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        검색결과 527

        41.
        2021.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Near infrared reflectance spectroscopy (NIRS) is routinely used for the determination of nutrient components of forages. However, little is known about the impact of sample preparation and wavelength on the accuracy of the calibration to predict minerals. This study was conducted to assess the effect of sample preparation and wavelength of near infrared spectrum for the improvement of calibration and prediction accuracy of Calcium (Ca) and Phosphorus (P) in imported hay using NIRS. The samples were scanned in reflectance in a monochromator instrument (680–2,500 nm). Calibration models (n = 126) were developed using partial least squares regression (PLS) based on cross-validation. The optimum calibrations were selected based on the highest coefficients of determination in cross validation (R2) and the lowest standard error of cross-validation (SECV). The highest R2 and the lowest SECV were obtained using oven-dry grinded sample preparation and 1,100-2,500 nm wavelength. The calibration (R2) and SECV were 0.99 (SECV: 468.6) for Ca and 0.91 (SECV: 224.7) for P in mg/kg DM on a dry weight, respectively. Results of this experiment showed the possibility of NIRS method to predict mineral (Ca and P) concentration of imported hay in Korea for routine analysis method to evaluate the feed value.
        4,000원
        42.
        2021.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : The purpose of this study is to evaluate the asphalt binder properties using FTIR analysis. METHODS : To investigate the chemical properties of asphalt binders, FTIR tests were performed. Recently, FTIR was used for quantification under various aging conditions. Three scans were averaged for each sample within the wavenumber range of 4000 to 400 cm-1, at a resolution of 4 cm-1 (default Simatech software settings). To determine the oxidation of the extracted asphalt binder and the remaining TCE solution in the extracted asphalt binder, the penetration test was adopted and compared. To track the changes in the chemical composition of the aged bitumens, the ATR spectrum of each sample was analyzed, both qualitatively and quantitatively. The qualitative analysis involved identifying characteristic absorption peaks for the functional group of interest, such as polymer components, carbon and sulfur oxidation products, and polar aromatics. RESULTS : The asphalt binder is easily oxidized in air during FTIR testing. To reduce the oxidization of the asphalt binder, the asphalt binder must avoid air contact to measure constant results. Sometimes, the extracted asphalt binder has a residual solvent (TCE), which affects the evaluation of the extracted asphalt binder rheology, such as absolute viscosity and penetration testing. To solve this problem, the research team adopted the FTIR test method. First, the TCE was scanned with FTIR to obtain the chemical characteristics of TCE. After that, the extracted asphalt binder was scanned and the FTIR spectra were compared with those of TCE. If there is a TCE in the extracted asphalt binder, a typical peak was found in the spectrum. Thus, it is possible to estimate the content of the TCE remaining in the extracted asphalt binder via the FTIR test method. CONCLUSIONS : It is possible to evaluate the aging of asphalt binder through FTIR analysis used for the analysis of the chemical structure of asphalt. In addition, during FTIR analysis, the sample is required to avoid air contact to obtain accurate results. FTIR analysis was conducted to confirm whether the solvent (TCE) remained in the extracted asphalt binder and it was confirmed that the penetration increased by a factor of two when the solvent remained. This suggests that it is difficult to control the quality of the asphalt mixture by controlling the amount of recycled additive, as well as the aging of the extracted asphalt binder.
        4,000원
        43.
        2021.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was developed to recognize the occurrence of 250[m] of experimental distance, rain and nighttime as an educational and training device without any safety accidents by applying algorithms to optical filters and noise filters to be used in all weather environments and closest to actual shooting training using IR Laser. There are live-fire shooting using live ammunition, screen shooting using beam project and screen, MILES using IR Laser and sensor, BB shooting using compressed gas and BB bullet, and painting shooting using CO2 gas and paint bullet. Among them, the actual shooting training is not efficient in terms of management and operation because it requires considerable risk factors and large costs in preparation for the highest efficiency. Therefore, training that replaces these problems is needed, and various alternative shooting training is being implemented. Therefore, research and development was conducted to solve these problems by using it as one of efficient shooting training and education systems. This study was conducted to develop high-performance and low-cost precision shooting training equipment to contribute to strengthening the defense of the Republic of Korea.
