• Asian Journal for Public Opinion Research
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• 제1권4호
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• pp.234-248
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• 2014

A telephone survey was conducted in a metropolitan city in 2012 to examine people's credibility ratings of different media outlets, in particular, Weibo - one of the most popular social media platforms in China. Our findings suggest: First, people place more trust in traditional news media than in online sources by a significant margin. Second, demographic influences on media trust seem to be minimal. Only age and gender were related to some credibility measures. Third, Weibo use was not related to one's credibility perception toward traditional media but interestingly, Weibo use showed different impacts on people's evaluation of Weibo's credibility. Commenting frequency was negatively related to one's trust in Weibo, while retweeting frequency was positively related to one's trust in Weibo.

• 대한가정학회지
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• 제24권2호
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• pp.93-112
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• 1986

The purpose of this study is to clarify which some factors among the socio-demographic factors have effect on the housewives behavior on how to buy small electric appliances and how to use them. The questionnaires were distributed in July 1985 to 491 housewives in Seoul. Satistical methods as percentage, frequency, arithmetic mean, chi-square test, t-test and F-test were used for data analysis. RESULTS : 1) The average rate of possessing the automatic rice cooker is 87.8%, the electric frypan is 81.0%, the toaster is 36.9% and the blender is 86.9%. 2. Generally the frequency of use were low. 3) Generally their knowledge on small electric appliances is low. 4) The ability of management in blender was influenced by age, education and in automatic rice cooker was influenced by only education.

• 한국군사과학기술학회지
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• 제10권3호
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• pp.129-138
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• 2007

Recently, Direction Finding(DF) System is using switching DF algorithm to reduce system-weight by eliminating RF cable as much as possible. Also, Correlation Vector Direction Finding(CVDF) algorithms is being used for Fast Direction finding in tactical environment. In this paper, I will give you burst error elimination algorithms and compare the performance in case we use switching CVDF algorithm. Although antenna array is not working, we will successfully perform direction finding when we use this burst error elimination algorithms. Also, we will be completely capable of DF mission despite of meeting the unwanted situation that the monitoring signal disappear in case we use Switching Direction Finding algorithms. That situation frequently occurs under the Frequency Hopping signal circumstances.

• 한국컴퓨터산업학회논문지
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• 제2권8호
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• pp.1063-1068
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• 2001

본 논문에서는 DDS 기법을 사용하여 광학음향효과 발생기의 고 정밀 6채널 DSB 변조기를 설계를 하였다. 또한 IEEE-488 인터페이스를 사용하여 다른 계측기와의 연동이 가능하도록 구성하였으며, DDS와 DAC의 제어를 위한 디바이스 드라이버를 80C51계열의 마이크로프로세서 어셈블러를 이용하여 작성하였다. 이러한 결과로 고 정밀 6채널 DSB 변조기는 기존의 변조기에 비해 주파수 가변 범위, 분해능, 스위칭 시간 등의 중요한 특성들이 개선되었으며, 이로 인해 정밀한 주파수 합성 시스템으로 사용이 가능할 것이라 예측된다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2007년도 하계학술대회 논문집
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• pp.428-430
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• 2007

Converter that is dc source equipment source's phase by reference control function that detect source's phase because should be done compulsorily use. Source's phase detect method there be method that use source's ac voltage directly by signal, and use methods that voltage detects status by PLL method and so on via point that '0' becomes usually. All above methods to detect phase are using, wrong action of phase detector converter's ailment or converter of burn can. Ths paper compares and examined usable phase detection method in source's frequency fluctuation presuming source's frequency using observer.

• 한국전자파학회논문지
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• 제30권2호
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• pp.152-159
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• 2019

도플러 레이다는 단일 주파수의 정현파를 이용하므로 움직이는 이동체의 속도만을 측정할 수 있다고 알려져 있다. 일반적으로 이동체의 거리를 측정하기 위해서는 FMCW 레이다나 펄스 레이다를 이용하여야 하는데, 이 경우 하드웨어 구성 및 신호처리가 복잡할 뿐만 아니라, 주파수 대역폭을 넓게 사용하기 때문에 24 GHz나 77 GHz 대역의 밀리미터파를 사용할 수밖에 없어 가격이 비싸다. 따라서 가격이 저렴한 도플러 레이다에서 다중 톤 주파수를 이용하여 이동체의 속도 외에 거리까지 센싱하는 연구가 시작되고 있다. 이에 본 연구에서는 2.4 GHz 도플러 레이다에 내장된 PLL만을 이용한 주파수 조정만으로도 이동체의 거리 센싱이 가능함을 보인다. 특히, 기존에 제안된 DC 기반의 거리 계산에서 필요한 DC 정보를 제거하고, 교류결합된 AC 정보만을 이용하여 거리를 센싱할 수 있음을 보인다. 제안된 기술은 2.4 GHz 대역의 이동체 식별용 특정소출력 무선기기 기술기준을 만족하므로 45 dBm EIRP 출력을 이용하여 이동체 거리 센싱이 필요한 다양한 응용이 가능하다.

