Ieee Transactions on Instrumentation and Measurement, Feb 1, 2008
This paper presents the first step in characterizing and detecting common household powders as ho... more This paper presents the first step in characterizing and detecting common household powders as hoax materials by investigating their broadband dielectric characteristics. Pesticide is also studied due to its similarities to anthrax. A modified two-beam polarizing interferometer and custom-made sample holders were utilized to obtain the refractive index (RFI), absorption coefficient, complex real and imaginary permittivity, and loss tangent of flour, dry milk, cornstarch, pesticide, baking soda, and talc as a continuous function of frequency in the range of 400-1200 GHz. Dispersive Fourier transform spectroscopy was employed to provide phase and amplitude information, leading to the accurate and direct acquisition of the complex RFI and complex dielectric permittivity spectra. It is the first time that such measurements were carried out over such an extended frequency range for common powders to reveal marked variation in absorption and RFI values for different powders. The powders exhibit high-absorption characteristics, and the RFI values lie between 2.4 and 3.4 in this spectral range. A unique resonance signature for talc was detected at 1135 GHz with an associated anomalous dispersion. Parameters such as grain size and orientation were analyzed for their effect on the dielectric properties of powders. Relationships between density, permittivity, and RFI are explored to provide the ability to extrapolate results for other densities. The RFI and the real part of the dielectric permittivity were found to be the most reliable for identification and detection purposes.
2009 2nd International Workshop on Nonlinear Dynamics and Synchronization, 2009
... JC Chedjou', K. Kyamakya', MA Latif&a... more ... JC Chedjou', K. Kyamakya', MA Latif' and UA Khan! ... It should be worth mentioning that a challenging and up-to-date research question concerns the development of effi-cient, accurate and ultra-fast (high speed) computing plat-forms to solve complex and stiff ODE and/or POE ...
A novel intelligent approach into 3D freeform surface reconstruction from planar sketches is prop... more A novel intelligent approach into 3D freeform surface reconstruction from planar sketches is proposed. A multilayer perceptron (MLP) neural network is employed to induce 3D freeform surfaces from planar freehand curves. Planar curves were used to represent the boundaries of a freeform surface patch. The curves were varied iteratively and sampled to produce training data to train and test the neural network. The obtained results demonstrate that the network successfully learned the inverse-projection map and correctly inferred the respective surfaces from fresh curves.
Proceedings of the International Conference on Advances in Computer Science and Electronics Engineering, 2012
This paper investigates aliasing along straight line segments or edges and its origin, and how it... more This paper investigates aliasing along straight line segments or edges and its origin, and how it is affected by the orientation or slope of the segment. A method for anti-aliasing or smoothing the straight line segments by modifying the intensity of the pixels is presented and this paper proposes a line drawing scheme to draw a line by calculating deflection-angle and error to draw the next possible pixel more accurately both starting from coordinate point (x 1 ,y 1) (x 2 ,y 2) to meet mid (m), so that there will be a pattern of pixels nearer to the imaginary line. The basis of the algorithm is to draw pairs of pixels from both the end points straddling the line.
In vivo Assay for Antagonistic Potential of Fungal Isolates against Faba bean (Vicia faba L.) Cho... more In vivo Assay for Antagonistic Potential of Fungal Isolates against Faba bean (Vicia faba L.) Chocolate Spot (Botrytis fabae Sard.
Measurements from the MF spaced antenna mode radar at Scott Base (78øS, 167øE) include an estimat... more Measurements from the MF spaced antenna mode radar at Scott Base (78øS, 167øE) include an estimate of the autocorrelation time scale (T0.5) of the scatterers, corrected for advection by the mean wind. Summer observations (December 1983) show a semidiurnal variation of T0.5. At heights of 87-95 km the minimum values of T0.• occur when the zonal component of the semidiurnal tide is at its westward maximum. If it is assumed that decreasing values of T0.• are associated with increasing turbulence, then these results are consistent with those of Balsley et al. (1983), who proposed that enhanced turbulence is generated in summer by low-frequency gravity waves and tidal components above the polar mesopause.
