Precise disturbance modeling for improvement of positioning performance

This paper presents a modeling methodology for unknown disturbances in mechatronics systems, based on disturbance estimation using an iterative learning process. In disturbance modeling, nonlinear frictions are specially handled as disturbances in the mechanisms, which mainly degrade trajectory control performance. Friction can be mathematically modeled by using learned estimation data as a function of the displacement, velocity. acceleration, and jerk of the actuator. This model has the distinctive feature that friction compensation can be achieved with a generalization capability for different conditions. The proposed positioning control approach with disturbance modeling and compensation has been verified by experiments using a table drive system on a machine stand. © 2010 Wiley Periodicals, Inc. Electr Eng Jpn, 171(2): 31–39, 2010; Published online in Wiley InterScience ( www. interscience.wiley.com ). DOI 10.1002/eej.20928     

Fundamental study of high Q‐factor RF spiral inductor using carbonyl‐iron/epoxy composite magnetic core

In order to increase the Q‐factor of an RF spiral inductor used in the RF front‐end circuit of smartphone handsets, we introduced a carbonyl‐iron/epoxy composite magnetic core in the air‐core spiral inductor. The composite magnetic core, which was made by metal‐mask printing, consisted of carbonyl‐iron powder of 1.1 μm mean diameter and an epoxy resin matrix. We found that the 45 vol.% CIP composite magnetic core had a saturation magnetization of 0.9 T, relative permeability of ∼6, and loss tangent (tan δ) of ∼0.2 at 1 GHz. A two‐turn copper spiral inductor fabricated with the composite magnetic core filled only in the spacing between the conductor lines showed a clear Q‐factor increase of ∼29% compared to the air‐core spiral inductor at 1 GHz. Thus we obtained a substantial increase in the Q‐factor by the embedded composite magnetic core in the spacing between the conductor lines. The main reason for this is that the magnetic flux passing through the conductor lines was decreased by the magnetic core embedded in the spacing between conductor lines as a result of the magnetic flux passing mainly through the embedded magnetic core. Therefore, proximity effect is suppressed in the conductor line of the spiral coil. © 2016 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Spectroscopic imaging and the characterization of the autofluorescence properties of human bronchus tissues using UV laser diodes

Ultraviolet laser diodes (UV-LD) were used for the excitation source of autofluorescence (AF) measurements and spectroscopic imaging of the AF originating from the human bronchus was obtained. The AF spectra from normal bronchus tissues were measured and a clear AF spectrum was obtained by using a short wavelength (400 nm) laser diode; the overlap of the AF signal and excitation source could be substantially eliminated. In order to study the origin of AF intensity deterioration from bronchus tissue due to the formation of tumor tissues, the fluorescence spectrum was measured for various AF substances under various conditions. The blue AF signal of elastin and NADH solutions, which could not be easily studied by conventional excitation light sources, as well as the green AF became weak by adding lactic acid. The AF spectrum was measured for 512/spl times/512 pixels and the intensity mapping as a function of emission wavelength was obtained. Two-dimensional information of the AF signal intensity distribution for a certain wavelength component was measured. The feature originating from a region as small as about 100 /spl mu/m could be recognized. Numerical calculations of the data were performed and precise features of the AF were revealed.     

Low‐Noise Fully Differential Amplifiers Using JFET‐CMOS Integration Technology for Smart Sensors

In this paper, CMOS‐based low‐noise amplifiers with JFET‐CMOS technology for high‐resolution sensor interface circuits are presented. A differential difference amplifier (DDA) configuration is employed to realize differential signal amplification with very high input impedance, which is required for the front‐end circuit in many sensor applications. Low‐noise JFET devices are used as input pair of the input differential stages or source‐grounded output load devices, which are dominant in the total noise floor of DDA circuits. A fully differential amplifier circuit with pure CMOS DDA and three types of JFET‐CMOS DDAs were fabricated and their noise performances were compared. The results show that the total noise floor of the JFET‐CMOS amplifier was much lower compared to that of the pure CMOS configuration. The noise‐reduction effect of JFET replacement depends on the circuit configuration. The noise reduction effect by JFET device was maximum of about − 18 dB at 2.5 Hz. JFET‐CMOS technology is very effective in improving the signal‐to‐noise ratio (SNR) of a sensor interface circuit with CMOS‐based sensing systems. © 2008 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Enzymatic Analysis of Positional Distribution of Fatty Acids in Solid Fat by 1,3-Selective Transesterification with Candida antarctica Lipase B

