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A New Soft-Fusion Approach for Multiple-Receiver Wireless Communication Systems
Ashraf M. Aziz,Ahmed M. ElBakly,Mohamed H.A. Azeem,Gamal A. Hamid 한국전자통신연구원 2011 ETRI Journal Vol.33 No.3
In this paper, a new soft-fusion approach for multiple-receiver wireless communication systems is proposed. In the proposed approach, each individual receiver provides the central receiver with a confidence level rather than a binary decision. The confidence levels associated with the local receiver are modeled by means of soft-membership functions. The proposed approach can be applied to wireless digital communication systems, such as amplitude shift keying, frequency shift keying, phase shift keying, multi-carrier code division multiple access, and multiple inputs multiple outputs sensor networks. The performance of the proposed approach is evaluated and compared to the performance of the optimal diversity, majority voting, optimal partial decision, and selection diversity in case of binary noncoherent frequency shift keying on a Rayleigh faded additive white Gaussian noise channel. It is shown that the proposed approach achieves considerable performance improvement over optimal partial decision, majority voting, and selection diversity. It is also shown that the proposed approach achieves a performance comparable to the optimal diversity scheme.
A. H. Hamid,Tariq Javed,N. Ali 한국물리학회 2018 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.73 No.9
In the present investigation, we have studied the magnetohydrodynamic (MHD) heat transfer of peristaltic ow in a tube. The analysis is made without imposing any assumption to obtain the streamline and isothermal line directly. Galerkin's finite element method has been used on the governing Navier-Stoke's equation in the form of -!. The graphs of the computed longitudinal velocity, temperature and pressure are plotted against different value of the emerging parameter by using the stream function and vorticity. The results are valid beyond the long wavelength and the low Reynolds number limits. We conclude that higher values of the parameters are not independent of the time mean ow rate.
Synthesis and Antimicrobial Activity of Certain New 1,2,4-Triazolo[1,5-a]Pyrimidine Derivatives
Yaser A.H. Mostafa,Mostafa A. Hussein,Awwad A. Radwan,Abd El-Hamid N. Kfafy 대한약학회 2008 Archives of Pharmacal Research Vol.31 No.3
Certain new derivatives of 1,2,4-triazolo[1,5-a]pyrimidines were synthesized through the reaction of 1,2,4-triazolo[1,5-a]pyrimidine-7-ol with ethyl bromoacetate to afford the ethyl acetate ester, which upon hydrazinolysis gives the corresponding hydrazide. The hydrazide is the key intermediate which was used for the synthesis of the target compounds. The structures of the new compounds were assigned by spectral and elemental methods of analyses. The synthesized compounds were tested for their in vitro antibacterial and antifungal activities. Most of the tested compounds showed comparable results with those of ampicillin and fluconazole reference drugs.
Rotor Fault Detection System for Inverter Driven Induction Motor Using Currents Signal
N.H Kim,M.H Kim,Hamid A. Toliyat,S.H. Lee,C.H. Choi,W.S. Baik 전력전자학회 2007 ICPE(ISPE)논문집 Vol.- No.-
In this paper, the induction motor rotor fault diagnosis system using current signals which are measured using axis-transformation method is presented. In inverter-fed motor drives unlike line-driven motor drives the stator currents are rich in harmonics and therefore fault diagnosis using stator current is not trivial. The current signals for rotor fault diagnosis need precise and high resolution information, which means the diagnosis system demands additional hardware such as low pass filter, high resolution ADC, encoder and etc. Therefore, the proposed axis-transformation method is expected to contribute to low cost fault diagnosis system in inverter-fed motor drives without the need for encoder and any additional hardware. In order to confirm validity of the developed algorithms, various experiments for rotor faults are tested and the line current spectrum of each faulty situation using Park transformation is compared with the results obtained from fast Fourier transforms.
Low cost fault detection system for inverter driven induction motor using currents signal
N.H Kim,Oh Yabg,M.H Kim,Hamid A. Toliyat,Yongmin Oh,C.H. Choi 전력전자학회 2007 ICPE(ISPE)논문집 Vol.- No.-
In this paper, the induction motor rotor fault diagnosis system using current signals which are measured for axis-transformation and speed which is estimated using current information are presented. In inverter-fed motor drives the stator currents have much harmonics components and therefore fault diagnosis using stator current is difficult. The current and speed signal for rotor fault diagnosis need precise and high resolution information, which means the diagnosis system demands additional hardware such as low pass filter, high resolution ADC, encoder. Therefore, the proposed method are expected to contribute to low cost fault diagnosis system in inverter-fed motor drives without the need for encoder and any additional hardware. In order to confirm validity of the developed algorithms, various experiments for rotor faults are tested and the line current spectrum of each faulty situation using Park transformation and speed estimation method are compared with the results obtained from fast Fourier transforms.
