Pub Date : 2008-12-01DOI: 10.1109/RFM.2008.4897423
A. Abidin, W. Abdullah, M. Jenu, A. Ramli
The amplitude probability distribution (APD) has been proposed within comite international special des perturbations radioelectriques (CISPR) as a measure of the emitted electromagnetic interference from electrical appliances or equipment. The APD approach is effective for estimating the noise impact towards degradation of digital communication performance. This paper presents the development of APD analyzer for simultaneous measurement of noise emission on digital subscriber line (DSL) communication. Noise statistics have been measured by using the analyser. It is vital to have correct measurement set-up, signal power level, sampling rate, sample points and filter characterization in order to acquire accurate data representation of the noise pattern. The APD graph was obtained from computer calculation that using the APD algorithm method which employing existing time ratio. The noises are characterized using alpha-distribution functions that exhibiting its own distinct APD parameters alpha, beta and gamma which will be verified in single modulation scheme for estimation of bit error probability. The analyser will record and analyse results of noise pattern emission from various sources of interference. The analyser provides the platform for interference verification of man-made noise emission towards DSL communication performance.
{"title":"The development of statistical parameter measuring analyser using the APD technique for DSL communication","authors":"A. Abidin, W. Abdullah, M. Jenu, A. Ramli","doi":"10.1109/RFM.2008.4897423","DOIUrl":"https://doi.org/10.1109/RFM.2008.4897423","url":null,"abstract":"The amplitude probability distribution (APD) has been proposed within comite international special des perturbations radioelectriques (CISPR) as a measure of the emitted electromagnetic interference from electrical appliances or equipment. The APD approach is effective for estimating the noise impact towards degradation of digital communication performance. This paper presents the development of APD analyzer for simultaneous measurement of noise emission on digital subscriber line (DSL) communication. Noise statistics have been measured by using the analyser. It is vital to have correct measurement set-up, signal power level, sampling rate, sample points and filter characterization in order to acquire accurate data representation of the noise pattern. The APD graph was obtained from computer calculation that using the APD algorithm method which employing existing time ratio. The noises are characterized using alpha-distribution functions that exhibiting its own distinct APD parameters alpha, beta and gamma which will be verified in single modulation scheme for estimation of bit error probability. The analyser will record and analyse results of noise pattern emission from various sources of interference. The analyser provides the platform for interference verification of man-made noise emission towards DSL communication performance.","PeriodicalId":329128,"journal":{"name":"2008 IEEE International RF and Microwave Conference","volume":"485 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123557303","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}
Pub Date : 2008-12-01DOI: 10.1109/RFM.2008.4897457
J. Marimuthu, Mona Riza Mohd Esa, S. Yusof
The frequency-dispersive characteristic of a two-port parallel coupled microstrip line (PCML) can be obtained using equivalent J-inverter network parameters. The latter is obtained from its corresponding admittance parameters. Hence, the behaviour of transmission zero frequency, fundamental response frequency and harmonic response frequency of the PCML can be shown. The former is realigned by varying a centrally located single groove size to suppress the first spurious harmonic passband of the filter. Using the J-inverter parameters, the transmission zero of J-susceptance null of a PCML can be realigned by employing a single groove with specific dimension. This simultaneously cancels the first harmonic resonance. In this paper, the behaviour of the J-inverter parameters with varying coupling gaps is presented. The effect of having weak coupling characteristic is then presented. The proposed technique is then justified by two single-stage bandpass filters of PCML with weak coupling characteristic.
