OPAC - Pencarian Artikel Jurnal & Majalah Library USD
Menampilkan semua artikel (Halaman 680 dari 34166, Total: 341652 data)
Power electronics and motion control-a future perspective
klik untuk membaca file PDF
| Pengarang | : | - |
| Nama Majalah/Jurnal | : | Proceedings of the IEEE |
| Volume / Edisi | : | 82-8, AUGUST (No. 8) |
| Halaman | : | 1107-1111 |
| Abstrak | : | The author deals with the present status and future perspective of power electronics and motion control. This discussion is particularly relevant today because some electrical engineers believe that motion control is a part of power electronics. However, one belief is that power electronics and motion control are now distinct fields-despite having common technologies and shared roots. |
Keutamaan Latihan Rohani in Action
| Pengarang | : | ANTONIUS SUMARWAN, SJ |
| Nama Majalah/Jurnal | : | Rohani |
| Volume / Edisi | : | 72 (No. 07) |
| Halaman | : | 1-6 |
| Abstrak | : | "Cinta diwujudkan dalam komunikasi timbal balik; artinya, yang mencintai memberi dan mengomunikasikan kepada yang dicintai apa yang dimilikinya, otau sebagian dari yang dimilikinya otau mampu diberikannya; begitu pula sebaliknya, yang dicintai pun melakukan hal yang soma kepada yang mencintai" (Latihan Rohani/LR 231). Catoton pen ting dolam "Kontemplasi untuk Mendapatkan Cinta" pada Latihan Rohani ini sering terabaikan. ANTONIUS SUMARWAN, SJ Pem1mp1n Redakst Dosen Umvers1tas Sanara Dharma, Yogyakarta |
Speech coding: a tutorial review
| Pengarang | : | A.S. Spanias |
| Nama Majalah/Jurnal | : | Proceedings of the IEEE |
| Volume / Edisi | : | 82-10, OCTOBER (No. 10) |
| Halaman | : | 1541-1582 |
| Abstrak | : | The past decade has witnessed substantial progress towards the application of low-rate speech coders to civilian and military communications as well as computer-related voice applications. Central to this progress has been the development of new speech coders capable of producing high-quality speech at low data rates. Most of these coders incorporate mechanisms to: represent the spectral properties of speech, provide for speech waveform matching, and "optimize" the coder's performance for the human ear. A number of these coders have already been adopted in national and international cellular telephony standards. The objective of this paper is to provide a tutorial overview of speech coding methodologies with emphasis on those algorithms that are part of the recent low-rate standards for cellular communications. Although the emphasis is on the new low-rate coders, we attempt to provide a comprehensive survey by covering some of the traditional methodologies as well. We feel that this approach will not only point out key references but will also provide valuable background to the beginner. The paper starts with a historical perspective and continues with a brief discussion on the speech properties and performance measures. We then proceed with descriptions of waveform coders, sinusoidal transform coders, linear predictive vocoders, and analysis-by-synthesis linear predictive coders. Finally, we present concluding remarks followed by a discussion of opportunities for future research. |
Fundamentals of low-noise analog circuit design
| Pengarang | : | W.M. Leach |
| Nama Majalah/Jurnal | : | Proceedings of the IEEE |
| Volume / Edisi | : | 82-10, OCTOBER (No. 10) |
| Halaman | : | 1515-1538 |
| Abstrak | : | This paper presents a tutorial treatment of the fundamentals of noise in solid-state analog electronic circuits. It is written for upper division students and practicing engineers who wish to gain a basic knowledge of the theory of electronic noise and techniques for low-noise circuit design. The paper presents an overview of noise fundamentals, a description of noise models for passive devices and active solid-state devices, methods of calculating the noise performance of amplifiers, and techniques for minimizing noise in circuit design. The theory and methods are applicable to both discrete and integrated circuits. |
The first compact blue/green diode lasers-wide-bandgap II-VI semiconductors come of age
| Pengarang | : | - |
| Nama Majalah/Jurnal | : | Proceedings of the IEEE |
| Volume / Edisi | : | 82-10, OCTOBER (No. 10) |
| Halaman | : | 1503-1513 |
| Abstrak | : | The first blue/green laser diode demonstrations reported in the summer of 1991 presented a hope that viable light-emitting devices based on the wide-bandgap II-VI compound were truly possible. In this paper we place those developments into the context of the 30-year research effort which has opened the possibility for the new laser diode, LED, and display devices operating in the short visible wavelengths. Active research interests worldwide have led to rapid progress in the field, culminating in the recent demonstration of room-temperature continuous wave diode lasers. |
The rewritable Mini Disc system
| Pengarang | : | Yoshida, T. |
| Nama Majalah/Jurnal | : | Proceedings of the IEEE |
| Volume / Edisi | : | 82-10, OCTOBER (No. 10) |
| Halaman | : | 1492-1500 |
| Abstrak | : | The MiniDisc system was designed with the obvious objective of replacing the conventional Compact Cassette tape recorder system. The MiniDisc format defines two types of optical discs. One is a recordable magneto-optical disc for user recording and another is a conventional read-only disc for music-software publishing. Audio data compression is used to achieve 74 min of playing time on a 64-mm disc. By means of a built-in buffer memory called Shock Resistant Memory, MiniDisc can be used for outdoor portable application with great ease. Furthermore, MiniDisc was evolved to MD Data system and with a data capacity of 140 Mbytes and a very compact size, the MD Data system is expected to become one of the standards for removable data storage systems. |
