• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 춘계학술대회논문집
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• pp.495-498
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• 2004

In the sound insulation measurements, the influence of background (extraneous) noise is often serious problem and how to reduce its effect and to improve the signal-to-noise(S/N) ratio is an important theme. As the background noise, such extraneous noises as road traffic noise and machine noise often disturb the measurement. In laboratory measurements on specimens with high sound insulation performances, even the internal noise of the measurement system can become a problem. To improve the signal-to-noise ratio and to improve the measurement accuracy, various kinds of digital signal processing techniques can be applied. In this paper, four kinds of digital signal processing techniques are applied and their effectiveness is examined by a simple sound insulation measurement.

• 제어로봇시스템학회논문지
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• 제16권10호
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• pp.969-974
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• 2010

In this paper, we propose a fault-tolerant controller for compensating measurement noise of feedback sensor. Because control systems operate via feedback sensor's signal, the measurement noise in sensor's signal results in performance degradation or even system failure. Therefore, control systems often demand on compensating measurement noise. Our controller is equipped with a compensator in order to reject or reduce the effect of measurement noise in feedback information. Our proposed method is verified via simulation and experiment for a Ball and Beam system.

• 한국초전도ㆍ저온공학회논문지
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• 제15권2호
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• pp.48-51
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• 2013

The thermal contact resistance (TCR) is one of the important components in the cryogenic systems. Especially, cryogenic measurement devices using a cryocooler can be affected by TCR because the systems have to consist of several metal components in contact with each other for heat transferring to the specimen without cryogen. Therefore, accurate measurement and understanding of TCR is necessary for the design of cryogenic measurement device using a cryocooler. The TCR occurs at the interface between metals and it can be affected by variable factors, such as roughness of metal surface, contact area and contact pressure. In this study, we designed TCR measurement system at various temperatures using a cryocooler as a heat sink and used steady state method to measure the TCR between metals. The copper is selected as a specimen in the experiment because it is widely used as a heat transfer medium in the cryogenic measurement devices. The TCR between Cu and Cu is measured for various temperatures and contact pressures. The effect of the interfacial materials on the TCR is also investigated.

• 산업경영시스템학회지
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• 제22권50호
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• pp.55-63
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• 1999

Past studies on economic control charts for controlling process means assumed that the measures of a quality characteristic do not have measurement error. In practice, however, this assumption is frequently violated. In this paper, the economic design models of three control charts(Xbar control chart, Xbar control chart with warning limits, and CUSUM control chart) for controlling process means are developed on the assumption that the measures can have measurement error. The effects of measurement error on the process control cost and design parameters of three economic control charts are examined. According to the experiments done in this study, when measurement error exists, the economic CUSUM control chart has lower process control cost in comparison with two other control charts. When measurement error becomes larger, both the sample size and the sampling interval increase while the control limits decrease.

• 제어로봇시스템학회논문지
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• 제17권4호
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• pp.299-303
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• 2011

In this paper, we propose an output feedback controller for a chain of integrators system compensating measurement noise of feedback sensor. Measurement noise makes feedback signals distorted, and results in performance degradation or even system failure. Therefore, we need to design a robust controller to accommodate the possible measurement noise in the feedback information. Our controller is equipped with a gain-scaling factor to reject or minimize the effect of measurement noise in output feedback information. We give a theoretical analysis of the controlled system and illustrate the improved control performance via an example.

• 비파괴검사학회지
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• 제27권6호
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• pp.576-581
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• 2007

Ultrasonic nonlinearity has been considered as a promising method to evaluate the micro damage of material; however, its magnitude is so small that its measurement is not easy. Especially, when we use contact PZT transducer, if the contacting pressure is not kept in constant during the measurement then there exists extraneous fluctuation in the measured nonlinearity caused by the unstable contact condition, In this paper, we developed a pneumatic control system to keep the contacting pressure of transducer in constant during the measurement and analyzed the effect of contacting pressure to the ultrasonic nonlinearity measurement As a result, we found that the pressure of transducer in our measurement system should be greater than 170 kPa to measure the ultrasonic nonlinear parameter in stable with no dependency on the contacting pressure.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2019년도 추계 학술논문 발표대회
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• pp.14-15
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• 2019

In this paper, it was tried to prove the possibility and effect of coordinate measurement by using MEP layout equipment at the construction stage, and to propose a method to improve measurement accuracy during construction. For this study, the passenger terminal site, which is a long span structure, was selected and compared with three dimensional CAD drawings and construction measurement results using MEP layout equipment for the precise construction of long-span irregular curved roof layers. As a result, it was found that it is possible to construct three-dimensional curved roof layers using MEP layout equipment through measurement and analysis.

