Supporting uninterrupted services for performance-sensitive distributed applications operating in resource-constrained environments is hard. It is even harder when the operating environment is dynamic and processor or process failures and system workload changes are common. Fault-tolerant middleware for these applications must assure high service availability and satisfactory response times for...

The production of electrical energy from renewable sources has, in recent years, increased significantly with wind generation as the predominant technology. This development is expected to continue in the near future. However, the integration of such stochastic and intermittent power sources into the existing power system implies a higher ratio of non-dispatchable generation which, in turn, lea...

Abstract. Despite the available monitor and control functionalities, the timely reconfiguration of modern power grids is not always feasible, due to the inherent inertia of the power elements. Therefore, especially in the case of abrupt phenomena (e.g. loss of power lines), power grids tend to suffer from severe cascade effects, since the triggering failure is usually followed by successive ove...

Existence of many different Operators in the new electricity has brought many challenges in the system operation and control to obtain minimum generation cost and security. With the growing demand of electricity in the competitive electricity market environment, one or more transmission lines could be overloaded, therefore causing congestion. The congestion can be eliminated/alleviated by impro...

The current social impact of new transmission and distribution lines and the growth in environmental requirements has not lead to the expansion of the electric power grid but to the optimization of the existing assets. Flexible AC Transmissions Systems (FACTS), developed during the last decades of the past century, have become one of the most remarkable solutions for the optimization of the ele...

Korea has industrialized since the 1970s. Pneumoconiosis in coal miners was the most common occupational disease in the 1970s to 1980s. With the industrialization, the use of many chemicals have increased since the 1970s. As a consequence, there were outbreaks of occupational diseases caused by poisonous chemicals, such as heavy metal poisoning, solvent poisoning and occupational asthma in the ...

The development of a control system and control strategies capable of governing multiple flexible AC transmission system (FACTS) devices in coordination with a load shedding is described here. The main purpose of the presented coordinated control system is to remove overloads caused by unplanned line outages in transmission network. A sensitivity analysis was used to find out an intercoupling b...

In this master thesis, work done in the TURBO POWER project High temperature fatigue crack propagation in nickel-based superalloys during spring 2012 will be presented. The overall objective of this project is to develop and evaluate tools for designing against fatigue in gas turbine applications, with special focus on the crack propagation in the nickel-based superalloy Inconel 718. Experiment...

A new probabilistic model describing the fatigue crack growth with retardation due to random overloads is developed. First, a crack growth equation is formulated based upon the Flber law, where a concept of retardation factor is introduced to quantify the retardation effect. Next, a new approach is discussed for describing the temporal variation of the retardation factor by the use of a system ...

For over a century, there has been intense debate as to the reason why some cardiac stresses are pathological and others are physiological. One long-standing theory is that physiological overloads such as exercise are intermittent, while pathological overloads such as hypertension are chronic. In this study, we hypothesized that the nature of the stress on the heart, rather than its duration, i...