Questions

Albedo refers to a material's ability to reflect sunlight. Since 30% of the sun's energy is reflected by the entire earth, the earth has an average albedo of 0.30.

Generally, dark surfaces have a low albedo and light surfaces have a high albedo.

It is a useful, memory-saving technique for multiprogrammed timesharing systems. A Reentrant Procedure is one in which multiple users can share a single copy of a program during the same period. Reentrancy has 2 key aspects: The program code cannot modify itself, and the local data for each user process must be stored separately. Thus, the permanent part is the code, and the temporary part is the pointer back to the calling program and local variables used by that program. Each execution instance is called activation. It executes the code in the permanent part, but has its own copy of local variables/parameters. The temporary part associated with each activation is the activation record. Generally, the activation record is kept on the stack.

Note: A reentrant procedure can be interrupted and called by an interrupting program, and still execute correctly on returning to the procedure.

Windows NT uses protection mechanism called rings provides by the process to implement separation between the user mode and kernel mode.

In direct marketing, there is a direct interaction of the customers with the seller without any intermediaries. Here, the role of the intermediaries is nil. The medium used is more direct using telephone, mail, internet where the seller can directly reach out to the consumer. Examples of such marketing include telemarketing, email, voicemail marketing, door-to-door selling etc. This kind of marketing is more time saving as the problem of distance which may otherwise exist between the buyer and seller is eliminated and is also cost effective as it minimizes commuting costs.