1,994 research outputs found
Regional Industry Analysis: An Approach for Economies Large and Smaller
Interest in cluster analysis for economic development in regions has been significant over the years. Knowing the strengths and weaknesses of a community’s industry clusters or economic agglomerations can provide regions with resilience to economic changes. Large and smaller economies that are able to identify their industry clusters and know their competitive strengths and weaknesses may be more adaptable and able to thwart the negative effects of economic change. One example of the value of knowing about the strengths and weaknesses of an economy and the potential to shift to new areas of production and service in a local economy is evidenced in Walla Walla, Washington. Smaller communities such as Walla Walla (population estimate 31,957 (U.S. Census)) that have a competitive advantage in wheat production but have found the need to transform their economies because global competition has made their wheat crop production less competitive. Walla Walla packaged some of its natural amenities and strengths in crop production, made use of the education infrastructure at its community college, and created a new industry stronghold of wine production and tourism and increasing restaurant and hotel attractions (Public Broadcasting Service, 2012). Walla Wall capitalized on their completive advantage in crop production, moving from wheat to grapes. This was necessary to stay competitive, but would have been unlikely had they not built on its existing competitive advantage in agriculture and made use of its community college to disseminate knowledge about wine production
Motion of vortices in type II superconductors
The methods of formal asymptotics are used to examine the behaviour of a system of curvilinear vortices in a type II superconductor as the thickness of the vortex cores tends to zero. The vortices then appear as singularities in the field equation and are analagous to line vortices in inviscid hydrodynamics. A local analysis near each vortex core gives an equation of motion governing the evolution of these singularities
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Death of an expert system: A case study of success and failure
A decision team composed of managers and staff experts at Mary Kay Cosmetics develops packaging for new and revised products as well as sets their prices. However, the potential for costly errors in the decision-making process motivated this group to pursue development of an expert system (ES) to assist with the problem. The ES performed so well that it changed the organization\u27s behavior—the group ceased to meet for the purpose of developing the packaging but instead gathered just to confirm and approve the expert system\u27s solution. Despite the clear benefits associated with using an ES approach, the group stopped using the ES application and the behavior of the group returned to pre-ES practices. This work describes from a managerial perspective how and why this valuable tool fell into disuse, and offers valuable lessons for management
Fast-slow asymptotic for semi-analytical ignition criteria in FitzHugh-Nagumo system
We study the problem of initiation of excitation waves in the FitzHugh-Nagumo
model. Our approach follows earlier works and is based on the idea of
approximating the boundary between basins of attraction of propagating waves
and of the resting state as the stable manifold of a critical solution. Here,
we obtain analytical expressions for the essential ingredients of the theory by
singular perturbation using two small parameters, the separation of time scales
of the activator and inhibitor, and the threshold in the activator's kinetics.
This results in a closed analytical expression for the strength-duration curve.Comment: 10 pages, 5 figures, as accepted to Chaos on 2017/06/2
Investigation of Wing Characteristics at a Mach Number of 1.53 II : Swept Wings of Taper Ratio 0.5
Measured values of lift, drag, and pitching moment at M(sub o) = 1.53 are presented for seven wings varying in sweep angle from 60 degrees sweepforward to 60 degrees sweepback. All wings had a cambered, double-wedge section 5-percent thick and a common taper ratio of 0.5. The experimental results are compared with the predictions of the linear theory
Interactions of inert confiners with explosives
The deformation of an inert confiner by a steady detonation wave in an
adjacent explosive is investigated for cases where the confiner is suciently strong
(or the explosive suciently weak) such that the overall change in the sound speed
of the inert is small. A coupling condition which relates the pressure to the deflection
angle along the explosive-inert interface is determined. This includes its dependence
on the thickness of the inert, for cases where the initial sound speed of the inert
is less than or greater than the detonation speed in the explosive (supersonic and
subsonic inert
ows, respectively). The deformation of the inert is then solved by
prescribing the pressure along the interface. In the supersonic case, the detonation
drives a shock into the inert, subsequent to which the
ow in the inert consists
of alternating regions of compression and tension. In this case reverberations or
`ringing' occurs along both the deflected interface and outer edge of the inert. For
the subsonic case, the
flow in the interior of the inert is smooth and shockless.
The detonation in the explosive initially defl
ects the smooth interface towards the
explosive. For sufficiently thick inerts in such cases, it appears that the deflection
of the confiner would either drive the detonation speed in the explosive up to the
sound speed of the inert or drive a precursor wave ahead of the detonation in the
explosive. Transonic cases, where the inert sound speed is close to the detonation
speed, are also considered. It is shown that the confinement affect of the inert on
the detonation is enhanced as sonic conditions are approached from either side
Identifying Motivational Factors Impacting Entrepreneurship: Evidence from an Emerging Economy
A self-interacting partially directed walk subject to a force
We consider a directed walk model of a homopolymer (in two dimensions) which
is self-interacting and can undergo a collapse transition, subject to an
applied tensile force. We review and interpret all the results already in the
literature concerning the case where this force is in the preferred direction
of the walk. We consider the force extension curves at different temperatures
as well as the critical-force temperature curve. We demonstrate that this model
can be analysed rigorously for all key quantities of interest even when there
may not be explicit expressions for these quantities available. We show which
of the techniques available can be extended to the full model, where the force
has components in the preferred direction and the direction perpendicular to
this. Whilst the solution of the generating function is available, its analysis
is far more complicated and not all the rigorous techniques are available.
However, many results can be extracted including the location of the critical
point which gives the general critical-force temperature curve. Lastly, we
generalise the model to a three-dimensional analogue and show that several key
properties can be analysed if the force is restricted to the plane of preferred
directions.Comment: 35 pages, 14 figure
Chromosome 5p Region SNPs Are Associated with Risk of NSCLC among Women
In a population-based case-control study, we explored the associations between 42 polymorphisms in seven genes in this region and non-small cell lung cancer (NSCLC) risk among Caucasian (364 cases; 380 controls) and African American (95 cases; 103 controls) women. Two TERT region SNPs, rs2075786 and rs2853677, conferred an increased risk of developing NSCLC, especially among African American women, and TERT-rs2735940 was associated with a decreased risk of lung cancer among African Americans. Five of the 20 GHR polymorphisms and SEPP1-rs6413428 were associated with a marginally increased risk of NSCLC among Caucasians. Random forest analysis reinforced the importance of GHR among Caucasians and identified AMACR, TERT, and GHR among African Americans, which were also significant using gene-based risk scores. Smoking-SNP interactions were explored, and haplotypes in TERT and GHR associated with NSCLC risk were identified. The roles of TERT, GHR, AMACR and SEPP1 genes in lung carcinogenesis warrant further exploration
The Effect of Three-Dimensional Freestream Disturbances on the Supersonic Flow Past a Wedge
The interaction between a shock wave (attached to a wedge) and small amplitude, three-dimensional disturbances of a uniform, supersonic, freestream flow are investigated. The paper extends the two-dimensional study of Duck et al, through the use of vector potentials, which render the problem tractable by the same techniques as in the two-dimensional case, in particular by expansion of the solution by means of a Fourier-Bessel series, in appropriately chosen coordinates. Results are presented for specific classes of freestream disturbances, and the study shows conclusively that the shock is stable to all classes of disturbances (i.e. time periodic perturbations to the shock do not grow downstream), provided the flow downstream of the shock is supersonic (loosely corresponding to the weak shock solution). This is shown from our numerical results and also by asymptotic analysis of the Fourier-Bessel series, valid far downstream of the shock
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