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Second-order Calibration

Max Nimmer, Gabriele Steidl, Rainer Riesenberg, Andreas Wuttig
We present a variational approach to reconstruct a multispectral image from an array of diffraction patterns captured in one monochromatic image. The mathematical model relies on the superposition of wavelength dependent calibration diffraction patterns and a spectral regularization with second order differences. The necessary preprocessing steps which influence the mathematical setting are discussed in detail. For computing a minimizer of our model we propose an active set method with model specific modifications...
October 29, 2018: Optics Express
Gareth D Lewis, Patrick Merken, Marijke Vandewal
In this paper, we demonstrate an improvement in the accuracy of a low-cost smart temperature sensor, by measurement of the nonlinear curvature correction at multiple temperature references. The sensors were positioned inside a climate chamber and connected outside to a micro-controller via a network cable. The chamber temperature was increased systematically over a wide range from -20 °C to 55 °C. A set of calibration curves was produced from the best fitting second-order polynomial curves for the offset in temperature between the sensor and reference...
November 22, 2018: Sensors
Shutao Wang, Qi Cheng, Yuanyuan Yuan, Changbing Wang, Shuangna Ma
Methanol gasoline, known as a new energy, has a certain degree of damage to automobile. The aim of this work was to identify and quantify the methanol in methanol gasoline using three-dimensional fluorescence spectroscopy technique combined with second order chemometric methods. Parallel factor analysis (PARAFAC) and self-weighted alternating trilinear decomposition (SWATLD) methods were used to analyse artificial samples. However, the obtained results by PARAFAC were not satisfactory. On the other hand, excellent prediction results were obtained when SWATLD model was applied, with recovery rate between 98...
November 15, 2018: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
Zakriya Mohammed, Ibrahim Abe M Elfadel, Mahmoud Rasras
With the continuous advancements in microelectromechanical systems (MEMS) fabrication technology, inertial sensors like accelerometers and gyroscopes can be designed and manufactured with smaller footprint and lower power consumption. In the literature, there are several reported accelerometer designs based on MEMS technology and utilizing various transductions like capacitive, piezoelectric, optical, thermal, among several others. In particular, capacitive accelerometers are the most popular and highly researched due to several advantages like high sensitivity, low noise, low temperature sensitivity, linearity, and small footprint...
November 16, 2018: Micromachines
Felix Leeb, Lutz Maibaum
We study the effect of cholesterol on the structure of dipalmitoylphosphatidylcholine phospholipid bilayers. Using extensive molecular dynamics computer simulations at atomistic resolution, we observe and quantify several structural changes upon increasing cholesterol content that are collectively known as the condensing effect: a thickening of the bilayer, an increase in lipid tail order, and a decrease in lateral area. We also observe a change in leaflet interdigitation and a lack thereof in the distributions of dipalmitoylphosphatidylcholine headgroup orientations...
November 2, 2018: Biophysical Journal
Zbigniew Suchorab, Marcin Konrad Widomski, Grzegorz Łagód, Danuta Barnat-Hunek, Dariusz Majerek
The article presents the potential application of the time domain reflectometry (TDR) technique to measure moisture transport in unsaturated porous materials. The research of the capillary uptake phenomenon in a sample of autoclaved aerated concrete (AAC) was conducted using a TDR sensor with the modified construction for non-invasive testing. In the paper the basic principles of the TDR method as a technique applied in metrology, and its potential for measurement of moisture in porous materials, including soils and porous building materials are presented...
November 14, 2018: Sensors
Yashar Seyed Vahedein, Alexander S Liberson
Reduced fluid-structure interaction models are the key component of hemodynamic simulation. In this work, a multi-purpose computational model applicable to specific physiological components such as arterial, venous and cerebrospinal fluid circulatory systems has been developed based on the Hamilton's variational principle. This model encompasses a viscous Newtonian fluid structure interaction (FSI) framework for the large compliant bifurcated arterial networks and its subsystems. This approach provides the groundworks for a correct formulation of reduced FSI models with an account for arbitrary non-linear viscoelastic properties of a compliant vascular tree...
