The capacity formulation of the capacitated edge activation problem

Networks ◽  
2017 ◽  
Vol 71 (4) ◽  
pp. 381-402 ◽  
Author(s):  
Sara Mattia
Keyword(s):  
2020 ◽  
Vol 4 ◽  
Author(s):  
Adam Calo

This special issue aims to develop how Diversified Farming Systems (DFS) may contribute to adaptive capacity in order to confer resilience to agricultural systems. In this perspective article, I argue that a framework for DFS and adaptive capacity must adequately contend with the role of farmland tenure on the shape of food systems to be both internally coherent and socially redistributive. Yet, both DFS and adaptive capacity scholarship deemphasize or mischaracterize the role of farmland tenure in favor of ecosystem dynamics. In this paper, I bring together lessons from the agrarian change literature and established critiques of resilience thinking to demonstrate core problems with a framework aimed at linking DFS to adaptive capacity without adequately addressing the role of farmland tenure. Namely, applying resilience thinking as a framework to understand food systems change prioritizes concern over final “states” or processes of farming systems and may ignore who has the power to adapt or who derives benefits from adaptation. The critiques of resilience thinking inform that the result of this apolitical elision is (1) entrenchment of neoliberal logics that place responsibility to cultivate adaptation on individual farmers and (2) provisioning of legitimacy for land tenure systems that can most readily adopt DFS, without understanding how well these systems distribute public benefits. Resilience reformers call for ways to include more power aware analysis when applying resilience thinking to complex socio-technical systems. I suggest that centering the role of land tenure into the frameworks of DFS and adaptive capacity provides a lens to observe the power relations that mediate any benefits of agricultural diversification. Integrating analysis of the social and legal structures of the food system into the DFS for adaptive capacity formulation is a crucial step to transforming resilience thinking from an apolitical tool to transformative and power-aware applied science.


2010 ◽  
Vol 02 (03) ◽  
pp. 617-633 ◽  
Author(s):  
SUSHIL KUMAR ◽  
V. K. KATIYAR

Biological tissues can be treated as porous media as it is composed of dispersed cell separated by connective voids which allow flow of nutrients, minerals, etc., to reach all cells within the tissue. In this present study, a mathematical model has been developed to study the phase change phenomena during the freezing and thawing process in biological tissues using porous media approach. Effective heat capacity formulation is used for the phase change problem. Numerical simulation is used to study the effect of porosity, on the motion of freezing and thawing front and transient temperature distribution in tissue. It is observed that porosity has significant effect on transient temp profile and phase change interfaces; further decrease in freezing and heating rate has been found with increased value of porosity.


2020 ◽  
Vol 80 (ET.2020) ◽  
pp. 1-17
Author(s):  
Raffaele Mauro

The determination of efficiency measures, under a known traffic demand, is a central aspect of roundabouts analysis. Many capacity formulations have been available for some time in different countries relating to different roundabout layouts. This paper refers to fifteen roundabout entry capacity models used above all in the European countries, highlighting their input requirements and their algorithm complexity. The formulations reviewed are then compared referring to a test roundabout, with a simple and widespread layout. Monte Carlo simulation have been performed considering 5,000 traffic distribution matrices for each capacity model. The results obtained are critically assessed resorting to the calculation of roundabout total capacity. The probability distributions of total capacity allow finding a model that stands out among all as an advisable choice for a suitable capacity formulation, acting as a synthesis of all those examined. This can be of considerable use in view of practical applications, for the design of efficient and safe roundabout intersections in situations in which a country-specific capacity formulation is not available.


