Results 71 to 80 of about 3,117 (262)

Models of linear operators satisfying operator inequalities

, 2020
Tesis doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias Económicas y Empresariales, Departamento de Matemáticas.
openaire   +1 more source

The Power of Unity: Collective Action and Smallholder Agricultural Performance in West Africa

Agribusiness, EarlyView.
ABSTRACT We analyze the impact of collective action through farmer‐based organizations (FBOs) on smallholders' farm performance and income inequality in Ghana, Benin, The Gambia, and Mali. We find that FBO membership increases cereal yield in Ghana and The Gambia, legume yield in Mali, ruminant numbers in Benin and The Gambia, and total farm income in ...
Emmanuel Donkor, Bright Owusu Asante, David Boansi, Victor Owusu   +3 more
wiley   +1 more source

The Role of Certifications in Improving Household Food Security Among Peruvian Farmers

Agribusiness, EarlyView.
ABSTRACT Achieving global food security requires sustainable transformations in agri‐food systems. Voluntary Sustainability Standards (VSS) such as Organic and Fairtrade aim to internalize certain social and environmental costs while promoting more equitable value distribution, improved market access, and sustainable production practices.
Lisa‐Marie Schulte, Awudu Abdulai
wiley   +1 more source

The Uniqueness Theorem of the Solution for a Class of Differential Systems with Coupled Integral Boundary Conditions

Discrete Dynamics in Nature and Society, 2018
We discuss the uniqueness of the solution to a class of differential systems with coupled integral boundary conditions under a Lipschitz condition. Our main method is the linear operator theory and the solvability for a system of inequalities.
Shuman Meng, Yujun Cui
doaj   +1 more source

Trust‐region filter algorithms utilizing Hessian information for gray‐box optimization

AIChE Journal, EarlyView.
Abstract Optimizing industrial processes often involves gray‐box models that couple algebraic glass‐box equations with black‐box components lacking analytic derivatives. Such systems challenge derivative‐based solvers. The classical trust‐region filter (TRF) algorithm provides a robust framework but requires extensive parameter tuning and numerous ...
Gul Hameed, Tao Chen, Antonio del Rio Chanona, Lorenz T. Biegler, Michael Short   +4 more
wiley   +1 more source

A trust‐region funnel algorithm for gray‐box optimization

AIChE Journal, EarlyView.
Abstract Gray‐box optimization, where parts of optimization problems are represented by algebraic models while others are treated as black‐box models lacking analytic derivatives, remains a challenge. Trust‐region (TR) methods provide a robust framework for gray‐box problems through local reduced models (RMs) for black‐box components, but they are ...
Gul Hameed, Tao Chen, Antonio del Rio Chanona, Lorenz T. Biegler, Michael Short   +4 more
wiley   +1 more source

Improving some operator inequalities for positive linear maps

Filomat, 2018
Let 0 < mI ? A ? m'I ? M'I ? B ? MI and p ? 1. Then for every positive unital linear map ?, ?2p(A?tB)?(K(h,2)/41p-1(1+Q(t)(log M'm')2) 2p?2p(A#tB) and ?2p(A?tB)?(K(h,2)/41p-1(1+Q(t)(logM'm')2) 2p(?(A)#t ?(B))2p, where t ? [0,1], h = M/m, K(h,2) = (h+1)2/4h, Q(t) = t2/2(1-t/t)2t and Q(0) = Q(1) = 0. Moreover, we give an improvement for
Yang, Chaojun, Lu, Fangyan
openaire   +3 more sources

Stochastic optimization of Power‐to‐Methanol: Production cost sensitivity to process design vs. scheduling

AIChE Journal, EarlyView.
Abstract Under time‐varying electricity prices, the production costs of Power‐to‐X processes with intermediate storage can be reduced by simultaneously optimizing the process unit design and size with their scheduling and operation. However, the production cost sensitivity to optimal process design or scheduling is unclear, especially when several ...
Simone Mucci, Dominik Bongartz
wiley   +1 more source

Some inequalities in B(H)

International Journal of Mathematics and Mathematical Sciences, 2001
Let H denote a separable Hilbert space and let B(H) be the space of bounded and linear operators from H to H. We define a subspace Δ(A,B) of B(H), and prove two inequalities between the distance to Δ(A,B) of each operator T in B(H), and the value sup ...
C. Duyar, H. Seferoglu
doaj   +1 more source

Graph‐based imitation and reinforcement learning for efficient Benders decomposition

AIChE Journal, EarlyView.
Abstract This work introduces an end‐to‐end graph‐based agent for accelerating the computational efficiency of Benders Decomposition. The agent's policy is parameterized by a graph neural network, which takes as input a bipartite graph representation of the master problem and proposes a candidate solution.
Bernard T. Agyeman, Zhe Li, Ilias Mitrai, Prodromos Daoutidis   +3 more
wiley   +1 more source