Synchronization

“ Even within the same layer, some processes may take different lengths of time to execute, so setting a clock cycle synchronizes these operations. Accordingly, as one layer builds on operations in a lower layer, the two layers are naturally synchronized. Synchronization alone is not sufficient for a quantum computer to function. Consider again the control cycle depicted in Fig. 2. Extracting and processing the error syndrome must be executed on time scales of the same
order as the duration of a logical gate or errors will accumulate faster than they can be detected. ”

“ The advent of correctly timed, 60-cycle A.C. electric power, available throughout the nation, was a great boon to the designers of printing telegraph apparatus and some types of facsimile telegraph and picture transmitting systems. In prior years, overline synchronization of send and receive apparatus was always a problem and never perfect. Today, synchronizing apparatus between terminals becomes the simple matter of providing 60-cycle A.C. synchronous motors. ”

“ To convert external names, array indices, or references within a data structure into address pointers when the data structure is brought into main memory from external storage (also called `pointer swizzling') ; this may be done for speed in chasing references or to simplify code (e.g., by turning lots of name lookups into pointer dereferences) . The converse operation is sometimes termed `unswizzling'. See also {snap}.
:sync: /sink/ (var. `synch') n., vi. 1. To synchronize, to bring into synchronization. 2. [techspeak] To force all pending I/O to the disk; see {flush}, sense 2. 3. ”

“ We have to take into consideration the fact that those of our conceptions, in which time plays a part, are always conceptions of synchronism. For example, we say that a train arrives here at 7 o'clock ”

“ Thus it will be seen that each cylinder begins its revolution from identical positions and at the same instant, and as the clockwork of both receiver and transmitter are duplicates, approximate synchronism is maintained during a revolution. ”

“ Fig. 2,570.—Westinghouse rotary type of synchroscope or synchronism indicator. The indication is by means of a pointer which assumes at every instant a position corresponding to the phase angle between the pressures of the busbars and the incoming machine, and therefore rotates when the incoming machine is not in synchronism. The direction of rotation indicates whether the machine be fast or slow, and the speed of rotation depends on the difference in frequency. The pointer is continuously visible, during both the dark and light periods of the synchronizing lamps. ”

“ Fig. 2,571.—General Electric synchronism indicator. The synchronism indicator is a motor whose field is supplied with single phase current from one of the machines to be synchronized, and its armature from the other. The armature carries two inductance coils placed at a large angle, one supplied through a resistance, the other through an inductance. This arrangement generates a rotating field in the armature, while the stationary field is alternating. The armature tends to assume a position where the two fields coincide when the alternating field passes through its maximum ”

“ The best illustration that can be given of the manner in which they take place is afforded by the system known as synchronous multiple telegraphy, in which, by means of an admirable apparatus, points on discs, representing makes and breaks of electric current, are, at stations distant from each other, adjusted to synchronous relations with each other, by means of electro-magnetic agency, tuning-forks, and self-adjusting varying resistances to the currents, so that receiving and transmitting proceeds with a continuousness just short of perfect continuity. ”

“ In one system of ordinary photo-telegraphy synchronism is obtained in the following manner. The receiving cylinder travels at a speed slightly in excess of the transmitting cylinder, and as its revolution is finished first is prevented from revolving by a check, and when in this position the receiving apparatus is thrown out of circuit and an electro-magnet which operates the check is switched in. ”

“ A synchronous motor will pull itself up to synchronism if brought near to its synchronous speed, but this requires a very large amount of current. Operating from a generator of its own, it can be brought to speed by giving it a small initial rotation and raising the generator speed very carefully and gradually, when the two machines will accelerate in synchronism. ”

“ A number of more or less imperfect arrangements, having the isolation of communications for their object, have been devised or patented, which are dependent upon the use of several aerials, each supposed to be responsive only to a particular frequency; and attempts have been made to solve the problem of isolation by MM. Tommasi, Tesla, Jegon, Tissot, Ducretet and others.
We may then pass on to notice the attempts that have been made to secure isolation by a plan which is not dependent on electrical syntony. ”

“ Suffice it to say that as one writes his message in one city another pen in another city follows the transmitting-pen with perfect synchronism; it is as though a man were writing with a pen with two points widely separated, both moving at the same time and both making exactly the same motions. By this system a man may transact business with the same accuracy as by the United States mail, and with the same celerity as by the electric telegraph. ”

“ A polyphase synchronous motor is self starting, because, before the current has died out in the coils of one phase, it is increasing in those of the other phase or phases, so that there is always some turning effort exerted on the armature. ”

“ Imagine two observers who wish to adjust their timepieces by optical signals; they exchange signals, but as they know that the transmission of light is not instantaneous, they are careful to cross them. When station B perceives the signal from station A, its clock should not mark the same hour as that of station A at the moment of sending the signal, but this hour augmented by a constant representing the duration of the transmission. ”

“ When the machines are running at the same frequency and in phase the pointer is stationary at the marked point. In construction, it is like a small, two phase, bipolar synchronous motor, the field being supplied with alternating instead of direct current. ”

“ A machine built as an induction motor and driven above synchronous speed, thus acting as an alternating-current generator; -- called also asynchronous generator. Below synchronism the machine takes in electrical energy and acts as an induction motor; at synchronism the power component of current becomes zero and changes sign, so that above synchronism the machine (driven for this purpose by mechanical power) gives out electrical energy as a generator. ”

