scholarly journals Problems of Accuracy of Measurements of Curves on International Transport Corridors of Ukraine

2018 ◽  
pp. 56-60
Author(s):  
A. Matvienko ◽  
A. Shevchenko
Keyword(s):  
High Speed ◽  
Measurement Method ◽  
Energy Resources ◽  
Maximum Speed ◽  
Saving Energy ◽  
Accuracy Measurement ◽  
Accuracy Of Measurements ◽  
International Transport ◽  
The Cost

The analysis of the line layout on curves and straight sections of international transport corridors, calculations based on the accuracy measurement method for rapid and high-speed traffic, confirmed the need to take into account the scope of work, the cost of reconstructing curves and saving energy resources to establish rational layout parameters in accordance with a specified level of maximum speed.

scholarly journals Accuracy of Location Currency and Processing of Received Data on International Transport Corridors and High-Speed Masters

2019 ◽  
pp. 21-24 ◽  
Author(s):  
V. Pogrebnyak ◽  
A. Shevchenko ◽  
A. Matvienko
Keyword(s):  
High Speed ◽  
Geodetic Survey ◽  
Maximum Speed ◽  
Accuracy Of Measurements ◽  
International Transport ◽  
New Construction

The main stages of geodetic survey of the railway are considered, both in the new construction and in the reconstruction of existing sites. The analysis of the line plan on curves and direct sections of the railways of Ukrainian international transport corridors is given. Calculations are made on the method of recording the accuracy of measurements at high speed and extra-high speed, confi rmed the need to take into account the type of volumes of work, the establishment of rational parameters of the plan in accordance with the specifi ed levels of maximum speed.

scholarly journals Geodesic accuracy of railway networks Ukraine in connection with accession to the eu

2021 ◽  
pp. 69-78
Author(s):  
Anna Shevchenko ◽  
◽  
Oleksander Matviienko ◽  
Vladimir Manuylenko ◽  
Elena Uzhvieva ◽  
...  
Keyword(s):  
High Speed ◽  
Energy Savings ◽  
Survey Design ◽  
Rolling Stock ◽  
Transition Curve ◽  
Maximum Speed ◽  
The European Union ◽  
Social Infrastructure ◽  
Labor Costs ◽  
International Transport

The operation of international transport corridors is primarily assessed in terms of direct economic efficiency. Profit associated with the transit of transport operations and cargo. However, projects for the creation and development of international transport corridors always entail socio-economic changes. Including: the development of industrial and social infrastructure, the transformation of industrial and economic relations, environmental change, etc. This article discusses the existing problems and the ways of Ukraine’s transition to standards (survey, design, construction, operation, modernization stages) and rules operating the railways of the European Union. Taking into account the actual technical condition of the infrastructure of the Ukrainian railway. The parameters limiting the speed of the existing sections of the railway are considered. These include - the radius of the curve, the length of the transition curve, displacement, increase in the external rail, insufficient increase; type of the upper part of the route and its wear; directed translations; artificial constructions; passenger platforms; communication and blocking systems; energy saving systems; rolling stock; train speed and more. Line plan analysis on curves and straight sections of international transport corridors. Calculations using the method of registration of measurement accuracy in high-speed movement confirmed the urgent need to account for the volume of labor costs. The cost of restructuring curves and energy savings to establish rational parameters of the plan in accordance with the specified maximum speed levels.

scholarly journals The Forces Acting on Swimming Squid

1988 ◽  
Vol 137 (1) ◽  
pp. 421-442 ◽  
Author(s):  
R. K. O'dor
Keyword(s):  
High Speed ◽  
Pressure Control ◽  
Maximum Speed ◽  
Total Force ◽  
Cost Of Transport ◽  
Loligo Opalescens ◽  
The Cost ◽  
Negative Buoyancy ◽  
Two Jets ◽  
Direct Use

1. Analysis of cine films and intramantle pressure records for squid Loligo opalescens Berry swimming in a tunnel respirometer provided estimates of all the forces acting in the horizontal and vertical planes for swimming speeds from 0.1 to 0.5 ms−1. 2. Different speeds used different gaits; fin thrust was only important below 0.2 ms−1, ‘anaerobic’ circular muscles were recruited only at supracritical speeds, and hyperinflation caused by contraction of the radial muscle was not seen in steady swimming. 3. The extent, rate and frequency of contraction of the obliquely striated circular muscles varied little with speed, and jet thrust was matched to speed primarily by active pressure control through adjustments in the size of the funnel orifice. 4. Hydrodynamic lift production to compensate for negative buoyancy during enforced horizontal swimming in the tunnel required 30–90% of the total force over the speed range studied and appears less efficient than direct use of jet thrust. This suggests a new rationale for ‘climb-and-glide’ swimming which reduces previous estimates of the gross cost of transport for squid under natural conditions by at least 35%, with no loss of speed. 5. The cost of accelerating water into the mantle of a squid moving at high speed appears to have been underestimated in previous studies. A simulation of a series of escape jets predicts a maximum speed of 8 body lengths s−1 (1.4ms−1), reached after only two jets, because of the high deceleration during refilling.

