The apparent angular size of the shadow a black hole in an expanding Universe is redshift-dependent. Since cosmological redshifts change with time - known as redshift drift all redshift-dependent quantities acquire time-dependence, and fortiori so do shadows. We find mathematical description show that amplitude this effect order $10^{-16}$ per day for M87$^{\star}$. While small, we argue its no...

The majority of Iran’s area is covered by arid and semiarid climates. In these areas, wind causes more erosion compared to water. Therefore, determination of wind characteristics especially its velocity is very important. One of the simplest methods that can supply researchers with the origin of wind erosion in the shortest time is synthesizing sand rose model and interpretation of aerial photo...

Traditional approaches to data mining are based on an assumption that the process that generated or is generating a data stream is static. Although this assumption holds for many applications, it does not hold for many others. Consider systems that build models for identifying important e-mail. Through interaction with and feedback from a user, such a system might determine that particular e-ma...

What is genetic drift? Say you have a population of 5,000 people. That makes 10,000 copies of each gene. Imagine a gene where 3,000 of those copies are of one particular allele or type. In the next generation, there won’t necessarily be exactly 3,000 copies again. There may be 3,050 or 2,960 copies instead. Some gametes get randomly picked out of all the possible gametes that could have been us...

Steel Special Moment Frames (SMFs) are favored seismic force-resisting systems due to their architectural flexibility and high ductility. While shallow columns (section depth less than 356 mm) were commonly used in these before the Northridge earthquake, deeper greater have become more popular recent years meet code-enforced story drift requirements economically. However, limited research exist...

A study of the generation of zonal flows and zonal magnetic fields by finite beta drift waves and kinetic drift-Alfvén waves is presented. The analysis is a generalization of recent investigations of the modulational instability for zonal flow generation by electrostatic drift waves to finite beta drift waves and kinetic drift-Alfvén waves. The drift wave driven unstable zonal flows/fields are ...

Time stability plays an important role in the applications of scanning probe microscopes (SPMs). Although SPMs integrated with a closed-loop control system could reduce the drift greatly, drift would still exist. The SPM drift in the lateral direction has been well studied, and several measurement methods have also been developed. However, due to coupling of the lateral drift, it is still diffi...

BACKGROUND Patients increasingly use online health communities to exchange health information and peer support. During the progression of health discussions, a change of topic-topic drift-can occur. Topic drift is a frequent phenomenon linked to incoherence and frustration in online communities and other forms of computer-mediated communication. For sensitive topics, such as health, such drift ...