55 research outputs found
Combined optimization algorithms applied to pattern classification
Accurate classification by minimizing the error on test samples is the main
goal in pattern classification. Combinatorial optimization is a well-known
method for solving minimization problems, however, only a few examples of
classifiers axe described in the literature where combinatorial optimization is
used in pattern classification. Recently, there has been a growing interest
in combining classifiers and improving the consensus of results for a greater
accuracy. In the light of the "No Ree Lunch Theorems", we analyse the combination
of simulated annealing, a powerful combinatorial optimization method
that produces high quality results, with the classical perceptron algorithm.
This combination is called LSA machine. Our analysis aims at finding paradigms
for problem-dependent parameter settings that ensure high classifica,
tion results. Our computational experiments on a large number of benchmark
problems lead to results that either outperform or axe at least competitive to
results published in the literature. Apart from paxameter settings, our analysis
focuses on a difficult problem in computation theory, namely the network
complexity problem. The depth vs size problem of neural networks is one of
the hardest problems in theoretical computing, with very little progress over
the past decades. In order to investigate this problem, we introduce a new
recursive learning method for training hidden layers in constant depth circuits.
Our findings make contributions to a) the field of Machine Learning, as the
proposed method is applicable in training feedforward neural networks, and to
b) the field of circuit complexity by proposing an upper bound for the number
of hidden units sufficient to achieve a high classification rate. One of the major
findings of our research is that the size of the network can be bounded by
the input size of the problem and an approximate upper bound of 8 + √2n/n
threshold gates as being sufficient for a small error rate, where n := log/SL
and SL is the training set
Continuing decrease in coronary heart disease mortality in Sweden
BACKGROUND: Deaths from coronary heart disease (CHD) have been decreasing in most Western countries over the last few decades. In contrast, a flattening of the decrease in mortality has been recently reported among younger age groups in some countries. We aimed to determine whether the decrease in CHD mortality is flattening among Swedish young adults. METHODS: We examined trends in CHD mortality in Sweden between 1987 and 2009 among persons aged 35 to 84 years using CHD mortality data from the Swedish National Register on Cause of Death. Annual percent changes in rates were examined using Joinpoint software. RESULTS: Overall, CHD mortality rates decreased by 67.4% in men and 65.1% in women. Among men aged 35–54 years, there was a modest early attenuation from a marked initial decrease. In the oldest women aged 75–84 years, an attenuation in the mortality decrease was observed from 1989 to 1992, followed by a decrease, as in all other age groups. CONCLUSIONS: In Sweden, coronary heart disease deaths are still falling. We were unable to confirm a flattening of the decline in young people. Death rates continue to decline in men and women across all age groups, albeit at a slower pace in younger men since 1991. Continued careful monitoring of CHD mortality trends in Sweden is required, particularly among young adults
Zato što je političko znanje bitno: utjecaj deliberacije na mišljenje mladih građana
This paper addresses the importance of “knowledge” and “access to information” in the formation of young citizens’ opinion through deliberative procedures. The research presented in this paper is grounded in the theoretical framework of deliberative democracy as a democratic model and procedure that allows participants to be engaged in a rational and open dialogue before deciding on a particular issue. Our research draws empirically upon a deliberative event that took place in October 2014 at the Western Macedonia University of Applied Sciences in Greece. The topic of deliberation was “Political Public Opinion Polls.” The results of this study are commensurate with the dominant thesis in the relevant literature, which underlines that the deliberative procedure enriches the knowledge of citizens and thus enables them to participate effectively in the decision making process.Ovaj rad bavi se važnošću „znanja“ i „pristupa informacijama“ u formiranju mišljenja mladih građana o pojedinim temama kroz deliberativne procedure. Deliberativna demokracija, kao demokratski model i demokratska procedura koja dopušta sudionicima uključivanje u racionalan i otvoren dijalog prije odlučivanja o određenoj temi, teorijski je okvir na kojem se temelji istraživanje predstavljeno u ovom radu. Empirijski dio našeg rada temelji se na deliberativnom događaju koji se odvio u listopadu 2014.