ANALISA PERBANDINGAN DALAM RANGKA PEMILIHAN BEBERAPA IP UPSTREAM PROVIDER DI PT. INDOSAT

2018 ◽  
Vol 4 (1) ◽  
pp. 57
Author(s):  
Yuli Anwar ◽  
Dahlar .
Keyword(s):  
Business Strategy ◽  
High Speed ◽  
Human Life ◽  
Sustainable Growth ◽  
The Internet ◽  
Network Service Provider ◽  
High Speed Data ◽  
Telecommunications Services ◽  
The Cost ◽  
Internet Network

Abstract. One of the advances in information technology that now has changed the outlook and human life, business process and business strategy of an institution is the internet. The internet is a very large networks that connected to computers and serves throughout the world in one centralized network. With the internet we can access data and information anytime and anywhere.    As one provider of high-speed data communications services and the pioneer of the internet network service provider in Indonesia that provides integrated services, as well as one of the pioneer development of internet services that provide extensive services in the building and apply it throughout Indonesia. Indosat ready to seize opportunities for sustainable growth of business spectrum are still sprawling Indonesia.    Therefore, Indosat continues to focus on the development of increased efforts to provide the best service for customers of Indosat. Indosat will continue to develop and expand network coverage and a larger investment that the company will achieve excellence in the field of integrated telecommunications services.    Ranking by region of the IP Providers can be seen by grouping IP Providers, and management over IP Providers prefer to choose providers based on where it orginates as an example for the region of the U.S if it will be preferred providers that come from U.S. providers.With the commencement of the internet network optimization start early in 2008 with the selection of the appropriate IP Upstream Provider criteria, it is up to date according to data obtained from Indosat, seen any significant changes to the cost of purchasing capacity of the IP Upstream.    Based on the data obtained that until Q3 or September 2008, the number of IP Upstream Providers that previously there were 20 to 10 IP Upstream Provider, IP Transit Price total decrease of 11% to the price of IP Transit Price / Mbps there is a decrease of 78%, while from the capacity bandwith an increase of 301% capacity from 2008.

Design of Electrolytic Strengthening Machine for Cutting Edge of Cutter

2016 ◽  
Vol 693 ◽  
pp. 1585-1590
Author(s):  
Yi Zhuo Guo ◽  
Xian Guo Yan ◽  
Shu Juan Li ◽  
Hong Guo
Keyword(s):  
Service Life ◽  
Calculation Method ◽  
High Speed ◽  
High Speed Steel ◽  
Cutting Edge ◽  
The Cost ◽  
Electric Quantity

Many studies have proved the service life of cutter can be prolonged by electrolytic strengthening. Based on the theory of electrolytic strengthening technology, this paper introduced and developed prototype equipment for strengthening cutting edge of rotary cutter and put forward a calculation method of total electric quantity consumption during the electrolysis suitable for microcontroller. The M8 high-speed steel tap is taken as a strengthening example. After finished the strengthening process that it clearly see the results of the surface of tap was obviously polished by observing the micrograph. This equipment improves the reliability of electrolytic strengthening and the cost is relatively cheap.

scholarly journals CFD Simulation of a Hyperloop Capsule Inside a Low-Pressure Environment Using an Aerodynamic Compressor as Propulsion and Drag Reduction Method

2021 ◽  
Vol 11 (9) ◽  
pp. 3934
Author(s):  
Federico Lluesma-Rodríguez ◽  
Temoatzin González ◽  
Sergio Hoyas
Keyword(s):  
Shock Waves ◽  
Power Consumption ◽  
High Speed ◽  
Cfd Simulation ◽  
Aerodynamic Drag ◽  
Flow Behavior ◽  
Critical Conditions ◽  
Vehicle Speed ◽  
Blockage Ratio ◽  
The Cost

One of the most restrictive conditions in ground transportation at high speeds is aerodynamic drag. This is even more problematic when running inside a tunnel, where compressible phenomena such as wave propagation, shock waves, or flow blocking can happen. Considering Evacuated-Tube Trains (ETTs) or hyperloops, these effects appear during the whole route, as they always operate in a closed environment. Then, one of the concerns is the size of the tunnel, as it directly affects the cost of the infrastructure. When the tube size decreases with a constant section of the vehicle, the power consumption increases exponentially, as the Kantrowitz limit is surpassed. This can be mitigated when adding a compressor to the vehicle as a means of propulsion. The turbomachinery increases the pressure of part of the air faced by the vehicle, thus delaying the critical conditions on surrounding flow. With tunnels using a blockage ratio of 0.5 or higher, the reported reduction in the power consumption is 70%. Additionally, the induced pressure in front of the capsule became a negligible effect. The analysis of the flow shows that the compressor can remove the shock waves downstream and thus allows operation above the Kantrowitz limit. Actually, for a vehicle speed of 700 km/h, the case without a compressor reaches critical conditions at a blockage ratio of 0.18, which is a tunnel even smaller than those used for High-Speed Rails (0.23). When aerodynamic propulsion is used, sonic Mach numbers are reached above a blockage ratio of 0.5. A direct effect is that cases with turbomachinery can operate in tunnels with blockage ratios even 2.8 times higher than the non-compressor cases, enabling a considerable reduction in the size of the tunnel without affecting the performance. This work, after conducting bibliographic research, presents the geometry, mesh, and setup. Later, results for the flow without compressor are shown. Finally, it is discussed how the addition of the compressor improves the flow behavior and power consumption of the case.

