• Title/Summary/Keyword: Standard error of prediction

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APPLICATION STUDY OF CHEMOINFOMETRICAL NEAR-INFRARED SPECTROSCOPY IN PHARMACEUTICAL INDUSTRY

  • Otsuka, Makoto;Kato, Fumie;Matsuda, Yoshihisa
    • Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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    • 2001.06a
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    • pp.2111-2111
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    • 2001
  • A chemoinfometrical method for evaluating the quantitative determination of crystallinity one polymorphs based on fourie-transformed near-infrared (FT-NIR) spectroscopy was established. A direct comparison of the data with the ones collected from using the and compared with the conventional powder X-ray diffraction method was performed. [Method] The pPure a and g forms of indomethacin (IMC) were prepared by reportedusing published methods. Six kinds of standard samples obtained by physically mixing of a and g forms. After the powder X-ray diffraction profiles of samples have been measured, the intensity values were normalized to against the intensity of silicon powder as the as an external standard. The calibration curves for quantification of crystal content were based upon the total relative intensity of four diffraction peaks from of the form g crystal. FT-NIR spectra of six calibration sample sets were recorded 5 times with the NIR spectrometer (BRAN+LUEBBE). Chemoinfometric analysis was performed on the NIR spectral data sets by applying the principal component regression (PCR). [Results] The relation between the actual and predicted polymorphic contents of form g IMC measured using by the X-ray diffraction method shows a good straight linen linear relation., and it has slope of 0.023, an intercept of 0.131 and a correlation coefficient of 0.986. PCR analyses wereis was performed based on normalized NIR spectra sets offer standard samples of known content of IMC g form. IMC. A calibration equation was determined to minimize the root mean square error of the predictionthe prediction. Figure 1 shows a plot of the calibration data obtained by NIR method between the actual and predicted contents of form g IMC. The predicted values were reproducible and had a smaller standard deviation. Figure 2 shows that the plot for the predicted transformation rate (%) of form a IMC to form g as measured by X-ray diffractomeoy against to those as measured by NIR method. The plot has a slope of 1.296, an intercept of 1,109, and a correlation coefficient of 0.992. The line represents a satisfactory correlation between the two predicted values of form g IMC content. Thus NIR spectroscopy is an effective method for the evaluation to the pharmaceutical products of quantitative of polymorph.

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Analytical Review of the Forensic Anthropological Techniques for Stature Estimation in Korea (한국에서 사용되는 법의인류학적 키 추정 방법에 대한 제언)

  • Jeong, Yangseung;Woo, Eun Jin
    • Anatomy & Biological Anthropology
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    • v.31 no.4
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    • pp.121-131
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    • 2018
  • Stature is one of the unique biological properties of a person, which can be used for identification of the individual. In this regard, statures are estimated for the unknown victims from crimes and disasters. However, the accuracy of estimates may be compromised by inappropriate methodologies and/or practices of stature estimation. Discussed in this study are the methodological issues related to the current practices of forensic anthropological stature estimation in Korea, followed by suggestions to enhance the accuracy of the stature estimates. Summaries of forensic anthropological examinations for 560 skeletal remains, which were conducted at the National Forensic Service (NFS), were reviewed. Mr. Yoo Byung-eun's case is utilized as an example of the NFS's practices. To estimate Mr. Yoo's stature, Trotter's (1970) femur equation was applied even though the fibula equation of a lower standard error was available. In his case report, the standard error associated with the equation (${\pm}3.8cm$) was interpreted as an 'error range', which gave a hasty impression that the prediction interval is that narrow. Also, stature shrinkage by aging was not considered, so the estimated stature in Mr. Yoo's case report should be regarded as his maximum living stature, rather than his stature-at-death. Lastly, applying Trotter's (1970) White female equations to Korean female remains is likely to underestimate their statures. The anatomical method will enhance the accuracy of stature estimates. However, in cases that the anatomical method is not feasible, the mathematical method based on Korean samples should be considered. Since 1980's, effort has been made to generate stature estimation equations using Korean samples. Applying the equations based on Korean samples to Korean skeletal remains will enhance the accuracy of the stature estimates, which will eventually increase the likelihood of successful identification of the unknowns.

