Pub Date : 2008-09-26DOI: 10.1109/SSD.2008.4632818
S. Ben Aoun, N. Derbel, H. Jerbi
This paper presents a design approach to hybrid control systems, combining analytical feedback linearization control techniques with neural networks. Such a mixed implementation leads to a more effective control design with improved system performance and robustness. The main objective of integrating neural networks is to overcome the problems with uncertainties in the plant parameters and structure encountered in the analytical model-based design. Shunt DC motor is characterized by complex nonlinear and time-varying dynamics and inaccessibility of some model parameters for on line measurements, and hence can be considered as an important challenging engineering topic. The input-state feedback linearization technique is known for its good results locally in a neighborhood of an operating point. However, these results are sensitive to model parameter variations and so performances may deteriorate. Neural network-based controllers are considered as candidates for this parameters sensitivity. In a first step, an algorithm for analytical exact input-state linearizing control is formulated. The following step is dedicated to the robust neural feedback controller design. A simulation study of these methods is presented. The effectiveness of the neural controller with respect to the analytical one is demonstrated for a large armature resistance variation.
{"title":"Synthesis of a robust neural input-state feedback controller for nonlinear systems","authors":"S. Ben Aoun, N. Derbel, H. Jerbi","doi":"10.1109/SSD.2008.4632818","DOIUrl":"https://doi.org/10.1109/SSD.2008.4632818","url":null,"abstract":"This paper presents a design approach to hybrid control systems, combining analytical feedback linearization control techniques with neural networks. Such a mixed implementation leads to a more effective control design with improved system performance and robustness. The main objective of integrating neural networks is to overcome the problems with uncertainties in the plant parameters and structure encountered in the analytical model-based design. Shunt DC motor is characterized by complex nonlinear and time-varying dynamics and inaccessibility of some model parameters for on line measurements, and hence can be considered as an important challenging engineering topic. The input-state feedback linearization technique is known for its good results locally in a neighborhood of an operating point. However, these results are sensitive to model parameter variations and so performances may deteriorate. Neural network-based controllers are considered as candidates for this parameters sensitivity. In a first step, an algorithm for analytical exact input-state linearizing control is formulated. The following step is dedicated to the robust neural feedback controller design. A simulation study of these methods is presented. The effectiveness of the neural controller with respect to the analytical one is demonstrated for a large armature resistance variation.","PeriodicalId":267264,"journal":{"name":"2008 5th International Multi-Conference on Systems, Signals and Devices","volume":"87 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128503437","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}
Multi-path effect in HF communication not only changes the amplitude, but changes the phase of receiving signal as well. The rapid and random movement of ionospheric causes the oscillation of the phase. It could be viewed as the Doppler shift of high-frequency carrier caused by ionospheric. The shift of frequency should be corrected because it brings difficulty in recovering the carrier. The non-blind method needs much quantities of training (or pilot frequency) sequences at the cost of system recourse (bandwidth). However, the blind estimation will wildly encounter the vague phase. In this paper, a semi-blind parameter estimation method is introduced which uses few training sequences to distinguish the carrier. In this way, the carrierpsilas phase and timing parameter could be recovered rapidly. Besides, this algorithm is easy to implement in hardware platform.
