38 research outputs found
Optimization of Fuel Consumption for Municipal Solid Waste Collection in Al Ain City, UAE
Collection and transportation of municipal solid waste (MSW) often account for a significant amount of the total budget allocated for waste management. A major portion of that is attributed to fuel consumption. Meanwhile, vehicles involved with waste collection can emit significant levels of atmospheric pollutants. Hence, optimization of waste collection yields both financial and environmental benefits. No work has been done to optimize fuel consumption during MSW collection in Al Ain city. In this study, several cases were developed using ArcGIS Network Analyst tool in order to establish optimum conditions for MSW collection in Um Gafa district in Al Ain city, with an objective function of minimization of fuel consumption. A geographic information system was created based on data collection and GPS tracking of collection route and bins position. The study revealed that waste collection at Um Gafa at the current time does not strictly follow U-turn and curb approach policies. When route optimization is applied for similar traffic conditions as the current ones, a saving of 14.3% in fuel consumption is gained. In addition, emitted CO2 is reduced by 7.2%. However, by strictly following the U-turn and curb approach policy of the traffic department, the relative saving in fuel consumption was much less (5%) as compared to the current practice of vehicle maneuvering for waste collection. Two new models were proposed for optimal number and location of bins. One model was based on a 40-m service zone while the other was based on population density and landuse. By adopting the first model, the number of bins was reduced by 12%, while in the second model the number of bins was reduced by 20%. In both models, more efficient routes in terms of fuel consumption and reduction in emissions have resulted, with second model showing superiority compared to the first model
Adaptive underfrequency load shedding based on real time simulation
Conventional Underfrequency Load Shedding (UFLS) is used to balance generation and load when underfrequency conditions occur. It sheds a fixed, predetermined amount of load irrespective of disturbance location. Several adaptive UFLS schemes are proposed in the literature. Recent research discussed utilizing synchrophasor messages to implement adaptive UFLS but these studies have been using virtual PMUs. Of late, hardware implementations for adaptive UFLS scheme using actual Phasor Measurement Units (PMUs) are reported but also these studies are based on small power systems. This study presents hardware implementation of adaptive UFLS based on real time simulation of IEEE39-bus system. The simulation tool used was OPAL-RT eMEGAsim real time digital simulator. To emulate the actual environment where the scheme could be used, a complete phasor network setup is established using actual devices, such as high accuracy Global Positioning System (GPS) clocks, PMUs and Synchrophasor Vector Processor (SVP). The results obtained show that the adaptive UFLS scheme restored the frequency and curtailed the load based on voltage sag. Furthermore, the results are compared with conventional UFLS scheme
Parameter Estimation Based on Double Ranked Set Samples with Applications to Weibull Distribution
In this paper, the likelihood function for parameter estimation based on double ranked set sampling (DRSS) schemes is introduced. The proposed likelihood function is used for the estimation of the Weibull distribution parameters. The maximum likelihood estimators (MLEs) are investigated and compared to the corresponding ones based on simple random sampling (SRS) and ranked set sampling (RSS) schemes. A Monte Carlo simulation is conducted and the absolute relative biases, mean square errors, and efficiencies are compared for the different schemes. It is found that, the MLEs based on DRSS is more efficient than MLE using SRS and RSS for estimating the two parameters of the Weibull distribution (WD)
On Discriminating between Gamma and Log-logistic Distributions in Case of Progressive Type II Censoring
Gamma and log-logistic distributions are two popular distributions for analyzing lifetime data. In this paper, the problem of discriminating between these two distribution functions is considered in case of progressive type II censoring. The ratio of the maximized likelihood test (RML) is used to discriminate between them. Some simulation experiments were performed to see how the probability of correct selection (PCS) under each model work for small sample sizes. Real data life is analyzed to see how the proposed method works in practice. As a special case of progressive type II censoring, the problem of discriminating between gamma and log-logistic in case of complete samples is considered. The RML and the ratio of Minimized Kullback-Leibler Divergence (RMKLD) tests are used to discriminate between them. The asymptotic results are used to estimate the PCS which is used to calculate the minimum sample size required for discriminating between two distributions. Two real life data are analyzed
Six-week physical rehabilitation protocol for anterior shoulder dislocation in athletes