A protocol for the analysis of the positional distribution of fatty acids (FA) in solid triacylglycerols (TAG) was developed using sn-1(3) selective alcoholysis catalyzed by immobilized Candida antarctica lipase B (CALB). One part by weight of solid fat and ten parts by weight of ethanol (99.5 %) were warmed to liquefy the fat. After adding 0.44 parts by weight of CALB, the mixture was shaken at 50 °C for 10 min then at 30 °C for 2.8 h. The recovery of 2-MAG after the 3-h transesterification reaction was ca. 85 % of the maximum theoretical yield (33 mol%), with the loss of 15 % attributable to the acyl migration from sn-2 to sn-1(3). The recovery was similar to that of the solvent-free alcoholysis of structured lipids, 1,3-dipalmitoyl, 2-oleoyl glycerol and 1,3-dioleoyl, 2-palmitoyl glycerol, conducted at 30 °C for 3 h. In contrast, the acyl migration from sn-1(3) to sn-2 was hardly observed. Because the detected acyl migration was only in the direction of sn-2 to sn-1(3), and not vice versa, it is proposed to determine the FA composition of the sn-2 position of TAG by the gas chromatographic analysis of 2-MAG fraction recovered from the enzymatic reaction mixture, and the FA composition of sn-1(3) position by a mass balance using the FA composition of TAG and of the sn-2 position as inputs. The procedure was successfully applied to palm oil and shea butter, and docosahexaenoic acid (DHA)-rich single cell oil from Aurantiochytrium sp. KH105 for the first time.     

Dyeing of natural fibres from perfluoro-polyether reverse micelles in supercritical carbon dioxide

The dyeing of natural fibres from a reverse-micellar system in supercritical carbon dioxide has been investigated using ammonium carboxylate perfluoropolyether as surfactant. Protein fibres such as silk and wool were satisfactorily dyed in deep shades with conventional acid dyes without special pretreatment. Exhaustion was excellent. It was however found that on these fibres the performance of acid dyes was strongly influenced by temperature and carbon dioxide density. Conventional reactive dyes in this system were adsorbed on cotton, even in the absence of dyeing auxiliaries, but the fixation of the dye was not satisfactory. Compared with supercritical dyeing methods reported previously, it was found in this study that the temperature and pressure required were significantly lower.     

Wide Color Variation in SiNO Thin Films Dispersed with Precipitated TiN Nano Particles

Amorphous thin films of Ti_1?ySi_y(N,O) with y ≥ 0.38 were prepared by reactive sputter deposition in a nitrogen atmosphere. Thermal annealing of the films in an ammonia flow above 800°C yielded Si(N,O) amorphous thin films dispersed with precipitated TiN nanosized particles. The film color changed with Si content y and the annealing conditions, from carrot orange to cream yellow in the as‐deposited films due to their oxynitride nature, and from dark green to canary yellow and from iron blue to horizon blue at respective annealing temperatures of 800°C and 900°C due to metallic nature of the TiN nanosized particles precipitated in the annealing.     

Verification of FM9801: An Out-of-Order Microprocessor Model with Speculative Execution, Exceptions, and Program-Modifying Capability

We have verified the FM9801, a microprocessor design whose features include speculative execution, out-of-order issue and completion of instructions using Tomasulo's algorithm, and precise exceptions and interrupts. As a correctness criterion, we used a commutative diagram that compares the result of the pipelined execution from a flushed state to another flushed state with that of the sequential execution. Like many pipelined microprocessors, the FM9801 may not operate correctly if the executed program modifies itself. We discuss the condition under which the processor is guaranteed to operate correctly. In order to show that the correctness criterion is satisfied, we introduce an intermediate abstraction that records the history of executed instructions. Using this abstraction, we define a number of invariant properties that must hold during the operation of the FM9801. We verify these invariant properties, and then derive the proof of the commutative diagram from them. The proof has been mechanically checked by the ACL2 theorem prover.     

A comparison of classification algorithms using Landsat-7 and Landsat-8 data for mapping lithology in Canada’s Arctic

To map Arctic lithology in central Victoria Island, Canada, the relative performance of advanced classifiers (Neural Network (NN), Support Vector Machine (SVM), and Random Forest (RF)) were compared to Maximum Likelihood Classifier (MLC) results using Landsat-7 and Landsat-8 imagery. A ten-repetition cross-validation classification approach was applied. Classification performance was evaluated visually and statistically using the global classification accuracy, producer’s and user’s accuracies for each individual lithological/spectral class, and cross-comparison agreement. The advanced classifiers outperformed MLC, especially when training data were not normally distributed. The Landsat-8 classification results were comparable to Landsat-7 using the advanced classifiers but differences were more pronounced when using MLC. Rescaling the Landsat-8 data from 16 bit to 8 bit substantially increased classification accuracy when MLC was applied but had little impact on results from the advanced classifiers.