• International Journal of Aerospace System Engineering
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• v.2 no.1
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• pp.43-46
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• 2015

Aeroelastic gust response analysis plays an important role in design of aircrafts. For gust response analysis, frequency domain aerodynamics method has been typically used with generalized aerodynamic influence coefficient matrices at various reduced frequencies. However, it cannot be applied to the aeroservoelastic analysis, such as gust alleviation control. Time-domain state space (SS) models must be built. It attacks little attention that gust response analysis relies on continuous gust time-domain input signal in terms of its PSD function. The aim the current study is to provide a reduced-order modeling (ROM) method based on CFD to model gust responses for continuous gust responses for continuou gust inputs in time domain. The paper analyzed the gust response of AGARD445.6 wing subjected to the Dryden gust with ROMs and compared the difference between the rigid structure and elastic one. The results demonstrate that structure elastic effect effect should be considered in the design of aircraft.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.05a
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• pp.452-456
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• 2004

A study on gust loads alleviation using aircraft control surface was performed. Aeroservoelastic model including control surface controller was formulated and validated by comparing the results of continuous turbulence response analysis with those of MSC/NASTRAN. Optimal control with output feedback was adopted for designing the control surface controller, and the effects of gust loads alleviation was validated by performing the numerical simulation for the controller designed.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.757-761
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• 2008

The aerostat dynamic equation of motion has been built including the tether cable dynamic effects. A numerical program to solve the derived equation of motion has been developed. The dynamic motion of the 32m aerostat has been analyzed under discrete gust and continuous turbulence. The aerostat behaviors under discrete gust which represents a deterministic approach for determining design loads for manned aircraft are solved to verify the effect of aerostat mechanical properties on the aerostat dynamic behavior. Continuous turbulences are simulated for each given altitude, translational mean wind velocity and gust intensity. Dynamic behaviors of the 32m aerostat are simulated for each continuous turbulence conditions. Translational and vertical velocity and pitching behavior and tether reaction force are monitored for each simulation.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.32 no.8
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• pp.109-117
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• 2004

A study on gust load alleviation using aircraft control surface was performed. Aeroservoelastic model including control surface controller was formulated and validated by comparing the results of continuous gust response analysis with those of MSC/NASTRAN. Optimal control with output feedback was adopted for designing the control surface controller, and the effects of gust load alleviation was validated by performing the numerical simulation for the controller designed.

• Wind and Structures
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• v.13 no.1
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• pp.37-55
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• 2010

In this paper South Africa is divided into strong wind climate zones, which indicate the main sources of annual maximum wind gusts. By the analysis of wind gust data of 94 weather stations, which had continuous climate time series of 10 years or longer, six sources, or strong-wind producing mechanisms, could be identified and zoned accordingly. The two primary causes of strong wind gusts are thunderstorm activity and extratropical low pressure systems, which are associated with the passage of cold fronts over the southern African subcontinent. Over the eastern and central interior of South Africa annual maximum wind gusts are usually caused by thunderstorm gust fronts during summer, while in the western and southern interior extratropical cyclones play the most dominant role. Along the coast and adjacent interior annual extreme gusts are usually caused by extratropical cyclones. Four secondary sources of strong winds are the ridging of the quasi-stationary Atlantic and Indian Ocean high pressure systems over the subcontinent, surface troughs to the west in the interior with strong ridging from the east, convergence from the interior towards isolated low pressure systems or deep coastal low pressure systems, and deep surface troughs on the West Coast.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.9 no.5
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• pp.38-48
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• 2010

Adverse weather (e.g. strong winds, snow and ice) will probably appear as a more serious and frequent threat to road traffic than in clear climate. Another consequence of climate change with a natural disastrous on road traffic is respond to traffic accident more the large and high-rise bridge zone, tunnel zone, inclined plane zone and de-icing zone than any other zone, which in turn calls for continuous adaption of monitoring procedures. Accident mitigating measures against this accident category may consist of intense winter maintenance, the use of road weather information systems for data collection and early warnings, road surveillance and traffic control. While hazard from reduced road friction due to snow and ice may be eliminated by snow removal and de-icing measures, the effect of strong winds on road traffic are not easily avoided. The purpose of the study described here, was to design of amber information the relationship between traffic safety, weather, user information on road weather and driving conditions in local-scale Geographic. The most applications are the optimization of the amber information definition, improvements to road surveillance, road weather monitoring and improved accuracy of user information delivery. Also, statistics on wind gust, surface condition, vehicle category and other relevant parameters for wind induced accidents provide basis for traffic control, early warning policies and driver education for improved road safety at bad weather-exposed locations.

• Journal of Veterinary Clinics
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• v.1 no.1
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• pp.11-23
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• 1984

Epizootiolosical factors of 166 cows with abomasal displacement were studied and in 21 out of 166 cows, the functions of liver and kidney were also tested. 1. Incidence of abomasal displacement was perdominant in small sized dairy herd less than 15 cows, using area of paddock below 165㎡. 2. Out of 166 cows with abomasal displacement, 116 cows (70%) were found left sided displacement and 50 cows (30%) were right. 3. Generally, one to two weeks were taken before treatment of veterinarian following onset of sign of the diseases. Therefore many cases were found to be severe in their illness. 4, Incidence rate of abomasal displacement was predominant in summer season (June, July and Au-gust). However, occurence of the disease was continuous throughout the year. About 80 percent of abomasal displacement was distributed from first to third purturition. 5. High milk production and feeding with high concentrates and low roughage showed a tendendy to occurs the disease. 6. Approximately 75% of abomasal displacement was distributed within 1 month pre and post partum. 7. Cows with abomasal displacement consumed little concetrates and 75% of cows with abomasal displacement passed abnormal fecal material. 8. Sixty six out of 166 cows with abomsal displacement were coincident with diseases such as retained placenta, metritis, traumatic reticulo-peritonitis and mastitis. 9. In many cass of abomasal displacement, abomasum was extended with gas. 10. Activities of AST ana LDH showed the trends to reduce after surgical intervention comparing with pre-surgery. Bilirubin concentration markedly decreased after surgical treatment comparing with pre-surgery. 11. The concentration of BUN and creatinine moderatly decreased after surgery compared with pre-surgery.