88 research outputs found

    Modelling dynamics of victims' stress during natural disaster

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    Natural disaster is one of the inescapable phenomenon through which numerous number of individuals are being affected via developing psychological problems. Stress is one of the essential psychological effects of natural disaster; it is a reality of nature where forces from the outside world affect individuals exposed to such phenomenon. In computational psychology domains, computational models were used as tools for understanding human cognitive functions and behavioural patterns. Meanwhile, psychological and cognitive theories as well as empirical studies have provided convergent evidence to identify important factors and psychological attributes that affect the stress level of victims during natural disaster. Therefore, this study implements a formal model (computational model) to understand the current state of victims' stress during natural disaster. From related theories, 22 of basic factors have been established and grouped into 7 main categories that include predisposed factors, resources, individual attributes, appraisal, resilience, coping, and stress. Those factors provide the fundamental knowledge of the behaviours of victims after disaster occurrence. A formal model was developed by using a set of differential equations. Later, this model was simulated by applying related scenarios based on three different cases, namely; 1) a good victim with low level of stress, 2) victim with high level of stress, and 3) victim with moderate level of stress) through the use of Matlab as a programming language. This computational model was then verified using two techniques; 1) logical verification (Temporal Trace Language) and 2) mathematical verification (stability analysis). The experimental results have approximately predicted why victims develop stress differently when facing natural disasters

    SIMULATION AND ANALYSIS OF VEHICULAR AD-HOC NETWORKS IN URBAN AND RURAL AREAS

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    According to the American National Highway Traffic Safety Administration, in 2010, there were an estimated 5,419,000 police-reported traffic crashes, in which 32,885 people were killed and 2,239,000 people were injured in the US alone. Vehicular Ad-Hoc Network (VANET) is an emerging technology which promises to decrease car accidents by providing several safety related services such as blind spot, forward collision and sudden braking ahead warnings. Unfortunately, research of VANET is hindered by the extremely high cost and complexity of field testing. Hence it becomes important to simulate VANET protocols and applications thoroughly before attempting to implement them. This thesis studies the feasibility of common mobility and wireless channel models in VANET simulation and provides a general overview of the currently available VANET simulators and their features. Six different simulation scenarios are performed to evaluate the performance of AODV, DSDV, DSR and OLSR Ad-Hoc routing protocols with UDP and TCP packets. Simulation results indicate that reactive protocols are more robust and suitable for the highly dynamic VANET networks. Furthermore, TCP is found to be more suitable for VANET safety applications due to the high delay and packet drop of UDP packets.fi=Opinnäytetyö kokotekstinä PDF-muodossa.|en=Thesis fulltext in PDF format.|sv=Lärdomsprov tillgängligt som fulltext i PDF-format

    Thermal performance of backflow solar air heating with integrated nanoparticle enhanced pcm absorber storage system

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    The present study has been executed to clarify the advantage of using latent thermal storage integrated with a back pass solar air heater (SAH). The purpose of this study is to design, fabricate and evaluate the performance of SAH with integrated nanoparticles enhanced phase change material (PCM) absorber storage system. Three different SAH configurations have been designed and studied; without thermal storage, with thermal storage using paraffin wax as a PCM and with thermal storage using Al2O3-paraffin wax. A three-dimensional Navier-Stokes equation coupled with the energy balance equation is solved using the computational fluid dynamics (CFD) software program to implement numerical computations. The numerical analysis is conducted to determine the optimum collector dimensions in terms of length (L), width (W) and depth of air flow channel (Hch) at air mass flow rate of 0.03 kg/s and solar irradiance of 1000 W/m2. Results obtained from the numerical analysis indicate that the collector dimensions of (L = 1.8 m, W = 0.7 m, Hch = 0.07 m) which are the best design. The numerical results show that the SAH with Al2O3-paraffin wax have the thermal efficiency ranged between 73 % and 78 % with air temperature difference from 25 °C to 46.6 °C when the solar irradiance of 1000 W/m2 at the air mass flow rates of 0.03 kg/s and 0.06 kg/s, respectively. The experimental setup is constructed using these optimum dimensions for each configuration and validated using the numerical results. All configurations are fabricated and tested outdoor under the Iraq climatic conditions according to ASHRAE standard tests at different air mass flow rates. The two steps method is used to prepare the mixture of nanoparticles with PCM and ultrasonic device is used to suspend the nanoparticles in the PCM. The experimental results show that the SAH with Al2O3-paraffin wax has the highest daily performance and thermal efficiency followed by SAH with pure paraffin wax and SAH without storage. Moreover, the discharging time in the SAH with pure paraffin wax of heat stored took 5.5, 5, 4.5 and 4 hours at the air mass flow rate 0.03, 0.04, 0.05 and 0.06 kg/s, respectively. As for the SAH with Al2O3-paraffin wax, the discharge time are 5, 4.5, 4 and 3.5 hours at the air mass flow rates of 0.03, 0.04, 0.05 and 0.06 kg/s, respectively. The experimental results also show that increment in the thermal conductivity of PCM with the dispersion 1wt. % Al2O3 which led to raise the outlet air temperature and thermal efficiency of the SAH compared to SAH with pure paraffin wax. In addition, good agreement are obtained when comparing between the numerical and experimental results. It was the average differences in percentage on outlet air temperatures obtained in the numerical and experimental results from 2.11 % to 2.47 % and on the thermal efficiency from 2.70% to 3.50 %, respectively

