Modeling and Control for Smart Grid Integration of Solar/Wind Energy Conversion System

Performance optimization, system reliability and operational efficiency are key characteristics of smart grid systems. In this paper a novel model of smart grid-connected PV/WT hybrid system is developed. It comprises photovoltaic array, wind turbine, asynchronous (induction) generator, controller and converters. The model is implemented using MATLAB/SIMULINK software package. Perturb and observe (P&O) algorithm is used for maximizing the generated power based on maximum power point tracker (MPPT) implementation. The dynamic behavior of the proposed model is examined under different operating conditions. Solar irradiance, temperature and wind speed data is gathered from a grid connected, 28.8kW solar power system located in central Manchester. Real-time measured parameters are used as inputs for the developed system. The proposed model and its control strategy offer a proper tool for smart grid performance optimization

Performance of Standard and Customized Search Interfaces

The research conducts a performance comparison between standard search interfaces available in modern search engines with a customized search interface that allows the user to change the way the information is presented on the screen. The tested hypothesis is that customized search interface results in a decrease in total search time and increase (or the same amount) of successful searches. Customizable options included font, background, help, tool tips, highlights, preview text and Boolean operators. Based on the performed study customized interfaces allowed users to increase the speed of obtaining correct search results by 10.2%. The benefit comes with a cost of time that users spend to configure the interface. Further research is recommended to both test the results on wider audiences, and test additional customization options

Performance Enhancement of Routing Protocols in Mobile Wireless Ad-Hoc Networks Using Fuzzy Reasoning Algorithm

The challenge in creating a routing protocol for ad-hoc networks is to design a single protocol that can adapt to the wide variety of conditions that can be present in any ad-hoc network enviroment. The routing protocol must perform efficiently in enviroments in which it suffers from high nodes mobility and many wireless transmission constraints. Because it it often impossible to know what enviroment the protocol will find itself in, and because the enviroment can change unpredictably, the routing protocol must be able to adapt automatically. In this thesis, we use a fuzzy reasoning algorithm (FRA) as a highly adaptive algorithm to achieve that goal. We will present the various application of that algorithm to ad-hoc routing protocols. Then, we will focus on four major applications that are the core of any ad-hoc routing protocol. These applications are: route lifetime estimation, local connectivity management, nodes affinity management, and active queue management. In the first method, the fuzzy reasoning is used to estimate the time route can stay active in the routing table. In the second method, fuzzy reasoning is used to optimize the maximum time period that can transpire before the node broadcast the ‘Hello” messages. Mapping the relationship between the signal strength fluctuation and links lifetime is presented in the third method. Finally, in the last method fuzzy reasoning is used for network congestion estimation and estimating time to start dropping incoming packets. Extensive performance analysis via simulation proves the effectiveness of using the FRA to improve the accuracy of routing protocol parameters and hence the overall network performance

FROM CHOCOLATE BARS TO MOTOR CARS: The separation seen from the perspective of goods trafficking between Israel and the West Bank (2007-2010)

This chapter analyses the change in the informal trafficking of standard consumer goods between Israel and the West Bank since summer 2007, when Palestinian Authority's security forces were redeployed under the supervision of General Dayton. Based on an examination of the trafficking and the strategies developed by the traffickers, the Palestinian Authority's capacity to territorialise its control in Palestinian enclaves will first be assessed. Changes in the nature of these transactions will then be studied to identify the new forms of regulation that are emerging between the Israeli and Palestinian economies, over and above formal exchanges

E-Recruitment & the effectiveness of the diffrernet means of internet as a recruitment source: A case study of five stars hotels in Qatar

The use of technology and internet has increased in the last few years in all fields. With the high competition in labor market to attract talents it was necessary for all organizations to enhance their recruitment process. The aim of this paper is to understand the effectiveness of the different means of internet as a recruitment source used by five stars hotels in Qatar and show if these hotels are benefiting from these tools to attract qualified applicants. It measures how company website, social media and recruitment websites are being effective to the hotels based on four factors. These factors are: quality of applicants, workload required, cost efficiency and geographical spread. The study adopted a multi-method approach combining literature review and a case study research using semi- structured interview. The results indicated that all five stars hotels and considered e-recruitment to be an effective tool. Company website is the most used method and most of the hotels link it to a recruitment website. Social media is not used by all of the hotels, for some of them it is not considered a professional method of recruitment. The study also includes some recommendations that can help the hotels to get the maximum benefits of e-recruitment

تأثير استخدام أنواع مختلفة من الأسمدة على نمو ونوعية الخس (Lactuca sativa L.)

