• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.1022-1023
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• 2006

본 논문에서는 MATLAB/SIMULINK와 dSPACE DS1104보드를 이용하여 유도전동기의 간접백터제어 알고리즘을 구현하였다. 유도전동기의 간접벡터제어를 위한 전체 시스템 모델은 SIMULINK 그래픽 모델과 dSPACE DS1104 R&D Control 보드의 Real Time Interface(RTI)를 이용하여 구현한 후에 실험을 수행하였다. 벡터제어를 위해서 전동기 전류의 측정은 16kHz로 측정하였고, 측정된 전류를 이용하여 8Hz로 전류제어기, 4kHz로 속도제어기를 구현하였다. MATLAB과 dSPACE 보드의 컴파일러가 설계된 그래픽 모델의 C source 파일과 object 파일을 자동으로 생성시켜주기 때문에 추가적인 프로그램의 coding 없이 실제 시스템의 시뮬레이션과 실험을 동시에 수행할 수 있으며 원하는 제어성능을 얻을 수 있다.

• Journal of Conservation Science
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• v.25 no.3
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• pp.233-244
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• 2009

This study was focused on the transducer and suitable contact material for stone cultural heritage, and the correlation of direct-indirect method in rock types for scientific development and quantitative evaluation technique of the ultrasonic measurements. As a result, it was identified the transducer (UTREXTX(RX)54kHz) and contact material (rubber clay) of the type 3 were appropriate for the ultrasonic measurements of stone cultural heritage. The direct-indirect correction factors of type 3 were calculated 1.50 for granite, 1.38 for gabbro, 1.58 for quartz diorite, respectively. This result is the first study for improvement in reliability for the ultrasonic measurements, and it will contribute to establishment of the ultrasonic survey method for stone cultural heritage. Also, complementary studies considering the surface irregularity of rocks and various contact materials will carry out, and the database about correlation of direct-indirect in rock types will establish.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.11
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• pp.221-228
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• 2014

The color and shape of the tongue reflect the physiological and clinico-pathological condition of the body. Recently, various tongue image acquisition devices have been developed for accurate diagnosis based on quantitative and objective tongue features. Since a color information is essential for tongue diagnosis, the performance of an illuminator is very important for the tongue image acquisition device. In this study, we developed an indirect illumination, which is possible to improve a homogeneity of light intensities on the tongue surface, and evaluated its performances. In order to realize the indirect illumination (II), a semi-ellipsoidal solid structure (SESS) for the light reflex was located in the system, and two high-brightness white LEDs were placed for illuminating the areas under frontal camera in the SESS. The tongue surface was illuminated by reflected light from the SESS. The light homogeneity induced by three different illuminations including the II was evaluated by calculating coefficient of variation (CV) of illuminance of five regions. The II showed less than 0.01 of CV and the direct illumination (DI) and the direct illumination with a light diffusion plate (DILDP) showed 0.16 and 0.13, respectively. The reflexed pixel ratios of tongue phantom images show 5.76%, 4.22%, 1.79% for the DI, the DILDP and the II, respectively. The homogeneity of a tongue phantom was evaluated by calculating CV of mean pixel values of six different tongue regions, and showed less than 0.06 in the II. If the II technique apply to tongue diagnosis system, it is expected to improve diagnostic accuracy in clinic.

• Journal of radiological science and technology
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• v.27 no.4
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• pp.37-41
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• 2004

Purpose : Raise ability cultivation in presence at a sicked business by performance management estimation of device through measurement. Also Learn a technology that measure exact tube voltage, exposure time, output dose. And it is to grasp photofluorography X-ray generator existing circumstances using at hospital. Material & Method : Investigated Photofluorography X-ray generator(inside, outside each 10) of 10 university hospitals using tube voltage, exposure time, output dose measuring instrument. Result : Photofluorography device that tube voltage correctness is incongruent by examination PAE decision came out 3, and at exposure time correctness examination 2 incongruent, Also 3 that calculate coefficient of variation about exposure in repeatability examination of exposure were incongruent. Inappropriate photofluorography device is 5 outside hospital(mobile unit) and the thing in hospital was 3 in 3 kind of efficiency test. It appeared high that photofluorography device outside hospital is more incongruent than thing in hospital. Conclusion : May ready situation that can offer patient medical service of good quality by radiation exposure reduction, image quality administration, retake decrease etc. by keeping performance of Photofluorography device. Therefore, is considered that need on-time efficiency test.

