Analysis and Optimization of Deep Counterfactual Value Networks

Recently a strong poker-playing algorithm called DeepStack was published, which is able to find an approximate Nash equilibrium during gameplay by using heuristic values of future states predicted by deep neural networks. This paper analyzes new ways of encoding the inputs and outputs of DeepStack's deep counterfactual value networks based on traditional abstraction techniques, as well as an unabstracted encoding, which was able to increase the network's accuracy.Comment: Long version of publication appearing at KI 2018: The 41st German Conference on Artificial Intelligence (http://dx.doi.org/10.1007/978-3-030-00111-7_26). Corrected typo in titl

Solving Games with Functional Regret Estimation

We propose a novel online learning method for minimizing regret in large extensive-form games. The approach learns a function approximator online to estimate the regret for choosing a particular action. A no-regret algorithm uses these estimates in place of the true regrets to define a sequence of policies. We prove the approach sound by providing a bound relating the quality of the function approximation and regret of the algorithm. A corollary being that the method is guaranteed to converge to a Nash equilibrium in self-play so long as the regrets are ultimately realizable by the function approximator. Our technique can be understood as a principled generalization of existing work on abstraction in large games; in our work, both the abstraction as well as the equilibrium are learned during self-play. We demonstrate empirically the method achieves higher quality strategies than state-of-the-art abstraction techniques given the same resources.Comment: AAAI Conference on Artificial Intelligence 201

Phase Diagrams For The Blue Phases Of Highly Chiral Liquid Crystals

Polarizing microscopy and optical-activity measurements are used to determine the phase diagram for the blue phases of chiral-racemic mixtures of terephthaloyloxy-bis-4-(2\u27-methylbutyl) benzoate. Contrary to an earlier report, it is the second blue phase (BP II) rather than the first blue phase (BP 1) that is not stable relative to the other blue phases at high chirality. With this development, all phase diagrams for the blue phases reported to date have the same topology. Using similar data for two other highly chiral systems, it is found that a simple scaling of the temperature and chiral-fraction axes produces phase diagrams in quantitative agreement with the present results. Thus, in spite of differences in molecular structure, the number of chiral centers, and phase-transition temperatures, these three systems possess remarkably similar phase diagrams and lend evidence for a universal phase diagram for the blue phases

How the Pandemic Affects Museums and Heritage

Heritage is a dynamic concept up to interpretation by individuals and communities. It is shaped by the culture we engage with. As a result of the COVID-19 pandemic, museums shifted to a much more virtual format and in-person attendance dropped. Virtual engagement with a museum bypasses any spatial and temporal restraints from physically going to a museum. This can both increase accessibility in heritage and remove vital context and importance from the object. The changes in how we engage with museums resulting from the pandemic fundamentally affect the way we engage with and interpret heritage

What proportion of adult allergy referrals to secondary care could be dealt with in primary care by a GP with special interest?

Background: The concept of a General Practitioner with Special Interest (GPwSI) was first proposed in the 2000 National Health Service Plan, as a way of providing specialised treatment closer to the patient’s home and reducing hospital waiting times. Given the patchy and inadequate provision of allergy services in the UK the introduction of GPwSIs might reduce the pressure on existing specialist services. Objectives: This study assessed what proportion of referrals to a specialist allergy clinic could be managed in a GPwSI allergy service with a predefined range of facilities and expertise (accurate diagnosis and management of allergy; skin prick testing; provision of advice on allergen avoidance; ability to assess suitability for desensitisation). Methods: 100 consecutive GP referrals to a hospital allergy clinic were reviewed to determine whether patients could be seen in a community-based clinic led by a general practitioner with special interest (GPwSI) allergy. The documentation relating to each referral was independently assessed by three allergy specialists. The referrals were judged initially on the referral letter alone and then re-assessed with the benefit of information summarised in the clinic letter, to determine whether appropriate triage decisions could be made prospectively. The proportion of referrals suitable for a GPwSI was calculated and their referral characteristics identified. Results: 29 % referrals were judged unanimously appropriate for management by a GPwSI and an additional 30 % by 2 of the 3 reviewers. 18 % referrals were unsuitable for a GPwSI service because of the complexity of the presenting problem, patient co-morbidity or the need for specialist knowledge or facilities. Conclusions and clinical relevance: At least a quarter, and possibly half, of allergy referrals to our hospital-based service could be dealt with in a GPwSI clinic, thereby diversifying the patient pathway, allowing specialist services to focus on more complex cases and reducing the waiting time for first appointments

Agreement between methods of measurement with multiple observations per individual

Limits of agreement provide a straightforward and intuitive approach to agreement between different methods for measuring the same quantity. When pairs of observations using the two methods are independent, i.e., on different subjects, the calculations are very simple and straightforward. Some authors collect repeated data, either as repeated pairs of measurements on the same subject, whose true value of the measured quantity may be changing, or more than one measurement by one or both methods of an unchanging underlying quantity. In this paper we describe methods for analysing such clustered observations, both when the underlying quantity is assumed to be changing and when it is not