July 2018: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
L F Sommer, C Barreira, C Noriega, F Camargo-Junior, R T Moura, A Forner-Cordero
This paper presents a method to estimate the elbow joint angle from surface electromyography (sEMG) measurements of biceps, triceps and brachioradialis. This estimation is of major importance for the design of human robot interfaces based on sEMG. It is also relevant to model the muscular system and to design biomimetic mechanisms. However, the processing and interpretation of electromyographic signals is challenging due to nonlinearities, unmodeled muscle dynamics, noise and interferences. In order to determine an estimation model and a calibration procedure for the model parameters, a set of experiments were carried out with six subjects...
July 2018: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
Michele Tepedino, Marie A Cornelis, Claudio Chimenti, Paolo M Cattaneo
INTRODUCTION: The selection of appropriate sites for miniscrew insertion is critical for clinical success. OBJECTIVES: The aim of the present study was to evaluate how interradicular spaces measured on panoramic radiograph compare with Cone-Beam Computed Tomography (CBCT), and how crowding can influence the presence of available space for miniscrew insertion, in order to define a new "safe zones" map. METHODS: A total of 80 pre-treatment panoramic radiographs and 80 CBCT scans with corresponding digital models were selected from the archives of the department of Dentistry, Aarhus University...
September 2018: Dental Press Journal of Orthodontics
S Kado, A Iwata, T Kanazawa, H Okada, S Yamamoto, G Motojima, H Okazaki, T Minami, S Kobayashi, K Nagasaki, S Ohshima, Y Nakamura, A Ishizawa, S Konoshima, T Mizuuchi
A simple near-infrared (NIR) spectrometer with a wavelength range of 898-2130 nm has recently been applied to diagnose Heliotron J plasmas. It adopts a symmetrical crossed Czerny-Turner mount equipped with a thermoelectrically cooled 512 channel InGaAs linear sensor. Reciprocal linear dispersion was deduced to 96.37 nm/mm at the center of the detector. External filters can be inserted into the path of the collection optics to reject second-order spectra, as needed. Absolute intensity calibration was performed together with a visible spectrometer using a tungsten halogen lamp, and the effect of the transmittance fringe in the visible region of the applied long-pass filter on the NIR calibration was investigated...
October 2018: Review of Scientific Instruments
Jungmin Jo, MunSeong Cheon, Junghee Kim, Soobin Lim, M Isobe, K Ogawa, T Nishitani, Seugil Park, I Murata, Kyoung-Jae Chung, Y S Hwang
In time-resolved measurement for triton burnup in Korea Superconducting Tokamak Advanced Research (KSTAR) deuterium plasmas, an NE213 liquid scintillation detector was installed and operated during the 2017 KSTAR campaign. The detector is composed of an NE213 scintillator (50 mm in diameter and 10 mm in thickness) and a photomultiplier tube (PMT). The PMT anode signal was processed under a data acquisition system which contains a field programmable gate array circuit and pulse processing software that is capable of discriminating gamma-ray and neutron pulse signals...
October 2018: Review of Scientific Instruments
E M Granstedt, D Fallah, M C Thompson
Two filtered, fast-imaging instruments, with radial and axial views, respectively, were used on the C-2U device to visualize line emission from impurities and hydrogenic neutrals. Novel calibration techniques needed to be developed for these instruments because the accelerated pace of C-2U operations precluded access to the interior of the vacuum vessel, targets used in typical calibration methods were not available, and in order to account for effects which have not been sufficiently addressed in the literature...
October 2018: Review of Scientific Instruments
Mohammed S Aldossary, Siti Suria Abu Hajia, Ario Santini
OBJECTIVE: To measure Total Light Energy (TLE) Transmission through six makes of ceramic orthodontic brackets alone and bracket-plus-adhesive samples, using the MARC™-Resin Calibrator (RC). METHODS: Six makes, three each monocrystalline (M) and polycrystalline (P) were used; PureSapphire (M), SPA Aesthetic (M), Ghost (M), Mist (P), Reflections (P), and Dual Ceramic (P). The Ortholux™ Light Curing Unit (LCU) was used to cure the orthodontic adhesive Transbond™XT...
December 2018: International Orthodontics
Dominik Schneidereit, Stefanie Nübler, Gerhard Prölß, Barbara Reischl, Sebastian Schürmann, Oliver J Müller, Oliver Friedrich
Skeletal muscle is an archetypal organ whose structure is tuned to match function. The magnitude of order in muscle fibers and myofibrils containing motor protein polymers determines the directed force output of the summed force vectors and, therefore, the muscle's power performance on the structural level. Structure and function can change dramatically during disease states involving chronic remodeling. Cellular remodeling of the cytoarchitecture has been pursued using noninvasive and label-free multiphoton second harmonic generation (SHG) microscopy...