        4,000원
        44.
        2020.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        기후변화와 지구환경변화에 중요한 역할을 하고 있는 해수면온도는 인공위성 적외선 센서가 관측하는 피층 수온과 측기들이 관측하는 표층 수온으로 나누어질 수 있다. 국외 여러 기관에서 보급되고 있는 해수면온도 관측 자료들은 각각 서로 다른 깊이의 수온을 나타내고 있어서 해양 피층과 표층 수온 사이의 관계를 이해하는 것은 매우 중요하 다. 본 연구에서는 적외선 라디오미터를 해양조사선에 장착하기 위한 시스템을 설계하고 부착하고 운용하여 국내에서 처음으로 해양 피층 수온을 산출할 수 있는 관측 환경을 구축하였다. 선박 관측 전에 실험실에서 라디오미터 기기의 검보정을 실시하여 보정 계수를 산출하였다. 관측된 해수면에서 방출된 복사에너지와 하늘 복사에너지를 피층 수온으로 산출하는 일련의 과정을 적용하였다. 산출된 피층 해수면온도를 현장 관측 표층 수온자료와 비교하여 표층과 피층 수온 차이를 정량적으로 조사하고자 하였으며, Himawari-8 정지궤도 위성 해수면온도 자료와의 비교를 통해 해양 상층 연직 구조의 특성을 이해하고자 하였다. 2020년 4월 21일부터 5월 6일까지 남해안의 장목항과 동해 남부를 관측한 해양 피층 수온은 전체적으로 표층 수온과 0.76oC 정도의 차이를 보였다. 또한 이 두 수온 차이의 평균제곱근오차는 약 0.6oC 에서 0.9oC까지의 일간변화를 가지고 있었으며, 하루 중 1-3시에 0.83-0.89oC로 가장 크게 나타났으며, 15시에 0.59oC로 최소의 차이를 가지고 있었다. 또한 편차도 0.47-0.75oC의 일간변화를 나타내었다. 해양 피층 관측 수온과 위성 해수면 온도 간 차이는 약 0.74oC의 평균제곱근오차, 0.37oC의 편차를 나타냈다. 본 연구의 분석을 통해 관측 수심에 따른 피 층-표층 수온의 차이를 확인할 수 있었으며, 피층-표층 수온 차의 계절적 변화를 정량적으로 이해하고 또 변동 요인과의 관련성을 연구하기 위하여 연구조사선을 이용한 추가적인 연안 및 대양 관측이 지속적으로 진행되어야 함을 시사한다.
        4,500원
        45.
        2020.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        적외선 유도 무기 체계의 발달로 항공기의 생존성은 지속적으로 위협받고 있으며, 항공기의 생존성을 향상시키기 위한 적외선 스텔스 기술 관련 연구가 진행되고 있다. 본 논문에서는 적외선 유도 미사일이 항공기와 배경 간의 대비 신호를 탐지하는 것에 주목하여 비행 조건에 따른 항공기의 최적 적외선 신호를 분석하고자 하였다. 이를 위해 항공기의 비행 조건을 고려하여 유동 해석과 대류, 전도, 복사 3차원 열전달 해석을 수행하였고, 동체 표면 온도를 도출하여 항공기 주변 유동 특성을 기반으로 항공기의 적외선 신호를 분석하였다. 더 나아가, 비행 조건 별로 최적 적외선 신호를 갖기 위한 최적 방사율을 도출하였고, 비행 조건 별로 최적 방사율을 동체 표면에 적용했을 때 적외선 신호 저감 효과를 분석하였다.
