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Search Results: 1 - 10 of 1468 matches for " Konstantinos Gkillas "
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The Efficiency in Liquidity Measures during the US Monetary Announcements  [PDF]
Dimitrios I. Vortelinos, Konstantinos Gkillas, Christoforos Konstantatos, George Peppas
Theoretical Economics Letters (TEL) , 2018, DOI: 10.4236/tel.2018.81006
Abstract: We examine the impact of US economic news releases in the liquidity of eleven not so extensively researched emerging stock markets. We employ ten liquidity measures. The sample begins from June 2007 up to December 2016. Analysis is performed in a weekly frequency. China is the least liquid Asian market. Peru is the most liquid Latin American market. Most of the emerging markets are positively affected by the US news, offering diversification benefits to international investors. India and Argentina (China and Chile) are the Asian and Latin American countries with the highest (lowest) impacts, respectively. There is not a single best-in-class liquidity measure. The country with the lowest liquidity has the lowest impact from the US news releases. This result holds for both groups of countries in Asia and Latin America.
Beyond the Dirac Phase Factor: Dynamical Quantum Phase-Nonlocalities in the Schrödinger Picture  [PDF]
Konstantinos Moulopoulos
Journal of Modern Physics (JMP) , 2011, DOI: 10.4236/jmp.2011.211156
Abstract: Generalized solutions of the standard gauge transformation equations are presented and discussed in physical terms. They go beyond the usual Dirac phase factors and they exhibit nonlocal quantal behavior, with the well-known Relativistic Causality of classical fields affecting directly the phases of wavefunctions in the Schrödinger Picture. These nonlocal phase behaviors, apparently overlooked in path-integral approaches, give a natural account of the dynamical nonlocality character of the various (even static) Aharonov-Bohm phenomena, while at the same time they seem to respect Causality. For particles passing through nonvanishing magnetic or electric fields they lead to cancellations of Aharonov-Bohm phases at the observation point, generalizing earlier semiclassical experimental observations (of Werner & Brill) to delocalized (spread-out) quantum states. This leads to a correction of previously unnoticed sign-errors in the literature, and to a natural explanation of the deeper reason why certain time-dependent semiclassical arguments are consistent with static results in purely quantal Aharonov-Bohm configurations. These nonlocalities also provide a remedy for misleading results propagating in the literature (concerning an uncritical use of Dirac phase factors, that persists since the time of Feynman’s work on path integrals). They are shown to conspire in such a way as to exactly cancel the instantaneous Aharonov-Bohm phase and recover Relativistic Causality in earlier “paradoxes” (such as the van Kampen thought-experiment), and to also complete Peshkin’s discussion of the electric Aharonov-Bohm effect in a causal manner. The present formulation offers a direct way to address time-dependent single- vs double-slit experiments and the associated causal issues—issues that have recently attracted attention, with respect to the inability of current theories to address them.
Classical Quantum Field Theory Based on the Hypothesis of the Absolute Reference System  [PDF]
Konstantinos Patrinos
Journal of Applied Mathematics and Physics (JAMP) , 2019, DOI: 10.4236/jamp.2019.74052
Abstract: The quantum field theory based on the hypothesis of the absolute reference system is a classical non-relativistic theory, which is compatible with current quantum theory. This conclusion arises when one compares the theoretical results of quantum electrodynamics using the basic principles of this hypothesis. Wave equation, which replaces this of Schrodinger, is the classical wave equation of a peculiar electromagnetic wave, derived from the study of particle structure.
The Physics of an Absolute Reference System  [PDF]
Konstantinos Patrinos
Journal of Applied Mathematics and Physics (JAMP) , 2019, DOI: 10.4236/jamp.2019.73033
Abstract: The hypothesis of the absolute reference system, unlike the existing physics theories, is not based on the concept of relativity (that is, it is not based on a relativistic description like Galileo’s relativity or Einstein’s theory of relativity). The absolute reference system is the framework of material in which any activity in the universe has begun. Also, each inertial reference system is accompanied by a peculiar electromagnetic wave due to the structure of matter. The physics of the absolute system of reference is based on three basic principles. The first of these principles is that the electromagnetic field quantitative estimates are made in the inertial reference system of the source of the electromagnetic field. The second principle is that the basic constituent of matter is “bound photons, which make up the internal structure of the elementary particles. The third principle is that the framework of material of an inertial system undergoes a contraction of length which is a real physical contraction and a corresponding real change in “time flow, not due to the geometry of space-time, but is due to the internal operation of the micro-structure of matter. These principles have the effect of changing the relativistic physical magnitudes, such as velocity, momentum and kinetic energy, into physical magnitudes described as absolute. This theory is consistent with experimental data so far and provides satisfactory answers to physics problems such as dark matter, particle physics experiments to confirm the dynamics, interpretation of experimental results of measurement of neutrinos velocity that are incompatible with the relativity, and magnetic induction experiments which are not explained by the classical electromagnetic theory.
Polynomial-Based Evaluation of the Impact of Aperture Phase Taper on the Gain of Rectangular Horns  [PDF]
Konstantinos B. Baltzis
Journal of Electromagnetic Analysis and Applications (JEMAA) , 2010, DOI: 10.4236/jemaa.2010.27055
Abstract: The aperture phase taper due to quadratic phase errors in the principal planes of a rectangular horn imposes signifi-cant constraints on the on-axis far-field gain of the horn. The precise calculation of gain reduction involves Fresnel integrals; therefore, exact results are obtained only from numerical methods. However, in horns’ analysis and design, simple closed-form expressions are often required for the description of horn-gain. This paper provides a set of simple polynomial approximations that adequately describe the gain reduction factors of pyramidal and sectoral horns. The proposed formulas are derived using least-squares polynomial regression analysis and they are valid for a broad range of quadratic phase error values. Numerical results verify the accuracy of the derived expressions. Application examples and comparisons with methods in the literature demonstrate the efficacy of the approach.
