100 research outputs found
The impact and penetration of location-based services
Since the invention of digital technology, its development has followed an entrenched path ofminiaturisation and decentralisation with increasing focus on individual and niche applications. Computerhardware has moved from remote centres to desktop and hand held devices whilst being embedded invarious material infrastructures. Software has followed the same course. The entire process has convergedon a path where various analogue devices have become digital and are increasingly being embedded inmachines at the smallest scale. In a parallel but essential development, there has been a convergence ofcomputers with communications ensuring that the delivery and interaction mechanisms for computersoftware is now focused on networks of individuals, not simply through the desktop, but in mobilecontexts. Various inert media such as fixed television is becoming more flexible as computers and visualmedia are becoming one.With such massive convergence and miniaturisation, new software and new applications define the cuttingedge. As computers are being increasingly tailored to individual niches, then new digital services areemerging, many of which represent applications which hitherto did not exist or at best were rarely focusedon a mass market. Location based services form one such application and in this paper, we will bothspeculate on and make some initial predictions of the geographical extent to which such services willpenetrate different markets. We define such services in detail below but suffice it to say at this stage thatsuch functions involve the delivery of traditional services using digital media and telecommunications.High profile applications are now being focused on hand held devices, typically involving information onproduct location and entertainment but wider applications involve fixed installations on the desktop whereservices are delivered through traditional fixed infrastructure. Both wire and wireless applications definethis domain. The market for such services is inevitably volatile and unpredictable at this early stage but wewill attempt here to provide some rudimentary estimates of what might happen in the next five to tenyears.The ?network society? which has developed through this convergence, is, according to Castells (1989,2000) changing and re-structuring the material basis of society such that information has come todominate wealth creation in a way that information is both a raw material of production and an outcome ofproduction as a tradable commodity. This has been fuelled by the way technology has expanded followingMoore?s Law and by fundamental changes in the way telecommunications, finance, insurance, utilitiesand so on is being regulated. Location based services are becoming an integral part of this fabric and thesereflect yet another convergence between geographic information systems, global positioning systems, andsatellite remote sensing. The first geographical information system, CGIS, was developed as part of theCanada Land Inventory in 1965 and the acronym ?GIS? was introduced in 1970. 1971 saw the firstcommercial satellite, LANDSAT-1. The 1970s also saw prototypes of ISDN and mobile telephone and theintroduction of TCP/IP as the dominant network protocol. The 1980s saw the IBM XT (1982) and thebeginning of de-regulation in the US, Europe and Japan of key sectors within the economy. Finally in the 1990s, we saw the introduction of the World Wide Web and the ubiquitous pervasion of business andrecreation of networked PC?s, the Internet, mobile communications and the growing use of GPS forlocational positioning and GIS for the organisation and visualisation of spatial data. By the end of the 20thcentury, the number of mobile telephone users had reached 700 million worldwide. The increasingmobility of individuals, the anticipated availability of broadband communications for mobile devices andthe growing volumes of location specific information available in databases will inevitably lead to thedemand for services that will deliver location related information to individuals on the move. Suchlocation based services (LBS) although in a very early stage of development, are likely to play anincreasingly important part in the development of social structures and business in the coming decades.In this paper we begin by defining location based services within the context we have just sketched. Wethen develop a simple model of the market for location-based services developing the standard non-linearsaturation model of market penetration. We illustrate this for mobile devices, namely mobile phones in thefollowing sections and then we develop an analysis of different geographical regimes which arecharacterised by different growth rates and income levels worldwide. This leads us to speculate on theextent to which location based services are beginning to take off and penetrate the market. We concludewith scenarios for future growth through the analogy of GIS and mobile penetration
Road junction configurations and the severity of traffic accidents in Japan