        4,000원
        46.
        2020.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The aim of this study was to investigate the feasibility of discrimination 12 different cultivar of sorghum × sudangrass hybrid (Sorghum genus) seed through near infrared spectroscopy (NIRS). The amount of samples for develop to the best discriminant equation was 360. Whole samples were applied different three spectra range (visible, NIR and full range) within 680-2500 nm wavelength and the spectrastar 2500 Near near infrared was used to measure spectra. The calibration equation for discriminant analysis was developed partial least square (PLS) regression and discrimination equation (DE) analysis. The PLS discriminant analysis model for three spectra range developed with mathematic pretreatment 1,8,8,1 successfully discriminated 12 different sorghum genus. External validation indicated that all samples were discriminated correctly. The whole discriminant accuracy shown 82 ~ 100 % in NIR full range spectra. The results demonstrated the usefulness of NIRS combined with chemometrics as a rapid method for discrimination of sorghum × sudangrass hybrid cultivar through seed.
        4,000원
        47.
        2020.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The feasibility of infrared assisted freeze drying (IRAFD) was evaluated for shelf stable sea cucumber to improve the traditional drying methods such as freeze drying (FD), vacuum drying (VD) and hot air drying (AD, 60, 80, 100oC). Infrared (IR) radiant energy was provided to accelerate the drying rate of freeze drying (FD). IRAFD had the most rapid drying rate among IRAFD, FD and VD. IRAFD showed drying time of 13.7 h followed by VD (18.7 h) and FD (24.3 h). In the final moisture content of sea cucumber, it decreased down to 3.25% at IRAFD. However, FD and VD could not reduce down the moisture content of sea cucumber below 7%. Quality attributes of AD sea cucumber were not acceptable with very low restoration rate and excessive hardness. For example, AD 100 had very low weight restoration rate of 23% and hardness of 22 N. IRAFD showed quite high restoration rates (weight: 50%, width: 82%, length: 91%) and acceptable hardness of 3.1 N. IRAFD consumed the minimal electrical energy of 120 kJ as compared to 209 kJ of FD. This study showed the potential application of IRAFD to produce the shelf stable dried sea cucumber with microbial safety.
        4,000원
        52.
        2020.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        목적 : 근적외선 차단렌즈의 색 왜곡을 평가하기 위하여 객관적 및 주관적 측색 결과를 분석하였다. 방법 : Colorchecker Classic의 15번(Red), 16번(Yellow) 및 14번(Green) 색표를 가상신호등으로 설정하여 객관적 측색을 실시하였다. 객관적 평가를 위하여 디지털 카메라에 각 렌즈를 장착한 후 가상신호등을 촬영하였 다. 본래 색상과 렌즈 장착 후 측정된 색을 CIE 1976 L*a*b* 색도좌표로 표시하였고, 좌표간 거리 값인 ΔE* ab를 산출하여 색 왜곡도를 비교 분석하였다. 32명을 대상으로 주관적 평가를 실시하였다. 교통신호등의 관찰된 색을 한국 색채 표준 디지털팔레트에서 선택하도록 하여 본래 색상과 비교하였다. 결과 : 객관적 평가에서, 황색 및 녹색 가상신호등의 색왜곡은 근적외선 차단렌즈 착용 시 가장 작은 것으로 나 타났다. 근적외선 차단렌즈에 의한 적색 가상신호등의 색왜곡은 녹색렌즈보다 크지만 갈색, 회색 및 청색렌즈에 비교하여 더 적은 것으로 나타났다. 주관적 평가에서, 적색 신호등을 주시했을 때 근적외선 차단렌즈에 의한 색왜곡은 갈색렌즈와 비교하여 더 많았으며, 청색 및 녹색렌즈 착용과 유사하였고, 회색렌즈 착용보다 적은 것으로 나타났다. 결론 : 근적외선 차단렌즈의 색왜곡은 다른 렌즈와 비교하여 객관적 평가에서 가장 낮았으나, 주관적 평가에서는 유의한 차이가 없었다. 근적외선 차단렌즈의 주관적 색 재현성을 정량적으로 조사할 수 있는 추가적인 연구가 필요할 것으로 생각된다.