{"title":"Rapid joint semi-blind estimation algorithm for carrier phase and timing parameter","authors":"Yang Jianxi, Wang Yuan, Chu Liang","doi":"10.1109/ICWMC.2008.68","DOIUrl":"https://doi.org/10.1109/ICWMC.2008.68","url":null,"abstract":"Multi-path effect in HF communication not only changes the amplitude, but changes the phase of receiving signal as well. The rapid and random movement of ionospheric causes the oscillation of the phase. It could be viewed as the Doppler shift of high-frequency carrier caused by ionospheric. The shift of frequency should be corrected because it brings difficulty in recovering the carrier. The non-blind method needs much quantities of training (or pilot frequency) sequences at the cost of system recourse (bandwidth). However, the blind estimation will wildly encounter the vague phase. In this paper, a semi-blind parameter estimation method is introduced which uses few training sequences to distinguish the carrier. In this way, the carrierpsilas phase and timing parameter could be recovered rapidly. Besides, this algorithm is easy to implement in hardware platform.","PeriodicalId":267264,"journal":{"name":"2008 5th International Multi-Conference on Systems, Signals and Devices","volume":"195 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114111060","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 : 2008-07-20DOI: 10.1109/SSD.2008.4632813
R. Hamza, M. Feki, B. Robert, A. El Aroudi
In this paper we deal with the control of a two-cell DC/DC buck converter. The design is based on a discrete state space model obtained by expressing current and voltage at the beginning of the (n+1)th period in terms of values of the preceding period. It is shown that the describing model is nonlinear, therefore it is expected that a standard linear controller (e.g. PID) would not be efficient. In this work, we suggest four controllers which are simple to construct. The investigation of their performance is based on linear analysis. The controllers are designed step-by-step where each next controller improves the action of the previous one. The first controller (CI) is found to be the simplest that can lead to a linear closed loop system, hence it can be considered as a simple input-to-state linearizing controller. With the application of CI we can only obtain a correct reference current but the voltage remains uncontrollable. The second controller (C2) is the classic proportional controller. Although, it has remedied the problem of voltage controlling, it resulted in a constant static error of the current. After analyzing the first two controllers, a third controller (C3) is designed to achieve the correct reference values. The only drawback of C3 was the slow convergence of the current to the desired value. The fourth controller (C4) has been finally suggested to circumvent all the crossed drawbacks of the preceding controllers. The efficiency of C4 is shown using numerical simulations. The application onto a real circuit is being carried and results will be published in a future work.
{"title":"Zero current and zero voltage static error control of a multi-cell dc/dc converter","authors":"R. Hamza, M. Feki, B. Robert, A. El Aroudi","doi":"10.1109/SSD.2008.4632813","DOIUrl":"https://doi.org/10.1109/SSD.2008.4632813","url":null,"abstract":"In this paper we deal with the control of a two-cell DC/DC buck converter. The design is based on a discrete state space model obtained by expressing current and voltage at the beginning of the (n+1)th period in terms of values of the preceding period. It is shown that the describing model is nonlinear, therefore it is expected that a standard linear controller (e.g. PID) would not be efficient. In this work, we suggest four controllers which are simple to construct. The investigation of their performance is based on linear analysis. The controllers are designed step-by-step where each next controller improves the action of the previous one. The first controller (CI) is found to be the simplest that can lead to a linear closed loop system, hence it can be considered as a simple input-to-state linearizing controller. With the application of CI we can only obtain a correct reference current but the voltage remains uncontrollable. The second controller (C2) is the classic proportional controller. Although, it has remedied the problem of voltage controlling, it resulted in a constant static error of the current. After analyzing the first two controllers, a third controller (C3) is designed to achieve the correct reference values. The only drawback of C3 was the slow convergence of the current to the desired value. The fourth controller (C4) has been finally suggested to circumvent all the crossed drawbacks of the preceding controllers. The efficiency of C4 is shown using numerical simulations. The application onto a real circuit is being carried and results will be published in a future work.","PeriodicalId":267264,"journal":{"name":"2008 5th International Multi-Conference on Systems, Signals and Devices","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125158621","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 : 2008-07-20DOI: 10.1109/SSD.2008.4632799
D. B. Issa, M. Samet, A. Kachouri
This paper presents a quadrature voltage controlled oscillator (QVCO) based on the electric coupling of two identical LC voltage controlled oscillator in 0.35μm CMOS technology. The proposed design of QVCO accomplishes extensive tuning by using binary weighted switched varactor in addition to a linearly varying varactor. The simulated results show the multi-band frequency of proposed QVCO using in multi-standard wireless applications. This structure presents a 50% of tuning range carrier frequency at a range of 2.3 to 3.8 GHz. The phase noise is −130dBc/Hz at 1MHz offset frequency from carrier frequency of 3.5GHz. The power consumption of QVCO is 13.6mW.
