140 research outputs found
Multicriteria sustainability evaluation of transport networks for selected European countries
As an essential economic activity, transportation has complex interactions with the environment and society. Since the concept of sustainable development has become one of the top priorities for nations, there has been a growing interest in evaluating the performance of transport systems with respect to sustainability issues. The main purpose of this study is to introduce a decision making framework to assess the sustainability of the transport networks in a multidimensional setting and a technique to identify non-compromise alternatives. We also propose an elucidation technique to identify according to which criteria a system needs to be improved and how much improvement is required to attain a certain level of sustainability. The proposed methods are applied to a set of selected European countries within a case study
Multi-Scale Deformable Alignment and Content-Adaptive Inference for Flexible-Rate Bi-Directional Video Compression
The lack of ability to adapt the motion compensation model to video content
is an important limitation of current end-to-end learned video compression
models. This paper advances the state-of-the-art by proposing an adaptive
motion-compensation model for end-to-end rate-distortion optimized hierarchical
bi-directional video compression. In particular, we propose two novelties: i) a
multi-scale deformable alignment scheme at the feature level combined with
multi-scale conditional coding, ii) motion-content adaptive inference. In
addition, we employ a gain unit, which enables a single model to operate at
multiple rate-distortion operating points. We also exploit the gain unit to
control bit allocation among intra-coded vs. bi-directionally coded frames by
fine tuning corresponding models for truly flexible-rate learned video coding.
Experimental results demonstrate state-of-the-art rate-distortion performance
exceeding those of all prior art in learned video coding.Comment: Accepted for publication in IEEE International Conference on Image
Processing (ICIP) 202
The Black Hole in the Compact, High-dispersion Galaxy NGC 1271
Located in the Perseus cluster, NGC 1271 is an early-type galaxy with a small
effective radius of 2.2 kpc and a large stellar velocity dispersion of 276 km/s
for its K-band luminosity of 8.9x10^{10} L_sun. We present a mass measurement
for the black hole in this compact, high-dispersion galaxy using observations
from the integral field spectrograph NIFS on the Gemini North telescope
assisted by laser guide star adaptive optics, large-scale integral field unit
observations with PPAK at the Calar Alto Observatory, and Hubble Space
Telescope WFC3 imaging observations. We are able to map out the stellar
kinematics on small spatial scales, within the black hole sphere of influence,
and on large scales that extend out to four times the galaxy's effective
radius. We find that the galaxy is rapidly rotating and exhibits a sharp rise
in the velocity dispersion. Through the use of orbit-based stellar dynamical
models, we determine that the black hole has a mass of (3.0^{+1.0}_{-1.1}) x
10^9 M_sun and the H-band stellar mass-to-light ratio is 1.40^{+0.13}_{-0.11}
M_sun/L_sun (1-sigma uncertainties). NGC 1271 occupies the sparsely-populated
upper end of the black hole mass distribution, but is very different from the
Brightest Cluster Galaxies (BCGs) and giant elliptical galaxies that are
expected to host the most massive black holes. Interestingly, the black hole
mass is an order of magnitude larger than expectations based on the galaxy's
bulge luminosity, but is consistent with the mass predicted using the galaxy's
bulge stellar velocity dispersion. More compact, high-dispersion galaxies need
to be studied using high spatial resolution observations to securely determine
black hole masses, as there could be systematic differences in the black hole
scaling relations between these types of galaxies and the BCGs/giant
ellipticals, thereby implying different pathways for black hole and galaxy
growth.Comment: accepted for publication in Ap
Multiagent cooperation for solving global optimization problems: an extendible framework with example cooperation strategies
This paper proposes the use of multiagent cooperation for solving global optimization problems through the introduction of a new multiagent environment, MANGO. The strength of the environment lays in itsflexible structure based on communicating software agents that attempt to solve a problem cooperatively. This structure allows the execution of a wide range of global optimization algorithms described as a set of interacting operations. At one extreme, MANGO welcomes an individual non-cooperating agent, which is basically the traditional way of solving a global optimization problem. At the other extreme, autonomous agents existing in the environment cooperate as they see fit during run time. We explain the development and communication tools provided in the environment as well as examples of agent realizations and cooperation scenarios. We also show how the multiagent structure is more effective than having a single nonlinear optimization algorithm with randomly selected initial points
