• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2013년도 춘계학술대회 논문집
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• pp.714-714
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• 2013

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2012년도 추계학술대회 논문집
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• pp.137-137
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• 2012

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2012년도 추계학술대회 논문집
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• pp.138-138
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• 2012

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2013년도 추계학술대회 논문집
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• pp.68-71
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• 2013

• 한국전자파학회논문지
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• 제25권11호
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• pp.1164-1171
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• 2014

Bulk Current Injection(BCI) 테스트는 전류 주입 프로브를 사용하여 측정하고자 하는 Integrated Circuit(IC)에 전류를 주입하여 Electromagnetic Compatibility(EMC) 규격을 충족시키는지 시험하는 방법이다. 본 논문에서는 국제전기표준회의에서 제정한 IEC 62132-part 3에서 규정하는 BCI 테스트의 전류 주입 프로브를 대체하여, RF 잡음을 인가할 수 있는 마이크로스트립 커플러 구조를 제안하였다. 전통적으로 높은 전원 전압을 사용하는 자동차 IC 테스트에 사용되어 오던 BCI 전류 주입 프로브를 저 전압을 사용하는 저 전력 IC의 테스트에 사용할 수 있는 마이크로스트립 커플러 구조를 개발하여 그 유효성을 100 MHz에서부터 1,000 MHz까지의 주파수 영역에서 비교 및 검증하였다. 또한, 주파수에 따라 전류 주입 프로브를 통한 RF 잡음 인가와 마이크로스트립 커플러 구조를 통한 RF 잡음 인가 시 규정한 노이즈를 얻는데 필요한 전력을 dBm 단위로 측정, 비교하여 마이크로스트립 커플러 구조를 이용한 경우에 더 적은 전력으로 필요한 RF 잡음을 주입할 수 있음을 확인하였다.

• Corrosion Science and Technology
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• 제12권2호
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• pp.93-101
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• 2013

The object of this work is to establish an electrochemical noise(EN) measurement technique combined with a direct current potential drop(DCPD) method for monitoring of localized corrosion cracking of nickel-based alloy, and to analyze its mechanism. The electrochemical current and potential noises were measured under various conditions of applied stress to a compact tension specimen in a simulated primary water chemistry of a pressurized water reactor. The amplitude and frequency of the EN signals were evaluated in both time and frequency domains based on a shot noise theory, and then quantitatively analyzed using statistical Weibull distribution function. From the spectral analysis, the effect of the current application in DCPD was found to be effectively excluded from the EN signals generated from the localized corrosion cracking. With the aid of a microstructural analysis, the relationship between EN signals and the localized corrosion cracking mechanism was investigated by comparing the shape parameter of Weibull distribution of a mean time-to-failure.

• JSTS:Journal of Semiconductor Technology and Science
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• 제7권1호
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• pp.11-19
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• 2007

This paper presents two novel compensation circuits for leakage current and power supply noise (PSN) in phase locked loop (PLL) using a nanometer CMOS technology. The leakage compensation circuit reduces the leakage current of the charge pump circuit which becomes more serious problem due to the thin gate oxide and small threshold voltage in nanometer CMOS technology and the PSN compensation circuit decreases the effect of power supply variation on the output frequency of VCO. The PLL design is based on a 32nm predictive CMOS technology and uses a 0.9V power supply voltage. The simulation results show that the proposed PLL achieves a 88% jitter reduction at 440MHz output frequency compared to the PLL without leakage compensator and its output frequency drift is little to 20% power supply voltage variations. The PLL has an output frequency range of $40M{\sim}725MHz$ with a multiplication range of 11023, and the RMS and peak-to-peak jitter are 5ps and 42.7ps, respectively.

• 전력전자학회논문지
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• 제27권2호
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• pp.85-91
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• 2022

This study proposes a high efficiency bridgeless Power Factor Correction (PFC) converter with improved common mode noise characteristics. Conventional PFC has limitations due to low efficiency and enlarged heat sink from considerable conduction loss of bridge diode. By applying a Common Mode (CM) coupled inductor, the proposed bridgeless PFC converter generates less conduction loss as only a small magnetizing current of the CM coupled inductor flows through the input diode, thereby reducing or removing heat sink. The input diode is alternately conducted every half cycle of 60 Hz AC input voltage while a negative node of AC input voltage is always connected to the ground, thus improving common mode noise characteristics. With the aim to improve switching loss and reverse recovery of output diode, the proposed circuit employs Critical Conduction Mode (CrM) operation and it features a simple Zero Current Detection (ZCD) circuit for the CrM. In addition, the input current sensing is possible with the shunt resistor instead of the expensive current sensor. Experimental results through 480 W prototype are presented to verify the validity of the proposed circuit.

• Journal of Preventive Medicine and Public Health
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• 제29권1호
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• pp.113-131
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• 1996

This study was carried out to evaluate the relations among workers' general characteristics, work-related behaviors and health related behaviors in a steel industry with 1,134 workers in Pohang. The results were as follows; 1. The mean age of workers was 50 years old and working duration was 15 years and over. Most of them were married(94.5%) and had studied beyond high school (53.0%). They performed three shift work and most of them(63.0%) had experienced industial accidents. The frequency of noise and dust exposure was defined by a minimum of 6 hours per day, and workers complained about noise exposure(62.9%) and dust(55.6%). There were current smokers(67.7%), current drinkers(74.3%) and current exercising workers(32.3%) in the industry. The number of cigarette consumption in current drinkers was significantly high $(13.6{\pm}8.4\;pieces/day)$ and the alcohol consumption in current smokers was significantly high$(104.5{\pm}113.5\;g/wk)$. And the number of cigarette consumption of exercisers was significantly low and the alcohol consumption of exercisers was higher than non-exercisers. 3. The ratio of current smokers on frequent noise in exposed workers versus non-exposed workers was not significantly high but the current drinkers in frequent noise and dust exposed workers was significantly higher than non-exposed. 4. The normal levels of SGOT workers in non-smokers were significantly higher than in current smokers, and the normal levels of LFT (SGOT, SGPT, $\gamma-GTP$ workers in nondrinkers were significantly high. The normal levels of SBP and DBP workers in current smokers were not significantly high but were significantly high in non-drinkers. 5. The ratio of current smokers in voters unsatisfied with their job and working condition was higher than non-smokers, but the ratio of current drinkers in workers satisfied with their job and working condition were higher. 6. The significant factors for SGOT and $\gamma-GTP$ were age, the drinking amount and BMI. But the only significant factor for r-GTP was BMI. The significant factors for DBP were age, the alcohol consumption and BMI. And the significant factors for SBP were age, BMI.

• 말소리와 음성과학
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• 제3권4호
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• pp.117-124
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• 2011

This study investigated the effects of the types of noise and signal to noise ratios (SNRs) on speech intelligibility of an adult with dysartrhia. Speech intelligibility was judged by 48 naive listeners using a word transcription task. Repeated measures design was used with the types of noise (multi-talker babble/environmental noise) and SNRs (0, +10 dB, +20 dB) as within-subject factors. The dependent measure was the percentage of correctly transcribed words. Results revealed that two main effects were statistically significant. Listeners performed significantly worse in the multi-talker babble condition than the environmental noise condition, and they performed significantly better at higher levels of SNRs. The current results suggested that the multi-talker babble and lower level of SNRs decreased the speech intelligibility of adults with dysarthria, and speech-language pathologists should consider environmental factors such as the types of noise and SNRs in evaluating speech intelligibility of adults with dysarthria.