Pub Date : 2013-05-02DOI: 10.1109/IBCAST.2013.6512142
R. Khan, M. Talha, A. Khattak, M. Qasim
Medical devices these days come with very high dynamic range outputs to diagnose various diseases. This high dynamic range images should not only be compressed but also the contrast of the image must be enhanced to preserve the details on common display devices. Such algorithms are usually run off-line on images due to the high cost of implementation. This paper looks into the implementation of Balanced Contrast Limited Adaptive Histogram Equalization (BCLAHE) for Adaptive Dynamic Range Compression (ADRC) of real time medical images. This method is specifically targeted at situations where continuous exposure is required. For example in X-ray, CT-Scan or IR imaging, the real time video of the target is observed until the region of interest (ROI) is identified. The proposed implementation scheme is tested and has shown good results in terms of latency and perceptibility of minute details.
{"title":"Realization of Balanced Contrast Limited Adaptive Histogram Equalization (B-CLAHE) for Adaptive Dynamic Range Compression of real time medical images","authors":"R. Khan, M. Talha, A. Khattak, M. Qasim","doi":"10.1109/IBCAST.2013.6512142","DOIUrl":"https://doi.org/10.1109/IBCAST.2013.6512142","url":null,"abstract":"Medical devices these days come with very high dynamic range outputs to diagnose various diseases. This high dynamic range images should not only be compressed but also the contrast of the image must be enhanced to preserve the details on common display devices. Such algorithms are usually run off-line on images due to the high cost of implementation. This paper looks into the implementation of Balanced Contrast Limited Adaptive Histogram Equalization (BCLAHE) for Adaptive Dynamic Range Compression (ADRC) of real time medical images. This method is specifically targeted at situations where continuous exposure is required. For example in X-ray, CT-Scan or IR imaging, the real time video of the target is observed until the region of interest (ROI) is identified. The proposed implementation scheme is tested and has shown good results in terms of latency and perceptibility of minute details.","PeriodicalId":276834,"journal":{"name":"Proceedings of 2013 10th International Bhurban Conference on Applied Sciences & Technology (IBCAST)","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130605723","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 : 2013-05-02DOI: 10.1109/IBCAST.2013.6512185
A. Kashif, S. Azam, K. Hayat, M. Imran
Technology Computer Aided Design (TCAD) provides an alternate method to study the power amplifier (PA) design prior to fabrication and is very useful for the extraction of an accurate large signal model. This paper presents a design approach from device to circuit level to study the performance of a broadband PA based on computational load-pull (CLP) analysis. To validate TCAD approach, we have designed a broadband (1.9 - 2.5 GHz) class AB PA with an output matching network. The large signal simulation results verify the optimum impedance value (Zf) by providing a desired RF output power of 30.8 dBm.
{"title":"Advantage of TCAD to analyze RF-LDMOS for the broadband power amplifier","authors":"A. Kashif, S. Azam, K. Hayat, M. Imran","doi":"10.1109/IBCAST.2013.6512185","DOIUrl":"https://doi.org/10.1109/IBCAST.2013.6512185","url":null,"abstract":"Technology Computer Aided Design (TCAD) provides an alternate method to study the power amplifier (PA) design prior to fabrication and is very useful for the extraction of an accurate large signal model. This paper presents a design approach from device to circuit level to study the performance of a broadband PA based on computational load-pull (CLP) analysis. To validate TCAD approach, we have designed a broadband (1.9 - 2.5 GHz) class AB PA with an output matching network. The large signal simulation results verify the optimum impedance value (Zf) by providing a desired RF output power of 30.8 dBm.","PeriodicalId":276834,"journal":{"name":"Proceedings of 2013 10th International Bhurban Conference on Applied Sciences & Technology (IBCAST)","volume":"124 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116333355","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 : 2013-05-02DOI: 10.1109/IBCAST.2013.6512170
M. Ashraf, M. Aslam
Impedance matching transformer is used to match the output impedance of the corresponding signal source to maximize the power transfer to the load. Design of impedance matching circuit by converting series circuit into parallel equivalent circuit is given. Instead of using conventional electromagnetic transformer, piezoelectric transformer is used. The piezoelectric transformer is treated as two port electrical circuit and electrical transfer function is measured by exciting the transformer at resonant frequency. Impedance matching theory is used to analyze the circuit in this paper. Theoretical considerations of the impedance matching using piezoelectric transformer are given. Using data of some piezoelectric transformers, their impedance matching parameters are calculated for parallel configuration, which can be used for design of a perfect matching circuit.
