Teleoperation of passivity-based model reference robust control over the internet

This dissertation offers a survey of a known theoretical approach and novel experimental results in establishing a live communication medium through the internet to host a virtual communication environment for use in Passivity-Based Model Reference Robust Control systems with delays. The controller which is used as a carrier to support a robust communication between input-to-state stability is designed as a control strategy that passively compensates for position errors that arise during contact tasks and strives to achieve delay-independent stability for controlling of aircrafts or other mobile objects. Furthermore the controller is used for nonlinear systems, coordination of multiple agents, bilateral teleoperation, and collision avoidance thus maintaining a communication link with an upper bound of constant delay is crucial for robustness and stability of the overall system. For utilizing such framework an elucidation can be formulated by preparing site survey for analyzing not only the geographical distances separating the nodes in which the teleoperation will occur but also the communication parameters that define the virtual topography that the data will travel through. This survey will first define the feasibility of the overall operation since the teleoperation will be used to sustain a delay based controller over the internet thus obtaining a hypothetical upper bound for the delay via site survey is crucial not only for the communication system but also the delay is required for the design of the passivity-based model reference robust control. Following delay calculation and measurement via site survey, bandwidth tests for unidirectional and bidirectional communication is inspected to ensure that the speed is viable to maintain a real-time connection. Furthermore from obtaining the results it becomes crucial to measure the consistency of the delay throughout a sampled period to guarantee that the upper bound is not breached at any point within the communication to jeopardize the robustness of the controller. Following delay analysis a geographical and topological overview of the communication is also briefly examined via a trace-route to understand the underlying nodes and their contribution to the delay and round-trip consistency. To accommodate the communication channel for the controller the input and output data from both nodes need to be encapsulated within a transmission control protocol via a multithreaded design of a robust program within the C language. The program will construct a multithreaded client-server relationship in which the control data is transmitted. For added stability and higher level of security the channel is then encapsulated via an internet protocol security by utilizing a protocol suite for protecting the communication by authentication and encrypting each packet of the session using negotiation of cryptographic keys during each session

Iran’s Banking and Monetary Problems

Iran has had many self-imposed economic crises. Many of which relate to the poorly managed banking system as well as flawed monetary and fiscal policy. Inefficiency of the banking-monetary system in Iran is a well known fact. A complete overhaul of the current system should be one of the essential priorities of any economic reformation and development. The banking-monetary system of any country has a key role in its economic efficiency and strength, price stability, production, and economic growth. The main functions of a banking-monetary system are to provide fiscal resources, to prepare ground for optimal allocation of capital in the economy, to distribute the wealth in the best possible way, and to ease economic development. This is particularly important in Iran because capital markets are underdeveloped.Iran; Banking; Monetary Policy; Fiscal Policy

Iran and the Global Financial Crisis

The global financial crisis is set to depress oil producing economies. As the crisis is already pushing down oil prices, a firm response to the fallout of the crisis from governments and central banks is expected. Oil prices have tumbled more than 70% since their July peak and there are fears they could continue their plunge because of diminishing demand caused by the current financial meltdown. Though, the Iranian government does not seem to be greatly concerned about the ongoing global situation, although many Iranian economists believe that sanctions and the international financial crisis will soon be taking their toll on Iran’s economy by unfavorably affecting oil, trade, and trade financing. Even if the relative isolation from the world’s economy may seem to protect Iran from the negative impact of the global financial crisis to a certain extend at least for now, plunging oil prices and a massive credit deterioration suggest otherwise.Iran; Financial Crisis; Oil Revenue; Currency Exchange; Currency Crash

Financial Crisis, Iranian Style

A steep fall in crude prices allied with lower output will decrease the Iranian government’s foreign revenues significantly. The Tehran Stock Exchange (TSE) has lost 30% of its value in the last four months, which points to a sizable economic slowdown in the near future. Perhaps Iran is among a handful of countries that has not properly planned to combat any potential economic crisis in the face of lower oil prices and the global financial meltdown that began to show its visage in the middle of 2007. The substantial inflow of petrodollars to the government’s account coupled with the faulty assumption that the oil prices will continue to rise triggered the government to infuse billions of dollars into the economic and banking system. Iranian officials have just begun to accept the new global circumstances and are after drafting a budget for the next Iranian year to ride out the financial turmoil. The administration is planning to eliminate energy subsidies and reduce its price controls in the new fiscal budget planning in order to reduce the massive deficit. It is indeed ironic from a government that has no belief in principles of a free market economy and denied it in the past to draw such a plan, many economists have stated. Whether the government has realized its past mistakes, is unknown and whether the new budget and policy will ease the current economic problems, remains to be seen! A more important question is whether the central bank and the administration will be able to employ the available monetary and fiscal tools to tackle the profound upcoming economic challenges, since they already tied their hands by their past mistakes and beliefs. Overall, the next few months or perhaps years will undoubtedly be very challenging times for the system.Iran; Budget Deficit; Economic Policy; Credit Crisis

