Fuzzy linear model for production optimization of mining systems with multiple entities

Planning and production optimization within multiple mines or several work sites （entities） mining systems by using fuzzy linear programming （LP） was studied. LP is the most commonly used operations research methods in mining engineering. After the introductory review of properties and limitations of applying LP, short reviews of the general settings of deterministic and fuzzy LP models are presented. With the purpose of comparative analysis, the application of both LP models is presented using the example of the Bauxite Basin Niksic with five mines. After the assessment, LP is an efficient mathematical modeling tool in production planning and solving many other single-criteria optimization problems of mining engineering. After the comparison of advantages and deficiencies of both deterministic and fuzzy LP models, the conclusion presents benefits of the fuzzy LP model but is also stating that seeking the optimal plan of production means to accomplish the overall analysis that will encompass the LP model approaches.

Fountain Set Limited Launched New Products of 2011 Autumn-Winter Collections:Eco-friendliness and Multi-category

Fountain Set Limited announced that its branch brand'Fountain Set' was producing 2011 autumn-winter collections on the 2010 Intertextile Shanghai Apparel Fabrics Trade Fair,displaying new products

THE DATA ENVELOPMENT ANALYSIS MODEL WITH INTERSECTION FORM PRODUCTION POSSIBILITY SET

The data envelopment analysis （DEA） model is used to evaluate the relative economic efficiency of a given set of decision making units （DMUs）. In this paper, the DEA production possibility set is transferred from the conventional sum form into the intersection form which is represented by a linear inequality system. Although it is time consuming to obtain the intersection form of the production possibility set, it suggests a new angle to investigate the properties of DMUs and to extend the DEA research further beyond the efficiency measurement. Following the intersection form, the analytical formula of the efficiency indicator and projection is given. Various aspects of technical efficiency, returns to scale and evidence of congestion of the DMUs are studied. The relationship between the weak DEA efficiency and the weak Pareto solution is discussed. Finally, a procedure for DMU grouping is proposed to help the decision makers for better resource reallocation and strategy adjustment.

Evaluating returns to scale and congestion by production possibility set in intersection form

This research proposes a new method to estimate returns to scale(RTS) of decision making units(DM Us) with multiple inputs and outputs.The state of return to scale includes increasing RTS,constant RTS,decreasing RTS and evidence of congestion.The method is based on the production possibility set in the intersection form given by a set of linear inequalities.We propose and prove the necessary and sufficient conditions for the RTS estimation.With the new procedure,to estimate the RTS of a DM U is simply to check the position of the DM U on the production frontiers.We point out that the procedure is particularly important for dealing with a large number of DM U s.Therefore,it can be regarded as a complementary to the data mining.

An algorithm for the anchor points of the PPS of the BCC model

Anchor points play an important role in data envelopment analysis theory and applications;they delineate the efficient part of the production possibility set(PPS)frontier.In this paper,we propose an approach for finding the anchor points of the PPS of the Banker,Charnes and Cooper(BCC)model.This approach is based on a variant of super-efficiency models and their duals.The necessary and sufficient conditions for the characterization of the anchor points are also provided.Finally,the applicability of the proposed model is illustrated with some numerical examples.

On Product-Cordial Index Sets and Friendly Index Sets of 2-Regular Graphs and Generalized Wheels

A vertex labeling f ： V →Z2 of a simple graph G = （V, E） induces two edge labelings The friendly index set and the product-cordial index set of G are defined as the setsf is friendly}. In this paper we study and determine the connection between the friendly index sets and product-cordial index sets of 2-regular graphs and generalized wheel graphs.

Dynamic Concept of Returns to Scales and Its Characteristics on Production Frontier in Intersection Form

This paper gives a dynamic concept and a new non-parametric method for evaluating returns to scale（RTS） of economic units with multiple inputs and outputs.It is frequently noticed that when we increase the input of a decision making unit（DMU） with a certain status of RTS,different status of RTS is observed.For example,when we increase the input of a DMU with constant RTS under the traditional method,a decreasing RTS is often observed instead of the expected constant RTS.We thus define the RTS of each DMU in both input expansion and contraction regions respectively.The research starts from transferring the production possibility set into the intersection form,by giving the explicit linear inequality representation of production frontiers.The RTS structural characteristics of DMUs＇ on the production frontier are described.Status of RTS of those DMUs on the production frontier include increasing RTS,constant RTS,decreasing RTS,saturated RTS and evidence of congestion.Necessary and suficient conditions for RTS evaluation are provided.The definition and evaluation method given here provide more detailed economic characteristics of DMU for policy makers.

Growth in Infinite Groups of Infinite Subsets

Given an infinite group G, we consider the finitely additive invariant measure defined on finite unions of cosets of finite index subgroups. We show that this shares many properties with the size of subsets of a finite group, for instance we can obtain equivalent results on the Ruzsa distance and product free sets. In particular, if G has infinitely many finite index subgroups, then it has subsets S of measure arbitrarily close to 1/2 with square S2 having measure less than 1. We also examine properties of the Ruzsa distance on the set of finite index subgroups of an infinite group, whereupon it becomes a genuine metric.

Optimal Production Functions and Their Homogeneity Superadditive，and Concavity

This paper, firstly, establishes the formula of production possibilities set by using axiomatic method, upon which some optimal production functions are based in different senses of optimization. Finally, this paper proves that the optimal production functions possess homogeneity,superadditive, and concavity.

The Existence of Supporting Prices and Economic Growth under Uncertainty

In our paper we will mainly construct a stochastic model from uncertainty and establish some properties on it.we will next show that the existence of supporting prices and optimal paths,and obtain some results similar to Optimal Growth in which there are the some methods

Analysis of ventilated cavitation around a cylinder vehicle with nature cavitation using a new simulation method

In the present paper, a new simulation method is developed for unsteady cavitating flow with air ventilation,which is very useful for alleviating the pressure oscillation in hydroturbine draft tube and reducing the drag force on an underwater vehicle. Because the fluid includes three components, i.e., the water, vapor, and air, the interactions between water–air and water–vapor are treated by applying the level set method, and the effect of surface tension is taken into account in governing equations. Further, the phase change between the water and the vapor is modeled by a homogeneous model,where the effect of air injection is considered by applying the air volume fraction in the mass transport equation. For calibration, the cavitating flows around a cylinder vehicle were simulated using the proposed method, and the numerical results were compared with the experimental data at three different ventilation conditions. The good agreement of cavitation evolutions between the simulation and the experiment indicated that the proposed method was acceptable for the simulation of ventilated cavitating flows with nature cavitation and would be usable for various engineering applications.Moreover, the vorticity analysis depicts that the vortex is closely related to cavitation evolution, and air injection much changes the vorticity production in cavitating flow. It was also revealed that vorticities only occurred in regions with high vapor/air volume fraction and the vortex stretching term created the most vorticities.

Advanced Geometric Modeler with Hybrid Representation

An advanced geometric modeler GEMS4.0 has been developed, in whichfeature representation is used at the highest level abstraction of a productmodel. Boundary representation is used at the bottom level, while CSG modelis adopted at the median level. A BRep data structure capable of modelingnon-manifold is adopted. NURBS representation is used for all curved surfaces.Quadric surfaces have dual representations consisting of their geometric datasuch as radius, center point, and center tals. Boundary representation of freeform surfaces is easily built by sweeping and skinning method with NURBSgeometry Set operations on curved solids with boundary representation areperformed by an evaluation process consisting of four steps. A file exchangefacility is provided for the conversion between product data described by STEPand product information generated by GEMS4.0