{"title":"Impedance matching for underwater piezoelectric transducers using piezoelectric transformer","authors":"M. Ashraf, M. Aslam","doi":"10.1109/IBCAST.2013.6512170","DOIUrl":"https://doi.org/10.1109/IBCAST.2013.6512170","url":null,"abstract":"Impedance matching transformer is used to match the output impedance of the corresponding signal source to maximize the power transfer to the load. Design of impedance matching circuit by converting series circuit into parallel equivalent circuit is given. Instead of using conventional electromagnetic transformer, piezoelectric transformer is used. The piezoelectric transformer is treated as two port electrical circuit and electrical transfer function is measured by exciting the transformer at resonant frequency. Impedance matching theory is used to analyze the circuit in this paper. Theoretical considerations of the impedance matching using piezoelectric transformer are given. Using data of some piezoelectric transformers, their impedance matching parameters are calculated for parallel configuration, which can be used for design of a perfect matching circuit.","PeriodicalId":276834,"journal":{"name":"Proceedings of 2013 10th International Bhurban Conference on Applied Sciences & Technology (IBCAST)","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127658088","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 : 2013-05-02DOI: 10.1109/IBCAST.2013.6512155
H. Rahman, S. Khushnood, A. Raza, K. Ahmad
The aerodynamic behavior of delta wing has been investigated both computationally and experimentally. Force measurement experiment has been performed on a 70 degree sweep delta wing model with sharp leading and trailing edges in wind tunnel for a range of angle of attack. A steady-state RANS investigation has been performed using the commercial CFD code ANSYS FLUENT-14. Different visualizations offered by the post-processing software ANSYS CFD-POST 14 has been used in order to observe the main primary vortex core which is providing the main suction peak on the upper surface of the wing. Results of lift and drag coefficients at different angles of attack from experiments and computations have been compared. The experimental and numerical results are in good agreement with each other.
{"title":"Experimental and computational investigation of delta wing aerodynamics","authors":"H. Rahman, S. Khushnood, A. Raza, K. Ahmad","doi":"10.1109/IBCAST.2013.6512155","DOIUrl":"https://doi.org/10.1109/IBCAST.2013.6512155","url":null,"abstract":"The aerodynamic behavior of delta wing has been investigated both computationally and experimentally. Force measurement experiment has been performed on a 70 degree sweep delta wing model with sharp leading and trailing edges in wind tunnel for a range of angle of attack. A steady-state RANS investigation has been performed using the commercial CFD code ANSYS FLUENT-14. Different visualizations offered by the post-processing software ANSYS CFD-POST 14 has been used in order to observe the main primary vortex core which is providing the main suction peak on the upper surface of the wing. Results of lift and drag coefficients at different angles of attack from experiments and computations have been compared. The experimental and numerical results are in good agreement with each other.","PeriodicalId":276834,"journal":{"name":"Proceedings of 2013 10th International Bhurban Conference on Applied Sciences & Technology (IBCAST)","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126835660","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 : 2013-05-02DOI: 10.1109/IBCAST.2013.6512154
D. Rehman, I. Akhtar, M. Naqvi
Proper Orthogonal Decomposition (POD) is used in fluid mechanics to compute optimal basis to span the desired subspace and extract coherent structures in the flow field. POD analysis of the pressure field in bluff body flow can provide insight to the pressure distribution on the surface of the structure. In this paper, we simulate the flow past a square cylinder in confined channel and record the snapshot data of the flow field over one shedding cycle. We compute the POD basis functions from the snapshots and their distribution in the domain. The dominant pressure modes are integrated on the surface to determine their contribution in the lift and drag components. Interestingly, the odd and even pairs of the pressure POD modes contribute to the lift and drag on the cylinder, respectively. Key contribution is that Galerkin expansion of the lift and drag coeffients is independent of the space since pressure POD modes are integrated over the surface of the cylinder.
