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Papers - MA Te

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Three-dimensional grain angle measurement of softwood (Hinoki cypress) using near infrared spatially and spectrally resolved imaging (NIR-SSRI) Reviewed

Te Ma, Tetsuya Inagaki, Satoru Tsuchikawa

Holzforschung Vol. 73 ( 9 ) page： 817 - 826 2019.9

Authorship：Lead author Language：English Publishing type：Research paper (scientific journal)

© 2019 Walter de Gruyter GmbH, Berlin/Boston. As the strength of wood is greatly affected by its three-dimensional (3D) grain angles (the dive angle and the surface angle), the wood industry today requires automatic, rapid, and robust measurement techniques for measuring them simultaneously. In the present study, a near infrared spatially and spectrally resolved imaging (NIR-SSRI) system was designed in a line scan model, mainly including an NIR hyperspectral imaging camera and a halogen spotlight source (Ø 1 mm). Spatially resolved diffuse reflectance images at three target wavelengths (1002 nm, 1217 nm, and 1413 nm) were obtained from Hinoki cypress [Chamaecyparis obtusa (Siebold & Zucc.) Endl.] samples at various (0°, 3°, 6°, ⋯ 45°) dive angles and surface angles (0°, 3°, 6°, ⋯ 45°). The scattering patterns caused by the "tracheid effect" were almost elliptical. Subsequently, nonlinear least squares fitting was used to determine their eccentricities (e) and rotation angles (θ). The e values at each selected wavelength were highly correlated with the dive angle reference values; and the global identification model developed using Gaussian process regression (GPR) under five-fold cross-validation (CV) reached a determination coefficient (r2) of 0.98 with a root mean square error (RMSE) of 2.2°. On the other hand, local surface angle identification models developed using linear regression analysis achieved determination coefficients higher than 0.90 on r2 and an RMSE of CV lower than 3.8° when the dive angle was lower than 30°.

DOI： 10.1515/hf-2018-0273

Web of Science

Scopus

Non-destructive evaluation of wood stiffness and fiber coarseness, derived from SilviScan data, via near infrared hyperspectral imaging Reviewed

Te Ma, Tatsuya Inagaki, Satoru Tsuchikawa

Vol. 26 ( 6 ) page： 398 - 405 2018.12

Optical characteristics of Douglas fir at various densities, grain directions and thicknesses investigated by near-infrared spatially resolved spectroscopy (NIR-SRS) Reviewed

Te Ma, Gary Schajer, Tetsuya Inagaki, Zarin Pirouz, Satoru Tsuchikawa

Holzforschung Vol. 72 ( 9 ) page： 789 - 796 2018.9

Authorship：Lead author Language：English Publishing type：Research paper (scientific journal) Publisher：Walter de Gruyter GmbH

© 2018 Walter de Gruyter GmbH, Berlin/Boston. A near-infrared spatially resolved spectroscopy (NIR-SRS) system, also called the hyperspectral imaging system, was applied in a line scanning model combined with a concentrated halogen light source (Ø 1 mm), and spatially resolved reflectance images of Douglas fir [Pseudotsuga menziesii (Mirb.) Franco] wood were obtained. The samples with various densities, grain directions and thicknesses were observed in the NIR range of 1000-1600 nm. Then, a nonlinear curve-fitting algorithm was applied based on the steady-state diffusion theory model to estimate the absorption coefficient (μa), and reduced scattering coefficients (μ′s μ) both parallel and perpendicular to the grain direction at each measurement position. The absorption scattering coefficients at 1457 nm and two kinds of reduced scattering coefficients at 1002 nm were highly correlated with wood densities measured by an X-ray densitometer. The correlation coefficients were 0.953 and 0.987 for 3 mm and 5 mm samples, respectively, while three optical profiles were combined. It can be concluded that NIR-SRS is a fast and simple method for measuring the optical characteristics of softwood, although it has a non-homogeneous cellular structure. Sub-surface density and grain direction could be predicted with satisfactory accuracy based on a few key wavelengths without relying on multivariate statistical analysis.