“ This is as fair a description of thought transference and its necessary condition as could well be devised, for as in wireless telegraphy, its mechanical counterpart, it depends upon synchronism of vibration in a "sphere which goes forth from the life of every one." Thought transference and kindred phenomena in which all categories of space and time lose their significance baffle our understanding because they appear to involve the idea of being in two places—in many places—at once, a thing manifestly at variance with our own conscious experience. ”

“ Of course, the sending machine and the receiving machines must run in exact synchronism. This synchronous control of the sending and receiving motors is maintained by the vibration of a rather heavy fork at each station, and adjusted to beat together, with such slight automatic correction by radio as may be required to keep all receiving forks in step with the fork of the station which at the moment is sending. It is a very simple and dependable 30mechanism, by which any number of motors, of any size, separated by any distance, can be made to run in synchronism. ”

“ In astronomy, where it is often of the utmost importance to secure perfect synchronism of observation, or the power of noting the exact difference of time between observations273 made at distant stations, not only can the same clock thus keep time for two observers hundreds of miles apart, but each observer can record by the same arrangement the moment of the occurrence of some phenomenon. ”

“ With several synchronous machines in parallel, the relays are arranged to operate with the least time delay with which it is possible to get selective action, in order to prevent the machines being thrown out of step in event of trouble conditions causing a decrease of voltage. ”

“ IV—A synchronous motor adjusts itself to changes of load by changing the phase difference between current and pressure. If there be no load and no friction, the motor when speeded up and connected in the circuit, will run in true synchronism with the alternator, that is, at any instant, the coils A B C D and A°B°C°D° will be in parallel planes. ”

“ The synchronous sensations produce synchronous ideas and the successive sensations successive ideas. Finally, the strength of the association between the ideas depends upon 'the vividness of the associated feelings, and the frequency of the association.' [518] Hume had said that association depended upon three [Pg 295] principles, 'contiguity in time and place,' 'causation,' and 'resemblance.' Contiguity in time corresponds to the successive, and contiguity in place to the synchronous, order. Causation, as Brown had finally proved, [519] means simply antecedence and consequence. ”

“ All things five, all things are in motion, all things correspond; the magnetic rays emanating from myself or others traverse without obstacle the infinite chain of created things: a transparent network covers the world, whose loose threads communicate more and more closely with the planets and the stars. ”

“ The several methods that have been proposed for the transmission of a number of messages in one direction on the same wire are reducible to two classes. In one the time which a revolving con tact slider takes to make one revolution is divided into as many intervals as there are sets of sending and receiving instruments on the line, and by means of it the current is closed through the different sets of apparatus in succession. ”

“ The wonderful mysteries of oscillatory currents, whose natural medium is the ether, currents which object to being confined to wires and cables, and defy all ordinary laws; currents that will melt masses of metal with the violence of an explosion, but yet pass through the human body without producing any sensation; currents that will instantly manifest themselves 2,000 miles away from their source, with no visible means of propagation, are the open sesame to the treasures of a wonderful future. ”

“ It is vain to undertake to 'cut in on' a series of wireless impulses made up of four different rates of vibration. The probability of getting the secret of the combination is as slight as of your solving the number combination on the door of a safe. From experiments I have concluded that 151 this individualization will allow the transmission of several million different messages. It is interesting when you think that one world telegraphy plant would have a greater capacity than all the ocean cables combined. ”

“ In the early days only one message could be sent over one wire at the same time, but now from four to six or even more messages may be sent over the same wire simultaneously without one message interfering with the other. Like most other inventions, many inventors have contributed to the development of multiple transmission, till finally some one did the last thing needed to make it a success. ”

“ No invention, no discovery can surpass in value this mode of silent yet eloquent communication, and only the interruption of the sun's beams by clouds or fogs can interfere with the transmission by signals, noiselessly, and in a manner almost imperceptible to all save the two interlocutors, who may be distant ten, twenty, thirty, or even forty miles. ”

“ It is more than likely that, in the far future, the proper study of oscillatory theories, the proper investigation of the spectrum only very partially explored by a few, will lead us to a better understanding of the nature of life, and will help us to appreciate the theories of electrical sonics. Theories of [Pg 42] preventing local thunderstorms, of growing babies and wheat effectively, by electrical or other similar oscillatory means, of helping ourselves to see by wireless and of affecting our health at the end of many generations for the better, may all be developed in the time to come. ”

“ Therefore, even in the appreciation of fraud, we must not forget to take into consideration the curious synchronism I am pointing out.
There is another useful observation to make known: namely that raps produced by synchronous movements can be produced by the sitters themselves. In many cases, I have seen experimenters, non-mediums, obtain louder raps than the medium; the presence of a medium, however, is necessary, for, the persons of whom I speak obtain no raps whatever when alone. ”

“ Wireless telegraphy.—To the men who were struggling to unite continents by electrical conductors the idea that connection for the purposes of communication could be established without any conductors whatever would have seemed an idle dream. ”

“ The construction is such that a hand moves around a dial so that the angle between the hand and the vertical is always the phase angle between the two sources of electric pressure to which the synchronizer is connected. ”