Finite Element Analysis of Cooling Tower Foundation Under Wind Load

The natural draught cooling tower is very important and essential component in the thermal nuclear power stations and industrial power plants. Due to their complexities in geometry the analysis of such type of structures has attracted many researches throughout the world. At the initial stage of this study an attempt was made to write a computer programme for calculating the symmetrical and unsymmetrical wind loading using FORTRAN program, which is compatible with FORTRAN 90 Power Station. The programme was written according to IS: 11504/BS: 4485. The present study deals with physical and material modeling of cooling towerfoundation- soil system. The physical modeling has been carried out using solid twenty-nodded isoparametric element to model the cooling tower, annular raft foundation and soil media. Coupled finite elements were employed to represent the soil media in the near and far field the cooling tower. Cooling tower, foundation-soil system was analyzed under vertical and lateral load generated from wind loads. The soil nonlinearity was taken into the consideration using DUNCAN’S hyperbolic constitutive stress strain law. Therefore, based on those physical and material modeling a finite element program has been written. The computer software package works under FORTRAN power station and the validity of this package has been verified by solving some examples available in the literature. Finally an attempt has been made to demonstrate the applicability of the finite element program in analysis of cooling tower with the total height of 115.35 m and the radius at top, bottom and throat level are 27.535 m, 52.877 m, 25.304 m respectively, subjected to static loading . The response of the structure has been discussed with respect to displacement and stresses. Moreover an attempt has been made to study the effect of the interactive and non-interactive analysis and comparison with conventional analysis was also made. It was concluded that the interactive analysis of the cooling tower-foundation-soil media plays a major role in releasing the stresses in the cooling tower, particular at the bottom ring beam

Control of Thermal Power System Using Adaptive Fuzzy Logic Control

Controlling thermal power systems increases the overall system efficiency and satisfies the desired requirements. In such a large system, fuel reduction of even a small percentage leads to large energy saving. Hence, power systems are gaining significant attention from engineers and scientists. In this thesis, the uncontrolled power system for single area, two area, and three area is modelled using state space representation. Frequency deviation is simulated using MATLAB and SIMULINK. PID control is added to the system to analyze the effect of conventional control on system output response. Adaptive fuzzy logic control is added to the uncontrolled system using MATLAB Fuzzy Inference System and its effect on the system output response is measured in terms of overshoot/undershoot percentage, settling time, and steady state frequency error. Effect of adaptive fuzzy logic control is analyzed on single area, two area, and three area power system. Tie-line power exchange among areas is investigated before and after implementation of PID and adaptive fuzzy logic control. For the purpose of comparison in this thesis, a conventional PID control and an adaptive fuzzy logic control is applied to two different thermal power systems. The simulations demonstrate that adaptive fuzzy logic control is proved to be more efficient and reliable than conventional PID control in power system control problem

Effects of Frying and Storage Conditions On Physicochemical Properties of Palm Olein and Olive Oil Blends

