In this paper, we analyze the performance of cooperative diversity using adaptive Decode and Forward (DF) relaying over independent but non-necessarily identical flat composite fading channels which include multipath fading and shadowing simultaneously. We have considered the transmission of M-QAM modulated signals over Generalized-K channel model which is very versatile and accurately approximates many of the commonly used channel models as Nakagami-m, Log-Normal distributions and the mixture of the two distributions for the composite fading. Using an approximation of the Generalized-K pdf by a Gamma pdf, we derive analytical expressions for the outage probability and the Average Symbol Error Probability (ASEP) of the proposed scenario and analyze their dependence on the channel parameters. We assume in our context that the relay decides independently whether or not to forward the signal to the destination based on the received signal quality. Simulations are provided for 16-QAM modulation for both the outage and the ASEP. The obtained results are discussed and proved to be in good agreement with our theoretical analysis.
{"title":"Performance Analysis of Decode and Forward Cooperative Relaying over the Generalized-K Channel","authors":"A. Dziri, M. Terré, N. Nasser","doi":"10.4236/WET.2013.42014","DOIUrl":"https://doi.org/10.4236/WET.2013.42014","url":null,"abstract":"In this paper, we analyze the performance of cooperative diversity using adaptive Decode and Forward (DF) relaying over independent but non-necessarily identical flat composite fading channels which include multipath fading and shadowing simultaneously. We have considered the transmission of M-QAM modulated signals over Generalized-K channel model which is very versatile and accurately approximates many of the commonly used channel models as Nakagami-m, Log-Normal distributions and the mixture of the two distributions for the composite fading. Using an approximation of the Generalized-K pdf by a Gamma pdf, we derive analytical expressions for the outage probability and the Average Symbol Error Probability (ASEP) of the proposed scenario and analyze their dependence on the channel parameters. We assume in our context that the relay decides independently whether or not to forward the signal to the destination based on the received signal quality. Simulations are provided for 16-QAM modulation for both the outage and the ASEP. The obtained results are discussed and proved to be in good agreement with our theoretical analysis.","PeriodicalId":68067,"journal":{"name":"无线工程与技术(英文)","volume":"4 1","pages":"92-100"},"PeriodicalIF":0.0,"publicationDate":"2013-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70837817","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
H. Olkkonen, S. Ahtiainen, K. Jarvinen, J. Olkkonen
In this framework we present a new method for measurement of the UWB impulse train based on the parallel sampling of the cascaded identical RC filters. We show that the amplitudes and time locations of p sequential impulses can be reconstructed from simultaneous measurement of the outputs from 2p cascaded identical RC filters. The parallel sampling scheme has a wide range of applications including the detection of the ultra wideband (UWB) impulses. Due to identical analog RC filters and buffer amplifiers, the parallel sampling scheme is flexible to implement in VLSI applications.
{"title":"Reconstruction of UWB Impulse Train by Parallel Sampling of Cascaded Identical RC Filters","authors":"H. Olkkonen, S. Ahtiainen, K. Jarvinen, J. Olkkonen","doi":"10.4236/WET.2013.42011","DOIUrl":"https://doi.org/10.4236/WET.2013.42011","url":null,"abstract":"In this framework we present a new method for measurement of the UWB impulse train based on the parallel sampling of the cascaded identical RC filters. We show that the amplitudes and time locations of p sequential impulses can be reconstructed from simultaneous measurement of the outputs from 2p cascaded identical RC filters. The parallel sampling scheme has a wide range of applications including the detection of the ultra wideband (UWB) impulses. Due to identical analog RC filters and buffer amplifiers, the parallel sampling scheme is flexible to implement in VLSI applications.","PeriodicalId":68067,"journal":{"name":"无线工程与技术(英文)","volume":"2013 1","pages":"71-76"},"PeriodicalIF":0.0,"publicationDate":"2013-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70837659","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A broadband feeding technique for the uniplanar tapered slot antenna (TSA) is presented. The TSA operates at a center frequency of 6.5 GHz with a 7 GHz bandwidth (107 percent). The antenna and feed are realized with a broadband microstrip-to-slotline transition on a low permittivity high frequency substrate, Rogers RT/Duroid 5880. The input impedance of the system is designed for 50 Ω compatibility with other system components, and the cross polarization is kept below –30 dB. The developed TSA system was simulated with commercially available electromagnetic software and manufactured. Measured results validate the design process and the antenna’s performance.
