M. Mohammad-Zamani - Academia.edu (original) (raw)
Papers by M. Mohammad-Zamani
We are introducing a new bias free CW terahertz photomixer emitter array. Each emitter consists o... more We are introducing a new bias free CW terahertz photomixer emitter array. Each emitter consists of an asymmetric metal-semiconductormetal (MSM) that is made of two side by side dis-similar Schottky contacts, on a thin layer of low temperature grown (LTG) GaAs, with barrier heights of difference (ΔΦ B ) and a finite lateral spacing (s). Simulations show that when an appropriately designed structure is irradiated by two coherent optical beams of different center wavelengths, whose frequency difference (∆f) falls in a desired THz band, the built-in field between the two dis-similar potential barriers can accelerate the photogenerated carriers that are modulated by ∆ω, making each pitch in the array to act as a CW THz emitter, effectively. We also show the permissible values of s and ΔΦ B pairs, for which the strengths of the built-in electric field maxima fall below that of the critical of 50 V/μm-i.e., the breakdown limit for the LTG-GaAs layer. Moreover, we calculate the THz radiation power per emitter in an array. Among many potential applications for these bias free THz emitters their use in endoscopic imaging without a need for hazardous external biasing circuitry that reduces the patient health risk, could be the most important one. A hybrid numerical simulation method is used to design an optimum emitter pitch, radiating at 0.5 THz.
ABSTRACT The high level of radiation generated by a spallation source requires the design of an a... more ABSTRACT The high level of radiation generated by a spallation source requires the design of an appropriate shielding to surround the source in order to fulfill radiation protection standards. A calculation of the spallation neutron attenuation is presented for various shielding materials, using a phenomenological model, based on the Moyer model. In the first step of the calculation, the interaction length of neutrons for each neutron energy and shielding material was estimated using inelastic cross-sections. In the second step the calculation deals with the attenuation of the neutron flux applying the Moyer model, for each material and neutron energy region. The transmission factors were calculated and compared with experimental data collected from the “Gamma-2” and the “E+T” projects running in JINR (Dubna, Russia). The results of the present work were also compared to the data obtained by different Monte Carlo codes such as MORSE, MCNPX, MARS14 and LAHET.
International Journal of Radiation Applications and Instrumentation. Part D. Nuclear Tracks and Radiation Measurements, 1991
Reactions of 15 MeV/n ~*U on Au have been studied by means of CR 39 solid state nuclear track det... more Reactions of 15 MeV/n ~*U on Au have been studied by means of CR 39 solid state nuclear track detectors. Among the different events observed, all 3-pronged events were selected and examined. It is found that at f'mal state the quasi totality of these events, say 87%, proceed by t'L~sion reactions. Analysis in the context of partlcipant-spectator model has shown evidence for two different fission processes. Fission events derived from the break-up of the participant nuclei represent -789'0 of the events, whereas -.9% issue from the spectator. The mean kinetic energy loss is -11% of the incident energy.
International Journal of Radiation Applications and Instrumentation. Part D. Nuclear Tracks and Radiation Measurements, 1988
Cu and Pb targets were irradiated by 3.7 GeV/n 12C ions and 1.8 GeV/n ions respectively at the Du... more Cu and Pb targets were irradiated by 3.7 GeV/n 12C ions and 1.8 GeV/n ions respectively at the Dubna (USSR) and Berkeley (USA) accelerators. CR 39 track detectors were placed up-and downstream of 2.0 em Cu and 0.8 cm Pb foils. Important attenuation of the number of beam particles passing through the targets was observed allowing for direct total reaction cross section measurements. Good agreement with theoretically calculated cross section was found.
Nuclear Tracks and Radiation Measurements, 1993
The existence of extra chiral generations with all fermions heavier than M Z is strongly disfavou... more The existence of extra chiral generations with all fermions heavier than M Z is strongly disfavoured by the precision electroweak data. However the data are fitted nicely even by a few extra generations, if one allows neutral leptons to have masses close to 50 GeV. The data allow inclusion of one additional generation of heavy fermions in SUSY extension of Standard Model if chargino and neutralino have masses close to 60 GeV with ∆m 1 GeV.
