• 센서학회지
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• 제18권4호
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• pp.294-300
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• 2009

Cardiopulmonary resuscitation(CPR) is performed by artificial ventilation and thoracic compression for the patient under emergent situation to maintain at least the minimum level of respiration and blood circulation for life survival. Quality of the pre-hospital CPR not only significantly affects the patient's survival rate but also minimizes side effects caused by CPR. Good quality CPR requires monitoring respiration, however, traditional respiratory air flow transducers cannot be used because the transducer elements are located on the flow axis. The present study developed a new technique with no physical object on the flow stream but enabling the air flow measurement and easily incorporated with the CPR devices. A turbulence chamber was formed in the middle of the respiratory tube by locally enlarging the cross-sectional area where the flow related turbulence was generated inducing energy loss which was in turn converted into pressure difference. The turbulence chamber was simply an empty enlarged air space, thus no physical object was placed on the flow stream, but still the flow rate could be evaluated. Both inspiratory and expiratory flows were obtained with symmetric measurement characteristics. Quadratic curve fitting provided excellent calibration formula with a correlation coefficient>0.999 (P<0.0001) and the mean relative error<1 %. The present results can be usefully applied to accurately monitor the air flow rate during CPR.

• 대한기계학회논문집A
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• 제41권11호
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• pp.1047-1053
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• 2017

무인지상차량의 자율주행을 위한 핵심센서로 사용되는 2D/3D 라이다(LIDAR) 센서에서 제공되는 거리 데이터는 지면 모델링 및 장애물 검출을 위해 효과적으로 활용되지만, 도로의 경계가 모호한 환경 등에서는 주행가능영역에 대한 분석이 어렵게 된다. 본 논문에서는 라이다의 반사율 특성을 이용하여 무인차량의 주행 가능한 영역에 대한 후보 영역을 추가로 분석함으로써 보다 효과적으로 주행가능영역을 검출할 수 있는 기법을 제안하였다. 3D LIDAR의 반사율을 보정하고 무인차량 전방 영역의 반사율에 대한 학습을 통해 주행가능 후보영역을 검출하였으며, 무인차량 실제 운용환경에서의 실험을 통해 후보영역 검출 결과를 검증하였다.

• 한국항공우주학회지
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• 제40권2호
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• pp.165-170
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• 2012

본 논문에서는 비행체 날개의 조종면에 작용하는 힌지 모멘트 분석을 위한 시험적 방법 및 결과를 수록하였다. 비행 공력 하중에 의하여 조종면에 힌지 모멘트가 작용할 경우, 조종면 구동장치에서 측정된 각도와 실제 조종면의 각도 사이에 탄성 변형에 의한 차이가 발생하며, 이 차이를 측정하여 힌지 모멘트로 환산할 수 있다. 이를 위하여 지상에서 조종면 구동장치 시스템의 비틀림 강성을 측정하기 위한 정하중 시험 및 조종면 각도 센서 교정시험을 수행하였다. 이 결과를 이용하여 비행 중 작용하는 힌지 모멘트를 계산할 수 있으며, 또한 체결부위의 미끄러짐 및 백래시 등의 기계적 오차도 예측할 수 있다. 실제 비행시험 결과를 이용하여 조종면에 작용한 힌지 모멘트를 계산한 결과와 수치 해석 결과의 비교를 통하여, 제시된 하중 측정 방법의 타당성을 입증하였다.

• Journal of Biosystems Engineering
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• 제40권3호
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• pp.296-304
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• 2015