The experiment was conducted during the period from March to the end of April 2019 to observe the effect of different fertilizer regimes on the growth, quality and yield of lettuce under field conditions. The experiment was consisting of four treatments as well as a control without fertilizer T1, compost T2, compost tea T3 and chemical fertilizer T4, in each treatment 50 replicates were planted. The measurements included wet and dry weight for shoot and root, plant length, and chlorophyll percentage. The study revealed that lettuce\u27s best growth values were obtained with the use of eco-friendly organic fertilizer accompanied by more than control one and chemical fertilizer. The average maximum length of plants after 60 days was recorded in T2 (42.3 cm) \u3e T3 (37.3 cm), T4 (35.9 cm) and \u3e T1 (23.8 cm). The results indicated that compost treated plant (T2 and tea compost T3) had highest chlorophyll content, i.e., 42.3 and 40.6%, respectively, as compared to chemical fertilizers T4 (37.3%) and the lowest chlorophyll content was in control T1 (30.9%). The values for wet shoot and root after 60 days were: 1575.2, 81.5 gm T2 \u3e 1367.6, 64.9 gm T3 \u3e 1251.1, 53.4 gm T4 and 612.1, 43.7 gm T1, respectively. The values for dry shoot and root after 60 days were: 131.5, 8.2 gm, T2 \u3e 112.7, 6.4 gm, T3 \u3e 101.9, 5.3 gm T4 and \u3e 51, 4.1 gm T1, respectively

Efficient Signatures Verification System Based on Artificial Neural Networks

Biometrics refer to the system of authenticating identities of humans, using features like retina scans, thumb and fingerprint scanning, face recognition and also signature recognition. Signatures are a simple and natural method of verifying a person’s identity. It can be saved as an image and verified by matching, using neural networks. Signature verification can be offline or online. In this work, we present a system for offline signature verification. The user has to submit a number of signatures that are used to extract two types of features, statistical features and structural features. A vector obtained from each of them is used to train propagation neural network in the verification stage. A test signature is then taken from the user, to compare it with those the network had been trained with. A test experiment was carried out with two sets of data. One set is used as a training set for the propagation neural network in its verification stage. This set with four signatures form each user is used for the training purpose. The second set consists of one sample of signature for each of the 20 persons is used as a test set for the system. A negative identification test was carried out using a signature of one person to test others’ signatures. The experimental results for the accuracy showed excellent false reject rate and false acceptance rate

Control of Chaotic Behaviour in Parallel-Connected DC-DC Boost Converters

AbstractChaos control means to design a controller that is able to eliminating the chaos behaviour of nonlinear systems that experiencing such phenomenon. In this paper, a delayed feedback control mode is presented. The paper describes the control of the bifurcation behaviour of a modular peak current-mode controlled DC-DC boost converter which is used to provide an interface between energy storage batteries and photovoltaic (PV) arrays renewable energy sources. The parallel-input/parallel-output converter comprises two identical boost circuits and operates in the continuous-current conduction mode. A comparison is made between waveforms obtained from a MATLAB/SIMULINK model for open-loop converter and the controlled one. The study shows the effectiveness of the designed delayed feedback control mode

Dopaminergic Modulation of Goal-Directed Behavior in a Rodent Model of Attention-Deficit/Hyperactivity Disorder

Aside from its clinical symptoms of inattention, impulsivity and hyperactivity, patients with Attention/Deficit-Hyperactivity Disorder (ADHD) display reward and motivational impairments. These impairments may reflect a deficit in action control, that is, an inability to flexibly adapt behavior to changing consequences. We previously showed that spontaneously hypertensive rats (SHR), an inbred rodent model of ADHD, show impairments in goal-directed action control, and instead are predominated by habits. In this study, we examined the effects of specific dopamine receptor sub-type (D1 and D2) agonists and antagonists on goal-directed behavior in SHR and the normotensive inbred control strain Wistar-Kyoto (WKY) rats. Rats acquired an instrumental response for different-flavored food rewards. A selective-satiety outcome devaluation procedure followed by a choice test in extinction revealed outcome-insensitive habitual behavior in SHR rats. Outcome-sensitive goal-directed behavior was restored in SHR rats following injection prior to the choice test of the dopamine D2 receptor agonist Quinpirole or dopamine D1 receptor antagonist SCH23390, whereas WKY rats showed habitual responding following exposure to these drugs. This novel finding indicates that the core behavioral deficit in ADHD might not be a consequence of dopamine hypofunction, but rather is due to a misbalance between activation of dopamine D1 and D2 receptor pathways that govern action control