Characteristics of patients operated for primary hyperparathyroidism at university hospitals in Türkiye: Differences among Türkiye's geographical regions
Purpose: The aim of this study was to define the clinical and laboratory characteristics of patients operated on for primary hyperpatathyroidism (PHPT) at university hospitals in Türkiye, and to investigate the differences in the clinical presentations of the disease between different geographical regions. Methods: Patients operated on for PHPT in the university hospitals of Türkiye were included in the study. The demographic, clinical, and laboratory findings and the operational data of the patients were investigated according to the whole country and to different geographical regions. Comparisons were performed according to whole country and regions. Results: A total of 1,162 cases were included in the study from different regions and 20 university hospitals. The mean age of patients was 52.4 ± 0.38 (mean ± standard error) in the general population of Türkiye. The rates of hypertension, urolithiasis, bone disease and 25-hydroxyvitamin D insufficiency were 35%, 18.6%, 67.6%, and 63%, respectively. The median parathormone (PTH), serum total calcium (Ca+2) and phosphorus value were 220 pg/mL (range, 70-2,500 pg/mL), 11.2 mg/dL (range, 9.5-11.2 mg/dL), and 2.4 mg/dL (range, 1-4.7 mg/dL), respectively. The median size of the adenomas resected was 16 mm (range, 4-70 mm). Significant differences were observed in the clinical and laboratory findings of the patients operated on due to PHPT between different geographical regions of Türkiye (P < 0.05). Conclusion: The clinical and laboratory characteristics of the patients with PHPT in different geographical regions of Türkiye differ. Furthermore, the general findings of the cases in Türkiye give us a hint that the severity of the disease here is somewhere between Eastern and Western countries. Copyright © 2016, the Korean Surgical Society
Turner syndrome and associated problems in turkish children: A multicenter study
Objective: Turner syndrome (TS) is a chromosomal disorder caused by complete or partial X chromosome monosomy that manifests various clinical features depending on the karyotype and on the genetic background of affected girls. This study aimed to systematically investigate the key clinical features of TS in relationship to karyotype in a large pediatric Turkish patient population. Methods: Our retrospective study included 842 karyotype-proven TS patients aged 0-18 years who were evaluated in 35 different centers in Turkey in the years 2013-2014. Results: The most common karyotype was 45,X (50.7%), followed by 45,X/46,XX (10.8%), 46,X,i(Xq) (10.1%) and 45,X/46,X,i(Xq) (9.5%). Mean age at diagnosis was 10.2±4.4 years. The most common presenting complaints were short stature and delayed puberty. Among patients diagnosed before age one year, the ratio of karyotype 45,X was significantly higher than that of other karyotype groups. Cardiac defects (bicuspid aortic valve, coarctation of the aorta and aortic stenosi) were the most common congenital anomalies, occurring in 25% of the TS cases. This was followed by urinary system anomalies (horseshoe kidney, double collector duct system and renal rotation) detected in 16.3%. Hashimoto’s thyroiditis was found in 11.1% of patients, gastrointestinal abnormalities in 8.9%, ear nose and throat problems in 22.6%, dermatologic problems in 21.8% and osteoporosis in 15.3%. Learning difficulties and/or psychosocial problems were encountered in 39.1%. Insulin resistance and impaired fasting glucose were detected in 3.4% and 2.2%, respectively. Dyslipidemia prevalence was 11.4%. Conclusion: This comprehensive study systematically evaluated the largest group of karyotype-proven TS girls to date. The karyotype distribution, congenital anomaly and comorbidity profile closely parallel that from other countries and support the need for close medical surveillance of these complex patients throughout their lifespan. © Journal of Clinical Research in Pediatric Endocrinology
Four Generations: SUSY and SUSY Breaking
We revisit four generations within the context of supersymmetry. We compute
the perturbativity limits for the fourth generation Yukawa couplings and show
that if the masses of the fourth generation lie within reasonable limits of
their present experimental lower bounds, it is possible to have perturbativity
only up to scales around 1000 TeV. Such low scales are ideally suited to
incorporate gauge mediated supersymmetry breaking, where the mediation scale
can be as low as 10-20 TeV. The minimal messenger model, however, is highly
constrained. While lack of electroweak symmetry breaking rules out a large part
of the parameter space, a small region exists, where the fourth generation stau
is tachyonic. General gauge mediation with its broader set of boundary
conditions is better suited to accommodate the fourth generation.Comment: 27 pages, 5 figure
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