The main objective of this study was to investigate the effect of type and concentrations of frying oil namely palm olein (POo) (0, 10, 25, 50, 75, 90 and 100% w/w) and olive oil (OO) (0, 10, 25, 50, 75, 90 and 100% w/w) contents on physicochemical properties of the oil blends. The main physicochemical properties of frying media namely iodine value (IV), peroxide value (PV), anisidine value (AV), totox value (TV), total polar component (TPC), free fatty acid (FFA), cloud point, color and viscosity were assessed as response variables in the present study. The results indicated that the type and concentration of frying media had no significant (p > 0.05) effect on FFA of oil blends; whereas the magnitudes of IV, PV, AV, TV, cloud point, color and viscosity were significantly (p < 0.05) influenced by the type and concentration of frying media. The highest TV (6.10) was shown in the oil blend containing 10% (w/w) POo and 90% (w/w) OO; while the least TV (2.41) was observed in the oil blend containing 90% (w/w) POo and 10% (w/w) OO. This observation could be explained by the high proportion of polyunsaturated fatty acids to monounsaturated fatty acids in former oil blend (POo:OO, 10:90) compared to latter oil blend (POo:OO, 90:10), thus indicating that the increase in the proportion of polyunsaturated/monounsaturated fatty acids led to decrease the chemical stability of the oil blend to the oxidative rancidity. Subsequently, the influence of partial replacement of olive oil (25 and 50% w/w) on frying performance was investigated during 5 consecutive days of frying process. In general, the physiochemical properties of oil blends were significantly (p < 0.05) influenced by the partial replacement of olive oil. The increase in the proportion of polyunsaturated/monounsaturated fatty acid significantly (p < 0.05) decreased the chemical stability of the oil blend during the frying process. The highest changes in AV (79.22), PV (13.55 meq O2/kg) and TV (103.18) were shown by the control (POo, 100% w/w); while the oil blend 2 (POo: OO, 50:50) containing higher concentration of olive oil exhibited the least changes in AV (53.17), PV (2 meq O2/kg) and TV (52.29) during 5 days frying process. Thus, the present study offers that the chemical stability of oil to the oxidative rancidity depends on not only the saturated fatty acid content but also on the proportion of monounsaturated to polyunsaturated fatty acids. The frying time also showed the significant (p < 0.05) effect on TPC of frying media. TPC increased by prolonging the frying time depending on type of frying oil. During 5 days of frying process, the highest increase in TPC (16.51%) was shown by control sample (i.e. POo, 100%); while the frying process using oil blend 2 containing 50% POo and 50% OO resulted in the least increase in TPC (14.63%). Thus, the results showed that the oil blend containing higher olive oil content (i.e. higher oleic acid) provided lower TPC (19.24%) than the TPC (20.92%) of frying media containing higher POo content. The last part of this study was conducted to evaluate the influence of storage time and type of frying media (POo: OO, 100:0, 75:25 and 50:50) as independent variables on the physicochemical properties of oil blends during 60 consecutive days under accelerated condition (60 ºC). The physiochemical properties of oil blends were significantly (p < 0.05) influenced by the independent variables studied. The increase in the proportion of polyunsaturated/monounsaturated fatty acid significantly (p < 0.05) decreased the chemical stability of the oil blend during storage time. The highest changes in AV (38), PV (39.98 meq O2/kg) and TV (117.26) were shown by the control (POO, 100% w/w); while the oil blend 2 (POo: OO, 50:50) containing higher concentration of olive oil (i.e. higher oleic acid content) exhibited the least changes in AV (29.31), PV (26.93 meq O2/kg) and TV (83.38) during 60 days storage. In fact, the oil blend 2 (POo: OO, 50:50) containing higher concentration ratio of oleic acid to linoleic acid (C18:2) was found to be stable during 60 days storage. Thus, the present study suggested that blending palm olein with high monounsaturated fatty acid-contained oil e.g. olive oil can provide the oil blend which is physically more stable than regular POo and remained liquid at ambient temperature

A Pilot Study of Pedestrians with Visual Impairments Detecting Traffic Gaps and Surges Containing Hybrid Vehicles

The increasing number of hybrid and quiet internal combustion engine vehicles may impact the travel abilities of pedestrians who are blind. Pedestrians who rely on auditory cues for structuring their travel may face challenges in making crossing decisions in the presence of quiet vehicles. This article describes results of initial studies looking at the crossing decisions of pedestrians who are blind at an uncontrolled crossing (no traffic control) and a light controlled intersection. The presence of hybrid vehicles was a factor in each situation. At the uncontrolled crossing, Toyota hybrids were most difficult to detect but crossing decisions were made more often in small gaps ended by a Honda hybrid. These effects were seen only at speed under 20 mph. At the light controlled intersection, parallel surges of traffic were most difficult to detect when made up only of a Ford Escape hybrid. Results suggest that more controlled studies of vehicle characteristics impacting crossing decisions of pedestrians who are blind are warranted

African economic growth must translate into positive change #ADFSOAS

Olivia Barnett-Naghshineh of SOAS previews some of the issues that will be under discussion at the African Development Forum 2012 at SOAS on Tuesday 29 May

Effects of frying condition on physicochemical properties of palm olein-olive oil blends.

The main objective of present study was to investigate the effects of frying conditions (i.e. the type of frying oil and frying time) on physicochemical properties of palm olein-olive oil blends (POo: Oo, 75:25 and 50:50 w/w) compared to the pure palm olein (100% w/w). The frying process of French fries was performed in duplicate at 180 ± 5 ºC for 5 consecutive days. The physicochemical properties of the frying media namely the fatty acids composition (FAC), iodine value (IV), free fatty acid (FFA) and color were considered as response variables. The present study clearly indicated that the frying performance of palm olein significantly (p < 0.05) improved by the blending of palm olein (Po) with the olive olein (Oo). As shown in the results, there was a significant (p < 0.05) positive correlation between FFA and color. The present work suggested that partial replacement of palm olein with olive oil provided the oil blends (POo: Oo, 75:25 and 50:50 w/w) with more desirable functional properties for the human health due to the high proportion of monounsaturated to saturated/polyunsaturated fatty acids