On the relationship between stress and elastic strain for porous and fractured rock

Modeling the mechanical deformations of porous and fractured rocks requires a stress–strain relationship. Experience with inherently heterogeneous earth materials suggests that different varieties of Hooke's law should be applied within regions of the rock having significantly different stress–strain behavior. We apply this idea by dividing a rock body conceptually into two distinct parts. The natural strain (volume change divided by rock volume at the current stress state), rather than the engineering strain (volume change divided by the unstressed rock volume), should be used in Hooke's law for accurate modeling of the elastic deformation of that part of the pore volume subject to a relatively large degree of relative deformation (i.e., cracks or fractures). This approach permits the derivation of constitutive relations between stress and a variety of mechanical and/or hydraulic rock properties. We show that the theoretical predictions of this method are generally consistent with empirical expressions (from field data) and also laboratory rock experimental data.     

Evaluation of the criteria and effectiveness of distance e-learning with consistent fuzzy preference relations

The electronic learning (e-learning) has gradually become more and more important in today’s school in Taiwan. Many colleges and universities offer distance e-learning courses or programs for students. An effective teaching or learning through a distance web e-learning system depends on many factors (or criteria). The analytic hierarchy process (AHP) model is suitable for dealing with the multi-criteria problems. This paper utilizes the consistent fuzzy preference relations (CFPR) in AHP model to evaluate these factors. The CFPR is computational simplicity and guarantees the consistence of decision matrices. Rating the criteria is important. An empirical example using CFPR in AHP model to find the weights is presented. The weight can point out which factor is important, especially when the time, manpower, and financial support are limited. The rating results can be directly used to evaluate the distance e-learning effectiveness and can provide teachers and decision-makers in schools important information for improving e-learning practice in the future.     

Goodness-of-fit tests for multi-dimensional copulas:Expanding application to historical drought data

The question of how to choose a copula model that best fits a given dataset is a predominant limitation of the copula approach, and the present study aims to investigate the techniques of goodness-of-fit tests for multi-dimensional copulas. A goodness-of-fit test based on Rosenblatt’s transformation was mathematically expanded from two dimensions to three dimensions and procedures of a bootstrap version of the test were provided. Through stochastic copula simulation, an empirical application of historical drought data at the Lintong Gauge Station shows that the goodness-of-fit tests perform well, revealing that both trivariate Gaussian and Student t copulas are acceptable for modeling the dependence structures of the observed drought duration, severity, and peak. The goodness-of-fit tests for multi-dimensional copulas can provide further support and help a lot in the potential applications of a wider range of copulas to describe the associations of correlated hydrological variables. However, for the application of copulas with the number of dimensions larger than three, more complicated computational efforts as well as exploration and parameterization of corresponding copulas are required.     

Convergence Mergers: A New Competitive Settlement Model from Detroit

The consent agreement involving the merger of DTE and MCN is the first to extend the release capacity concept from interstate pipelines to the level of the local distribution company. The settlement has implications for reintroducing competition between gas and electric local distribution networks where these networks have merged in the past.     

Voltage control integrated in distribution management system

The voltage control in distribution networks is established as a centralized analytical function in this paper. It is integrated in the Distribution Management System. Control devices consist of under-load and off-voltage tap changing transformers, feeder voltage regulators and buck/boost transformers. On the basis of areas whose voltages are influenced by these control devices and their action speeds, the voltage control problem is decomposed in space and time. The space decomposition enables a solution of the distribution voltage control problem for the medium voltage (MV) network of each supply transformer (substation) separately. As well, the time decomposition enables a solution in the operation planning mode and the real time mode separately. The voltage control is each time stated as a constrained optimization problem. The network voltage profile quality is quantified by the damage (inconvenience) that electric consumers sustain due to steady state voltage deviations. Therefore, this damage is used as the optimization objective. The effectiveness of the voltage control is demonstrated on a real-life DN.     