{"title":"Single-stage parallel coupled microstrip line bandpass filter using weak coupling technique","authors":"J. Marimuthu, Mona Riza Mohd Esa, S. Yusof","doi":"10.1109/RFM.2008.4897457","DOIUrl":"https://doi.org/10.1109/RFM.2008.4897457","url":null,"abstract":"The frequency-dispersive characteristic of a two-port parallel coupled microstrip line (PCML) can be obtained using equivalent J-inverter network parameters. The latter is obtained from its corresponding admittance parameters. Hence, the behaviour of transmission zero frequency, fundamental response frequency and harmonic response frequency of the PCML can be shown. The former is realigned by varying a centrally located single groove size to suppress the first spurious harmonic passband of the filter. Using the J-inverter parameters, the transmission zero of J-susceptance null of a PCML can be realigned by employing a single groove with specific dimension. This simultaneously cancels the first harmonic resonance. In this paper, the behaviour of the J-inverter parameters with varying coupling gaps is presented. The effect of having weak coupling characteristic is then presented. The proposed technique is then justified by two single-stage bandpass filters of PCML with weak coupling characteristic.","PeriodicalId":329128,"journal":{"name":"2008 IEEE International RF and Microwave Conference","volume":"68 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122557523","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}
Pub Date : 2008-12-01DOI: 10.1109/RFM.2008.4897372
N. M. Zawawi, M. F. Ain, S. Hassan, M. Zakariya, C.Y. Hui, R. Hussin
This paper will discuss the design and implementation of the digital up converter (DUC) in Field Programmable Gate Array (FPGA). DUC is a digital circuit which generating digital intermediate frequency (IF) signal from low complex digital baseband signal. The DUC provides pulse shaping, interpolation and frequency translation where the up-sampled signal is shifted from centered frequency (0 Hz) to intermediate frequency. Due to Wideband Code Division Multiple Access (WCDMA) specifications, the DUC is to pulse shaped and up sampled the baseband signal by a factor of 16. The DUC up sampled the signal up to 61.44 MHz.
{"title":"Implementing WCDMA digital up converter in FPGA","authors":"N. M. Zawawi, M. F. Ain, S. Hassan, M. Zakariya, C.Y. Hui, R. Hussin","doi":"10.1109/RFM.2008.4897372","DOIUrl":"https://doi.org/10.1109/RFM.2008.4897372","url":null,"abstract":"This paper will discuss the design and implementation of the digital up converter (DUC) in Field Programmable Gate Array (FPGA). DUC is a digital circuit which generating digital intermediate frequency (IF) signal from low complex digital baseband signal. The DUC provides pulse shaping, interpolation and frequency translation where the up-sampled signal is shifted from centered frequency (0 Hz) to intermediate frequency. Due to Wideband Code Division Multiple Access (WCDMA) specifications, the DUC is to pulse shaped and up sampled the baseband signal by a factor of 16. The DUC up sampled the signal up to 61.44 MHz.","PeriodicalId":329128,"journal":{"name":"2008 IEEE International RF and Microwave Conference","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127529638","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}
Pub Date : 2008-12-01DOI: 10.1109/RFM.2008.4897442
R. A. Bakar, Zaiki Awang, S. Sulaiman, Nor Fazlina Mohd Lazim, Zuhani Ismail Khan
This paper reports on the performance and effects of via holes fabricated in lead zirconate titanate (PZT) thin films intended for microwave integrated circuit applications. Square and cylindrical vias were simulated at microwave frequencies using a 3D electromagnetic simulator. The performance of via hole grounding was then compared to the edge grounding at the PZT/Pt interface. An equivalent circuit model is proposed and the models parameters are extracted. The simulation results showed that using via hole resulted in low inductance (3.848 nH) and resistance (0.017 Omega) values compared to edge grounding technique (L = 10.192 nH and R = 0.074 Omega).