Purpose: The balance between miscanthus production and its cost effectiveness depends greatly on its moisture content during post processing. The objective of this research was to measure the moisture content using a non-destructive and non-contact methodology for in situ applications. Methods: The moisture content of comminuted miscanthus was controlled using a closed chamber, a humidifier, a precision weigher, and a real-time monitoring software developed in this research. A CMOS sensor equipped with $50{\times}$ magnifier lens was used to capture magnified images of the conditioned materials with moisture content level from 5 to 30%. The hypothesis is that when light is incident on the comminuted particles in an inclined manner, higher moisture content results in light being reflected with a higher intensity. Results: A linear regression analysis for an initiative hypothesis based on general histogram analysis yielded insufficient correlations with low significance level (<0.31) for the determination coefficient. A significant relationship (94% confidence level) was determined at level 108 in a reverse accumulative histogram proposed based on a revised hypothesis. A linear regression model with the value at level 108 in the reverse accumulative histogram for a magnified image as the independent variable and the moisture content of comminuted miscanthus as the dependent variable was proposed as the estimation model. The calibrated linear regression model with a slope of 92.054 and an offset of 32.752 yielded 0.94 for the determination coefficient (RMSE = 0.2%). The validation test showed a significant relationship at the 74% confidence level with RMSE 6.4% (n = 36). Conclusions: To compensate the inconsistent significance between calibration and validation, an estimation model robust against various systematic interferences is necessary. The economic efficiency of miscanthus, which is a promising energy resource, can be improved by the real-time measurement of its crucial material properties.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 2004년도 한국우주과학회보 제13권2호
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• pp.372-375
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• 2004

The UV radiometer payload was launched successfully from the west coastal area of Korea Peninsula aboard KSR-III on 28, Nov 2002. KSR-III was the Korean third generation sounding rocket and was developed as intermediate step to larger space launch vehicle with liquid propulsion engine system. UV radiometer onboard KSR-III consists of UV and visible band optical phototubes to measure the direct solar attenuation during rocket ascending phase. For UV detection, 4 channel of sensors were installed in electronics payload section and each channel has 255, 290, 310nm center wavelengths, respectively. 450nm channel was used as reference for correction of the rocket attitude during the flight. Transmission characteristics of all channels were calibrated precisely prior to the flight test at the Optical Lab. in KARI (Korea Aerospace Research Institute). During a total of 231s flight time, the onboard data telemetered to the ground station in real time. The ozone column density was calculated by this telemetry raw data. From the calculated column density, the vertical ozone profile over Korea Peninsula was obtained with sensor calibration data. Our results had reasonable agreements compared with various observations such as ground Umkhr measurement at Yonsei site, ozonesonde at Pohang site, and satellite measurements of HALOE and POAM. The sensitivity analysis of retrieval algorithm for parameters was performed and it was provided that significant error sources of the retrieval algorithm.

• Environmental Engineering Research
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• 제22권2호
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• pp.186-192
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• 2017

The carbon paste electrode (CPE) was modified with the pristine bentonite and hybrid material (HDTMA-modified bentonite). The modified-CPEs are then employed as working electrode in an electrochemical detection of As(V) from aqueous solutions using the cyclic voltammetric measurements. Cyclic voltammograms revealed that As(V) showed reversible behavior onto the working electrode. The hybrid material-modified carbon paste electrode showed significantly enhanced electrochemical signal which was then utilized in the low level detection of As(V). Moreover, the studies were conducted at neutral pH conditions. The electrochemical studies were conducted with scan rates (20 to 200 mV/s) to deduce the mechanism of redox processes involved at the electrode surface. The anodic current was linearly increased, increasing the concentration of As(V) from 5.0 to $35.0{\mu}g/g$ using the hybrid material-modified electrode. This provided fairly a good calibration line for As(V) detection. The presence of varied concentrations of As(III) in the determination of total arsenic was studied. The influence of several cations and anions viz., Cu(II), Mn(II), Zn(II), Pb(II), Cd(II), Fe(III), $Cl^-$, $NO_3{^-}$, $PO_4{^{3-}}$, EDTA and glycine in the detection of As(V) from aqueous solution was also studied. Further, in an attempt to simulate the real matrix analysis, the tap water sample was spiked with As(V) and subjected for As(V) detection using the modified-CPE.