There is a huge demand to accurately determine the magnetoelectrical properties of particles in t... more There is a huge demand to accurately determine the magnetoelectrical properties of particles in the nano-sized regime due to the modern IC technology revolution and biomedical applications. In this paper, we present a microwave waveguide measurement technique for measuring complex permeability and permittivity of expensive nano-sized magnetic powder materials. We used a vector network analyzer to provide a standard TRL calibration for free space inside waveguide measurements. In order to maintain the recommended insertion phase range, a very thin prepared sample was loaded inside the calibrated waveguide. The loaded material's magnetic and dielectric effects were also considered in the cutoff wavelength calculation of the propagation constant of the TE 10 wave from the geometrical dimensions of the waveguides. These provisions make the permeability and permittivity measurements more reliable than those found by commonly used techniques. We used six different compounds of nano-sized ferrite powders (Fe 3 O 4 , CuFe 2 O 4 , CuFe 2 O 4 Zn, Fe 2 NiO 3 Zn, BaFe 12 O 19 , and SrFe 12 O 19), in which the average diameter of nano particles is less than 40 nm, for measurement purposes. We measured the complex permeability and permittivity from 3.95 to 5.85 GHz. The results show that the dielectric permittivity of these materials is quite different from that of solid-state materials.
WiMAX stands for Worldwide Interoperability for Microwave Access. WiMAX is based on wireless Metr... more WiMAX stands for Worldwide Interoperability for Microwave Access. WiMAX is based on wireless Metropolitan Area Network (MAN) standards developed by IEEE 802.16 group. It operates in the licensed exempt and licensed spectrum between 2-11 GHz and 10-66 GHz frequency ...
The Worst-Case Execution Time (WCET) is an important execution metric for real-time systems, and ... more The Worst-Case Execution Time (WCET) is an important execution metric for real-time systems, and an accurate estimate for this increases the reliability of subsequent schedulability analysis. Performance enhancing features on modern processors, such as pipelines and caches, however, make it difficult to accurately predict the WCET. One technique for finding the WCET is to use test data generated using search
Ieee Transactions on Instrumentation and Measurement, Feb 1, 2008
This paper presents the first step in characterizing and detecting common household powders as ho... more This paper presents the first step in characterizing and detecting common household powders as hoax materials by investigating their broadband dielectric characteristics. Pesticide is also studied due to its similarities to anthrax. A modified two-beam polarizing interferometer and custom-made sample holders were utilized to obtain the refractive index (RFI), absorption coefficient, complex real and imaginary permittivity, and loss tangent of flour, dry milk, cornstarch, pesticide, baking soda, and talc as a continuous function of frequency in the range of 400-1200 GHz. Dispersive Fourier transform spectroscopy was employed to provide phase and amplitude information, leading to the accurate and direct acquisition of the complex RFI and complex dielectric permittivity spectra. It is the first time that such measurements were carried out over such an extended frequency range for common powders to reveal marked variation in absorption and RFI values for different powders. The powders exhibit high-absorption characteristics, and the RFI values lie between 2.4 and 3.4 in this spectral range. A unique resonance signature for talc was detected at 1135 GHz with an associated anomalous dispersion. Parameters such as grain size and orientation were analyzed for their effect on the dielectric properties of powders. Relationships between density, permittivity, and RFI are explored to provide the ability to extrapolate results for other densities. The RFI and the real part of the dielectric permittivity were found to be the most reliable for identification and detection purposes.
2009 2nd International Workshop on Nonlinear Dynamics and Synchronization, 2009
... JC Chedjou', K. Kyamakya', MA Latif&a... more ... JC Chedjou', K. Kyamakya', MA Latif' and UA Khan! ... It should be worth mentioning that a challenging and up-to-date research question concerns the development of effi-cient, accurate and ultra-fast (high speed) computing plat-forms to solve complex and stiff ODE and/or POE ...
