vibration generated by vehicles during road transport has an important effect on the agricultural products damage process, particularly vegetable and fruit. modulus of elasticity is one of the most important mechanical properties of fruits and its variation can be described as one of the damage criteria during transportation. this research was conducted to evaluate the effects of vibration para...

Scheduling of contacts between several satellites and ground stations has been historically sub-optimally approached. This fact raises the question: can this problem be solved in polynomial time? Although existing literature provided optimal solutions for some simplified versions of this problem and studied some connections with general scheduling, fewhas been said on the complexity ofmore gene...

Introduction To DETERM INE THE ORBIT OF AN EARTH SATELLITE, or conversely, to use a known satellite orbit to find the location of a point on the earth, it is necessary to use some sort of electromagnetic signal (light or radio signal) passing between the satellite and the earth station. This signal traverses the earth's atmosphere, where its velocity is not the same as in free space (the index ...

We analyse five-year (63 months) data of the Large Area Telescope on board Fermi satellite from the Coma galaxy cluster in the energy range between 100 MeV and 100 GeV. The likelihood analyses are performed with several templates motivated by models predicting gamma-ray emission due to structure formation processes. We find no excess emission and derive the most stringent constraints to date on...

BACKGROUND Understanding the long-distance movement of bats has direct relevance to studies of population dynamics, ecology, disease emergence, and conservation. METHODOLOGY/PRINCIPAL FINDINGS We developed and trialed several collar and platform terminal transmitter (PTT) combinations on both free-living and captive fruit bats (Family Pteropodidae: Genus Pteropus). We examined transmitter wei...

The satellite scheduling community has provided several algorithms for allocating interaction windows between ground stations and satellites, from simple greedy approaches to more complex hybrid-genetic or Lagrangian-relaxation techniques. Single-location ground station problems, where requests have fixed time intervals and no priorities, are known to be solvable in polynomial time. To the best...

To reduce the sampling rate in global navigation satellite system (GNSS)-radio occultation receivers, it is essential to establish a suitable estimation of Doppler frequency from the received signal in the satellite onboard receiver. This receiver is usually located on low earth orbit satellite and receives GNSS satellites signal in the occultation situation. The occurred Doppler on the signal ...

Endurance Time Acceleration Functions are specially predesigned intensifying excitation functions that their amplitude increases with time. On the other hand, wavelet transform is a mathematical tool that indicates time variations of frequency in a signal. In this paper, an approach is presented for generating endurance time acceleration functions (ETAFs) whose response spectrum is compatible w...

Abstract The Satellite Laser Ranging (SLR) technique provides very accurate distance measurements to artificial Earth satellites. SLR is employed for the realization of origin and scale terrestrial reference frame. Despite high precision, observations can be affected by various systematic errors. So far, range biases were used account measurement errors mismodeling effects in SLR. Range are con...