1,225 research outputs found
AN INDEX METHOD FOR SELECTING REPRESENTATIVE CITIES OF A TARGET MARKET
An index was developed to rank U.S. metropolitan areas according to overall similarities in their socio-economic characteristics to the U.S. average. This index is given as a solution to matching a representative city or market area to a target market as well as matching a group of cities which are similar to each other. The index shows stability in ranking these cities with different consumption data for similar products and proves to be a promising approach whenever the researcher must find a group of cities which are similar to each other and to the target market.Research Methods/ Statistical Methods,
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Interactive learning systems for higher education: Learning styles and students' attitude
This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.This dissertation reports research concerning the adaptation of learning systems to students' different learning styles (LSs), particularly in relation to the analysis and planning of Interactive Learning Systems (ILSs). Given the primacy of Interactive Learning and its pedagogical implication on educational designs, the motivation for this research is better understanding of students' different learning preferences and perceptions of Computer Mediated Learning Interactions (CMLIs), as this may present some insights into what and how interactivity can be incorporated more purposefully and efficiently into learning systems designs. This research undertakes a review of the literature relating to LSs' theories, which have been used to explore how individual learners approach learning, as well as different Learning Interactions in relation to Interactive Learning Systems (ILSs). The work undertaken in this research makes its contribution to the field in that it represents one of the first explicit investigations of the relationship between students' LSs (Active-Reflective/Visual Verbal dimensions) and their attitude towards different CMLIs that constitute essential part of ILSs, in terms of use, perceptions and learning preferences, from the users' (learners) perspective rather than the teachers and/or designers of these systems. The research provides evidence to support the differing views of learners of different LSs as well as evidence of common attitudes towards certain CMLIs. However, it warns against and highlights some of the limitations of using the LSs in isolation and the importance of considering other factors and aspects of students' individual differences. A model is proposed to guide the planning and design of ILSs, and to raise the designers' and teachers' awareness of learners' differences and call upon them to take necessary steps to consider actual learners' LSs in the learning design. Implications of the findings in terms of interactivity design considerations are discussed; research limitations and recommendations for future work are made
Geometry of Discrete Quantum Computing
Conventional quantum computing entails a geometry based on the description of
an n-qubit state using 2^{n} infinite precision complex numbers denoting a
vector in a Hilbert space. Such numbers are in general uncomputable using any
real-world resources, and, if we have the idea of physical law as some kind of
computational algorithm of the universe, we would be compelled to alter our
descriptions of physics to be consistent with computable numbers. Our purpose
here is to examine the geometric implications of using finite fields Fp and
finite complexified fields Fp^2 (based on primes p congruent to 3 mod{4}) as
the basis for computations in a theory of discrete quantum computing, which
would therefore become a computable theory. Because the states of a discrete
n-qubit system are in principle enumerable, we are able to determine the
proportions of entangled and unentangled states. In particular, we extend the
Hopf fibration that defines the irreducible state space of conventional
continuous n-qubit theories (which is the complex projective space CP{2^{n}-1})
to an analogous discrete geometry in which the Hopf circle for any n is found
to be a discrete set of p+1 points. The tally of unit-length n-qubit states is
given, and reduced via the generalized Hopf fibration to DCP{2^{n}-1}, the
discrete analog of the complex projective space, which has p^{2^{n}-1}
(p-1)\prod_{k=1}^{n-1} (p^{2^{k}}+1) irreducible states. Using a measure of
entanglement, the purity, we explore the entanglement features of discrete
quantum states and find that the n-qubit states based on the complexified field
Fp^2 have p^{n} (p-1)^{n} unentangled states (the product of the tally for a
single qubit) with purity 1, and they have p^{n+1}(p-1)(p+1)^{n-1} maximally
entangled states with purity zero.Comment: 24 page
Offshore Stone Columns Under Embankment With Embedded Pipes