        4,000원
        53.
        2019.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        목적 : 근적외선 흡수렌즈의 광학적 특성과 단열특성을 분석하였다. 방법 : 선명도를 분석하기 위해 화상테스트 차트를 카메라로 촬영하였고, 이미지 분석 프로그램을 이용하여 분석하였다. 32명을 대상으로 시력을 측정하였다. 단열효과를 분석하기 위해 돼지피부와 안검 피부에 근적외선을 조사하고 디지털온도계와 열화상카메라를 사용하여 온도를 측정했다. 렌즈 표면에 근적외선을 조사하여 표면온도를 측정하였고, 열에 의한 렌즈손상을 관찰하였다. 근적외선 흡수안경과 착색안경을 착용하고 선명도, 눈부심, 열감, 광량에 대한 주관적 만족도를 평가하였다. 결과 : 근적외선 흡수렌즈와 착색렌즈에 의한 선명도와 시력은 유의한 차이가 없었다. 근적외선 흡수렌즈를 착용 했을 때 돼지피부와 사람 안검의 온도변화는 착색렌즈를 착용했을 때보다 더 낮았다. 근적외선 조사에 의해 근적외선 흡수렌즈가 착색렌즈보다 표면의 온도가 더 높았고, 더 빨리 손상되었다. 설문조사에서 근적외선 흡수렌즈에 의한 선명도(p=0.040)와 눈부심(p=0.000)에 관한 만족도는 모두 청색렌즈보다 더 높았지만 나머지 착색렌즈들과 유의한 차이가 없었다. 근적외선 흡수렌즈에 의한 열감과 광량에 관한 주관적 만족도는 착색렌즈보다 더 높았다. 결론 : 근적외선 흡수렌즈와 착색렌즈에 의한 선명도와 시력은 유의한 차이가 없었으며, 근적외선 흡수렌즈의 단열효과는 착색렌즈보다 더 좋았다. 본 연구는 근적외선 흡수렌즈의 단열효과에 대한 기초자료를 제시하였다고 생각된다.
        4,500원
        54.
        2019.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, whole crop rice samples were used to develop near-infrared reflectance (NIR) equations to estimate six forage quality parameters: Moisture, crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), Ash and relative feed value (RFV). A population of 564 whole crop rice representing a wide range in chemical parameters was used in this study. Undried finely chopped whole crop rice samples were scanned at 1 nm intervals over the wavelength range 680–2500 nm and the optical data recorded as log 1/Reflectance (log 1/R). NIRS calibrations were developed by means of partial least-squares (PLS) regression. The correlation coefficients of cross-validation (R2 cv) and standard error of cross-validation (SECV) for whole crop rice calibration were 0.98 (SECV 1.81%) for moisture, 0.89 (SECV 0.50%) for CP, 0.86 (SECV 1.79%) for NDF, 0.89 (SECV 0.86%) for ash, and 0.84 (SECV 5.21%) for RFV on a dry matter (%), respectively. The NIRS calibration equations developed in this study will be useful in predicting whole crop rice quality for these six quality parameters.
        4,000원
        55.
