2,452 research outputs found
Axial anomaly of QED in a strong magnetic field and noncommutative anomaly
The Adler-Bell-Jackiw (ABJ) anomaly of a 3+1 dimensional QED is calculated in
the presence of a strong magnetic field. It is shown that in the regime with
the lowest Landau level (LLL) dominance a dimensional reduction from D=4 to D=2
dimensions occurs in the longitudinal sector of the low energy effective field
theory. In the chiral limit, the resulting anomaly is therefore comparable with
the axial anomaly of a two dimensional massless Schwinger model. It is further
shown that the U(1) axial anomaly of QED in a strong magnetic field is closely
related to the ``nonplanar'' axial anomaly of a conventional noncommutative
QED.Comment: 18 pp, no figure. v2: The version accepted to be publidhed in PR
The power of implicit social relation in rating prediction of social recommender systems of social recommender
The explosive growth of social networks in recent times has presented a powerful source of information to be utilized as an extra source for assisting in the social recommendation problems. The social recommendation methods that are based on probabilistic matrix factorization improved the recommendation accuracy and partly solved the cold-start and data sparsity problems. However, these methods only exploited the explicit social relations and almost completely ignored the implicit social relations. In this article, we firstly propose an algorithm to extract the implicit relation in the undirected graphs of social networks by exploiting the link prediction techniques. Furthermore, we propose a new probabilistic matrix factorization method to alleviate the data sparsity problem through incorporating explicit friendship and implicit friendship. We evaluate our proposed approach on two real datasets, Last.Fm and Douban. The experimental results show that our method performs much better than the state-of-the-art approaches, which indicates the importance of incorporating implicit social relations in the recommendation process to address the poor prediction accuracy
The Evaluation of Relationship Marketing of Skin Care Services at PKU Muhammadiyah YOGYAKARTA Hospital
Skin care is a service which is taken into account by PKU Muhammadiyah Yogyakarta hospital as a way to cope with the competition among the hospitals. PKU Muhammadiyah Yogyakarta skin care was established in July, 2010. In a year, visit amount had fluctuated. One fluctuated impact is negative evaluation of market because hospital can not control skin care service. marketing evaluation a principles on relationship marketing. Handled fluctuated way of marketing evaluation principled on relationship marketing. To evaluate of relationship marketing on skin care service in PKU Muhammadiyah Yogyakarta Hospital. This research used a mixed method with design sequential explanatory. The subject quantitative is 112 respondents and subject qualitative is 7 respondents selected from subject quantitative. The data was taken from questionnaires and in-depth interviews. The data analysis is double linear regression. Communication have association on trust, commitment and relationship satisfaction.Relationship duration have association on commitment and relationship satisfaction. Interaction frequency have no association on trust. Commitment and relationship satisfaction have association on word of mouth. Factors affecting no customer commitment is customer must wait whereas did appoitment, beautician can not answer the question of customers, no drugs in pharmacy and no resulting skin care in PKU Muhammadiyah Yogyakarta Hospital. Commitment and relationship satisfaction have association on word of mouth. Communication and relationship duration can increase of commitment and relationship satisfactio
Dynamic mechanical analysis of Dwimatrix Biopolymer from waste oil blended with thermoplastic; LDPE/HDPE
This paper presents results from an experimental study on the dynamic mechanical and viscoelastic properties
of Biopolymer (BP) from Waste vegetable oils (WVO) blended with two types of thermoplastic polyethylene (PE) which
are Low Density Polyethylene (LDPE) and High Density Polyethylene (HDPE). BP blended containing 10–30wt.% of BP
were injection moulded. MDI were used as crosslinker agent for modifying the matrices. Dynamic mechanical analysis
(DMA) of the blended were performed over a temperature range of 30–120°C for BL and 30-140°C for BH under frequency
of 1 Hz. DMA revealed no noticeable changes in a-transition temperature when the BP content was increased or were
added. The BP blended revealed better temperature resistance at higher BP content. However, the increase in storage
modulus was negligible at BL10 and BH20; due to the agglomeration of the BP. The results of the damping ratio analysis
revealed that higher interfacial bonding was achieved by addition of MDI crosslinker agent
Deadly heat wave in Karachi, July 2015: Negligence or mismanagement?
[No abstract available
Deep UV Luminosity Functions at the Infall Region of the Coma Cluster
We have used deep GALEX observations at the infall region of the Coma cluster
to measure the faintest UV luminosity functions (LFs) presented for a rich
galaxy cluster thus far. The Coma UV LFs are measured to M_UV = -10.5 in the
GALEX FUV and NUV bands, or 3.5 mag fainter than previous studies, and reach
the dwarf early-type galaxy population in Coma for the first time. The
Schechter faint-end slopes (alpha = -1.39 in both GALEX bands) are shallower
than reported in previous Coma UV LF studies owing to a flatter LF at faint
magnitudes. A Gaussian-plus-Schechter model provides a slightly better
parametrization of the UV LFs resulting in a faint-end slope of ~ -1.15 in both
GALEX bands. The two-component model gives faint-end slopes shallower than -1
(a turnover) for the LFs constructed separately for passive and star forming
galaxies. The UV LFs for star forming galaxies show a turnover at M_UV ~ -14
owing to a deficit of dwarf star forming galaxies in Coma with stellar masses
below M*=10^8 Msun. A similar turnover is identified in recent UV LFs measured
for the Virgo cluster suggesting this may be a common feature of local galaxy
clusters, whereas the field UV LFs continue to rise at faint magnitudes. We did
not identify an excess of passive galaxies as would be expected if the missing
dwarf star forming galaxies were quenched inside the cluster. In fact, the LFs
for both dwarf passive and star forming galaxies show the same turnover at
faint magnitudes. We discuss the possible origin of the missing dwarf star
forming galaxies in Coma and their expected properties based on comparisons to
local field galaxies.Comment: accepted for publication in Ap
A model for time-dependent cosmological constant and its consistency with the present Friedmann universe
We use a model where the cosmological term can be related to the chiral gauge
anomaly of a possible quantum scenario of the initial evolution of the
universe. We show that this term is compatible with the Friedmann behavior of
the present universe.Comment: 5 pages, Revtex 4, twocolumn (minor corrections and improved
reference list. To appear in Classical and Quantum Gravity
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