Voltage stability analysis with optimum size and location based synchronous machine DG

Power loss of a distribution system can be reduced significantly by using optimum size and location of distributed generation (DG). Proper allocation of DG with appropriate size maximizes overall system efficiency. Moreover it improves the reliability and voltage profile of the distribution system. In this paper, IEEE 123 node test feeder has been considered to determine the optimum size and location of a synchronous machine based DG for loss reduction of the system. This paper also investigates the steady-state and dynamic voltage profile of that three phase unbalance distribution network in presence of DG with optimum size. This analysis shows that optimum size of DG at proper location minimizes the power loss as well as improves the dynamic voltage profile of the distribution system.

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.

Rethinking the univariate approach to panel unit root testing: using covariates to resolve the incidental trend problem

In an influential article, Hansen showed that covariate augmentation can lead to substantial power gains when compared to univariate tests. In this article, we ask if this result extends also to the panel data context? The answer turns out to be yes, which is maybe not that surprising. What is surprising, however, is the extent of the power gain, which is shown to more than outweigh the well-known power loss in the presence of incidental trends. That is, the covariates have an order effect on the neighborhood around unity for which local asymptotic power is negligible.

Rationale for the use of DC microgrids: feasibility, efficiency and protection analysis

Electrical power systems are undergoing highly significant changes in their structures. The emergence of renewable energy units in the power generation sector, the use of high-voltage DC in the power transmission sector, and the prevalence of islanded or integrated microgrids in the distribution sector are the strongest evidence supporting this claim. These changes are mostly the consequences of the increasing energy demand rate, climate change, and environmental challenges, as well as the high investment and maintenance cost of the previous structures. Considering these new conditions and according to the recent development in DC/DC conversion topologies and control techniques, different studies have been conducted on how and why DC microgrids outperform AC microgrids. This study discusses the feasibility of the DC microgrid system according to recent developments in power systems. The efficiency and power loss reduction in DC distribution systems are then analyzed, some of the common strategies and devices for protection systems in such networks are reviewed, and the possible and existing challenges in developing the DC microgrids are highlighted. The mathematical calculations and theories for this evaluation are presented to determine the reliable justification for selecting the appropriate microgrid systems.

Application of neural networks as an auxiliary technique in the modelling of power station

Artificial neural network (NN) is an alternative way (to conventional physical or chemical based modeling technique) to solve complex ill-defined problems. Neural networks trained from historical data are able to handle nonlinear problems and to find the relationship between input data and output data when there is no obvious one between them. Neural Networks has been successfully used in control, robotic, pattern recognition, forecasting areas. This paper presents an application of neural networks in finding some key factors eg. heat loss factor in power station modeling process. In the conventional modeling of power station, these factors such as heat loss are normally determined by experience or “rule of thumb”. To get an accurate estimation of these factors special experiment needs to be carried out and is a very time consuming process. In this paper the neural networks (technique) is used to assist this difficult conventional modeling process. The historical data from a real running brown coal power station in Victoria has been used to train the neural network model and the outcomes of the trained NN model will be used to determine the factors in the conventional energy modeling of the power stations that is under the development as a part of an on-going ARC Linkage project aiming to detail modeling the internal energy flows in the power station.

Framing the discourses of harm and loss: a case study of power relations, mobile phones, and children in Australia

The current penetration of mobile phones in Australia is 92% and it records one of the world’s highest rates of ownership among children under 18. The paper reviews the literature on mobile phones and Australian children and examines the various discourses dominating the public debates; the systematic frames used in these discourses; and whose interests are served in the process. The frames discussed fall under the optimistic (gains); pessimistic (losses, costs or harms); pluralistic (technology per se is neutral but how it is used matters); historical development (skills learnt and the importance of using mobiles); futuristic predictions (promises and dangers for the future); current uses (connectivity, convergence and interactivity); and the techno-realist view (as a mixed blessing) views of technology. Taking the critical perspective and borrowing from Joshua Meyrowitz, the paper illustrates how mobile phones have eroded parental power over how, when, where and with whom their children communicate, surpassing adult supervision, intervention or knowledge, while at the same time, becoming a ‘digital leash’ for parents to re-establish their control an d an ‘umbilical cord’ for their off spring to remain connect! ed with parents, at all times.

