Characteristics of chaotic pulse trains associated with dart and dart-stepped leader in lightning... more Characteristics of chaotic pulse trains associated with dart and dart-stepped leader in lightning flashes in Sweden
This paper presents the characteristics of the first and subsequent strokes observed in positive ... more This paper presents the characteristics of the first and subsequent strokes observed in positive ground flashes during 2014 summer thunderstorms in Uppsala, Sweden. We obtained the average number of strokes in the positive ground flashes and the relative amplitude of the subsequent stroke peak to the first stroke peak. We also determined the characteristics of the first and subsequent strokes, and compared the values between them. In our analysis, only 12% of the cases were multiple-stroke flashes while majority (88%) were single-stroke flashes. On average, the number of strokes per flash was 1.20 and the highest number of strokes per flash recorded was 4. The relative peak amplitude of the subsequent stroke to the first stroke peak was 0.83 with values ranging between 0.09 and 2.33. As for the stroke characteristics, we found that the average values for all parameters for the subsequent stroke were smaller than that of the first stroke. The average values for the slow front duratio...
Physical mechanism of initial breakdown pulses and narrow bipolar pulses in lightning discharges ... more Physical mechanism of initial breakdown pulses and narrow bipolar pulses in lightning discharges is not well understood. There are different opinions about the origins of these two phenomenology. In this study, we make an attempt to compare this two phenomenology based on their electric fields and field derivatives produced by them. The comparison shows that the electric field derivative characteristics of these two phenomenology are different which makes us to believe that the origin of these two kinds of pulses may not be the same. Keywords-IBP; NBP; electric field from lightning; field derivative from lightning; cloud discharges; lightning discharges
This paper aim to present the design technique, parameter analysis, real prototype fabrication an... more This paper aim to present the design technique, parameter analysis, real prototype fabrication and measurement results compared to simulation of 5.8 GHz rectangular microstrip inset feed patch antenna. The antenna design calculation, simulation study and practical measurement results are well presented and compared. This study would be useful to realize low cost 5.8 GHz rectangular microstrip patch antenna for any appropriate system developments and investigate the parameter study. The information shared is aimed to serve the similar scientific field and improve the system features.
This paper presents the characteristics of the preliminary breakdown pulses (PBP) in 51 positive ... more This paper presents the characteristics of the preliminary breakdown pulses (PBP) in 51 positive ground flashes recorded during 2014 summer thunderstorms in Sweden. Electric field measurements were conducted remotely using a broadband antenna system (up to 100 MHz) for a recording length of 1 s with 200 ms trigger time. In the analysis, PBP trains were observed in 86% of the cases. Based on the number of trains preceding the first return stroke, the PBP were classified into single and multiple train PBP. Characteristics of the first PBP train were determined and based on the initial polarity of the pulses, three types of PBP were identified. Characteristics of the subsequent PBP trains in the multiple train PBP were also analyzed and they were compared with the first PBP train. Based on the conceptual charge cloud configuration, we found that the inverted dipole is consistent with our observation. We also found that PBP in positive ground flashes during summer thunderstorms in Sweden are weak since the average ratios of the PBP peak to the first return stroke peak lie only between 0.21 and 0.26. Possible reasons for no detection of PBP and the different types of PBP observed were also discussed.
Industrial production machines of today must be highly flexible in order to competitively account... more Industrial production machines of today must be highly flexible in order to competitively account for dynamic and unforeseen changes in the product demands. Field-programmable gate arrays (FPGAs) are especially suited to fulfill these requirements; FPGAs are very powerful, relatively inexpensive, and adaptable, since their configuration is specified in an abstract hardware description language. Thus, in order to design and implement VGA Controller on FPGA, Verilog Hardware Description Language (Verilog HDL) is used. Verilog HDL is used to describe and program the gates and counters in FPGA blocks in order to construct an internal logic circuit in FPGA. The main purpose of this project is to design and implement VGA Controller on FPGA. Therefore, the block diagram for VGA Controller is designed and the VGA Controller program is written based on the block diagram using Verilog HDL. Also, functions required for VGA Controller are included in the Verilog code and test bench is created to test the functions written to ensure the FPGA VGA Controller works correctly and accurately without errors. Finally, the completed program is implemented on FPGAs chip of Altera DE2-115 Development and Educational Board.
