619 research outputs found
Orthogonal perfect DFT Golay codes
Deciding about which coding sequences should be used is an important issue in many communication
systems, such as those employing Code Division Multiple Access (CDMA). In this paper, we propose a cascading electronic codec based on a recursive algorithm for the generation of perfect sequences, derived from an Inverse Discrete Fourier Transform (IDFT) of Golay codes. The sequences generated have a low Peak-to-Average Power Ratio (PAPR), around 3 dB, which is the PAPR of a sine wave. The proposal is compared to the original Golay codes, verifying that our codec provides better crosscorrelation and autocorrelation results, crucial to gain immunity to multi-path interference.info:eu-repo/semantics/publishedVersio
Research Blogs and the Discussion of Scholarly Information
The research blog has become a popular mechanism for the quick discussion of scholarly information. However, unlike peer-reviewed journals, the characteristics of this form of scientific discourse are not well understood, for example in terms of the spread of blogger levels of education, gender and institutional affiliations. In this paper we fill this gap by analyzing a sample of blog posts discussing science via an aggregator called ResearchBlogging.org (RB). ResearchBlogging.org aggregates posts based on peer-reviewed research and allows bloggers to cite their sources in a scholarly manner. We studied the bloggers, blog posts and referenced journals of bloggers who posted at least 20 items. We found that RB bloggers show a preference for papers from high-impact journals and blog mostly about research in the life and behavioral sciences. The most frequently referenced journal sources in the sample were: Science, Nature, PNAS and PLoS One. Most of the bloggers in our sample had active Twitter accounts connected with their blogs, and at least 90% of these accounts connect to at least one other RB-related Twitter account. The average RB blogger in our sample is male, either a graduate student or has been awarded a PhD and blogs under his own name
Universal Rights and Wrongs
This paper argues for the important role of customers as a source of competitive advantage and firm growth, an issue which has been largely neglected in the resource-based view of the firm. It conceptualizes Penrose’s (1959) notion of an ‘inside track’ and illustrates how in-depth knowledge about established customers combines with joint problem-solving activities and the rapid assimilation of new and previously unexploited skills and resources. It is suggested that the inside track represents a distinct and perhaps underestimated way of generating rents and securing long-term growth. This also implies that the sources of sustainable competitive advantage in important respects can be sought in idiosyncratic interfirm relationships rather than within the firm itself
EPR analysis of multiple forms of [4Fe–4S] 3+ clusters in HiPIPs
The electron paramagnetic resonance (EPR) spectrum from the [4Fe–4S] 3+ cluster in several high-potential iron–sulfur proteins (HiPIPs) is complex: it is not the pattern of a single, isolated S =1/2 system. Multifrequency EPR from 9 to 130 GHz reveals that the apparent peak positions ( g values) are frequency-independent: the spectrum is dominated by the Zeeman interaction plus g -strain broadening. The spectra taken at frequencies above the X-band are increasingly sensitive to rapid-passage effects; therefore, the X-band data, which are slightly additionally broadened by dipolar interaction, were used for quantitative spectral analysis. For a single geometrical [4Fe–4S] 3+ structure the (Fe–Fe) 5+ mixed-valence dimer can be assigned in six different ways to a pair of iron ions, and this defines six valence isomers. Systematic multicomponent g -strain simulation shows that the [4Fe–4S] 3+ paramagnets in seven HiPIPs from different bacteria each consist of three to four discernible species, and these are assigned to valence isomers of the clusters. This interpretation builds on previous EPR analyzes of [4Fe–4S] 3+ model compounds, and it constitutes a high-resolution extension of the current literature model, proposed from paramagnetic NMR studies.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47867/1/775_2005_Article_656.pd
Shipping as a Knowledge Industry: Research and Strategic Planning at Ocean Group
This chapter approaches the question of how transformations in the world of shipping relate to wider trends in business and general history through the lens of knowledge. It will investigate how technological and managerial knowledge was created, developed and exploited as a corporate resource from the 1950s onwards in Ocean Transport and Trading, one of the UK’s leading liner shipping firms. The chapter will, first, briefly discuss the resource-based view of the firm and the importance of knowledge as a corporate resource. It will then examine Ocean’s use of technological and operational knowledge in the post-war era. The following section examines the introduction of modern management concepts at Ocean from the late 1960s and their impact on corporate strategy. In conclusion, the chapter will argue that the introduction of managerial concepts of knowledge contributed to Ocean’s gradual withdrawal from shipping and transformation into a provider of global logistics services and that analyzing shipping as a knowledge industry helps make sense of the transformation of the industry
Theoretical and technological building blocks for an innovation accelerator
The scientific system that we use today was devised centuries ago and is
inadequate for our current ICT-based society: the peer review system encourages
conservatism, journal publications are monolithic and slow, data is often not
available to other scientists, and the independent validation of results is
limited. Building on the Innovation Accelerator paper by Helbing and Balietti
(2011) this paper takes the initial global vision and reviews the theoretical
and technological building blocks that can be used for implementing an
innovation (in first place: science) accelerator platform driven by
re-imagining the science system. The envisioned platform would rest on four
pillars: (i) Redesign the incentive scheme to reduce behavior such as
conservatism, herding and hyping; (ii) Advance scientific publications by
breaking up the monolithic paper unit and introducing other building blocks
such as data, tools, experiment workflows, resources; (iii) Use machine
readable semantics for publications, debate structures, provenance etc. in
order to include the computer as a partner in the scientific process, and (iv)
Build an online platform for collaboration, including a network of trust and
reputation among the different types of stakeholders in the scientific system:
scientists, educators, funding agencies, policy makers, students and industrial
innovators among others. Any such improvements to the scientific system must
support the entire scientific process (unlike current tools that chop up the
scientific process into disconnected pieces), must facilitate and encourage
collaboration and interdisciplinarity (again unlike current tools), must
facilitate the inclusion of intelligent computing in the scientific process,
must facilitate not only the core scientific process, but also accommodate
other stakeholders such science policy makers, industrial innovators, and the
general public
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