• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.16 no.11
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• pp.1035-1043
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• 2004

For a long road tunnel, a tunnel ventilation system may be used in order to reduce the pollution level below the required level. To control the tunnel pollution level, a closed loop control algorithm may be used. The feedforward prediction algorithm and the cascade control algorithm were developed to regulate the CO level in a tunnel. The feedforward prediction algorithm composed of the traffic estimation algorithm and the CO density prediction algorithm, and the cascade control algorithm composed of the jet fan control algorithm and the air velocity setpoint algorithm. The verification of control algorithms was carried out by dynamic models developed from the actual tunnel data. The simulation results showed that control algorithms developed for this study were effective for the control of the tunnel ventilation system.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.18 no.1
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• pp.72-82
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• 2010

This study investigated how air traffic controllers (ATCs) perceive the visual information on radar screen and examined quantitative and qualitative differences as a function of expertise. Little research has shown that how much information is processed by ATC visually and perceptually, how ATCs represent the information, and what difference exists between experts and novices. Participants were asked to draw representing visual information on the blank sector map after a 5-second exposure. Data were analyzed by a superimposing method to identify correctly represented information. Results showed that the expert group had much larger size of chunking and their pattern was wider and more accurate than the novice group. The practical application and methodological implications are also discussed for further research.

• Journal of Advanced Navigation Technology
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• v.10 no.1
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• pp.26-33
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• 2006

This paper discusses the design and fabrication of a wireless VHF receiver for use in air traffic control. The VHF receiver was designed and tested in three modules: a control module, a receiver module and a power module, all of which were integrated into a single block for final testing. The fundamental performance of the receiver, and in particular, sensitivity, the most important factor, is designed to satisfy existing commercial wireless transmitter specifications for air traffic control. The receiver displays a sensitivity of -113 dBm, which is higher performance than existing commercial products, and is suitable for use as a basic component of CNS/ATM.

• Journal of Aerospace System Engineering
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• v.6 no.3
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• pp.19-23
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• 2012

"The FAA's Next Generation Air Transportation System" is a comprehensive overhaul of U.S National Airspace System to make air travel more convenient and dependable, while ensuring the flight is as safe, secure and hassle-free as possible. At its most basic level, NextGen represents an evolution from a ground-based system of air traffic control to a satellite-based system of air traffic management. This evolution is vital to meeting future demand, and to avoiding gridlock in the sky and at U.S airports. NextGen will open worldwide's skies to continued growth and increased safety while reducing aviation's environmental impact.

• Journal of Advanced Navigation Technology
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• v.20 no.5
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• pp.387-393
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• 2016

To perform realistic air traffic control (ATC) simulation in various air traffic situations, an aircraft dynamic model that is accurate and efficient is required. In this research, an improved five degree of freedom (5-DOF) dynamic model with feedback control and guidance law is developed, which utilizes selected performance data and operational specifications from the base of aircraft data (BADA) and estimations using aircraft design techniques to improve the simulation fidelity. In addition, takeoff weight is estimated based on the aircraft type and flight plan to improve simulation accuracy. The dynamic model is validated by comparing the simulation results with recorded flight trajectories. An ATC simulation system using this 5-DOF model can be used for various ATC related research.

• Journal of Advanced Navigation Technology
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• v.28 no.2
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• pp.201-209
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• 2024

This study investigates the operational facets of low-density urban air mobility (UAM) from an airline's perspective amid burgeoning concerns about urban congestion in megacities. UAM, employing electric vertical takeoff and landing (eVTOL) technology, emerges as a potential remedy to the challenges of traffic gridlock and environmental degradation. As the UAM market progresses from initial stages to maturity, tailored traffic control systems become paramount. Focused on the context of low-density environments during UAM's inception, this research scrutinizes operational frameworks, essential infrastructure, and likely scenarios. It aims to bolster the safety and efficiency of UAM operations by delving into the specifics of traffic control concepts designed for these unique settings. The study seeks to significantly contribute to optimizing UAM's initial phases, providing insights into crucial operational dynamics for a smoother integration of urban air mobility into contemporary urban landscapes.

• Proceedings of the SAREK Conference
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• 2006.06a
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• pp.9-14
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• 2006

This study presented the feasibility of R152a refrigerant as an alternative of R134a which is used in the current automobile air conditioning system. The performance of air conditioning system installed in the actual vehicle was tested using the climate wind tunnel. The experiments were conducted at various refrigerant charge quantities and various driving conditions such as city traffic, highway traffic and parking. Same components and lubricant were used for both R134a and R152a system. The effects of air set values of thermal expansion valve on the performance were also investigated. In case of the R152a system, refrigerant charge quantity can be reduced about 20%, better performance and superior compressor durability is expected due to the lower discharge pressure compared to the R134a system.

• Journal of Environmental Health Sciences
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• v.30 no.3
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• pp.293-299
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• 2004

Traffic represents one of the largest sources of primary air pollutants in urban area. As a consequence, numerous abatement strategies are being pursued to decrease the ambient concentration of pollutants. A characteristics of most of the these strategies is a requirement for accurate data on both the quantity and spatial distribution of emissions to air in the form of an atmospheric emission inventory database. In the case of traffic pollution, such an inventory must be compiled using activity statistics and emission factors for vehicle types. The majority of inventories are compiled using passive data from either surveys or transportation models and by their very nature tend to be out-of-date by the time they are compiled. The study of current trends is towards integrating urban traffic control systems and assessments of the environmental effects of motor vehicles. In this study, a model of vehicle emission calculation by using real-time traffic data was studied. Traffic data, which are required on a street-by-street basis, is obtained from induction loops of traffic control system. It is possible that characteristics of hourly air pollutants emission rates is obtained from hourly traffic volume and speed. An emission rates model is allocated with a high resolution space by using geographic information system (GIS). Vehicle emission model was developed with a high resolution spatial, gridded and hourly emission rates.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.18 no.2
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• pp.9-15
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• 2010

ADS-B(Automatic Dependent Surveillance-Broadcast) has been recognized as a key component of Surveillance and ATM in CNS/ATM System. In addition to providing surveillance for air traffic control(ATC), ADS-B also supports airborne applications such as enhanced traffic situational awareness through the display of other aircraft to pilots and flight crew. It provides the real-time and same air traffic information to pilots in the aircraft cockpit, air traffic controllers in tower and surface vehicles on the ground at the same time. Aircraft Cockpit Display Unit will display the given information precisely and accurately. This paper describes progress in the development of a Cockpit Display with ADS-B data that enable pilots to acquire, verify and maintain pre-defined spacing intervals from other aircraft for general aviation and small regional aircraft. The designed display provides analogous information in the form of traffic position, range, and ground speed, etc.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.4
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• pp.305-313
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• 2013

This paper presents a simulation system for air traffic control (ATC) training. The structure of the ATC is analyzed to define simulation components to be developed. Requirements that must be satisfied by a training simulator are also identified. The results were reflected in the design of the simulator. The training simulator is composed of three modules same as in real life : air traffic controller, aircraft, radar. Each developed module performs the strict unit tests and combine test based on the scalability, ease, real-time, the operating range of the algorithm derived from the requirements. The simulation system can be connected to an actual ATC, and used to validate the ATC system. At peak load, 1200 aircraft and 30 radars can be operated simultaneously.