Digital compact cassette
| Pengarang | : | - |
| Nama Majalah/Jurnal | : | Proceedings of the IEEE |
| Volume / Edisi | : | 82-10, OCTOBER (No. 10) |
| Halaman | : | 1479-1489 |
| Abstrak | : | A description is given of the Digital Compact Cassette system (DCC) and how it could be integrated with the existing analog Compact Cassette system (CC). An improved version of the CC cassette suitable for higher frequencies was developed and special DCC components were added to a CC mechanism, resulting in a first product for the consumer market in 1992. Two major efforts are described. One is the development of the Precision Adaptive Subband Coding algorithm (PASC) in order to lower the needed bit rate to be recorded on tape without affecting the audio sound quality. The subband structure and the principles of PASC coding are now widely accepted for use in high-quality sound application. The other effort is the design and production of a multitrack magnetic readwrite head in thin-film technology, also suited for analog playback of CC, and meeting the price demands and quantities of the consumer market. By extensive use of integrated circuits, including a digital equalization of the magnetic read head and a complete digitalization of the PASC circuit, the number of discrete electronic components for a DCC system could be minimized. |
Millimeter-wave remote sensing of ozone and trace constituents in the stratosphere
| Pengarang | : | - |
| Nama Majalah/Jurnal | : | Proceedings of the IEEE |
| Volume / Edisi | : | 82-12, DECEMBER (No. 12) |
| Halaman | : | 1915-1929 |
| Abstrak | : | The application of millimeter-wave heterodyne spectroscopy to measurements of ozone and trace constituents in the upper atmosphere (between about 20- and 70-km altitude) is discussed. Brief, introductory reviews, with references, of the chemistry of ozone creation and destruction are given. The technical considerations involved in making the measurements are discussed. A millimeter-wave instrument for measuring stratospheric ozone is described as an example of the application of the technical considerations to instrument design. Results achieved with this instrument are reviewed. |
Advances in polarization diversity lidar for cloud remote sensing
| Pengarang | : | - |
| Nama Majalah/Jurnal | : | Proceedings of the IEEE |
| Volume / Edisi | : | 82-12, DECEMBER (No. 12) |
| Halaman | : | 1907-1914 |
| Abstrak | : | As soon as high-energy pulsed lasers became available in the mid-1960s, atmospheric scientists began assessing the information contents of various light detection and ranging (lidar) techniques in the field and laboratory. A particularly promising approach, which has recently gained increased stature as a result of growing interests in previously overlooked cloud types important to climate research (e.g. high-altitude cirrus), involves the polarization analysis of the backscattered laser return. Polarization diversity lidars collect data simultaneously in two or more channels to remotely determine the thermodynamic cloud phase, structure, and boundaries, and infer a variety of other climatically important cloud microphysical properties. As illustrated by the description of the mobile University of Utah Polarization Diversity Lidar system, commercially available dual-wavelength transmitters and improved electronic technologies to process high-resolution multichannel lidar signals represent significant advantages over earlier devices used in cloud studies. Polarization diversity can be added rather economically to more specialized lidars employing spectroscopic techniques, for other forms of atmospheric probing, such as Raman, differential absorption, and high spectral resolution lidars, in order to enhance instrument accuracy and versatility for cloud an aerosol research. Future engineering challenges remain in the "hardening" of compact lidar systems for extraterrestrial deployment, the achievement of unattended eye-safe operations, and in the improved integration of multiple remote sensor data streams and supporting in situ measurements to more fully characterize cloud systems and their effects on the Earth's radiation balance. |
Millimeter-wave radars for remotely sensing clouds and precipitation
| Pengarang | : | John Bamba |
| Nama Majalah/Jurnal | : | Proceedings of the IEEE |
| Volume / Edisi | : | 82-12, DECEMBER (No. 12) |
| Halaman | : | 1891-1906 |
| Abstrak | : | Millimeter-wave radars have been used since the early 1950s to study clouds and precipitation, but until recently these early instruments were limited to simple backscatter power measurements and were plagued by hardware problems. However, development of solid-state millimeter-wave componentry and high-power klystron amplifiers has spurred the evolution of reliable, coherent radars operating up to 95 GHz. In addition, advances in digital signal processing technology have resulted in single-card processors that can simultaneously execute algorithms to compute reflectivity, Doppler, and polarimetric quantities in real time. A review of the current state of the art in millimeter-wave cloud radars is presented, including a discussion of transmitters, antennas, and receiver components. Two radar systems built by the University of Massachusetts are described, including a mobile, dual-frequency (33- and 95-GHz) polarimetric radar, and an airborne 95-GHz polarimetric radar that was recently flown in a cooperative experiment with the University of Wyoming. Spaceborne applications are also discussed, especially the use of satellite-based 95-GHz radars for measuring the vertical distribution of clouds. |