Fuzzy logic controller and cascade inverter for direct torque control of IM

In this paper, a five-level cascaded H-bridge multilevel inverters topology is applied on induction motor control known as direct torque control (DTC) strategy. More inverter states can be generated by a five-level inverter which improves voltage selection capability. This paper also introduces two different control methods to select the appropriate output voltage vector for reducing the torque and flux error to zero. The first is based on the conventional DTC scheme using a pair of hysteresis comparators and look up table to select the output voltage vector for controlling the torque and flux. The second is based on a new fuzzy logic controller using Sugeno as the inference method to select the output voltage vector by replacing the hysteresis comparators and lookup table in the conventional DTC, to which the results show more reduction in torque ripple and feasibility of smooth stator current. By using Matlab/Simulink, it is verified that using five-level inverter in DTC drive can reduce the torque ripple in comparison with conventional DTC, and further torque ripple reduction is obtained by applying fuzzy logic controller. The simulation results have also verified that using a fuzzy controller instead of a hysteresis controller has resulted in reduction in the flux ripples significantly as well as reduces the total harmonic distortion of the stator current to below 4 %.

Digital literacies in the middle years of schooling

This paper uses Glister's interpretation of digital literacy whilst acknowledging that a computer is not the only means for the delivety of digital texts. I will explore how we can support student teachers to develop understandings about the teaching in the middle years in order to work with students in schools to successfully read digital texts, create digital texts, search, fmd and use information in the digital world and to become critical users of digital texts. Students in the middle years of schooling are facing increasingly sophisticated literacy demands of new technologies that go well beyond that of the traditional printed page as they interact with information communicated through a range of digital media both inside and outside of school. At best new technologies can open doors to students for researching and accessing a world far beyond their own environment, empowering them to direct and control their own learning and produce quality work.

Verfahren zur Entlüftung eines Kurbelgehäuses einer Brennkraftmaschine und Brennkraftmaschine zur Durchführung eines derartigen Verfahrens

The method involves performing load control of an internal combustion engine by a throttle valve provided in a suction line. An exhaust line is provided at a crankcase and is connected with the suction line. An electronically controllable valve (115) is arranged in the exhaust line to control the exhaust flow of the internal combustion engine depending on the operating condition of the internal combustion engine. An independent claim is also included for an internal combustion engine for the execution of a crankcase ventilating method.

Political transition in Myanmar: prospects and problems

Since 2011, Myanmar has been undergoing a political transition that, in keeping with the Myanmar government's own claims, has been hailed by many previously critical countries as the start of a process of democratization. Myanmar has become a substantially more liberal country, and in particular its economy has been increasingly liberalized, away from the tight restrictions of the past. However, Myanmar's economic liberalization primarily benefits its entrenched and usually military-dominated or linked elites, while its political liberalization may be just enough to satisfy an appearance of democratization without the army giving up real power. This article looks at Myanmar's process of political liberalization set against some of the literature on political transitions, and highlights some factors that could militate against extensive reform, much less democratization. It concludes by noting that while Myanmar's military has started to step back from direct political control, it still retains ultimate state authority. © 2014 Policy Studies Organization.

Seasonal timing of the spring departure of waders from the Banc D'Arguin, Mauritania

The northward departure of 13 wader species was studied in the Baie d' Aouatif, Bane d'Arguin, Mauritania, in the springs of 1985, 1986 and 1988. Waders left the area in the late afternoon. Wind speed and direction were registered near ground level (all years) and at altitudes up to 5 km (in 1988). A total of 31 000 waders were observed heading northwards, with those species wintering locally in largest numbers being most common. The majority of wader species showed fairly short periods of departure and unimodal departure peaks. Redshank and Dunlin departed over extended periods. Average departure dates of species correlated positively with the estimated midpoints of ranges in breeding latitude (ca. 2 d per 0 latitude).  Since winds at ground level did not correlate with winds at higher altitudes, and since it is likely that the departing waders traveled at great heights, it was not surprising that there is no correlation between the average afternoon tail wind vector at ground level and the daily departure intensity. We suggest that the timing ofdeparture from the Bane d'Arguin is largely under internal, instead of under direct environmental, control.

Load frequency control of power systems with electric vehicles and diverse transmission links using distributed functional observers

This paper presents a load frequency control scheme using electric vehicles (EVs) to help thermal turbine units to provide the stability fluctuated by load demands. First, a general framework for deriving a state-space model for general power system topologies is given. Then, a detailed model of a four-area power system incorporating a smart and renewable discharged EVs system is presented. The areas within the system are interconnected via a combination of alternating current/high voltage direct current links and thyristor controlled phase shifters. Based on some recent development on functional observers, novel distributed functional observers are designed, one at each local area, to implement any given global state feedback controller. The designed observers are of reduced order and dynamically decoupled from others in contrast to conventional centralized observer (CO)-based controllers. The proposed scheme can cope better against accidental failures than those CO-based controllers. Extensive simulations and comparisons are given to show the effectiveness of the proposed control scheme.

Mediated and direct effects of general control beliefs on obsessive compulsive symptoms

Although control-related cognitions have often been implicated in discussions of obsessive compulsive disorder (OCD), empirical investigations of the relationship between control constructs and OCD symptoms have been relatively limited. This article investigated the hypothesis that OCD symptoms may be linked with a higher desire for control (DC), but a lower sense of control (SC) over the self and environment, leading to motivation for compulsive symptoms. It also investigated whether this effect was direct, or mediated through other OCD-related cognitions. This hypothesis was investigated in a nonclinical population, using path analyses controlling for depression. It was found that higher levels of DC and lower levels of SC were associated with higher levels of OCD-related beliefs, and with symptoms via higher OCD-related beliefs. SC was also directly linked with higher OCD symptoms. Control beliefs regarding both the internal (emotions) and external (threat) environment were related to OCD symptoms. Implications for therapy and research are discussed.

