We introduce June, an open-source framework for the detailed simulation of epidemics on the basis of social interactions in a virtual population constructed from geographically granular census data, ...reflecting age, sex, ethnicity and socio-economic indicators. Interactions between individuals are modelled in groups of various sizes and properties, such as households, schools and workplaces, and other social activities using social mixing matrices. June provides a suite of flexible parametrizations that describe infectious diseases, how they are transmitted and affect contaminated individuals. In this paper, we apply June to the specific case of modelling the spread of COVID-19 in England. We discuss the quality of initial model outputs which reproduce reported hospital admission and mortality statistics at national and regional levels as well as by age strata.
Security managers face the challenge of designing security policies that deliver the objectives required by their organizations. We explain how a rigorous modelling framework and methodology—grounded ...in semantically justified mathematical systems modelling, the economics of decision-making, and simulation—can be used to explore the operational consequences of their design choices and help security managers to make better decisions. The methodology is based on constructing executable system models that illustrate the effects of different policy choices. Models are compositional, allowing complex systems to be expressed as combinations of smaller, complete models. They capture the logical and physical structure of systems, the choices and behaviour of agents within the system, and the security managers’ preferences about outcomes. Utility theory is used to describe the extent to which security managers’ policies deliver their security objectives. Models are parametrized based on data obtained from observations of real-world systems that correspond closely to the examples described.
We compare two bootstrap methods for assessing mutual fund performance. The first produces narrow confidence intervals due to pooling over time, whereas the second produces wider confidence intervals ...because it preserves the cross correlation of fund returns. We then show that the average U.K. equity mutual fund manager is unable to deliver outperformance net of fees under either bootstrap. Gross of fees, 95% of fund managers on the basis of the first bootstrap and all fund managers on the basis of the second bootstrap fail to outperform the luck distribution of gross returns.
Abstract Data protection regulations like the General Data Protection Regulation (GDPR) are increasingly important in securing individuals’ privacy as society goes digital. The success of any ...regulation, however good, ultimately depends on how well it is executed. Existing literature fails to answer what good execution means in this context. We research what practitioners think are the objectives of data protection regulators and how they evaluate their effectiveness. We explore novel ways to assess regulator performance more systematically. We surveyed 70 chief information security officers and conducted 23 structured interviews. The interviewees included informed business executives, lawyers, digital rights activists, and four national regulators. We supplement it with an analysis of diverse enforcement databases. Our findings indicate a mismatch between the broad presumed objectives attributed to regulators and the narrow criteria used to judge them in practice. Perception of the regulator’s effectiveness is subjective, sanctions-focused, and influenced by one’s role and responsibilities. Moreover, the independence of regulators, intentionally designed to insulate them from daily politics, raises serious questions of accountability. We examine the historical, cultural, and organizational motivations behind the current byzantine complexity of the GDPR regime. Lastly, we contribute a series of key performance indicators and make structural suggestions around centralized and standardized reporting of cases to deliver improved learning, legitimacy, transparency, and comparability. We believe our findings have important implications for the future development of regulator assessment and accountability in Europe and in the growing number of GDPR-like regimes outside Europe.
Abstract Increasingly, organizations are acknowledging the importance of human factors in the management of security in workplaces. There are challenges in managing security infrastructures in which ...there may be centrally mandated and locally managed initiatives to promote secure behaviours. We apply a co-design methodology to harmonize employee behaviour and centralized security management in a large university. This involves iterative rounds of interviews connected by the co-design methodology: 14 employees working with high-value data with specific security needs; seven support staff across both local and central IT and IT-security support teams; and two senior security decision-makers in the organization. We find that employees prefer local support together with assurances that they are behaving securely, rather than precise instructions that lack local context. Trust in support teams that understand local needs also improves engagement, especially for employees who are unsure what to do. Policy is understood by employees through their interactions with support staff and when they see colleagues enacting secure behaviours in the workplace. The iterative co-design approach brings together the viewpoints of a range of employee groups and security decision-makers that capture key influences that drive secure working practices. We provide recommendations for improvements to workplace security, including recognizing that communication of the policy is as important as what is in the policy.
Two new methodologies are introduced to improve inference in the evaluation of mutual fund performance against benchmarks. First, the benchmark models are estimated using panel methods with both fund ...and time effects. Second, the non-normality of individual mutual fund returns is accounted for by using panel bootstrap methods. We also augment the standard benchmark factors with fund-specific characteristics, such as fund size. Using a dataset of UK equity mutual fund returns, we find that fund size has a negative effect on the average fund manager’s benchmark-adjusted performance. Further, when we allow for time effects and the non-normality of fund returns, we find that there is no evidence that even the best performing fund managers can significantly out-perform the augmented benchmarks after fund management charges are taken into account.
The presence of unpatched, exploitable vulnerabilities in software is a prerequisite for many forms of cyberattack. Because of the almost inevitable discovery of a vulnerability and creation of an ...exploit for all types of software, multiple layers of security are usually used to protect vital systems from compromise. Accordingly, attackers seeking to access protected systems must circumvent all of these layers. Resource- and budget-constrained defenders must choose when to execute actions such as patching, monitoring and cleaning infected systems in order to best protect their networks. Similarly, attackers must also decide when to attempt to penetrate a system and which exploit to use when doing so. We present an approach to modelling computer networks and vulnerabilities that can be used to find the optimal allocation of time to different system defence tasks. The vulnerabilities, state of the system and actions by the attacker and defender are used to build partially observable stochastic games. These games capture the uncertainty about the current state of the system and the uncertainty about the future. The solution to these games is a policy, which indicates the optimal actions to take for a given belief about the current state of the system. We demonstrate this approach using several different network configurations and types of player. We consider a trade-off for the system administrator, where they must allocate their time to performing either security-related tasks or performing other required non-security tasks. The results presented highlight that, with the requirement for other tasks to be performed, following the optimal policy means spending time on only the most essential security-related tasks, while the majority of time is spent on non-security tasks.
We introduce
J
une
, an open-source framework for the detailed simulation of epidemics on the basis of social interactions in a virtual population constructed from geographically granular census ...data, reflecting age, sex, ethnicity and socio-economic indicators. Interactions between individuals are modelled in groups of various sizes and properties, such as households, schools and workplaces, and other social activities using social mixing matrices.
J
une
provides a suite of flexible parametrizations that describe infectious diseases, how they are transmitted and affect contaminated individuals. In this paper, we apply
J
une
to the specific case of modelling the spread of COVID-19 in England. We discuss the quality of initial model outputs which reproduce reported hospital admission and mortality statistics at national and regional levels as well as by age strata.
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