    An ambient agent model for reading companion robot

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    Reading is essentially a problem-solving task. Based on what is read, like problem solving, it requires effort, planning, self-monitoring, strategy selection, and reflection. Also, as readers are trying to solve difficult problems, reading materials become more complex, thus demands more effort and challenges cognition. To address this issue, companion robots can be deployed to assist readers in solving difficult reading tasks by making reading process more enjoyable and meaningful. These robots require an ambient agent model, monitoring of a reader’s cognitive demand as it could consist of more complex tasks and dynamic interactions between human and environment. Current cognitive load models are not developed in a form to have reasoning qualities and not integrated into companion robots. Thus, this study has been conducted to develop an ambient agent model of cognitive load and reading performance to be integrated into a reading companion robot. The research activities were based on Design Science Research Process, Agent-Based Modelling, and Ambient Agent Framework. The proposed model was evaluated through a series of verification and validation approaches. The verification process includes equilibria evaluation and automated trace analysis approaches to ensure the model exhibits realistic behaviours and in accordance to related empirical data and literature. On the other hand, validation process that involved human experiment proved that a reading companion robot was able to reduce cognitive load during demanding reading tasks. Moreover, experiments results indicated that the integration of an ambient agent model into a reading companion robot enabled the robot to be perceived as a social, intelligent, useful, and motivational digital side-kick. The study contribution makes it feasible for new endeavours that aim at designing ambient applications based on human’s physical and cognitive process as an ambient agent model of cognitive load and reading performance was developed. Furthermore, it also helps in designing more realistic reading companion robots in the future

    STABILIZATION POND FOR WASTEWATER TREATMENT

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    This research is concerned with study and check the suitability of waste stabilization ponds (WSPs) for treating wastewater in Al-Dewaniyah province by taking a sample of community of 10000 population.Experimental work had three cases depending on many considerations such as economical and specification of final effluent. A model of two ponds (facultative and aerobic) in series was used as first case of experimental work. Then third pond with aeration process to aerobic pond were added to the series as second case to improve the effluent. At last, sand filter was used to polish the final effluent from aerobic pond.The three ponds had the same surface area (5.75m*2m) but with different depths, where it was 2m for anaerobic pond, 1.5m for facultative pond and 0.75m for aerobic pond. From the tests taken for the three cases, the results obtained for the last two cases were much better when compared with first case. Sand filter contributed in improving final effluent by decreasing total suspended solid (TSS) also in increasing removal efficiency of biochemical oxygen demand (BOD) and chemical oxygen demand (COD). At the end, the results of this work could be an invitation to use waste stabilization pond for wastewater treatment in rural areas or even small communities but it may need more examinations to get best results

    Improvement of the operation and safety of nuclear power plants

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    This study investigated the importance of heating processes within a nuclear power plant. The application of Fourier’s law of heat conduction enables determining temperature distributions within the nuclear fuel rods. In contrast, convective cooling occurs on the road surface. The coolant, cladding, and fuel temperature distributions through a reactor are determined. In addition to heat transfer in the reactor core, some power plants engage heat exchangers to produce steam that is fed to a turbine-generator to produce electricity. Thermal power plants reject condenser heat to the environment through mechanisms such as cooling towers as according to a consequence of the second law of thermodynamics. These investigations provide a possible modeling approach and load the following control strategies for problematic nuclear power plants to provide an assessment of the concept designs. A load frequency control strategy and average temperature control mechanism are studied to get load following nuclear power plants. This study reports on the development and analysis of some novel versions and approximations of the fractional-order (FO) point reactor kinetics model for a nuclear reactor with slab geometry. These models evolve from the FO point reactor kinetics model, which has been derived from the FO Neutron Telegraph Equation for the neutron transport considering the subdiffusive neutron transport. This study also proposes a water level control system for a nuclear steam generator (SG). The control system consists of a feedback controller and a feedforward controller. The feedback controller comprised in the first order, the feedforward controller is of second order, and parameters of the two controllers are linked with the parameters of plant model; thus scheduling is easily implemented in practice. A model was developed for the thermal analysis of closed feedwater heaters in which wet steam is extracted from the steam turbine (and piped into the heater). Application of this model is of relevance to nuclear power plant diagnostics where the fluid flowing through the steam turbine is wet steam

