A Coverage Monitoring algorithm based on Learning Automata for Wireless Sensor Networks

To cover a set of targets with known locations within an area with limited or prohibited ground access using a wireless sensor network, one approach is to deploy the sensors remotely, from an aircraft. In this approach, the lack of precise sensor placement is compensated by redundant de-ployment of sensor nodes. This redundancy can also be used for extending the lifetime of the network, if a proper scheduling mechanism is available for scheduling the active and sleep times of sensor nodes in such a way that each node is in active mode only if it is required to. In this pa-per, we propose an efficient scheduling method based on learning automata and we called it LAML, in which each node is equipped with a learning automaton, which helps the node to select its proper state (active or sleep), at any given time. To study the performance of the proposed method, computer simulations are conducted. Results of these simulations show that the pro-posed scheduling method can better prolong the lifetime of the network in comparison to similar existing method

Influence of Leadership Approaches on Intrinsic Motivation of Career Professionals in Ontario Non-profit Employment Agencies: An Exploratory Case Study

This exploratory case study (Yin, 2009) investigated those leadership approaches that are used by mid-level managers of seven non-profit employment agencies in Ontario, Canada, to support the intrinsic motivation of seven career professionals who work with them. Unlike profit-earning organizations, career professionals of non-profit employment agencies in Ontario do not get any additional financial incentives for exceeding their targets of helping job seekers find sustainable employment. The research used a transformative learning theory lens (Mezirow, 1991), and also an Interpretivist framework (Merriam, 1998) to understand the data. This study also sought to find what motivates career professionals to reach and exceed their pre-set targets without the availability of any additional bonus. Seven mid-level managers and seven career professionals of non-profit employment agencies were interviewed. A semi-structured interview format was used for the one-on-one interviews. Additional data were collected via document perusal, and the researcher’s reflective journals. Data were coded and analyzed thematically using a content analysis method. Triangulation and member-checking were performed for ensuring reliability of data (Yin, 2009). Findings of the study suggest that mid-level managers of Ontario non-profit employment agencies largely use transformational leadership approaches for building and sustaining career professionals’ intrinsic motivation, although, they sometimes use transactional approaches as well. The study also suggests that the career professionals of the seven non-profit employment agencies are by and large, intrinsically motivated, and three of their key motivators are “passion for their jobs”, “empathy for the clients” and “changing other people’s lives”

Current status and new horizons in Monte Carlo simulation of X-ray CT scanners

With the advent of powerful computers and parallel processing including Grid technology, the use of Monte Carlo (MC) techniques for radiation transport simulation has become the most popular method for modeling radiological imaging systems and particularly X-ray computed tomography (CT). The stochastic nature of involved processes such as X-ray photons generation, interaction with matter and detection makes MC the ideal tool for accurate modeling. MC calculations can be used to assess the impact of different physical design parameters on overall scanner performance, clinical image quality and absorbed dose assessment in CT examinations, which can be difficult or even impossible to estimate by experimental measurements and theoretical analysis. Simulations can also be used to develop and assess correction methods and reconstruction algorithms aiming at improving image quality and quantitative procedures. This paper focuses mainly on recent developments and future trends in X-ray CT MC modeling tools and their areas of application. An overview of existing programs and their useful features will be given together with recent developments in the design of computational anthropomorphic models of the human anatomy. It should be noted that due to limited space, the references contained herein are for illustrative purposes and are not inclusive; no implication that those chosen are better than others not mentioned is intende

Assessment of errors caused by X-ray scatter and use of contrast medium when using CT-based attenuation correction in PET

