scholarly journals A novel Technique for Improving the Angular Accuracy of Doppler VOR Receivers

2021 ◽  
Vol 19 ◽  
pp. 1-7 ◽  
Author(s):  
Karsten Schubert ◽  
Jens Werner ◽  
Jens Wellhausen
Keyword(s):  
Azimuth Angle ◽  
New Method ◽  
Two Phase ◽  
Directional Information ◽  
Total Uncertainty ◽  
Novel Technique ◽  
Novel Method ◽  
Phase Uncertainty ◽  
The Difference ◽  
Increase In Accuracy

Abstract. Doppler VOR (D-VOR) transmitters are used as navigation aids in aviation. They transmit an omnidirectional phase reference in an amplitude-modulated (AM) sideband and directional phase information on a frequency-modulated (FM) subcarrier. In an airborne D-VOR navigation receiver, a directional information (azimuth angle) related to the position of the aircraft and the location of the transmitter can be derived from the difference of these two phase signals. In this work, the accuracy of AM and FM phase signals is firstly investigated analytically and afterwards verified by measurements. It will be shown that in established procedures, phase inaccuracy is dominated by the AM signal, since the FM signal is about 21 dB less noisy. Subsequently, a novel method is presented that improves the accuracy of the azimuth angle by orders of magnitude in case of D-VOR transmitters. This new method inherently reduces noise of the AM phase and thus yields a significant increase in accuracy. As a result, the remaining FM phase uncertainty becomes dominant for the total uncertainty of the bearing indication. Finally, the application of the new method to real measured signals confirms the theoretical expectations.

A novel technique for fabricating an ear prosthesis in a patient with congenital ear deformity

2012 ◽  
Vol 37 (4) ◽  
pp. 340-343 ◽  
Author(s):  
Mohammad Ali Mardani ◽  
Gholamreza Aminian ◽  
Farhad Tabatabaian ◽  
Mokhtar Arazpour ◽  
Stephen W Hutchins ◽  
...  
Keyword(s):  
Clinical Relevance ◽  
Low Cost ◽  
Ease Of Use ◽  
Psychological Effects ◽  
New Method ◽  
Novel Technique ◽  
Ear Deformity ◽  
The Social ◽  
Novel Method

Background and aim: Microtia is one of the forms of ear loss and deformity. A prosthesis that is simple to apply, and which has adequate suspension and acceptable aesthetics, can be useful in the rehabilitation of patients with this deficit and can improve the social and psychological effects of patients with ear amputation. The aim of this article was to describe a novel technique for fabricating ear prosthesis in a patient with congenital ear deformity. Technique: This method involves a novel method to produce an ear prosthesis using clips that were located within the layers of the final silicone ear. Discussion: This study demonstrated ease of use and acceptance by the patient. Design and fabrication of silicone ear prosthesis via this new method of suspension could also be suitable for provision to children with ear microtia who are not yet suitable for surgery or would not be suited to other methods of suspension. Clinical relevance The new method of suspension demonstrated that this approach could be used to provide low cost and acceptable silicone ear prosthesis for patients with microtia and partial ear amputation.

scholarly journals Machine Learning Model of Dimensionless Numbers to Predict Flow Patterns and Droplet Characteristics for Two-Phase Digital Flows

2021 ◽  
Vol 11 (9) ◽  
pp. 4251
Author(s):  
Jinsong Zhang ◽  
Shuai Zhang ◽  
Jianhua Zhang ◽  
Zhiliang Wang
Keyword(s):  
Machine Learning ◽  
Learning Algorithms ◽  
Digital Microfluidics ◽  
Flow Patterns ◽  
Machine Learning Algorithms ◽  
Dimensionless Numbers ◽  
Two Phase ◽  
The Difference ◽  
Input Variables ◽  
Digital Microfluidic

In the digital microfluidic experiments, the droplet characteristics and flow patterns are generally identified and predicted by the empirical methods, which are difficult to process a large amount of data mining. In addition, due to the existence of inevitable human invention, the inconsistent judgment standards make the comparison between different experiments cumbersome and almost impossible. In this paper, we tried to use machine learning to build algorithms that could automatically identify, judge, and predict flow patterns and droplet characteristics, so that the empirical judgment was transferred to be an intelligent process. The difference on the usual machine learning algorithms, a generalized variable system was introduced to describe the different geometry configurations of the digital microfluidics. Specifically, Buckingham’s theorem had been adopted to obtain multiple groups of dimensionless numbers as the input variables of machine learning algorithms. Through the verification of the algorithms, the SVM and BPNN algorithms had classified and predicted the different flow patterns and droplet characteristics (the length and frequency) successfully. By comparing with the primitive parameters system, the dimensionless numbers system was superior in the predictive capability. The traditional dimensionless numbers selected for the machine learning algorithms should have physical meanings strongly rather than mathematical meanings. The machine learning algorithms applying the dimensionless numbers had declined the dimensionality of the system and the amount of computation and not lose the information of primitive parameters.

