• Journal of the Institute of Electronics Engineers of Korea SD
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• v.40 no.4
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• pp.34-41
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• 2003

A new technique for detecting parametric faults in mixed signal circuits is proposed Pseudo-random sequence from linear feedback shift register(LFSR) is fed to circuit-under-test (CUT) as stimulus and wavelets are used to compact the transient response under this stimulus into a small number of signature. Wavelet based scheme decomposes the transient response into a number of signal in different frequency bands. Each decomposed signal is compacted into a signature using digital integrator. The digital pulses from LFSR, owing to its pseudo-randomness property, are almost uniform in frequency domain, which generates multi-frequency response when passed through CUT. The effectiveness of this technique is demonstrated in our experimental results.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.2
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• pp.43-52
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• 2012

This paper presents and analyzes laboratory test results of Interference Cancellation Digital On Channel Regenerative Repeater(IC-DOCR) to broadcast digital television signals in the Advanced Television Systems Committee(ATSC) transmission systems using single frequency networks(SFN). IC-DOCR laboratory test is classified to receiver test, transmitter test, and feedback interference cancellation test. The receiver part includes random noise, single echo, multi-path ensembles, and adjacent channel interference test. The transmitter part includes out-of channel emission, equality of transmitting signal, and phase noise test. By the laboratory test, the receiver part of the IC-DOCR eliminates 28dB of feedback signal higher than the received signal and has 17.8dB at TOV(Threshold Of Visibility) under random noise environment. Also, the transmitter part satisfies the specification of US FCC(Federal Communications Commission) as well as maintains good output signal quality for guaranteeing more than SNR 30dB.

• Proceedings of the IEEK Conference
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• 1998.06a
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• pp.791-794
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• 1998

칩의 집적도에 비레한 테스트 문제의 원초적인 해결은 VHDL등으로 기술되는 상위기능 수준에서부터 고려되어야 한다. 본 논문에서는 상위수준의 기능정보에서 테스트점을 삽입 제어흐름(control flow)를 변경하여 고집적 회로의 고장점검도를 증진시키는 기술을 소개한다. while 푸프와 if-then-else 제어문에 AND 및 OR 타입 등의 테스점을 삽입하여 내부 신호의 조정도를 최적화시킨다. 랜덤패턴 시뮬레이션을 벤치마크 회로에 적용 각 변수의 조정도를 산출하여 테스트점의 종류 및 삽입할 위치를 결정하였다. 본 연구에서 제안하는 상대적 랜덤도에 의하여 VHDL 코드에 단일 테스트점을 삽입 합성한 결과 게이트 수준회로에 대한 고장점검도가 최대 30% 까지 증진됨을 알 수 있었다.

• Journal of Broadcast Engineering
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• v.10 no.2
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• pp.210-220
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• 2005

This paper presents and analyzes laboratory test results of Equalization Digital On-Channel Repeater (EDOCR) using ATSC(Advanced Television Systems Committee) terrestrial digital TV broadcasting system. The EDOCR laboratory test, which is done at CRC(Communications Research Centre) Canada, is classified to receiver test, transmitter test, and synchronization test between transmission and reception frequencies. The receiver part includes feedback signal, random noise, single echo, multi-path ensemble, and NTSC/DTV interference test. The transmitter part includes out-of channel emission, quality of transmitting signal, and phase noise test. By the field test results, the receiver part of the EDOCR eliminates average 5.5 dB of feedback or single echo signal in range of 0 to 11 ${\mu}s$ and has average 18.6 dB at TOV(Threshold of Visibility) under random noise environment. Also, the transmitter part of the EDOCR satisfies the specification of US FCC(Federal Communications Commission), and frequency difference between transmitter and receiver is zero.

• Journal of Broadcast Engineering
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• v.15 no.1
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• pp.29-39
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• 2010

This paper presents and analyzes laboratory test results of distributed translator (DTxR) for distributed frequency network (DFN) in the ATSC (Advanced Television Systems Committee) terrestrial digital TV broadcasting system. The DTxR laboratory test is classified to receiving part test and transmitting part test. The receiving part test includes dynamic range, random noise, single echo, and adjacent channel interference. The transmitting part test includes quality of output signal (out-of channel emission, quality of transmitting signal, and phase noise), frequency synchronization among output signals, and TxID (Transmitter Identification) signal's affect to the legacy receiver. By the laboratory test results, the receiving part of DTxR eliminates average -2.5 dB of single echo and has average 17.5 dB at TOV (Threshold of Visibility) under random noise environment. In addition, the transmitting part of DTxR satisfies the specification of US FCC (Federal Communications Commission), and frequency difference among DTxR output signals is less than 0.001 Hz.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2000.11b
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• pp.37-41
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• 2000