DOI： 10.1515/hf-2017-0213

Web of Science

Scopus

Effect of knots and holes on the modulus of elasticity prediction and mapping of sugi (Cryptomeria japonica) veneer using near-infrared hyperspectral imaging (NIR-HSI) Reviewed

Imran Arra'd Sofianto, Tetsuya Inagaki, Te Ma, Satoru Tsuchikawa

Holzforschung 2018.9

Noncontact evaluation of soluble solids content in apples by near-infrared hyperspectral imaging Reviewed

Te Ma, Xinze Li, Tetsuya Inagaki, Haoyu Yang, Satoru Tsuchikawa

Journal of Food Engineering Vol. 224 page： 53 - 61 2018.5

Authorship：Lead author Language：English Publishing type：Research paper (scientific journal) Publisher：Elsevier Ltd

© 2017 Elsevier Ltd Near-infrared (NIR) hyperspectral imaging was used to evaluate soluble solids content (SSC) in ‘Fuji’ apples [Malus sylvestris (L.) Mill. var. domestica (Borkh. Mansf.)]. Eighty ‘Fuji’ apples were analyzed by collecting four small block samples from each one (approximately 2.0 cm × 2.0 cm × 1.5 cm). Partial least squares (PLS) regression analysis was performed to determine the relation between SSC reference data and NIR spectral data measured from each sample. The cross-validation coefficient of determination (r2) between predicted and measured SSC values is 0.89 with a root mean squared error of cross-validation (RMSECV) of 0.55%. Then, we successfully mapped SSC at a high spatial resolution (375 μm per pixel). In addition, the absorption and reduced scattering coefficients of the measured samples were determined based on a diffusion theory model. The absorption coefficients are positively correlated to the SSC values (chemical information), whereas water cored tissue content (physical information) causes a characteristic change in light scattering coefficients. The fitting results were validated by Monte Carlo simulation, and the light penetration depth in ‘Fuji’ apples was estimated to be around 0.33 cm at 1198 nm and 0.17 cm at 1450 nm, respectively.

DOI： 10.1016/j.jfoodeng.2017.12.028

Web of Science

Scopus

Effect of cellular structure on the optical properties of wood Reviewed

Mayuka Ban, Tetsuya Inagaki, Te Ma, Satoru Tsuchikawa

Journal of Near Infrared Spectroscopy Vol. 26 ( 1 ) page： 53 - 60 2018.2

Language：English Publishing type：Research paper (scientific journal) Publisher：SAGE Publications Ltd

© 2018, © The Author(s) 2018. To construct robust calibrations of wood properties by near infrared spectroscopy, one must independently evaluate the spectral contributions of light absorption and light scattering. However, the light propagation in wooden cellular structures is difficult to interpret because these structures are complex, heterogeneous, and anisotropic. This study investigates the reduced scattering coefficients of softwood and hardwood (with ring-porous or diffuse-porous vessels) at 846 nm by time-resolved spectroscopy. It also evaluates the effect of wooden cellular structure and air-dry density on the light propagation. After determining the reduced scattering coefficients, we observed cross-sectional microscopic images of the wood samples. Eighty-five percent of the variation in the reduced scattering coefficients was explainable by the air-dry density, area ratio of the cell wall, and the median pore area. Monte Carlo simulations of the light propagation through wood revealed that most of the photon transport occurs in the cell-wall substance.

DOI： 10.1177/0967033518757233

Web of Science

Scopus

Near-infrared hyperspectral imaging for classification of mung bean seeds Reviewed

International Journal of Food Properties Vol. 21 ( 1 ) page： 799 - 807 2018

Rapid identification of wood species by near-infrared spatially resolved spectroscopy (NIR-SRS) based on hyperspectral imaging (HSI) Reviewed

Te Ma, Tetsuya Inagaki, Mayuka Ban, Satoru Tsuchikawa

Holzforschung 2018

High-resolution and non-destructive evaluation of the spatial distribution of nitrate and its dynamics in spinach (Spinacia oleracea l.) leaves by near-infrared hyperspectral imaging Reviewed

Hao Yu Yang, Tetsuya Inagaki, Te Ma, Satoru Tsuchikawa

Frontiers in Plant Science Vol. 8 page： 1937 2017.11

Language：English Publishing type：Research paper (scientific journal) Publisher：FRONTIERS MEDIA SA

© 2017 Yang, Inagaki, Ma and Tsuchikawa. Nitrate is an important component of the nitrogen cycle and is therefore present in all plants. However, excessive nitrogen fertilization results in a high nitrate content in vegetables, which is unhealthy for humans. Understanding the spatial distribution of nitrate in leaves is beneficial for improving nitrogen assimilation efficiency and reducing its content in vegetables. In this study, near-infrared (NIR) hyperspectral imaging was used for the non-destructive and effective evaluation of nitrate content in spinach (Spinacia oleracea L.) leaves. Leaf samples with different nitrate contents were collected under various fertilization conditions, and reference data were obtained using reflectometer apparatus RQflex 10. Partial least squares regression analysis revealed that there was a high correlation between the reference data and NIR spectra (r2 = 0.74, root mean squared error of cross-validation = 710.16 mg/kg). Furthermore, the nitrate content in spinach leaves was successfully mapped at a high spatial resolution, clearly displaying its distribution in the petiole, vein, and blade. Finally, the mapping results demonstrated dynamic changes in the nitrate content in intact leaf samples under different storage conditions, showing the value of this non-destructive tool for future analyses of the nitrate content in vegetables.

