Given a mixed graph G with vertex set V, let E and A denote the sets of edges and arcs, respectively. We use Q+ and Z+ to denote the sets of positive rational numbers and positive integers, respectively. For any connected mixed graph G=(V,E∪A;w;l,u) with a length function w:E∪A→Q+ and two...

Risk aggregation considering inter-risk dependence has always been a challenge to both researchers and practitioners. The objective of this study is to formulate ways of aggregation of bank risks and comprehensively compare simple summation, variance–covariance and copula approach. Firstly,...

Sovereign Wealth Funds (SWFs) are state-owned investment funds that invest in real and financial assets. Since the global financial crisis in 2008, SWFs' investments have resulted in national security concerns of host countries because SWFs continue to expand rapidly and have become increasingly...

External oil supply risk is an important aspect of energy security and oil import diversification is viewed as one of the most effective measures to reduce supply risk. By using the diversification index approach, this research attempts to assess external oil supply risks of oil importers with...

The probability of two nodes to be linked is related to their similarities in the network. Based on statistical inference, a network-structure similarity index, therefore, is proposed to find the potential links. This index quantifies the effects of the node communities on these links. And an...

We consider the offline scheduling problem to minimize the makespan on m parallel and identical machines with certain features. Each job and machine are labeled with the grade of service (GoS) levels, and each job can only be executed on the machine whose GoS level is no more than that of the...

We consider a new problem of constructing some required structures in digraphs, where all arcs installed in such required structures are supposed to be cut from some pieces of a specific material of length L. Formally, we consider the model: a digraph D=(V, A; w), a structure S and a specific...

The tanker shipping market has been treated as the key extension of the world oil market and inevitably, its uncertainty is correlated to volatility of the oil market, besides supply and demand factors. Therefore, for improving operational management and budget planning decisions, it is...

In this paper, a novel hybrid ensemble learning paradigm integrating ensemble empirical mode decomposition (EEMD) and least squares support vector regression (LSSVR) is proposed for nuclear energy consumption forecasting, based on the principle of “decomposition and ensemble”. This hybrid...

Given n terminals in the Euclidean plane and a positive constant l, find a Steiner tree T interconnecting all terminals with the minimum total cost of Steiner points and a specific material used to construct all edges in T such that the Euclidean length of each edge in T is no more than l. In...