7,077 research outputs found
Formulating layered adjustable autonomy for unmanned aerial vehicles
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
Inhibition of the mevalonate pathway augments the activity of pitavastatin against ovarian cancer cells
Only 40% of patients with advanced ovarian cancer survive more than 5 years. We have previously shown that pitavastatin induces regression of ovarian cancer xenografts in mice. To evaluate whether the response of ovarian cancer cells to pitavastatin is potentiated by farnesyl diphosphate synthase inhibitors or geranylgeraniol transferase I inhibitors, we evaluated combinations of pitavastatin with zoledronic acid, risedronate and GGTI-2133 in a panel of ovarian cancer cells. Pitavastatin (IC50 = 0.6-14 μM), zoledronic acid (IC50 = 21-57 μM), risedronate (IC50 > 100 μM) or GGTI-2133 (IC50 > 25 μM) inhibited the growth of ovarian cancer cell cultures. Combinations of pitavastatin with zoledronic acid displayed additive or synergistic effects in cell growth assays in 10 of 11 cell lines evaluated as well as in trypan blue exclusion, cellular ATP or caspase 3/7, 8 and 9 assays. Pitavastatin reduced levels of GGT-IIβ and the membrane localization of several small GTPases and this was potentiated by zoledronic acid. siRNA to GGT-Iβ and GGT-IIβ used in combination, but not when used individually, significantly increased the sensitivity of cells to pitavastatin. These data suggest that zoledronic acid, a drug already in clinical use, may be usefully combined with pitavastatin in the treatment of ovarian cancer
Inclusion of chemical effect in a fully coupled THM finite element code
Bentonite-rich clays can be used as a buffer / backfill material in deep geological repositories for nuclear waste. The prediction of the long-term performance of a buffer / backfill in such a complex environment, where the temperature, humidity and chemistry of water change, requires a fully thermo-hydro-mechanical-chemical (THMC) coupled numerical code. This paper presents a simple extension of a THM coupled finite element code to include chemical effects. After deriving the governing salt mass balance equation and discussing its implementation into the code, the paper verifies the extended framework against an analytical solution for 1D salt transport. In addition, the article presents a validation example in which the code replicates experimental data. The numerical results obtained from the extended THMC coupled finite element code encourage further investigation of the chemical effects on the mechanical and thermal behaviour of the material, which would serve the ultimate goal of achieving a safer design of the nuclear waste storage facility.Postprint (published version
Modeling and Experimental Investigation of Laminar Ceiling Air Distribution System for Operating Room in Merjan Teaching Hospital
Room air distribution in operating rooms is critical to successful surgical treatment. The present study investigated the effects of the location of the air supply and exhaust grills on the air movement and air parameters inside an operating room. This paper presents an experimental and numerical analysis of air distribution in the operating room. The experimental work was conducted in an operating room in Merjan Teaching Hospital in the city of Babylon. Air was supplied from one square plenum box located in the middle of the ceiling, while air was exhausted through eight grills: large exhaust grills in the four upper corners and small exhaust grills in the four lower corners. In the theoretical work, a model of the operating room was developed and two cases were analyzed using the FLUEN 6.3.26 software program. The first case included all eight exhaust grills, while the second case included only the four lower exhaust grills. The ceiling system gave good ventilation for air distribution inside the operating room. There was no clear effect of the small exhaust grills located in the upper corners of the operating room. The height of the ceiling room is an effective factor in air distribution
The Relationship between Correcting Deviations in Measuring Performance and Achieving the Objectives of Control - The Islamic University as a Model
The study aimed to identify the relationship between correcting the deviations in the measurement of performance and achieving the objectives of control and the performance of the job at the Islamic University in the Gaza Strip. To achieve the objectives of the research, the researchers used the descriptive analytical approach to collect information. The questionnaire consisted of (20) statements distributed to three categories of employees of the Islamic University (senior management, faculty members, their assistants and members of the administrative board). A random sample of 314 employees was selected and 276 responses were retrieved with a recovery rate of 88.1%. The Statistical Analysis Program (SPSS) was used to enter, process, and analyze the data. The results of the study showed a positive relationship between correcting deviations in performance measurement and achieving the control objectives represented by the functional performance in the Islamic University from the point of view of the members (senior management, faculty and their assistants, and the administrative board), where the relative weight of all the paragraphs was (74.25%). The study recommended the need to ensure that the actual performance of the planned performance is matched and decisions are taken to correct the serious deviations and take the necessary measures in terms of retraining and change in regulations, wages and bonuses and punishment of the culprit, neglect and negligence by mistake
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