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Comparing Genetic Algorithms and Simulated Annealing for Solving the Pickup and Delivery Problem with Time Windows
No full textSolving the Vehicle Routing Problem (VRP) and its related variants is significant for optimizing logistic planning. One important variant of the VRP is the Pickup and Delivery Problem with Time Windows (PDPTW), where it is assumed that a client may request one of two service types, a pickup or a delivery. It is required to find a set of minimum cost routes for a fleet of vehicles, while observing a number of predefined constraints. In this research, we try to handle the difficult constraints using a new solution representation and simple neighborhood moves that will maintain the feasibility of solutions throughout the search. Our solution method is tried within two meta-heuristic approaches, a Genetic Algorithm and a Simulated Annealing. Based on the performance of the two algorithms on a number of benchmark problems, we draw conclusions about which among the two algorithms seems more appropriate for solving the problem.The Berkeley Initiative in Soft Computin
Ensemble Classifiers for Dynamic Signature Authentication
No full textRapid advances in technology, that made almost everything goes digital have entailed a persistent need for a stronger means of information security. Furthermore, new advanced devices are now available to capture the dynamic of a person’s signature. Therefore, the reliance on the dynamic signature for authenticating entities in secure system became crucial. In this paper, we investigate the problem of dynamic signature verification and recognition using Ensemble of Classifiers, where we used multiple Fisher based probabilistic neural networks as the component classifiers to construct the Ensemble. Two key issues are studied; the first issue is how to construct the Ensemble. The second issue is how to combine the predictions of the component classifiers in order to accomplish the decision-making process. Data sets from SVC dataset have been used to assess the performance of the proposed ensemble of classifiers. Obtained results are very encouraging and show the ability of ensemble classifiers to deal with the tackled problem.King Saud Universit
Optimal grade transition control for liquid-propylene polymerization reactor
No full textA nonlinear control system integrating an off-line optimizer and a nonlinear model-based controller is developed to perform optimal grade transition operations in a continuous pilot plant reactor. A simple black-box model is developed and used to determine optimal trajectories of inputs and outputs for a series of three polypropylene grades. The simplified model is also used to develop a nonlinear controller. This controller is similar to generic model control; however, the integral action is omitted and an on-line updating scheme is incorporated to update pre-specified model parameters using delayed process measurements. The time optimal inputs, which are calculated by the off-line optimizer, are introduced to the plant in a feed forward manner. At the same time, the deviations from the optimal output are corrected using the feedback nonlinear controller. The simulations on a complex mechanistic model of the process reveal that the nonlinear control scheme performs well for both set point tracking and disturbance rejection. This paper integrates well-known methodologies, such as the generic-model control algorithm, parameter update schemes, and off-line optimization, together to develop an applicable and robust control technique for continuous polymerization reactors. © 2010 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
Isolation and Characterization of Thielaviopsis paradoxa L-alanine Dehydrogenase
No full textAlanine dehydrogenase has not yet been purified from any fungal sources. The aims of this study was to isolate alanine dehydrogenase from Thielauiopsis paradoxa. The biochemical kinetic properties of the enzyme like Km, Vmax, optimum Temperature and pH were also determined. In this study, effect of certain inhibitors on the enzyme was tested. Alanine dehydrogenase (EC 1.4.1.1), an enzyme that catalyzes the reversible deamination of L-alanine in the presence of NAD+, was extracted and characterized from Thielauiopsis paradoxa, a pathogenic fungi for the date palm (Phoenix dactylifera). The enzyme showed maximal activity at pH 9.5 for the deamination of L-alanine and at pH 8.5 for the amination of pyruvate. It was active in the presence of both NAD+ and NADP+ as coenzymes for the deamination of L-alanine. In addition, the enzyme was not absolutely specific to L-alanine as a substrate in the deamination of L-alanine. L-alanine dehydrogenase had Km value for L-alanine (1.35 mM), for NAD+ 0.274 mM, NADH (0.197 mM), pyruvate (8.16 mM) and ammonia (33.5 mM). It was inhibited by Zn2+, CO" and by iodoacetate. Activation by using reduced glutathione and DTT are suggestive of sulfhydryl group participation in enzyme activity.King Saud Universit
Relationship between chronic lead toxicity and plasma neurotransmitters in autistic patients from Saudi Arabia.
No full textOBJECTIVE:
This study aims to clarify the relationship between blood Pb(2+) concentration as a ubiquitous environmental pollutant and plasma neurotransmitters as biochemical parameters that reflect brain function in Saudi autistic patients.
METHODS:
RBC's lead content together with plasma concentration of gamma aminobutyric acid (GABA), serotonin (5HT) and dopamine (DA) were measured in 25 Saudi autistic patients and compared to 16 age-matching control samples.