• 한국안전학회지
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• 제31권1호
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• pp.1-6
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• 2016

Severity and frequency of industrial accidents are typically used to assess the "absolute" risk associated with the industrial machines and devices ("items") which are subject to safety certification or self-declaration of conformity. However, the "relative" risk associated with a particular item can further be assessed based on unit severity and unit frequency where the total number of item in use is taken into account. This study first attempts to estimate the total number of each item in use which was recently selected for safety certification or self-declaration of conformity. The appropriateness of such selection is recapitulated based on the relative risk involved. Analysis results indicate that depending on items, the relative risk is differentiated from the absolute risk. Recent selection of items for safety certification or self-declaration of conformity is then revisited for its validity. The relative risk based on unit severity and unit frequency of industrial accidents, together with the absolute risk, may be used to further categorize items for safety certification or self-declaration of conformity in the future.

• 품질경영학회지
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• 제47권3호
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• pp.597-613
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• 2019

Purpose: The purpose of this study is to analyze the trend of quality research by analyzing the entire JKSQM(Journal of the Korean Society for Quality Management). Methods: This study is to analyze the frequency of words used in the abstract of the all JKSQM by applying the text mining processing. We use wordcrowd among text mining techniques. Results: 22 words of high frequency were presented in the abstract of the paper published in the JKSQM for 42 years. The frequency of words was shown on a 10 year basis, and the four important words were plotted on a change graph for each Vol. Frequent words of each Vol. are added in the appendix. Conclusion: The main research results are as follows. First, there has been no significant change in research trends over the last 40 years. Second, the early SQC words have been widely used, and since 1990, many words such as service-oriented words have been used, indicating a change in the times. Third, the use of the words of the 4th industrial revolution since 2010 is weak. In the above analysis, the trend of quality research in Korea is within the quality category and can be considered conservative. Now, it is expected that everything will be changed in the period of the 4th Industrial Revolution, and it is time to study the direction of quality in Korea.

• 대한의용생체공학회:의공학회지
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• 제31권6호
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• pp.417-426
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• 2010

We present a speech processing strategy incorporating instantaneous frequency (IF) encoding for the enhancement of melody recognition performance of cochlear implants. For the IF extraction from incoming sound, we propose the use of a Teager energy operator (TEO), which is advantageous for its lower computational load. From time-frequency analysis, we verified that the TEO-based method provides proper IF encoding of input sound, which is crucial for melody recognition. Similar benefit could be obtained also from the use of a Hilbert transform (HT), but much higher computational cost was required. The melody recognition performance of the proposed speech processing strategy was compared with those of a conventional strategy using envelope extraction, and the HT-based IF encoding. Hearing tests on normal subjects were performed using acoustic simulation and a musical contour identification task. Insignificant difference in melody recognition performance was observed between the TEO-based and HT-based IF encodings, and both were superior to the conventional strategy. However, the TEO-based strategy was advantageous considering that it was approximately 35% faster than the HT-based strategy.

• 한국식품영양과학회지
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• 제28권1호
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• pp.246-256
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• 1999

This study was undertaken to investigate the perception and the consumption behavior for the meats in Koreans. The subjects were 491 Koreans including the ones residing in New Zealand. Most of subjects answered the meats are used for supper time. The frequency of the meats intake was affected by education and monthly income level. 69.2% of the subjects had positive response such as increased stamina and fulled stomach for psychological state after the meats intake. The use of meats recently revealed that 48% of the subjects have decreased its consumption. The main reasons diminished the use of meats were for the good health and economic state. Women were found to avoid the meats fat to a greater degree than men. The kinds of the meat used frequently were beef, pork and chicken. The younger tended to higher the frequency of the processed meats intake than the older. According to 3 level of BMI of the subjects, there were significant differences in the amount of the meat intake and perception for necessity of the meat. This study showed that the higher the preference for meat, the education and the monthly income level, the more the meat intake frequency. There were not significant differences between Koreans residing in domestic and New Zealand except the dog meat in the perception and consumption of the meat.