{"title":"Concept of wide tuning QVCO adapted for multi-standards applications","authors":"D. B. Issa, M. Samet, A. Kachouri","doi":"10.1109/SSD.2008.4632799","DOIUrl":"https://doi.org/10.1109/SSD.2008.4632799","url":null,"abstract":"This paper presents a quadrature voltage controlled oscillator (QVCO) based on the electric coupling of two identical LC voltage controlled oscillator in 0.35μm CMOS technology. The proposed design of QVCO accomplishes extensive tuning by using binary weighted switched varactor in addition to a linearly varying varactor. The simulated results show the multi-band frequency of proposed QVCO using in multi-standard wireless applications. This structure presents a 50% of tuning range carrier frequency at a range of 2.3 to 3.8 GHz. The phase noise is −130dBc/Hz at 1MHz offset frequency from carrier frequency of 3.5GHz. The power consumption of QVCO is 13.6mW.","PeriodicalId":267264,"journal":{"name":"2008 5th International Multi-Conference on Systems, Signals and Devices","volume":"70 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116087627","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 : 2008-07-20DOI: 10.1109/SSD.2008.4632898
Z. Muhsin, A. El-Mousa, M. Al-Taee
Distributed workflow management systems are increasingly gaining momentum due to the emergence of virtual and distributed organizations, as well as cross-organizational workflows. This paper presents an effective development process for a distributed workflow management system (WKFMS) which is utilized to automate the management processes related to computer and peripheral repair requests in the Faculty of Engineering and Technology (FET) at the University of Jordan. First, the paper explores the reasoning and motivation behind the choice of the management processes involved in the WKFMS. Phases of the development process that is based on the rapid prototyping paradigm are then described. Particular focus is given to the modeling of business scenarios using the Model-View-Control (MVC) architecture. The distributed network layout and system security measures are also investigated. Reduction of manual human intervention in the decision process is achieved through the implementation of a neuro-fuzzy computational intelligence processor to automate the major decision making process of tasks distribution. It is shown that the application of the proposed development process helped in reducing the overall system development time and effort. The successful deployment and functional testing of the developed industrial prototype has proved that it works smoothly according to the desired features.
{"title":"A distributed workflow management system utilizing computational intelligence for decision support","authors":"Z. Muhsin, A. El-Mousa, M. Al-Taee","doi":"10.1109/SSD.2008.4632898","DOIUrl":"https://doi.org/10.1109/SSD.2008.4632898","url":null,"abstract":"Distributed workflow management systems are increasingly gaining momentum due to the emergence of virtual and distributed organizations, as well as cross-organizational workflows. This paper presents an effective development process for a distributed workflow management system (WKFMS) which is utilized to automate the management processes related to computer and peripheral repair requests in the Faculty of Engineering and Technology (FET) at the University of Jordan. First, the paper explores the reasoning and motivation behind the choice of the management processes involved in the WKFMS. Phases of the development process that is based on the rapid prototyping paradigm are then described. Particular focus is given to the modeling of business scenarios using the Model-View-Control (MVC) architecture. The distributed network layout and system security measures are also investigated. Reduction of manual human intervention in the decision process is achieved through the implementation of a neuro-fuzzy computational intelligence processor to automate the major decision making process of tasks distribution. It is shown that the application of the proposed development process helped in reducing the overall system development time and effort. The successful deployment and functional testing of the developed industrial prototype has proved that it works smoothly according to the desired features.","PeriodicalId":267264,"journal":{"name":"2008 5th International Multi-Conference on Systems, Signals and Devices","volume":"256 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114401612","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 : 2008-07-20DOI: 10.1109/SSD.2008.4632821
M. Benzaoui, H. Chekireb
To meet the requirements due to the existing constraints in addition to the main task, it is possible to use, for the redundant robots, the self-motion (internal motion of joints). However, this solution can lead to a loss of the motion cyclicity in joints space. In this work, three methods are compared which ensure the conservation of the movement cyclicity. These latter are based respectively on the Lagrangian one (to improve selfmotion solution), a compliance function (to improve inverse jacobian solution) and the last is a combination of both methods. We consider the control of a redundant robot which carries out a trajectory tacking in operational space with the constraints due to the position and velocity limits of joints. Also, the proposed methods are tested in the case of the 3 DOF planar robots deduced from the PUMA 560. The obtained results show that the two methods alone can ensure the motion cyclicity meanwhile the combined method is more efficient.