本文报道了微波集成电路用锆钛酸铅(PZT)薄膜中通孔的性能及其影响。利用三维电磁模拟器对微波频率下的方形和圆柱形过孔进行了仿真。然后将过孔接地与PZT/Pt界面边接地的性能进行了比较。提出了等效电路模型，并提取了模型参数。仿真结果表明，与边缘接地技术(L = 10.192 nH, R = 0.074 Omega)相比，采用过孔接地技术的电感(3.848 nH)和电阻(0.017 Omega)值较低。
{"title":"Via hole modeling of PZT thin films for MMIC applications","authors":"R. A. Bakar, Zaiki Awang, S. Sulaiman, Nor Fazlina Mohd Lazim, Zuhani Ismail Khan","doi":"10.1109/RFM.2008.4897442","DOIUrl":"https://doi.org/10.1109/RFM.2008.4897442","url":null,"abstract":"This paper reports on the performance and effects of via holes fabricated in lead zirconate titanate (PZT) thin films intended for microwave integrated circuit applications. Square and cylindrical vias were simulated at microwave frequencies using a 3D electromagnetic simulator. The performance of via hole grounding was then compared to the edge grounding at the PZT/Pt interface. An equivalent circuit model is proposed and the models parameters are extracted. The simulation results showed that using via hole resulted in low inductance (3.848 nH) and resistance (0.017 Omega) values compared to edge grounding technique (L = 10.192 nH and R = 0.074 Omega).","PeriodicalId":329128,"journal":{"name":"2008 IEEE International RF and Microwave Conference","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127677068","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}
Pub Date : 2008-12-01DOI: 10.1109/RFM.2008.4897458
K. Sahal Bin Sahaq, S. Hassan
The effect of rain water accumulated on the antenna surfaces during the rain event is one of some other factors that can degrade the system performance at higher frequency-bands like the Ku-band. In this paper we present the results of measurements dealing with the wet antenna attenuation under the influence of simulated wind conditions at Ku band frequencies at different simulated rain rate. Rain water on the antenna surfaces can cause additional significant signal attenuation. The experiments were conducted at USM engineering campus to measure and analysis the attenuation caused by wet antenna under different wind conditions. A Ku band link was constructed using a parabolic offset 0.6 m antenna as receive antenna. A rain simulator was used to simulate various rain rates and an industrial fan was used to simulate the wind conditions. It was found that the wind condition has a reasonable influence on the wet antenna attenuation.
{"title":"Measurements of the effect of simulated rain and wind on the offset parabolic receiver antenna at Ku-band frequencies","authors":"K. Sahal Bin Sahaq, S. Hassan","doi":"10.1109/RFM.2008.4897458","DOIUrl":"https://doi.org/10.1109/RFM.2008.4897458","url":null,"abstract":"The effect of rain water accumulated on the antenna surfaces during the rain event is one of some other factors that can degrade the system performance at higher frequency-bands like the Ku-band. In this paper we present the results of measurements dealing with the wet antenna attenuation under the influence of simulated wind conditions at Ku band frequencies at different simulated rain rate. Rain water on the antenna surfaces can cause additional significant signal attenuation. The experiments were conducted at USM engineering campus to measure and analysis the attenuation caused by wet antenna under different wind conditions. A Ku band link was constructed using a parabolic offset 0.6 m antenna as receive antenna. A rain simulator was used to simulate various rain rates and an industrial fan was used to simulate the wind conditions. It was found that the wind condition has a reasonable influence on the wet antenna attenuation.","PeriodicalId":329128,"journal":{"name":"2008 IEEE International RF and Microwave Conference","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127941527","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}
Pub Date : 2008-12-01DOI: 10.1109/RFM.2008.4897376
M. Tan, S. Rahim, M.T. Ali, T. Rahman
This paper is divided into two parts. The first part presents the study of smart antenna beamforming where a single beam is shaped by weighting and summing the antenna outputs. In order to calculate the weight of the array elements, the conventional beam-former (known as delay and sum) has been chosen. Matlab software is used to calculate the weights, and to obtain the array factor of 8 elements linear array antenna. The second part illustrates that, the side-lobe can be reduced by using unequal spacing technique, but the number of elements is remained unchanged. The comparison between symmetric and asymmetric arrangement for unequal spacing is also presented. The results show that by using the symmetrical arrangement, the side-lobe obtained is much better than asymmetrical arrangement. In fact, the side-lobe produced by asymmetrical arrangement is worse than the equal arrangement.
