Features of Communication Equipment Synchronization In Hydroacoustic Telemetry Systems

Author(s):  
Boris Filippov
2005 ◽  
Author(s):  
Masayoshi Yoneda ◽  
Kenji Haga ◽  
Hideto Okada ◽  
Hideki Katagiri

Alloy Digest ◽  
1975 ◽  
Vol 24 (6) ◽  

Abstract ALLOY 48 is a vacuum-melted, 48% nickel-iron alloy designed for high permeability, and low core losses. It is ideal in applications requiring efficient magnetic core materials, such as audio and instrument transformers, instrument relays, and many other communication equipment devices. It is excellent for rotor and stator laminations, and is also a very effective magnetic shielding material. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Fe-52. Producer or source: Magnetics Specialty Metals Division. See also Alloy Digest Fe-96, April 1992.


2016 ◽  
Vol 8 (1) ◽  
pp. 45-59 ◽  
Author(s):  
Rongwei Ren ◽  
Lei Yu ◽  
Yunxia Zhu

Purpose – This paper aims to study the evolution of innovation-based dynamic capabilities in informal copycat-style firms. As a kind of informal economical organizations, copycat-style firms in many emerging economies play an important role in their development of the economics. The development of Shanzhai firms, Chinese-style copycat firms, from imitation to innovation has become an important micro-foundation of China’s economic growth and the manufacturing development. With the cluster development of the Chinese mobile phone industry as the macro and industrial environment background, this paper chose Beijing Tianyu Communication Equipment Co. Ltd as the typical example of innovation in Shanzhai firms and studied the evolution of innovation-based dynamic capabilities in this company. Design/methodology/approach – This paper chose Beijing Tianyu Communication Equipment Co. Ltd as the typical example of innovation in Shanzhai firms and studied the evolution of innovation-based dynamic capabilities in this company by adopting the leading-edge dynamic capability theory, innovation theory and industrial cluster theory. The authors further discussed how to improve the dynamic capabilities in Shanzhai firms in China. Findings – It is finally suggested that Shanzhai firms should reduce innovation failures and lower damage degree of dynamic capabilities through consistent innovation and paying attention to their innovation improvement. Originality/value – It will be very significant to research the survival or diminishing of Shanzhai firms from a theoretical perspective, which will eventually enhance property right protection and innovation development in China.


The feasibility and utility of long-distance communication via Earth-orbiting satellites has been demonstrated during recent years and it is appropriate therefore to focus attention on the more important scientific studies and technical developments that will be needed if full use is to be made of this valuable mode of communication in the future. The early communication satellites (the Telstar and Relay series) were pioneers in a relatively unknown propagation environment. The satellites themselves were conceptually simple and the communication equipment consisted essentially of a frequency-changing transponder with an r. f. power output of a few watts and a bandwidth some tens of megahertz. Carrier frequencies in the range 2 to 6 GHz were employed; typically either 2 or 6 GHz was used for transmission and 4 GHz for reception at the Earth station. To obtain an adequate signal/noise ratio at the output of the Earth station receiver, frequency modulation was employed, the frequency deviations being greater than those used on terrestrial microwave links. Launcher limitations and other factors meant that the satellites had to be placed in inclined elliptical orbits (see figure 1) with maximum heights of only a few thousand miles. Nevertheless, these satellites demonstrated that some hundreds of frequency-division multiplex telephony circuits, or a television channel, could be achieved with generally satisfactory quality of transmission. It is to be noted, however, that the satellite transponders accommodated only one, or at the most two, r. f. carriers at any time, and that the transmission performance was at times marginal due to limitations of the satellite effective radiated power. Furthermore, these relatively low orbit satellites provided communication in periods of generally less than an hour at a time and required continuous tracking by the Earth station aerials, due to movement of the satellites relative to the Earth.


2014 ◽  
Vol 568-570 ◽  
pp. 1331-1335 ◽  
Author(s):  
Shao Jun Zhang ◽  
Dong Lin Su ◽  
Jian Wang ◽  
Rui Wang

To improve the objectivity and accuracy of evaluation for electromagnetic environment complexity and its influence on communication equipment, a subjective complexity evaluation method of electromagnetic environment oriented to the communication equipment is presented based on sensitivity and RF protection ratio of communication equipment. Based on statistical concept, the energy correlation factor is modified, and modulation and polarization correlation concept are imported into this method, by which the factor of energy correlation is modified and the subjective evaluation is made by analyzing the time domain correlation, frequency domain correlation, energy domain correlation, modulation correlation and polarization correlation of the electromagnetic environment. These simulation results indicate that communication equipment with various working parameters are influenced differently under the same electromagnetic environment. Namely, the complexities of electromagnetic environment for communication equipment with various working parameters are different.


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