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2. Multi-agent Reinforcement Learning in OpenSpiel: A Reproduction Report

Author

Walton, Michael and Lisy, Viliam

Subjects
Computer Science - Artificial Intelligence
Abstract

In this report, we present results reproductions for several core algorithms implemented in the OpenSpiel framework for learning in games. The primary contribution of this work is a validation of OpenSpiel's re-implemented search and Reinforcement Learning algorithms against the results reported in their respective originating works. Additionally, we provide complete documentation of hyperparameters and source code required to reproduce these experiments easily and exactly.

Published
2021

3. Theory of Mind for Deep Reinforcement Learning in Hanabi

Author

Fuchs, Andrew, Walton, Michael, Chadwick, Theresa, and Lange, Doug

Subjects
Computer Science - Artificial Intelligence
Abstract

The partially observable card game Hanabi has recently been proposed as a new AI challenge problem due to its dependence on implicit communication conventions and apparent necessity of theory of mind reasoning for efficient play. In this work, we propose a mechanism for imbuing Reinforcement Learning agents with a theory of mind to discover efficient cooperative strategies in Hanabi. The primary contributions of this work are threefold: First, a formal definition of a computationally tractable mechanism for computing hand probabilities in Hanabi. Second, an extension to conventional Deep Reinforcement Learning that introduces reasoning over finitely nested theory of mind belief hierarchies. Finally, an intrinsic reward mechanism enabled by theory of mind that incentivizes agents to share strategically relevant private knowledge with their teammates. We demonstrate the utility of our algorithm against Rainbow, a state-of-the-art Reinforcement Learning agent.

Published
2021

4. The machine that lives forever

Author

Walton, Michael

Subjects
621.3, T Technology (General), TK Electrical engineering. Electronics Nuclear engineering
Abstract

Design an intelligent micromachine that can self-power and sustain from environmental energy scavenging to achieve an autonomous device that can communicate at will with peers indefinitely. Explore sleep/wake hibernation strategies coupled with food scavenging off-grid traits to identify the tightest work to sleep efficiency schedule, incorporating adaptive reconfiguration to manage significant environmental impacts. Capture, store and manage background radiations and stray RF signals to feed on in a continued effort to make intelligent survival decisions and oversee management protocols. Ensure that every micro Watt of usable energy gets extracted from every part of the harvest and then forward-scheduled it for productive use. Finally, employ natures tricks and experience to introduce essential personality traits, pursuing maximising survival numbers and increasing dispersal target area sizes of large self-sufficient wireless sensor deployments. This research intends to provide a closely coupled software-hardware foundation that aids implementers in intelligently harnessing and using tiny amounts of ambient energy in a highly autonomous way. This platform then continues on to explore ways of maximising the efficient usage of the harvested energy using various hibernation/wake strategies and then making objective comparisons with proposed intelligent energy management protocols. Finally, the protocol extends to enable the device to manage its personal survival possibilities so the devices can use an evolutional personality-based approach to deal with the unknown environmental situations they will encounter. This work examines a machine that can self-power and sustain from environmental energy scavenging with the aim to live forever. Living forever implies a brain (microcontroller) that can manage energy and budget for continuous faculty. With these objectives, sleep/wake/hibernation and scavenging strategies are examined to efficiently schedule resources within a transient environment. Example harvesting includes induced and background radiation. Intelligent, biologically-inspired strategies are adopted in forward-scheduling strategies given temporal energy relative to the machine's function (the Walton).

Published
2021

21. Michael Walton

Author

Walton, Richard and Walton, Michael

Published
1998

22. A randomized prospective study comparing migration of hydroxyapatite and non-hydroxyapatite coated glenoid components using radiostereometric analysis

Author

Akhtar, Ahsan, Ricks, Matthew, Cunningham, Lindsay, Moffatt, Maria, Bale, Steve, Walton, Michael, Monga, Puneet, Trail, Ian, Akhtar, Ahsan, Ricks, Matthew, Cunningham, Lindsay, Moffatt, Maria, Bale, Steve, Walton, Michael, Monga, Puneet, and Trail, Ian

