A Novel Estimation Method of Wind Speed and Direction Based on GNSS/INS/ADS Integrated Navigation

Arriving on time is of great importance for flight management and passenger experience. One of the essential factors that impacts on-time arrival is the wind condition. Accurate information of wind speed and direction around the fuselage helps to improve the performance of on-time arrival and four-dimensional trajectory (4DT) planning. To determine accurate wind information in real-time, a novel airborne estimation method of wind speed and direction is proposed in this paper. Inertial Navigation System (INS), Global Satellite Navigation System (GNSS), and Air Data System (ADS) are fused in an Unscented Kalman Filter (UKF), which provides great accuracy and robustness in nonlinearity conditions. The dynamic models of wind are established, and implementations of the UKF are detailed. Finally, simulations are designed and the effectiveness of the proposed method is verified through the comparison with the traditional direct measurement method. Results demonstrate that the accuracy of wind speed and direction obtained by our method is nearly two times higher than the traditional direct measurement method.

JOM-4S Overhauser Magnetometer and Sensitivity Estimation

The Overhauser magnetometer is a scalar quantum magnetometer based on the dynamic nuclear polarization (DNP) effect in the Earth’s magnetic field. Sensitivity is a key technical specification reflecting the ability of instruments to sense small variations of the Earth’s magnetic field and is closely related to the signal-to-noise ratio (SNR) of the free induction decay (FID) signal. In this study, deuterated 15N TEMPONE radical is used in our sensor to obtain high DNP enhancement. The measured SNR of the FID signal is approximately 63/1, and the transverse relaxation time T2 is 2.68 s. The direct measurement method with a single instrument and the synchronous measurement method with two instruments are discussed for sensitivity estimation in time and frequency domains under different electromagnetic interference (EMI) environments and different time periods. For the first time, the correlation coefficient of the magnetic field measured by the two instruments is used to judge the degree of the influence of the environmental noise on the sensitivity estimation. The sensitivity evaluation in the field environment is successfully realized without electrical and magnetic shields. The direct measurement method is susceptible to EMI and cannot work in general electromagnetic environments, except it is sufficiently quiet. The synchronous measurement method has an excellent ability to remove most natural and artificial EMIs and can be used under noisy environments. Direct and synchronous experimental results show that the estimated sensitivity of the JOM-4S magnetometer is approximately 0.01 nT in time domain and approximately 0.01 nT/ in frequency domain at a 3 s cycling time. This study provides a low-cost, simple, and effective sensitivity estimation method, which is especially suitable for developers and users to estimate the performance of the instrument.

Measurement method for incisions ablated by femtosecond laser in biological soft tissues

BackgroundHematoxylin and Eosin staining in paraffin embedded tissue (H&E staining in paraffin embedded tissue) is a widely used method in the incision dimensions measurement. Since H&E staining in paraffin embedded tissue requires complicated process and spends a lot of time, a direct measurement method based on a microscope is proposed to measure the incision dimensions, which greatly improves the efficiency.AimIn this paper, a direct measurement method using optical microscope and an indirect measurement method based on H&E staining in paraffin embedded tissue are presented and compared, so as to obtain a better method of measurement efficiency and accuracy.ApproachThe femtosecond laser is used to process chicken breast tissue, the directly measurement method based on a microscope and indirectly measurement method based on H&E staining are used to measure dimensions. Moreover, the laser confocal microscopy measurement (LCM) is also used to measure the incision depth.ResultsIt was found that the direct measurement method has high measurement efficiency and accuracy for incision dimensions measurement.ConclusionsOverall, the incision dimensions obtained by femtosecond laser processing can be measured through the direct measurement method instead of H&E staining in paraffin embedded tissue.

Seabird Biologging System with Compact Waterproof Airflow Sensor

This paper presents a seabird biologging system with a compact waterproof airflow sensor. Although biologging methods have attracted attention in the evaluation of seabird flight performance, a direct measurement method of airflow velocity has not yet been established. When an airflow sensor is added to a biologging system, a more accurate assessment of the flight performance can be obtained. We developed a compact Pitot tube-type airflow sensor that is specialized for seabird biologging systems. Here, we integrated micro electro mechanical system (MEMS) sensor chips and a sensing circuit into the Pitot tube housing. Then, we conducted a wind tunnel experiment using a stuffed seabird and the fabricated sensor. The results confirmed that the sensor responds to the wind speed even when attached to the dorsal surface of the seabird. Based on the above, we believe that the proposed sensor can be applied to practical seabird biologging systems.

