Caffeine-Induced Global Reductions in Resting-State BOLD Connectivity Reflect Widespread Decreases in MEG Connectivity.

In resting-state functional magnetic resonance imaging (fMRI), the temporal correlation between spontaneous fluctuations of the blood oxygenation level dependent (BOLD) signal from different brain regions is used to assess functional connectivity. However, because the BOLD signal is an indirect measure of neuronal activity, its complex hemodynamic nature can complicate the interpretation of differences in connectivity that are observed across conditions or subjects. For example, prior studies have shown that caffeine leads to widespread reductions in BOLD connectivity but were not able to determine if neural or vascular factors were primarily responsible for the observed decrease. In this study, we used source-localized magnetoencephalography (MEG) in conjunction with fMRI to further examine the origins of the caffeine-induced changes in BOLD connectivity. We observed widespread and significant (p < 0.01) reductions in both MEG and fMRI connectivity measures, suggesting that decreases in the connectivity of resting-state neuro-electric power fluctuations were primarily responsible for the observed BOLD connectivity changes. The MEG connectivity decreases were most pronounced in the beta band. By demonstrating the similarity in MEG and fMRI based connectivity changes, these results provide evidence for the neural basis of resting-state fMRI networks and further support the potential of MEG as a tool to characterize resting-state connectivity

Pseudorandomness for Regular Branching Programs via Fourier Analysis

We present an explicit pseudorandom generator for oblivious, read-once, permutation branching programs of constant width that can read their input bits in any order. The seed length is $O(log^2 n)$, where n is the length of the branching program. The previous best seed length known for this model was $n^{ 1/2 + o(1)}$, which follows as a special case of a generator due to Impagliazzo, Meka, and Zuckerman (FOCS 2012) (which gives a seed length of $s^{ 1/2 + o(1)}$ for arbitrary branching programs of size s). Our techniques also give seed length $n^{ 1/2 + o(1)}$ for general oblivious, read-once branching programs of width $2^{n^{o(1)}}$, which is incomparable to the results of Impagliazzo et al. Our pseudorandom generator is similar to the one used by Gopalan et al. (FOCS 2012) for read-once CNFs, but the analysis is quite different; ours is based on Fourier analysis of branching programs. In particular, we show that an oblivious, read-once, regular branching program of width w has Fourier mass at most $(2w^ 2) ^k$ at level k, independent of the length of the program.Engineering and Applied Science

Management of collaborative BIM data by the Federatinon of Distributed Models

The architecture engineering and construction sector is currently undergoing a significant period of change and modernization. In the United Kingdom in particular this is driven by the government’s objective of reducing the cost of construction projects. This is to be achieved by requiring all publicly funded projects to utilize fully collaborative building information modeling by 2016. A common goal in increasing building information model (BIM) adoption by the industry is the movement toward the realization of a BIM as either a single data model or a series of tightly coupled federated models. However, there are key obstacles to be overcome, including uncertainty over data ownership, concerns relating to the security/privacy of data, and reluctance to “outsource” data storage. This paper proposes a framework that is able to provide a solution for managing collaboration in the architecture engineering and construction (AEC) sector. The solution presented in this paper provides an overlay that automatically federates and governs distributed BIM data. The use of this overlay provides an integrated BIM model that is physically distributed across the stakeholders in a construction project. The key research question addressed by this paper is whether such an overlay can, by providing dynamic federation and governance of BIM data, overcome some key obstacles to BIM adoption, including questions over data ownership, the security/privacy of data, and reluctance to share data. More specifically, this paper provides the following contributions: (1) presentation of a vision for the implementation and governance of a federated distributed BIM data model; (2) description of the BIM process and governance model that underpins the approach; (3) provision of a validation case study using real construction data from a U.K. highways project, demonstrating that both the federated BIM overlay and the process and governance model are fit for purpose. - See more at: http://ascelibrary.org/doi/full/10.1061/(ASCE)CP.1943-5487.0000657#sthash.jIj574Lh.dpu

