Exclusive Queueing Process with Discrete Time

In a recent study [C Arita, Phys. Rev. E 80, 051119 (2009)], an extension of the M/M/1 queueing process with the excluded-volume effect as in the totally asymmetric simple exclusion process (TASEP) was introduced. In this paper, we consider its discrete-time version. The update scheme we take is the parallel one. A stationary-state solution is obtained in a slightly arranged matrix product form of the discrete-time open TASEP with the parallel update. We find the phase diagram for the existence of the stationary state. The critical line which separates the parameter space into the regions with and without the stationary state can be written in terms of the stationary current of the open TASEP. We calculate the average length of the system and the average number of particles

Superiority of deformable image co-registration in the integration of diagnostic positron emission tomography-computed tomography to the radiotherapy treatment planning pathway for oesophageal carcinoma

Aims To investigate the use of image co-registration in incorporating diagnostic positron emission tomography-computed tomography (PET-CT) directly into the radiotherapy treatment planning pathway, and to describe the pattern of local recurrence relative to the PET-avid volume. Materials and methods Fourteen patients were retrospectively identified, six of whom had local recurrence. The accuracy of deformable image registration (DIR) and rigid registration of the diagnostic PET-CT and recurrence CT, to the planning CT, were quantitatively assessed by comparing co-registration of oesophagus, trachea and aorta contours. DIR was used to examine the correlation between PET-avid volumes, dosimetry and site of recurrence. Results Positional metrics including the dice similarity coefficient (DSC) and conformity index (CI), showed DIR to be superior to rigid registration in the co-registration of diagnostic and recurrence imaging to the planning CT. For diagnostic PET-CT, DIR was superior to rigid registration in the transfer of oesophagus (DSC = 0.75 versus 0.65, P < 0.009 and CI = 0.59 versus 0.48, P < 0.003), trachea (DSC = 0.88 versus 0.65, P < 0.004 and CI = 0.78 versus 0.51, P < 0.0001) and aorta structures (DSC = 0.93 versus 0.86, P < 0.006 and CI = 0.86 versus 0.76, P < 0.006). For recurrence imaging, DIR was superior to rigid registration in the transfer of trachea (DSC = 0.91 versus 0.66, P < 0.03 and CI = 0.83 versus 0.51, P < 0.02) and oesophagus structures (DSC = 0.74 versus 0.51, P < 0.004 and CI = 0.61 versus 0.37, P < 0.006) with a non-significant trend for the aorta (DSC = 0.91 versus 0.75, P < 0.08 and CI = 0.83 versus 0.63, P < 0.06) structure. A mean inclusivity index of 0.93 (range 0.79–1) showed that the relapse volume was within the planning target volume (PTVPET-CT); all relapses occurred within the high dose region. Conclusion DIR is superior to rigid registration in the co-registration of PET-CT and recurrence CT to the planning CT, and can be considered in the direct integration of PET-CT to the treatment planning process. Local recurrences occur within the PTVPET-CT, suggesting that this is a suitable target for dose-escalation strategies

Corrections to Hawking-like Radiation for a Friedmann-Robertson-Walker Universe

Recently, a Hamilton-Jacobi method beyond semiclassical approximation in black hole physics was developed by \emph{Banerjee} and \emph{Majhi}\cite{beyond0}. In this paper, we generalize their analysis of black holes to the case of Friedmann-Robertson-Walker (FRW) universe. It is shown that all the higher order quantum corrections in the single particle action are proportional to the usual semiclassical contribution. The corrections to the Hawking-like temperature and entropy of apparent horizon for FRW universe are also obtained. In the corrected entropy, the area law involves logarithmic area correction together with the standard inverse power of area term.Comment: 10 pages, no figures, comments are welcome; v2: references added and some typoes corrected, to appear in Euro.Phys.J.C; v3:a defect corrected. We thank Dr.Elias Vagenas for pointing out a defect of our pape

Multiple band structures in Ta169

Rotational structures in the Ta169 nucleus were studied via the Sn124(V51, 6n) reaction. These data were obtained as a side channel of an experiment focusing on Ta171, but the sensitivity provided by the Gammasphere spectrometer proved sufficient for a significant extension of the level scheme of this rare-earth nucleus. Over 170 new transitions and four new band structures were placed in Ta169, including the intruder πi13/2 structure. Linking transitions between all of the sequences were identified, and the relative excitation energies between the different configurations were determined for the first time. The rotational sequences were interpreted within the framework of the cranked shell model