Effect of Sample Preparations on Prediction of Chemical Composition for Corn Silage by Near Infrared Reflectance Spectroscopy (시료 전처리 방법이 근적외선분광법을 이용한 옥수수 사일리지의 화학적 조성분 평가에 미치는 영향)

  • Park Hyung-Soo;Lee Jong-Kyung;Lee Hyo-Won;Hwang Kyung-Jun;Jung Ha-Yeon;Ko Moon-Suck
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.26 no.1
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    • pp.53-62
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    • 2006
  • Near infrared reflectance spectroscopy (NIRS) has been increasingly used as a rapid, accurate method of evaluating some chemical compositions in forages. Analysis of forage quality by NIRS usually involves dry ground samples. Costs might be reduced if samples could be analyzed without drying or grinding. The objective of this study was to investigate effect of sample preparations and spectral math treatments on prediction ability of chemical composition for corn silage by NIRS. A population of 112 corn silage representing a wide range in chemical parameters were used in this investigation. Samples of com silage were scanned at 2nm intervals over the wavelength range 400-2500nm and the optical data recorded as log l/Reflectance(log l/R) and scanned in overt-dried grinding(ODG), liquid nitrogen grinding(LNG) or intact fresh(IF) condition. Samples were analysed for neutral detergent fiber(NDF), acid detergent fiber(ADF), acid detergent lignin(ADL), crude protein(CP) and crude ash content were expressed on a dry-matter(DM) basis. The spectral data were regressed against a range of chemical parameters using modified partial least squares(MPLS) multivariate analysis in conjunction with four spectral math treatments to reduce the effect of extraneous noise. The optimum calibrations were selected on the basis of minimizing the standard error of cross validation(SECV). The results of this study show that NIRS predicted the chemical parameters with very high degree of accuracy(the correlation coefficient of cross validation$(R^2cv)$ range from $0.70{\sim}0.95$) in ODG. The optimum equations were selected on the basis of minimizing the standard error of prediction(SEP). The Optimum sample preparation methods and spectral math treatment were for ADF, the ODG method using 2,10,5 math treatment(SEP = 0.99, $R^2v=0.93$), and for CP, the ODG method using 1,4,4 math treatment(SEP = 0.29. $R^2v=0.91$).

Development of Prediction Model for Capsaicinoids Content in Red-Pepper Powder Using Near-Infrared Spectroscopy - Particle Size Effect (근적외선 스펙트럼을 이용한 고춧가루의 캡사이신 함량 예측 모델 개발 - 입자의 영향)

  • Mo, Changyeun;Kang, Sukwon;Lee, Kangjin;Lim, Jong-Guk;Cho, Byoung-Kwan;Lee, Hyun-Dong
    • Food Engineering Progress
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    • v.15 no.1
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    • pp.48-55
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    • 2011
  • In this research, the near-infrared absorption from 1,100-2,300 nm was used to measure the content of capsaicinoids in the red-pepper powder by using the Acousto-optic tunable filters (AOTF) spectrometer with sample plate and sample rotating unit. Non-spicy red-pepper samples from one location (Younggwang-gun. Korea) were mixed with spicy one (var. Chungyang) to make samples separated by particle size (below 0.425 mm, 0.425-0.71 mm, and 0.71- 1.4 mm). The Partial Least Squares Regression (PLSR) model to predict the capsaicinoid content on particle sizes was developed with measured spectra by AOTF spectrometer and used to analyze the amount of capsaicinoids by HPLC. The PLSR Model of red-pepper powder of below 0.425 mm, 0.425-0.71 mm, and 0.71-1.4 mm with cross validation had ${R_V}^2$ = 0.948-0.979 and Standard Error of Prediction (SEP) = 6.56-7.94 mg%. The prediction error of smaller particle size of red-pepper powder was low. The best PLSR model was found in pretreatment of Range Normalization, Standard Normal Variate, and 1st Derivatives of red-pepper powder of below 1.4 mm with cross validation, having ${R_V}^2$ = 0.959 and SEP = 8.82 mg%.

A Melon Fruit Grading Machine Using a Miniature VIS/NIR Spectrometer: 2. Design Factors for Optimal Interactance Measurement Setup

