scholarly journals Air Corridors: Concept, Design, Simulation, and Rules of Engagement

2021 ◽  
Author(s):  
Sabrina Islam Muna ◽  
Srijita Mukherjee ◽  
Kamesh Namuduri ◽  
Marc Compere ◽  
M. Ilhan Akbas ◽  
...  
Keyword(s):  
Ground Level ◽  
Operational Efficiency ◽  
Collision Probability ◽  
Concept Design ◽  
Traffic Flows

Air corridors are an integral part of the advanced air mobility infrastructure. They are the virtual highways in the sky for transportation of people and cargo in the controlled airspace at an altitude of around 1000 ft. to 2000 ft. above the ground level. This paper presents fundamental insights into the design of air corridors with high operational efficiency as well as zero collisions. It begins with the definitions of air cube, skylane or track, intersection, vertiport, gate, and air corridor. Then, a multi-layered air corridor model is proposed. Traffic at intersections is analyzed in detail with examples of vehicles turning in different directions. The concept of capacity of an air corridor is introduced along with the nature of distribution of locations of vehicles in the air corridor and collision probability inside the corridor are discussed. Finally, the results of simulations of traffic flows are presented.

scholarly journals Air Corridors: Concept, Design, Simulation, and Rules of Engagement

Sensors ◽  
2021 ◽  
Vol 21 (22) ◽  
pp. 7536
Author(s):  
Sabrina Islam Muna ◽  
Srijita Mukherjee ◽  
Kamesh Namuduri ◽  
Marc Compere ◽  
Mustafa Ilhan Akbas ◽  
...  
Keyword(s):  
Traffic Flow ◽  
Ground Level ◽  
Operational Efficiency ◽  
Collision Probability ◽  
Concept Design ◽  
First Responder ◽  
Air Ambulances ◽  
Metropolitan Regions ◽  
Above Ground Level ◽  
Flow Simulations

Air corridors are an integral part of the advanced air mobility infrastructure. They are the virtual highways in the sky for the transportation of people and cargo in a controlled airspace at an altitude of around 1000 ft. to 2000 ft. above ground level. These corridors will be utilized by (unmanned) air taxis, which will be deployed in rural and metropolitan regions to carry passengers and freight, as well as air ambulances, which will be deployed to offer first responder services such as 911 emergencies. This paper presents fundamental insights into the design of air corridors with high operational efficiency as well as zero collisions. It begins with the definitions of air cube, skylane or track, intersection, vertiport, gate, and air corridor. Then a multi-layered air corridor model is proposed. Traffic at intersections is analyzed in detail with examples of vehicles turning in different directions. The concept of capacity of an air corridor is introduced along with the nature of distribution of locations of vehicles in the air corridor and collision probability inside the corridor are discussed. Finally, results of traffic flow simulations are presented.

scholarly journals The Influence of Meteorological Parameters and Traffic Flows on the Concentration of Ozone (O3) in Urban Areas in Brcko

2016 ◽  
Vol 1 (1) ◽  
Author(s):  
Radoslav Kojić ◽  
Matija Antić
Keyword(s):  
Wind Speed ◽  
Correlation Coefficient ◽  
Urban Areas ◽  
Meteorological Parameters ◽  
Size Structure ◽  
Ground Level ◽  
Motor Vehicles ◽  
Traffic Flows ◽  
Minimum Concentration ◽  
Ground Level Ozone

Meteorological parameters and traffic flows have a direct impact on air quality in large urban areas, and hence on the quality of life in them. A large number of done surveys confirmed the great dependence of the concentration of ground-level ozone (O3) upon meteorological parameters and the size, structure and imbalances of traffic flows. As part of the research conducted in the period from November 5th to December 8th 2014 in Brcko in Muderis Ibrahimbegic St concentrations of ground-level ozone (O3) were measured, meteorological parameters (temperature, humidity, wind speed and intensity of solar radiation) and characteristics of traffic flow of road motor vehicles. The maximum concentrations of ground-level ozone (O3) in the measurement period was 106.54μg/m³, while the minimum concentration was 4.794μg/m³. By analyzing the results of measurements the high coefficient of correlation between wind speed, air temperature and humidity was established. The correlation coefficient between the traffic flows on the one hand and the concentration of ground-level ozone (O3), on the other hand is very low and does not exceed the value of 0.301. A negative correlation coefficient between traffic flows and concentrations of ground-level ozone (O3) is also observed in the certain time of the day.

scholarly journals Holding Area Conceptual Design and Validation for Various Urban Air Mobility (UAM) Operations: A Case Study in Seoul–GyungIn Area