{"title":"Proper Orthogonal Decomposition of the pressure field in bluff bodies","authors":"D. Rehman, I. Akhtar, M. Naqvi","doi":"10.1109/IBCAST.2013.6512154","DOIUrl":"https://doi.org/10.1109/IBCAST.2013.6512154","url":null,"abstract":"Proper Orthogonal Decomposition (POD) is used in fluid mechanics to compute optimal basis to span the desired subspace and extract coherent structures in the flow field. POD analysis of the pressure field in bluff body flow can provide insight to the pressure distribution on the surface of the structure. In this paper, we simulate the flow past a square cylinder in confined channel and record the snapshot data of the flow field over one shedding cycle. We compute the POD basis functions from the snapshots and their distribution in the domain. The dominant pressure modes are integrated on the surface to determine their contribution in the lift and drag components. Interestingly, the odd and even pairs of the pressure POD modes contribute to the lift and drag on the cylinder, respectively. Key contribution is that Galerkin expansion of the lift and drag coeffients is independent of the space since pressure POD modes are integrated over the surface of the cylinder.","PeriodicalId":276834,"journal":{"name":"Proceedings of 2013 10th International Bhurban Conference on Applied Sciences & Technology (IBCAST)","volume":"55 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133040738","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 : 2013-05-02DOI: 10.1109/IBCAST.2013.6512132
A. Tahir, S. Iqbal, A. I. Bhatti, M. Pervaiz
In the area of control theory and engineering, the stabilization of an inverted pendulum with the help of moving cart is one of the attractive regulation problem. It is a perfect benchmark for testing of a wide range of classical and modern control techniques. In this paper Sliding Mode Control (SMC) technique is used to design a control law for stabilization of one stage cart-pole type inverted pendulum system. The chattering problem is solved by using saturation function. The simulations and experimental results are highlighted to evaluate the robustness of the control design.
{"title":"Steadiness of real time inverted pendulum","authors":"A. Tahir, S. Iqbal, A. I. Bhatti, M. Pervaiz","doi":"10.1109/IBCAST.2013.6512132","DOIUrl":"https://doi.org/10.1109/IBCAST.2013.6512132","url":null,"abstract":"In the area of control theory and engineering, the stabilization of an inverted pendulum with the help of moving cart is one of the attractive regulation problem. It is a perfect benchmark for testing of a wide range of classical and modern control techniques. In this paper Sliding Mode Control (SMC) technique is used to design a control law for stabilization of one stage cart-pole type inverted pendulum system. The chattering problem is solved by using saturation function. The simulations and experimental results are highlighted to evaluate the robustness of the control design.","PeriodicalId":276834,"journal":{"name":"Proceedings of 2013 10th International Bhurban Conference on Applied Sciences & Technology (IBCAST)","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133306557","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 : 2013-05-02DOI: 10.1109/IBCAST.2013.6512193
N. Cheema, S. Azam, A. Kashif, F. Mughal, M. Imran
GaN HEMT with silicon substrate is famous and considered as the next generation of RF power transistor technology. It has major advantages of high power, low cost and reliability etc., GaN HEMT requires special attention in bias circuit to avoid the instability of the device. Sequence circuit is required to supply voltages in order. In this paper, we have design and implemented the sequential circuits in bias network for pulsed and CW applications. MAX881R is used in power supply for pulsed while LTI1964ES5-BYP with R2D Recon 2405 is used for high current application in CW. For pulsed applications in ON sequence the gate is turned-on ~ 220 ms before the drain, while in OFF sequence the drain is turned-off ~ 1.7 s before the gate. While in CW applications in ON sequence the gate is turned-on ~ 130ms before the drain and in OFF sequence, the drain is turned-off ~ 633ms before the gate.
{"title":"Design and implementation of bias sequence circuits for GaN HEMT amplifiers both pulsed and CW applications","authors":"N. Cheema, S. Azam, A. Kashif, F. Mughal, M. Imran","doi":"10.1109/IBCAST.2013.6512193","DOIUrl":"https://doi.org/10.1109/IBCAST.2013.6512193","url":null,"abstract":"GaN HEMT with silicon substrate is famous and considered as the next generation of RF power transistor technology. It has major advantages of high power, low cost and reliability etc., GaN HEMT requires special attention in bias circuit to avoid the instability of the device. Sequence circuit is required to supply voltages in order. In this paper, we have design and implemented the sequential circuits in bias network for pulsed and CW applications. MAX881R is used in power supply for pulsed while LTI1964ES5-BYP with R2D Recon 2405 is used for high current application in CW. For pulsed applications in ON sequence the gate is turned-on ~ 220 ms before the drain, while in OFF sequence the drain is turned-off ~ 1.7 s before the gate. While in CW applications in ON sequence the gate is turned-on ~ 130ms before the drain and in OFF sequence, the drain is turned-off ~ 633ms before the gate.","PeriodicalId":276834,"journal":{"name":"Proceedings of 2013 10th International Bhurban Conference on Applied Sciences & Technology (IBCAST)","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125949140","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 : 2013-05-02DOI: 10.1109/IBCAST.2013.6512161
M. O. Khan, S. Hussain, M. Rafique, A. Ahmad, W. Akhtar
Spacer grids are an integral part of pressurized water reactor (PWR) fuel assemblies. They provide structural integrity as well as play a vital role in defining the thermal hydraulic behavior of the fuel assembly. The spacer grid design is continuously being improved to achieve better heat transfer characteristics. The studies performed to date include the design optimization and effects of mixing vanes on the thermal hydraulic behavior of fuel assembly. Majority of these studies do not include the effects of springs and dimples of the spacer grid. The present study was performed to analyze the flow behavior and pressure drop across a single coolant channel in the region of spacer grid along with all geometrical details. Detailed analysis of a single coolant channel comprising spacer-grid cell with dimples and spring was done using Ansys-CFX. The mesh independency study was carried out to make a compromise between solution time and accuracy. The problem was solved using K-ε model along with scalable-wall-function option. The Reynolds averaged mass conservation and momentum conservation equations were solved and the pressure and velocity field of flow channel was obtained. The average velocity varies from 2.52m/s to 7.35m/s for Reynolds number variation from 4.0×104 to 11.7×104. The cross flow velocities vary from 0.2 to 0.57m/s for these flow conditions. The Euler numbers calculated for these flow conditions were compared to the documented experimental results and were found to be in very good agreement. The analysis results conclude that single cell approach is an accurate and economical approach for predicting the pressure drop across the spacer-grid. The analysis also confirmed the applicability of k-ε model with scalable-wall-function for the prediction of the single phase hydraulic characteristics of spacer-grids.