Automated standardization of images of Drosophila embryos

Modeling expression patterns of Drosophila, in space and time, plays a critical role to understand the development of multicellular organisms. In confocal microscopy, to produce precise quantitative data it is frequently necessary to process and analyze large amounts of digital images. Automatic preprocessing is a crucial step in this scenario, essential to standardize significant features such as orientation, size, position, direction, lighting condition and texture of embryo images. Even though a lot of efforts have been made, a robust embryo standardization strategy is still needed. In this paper, we propose the method Embrystandar. It is designed to remove background artifacts and standardize the direction and orientation of a Drosophila embryo through a sequence of automatic operations. To test its potential for large-scale image processing, Embrystandar was applied in different databases. It showed to be robust and precise, reaching more than 90% success rate.     

An improved ant colony optimization algorithm for nonlinear resource-leveling problems

The notion of using a meta-heuristic approach to solve nonlinear resource-leveling problems has been intensively studied in recent years. Premature convergence and poor exploitation are the main obstacles for the heuristic algorithms. Analyzing the characteristics of the project topology network, this paper introduces a directional ant colony optimization (DACO) algorithm for solving nonlinear resource-leveling problems. The DACO algorithm introduced can efficiently improve the convergence rate and the quality of solution for real-project scheduling.     

A method for large group decision-making based on evaluation information provided by participators from multiple groups

Large group decision-making (LGDM) is a special group decision-making (GDM) problem, in which a large number of persons take part in decision process, while research concerning this issue is still relatively scarce. The objective of this paper is to develop a method to solve the LGDM problem, in which a large number of persons from multiple groups take part in the decision process and express their personal evaluations on the alternatives according to the pre-established identifier set. In the method, the percentage distribution on evaluations of each group concerning each alternative is determined. The decision weight of each group concerning each alternative is obtained by aggregating the subjective weight, which is provided by the organizer, and the objective weight, determined according to the level of consensus among participators' evaluations. According to the percentage distributions and decision weights, the dominance degrees on pairwise comparisons of alternatives are calculated, and a ranking of alternatives can be determined using the PROMETHEE II method. Finally, an example is given to illustrate the use of the proposed method.     

Linguistic stochastic dominance to support consensus reaching in group decision making with linguistic distribution assessments

The complexity of linguistic distribution assessments increases the difficulty for the decision makers dealing with them. Recently, stochastic dominance has been varied to be a useful tool to compare two stochastic variables. Inspired by this, in this paper we dedicate to utilizing the stochastic dominance to compare the linguistic distribution assessments and further discuss the consensus reaching issue in GDM with linguistic distribution assessments. First, we introduce three types of individuals’ semantic sensitivity. Based on this, we define the linguistic stochastic dominances respectively under different semantic sensitivity contexts, and then provide several desirable properties. Then, we design a consensus reaching resolution framework based on linguistic stochastic dominance (CRRF-LSD). Finally, a case study is provided to show the application value of the CRRF-LSD, and two comparison analyses are further conducted to show the advantages of the linguistic stochastic dominance and the CRRF-LSD. The comparison results show that the proposed linguistic stochastic dominances method has clear advantages over several classical existing methods in comparing two linguistic distribution assessments. Meanwhile, the comparison results show that only the CRRF-LSD method takes the PIS and semantic sensitivity into account, which is helpful to determine more accurate individual ranking results.     

Bankruptcy to Surplus: Sharing Transboundary River Basin’s Water under Scarcity

In this article a three-stage framework is proposed for allocating water and welfare in transboundary river basins under water scarcity. The proposed allocation framework combines the bargaining theory with resource allocation and bankruptcy games. The water bankrupt Euphrates River was taken as a case study to demonstrate the applicability of the allocation framework. The results showed that the total monetary welfare that can be generated by reallocating the water in order of decreasing water productivity value of each riparian country is greater by 43.43% of total monetary warfare that can be made if each country were to utilize the water allocated to it independently. The proposed allocation framework rewarded Turkey, Syria and Iraq with welfare assignments which are 41.5%, 42.1% and 57.45% greater than what they could have achieved by unilaterally utilizing the water allocated to them. Generally, the proposed water allocation, water reallocation and welfare assignment framework provide some insights for allocating transboundary water in a way which is efficient, fair and sustainable.