• Journal of Dental Rehabilitation and Applied Science
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• v.31 no.1
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• pp.1-9
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• 2015

Purpose: The purpose of this study was to evaluate the mechanical properties of several dual-cure cements by different curing modes. Materials and Methods: One resin-modified glass ionomer cement (FujiCEM 2), two conventional dual-cure resin cements (RelyX ARC, Multilink N), and two dual-cure self-adhesive resin cements (RelyX U200, G-CEM LinkAce) were used. To evaluate the influence of the curing methods, each cements divided into four conditions (n = 20); Condition 1: self-curing for 10 minutes, Condition 2: immediate after 20 seconds light-curing, Condition 3: 24 hours after self-curing, Condition 4: 24 hours after light-curing. The compressive strength and diametral tensile strength were measured with a universal testing machine. All data were statistically analyzed using t-test, one-way ANOVA and Scheffe's test. Results: The results showed the compressive strength and diametral tensile strength after 24 hours in all curing modes were higher than immediate except RelyX ARC light-cured and Multilink N light-cured. The FujiCEM 2 showed lowest values (P < 0.05). Conclusion: The outcome was cement-depend, but there is no significant difference about compressive strength and diametral tensile strength between dual-cure self-adhesive resin cements and conventional resin cements. And this result will be used as a base line data selecting resin cement for favorable long-term prognosis.

• Journal of the Institute of Convergence Signal Processing
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• v.13 no.1
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• pp.44-49
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• 2012

The indirect-contact ECG measurement is a newly developed method for unconstrained and nonconscious measurement in daily Life. This study is the first step to reducing the large background noise appearing in indirect-contact ECG. This study built the thermal noise model of capacitively coupled active electrode which is used in indirect-contact ECG. The results show that the level of thermal noise estimated by the thermal noise model is much the same as that of actual background noise for the capacitively coupled active electrode alone. By applying the actual electrical properties of a sample cotton cloth to the thermal noise model, the theoretical level of thermal noise in the indirect-contact ECG was estimated. The results also show that the level of op-amp's intrinsic noise is so small that it can be negligible in comparison with thermal noise of resistors. The relationship between the level of thermal noise and the resistance of the bias resistor was derived, and it is the base for the further study how to choice the optimal resistance for the bias resistor.

• Research in Community and Public Health Nursing
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• v.7 no.1
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• pp.170-177
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• 1996

신체의 활력을 측정하는 혈압은 다른 어느 측정치보다 변동이 심하고 정상적으로 변할 수 있는 생리적 현상이어서 정확하게 측정하기란 쉽지 않다. 1mmHg 차이의 혈압일지라도, 특히 큰 집단일 경우, 연구목적에서 그 결과를 크게 왜곡 시킬 수 있다. (Wright & dore, 1970). 혈압 측정에는 직접적 방법과 간접적 방법이 있다. 이 중 간접적 방법은 임상분야와 연구분야에서 실제로 넓게 사용되고 있을 분만 아니라 신체로의 직접적 침투하는 방법도 아니고 가격 또한 비싸지 않다. 그러나, 간접적 측정 방법은 혈압에 영향을 끼치는 많은 요인들인 관찰자 편견, 확장기음의 청취음 선택, 관찰자와 환자 사이의 상호관계 때문에 방법론적으로 문제제기가 되기도 한다. 이런 요인을 최소화하기 위하여 가장 타당도가 높은 측정도구의 선택이 필요하다. 도시지역의(Ease Baltimore) 고혈압을 가진 젊은 흑인 남성(연령별/성별/종속별/거주지역) 중 수축기 혈압이 140mmHg 이고 확장기 혈압이 90mmHg인 사람, 또는 확장기 혈압이 90mmHg인 사람, 또는 혈압하강제를 먹고 있는 사람 200명을 대상으로 훈련받은 community health worker(CHW)에 의해 Random-Zero Sphygmdmanometer(RZS)와 Digit Automatic Device(DAD)로 혈압을 측정하게 하였다. 이 중 36명을 무작위 추출하여 regular Mercury Sphygmdmanometer (RMS)로 혈압을 측정하게 했다. Bland 와 Altman에 의해 제기된 두측정값의 차이에 대한 scattergram(일치도 검증법)과 AAMI(Association for the Advancement of Medical Instrument) 기준, BHS 기준, Central Tendency와 숫자선호도로 검증되었다. AAMI와 BHS 기준에 의하면 확장기 혈압에서 RZS와 DAD의 일치도와 평균을 중심으로 더 넓게 퍼져있어 낮은 일치도를 보였으며 또 DAD와 RMS의 혈압치는 숫자 선호도를 볼 수 있는데 특히 RMS는 더 뚜렷하게 나타났는데 확장기 혈압의 최빈치(30.6)는 100mmHg이었다. 혈압치들이 가장 가까이 "0"점으로 치우쳐져 있었다. RZS의 Central tendency는 DAD와 RMS보다 뚜렷하였다. 결론적으로 RZS는 이 연구목적으로 가장 적절함을 보여준다.