2007 10th Canadian Workshop on Information Theory (CWIT), 2007
A variable rate Slepian-Wolf (SW) code is constructed which is vital for wireless sensor network ... more A variable rate Slepian-Wolf (SW) code is constructed which is vital for wireless sensor network applications. A practical scheme to construct SW codes is to use the syndrome of a channel code as a compressed representation of a codeword in presence of a side information [3]. The proposed solution is based on an efficient and practical algorithm to compute the syndrome of rate-compatible convolutional codes (RCPC). By using this algorithm, there is no need to compute the syndrome of punctured version of the mother code for each puncturing matrix which is complex. Instead, the the syndrome of the punctured code is designed to be the punctured version of the syndrome of the mother code using the same pattern of puncturing. The algorithm is general for all convolutional codes in Z q . The strategy is also generalized for parallel and serial concatenated convolutional codes.
Radiation Measurements, 2009
Metal-Oxide-Semiconductor Field Effect Transistors (MOSFETs) with a LiF powder placed on their su... more Metal-Oxide-Semiconductor Field Effect Transistors (MOSFETs) with a LiF powder placed on their surface were used as neutron dosemeter. The effect of thermal neutron irradiation on the threshold voltage of the transistor was studied in order to determine the sensitivity of these detectors. Irradiations were performed at the thermal column of the reactor in IPTA, Demokritos, Athens and at the subcritical reactor of Nuclear Physics Laboratory, Thessaloniki. The sensitivity of the MOSFETs as a function of thermal neutron dose was found to be practically linear up to 100 mSv. The lower detectable dose appears to be depended on the dose rate.
![Research paper thumbnail of Erratum to “Neutron yields from massive lead and uranium targets irradiated with relativistic protons” [Radiation Measurements 40 (2005) 410–414]](https://attachments.academia-assets.com/48337713/thumbnails/1.jpg)
](Radiation Measurements, 2009
Radiation Measurements, 2008
A spallation neutron source consisted of a cylindrical Pb target and surrounded by uranium blanke... more A spallation neutron source consisted of a cylindrical Pb target and surrounded by uranium blanket was irradiated by deuteron beam 1.25 GeV/amu provided from the Nuclotron accelerator at High Energy Laboratory, JINR, Dubna. For radiation protection purpose a polyethylene shielding was placed around the spallation neutron source. Neutron distributions along the surface of the U-blanket were measured by using solid state nuclear track detectors (SSNTDs) as particle and fission detectors. The neutron distributions appear to be similar to those obtained by proton irradiations. Applying a fitting procedure to the experimental data the inelastic cross section of deuteron in Pb was estimated. The escaping neutron distribution from the polyethylene shielding and parallel to the target was also measured and presented to be two orders of magnitude less than that over the U-blanket surface.
Radiation Measurements, 1999
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2003
A large Pb target with a U blanket was irradiated with 1.5 GeV protons at the Dubna Nuclotron acc... more A large Pb target with a U blanket was irradiated with 1.5 GeV protons at the Dubna Nuclotron accelerator. Solidstate nuclear track detectors measured neutron spatial distributions in the new experimental transmutation assembly. Slow and fast neutron components were studied inside sections of the setup and on the U blanket surface. Neutron distributions after Cd and polyethylene shielding were also investigated. The results show that the new arrangement is efficient for transmutation experiments by (n; f) and (n;xn) reactions as well as by (n; g) reactions. r
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2009
... doi:10.1016/j.nima.2008.10.034 | How to Cite or Link Using DOI Copyright © 2008 Elsevier BV A... more ... doi:10.1016/j.nima.2008.10.034 | How to Cite or Link Using DOI Copyright © 2008 Elsevier BV All rights reserved. ... Author Contact Information , E-mail The Corresponding Author , M. Fragopoulou a , A. Sosnin b , M. Manolopoulou a , M. Krivopustov b and M. Zamani a. ...
