493 research outputs found

    A Redesigned Benders Decomposition Approach for Large-Scale In-Transit Freight Consolidation Operations

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    The growth in online shopping and third party logistics has caused a revival of interest in finding optimal solutions to the large scale in-transit freight consolidation problem. Given the shipment date, size, origin, destination, and due dates of multiple shipments distributed over space and time, the problem requires determining when to consolidate some of these shipments into one shipment at an intermediate consolidation point so as to minimize shipping costs while satisfying the due date constraints. In this paper, we develop a mixed-integer programming formulation for a multi-period freight consolidation problem that involves multiple products, suppliers, and potential consolidation points. Benders decomposition is then used to replace a large number of integer freight-consolidation variables by a small number of continuous variables that reduces the size of the problem without impacting optimality. Our results show that Benders decomposition provides a significant scale-up in the performance of the solver. We demonstrate our approach using a large-scale case with more than 27.5 million variables and 9.2 million constraints

    Effect of repetitive education on cognitive-social factors among type 2 diabetic patients

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    Background: Psychological, cognitive and social factors are also effective in helping the diabetes patient show behavioral changes in terms of the treatment process. The purpose of this study was to examine the effect of repetitive education on cognitive-social factors and metabolic control variables among patients with type 2 diabetes (T2DM).Methods: The study was conducted with one group using the same test at pre-determined times.  62 outpatients with T2DM were recruited for this study. The data was collected using a Patient Information Form that was prepared by the researchers, the Turkish multidimensional diabetes questionnaire, and the metabolic control follow-up form. The data was analyzed using SPSS 19 and descriptive statistics (Kolmogorov-Smirnov Test, Paired t Test, and Wilcoxon Signed-Rank Test).Results: While there was a statistically significant difference between the mean scores of interference, severity, positive reinforcing behaviors, outcome expectancies before and after the diabetes education (p˂0.05), a statistically significant difference was not found between mean values of fasting and random plasma glucose, HbA1C, HDL, LDL, triglyceride, waist circumference and body mass index (p˃0.05).Conclusions: Repetitive diabetes education provided to patients with T2DM positively affected other cognitive-social factors except for social support and self-efficacy, but did not affect metabolic control variables except for blood pressure

    Strain engineered graphene using a nanostructured substrate: I Deformations

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    Using atomistic simulations we investigate the morphological properties of graphene deposited on top of a nanostructured substrate. Sinusoidally corrugated surfaces, steps, elongated trenches, one dimensional and cubic barriers, spherical bubbles, Gaussian bump and Gaussian depression are considered as support structures for graphene. The graphene-substrate interaction is governed by van der Waals forces and the profile of the graphene layer is determined by minimizing the energy using molecular dynamics simulations. Based on the obtained optimum configurations, we found that: (i) for graphene placed over sinusoidally corrugated substrates with corrugation wave lengths longer than 2\,nm, the graphene sheet follows the substrate pattern while for supported graphene it is always suspended across the peaks of the substrate, (ii) the conformation of graphene to the substrate topography is enhanced when increasing the energy parameter in the van der Waals model, (iii) the adhesion of graphene into the trenches depends on the width of the trench and on graphene's orientation, i.e. in contrast to a small width (3 nm) nanoribbon with armchair edges, the one with zig-zag edges follows the substrate profile, (iv) atomic scale graphene follows a Gaussian bump substrate but not the substrate with a Gaussian depression, and (v) the adhesion energy due to van der Waals interaction varies in the range [0.1-0.4] J/m^2.Comment: 12 pages and 16 figures, To appear in Phys. Rev.

    Determination of the lowest energy structure of Ag8_8 from first-principles calculations

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    The ground-state electronic and structural properties, and the electronic excitations of the lowest energy isomers of the Ag8_8 cluster are calculated using density functional theory (DFT) and time-dependent DFT (TDDFT) in real time and real space scheme, respectively. The optical spectra provided by TDDFT predict that the D2d_{2d} dodecahedron isomer is the structural minimum of Ag8_8 cluster. Indeed, it is borne out by the experimental findings.Comment: 4 pages, 2 figures. Accepted in Physical Review A as a brief repor

    Graphical Evaluation of the Ridge-Type Robust Regression Estimators in Mixture Experiments

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    In mixture experiments, estimation of the parameters is generally based on ordinary least squares (OLS). However, in the presence of multicollinearity and outliers, OLS can result in very poor estimates. In this case, effects due to the combined outlier-multicollinearity problem can be reduced to certain extent by using alternative approaches. One of these approaches is to use biased-robust regression techniques for the estimation of parameters. In this paper, we evaluate various ridge-type robust estimators in the cases where there are multicollinearity and outliers during the analysis of mixture experiments. Also, for selection of biasing parameter, we use fraction of design space plots for evaluating the effect of the ridge-type robust estimators with respect to the scaled mean squared error of prediction. The suggested graphical approach is illustrated on Hald cement data set

    A rare cause of inguinal mass in a female child: Hydrocele or cyst of the canal of Nuck

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    The canal of Nuck is a different type of a patent processus vaginalis in females. It loses its communication between peritoneal cavity within the first year of the life. It presents as an inguinal mass in female. Sometimes it may present as incarcerated inguinal hernia and necessitates emergency exploration. It can be diagnosed on the operating table at the time of suspected incarcerated inguinal hernia

    The effects of Juglone-Selenium combination on invasion and metastasis in pancreatic cancer cell lines

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    Background: Pancreatic cancer does not show any symptoms in the early period and metastatic process is already passed when the diagnosis is done. Therefore, in the battle with pancreatic cancer, novel treatment strategies, particularly antiinvasive and antimetastatic strategies, are needed. The cytotoxic and anticancer effects of juglone and sodium selenite (NaSe) have been showed in various cancer cells. Objectives: In this study, it is aimed to investigate the synergistic effects of juglone and selenium on PANC-1 and BxPC-3 pancreatic cancer cells. Methods: Antimetastatic effects of juglone-NaSe were carried out by adhesion and invasion assays and the genes and protein expressions. Expression analysis of the CDH1, ITGB3 and COL4A3 genes and their proteins E-cadherin, β3 integrin and tumstatin which play role in metastasis and angiogenesis processes, were done by qPCR and immunohistochemical analysis, respectively. Results: Study findings have provided evidences that the juglone-selenium has a cytotoxic and dose dependent suppressive effect on invasion and metastasis in PANC-1 and BxPC-3 cells. Conclusion: The juglone-NaSe has the potential to be a promising agent especially to inhibit invasion and metastasis in pancreatic cancer treatment. However, more in depth studies are needed to more clearly demonstrate the effects of juglone-selenium. Keywords: Pancreatic cancer cell lines; juglone-selenium; invasion; metastasis
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