  • Suh, Sang-Ryong;Lee, Kyeong-Hwan;Yu, Seung-Hwa;Shin, Hwa-Sun;Yoo, Soo-Nam;Choi, Yong-Soo
    • Journal of Biosystems Engineering
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    • v.37 no.3
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    • pp.177-183
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    • 2012
  • Purpose: In near infrared spectroscopy, interactance configuration of a light source and a spectrometer probe can provide more information regarding fruit internal attributes, compared to reflectance and transmittance configuration. However, there is no through study on the parameters of interactance measurement setup. The objective of this study was to investigate the effect of the parameters on the estimation of soluble solids content (SSC) and firmness of muskmelons. Methods: Melon samples were taken from greenhouses at three different harvesting seasons. The prediction models were developed at three distances of 2, 5, and 8 cm between the light source and the spectrometer probe, three measurement points of 2, 3, and 6 evenly distributed on each sample, and different number of fruit samples for calibration models. The performance of the models was compared. Results: In the test at the three distances, the best results were found at a 5 cm distance. The coefficient of determination ($R_{cv}{^2}$) values of the cross-validation were 0.717 (standard error of prediction, SEP=$1.16^{\circ}Brix$) and 0.504 (SEP=4.31 N) for the estimation of SSC and firmness, respectively. The minimum measurement point required to fully represent the spectral characteristics of each fruit sample was 3. The highest $R_{cv}{^2}$ values were 0.736 (SEP=$0.87^{\circ}Brix$) and 0.644 (SEP=4.16 N) for the estimation of SSC and firmness, respectively. The performance of the models began to be saturated when 60 fruit samples were used for developing calibration models. The highest $R_{cv}{^2}$ of 0.713 (SEP=$0.88^{\circ}Brix$) and 0.750 (SEP=3.30 N) for the estimation of SSC and firmness, respectively, were achieved. Conclusions: The performance of the prediction models was quite different according to the condition of interactance measurement setup. In designing a fruit grading machine with interactance configuration, the parameters for interactance measurement setup should be chosen carefully.

COMPARISON OF LINEAR AND NON-LINEAR NIR CALIBRATION METHODS USING LARGE FORAGE DATABASES

  • Berzaghi, Paolo;Flinn, Peter C.;Dardenne, Pierre;Lagerholm, Martin;Shenk, John S.;Westerhaus, Mark O.;Cowe, Ian A.
    • Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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    • 2001.06a
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    • pp.1141-1141
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    • 2001
  • The aim of the study was to evaluate the performance of 3 calibration methods, modified partial least squares (MPLS), local PLS (LOCAL) and artificial neural network (ANN) on the prediction of chemical composition of forages, using a large NIR database. The study used forage samples (n=25,977) from Australia, Europe (Belgium, Germany, Italy and Sweden) and North America (Canada and U.S.A) with information relative to moisture, crude protein and neutral detergent fibre content. The spectra of the samples were collected with 10 different Foss NIR Systems instruments, which were either standardized or not standardized to one master instrument. The spectra were trimmed to a wavelength range between 1100 and 2498 nm. Two data sets, one standardized (IVAL) and the other not standardized (SVAL) were used as independent validation sets, but 10% of both sets were omitted and kept for later expansion of the calibration database. The remaining samples were combined into one database (n=21,696), which was split into 75% calibration (CALBASE) and 25% validation (VALBASE). The chemical components in the 3 validation data sets were predicted with each model derived from CALBASE using the calibration database before and after it was expanded with 10% of the samples from IVAL and SVAL data sets. Calibration performance was evaluated using standard error of prediction corrected for bias (SEP(C)), bias, slope and R2. None of the models appeared to be consistently better across all validation sets. VALBASE was predicted well by all models, with smaller SEP(C) and bias values than for IVAL and SVAL. This was not surprising as VALBASE was selected from the calibration database and it had a sample population similar to CALBASE, whereas IVAL and SVAL were completely independent validation sets. In most cases, Local and ANN models, but not modified PLS, showed considerable improvement in the prediction of IVAL and SVAL after the calibration database had been expanded with the 10% samples of IVAL and SVAL reserved for calibration expansion. The effects of sample processing, instrument standardization and differences in reference procedure were partially confounded in the validation sets, so it was not possible to determine which factors were most important. Further work on the development of large databases must address the problems of standardization of instruments, harmonization and standardization of laboratory procedures and even more importantly, the definition of the database population.

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Prediction of the content of white clover and perennial ryegrass in fresh or dry mixtures made up from pure botanical samples, by near infrared spectroscopy

  • Blanco, Jose A.;Alomar, Daniel J.;Fuchslocher, Rita I.
    • Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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    • 2001.06a
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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.

