Commodity operating systems fail to meet the security, resource management and integration expectations of users. We propose a unified solution based on a capability framework as it supports fine grained objects, straightforward access propagation and virtualizable interfaces and explore how to improve resource use via access decomposition and policy refinement with minimum interposition. We ar...

We consider two-stage tandem queuing systems with dedicated servers in each station and flexible servers that can serve in both stations. We assume exponential service times, linear holding costs, and operating costs incurred by the servers at rates proportional to their speeds. Under conditions that ensure the optimality of nonidling policies, we show that the optimal allocation of flexible se...

This paper presents a new method for predicting the values of policies for cloned multiple teleo-reactive robots operating in the context of exogenous events. A teleo-reactive robot behaves autonomously under the control of a policy and is pre-disposed by that policy to achieve some goal. Our approach plans for a set of conjoint robots by focusing upon one representative of them. Simulation res...

Background: One of the important strategies to provide quality care is to motivate healthcare workers. Objectives: This study aimed to determine the components of job motivation among operating-room and anesthesia staff. Methods: This cross-sectional study was performed on 152 operating-room and anesthesia staff working in Zanjan hospitals and by the convenience sampling method. Data were co...

A ‘system of systems’ (SoS) comprises many other systems operating collectively with a shared purpose. Individual system autonomy can give rise to unpredictable, and potentially undesirable, emergent behaviour. A policy is a set of rules that bounds the behaviours of entities. Policy can be expressed at various levels of abstraction. By building on existing goal-based decomposition approaches t...

Policy search is a class of reinforcement learning algorithms for finding optimal policies in control problems with limited feedback. These methods have been shown to be successful in high-dimensional problems such as robotics control. Though successful, current methods can lead to unsafe policy parameters that potentially could damage hardware units. Motivated by such constraints, we propose p...

We present two generic formal security models for operating systems of multiapplicative smart cards. The models formalize the main security aspects of secrecy, integrity, secure communication between applications and secure downloading of new applications. The first model is maximally abstract, whereas the second extends the first by adding practically relevant issues such as a structured file ...

This paper analyzes a series inventory system with stationary costs and stochastic demand over an infinite horizon. A distinctive feature is that demand can be negative, representing returns from customers, as well as zero or positive. We observe that, as in a system with nonnegative demand, a stationary echelon base-stock policy is optimal here. However, the steadystate behavior of the system ...

A significant volume of research has concentrated on operating-system directed power management (OSPM). The primary focus of previous research has been the development of OSPM policies. Under different conditions, one policy may outperform another and vice versa. Hence, it is difficult, or even impossible, to design the “best” policy for all computers. We present a software framework called the...

This paper presents a new method for finding and evaluating policies for cloned multiple teleo-reactive agents operating in the context of exogenous events. The method is based upon discounted reward evaluation of policy restricted situation graphs. A teleo-reactive agent behaves autonomously under the control of a policy and is predisposed by that policy to achieve some goal. Our framework pla...