A breakwater embankment was constructed as part of a settling basin for the intake of a thermal power plant in the north of Egypt. The 440-m long breakwater surrounds the intake basin which has an area of about 18000 m2. Sea water is supplied to the intake basin through 50 concrete pipes embedded in the breakwater. Subsurface soil conditions in the area indicated that the embankment would be founded on soft silty clay underlain by a layer of silty sand. Results from the settlement analysis showed that the embedded pipes could not tolerate the predicted differential settlement in the embankment. Accordingly, it was determined that the embankment could not be founded on natural soil and that this soil would require improvement using stone columns. Offshore stone columns were constructed using the blanket method utilizing two vibro flotation probes. The layout was designed such that the stone columns were arranged in a triangular pattern below the embedded pipes, and in a rectangular pattern elsewhere. This paper presents the design method using numerical modeling to show the amount of expected settlement with and without stone columns. The method of construction is discussed showing how the stone columns were constructed using the blanket method. The full-scale load test that was constructed offshore to validate the design is described. The results from the load test and post-construction settlement readings indicated that the stone columns proved to be an efficient and economical solution in reducing the differential settlement to tolerable limits for the embedded pipes
Microbial-Physical Synthesis of Fe and Fe3O4 Magnetic Nanoparticles Using Aspergillus niger YESM1 and Supercritical Condition of Ethanol
Magnetic Fe and Fe3O4 (magnetite) nanoparticles are successfully synthesized using Aspergillus niger YESM 1 and supercritical condition of liquids. Aspergillus niger is used for decomposition of FeSO4 and FeCl3 to FeS and Fe2O3, respectively. The produced particles are exposed to supercritical condition of ethanol for 1 hour at 300∘ C and pressure of 850 psi. The phase structure and the morphology measurements yield pure iron and major Fe3O4 spherical nanoparticles with average size of 18 and 50 nm, respectively. The crystal size amounts to 9 nm for Fe and 8 nm for Fe3O4. The magnetic properties are measured to exhibit superparamagneticand ferromagnetic-like behaviors for Fe and Fe3O4 nanoparticles, respectively. The saturation magnetization amounts to 112 and 68 emu/g for Fe and Fe3O4, respectively. The obtained results open new route for using the biophysical method for large-scale production of highly magnetic nanoparticles to be used for biomedical applications
Prognostic utility of negative stress/rest myocardial SPECT studies among patients with different clinical categories of chronic kidney disease: Data from an Egyptian cohort
AbstractPrognostic value of negative myocardial SPECT study is well established. However, patients with chronic kidney disease (CKD) are a special group showing increased risk of cardiac events. We thought to investigate the prognostic value of negative SPECT study among patients on regular hemodialysis compared to other clinical categories of CKD.Methods186 consecutive patients with CKD and negative SPECT study were enrolled. 93 (50%) were on hemodialysis with an eGFR<30mL/min/1.73m2 (Group I); 25 (13.4%) had uncomplicated renal transplantation with eGFR between 45 and 90mL/min/1.73m2 (Group II) and 68 (36.6%) with CKD on conservative management and no prior history of hemodialysis (eGFR between 30 and 60mL/min/1.73m2), Group (III). End points (CD, STEMI/NSTEMI, need for revascularization and hospitalized HF) were traced at 6months, one year and 2years.ResultsTotal events in all groups were 5 (2.70%) at 6months, and 18 (9.70%) and 36 (19.30%) at one year and 2years respectively. At one year 16 (17.20%) cardiac events happened in Group I compared to one (4.0%) and one (1.50%) event(s) in Groups II and III respectively (p values 0.001). At 2years, 29 (31.20%) cardiac events happened in Group I while 2 (8.0%) and 5 (7.30%) happened in Groups II and III respectively (p values 0.01, 0.001 respectively). eGFR and duration of hemodialysis were the independent predictors of cardiac events.ConclusionDespite negative MPI study, patients on hemodialysis showed higher event (including CD, STEMI/NSTEMI and revascularization) rate at one and 2years of follow-up compared to other clinical categories of CKD
The Balanced Two-String Technique for Sulcus Intraocular Lens Implantation in the Absence of Capsular Support
Purpose. To describe and explore an alternative approach for sulcus intraocular lens (IOL) implantation in the absence of capsular support. Methods. The commonly available one-piece poly(methyl methacrylate) (PMMA) lens is stabilized in the sulcus by two intraocular horizontal strings of 10/0 polypropylene suture passed through the lens dialing holes in opposite directions to achieve a mechanical balance. The horizontal strings of 10/0 polypropylene work as a rail track for the IOL optics, allowing some side to side lens adjustment even following wound closure. The stability of the IOL was tested in vitro. Six aphakic patients underwent in-sulcus IOL secondary implantation using the balanced two-string technique. Patients were followed up for a minimum of six months. Best spectacle corrected vision was assessed. Lens centration and lens tilt were measured by anterior segment optical coherence tomography (AS-OCT). Results. All patients had successful lens insertion. Best spectacle corrected visual acuity (BSCVA) improved in all patients. Lens decentration ranged between 0.21 mm and 0.9 mm (average 0.53 mm). Lens tilt ranged between 1.2° and 2.8° (average 2.17°). Conclusion. The mechanically balanced two-string technique is an alternative option for sulcus IOL implantation in absence of capsular support, allowing lens centration adjustment with no additional risks
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