In many countries, 40–60% of the traffic accidents occur at junctions, making the reduction of junction accidents paramount to achieving UN Sustainable Development Goals. In Japan, the road safety guidelines specify the proximity between junctions and non-perpendicular angles at junctions as the two main risk factors behind junction accidents, yet their impact remains understudied. Using binomial logistic regression models, this study investigates the impact of junction intervals and junction angles on the severity of traffic accidents. The study found that, in general, (1) shorter intervals between adjacent junctions helps reduce the risk of serious accidents, which is the opposite of the current road safety guidelines in Japan, and (2) results from the junction angle analysis were mixed but there was no evidence that the roads should meet at a right angle to reduce traffic accidents. Some types of accidents also returned a non-linear curve, e.g., vehicle-to-vehicle collisions at four-armed junctions involving a driver aged 65 years and over have the highest risk of fatal/serious accidents when adjacent junctions were 32 m apart, and the risk reduces at a shorter or longer interval. These results suggest that the current road safety guidelines require updating to improve road safety around junctions
Three-dimensional modeling of a primary health care clinic in Ho, Ghana: its contribution to student engagement, fundraising, and program planning
Improvements in computer-based technologies can be leveraged to enhance engagement of remote stakeholders with the health needs of a geographically distant community. Three-dimensional (3D) modeling offers a platform to create detailed spatial representations through which stakeholders can experience improvements in shared understanding as well as increased involvement in community health projects occurring anywhere in the world. This case study describes the development of a 3D model of a community health clinic in rural Ghana used to encourage fundraising and sustain global engagement among students at Northwestern University. The resulting ‘virtual clinic’ was achieved quickly and at little cost, suggesting a broader utility of 3D modeling for global health practitioners for increasing donor engagement and resource mapping
Observed Consequences of Presupernova Instability in Very Massive Stars
This chapter concentrates on the deaths of very massive stars, the events
leading up to their deaths, and how mass loss affects the resulting death. The
previous three chapters emphasized the theory of wind mass loss, eruptions, and
core collapse physics, but here we emphasize mainly the observational
properties of the resulting death throes. Mass loss through winds, eruptions,
and interacting binaries largely determines the wide variety of different types
of supernovae that are observed, as well as the circumstellar environments into
which the supernova blast waves expand. Connecting these observed properties of
the explosions to the initial masses of their progenitor stars is, however, an
enduring challenge and is especially difficult for very massive stars.
Superluminous supernovae, pair instability supernovae, gamma ray bursts, and
"failed" supernovae are all end fates that have been proposed for very massive
stars, but the range of initial masses or other conditions leading to each of
these (if they actually occur) are still very certain. Extrapolating to infer
the role of very massive stars in the early universe is essentially
unencumbered by observational constraints and still quite dicey.Comment: 39 pages, 5 figures, to appear as chapter in the book "Very Massive
Stars in the Local Universe", ed. J. Vin
The Exceptionally Luminous Type II-L SN 2008es
We report on our early photometric and spectroscopic observations of the
extremely luminous Type II supernova (SN) 2008es. With an observed peak optical
magnitude of m_V = 17.8 and at a redshift z = 0.213, SN 2008es had a peak
absolute magnitude of M_V = -22.3, making it the second most luminous SN ever
observed. The photometric evolution of SN 2008es exhibits a fast decline rate
(~0.042 mag d^-1), similar to the extremely luminous Type II-L SN 2005ap. We
show that SN 2008es spectroscopically resembles the luminous Type II-L SN
1979C. Although the spectra of SN 2008es lack the narrow and intermediate-width
line emission typically associated with the interaction of a SN with the
circumstellar medium of its progenitor star, we argue that the extreme
luminosity of SN 2008es is powered via strong interaction with a dense,
optically thick circumstellar medium. The integrated bolometric luminosity of
SN 2008es yields a total radiated energy at ultraviolet and optical wavelengths
of >10^51 ergs. Finally, we examine the apparently anomalous rate at which the
Texas Supernova Search has discovered rare kinds of supernovae, including the
five most luminous supernovae observed to date, and find that their results are
consistent with those of other modern SN searches.Comment: accepted to ApJ, 10 pages, 7 figures, 6 tables. Minor revisions,
conclusions remain unchange
First Results from the Lick AGN Monitoring Project: The Mass of the Black Hole in Arp 151
We have recently completed a 64-night spectroscopic monitoring campaign at
the Lick Observatory 3-m Shane telescope with the aim of measuring the masses
of the black holes in 13 nearby (z < 0.05) Seyfert 1 galaxies with expected
masses in the range ~10^6-10^7 M_sun. We present here the first results from
this project -- the mass of the central black hole in Arp 151. Strong
variability throughout the campaign led to an exceptionally clean Hbeta lag
measurement in this object of 4.25(+0.68/-0.66) days in the observed frame.
