4,214 research outputs found

    Bus Network Scheduling with Genetic Algorithms and Simulation

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    This thesis investigates the costs associated with a bus scheduling problem in an urban transit network for both deterministic and stochastic arrival processes and proposes computerized models for each. A simple genetic algorithm (SGA) with some problem-specific genetic operators is developed for the deterministic arrival process and a simulation-based genetic algorithm (SBGA) is developed for the stochastic arrival process. The new models are applied to an artificial bus network to test their efficiency. Several sensitivity analyses and a goodness test are conducted for each arrival process. The results show that the SGA model can find the optimized solution very quickly when it uses problem-specific operators such as the coordinated headway generator, coordinated headway crossover and coordinated headway mutation. They also show that the SBGA model can find a good solution even though it uses general genetic operators

    Holographic entanglement entropy probe on spontaneous symmetry breaking with vector order

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    We study holographic entanglement entropy in 5-dimensional charged black brane geometry obtained from Einstein-SU(2)Yang-Mills theory defined in asymptotically AdS space. This gravity system undergoes second order phase transition near its critical point affected by a spatial component of the Yang-Mills fields, which is normalizable mode of the solution. This is known as phase transition between isotropic and anisotropic phases. We get analytic solutions of holographic entanglement entropies by utilizing the solution of bulk spacetime geometry given in arXiv:1109.4592, where we consider subsystems defined on AdS boundary of which shapes are wide and thin slabs and a cylinder. It turns out that the entanglement entropies near the critical point shows scaling behavior such that for both of the slabs and cylinder, ΔεS(1TTc)β\Delta_\varepsilon S\sim\left(1-\frac{T}{T_c}\right)^\beta and the critical exponent β=1\beta=1, where ΔεSSisoSaniso\Delta_\varepsilon S\equiv S^{iso}-S^{aniso}, and SisoS^{iso} denotes the entanglement entropy in isotropic phase whereas SanisoS^{aniso} denotes that in anisotropic phase. We suggest a quantity O12S1S2O_{12}\equiv S_1-S_2 as a new order parameter near the critical point, where S1S_1 is entanglement entropy when the slab is perpendicular to the direction of the vector order whereas S2S_2 is that when the slab is parallel to the vector order. O12=0O_{12}=0 in isotropic phase but in anisotropic phase, the order parameter becomes non-zero showing the same scaling behavior. Finally, we show that even near the critical point, the first law of entanglement entropy is hold. Especially, we find that the entanglement temperature for the cylinder is Tcy=centa\mathcal T_{cy}=\frac{c_{ent}}{a}, where cent=0.163004±0.000001c_{ent}=0.163004\pm0.000001 and aa is the radius of the cylinder.Comment: 1+29 pages, 4 figure

    Tonicity response element binding protein associated with neuronal cell death in the experimental diabetic retinopathy

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    AIM: To study the contribution of tonicity response element binding protein (TonEBP) in retinal ganglion cell (RGC) death of diabetic retinopathy (DR). METHODS: Diabetes was induced in C57BL/6 mice by five consecutive intraperitoneal injections of 55 mg/kg streptozotocin (STZ). Control mice received vehicle (phosphate -buffered saline). All mice were killed 2mo after injections, and the extent of cell death and the protein expression levels of TonEBP and aldose reductase (AR) were examined. RESULTS: The TonEBP and AR protein levels and the death of RGC were significantly increased in the retinas of diabetic mice compared with controls 2mo after the induction of diabetes. Terminal deoxynucleotidyl transferase (TdT) -mediated dUTP nick end labeling (TUNEL) -positive signals co -localized with TonEBP immunoreactive RGC. These changes were increased in the diabetic retinas compared with controls. CONCLUSION: The present data show that AR and TonEBP are upregulated in the DR and TonEBP may contribute to apoptosis of RGC in the DR.close2

    The Impact of Body Mass Index on Pancreatic Fistula After Pancreaticoduodenectomy in Asian Patients on the Basis of Asia-Pacific Perspective of Body Mass Index

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     Context Several surgical complications are related to obesity. Objective This study evaluated the impact of obesity on pancreatic fistula after pancreaticoduodenectomy. Design We retrospectively reviewed the medical records of 159 patients who underwent pancreaticoduodenectomy between October 2002 and December 2008. Setting The patients were divided according to the body mass index as obese (body mass index equal to, or greater than, 25 kg/m2), or normal (body mass index less than 25 kg/m2). Methods Univariate and multivariate analyses were applied. Two-tailed P values less than 0.05 were considered as significant. Results Forty-six patients (28.9%) were obese and 113 patients (71.1%) were normal-weight. Obese group had a significantly higher incidence of pancreatic fistula and a greater amount of intraoperative blood loss. Other surgical complications were not significantly different between the two groups. Multivariate analysis found obesity, small pancreatic duct size (less than, or equal to, 3 mm), intraoperative blood loss, and combined resection as significant factors affecting pancreatic fistula. Conclusions Obese patients have an increased risk for pancreatic fistula after pancreaticoduodenectomy.

    Flake Orientation in Injection Molding of Pigmented Thermoplastics

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    In the present work, experimental studies are carried out to understand orientation kinematics of pigment flakes during the injection molding process. The injection molding experiments are carried out using ABS resin compounded with aluminum flakes. Thin specimens are sliced off from the injection molded sample, and then the orientation distribution is observed using transmitted microscopy. Generally, the microscopic result shows a sandwich structure where the orientation state near the mid-plane differs significantly from that around the surface. Particularly at the weldline region, locally different orientation is observed near the part surface, which is the result of fountain flow at the melt front. Also the effect of mold temperature on the flake orientation is presented
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