• 한국해양공학회지
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• 제29권2호
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• pp.169-174
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• 2015

This paper addresses experimental methodologies to measure the temperature-dependent thermal conductivity of the insulation materials popularly used for LNG cargo containment systems. The measurement techniques considered in this paper are the guarded hot plate (GHP) method and heat flow method (HFM). The former is based on the power supplied to the hot plate to keep the temperature constant, and the latter is based on a direct heat flux measurement. In order to improve the accuracy of the HFM, the thermal conductivity obtained by GHP was cross-compared with the HFM results, and a calibration factor was derived. It was found that the thermal conductivities measured by the two methods corresponded well under room temperature, but the deviation tended to slightly increase as the temperature decreased. Because of the easy installation and operability of HFM, it can be used to measure thermal conductivity in a large scale mock-up test or unit insulation panel test, where the GHP method is difficult to apply.

• 한국조명전기설비학회지:조명전기설비
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• 제11권1호
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• pp.92-98
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• 1997

본 노문에서는 154[kv] 가공송전선로의 주변에서 발생하는 극저주파 영역(ELF)의 전장의 측정·분석한 결과에 대해서 기술하였다. 상용주파수와같은 저주파 성분의 검출을 3차원 평행평판형 전장센서를 제작하였으며, IEEE에서 추천하는 실험방법을 적용하여 교정실험을 수행한 바 제작된 전계측정장치의 수파수 대력은 7[Hz]에서 2.7[MHz]이고, 응답 감도는 0.0094[mV/V/m]이었다. 154[kv] 2회선 가공송전선로 아래에서 전장의 실측실험을 수행하고, 그 결과를 분석하였다. 가공송전선 아래에서 의전장의 분포는 주변의 금속 물체 때문에 비대칭 형상을 나타내었으며, 그리고 최대 전계의 세기는 3[kV/m]이하이었다. 본 연구에서의 측정 결과는 관련 여러 국제기관의 제한·권고치를 만족시키고 있다.

• 한국조명전기설비학회지:조명전기설비
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• 제11권1호
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• pp.14-23
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• 1997

본 논문에서는 154[㎸] 가공송전손로의 주변에서 발생하는 극저주파 영역(ELF)의 전장의 측정 분석한 결과에 대해서 기술하였다. 상용주파수와 같은 저주파 성분의 검출을 위한 3차원 평행평판형 전장센서를 제작하였으며, IEEE에서 추천하는 실험방법을 적용하여 교정실험을 수행한 바 제작된 전계측정장치의 주파수 대역은 7[Hz]에서 2.7[MHz]이고, 응답 감도는 0.094[mV/V/m]이었다. 154[㎸] 2회선 가공송전선로 아래에서 전장의 실측 실험을 수행하고, 그 결과를 분석하였다, 가공송전선 아래에서의 전장의 분포는 주변의 금속 물체 때문에 비대칭 형상을 나타내었으며 그리고 최대 전계의 세기는 3[㎸/m]이하이었다. 본 연구에서는 측정 결과는 관련 여러 국제기관의 제한 권고치를 만족시키고 있다.

• 대한기계학회논문집A
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• 제20권8호
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• pp.2555-2560
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• 1996

Inspecting the dimensional accuracy of a car-body in assembly line is a very important process to assure high productivity. Now there exist two common inspecting methods in practice. One is to measure a sampled car-body with three dimensional measuring machine, and the other is to measure car-body with three dimensional measuring machine, and the other is to measure car-body in assembly line using many sensors fixed to a large jig frame. The formal method takes too long to inspect a sampled car-body of a same sort, and cannot therefore give an useful error trend for the whole production. On the other hand, the latter lacks flexibility and is very cost-intensive. By using industrial robots and sensors, an in-line Car-Body Measuring(CBM) system which ensured high flexiblity and sufficient accuracy was developed. This CBM cell operates in real production line and measures the check points by the non-contact type using camera and laser displacement sensor(LDS). This system can handle about 15 Measuring points within a cycle time of 40 seconds. A process computer controls whole process such as data acquisition file handling and data analysis. Robot arms changes in length due to ambient temperature fluctuation affecting the measuring accuracy. To compensate this error, a robot arm calibration process was developed.