468 research outputs found
The prediction of wake wash in the towing tank
The wash or ship-generated waves from high speed craft has become a common subject in research and development of marine transportation. Since some time now the wake wash of high speed craft has become a problem in particular on inland or confined waterways. This wake wash has an impact on safety and environment such as bank/shoreline erosion, risk to people on shore and small boats in harbors and changes in the local ecology. This paper describes the results of model test of a high speed patrol, together with theoretical prediction of wake wash
Synthesis and Characterization of New Schiff Bases Derived from N (1)-Substituted Isatin with Dithiooxamide and Their Co(II), Ni(II), Cu(II), Pd(II), and Pt(IV) Complexes
Three new Schiff bases of N-substituted isatin LI, LII, and LIII = Schiff base of N-acetylisatin, N-benzylisatin, and N-benzoylisatin, respectively, and their metal complexes C1a,b = [Co2(LI)2Cl3]Cl, C2 = [Ni(LI)2Cl2]0.4BuOH, C3 = [CuLICl(H2O)]Cl ⋅ 0.5BuOH,
C4 = [Pd(LI)2Cl]Cl, C5 = [Pt(L1)2Cl2]Cl2 ⋅ 1.8EtOH.H2O, C6a = [CoLIICl]Cl ⋅ 0.4H2O ⋅ 0.3DMSO, C6b = [CoLIICl]Cl ⋅ 0.3H2O ⋅ 0.1BuOH, C7 = [NiLIICl2], C8 = [CuLII]Cl2 ⋅ H2O , C9 = [Pd(LII)2]Cl2, C10 = [Pt(LII)2.5Cl]Cl3, C11a = [Co(LIII)]C12 ⋅ H2O, C11b = [Co(LIII)]Cl2 ⋅ 0.2H2O, and C12 = [Ni(LIII)2]Cl2, C13 = [Ni(LIII)2]Cl2 were reported. The complexes were characterized by elemental analyses, metal and chloride content, spectroscopic methods, magnetic moments, conductivity measurements, and thermal studies. Some of these compounds were tested as antibacterial and antifungal agents against Staphylococcus aureus, Proteus vulgaris, Candida albicans, and Aspergillus niger
One-Hour Plasma Glucose Concentration and the Metabolic Syndrome Identify Subjects at High Risk for Future Type 2 Diabetes
OBJECTIVE—To assess the efficacy of 1-h plasma glucose concentration and the metabolic syndrome in predicting future risk of type 2 diabetes
Benchmarking Environmental Efficiency of Ports Using Data Mining and RDEA: The Case of a U.S. Container Ports
This study provides step-wise benchmarking practices of each port to enhance the environmental performance using a joint application of the data-mining technique referred to as Kohonen’s self-organizing map (KSOM) and recursive data envelopment analysis (RDEA) to address the limitation of the conventional data envelopment analysis. A sample of 20 container ports in the U.S.A. were selected, and data on input variables (number of quay crane, acres, berth and depth) and output variables (number of calls, throughput and deadweight tonnage, and CO2 emissions) are used for data analysis. Among the selected samples, eight container ports are found to be environmentally inefficient. However, there appears to be a high potential to become environmentally efficient ports. In conclusion, it can be inferred that the step-wise benchmarking process using two combined methodologies substantiates that a more applicable benchmarking target set of decision-making units is be projected, which consider the similarity of the physical and operational characteristics of homogenous ports for improving environmental efficiency
Two-Wheeled LEGO EV3 Robot Stabilisation Control Using Fuzzy Logic Based PSO Algorithm
This paper presents a control system design to stabilise a two-wheeled Lego EV3 robot. This robot is developed based on the inverted pendulum. The mathematical modelling is derived based on this robot and using Euler Lagrange equation and represented in Simulink block diagram. The fuzzy logic controller is used to stabilise this robot with Particle Swarm Optimization algorithm for optimum performance of the system. The result of the fuzzy logic controller without optimisation is compared with the fuzzy logic controller with optimisation. Using the Simulink block diagram, the result of optimum tilt angle and control input signal are presented. The results show that the fuzzy logic controller with optimisation is able to improve the performance of the solution when compared to the fuzzy logic controller without optimisation
Improving total sediment load prediction using genetic programming technique (Case Study: Malaysia)
