Understanding Fiber-Optic Cable Signal Loss, Attenuation, and Dispersion This topic describes signal loss, attenuation, and dispersion in fiber-optic cable. Signal Loss in Multimode and Single-Mode Fiber-Optic Cable Multimode fiber is large enough in diameter to allow rays of light to reflect internally bounce off the walls of the fiber.
In casual encounters with the material universe, we rarely feel any difficulty here, since we usually deal with things that are clearly alive, such as a dog or a rattlesnake; or with things that are clearly nonalive, such as a brick or a typewriter.
Nevertheless, the task of defining "life" is both difficult and subtle; something that at once becomes evident if we stop to think. Consider a caterpillar crawling over a rock.
The caterpillar is alive, but the rock is not; as you guess at once, since the caterpillar is moving and the rock is not. Yet what if the caterpillar were crawling over the trunk of a tree? The trunk isn't moving, yet it is as alive as the caterpillar.
Or what if a drop of water were trickling down the trunk of the tree? The water in motion would not be alive, but the motionless tree trunk would be. It would be expecting much of anyone to guess that an oyster were alive if he came across one for the first time with a closed shell.
Could a glance at a clump of trees in midwinter, when all are standing leafless, easily distinguish those which are alive and will bear leaves in the spring from those which are dead and will not? Is it easy to tell a live seed from a dead seed, or either from a grain of sand?
For that matter, is it always easy to tell whether a man is merely unconscious or quite dead? Modern medical advances are making it a matter of importance to decide the moment of actual death, and that is not always easy. Nevertheless, what we call "life" is sufficiently important to warrant an attempt at a definition.
We can begin by listing some of the things that living things can do, and nonliving things cannot do, and see if we end up with a satisfactory distinction for this particular twofold division of the Universe.
A living thing shows the capacity for independent motion against a force. A drop of water trickles downward, but only because gravity is pulling at it; it isn't moving "of its own accord.
Living things that seem to be motionless overall, nevertheless move in part. An oyster may lie attached to its rock all its adult life, but it can open and close its shell. Furthermore, it sucks water into its organs and strains out food, so that there are parts of itself that move constantly.
Plants, too, can move, turning their leaves to the sun, for instance; and there are continuous movements in the substance making it up.
A living thing can sense and it can respond adaptively. That is, it can become aware, somehow, of some alteration in its environment, and will then produce an alteration in itself that will allow it to continue to live as comfortably as possible.
To give a simple example, you may see a rock coming toward you and will quickly duck to avoid a collision of the rock with your head.A typical attenuation coefficient of optical fibers for transmission is dB/km. Optical fibers are not only used as a transmission medium, but also for components within an optical communications system.
Vol.7, No.3, May, Mathematical and Natural Sciences. Study on Bilinear Scheme and Application to Three-dimensional Convective Equation (Itaru . Type or paste a DOI name into the text box. Click Go. Your browser will take you to a Web page (URL) associated with that DOI name.
Send questions or comments to doi. The overall optical throughput (transmission) of an optical fiber can be quantified in terms of the input optical power, P(0), and the output power, P(z) observed after light propagates a distance, z, along the fiber length.
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Click Go. Your browser will take you to a Web page (URL) associated with that DOI name. Send questions or comments to doi. is and in to a was not you i of it the be he his but for are this that by on at they with which she or from had we will have an what been one if would who has her.