{"title":"Smart antenna:Weight calculation and side-lobe reduction by unequal spacing technique","authors":"M. Tan, S. Rahim, M.T. Ali, T. Rahman","doi":"10.1109/RFM.2008.4897376","DOIUrl":"https://doi.org/10.1109/RFM.2008.4897376","url":null,"abstract":"This paper is divided into two parts. The first part presents the study of smart antenna beamforming where a single beam is shaped by weighting and summing the antenna outputs. In order to calculate the weight of the array elements, the conventional beam-former (known as delay and sum) has been chosen. Matlab software is used to calculate the weights, and to obtain the array factor of 8 elements linear array antenna. The second part illustrates that, the side-lobe can be reduced by using unequal spacing technique, but the number of elements is remained unchanged. The comparison between symmetric and asymmetric arrangement for unequal spacing is also presented. The results show that by using the symmetrical arrangement, the side-lobe obtained is much better than asymmetrical arrangement. In fact, the side-lobe produced by asymmetrical arrangement is worse than the equal arrangement.","PeriodicalId":329128,"journal":{"name":"2008 IEEE International RF and Microwave Conference","volume":"5 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120902219","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}
Pub Date : 2008-12-01DOI: 10.1109/RFM.2008.4897390
M. H. Siti Maisurah, I. M. Azmi, S. Rasidah, A. I. Abdul Rahim, Y. M. Razman
A single-pole double-throw (SPDT) transmit/receive (T/R) switch for 900 MHz applications has been designed in a 0.18 mum CMOS process. The switch exhibit a 16 dB input 1-dB compression point with output 1-dB compression point of 12.9 dB. At 900 MHz of frequency operation, the switch has excellent characteristics whereby the insertion loss is only around 3 dB and isolation around 40 dB for both transmitting and receiving operations. The proposed switch achieves return loss of -11 dB during these operations with switching response time around 4.5 ns.
{"title":"A 0.18μm CMOS T/R switch for 900MHz wireless application","authors":"M. H. Siti Maisurah, I. M. Azmi, S. Rasidah, A. I. Abdul Rahim, Y. M. Razman","doi":"10.1109/RFM.2008.4897390","DOIUrl":"https://doi.org/10.1109/RFM.2008.4897390","url":null,"abstract":"A single-pole double-throw (SPDT) transmit/receive (T/R) switch for 900 MHz applications has been designed in a 0.18 mum CMOS process. The switch exhibit a 16 dB input 1-dB compression point with output 1-dB compression point of 12.9 dB. At 900 MHz of frequency operation, the switch has excellent characteristics whereby the insertion loss is only around 3 dB and isolation around 40 dB for both transmitting and receiving operations. The proposed switch achieves return loss of -11 dB during these operations with switching response time around 4.5 ns.","PeriodicalId":329128,"journal":{"name":"2008 IEEE International RF and Microwave Conference","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121160421","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}
Pub Date : 2008-12-01DOI: 10.1109/RFM.2008.4897359
M. H. Badjian, C. Chakrabarty, S. Devkumar, G. C. Hock
An ultra wideband (UWB) patch antenna is analyzed in this paper. The design uses FR-4 substrate with dielectric constant of 4.9 and thickness of 1.6 mm. Circuit model of such antenna is developed under AWR microwave office environment. Obtained results from simulating the antenna in CST microwave studio are then compared with the results taken from the Circuit Model.
