A module-theoretic approach to matroids

Speyer recognized that matroids encode the same data as a special class of tropical linear spaces and Shaw interpreted tropically certain basic matroid constructions; additionally, Frenk developed the perspective of tropical linear spaces as modules over an idempotent semifield. All together, this provides bridges between the combinatorics of matroids, the algebra of idempotent modules, and the geometry of tropical linear spaces. The goal of this paper is to strengthen and expand these bridges by systematically developing the idempotent module theory of matroids. Applications include a geometric interpretation of strong matroid maps and the factorization theorem; a generalized notion of strong matroid maps, via an embedding of the category of matroids into a category of module homomorphisms; a monotonicity property for the stable sum and stable intersection of tropical linear spaces; a novel perspective of fundamental transversal matroids; and a tropical analogue of reduced row echelon form.Comment: 22 pages; v3 minor corrections/clarifications; to appear in JPA

Hyperplane Arrangements and Compactifications of Vector Groups

Schubert varieties of hyperplane arrangements, also known as matroid Schubert varieties, play an essential role in the proof of the Dowling-Wilson conjecture and in Kazhdan-Lusztig theory for matroids. We study these varieties as equivariant compactifications of affine spaces, and give necessary and sufficient conditions to characterize them. We also generalize the theory to include partial compactifications and morphisms between them. Our results resemble the correspondence between toric varieties and polyhedral fans.Comment: 23 pages; v2: Minor edit

Learning when to observe: A frugal reinforcement learning framework for a high-cost world

Reinforcement learning (RL) has been shown to learn sophisticated control policies for complex tasks including games, robotics, heating and cooling systems and text generation. The action-perception cycle in RL, however, generally assumes that a measurement of the state of the environment is available at each time step without a cost. In applications such as materials design, deep-sea and planetary robot exploration and medicine, however, there can be a high cost associated with measuring, or even approximating, the state of the environment. In this paper, we survey the recently growing literature that adopts the perspective that an RL agent might not need, or even want, a costly measurement at each time step. Within this context, we propose the Deep Dynamic Multi-Step Observationless Agent (DMSOA), contrast it with the literature and empirically evaluate it on OpenAI gym and Atari Pong environments. Our results, show that DMSOA learns a better policy with fewer decision steps and measurements than the considered alternative from the literature. The corresponding code is available at: \url{https://github.com/cbellinger27/Learning-when-to-observe-in-RLComment: Accepted for presentation at ECML-PKDD 2023 workshop track: Simplification, Compression, Efficiency and Frugality for Artificial Intelligence (SCEFA

BUILDING THE CAPABILITY FOR BENEFITS REALISATION: LEADING WITH BENEFITS (6)

It is now 20 years since the publication of the paper that launched Benefits Management (BM), by Prof. John Ward and colleagues, and the launch of an open course on BM at Cranfield. This paper draws on recent work reflecting on the translation of BM into practice as well as a 10+ year programme of research seeking to understand how to develop the Benefits Realisation Capability of an organisation. In particular it draws on two longitudinal studies exploring the adoption of benefits-driven approaches. An important lesson is that BM needs to reflect a new mindset and is not simply another technique to add to our project management toolbox. Without a shift in mindset, BM becomes another technical, rational, approach that brings a new bureaucracy to the management of Information Technology (IT) investments when the need is speed to benefit. BM is primarily about people – about vision, engagement and motivation. It can contribute to the craft of leading change and help build an organisational change capability

Maturity Models as a Tool for Benefits-Driven Change: A Qualitative Investigation of ten Organisations

If Information Technology (IT) is to deliver change with clear benefits a complex mix of organizational resources (i.e. the IT capability), need to be mobilized. Improving IT capability is essential but often challenging for organizations. Maturity models are used to assist change management for IT capability improvement, but there has been limited research on how they are used and their efficacy in different organizational contexts. This paper addresses this gap through exploring the experiences of ten organizations who used the IT Capability Maturity Framework (IT-CMF), to help them address the challenge of gaining benefits from IT. Key topics are: motivations for using a maturity model; change management actions and improvements; success factors; barriers to success. The data was collected through qualitative interviews and interpreted through a benefits-driven change management approach. This analysis provides key insights into the context and challenges of using maturity models for IT capability improvements, and suggests that capability improvement will to some extent address the ‘knowing-doing gap’ highlighted with respect to maturity model implementation

How Weak Mindreaders Inherited the Earth

Carruthers argues that an integrated faculty of metarepresentation evolved for mindreading and was later exapted for metacognition. A more consistent application of his approach would regard metarepresentation in mindreading with the same skeptical rigor, concluding that the faculty may have been entirely exapted. Given this result, the usefulness of Carruthers’ line-drawing exercise is called into question

Executive Briefing: IT Capability Improvement - Key Lessons Learned from Executive Assessments

Organizations are increasingly looking for ways to derive more business value from their IT investments. A popular approach is to achieve this value through building an organization’s IT capability. In the current fast-changing business environment organizations need to anticipate and respond to shifting opportunities. A well-developed IT capability provides a stable platform on which to enhance competitive advantage or, within the public or voluntary sector, to facilitate the delivery of cost effective and high quality services. In this briefing we explore the lessons learned by 10 large organizations through undertaking one or more IT maturity assessments between 2010 and 2015 using the IT Capability Maturity Framework’s (IT-CMF) Executive Assessment (EA) tool. We further examine their experience and their success in building their organizational capabilities