RESULTS:
The obtained data recorded that Saudi autistic patients have a remarkable higher levels of Pb(2+) and significantly elevated levels of GABA, 5HT and DA compared to healthy subjects. ROC analysis revealed satisfactory values of specificity and sensitivity of the measured parameters.
CONCLUSION:
This study suggests that postnatal lead toxicity in autistic patients of Saudi Arabia could represent a causative factor in the pathogenesis of autism. Elevated GABA, 5HT and DA were discussed in relation to the chronic lead toxicity recorded in the investigated autistic samples.Autism research and treatment center; Al-Amoud
Synthesis and X-ray structure of an octahedral platinum–silver cluster [(Ph3P)2N]2[Pt2Ag4Cl2(C2Ph)8] with disordered silver atoms
No full textVariable-temperature X-ray structural study of the complex [(Ph3P)2N]2[Pt2Ag4Cl2(C2Ph)8] prepared by the reaction of cis-[PtCl2(AsPh3)2] and [(Ph3P)2N][Ag(C2Ph)2] in 1:2 M ratio, revealed isolated (non-polymerised) [Pt2Ag4Cl2(C CPh)8]2− anions with a pseudo-octahedral arrangement of metal atoms. The Pt atoms (in mutually trans vertices) are each σ-bonded to four alkynyl ligands in a square planar arrangement; these moieties are bridged by four Ag atoms; each silver atom being η2-bonded to two alkynyl groups. Chloride ligands are asymmetrically bridging two opposite Ag–Ag edges. Silver atoms show strong and unusual temperature-dependent disorder
Phytochemical and biological studies of Sisymbrium irio L.Growing in Saudi Arabia
No full textTen flavonoids were isolated for the first time from the aerial parts of Sisymbrium irio L. grown in Saudia Arabia, using chromatographic methods, and identified as apigenin, apigenin-7-galactoside, apigenin-7-O-β-D-glucoside, luteolin-7-O-glucoside, apigenin-7-di-glucoside 5, apigenin-7-O-(6″acetyl) glucoside, apigenin-7-O-gluco(6″-1″′) rhamnoside, apigenin-7-O-gluco(6″-1″′)rhamnoside-5-methoxide, kampferol and kampferol-3-xyloside-7-galactoside. The median lethal dose of the extract was determined in mice and found to be greater than 5000 mg/kg body weight, suggesting that this plant is non-toxic. Antioxidant activities were assessed for all extracts and fractions (total, ether, chloroform, ethyl acetate and butanol) and isolated compounds, and showed variable antioxidant activity, with apigenin-7-O-galactoside being the most potent.Scientific
Research at King Saud University for the work through
the research group project NO RGP-VPP-060
The Effect of Four Coffee types on Normotensive rats and Normal/Hypertensive Human Volunteers
No full textCoffee is acommonly consumed beverage. The purpose of this study was to determine the four Coffee types on blood pressure (bp) .KS
Biochemical and molecular characterization of Haemophilus influenza isolated from Riyadh, Kingdom of Saudi Arabia
No full textThe objective of this study focused on the prevalence of Haemophilus influenza to confirm the colonies of H. influenza on the basis of their growth requirements and serotype distribution. This study prepared 80 isolates of H. influenze isolated from five different sources (eye, ear, sputum (SP), lower genital tract (TA), and nasopharyngeal (NPA)) with different ages for infants and elderly persons. The phenotypic characteristics, which included the biotype, serotype, antibiogram and β-lactamase production, were applied by using APINH and minimum inhibitory concentration (MIC). Also, the study focused on the identification of selected serotype using PFGE analysis. The discussion of this study differentiates the age groups occurrence in the isolates, alongside with non-typeable strain versus the typeable ones and their percentages in the sample of isolates. This clustering of most strains in on e PFGE pattern might be explained with the colonel population structure of the encapsulated H. influenza
Design, synthesis, and biological evaluation of substituted hydrazone and pyrazole derivatives as selective COX
No full textNew arylhydrazone derivatives and a series of 1,5-diphenyl pyrazoles were designed and synthesized from 1-(4-chlorophenyl)-4,4,4-trifuorobutane-1,3-dione 1. The newly synthesized compounds were investigated in vivo for their anti-inflammatory activities using carrageenan-induced rat paw oedema model. Moreover, they were tested for their inhibitory activity against ovine COX-1 and COX-2 using an in vitro cyclooxygenase (COX) inhibition assay. Some of the new compounds (2f, 6a and 6d) showed a reasonable in vitro COX-2 inhibitory activity, with IC(50) value of 0.45μM and selectivity index of 111.1. A virtual screening was carried out through docking the designed compounds into the COX-2 binding site to predict if these compounds have analogous binding mode to the COX-2 inhibitors. Docking study of the synthesized compounds 2f, 6a and 6d into the active site of COX-2 revealed a similar binding mode to SC-558, a selective COX-2 inhibitor.
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