{"title":"CFD study of single phase flow in a PWR spacer grid","authors":"M. O. Khan, S. Hussain, M. Rafique, A. Ahmad, W. Akhtar","doi":"10.1109/IBCAST.2013.6512161","DOIUrl":"https://doi.org/10.1109/IBCAST.2013.6512161","url":null,"abstract":"Spacer grids are an integral part of pressurized water reactor (PWR) fuel assemblies. They provide structural integrity as well as play a vital role in defining the thermal hydraulic behavior of the fuel assembly. The spacer grid design is continuously being improved to achieve better heat transfer characteristics. The studies performed to date include the design optimization and effects of mixing vanes on the thermal hydraulic behavior of fuel assembly. Majority of these studies do not include the effects of springs and dimples of the spacer grid. The present study was performed to analyze the flow behavior and pressure drop across a single coolant channel in the region of spacer grid along with all geometrical details. Detailed analysis of a single coolant channel comprising spacer-grid cell with dimples and spring was done using Ansys-CFX. The mesh independency study was carried out to make a compromise between solution time and accuracy. The problem was solved using K-ε model along with scalable-wall-function option. The Reynolds averaged mass conservation and momentum conservation equations were solved and the pressure and velocity field of flow channel was obtained. The average velocity varies from 2.52m/s to 7.35m/s for Reynolds number variation from 4.0×104 to 11.7×104. The cross flow velocities vary from 0.2 to 0.57m/s for these flow conditions. The Euler numbers calculated for these flow conditions were compared to the documented experimental results and were found to be in very good agreement. The analysis results conclude that single cell approach is an accurate and economical approach for predicting the pressure drop across the spacer-grid. The analysis also confirmed the applicability of k-ε model with scalable-wall-function for the prediction of the single phase hydraulic characteristics of spacer-grids.","PeriodicalId":276834,"journal":{"name":"Proceedings of 2013 10th International Bhurban Conference on Applied Sciences & Technology (IBCAST)","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117078435","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 : 2013-05-02DOI: 10.1109/IBCAST.2013.6512152
A. Shahzad, H. Hamdani, M. Mumtaz, K. Parvez, M. Aqib
The present study focuses on investigating the persistence of delayed stall for Micro Air Vehicles at Re-34,000. The motivation behind present research is to find out the effect of Reynolds number on aerodynamic force production and formation of leading edge vortex on a wing in unsteady motion. Computations are done on a corrugated wing in sweeping motion and pure translation at Reynolds number 3500 and 34,000. For sweeping motion, at 10 degree angle of attack, flow remain attached to the wing with no signs of leading edge vortex and the force coefficients at Re 34000 were higher than Re 3500 throughout the sweeping motion. For sweeping motion, at angle of attack of 40°, delayed stall continued to manifest itself at Re 34000. At Re 34000, the size of leading edge vortex was comparatively small but the strength of leading edge vortex core was relatively more and signs of vortex break down were eminent at 90 percent of wingspan. However, at Re 3500, signs of vortex break down were observed at 70 percent of wingspan. In pure translation, “stall absent” mechanism was not seen at any Re, as leading edge vortex was formed and it then shed into the wake. In short, it can be concluded that delayed stall continues to act as lift enhancement mechanism for MAV but flow structure and span wise vortex break down pattern changes with the change in Reynolds number.