{"title":"Broadband Feed for Low Cross-Polarization Uniplanar Tapered Slot Antennas on Low-Permittivity Substrate","authors":"J. Schorer, J. Bornemann","doi":"10.4236/WET.2013.41003","DOIUrl":"https://doi.org/10.4236/WET.2013.41003","url":null,"abstract":"A broadband feeding technique for the uniplanar tapered slot antenna (TSA) is presented. The TSA operates at a center frequency of 6.5 GHz with a 7 GHz bandwidth (107 percent). The antenna and feed are realized with a broadband microstrip-to-slotline transition on a low permittivity high frequency substrate, Rogers RT/Duroid 5880. The input impedance of the system is designed for 50 Ω compatibility with other system components, and the cross polarization is kept below –30 dB. The developed TSA system was simulated with commercially available electromagnetic software and manufactured. Measured results validate the design process and the antenna’s performance.","PeriodicalId":68067,"journal":{"name":"无线工程与技术(英文)","volume":"2013 1","pages":"13-18"},"PeriodicalIF":0.0,"publicationDate":"2013-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70837555","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Compact microstrip antennas have recently received much attention due to the increasing demand of small antennas for personal communication equipment. The problem of achieving a wide impedance bandwidth for compact microstrip antennas is becoming an important topic in microstrip antenna design. In this paper the design and development of a 2 × 1 array of a low cost slotted microstrip line fed shorted patch antenna (MFSPA) has been presented. Both the shorted patch and microstrip line feed network have air substrate. The material cost is thus reduced to a minimum. The array consists of two adjacent patches fed, using a simple microstrip T network. The impedance bandwidth of nearly 40%, covering the bandwidth requirement of 1750 MHz band is obtained. Also the antenna exhibits dual band operation. The cross polarization radiation in H-Plane observed with a single element antenna has been reduced considerably with 2 × 1 array. A peak antenna gain of 9.2 dBi is obtained with a small variation of 0.8 dBi. From the results obtained it is clear that the antenna array studied has a low cost fabrication and is suitable for applications in DCS mobile communication base station.
{"title":"Design and Development of a 2 × 1 Array of Slotted Microstrip Line Fed Shorted Patch Antenna for DCS Mobile Communication System","authors":"G. Bidkar, R. Vani, P. Hungund","doi":"10.4236/WET.2013.41009","DOIUrl":"https://doi.org/10.4236/WET.2013.41009","url":null,"abstract":"Compact microstrip antennas have recently received much attention due to the increasing demand of small antennas for personal communication equipment. The problem of achieving a wide impedance bandwidth for compact microstrip antennas is becoming an important topic in microstrip antenna design. In this paper the design and development of a 2 × 1 array of a low cost slotted microstrip line fed shorted patch antenna (MFSPA) has been presented. Both the shorted patch and microstrip line feed network have air substrate. The material cost is thus reduced to a minimum. The array consists of two adjacent patches fed, using a simple microstrip T network. The impedance bandwidth of nearly 40%, covering the bandwidth requirement of 1750 MHz band is obtained. Also the antenna exhibits dual band operation. The cross polarization radiation in H-Plane observed with a single element antenna has been reduced considerably with 2 × 1 array. A peak antenna gain of 9.2 dBi is obtained with a small variation of 0.8 dBi. From the results obtained it is clear that the antenna array studied has a low cost fabrication and is suitable for applications in DCS mobile communication base station.","PeriodicalId":68067,"journal":{"name":"无线工程与技术(英文)","volume":"2013 1","pages":"59-63"},"PeriodicalIF":0.0,"publicationDate":"2013-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70837590","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study proposes a simple scaling factor approach to improve the performance of parallel-concatenated convolutional code (PCCC) and serial concatenated convolutional code (SCCC) systems based on suboptimal soft-input soft-output (SISO) decoders. Fixed and adaptive scaling factors were estimated to mitigate both the optimistic nature of a posteriori information and the correlation between intrinsic and extrinsic information produced by soft-output Viterbi (SOVA) decoders. The scaling factors could be computed off-line to reduce processing time and implementation complexity. The simulation results show a significant improvement in terms of bit-error rate (BER) over additive white Gaussian noise and Rayleigh fading channel. The convergence properties of the suggested iterative scheme are assessed using the extrinsic information transfer (EXIT) chart analysis technique.