A variable gain amplifier (VGA) is one of the most significant component in many applications suc... more A variable gain amplifier (VGA) is one of the most significant component in many applications such as analog to digital converter (ADC). In communication receiver, VGA is typically employed in a feedback loop to realize an automatic gain control (AGC), to provide constant signal power to baseband analog-to-digital converter (ADC) for unpredictable received signal strengths. Gain range, power consumption and bandwidth of ADC are strongly influenced by the performance of operational amplifier. VGA is the key element for amplifying process in ADC. However, current class AB VGA is experiencing the limit of bandwidth, which is not suitable for high speed automatic gain control AGC. In order to overcome these limitations a high linearity and wide bandwidth of VGA is indispensable. The aim of this research is to get higher gain and larger bandwidth for VGA. In this research, a low cost, low power voltage and wide bandwidth class AB VGA is designed to mitigate this constraint. Superiority of the proposed VGA has been confirmed by circuit simulation using CEDEC 0.18-μm CMOS process with the help of tools from Mentor Graphics in designing a 100-MHz VGA under 1V supply voltage draining total static power consumption less than 125uW. The results show that the circuit is able to work with high linearity and wide bandwidth by varying R f and R s. Therefore, the frequency response (Gain) and the wide bandwidth of this class AB VGA is better than previously reported class AB VGA. Consequently, this modified class AB VGA is appropriate for high speed applications.
2012 International Conference on Computer & Information Science (ICCIS), 2012
Bit communication in swarm agents is a communication process of transmitting data within specific... more Bit communication in swarm agents is a communication process of transmitting data within specific area. The data must be delivered to all agents in the area which this process also closely related to broadcasting manner through bitcommunication as a way to spread out the data among all those agents. This research field is supposed to have a deep study of behavior of homogeneous agents by inspecting the reversing and non-reversing approach. It also included the investigation of the independent and characteristic of transmitting and receiving data for random process of swarm. In this paper, swarm technique is implemented which is useful for bit-communication behavior. There are two approaches are used for transmitting and receiving process. For the reverse approach, the data can be resend back to the sender for the next cycle where the program randomly select one-of nearest agent for transmitting the data. While in non-reversing approach, the data cannot retransmit back to the sender in the previous cycle; this approach may increase the system performance and efficiency.
2011 IEEE International RF & Microwave Conference, 2011
the investigation between electromagnetic waves (conduction current) and human cell as lossless m... more the investigation between electromagnetic waves (conduction current) and human cell as lossless material has received renewed attention recently. This propagation can come from many sources such as cellular phone. The structure of a human cell were studied from many school of thinking such as biochemical in cell, cytoplasm, nucleus and membrane and the understanding obtained have been used as the basis in the developing of mathematical model. The main objective of this project is to analyze the behavior and determine the parameters of the interaction and propagation in a single cell when expose to electromagnetic wave from lossy material to lossless material such as the attenuation coefficient, electric field and skin depth. The Maxwell equations were used as the basis of the modeling in this project with aid of numerical method approaches specifically Finite-Difference Time Domain (FDTD) techniques and applications. To develop the model MATLAB tool and Graphical Users Interface (GUI) were used. Results obtained from the developed model ware verified with known result obtained from others researchers and with experimentally.
The interaction between electromagnetic waves and human cellvery importance to study. This intera... more The interaction between electromagnetic waves and human cellvery importance to study. This interaction can come from many sources such as cellular phone. The structure of a human cell was studied from many school of taught such as biochemical in cell, cytoplasm, nucleus and membrane and the understanding obtained was used as the basis in the developing of mathematical model. The main objective of this project is to analyze the behavior and determine the parameters of the interaction in a single cell when expose to electromagnetic wave such as the attenuation coefficient and electric fields of difference frequency. The Maxwell equations were used as the basis of the modeling in this project with aid of numerical method approaches specifically Finite Difference Time Domain (FDTD) techniques. To develop the model MATLAB tool was used. Results obtained from the developed model was verified with known result obtained from others researchers.
