• 한국근적외분광분석학회:학술대회논문집
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• 한국근적외분광분석학회 2001년도 NIR-2001
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• pp.1266-1266
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• 2001

Pasture composition, an important attribute determining sward condition and value, is normally assessed by hand separation, drying and measuring weight contribution of each species in the mixture. This is a tedious, time and labour consuming procedure. NIRS has demonstrated the potential for predicting botanical composition of swards, but most of the work has been carried out on dry samples. The aim of this work was to evaluate the feasibility of developing NIR models for predicting the white clover and ryegrass content in fresh or dry mixtures artificially prepared from pure samples of both species. Mixtures from pure stands of white clover(Trifolium repens) and perennial ryegrass (Lolium perenne) were prepared with different proportions (0 to 100%) of each species (fresh weight). A total of 55 samples were made (11 mixtures,5 cuts). Spectra (400 to 2500 nm) were taken from fresh chopped (rectangular cuvettes, transport sample module) samples, in a NIR Systems 6500 scanning monochromator controlled by the software NIRS 3 (Infrasoft International), which was also utilized for calibration development. Different math treatments (derivative order, subtraction gap and smooth segment) and a scatter correction treatment of the spectra (SNV and Detrend) were tested. Equations were developed by modified partial least squares. Prediction accuracy evaluated by cross-validation, showed that percentage of clover or ryegrass, as contribution in dry weight, can be successfully percentage of clover or ryegrass, as contribution in dry weight, can be successfully predicted either on fresh or dried samples, with equations developed by different math treatments. Best equations for fresh samples were developed including a first, second, or third derivative, whereas for dry samples best equations included a second or third derivative. Standard errors of ross validation were about 6% for fresh and 3.6% for dry samples, Coefficient of determination of cross validation (1-VR) were over 0.95 times the value of SECV for fresh samples and over 8 times the value of SECV for dry samples. Scatter correction (SNV and Detrend) in general improved prediction accuracy. It is concluded more precise on dried and ground samples, it can be used with an acceptable error level and less time and labour, on fresh samples.

• The Korean Journal of Pain
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• 제27권2호
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• pp.145-151
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• 2014

Background: The physician's hands are close to the X-ray field in C-arm fluoroscopy-guided pain interventions. We prospectively investigated the radiation attenuation of Proguard RR-2 gloves. Methods: In 100 cases, the effective doses (EDs) of two dosimeters without a radiation-reducing glove were collected. EDs from the two dosimeters-one dosimeter wrapped with a glove and the other dosimeter without a glove-were also measured at the side of the table (Group 1, 140 cases) and at a location 20 cm away from the side of the table (Group 2, 120 cases). Mean differences such as age, height, weight, radiation absorbed dose (RAD), exposure time, ED, and ratio of EDs were analyzed. Results: In the EDs of two dosimeters without gloves, there were no significant differences ($39.0{\pm}36.3{\mu}Sv$ vs. $38.8{\pm}36.4{\mu}Sv$) (P = 0.578). The RAD ($192.0{\pm}182.0radcm^2$) in Group 2 was higher than that ($132.3{\pm}103.5radcm^2$) in Group 1 (P = 0.002). The ED ($33.3{\pm}30.9{\mu}Sv$) of the dosimeter without a glove in Group 1 was higher than that ($12.3{\pm}8.8{\mu}Sv$) in Group 2 (P < 0.001). The ED ($24.4{\pm}22.4{\mu}Sv$) of the dosimeter wrapped with a glove in Group 1 was higher than that ($9.2{\pm}6.8{\mu}Sv$) in Group 2 (P < 0.001). No significant differences were noted in the ratio of EDs ($73.5{\pm}6.7%$ vs. $74.2{\pm}9.3%$, P = 0.469) between Group 1 and Group 2. Conclusions: Proguard RR-2 gloves have a radiation attenuation effect of 25.8-26.5%. The radiation attenuation is not significantly different by intensity of scatter radiation or the different RADs of C-arm fluoroscopy.

• 한국작물학회지
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• 제54권1호
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• pp.24-28
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• 2009

This study was conducted to evaluate the growth characters and yield components of 18 collected sesame cultivars to get basic information on the variation for the sesame breeding using principal component analysis. All characters except days to flowering, days to maturity and 1,000 seed weight showed significantly different. Seed weight per 10 are showed higher coefficient of variance. Capsule bearing stem length and liter weight showed positive correlation with seed yield per 10 are. The principal components analysis grouped the estimated sesame cultivars into four main components which accounted for 83.7% of the total variation at the eigenvalue and its contribution to total variation obtained from principal component analysis. The first principal component ($Z_1$) was applicable to increase plant height, capsule bearing stem length and 1,000-seed weight. The second principal component ($Z_2$) negatively correlated with days to flowering and maturity by which it was applicable to shorten flowering and maturity date of sesame. At the scatter diagram, Yangbaek, Ansan, M1, M2, M4, M7 and M9 were classified as same group, but M10, Yanghuk, Kanghuk, M5, M6, M12 and M13 were classified as different group. This results would be helpful for sesame breeder to understand genetic relationship of some agronomic characters and select promising cross lines for the development of new sesame variety.

