63 research outputs found
Local well-posedness for the nonlinear Schr\"odinger equation in the intersection of modulation spaces
We introduce a Littlewood-Paley characterization of modulation spaces and use
it to give an alternative proof of the algebra property, somehow implicitly
contained in Sugimoto (2011), of the intersection for , and
. We employ this algebra property to show the local well-posedness of
the Cauchy problem for the cubic nonlinear Schr\"odinger equation in the above
intersection. This improves Theorem 1.1 by B\'enyi and Okoudjou (2009), where
only the case is considered, and closes a gap in the literature. If and or if and then
and the
above intersection is superfluous. For this case we also reobtain a
H\"older-type inequality for modulation spaces.Comment: 14 page
A public health threat in Hungary: obesity, 2013
Background: In Hungary, the last wide-range evaluation about nutritional status of the population was completed in 1988. Since then, only limited data were available. Our aim was to collect, analyze and present updated prevalence data. Methods. Anthropometric, educational and morbidity data of persons above 18 y were registered in all geographical regions of Hungary, at primary care encounters and within community settings. Results: Data (BMI, waist circumference, educational level) of 40,331 individuals (16,544 men, 23,787 women) were analyzed. Overall prevalence for overweight was 40.4% among men, 31.3% among women, while for obesity 32.0% and 31.5%, respectively. Abdominal obesity was 37.1% in males, 60.9% in females. Among men, the prevalence of overweight-obesity was: under 35 y = 32.5%-16.2%, between 35-60 y = 40.6%-34.7%, over 60 y = 44.3%-36.7%. Among women, in the same age categories were: 17.8%-13.8%, 29.7%-29.0%, and 36.9%-39.0%. Data were presented according to age by decades as well. The highest odds ratio of overweight (OR: 1.079; 95% CI [1.026-1.135]) was registered by middle educational level, the lowest odds ratio of obesity (OR: 0.500; 95% CI [0.463-0.539]) by the highest educational level. The highest proportion of obese people lived in villages (35.4%) and in Budapest (28.9%). Distribution of overweighed persons were: Budapest (37.1%), other cities (35.8%), villages (33.8%). Registered metabolic morbidities were strongly correlated with BMIs and both were inversely related to the level of urbanization. Over the previous decades, there has been a shift in the distribution of population toward being overweight and moreover obese, it was most prominent among males, mainly in younger generation. Conclusions: Evaluation covered 0.53% of the total population over 18 y and could be very close to the proper national representativeness. The threat of obesity and related morbidities require higher public awareness and interventions
On the probabilistic Cauchy theory for nonlinear dispersive PDEs
In this note, we review some of the recent developments in the well-posedness
theory of nonlinear dispersive partial differential equations with random
initial data.Comment: 26 pages. To appear in Landscapes of Time-Frequency Analysis, Appl.
Numer. Harmon. Ana
Primary care obesity management in Hungary: evaluation of the knowledge, practice and attitudes of family physicians
BACKGROUND: Obesity, a threatening pandemic, has an important public health implication. Before proper medication is available, primary care providers will have a distinguished role in prevention and management. Their performance may be influenced by many factors but their personal motivation is still an under-researched area. METHOD: The knowledge, attitudes and practice were reviewed in this questionnaire study involving a representative sample of 10% of all Hungarian family physicians. In different settings, 521 practitioners (448 GPs and 73 residents/vocational trainees) were questioned using a validated questionnaire. RESULTS: The knowledge about multimorbidity, a main consequence of obesity, was balanced.Only 51% of the GPs were aware of the diagnostic threshold for obesity; awareness being higher in cities (60%) and the highest among residents (90%). They also considered obesity an illness rather than an aesthetic issue.There were wider differences regarding attitudes and practice, influenced by the the doctors' age, gender, known BMI, previous qualification, less by working location.GPs with qualification in family medicine alone considered obesity management as higher professional satisfaction, compared to physicians who had previously other board qualification (77%vs68%). They measured their patients' waist circumference and waist/hip ratio (72%vs62%) more frequently, provided the obese with dietary advice more often, while this service was less frequent among capital-based doctors who accepted the self-reported body weight dates by patients more frequently / commonly. Similar reduced activity and weight-measurement in outdoor clothing were more typical among older doctors.Diagnosis based on BMI alone was the highest in cities (85%). Consultations were significantly shorter in practices with a higher number of enrolled patients and were longer by female providers who consulted longer with patients about the suspected causes of developing obesity (65%vs44%) and offered dietary records for patients significantly more frequently (65%vs52%). Most of the younger doctors agreed that obesity management was a primary care issue.Doctors in the normal BMI range were unanimous that they should be a model for their patients (94%vs81%). CONCLUSION: More education of primary care physicians, available practical guidelines and higher community involvement are needed to improve the obesity management in Hungary
Linear perturbations of the Wigner transform and the Weyl quantization
We study a class of quadratic time-frequency representations that, roughly
speaking, are obtained by linear perturbations of the Wigner transform. They
satisfy Moyal's formula by default and share many other properties with the
Wigner transform, but in general they do not belong to Cohen's class. We
provide a characterization of the intersection of the two classes. To any such
time-frequency representation, we associate a pseudodifferential calculus. We
investigate the related quantization procedure, study the properties of the
pseudodifferential operators, and compare the formalism with that of the Weyl
calculus.Comment: 38 pages. Contributed chapter for volume on the occasion of Luigi
Rodino's 70th birthda
Modulation Invariant Bilinear T(1) Theorem
We prove a T(1) theorem for bilinear singular integral operators (trilinear forms) with a one-dimensional modulation symmetry
Endpoint Estimates for N-dimensional Hardy Operators and Their Commutators
In this paper, it is proved that the higher dimensional Hardy operator is
bounded from Hardy space to Lebesgue space. The endpoint estimate for the
commutator generated by Hardy operator and (central) BMO function is also
discussed.Comment: 8 page
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