{"title":"Performance Enhancement of SOVA Based Decoder in SCCC and PCCC Schemes","authors":"A. Hamad","doi":"10.4236/WET.2013.41006","DOIUrl":"https://doi.org/10.4236/WET.2013.41006","url":null,"abstract":"This study proposes a simple scaling factor approach to improve the performance of parallel-concatenated convolutional code (PCCC) and serial concatenated convolutional code (SCCC) systems based on suboptimal soft-input soft-output (SISO) decoders. Fixed and adaptive scaling factors were estimated to mitigate both the optimistic nature of a posteriori information and the correlation between intrinsic and extrinsic information produced by soft-output Viterbi (SOVA) decoders. The scaling factors could be computed off-line to reduce processing time and implementation complexity. The simulation results show a significant improvement in terms of bit-error rate (BER) over additive white Gaussian noise and Rayleigh fading channel. The convergence properties of the suggested iterative scheme are assessed using the extrinsic information transfer (EXIT) chart analysis technique.","PeriodicalId":68067,"journal":{"name":"无线工程与技术(英文)","volume":"2013 1","pages":"40-45"},"PeriodicalIF":0.0,"publicationDate":"2013-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70837742","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mixers in the communication system provide the possibility of encoding and decoding radio-frequency EM waves with signals through the help of local oscillators. A mixer with capability of high conversion gain, good isolation, and good linearity is comparably appreciated. Extensively wide ranges of frequencies, from 5.0 to 18.0 GHz, are to be examined addressing the promising functions of mixers in this study. A TSMC 0.18 μm CMOS model implanted in Agilent ADS is used for the circuit designs. Generated from Gilbert Cell Mixer, the modified circuits take advantage of extra active and passive devices to optimize the conversion gains. Characteristics of high conversion gain over 20 dB or even higher (as high as 29.842 dB at -40 mW RF power at working frequency 6 GHz) and low noise figures (NF) are shown.
{"title":"Mixers of Ultra-High Gain from 5.0 to 18.0 GHz","authors":"Hsin-Chia Yang, Jui-Ming Tsai, Cheng Tsao, Mu-Chun Wang, Sung-Ching Chi, Tsin-Yuan Chang","doi":"10.4236/WET.2013.41001","DOIUrl":"https://doi.org/10.4236/WET.2013.41001","url":null,"abstract":"Mixers in the communication system provide the possibility of encoding and decoding radio-frequency EM waves with signals through the help of local oscillators. A mixer with capability of high conversion gain, good isolation, and good linearity is comparably appreciated. Extensively wide ranges of frequencies, from 5.0 to 18.0 GHz, are to be examined addressing the promising functions of mixers in this study. A TSMC 0.18 μm CMOS model implanted in Agilent ADS is used for the circuit designs. Generated from Gilbert Cell Mixer, the modified circuits take advantage of extra active and passive devices to optimize the conversion gains. Characteristics of high conversion gain over 20 dB or even higher (as high as 29.842 dB at -40 mW RF power at working frequency 6 GHz) and low noise figures (NF) are shown.","PeriodicalId":68067,"journal":{"name":"无线工程与技术(英文)","volume":"04 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2013-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70837366","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study presents a new, simple method for reducing the back-lobe radiation of a microstrip antenna (MSA) by a partially removed ground plane of the antenna. The effect of the partial ground plane removal in different configurations on the radiation characteristics of a MSA are investigated numerically. The partial ground plane removal reduces the backlobe radiation of the MSA by suppressing the surface wave diffraction from the edges of the antenna ground plane. For further improving the front-to-back (F/B) ratio of the MSA, a new soft-surface configuration consisting of an array of stand-up split ring resonators (SRRs) are placed on a bare dielectric substrate near the two ground plane edges. Compared to the F/B ratio of a conventional MSA with a full ground plane of the same size, an improved F/B ratio of 9.7 dB has been achieved experimentally for our proposed MSA.
