Laboratory ultrasonics provides an ideal opportunity for studying wave propagation in random media. Models are relatively easy to construct and both the phase and amplitude of the wave field can be measured, so we can separate the coherent from the incoherent intensity. Here we show detailed measurements of wave propagation in a 1D strongly scattering medium that fit the theory of radiative tra...

A common problem in radar, ultrasound, acoustic and other fields is that of determining the delay between two signals. In many situations, it is possible to determine the delay of a sampled signal to an accuracy better than the sample period. This paper presents a comparison of a number of methods of estimating this subsample delay, with special attention to the case of periodic signals. The au...

Protocols such as TCP requires packets to be accepted (i.e., delivered to the receiving application) in the order they are transmitted at the sender. Packets are sometimes misordered in the network. In order to deliver the arrived packets to the application in sequence, the receiver’s transport layer needs to temporarily buffer out-of-order packets and re-sequence them as more packets arrive. E...

Most theories of arithmetic assume that verification tasks are performed by producing an answer and comparing it with the presented answer. Verification is production plus comparison. We tested this hypothesis by imposing delays between arithmetic arguments and answers, in theory imposing delays between production and comparison. Long delays should absorb effects on production, and reaction tim...

This work investigates the channel thickness dependency of high-k gate dielectric-based complementary metal-oxide-semiconductor (CMOS) inverter circuit built using a conventional double-gate metal gate oxide semiconductor field-effect transistor (DG-MOSFET). It is espied that the use of high-k dielectric as a gate oxide in n/p DG-MOSFET based CMOS inverter results in a high noise margin as well...

A Time Interval Petri net (TIPN) is proposed and used to model flight operation. Based on the TIPN model, the flight delay propagation analysis algorithm is provided, which reduces the complexity of flight delay propagation analysis algorithm. Time interval constraints are attached to places and transitions in TIPN model, which could model the flight turnaround time and flight flying period. Me...

Delay propagation is a well-known phenomenon within the global air transportation system. Specifically, because of equipment and crew connectivity, a flight delayed early in the day can induce delays to multiple flights later in the day. In this paper we investigate this phenomenon by developing a statistical model that predicts the average flight delay after a given breakpoint time b, based on...

propagation of radio waves through the troposphere is based on minimum travel time between transmitter and receiver. the troposphere layer affects the propagation of gnss signals and causes errors in point positioning due to (1) delay of the signal, and (2) change of the curvature of the signal path. for this reason gnss users apply models for tropospheric error corrections. one of the commonly...

Satellite communication systems suffer from the systematic error of tropospheric delay. Accurate estimation this delay is essential for budget and planning. This study investigates in three Nigeria cities: Abuja, Lagos, Port Harcourt using two different models (Saastominen Hopfield). Three-year atmospheric data surface pressure, relative humidity temperature obtained at 5-min interval were acqu...