Abstract

Background Primary shoulder arthroplasty can significantly improve quality of life; however, the glenoid baseplate remains the most common component to loosen, which may result in implant failure and subsequent revision surgery. Radiostereometric analysis (RSA) is considered the gold standard for accurate measurement of micro-motion between implant and bone. The aims of this study were to compare migration of the Lima SMR porous titanium hydroxyapatite (HA) coated and non-hydroxyapatite (non-HA) coated glenoid components through a prospective, randomized 2-arm trial using RSA, whilst also comparing clinical and functional outcomes. Methods Twenty patients were randomized into 2 equal (HA and non-HA coated) groups with all patients undergoing primary anatomic shoulder arthroplasty, at which time tantalum beads were also inserted. RSA imaging was performed immediately postoperatively, then at 3, 6, 12, and 24 months postprocedure. These images were digitized and analyzed using model-based RSA software. All patients completed Oxford Shoulder Score (OSS), American Shoulder and Elbow Surgeons (ASES) score, Constant Score (CS) and Visual Analogue Scale (VAS) pain scores pre-and postoperatively at the aforementioned time points. Unpaired t-tests were used for clinical outcome data; Mann-Whitney U tests were used for RSA data. Significance levels were set at P < .05. Results Mean age for the HA group was 72.3 years; 69.5 years for the non-HA group. Mean follow-up for both groups was above 36 months. No significant differences in glenoid migration were observed at each of the postoperative time points; the only exception being at 12 months (non-HA group displaying significantly greater rotation in the z-axis). The HA group displayed fractionally more translation in the x- and z-axes at all time points (not significant). Rotation in the z-axis was marginally greater at all postoperative time points in the non-HA group. Median total migration values revealed greater motion for

Published
2021

23. LETTERS

Author

Hoins, Laurence F., Walton, Michael T., and Thurston, Rhoda

Published
1997
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24. Assessing the required glenoid peg penetration in native scapula when bone graft is used during primary and revision shoulder arthroplasty.

Author

Makki, Daoud, Balbisi, Basel, Arshad, Mohammed S, Monga, Puneet, Bale, Steven, Trail, Ian, and Walton, Michael

Subjects
TOTAL shoulder replacement, BONE grafting, ARTHROPLASTY, SCAPULA, SHOULDER, COMPUTED tomography
Abstract

Aims: Achieving purchase in native glenoid bone is essential for the stability of the glenoid baseplate when bone graft is used to address bone loss in both primary and revision shoulder arthroplasty procedures. The aim of this study is to assess the required depth of the baseplate peg in native bone when bone graft is used to result in satisfactory integration. Patients and methods: The CT scans of patients who underwent either primary or revision arthroplasty procedures with bone graft using the SMR Axioma Trabecular Titanium (TT) Metal Backed glenoid system were assessed. We measured the depth of the glenoid peg in native glenoid bone. Measurements were taken by two authors separately. Results: The scans of 53 patients (mean age 68 years) with a minimum follow-up of two years were reviewed. Implants included 12 anatomical and 41 reverse geometry prostheses. There were 17 primaries and 36 revisions: hemiarthroplasties (20) total (14) and reverse (2) implants. Bone grafts were from humeral head (15), iliac crest (34) and allograft (4). The mean depths were 8.8 mm (first assessor) and 9.10 mm (second assessor). The glenoid peg violated the glenoid vault in 32 patients and this did not adversely affect the outcome. There were three failures of implants all of which were aseptic failures and had peg penetration of less than 6 mm. Conclusions: The mean depth of glenoid peg in native bone was 9 mm (variation between 0.2 and 0.52 mm at 95% confidence interval). Aseptic loosening was seen with peg penetration less than 6 mm in native bone. Glenoid vault violation was not associated with loosening. [ABSTRACT FROM AUTHOR]

Published
2022
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32. 10 Tips for Outsourcing COATINGS MANUFACTURING

Author

Walton, Michael

Subjects
Contract manufacturing, Outsourcing, Coatings industry -- Outsourcing, Production management, Outsourcing, Business, Chemicals, plastics and rubber industries
Abstract

Are you hesitant to add capacity with uncertain market conditions? Are some formulas a bad match for your existing equipment or expertise? Are you seeking lower-cost manufacturing? Are your manufacturing [...]

Published
2019

33. Magic as a therapeutic intervention to promote coping in hospitalized pediatric patients

Author

Hart, Robyn and Walton, Michael

Subjects
Hospital care -- Psychological aspects -- Health aspects, Life skills -- Analysis, Children -- Health aspects, Company business management, Health
Abstract

Magic as a therapeutic intervention is used in an innovative, hospital-based program to address the psychosocial issues children and adolescents often experience as a result of illness and hospitalization. A child life specialist and a magician with an MBA collaborated, blending clinical expertise with business acumen and professional-level magic skills to create the program. The program has two distinct components: (1) magicians using interactive, close-up magic and humor as a technique to promote socialization, enhance self-esteem, and increase opportunities for choice and control, and (2) magicians providing the personal instruction and materials that enable chronically ill and long-term patients to learn and perform magic to promote a sense of empowerment and feelings of mastery. Positive responses from patients, families, and staff to the program at one hospital led to the creation of Open Heart Magic, a non-profit children's foundation that maintains and staffs bedside, interactive therapeutic magic programs in five hospitals in the Chicago metropolitan area., Hospitalization can be an extremely stressful event for many children and adolescents. Emotions of fear, sadness, loneliness, boredom, and helplessness can have immediate and long-term consequences for the child's and [...]