![Research paper thumbnail of Erratum to “Neutron measurements by passive methods in the Dubna transmutation assemblies” [Nucl. Instr. and Meth. Phys. Res. A 519 (2004) 651–658]](https://attachments.academia-assets.com/48337709/thumbnails/1.jpg)
](Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2008
Journal of Physics: Conference Series, 2006
Spallation neutron sources provide more intense and harder neutron spectrum than nuclear reactors... more Spallation neutron sources provide more intense and harder neutron spectrum than nuclear reactors for which a substantial amount of shielding measurements have been performed. Although the main part of the cost for a spallation station is the cost of the shielding, measurements regarding shielding for the high energy neutron region are still very scarce. In this work calculation of the neutron interaction length in polyethylene moderator for different neutron energies is presented. Measurements which were carried out in Nuclotron accelerator at the
International Journal of Immunogenetics, 2007
We studied allele frequency and other statistical parameters of six short-tandem repeat (STR) loc... more We studied allele frequency and other statistical parameters of six short-tandem repeat (STR) loci: D6S265, D6S439, D6S105, D6S82-1, MICA, and MOGd, which are located in major histocompatibility complex (MHC) region (6p21.3) in 101 Iranian individuals. STR polymorphisms were analysed by PCR and polyacrylamide gel electrophoresis and subsequent comparison with standard (allelic) ladders. Exact tests of Hardy-Weinberg equilibrium were performed for the six loci. All loci, except the MOGd (P = 0.4291), were in Hardy-Weinberg equilibrium. These data may be useful in PGD-HLA matching and forensic science.
IEEE Transactions on Communications, 2000
A flexible rate Slepian-Wolf (SW) code is constructed, which is vital for wireless sensor network... more A flexible rate Slepian-Wolf (SW) code is constructed, which is vital for wireless sensor network applications. The proposed solution is based on an efficient and practical algorithm to compute the syndrome of the rate-compatible convolutional codes (RCPC). Using this algorithm, there is no need to compute the syndrome of punctured version of the mother code for each puncturing matrix, which is complex. Instead, the syndrome of the punctured code is the punctured version of the syndrome of the mother code using the same pattern of puncturing. The algorithm is general for all convolutional codes in Zq. The strategy is also generalized for parallel and serial concatenated convolutional codes. For the cases, where the dependencies among sources are modeled as a virtual discrete channel, a simplified decoding scheme is suggested. This method is generalized to achieve all points on the SW boundary using a simple code design technique. Simulation results demonstrate the performance and effectiveness of the proposed methods.
Clinical and Experimental Dermatology, 2009
Background. Vitiligo is an acquired idiopathic and polygenic disorder with progressive depigmenta... more Background. Vitiligo is an acquired idiopathic and polygenic disorder with progressive depigmentation of circumscribed patches. Its exact pathogenesis is unknown. The CD4 gene plays an important role in the cell-mediated immune response and its association with type 1 diabetes mellitus, which is an autoimmune disease, has been previously reported. Methods. Based on the assumption that autoimmunity is also involved in vitiligo, the CD4 gene was selected for study using a candidate gene approach. The pyrimidinerich pentanucleotide repeat length polymorphism located in the promoter of the gene was studied. We screened 144 unrelated Iranian patients with vitiligo and 144 healthy matched controls by PCR. Results. The CD4*A4 allele has a susceptibility association with the development of vitiligo in the Iranian population (OR = 1.68, 95% CI 1.18-2.42; P < 0.01, P c = 0.02). When we compared CD4*A4-containing genotypes in the case and control groups, even more significant positive association was identified (OR = 2.02, 95% CI 1.26-3.22; P < 0.01 and P c < 0.01). The CD4 gene polymorphism has a modest association with the development of vitiligo in Iranian patients.
