This paper investigates the problem of selecting and scheduling a set of projects among available projects. Each project consists of several tasks and to perform each one some resource is required. The objective is to maximize total benefit. The paper constructs a mathematical formulation in form of mixed integer linear programming model. Three effective metaheuristics in form of the imperialis...

background: light is an important and adjustable physical factor in the job environment.this study aimed to determine the intensity of natural and mixed light and also the level of ultraviolet radiation in libraries and computer sites of ilam universities in spring 2011.   methods: in this cross-sectional study, 10 libraries, 16 study saloons, and 7 computer sites were selected. luminosity asse...

We present a version of GMI (Gomory mixed-integer) cuts in a way so that they are derived with respect to a “dual form” mixed-integer optimization problem and applied on the standard-form primal side as columns, using the primal simplex algorithm. This follows the general scheme of He and Lee, who did the case of Gomory pure-integer cuts. Our input mixed-integer problem is not in standard form,...

pure anatase titania (tio2), mixed 1.0 wt.% cerium-anatase titania (1.0 wt.%ceo2-tio2), and mixed 1.0 wt.% zirconia-anatase titania (1.0 wt.%zro2-tio2) nano powders were synthesized by co-precipitation method and characterized using x-ray diffraction (xrd), brunauer-emmett-teller (bet) surface area analysis, uv-vis diffuse reflectance spectroscopy (drs), and transmission electron microscope (te...

this study examines technical efficiency in iran's banking system using unbalanced panel data for 17 state and private banks during the 1997-2009 period. therefore, technical efficiency of banks was measured through estimating a translog cost function in the form of a panel sfa error compound model. then, the effect of underlying factors including both individual and structural (ownership/...

With the increasing use of electronics in a wide range of applications, it is imperative to keep the pace of product design high, while maintaining the quality of output. Consumer electronic gadgets continue to see an increased level of innovation as form factors become slimmer; even as multiple features are being packed in the same design. Consumers have come to expect the features seen in mul...

Sucrose thermal degradation is an important reaction in the food industry. When in concentrated and neutral solutions, pure sucrose presents a lag phase in the reaction. This work aimed at: (i) modelling sucrose thermal degradation autocatalytic behaviour and (ii) studying the concentration and temperature effects on kinetic parameters. Isothermal experiments were conducted at temperatures rang...

The waterproofing effect of a number of creams, oils, and greases was examined by measuring water loss from adult skin before and after topical application. Creams had a high water content and were ineffective, oils produced a modest fall in water loss, but paraffin in grease form had a pronounced, sustained waterproofing effect. A paraffin mixture (80% soft, 20% hard paraffin (BP) was then app...