{"title":"Cyclic control of redundatn robot under constraint with the self-motion method","authors":"M. Benzaoui, H. Chekireb","doi":"10.1109/SSD.2008.4632821","DOIUrl":"https://doi.org/10.1109/SSD.2008.4632821","url":null,"abstract":"To meet the requirements due to the existing constraints in addition to the main task, it is possible to use, for the redundant robots, the self-motion (internal motion of joints). However, this solution can lead to a loss of the motion cyclicity in joints space. In this work, three methods are compared which ensure the conservation of the movement cyclicity. These latter are based respectively on the Lagrangian one (to improve selfmotion solution), a compliance function (to improve inverse jacobian solution) and the last is a combination of both methods. We consider the control of a redundant robot which carries out a trajectory tacking in operational space with the constraints due to the position and velocity limits of joints. Also, the proposed methods are tested in the case of the 3 DOF planar robots deduced from the PUMA 560. The obtained results show that the two methods alone can ensure the motion cyclicity meanwhile the combined method is more efficient.","PeriodicalId":267264,"journal":{"name":"2008 5th International Multi-Conference on Systems, Signals and Devices","volume":"66 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124602327","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 : 2008-07-20DOI: 10.1109/SSD.2008.4632797
M. Sharawi, M. Al-Qdah
A major bottleneck in todaypsilas computer system performance is the speed of the main memory bus. A memory bus should be carefully designed for good signal integrity (SI) and timing performance. This paper presents the design, modelling and simulation of a double data rate synchronous dynamic RAM (DDR-II SDRAM) memory bus operating at 400/533 Mbps. Three bus topologies are investigated and compared in terms of the amount of inter-symbol-interference (ISI) and the eye-width (EW). The topology with on-die-termination (ODT) gave about 95% improvement in ISI reduction, and about 37% and 12% improvement in the eye-width for the worst case write and read operations for the 400 Mbps data rate, respectively, when compared to the conventional mother board termination (MBT) scheme.
{"title":"The design and simulation of a 400/533Mbps DDR-II SDRAM memory interconnect bus","authors":"M. Sharawi, M. Al-Qdah","doi":"10.1109/SSD.2008.4632797","DOIUrl":"https://doi.org/10.1109/SSD.2008.4632797","url":null,"abstract":"A major bottleneck in todaypsilas computer system performance is the speed of the main memory bus. A memory bus should be carefully designed for good signal integrity (SI) and timing performance. This paper presents the design, modelling and simulation of a double data rate synchronous dynamic RAM (DDR-II SDRAM) memory bus operating at 400/533 Mbps. Three bus topologies are investigated and compared in terms of the amount of inter-symbol-interference (ISI) and the eye-width (EW). The topology with on-die-termination (ODT) gave about 95% improvement in ISI reduction, and about 37% and 12% improvement in the eye-width for the worst case write and read operations for the 400 Mbps data rate, respectively, when compared to the conventional mother board termination (MBT) scheme.","PeriodicalId":267264,"journal":{"name":"2008 5th International Multi-Conference on Systems, Signals and Devices","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126840333","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 : 2008-07-20DOI: 10.1109/SSD.2008.4632802
T. Djamah, S. Djennoune, M. Bettayeb
This article deals with heat transfer modeling and identification, based on fractional non commensurate order state space models. An output error method is developed to estimate the model parameters including the fractional order and an iterative non-linear programming method is used, based on a novel fractional multivariable sensitivity functions model. Numerical simulation data of the heat transfer problem are performed using finite differences, and the suggested method is applied to identify the thermal process. Two fractional non commensurate models are tested in order to analyze their fitting ability to approximate the interface diffusion in the frequency domain.