{"title":"Effect of Partial Ground Plane Removal on the Radiation Characteristics of a Microstrip Antenna","authors":"Hong-min Lee, W. Choi","doi":"10.4236/WET.2013.41002","DOIUrl":"https://doi.org/10.4236/WET.2013.41002","url":null,"abstract":"This study presents a new, simple method for reducing the back-lobe radiation of a microstrip antenna (MSA) by a partially removed ground plane of the antenna. The effect of the partial ground plane removal in different configurations on the radiation characteristics of a MSA are investigated numerically. The partial ground plane removal reduces the backlobe radiation of the MSA by suppressing the surface wave diffraction from the edges of the antenna ground plane. For further improving the front-to-back (F/B) ratio of the MSA, a new soft-surface configuration consisting of an array of stand-up split ring resonators (SRRs) are placed on a bare dielectric substrate near the two ground plane edges. Compared to the F/B ratio of a conventional MSA with a full ground plane of the same size, an improved F/B ratio of 9.7 dB has been achieved experimentally for our proposed MSA.","PeriodicalId":68067,"journal":{"name":"无线工程与技术(英文)","volume":"2013 1","pages":"5-12"},"PeriodicalIF":0.0,"publicationDate":"2013-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70837537","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
I. Alam, V. Srivastva, A. Prakash, R. Tripathi, A. K. Shankhwar
In today’s scenario mobile phones are not used only for messaging and talking, now we use mobiles also to access internet. For that we need higher data rates. Mobiles use wireless communication channel, which is very fast varying channel. To increase the data rate we have to utilize the full channel based on the channel condition. For that we have to estimate the channel condition and based on that we have to vary the data rate so that our communication system performance parameters (bit error rate, throughput) do not change beyond the accepted level. To increase the data rate we are also using the multi-carrier CDMA system in conjunction with the above described adaptive modulation. Adaptive modulation, in conjunction with MC-CDMA transmission system is very assuring way to increase data rate. In current scenario demand of very high data rates up to 100 Mbits/s may be achieved with this scheme. In this paper, adaptive modulation based M-ary QAM, M-PSK and M-ary CPM systems applied to a MC-CDMA system in Rayleigh fading channel environment have been investigated and BER performances of all these digital modulation schemes have been compared.
{"title":"Performance Evaluation of Adaptive Modulation Based MC-CDMA System","authors":"I. Alam, V. Srivastva, A. Prakash, R. Tripathi, A. K. Shankhwar","doi":"10.4236/WET.2013.41008","DOIUrl":"https://doi.org/10.4236/WET.2013.41008","url":null,"abstract":"In today’s scenario mobile phones are not used only for messaging and talking, now we use mobiles also to access internet. For that we need higher data rates. Mobiles use wireless communication channel, which is very fast varying channel. To increase the data rate we have to utilize the full channel based on the channel condition. For that we have to estimate the channel condition and based on that we have to vary the data rate so that our communication system performance parameters (bit error rate, throughput) do not change beyond the accepted level. To increase the data rate we are also using the multi-carrier CDMA system in conjunction with the above described adaptive modulation. Adaptive modulation, in conjunction with MC-CDMA transmission system is very assuring way to increase data rate. In current scenario demand of very high data rates up to 100 Mbits/s may be achieved with this scheme. In this paper, adaptive modulation based M-ary QAM, M-PSK and M-ary CPM systems applied to a MC-CDMA system in Rayleigh fading channel environment have been investigated and BER performances of all these digital modulation schemes have been compared.","PeriodicalId":68067,"journal":{"name":"无线工程与技术(英文)","volume":"4 1","pages":"54-58"},"PeriodicalIF":0.0,"publicationDate":"2013-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70837531","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper reports design of a CMOS optical receiver front-end using 0.18 μm technology. Design process is current associated with photodiode using trans-impedance amplifier (TIA) for wide bandwidth, high gain, low input referred noise and wide dynamic range. The Automated Gain Control (AGC) voltage is used to provide variable gain for multilevel signals. This design is simulated in 0.18 μm UMC technology for the performance analysis. The best simulation results are reported the maximum TIA gain of 67.26 dB? at 0 V AGC followed by a post amplifier gain of 86.70 dB?. The bandwidth range is 7.03 GHz to 11.5 GHz corresponding to 0 - 3 V AGC respectively. The input referred noise level value is 43.86 pA/√Hz up to 10 GHz frequency. In addition authors have obtained the common mode rejection ratio (CMRR) is 72.42 dB and rectified group delay is 144.48 ps. Verification of the design, reported results are compared with earlier published work and improvements obtained in the present results.