Purpose: Quantitative image reconstruction in positron emission tomography (PET) requires an accurate attenuation map of the object under study for the purpose of attenuation correction. Current dual-modality PET/CT systems offer significant advantages over stand-alone PET, including decreased overall scanning time and increased accuracy in lesion localisation and detectability. However, the contamination of CT data with scattered radiation and misclassification of contrast medium with high-density bone in CT-based attenuation correction (CTAC) are known to generate artefacts in the attenuation map and thus the resulting PET images. The purpose of this work was to quantitatively measure the impact of scattered radiation and contrast medium on the accuracy of CTAC. Methods: Our recently developed MCNP4C-based Monte Carlo X-ray CT simulator for modelling both fan- and cone-beam CT scanners and the Eidolon dedicated 3D PET Monte Carlo simulator were used to generate realigned PET/CT data sets. The impact of X-ray scattered radiation on the accuracy of CTAC was investigated through simulation of a uniform cylindrical water phantom for both a commercial fan-beam multi-slice and a prototype cone-beam flat panel detector-based CT scanner. The influence of contrast medium was studied by simulation of a cylindrical phantom containing different concentrations of contrast medium. Moreover, an experimental study using an anthropomorphic striatal phantom was conducted for quantitative evaluation of errors arising from the presence of contrast medium by calculating the apparent recovery coefficient (ARC) in the presence of different concentrations of contrast medium. Results: The analysis of attenuation correction factors (ACFs) for the simulated cylindrical water phantom in both fan- and cone-beam CT scanners showed that the contamination of CT data with scattered radiation in the absence of scatter removal causes underestimation of the true ACFs, namely by 7.3% and 28.2% in the centre for the two geometries, respectively. The ARC was 190.7% for a cylindrical volume of interest located in the main chamber of the striatal phantom containing contrast medium corresponding to 2,000 Hounsfield units, whereas the ARC was overestimated by less than 5% for the main chamber and by ∼2% for the left/right putamen and caudate nucleus compared with the absence of contrast medium. Conclusion: Without X-ray scatter compensation, the visual artefacts and quantitative errors in flat panel detector-based cone-beam geometry are substantial and propagate cupping artefacts to PET images during CTAC. Likewise, contrast-enhanced CT images may create considerable artefacts during CTAC in regions containing high concentrations of contrast mediu

Aerodynamics and Vibrations of a Helicopter Rotor Blade

The nature of the aerodynamic environment surrounding a helicopter causes a significant amount of vibration to its whole body. Among different sources of vibrations, the aerodynamic loading on the main rotor blade is the major contributor. Therefore, analyzing a rotor blade\u27s vibration characteristics and aerodynamic behavior becomes essential. The vortex characteristics and the wake surrounding a helicopter rotor blade play an important role because they affect the aerodynamic behavior of the rotor blade. An advanced mathematical and computational model of rotor wake and blade vortex gives a better understanding of the helicopter rotor dynamics. This study develops computational models of a helicopter rotor blade to obtain the vibration characteristics and aerodynamic behavior. In addition, a mathematical model of the wake is also used, consisting of the fundamental wake geometry. A Bo 105 helicopter rotor blade is considered for computational aerodynamic analysis. A fluid-structure interaction model of the rotor blade with surrounding air is developed, where the finite element model of the blade is coupled with the computational fluid dynamics model of the surrounding air. The fluid-structure interaction model analyzes aerodynamic coefficients, velocity profiles, and pressure profiles. The resonance frequencies and mode shapes are also obtained by the computational method. A small-scale model of the rotor blade is manufactured, and an experimental analysis of similar contemplation is conducted to validate the numerical results. Wind tunnel and vibration testing arrangements are used for the experimental validation of the aerodynamic and vibration characteristics, respectively. The computational results show that the coefficient of lift increases with the angle of attack up to a critical value. The coefficient of drag also increases with the angle of attack. The elastic rotor blades are subjected to coupled flapping, lead-lag, and torsional (triply coupled) deflections. The resonance frequencies and mode shapes in each direction vary with the size and shape of the rotor blade and the mode number. The wake and vortex analysis showed that the swirl velocity is minimum, and the axial velocity is maximum at the vortex center. The axial velocity decreases, and swirl velocity increases with increasing the distance from the vortex center to the core radius