{"title":"Circuit modeling of an UWB patch antenna","authors":"M. H. Badjian, C. Chakrabarty, S. Devkumar, G. C. Hock","doi":"10.1109/RFM.2008.4897359","DOIUrl":"https://doi.org/10.1109/RFM.2008.4897359","url":null,"abstract":"An ultra wideband (UWB) patch antenna is analyzed in this paper. The design uses FR-4 substrate with dielectric constant of 4.9 and thickness of 1.6 mm. Circuit model of such antenna is developed under AWR microwave office environment. Obtained results from simulating the antenna in CST microwave studio are then compared with the results taken from the Circuit Model.","PeriodicalId":329128,"journal":{"name":"2008 IEEE International RF and Microwave Conference","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126411717","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}
Pub Date : 2008-12-01DOI: 10.1109/RFM.2008.4897356
Z. Shamsan, L. Abdulrazak, T. Rahman
Due to spectrum scarcity and emerging various wireless applications, coexistence and sharing between IMT-advanced and fixed wireless access (FWA) systems becomes a recently critical issue. At WRC-07, ITU-R allocated 3400-3600 MHz band for the coming fourth generation (4G) or IMT-Advanced on a co-primary basis along with existing FWA systems. Therefore, coexistence and sharing requirements like separation distance and frequency separation coordination must be achieved in terms of both co-channel and adjacent channel frequencies. Co-sited the two base stations antennas and non co-sited coexistence of the two systems are analyzed (depending on interference to noise ratio of -6 dB as a standard coexistence criteria). The interference analysis models, adjacent channel interference ratio ACIR and spectral emission mask (SEM) are applied in the mentioned band to extract the additional isolation needed to protect adjacent channel interference. Finally, possible intersystem interference mitigation techniques are suggested.
{"title":"Co-channel and adjacent channel interference evaluation for IMT-Advanced coexistence with existing fixed systems","authors":"Z. Shamsan, L. Abdulrazak, T. Rahman","doi":"10.1109/RFM.2008.4897356","DOIUrl":"https://doi.org/10.1109/RFM.2008.4897356","url":null,"abstract":"Due to spectrum scarcity and emerging various wireless applications, coexistence and sharing between IMT-advanced and fixed wireless access (FWA) systems becomes a recently critical issue. At WRC-07, ITU-R allocated 3400-3600 MHz band for the coming fourth generation (4G) or IMT-Advanced on a co-primary basis along with existing FWA systems. Therefore, coexistence and sharing requirements like separation distance and frequency separation coordination must be achieved in terms of both co-channel and adjacent channel frequencies. Co-sited the two base stations antennas and non co-sited coexistence of the two systems are analyzed (depending on interference to noise ratio of -6 dB as a standard coexistence criteria). The interference analysis models, adjacent channel interference ratio ACIR and spectral emission mask (SEM) are applied in the mentioned band to extract the additional isolation needed to protect adjacent channel interference. Finally, possible intersystem interference mitigation techniques are suggested.","PeriodicalId":329128,"journal":{"name":"2008 IEEE International RF and Microwave Conference","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126423049","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}
Pub Date : 2008-12-01DOI: 10.1109/RFM.2008.4897460
P. Collins, H. Matsuoka
The paper discusses the potential advantages of operating a microwave power-generating solar power satellite demonstrator in low equatorial orbit. Advantages include being able to deliver power to receiving antennas in a dozen countries around the equator many times/day, and enabling progressive growth to become a large scale system, including geo-stationary satellites. Solar power satellites operating at progressively higher altitudes can deliver power to cities at progressively higher latitudes: within 24 degrees of the equator there is potential demand for several hundred GW of power. Planning an international conference to discuss such a project is recommended.
{"title":"Comparative benefits of a low equatorial orbit microwave solar power satellite (SPS) operational demonstrator","authors":"P. Collins, H. Matsuoka","doi":"10.1109/RFM.2008.4897460","DOIUrl":"https://doi.org/10.1109/RFM.2008.4897460","url":null,"abstract":"The paper discusses the potential advantages of operating a microwave power-generating solar power satellite demonstrator in low equatorial orbit. Advantages include being able to deliver power to receiving antennas in a dozen countries around the equator many times/day, and enabling progressive growth to become a large scale system, including geo-stationary satellites. Solar power satellites operating at progressively higher altitudes can deliver power to cities at progressively higher latitudes: within 24 degrees of the equator there is potential demand for several hundred GW of power. Planning an international conference to discuss such a project is recommended.","PeriodicalId":329128,"journal":{"name":"2008 IEEE International RF and Microwave Conference","volume":" 11","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131977071","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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