To increase the adequacy of the dynamic models of sophisticated high-performance elastic electromechanical systems, it is necessary to understand complicated processes involving multimodal and high-frequency vibration...
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To increase the adequacy of the dynamic models of sophisticated high-performance elastic electromechanical systems, it is necessary to understand complicated processes involving multimodal and high-frequency vibrations of the system's components, which limit the accuracy of digital control of the system. The identification of such a dynamic state is complicated because it is necessary to use parametric functions as space-time characteristics. The problem is investigated for a microprocessor-controlled magnetic-disk storage device. The results of theoretical amplitude-frequency analysis, computer simulation, and dynamic measurements are used to obtain reliable identification data for system design.< >
Recent advances in InP-based HEMT/HBT (high electron mobility transistor/heterojunction bipolar transistor) device technology are reviewed. It is pointed out that, while the potential superiority of the InP-based hete...
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Recent advances in InP-based HEMT/HBT (high electron mobility transistor/heterojunction bipolar transistor) device technology are reviewed. It is pointed out that, while the potential superiority of the InP-based heterostructure devices in high-speed and low-noise performances over GaAs devices has been verified, problems that are mainly related to the narrow bandgap of InGaAs are still left to be solved. Low breakdown voltages and kink effects in I-V characteristics are common problems in these devices. Device isolation for InP-based HBTs also needs improvement. It is expected, however, that with progress in crystal growth technologies, these problems will largely be solved in the near future, for instance, by the incorporation of InP or InGaAsP active layers. The reliability problem is also considered. Since the reliability data are too scarce, studies on this subject must be performed more intensively for the practical use of InP-based HEMTs and HBTs.< >
High-speed optoelectronics is a rapidly advancing area driven by the need for higher-speed fiber-optic transmission systems. This area is reviewed, with attention given to high-speed semiconductor lasers, mode-locked ...
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High-speed optoelectronics is a rapidly advancing area driven by the need for higher-speed fiber-optic transmission systems. This area is reviewed, with attention given to high-speed semiconductor lasers, mode-locked semiconductor lasers, and high-speed photodetectors. It is concluded that the prospects look good for expanded use of the large bandwidth capability of optical fiber. This expansion is driven by the increased demands of wideband video and data transmission. It is projected that, with the reduction of transport limitations in semiconductor lasers, bandwidths of semiconductor lasers will soon exceed 30 GHz and operation at 40 Gb/s is possible. advances in high speed electronics should allow the goal of 40-Gb/s transmission to be realized over the next five years.< >
Summary form only given. The ability of ferroelectric materials such as Pb(Zr/sub x/Ti/sub 1-x/)O/sub 3/ (PZT) piezoceramics to switch from one stable polarization state to another forms the basis of a new thin film t...
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Summary form only given. The ability of ferroelectric materials such as Pb(Zr/sub x/Ti/sub 1-x/)O/sub 3/ (PZT) piezoceramics to switch from one stable polarization state to another forms the basis of a new thin film technology for datastorage. Thin PZT films are used in prototype nonvolatile ferroelectric random access memory (NVFRAM) and dynamic random-access memory (DRAM) devices. We report second harmonic imaging of the surface of a PZT ceramic obtained in a near-field microscopy setup using a Ti:sapphire laser system consisting of an oscillator and a regenerative amplifier operating at 810 nm.
Total internal reflection holography has been demonstrated as a technique for submicrometer lithography: A prototype system is described which is capable of printing 0.3-mu-m features over a very large field. Applicat...
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Total internal reflection holography has been demonstrated as a technique for submicrometer lithography: A prototype system is described which is capable of printing 0.3-mu-m features over a very large field. Applications in IC, display, and opticaldatastorage technologies are discussed.
Magnetic recording now dominates the data, video, and audio storage for both professional and consumer applications. The technology has improved immensely as understanding of the physics of recording and reproducing p...
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ISBN:
(纸本)0819406465
Magnetic recording now dominates the data, video, and audio storage for both professional and consumer applications. The technology has improved immensely as understanding of the physics of recording and reproducing processes is gained. advances in recording materials and processes for fabricating components, especially with the thin film media and heads, have contributed in a major way to extending the performance of magnetic recording technology into different industries. Some examples of magnetic thin films applicating for recording media and heads studied in Information storage Research Centre of Shanghai Jiao Tong University are described.
data integrity is a primary concern for the users of any datastorage medium. For opticaldatastorage, the integrity is directly related to the performance and defect level of the storage media and how they change as...
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ISBN:
(纸本)0879425792
data integrity is a primary concern for the users of any datastorage medium. For opticaldatastorage, the integrity is directly related to the performance and defect level of the storage media and how they change as the media ages. A discussion is presented of some of the test methods that have been used while surveying commercially available, rewriteable optical media.
It is pointed out that, in the 1980s, many companies erroneously believed that it was possible to modify a commercial optical drive and media design for use in the military environment. Over the past 5 years, Honeywel...
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ISBN:
(纸本)078030084X
It is pointed out that, in the 1980s, many companies erroneously believed that it was possible to modify a commercial optical drive and media design for use in the military environment. Over the past 5 years, Honeywell has successfully developed a militarized 300-Mbyte write-once read-many (WORM) optical drive, took it into full production, and is now applying this flight-proven knowledge to rewritable magnetooptic (MO) technology. The authors describe the lessons learned and how those lessons apply to current and future military optical drive developments.
The authors discuss the advantages and tradeoffs (from both economic and technical aspects) of using multimode optical media, i.e., media which incorporate both rewritable (RAM) and permanent (ROM) data types on the s...
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ISBN:
(纸本)078030084X
The authors discuss the advantages and tradeoffs (from both economic and technical aspects) of using multimode optical media, i.e., media which incorporate both rewritable (RAM) and permanent (ROM) data types on the same physical optical disk versus other types of optical media, namely CD-ROM, WORM (write-once, read-many), and straight REWRITABLE, for Naval/tactical applications. An overview of the implementation used by Sundstrand data Control is also given.
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