Synthesis and Antimicrobial Activity of Certain New 1,2,4-Triazolo[1,5-a]Pyrimidine Derivatives
Mostafa, Yaser A.H.,Hussein, Mostafa A.,Radwan, Awwad A.,Krafy, Abd El-Hamid 대한약학회 2008 Archives of Pharmacal Research Vol.31 No.3
Certain new derivatives of 1,2,4-triazolo[1,5-a]pyrimidines were synthesized through the reaction of 1,2,4-triazolo[1,5-a]pyrimidine-7-o1 with ethyl bromoacetate to afford the ethyl acetate ester, which upon hydrazinolysis gives the corresponding hydrazide. The hydrazide is the key intermediate which was used for the synthesis of the target compounds. The structures of the new compounds were assigned by spectral and elemental methods of analyses. The synthesized compounds were tested for their in vitro antibacterial and antifungal activities. Most of the tested compounds showed comparable results with those of ampicillin and fluconazole reference drugs.
Almuqrin Aljawhara H.,Abd El-Hamid Abd Allh M.,Sayyed M.I.,Mahmoud K.A. 한국원자력학회 2024 Nuclear Engineering and Technology Vol.56 No.6
The current study investigated Saudi Arabian oil fly ash impacts on Egyptian clay bricks’ structural and radiation shielding properties. To produce the required bricks, crushed clay minerals from the Hafafit area were mixed with 0, 10, 20, 30, and 40 % wt.% Saudi Arabian oil fly ash and pressed at a pressure rate of 68.55 MPa. Identification of the minerals in the chosen clay was achieved via X-ray diffraction. Additionally, the material’s morphology and chemical composition were determined through scanning electron microscope and energydispersive X-ray. The fabricated bricks’ density was reduced by 36.3 % through increasing the concentration of fly ash from 0 to 40 wt%. Then, the fly ash addition’s influence on the fabricated clay bricks’ γ-ray shielding properties was investigated by Monte Carlo simulation, which found a reduction in the fabricated bricks’ linear attenuation coefficient (LAC) by 41.2, 36.0, 33.8, and 33.8 % at the 0.059, 0.103, 0.662, and 1.252 MeV γ-ray energies, respectively. The LAC reduction caused an increase in the fabricated bricks’ half-value thickness, transmission factor, and the equivalent thickness of the lead. Moreover, the thicker fabricated sample thicknesses were found to have high γ-ray shielding capacity and can thus be used in radiation shielding applications.
Fars K. Alanazi,Ibrahim A. Alsarra,Gamal El-Din I. Harisa,Ahmad Maqboul,Magdi Abdel-Hamid,Steven H. Neau 대한약학회 2011 Archives of Pharmacal Research Vol.34 No.4
The aim of this study was to investigate human erythrocytes as a carrier for targeted drug delivery of primaquine (PQ). The process of PQ loading in human erythrocytes, as well as the effect of PQ loading on the oxidative status of erythrocytes, was also studied. At PQ concentrations of 2, 4, 6, and 8 mg/mL and an incubation time of 2 h, the ratios of the concentrations of PQ entrapped in erythrocytes to that in the incubation medium were 0.515, 0.688, 0.697 and 0.788, respectively. The maximal decline of erythrocyte reduced glutathione content was observed at 8 mg/mL of PQ compared with native erythrocytes p < 0.001. In contrast, malondialdehyde and protein carbonyl were significantly increased in cells loaded with PQ (p < 0.001). Furthermore, osmotic fragility of PQ carrier erythrocytes was increased in comparison with unloaded cells. Electron microscopy revealed spherocyte formation with PQ carrier erythrocytes. PQ-loaded cells showed sustained drug release over a 48 h period. Erythrocytes were loaded with PQ successfully, but there were some biochemical as well as physiological changes that resulted from the effect of PQ on the oxidative status of drugloaded erythrocytes. These changes may result in favorable targeting of PQ-loaded cells to reticulo-endothelial organs. The relative impact of these changes remains to be explored in ongoing animal studies.
Hillman, F.,Zimmerman, J.,Paek, S. M.,Hamid, M. A.,Lim, W.,Jeong, H. K. Royal Society of Chemistry 2017 Journal of materials chemistry. A, Materials for e Vol.5 No.13
<P>Herein we report a new microwave-assisted synthetic strategy to rapidly prepare hybrid zeolitic-imidazolate frameworks (ZIFs): ZIFs with mixed metal centers and/or mixed linkers. The microwave-based method significantly shortens synthesis time, produces a higher yield, substantially reduces the amounts of ligands, and eliminates the use of deprotonating agents. The X-ray diffraction pattern reveals that mixed metal CoZn-ZIF-8 (i.e., ZIF-8 with both Co and Zn centers) maintains the sodalite (SOD) zeolitic topology from the ZIF-8 parent. Elemental mapping using energy-dispersive X-ray spectroscopy (EDS)and electronic/geometric information obtained from X-ray absorption spectroscopy (XAS) confirm the uniform distribution of tetrahedral Co and Zn metal centers within the same framework of the mixed-metal ZIF. The metal to nitrogen (M-N) stretching frequencies of IR bands were observed to be systematically blue-shifted as the Co/Zn ratio in the mixed metal ZIF increases. Furthermore, for the first time, a hybrid ZIF with both mixed metal centers (Co and Zn) and mixed linkers (2-methylimidazolate and benzimidazolate) was prepared through one-step microwave synthesis. Finally, mixed metal CoZn-ZIF-8 with a Co/Zn ratio of similar to 1 was grown as membranes on porous alpha-Al2O3 supports, showing a higher propylene/propane separation factor (similar to 120) when compared to pure Zn-ZIF-8 membranes (similar to 63) prepared by a similar method.</P>