• International Journal of Aeronautical and Space Sciences
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• 제17권3호
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• pp.409-422
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• 2016

A parametric study based on an unsteady mathematical model of a pyrotechnically actuated device was performed for design optimization. The model simulates time histories for the chamber pressure, temperature, mass transfer and pin motion. It is validated through a comparison with experimentally measured pressure and pin displacement. Parametric analyses were conducted to observe the detailed effects of the design parameters using a validated performance analysis code. The detailed effects of the design variables on the performance were evaluated using the one-at-a-time (OAT) method, while the scatter plot method was used to evaluate relative sensitivity. Finally, the design optimization was conducted by employing a genetic algorithm (GA). Six major design parameters for the GA were chosen based on the results of the sensitivity analysis. A fitness function was suggested, which included the following targets: minimum explosive mass for the uniform ignition (small deviation), light casing weight, short operational time, allowable pyrotechnic shock force and finally the designated pin kinetic energy. The propellant mass and cross-sectional area were the first and the second most sensitive parameters, which significantly affected the pin's kinetic energy. Even though the peak chamber pressure decreased, the pin kinetic energy maintained its designated value because the widened pin cross-sectional area induced enough force at low pressure.

• 한국자동차공학회논문집
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• 제18권3호
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• pp.37-42
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• 2010

Plastic region tightening is widely used in critical bolted joints in internal combustion engines in order to reduce the engine weight by maximizing the use of load-carrying capacity of bolt. Mechanical behavior of bolt tightened in plastic region under external axial tensile load is investigated for various friction conditions using three dimensional finite element analysis. The behavior of bolt tightened in elastic region as well as that in tensile test are investigated for comparison. Tightening process is simulated by rotating the bolt in order to examine the friction effect realistically. It is revealed that the bolt tightened in plastic region can carry more external load until the joint is opened, and yields at lower bolt load than the bolt tightened in elastic region. The friction coefficient has effect on the yield load, but not on the load-carrying capacity. Moreover, the scatter in the bolt preload due to friction begins with plastic deformation of bolt in the angle tightening control, whereas it begins with the onset of tightening in the torque tightening control. The observations are interpreted with the residual torsional stress in the bolt generated during the tightening.

• 천문학회보
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• 제42권2호
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• pp.44.2-44.2
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• 2017

We obtained near-infrared spectra of 26 SDSS quasars at 0.7${\sim}10^{{\wedge}{10}}M{\odot}$ to critically examine the systematic effects involved with their mass estimations. We find that active galactic nuclei (AGNs) heavier than $10^{{\wedge}{10}}M{\odot}$ often display double-peaked $H{\alpha}$ emission, extremely broad FeII complex emission around MgII, and highly blueshifted and broadened CIV emission. The weight of this evidence, combined with previous studies, cautions against the use of MBH values based on any emission line with a width over 8000 km/s. Also, the MBH estimations are not positively biased along the presence of ionized narrow line outflows, anisotropic radiation, or the use of line FWHM instead of ${\sigma}$ for our sample, and unbiased with variability, scatter in broad line equivalent width, or obscuration for general type-1 quasars. Removing the systematically uncertain MBH values, ${\sim}10^{{\wedge}{10}}M{\odot}$ BHs in 1${\sim}10^{{\wedge}{9.5}}M{\odot}$ BHs, although current observations support they are intrinsically most massive, and overmassive to the host's bulge mass.

• Preventive Nutrition and Food Science
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• 제8권1호
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• pp.7-12
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• 2003

This study examined the effect of pine needle distillate (Pinus densiflora Sieb. et Zucc) on the immune system and hematological parameters. C57BL/6 male mice weighing 20 ~21 g were divided into 3 groups and intraperitonially injected with either 200 $\mu$L of saline (control), 50% diluted (P50) or 100% pine needle distillate (P100) once a day for 24 days. At the end of the experiment, the mice were anesthetized by ether and peripheral blood was collected from the femoral artery and the spleen was excised. Spleen weight decreased significantly (p<0.001) in the pine needle groups compared to the control group. The blood was used for a complete blood count and flow cytometrical analysis after immunofluorescence staining. The pine needle distillate dose-dependently decreased the CD4$^{＋}$/CD8 sup ＋/ ratio (p <0.05), and showed a tendency to increase the mean FSC (forward scatter) values of the CD8$^{＋}$T cells, while decrease the values of the CD4$^{＋}$T cells. There were no significant differences in WBC, RBC and platelet counts among the three groups, but hemoglobin and hemoglobin-related parameters and platelet volume increased and red blood cell volumes decreased with the administration of the pine needle distillate. These results suggest that the pine needle distillate may have immunosuppressive effects.