Effectiveness of dual-task functional power training for preventing falls in older people: study protocol for a cluster randomised controlled trial

BACKGROUND: Falls are a major public health concern with at least one third of people aged 65 years and over falling at least once per year, and half of these will fall repeatedly, which can lead to injury, pain, loss of function and independence, reduced quality of life and even death. Although the causes of falls are varied and complex, the age-related loss in muscle power has emerged as a useful predictor of disability and falls in older people. In this population, the requirements to produce explosive and rapid movements often occurs whilst simultaneously performing other attention-demanding cognitive or motor tasks, such as walking while talking or carrying an object. The primary aim of this study is to determine whether dual-task functional power training (DT-FPT) can reduce the rate of falls in community-dwelling older people. METHODS/DESIGN: The study design is an 18-month cluster randomised controlled trial in which 280 adults aged ≥65 years residing in retirement villages, who are at increased risk of falling, will be randomly allocated to: 1) an exercise programme involving DT-FPT, or 2) a usual care control group. The intervention is divided into 3 distinct phases: 6 months of supervised DT-FPT, a 6-month 'step down' maintenance programme, and a 6-month follow-up. The primary outcome will be the number of falls after 6, 12 and 18 months. Secondary outcomes will include: lower extremity muscle power and strength, grip strength, functional assessments of gait, reaction time and dynamic balance under single- and dual-task conditions, activities of daily living, quality of life, cognitive function and falls-related self-efficacy. We will also evaluate the cost-effectiveness of the programme for preventing falls. DISCUSSION: The study offers a novel approach that may guide the development and implementation of future community-based falls prevention programmes that specifically focus on optimising muscle power and dual-task performance to reduce falls risk under 'real life' conditions in older adults. In addition, the 'step down' programme will provide new information about the efficacy of a less intensive maintenance programme for reducing the risk of falls over an extended period. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry: ACTRN12613001161718 . Date registered 23 October 2013.

Energy expenditure in relation to flight speed: what is the power of mass loss rate estimates?

The relationship between mass loss rate and chemical power in flying birds is analysed with regard to water and heat balance. Two models are presented: the first model is applicable to situations where heat loads are moderate. i.e. when heat balance can be achieved by regulating non-evaporative heat loss, and evaporative water loss is minimised. The second model is applicable when heat loads are high, non-evaporative heat loss is maximised. and heat balance has to be achieved by regulating evaporative heat loss. The rates of mass loss of two Thrush Nightingales Luscinia luscinia and one Teal Anas crecca were measured at various flight speeds in a wind tunnel. Estimates of metabolic water production indicate that the Thrush Nightingales did not dehydrate during experimental flights. Probably, the Thrush Nightingales maintained heat balance without actively increasing evaporative cooling. The Teal, however, most likely had to resort to evaporative cooling, although it may not have dehydrated. Chemical power was estimated from our mass loss rate data using the minimum evaporation model for the Thrush Nightingales and the evaporative heat regulation model for the Teal. For both Thrush Nightingales and the Teal, the chemical power calculated from our mass loss rate data showed a greater change with speed (more 'U-shaped' curve) than the theoretically predicted chemical power curves based on aerodynamic theory. The minimum power speeds calculated from our data differed little from theoretical predictions but maximum range speeds were drastically different. Mass loss rate could potentially be used to estimate chemical power in flying birds under laboratory conditions where temperature and humidity are controlled. However, the assumptions made in the models and the model predictions need further testing.