A novel intelligent approach into 3D freeform surface reconstruction from planar sketches is prop... more A novel intelligent approach into 3D freeform surface reconstruction from planar sketches is proposed. A multilayer perceptron (MLP) neural network is employed to induce 3D freeform surfaces from planar freehand curves. Planar curves were used to represent the boundaries of a freeform surface patch. The curves were varied iteratively and sampled to produce training data to train and test the neural network. The obtained results demonstrate that the network successfully learned the inverse-projection map and correctly inferred the respective surfaces from fresh curves.
Proceedings of the International Conference on Advances in Computer Science and Electronics Engineering, 2012
This paper investigates aliasing along straight line segments or edges and its origin, and how it... more This paper investigates aliasing along straight line segments or edges and its origin, and how it is affected by the orientation or slope of the segment. A method for anti-aliasing or smoothing the straight line segments by modifying the intensity of the pixels is presented and this paper proposes a line drawing scheme to draw a line by calculating deflection-angle and error to draw the next possible pixel more accurately both starting from coordinate point (x 1 ,y 1) (x 2 ,y 2) to meet mid (m), so that there will be a pattern of pixels nearer to the imaginary line. The basis of the algorithm is to draw pairs of pixels from both the end points straddling the line.
In vivo Assay for Antagonistic Potential of Fungal Isolates against Faba bean (Vicia faba L.) Cho... more In vivo Assay for Antagonistic Potential of Fungal Isolates against Faba bean (Vicia faba L.) Chocolate Spot (Botrytis fabae Sard.
Measurements from the MF spaced antenna mode radar at Scott Base (78øS, 167øE) include an estimat... more Measurements from the MF spaced antenna mode radar at Scott Base (78øS, 167øE) include an estimate of the autocorrelation time scale (T0.5) of the scatterers, corrected for advection by the mean wind. Summer observations (December 1983) show a semidiurnal variation of T0.5. At heights of 87-95 km the minimum values of T0.• occur when the zonal component of the semidiurnal tide is at its westward maximum. If it is assumed that decreasing values of T0.• are associated with increasing turbulence, then these results are consistent with those of Balsley et al. (1983), who proposed that enhanced turbulence is generated in summer by low-frequency gravity waves and tidal components above the polar mesopause.
There is a huge demand to accurately determine the magnetoelectrical properties of particles in t... more There is a huge demand to accurately determine the magnetoelectrical properties of particles in the nano-sized regime due to the modern IC technology revolution and biomedical applications. In this paper, we present a microwave waveguide measurement technique for measuring complex permeability and permittivity of expensive nano-sized magnetic powder materials. We used a vector network analyzer to provide a standard TRL calibration for free space inside waveguide measurements. In order to maintain the recommended insertion phase range, a very thin prepared sample was loaded inside the calibrated waveguide. The loaded material's magnetic and dielectric effects were also considered in the cutoff wavelength calculation of the propagation constant of the TE 10 wave from the geometrical dimensions of the waveguides. These provisions make the permeability and permittivity measurements more reliable than those found by commonly used techniques. We used six different compounds of nano-sized ferrite powders (Fe 3 O 4 , CuFe 2 O 4 , CuFe 2 O 4 Zn, Fe 2 NiO 3 Zn, BaFe 12 O 19 , and SrFe 12 O 19), in which the average diameter of nano particles is less than 40 nm, for measurement purposes. We measured the complex permeability and permittivity from 3.95 to 5.85 GHz. The results show that the dielectric permittivity of these materials is quite different from that of solid-state materials.
WiMAX stands for Worldwide Interoperability for Microwave Access. WiMAX is based on wireless Metr... more WiMAX stands for Worldwide Interoperability for Microwave Access. WiMAX is based on wireless Metropolitan Area Network (MAN) standards developed by IEEE 802.16 group. It operates in the licensed exempt and licensed spectrum between 2-11 GHz and 10-66 GHz frequency ...
The Worst-Case Execution Time (WCET) is an important execution metric for real-time systems, and ... more The Worst-Case Execution Time (WCET) is an important execution metric for real-time systems, and an accurate estimate for this increases the reliability of subsequent schedulability analysis. Performance enhancing features on modern processors, such as pipelines and caches, however, make it difficult to accurately predict the WCET. One technique for finding the WCET is to use test data generated using search
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