396 research outputs found

    Near-linear dynamics in KdV with periodic boundary conditions

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    Near linear evolution in Korteweg de Vries (KdV) equation with periodic boundary conditions is established under the assumption of high frequency initial data. This result is obtained by the method of normal form reduction

    How the design of Complete Streets affects mode choice: Understanding the behavioral responses to the level of traffic stress

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    Following a federal policy statement in 2010 supporting bicycle and pedestrian accommodation in federal-aid transportation projects, many cities across the US have implemented Complete Streets principles and invested in developing better-planned infrastructure that can be safely accessed by a diversity of modes of transportation by all types of users, in a mix of land uses. However, most of the travel demand forecasting models and planning tools used in practice are not sensitive to changes in demand for non-motorized modes such as walking and cycling in response to road infrastructure improvements. Hence, there is a need for models and tools that are capable of evaluating impacts of infrastructure changes that include Complete Streets implementations on the travel behavior, and estimate shifts in mode choices from motorized to non-motorized modes. This paper proposes a specific data collection plan, a multi-modal choice model, and strategies to update traditional trip-based transportation models to forecast rates of non-motorized trips for evaluating Complete Streets plans at a higher level. Concretely, we estimate elasticities to Level of Traffic Stress, which defines the comfort or discomfort experienced by walkers and bikers, segmented by income levels and trip purposes. We then use them to compute the new non-motorized mode shares that would be achieved by improving CS attributes leading to lower levels of traffic stress. The proposed modeling framework has been successfully applied to the Maryland Statewide Transportation Model, producing reliable non-motorized trip rates, and can be extended to other methodological frameworks used by public agenciesThis research was sponsored by the Maryland Department of Transportation State Highway Administration (Project No: MD-21- SHA/UM/5-25, Erdogan et al., 2021), and the Urban Mobility & Equity Center (UMEC), based at Morgan State Universit

    Similarity or Diversity Between Fields? The Case of Charity Markets in Türkiye

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    Neo-Institutional Theory assumes that there is homogeneity within and heterogeneity between organizational fields. However, institutional scholars prioritize in-field comparisons more than they do across organizational fields. Moreover, these comparisons have been made between exchange fields, or between exchange fields and issue fields. In this study, we compared charity markets described as interstitial issue fields based on 13 institutional infrastructure elements embedded within them, derived from the relevant theory and prior research findings. We conducted 44 in-depth interviews with experienced charity market organizers from 10 nonprofit organizations. Furthermore, four days of participant observation were conducted with field notes in each market lasted between 7-10 days. Data were analyzed with a directed content analysis technique adopting a deductive approach. Contrary to the basic premise of the Neo-Institutional Theory, we concluded that organizational fields could be isomorphic, just like organizations. This result is expected to present a new perspective on the theory’s basic assumptions

    Effects of Estrogen Replacement Therapy on Lipid Peroxidation and Antioxidant Enzyme Activities of Ovariectomized and Ovariectomized-Diabetic Rats

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    Menopause and diabetes are conditions producing free radicals independently from each other. Estrogen replacement therapy which widely used in postmenopausal period has beneficial effects because of its antioxidant property. The study groups were as follows: ovariectomy (n=8), ovariectomy+17-östradiol (n=8), ovariectomy+diabetes (n=10) and ovariectomy+diabetes+17-östradiol (n=8). Diabetes was induced by streptozotocin (45 mg/kg i.p.) and the treatment with 17-östradiol (0.1 mg/kg/day) was started a week after ovariectomy. After–week long experimental period aortic and uterine tissues were collected from the animals and the malondialdehyde concentration, glutathione peroxidase and catalase activities were quantified. The treatment did not effect blood glucose concentrations, but increased plasma estradiol concentrations. Increased malondialdehyde concentrations were reduced by the treatment in aorta from diabetics and nondiabetics, but the treatment increased malondialdehyde concentrations in nondiabetic uterine while were reducing in diabetic uterine. The treatment also reduced the increased activities of catalase and glutathione peroxidase in aorta from diabetics and nondiabetics, on the other hand the treatment increased the activities of those enzymes in uterine from diabetics and nondiabetics. Our results suggested that estrogen acts as an antioxidant or prooxidant depending on the tissues

    Archample-Architectural Analysis Approach for Multiple Product Line Engineering

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    The increased size and complexity of software systems has led to the notion of multiple software product lines (MPLs) in which products are composed from subproducts in separate software product lines. Thus, it is important to identify the proper architectural decomposition of the MPL with respect to the stakeholders' concerns before large organizational resources are committed to the development. Designing MPL architectures is challenging due to the higher level of abstraction and the integration of different product lines. Different architecture analysis approaches have been introduced, but none of these focuses on the evaluation of MPL architectures. We propose the architecture analysis approach for MPL Engineering (Archample), which has been particularly defined for the analysis of MPL architectures. Archample also introduces architectural viewpoints for modeling and documenting MPL and likewise supporting the analysis of the decomposition of an MPL architecture. The approach has been designed and validated within a real industrial context of Aselsan REHI˙S Group (Aselsan REHI˙S), a leading high-technology company in defense systems development in Turkey. © 2014 Elsevier Inc. All rights reserved
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