Analysis of the Permanent Magnet Guideway of High Temperature Superconducting Maglev

2013 ◽  
Vol 745-746 ◽  
pp. 197-202 ◽  
Author(s):  
Chang Qing Ye ◽  
Zi Gang Deng ◽  
Jia Su Wang
Keyword(s):  
High Temperature ◽  
Permanent Magnet ◽  
High Speed ◽  
Optimization Design ◽  
Optimization Methods ◽  
High Temperature Superconducting ◽  
Practical Engineering ◽  
Hts Maglev ◽  
Ndfeb Permanent Magnet ◽  
The Cost

t was theoretically and experimentally proved that High Temperature Superconducting (HTS) Maglev had huge potential employment in rail transportation and high speed launch system. This had attracted great research interests in practical engineering. The optimization design was one of the most important works in the application of the HTS Maglev. As the NdFeB permanent magnet and HTS materials prices increased constantly, the design optimization of the permanent guideway (PMG) of HTS maglev became one of the indispensable works to decrease the cost of the application. This paper first reviewed four types of PMGs used by the HTS Maglev, then disucssed their structures and magnetic fields. Finally, the optimization methods of these four PMGs were compared. It was suggested that with better optimization methods, the levitation performance within a limit cost got better. That would be helpful to the future numerical optimization of the PMG of the HTS maglev.

scholarly journals Specific Absolute Velocity Thresholds during Male Basketball Games Using Local Positional System; Differences between Age Categories

2021 ◽  
Vol 11 (10) ◽  
pp. 4390
Author(s):  
Carlos Sosa ◽  
Alberto Lorenzo ◽  
Juan Trapero ◽  
Carlos Ribas ◽  
Enrique Alonso ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Real Time ◽  
Effect Size ◽  
High Speed ◽  
Maximum Speed ◽  
Large Effect Size ◽  
Moderate Effect Size ◽  
Positional System ◽  
Moderate Effect ◽  
Distance Zone

The aim of this study was (I) to establish absolute specific velocity thresholds during basketball games using local positional system (LPS) and (II) to compare the speed profiles between various levels of competitions. The variables recorded were total distance (TD); meters per minute (m·min); real time (min); maximum speed (Km h−1), distance (m), percentage distance, and percentage duration invested in four speed zones (standing–walking; jogging; running; and high-speed running). Mean and standard deviation (±SD) were calculated, and a separate one-way analysis of variance was undertaken to identify differences between competitions. TD (3188.84 ± 808.37 m) is covered by standing–walking (43.51%), jogging (36.58%), running (14.68%), and sprinting (5.23%) activities. Overall, 75.22% of the time is invested standing–walking, jogging (18.43%), running (4.77%), and sprinting (1.89%). M·min (large effect size), % duration zone 2 (moderate effect size); distance zone 4 (large effect size), and % distance zone 4 (very large effect size) are significantly higher during junior than senior. However, % distance zone 1 (large effect size) and % duration zone 1 (large effect size) were largely higher during senior competition. The findings of this study reveal that most of the distance and play time is spent during walking and standing activities. In addition, the proportion of time spent at elevated intensities is higher during junior than in senior competition.

High-Speed End Milling Using a Feedforward Control Architecture

1996 ◽  
Vol 118 (2) ◽  
pp. 178-187 ◽  
Author(s):  
E. D. Tung ◽  
M. Tomizuka ◽  
Y. Urushisaki
Keyword(s):  
High Speed ◽  
Feedforward Control ◽  
End Milling ◽  
Phase Error ◽  
Cutting Speed ◽  
Frequency Domain Analysis ◽  
Maximum Speed ◽  
Drive Control ◽  
Machining Errors ◽  
Feedforward Controller

Experiments are performed for end milling aluminum at 15,000 RPM spindle speed (1,508 m/min cutting speed) and up to 3 m/min table feedrate using an experimental machine tool control system. A digital feedforward controller for feed drive control incorporates the Zero Phase Error Tracking Controller (ZPETC) and feedforward friction compensation. The controller achieves near-perfect (±3 μm) tracking over a 26 mm trajectory with a maximum speed of 2 m/min. The maximum contouring error for a 26 mm diameter circle at this speed is less than 4 μm. Tracking and contouring experiments are conducted for table feedrates as high as 10 m/min. Frequency domain analysis demonstrates that the feedforward controller achieves a bandwidth of 10 Hz without phase distortion. In a direct comparison of accuracy, the machining errors in specimens produced by the experimental controller were up to 20 times smaller than the errors in specimens machined by an industrial CNC.

Sign in / Sign up

Export Citation Format

Share Document