A Study of the Effect of Fusion of Multi-Sensor and Cutting Chip Color on the Lifetime of Cutting Tool Coated with TiAlN

In the mold machining process, the cutting tool is worn with machining time, thereby affecting the surface accuracy, leading to poor workpiece dimensions, even fracture. At present, many studies have used multiple sensors to detect the machining conditions of cutting tool and workpiece, including indirect measurement method and direct measurement method. The indirect measurement method, which has been studied widely, mainly uses sensors to capture signals for subsequent data analysis; the direct measurement method mainly analyzes the state of cutting shear zone. Due to the cut-in of cutting tool in the machining process, the workpiece is dislocated rapidly, generating considerable amount of heat, which is transferred to the chips, inducing color change on the surface of chips. Many engineers with machining experience often judge the machining state and tool life according to the chips. The engineers' experience is digitized in this study, and indirect measuring sensors are used to predict the tool life, so as to attain the objective for smart manufacturing, the average percentage error of MAPE using single vibration and voltage eigenvalues as input features is 10%, the voltage signal characteristic values and vibration signal characteristic values are combined. Finally, the chip surface chromaticity eigenvalue is combined with signal characteristic value. The average prediction error of BP-LM method is 7.85%, the average prediction error of GRNN method is 6.59%. Therefore, when the eigenvalue of chip surface chromaticity is added to the prediction result, it can enhance the accuracy of cutting tool wear value prediction more effectively than single sensor signal characteristic value.

MACRO- AND MICRO-DISPERSION OF SILICA IN TIRE TREAD COMPOUNDS: ARE THEY RELATED?

ABSTRACT The dispersion of rubber fillers, such as silica, can be divided into two categories: macro- and micro-dispersion. Both dispersions are important; however, to achieve the best reinforcement of rubber, micro-dispersion of silica is crucial. The common view is that these filler dispersions are strongly related. The micro-dispersion is understood as the consequence of the continuous breakdown of filler clusters from macro-dispersion. Yet, a large problem is that an objective unequivocal direct measurement method for micro-dispersion is not available. In this study, a set of parameters is defined that are anticipated to have an influence on the micro- as well as the macro-dispersion. Mixing trials are performed with varying silanization temperature and time, different amounts of silane coupling agent, and by using silicas with different structures and specific surface areas. The degrees of micro- and macro-dispersion are evaluated by measuring the Payne effect as an indirect method for micro-dispersion and using a dispergrader for quantitative measurement of macro-dispersion. The results show that the filler dispersion processes happen simultaneously but independently. These results are supported by earlier work of Blume and Uhrlandt, who stated as well that micro- and macro-dispersion are independent. The major influencing factors on micro- and macro-dispersion of silica are also identified.

Gingival biotype - comparative analysis of different evaluation methods

Background/Aim. Gingival biotype can have a significant impact on the outcome of the periodontal therapeutic procedures and on the predictability of their aesthetic outcome. There is a strong correlation between the types of biotype and the potential gingival recession after restorative, periodontal and implant surgical procedures. Therefore, accurate identification of gingival biotypes, before initiating these procedures, is one of the significant predictive factors for their success. The aim of this study was to evaluate reliability of accurate gingival biotype determination with the use of visual method, periodontal and trans-gingival probing compared to the direct measurement method. Methods. This prospective study involved 33 patients indicated for the apical root resection in the intercanine sector of the upper jaw. Gingival biotype identification was performed in all of the patients using the following techniques: 1) visual method; 2) periodontal probe technique; 3) trans-gingival probing; 4) direct measurement after flap elevation was performed. Statistical analysis of the obtained data was performed to assess the diagnostic accuracy of the visual method, periodontal probing method and trans-gingival probing method, in relation to the direct measurement method, used as a gold standard, to discriminate the gingival thickness biotype (thin versus thick). Results. The overall accuracy of the tested diagnostic procedures, compared to direct gingival biotype measurement, was: 66.7% for visual method; 78.8% for periodontal probing; and 97.0% for trans-mucosal probing. Conclusion. Periodontal probing method can be recommended for gingival biotype determination as a routine method, due to the fact that its sensitivity and overall accuracy is higher compared to the visual method. The trans-gingival method, in terms of sensitivity and comprehensive accuracy, almost completely coincides with the direct method, but it is more invasive compared to periodontal probing method and it has to be conducted in local anesthesia.

Effect of Fe2O3 and CeO2 on Transmittance of Y2O3 Stabilized Tetragonal Zirconia Polycrystals

The present study is to investigate the effect of metal oxides Fe2O3 and CeO2 on the structural and optical characteristics of Y2O3 stabilized tetragonal zirconia ceramic (Y-TZP). Different concentrations of Fe2O3 and CeO2 are added into Y-TZP to fabricate the colored Y-TZP. The chromaticity and transmittance were measured by spectrophotometer. The effect of each colorant on color and transmittance of Y-TZP is quantitatively studied. Most of the previous related studies used indirect methods for measurement, but in order to get more accurate results, we chose the direct measurement method. It is found that the addition of Fe2O3 and CeO2 not only changes the color of Y-TZP, but also reduces the light transmittance. The SEM characterization and XRD analysis are then performed to check the microstructure and crystal structure respectively, by which we try to understand the microscopic principle. Our findings can improve the understanding of coloration of Y-TZP by mental oxides, and support a quantitative assessment approach for aesthetic performance of dental restoration material.