摘要:
A random number generator comprising a plurality of pseudo random number generating units that can respectively output random numbers in specified pseudo random number systems, an output random number generating unit that generates output random numbers based on outputs from a plurality of pseudo random number generating units, a physical random number generator that generates physical random numbers, and a switching unit for switching between the necessity and the non-necessity of updating output values from pseudo random number generating units based on physical random numbers generated by the physical random number generator. Based on which pseudo random number system an output random number is generated is randomly switched based on a physical random number, making it very difficult to predict a random number compared with a conventional one.
摘要:
A random number generation device comprises a pseudo random number generation section that is capable of outputting random numbers of a plurality of different pseudo random number sequences, a physical random number generation section for generating physical random numbers, and a switching section for switching the pseudo random number sequence of random numbers output by the pseudo random number generation section on the basis of the physical random numbers generated by the physical random number generation section, where the output of the pseudo random number generation section is used as output random numbers. Since the plurality of different pseudo random number sequences are switched and output according to the physical random numbers, predictability of the random numbers can be reduced in comparison to a conventional random number generation device that uses only pseudo random numbers. Furthermore, since the physical random numbers are not directly used as the output random numbers, any adverse effect on the predictability of the output random numbers is substantially reduced compared with a conventional device even if the physical random number generating means are somehow manipulated from the outside.
摘要:
In the semiconductor laser device of the present invention, a semiconductor stacked structure including an active layer comprising a strained multi-quantum well structure is formed on a substrate 1, a cavity length is larger than 1000 &mgr;m but equal to or smaller than 1800 &mgr;m, and a low-reflection film S1 having a reflectance of 3% or less is formed on one facet and a high-reflection film S2 having a reflectance of 90% or more is formed on the other facet. The semiconductor laser module has a structure in which the semiconductor laser device is set to a cooling device constituted by electrically alternately arranging 40 pairs or more of the Peltier elements and holding them by top and bottom ceramic plates and sealed in the package. A grating having a reflection bandwidth of 1.5 nm or less is formed on an optical fiber to be built in.
摘要:
A plurality of digital signals having total data rates of n bit/s or less are input to a digital recording device recording digital signals having a data rate of n bit/s. The digital signals are subjected to format-conversion for the digital recording device to be recorded therein. Furthermore, signals having a data rate of n/i1 bit/s or less are subjected to format-conversion to be recorded i1 times in the digital recording device. In the case where the data rate of the digital signals to be input is n/j bit/s, the digital signals are subjected to format-conversion so that the amount of data capable of being recorded per unit time is decreased by i/j; thus, the digital signals are recorded for a long period of time under the condition that the data recording time is prolonged j times. Furthermore, when input data to be recorded on a magnetic tape at a normal data rate by using a magnetic head mounted on a rotary cylinder is recorded, the recording device of the present invention makes it possible to select a plurality of types of track angles generated by the rotation number of the cylinder, the tape traveling speed, and the like.
摘要:
A digital data recording apparatus records digital data in tracks on a tape. Each track has a first signal area for storing track format information and a second signal area for storing a plurality of sync blocks. The apparatus includes a circuit for inserting, in the first signal area, regular TDS information indicating the track data structure of digital data, and a circuit for inserting, in the final sync block, backup TDS information having the same structure as the regular TDS information.
摘要:
A digital signal recording apparatus for recording digital signal in synchronization blocks includes a generator for generating a synchronization pattern for indicating the beginning of each synchronization block, a generator for generating an ID data for indicating the sequence of the synchronization blocks, a generator for generating an ID parity for checking the ID data, a generator for generating additional information signal, which is a track width data, a generator for generating audio and video signals. Above data are applied to a pattern generator for generating track data comprising plural consecutive normal synchronization blocks immediately preceded by two mini-synchronization blocks and immediately followed by one mini-synchronization block. Each mini-synchronization block includes the synchrionization pattern, ID data, ID parity, and additional information signal. Each normal synchronization block includes the synchronization pattern, ID data, ID parity, and audio and video signal.
摘要:
In a digital video signal recording/reproducing apparatus for recording digital VCR video and audio signals by using a rotary cylinder, for a video signal with a frame frequency fN of 30 Hz or 29.97 Hz, the rotating frequency of the cylinder is set to 2.5 times fN. On the other hand, for a signal with a frame frequency fP of 25 Hz, the rotating frequency of the cylinder is set to 3.0 times fP. As a result, as long as the cylinder diameters are identical, the relative speed of the tape and the head is the same for video signals of either frame frequency fN or fP.
摘要:
A keyless entry system comprising a transmitter and a receiver. The transmitter increases a first number stored in the volatile memory according to rules, and transmits the first number by radio. The receiver receives the first number, and if the first number is greater than a second number stored in a memory, outputs a signal to indicate being authenticated as correct and updates the second number to the first number. Further, each time increase in the first number becomes a multiple of a predetermined number, the transmitter writes into a non-volatile memory a third number equal to the predetermined number plus the first number. When the first number in the volatile memory is erased due to the exchange, etc., of the battery, the transmitter reads out the third number from the non-volatile memory and writes the third number as the first number into the volatile memory.
摘要:
When transmitting encoded video data and audio data, a transmitter 201 also transmits a decoding method 107 generated by decoding-method generation means 203. In the case of a receiver 202, decoding control means 111 controls decoding means 208 in accordance with a received decoding method 113 and thereby, decodes video data and audio data 115. Thus, it is unnecessary for the receiver 202 to previously prepare all of a plurality of decoding methods and the transmitter 201 does not need to encode video data or audio data in accordance with the decoding method owned by the receiver 202.