Annals of Nuclear Energy, 2010
The inelastic cross section of relativistic protons in Pb was determined indirectly by measuring ... more The inelastic cross section of relativistic protons in Pb was determined indirectly by measuring the neutron distribution along a Lead spallation neutron source. The spallation neutron source was irradiated by 1, 1.5 and 2 GeV protons. The experimental results were obtained using passive methods. By the use of the beam attenuation coefficient, deduced by a fitting procedure of experimental data, the inelastic cross section of protons in Pb was determined.
ABSTRACT In this paper, we investigate the efficiency of a number of commonly used amino acid enc... more ABSTRACT In this paper, we investigate the efficiency of a number of commonly used amino acid encodings by using artificial neural networks and substitution scoring matrices. An important step in many machine learning techniques applied in computational biology is encoding the symbolic data of protein sequences reasonably efficient in numeric vector representations. This encoding can be achieved by either considering the amino acid physicochemical properties or a generic numerical encoding. In order to be effective in the context of a machine learning system, an encoding must preserve information relative to the problem at hand, while diminishing superfluous data. To this end, it is important to measure how much an encoding scheme can conserve the underlying similarities and differences that exist among the amino acids. One way to evaluate the effectiveness of an amino acid encoding scheme is to compare it to the roles that amino acids are actually found to play in biological systems. A numerical representation of the similarities and differences between amino acids can be found in substitution matrices commonly used for sequence alignment, since these substitution matrices are based on measures of the interchangeability of amino acids in biological specimens. In this study, a new encoding scheme is also proposed based on the genetic codon coding occurs during protein synthesis. The experimental results indicate better performances compared to the other commonly used encodings.
Neural network is one of the successful methods for protein secondary structure prediction. Day t... more Neural network is one of the successful methods for protein secondary structure prediction. Day to day this technology is modified, improved, even other methods also combined with it to get better result. In this paper we trained feed-forward neural network with proteins for secondary structure prediction. Using Java Object Oriented Neural Engine (JOONE) our achieved accuracy for helix prediction is 71% and for sheet prediction is 65%. This paper is expected to benefit researchers in proteomics by presenting a summary of developments of neural network in this area.
We are introducing a new bias free CW terahertz photomixer emitter array. Each emitter consists o... more We are introducing a new bias free CW terahertz photomixer emitter array. Each emitter consists of an asymmetric metal-semiconductormetal (MSM) that is made of two side by side dis-similar Schottky contacts, on a thin layer of low temperature grown (LTG) GaAs, with barrier heights of difference (ΔΦ B ) and a finite lateral spacing (s). Simulations show that when an appropriately designed structure is irradiated by two coherent optical beams of different center wavelengths, whose frequency difference (∆f) falls in a desired THz band, the built-in field between the two dis-similar potential barriers can accelerate the photogenerated carriers that are modulated by ∆ω, making each pitch in the array to act as a CW THz emitter, effectively. We also show the permissible values of s and ΔΦ B pairs, for which the strengths of the built-in electric field maxima fall below that of the critical of 50 V/μm-i.e., the breakdown limit for the LTG-GaAs layer. Moreover, we calculate the THz radiation power per emitter in an array. Among many potential applications for these bias free THz emitters their use in endoscopic imaging without a need for hazardous external biasing circuitry that reduces the patient health risk, could be the most important one. A hybrid numerical simulation method is used to design an optimum emitter pitch, radiating at 0.5 THz.