A novel technique for mapping biopsy of bile duct cancer

Endoscopy ◽  
2020 ◽  
Author(s):  
Hirokazu Okada ◽  
Norimitsu Uza ◽  
Tomoaki Matsumori ◽  
Shimpei Matsumoto ◽  
Yuya Muramoto ◽  
...  
Keyword(s):  
Bile Duct ◽  
Intrahepatic Bile Duct ◽  
Preoperative Assessment ◽  
Median Number ◽  
Novel Technique ◽  
Minimal Trauma ◽  
Adequate Sampling ◽  
Novel Method ◽  
Longitudinal Extension ◽  
Mapping Biopsy

Abstract Background Accurate preoperative assessment of the longitudinal extension of perihilar cholangiocarcinoma (PHCC) is essential for treatment planning. Mapping biopsies for PHCC remain challenging owing to technical difficulties and insufficient sample amounts. The aim of this study was to investigate the usefulness of a novel technique for mapping biopsies of PHCC. Methods Our novel method focused on a biliary stent delivery system for mapping biopsies. Fifty patients with PHCC undergoing endoscopic transpapillary mapping biopsy using the novel method were reviewed from August 2015 to June 2019. Results The median number of biopsy samples was six (range 1 – 17), and the rate of adequate sampling was 91.4 % (266 /291). Biopsy from the intrahepatic bile duct was possible in 82.0 % of patients (41 /50), and negative margins were confirmed in the resected specimens from 34 /39 patients who underwent surgery (87.2 %). None of the patients had post-endoscopic retrograde cholangiopancreatography pancreatitis. Conclusions With our novel method, accurate assessment of the longitudinal extension of PHCC might be expected with minimal trauma to the duodenal papilla.

Separation and purification of horseradish peroxidase from horseradish roots using a novel integrated method

2021 ◽  
Author(s):  
Wei Ji ◽  
Wenmei Ao ◽  
Mengqiu Sun ◽  
Chunlai Feng ◽  
Yun Wang
Keyword(s):  
Horseradish Peroxidase ◽  
Phase Extraction ◽  
Separation And Purification ◽  
Two Phase ◽  
Affinity Precipitation ◽  
Integrated Method ◽  
Novel Method ◽  
Temperature Controlled ◽  
Aqueous Two Phase Extraction

The aim of the present work was to develop a novel method integrating two-step aqueous two-phase extraction and temperature-controlled affinity precipitation for the separation and purification horseradish peroxidase (HRP) from...

scholarly journals Clustering-Based Component Fraction Estimation in Solid–Liquid Two-Phase Flow in Dredging Engineering

Sensors ◽  
2020 ◽  
Vol 20 (19) ◽  
pp. 5697
Author(s):  
Chang Sun ◽  
Shihong Yue ◽  
Qi Li ◽  
Huaxiang Wang
Keyword(s):  
Clustering Algorithm ◽  
Two Phase Flow ◽  
Low Cost ◽  
Fast Response ◽  
New Method ◽  
Phase Flow ◽  
Reference Distribution ◽  
Two Phase ◽  
Long Time ◽  
Solid Liquid

Component fraction (CF) is one of the most important parameters in multiple-phase flow. Due to the complexity of the solid–liquid two-phase flow, the CF estimation remains unsolved both in scientific research and industrial application for a long time. Electrical resistance tomography (ERT) is an advanced type of conductivity detection technique due to its low-cost, fast-response, non-invasive, and non-radiation characteristics. However, when the existing ERT method is used to measure the CF value in solid–liquid two-phase flow in dredging engineering, there are at least three problems: (1) the dependence of reference distribution whose CF value is zero; (2) the size of the detected objects may be too small to be found by ERT; and (3) there is no efficient way to estimate the effect of artifacts in ERT. In this paper, we proposed a method based on the clustering technique, where a fast-fuzzy clustering algorithm is used to partition the ERT image to three clusters that respond to liquid, solid phases, and their mixtures and artifacts, respectively. The clustering algorithm does not need any reference distribution in the CF estimation. In the case of small solid objects or artifacts, the CF value remains effectively computed by prior information. To validate the new method, a group of typical CF estimations in dredging engineering were implemented. Results show that the new method can effectively overcome the limitations of the existing method, and can provide a practical and more accurate way for CF estimation.

