623 research outputs found
An exploratory study of an enterprise systems implementation methodology in action
Previous studies have demonstrated the importance of Internet and e-commerce technologies in the tourism industry. The tourism industry is one of the most important that contribute to Thailand’s economic growth. The Thai government has promoted e-strategies in the tourism industry for economic reform. Although the government has encouraged the use of Internet technology for effective communication and collaboration across a broad range of tourism related activities, it has not yet been widely accepted. This study examines the roles of culture in the Thai business community, and how its underlying assumptions affect the adoption of technology in the Thai tourism industry. The findings are presented in two main parts: visions and currents issues from the Thai government and the actual technology adoption issues faced by practitioners
Large N WZW Field Theory Of N=2 Strings
We explore the quantum properties of self-dual gravity formulated as a large
two-dimensional WZW sigma model. Using a non-trivial classical background,
we show that a space-time is generated. The theory contains an infinite
series of higher point vertices. At tree level we show that, in spite of the
presence of higher than cubic vertices, the on-shell 4 and higher point
functions vanish, indicating that this model is related with the field theory
of closed N=2 strings. We examine the one-loop on-shell 3-point amplitude and
show that it is ultra-violet finite.Comment: This is the final version. By editorial mistake at Phys.Lett.B an
older version was published in prin
Lumps and P-branes in Open String Field Theory
We describe numerical methods for constructing lump solutions in open string
field theory. According to Sen, these lumps represent lower dimensional
Dp-Branes and numerical evaluation of their energy can be compared with the
expected value for the tension. We take particular care of all higher
derivative terms inherent in Witten's version of open string field theory. The
importance of these terms for off shell phenomena is argued in the text.
Detailed numerical calculations done for the case of general brane show
very good agreement with Sen's conjectured value. This gives credence to the
conjecture itself and establishes further the usefulness of Witten's version of
SFT .Comment: 11 pages, 1 figure, 1 table; v2: small typos correcte
Hidden classical symmetry in quantum spaces at roots of unity : From q-sphere to fuzzy sphere
19 pages in harvmac big, 5 figures; v2: refs added ; v3: more refs added19 pages in harvmac big, 5 figures; v2: refs added ; v3: more refs added19 pages in harvmac big, 5 figures; v2: refs added ; v3: more refs addedWe study relations between different kinds of non-commutative spheres which have appeared in the context of ADS/CFT correspondences recently, emphasizing the connections between spaces that have manifest quantum group symmetry and spaces that have manifest classical symmetry. In particular we consider the quotient at roots of unity, and find its relations with the fuzzy sphere with manifest classical SU(2) symmetry. Deformation maps between classical and quantum symmetry, the module structure of quantum spheres and the structure of indecomposable representations of at roots of unity conspire in an interesting way to allow the relation between manifestly symmetric spheres and manifestly U(SU(2)) symmetric spheres. The relation suggests that a subset of field theory actions on the q-sphere are equivalent to actions on the fuzzy sphere. The results here are compatible with the proposal that quantum spheres at roots of unity appear as effective geometries which account for finite N effects in the ADS/CFT correspondence
Compact system design based on digital in-line holographic microscopy configuration
We present our study regarding a compact system design for cell counting and simultaneous 3D imaging, based on digital in-line holographic microscopy configuration. The system is built around the known experimental configuration which includes a pinhole but we also investigate the configuration with a monomode fiber as a light source. Considered samples consist of a very low concentration of cells in flow in a microchannel. The main challenge in our design is to obtain the digital hologram of one cell on a regular video camera sensor in proper resolution conditions, as opposed to the usual configurations where the aim is to visualize a large area. This fact is possible with shorter distances between pinhole and sample and with pinholes with diameters slightly larger than 1micron. These can now be realized by considering the microtechnological processes for microchannel and pinhole fabrication on the same substrate with high refractive index - to increase the numerical aperture of the system The geometrical parameters are established after the numerical analysis of the diffracted field from a single cell and of the entire system numerical aperture values
Effect of Maleic Anhydride-aniline Derivative Buffer Layer on the Properties of Flexible Substrate Heterostructures: ITO/Nucleic Acid Base/Metal
Date du colloque : 10/2010International audienc
3D-QSAR Design of New Escitalopram Derivatives for the Treatment of Major Depressive Disorders
Antidepressants are psychiatric agents used for the treatment of different types of depression being at present amongst the most commonly prescribed drug, while their effectiveness and adverse effects are the subject of many studies and competing claims. Having studied five QSAR models predicting the biological activities of 18 antidepressants, already approved for clinical treatment, in interaction with the serotonin transporter (SERT), we attempted to establish the membrane ions’ contributions (sodium, potassium, chlorine and calcium) supplied by donor/acceptor hydrogen bond character and electrostatic field to the antidepressant activity. Significant cross-validated correlation q2 (0.5–0.6) and the fitted correlation r2 (0.7–0.82) coefficients were obtained indicating that the models can predict the antidepressant activity of compounds. Moreover, considering the contribution of membrane ions (sodium, potassium and calcium) and hydrogen bond donor character, we have proposed a library of 24 new escitalopram structures, some of them probably with significantly improved antidepressant activity in comparison with the parent compound
The magnetic field environment of active region 12673 that produced the energetic particle events of September 2017
Forecasting solar energetic particles (SEPs), and identifying flare/CMEs from
active regions (ARs) that will produce SEP events in advance is extremely
challenging. We investigate the magnetic field environment of AR 12673,
including the AR's magnetic configuration, the surrounding field configuration
in the vicinity of the AR, the decay index profile, and the footpoints of
Earth-connected magnetic field, around the time of four eruptive events. Two of
the eruptive events are SEP-productive (2017 September 4 at 20:00~UT and
September 6 at 11:56~UT), while two are not (September 4 at 18:05~UT and
September 7 at 14:33~UT). We analysed a range of EUV and white-light
coronagraph observations along with potential field extrapolations and find
that the CMEs associated with the SEP-productive events either trigger null
point reconnection that redirects flare-accelerated particles from the flare
site to the Earth-connected field and/or have a significant expansion (and
shock formation) into the open Earth-connected field. The rate of change of the
decay index with height indicates that the region could produce a fast CME ( 1500~km~s), which it did during events two and three. The AR's
magnetic field environment, including sites of open magnetic field and null
points along with the magnetic field connectivity and propagation direction of
the CMEs play an important role in the escape and arrival of SEPs at Earth.
Other SEP-productive ARs should be investigated to determine whether their
magnetic field environment and CME propagation direction are significant in the
escape and arrival of SEPs at Earth.Comment: Accepted in ApJ, 18 pages, 8 Figures, 2 Table
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