ABSTRACT The high level of radiation generated by a spallation source requires the design of an a... more ABSTRACT The high level of radiation generated by a spallation source requires the design of an appropriate shielding to surround the source in order to fulfill radiation protection standards. A calculation of the spallation neutron attenuation is presented for various shielding materials, using a phenomenological model, based on the Moyer model. In the first step of the calculation, the interaction length of neutrons for each neutron energy and shielding material was estimated using inelastic cross-sections. In the second step the calculation deals with the attenuation of the neutron flux applying the Moyer model, for each material and neutron energy region. The transmission factors were calculated and compared with experimental data collected from the “Gamma-2” and the “E+T” projects running in JINR (Dubna, Russia). The results of the present work were also compared to the data obtained by different Monte Carlo codes such as MORSE, MCNPX, MARS14 and LAHET.
International Journal of Radiation Applications and Instrumentation. Part D. Nuclear Tracks and Radiation Measurements, 1991
Reactions of 15 MeV/n ~*U on Au have been studied by means of CR 39 solid state nuclear track det... more Reactions of 15 MeV/n ~*U on Au have been studied by means of CR 39 solid state nuclear track detectors. Among the different events observed, all 3-pronged events were selected and examined. It is found that at f'mal state the quasi totality of these events, say 87%, proceed by t'L~sion reactions. Analysis in the context of partlcipant-spectator model has shown evidence for two different fission processes. Fission events derived from the break-up of the participant nuclei represent -789'0 of the events, whereas -.9% issue from the spectator. The mean kinetic energy loss is -11% of the incident energy.
International Journal of Radiation Applications and Instrumentation. Part D. Nuclear Tracks and Radiation Measurements, 1988
Cu and Pb targets were irradiated by 3.7 GeV/n 12C ions and 1.8 GeV/n ions respectively at the Du... more Cu and Pb targets were irradiated by 3.7 GeV/n 12C ions and 1.8 GeV/n ions respectively at the Dubna (USSR) and Berkeley (USA) accelerators. CR 39 track detectors were placed up-and downstream of 2.0 em Cu and 0.8 cm Pb foils. Important attenuation of the number of beam particles passing through the targets was observed allowing for direct total reaction cross section measurements. Good agreement with theoretically calculated cross section was found.
Nuclear Tracks and Radiation Measurements, 1993
The existence of extra chiral generations with all fermions heavier than M Z is strongly disfavou... more The existence of extra chiral generations with all fermions heavier than M Z is strongly disfavoured by the precision electroweak data. However the data are fitted nicely even by a few extra generations, if one allows neutral leptons to have masses close to 50 GeV. The data allow inclusion of one additional generation of heavy fermions in SUSY extension of Standard Model if chargino and neutralino have masses close to 60 GeV with ∆m 1 GeV.
2007 10th Canadian Workshop on Information Theory (CWIT), 2007
A variable rate Slepian-Wolf (SW) code is constructed which is vital for wireless sensor network ... more A variable rate Slepian-Wolf (SW) code is constructed which is vital for wireless sensor network applications. A practical scheme to construct SW codes is to use the syndrome of a channel code as a compressed representation of a codeword in presence of a side information [3]. The proposed solution is based on an efficient and practical algorithm to compute the syndrome of rate-compatible convolutional codes (RCPC). By using this algorithm, there is no need to compute the syndrome of punctured version of the mother code for each puncturing matrix which is complex. Instead, the the syndrome of the punctured code is designed to be the punctured version of the syndrome of the mother code using the same pattern of puncturing. The algorithm is general for all convolutional codes in Z q . The strategy is also generalized for parallel and serial concatenated convolutional codes.
Radiation Measurements, 2009
Metal-Oxide-Semiconductor Field Effect Transistors (MOSFETs) with a LiF powder placed on their su... more Metal-Oxide-Semiconductor Field Effect Transistors (MOSFETs) with a LiF powder placed on their surface were used as neutron dosemeter. The effect of thermal neutron irradiation on the threshold voltage of the transistor was studied in order to determine the sensitivity of these detectors. Irradiations were performed at the thermal column of the reactor in IPTA, Demokritos, Athens and at the subcritical reactor of Nuclear Physics Laboratory, Thessaloniki. The sensitivity of the MOSFETs as a function of thermal neutron dose was found to be practically linear up to 100 mSv. The lower detectable dose appears to be depended on the dose rate.
