scholarly journals AFOCAL SYSTEMS FORMED BY MIRROR OFF-AXIS PARABOLOID

2017 ◽  
Vol 16 (5) ◽  
pp. 407-414
Author(s):  
N. K. Artiukhina ◽  
L. A. Perosa ◽  
L. Zambrano
Keyword(s):  
Spherical Aberration ◽  
Alternative Methods ◽  
Meridian Plane ◽  
Central Field ◽  
Practical Application ◽  
Software Environment ◽  
Entrance Pupil ◽  
Aperture Diaphragm ◽  
Calculation Results ◽  
Lower Image Quality

Mirror systems make it possible to reduce device dimensions and its weight while preserving high input aperture and these systems are characterized by a number of other advantages. Their significant disadvantage is a central screening of an entrance pupil that leads to lower image quality. The paper contains description of the investigations on afocal systems formed by eccentrically cut-out mirror paraboloids (off-axis mirrors) where aperture diaphragm is displaced in the meridian plane for a defined value and a central field point is located on the optical axis. The canonic Mersenne systems are accepted as base schemas (modules) for these compositions. The paper considers two types of such systems: visible increases – Г > 0 and Г < 0. Algorithms for calculation of centered afocal systems with two and four reflections have been written in the paper and the systems are free from spherical aberration, coma, astigmatism when an input pupil is located in superimposed focal planes of all parabolic mirrors. An aberration in curvature image has been additionally corrected in three-mirror quart-parabolic scheme which is a combination of two classical telescopic Mersenne systems. The paper presents schemes and calculation results. Two-mirror schemes with non-screened input pupil have been studied in the paper and in this case all the system remains centered and an aperture diaphragm is decentered for the distance Cm which is commensurable with the diaphragm size. The paper contains description of the investigated afocal schemes with four reflections from off-axis mirror paraboloids, a prepared algorithm for calculation, the obtained formulas for making combination of canonic afocal systems formed by two mirrors. Computer simulation in software environment Opal and Zemax has been carried out in the paper. Basic description has been prepared while using two alternative methods for the class of decentered systems and aberration characteristics and schematic solutions for telescopic systems without screening with two and four reflections have been ob-tained in the paper. Two-mirror afocal systems with low-powered magnification are of some interest for practical application as accessories for registering object lenses. 

scholarly journals Construction Work Cost Determination

2018 ◽  
Vol 7 (3.2) ◽  
pp. 169
Author(s):  
Оlena Koba ◽  
Yulia Myronova ◽  
Volodymyr Byba
Keyword(s):  
Conceptual Model ◽  
Construction Industry ◽  
Model Construction ◽  
Alternative Methods ◽  
Practical Application ◽  
Construction Work ◽  
Cost Calculations ◽  
Cost Determination

The main Ukraine construction industry tendencies during 2010-2017 are described in the article. The order of construction and installation work formation is determined. The practical application peculiarities of cost calculations traditional and alternative methods in construction industry are considered. Based on the principles, methods and tools created a new conceptual model construction work cost determination.  

Research on the Cost Sharing of Customer Collaborative Product Innovation

2013 ◽  
Vol 711 ◽  
pp. 677-682
Author(s):  
Xue Zhang ◽  
Guang Chen
Keyword(s):  
Cost Sharing ◽  
Product Innovation ◽  
Cooperative Game Theory ◽  
Innovation System ◽  
Practical Application ◽  
Software Environment ◽  
Application Study ◽  
Innovation Activities ◽  
The Cost ◽  
Stable Development

Customer collaborative product innovation is the major style of the innovation activities of enterprises, which not only needs supporting by the hardware and software environment, but the participations of both customers and staffs of enterprises. This paper analyzes the participators in customer collaborative product innovation system form the viewpoints of customers and enterprises respectively. Based on Cooperative game theory, the cost sharing model for customer collaborative product innovation is established. Practical application study is provided for the model use, which analyzes the costs sharing of each participator quantitatively so as to guarantee a long-lasting and stable development for customer collaborative product innovation system.

scholarly journals Direct application of an ECG-based sleep staging algorithm on reflective photoplethysmography data decreases performance

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
M. M. van Gilst ◽  
B. M. Wulterkens ◽  
P. Fonseca ◽  
M. Radha ◽  
M. Ross ◽  
...  
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Direct Application ◽  
Alternative Methods ◽  
Sleep Staging ◽  
Practical Application ◽  
Sleep Monitoring ◽  
Data Source ◽  
Variability Data ◽  
Ecg Data