Characteristics of chaotic pulse trains associated with dart and dart-stepped leader in lightning... more Characteristics of chaotic pulse trains associated with dart and dart-stepped leader in lightning flashes in Sweden
This paper presents the characteristics of the first and subsequent strokes observed in positive ... more This paper presents the characteristics of the first and subsequent strokes observed in positive ground flashes during 2014 summer thunderstorms in Uppsala, Sweden. We obtained the average number of strokes in the positive ground flashes and the relative amplitude of the subsequent stroke peak to the first stroke peak. We also determined the characteristics of the first and subsequent strokes, and compared the values between them. In our analysis, only 12% of the cases were multiple-stroke flashes while majority (88%) were single-stroke flashes. On average, the number of strokes per flash was 1.20 and the highest number of strokes per flash recorded was 4. The relative peak amplitude of the subsequent stroke to the first stroke peak was 0.83 with values ranging between 0.09 and 2.33. As for the stroke characteristics, we found that the average values for all parameters for the subsequent stroke were smaller than that of the first stroke. The average values for the slow front duratio...
Physical mechanism of initial breakdown pulses and narrow bipolar pulses in lightning discharges ... more Physical mechanism of initial breakdown pulses and narrow bipolar pulses in lightning discharges is not well understood. There are different opinions about the origins of these two phenomenology. In this study, we make an attempt to compare this two phenomenology based on their electric fields and field derivatives produced by them. The comparison shows that the electric field derivative characteristics of these two phenomenology are different which makes us to believe that the origin of these two kinds of pulses may not be the same. Keywords-IBP; NBP; electric field from lightning; field derivative from lightning; cloud discharges; lightning discharges
This paper aim to present the design technique, parameter analysis, real prototype fabrication an... more This paper aim to present the design technique, parameter analysis, real prototype fabrication and measurement results compared to simulation of 5.8 GHz rectangular microstrip inset feed patch antenna. The antenna design calculation, simulation study and practical measurement results are well presented and compared. This study would be useful to realize low cost 5.8 GHz rectangular microstrip patch antenna for any appropriate system developments and investigate the parameter study. The information shared is aimed to serve the similar scientific field and improve the system features.
This paper presents the characteristics of the preliminary breakdown pulses (PBP) in 51 positive ... more This paper presents the characteristics of the preliminary breakdown pulses (PBP) in 51 positive ground flashes recorded during 2014 summer thunderstorms in Sweden. Electric field measurements were conducted remotely using a broadband antenna system (up to 100 MHz) for a recording length of 1 s with 200 ms trigger time. In the analysis, PBP trains were observed in 86% of the cases. Based on the number of trains preceding the first return stroke, the PBP were classified into single and multiple train PBP. Characteristics of the first PBP train were determined and based on the initial polarity of the pulses, three types of PBP were identified. Characteristics of the subsequent PBP trains in the multiple train PBP were also analyzed and they were compared with the first PBP train. Based on the conceptual charge cloud configuration, we found that the inverted dipole is consistent with our observation. We also found that PBP in positive ground flashes during summer thunderstorms in Sweden are weak since the average ratios of the PBP peak to the first return stroke peak lie only between 0.21 and 0.26. Possible reasons for no detection of PBP and the different types of PBP observed were also discussed.
Industrial production machines of today must be highly flexible in order to competitively account... more Industrial production machines of today must be highly flexible in order to competitively account for dynamic and unforeseen changes in the product demands. Field-programmable gate arrays (FPGAs) are especially suited to fulfill these requirements; FPGAs are very powerful, relatively inexpensive, and adaptable, since their configuration is specified in an abstract hardware description language. Thus, in order to design and implement VGA Controller on FPGA, Verilog Hardware Description Language (Verilog HDL) is used. Verilog HDL is used to describe and program the gates and counters in FPGA blocks in order to construct an internal logic circuit in FPGA. The main purpose of this project is to design and implement VGA Controller on FPGA. Therefore, the block diagram for VGA Controller is designed and the VGA Controller program is written based on the block diagram using Verilog HDL. Also, functions required for VGA Controller are included in the Verilog code and test bench is created to test the functions written to ensure the FPGA VGA Controller works correctly and accurately without errors. Finally, the completed program is implemented on FPGAs chip of Altera DE2-115 Development and Educational Board.
