Globally reasoning about localised security policies in distributed systems

In this report, we aim at establishing proper ways for model checking the global security of distributed systems, which are designed consisting of set of localised security policies that enforce specific issues about the security expected. The systems are formally specified following a syntax, defined in detail in this report, and their behaviour is clearly established by the Semantics, also defined in detail in this report. The systems include the formal attachment of security policies into their locations, whose intended interactions are trapped by the policies, aiming at taking access control decisions of the system, and the Semantics also takes care of this. Using the Semantics, a Labelled Transition System (LTS) can be induced for every particular system, and over this LTS some model checking tasks could be done. We identify how this LTS is indeed obtained, and propose an alternative way of model checking the not-yet-induced LTS, by using the system design directly. This may lead to over-approximation thereby producing imprecise, though safe, results. We restrict ourselves to finite systems, in the sake of being certain about the decidability of the proposed method. To illustrate the usefulness and validity of our proposal, we present 2 small case-study-like examples, where we show how the system can be specified, which policies could be added to it, and how to decide if the desired global security property is met. Finally, an Appendix is given for digging deeply into how a tool for automatically performing this task is being built, including some implementation issues. The tool takes advantage of the proposed method, and given some system and some desired global security property, it safely (i.e. without false positives) ensures satisfaction of it

MODELS FOR MEASURING THE RESEARCH PERFORMANCE AND MANAGEMENT OF THE PUBLIC LABS

The science sector, in some European countries, is doing a strategic restructuring due to budget cuts (e.g. Italy). Thus, the measure and evaluation of research performance (metrics) of its units (public research institute) is needed. General models to assess the R&D performance of a public research lab are presented here. The methodology uses the discriminant analysis and the results are two canonical discriminant functions (direct and Wilks methods) that could provide indications about the performance of research bodies. The functions are successfully applied to 200 public research institutes belonging to the Italian National Research Council. These functions are also tools for appropriate decisions and actions to improve research performance, especially by the more effective use of existing resources and for reducing the X-inefficiency. Some policy and management implications are discussed.Research performance, Performance measurement, Performance indicators, R&D evaluation, Public research lab, Discriminant analysis, X-inefficiency

A decision support system for demand and capacity modelling of an accident and emergency department

© 2019 Operational Research Society.Accident and emergency (A&E) departments in England have been struggling against severe capacity constraints. In addition, A&E demands have been increasing year on year. In this study, our aim was to develop a decision support system combining discrete event simulation and comparative forecasting techniques for the better management of the Princess Alexandra Hospital in England. We used the national hospital episodes statistics data-set including period April, 2009 – January, 2013. Two demand conditions are considered: the expected demand condition is based on A&E demands estimated by comparing forecasting methods, and the unexpected demand is based on the closure of a nearby A&E department due to budgeting constraints. We developed a discrete event simulation model to measure a number of key performance metrics. This paper presents a crucial study which will enable service managers and directors of hospitals to foresee their activities in future and form a strategic plan well in advance.Peer reviewe

Probabilistic constraints via SQP solver: Application to a renewable energy management problem

The aim of this paper is to illustrate the efficient solution of nonlinear optimization problems with joint probabilistic constraints by means of an SQP method. Here, the random vector is assumed to obey some multivariate Gaussian distribution. The numerical solution approach is applied to a renewable energy management problem. We consider a coupled system of hydro and wind power production used in order to satisfy some local demand of energy and to sell/buy excessive or missing energy on a day-ahead and intraday market, respectively. A short term planning horizon of 2 days is considered and only wind power is assumed to be random. In the first part of the paper, we develop an appropriate optimization problem involving a probabilistic constraint reflecting demand satisfaction. Major attention will be payed to formulate this probabilistic constraint not directly in terms of random wind energy produced but rather in terms of random wind speed, in order to benefit from a large data base for identifying an appropriate distribution of the random parameter. The second part presents some details on integrating Genz' code for Gaussian probabilities of rectangles into the environment of the SQP solver SNOPT. The procedure is validated by means of a simplified optimization problem which by its convex structure allows to estimate the gap between the numerical and theoretical optimal values, respectively. In the last part, numerical results are presented and discussed for the original (nonconvex) optimization problem

How Distinct are Intuition and Deliberation? An Eye-Tracking Analysis of Instruction-Induced Decision Modes