Abstract Objective The maturation of neural network-based techniques in combination with the availability of large sleep datasets has increased the interest in alternative methods of sleep monitoring. For unobtrusive sleep staging, the most promising algorithms are based on heart rate variability computed from inter-beat intervals (IBIs) derived from ECG-data. The practical application of these algorithms is even more promising when alternative ways of obtaining IBIs, such as wrist-worn photoplethysmography (PPG) can be used. However, studies validating sleep staging algorithms directly on PPG-based data are limited. Results We applied an automatic sleep staging algorithm trained and validated on ECG-data directly on inter-beat intervals derived from a wrist-worn PPG sensor, in 389 polysomnographic recordings of patients with a variety of sleep disorders. While the algorithm reached moderate agreement with gold standard polysomnography, the performance was significantly lower when applied on PPG- versus ECG-derived heart rate variability data (kappa 0.56 versus 0.60, p < 0.001; accuracy 73.0% versus 75.9% p < 0.001). These results show that direct application of an algorithm on a different source of data may negatively affect performance. Algorithms need to be validated using each data source and re-training should be considered whenever possible.

Effect of Mid-Roll Shift on the Strip Flatness for CVC 6-H Mill

2014 ◽  
Vol 941-944 ◽  
pp. 1740-1743
Author(s):  
Dong Cheng Wang ◽  
Zhi Qun Wang ◽  
Hong Min Liu
Keyword(s):  
Influence Function ◽  
Function Method ◽  
Variation Method ◽  
Practical Application ◽  
Strip Flatness ◽  
Influence Function Method ◽  
Strip Shape ◽  
Calculation Results ◽  
Element Variation

In order to obtain the best position of mid-roll shift, this paper studies the effect of different mid-roll shift position on the strip flatness of CVC 6-H mill. Strip element variation method and influence function method are put forward to analyze the effect of mid-roll shift on strip flatness. The results show the CVC 6-H mill is able to get good strip shape. The best shift position is obtained from the calculation results. The conclusion has a good significance for the practical application.

The Future of ECVAM: A Personal Perspective

2002 ◽  
Vol 30 (2_suppl) ◽  
pp. 239-241
Author(s):  
Michael Balls
Keyword(s):  
Alternative Methods ◽  
Personal Perspective ◽  
Practical Application ◽  
Validation Process ◽  
The Future ◽  
Chemicals Policy ◽  
The Three Rs ◽  
Made In

Progress made in the practical application of the validation process is summarised, and some of the remaining problems are considered. Highlights of the first ten years of ECVAM are reviewed, and ECVAM's activities as a route of communication on the Three Rs are discussed. Finally, some suggestions are made for maintaining ECVAM's momentum in the future, especially in relation to the challenge and opportunity for alternative methods afforded by the new EU Chemicals Policy.

Comparison between Different Apparent Resistivity Definitions of CSAMT

2019 ◽  
Vol 24 (1) ◽  
pp. 119-127 ◽  
Author(s):  
Dongyang Hou ◽  
Guoqiang Xue ◽  
Nannan Zhou ◽  
Yiming He ◽  
Wen Chen
Keyword(s):  
Magnetic Field ◽  
Apparent Resistivity ◽  
Field Component ◽  
Single Component ◽  
Alternative Methods ◽  
Theoretical Formula ◽  
Controlled Source ◽  
Resistivity Method ◽  
Calculation Results

Controlled source audio-frequency magnetotelluric (CSAMT) is typically used to obtain data regarding Cagniard resistivity by calculating the ratio between the electric field and magnetic field. However, noise conditions tend to provide different influences on the electrical and magnetic field component data. Therefore, it has become necessary to develop alternative methods to define apparent resistivity using suitable component data. In addition to the traditional Cagniard resistivity, the conventional single-component and modified single-component apparent resistivity methods have been proposed. In this research we discuss those three different apparent resistivity definitions from the aspects of theoretical formula, applicability, and calculation results of a synthetic model. We find that the modified single-component apparent resistivity method can be successfully used to achieve higher data quality nearer the source, thereby improving the exploration precision. Finally, a case study is conducted to verify our results, which show that the modified apparent resistivity method has the ability to effectively reflect the geoelectric profiling information.

Characteristics of the foil lens for the correction of the spherical aberration and its application to STEM

1978 ◽  
Vol 36 (1) ◽  
pp. 38-39
Author(s):  
M. Hibino ◽  
M. Kuzuya ◽  
T. Hanai ◽  
S. Maruse
Keyword(s):  
Electron Beam ◽  
Potential Distribution ◽  
Spherical Aberration ◽  
Magnetic Lens ◽  
Aperture Diaphragm ◽  
Concave Lens ◽  
Thin Conducting

There have been a number of methods proposed and investigated for the correction of the spherical aberration, since this aberration is one of the most important factors which limit the performance of various kinds of electron beam instruments. A foil lens has been investigated preliminarily and the possibility of correcting the spherical aberration of a conventional magnetic lens with reasonable ease has been shown for the first time.The foil lens studied consists of an aperture diaphragm and a thin conducting foil fundamentally as is shown in Fig. 1, and is simple enough in design and adjustment. When the voltage is applied between the diaphragm and the foil, the curved potential distribution is produced around the aperture and the foil lens acts as a concave or negative lens. This concave lens produces the negative spherical aberration and can be utilized to correct the positive spherical aberration of the conventional magnetic lens.

