We analyze the evolution of the scientific consensus on anthropogenic global warming (AGW) in the peer-reviewed scientific literature, examining 11 944 climate abstracts from 1991–2011 matching the topics 'global climate change' or 'global warming'. We find that 66.4% of abstracts expressed no position on AGW, 32.6% endorsed AGW, 0.7% rejected AGW and 0.3% were uncertain about the cause of global warming. Among abstracts expressing a position on AGW, 97.1% endorsed the consensus position that humans are causing global warming. In a second phase of this study, we invited authors to rate their own papers. Compared to abstract ratings, a smaller percentage of self-rated papers expressed no position on AGW (35.5%). Among self-rated papers expressing a position on AGW, 97.2% endorsed the consensus. For both abstract ratings and authors' self-ratings, the percentage of endorsements among papers expressing a position on AGW marginally increased over time. Our analysis indicates that the number of papers rejecting the consensus on AGW is a vanishingly small proportion of the published research. 2013 Environ. Res. Lett. 8 024024

/pdf/quantifying-the-consensus-on-anthropogenic-global-warming-in-4yu57rn69r.pdf

Quantifying the consensus on anthropogenic global warming in the scientific literature

This paper proposes a feedback control scheme for an omnidirectional holonomic autonomous platform, which is equipped with three lateral orthogonal-wheel assemblies. Firstly, the dynamic properties of the platform are studied, and a dynamic model suitable for the application of control is derived. The control scheme constructed is of the resolved-acceleration type, with PI and PD feedback. The control scheme was experimentally applied to an actual mobile robotic platform. The results obtained show that full omnidirectionality can be achieved with decoupled rotational and translational motions. Omnidirectionality is one of the principal requirements for mobile robots designed for health-care and other general-hospital services.

Feedback Control of an Omnidirectional Autonomous Platform for Mobile Service Robots

A process classification framework for defining and describing Digital Fabrication with Concrete

On-site autonomous construction robots: Towards unsupervised building

Holonomic or nonholonomic omnidirectional mobile robots are known to be constructed by applying a specialized wheel or mobile mechanism In particular, some representative control approaches are described for a holonomic and omnidirectional mobile robot with three lateral orthogonal-wheel assemblies The uses of resolved acceleration control method, PID method, fuzzy model method, and stochastic fuzzy servo method are highlighted

Control of an omnidirectional mobile robot

The concept of casting concrete in fabrics, fabric formwork technology, has resurfaced at various times and in different forms throughout the past century. The following paper traces developments that have used fabrics for concrete formwork, including different types of flexible formwork, controlled permeability formwork and pneumatic formwork. This paper presents a comprehensive historical overview of fabric formwork, listing key innovators, technological developments and their advantages, and offering examples of structures built with these methods. The information gathered is used to present a taxonomy of these related formwork technologies as well as a formal definition of the term “fabric formwork” that encompasses them. The paper is intended to introduce readers to these technologies and offer readers already familiar with these methods additional historical background.

/pdf/history-and-overview-of-fabric-formwork-using-fabrics-for-4ec62sjhb1.pdf

History and overview of fabric formwork: using fabrics for concrete casting

Concrete is our most widely used construction material. Worldwide consumption of cement, the strength-giving component of concrete, is estimated at 4.10 Gt per year, rising from 2.22 Gt just ten years ago [1]. This rate of consumption means that cement manufacture alone is estimated to account for 5.2 % of global carbon dioxide emissions [2]. Concrete offers the opportunity to economically create structures of almost any geometry. Yet its unique fluidity is seldom capitalised upon, with concrete instead being cast into rigid, flat moulds to create unoptimised geometries that result in high material use structures with large carbon footprints. This paper will explore flexible formwork construction technologies which embrace the fluidity of concrete to facilitate the practical construction of concrete structures with complex and efficient geometries. This paper presents the current state of the art in flexible formwork technology, highlighting practical uses, research challenges and new opportunities.

/pdf/flexible-formwork-technologies-a-state-of-the-art-review-44r0r86b67.pdf

Flexible formwork technologies – a state of the art review

The Fabric Formwork Book: Methods for Building New Architectural and Structural Forms in Concrete

A new design of holonomic omnidirectional vehicle and a laser guidance technique for the vehicles are presented. The holonomic mechanism allows the vehicle to maneuver in an arbitrary direction from an arbitrary configuration on a plane. This significantly simplifies control problems and improves positioning accuracy. A fundamental method of obtaining omnidirectional motion with holonomic constraints on the floor, using a mechanism with spherical tires, is described. Each vehicle can be viewed as an XYθ positioning table with an infinite workspace. For accurate guidance and positioning, a laser guidance technique is developed. A prototype system is designed, built and tested. Upon experiments, omnidirectional motion of the vehicle and the effectiveness of the guidance method were confirmed.

Development of a Holonomic Omnidirectional Vehicle and an Accurate Guidance Method of the Vehicles

Fabric formwork entails the use of fabrics as the main contact material for a concrete mould. The fabric is either hung or prestressed in a supporting falsework frame. Beams or trusses cast in fabric formwork are inherently non-prismatic and have been shown to offer potential for structurally efficient shapes. The casting of beams or trusses in fabric formwork is a highly non-linear problem due to the interaction of the fluid concrete with the woven, prestressed fabric material. Numerical models need to be developed for the engineering of these elements. To this end, it is demonstrated that it is feasible to integrate manufacturing constraints in an automatic optimization process. This is achieved by creating an automated computational framework that includes fabric form-finding and finite element analysis, which operate within an optimization process that uses principles from biological evolution. The results show structurally efficient and manufacturable beams and demonstrate potential for optimization in general that explicitly includes fabrication considerations.

Mark West

Papers

History and overview of fabric formwork: using fabrics for concrete casting

Flexible formwork technologies – a state of the art review

The Fabric Formwork Book: Methods for Building New Architectural and Structural Forms in Concrete

Development of a Holonomic Omnidirectional Vehicle and an Accurate Guidance Method of the Vehicles

Design and optimization of fabric-formed beams and trusses: evolutionary algorithms and form-finding