Radiation Measurements, 2009
Radiation Measurements, 2008
A spallation neutron source consisted of a cylindrical Pb target and surrounded by uranium blanke... more A spallation neutron source consisted of a cylindrical Pb target and surrounded by uranium blanket was irradiated by deuteron beam 1.25 GeV/amu provided from the Nuclotron accelerator at High Energy Laboratory, JINR, Dubna. For radiation protection purpose a polyethylene shielding was placed around the spallation neutron source. Neutron distributions along the surface of the U-blanket were measured by using solid state nuclear track detectors (SSNTDs) as particle and fission detectors. The neutron distributions appear to be similar to those obtained by proton irradiations. Applying a fitting procedure to the experimental data the inelastic cross section of deuteron in Pb was estimated. The escaping neutron distribution from the polyethylene shielding and parallel to the target was also measured and presented to be two orders of magnitude less than that over the U-blanket surface.
Radiation Measurements, 1999
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2003
A large Pb target with a U blanket was irradiated with 1.5 GeV protons at the Dubna Nuclotron acc... more A large Pb target with a U blanket was irradiated with 1.5 GeV protons at the Dubna Nuclotron accelerator. Solidstate nuclear track detectors measured neutron spatial distributions in the new experimental transmutation assembly. Slow and fast neutron components were studied inside sections of the setup and on the U blanket surface. Neutron distributions after Cd and polyethylene shielding were also investigated. The results show that the new arrangement is efficient for transmutation experiments by (n; f) and (n;xn) reactions as well as by (n; g) reactions. r
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2009
... doi:10.1016/j.nima.2008.10.034 | How to Cite or Link Using DOI Copyright © 2008 Elsevier BV A... more ... doi:10.1016/j.nima.2008.10.034 | How to Cite or Link Using DOI Copyright © 2008 Elsevier BV All rights reserved. ... Author Contact Information , E-mail The Corresponding Author , M. Fragopoulou a , A. Sosnin b , M. Manolopoulou a , M. Krivopustov b and M. Zamani a. ...
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2008
Journal of Physics: Conference Series, 2006
Spallation neutron sources provide more intense and harder neutron spectrum than nuclear reactors... more Spallation neutron sources provide more intense and harder neutron spectrum than nuclear reactors for which a substantial amount of shielding measurements have been performed. Although the main part of the cost for a spallation station is the cost of the shielding, measurements regarding shielding for the high energy neutron region are still very scarce. In this work calculation of the neutron interaction length in polyethylene moderator for different neutron energies is presented. Measurements which were carried out in Nuclotron accelerator at the
International Journal of Immunogenetics, 2007
We studied allele frequency and other statistical parameters of six short-tandem repeat (STR) loc... more We studied allele frequency and other statistical parameters of six short-tandem repeat (STR) loci: D6S265, D6S439, D6S105, D6S82-1, MICA, and MOGd, which are located in major histocompatibility complex (MHC) region (6p21.3) in 101 Iranian individuals. STR polymorphisms were analysed by PCR and polyacrylamide gel electrophoresis and subsequent comparison with standard (allelic) ladders. Exact tests of Hardy-Weinberg equilibrium were performed for the six loci. All loci, except the MOGd (P = 0.4291), were in Hardy-Weinberg equilibrium. These data may be useful in PGD-HLA matching and forensic science.
