747 research outputs found
The Impact of Employment Web Sites' Traffic on Unemployment: A Cross Country Comparison
Although employment web sites have recently become the main source for re-
cruitment and selection process, the relation between those sites and unemploy-
ment rates is seldom addressed. Deriving data from 32 countries and 427 web
sites, this study explores the correlation between unemployment rates of
European countries and the attractiveness of country specific employment web
sites. It also compares the changes in unemployment rates and traffic on all
the aforementioned web sites. The results showed that there is a strong
correlation between web sites traffic and unemployment rates.Comment: 9 page
Analysis of hospital service areas in Istanbul
After 1950's, the rapid expansion of Istanbul has created tremendous demand for new public facilities as well as the need for evaluation of existing facilities. Although the service areas of hospital is a very important information in order to use efficently scarce resources, there are very few studies on this subject in devoloping countries. This study investigates the spatial behavior of in patients in relation to three different types of hospitals ( teaching, general public and private) in order to provide background for the efficient planning of health facilities in Istanbul. According to the results, all three types of hospitals receive patients from different parts of the city as well as throughout the country. The service areas of these hospitals are investigated also according to their location within the different zones of the city. As the speciality of the hospitals increases, the density of the patients becomes more widely distributed than the local hospitals. According to the results, the areas which are not served by any hospital are determined. Further, research is suggested on more detailed analysis of spatial behavior of patients with respect to patients' characteristics.
A Novel Approach to Minimizing the Risks of Soft Errors in Mobile and Ubiquitous Systems
A novel approach to minimizing the risks of soft errors at modelling level of mobile and ubiquitous systems is outlined. From a pure dependability viewpoint, critical components, whose failure is likely to impact on system functionality, attract more attention of protection/prevention mechanisms (against soft errors) than others do. Tolerating soft errors can be much improved if critical components can be identified at an early design phase and measures are taken to lower their criticalities at that stage. This improvement is achieved by presenting a criticality ranking (among the components) formed by combining a prediction of soft errors, consequences of them, and a propagation of failures at system modelling phase; and pointing out the ways to apply changes in the model to minimize the risks of degradation of desired functionalities. Case study results are given to illustrate and validate the approach
Data-driven feature identification and sparse representation of turbulent flows
Identifying coherent structures in fluid flows is of great importance for reduced order modelling and flow control. However, extracting such structures from experimental or numerical data obtained from a turbulent flow can be challenging. A number of modal decomposition algorithms have been proposed in recent years which decompose time-resolved snapshots of data into spatial modes, each associated with a single frequency and growth-rate. Most prominently among them is dynamic mode decomposition (DMD). However, DMD-like algorithms create an arbitrary number of modes. It is common practice to then choose a smaller subset of these modes, for the purpose of model reduction and analysis, based on some measure of significance. In this work, we present a method of post-processing DMD modes for extracting a small number of dynamically relevant modes. We achieve this through an iterative approach based on the graph-theoretic notion of maximal cliques to identify clusters of modes and representing each cluster with a single representative mode
A Design Approach for Soft Errors Protection in Real-Time Systems
This paper proposes the use of metrics to refine system design for soft errors protection in system on chip architectures. Specifically this research shows the use of metrics in design space exploration that highlight where in the structure of the model and at what point in the behaviour, protection is needed against soft errors. As these metrics improve the ability of the system to provide functionality, they are referred to here as reliability metrics. Previous approaches to prevent soft errors focused on recovery after detection. Almost no research has been directed towards preventive measures. But in real-time systems, deadlines are performance requirements that absolutely must be met and a missed deadline constitutes an erroneous action and a possible system failure. This paper focuses on a preventive approach as a solution rather than recovery after detection. The intention of this research is to prevent serious loss of system functionality or system failure though it may not be able to eliminate the impact of soft errors completely
A Model-Based Soft Errors Risks Minimization Approach