Pump Performance Improvement by Restraining Back Flow in Screw-Type Centrifugal Pump

2005 ◽  
Vol 127 (4) ◽  
pp. 755-762 ◽  
Author(s):  
Yasushi Tatebayashi ◽  
Kazuhiro Tanaka ◽  
Toshio Kobayashi
Keyword(s):  
Pressure Fluctuations ◽  
Centrifugal Pumps ◽  
Two Phase ◽  
Simple Method ◽  
Back Flow ◽  
Pump Performance ◽  
Impeller Outlet ◽  
Pump Head ◽  
The Difference ◽  
Set Up

The authors have been investigating the various characteristics of screw-type centrifugal pumps, such as pressure fluctuations in impellers, flow patterns in volute casings, and pump performance in air-water two-phase flow conditions. During these investigations, numerical results of our investigations made it clear that three back flow regions existed in this type of pump. Among these, the back flow from the volute casing toward the impeller outlet was the most influential on the pump performance. Thus the most important factor to achieve higher pump performance was to reduce the influence of this back flow. One simple method was proposed to obtain the restraint of back flow and so as to improve the pump performance. This method was to set up a ringlike wall at the suction cover casing between the impeller outlet and the volute casing. Its effects on the flow pattern and the pump performance have been discussed and clarified to compare the calculated results with experimental results done under two conditions, namely, one with and one without this ring-type wall. The influence of wall’s height on the pump head was investigated by numerical simulations. In addition, the difference due to the wall’s effect was clarified to compare its effects on two kinds of volute casing. From the results obtained it can be said that restraining the back flow of such pumps was very important to achieve higher pump performance. Furthermore, another method was suggested to restrain back flow effectively. This method was to attach a wall at the trailing edge of impeller. This method was very useful for avoiding the congestion of solids because this wall was smaller than that used in the first method. The influence of these factors on the pump performance was also discussed by comparing simulated calculations with actual experiments.

scholarly journals An experimental and theoretical investigation of diffusion in a two-phase alloy

1948 ◽  
Vol 192 (1031) ◽  
pp. 575-592 ◽  
Keyword(s):  
Free Energy ◽  
Single Phase ◽  
Phase State ◽  
Theoretical Treatment ◽  
Research Association ◽  
Essential Difference ◽  
Two Phase ◽  
Two Factors ◽  
Order Of Magnitude ◽  
The Difference

The present paper describes an investigation of diffusion in the solid state. Previous experimental work has been confined to the case in which the free energy of a mixture is a minimum for the single-phase state, and diffusion decreases local differences of concentration. This may be called ‘diffusion downhill’. However, it is possible for the free energy to be a minimum for the two-phase state; diffusion may then increase differences of concentration; and so may be called ‘diffusion uphill’. Becker (1937) has proposed a simple theoretical treatment of these two types of diffusion in a binary alloy. The present paper describes an experimental test of this theory, using the unusual properties of the alloy Cu 4 FeNi 3 . This alloy is single phase above 800° C and two-phase at lower temperatures, both the phases being face-centred cubic; the essential difference between the two phases is their content of copper. On dissociating from one phase into two the alloy develops a series of intermediate structures showing striking X-ray patterns which are very sensitive to changes of structure. It was found possible to utilize these results for a quantitative study of diffusion ‘uphill’ and ‘downhill’ in the alloy. The experimental results, which can be expressed very simply, are in fair agreement with conclusions drawn from Becker’s theory. It was found that Fick’s equation, dc / dt = D d2c / dx2 , can, within the limits of error, be applied in all cases, with the modification that c denotes the difference of the measured copper concentration from its equilibrium value. The theory postulates that D is the product of two factors, of which one is D 0f the coefficient of diffusion that would be measured if the alloy were an ideal solid solution. The theory is able to calculate D/D 0 , if only in first approximation, and the experiments confirm this calculation. It was found that in most cases the speed of diffusion—‘uphill’ or ‘downhill’—has the order of magnitude of D 0 . * Now with British Electrical Research Association.

A Novel Technique for Two-Phase BLDC Motor to Avoid Demagnetization

2016 ◽  
Vol 52 (7) ◽  
pp. 1-4 ◽  
Author(s):  
Tanveer Yazdan ◽  
Wenliang Zhao ◽  
Thomas A. Lipo ◽  
Byung-Il Kwon
Keyword(s):  
Bldc Motor ◽  
Two Phase ◽  
Novel Technique
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