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Ten nanoseconds is the demarcation time for the latent irradiance emitted from a material, which defines whether the emission is fluorescent or phosphorescent. For example phosphorescence is luminance or the emission of light from a source, which is delayed by more than ten nanoseconds following excitation. Glow in the dark items phosphoresce. Fluorescence is where the wavelength-shifted emission continues only as long as the stimulus producing it is maintained. Hence, the 10 nanosecond demarcation time. Many substances fluoresce in ultraviolet light (black light) including detergents and cat urine.
The Photonics Dictionary
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The read transition time for one user bit off of a ROM disk in the fastest CD drives on the market today is about 16 nanoseconds or 62.4 megabits/second. Typically, you will see CD speeds in groups of three numbers, for example: 2x1x8x. These speeds refer to the following functions of the CD drive: Writing to 'R' media x Writing to 'RW' media x Reading 'ROM' media (R = Recordable, RW = ReWritable, and ROM = Read Only Memory.) 1X CD transfer rate is defined as 150 kilobytes/second (KB/s). Today’s peak performance CD/CDRW drives are rated at 52x32x52x or 7.8 MB/s – 4.8 MB/s – 7.8 MB/s (megabytes/sec).
The promised minimum data transfer transition time for one user bit for Blu-ray drives is about 27.8 nanoseconds or a peak data rate of 36 megabits/second (Mb/s) or 4.5 megabytes/sec. (MB/s). As the format name directly indicates, a newly developed blue laser diode (405 nm) has been adopted as the optical stylus, providing a storage capacity of 25 GB on a single-layered disc or 50 GB on a dual-layered disc with a 12 cm diameter (same size as CD and DVD). The Blu-ray disc is held in a cartridge. The peak write transfer rate for presently (08/04) shipping Blu-ray drives from Sony Corp. is 24 Mb/s or 3 MB/s.
Blu-ray Technology Website
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The minimum data transfer transition time for one user bit for a removable hard disk (HD) is about 4.92 nanoseconds or a peak data rate of 24.5 megabytes/sec. (MB/s). The REV removable magnetic data storage drive from Iomega is presently the fastest performer in this data storage category. This drive uses 2 ½” diameter glass disks spun at 4200 RPM. This products maximum data transfer rate at the disk’s inner diameter (ID) is 12.7 MB/s while it’s maximum rate at the outer diameter (OD) is 25.4 MB/s. The rate difference is due to the difference in linear velocity of a disk at the OD versus the ID for a constant RPM.
The minimum data transfer transition time for one user bit for a shipping magnetic hard disk drive is about 1.45 nanoseconds or a peak data rate of 86 megabytes/sec. (MB/s). The Cheetah 15K.3 magnetic storage hard drive from Seagate is presently the fastest performer in this data storage category. This drive uses 3 ½” diameter disks spun at 15,000 RPM. This products maximum data transfer rate at the disk’s inner diameter (ID) is 52 MB/s while it’s maximum rate at the outer diameter (OD) is 86 MB/s. The rate difference is due to the difference in linear velocity of a disk at the OD versus the ID for a constant RPM.
The minimum data transfer transition time for one user bit for a Super DLT magnetic tape drive is about 3.47 nanoseconds or a peak native data rate of 36 megabytes/sec. (MB/s). The “SDLT 600” magnetic storage tape drive from Quantum is presently the fastest performer in the DLT tape technology family. This drive uses a ½” wide tape with a pivoting optical servo system for track following. Quantum Corporation invented Super DLT and the lower capacity and transfer rate DLT tape technologies. The present maximum capacity point for the Super4 DLT family is 300 GB native.
The minimum data transfer transition time for one user bit for a LTO (Linear Tape-Open) magnetic tape drive is about 3.57 nanoseconds or a peak native data rate of 35 megabytes/sec. (MB/s). The “Ultrium 3580” magnetic storage tape drive from IBM is presently one of these fastest performers in the LTO tape technology family. The LTO specification was jointly developed by three of the world’s leading storage producers— IBM, Hewlett-Packard, and Seagate. The present maximum capacity point for the LTO family is 200 GB native.
Resolution - 720 x 486 x 29.97 frames per sec. (Fps), Sample Size - 8 bits per pixel, Sampling - 4:2:2 (or every two horizontal pixels = 2 Y : 1 Cr : 1 Cb). Therefore: Luminance (Y) 720 x 486 x 29.97 Fps = 10,487,102.4 bytes/sec.x 8 bits per byte = 83,896,819.2 bits/sec., Chrominance R (Cr) 360 x 486 x 29.97 Fps = 5,243,551.2 bytes/sec., x 8 bits/byte = 41,948,409.6 bits/sec., Chrominance B (Cb) 360 x 486 x 29.97 Fps = 5,243,551.2 bytes/sec., x 8 bits/byte = 41,948,409.6 bits/sec. Total = 20,974,204.8 bytes/ sec.= 167,793,638.4 bits/sec. Roughly 20 MB/s or 160 Mb/s. Single bit time is hence 5.96 nanoseconds.
USB 2.0 has a raw data rate at 480Mbps or 60 megabytes/sec., and it is rated 40 times faster than its predecessor interface, USB 1.1, which tops at 12Mbps. Originally, USB 2.0 was intended to go only as fast as 240Mbps, but then, USB 2.0 Promoter Group increased the speed to 480Mbps in October 1999. USB is extendible to support up to 127 external devices; features hot-plug, unplug, and auto configuration; and supports a wide variety of devices. The bit rate time for 480 Mbps is 2.08 nanoseconds.
