8,470 research outputs found
Justifying the investment in information systems
The original publication is available at http://www.sajim.co.za/The environment in which organizations operate has changed dramatically over the last few years. Increased competition, globalization, the influence of the Internet and international events affect the performance and survival of organizations on a world-wide scale. The Internet has changed the way organizations do business, from the acquisition and servicing of customers to the management of their relations with suppliers. This is not only revolutionizing the way people access information, communicate, shop and entertain themselves, but also the way organizations compete and operate. With the extensive use and familiarity of the Internet, a trend has developed where organizations are moving their
information systems to Web-centered information systems. A Web-centered information system interrelates all the different information systems in an organization using Web-based technologies and interfaces. Organizations also use the Internet to electronically provide
innovative products and services. Users in organizations are demanding that the information systems used by the organization should become more efficient and effective. Therefore, organizations are forced to invest heavily in the deployment of information systems to obtain
value and benefit, and to stay competitive in this new environment. According to the Gartner Group (2002), world-wide spending on information communication technology alone totaled over $2,7 trillion in 2001, with an estimated wastage of 20% on corporate information
technology budgets with purchases failing to achieve their objectives. Although information systems expenditure is regarded as costly and risky, many information systems investments appear to go ahead without the use of formal investment appraisal and risk management
techniques (Ward 1996). However, tougher economic times are forcing businesses to treat information technology (IT) investments just like other fixed investments that are driven by sound business considerations and not hype (Van der Merwe 2002:116). The old argument,
that it is not necessary to formally justify the investment in information systems because they are strategically important to stay 'in business', is being questioned. In a business environment where senior managers and decision makers are held more and more accountable to the shareholders for their investment decisions, the need for using generally accepted techniques and methods to justify the investment decisions exists. This research investigated some relevant issues regarding the decision to invest in information systems, as well as the methods that organizations currently employ to justify their investment in information systems.Publishers' Versio
How robust is a thermal photon interpretation of the ALICE low-p_T data?
We present a rigorous theoretical analysis of the ALICE measurement of
low-p_T direct-photon production in central lead-lead collisions at the LHC
with a centre-of-mass energy of \sqrt{s_{NN}}=2.76 TeV. Using NLO QCD, we
compute the relative contributions to prompt-photon production from different
initial and final states and the theoretical uncertainties coming from
independent variations of the renormalisation and factorisation scales, the
nuclear parton densities and the fragmentation functions. Based on different
fits to the unsubtracted and prompt-photon subtracted ALICE data, we
consistently find T = 304 \pm 58 MeV and 309 \pm 64 MeV for the effective
temperature of the quark-gluon plasma (or hot medium) at p_T \in [0.8;2.2] GeV
and p_T \in [1.5;3.5] GeV as well as a power-law (p_T^{-4}) behavior for p_T >
4 GeV as predicted by QCD hard scattering.Comment: 18 pages, 7 figures, 1 tabl
The ALICE Transition Radiation Detector
In this talk an overview of the ALICE TRD is presented. The ALICE TRD consists of 540 individual detector modules with a total of 1.2 million readout channels. It allows electron identification above a momentum of 1 GeV/c and is capable of providing a very fast and efficient trigger on electrons with large transverse momentum pt. It will operate in a very high multiplicity environment. The rapidity density of charged particles in collisions of Pb nuclei at ps = 5:5 ATeV is expected to be as high as dN/dy = 8000
Projections for future radiocarbon content in dissolved inorganic carbon in hardwater lakes: a retrospective approach
Inland water bodies contain significant amounts of carbon in the form of dissolved inorganic carbon (DIC) derived from a mixture of modern atmospheric and pre-aged sources, which needs to be considered in radiocarbon-based dating and natural isotope tracer studies. While reservoir effects in hardwater lakes are generally considered to be constant through time, a comparison of recent and historical DI14C data from 2013 and 1969 for Lake Constance reveals that this is not a valid assumption. We hypothesize that changes in atmospheric carbon contributions to lake water DIC have taken place due to anthropogenically forced eutrophication in the 20th century. A return to more oligotrophic conditions in the lake led to reoxygenation and enhanced terrigenous organic matter remineralization, contributing to lake water DIC. Such comparisons using DI14C measurements from different points in time enable nonlinear changes in lake water DIC source and signature to be disentangled from concurrent anthropogenically induced changes in atmospheric 14C. In the future, coeval changes in lake dynamics due to climate change are expected to further perturb these balances. Depending on the scenario, Lake Constance DI14C is projected to decrease from the 2013 measured value of 0.856 Fm to 0.54–0.62 Fm by the end of the century
Venous thromboembolism in pregnancy
Pregnancy-related venous thromboembolic events are important preventable causes of morbidity and mortality in South Africa. All pregnant patients should be evaluated for thrombotic risk at different stages of their pregnancy and appropriate preventive steps taken. Maternal and fetal wellbeing must be kept in mind, as well as physiological changes leading to altered drug pharmacokinetics. Managing the patient with thrombotic risk in pregnancy, diagnosing venous thromboembolism (VTE) during pregnancy and treatment of venous thromboembolic events should be managed by a team. Excellent recent reviews on this subject are available, including risk factor stratification in anticoagulant therapy; managing the patient at time of labour; diagnosing VTE; and managing neuraxial anaesthesia in the pregnant patient on anticoagulant therapy
Flow-gauging structures in South African rivers Part 1: An overview
Accurate hydrological information is of paramount importance in a dry country such as South Africa. Flow measurements in rivers are complicated by the high variability of flows as well as by sediment and debris loads. It has been found necessary to modify and even substitute certain internationally accepted gauging structure designs to overcome local practical problems and improve accuracies.This, Part 1 of a paper in 2 parts, concentrates on the attributes of different types of gauging structures and the informationprovided on the different structures will assist the reader with the selection of an appropriate structure. The historical development of the gauging structure network in South African rivers is briefly discussed. Gauging structures used in South African rivers and basic design criteria for the preferred structures at this stage, based on past experience, are discussed:• Crump weirs• Sharp-crested weirs• Sluicing flumes.This paper reflects the lessons that have been learnt by DWAF and other South African organisations and should be of value to others who have to perform flow measurements under similar climatic conditions. Factors that may adversely impact on gauging accuracy are also pointed out in the conclusion. Part 2 of the paper contains information on the calibration theory and techniques to rate the preferred gauging structures
Optical properties of Mn4+ ions in GaN:Mn codoped with Mg acceptors
The optical properties of Mn-Mg codoped epitaxial GaN were studied. Addition
of Mg acceptors quenches the weak manganese-related photoluminescence (PL) band
at 1.3 eV in GaN:Mn and a series of sharp PL peaks are observed at 1 eV in
codoped epilayers. The change in PL spectra indicates that Mg addition
stabilizes the Mn4+ charge state by decreasing the Fermi level. The 1 eV PL
peaks are tentatively attributed to intra center transitions involving Mn4+
ions. Spin allowed 3d-shell 4T2-4T1 transitions and their phonon replicas are
involved. The relative intensities of the sharp peaks are strongly dependent on
the excitation wavelength, indicating the optically active Mn4+ centers
involved in the separate peaks are different. The temperature dependence of the
PL spectrum suggests the presence of at least three distinct Mn4+ complex
centers.Comment: 14 pages, 3 figures, 1 table, accepted by Appl. Phys. Let
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