Coupled with the width of the Hbeta emission line in the variable spectrum, we
determine a black hole mass of (7.1 +/- 1.2)x10^6 M_sun, assuming the Onken et
al. normalization for reverberation-based virial masses. We also find
velocity-resolved lag information within the Hbeta emission line which clearly
shows infalling gas in the Hbeta-emitting region. Further detailed analysis may
lead to a full model of the geometry and kinematics of broad line region gas
around the central black hole in Arp 151.Comment: 4 pages, 4 figures and 2 tables, accepted for publication in ApJ
Letter
The Evolution of Compact Binary Star Systems
We review the formation and evolution of compact binary stars consisting of
white dwarfs (WDs), neutron stars (NSs), and black holes (BHs). Binary NSs and
BHs are thought to be the primary astrophysical sources of gravitational waves
(GWs) within the frequency band of ground-based detectors, while compact
binaries of WDs are important sources of GWs at lower frequencies to be covered
by space interferometers (LISA). Major uncertainties in the current
understanding of properties of NSs and BHs most relevant to the GW studies are
discussed, including the treatment of the natal kicks which compact stellar
remnants acquire during the core collapse of massive stars and the common
envelope phase of binary evolution. We discuss the coalescence rates of binary
NSs and BHs and prospects for their detections, the formation and evolution of
binary WDs and their observational manifestations. Special attention is given
to AM CVn-stars -- compact binaries in which the Roche lobe is filled by
another WD or a low-mass partially degenerate helium-star, as these stars are
thought to be the best LISA verification binary GW sources.Comment: 105 pages, 18 figure
Change in alcohol outlet density and alcohol-related harm to population health (CHALICE): a comprehensive record-linked database study in Wales
Excess alcohol consumption has many adverse effects on health, including an increased risk of liver cirrhosis, gastrointestinal tract and breast cancers, high blood pressure and stroke. There is also an increased risk of harm resulting from antisocial behaviour and violence. Binge drinking is a particular problem, with the highest prevalence in the 16- to 24-year age group for women and men. Up to 40% of attendances at accident and emergency (A&E) departments and around half of all violent crimes in the UK are alcohol related. Around 37% of men and 25% of women exceeded UK guidelines for safe levels of alcohol consumption in 2014 (women more than three units per day; men more than four units per day) and 19% of men and 11% of women binge drink (women more than six units per day; men more than eight units per day). Given the wide range of harm resulting from this substantial level of excess consumption, the potential impact on health at the population level from a reduction in consumption is considerable. One of the principal policies recommended by the British Medical Association to reduce alcohol consumption is to reduce easy access to alcohol through controls on hours of sale and outlet density. This uses the availability theory of alcohol-related harm, which states that harmful outcomes are linked directly or indirectly to a greater availability of alcohol, through a higher density of alcohol outlets, leading to higher consumption and hence alcohol-related harm. However, the evidence relating outlet density to alcohol-related harm is not consistent. Many cross-sectional studies have suggested that high outlet densities are associated with a higher rate of a wide range of alcohol-related injuries. Fewer studies have investigated associations between outlet density and non-injury health outcomes, suggesting that high outlet densities are associated with high levels of consumption, sexually transmitted infections and alcohol-related hospital admissions. There have been few longitudinal studies but these have provided limited evidence that an increase in outlet density is associated with increased consumption and interpersonal violence and that a decrease in proximity to outlets is associated with a small decrease in consumption. No longitudinal studies of admissions to hospital have been published for non-violent outcomes. Many methodological questions remain over the best way to measure outlet density and how to model the relationship with alcohol-related harms. Little is known about the effects of a change in outlet density on inequalities in alcohol-related health and the role of population migration
CVIT expert consensus document on primary percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI) in 2018
While primary percutaneous coronary intervention (PCI) has significantly contributed to improve the mortality in patients with ST segment elevation myocardial infarction even in cardiogenic shock, primary PCI is a standard of care in most of Japanese institutions. Whereas there are high numbers of available facilities providing primary PCI in Japan, there are no clear guidelines focusing on procedural aspect of the standardized care. Whilst updated guidelines for the management of acute myocardial infarction were recently published by European Society of Cardiology, the following major changes are indicated; (1) radial access and drug-eluting stent over bare metal stent were recommended as Class I indication, and (2) complete revascularization before hospital discharge (either immediate or staged) is now considered as Class IIa recommendation. Although the primary PCI is consistently recommended in recent and previous guidelines, the device lag from Europe, the frequent usage of coronary imaging modalities in Japan, and the difference in available medical therapy or mechanical support may prevent direct application of European guidelines to Japanese population. The Task Force on Primary Percutaneous Coronary Intervention of the Japanese Association of Cardiovascular Intervention and Therapeutics (CVIT) has now proposed the expert consensus document for the management of acute myocardial infarction focusing on procedural aspect of primary PCI
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