Multi-objective optimization for the multi-mode finance-based project scheduling problem

The finance-based scheduling problem (FBSP) is about scheduling project activities without exceeding a credit line financing limit. The FBSP is extended to consider different execution modes that result in the multi-mode FBSP (MMFBSP). Unfortunately, researchers have abandoned the development of exact models to solve the FBSP and its extensions. Instead, researchers have heavily relied on the use of heuristics and meta-heuristics, which do not guarantee solution optimality. No exact models are available for contractors who look for optimal solutions to the multi-objective MMFBSP. CPLEX, which is an exact solver, has witnessed a significant decrease in its computation time. Moreover, its current version, CPLEX 12.9, solves multi-objective optimization problems. This study presents a mixed-integer linear programming model for the multi-objective MMFBSP. Using CPLEX 12.9, we discuss several techniques that researchers can use to optimize a multi-objective MMFBSP. We test our model by solving several problems from the literature. We also show how to solve multi-objective optimization problems by using CPLEX 12.9 and how computation time increases as problem size increases. The small increase in computation time compared with possible cost savings make exact models a must for practitioners. Moreover, the linear programming-relaxation of the model, which takes seconds, can provide an excellent lower bound.     

Numerical Curve Length Calculation Using Polynomial Interpolation

In this paper we present a method and algorithm for computing curve length approximately using a fixed rule resulting from polynomial interpolation of the points on the curve. The method can applied efficiently calculating digital curves by considering the control points of the interpolation as the pixels centers points. In the paper several examples are presented and the calculated lengths are compared to other methods found in the literature and we have shown progress. We provided MATLAB^® code to simulate the algorithm. The advantage of the proposed method is in the approximation of the digital curve with the continuous curve rather than with piecewise linear sections used by most other methods.     

Design and simulation of single-source single-electron complementary 4-bit multiplexing nano-circuits

The Single-Electron Transistor (SET) and Linear Threshold Gate (LTG) are among the basic functional Single-Electron Nano-Devices (SENDs). In this paper, these basic SENDs are used to design a single-source (SS) single-electron (SE) complementary 4-bit (4–1) multiplexer. This design is compared with the previously reported multiple-source SE complementary 4-bit multiplexer. The first reported SS SE complementary 4-bit demultiplexer is also introduced. The detailed schematic diagrams as well as the corresponding simulation results of the designed SE 4-bit multiplexer/demultiplexer (using SIMON 2.0 and SECS Monte Carlo SE simulators) are illustrated. The simulation results include input, control, and output signals; free energy and stability diagrams; and maximum allowed signal frequency. The estimated delay and energy consumption is calculated and presented.     

Rep-PCR characterization and biochemical selection of lactic acid bacteria isolated from the Delta area of Egypt

Samples of raw milk and traditional dairy products were collected from different rural areas in the Delta region. 170 isolates from these products were identified using repetitive genomic element-PCR (Rep-PCR) fingerprinting. The identified isolates were tested for efficiency of biomass production and separation, acidifying activity, autolytic and aminopeptidase properties, antagonistic activities and exopolysaccharide production. The obtained results revealed that the Lactobacillus delbrueckii subsp. lactis, Lactobacillus fermentum, Enterococcus faecium Lactobacillus delbrueckii subsp. bulgaricus, Lactobacillus paracasei subsp. paracasei, Lactobacillus plantarum and Lactococcus lactis subsp. lactis were the predominant species in Egyptian dairy products. Two percent of Lactococcus, 10% of Lactobacillus and 1% of Enterococcus isolates showed fast acidifying activity. Aminopeptidase and autolytic properties were generally higher for most Lactobacillus strains when compared to other strains. Among these species, lactobacillus paracasei subsp. paracasei was the highest in Aminopeptidase activity and autolytic properties. Antagonistic activity was detected in 40% of Lactococcus, 70% of Lactobacillus and 50% of Enterococcus isolates. Some isolates produced exopolysaccharides in milk and dairy products.     

Nano-Ceramic Coating: A Novel Idea to Reduce Laparoscope Lens Fogging – Experimental Study

Silicon - One of the basic principles of a successful laparoscopic procedure is a clear operating area. The endoscopic lens should be able to visualize the internal organs as clearly as possible....     

A cost-effective approach to synthesize NiFe2O4/MXene heterostructures for enhanced photodegradation performance and anti-bacterial activity

A cost-effective ultrasonication approach was employed to synthesize NiFe₂O₄/MXene heterostructures. The as-synthesized heterostructures demonstrated outstanding photodegradation performance and anti-bacterial activity as compared to individual NiFe₂O₄ (NiFe) or MXene. The NiFe nanoparticles (NPs) helped in effectively preventing the re-stacking of MXene flakes and in increasing the surface area of the heterostructure. The obtained sheet-sheet linkage provided an admirable opportunity for excellent wastewater treatment and antibacterial activity. The photocatalytic degradation of organic pollutants by the introduced photocatalyst NiFe/MXene heterostructures has been observed to be about 4 and 6.72 times boosted compared to MXene and NiFe, respectively. Furthermore, the heterostructure materials demonstrated outstanding anti-bacterial activity against gram negative E-coli bacteria, while the mechanism of methylene blue dye degradation by NiFe/MXene was clarified through kinetic studies of the degradation process. We hope this work will be considered a significant scientific contribution for young researchers dealing with water desalination.     

A randomized algorithm for determining dominating sets in graphs of maximum degree five

The paper is devoted to demonstrating a randomized algorithm for determining a dominating set in a given graph having a maximum degree of five. The algorithm follows the Las Vegas technique. Furthermore, the concept of a 2-separated collection of subsets of vertices in graphs is used. The suggested algorithm is based on a condition of the upper bound of the cardinality of a local dominating set. If the condition is not satisfied, then the algorithm halts with an appropriate message. Otherwise, the algorithm determines the dominating set. The given algorithm is considered a polynomial-time approximation one.     

A hybrid algorithm for the cyclic hoist scheduling problem with two transportation resources

In automated electroplating lines, computer-controlled hoists are used to transfer parts from a processing resource to another one. Products are mounted into carriers and immersed sequentially in a series of tanks following a given sequence.