B i o p h y s i c s D emys tifie D in .NET

Develop qr-codes in .NET B i o p h y s i c s D emys tifie D

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Noise. There are several variations on noise measurements that can be made by TIMS. A noise measurement presumes some sort of conditioning or weighting filter, of which there are several to be considered. To cover the unbalanced cable problem, there also might be an unbalanced or noise-to-ground measurement. Noise measurements require an RMS detector; a QRMS (quasi-RMS) has been developed as a reasonable compromise. The s/n ratio, a computed number based on a sequential level and noise measurement algorithm, is covered in a subsequent section. The transmitter for noise measurements operates in only two modes. One is an off condition, referred to as a quiet termination. It provides the chosen transmitter termination impedance to the line. The second mode generates a fixed tone of 1004 Hz (820 or 1020 Hz for ITU) with a user-adjustable level. If there is a compander (compressor/expander for signal level control) in the circuit, it detects the tone and fixes its gain. Without this tone, the compander would try to compensate for the lack of a signal and wreak havoc with any attempts to measure noise levels. Figure 25.8 depicts the general noise measurement conditions. The receiver uses much of the same measuring circuitry found in the level measurement. Table 25.2 lists first the weighting filters, followed by brief notes on their purposes.

There are only four arithmetic operators that can be used on pointers: ++, , +, and . To understand what occurs in pointer arithmetic, let p1 be an integer pointer with a current value of 2,000 (that is, it contains the address 2,000). Assuming 32-bit integers, after the expression

ciscoasa(config)# access-list ACL_ID [extended] {deny | permit} IP_protocol {src_addr subnet_mask | host src_addr | any} [protocol_info] {dst_addr subnet_mask | host dst_addr | any} [protocol_info] [disable | default]

Four key features included in the IOS relate to entering commands:

In 1 you learned that the electric motor is ubiquitous because of its simplicity. All electric motors by definition have a fixed stator or stationary part, and a rotor or moveable part. This simplicity is the secret of their dependability, and why in direct contrast to the internal combustion engine with its hundreds of moving parts, electric motors are a far superior source of propulsion: Electric motors are inherently powerful. By selecting a design that delivers peak torque at or near stall, you can move a mountain. Nearly all traction motors deliver near peak torque at zero rpm. That s why electric traction motors have powered our trolley cars, subways, and diesel-electric railroad locomotives for