Minimizing the risk of system failure in any computer structure requires identifying those components whose failure is likely to impact on system functionality. Clearly, the degree of protection or prevention required against faults is not the same for all components. Tolerating soft errors can be much improved if critical components can be identified at an early design phase and measures are taken to lower their criticalities at that stage. This improvement is achieved by presenting a criticality ranking (among the components) formed by combining a prediction of faults, consequences of them, and a propagation of errors at the system modeling phase; and pointing out ways to apply changes in the model to minimize the risk of degradation of desired functionalities. Case study results are given to validate the approach
Gauge covariance and spin-current conservation in the gauge-field formulation of systems with spin–orbit coupling
The question of gauge covariance in the non-Abelian gauge-field formulation of two space-dimensional systems with spin-orbit coupling relevant to spintronics is investigated. Although these are generally gauge-fixed models, it is found that for the class of gauge fields that are spacetime independent and satisfy a U(1) algebra, thus having a vanishing field strength, there is a residual gauge freedom in the Hamiltonian. The gauge transformations assume the form of a space-dependent rotation of the transformed wavefunctions with rotation angles and axes determined by the specific form of the gauge field, i.e. the spin-orbit coupling. The fields can be gauged away, reducing the Hamiltonian to one which is isospectral to the free-particle Hamiltonian, and giving rise to the phenomenon of persistent spin helix reported first by Bernevig et al (2006 Phys. Rev. Lett. 97 236601). The investigation of the global gauge transformations leads to the derivation of a continuity equation where the component of the spin density along given directions, again fixed by the specific form of the gauge field, is conserved
Study of the mechanical behavior of leaded copper by scratch test and nanoindentation
Copper-lead was investigated by scratch tests under two set of experiments conditions: at progressive loads (0 – 200 N) and at two different constant loads (20 – 30 N). These tests were made to assess the adhesion properties to determine the critical normal load of copper- lead journal bearings material. The morphologies of material after scratches are synthesized by optical microscope. Nanoindentation studies of copper-lead provide the possibility of examining a variety of mechanical events due to porosity and pre-existing defects in material. The resulting data are analyzed in terms of load–displacement curves and various comparative parameters, such as hardness and Young’s modulus
Using Community-Owned Resource Persons to Provide Early Diagnosis and Treatment and Estimate Malaria Burden at Community Level in North-Eastern Tanzania.
Although early diagnosis and prompt treatment is an important strategy for control of malaria, using fever to initiate presumptive treatment with expensive artemisinin combination therapy is a major challenge; particularly in areas with declining burden of malaria. This study was conducted using community-owned resource persons (CORPs) to provide early diagnosis and treatment of malaria, and collect data for estimation of malaria burden in four villages of Korogwe district, north-eastern Tanzania.In 2006, individuals with history of fever within 24 hours or fever (axillary temperature ≥37.5°C) at presentation were presumptively treated using sulphadoxine/pyrimethamine. Between 2007 and 2010, individuals aged five years and above, with positive rapid diagnostic tests (RDTs) were treated with artemether/lumefantrine (AL) while under-fives were treated irrespective of RDT results. Reduction in anti-malarial consumption was determined by comparing the number of cases that would have been presumptively treated and those that were actually treated based on RDTs results. Trends of malaria incidence and slide positivity rates were compared between lowlands and highlands. Of 15,729 cases attended, slide positivity rate was 20.4% and declined by >72.0% from 2008, reaching <10.0% from 2009 onwards; and the slide positivity rates were similar in lowlands and highlands from 2009 onwards. Cases with fever at presentation declined slightly, but remained at >40.0% in under-fives and >20.0% among individuals aged five years and above. With use of RDTs, cases treated with AL decreased from <58.0% in 2007 to <11.0% in 2010 and the numbers of adult courses saved were 3,284 and 1,591 in lowlands and highlands respectively. Malaria incidence declined consistently from 2008 onwards; and the highest incidence of malaria shifted from children aged <10 years to individuals aged 10-19 years from 2009. With basic training, supervision and RDTs, CORPs successfully provided early diagnosis and treatment and reduced consumption of anti-malarials. Progressively declining malaria incidence and slide positivity rates suggest that all fever cases should be tested with RDTs before treatment. Data collected by CORPs was used to plan phase 1b MSP3 malaria vaccine trial and will be used for monitoring and evaluation of different health interventions. The current situation indicates that there is a remarkable changing pattern of malaria and these areas might be moving from control to pre-elimination levels
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