9,184 research outputs found
Thin-shell wormholes from the regular Hayward black hole
We revisit the regular black hole found by Hayward in dimensional static,
spherically symmetric spacetime. To find a possible source for such a spacetime
we resort to the non-linear electrodynamics in general relativity. It is found
that a magnetic field within this context gives rise to the regular Hayward
black hole. By employing such a regular black hole we construct a thin-shell
wormhole for the case of various equations of state on the shell. We abbreviate
a general equation of state by where is the
surface pressure which is the function of the mass density (). In
particular, a linear, logarithmic, Chaplygin, etc. forms of equations of state
are considered. In each case we study the stability of the thin-shell against
linear perturbations. We plot the stability regions by tuning the parameters of
the theory. It is observed that the role of the Hayward parameter is to make
the TSW more stable. Perturbations of the throat with small velocity condition
is also studied. The matter of our TSWs, however, remains to be exotic.Comment: 7 pages 5 figures, extended versio
KEJAWEN SCIENCE IN JAVANESE MARRIAGE AND ITS IMPLICATIONS FOR HOUSEHOLD HARMONY HOUSEHOLD HARMONY
This article discusses the application of kejawen science in marriage. The purpose of writing this article is why some Javanese people still believe and practice kejawen science, especially in marriage, whether kejawen science has an impact on household harmony. Type of qualitative article, object of research in Kotabaru Village, Central Lampung, phenomenological study approach method, primary data sources are parents of married couples, religious leaders and community leaders. Data collection techniques through observation, interviews and documentation. The results showed that the Javanese community still believes and applies kejawen science in marriage. The reason is that it is believed that married couples have different wetons, have conflicting characters and traits, so the implication is that marriage is full of conflict and ends in divorce. Believing in Islamic divination is contradictory and forbidden for the reason of polytheism.Keywords: Kejawen Science, Marriage, Household Harmony
Colourings of cubic graphs inducing isomorphic monochromatic subgraphs
A -bisection of a bridgeless cubic graph is a -colouring of its
vertex set such that the colour classes have the same cardinality and all
connected components in the two subgraphs induced by the colour classes
(monochromatic components in what follows) have order at most . Ban and
Linial conjectured that every bridgeless cubic graph admits a -bisection
except for the Petersen graph. A similar problem for the edge set of cubic
graphs has been studied: Wormald conjectured that every cubic graph with
has a -edge colouring such that the two
monochromatic subgraphs are isomorphic linear forests (i.e. a forest whose
components are paths). Finally, Ando conjectured that every cubic graph admits
a bisection such that the two induced monochromatic subgraphs are isomorphic.
In this paper, we give a detailed insight into the conjectures of Ban-Linial
and Wormald and provide evidence of a strong relation of both of them with
Ando's conjecture. Furthermore, we also give computational and theoretical
evidence in their support. As a result, we pose some open problems stronger
than the above mentioned conjectures. Moreover, we prove Ban-Linial's
conjecture for cubic cycle permutation graphs.
As a by-product of studying -edge colourings of cubic graphs having linear
forests as monochromatic components, we also give a negative answer to a
problem posed by Jackson and Wormald about certain decompositions of cubic
graphs into linear forests.Comment: 33 pages; submitted for publicatio
Performance of modified non-linear shooting method for simulation of 2nd order two-point BVPS
In this research article, numerical solution of nonlinear 2nd order two-point boundary value problems (TPBVPs) is discussed by the help of nonlinear shooting method (NLSM), and through the modified nonlinear shooting method (MNLSM). In MNLSM, fourth order Runge-Kutta method for systems is replaced by Adams Bashforth Moulton method which is a predictor-corrector scheme. Results acquired numerically through NLSM and MNLSM of TPBVPs are discussed and analyzed. Results of the tested problems obtained numerically indicate that the performance of MNLSM is rapid and provided desirable results of TPBVPs, meanwhile MNLSM required less time to implement as comparable to the NLSM for the solution of TPBVPs
A low-cost spatial tool for transforming feature positions of cad-based topographic mapping
© 2019 The Author(s). In fact, Computer Aided Design (CAD) offers powerful design tools to produce digital large scale topographic mapping that is considered the backbone for construction projects, urban planning and landscape architecture. Nowadays local agencies in small communities and developing countries are facing some difficulties in map to map transformation and handling discrepancies between the physical reality and represented spatial data due to the need for implementing high cost systems such as GIS and the experienced staff required. Therefore, the require for providing a low-cost tool based on the most common CAD system is very important to guarantee a quality and positional accuracy of features. The main aim of this study is to describe a mathematical relationship to fulfil the coordinate conversion between two different grid references applying two-dimensional conformal polynomial models built on control points and a least squares fitting algorithm. In addition, the automation of this model was performed in the Microsoft Visual Studio environment to calculate polynomial coefficients and convert the positional property of entities in AutoCAD by developing spatial CAD tool. To evaluate the proposed approach the extracted coordinates of check points from the interpolation surface are compared with the known ones
LINEAR FEATURES IN PHOTOGRAMMETRY
Traditional photogrammetric activities such as orientation, triangulation, and object
space reconstruction have been relying on distinct points in their underlying
operations. With the evolution of digital photogrammetry, there has been a
tremendous interest in utilizing linear features in various photogrammetric
activities. This interest has been motivated by the fact that the extraction of linear
features from the image space is easier to automate than distinct points. On the other
hand, object space linear features can be directly derived form terrestrial Mobile
Mapping Systems (MMS), GIS databases, and/or existing maps. Moreover,
automatic matching of linear features, either within overlapping images or between
image and object space, is easier than that of distinct points. Finally, linear features
possess more semantic information than distinct points since they most probably
correspond to object boundaries. Such semantics can be automatically identified in
imagery to facilitate higher-level tasks (e.g., surface reconstruction and object
recognition). This paper summarizes the use of linear features, which might be
represented by analytical functions (e.g., straight-line segments) or irregular (freeform)
shapes, in photogrammetric activities such as automatic space resection,
photogrammetric triangulation, camera calibration, image matching, surface
reconstruction, image-to-image registration, and absolute orientation. Current
progress, future expectations, and possible research directions are discussed as well
The Inhibitory Effect of Lactobacillus acidophilus and Lactobacillus plantarum against Candida albicans Associated with Denture Stomatitis
In this study Candida speices was diagnosed in 26 swab samples from patients with denture stomatitis , investigates the antagonism activity of Lactobacillus was investigated against the yeast of Candida albicans in vitro.Results revealed that The inhibition effect of Lactic Acid Bacteria against C.albicans was examined in solid medium, L.plantarum gave higher inhibition average 11mm followed by L.acidophillus with average 9 mm and, L.fermentum , L.casei with averages 7 mm. Whereas the filtrates, the highest inhibition zone were 20 and 16 mm by L. plantarum and L.acidophillus, respectively
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