The authors propose novel nongrooming, optical path cross-connect (OXC), single-layer optical path (OP) networks that can route multigranularity optical paths with reduced optical switch (OSW) size. ...Since the multigranularity OPs are handled in one OP layer, the configuration and path administration of the OXCs become simple. The authors evaluate the network topology dependency of the network elements, i.e., the required number of OSW ports and fibers in networks consisting of 36 fixed nodes with different network topologies as well as that of a 16-OXC, 25-link NSFNET. The proposed networks require 60% fewer OSW ports, enabling efficient link resource utilization. A 60% reduction in total network cost is also confirmed.
Summary
An attempt was made to determine whether amino acid variation at position 631 in the chicken Mx protein definitely influences antiviral specificity, using an artificial mutation technique by ...which a single amino acid was reciprocally substituted between Ser (AGT) and Asn (AAT) at position 631 of the negative and positive chicken Mx, respectively. Using permanently transfected 3T3 cell lines, the antiviral potential of chicken Mx against vesicular stomatitis virus infection was analysed. The results indicated that the phenotype of antiviral activity depends on the amino acid difference at position 631; that is, the genotype coding Asn at position 631 corresponds to the positive antiviral phenotype, and the genotype coding Ser corresponds to the negative phenotype. The present study has confirmed that the antiviral specificity of chicken Mx protein is determined by an amino acid substitution at the carboxy terminus.
The noise figure (NF) of a phase-sensitive parametric amplifier using a nonlinear Mach-Zehnder interferometer (NMZI) with Kerr media is analyzed for amplitude-modulation signals. In the analysis, the ...distributed loss of the Kerr media and the excess noise of the pump light are taken into account. As for the distributed loss of the Kerr media, the quantum Langevin equation for the NMZI is derived and solved. The results elucidate a simple degradation factor in the NF representation of the amplifier. This factor implies that the NF can be less than the standard quantum limit (SQL) of 3 dB, even if the total loss of the Kerr media exceeds 3 dB. As for the excess noise of the pump light, the semi-classical small signal analysis is utilized. The results clearly indicate that the signal-to-noise ratio of the pump light must be four times higher than that of the input signal in order to realize a low-noise optical amplifier under the SQL of 3 dB.
An active target system MAIKo (μ-PIC based active target for inverse kinematics.) is under development at RCNP. MAIKo is designed to investigate inelastic scattering at forward angles with a radio ...isotope (RI) beam. The active target is a promising device to study excited states above particle decay thresholds in unstable nuclei. In the present paper, the detailed design of the detector system is described. The first experiment using an accelerated beam was performed to study the detector performance under high counting rate. Preliminary results of the experiment are also discussed.
We have developed LaBr3(Ce) pixel scintillator arrays for an electron-tracking Compton camera (ETCC) that consists of a gaseous time projection chamber (TPC) and the scintillators. The TPC measures ...the three-dimensional track and energy of a Compton recoil electron, while the scintillators measure the energy and position of the scattered gamma ray. Therefore, the ETCC is able to reconstruct Compton scattering event by event. We adopted LaBr3(Ce) scintillators because the angular resolution of the ETCC depends on the energy resolution of the scintillators, and LaBr3(Ce) has an FWHM energy resolution of about 3% at 662keV using a single-anode photomultiplier tube (PMT). We have developed an 8×8 array of LaBr3(Ce) scintillator pixels with a pixel size of 5.8×5.8×15.0mm3, which has an FWHM energy resolution of 5.8±0.9% at 662keV when coupled to a multi-anode PMT (Hamamatsu H8500). The ETCC with the LaBr3(Ce) arrays has an FWHM angular resolution of 4.2±0.3∘ at 662keV.
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