{"title":"Identification of diffusion processes using fractional non commensurate order models","authors":"T. Djamah, S. Djennoune, M. Bettayeb","doi":"10.1109/SSD.2008.4632802","DOIUrl":"https://doi.org/10.1109/SSD.2008.4632802","url":null,"abstract":"This article deals with heat transfer modeling and identification, based on fractional non commensurate order state space models. An output error method is developed to estimate the model parameters including the fractional order and an iterative non-linear programming method is used, based on a novel fractional multivariable sensitivity functions model. Numerical simulation data of the heat transfer problem are performed using finite differences, and the suggested method is applied to identify the thermal process. Two fractional non commensurate models are tested in order to analyze their fitting ability to approximate the interface diffusion in the frequency domain.","PeriodicalId":267264,"journal":{"name":"2008 5th International Multi-Conference on Systems, Signals and Devices","volume":"70 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123187072","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 : 2008-07-20DOI: 10.1109/SSD.2008.4632850
M. Mohammadi, M. Eshghi
Quantum gates which are represented by unitary matrices have potentials to implement reversible logic circuits. V and V+ gates are two well known quantum gates which are used to synthesize the reversible logic circuits. In this paper we have used behavioral description of these gates, instead of unitary matrix description, to synthesize reversible logic circuits. By this method, V and V+ gates are shown in the truth table form. Results show that bigger circuits with more number of gates can be synthesized using proposed method. Some benchmarks of reversible logic circuits are also optimized and compared to other works.
{"title":"Behavioral description of quantum V and V+ gates to design quantum logic circuits","authors":"M. Mohammadi, M. Eshghi","doi":"10.1109/SSD.2008.4632850","DOIUrl":"https://doi.org/10.1109/SSD.2008.4632850","url":null,"abstract":"Quantum gates which are represented by unitary matrices have potentials to implement reversible logic circuits. V and V+ gates are two well known quantum gates which are used to synthesize the reversible logic circuits. In this paper we have used behavioral description of these gates, instead of unitary matrix description, to synthesize reversible logic circuits. By this method, V and V+ gates are shown in the truth table form. Results show that bigger circuits with more number of gates can be synthesized using proposed method. Some benchmarks of reversible logic circuits are also optimized and compared to other works.","PeriodicalId":267264,"journal":{"name":"2008 5th International Multi-Conference on Systems, Signals and Devices","volume":"228 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132766843","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 : 2008-07-20DOI: 10.1109/SSD.2008.4632878
A. Zribi, M. Djemel, M. Chtourou
This paper presents popular unsupervised clustering algorithms based on neuro-fuzzy, fuzzy c-means (FCM) and agglomerative techniques. The purpose of this paper is to provide clustering methods able to cluster the data patterns without a priori information about the number of clusters. We will show that it is possible to reconcile the FCM algorithm with the unsupervised clustering algorithms. Finally, to show the efficiencies of these algorithms, we will apply them to model the behaviour of uncertain system.
{"title":"Some clustering techniques for modelling uncertain nonlinear systems","authors":"A. Zribi, M. Djemel, M. Chtourou","doi":"10.1109/SSD.2008.4632878","DOIUrl":"https://doi.org/10.1109/SSD.2008.4632878","url":null,"abstract":"This paper presents popular unsupervised clustering algorithms based on neuro-fuzzy, fuzzy c-means (FCM) and agglomerative techniques. The purpose of this paper is to provide clustering methods able to cluster the data patterns without a priori information about the number of clusters. We will show that it is possible to reconcile the FCM algorithm with the unsupervised clustering algorithms. Finally, to show the efficiencies of these algorithms, we will apply them to model the behaviour of uncertain system.","PeriodicalId":267264,"journal":{"name":"2008 5th International Multi-Conference on Systems, Signals and Devices","volume":"83 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115731037","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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