Published
2010

34. Shoulder hydrodilatation for primary, post-traumatic and post-operative adhesive capsulitis.

Author

Makki, Daoud, Al-Yaseen, Mustafa, Almari, Fayez, Monga, Puneet, Funk, Lennard, Basu, Subhasis, and Walton, Michael

Subjects
SHOULDER joint, RANGE of motion of joints, ADHESIVES, OPERATIVE surgery, SHOULDER, DENTAL acid etching, ARTHROSCOPY
Abstract

Background: Adhesive capsulitis (frozen shoulder) is characterised by pain and loss of range of motion of the glenohumeral joint. It can be present as primary (idiopathic) or secondary to surgery, trauma or other conditions that restrict the use of the shoulder joint. Various treatment options have been adopted including physiotherapy, manipulation under anaesthetic, hydrodilatation and arthroscopic or open capsular release but the optimal form of management remains uncertain. Objectives: The purpose of the study was to assess the clinical outcome of glenohumeral hydrodilatation in three cohorts of patients with different aetiologies with adhesive capsulitis. Study design & methods: We carried out a retrospective study of patient who underwent hydrodilatation for adhesive capsulitis between 2013 and 2015. The procedure was performed by a specialist musculoskeletal radiologist under radiological guidance. The injection consisted of steroids, local anaesthetics and NaCl solution with a target volume around 35 mL. Our outcome measures were range of motion, and pre- and post-operative pain. Patients were divided into three groups based on the presumed cause of their stiffness: idiopathic, post-traumatic and post-surgical. Results: Two hundred fifty patients were included, with a mean age of 59 years (range: 20–79). Of these, 180 had idiopathic primary adhesive capsulitis (27 were diabetic), 23 were post-traumatic, and 20 following surgical procedures. Thirty-four required further intervention following initial hydrodilatation with 8 undergoing repeat hydrodilatation, and 26 requiring arthroscopic capsular release. The diabetic group accounted for 16 capsular releases and 4 repeat procedures, while the idiopathic group accounted for 9 and 4, respectively. One patient required capsular release in the surgical group. An improvement was recorded in ROM in all groups with mean abduction improving from 59° to 110°, flexion from 50° to 120° and external rotation from 20° to 50°. With regards to pain, the majority showed an improvement from severe or moderate pain to no or mild pain. Conclusions: Results show that hydrodilatation resulted in an improvement in all outcome measures, with only a small number of patients, especially those with diabetes, needing further procedures or showing no improvement in range of motion and pain. There was no difference between the post-traumatic and post-surgical groups. [ABSTRACT FROM AUTHOR]

Published
2021
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38. The inequality TRAP: why equity must be central to development policy

Author

Ferreira, Francisco H.G. and Walton, Michael

Subjects
Equality -- Evaluation -- Economic aspects, Developing countries -- Economic aspects, Gender equality -- Evaluation -- Economic aspects, Caste -- Economic aspects, Banking, finance and accounting industries, Business, Business, international
Abstract

A GIRL born to a lower-caste family of nine in the slums of Dhaka has vastly different opportunities from a boy born to well-educated and affluent parents in the well-heeled [...]

Published
2005

44. Building on East Asia's infrastructure foundations

Author

Mody, Ashoka and Walton, Michael

Subjects
Public works, Infrastructure (Economics) -- Finance, Privatization -- East Asia, Project finance -- East Asia, Banking, finance and accounting industries, Business, Business, international, Company financing, Finance
Abstract

The halfway measures taken toward privatizing East Asia's infrastructure have resulted in weak corporate governance, vulnerability to crises, and inefficiency. Faced with slowing growth, the region needs to shift its [...]

Published
1998

45. The maturation of the East Asian miracle

Author

Walton, Michael

Subjects
East Asia -- Economic aspects, Economic development -- East Asia -- Economic aspects, Banking, finance and accounting industries, Business, Business, international
Abstract

The sustainability of the East Asian miracle is being questioned as the region's economies are buffeted by problems. What are the problems, and how can East Asian countries cope with [...]

