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For globally solving sum of linear ratios problem (SLRP), this paper presents a new branch-and-bound method. In this method, a new linear relaxation technique is proposed firstly; then, the initial problem SLRP is solved by a sequence of linear programming problems. Meanwhile, to improve the convergence speed of our algorithm, two accelerating techniques are presented. The proposed algorithm is proved to be convergent, and some experiments are provided to show its feasibility and efficiency. [ABSTRACT FROM AUTHOR]

In this paper, for solving generalized linear fractional programming (GLFP), a new branch-and-reduce approach is presented. Firstly, an equivalent problem (EP) of GLFP is given; then, a new linear relaxation technique is proposed; finally, the problem EP is reduced to a sequence of linear programming problems by using the new linear relaxation technique. Meanwhile, to improve the convergence speed of our algorithm, two reducing techniques are presented. The proposed algorithm is proved to be convergent, and some experiments are provided to show its feasibility and efficiency. [ABSTRACT FROM AUTHOR]

Hybrid materials integrated with a variety of physical properties, such as spin crossover (SCO) and fluorescence, may show synergetic effects that find applications in many fields. Herein we demonstrate a promising postsynthetic approach to achieve such materials by grafting fluorophores (1-pyrenecarboxaldehyde and Rhodamine B) on one-dimensional SCO FeII structures. The resulting hybrid materials display expected one-step SCO behavior and fluorescent properties, in particular showing a coupling between the transition temperature of SCO and the temperature where the fluorescent intensity reverses. Consequently, synergetic effect between SCO and fluorescence is incorporated into materials despite different fluorophores. This study provides an effective strategy for the design and development of novel magnetic and optical materials. [ABSTRACT FROM AUTHOR]

We consider a branch-and-reduce approach for solving generalized linear multiplicative programming. First, a new lower approximate linearization method is proposed; then, by using this linearization method, the initial nonconvex problem is reduced to a sequence of linear programming problems. Some techniques at improving the overall performance of this algorithm are presented. The proposed algorithm is proved to be convergent, and some experiments are provided to show the feasibility and efficiency of this algorithm. [ABSTRACT FROM AUTHOR]

Abstract: This paper presents an efficient branch and bound algorithm for globally solving sum of geometric fractional functions under geometric constraints, which arise in various practical problems. By using an equivalent transformation and a new linear relaxation technique, a linear relaxation programming problem of the equivalent problem is obtained. The proposed algorithm is convergent to the global optimal solution by means of the subsequent solutions of a series of linear programming problems. Numerical results are reported to show the feasibility of our algorithm. [Copyright &y& Elsevier]

This paper is concerned with an efficient global optimization algorithm for solving a kind of fractional program problem (P), whose objective and constraints functions are all defined as the sum of ratios generalized polynomial functions. The proposed algorithm is a combination of the branch-and-bound search and two reduction operations, based on an equivalent monotonic optimization problem of (P). The proposed reduction operations specially offer a possibility to cut away a large part of the currently investigated region in which the global optimal solution of (P) does not exist, which can be seen as an accelerating device for the solution algorithm of (P). Furthermore, numerical results show that the computational efficiency is improved by using these operations in the number of iterations and the overall execution time of the algorithm, compared with other methods. Additionally, the convergence of the algorithm is presented, and the computational issues that arise in implementing the algorithm are discussed. Preliminary indications are that the algorithm can be expected to provide a practical approach for solving problem (P) provided that the number of variables is not too large. [ABSTRACT FROM AUTHOR]

Toxoplasma gondii is an important intracellular parasite, which can infect endothermic vertebrate animals, including minks (Neovison vison). However, information on T. gondii infection in minks in China is limited. Therefore, we investigated the seroprevalence and risk factors of T. gondii infection in minks in northeastern and eastern China. A total of 1499 mink blood samples were randomly collected from eight cities between March 2014 and January 2015 in northeastern and eastern China, and antibodies to T. gondii were examined using the modified agglutination test. Overall, the seroprevalence of T. gondii infection was 8.14% in the examined minks. The T. gondii seroprevalence was different among cities (ranging from 1.85% in Changchun to 15.75% in Dalian), genders (4.31% in male and 6.22% in female), seasons (spring: 11.64%; summer: 7.34%; autumn: 7.37%; and winter: 7.32%), and ages (young: 5.79%; subadult: 5.03%; and adult: 11.08%). Region and age were considered as risk factors for T. gondii infection. These results provided baseline data for the prevention and control of T. gondii infection in minks in China. [ABSTRACT FROM AUTHOR]