3,629 research outputs found

    Identifikasi Potensi Penumpang Moda Pesawat Terbang Rute Bandar Lampung – Jogjakarta Dan Solo

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    Movement pattern that done by the resident of Lampung Province to Central Java Province likeSolo and Yogyakarta such as by using direct bus from Lampung to Yogyakarta-Solo, using bus toJakarta and then continued by plane, and using plane from Lampung to Jakarta and thencontinued by plane again. The purpose of this research are knowing about the passengerscharacteristics, so we can identify the factors that influence passengers in choosing the kind oftransportation and to know the passenger\u27s potency that using plane from Lampung Province toYogyakarta-Solo.From surveys that have been done, the opinion of responders about new plan route of plane fromLampung to Yogyakarta-Solo are 93,79 % of the responders that using bus agree and 6,21 %disagree, otherwise opinion of responders that do movement pattern by using bus and thencontinued by plane, and also movement pattern fully by plane express 100% agreement. Factorswhich influence the election of transportation from the responders are cost for the bus ( 43,79%), comfortable for the movement pattern by using bus continued by plane ( 65 %), and time tripfor the movement pattern by using plane continued by plane ( 82,05 %)

    The time-dependent vehicle routing problem with soft time windows and stochastic travel times

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    This paper studies a vehicle routing problem with time-dependent and stochastic travel times. In our problem setting, customers have soft time windows. A mathematical model is used in which both efficiency for service as well as reliability for customers are taken into account. Depending on whether service times are included or not, we consider two versions of this problem. Two metaheuristics are built: a Tabu Search and an Adaptive Large Neighborhood Search. We carry out our experiments for well-known problem instances and perform comprehensive analyses on the numerical results in terms of the computational time and the solution quality. Experiments confirm that the proposed procedure is effective to obtain very good solutions to be performed in real-life environment

    Consumer credit in comparative perspective

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    We review the literature in sociology and related fields on the fast global growth of consumer credit and debt and the possible explanations for this expansion. We describe the ways people interact with the strongly segmented consumer credit system around the world—more specifically, the way they access credit and the way they are held accountable for their debt. We then report on research on two areas in which consumer credit is consequential: its effects on social relations and on physical and mental health. Throughout the article, we point out national variations and discuss explanations for these differences. We conclude with a brief discussion of the future tasks and challenges of comparative research on consumer credit.Accepted manuscrip

    Vehicle routing with soft time windows and stochastic travel times : a column generation and branch-and-price solution approach

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    We study a vehicle routing problem with soft time windows and stochastic travel times. In this problem, we consider stochastic travel times to obtain routes which are both efficient and reliable. In our problem setting, soft time windows allow early and late servicing at customers by incurring some penalty costs. The objective is to minimize the sum of transportation costs and service costs. Transportation costs result from three elements which are the total distance traveled, the number of vehicles used and the total expected overtime of the drivers. Service costs are incurred for early and late arrivals; these correspond to time-window violations at the customers. We apply a column generation procedure to solve this problem. The master problem can be modeled as a classical set partitioning problem. The pricing subproblem, for each vehicle, corresponds to an elementary shortest path problem with resource constraints. To generate an integer solution, we embed our column generation procedure within a branch-and-price method. Computational results obtained by experimenting with well-known problem instances are reported

    Numerical ordinality in a wild nectarivore

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    This work was supported by the Association for the Study of Animal Behaviour (S.D.H.), the University of Lethbridge, and the Natural Sciences and Engineering Research Council of Canada (RGPIN 121496-2003; T.A.H.)Ordinality is a numerical property that nectarivores may use to remember the specific order in which to visit a sequence of flowers, a foraging strategy also known as traplining. In this experiment, we tested whether wild, free-living rufous hummingbirds (Selasphorus rufus) could use ordinality to visit a rewarded flower. Birds were presented with a series of linear arrays of 10 artificial flowers; only one flower in each array was rewarded with sucrose solution. During training, birds learned to locate the correct flower independent of absolute spatial location. The birds' accuracy was independent of the rewarded ordinal position (1st, 2nd, 3rd or 4th), which suggests that they used an object-indexing mechanism of numerical processing, rather than a magnitude-based system. When distance cues between flowers were made irrelevant during test trials, birds could still locate the correct flower. The distribution of errors during both training and testing indicates that the birds may have used a so-called working up strategy to locate the correct ordinal position. These results provide the first demonstration of numerical ordinal abilities in a wild vertebrate and suggest that such abilities could be used during foraging in the wild.PostprintPeer reviewe

    Subclinical immune reactions to viral infections may correlate with child and adolescent diagnosis of attention-deficit/hyperactivity disorder: A preliminary study from Turkey

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    Background: Attention-Deficit/Hyperactivity Disorder (ADHD) is one of the most common neuro-developmental disorders of childhood and  adolescence. Studies focusing on the relationship of infectious agents and ADHD are scarce. It is also known that cerebellar injury may lead to  hyperactive behavior. This study aimed to evaluate the relationship  between viral agents of cerebellitis and the diagnosis of ADHD.Methods: The study group was formed of 60 consecutive ADHD patients and 30 healthy children. IgG levels for VZV; HSV-1, CMV, Measles, Mumps, Rubella and EBV were evaluated.Results: Males were significantly higher among patients with ADHD (65% vs. 40%, p=0.025). Patients with ADHD displayed significantly higher positivity for measles IgG (80% vs. 60%, p=0.044). When patients with ADHD were classified according to their pubertal status, adolescents with ADHD displayed higher positivity for mumps (100% vs. 74.4%, p=0.043). Most of the patients were diagnosed with ADHD-Combined or  Hyperactive/Impulsive Subtypes (56.6%) while 43.3% were diagnosed with ADHD-predominantly inattentive type. When patients with subtypes of ADHD were compared in terms of seropositivity, it was found that patients with ADHD-Combined/ Hyperactive-Impulsive subtypes had significantly elevated reactions for Rubella (100% vs. 88.5%, p=0.044).Conclusion: Although limited to a single center and may be prone to sampling biases, our results may support the notion that immune reactions may be related with ADHD among children and adolescents. Further,  prospective studies from multiple centers are needed to support our  findings and establish causality.Key words: ADHD, infection, immunology, measles, rubella, mumps, Ig

    Broadband and Wide-Angle Invisibility with PT-Symmetric 2D-Weyl Semimetal

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    Inspired by the magnificent features of two-dimensional (2D) materials which aroused much of the interest in recent materials science research, we study PT-symmetric 2D Weyl semimetal (WSM) to reveal the broadband and wide-angle invisible configurations in a PT-symmetric optical slab system. Desired unidirectional reflectionlessness and invisibility phenomena is obtained by the optimal control of system parameters. We unravel the mystery of broadband and wide-angle invisibility in regular slab materials with finite refractive indices by means of the plenary expressions. We show that materials whose refractive indices relatively small (usually around η=1\eta =1) give rise to quite a lot broadband and wide-angle (almost all incidence angles) invisible configurations. This is not observed with any 2D material other than 2D WSMs. Our findings suggest a concrete expedience to experimental realizations in this direction.Comment: 8 pages, 11 figure
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