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Near Infrared Spectroscopy for Diagnosis: Influence of Mammary Gland Inflammation on Cow´s Milk Composition Measurement

  • Roumiana Tsenkova;Stefka Atanassova;Kiyohiko Toyoda
    • Near Infrared Analysis
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    • v.2 no.1
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    • pp.59-66
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    • 2001
  • Nowadays, medical diagnostics is efficiently supported by clinical chemistry and near infrared spectroscopy is becoming a new dimension, which has shown high potential to provide valuable information for diagnosis. The investigation was carried out to study the influence of mammary gland inflammation, called mastitis, on cow´s milk spectra and milk composition measured by near infrared spectroscopy (NIRS). Milk somatic cell counts (SCC) in milk were used as a measure of mammary gland inflammation. Naturally occurred variations with milk composition within lactation and in the process of milking were included in the experimental design of this study. Time series of unhomogenized, raw milk spectral data were collected from 3 cow along morning and evening milking, for 5 consecutive months, within their second lactation. In the time of the trial, the investigated cows had periods with mammary gland inflammation. Transmittance spectra of 258 milk samples were obtained by NIRSystem 6500 spectrophotometer in 1100-2400 nm region. Calibration equations for the examined milk components were developed by PLS regression using 3 different sets of samples: samples with low somatic cell count (SCC), samples with high SCC and combined data set. The NIR calibration and prediction of individual cow´s milk fat, protein, and lactose were highly influenced by the presence of mil samples from animals with mammary gland inflammation in the data set. The best accuracy of prediction (i.e. the lower SEP and the higher correlation coefficient) for fat, protein and lactose was obtained for equations, developed when using only “healthy” samples, with low SCC. The standard error of prediction increased and correlation coefficient decreased significantly when equations for low SCC milk were used to predict examined components in “mastitis” samples with high SCC, and vice versa. Combined data set that included samples from healthy and mastitis animals could be used to build up regression models for screening. Further use of separate model for healthy samples improved milk composition measurement. Regression vectors for NIR mild protein measurement obtained for “healthy” and “mastitic” group were compared and revealed differences in 1390-1450 nm, 1500-1740 nm and 1900-2200 nm regions and thus illustrated post-secretory breakdown of milk proteins by hydrolytic enzymes that occurred with mastitis. For the first time it has been found that monitoring the spectral differences in water bands at 1440 nm and 1912 nm could provide valuable information for inflammation diagnosis.

Development of Rapid Prediction Model of C3G Content in Black Pigmented Rice (흑자색미의 C3G 색소함량 신속 예측모델 개발)

  • Ryu Su-Noh;Yang Jong-Jin;Park Sun-Zik
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.50 no.spc1
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    • pp.1-3
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    • 2005
  • It has been reported that Cyanidin 3-Glu-coside (C3G) of the black pigmented rice was as the high anti-oxidency and analyzed by high performance liquid chromatography (HPLC). However, the analysis of C3G by HPLC is needed long pre-treated steps, so development of methods with simple pre-treated steps is needed in order to breed vices with high C3G contents. The analysis of components using near infrared reflectance (NIR) was well known as non pre-treated and nondestructive. C3G contents of Bengjinjubyeo$\times$Suwon425 $F_{10}$ 385 lines were used in order to develop C3G content prediction model in pigmented rice using FT-NIR. The results of C3G content of FT-NIR compared with HPLC were showed that the equation was f(x)=0.9427x+34.0430, $R^2$, standard error of calibration was 0.943, 0.116 and those of validation was 0.928, 0.122, respectively. This prediction model will be able to be used for analyzing C3G contents in black pigmented rice.

Prediction of Wind Damage Risk based on Estimation of Probability Distribution of Daily Maximum Wind Speed (일 최대풍속의 추정확률분포에 의한 농작물 강풍 피해 위험도 판정 방법)

  • Kim, Soo-ock
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.19 no.3
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    • pp.130-139
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    • 2017
  • The crop damage caused by strong wind was predicted using the wind speed data available from Korean Meteorological Administration (KMA). Wind speed data measured at 19 automatic weather stations in 2012 were compared with wind data available from the KMA's digital forecast. Linear regression equations were derived using the maximum value of wind speed measurements for the three-hour period prior to a given hour and the digital forecasts at the three-hour interval. Estimates of daily maximum wind speed were obtained from the regression equation finding the greatest value among the maximum wind speed at the three-hour interval. The estimation error for the daily maximum wind speed was expressed using normal distribution and Weibull distribution probability density function. The daily maximum wind speed was compared with the critical wind speed that could cause crop damage to determine the level of stages for wind damage, e.g., "watch" or "warning." Spatial interpolation of the regression coefficient for the maximum wind speed, the standard deviation of the estimation error at the automated weather stations, the parameters of Weibull distribution was performed. These interpolated values at the four synoptic weather stations including Suncheon, Namwon, Imsil, and Jangsu were used to estimate the daily maximum wind speed in 2012. The wind damage risk was determined using the critical wind speed of 10m/s under the assumption that the fruit of a pear variety Mansamgil would begin to drop at 10 m/s. The results indicated that the Weibull distribution was more effective than the normal distribution for the estimation error probability distribution for assessing wind damage risk.