KESETARAAN GENDER DALAM FIKIH PEREMPUAN PERSPEKTIF MAQASID SYARIAH JASSER AUDA

The dynamics of today's civilization are growing, it continues to drive changes significantly, both in the technological and other spheres. Existing social construction has shifted, and even needs to be updated to keep up with developments. This includes the role and position of women. In the past, women in the discussion of jurisprudence were only about worship, the treatment of worship that there were differences with men. For example, if the congregation, men are encouraged to read Subhanallah while women pat both palms. But now the discussion of women is getting wider to their roles, positions and relationships with men. This research focused on the gender equality thinking of Husein Muhammad and Musdah Mulia. This research is a normative research (library research) with research sources including several books by Husein Muhammad, Musdah Mulia and Jasser Auda. The thinking of gender equality (women's jurisprudence) of the two figures was then analyzed with Jasser Auda's system (maslahah) approach. The gender equality of women's jurisprudence in the perspective of the Jasser Auda system has conformity with Islamic law. The gender equality of women's jurisprudence has fulfilled all six systems of features (benefits). In the cognitive system, equality has a cognitive conformity capable of uncovering the meaning or practical implications of Islamic law. The argumentation of women's jurisprudence was also adopted from the powerful nash texts, this corresponded to the system of wholeness. Thus with the system of openness and interrelationship, which demands to open wide the thinking of equality to respond to the development of the times. Gender equality view Women's jurisprudence provides answers to these changes in a measured and directed manner, so that Islamic law is always contextual based on the multidimensional system and the meaning of Jasser Auda

The UK Infrared Telescope M33 monitoring project. III. Feedback from dusty stellar winds in the central square kiloparsec

We have conducted a near-infrared monitoring campaign at the UK InfraRed Telescope (UKIRT), of the Local Group spiral galaxy M33 (Triangulum). The main aim was to identify stars in the very final stage of their evolution, and for which the luminosity is more directly related to the birth mass than the more numerous less-evolved giant stars that continue to increase in luminosity. In this third paper of the series, we measure the dust production and rates of mass loss by the pulsating Asymptotic Giant Branch (AGB) stars and red supergiants. To this aim, we combined our time-averaged near-IR photometry with the multi-epoch mid-IR photometry obtained with the Spitzer Space Telescope. The mass-loss rates are seen to increase with increasing strength of pulsation and with increasing bolometric luminosity. Low-mass stars lose most of their mass through stellar winds, but even super-AGB stars and red supergiants lose $\sim40$% of their mass via a dusty stellar wind. More than three-quarters of the dust return is oxygenous. We construct a 2-D map of the mass-return rate, showing a radial decline but also local enhancements due to agglomerations of massive stars. We estimate a total mass-loss rate of 0.004--0.005 M$_\odot$ yr$^{-1}$ kpc$^{-2}$, increasing to $\sim0.006$ M$_\odot$ yr$^{-1}$ kpc$^{-2}$ when accounting for eruptive mass loss (e.g., supernov{\ae}); comparing this to the current star formation rate of $\sim0.03$ M$_\odot$ yr$^{-1}$ kpc$^{-2}$ we conclude that star formation in the central region of M\,33 can only be sustained if gas is accreted from further out in the disc or from circum-galactic regions.Comment: Accepted for publication in MNRA

Analysis of Electrolyte Flow in Localized Electrochemical Deposition

AbstractLocalized electrochemical deposition (LECD) is a favorable technology for fabrication of the high-aspect ratio electrodes of various materials. This technology is found to be one of the simple and inexpensive ways to fabricate non-circular electrodes for micro-EDM. In order to fabricate non-circular electrodes a mask of non-conductive material is placed between the anode and cathode, which is immersed in a mixed electrolyte of copper sulfate, 1.0M sulfuric acid and as an additive agent 0.04 gm/liter of thiourea. The deposition of copper is localized on the cathode surface using a mask and applying ultra-short voltage pulses between the anode and cathode. In this set up the cathode is placed above the anode and mask, so that the deposited electrode can be used directly for EDM or any application without changing its orientation. In order to localize the deposited structure on the cathode surface, the electrolyte needs to flow through the mask and needs to touch the cathode and a constant flow rate of the electrolyte is maintained by using a pump. For this reason, micro holes of desired shapes are fabricated in the mask using micro milling. This study shows the effect of electrolyte flow through the micro holes of the mask and micro gap between the mask and anode on the microstructure of deposited electrode using FLUENT analysis. Moreover, an optimum range of electrolyte flow rate through the micro passages is also shown for the LECD process in order to fabricate high aspect ratio microstructures