1,278 research outputs found

    Formulating layered adjustable autonomy for unmanned aerial vehicles

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    Purpose - In this paper, we propose a Layered Adjustable Autonomy (LAA) as a dynamically adjustable autonomy model for a multi-agent system. It is mainly used to efficiently manage humans and agents share control of autonomous systems and maintain humans’ global control over the agents. Design/Methodology/Approach - We apply the LAA model in an agent-based autonomous Unmanned Arial Vehicle (UAV) system. The UAV system implementation consists of two parts, software, and hardware. The software part represents the controller and the cognitive and the hardware represents the computing machinery and the actuator of the UAV system. The UAV system performs three experimental scenarios of dance, surveillance and search missions. The selected scenarios demonstrate different behaviors in order to create a suitable test plan and ensure significant results. Findings - The results of the UAV system tests prove that segregating the autonomy of a system as multidimensional and adjustable layers enables humans and/or agents to perform actions in a convenient autonomy levels. Hence, reducing the adjustable autonomy drawbacks of constraining the autonomy of the agents, increasing humans’ workload and exposing the system to disturbances. Originality/value - The application of the LAA model in a UAV manifests the significance of implementing dynamic adjustable autonomy. Assessing the autonomy within three phases of agents run cycle (task-selection, actions-selection, actions-execution) is an original idea that aims to direct agents’ autonomy towards performance competency. The agents’ abilities are well exploited when an incompetent agent switches with a more competent on

    Construction of Codes By Hyper KU-Valued Functions

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    Coding Theory is a mathematical domain with many applications in Information theory. Various type of codes and their connections with other mathematical objects have been intensively studied. One of these applications, namely connections between binary block codes and BCK-algebras, was recently studied in (Jun, Song,  Flaut ).In this paper, we will focus to one of the recent applications of KU-algebras in the coding theory, namely the Construction of codes by hyper KU-valued functions. First, we shall introduce the notion of hyper KU -valued functions, on a set and  investigate some of it’s related properties. Moreover the codes generated by a hyper  K U- valued function are constructed and several Examples are given. Furthermore, Example with graphs of binary block code constructed from a hyper  KU-algebra and hyper KU-algebra are constructed

    Effect of silicon application on roselle (Hibiscus sabdariffa L.) grown in a Vertisol in Egypt

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    Roselle (Hibiscus sabdariffa L.) is an important tropical and subtropical crop, because of its multi uses in the medicinal purposes as well as food industries. A plot experiment was conducted in a Vertisol in Egypt over two sequential seasons (2013 and 2014) to assess the effect of silicon (Si) fertilization on roselle growth and yield. Specific growth characteristics measured were: plant heights, branching, and leaves; biomass and calyces yield; and concentrations of anthocyanin, total soluble solids (TSS), carbohydrates, N, P, and K in the calyces. The experiment compared five rates of Si fertilization (0.00, 1.75, 3.50, 5.25, and 7.00 kg Si ha-1). One-third of each rate was applied as a foliar spray at 45, 60, and 75 days after sowing, respectively. Results showed an increase in plant height, number of branches and leaves to Si fertilization rates. Similarly, anthocyanin and TSS concentration increased with increasing Si rates. Anthocyanin concentration significantly increased by 16.3% as the applied Si rate increased from 0.00 to 5.25 kg Si ha-1. However, carbohydrate content was not affected by the applied Si rates. Nutrients (N, P, and K) concentrations, in the calyces extract, increased with increasing the applied Si rate. Biomass and calyces yield increased by 23 and 33%, respectively, as the applied Si rate increased from 0.00 to 5.25 kg Si ha-1. The highest values of all of the measured properties were observed under the Si rate of 5.25 kg Si ha-1, and the lowest values were obtained from the control treatment (0.00 kg Si ha-1)

    Prevalence of Elevated Blood Pressure and Association with Obesity in Egyptian School Adolescents

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    Aim. To investigate the relationship between high blood pressure (HBP) and obesity in Egyptian adolescents. Methods. A cross-sectional study of 1500 adolescents (11–19 years) in Alexandria, Egypt, was conducted. Resting BP was measured and measurements were categorized using the 2004 fourth report on blood pressure screening recommendations. Additional measures included height, weight, and waist and hip circumferences. Obesity was determined based on BMI, waist circumference (WC) and waist-to-hip ratio (WHR), and waist-to-height ratio (WHtR) indicators. Crude and adjusted odds ratios were used as measures of association between BP and obesity. Results. Prevalence rates of prehypertension and hypertension were 5.7% and 4.0%, respectively. Obesity was seen in 34.6%, 16.1%, 4.5%, and 16.7% according to BMI, WHR, WC, and WHtR, respectively. Adjusting for confounders, HBP was significantly associated with overall obesity based on BMI (OR = 2.18, 95%, CI = 1.38-3.44) and central obesity based on WC (OR = 3.14, 95%, CI = 1.67-5.94). Conclusion. Both overall obesity and central obesity were significant predictors of HBP in Egyptian adolescents