na instituciji za visoko obrazovanje Western Macedonia University of Applied Sciences u Grčkoj. Tema deliberacije bila je „Anketna istraživanja javnog mnijenja o politici“. Rezultati ovog istraživanja potvrđuju tezu iz relevantne literature koja naglašava kako deliberativne procedure obogaćuju znanje građana i tako im omogućavaju da učinkovito sudjeluju u procesu donošenja odluka
The first Anatomy professors in the Medical School of the University of Athens
The purpose of this historical review is to add new elements to the international literature in relation to the birth and progress of the science of anatomy in modern Greece. Step by step, it outlines the efforts of prominent Greek anatomists to establish the course of the basic science of anatomy in the newly founded Medical School, the laborious effort to collect cadaveric material, to compile museum anatomical collections and to gradually build the foundations of modern anatomy science at the Medical School of the Athenian University
The first Anatomy professors in the Medical School of the University of Athens
The purpose of this historical review is to add new elements to the international literature in relation to the birth and progress of the science of anatomy in modern Greece. Step by step, it outlines the efforts of prominent Greek anatomists to establish the course of the basic science of anatomy in the newly founded Medical School, the laborious effort to collect cadaveric material, to compile museum anatomical collections and to gradually build the foundations of modern anatomy science at the Medical School of the Athenian University
Severe COVID-19 in people with type 1 and type 2 diabetes in Sweden: a nationwide retrospective cohort study
Background:
Whether infection with SARS-CoV-2 leads to excess risk of requiring hospitalization or intensive care in persons with diabetes has not been reported, nor have risk factors in diabetes associated with increased risk for these outcomes.
Methods:
We included 44,639 and 411,976 adult patients with type 1 and type 2 diabetes alive on Jan 1, 2020, and compared them to controls matched for age, sex, and county of residence (n=204,919 and 1,948,900). Age- and sex-standardized rates for COVID-19 related hospitalizations, admissions to intensive care and death, were estimated and hazard ratios were calculated using Cox regression analyses.
Findings:
There were 10,486 hospitalizations and 1,416 admissions into intensive care. A total of 1,175 patients with diabetes and 1,820 matched controls died from COVID-19, of these 53•2% had been hospitalized and 10•7% had been in intensive care. Patients with type 2 diabetes, compared to controls, displayed an age- and sex-adjusted hazard ratio (HR) of 2•22, 95%CI 2•13-2•32) of being hospitalized for COVID-19, which decreased to HR 1•40, 95%CI 1•34-1•47) after further adjustment for sociodemographic factors, pharmacological treatment and comorbidities, had higher risk for admission to ICU due to COVID-19 (age- and sex-adjusted HR 2•49, 95%CI 2•22-2•79, decreasing to 1•42, 95%CI 1•25-1•62 after adjustment, and increased risk for death due to COVID-19 (age- and sex-adjusted HR 2•19, 95%CI 2•03-2•36, complete adjustment 1•50, 95%CI 1•39-1•63). Age- and sex-adjusted HR for COVID-19 hospitalization for type 1 diabetes was 2•10, 95%CI 1•72-2•57), decreasing to 1•25, 95%CI 0•3097-1•62) after adjustment• Patients with diabetes type 1 were twice as likely to require intensive care for COVID-19, however, not after adjustment (HR 1•49, 95%CI 0•75-2•92), and more likely to die (HR 2•90, 95% CI 1•6554-5•47) from COVID-19, but not independently of other factors (HR 1•38, 95% CI 0•64-2•99). Among patients with diabetes, elevated glycated hemoglobin levels were associated with higher risk for most outcomes.
Interpretation:
In this nationwide study, type 2 diabetes was independently associated with increased risk of hospitalization, admission to intensive care and death for COVID-19. There were few admissions into intensive care and deaths in type 1 diabetes, and although hazards were significantly raised for all three outcomes, there was no independent risk persisting after adjustment for confounding factors
Association of anthropometry and weight change with risk of dementia and its major subtypes : A meta-analysis consisting 2.8 million adults with 57 294 cases of dementia
Uncertainty exists regarding the relation of body size and weight change with dementia risk. As populations continue to age and the global obesity epidemic shows no sign of waning, reliable quantification of such associations is important. We examined the relationship of body mass index, waist circumference, and annual percent weight change with risk of dementia and its subtypes by pooling data from 19 prospective cohort studies and four clinical trials using meta-analysis. Compared with body mass index-defined lower-normal weight (18.5-22.4 kg/m(2)), the risk of all-cause dementia was higher among underweight individuals but lower among those with upper-normal (22.5-24.9 kg/m(2)) levels. Obesity was associated with higher risk in vascular dementia. Similarly, relative to the lowest fifth of waist circumference, those in the highest fifth had nonsignificant higher vascular dementia risk. Weight loss was associated with higher all-cause dementia risk relative to weight maintenance. Weight gain was weakly associated with higher vascular dementia risk. The relationship between body size, weight change, and dementia is complex and exhibits non-linear associations depending on dementia subtype under scrutiny. Weight loss was associated with an elevated risk most likely due to reverse causality and/or pathophysiological changes in the brain, although the latter remains speculative.Peer reviewe
- …