2,327 research outputs found
Redefining the Use of Sustainable Development Goals at the Organisation and Project Levels—A Survey of Engineers
The United Nations’ (UN) Sustainable Development Goals (SDGs) aim to deliver an improved future for people, planet and profit. However, they have not gained the required traction at the business and project levels. This article explores how engineers rate and use the SDGs at the organisational and project levels. It adopts the Realist Evaluation’s Context−Mechanism−Outcomes model to critically evaluate practitioners’ views on using SDGs to measure business and project success. The study addresses the thematic areas of sustainability and business models through the theoretical lens of Creating Shared Value and the Triple Bottom Line. A survey of 325 engineers indicated four primary shortfalls for measuring SDGs on infrastructure projects, namely (1) leadership, (2) tools and methods, (3) engineers’ business skills in measuring SDG impact and (4) how project success is too narrowly defined as outputs (such as time, cost and scope) and not outcomes (longer-term local impacts and stakeholder value). The research study is of value to researchers developing business models that address the SDGs and also practitioners in the construction industry who seek to link their investment decisions to the broader outcomes of people, planet and profit through the UN SDGs
Local Yang--Baxter correspondences and set-theoretical solutions to the Zamolodchikov tetrahedron equation
We study tetrahedron maps, which are set-theoretical solutions to the
Zamolodchikov tetrahedron equation, and their matrix Lax representations
defined by the local Yang--Baxter equation.
Sergeev [S.M. Sergeev 1998 Lett. Math. Phys. 45, 113--119] presented
classification results on three-dimensional tetrahedron maps obtained from the
local Yang--Baxter equation for a certain class of matrix-functions in the
situation when the equation possesses a unique solution which determines a
tetrahedron map. In this paper, using correspondences arising from the local
Yang--Baxter equation for some simple matrix-functions, we show
that there are (non-unique) solutions to the local Yang--Baxter equation which
define tetrahedron maps that do not belong to the Sergeev list; this paves the
way for a new, wider classification of tetrahedron maps. We present invariants
for the derived tetrahedron maps and prove Liouville integrability for some of
them.
Furthermore, using the approach of solving correspondences arising from the
local Yang--Baxter equation, we obtain several new birational tetrahedron maps,
including maps with matrix Lax representations on arbitrary groups, a
-dimensional map associated with a Darboux transformation for the derivative
nonlinear Schr\"odinger (NLS) equation, and a -dimensional generalisation of
the -dimensional Hirota map.Comment: 18 pages. New results added (section 4), and also the references list
was update
Delivering UN Sustainable Development Goals’ Impact on Infrastructure Projects: An Empirical Study of Senior Executives in the UK Construction Sector
Achievement of the United Nations’ 2030 Sustainable Development Goals (SDG) is of paramount importance for both business and society. Across the construction sector, despite evidence that suggests 88% of those surveyed want to measure the SDG impact at both the business and project levels, there continues to be major challenge in achieving this objective. This paper shares the results of a qualitative research study of 40 interviews with executives from the United Kingdom (UK) construction industry. It was supported by a text-based content analysis to strengthen the findings. The results indicate that SDG measurement practices are embraced in principle but are problematic in practice and that rarely does action match rhetoric. While the research was completed in the UK, the findings have broader applicability to other countries since most construction firms have extensive global business footprints. Researchers can use the findings to extend the current understanding of measuring outcomes and impact at project level, and, for practitioners, the study provides insights into the contextual preconditions necessary to achieve the intended outcomes of adopting a mechanism for the measurement of SDGs. The international relevance of this research is inherently linked to the global nature of the SDGs and therefore the results could be used outside of UK
Spatial modeling of epidermal nerve fiber patterns
Peripheral neuropathy is a condition associated with poor nerve functionality. Epidermal nerve fiber (ENF) counts per epidermal surface are dramatically reduced and the two-dimensional (2D) spatial structure of ENFs tends to become more clustered as neuropathy progresses. Therefore, studying the spatial structure of ENFs is essential to fully understand the mechanisms that guide those morphological changes. In this article, we compare ENF patterns of healthy controls and subjects suffering from mild diabetic neuropathy by using suction skin blister specimens obtained from the right foot. Previous analysis of these data has focused on the analysis and modeling of the spatial ENF patterns consisting of the points where the nerves enter the epidermis, base points, and the points where the nerve fibers terminate, end points, projected on a 2D plane, regarding the patterns as realizations of spatial point processes. Here, we include the first branching points, the points where the nerve trees branch for the first time, and model the three-dimensional (3D) patterns consisting of these three types of points. To analyze the patterns, spatial summary statistics are used and a new epidermal active territory that measures the volume in the epidermis that is covered by the individual nerve fibers is constructed. We developed a model for both the 2D and the 3D patterns including the branching points. Also, possible competitive behavior between individual nerves is examined. Our results indicate that changes in the ENFs spatial structure can more easily be detected in the later parts of the ENFs
A non-commutative extension of the Adler-Yamilov Yang-Baxter map
In this paper, we construct a noncommutative extension of the Adler-Yamilov Yang-Baxter map which is related to the nonlinear Schr�dinger equation. Moreover, we show that this map is partially integrable
Tetrahedron maps, Yang-Baxter maps, and partial linearisations
We study tetrahedron maps, which are set-theoretical solutions to the
Zamolodchikov tetrahedron equation, and Yang-Baxter maps, which are
set-theoretical solutions to the quantum Yang-Baxter equation.
In particular, we clarify the structure of the nonlinear algebraic relations
which define linear (parametric) tetrahedron maps (with nonlinear dependence on
parameters), and we present several transformations which allow one to obtain
new such maps from known ones. Furthermore, we prove that the differential of a
(nonlinear) tetrahedron map on a manifold is a tetrahedron map as well. Similar
results on the differentials of Yang-Baxter and entwining Yang-Baxter maps are
also presented.
Using the obtained general results, we construct new examples of (parametric)
Yang-Baxter and tetrahedron maps. The considered examples include maps
associated with integrable systems and matrix groups. In particular, we obtain
a parametric family of new linear tetrahedron maps, which are linear
approximations for the nonlinear tetrahedron map constructed by Dimakis and
M\"uller-Hoissen [arXiv:1708.05694] in a study of soliton solutions of vector
Kadomtsev-Petviashvili (KP) equations. Also, we present invariants for this
nonlinear tetrahedron map.Comment: 23 pages; v2: new results and references added, minor corrections
mad
Measurement and Modelling of the Propagation Channel between Low Height Terminals
The evaluation of communication systems with low-height terminals requires path loss models that are applicable to low-height links. For the terminology low-height, the range 0.5 (mobile-) to 3m (fixed-node) above ground is considered. Herein, empirical non-time-dispersive propagation models for relaying systems with low-height terminals are proposed. The models consist of line-of-sight and non-line-of-sight branches. Single- and two-slope modelling approaches were examined. The models take into account the effect of frequency, transmitter and receiver height, and environment. They are complemented by shadowing and fast-fading distribution and correlation statistics. The performance of the models in producing accurate estimations is evaluated by comparison with sets of independent data
Anticommutative extension of the Adler map
We construct a noncommutative (Grassmann) extension of the well-known Adler Yang–Baxter map. It satisfies the Yang–Baxter equation, it is reversible and birational. Our extension preserves all the properties of the original map except the involutivity
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