{"title":"Design of a CMOS Optical Receiver Front-End Using 0.18 μm Technology","authors":"A. Shukla, R. Gamad, Rohan Raikwar","doi":"10.4236/WET.2013.41007","DOIUrl":"https://doi.org/10.4236/WET.2013.41007","url":null,"abstract":"This paper reports design of a CMOS optical receiver front-end using 0.18 μm technology. Design process is current associated with photodiode using trans-impedance amplifier (TIA) for wide bandwidth, high gain, low input referred noise and wide dynamic range. The Automated Gain Control (AGC) voltage is used to provide variable gain for multilevel signals. This design is simulated in 0.18 μm UMC technology for the performance analysis. The best simulation results are reported the maximum TIA gain of 67.26 dB? at 0 V AGC followed by a post amplifier gain of 86.70 dB?. The bandwidth range is 7.03 GHz to 11.5 GHz corresponding to 0 - 3 V AGC respectively. The input referred noise level value is 43.86 pA/√Hz up to 10 GHz frequency. In addition authors have obtained the common mode rejection ratio (CMRR) is 72.42 dB and rectified group delay is 144.48 ps. Verification of the design, reported results are compared with earlier published work and improvements obtained in the present results.","PeriodicalId":68067,"journal":{"name":"无线工程与技术(英文)","volume":"04 1","pages":"46-53"},"PeriodicalIF":0.0,"publicationDate":"2013-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70837849","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper demonstrates wide-band CMOS VCO based on the transformer feedback from traditional circuit to our proposed work. The start up condition of the traditional cross-coupled pair is expressed by the high frequency model. The wide band technique of this structure is derived with the help of the high frequency model of the transistor. Therefore, the wide band CMOS VCO based on the common source transformer feedback topology can achieves the high performance in the low voltage and low phase noise. The measurement result of the VCO exhibits the figure of merit, core power consumption and output power at supply voltage 0.8 V are –193.1 dBc/Hz, 4.4 mW and –2.3 dBm, respectively. The phase noise is –124.3 dBc/Hz at 1 MHz offset under the operation frequency 5.8 GHz. And the tuning range of the circuit can obtain 28%, this VCO is fabricated in TSMC 0.18 μm 1P6MCMOS process.
{"title":"Design of Wide Band CMOS VCO with Common Source Transformer Feedback Topology","authors":"Meng-Ting Hsu, Ying-Hsiang Huang, Cheng-Chuan Chung","doi":"10.4236/WET.2013.41004","DOIUrl":"https://doi.org/10.4236/WET.2013.41004","url":null,"abstract":"This paper demonstrates wide-band CMOS VCO based on the transformer feedback from traditional circuit to our proposed work. The start up condition of the traditional cross-coupled pair is expressed by the high frequency model. The wide band technique of this structure is derived with the help of the high frequency model of the transistor. Therefore, the wide band CMOS VCO based on the common source transformer feedback topology can achieves the high performance in the low voltage and low phase noise. The measurement result of the VCO exhibits the figure of merit, core power consumption and output power at supply voltage 0.8 V are –193.1 dBc/Hz, 4.4 mW and –2.3 dBm, respectively. The phase noise is –124.3 dBc/Hz at 1 MHz offset under the operation frequency 5.8 GHz. And the tuning range of the circuit can obtain 28%, this VCO is fabricated in TSMC 0.18 μm 1P6MCMOS process.","PeriodicalId":68067,"journal":{"name":"无线工程与技术(英文)","volume":"2013 1","pages":"19-27"},"PeriodicalIF":0.0,"publicationDate":"2013-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4236/WET.2013.41004","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70837671","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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