    A Bibliometric Analysis of Electronic Human Resource Management E-HRM in Scopus Database

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    Purpose: This study aims to Analyze the articles published in SCOPUS database relevant to EHRM. Toward future expanding and exploration to the EHRM area and shows the critical details about the relevant literature.   Design/Methodology/Approach: A bibliometric analysis for the articles published in SCOPUS database, contains the countries of the publications, authors, author’s nationality, number of articles been published according to authors and authors nationality, keywords, most repeated words and furthermore.   Findings: The outcomes of the analysis asserted that there is a lack of publications in general, the researchers of the publications were students and from educational institutions. Malaysian an Jordanian universities were amongst the highest papers published in EHRM. The importance of EHRM was clarified as well according to the previous literature. EHRM could simplify the HRM functions, cut costs, improve performance, generate a systematic HR function, and utilizing or integrating the information technology and HRM.   Research, practical & social implications: the implications of EHRM are beneficial for the fields and organizations which they use it, it’s the modern method to practice the HR functions which it might make the accessibility of the HR functions from the organizations and customers, suppliers and stakeholders.   Originality/Value: The paper contributes to the body of knowledge and guide the researchers toward valuable future research and filling up the several gaps in the area of the study

    A review of offshore wind turbines: global added capacity, monopile structure foundations stresses and deflection

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    Offshore wind power is now a significant source of clean renewable energy. The paper summarizes the key findings from recent energy studies on the growth in offshore wind power's added capacity to the global energy system. The review paper referred to parts of the configuration of offshore wind turbines (OWTs) and their supporting structures, and focused on the monopole support structure due to its importance in building offshore wind farms and studying and discussing the most published research related to the mono support structure and its response to wind loads and wave loads affecting them. Recent studies have varied between numerical analysis research, research and master's theses and doctoral theses on calculating stresses on offshore wind turbines. Due to the importance of the topic, studies on computational fluid dynamics (CFD), which have developed greatly in recent years, have been reviewed (simulation and simulation research). Hybrids (RTHS) and experimental research. The paper concluded with the conclusion that the interest in experimental studies and research close to the conditions of marine turbines is through the construction of special laboratories that include advanced equipment with quantitative measurements, with high technical standards and good reliability, developments of simulation tools of various forms in order to approach efficient and low-cost design

    Performance assessment of parabolic trough collector (ptc) by using three passes receiver for preheating the fuel oil under Iraq climate for different mass flow rates

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    An alternative design receiver of parabolic trough collector (PTC) has been discussed in the present study. The three passes design (3p) receiver made from copper and coated with selective black paint was studied and optimized experimentally. Mass flow rates were varied alongside number of days. The proposed design was compared with the PTC equipped with smooth receiver (SM). The aforementioned variations resulted in the experiments performed in September 2018. The 17th, 18th, 19th, and 20th, were chosen for the PTC with smooth receiver, while 25th , 26th, 27th, and 28th were for the receiver with three passes). The solar irradiances for these days were similar. The heat transfer fluid (HTF) was fuel oil. Mass flow rates of 2, 2.5, 3, 3.5 LPM were observed alongside change in number of days for the experiment. The results show that the PTC with three passes receiver achieved higher average thermal efficiency and average useful energy than the PTC with smooth receiver

    Evaluation of electrical load estimation in Diyala governorate (Baaquba city) based on fuzzy inference system

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    The evaluation of electrical load estimation is requisitely of any electrical power system. This manner is needed for system obligation, economical distribution and maintenance time of electrical system. In this paper, we propose electrical load estimation method based on fuzzy inference system which gives accurate results for estimated loads in Iraq (Diyala governorateBaaquba city). And it can assist the electrical generation and distribution system that depends on important parameters (temperature, humidity and the speed of the wind). By considering the parameters temperature, humidity and the speed of the wind. These parameters are applied as inputs to the fuzzy logic control system to obtain the normalize estimated load as output by electing membership functions. It is exceptionally valuable to form a choice by taking into consideration these assessed readings that come to from the proposed FIS that displayed in this paper with precision of 0.969 from the real stack request
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