{"title":"Effect of Reynolds number on leading edge vortex for a wing in unsteady motion","authors":"A. Shahzad, H. Hamdani, M. Mumtaz, K. Parvez, M. Aqib","doi":"10.1109/IBCAST.2013.6512152","DOIUrl":"https://doi.org/10.1109/IBCAST.2013.6512152","url":null,"abstract":"The present study focuses on investigating the persistence of delayed stall for Micro Air Vehicles at Re-34,000. The motivation behind present research is to find out the effect of Reynolds number on aerodynamic force production and formation of leading edge vortex on a wing in unsteady motion. Computations are done on a corrugated wing in sweeping motion and pure translation at Reynolds number 3500 and 34,000. For sweeping motion, at 10 degree angle of attack, flow remain attached to the wing with no signs of leading edge vortex and the force coefficients at Re 34000 were higher than Re 3500 throughout the sweeping motion. For sweeping motion, at angle of attack of 40°, delayed stall continued to manifest itself at Re 34000. At Re 34000, the size of leading edge vortex was comparatively small but the strength of leading edge vortex core was relatively more and signs of vortex break down were eminent at 90 percent of wingspan. However, at Re 3500, signs of vortex break down were observed at 70 percent of wingspan. In pure translation, “stall absent” mechanism was not seen at any Re, as leading edge vortex was formed and it then shed into the wake. In short, it can be concluded that delayed stall continues to act as lift enhancement mechanism for MAV but flow structure and span wise vortex break down pattern changes with the change in Reynolds number.","PeriodicalId":276834,"journal":{"name":"Proceedings of 2013 10th International Bhurban Conference on Applied Sciences & Technology (IBCAST)","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120962865","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 : 2013-05-02DOI: 10.1109/IBCAST.2013.6512180
F. Zaman, J. A. Khan, Z. Khan, I. Qureshi
In this paper, utilization of hybrid computational approach is evaluated for the joint estimation of amplitude and Direction of Arrival of far field sources impinging on a uniform linear array. In this hybrid approach, swarm intelligence based on Particle swarm optimization is exploited as a global optimizer assisted with pattern search technique as a rapid local search technique. The optimization of adaptive parameters depending upon the amplitudes and direction of arrival is performed using the fitness function based on Mean Square Error that defines an error between desired response and estimated response. The interest in this function is due to its ease in implementation, efficiency and simplicity of concept. It is derived from Maximum Likelihood and requires only single snapshot to converge. The proposed algorithm is robust enough to produce fairly good results even in the presence of low signal-to-Noise Ratio and requires relatively less number of antenna elements in the array. The results of hybrid technique are much better as compared to Particle Swarm Optimization and pattern search alone. A number of test cases are discussed on the basis of different number of sources impinging on the array with different number of sensors in the array. The accuracy and reliability of the proposed scheme is tested on the basis of Monte-Carlo simulations and its superior statistical analysis.
{"title":"An application of hybrid computing to estimate jointly the amplitude and Direction of Arrival with single snapshot","authors":"F. Zaman, J. A. Khan, Z. Khan, I. Qureshi","doi":"10.1109/IBCAST.2013.6512180","DOIUrl":"https://doi.org/10.1109/IBCAST.2013.6512180","url":null,"abstract":"In this paper, utilization of hybrid computational approach is evaluated for the joint estimation of amplitude and Direction of Arrival of far field sources impinging on a uniform linear array. In this hybrid approach, swarm intelligence based on Particle swarm optimization is exploited as a global optimizer assisted with pattern search technique as a rapid local search technique. The optimization of adaptive parameters depending upon the amplitudes and direction of arrival is performed using the fitness function based on Mean Square Error that defines an error between desired response and estimated response. The interest in this function is due to its ease in implementation, efficiency and simplicity of concept. It is derived from Maximum Likelihood and requires only single snapshot to converge. The proposed algorithm is robust enough to produce fairly good results even in the presence of low signal-to-Noise Ratio and requires relatively less number of antenna elements in the array. The results of hybrid technique are much better as compared to Particle Swarm Optimization and pattern search alone. A number of test cases are discussed on the basis of different number of sources impinging on the array with different number of sensors in the array. The accuracy and reliability of the proposed scheme is tested on the basis of Monte-Carlo simulations and its superior statistical analysis.","PeriodicalId":276834,"journal":{"name":"Proceedings of 2013 10th International Bhurban Conference on Applied Sciences & Technology (IBCAST)","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121664550","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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