)을 위하여 IEEE 802.15.3a의 표준안으로 제안된 Ultra WideBand(UWB) Multi-Band OFDM(MB-OFDM) 시스템에서의 프리앰블 모델을 분석하교, 효율적이며 향상된 성능을 제공하는 심볼 타이밍 및 반송파 주파수 오프셋 추정 알고리즘을 적용한 후 AWGN 및 UWB 채널 환경에서 모의 실험을 통하여 심볼 타이밍 오프셋 추정 성능은 Detection Probability, False Alarm Probability, Missing Probability 및 Mean Acquisition Time으로, 반송파 주파수 오프셋 추정 성능은 MSE(Mean Square Error)로 확인한다.

• Journal of Information Processing Systems
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• 제13권4호
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• pp.1029-1042
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• 2017

A joint channel estimation and data detection technique for a multiple input multiple output (MIMO) wireless communication system is proposed. It combines the least square (LS) training based channel estimation (TBCE) scheme with sphere decoding. In this new approach, channel estimation is enhanced with the help of blind symbols, which are selected based on their correctness. The correctness is determined via sphere decoding. The performance of the new scheme is studied through simulation in terms of the bit error rate (BER). The results show that the proposed channel estimation has comparable performance and better computational complexity over the existing semi-blind channel estimation (SBCE) method.

• 사물인터넷융복합논문지
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• 제6권3호
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• pp.15-20
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• 2020

본 논문에서는 사물인터넷 서비스 개발 과정에서 발생할 수 있는 오류에 대한 분석 및 추적, 알림 시스템을 설계하였다. 오류에 대한 세부적인 부가정보(OS, Browser, Device)들을 체계적으로 분석하고 오류가 발생한 상황을 개발자가 인지하도록 하여 시스템의 신뢰성을 강화하였다. 특히 서비스 내에서 오류가 발생한 경우 개발자가 이를 인지하기 어려운 상황을 고려하여 다양한 알림 매체(Email, Slack, SMS)를 통해서 인지할 수 있도록 하였다. 설계 및 개발과정에서 사물인터넷 환경의 특성 상 여러 언어(Typescript, Swift, Android)에 대해 수용할 수 있도록 공용 인터페이스를 고안했으며, 이 인터페이스를 활용하여 모바일, 웹, 데스크톱 어플리케이션 등 여러 사물인터넷 시스템에서 발생한 오류를 수용해서 분석할 수 있다. 또한 각각의 오류 이슈를 통해 집합으로 표현함으로써 개발자가 서비스 개발 시 어떤 이슈가 있는지 쉽게 파악할 수 있으며 대시보드를 통해서 발생한 오류들을 인지할 수 있는 시각화 기능을 제공하였다.