• Nuclear Medicine and Molecular Imaging
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• 제40권1호
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• pp.40-47
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• 2006

목적 : 이 연구에서는 고양이 뇌 PET 영상을 감쇠, 산란 보정 후 정량 평가하여 감쇠, 산란보정의 필요성에 대하여 연구하였다. 대상 및 방법 : 감쇠, 산란보정의 영향을 평가하기 위하여 microPET R4 스캐너를 이용하여 팬텀과 5마리 고양이의 $^{18}F$-FDG PET 스캔을 얻었다. $^{68}Ge$ 선원을 이용하여 30분 동안 투과영상을 얻은 후 FDG를 정맥주사한 다음 방출 영상을 얻었다. PET 영상은 OSEM을 이용하여 영상을 재구성하였고, 감쇠, 산란보정을 하였다. 전두엽, 두정엽 외측 측두엽 등을 포함하는 대뇌피질 영역과 꼬리핵머리, 조가비핵, 시상을 포함하는 심부피질 영역에 관심영역을 그린 다음 감쇠, 산란보정 전, 후의 계수를 측정하였다. 각각의 계수는 방사선원 투여량과 중량으로 정규화하였다. 감쇠보정의 영향을 평가하기 위하여 "심부피질/대뇌피질"의 비를 계산하였다. 산란보정의 영향을 평가하기 위하여 회백질과 백질에 관심영역을 그린 다음 "(회백질-백질)/회백질"의 비를 구하여 대조도를 계산하였다. 결과: 감쇠보정 후, "심부피질/대뇌피질"의 비는 $17{\pm}7%$ 증가하였다. 산란보정 후, "(회백질-백질)/회백질"의 비는 $12{\pm}3%$ 증가하였다. 결론: 감쇠보정 후 "심부피질/대뇌피질"의 계수비가 증가하였고, 산란보정 후 회백질과 백질 사이의 대조도가 증가하였다. 이는 고양이 뇌 PET 영상 획득 및 정량화를 할 때 감쇠보정이 특히 중요함을 반영한다.

• 한국표면공학회지
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• 제52권6호
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• pp.283-288
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• 2019

MCrAlY overaly coatings are used as oxidation barrier coatings to prevent degradation of the underlying substrate in high temperature and oxidizing environment of the hot section of gas turbines. Therefore, oxidation resistance in high temperature is important property of MCrAlY coatings. Also, coefficients of thermal expansion (CTE) of MCrAlY have middle value of that of Ni-based superalloys and oxides, which have the effect of preventing the delamination of the surface oxides. Cyclic oxidation test is one of the most useful methods for evaluating the high temperature durability of coatings used in gas turbines. In this study, NiCoCrAlY overlay coatings were formed on Inconel 792(IN 792) substrates by vacuum plasma spraying process. Vacuum plasma sprayed NiCoCrAlY coatings and IN 792 susbstrates were exposed to 1000℃ one-hour cyclic oxidation environment. NiCoCrAlY coatings showed lower weight gain in short-term oxidation. In long-term oxidation, IN 792 substrates showed higher weight loss due to delamination of surface oxide but NiCoCrAlY coatings showed lower weight loss. X-ray diffraction (XRD) analysis showed α-Al2O3 and NiCr₂O₄ was formed during the cyclic oxidation test. Through cross-section observation using scanning electron microscopy (SEM) and electron back scatter diffraction (EBSD) analysis, thermally grown oxide (TGO) layer composed of α-Al₂O₃ and NiCr₂O₄ was formed and the thickness of TGO increased during 1000℃ cyclic oxidation test. β phase in upper side of NiCoCrAlY coating was depleted due to oxidation of Al and outer beta depletion zone thickness also increased as the cyclic oxidation time increased.

• 현장농수산연구지
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• 제22권2호
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• pp.59-67
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• 2020

본 연구는 전남 고흥 명천·계도 양식어장에서 2003년 2월부터 7월까지 완도와 백령도산 다시마 종묘를 이식, 시험양식을 실시하였다. 다섯 가지 환경 조건(수온, 염분, 총질소, 총인, 부유물질)과 두 가지 형질(엽장, 엽중량)을 매월 측정하였다. 이 데이터를 이용하여 성장 패턴, 형질간의 상관관계 및 PCA를 분석하는데 이용하였다. Box plot은 성장 패턴을 확인하기 위해 사용하였고, 형질들 간의 상호관계를 파악하기 위해 산점도, 회귀 계수 및 상관 계수를 이용하였다. 주성분 분석 결과 명천·계도 양식어장의 총 분산의 91.4%, 90.5% 이상을 제2주성분으로 설명할 수 있었다. 주성분분석(PCA)으로 두 어장에서 엽장과 엽중량의 성장에 가장 크게 영향을 주는 환경변수는 수온과 부유물질로 나타났다. 두 품종 모두 명천 어장보다 계도 어장에서 성장이 빨랐고, '백령도' 품종이 '완도' 품종보다 성장이나 중량에서 더 우수하였다.