IEEE Transactions on Communications, 2000
A flexible rate Slepian-Wolf (SW) code is constructed, which is vital for wireless sensor network... more A flexible rate Slepian-Wolf (SW) code is constructed, which is vital for wireless sensor network applications. The proposed solution is based on an efficient and practical algorithm to compute the syndrome of the rate-compatible convolutional codes (RCPC). Using this algorithm, there is no need to compute the syndrome of punctured version of the mother code for each puncturing matrix, which is complex. Instead, the syndrome of the punctured code is the punctured version of the syndrome of the mother code using the same pattern of puncturing. The algorithm is general for all convolutional codes in Zq. The strategy is also generalized for parallel and serial concatenated convolutional codes. For the cases, where the dependencies among sources are modeled as a virtual discrete channel, a simplified decoding scheme is suggested. This method is generalized to achieve all points on the SW boundary using a simple code design technique. Simulation results demonstrate the performance and effectiveness of the proposed methods.
Clinical and Experimental Dermatology, 2009
Background. Vitiligo is an acquired idiopathic and polygenic disorder with progressive depigmenta... more Background. Vitiligo is an acquired idiopathic and polygenic disorder with progressive depigmentation of circumscribed patches. Its exact pathogenesis is unknown. The CD4 gene plays an important role in the cell-mediated immune response and its association with type 1 diabetes mellitus, which is an autoimmune disease, has been previously reported. Methods. Based on the assumption that autoimmunity is also involved in vitiligo, the CD4 gene was selected for study using a candidate gene approach. The pyrimidinerich pentanucleotide repeat length polymorphism located in the promoter of the gene was studied. We screened 144 unrelated Iranian patients with vitiligo and 144 healthy matched controls by PCR. Results. The CD4*A4 allele has a susceptibility association with the development of vitiligo in the Iranian population (OR = 1.68, 95% CI 1.18-2.42; P < 0.01, P c = 0.02). When we compared CD4*A4-containing genotypes in the case and control groups, even more significant positive association was identified (OR = 2.02, 95% CI 1.26-3.22; P < 0.01 and P c < 0.01). The CD4 gene polymorphism has a modest association with the development of vitiligo in Iranian patients.
Annals of Nuclear Energy, 2010
The inelastic cross section of relativistic protons in Pb was determined indirectly by measuring ... more The inelastic cross section of relativistic protons in Pb was determined indirectly by measuring the neutron distribution along a Lead spallation neutron source. The spallation neutron source was irradiated by 1, 1.5 and 2 GeV protons. The experimental results were obtained using passive methods. By the use of the beam attenuation coefficient, deduced by a fitting procedure of experimental data, the inelastic cross section of protons in Pb was determined.
ABSTRACT In this paper, we investigate the efficiency of a number of commonly used amino acid enc... more ABSTRACT In this paper, we investigate the efficiency of a number of commonly used amino acid encodings by using artificial neural networks and substitution scoring matrices. An important step in many machine learning techniques applied in computational biology is encoding the symbolic data of protein sequences reasonably efficient in numeric vector representations. This encoding can be achieved by either considering the amino acid physicochemical properties or a generic numerical encoding. In order to be effective in the context of a machine learning system, an encoding must preserve information relative to the problem at hand, while diminishing superfluous data. To this end, it is important to measure how much an encoding scheme can conserve the underlying similarities and differences that exist among the amino acids. One way to evaluate the effectiveness of an amino acid encoding scheme is to compare it to the roles that amino acids are actually found to play in biological systems. A numerical representation of the similarities and differences between amino acids can be found in substitution matrices commonly used for sequence alignment, since these substitution matrices are based on measures of the interchangeability of amino acids in biological specimens. In this study, a new encoding scheme is also proposed based on the genetic codon coding occurs during protein synthesis. The experimental results indicate better performances compared to the other commonly used encodings.
Neural network is one of the successful methods for protein secondary structure prediction. Day t... more Neural network is one of the successful methods for protein secondary structure prediction. Day to day this technology is modified, improved, even other methods also combined with it to get better result. In this paper we trained feed-forward neural network with proteins for secondary structure prediction. Using Java Object Oriented Neural Engine (JOONE) our achieved accuracy for helix prediction is 71% and for sheet prediction is 65%. This paper is expected to benefit researchers in proteomics by presenting a summary of developments of neural network in this area.