Informal Financing of Small – Medium Enterprise Sector: The Case of Greece  [PDF]
Panagiotis Petrakis, Konstantinos Eleftheriou
Journal of Service Science and Management (JSSM) , 2009, DOI: 10.4236/jssm.2009.24045
Abstract: In this paper, we attempt to find a “channel” through which Greek economy can exhibit a relative “resistance” in a credit crunch. For this purpose, we specify an error correction model so as to test the relationship between corporate bank loans and commercial papers comprised of post-dated cheques and bills of exchange. The results show that corporate bank loans and cheques - bills of exchange are substitutes. This finding combined with the fact that in Greece, the issuance of these papers is positively connected with the informal economic activity which in turn rises during economic downturns, has a strong economic implication regarding the ability of Greek economy to partly “amortize” the shocks connected with the current financial crisis.
Presentation of a Rare Case of Bilateral Lumbar Synovial Cysts  [PDF]
Konstantinos Violaris, Maria Karakyriou
Open Journal of Modern Neurosurgery (OJMN) , 2012, DOI: 10.4236/ojmn.2012.22006
Abstract: Purpose: To report a quite rare case of bilateral symptomatic synovial cysts of the lumbar spine. Surgical resection is usually the cure for this condition. Methods: A 65 year old female patient came to our department, complaining for severe lumbar and sciatic pain. MRI and CT were used to diagnose bilateral synovial cysts. Because of the intensity of symptoms, she was subjected to surgery. Laminectomy and cyst resection were performed. Results: The patient showed complete resolution of pain after the resection of the cysts. Conclusion: Although rare, bilateral synovial cysts may be the cause of severe lumbar pain. In cases of failure of conservative treatment, surgical resection offers good results.
Poly(Vinyl Alcohol)-Infiltrated Carbon Nanotube Carpets  [PDF]
Konstantinos G. Dassios
Materials Sciences and Applications (MSA) , 2012, DOI: 10.4236/msa.2012.39096
Abstract: Carbon nanotube-polymer interaction is one of the key factors controlling the mechanical properties in composite and hybrid systems of such constituents. The current study reports a series of direct observations of substantial polymer sheathing phenomena on millimeters-high carpets of vertically aligned tubes infiltrated by Poly(vinyl alcohol) (PVA). SEM and TEM images of the composite’s fracture surface revealed that sheathing was extensive and universal over the carpet’s volume and did not influence the morphology, alignment or physical characteristics of the tubes. A significant increase in the tubes’ diameters due to PVA coating was measured. Thermogravimetric analysis results were compatible with a crystallinity increase of the polymer phase due to the presence of CNTs, indicating the potential of CNTs in nucleating polymer crystallinity. Potential applications of the nanocomposite are discussed.
Death Shall Have No Dominion: Representations of Grandfathers’ Death in Contemporary Picturebooks*  [PDF]
Konstantinos D. Malafantis
Advances in Literary Study (ALS) , 2013, DOI: 10.4236/als.2013.14009
Abstract:

The topic of death usually advocates the resistance of language, therefore creators search for linguistic or visual codes suitable for expressing the unutterable loss of beloved people in contemporary picture or illustrated books for children. For that reason, the meaning of death is portrayed in picturebooks with an immediate and symbolic way in both text and picture. Adopting a visual and textual approach, we examine the ways in which authors and illustrators portray the relationship between grandparent and grandchildren in picturebooks. Many stories in children’s literature deal with the archetypal pattern of death and present it in a way which enables young readers to come to terms with it. In such stories, young protagonists, and thus young readers, are introduced into questions of ageing and decay, and inevitably of death, through an imaginative “travel” in time and space which is engendered by the grandparent’s enchanting storytelling. Death comes to be viewed as simply a stage toward reunion with eternal nature in the hereafter. The grandparent’s death is pictured as a “justifiable” event, integrated in the life cycle. Bereavement and grief seem to rely on the principal motifs of nature-as-space and nature-as-knowledge, which eventually manage to negate the dominion of death upon life.

Sea State Primitive Object Creation from SAR Data  [PDF]
Konstantinos Topouzelis, Dimitra Kitsiou
International Journal of Geosciences (IJG) , 2014, DOI: 10.4236/ijg.2014.513127
Abstract: Wide swath Synthetic Aperture Radar (SAR) images acquired over sea areas contain a variety of information regarding small scale and mesoscale phenomena in the ocean and marine boundary layer e.g. spills, slicks, surface or internal waves, eddies, oceanic fronts. One of most challenging processing step is to create image objects describing these phenomena on SAR images. The most significant problem in the wide swath images is the backscattering trend at the range direction, which results a progressive brightness reduction over images from near to far range. This reduction affects the detection and classification of sea surface features on wide swath SAR images and a normalization step is needed in a certain incidence angle for compensating the brightness reduction. The aim of the present paper is to investigate the result of image normalization to a set of Wide Swath Mode SAR images. Dark areas were initially detected in SAR images using thresholds, adapted or not. Afterwards, SAR images were normalized and a global threshold was calculated for each image. Images were segmented and objects were created for each dark area. The results were compared to a reference dataset created from theoretical modeled values and extracted in a GIS environment. Results clearly indicate that overall accuracy of the detected dark areas has been increased after normalization. On the contrary, local thresholds were insufficient in producing acceptable results. The proposed normalization can be used as a pre-processing step in image classification.
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