        2019.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Near infrared reflectance spectroscopy (NIRS) has become increasingly used as a rapid and accurate method of evaluating some chemical compositions in forages. The objective of this study was to evaluate the potential of NIRS, applied to imported forage, to estimate the moisture and chemical parameters for imported hays. A population of 392 imported hay representing a wide range in chemical parameters was used in this study. Samples of forage were scanned at 1 nm intervals over the wavelength range 680-2500nm and the optical data was recorded as log 1/Reflectance(log 1/R), which scanned in intact fresh condition. The spectral data were regressed against a range of chemical parameters using partial least squares(PLS) multivariate analysis in conjunction with spectral math treatments to reduced the effect of extraneous noise. The optimum calibrations were selected based on the highest coefficients of determination in cross validation(R2) and the lowest standard error of cross-validation(SECV). The results of this study showed that NIRS predicted the chemical parameters with very high degree of accuracy. The R2 and SECV for imported hay calibration were 0.92(SECV 0.61%) for moisture, 0.98(SECV 0.65%) for acid detergent fiber, 0.97(SECV 0.40%) for neutral detergent fiber, 0.99(SECV 0.06%) for crude protein and 0.97(SECV 3.04%) for relative feed value on a dry matter(%), respectively. Results of this experiment showed the possibility of NIRS method to predict the moisture and chemical composition of imported hay in Korea for routine analysis method to evaluate the feed value.
        4,000원
        56.
        2019.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted to investigate the potential of infrared assisted air drying (IRAD) to dry dorumuk (Arctoscopus japonicus). The IRAD system is composed of a far infrared lamp, convection fan, data loggable electronic balance, and proportional-integral-differential temperature controller. The infrared lamp provided radiative energy for temperature increase and substance moisture vaporization. The convection fan removed the moisture outside the drying chamber. Various IRAD conditions were tested at 40oC & 5 m/s, 40oC &11 m/s, 50oC & 5 m/s, 50oC & 11 m/ s, 60oC & 5 m/s, or 60oC & 11 m/s. The IRAD of 40oC & 5 m/s could reduce the moisture content by 42.2 %. The IRAD of 60oC and 11 m/s could further reduce the moisture content to 16.7% within 17 h. During the IRAD test, electrical energy consumption ranged from 1.16 to 1.38 kWh which is lower than that of hot air drying. IRAD resulted in dried dorumuk with yellow color and crispy texture. In this study, IRAD showed potential for the production of high-quality, dried dorumuk products.
        4,000원
        57.
        2019.09 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We investigate the characteristics of self-assembled quantum dot infrared photodetectors(QDIPs) based on doping level. Two kinds of QDIP samples are prepared using molecular beam epitaxy : n+-i(QD)-n+ QDIP with undoped quantum dot(QD) active region and n+-n−(QD)-n+ QDIP containing Si direct doped QDs. InAs QDIPs were grown on semi-insulating GaAs (100) wafers by molecular-beam epitaxy. Both top and bottom contact GaAs layer are Si doped at 2×1018/cm3. The QD layers are grown by two-monolayer of InAs deposition and capped by InGaAs layer. For the n+-n−(QD)-n+ structure, Si dopant is directly doped in InAs QD at 2×1017/cm3. Undoped and doped QDIPs show a photoresponse peak at about 8.3 μm, ranging from 6~10 μm at 10 K. The intensity of the doped QDIP photoresponse is higher than that of the undoped QDIP on same temperature. Undoped QDIP yields a photoresponse of up to 50 K, whereas doped QDIP has a response of up to 30 K only. This result suggests that the doping level of QDs should be appropriately determined by compromising between photoresponsivity and operating temperature.
        4,000원
        58.
        2019.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this paper, optical infrared thermography simulation using thermal wave imaging technique is performed to analyze the thermal characteristics of delamination defects. In this study, lock-in thermography(LIT) and pulsed thermography(PT) simulation was performed to analyze the samples of european traditional tiles with delamination defects, and the analytical modeler was developed through the ANSYS 19.2 transient thermal analysis tool. Applied sinusoidal heating with modulation frequency according to pulse heating and phase locking technique. The thermal response of the sample surface by heating was recorded and then data analysis was performed. The temperature gradient characteristics of each technique were compared, and phase angle was calculated for the LIT to analyze the parameters for the experiment setting. The simulation model was developed as a useful data for practical optical infrared thermography tests.
        4,000원
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