    A Unique Solution of Stochastic Partial Differential Equations with Non-Local Initial condition

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    In this paper, we shall discuss the uniqueness ”pathwise uniqueness” of the solutions of stochastic partial differential equations (SPDEs) with non-local initial condition,We shall use the Yamada-Watanabe condition for ”pathwise uniqueness” of the solutions of the stochastic differential equation; this condition is weaker than the usual Lipschitz condition. The proof is based on Bihari’sinequality

    Existence and Uniqueness of Abstract Stochastic Fractional-Order Differential Equation

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    In this paper, the existence and uniqueness about the solution for a class of abstract stochastic fractional-order differential equations                                           where  in and  are given functions, are investigated, where the fractional derivative is described in Caputo sense. The fractional calculus, stochastic analysis techniques and the standard PicardsPicard's iteration method are used to obtain the required

    Pattern of Anorectal malformations in Gzira National Center for Pediatric Surgery (GNCPS)

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    Background: Anorectal malformations (ARM) are one of the common clinically and socially demanding problems in the world especially in the poorly resourced countries. Patients and Methods: It is a cross-sectional descriptive hospital based study, in the period from June 2009 to December 2011 of 80 patients of ARM in Gezira National Center for Pediatric Surgery (GNCPS). History and examination in addition to invertogram and distal loopogram were the tools of assessment. Results: Eighty children with ARM were studied, 64 males and 16 females. Sixty six patients have delayed presentation. More than 61% presented from rural areas. Twenty-one (26%) patients had one or more associated congenital anomalies, with cardiac and limb anomalies being the most common associated malformation. High anomaly was found in 48.75% of patients, intermediate type was found in 5%, while 43.75% of patients had low anomaly. Conclusion: Delayed presentation entails suboptimal training of midwives and resident doctors in obstetric hospitals and nurseries to evaluate congenital defects in the newborn

    HSO: A Hybrid Swarm Optimization Algorithm for Re-Ducing Energy Consumption in the Cloudlets

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    Mobile Cloud Computing (MCC) is an emerging technology for the improvement of mobile service quality. MCC resources are dynamically allocated to the users who pay for the resources based on their needs. The drawback of this process is that it is prone to failure and demands a high energy input. Resource providers mainly focus on resource performance and utilization with more consideration on the constraints of service level agreement (SLA). Resource performance can be achieved through virtualization techniques which facilitates the sharing of resource providers’ information between different virtual machines. To address these issues, this study sets forth a novel algorithm (HSO) that optimized energy efficiency resource management in the cloud; the process of the proposed method involves the use of the developed cost and runtime-effective model to create a minimum energy configuration of the cloud compute nodes while guaranteeing the maintenance of all minimum performances. The cost functions will cover energy, performance and reliability concerns. With the proposed model, the performance of the Hybrid swarm algorithm was significantly increased, as observed by optimizing the number of tasks through simulation, (power consumption was reduced by 42%). The simulation studies also showed a reduction in the number of required calculations by about 20% by the inclusion of the presented algorithms compared to the traditional static approach. There was also a decrease in the node loss which allowed the optimization algorithm to achieve a minimal overhead on cloud compute resources while still saving energy significantly. Conclusively, an energy-aware optimization model which describes the required system constraints was presented in this study, and a further proposal for techniques to determine the best overall solution was also made

    Genetic algorithm for the design and optimization of a shell and tube heat exchanger from a performance point of view

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    A new approach to optimize the design of a shell and tube heat exchanger (STHX) is developed via a genetic algorithm (GA) to get the optimal configuration from a performance point of view. The objective is to develop and test a model for optimizing the early design stage of the STHX and solve the design problem quickly. GA is implemented to maximize heat transfer rate while minimizing pressure drop. GA is applied to oil cooler type OKG 33/244, and the results are compared with the original data of the STHX. The simulation outcomes reveal that the STHX\u27s operating performance has been improved, indicating that GA can be successfully employed for the design optimization of STHX from a performance standpoint. A maximum increase in the effectiveness achieves 57% using GA, while the achieved minimum increase is 47%. Furthermore, the average effectiveness of the heat exchanger is 55%, and the number of transfer units (NTU) has improved from 0.475319 to 1.825664 by using GA
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