An improved stability criterion for time-delay power systems with electric vehicles and high voltage direct current power links

This paper presents an improved stability criterion for load frequency control (LFC) of time-delay power systems including AC/HVDC transmission links and EVs. By employing a novel refined Jensen-based inequality, an improved stability condition is derived in terms of feasible linear matrix inequalities (LMIs) which allow us to compute the maximal upper bounds of time-delay ensuring stability of the LFC scheme equipped with an embedded controller. Cases studies here are implemented for LFC scheme of a two-area power system, which is interconnected by parallel (AC/HVDC) links, with embedded proportional integral (PI) controller for discharged EVs. The relationships between the parameters of PI controller, supplementary control of HVDC links and delay margins of the LFC scheme are also discussed. As a consequence of facts, the results of delay margins can be used as a guideline to tune PI controller and set-up parameters for HVDC control.

Integration of electric vehicles for load frequency output feedback H ∞ control of smart grids

This study considers a novel application of electric vehicles (EVs) to quickly help reheated thermal turbine units to provide the stability fluctuated by load demands. A mathematical model of a power system with EVs is first derived. This model contains the dynamic interactions of EVs and multiple network-induced time delays. Then, a dynamic output feedback H∞ controller for load frequency control of power systems with multiple time delays in the control input is proposed. To address the multiple time delays issue, a refined Jensen-based inequality, which encompasses the Jensen inequality, is used to derive less conservative synthesis conditions in terms of tractable linear matrix inequalities. A procedure is given to parameterise an output feedback controller to guarantee stability and H∞ performance of the closed-loop system. Extensive simulations are conducted to validate the proposed control method.

Cold rolling mill thickness control using the cascade-correlation neural network

The improvements in thickness accuracy of a steel strip produced by a tandem cold-roIling mill are of substantial interest to the steel industry. In this paper, we designed a direct model-reference adaptive control (MRAC)  scheme that exploits the natural level of excitation existing in the closed-loop with a dynamically constructed cascade-correlation neural network (CCNN) as a controller for cold roIling mill thickness control. Simulation results show that the combination of a such a direct MRAC scheme and the dynamically constructed CCNN significantly improves the thickness accuracy in the presence of disturbances and noise in comparison with to the conventional PID controllers.

The long and the short of flagellar length control

Discusses key issues concerning the length control of flagellates. How the cell maintains the consistency of length; Final flagellar length achieved when the rate of flagellar assembly slows down to a point where it exactly balances the rate of flagellar disassembly; Implications on phycology.

Teachers' work hours, work-family conflict and health: the mediating effects of perceived control and organisational support

Teachers are among those working longer hours more than ever before. the implications of these long hours on teachers' health, through work-family conflict, control over hours worked and organisational support were investigated. 120 teachers, of whom 91 (59.3% female) reported
working in excess of 37 1/2 hours in the week prior, participated in the study. Long hours, work-family conflict, control and organisational support, explained 69% of the variance in health. There was no direct effect of long worked hours on health however long hours did have a direct impact on work-family conflict, organisational support, and control and, through
these, teachers' health. Work-family conflict exerted a direct negative impact on health. These findings are discussed in individual and organisational tenns.

Terrify and control: the politics of risk society

The article presents information on the idea of risk management. The origins of the contemporary constructions of risk are found in the seventeenth century, with the development of maritime insurance. In the context of maritime trading, risk came to be seen in terms of the balance between acquisitive opportunities and potential dangers and calculations of future loss of a ship or cargo. Today perceptions of risk affect our actions and strategies in areas of our life as diverse as health, parenting, crime prevention, recreation and travel. Public policy tends to be focused around risk avoidance and risk management, particularly in areas of child protection and aged care. While most of the discussions of risk have focused on risks as bads in society, risk has also been identified as a good. Risk is deemed a good when it challenges people to think differently and creatively. From a neo-liberal perspective risk opens up opportunities for unleashing of entrepreneurial capacity. In the context of the modernist commitment to the idea that people have the potential to control their own destiny, identification of threats and dangers can energize people to be adventurous. The discourse of risk has framed all the reports of the outbreaks of new strains of infection and includes instructions on how to recognize the risk assessments of its spread and instructions on how to avoid its spread.

Habitat manipulation and rodent damage control: reducing rodent damage in Australian macadamia orchards

This paper examines the relationship between adjacent non-crop vegetation and rodent (Rattus rattus) damage in Australian macadamia (Macadamia integrifolia) orchard systems. Orchards adjacent to structurally diverse, non-crop vegetation dominated by woody weeds exhibited significantly higher damage when compared to orchards adjacent to managed grasslands. This relationship formed the basis for a rodent damage reduction strategy utilising habitat manipulation. Structurally diverse, non-crop habitats were modified to grasslands leading to a reduction in rodent damage of 65%. This strategy was cost-effective and has the potential to be long-term with minimal effort needed to maintain sites in a modified state. Habitat manipulation is a process whereby the resource load in a system is reduced and hence rodent densities cannot reach levels where they cause significant crop damage. This paper provides empirical evidence to support habitat manipulation as a practical, cost-effective control strategy for rodent pests.