• 대한공업교육학회지
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• 제34권2호
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• pp.346-362
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• 2009

본 연구는 광섬유센서를 이용하여 표면조도의 간이 비접촉 측정기를 개발하는데 목적이 있다. 광섬유 센서의 장점은 우수한 고속 응답성, 자기의 무영향, 제작의 편이성이다. 광섬유센서 표면조도 측정 원리는 측정물의 표면조도에 따라 반사되는 광의 세기와 기지의 표면조도 값을 일대일 대응시키는 것이다. 반사광의 세기는 센서 프로브로부터 표면까지의 거리와 표면조도에 따른 반사한계각에 따라 결정되는데 본 연구에서는 표면까지의 거리를 일정하게 하여 표면조도에 따른 반사한계각만을 가지고 표면조도가 결정되도록 측정 프로브를 제작하였다. 측정 시스템은 발광부, 수광부과 신호처리부로 구성되었다. 이 실험에서 사용된 표준 측정 재료는 SM45C, STS303과 Al60이었다. 연구결과 첫째, 재료에 따른 표면조도와 센서출력의 상관관계로부터 근사표면조도식을 도출하고 임의 가공된 시료의 표면조도 측정을 통해 근사표면조도식이 유효함을 입증하였다. 둘째, 실제 제작한 간이 광섬유센서 표면조도 측정기가 유용함을 입증하였다.

• Child Health Nursing Research
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• 제6권1호
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• pp.60-68
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• 2000

The purpose of this study is to assess the effect of progressive muscle relaxation therapy on nausea, vomiting and anxiety experienced by children who were histologically diagnosed as malignancy and have received cancer chemotherapy. Twenty subjects with 10 in experimental group and 10 in control group, between the age of 7 to 12 years participated in this study. All subjects were admitted for inpatients chemotherapy at the S hospital between April to August 1998. The methods used for interventional muscle relaxation were both the 16 items of the progressive muscle relaxation therapy developed by Jacobson and the 4 items of the muscle relaxation therapy by Wolpe. The method for assessing nausea, vomiting was the Index of Nausea and Vomiting by Rhodes et al and that for anxiety was State-Trait Anxiety Inventory for Children by Spielberger. The data was analysed by repeated measures ANOVA and Scheffe test using SAS program. The results were as follows : 1. On measurement of nausea, vomiting, in the experimental group, the mean values of the second and the third measurements showed tendency to slightly decrease compared with the first measurement, but there was no statistically significance. And in the control group, there were no significant differences among first measurement, second measurement and third measurement. Also there was no significant difference in the mean values assessing nausea, vomiting between experimental and control group (F=1.33, p=0.2645). 2. The results assessing state anxiety showed, in the experimental group, progressive decrease in mean values at each measurement, while the control group showed no significant differences between the mean values of each measurement. Also there was statistically significant difference in state anxiety measurements between experimental and control group(F=4.36, p=0.05). In conclusion, muscle relaxation therapy for school-aged children with chemotherapy could not be effective to decrease nausea, vomiting, but it could be effective to decrease anxiety.

• 한국산학기술학회논문지
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• 제16권3호
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• pp.1972-1980
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• 2015

이 연구의 목적은 한국에서 2011년 3월 9일 부터 2013년 4월 3일 사이에 수행된 스마트케어 비만 관리 시범사업의 효과를 분석하는 것이었다. 연구에 등록된 212명 참여자 중에서 6개월 동안의 스마트케어 서비스 기간이 종료되는 시점까지 자가 체중 측정을 모두 완료한 147명을 최종 분석 대상자로 하였다. 평가를 위한 자가 측정 그룹은 6개월 기간의 월 평균자가 측정 빈도를 균등하게 나누어 3그룹(Low, Middle, High)으로 분류를 하였으며 평가 대상 지표는 스마트케어 시스템으로 전송된 체중과 BMI(Body Mass Index)로 하였다. 체중과 BMI의 월별 평균은 High 그룹이 Middle 과 Low 그룹보다 더 많이 감소하였으며(M5: High>Middle>Low) 통계적으로도 유의하게 차이가 있는 것으로 나타났다 (p< 0.05). 결론적으로, 체중과 BMI의 개선 효과 분석은 자가 측정 빈도 수준이 높을 때 더 개선 효과가 있는 것으로 나타났다.