Numerical simulation of fracture characteristics of jointed rock masses under blasting load

2019 ◽  
Vol 36 (6) ◽  
pp. 1835-1851 ◽  
Author(s):  
Chao Liu ◽  
Mingyang Yang ◽  
Haoyu Han ◽  
Wenping Yue
Keyword(s):  
Jointed Rock ◽  
Rock Masses ◽  
The Finite Element Method ◽  
Practical Application ◽  
Fracture Characteristics ◽  
Content Type ◽  
Jointed Rock Masses ◽  
Calculation Results ◽  
Damage Theory ◽  
Blasting Load

Purpose To study fracture characteristics of jointed rock masses under blasting load, the RFPA2D analysis software for dynamic fracture of rocks based on the finite element method and statistical damage theory was used. Design/methodology/approach On this basis, this research simulated the fracture process of rock masses in blasting with different joint geometrical characteristics and mainly analysed the influences of distance from joints to blasting holes, the length of joints, the number of joints and joint angle on fracture of rock masses. Findings The calculation results show that with the constant increase of the distance from joints to blasting holes, the influences of joints on blasting effects of rock masses gradually reduced. Rock masses with long joints experienced more serious damages than those with short joints. Damages obviously increased with the changing from rock masses without joints to rock masses with joints, and when there were three joints, the further increase of the number of joints had unobvious changes on blasting effects of rock masses. Joints showed significant guidance effect on the propagation of cracks in blasting: promoting propagation of main vertical cracks deflecting to the ends of joints. Originality/value The research results are expected to provide some theoretical bases in practical application of engineering blasting.

Numerical Simulation and Experimental Study of Inner Flow Field in Marine Centrifugal Pump

2014 ◽  
Vol 513-517 ◽  
pp. 4593-4596
Author(s):  
Xin Xiang Chen ◽  
Guo You Wang ◽  
Kai Wang ◽  
Ming Gao Tan ◽  
Liang Dong
Keyword(s):  
Flow Field ◽  
Centrifugal Pump ◽  
Particle Image ◽  
Practical Application ◽  
Total Head ◽  
Piv Measurement ◽  
Image Velocimetry ◽  
Calculation Results ◽  
Shaft Power ◽  
The Relationship

It was simulated the flow fields of the CLH-type marine centrifugal pump based on average N-S equations and standard k-ε turbulent model, using the ANSYS CFX12.1 code. With the calculation results, the velocity distribution of the flow field in the centrifugal pump is analyzed under different working conditions. The analogue results, which indicate the relationship between the total head, efficiency, shaft power and flow rate, are compared with performance experimental ones, and it shows that the simulation data coincides with experimental ones in allowable acceptance, which meet the requirements of practical application. Furthermore, in order to analyze the inner flow field distribution in the centrifugal pump in detail, and validate the simulation results, the inner flow field is tested by particle image velocimetry (PIV) measurement.

The Definition of Apparent Resistivity in Magnetotelluric Sounding

2014 ◽  
Vol 962-965 ◽  
pp. 189-192
Author(s):  
Bao Sheng Huang ◽  
Guo Xiang Yan
Keyword(s):  
Theoretical Calculation ◽  
Model Calculation ◽  
Imaginary Part ◽  
Apparent Resistivity ◽  
Calculation Formula ◽  
Practical Application ◽  
The Real ◽  
Calculation Results ◽  
Definition Of ◽  
Different Characteristics

Different apparent resistivity exists many different characteristics, such as in terms of the speed of tending to real resistivity, the strength of oscillation sexual and the resolution. Aimed at the problem of how to select apparent resistivity in magnetotelluric (MT), this paper compares and analyzes the characteristics of different apparent resistivity in reflecting underground electrical structure by theoretical calculation formula and model calculation, and then summarizes the advantage and disadvantage of different apparent resistivity. The calculation results of several typical geoelectric models show that Basukur apparent resistivity is the best definition method of apparent resistivity, followed in turn, from good to bad, is the apparent resistivity defined by the real part of impedance, discount apparent resistivity, Cagniard apparent resistivity and the apparent resistivity defined by the impedance square module and the apparent resistivity defined by the imaginary part of impedance square, and the apparent resistivity defined by the imaginary part of impedance is the worst. this conclusions provide the judgment basis for practical application.

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