Published
1997

46. From Proof of Concept to Scalable Policies: Challenges and Solutions, with an Application

Author

Massachusetts Institute of Technology. Department of Economics, Abdul Latif Jameel Poverty Action Lab (Massachusetts Institute of Technology), Banerjee, Abhijit, Duflo, Esther, Banerji, Rukmini, Berry, James, Kannan, Harini, Mukerji, Shobhini, Shotland, Marc, Walton, Michael, Massachusetts Institute of Technology. Department of Economics, Abdul Latif Jameel Poverty Action Lab (Massachusetts Institute of Technology), Banerjee, Abhijit, Duflo, Esther, Banerji, Rukmini, Berry, James, Kannan, Harini, Mukerji, Shobhini, Shotland, Marc, and Walton, Michael

Abstract

The promise of randomized controlled trials is that evidence gathered through the evaluation of a specific program helps us—possibly after several rounds of fine-tuning and multiple replications in different contexts—to inform policy. However, critics have pointed out that a potential constraint in this agenda is that results from small "proof-of-concept" studies run by nongovernment organizations may not apply to policies that can be implemented by governments on a large scale. After discussing the potential issues, this paper describes the journey from the original concept to the design and evaluation of scalable policy. We do so by evaluating a series of strategies that aim to integrate the nongovernment organization Pratham's "Teaching at the Right Level" methodology into elementary schools in India. The methodology consists of reorganizing instruction based on children's actual learning levels, rather than on a prescribed syllabus, and has previously been shown to be very effective when properly implemented. We present evidence from randomized controlled trials involving some designs that failed to produce impacts within the regular schooling system but still helped shape subsequent versions of the program. As a result of this process, two versions of the programs were developed that successfully raised children's learning levels using scalable models in government schools. We use this example to draw general lessons about using randomized control trials to design scalable policies.

Published
2018

47. Transfers and the transition from central planning

Author

Krumm, Kathie, Milanovic, Branko, and Walton, Michael

Subjects
Capitalism -- Analysis, Economic security -- Analysis, Central planning -- Analysis, Economic policy -- Analysis, Banking, finance and accounting industries, Business, Business, international, Analysis
Abstract

As former centrally planned economies make the transition to market orientation, they are finding it hard to both achieve strong economic growth and maintain the system of cradle-to-grave security their [...]

Published
1995

48. Workers need open markets and active governments

Author

Ghanem, Hafez and Walton, Michael

Subjects
Labor unions -- Analysis, Employment -- Analysis, Labor law -- Analysis, Labor market -- Analysis, Labor policy -- Analysis, Banking, finance and accounting industries, Business, Business, international
Abstract

Nearly everywhere, countries are moving toward greater use of markets. This change can expand opportunities for workers, but only if they are equipped to make use of them. Governments retain [...]

Published
1995

49. The economy of the West Bank and Gaza: from dependent to autonomous growth

Author

Diwan, Ishac and Walton, Michael

Subjects
Palestinian Territories -- Economic aspects, Gaza Strip -- Economic policy, West Bank -- Economic policy, Banking, finance and accounting industries, Business, Business, international
Abstract

THE HANDOVER of power in the West Bank and Gaza was a source of euphoria for many Palestinians. But they are entering a new era in an economically more fragile [...]

Published
1994

50. Rent Creation and Rent Containment : The Political Economy of Telecommunications in Mexico, South Africa, and Turkey

Author

Atiyas, Izak, Levy, Brian, and Walton, Michael

Subjects
political economy, telecommunications, citizen engagement, access to services
Abstract

The evolution of the telecommunications sector is of keen interest from both a development and a political economy perspective. Telecommunications is critical to economic dynamics, to the quality of life, to social service provision, and to citizen engagement. This paper explores the political economy of telecommunications in three middle income countries - Mexico, South Africa, and Turkey. It undertakes an interpretation of the processes at work through the lens of these comparative cases. It is also intended as a case study of a set of broader questions over the development process, as this is shaped by the central nexus of relations between business and state actors. The paper is specifically concerned with the following questions: how does policy change in real polities, in terms of both policy design and implementation?; how is this shaped by the underlying nature of business-state relations, and to the overall political settlement in a country?; is there a tendency for economic entrenchment in typical middle income countries?; by this the authors mean consolidation of economic activities in ways that support sustained economic rents, underpinned by various mixes of regulatory capture and market power. And what countervailing forces are there to support a more dynamic and competitive equilibrium?; how is the state understood in the context of these business-state relations?; how is it useful to deconstruct the state, and in particular, do checks and balances institutions have the autonomy to provide a check on entrenchment?; and how do these processes interact with technological change? These questions relate to the broader issue of whether governance arrangements can countervail unequal political and economic power in ways that foster inclusive development.

Published
2017

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