Predicted total sediment load is usually used to identify the intensity of a sedimentation process. Currently, the existing available models to predict total load are mostly developed based on data collected from flumes, channels and rivers located in western countries. These models known as sediment transport model may not be valid to predict total sediment load of rivers in the tropics due to significant differences in the hydrological and sediment characteristics conditions. A new technique called Genetic programming (GP) technique is used to develop a new model to improve the prediction of total sediment load for rivers in tropical Malaysia. The new model named Evolutionary Polynomial Regression (EPR) model is compared with other three available sediment transport models using the different techniques including, Regression Equation, Modified Graf and Multiple Regression. Statistical analyses based on 82 data sets show the sediment transport model using this new technique perform well compare to other models
Stabilizing control of two-wheeled wheelchair with movable payload using optimized interval type-2 fuzzy logic
The control schemes of a wheelchair having two wheels with movable payload utilizing the concept of a double-link inverted pendulum have been investigated in this article. The proposed wheelchair has been simulated using SimWise 4D software considering the most efficient parameters. These parameters are extracted using the spiral dynamic algorithm while being controlled with interval type-2 fuzzy logic controller (IT2FLC). The robustness and stability of the implemented controller are assessed under different situations including standing upright, forward motion and application of varying directions and magnitudes of outer disturbances to movable (up and down) system payload. It is shown that the two-wheeled wheelchair adopted by the newly introduced controller has achieved a 94% drop in torque for both Link1 and Link2 and more than 98% fall in distance travelled in comparison with fuzzy logic control type-1 (FLCT1) controller employed in an earlier design. The present study has further considered the increased nonlinearity and complexity of the additional moving payload. From the outcome of this study, it is obvious that the proposed IT2FLC-spiral dynamic algorithm demonstrates better performance than FLCT1 to manage the uncertainties and nonlinearities in case of a movable payload two-wheel wheelchair system
Botnet detection using ensemble classifiers of network flow
Recently, Botnets have become a common tool for implementing and transferring various malicious codes over the Internet. These codes can be used to execute many malicious activities including DDOS attack, send spam, click fraud, and steal data. Therefore, it is necessary to use Modern technologies to reduce this phenomenon and avoid them in advance in order to differentiate the Botnets traffic from normal network traffic. In this work, ensemble classifier algorithms to identify such damaging botnet traffic. We experimented with different ensemble algorithms to compare and analyze their ability to classify the botnet traffic from the normal traffic by selecting distinguishing features of the network traffic. Botnet Detection offers a reliable and cheap style for ensuring transferring integrity and warning the risks before its occurrence
New flavonoids from the Saudi Arabian plant:Retama raetam which stimulates secretion of insulin and inhibits α-glucosidase
Retama raetam is a bush which is a member of the family Fabaceae. It is used traditionally in North Africa and Saudi Arabia for the treatment of diabetes. Several flavonoids and alkaloids are already known from this plant. Chromatographic fractionation and purification led to the isolation of three new derivatives of prenylated flavones, retamasin C-E, and four new derivatives of prenylated isoflavones, retamasin F-I, in addition to two isoflavones which have not been previously reported in this plant. Particularly interesting structures included isoflavones containing 3,5-dihydro-2H-2,5-methanobenzo[e][1,4]dioxepine and 3a,8b-dihydro-7-hydroxyfuro[3,2-b]benzo[2,1-d]furan units, both of which are new amongst natural product flavonoids. Five new examples (two flavones and three isoflavones) strongly enhanced the glucose-triggered release of insulin by murine pancreatic islets and one isoflavone was a potent inhibitor of α-glucosidase. This study may rationalise the traditional medicinal use of R. raetam and provide new leads for drug design in the treatment of diabetes.</p
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