The first atomic clock, invented in 1948, utilized the vibrations of ammonia molecules. Today’s atomic clocks are based upon the oscillations of the cesium 133 atom. A second is the duration of 9,192, 631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the cesium 133 atom. The duration of each oscillation/transition is hence 108.8 picoseconds or has an oscillation rate of over 9 gigahertz (GH). The U.S. standard is the NIST-F1, which went into service in 1999 and should neither gain nor lose a second in 20 million years.
WiFi is a wireless networking technology for computers. Most WiFi works in the 2.4 Ghz frequency band. There are three standards, and they all begin with 802.11, the WiFi specification. The three variants are "b", "g", and "a", which gives us 802.11b, 802.11g, and 802.11a. What are the differences? Between b and g, the difference is speed. "a" is a 5Ghz band WiFi. The fastest WiFi currently works at 54 Megabits/sec. That's about 1000 times faster than a 54Kbps modem. This data rate converts to a single bit transition time of about 18.5 nanoseconds. "g" and "a" both work at this speed. "b" works at a relatively slower 11Mbps.
The read transition time for one user bit off of a ROM disk in the fastest DVD drives on the market today is about 8.33 nanoseconds or 120 megabits/second. Typically, you will see DVD speeds in groups of three numbers, for example: 2x1x8x. These speeds refer to the following functions of the DVD drive: Writing to 'R' media x Writing to 'RW' media x Reading 'ROM' media (R = Recordable, RW = ReWritable, and ROM = Read Only Memory.) 1X DVD transfer rate is defined as 1.25 megabytes/second (MB/s). Today’s peak performance DVD+R/RW drives are rated at 4x2.4x12x or 5 MB/s - 3 MB/s - 15 MB/s.
Plextor DVD Product Specifications
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ClickBook! an educational tool...
"As part of our Classroom Publishing project, we have used ClickBook 2000 to help parent volunteers turn student creative works into mini-books. The program has helped students improve their writing and reading skills. It has also helped them develop a sense of ownership and pride in their works -- works which they then share with teachers and classmates. ClickBook is a wonderful little program. It has been critical to the success of our project, and we highly recommend it!"
-Elaine Woerner, University of Chicago Laboratory Schools, Co-Chair - Lower School Council of the Parents' Association
“With up to 2-Gbyte storage capacity, the latest DoK (Disk on Key) USB 2.0 flash storage devices from M-Systems deliver the highest capacity combined with the fastest read and write speeds. The embedded DoK T5 ARM processor runs the company's True Flash File System (TFFS) and maximizes the data throughput such that the 2-Gbyte DoK storage unit can read data at 23 Mbytes/s and write data at 15 Mbytes/s.” This read transfer rates (23 MB/s) equivalent bit transition time is 4.46 nanoseconds. Pricing for this offering is at about $0.23/MB.
Electronic Design Magazine
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Fiber Channel (ANSI X3T9) was designed to transport many protocols such as FDDI, serial HIPPI, SCSI, Giabit Ethernet, IP and others. Fiber Channel is an optical fiber based channel. Data transfer rates of between 100Mbits/s to 3.2 Gbits/s are supported. 3.2 Gbits/s is equivalent to 400 megabytes/sec or a single data bit time of 0.313 nanoseconds. Transmission distances are up to 10 km for a single mode fiber. Fiber Channel is support by a jungle of standards (over 20 different standards). Various network topologies are support such as point-to-point, arbitrated loop and fabric. Fabric connects up to 224 devices.
Digital TV relies on a compression and encoding scheme known as MPEG-2 to fit its stunning images into a reasonable amount of bandwidth. In each image, the MPEG-2 software records just enough of the picture without making it look like something is missing. In subsequent frames, the software only records changes to the image and leaves the rest of the image as-is from the previous frame. MPEG-2 reduces the amount of data by about 55 to 1. Hence, the 1.5 gigibit/sec. (Gb/s) data rates for highest resolution HDTV (1920 x 1080) can be reduced to about 27 Mb/s or 3.4 megabytes/sec. This bit time is 37 nanoseconds.
There are three standard formats for HDTV: a) 720p, 1280x720 pixels, progressive @ 24, 30 or 60 frames/sec. (fs), b) 1080i, 1920x1080 pixels, interlaced @ 60 fs and c) 1080p 1920x1080 pixels, progressive @ 24 or 30 fs. Where, interlaced is half of frame every 1/60th of a sec. and progressive is entire frame every 1/30th of a sec . The highest data rates for 1080p are calculated as follows: 1920 x 1080 resolution, 24-bit color – 8-bit red, green and blue values and 30 progressive frames per second. Hence, the bandwidth required is 1920 x 1080 x 24 x 30 = 1.49 gigabits/sec. or 186 megabytes/sec.
Ten nanoseconds is the demarcation time for the latent irradiance emitted from a material, which defines whether the emission is fluorescent or phosphorescent. For example phosphorescence is luminance or the emission of light from a source, which is delayed by more than ten nanoseconds following excitation. Glow in the dark items phosphoresce. Fluorescence is where the wavelength-shifted emission continues only as long as the stimulus producing it is maintained. Hence, the 10 nanosecond demarcation time. Many substances fluoresce in ultraviolet light (black light) including detergents and cat urine.