In recent years, numerous studies comparing intuition and deliberation have been published. However, until now relatively little is known about the cognitive processes underlying the two decision modes. Therefore, we analyzed processes of information search and integration using eye-tracking technology. We tested hypotheses derived from dual-process models which postulate that intuition and deliberation are completely distinct processes against predictions of interventionist models. The latter assume that intuitive and deliberate decisions are based on the same basic process which is supplemented by additional processes in the deliberate decision mode. We manipulated decision mode between-participants by means of instructions and participants completed simple and complex city-size tasks as well as complex legal inference tasks. Our findings indicate that the instruction to deliberate does not necessarily increase levels of processing. We found no difference in mean fixation duration and the distribution of short, medium and long fixations. Instruction-induced deliberation led to a higher number of fixations, a more complete information search and more repeated information investigations. Overall, the data support interventionist models suggesting that decisions mainly rely on automatic processes which are supplemented by additional operations in the deliberate decision mode.Decision Making, Decision Mode, Intuition, Deliberation, Eye-Tracking

Design Decisions Under Risk and Uncertainty

In the contemporary world of engineering, engineers strive towards designing reliable and robust artifacts while considering and attempting to control manufacturing costs. In due course they have to deal with some sort of uncertainty. Many aspects of the design are the result of properties that are defined within some tolerances, of measurements that are appropriate, and of circumstances and environmental conditions that are out of their control. This uncertainty was typically handled by using factors of safety, and resulted in designs that may have been overly conservative. Therefore, understanding and handling the uncertainties is critical in improving the design, controlling costs and optimizing the product. Since the engineers are typically trained to approach problems systematically, a stepwise procedure which handles uncertainties efficiently should be of significant benefit. This thesis revises the literature, defines some terms, then describes such a stepwise procedure, starting from identifying the sources of uncertainty, to classifying them, handling these uncertainties, and finally to decision making under uncertainties and risk. The document elucidates the methodology introduced by Departments of Mathematical Science and Mechanical Engineering, which considers the after effects of violation of a constraint as a criterion along with the reliability percentage of a design. The approach distinguishes between aleatory and epistemic uncertainties, those that can be assumed to have a certain distribution and those that can only be assumed to be within some bounds. It also attempts to deal with the computational cost issue by approximating the risk surface as a function of the epistemic uncertain variables. The validity of this hypothesis, for this particular problem, is tested by approximating risk surfaces using various numbers of scenarios

Predictors of Texas Police Chiefs’ Satisfaction with Police-Prosecutor Relationships

Although strain in police-prosecutor relationships may be built into the criminal justice system’s checks and balances, the administration of criminal justice can benefit from the adoption of practices which improve these working relationships. A first step towards the adoption of such practices can be taken by first adding to the knowledge base regarding this understudied topic. Using a survey of a state-wide sample of Texas police chiefs, this exploratory study identifies which aspects of police-prosecutor interaction styles are predictors of police chiefs’ satisfaction with police-prosecutor relationships. Results indicate that perceived level of police input in prosecutors’ plea bargain and charging decisions, perceived directness of felony trial preparation communication method, and perceived frequency of decision-maker interactions predict police chiefs’ satisfaction with police-prosecutor relationships. Policy implications are discussed

Examination of Adoption Theory on the DevOps Practice of Continuous Delivery

Many organizations have difficulty adopting advanced software development practices. Some software development project managers in large organizations are not aligned with the relationship between performance expectancy, effort expectancy, social influence, and facilitating conditions, as moderated by experience, with intent to adopt the DevOps practice of continuous delivery. The purpose of this study was to examine the statistical relationships between the independent variablesâperformance expectancy, effort expectancy, social influence, and facilitating conditions, as moderated by experienceâand the dependent variable of behavioral intent to adopt a continuous delivery system. Venkatesh, Morris, Davis, and Davis\u27s unified theory of acceptance and use of technology provided the theoretical framework. A stepwise multiple linear regression analysis was performed on survey data from 85 technical project managers affiliated with LinkedIn project management groups. The analysis reflected that only performance expectancy was significant in predicting intent to adopt continuous delivery. The findings may contribute to social change by providing project managers with the information they need to support organizational change, collaboration, and facilitation. The knowledge gained may additionally help organizations develop operational efficiency, competitive advantage, and generate higher value to their clients and society

Organisational participation and women - an attitude problem?

Employee participation is a dynamic and contested area of organisational behaviour, attracting continuing academic, practitioner and policy interest and debate. This chapter focuses on organisational participation and women