Entropy ◽  
2020 ◽  
Vol 22 (8) ◽  
pp. 899
Author(s):  
Yu Chen ◽  
Iman Tavakkolnia ◽  
Alex Alvarado ◽  
Majid Safari

The capacity limits of fiber-optic communication systems in the nonlinear regime are not yet well understood. In this paper, we study the capacity of amplitude modulated first-order soliton transmission, defined as the maximum of the so-called time-scaled mutual information. Such definition allows us to directly incorporate the dependence of soliton pulse width to its amplitude into capacity formulation. The commonly used memoryless channel model based on noncentral chi-squared distribution is initially considered. Applying a variance normalizing transform, this channel is approximated by a unit-variance additive white Gaussian noise (AWGN) model. Based on a numerical capacity analysis of the approximated AWGN channel, a general form of capacity-approaching input distributions is determined. These optimal distributions are discrete comprising a mass point at zero (off symbol) and a finite number of mass points almost uniformly distributed away from zero. Using this general form of input distributions, a novel closed-form approximation of the capacity is determined showing a good match to numerical results. Finally, mismatch capacity bounds are developed based on split-step simulations of the nonlinear Schro¨dinger equation considering both single soliton and soliton sequence transmissions. This relaxes the initial assumption of memoryless channel to show the impact of both inter-soliton interaction and Gordon–Haus effects. Our results show that the inter-soliton interaction effect becomes increasingly significant at higher soliton amplitudes and would be the dominant impairment compared to the timing jitter induced by the Gordon–Haus effect.


Author(s):  
Ha˚vard Nyseth ◽  
Gabriel Holtsmark

The response of plates subjected to patch loads with length/ height less than the dimensions of the plate field is of importance for the design of hulls strengthened for operation in ice covered waters and other comparable types of loading. An analytical plastic capacity formulation for plates subjected to patch loading of any rectangular geometry configuration has been derived, which from comparison with nonlinear finite element analysis is seen implicitly to limit the permanent deflection to be up to 0,40% of the frame spacing. The analytically derived formulations for the plastic bending based load capacity are based on yield line theory. Expressions for single and multiple patch loads are included, where the derivation is based on the assumption that the response for a single patch load is equal to the response from a sequence of identical patch loads located within the same plate field, and spaced a certain minimum distance apart. The expressions may serve as basis for rule requirements for plates subject to ice loads and other types of patch loads. For the considered longitudinally and transversely stiffened plate cases, nonlinear FE calculations show that the proposed plate bending based load capacity formulations generally give rise to permanent deformations in the plate up to 0.40% of the frame spacing, when the plate model analyzed is extended to include adjacent plate fields. Comparisons of nonlinear FE calculations show the pressure-deformation relationship of the single and repeated load patch to be the same within the range of permanent deformations considered. Comparison of the analytically derived plate formula with DNV Arctic Rules and Finnish-Swedish Ice Class Rules (FSICR) indicates that the plate formula of the DNV/FSICR gives similar results for the same load levels. The analytically derived formula, however, provides a more consistent utilization of the plate bending based capacity that is valid for a wider range of patch load geometries. Comparison of the IACS Polar Class (PC) Rules formulation indicates that the IACS plate formulation is increasingly non-conservative for small patch lengths, and that the application should be restricted to cover larger patch lengths only, e.g. l/s > 1,0.


2003 ◽  
Vol 21 (1) ◽  
pp. 25-46 ◽  
Author(s):  
Dipankor Coondoo ◽  
Amita Majumder ◽  
Robin Mukherjee ◽  
Chiranjib Neogi

Abstract In a federal form of government structure, the state-level governments generally receive supplementary budgetary resources from the central/federal government as support for the formers’ public expenditure activities. Such devolution of funds from the centre to the states takes the form of share of the revenue raised by central taxes and grants-in-aid. It is felt that such resource transfers should be made according to a policy based on the criteria of equity and efficiency. Formally, these criteria are defined with reference to individual state’s tax revenue collection relative to its taxable capacity. Formulation of a concrete transfer policy, however, crucially requires measures of individual state’s taxable capacity. Given an appropriate definition of a state’s taxable capacity, measurement of taxable capacity of states involves both conceptual and econometric issues. This paper proposes an econometric approach to the measurement of taxable capacity, which is similar to estimating a frontier production function using panel data. To illustrate the proposed method, it is applied to the panel data on annual state tax revenue and related variables of some selected Indian states for the period 1986-87 to 1996-97 and the relative taxable capacity and tax efforts of the states are compared.


2019 ◽  
Vol 184 ◽  
pp. 186-193 ◽  
Author(s):  
Luisa María Gil-Martín ◽  
Enrique Hernández-Montes
Keyword(s):  

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