본 연구는 디지털 오디오 데이터의 전송 및 배포과정에서 필요한 워터마크기술에 관한 것이 다. 삽입 방법은 일종의 확산 스펙트럼 방식으로 특정 Key 에 의해 생성된 의사난수신호를 인간의 가청주파수모델과 오디오 신호의 특성에 따라 조작 한 후 삽입하게 된다. 이러한 주파수 조작은 데이터 은닉의 inaudibility 와 audio compression에의 견고성을 위하여 필요 한 사항이다. 워터마크 추출과정에서는 일정한 길이의 오디오 신호 앙상블 평균을 구하고, 이 신호와 워터마크와의 상호 상관함수를 구하여 워터마크의 삽입 유무를 판단하게 된다. 알고리즘의 테스트 결과 본 기술은 오디오 압축 및 오디오 조작에 강인한 것으로 나타났다.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.49 no.5
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• pp.30-36
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• 2012

A new BIST(Built-In Self-Test) scheme to test ADC(Analog-to-Digital Converter) with a transition detector is proposed. The proposed BIST is able to replaces histogram method, the most popular approach in static testing of ADC. With a ramp signal as an input test stimulus, the proposed BIST calculates ADC's static parameters such as offset, gain, INL(Integral Non-Linearity) and DNL(Differential Non-Linearity). The three detectors in the proposed BIST can deal with a transient zone problem, a phenomenon due to random noise in real test environments and are cost efficient at various acceptable ranges determined as a test spec. The simulation results validate that our method performs accurate static test and show the reduction of the hardware overhead.

• Journal of the Institute of Convergence Signal Processing
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• v.6 no.4
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• pp.206-211
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• 2005

We describe the design for a correlator and an access code generator in bluetooth system. These are used for a connection setting, a packet decision and a clock synchronization between Bluetooth units. The correlator consists of two blocks; carry save adder based on Wallace tree and threshold-value decision block. It determines on an useful packet and clock-synchronization for input signal of 1.0Mbps through the sliding-window correlating. The access-code generator also consists of two blocks; BCH(Bose-Chadhuri-Hocquenghem) cyclic encoder and control block. It generates the access-codes according to four steps' generation process based on Bluetooth standard. In order to solve synchronization problem, we make use of any memory as a pseudo random sequence. The proposed correlator and access-code generator were coded with VHDL. An FPGA Implementation of these modules and the simulation results are proved by Xilinx chip. The critical delay and correlative margin based on synthesis show the 4.689ns and the allowable correlation-error up to 7-bit.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.3
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• pp.661-668
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• 2018

Biomedical signals using skin resistance have different characteristics according to stress diseases. Biological diagnostic devices for diagnosing stress diseases have been developed by using these characteristics, and devices have been developed so that the signals measured by the skin storage meter can be easily analyzed. Experts in the field will look directly at the output signal to determine the likelihood of any stress disorder. However, it is very difficult for a person to accurately determine whether a person to be measured has a stress disorder by analyzing a bio-signal measured by each person to be measured, and the result of the judgment is very likely to be wrong. In order to solve these problems, we implemented the function of determining the signal of a stress disorder by using the machine learning technique. SVM was used as a classification method in consideration of low computing ability of measurement equipment. Training data and test data were randomly generated for each disease using error range 5 based on 13 diseases. Simulation results showed more than 90% decision accuracy. In the future, if the measurement equipment is actually applied to the patients, we can retrain the classifier with the newly generated data.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.10 no.4
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• pp.315-320
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• 2016

In this study, we developed a response time measuring apparatus for fencing which can use fencing athlete's own electric sword and connectors. The measuring apparatus designed to be connected to upper back of dummy body and it's position can be changed by spinning itself. And it operates like a closed circuit composed of dummy helmet, the apparatus, reel signal connection, connector and electric sword of athlete. This measuring apparatus can provide response time to athlete immediately which response time is measured from the time of indicating random signal of light and sound to the time of attacking dummy by athlete. we carried out pilot test for couch and athlete of national fencing team and could validate availability of this system.