2018: Light, Science & Applications
Barbara Schneider-Muntau, Iman Bathaeian
In this study we investigate the development of shear zones due to the settlement of shallow foundations and their load-settlement behavior. Firstly, a well-documented experiment of shallow penetration into sand is used for the validation of the soft particle code (SPARC). For these simulations a hypoplastic material model for sand with calibration for the model sand is implemented in SPARC. In order to deliver a more comprehensive investigation, the shape of the shear zones predicted by SPARC is also compared with the analytical solution...
2018: GEM: International Journal on Geomathematics
Giovanna Dipasquale, Alexis Poirier, Yannick Sprunger, Johannes Wilhelmus Edmond Uiterwijk, Raymond Miralbell
BACKGROUND: Computed tomography (CT) data used for patient radiotherapy planning can nowadays be used to create 3D-printed boluses. Nevertheless, this methodology requires a second CT scan and planning process when immobilization masks are used in order to fit the bolus under it for treatment. This study investigates the use of a high-grade surface-scanner to produce, prior to the planning CT scan, a 3D-printed bolus in order to increase the workflow efficiency, improve treatment quality and avoid extra radiation dose to the patient...
October 19, 2018: Radiation Oncology
Yongsheng Hong, Ruili Shen, Hang Cheng, Yiyun Chen, Yong Zhang, Yaolin Liu, Min Zhou, Lei Yu, Yi Liu, Yanfang Liu
Heavy metal contamination of peri-urban agricultural soil is detrimental to soil environmental quality and human health. A rapid assessment of soil pollution status is fundamental for soil remediation. Heavy metals can be monitored by visible and near-infrared spectroscopy coupled with chemometric models. First and second derivatives are two commonly used spectral preprocessing methods for resolving overlapping peaks. However, these methods may lose the detailed spectral information of heavy metals. Here, we proposed a fractional-order derivative (FOD) algorithm for preprocessing reflectance spectra...
February 15, 2019: Science of the Total Environment
Tie Liu, Xiao-Na An, De-Long Liu, Yong-Ju Wei
This work presents a greener approach for simultaneous determination of neomangiferin and mangiferin, the major bioactive constituents with severe spectral overlapping in Anemarrhenae Rhizoma, combining the sensitivity of molecular fluorescence and the selectivity of chemometric multivariate calibration algorithms. In this study, we compared the analytical performance of two group chemometric algorithms including trilinear algorithms such as parallel factor analysis (PARAFAC), alternating trilinear decomposition (ATLD), self-weighted alternating trilinear decomposition (SWATLD) and alternating penalized trilinear decomposition (APTLD), and PLS-based methods such as unfolded partial least-squares or the multi-dimensional partial least-squares, both combined with residual bilinearization (U-PLS/RBL, N-PLS/RBL)...
February 5, 2019: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
Samaneh Fooladi, Tribikram Kundu
The Distributed Point Source Method (DPSM) is a modeling technique based on superposition of fundamental solutions corresponding to individual pair of source and target points. A collection of source points distributed over the boundaries and interfaces are responsible for transmission, reflection, and refraction of acoustic waves in the solution domain. The strength of the source points may not be known a priory. By imposing the prescribed conditions on the boundaries and interfaces, a system of equations with the source strengths as the unknowns is obtained...
September 7, 2018: Ultrasonics
Xiao-Li Yin, Hui-Wen Gu, Ali R Jalalvand, Ya-Juan Liu, Ying Chen, Tian-Qin Peng
The quantification of preservatives in cosmetics has attracted great attentions for their controversial and widespread use. HPLC is a prevailing method for preservatives determination among various analytical methods. However, it takes long time to fully separate these compounds because of the complexity of cosmetic matrices. In this study, a fast and green HPLC-DAD strategy assisted with second-order multivariate calibration methods based on alternating trilinear decomposition (ATLD) and multivariate curve resolution-alternating least squares (MCR-ALS) was developed for the simultaneous determination of eight selected preservatives in complex facial mask samples...
October 26, 2018: Journal of Chromatography. A
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