• Bulletin of the Korean Space Science Society
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• 2003.10a
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• pp.23-23
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• 2003

천체의 거리는 다양한안 방법을 사용하여 직접 혹 간접적으로 측정되어왔다. 특히 우주배경복사를 측정하는 인공위성 관측의 정밀도가 혁명적으로 향상됨에 따라 우주의 나이는 수 % 이내의 정밀도로 결정할 수 있는 수준으로 발전하였다. 우주의 규모가 구체적으로 정의되는 가운데 우주의 절대적인 크기를 제시하기 위하여 천체의 거리를 측정하는데 사용되는 표준등불로 세페이드 변광성 이외에 식쌍성이 새롭게 대두되었다. 이 논문에서는 식쌍성이 거리척도의 표준등불이 될 수 잇는지 검증하기 위하여 광도곡선과 시선속도곡선이 잘 알려진 알골형 쌍성 식쌍성 RY Aqr, RX Gem, RS Vul을 선정하여 거리를 산출하였다. 별을 선정한 기준은 2색 이상의 광도곡선이 발표되고, 이중 분광쌍성으로 시선속도곡선이 각 성분별로 잘 관측되어 발표되고, IUE 관측 자료가 있는 알골형 쌍성이다. 거리 산출과정에서 간접적으로 유추하여 얻는 인자를 줄이기 위하여, 광도곡선으로부터 별의 상대적인 크기를 구하고, 시선속도곡선으로부터 공전궤도의 장반경을 구하고, 별의 에너지 분포 곡선으로부터 별의 온도를 측정하였다. 위 3종류의 관측 결과를 종합하여 식쌍성의 물리적 인자와 거리를 구하였다. 이와 같은 방법으로 구한 거리는 히파크러스를 이용하여 관측한 시차와 비교하였다.

• Journal of KSNVE
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• v.6 no.6
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• pp.727-733
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• 1996

Machines installed in various structures emit airborne sound and structureborne sound and are major source of noise and vibration. Especially when machines are installed upon a flexible foundation, most of noise and vibration are due to transmission of structureborne sound. Therefore, characterization and measurement of structureborne sound source level are necessary for controlling noise and vibration. But structureborne sound from vibrating machine is strongly coupled to the supportingstructure. This paper proposes the method of estimating the supporting sturcture's dynamic character- istic and structureborne sound source level for machine installed system without separating the machine, resilient mount and foundation.

• Journal of the Korean Chemical Society
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• v.33 no.4
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• pp.406-412
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• 1989

Indirect photometric detection of aliphatic compounds such as alcohols, ketones and esters was investigated in high-performance liquid chromatography, These samples possessing nonchromophore or weak chromophore could be indirectly detected by a UV detector with addition of UV absorbing, p-chlorophenol or p-nitrophenol in mobile phase as detection reagent, and submicrogram detection limits were achieved. Some mixtures of samples were also able to be separated and quantitated with good resolution and comparatively high sensitivity under optimum conditions.