A variable gain amplifier (VGA) is one of the most significant component in many applications suc... more A variable gain amplifier (VGA) is one of the most significant component in many applications such as analog to digital converter (ADC). In communication receiver, VGA is typically employed in a feedback loop to realize an automatic gain control (AGC), to provide constant signal power to baseband analog-to-digital converter (ADC) for unpredictable received signal strengths. Gain range, power consumption and bandwidth of ADC are strongly influenced by the performance of operational amplifier. VGA is the key element for amplifying process in ADC. However, current class AB VGA is experiencing the limit of bandwidth, which is not suitable for high speed automatic gain control AGC. In order to overcome these limitations a high linearity and wide bandwidth of VGA is indispensable. The aim of this research is to get higher gain and larger bandwidth for VGA. In this research, a low cost, low power voltage and wide bandwidth class AB VGA is designed to mitigate this constraint. Superiority of the proposed VGA has been confirmed by circuit simulation using CEDEC 0.18-μm CMOS process with the help of tools from Mentor Graphics in designing a 100-MHz VGA under 1V supply voltage draining total static power consumption less than 125uW. The results show that the circuit is able to work with high linearity and wide bandwidth by varying R f and R s. Therefore, the frequency response (Gain) and the wide bandwidth of this class AB VGA is better than previously reported class AB VGA. Consequently, this modified class AB VGA is appropriate for high speed applications.
2012 International Conference on Computer & Information Science (ICCIS), 2012
Bit communication in swarm agents is a communication process of transmitting data within specific... more Bit communication in swarm agents is a communication process of transmitting data within specific area. The data must be delivered to all agents in the area which this process also closely related to broadcasting manner through bitcommunication as a way to spread out the data among all those agents. This research field is supposed to have a deep study of behavior of homogeneous agents by inspecting the reversing and non-reversing approach. It also included the investigation of the independent and characteristic of transmitting and receiving data for random process of swarm. In this paper, swarm technique is implemented which is useful for bit-communication behavior. There are two approaches are used for transmitting and receiving process. For the reverse approach, the data can be resend back to the sender for the next cycle where the program randomly select one-of nearest agent for transmitting the data. While in non-reversing approach, the data cannot retransmit back to the sender in the previous cycle; this approach may increase the system performance and efficiency.
2011 IEEE International RF & Microwave Conference, 2011
the investigation between electromagnetic waves (conduction current) and human cell as lossless m... more the investigation between electromagnetic waves (conduction current) and human cell as lossless material has received renewed attention recently. This propagation can come from many sources such as cellular phone. The structure of a human cell were studied from many school of thinking such as biochemical in cell, cytoplasm, nucleus and membrane and the understanding obtained have been used as the basis in the developing of mathematical model. The main objective of this project is to analyze the behavior and determine the parameters of the interaction and propagation in a single cell when expose to electromagnetic wave from lossy material to lossless material such as the attenuation coefficient, electric field and skin depth. The Maxwell equations were used as the basis of the modeling in this project with aid of numerical method approaches specifically Finite-Difference Time Domain (FDTD) techniques and applications. To develop the model MATLAB tool and Graphical Users Interface (GUI) were used. Results obtained from the developed model ware verified with known result obtained from others researchers and with experimentally.
The interaction between electromagnetic waves and human cellvery importance to study. This intera... more The interaction between electromagnetic waves and human cellvery importance to study. This interaction can come from many sources such as cellular phone. The structure of a human cell was studied from many school of taught such as biochemical in cell, cytoplasm, nucleus and membrane and the understanding obtained was used as the basis in the developing of mathematical model. The main objective of this project is to analyze the behavior and determine the parameters of the interaction in a single cell when expose to electromagnetic wave such as the attenuation coefficient and electric fields of difference frequency. The Maxwell equations were used as the basis of the modeling in this project with aid of numerical method approaches specifically Finite Difference Time Domain (FDTD) techniques. To develop the model MATLAB tool was used. Results obtained from the developed model was verified with known result obtained from others researchers.
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