Evaluating Local Government Usage of GIS: A New Maturity Model

GIS is a technology with the potential to transform government by enhancing business processes and providing a platform to manage spatial and non-spatial data, which is expected to result in better decision-making. However, little is known about how this technology is actually implemented organization-wide and the environment surrounding its use. Current GIS maturity models have not examined usage broadly or in-depth, lack empirical validation, and measurement tools to diagnose maturity are not readily available. Based on GIS, maturity models, and system usage literature this study presents a more comprehensive maturity model for evaluating local government usage of GIS along with a measurement tool. The study followed De Bruin guidelines for developing maturity models. This new model was discussed with practitioners and academics, was pilot-tested, and then widely tested on Southern California local governments through an online questionnaire. Results show support for the validity of the model and demonstrate its utility

An Organizational Perspective On GIS Payoffs for the Public Sector: Is Usage the Missing Link?

GIS offers a unique way of layering spatial data, and its related tabular data, that can be visualized through a single map. This feature has made GIS attractive for governments, and especially local governments, as they work with such data on daily basis. Many local governments are currently using GIS and are planning to expand their usage; many are expected to follow in kind. Now is the time to ask the question, “What benefits have the public sector gained from GIS?” This study seeks to answer this question and investigates the role of GIS usage in determining GIS value at the organizational level. A survey was carried out with Southern California local governments. Results suggest that increasing actual GIS usage leads to an increase in GIS value. Results further show that efficiency and effectiveness benefits of GIS are mostly realized, however, societal benefits of GIS are small

Performance analysis of multi-institutional data sharing in the Clouds4Coordination system

Cloud computing is used extensively in Architecture/ Engineering/ Construction projects for storing data and running simulations on building models (e.g. energy efficiency/environmental impact). With the emergence of multi-Clouds it has become possible to link such systems and create a distributed cloud environment. A multi-Cloud environment enables each organisation involved in a collaborative project to maintain its own computational infrastructure/ system (with the associated data), and not have to migrate to a single cloud environment. Such infrastructure becomes efficacious when multiple individuals and organisations work collaboratively, enabling each individual/ organisation to select a computational infrastructure that most closely matches its requirements. We describe the “Clouds-for-Coordination” system, and provide a use case to demonstrate how such a system can be used in practice. A performance analysis is carried out to demonstrate how effective such a multi-Cloud system can be, reporting “aggregated-time-to-complete” metric over a number of different scenarios

Cloud computing for the architecture, engineering & construction sector: requirements, prototype & experience

The Architecture, Engineering \& Construction (AEC) sector is a highly fragmented, data intensive, project based industry, involving a number of very different professions and organisations. Projects carried out within this sector involve collaboration between various people, using a variety of different systems. This, along with the industry's strong data sharing and processing requirements, means that the management of building data is complex and challenging. This paper presents a solution to data sharing requirements of the AEC sector by utilising Cloud Computing. Our solution presents two key contributions, first a governance model for building data, based on extensive research and industry consultation. Second, a prototype implementation of this governance model, utilising the CometCloud autonomic cloud computing engine based on the Master/Work paradigm. we have integrated our prototype with the 3D modelling software Google Sketchup. The approach and prototype presented has applicability in a number of other eScience related applications involving multi-disciplinary, collaborative working using Cloud computing infrastructure

Periodicities in the K2 light curve of HP Librae

We analyse Kepler/K2 light-curve data of the AM CVn system HP Librae (HP Lib). We detect with confidence four photometric periodicities in the system: the orbital frequency, both positive and negative superhumps, and the positive apsidal precession frequency of the accretion disc. This is only the second time that the apsidal precession frequency has ever been directly detected in the photometry of a helium accreting system, after SDSS J135154.46-064309.0. We present phase-folded light curves and sliding power spectra of each of the four periodicities. We measure rates of change of the positive superhump period of ∼10−7 d. We also redetect a quasi-periodic oscillation (QPO) at ∼300 cyc d–1, a feature that has been stable over decades, and show that it is harmonically related to two other QPOs, the lowest of which is centred on the superhump/orbital frequency. The continuum power spectrum is consistent with a single power law with no evidence of any breaks within our observed frequency range