DOI： 10.3389/fpls.2017.01937

Web of Science

Scopus

PubMed

Calibration of SilviScan data of Cryptomeria japonica wood concerning density and microfibril angles with NIR hyperspectral imaging with high spatial resolution Reviewed

Te Ma, Tetsuya Inagaki, Satoru Tsuchikawa

Holzforschung Vol. 71 ( 4 ) page： 341 - 347 2017.4

Authorship：Lead author Language：English Publishing type：Research paper (scientific journal) Publisher：WALTER DE GRUYTER GMBH

© 2017 Walter de Gruyter GmbH, Berlin/Boston. Wood density and microfibril angle (MFA) are strongly correlated with wood stiffness, swelling/shrinkage, and its anisotropy. Understanding the spatial distribution of these data is critical for solid timber applications. In this study, near-infrared (NIR) hyperspectral imaging has been calibrated for evaluation of wood density and MFA in an effective manner. Briefly, five wood samples collected from both normal wood (NW) and compression wood (CW) moieties of two different Cryptomeria japonica trees were analyzed. Partial least squares (PLS) regression analysis was performed to determine the relationship between X-ray densitometry data obtained by SilviScan and NIR spectra, and cross-validation (leave-one-out) approach served for prediction performances. The validation coefficient of determination (r2) between the predicted densities by the NIR technique and the X-ray data was 0.83 with a root mean squared error of cross-validation (RMSECV) of 105.2 kg m-3. Regarding MFA, the r2 was 0.77 and RMSECV 5.36°. Wood density was successfully maped as well as the MFA at a high spatial resolution. As a result, the detection of annual growth ring features and evaluation of aspects of heterogeneous wood quality has been facilitated. The mapping results were visually checked by looking at the difference between earlywood (EW) and latewood (LW) for density and by means of the Mäule color reaction indicating high lignin contents in CW in terms of MFA validation as CWs have high MFA values.

DOI： 10.1515/hf-2016-0153

Web of Science

Scopus

High spatial resolution and non-destructive evaluation of wood density and microfibril angle by NIR hyperspectral imaging Reviewed

Te Ma, Tetsuya Inagaki, Satoru Tsuchikawa

NIR news Vol. 28 ( 5 ) page： 7-12 2017

Classification of mung bean seeds for sprout production using near-infrared spectroscopy and hyperspectral imaging Reviewed

Kaewkarn Phuangsombu, Anupun Terdwongworakul, Nattaporn Suttiwijitpukdee, Arthit Phuangsombu, Satoru Tsuchikawa, Tetsuya Inagaki, Te Ma

Thai Society of Agricultural Engineering Journal Vol. 23 ( 1 ) page： 23-29 2017

High spatial resolution and non-destructive evaluation of wood density and microfibril angle by NIR hyperspectral imaging Reviewed

Te Ma, Tetsuya Inagaki, Satoru Tsuchikawa

NIR news Vol. 28 ( 5 ) page： 7-12 2017

Non-destructive inspection of insects in chocolate using near infrared multispectral imaging Reviewed

Te Ma, Hikaru Kobori, Norihisa Katayama, Satoru Tsuchikawaa

Journal of Near Infrared Spectroscopy Vol. 24 ( 4 ) page： 391 - 397 2016

Authorship：Lead author Language：English Publishing type：Research paper (scientific journal) Publisher：N I R PUBLICATIONS

© IM Publications LLP 2016. Foreign matters in food products strongly affect the commercial viability of food production companies. To monitor and improve the reliability of food production processes, fast and non-destructive online inspection methods are urgently required. In this study, we exploited the high transmittance of near infrared (NIR) light, and designed an NIR transmission-type imaging device that detects lowdensity foreign matters (such as insects) inside chocolate. Insect parts had consistently lower transmittance than chocolate parts. To enhance the important differences between the two parts, the images were processed using principal component analysis. Furthermore, an algorithm for detecting the insect parts was developed in conjunction with image threshold processing and Laplacian of Gaussian edge detection. A favourable detection rate (93%) was achieved using spectral regions 840-870 nm, 870-900 nm and 900-930 nm. The results suggested that NIR multispectral imaging is useful for detecting low-density matter (insects) in the chocolate manufacturing industry.

DOI： 10.1255/jnirs.1237

Web of Science

Scopus

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Papers - MA Te