Alignments, additivity, and signature inversion in odd-odd Ta170: A comprehensive high-spin study

High-spin states (I 50) of the odd-odd nucleus Ta170 have been investigated with the Sn124(51V,5n) reaction. The resolving power of Gammasphere has allowed for the observation of eleven rotational bands (eight of which are new) and over 430 transitions (~350 of which are new) in this nucleus. Many interband transitions have been observed such that the relative spins and excitation energies of the 11 bands have been established. This is an unusual circumstance in an odd-odd study. Configurations have been assigned to most of these bands based upon features such as alignment properties, band crossings, B(M1)/B(E2) ratios, and the additivity of Routhians. A systematic study of the frequency at which normal signature ordering occurs in the πh9/2νi13/2 band has been performed and it is found that its trend is opposite to that observed in the πh11/2νi13/2 bands. A possible interpretation of these trends is discussed based on a proton-neutron interaction

First observation of rotational structures in Re 168

The first rotational sequences have been assigned to the odd-odd nucleus Re168. Coincidence relationships of these structures with rhenium x rays confirm the isotopic assignment, while arguments based on the γ-ray multiplicity (K-fold) distributions observed with the new bands lead to the mass assignment. Configurations for the two bands were determined through analysis of the rotational alignments of the structures and a comparison of the experimental B(M1)/B(E2) ratios with theory. Tentative spin assignments are proposed for the πh11/2νi13/2 band, based on energy level systematics for other known sequences in neighboring odd-odd rhenium nuclei, as well as on systematics seen for the signature inversion feature that is well known in this region. The spin assignment for the πh11/2ν(h9/2/f7/2) structure provides additional validation of the proposed spins and configurations for isomers in the Au176 → Ir172→Re168 α-decay chain

Multiple band structures in 169,170Re: Search for the wobbling mode in 169Re, and residual-interaction analysis of structures in 170Re

Although the observation of wobbling was once thought to be possibly confined to lutetium isotopes in N≈94 nuclei, the identification of this exotic collective mode in 167Ta has raised the question of the role of the proton Fermi surface with regard to this phenomenon. To investigate this issue, an experiment was performed to populate high-spin states in the N=94 nucleus 169Re. The heavy-ion reaction 55Mn+118Sn was used in conjunction with Gammasphere to detect the emitted γ rays. More than 130 new transitions were added to the 169Re level scheme, including the first identification of the πi13/2 rotational sequence in this nucleus. This configuration is the structure on which all known wobbling sequences are based, but no wobbling band was observed, likely owing to the fact that the πi13/2 sequence is located at a relatively high energy in comparison with the other structures found in 169Re. Nine decay sequences are now established in this nucleus and are described within the context of the cranked shell model. In addition, significant extension of the level scheme of the odd-odd 170Re nucleus was possible and a discussion of the residual interactions for the πh 9/2νi13/2 and πi13/2νi13/2 configurations in this region is given as well

Band crossings in Ta166

High-spin states in the odd-odd nucleus Ta166 are investigated through the 5n channel of the V51+Sn120 reaction. Four new bands are observed and linked into the previous level scheme. Configurations for the bands are proposed, based on measured alignments and B(M1)/B(E2) transition strength ratios

High-spin structure of odd-odd Re 172

A significant extension of the level scheme for the odd-odd nucleus Re172 was accomplished through the use of the Gammasphere spectrometer. States up to a tentative spin assignment of 39 were observed and two new structures were identified. Configuration assignments are proposed based on alignment properties and observed band crossings

Possible deformation evolution in the πi13/2 structure of 171Re

The phenomenon of wobbling can only occur for a nuclear shape with stable triaxial deformation. To date, only a few examples of this exotic collective mode have been observed in lutetium and tantalum isotopes. A search for a wobbling sequence was performed in 171Re to determine if this feature can be observed in Z&gt;73 nuclei. No evidence was found for wobbling; however, an interaction between the πi13/2 sequence and another positive-parity band may give an indication on why wobbling may not occur in this nucleus. The level scheme for 171Re was significantly extended and interpretations for the decay sequences are proposed within the context of the cranked shell model