Smart cities: A literature review and business network approach discussion on the management of organisations

Purpose: The smart city idea refers to new ways of organising city functions and urban life, which are believed to move production and consumption from global to local, manufacturing from competitive to collaborative, and business from a shareholder to a multiple-stakeholder point of view. Most previous research has focussed on the societal level of smart cities, while less seems to be known about the management of business as part of smart cities. The purpose of this paper is to present a literature review on the state of the art of management research on smart cities. The following research question is addressed: How has previous research captured the management of organisations in smart cities? Design/methodology/approach: A literature review using the search term “smart city/cities” in research on business, management, and operational management was conducted for the purpose of capturing previous research. Findings were coded based on main ideas, central concepts, and theories, thematic content of the articles related to the main ideas underpinning smart cities (digitalization, urbanisation, and sustainability as antecedents, and local, collaborative and multiple-stakeholder manufacturing as indicators), and units of analysis. Findings: The paper points to how most studies on the management of organisations as part of smart cities focus on sustainability and how digitalisation enables new businesses. Collaborative efforts are emphasised and the theoretical framing is fragmented. Issues related to the organising of business is also not problematised and the business network approach could, as discussed in the paper, provide valuable insights related to the collaborative efforts of organisations and the multiple-stakeholder perspective. Originality/value: The paper is the first to capture and present an overview of previous research on the management of business as part of smart cities. Research on smart cities has focussed on the policy and societal levels, and so far there is a lack of problematisation on how organisations may act, and potentially change their way of acting, should smart cities become a reality

How will smart city production systems transform supply chain design: a product-level investigation

© 2016 Informa UK Limited, trading as Taylor & Francis Group.This paper is a first step to understand the role that a smart city with a distributed production system could have in changing the nature and form of supply chain design. Since the end of the Second World War, most supply chain systems for manufactured products have been based on ‘scale economies’ and ‘bigness’; in our paper we challenge this traditional view. Our fundamental research question is: how could a smart city production system change supply chain design? In answering this question, we develop an integrative framework for understanding the interplay between smart city technological initiatives (big data analytics, the industrial Internet of things) and distributed manufacturing on supply chain design. This framework illustrates synergies between manufacturing and integrative technologies within the smart city context and links with supply chain design. Considering that smart cities are based on the collaboration between firms, end-users and local stakeholders, we advance the present knowledge on production systems through case-study findings at the product level. In the conclusion, we stress there is a need for future research to empirically develop our work further and measure (beyond the product level) the extent to which new production technologies such as distributed manufacturing are indeed democratising supply chain design and transforming manufacturing from ‘global production’ to a future ‘city-oriented’ social materiality

Numerical sampling rules for paraxial regime pulse diffraction calculations

Sampling rules for numerically calculating ultrashort pulse fields are discussed. Such pulses are not monochromatic but rather have a finite spectral distribution about some central (temporal) frequency. Accordingly, the diffraction pattern for many spectral components must be considered. From a numerical implementation viewpoint, one may ask how many of these spectral components are needed to accurately calculate the pulse field. Using an analytical expression for the Fresnel diffraction from a 1-D slit, we examine this question by varying the number of contributing spectral components. We show how undersampling the spectral profile produces erroneous numerical artifacts (aliasing) in the spatial–temporal domain. A guideline, based on graphical considerations, is proposed that determines appropriate sampling conditions. We show that there is a relationship between this sampling rule and a diffraction wave that emerges from the aperture edge; comparisons are drawn with boundary diffraction waves. Numerical results for 2-D square and circular apertures are presented and discussed, and a potentially time-saving calculation technique that relates pulse distributions in different z planes is described

Numerical sampling rules for paraxial regime pulse diffraction calculations

Sampling rules for numerically calculating ultrashort pulse fields are discussed. Such pulses are not monochromatic but rather have a finite spectral distribution about some central (temporal) frequency. Accordingly, the diffraction pattern for many spectral components must be considered. From a numerical implementation viewpoint, one may ask how many of these spectral components are needed to accurately calculate the pulse field. Using an analytical expression for the Fresnel diffraction from a 1-D slit, we examine this question by varying the number of contributing spectral components. We show how undersampling the spectral profile produces erroneous numerical artifacts (aliasing) in the spatial–temporal domain. A guideline, based on graphical considerations, is proposed that determines appropriate sampling conditions. We show that there is a relationship between this sampling rule and a diffraction wave that emerges from the aperture edge; comparisons are drawn with boundary diffraction waves. Numerical results for 2-D square and circular apertures are presented and discussed, and a potentially time-saving calculation technique that relates pulse distributions in different z planes is described

Fresnel and Fourier digital holography architectures: a comparison.

In this manuscript we examine the characteristics of holograms that are captured using both Fresnel and lens-less Fourier digital holographic systems. We begin by introducing some of the fundamental equations describing the intensity distribution captured by the camera. Naturally this captured intensity will vary depending on whether the system used is a Fourier or a Fresnel due to the different reference field in each case, however as we shall see with appropriate numerical processing it is possible to obtain similar performance from both systems. We discuss a reconstruction algorithm for changing the focus depth in Fourier holograms and examine how it effects the twin image and dc terms. A theoretical comparison with Fresnel holograms is made. Experimental results are provided to support our analysis. We finish with a brief conclusion

Speed up of Fresnel transforms for Digital holography using pre-computation

We show how the common Fresnel reconstruction of digital holograms can be speeded up on ordinary computers by precomputing the two chirp factors for a given detector array size and then calling these values from memory during the reconstruction. The speedup in time is shown for various hologram sizes. We also run the same algorithm on a Nvidia GPU using Matlab

A Practical Guide to Digital Holography and Generalized Sampling

The theorems of Nyquist, Shannon and Whittaker have long held true for sampling optical signals. They showed that a signal (with finite bandwidth) should be sampled at a rate at least as fast as twice the maximum spatial frequency of the signal. They proceeded to show how the continuous signal could be reconstructed perfectly from its well sampled counterpart by convolving a Sinc function with the sampled signal. Recent years have seen the emergence of a new generalized sampling theorem of which Nyquist Shannon is a special case. This new theorem suggests that it is possible to sample and reconstruct certain signals at rates much slower than those predicted by Nyquist-Shannon. One application in which this new theorem is of considerable interest is Fresnel Holography. A number of papers have recently suggested that the sampling rate for the digital recording of Fresnel holograms can be relaxed considerably. This may allow the positioning of the object closer to the camera allowing for a greater numerical aperture and thus an improved range of 3D perspective. In this paper we: (i) Review generalized sampling for Fresnel propagated signals, (ii) Investigate the effect of the twin image, always present in recording, on the generalized sampling theorem and (iii) Discuss the effect of finite pixel size for the first time

Review of Twin Reduction and Twin Removal Techniques in Holography

In this paper we review the major contributions over the past sixty years to the subject of twin reduction and twin removal in holography. We show that this collective work may be broken down into a number of categories including the well known techniques of off-axis holography and phase retrieval