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Zheng L.,Wireless Industrial Technologies, Inc.
Proceedings of the SICE Annual Conference | Year: 2010

This paper describes the resent industrial wireless sensor network technologies for process automation. It explains expected use cases, applications and technical requirements for the industrial wireless sensor networks. It introduces the trend of the industrial wireless communications standardization such as WirelessHART and ISA SP100.11a. © 2010 SICE.

Yang A.,Beijing Institute of Technology | Fei Z.,Beijing Institute of Technology | Yang N.,Wireless Industrial Technologies, Inc. | Yang N.,University of New South Wales | And 2 more authors.
IEEE Transactions on Vehicular Technology | Year: 2013

In this paper, we analyze the symbol error rate (SER) of space-time network coding (STNC) in a distributed cooperative network over independent but not necessarily identically distributed (i.n.i.d.) Nakagami-m fading channels. In this network, multiple sources communicate with a single destination with the assistance of multiple decode-and-forward (DF) relays. We first derive new exact closed-form expressions for the SER with M-ary phase-shift keying modulation (M-PSK) and M-ary quadrature-amplitude modulation ( M-QAM). We then derive new compact expressions for the asymptotic SER to offer valuable insights into the network behavior in the high signal-to-noise ratio (SNR) regime. Importantly, we demonstrate that STNC guarantees full diversity order, which is determined by the Nakagami-m fading parameters of all the channels but independent of the number of sources. Based on the new expressions, we examine the impact of the number of relays, relay location, Nakagami-m fading parameters, power allocation, and nonorthogonal codes on the SER. © 1967-2012 IEEE.

Agency: Environmental Protection Agency | Branch: | Program: SBIR | Phase: Phase I | Award Amount: 70.00K | Year: 2010

There are 315 to 458 million metric tons of CO2 (or equivalents) emissions per year due to primary aluminum production, of which 21 to 31 million metric tons are estimated to be produced in the United States. In part, this is due to the enormous electrical energy consumption entailed:  548,350 gigawatt hours worldwide (more than the electricity consumed by the whole of Germany), and the energy inefficiency of primary aluminum production (only 40-45% energy efficiency). It also is due to the emission of polyfluorinated hydrocarbons (PFCs). PFCs are more pernicious than CO2 in their impact on global warming with a global warming potential of 6,500 – 9,200 that of CO2. These PFCs are emitted by the large electrolytic cells in aluminum smelters at a level equivalent to 0.7 tons of CO2 equivalents per ton of aluminum produced. PFCs are emitted mainly during an upset condition of the cells known as an “anode effect”. These anode effects are marked by a large increase in cell voltage; methods are available for their quenching, but only after the excursion of cell voltage is detected, and typical effects last around 2 minutes. A typical aluminum plant, with a few hundred cells, would experience on the order of 100 anode effects per day. An alternative method of detecting anode effects has been investigated in prior work at Wireless Industrial Technologies (WIT). Hall effect sensors, connected to wireless transceivers, were used to tract the currents passing through individual anodes. Preliminary results indicated that the “signature” on an incipient anode effect was discernible in the anode currents approximately 1 minute before the cell voltage increase, providing an opportunity for earlier quenching of the effect or, perhaps, avoidance of the anode effect. In addition, measurement of individual anode currents has been shown by WIT to provide a means of detecting cells, which otherwise are performing below par (“noisy” cells or shorted cells) and thereby provides a further opportunity for reduction of greenhouse gas (GHG) emissions by reduction in electrical energy consumed per ton of aluminum produced. This project will allow WTI to carry the technology to the next stage:  demonstration of technical viability and potential benefits on all anodes of one cell of a primary aluminum plant.  Potential commercial applications are in the world aluminum industry. Projected gross revenues for WIT at Year 5 are $24 million with deployment completed at 21 of the world’s 200 primary aluminum plants.

Agency: National Science Foundation | Branch: | Program: SBIR | Phase: Phase I | Award Amount: 100.00K | Year: 2007

This Small Business Innovation Research (SBIR) Phase I project will use Wireless Sensor Networks (WSNs), mesh networking, appropriate sensors, and model-based control software to improve both the efficiency and the environmental impacts of aluminum smelting. The project includes 1) Evaluation of the robustness, latency, & desirable power management issues when WSNs are employed in ""hostile"" heavy industries; 2) ""Micro-energy audits"" to measure typical heat fluxes and vibrations in order to provide design rules for other researchers who desire to run WSN nodes without replaceable batteries; 3) Determining the energy efficiency and pollution control; and 4) Large current measurements with precision in hostile environments. It is estimated that the value of energy saving resulting from full deployment of the wireless technology throughout the US aluminum industry would be approximately $130 million/year with comparable savings possible in Canada, the EU and other nations. Such energy savings would likely be accompanied by savings of maintenance cost and the benefits of diminished fluoride emissions. The proposed technolgy can contribute to the advancement of wireless technology in many fields. Examples include the copper industry or chlor-alkali industry, the tanks, distillation columns and other equipment of an oil refinery and the looms of the weaving industry.

Lu Y.,China Unicom | Yang N.,Wireless Industrial Technologies, Inc. | Dai H.,North Carolina State University | Wang X.,Beijing University of Posts and Telecommunications
IEEE Transactions on Vehicular Technology | Year: 2012

In this paper, we propose new opportunistic decode-and-forward (DF) relaying with beamforming for multirelay networks, where an N s-antenna source communicates with an N d-antenna destination with the aid of N parallel single-antenna relays. Among these relays, only one relay that correctly decodes the signal from the source and has the highest instantaneous signal-to-noise ratio (SNR) to the destination is selected for transmission. The source employs maximum ratio transmission (MRT) to transmit, whereas the destination performs maximum ratio combining (MRC) to the received signals. To examine the benefits of the proposed scheme, we first derive the exact outage probability for independently but nonidentically distributed (i.n.i.d.) two-wave with diffuse power (TWDP) fading channels. We then derive an easy-to-compute expression for the exact outage probability to reduce computational cost. Our results encompass Rayleigh and Rician fading as special cases. We further derive a compact expression for the asymptotic outage probability, which characterizes two factors governing the network performance at high SNRs, i.e., the diversity order and the array gain. We demonstrate that our scheme preserves the maximum diversity order of N × min{N s,N d}. Additionally, we derive the optimal power allocation factor, which provides a practical design rule to optimally distribute the total transmission power between the source and the selected relay to minimize the outage probability. © 1967-2012 IEEE.

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