Distributed generation capacity planning for distribution networks to minimize energy loss: an unbalanced multi-phase optimal power flow based approach

This chapter presents an unbalanced multi-phase optimal power flow (UMOPF) based planning approach to determine the optimum capacities of multiple distributed generation units in a distribution network. An adaptive weight particle swarm optimization algorithm is used to find the global optimum solution. To increase the efficiency of the proposed scheme, a co-simulation platform is developed. Since the proposed method is mainly based on the cost optimization, variations in loads and uncertainties within DG units are also taken into account to perform the analysis. An IEEE 123 node distribution system is used as a test distribution network which is unbalanced and multi-phase in nature, for the validation of the proposed scheme. The superiority of the proposed method is investigated through the comparisons of the results obtained that of a Genetic Algorithm based OPF method. This analysis also shows that the DG capacity planning considering annual load and generation uncertainties outperform the traditional well practised peak-load planning.

Deconstructing power within a strategic information system

Strategy is a political act, and yet that has received very little attention in IS strategy research. The purpose of this paper is to explore the mixes between politics, power and strategy using a case study of implementation of a Student Administration System. This takes Strategic Information Systems out of the realm of the purely socia-technical view of information systems and moves it into a dimension which deals with the real social interactions that occur within organisations as a result of the implementation of a strategy in the form of a Student Administration System. This case study shows the power struggles, primarily by two Senior Executives and the users of the information system. The discourse behind this project was initially to create uniformity across a system therefore enabling more than 30 universities around Australia to move from a diversified system to a centralized system. It was through this resistance and through their positions that the two Senior Executives were able to create the discourse that framed many of the decisions and implementation of the system. There eventually became an acceptance that it was for the social good of the University that the Student Administration System was adopted across the University of Australia.

Are real exchange rates nonlinear with a unit root? Evidence on PPP for Italy : a note

In this article, we apply the recently developed threshold autoregression model to examine both linearity and stationarity of Italy's real exchange rate vis--vis her six trading partner (G6) countries. Our main finding is that Italy's real exchange rate is a nonlinear process that is not characterized by a unit root process for five of six trading partner countries. This provides strong support for purchasing power parity.

Real footballers don`t eat quiche: old narratives in new times

In this article, the authors examine the way that sport acts as a contradictory and complex medium for masculinity making. The analysis illustrates the way that many discourses now unite in a cybernetic mix that offers both new opportunities and presents complex challenges for educators, coaches, and administrators. The method used combines a number of strategies and narratives pitched at the local, national, and international levels. The analysis is grounded in the game of football, although it is argued that the issues raised translate to other settings. At the same time, the authors demonstrate that large-scale, macro level analyses miss an important force working within the dynamics of masculinity making and sport, namely, peer group power. The analysis concludes with insights from a junior coach who has consciously "worked" the peer group dynamics to foster a strong sense of personal and group responsibility.

Exploring the increasing role of the real estate sector in the Chinese economy : 1997-2002

The Chinese government launched a series of real estate reform policies in 1998, which further changed the real estate sector from socialist plan-oriented to modern marketoriented. This paper compares the role of the real estate sector in the Chinese economy in years 1997 and 2002 by using the recently published input-output OECD database. Results verify that the Chinese real estate sector played an increasing role in the Chinese economy with higher contributions and stronger push and pull power in 2002 than those in 1997. However, compared with other countries, especially for some OECD countries, the Chinese real estate sector has a relative lower contribution.

TDOA based transmitter localization with minimum number of teceivers and power measurements

This paper investigates the problem of localizing a wireless transmitter using a minimum number of receivers and other readily available means in a time difference of arrival (TDOA) setting. Using the necessary and sufficient conditions for unique solution, we use power measurements to compensate for the reduced number of receivers. In other words, if the transmitter is not located in the unique solution area, we provides a technique to find the true location via the measured received signal power. Our approach neither requires the knowledge of the transmission power nor the path loss exponent.