2021 ◽  
Vol 11 (22) ◽  
pp. 10707
Author(s):  
Youngjae Lee ◽  
Junseok Lee ◽  
Jae-Woo Lee
Keyword(s):  
Operating Systems ◽  
Traffic Congestion ◽  
Weather Conditions ◽  
Urban Air ◽  
Concept Design ◽  
Traffic Flows ◽  
The World ◽  
Turning Radius ◽  
Bad Weather

As populations become concentrated in cities, traffic congestion increases, and urban air mobility (UAM) is being considered to face this problem. Accordingly, many institutions and companies around the world are developing UAM vehicles, building infrastructure, and researching flight operating systems. In this study, three holding area concepts have been designed that can control air traffic flows and avoid bad weather conditions when UAM vehicles are operating. These holding areas have been considered to allow UAM vehicles to fly by avoiding collisions with other UAM vehicles or structures such as buildings. After validating the turning radius analysis with existing aircraft, a case study on the holding area concept design for the Seoul–GyungIn area was performed to determine whether UAM vehicles can turn within a narrow radius. It was not possible for winged-type UAM vehicles to turn across the Han River at cruise speed. The holding area concepts and the turning procedure of this study can be used as guidelines when designing UAM corridors or UAM flight routes.

Effects of Vibration on the Preparation of Ultrathin Sections

1973 ◽  
Vol 31 ◽  
pp. 358-359
Author(s):  
Joseph M. Blum ◽  
Edward P. Gargiulo ◽  
J. R. Sawers
Keyword(s):  
Cutting Speed ◽  
Ground Level ◽  
Environmental Vibration ◽  
Block Face ◽  
Ultrathin Sections ◽  
Embedding Medium ◽  
Thickness Variations ◽  
Building Walls ◽  
Cutting Direction ◽  
Diamond Knife

It is now well-known that chatter (Figure 1) is caused by vibration between the microtome arm and the diamond knife. It is usually observed as a cyclical variation in “optical” density of an electron micrograph due to sample thickness variations perpendicular to the cutting direction. This vibration might be induced by using too large a block face, too large a clearance angle, excessive cutting speed, non-uniform embedding medium or microtome vibration. Another prominent cause is environmental vibration caused by inadequate building construction. Microtomes should be installed on firm, solid floors. The best floors are thick, ground-level concrete pads poured over a sand bed and isolated from the building walls. Even when these precautions are followed, we recommend an additional isolation pad placed on the top of a sturdy table.

A global perspective of ground level, 'ambient' carbon dioxide for assessing the response of plants to atmospheric CO2

2001 ◽  
Vol 7 (7) ◽  
pp. 789-796 ◽  
Author(s):  
L. H. Ziska ◽  
O. Ghannoum ◽  
J. T. Baker ◽  
J. Conroy ◽  
J. A. Bunce ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Ground Level ◽  
Global Perspective ◽  
Atmospheric Co2

Managing for Operational Efficiency Using Activity Based Costing

1996 ◽  
Vol 13 (1) ◽  
pp. 73-88
Author(s):  
James D. Cashell ◽  
Anthony H. Presutti
Keyword(s):  
Operational Efficiency ◽  
Activity Based Costing

Income Diversification and Bank Efficiency in Vietnam

2017 ◽  
pp. 52-67
Author(s):  
Sang Nguyen Minh
Keyword(s):  
Regression Model ◽  
Commercial Banks ◽  
Banking System ◽  
Operational Efficiency ◽  
Commercial Banking ◽  
Tobit Regression ◽  
Income Diversification ◽  
Positive Effects ◽  
Study Results ◽  
The Impact

This study uses the DEA (Data Envelopment Analysis) method to estimate the technical efficiency index of 34 Vietnamese commercial banks in the period 2007-2015, and then it analyzes the impact of income diversification on the operational efficiency of Vietnamese commercial banks through a censored regression model - the Tobit regression model. Research results indicate that income diversification has positive effects on the operational efficiency of Vietnamese commercial banks in the research period. Based on study results, in this research some recommendations forpolicy are given to enhance the operational efficiency of Vietnam’s commercial banking system.

The Sovereign States of Vietnam, 1945–1955

2016 ◽  
Vol 11 (3-4) ◽  
pp. 103-139 ◽  
Author(s):  
Brett Reilly
Keyword(s):  
Ground Level ◽  
Indochina War

This paper revisits the “bricolage” State of Vietnam and the fractured system of sovereignty that characterized its halting practice of sovereignty at the ground level during the First Indochina War. In addition, it examines how the French Union’s concept of shared external sovereignty became discredited by the end of the war.

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