Anterior shoulder dislocations are common in young athletes. The mechanism for the first or primary shoulder dislocation may involve a collision or a fall typically with the arm in an abducted and externally rotated position. The aim of this study was to design a physical rehabilitation program using the elastic band and resistive exercise to improve joint strength and range of motion in individuals diagnosed with a first-time shoulder dislocation. Twelve physically active males with a first-time acute shoulder dislocation were asked to volunteer. Participants began a physical rehabilitation program 2 weeks after the shoulder dislocation, which was confirmed by a referring physician. The rehabilitation program was 6 weeks in duration and required the participants to engage in progressive resistive loads/duration using elastic bands and weights 5 days per week. Pretest and posttest measures included shoulder strength and range of motion. All outcome measures were compared between the injured and uninjured shoulder, which served as the control condition in this study. There were statistically significant differences between the injured and uninjured shoulder for measures of strength and range of motion during pretests (P\u3c0.01) but not post-tests (P\u3c0.53). Finally, there were no differences between shoulders in regards to the volume measure suggesting that any changes in muscle atrophy or swelling were not detected. The physical rehabilitation program proposed in this study was effective at improving strength and range of motion in the injured shoulder as evidenced by the similarity in posttest values between the injured and uninjured shoulder
Novel Results for Two Generalized Classes of Fibonacci and Lucas Polynomials and Their Uses in the Reduction of Some Radicals
The goal of this study is to develop some new connection formulae between two generalized classes of Fibonacci and Lucas polynomials. Hypergeometric functions of the kind 2F1(z) are included in all connection coefficients for a specific z. Several new connection formulae between some famous polynomials, such as Fibonacci, Lucas, Pell, Fermat, Pell–Lucas, and Fermat–Lucas polynomials, are deduced as special cases of the derived connection formulae. Some of the introduced formulae generalize some of those existing in the literature. As two applications of the derived connection formulae, some new formulae linking some celebrated numbers are given and also some newly closed formulae of certain definite weighted integrals are deduced. Based on using the two generalized classes of Fibonacci and Lucas polynomials, some new reduction formulae of certain odd and even radicals are developed
Novel Results for Two Generalized Classes of Fibonacci and Lucas Polynomials and Their Uses in the Reduction of Some Radicals
The goal of this study is to develop some new connection formulae between two generalized classes of Fibonacci and Lucas polynomials. Hypergeometric functions of the kind 2F1(z) are included in all connection coefficients for a specific z. Several new connection formulae between some famous polynomials, such as Fibonacci, Lucas, Pell, Fermat, Pell–Lucas, and Fermat–Lucas polynomials, are deduced as special cases of the derived connection formulae. Some of the introduced formulae generalize some of those existing in the literature. As two applications of the derived connection formulae, some new formulae linking some celebrated numbers are given and also some newly closed formulae of certain definite weighted integrals are deduced. Based on using the two generalized classes of Fibonacci and Lucas polynomials, some new reduction formulae of certain odd and even radicals are developed
Impact of Field Topography and Soil Characteristics on the Productivity of Alfalfa and Rhodes Grass: RTK-GPS Survey and GIS Approach
Understanding the spatial pattern of soil chemical properties along with the topologic indicators is essential for site-specific agriculture management. A study was conducted on a 50 ha field to investigate the effect of selected topographic indicators, including elevation (DEM), slope (SL), flow accumulation (FA) and Topographic Wetness Index (TWI) on forage crop production. The soil samples and yield data were obtained from the field inventory. Topographical parameters of elevation and slope were estimated with the use of a real-time kinematic global positioning system (RTK-GPS), and then the DEM was generated. The collected soil samples were analyzed for pH, EC, nitrogen and soil organic carbon. Sentinel-2 images were for the creation of yield maps of alfalfa and Rhodes grass. Subsequently, on the basis of DEM, the generated elevation, slope and FA model were then compared with the yield and soil chemical properties. Statistical analysis revealed that the SL, FA and TWI, which are associated with water distribution, were significantly related to crop yields. The FA showed a medium-to-non-significant correlation with the productivity of both alfalfa (R2 = 0.586; p = 0.015) and Rhodes grass (R2 = 0.578; p = 0.01). A significant inverse correlation was recorded between the SL and the yield of both crops (R2 = −0.591 to −0.617; p = 0.01). The yield map revealed that the majority of the area (37.56%) of the experimental field was occupied by the medium-yield class, followed by the high-yield class (33.03%)