76 research outputs found
Measuring banking efficiency in the pre- and post-liberalization environment : evidence from the Turkish banking system
The authors examine banking efficiency before and after liberalization, drawing on Turkey's experience. They also investigate the scale effect on efficiency by type of ownership. Their findings suggest that liberalization programs were followed by an observable decline in efficiency, not an improvement. During the study period Turkish banks did not operate at the optimum scale. Another unexpected result was that efficiency was no different between state-owned and privately owned banks. Banks that were privately owned or foreign owned had been expected to respond better to liberalization, because they were smaller and more dynamically structured, but they were no more efficient than state-owned banks. One reason for the systemwide decline in efficiency might have been the general increase in macroeconomic instability during the period studied.Financial Crisis Management&Restructuring,Banks&Banking Reform,Environmental Economics&Policies,Financial Intermediation,Economic Theory&Research
Nonlinear Processing with Linear Optics
Deep neural networks have achieved remarkable breakthroughs by leveraging
multiple layers of data processing to extract hidden representations, albeit at
the cost of large electronic computing power. To enhance energy efficiency and
speed, the optical implementation of neural networks aims to harness the
advantages of optical bandwidth and the energy efficiency of optical
interconnections. In the absence of low-power optical nonlinearities, the
challenge in the implementation of multilayer optical networks lies in
realizing multiple optical layers without resorting to electronic components.
In this study, we present a novel framework that uses multiple scattering that
is capable of synthesizing programmable linear and nonlinear transformations
concurrently at low optical power by leveraging the nonlinear relationship
between the scattering potential, represented by data, and the scattered field.
Theoretical and experimental investigations show that repeating the data by
multiple scattering enables non-linear optical computing at low power
continuous wave light.Comment: 20 pages, 9 figures and 1 tabl
Multicasting Optical Reconfigurable Switch
Artificial Intelligence (AI) demands large data flows within datacenters,
heavily relying on multicasting data transfers. As AI models scale, the
requirement for high-bandwidth and low-latency networking compounds. The common
use of electrical packet switching faces limitations due to
optical-electrical-optical conversion bottlenecks. Optical switches, while
bandwidth-agnostic and low-latency, suffer from having only unicast or
non-scalable multicasting capability. This paper introduces an optical
switching technique addressing this challenge. Our approach enables arbitrarily
programmable simultaneous unicast and multicast connectivity, eliminating the
need for optical splitters that hinder scalability due to optical power loss.
We use phase modulation in multiple layers, tailored to implement any multicast
connectivity map. Phase modulation also enables wavelength selectivity on top
of spatial selectivity, resulting in an optical switch that implements
space-wavelength routing. We conducted simulations and experiments to validate
our approach. Our results affirm the concept's feasibility, effectiveness, and
scalability, as a multicasting switch by experimentally demonstrating 16
spatial ports using 2 wavelength channels. Numerically, 64 spatial ports with 4
wavelength channels each were simulated, with approximately constant efficiency
(< 3 dB) as ports and wavelength channels scale.Comment: 17 pages, 4 figures, articl
Forward-Forward Training of an Optical Neural Network
Neural networks (NN) have demonstrated remarkable capabilities in various
tasks, but their computation-intensive nature demands faster and more
energy-efficient hardware implementations. Optics-based platforms, using
technologies such as silicon photonics and spatial light modulators, offer
promising avenues for achieving this goal. However, training multiple trainable
layers in tandem with these physical systems poses challenges, as they are
difficult to fully characterize and describe with differentiable functions,
hindering the use of error backpropagation algorithm. The recently introduced
Forward-Forward Algorithm (FFA) eliminates the need for perfect
characterization of the learning system and shows promise for efficient
training with large numbers of programmable parameters. The FFA does not
require backpropagating an error signal to update the weights, rather the
weights are updated by only sending information in one direction. The local
loss function for each set of trainable weights enables low-power analog
hardware implementations without resorting to metaheuristic algorithms or
reinforcement learning. In this paper, we present an experiment utilizing
multimode nonlinear wave propagation in an optical fiber demonstrating the
feasibility of the FFA approach using an optical system. The results show that
incorporating optical transforms in multilayer NN architectures trained with
the FFA, can lead to performance improvements, even with a relatively small
number of trainable weights. The proposed method offers a new path to the
challenge of training optical NNs and provides insights into leveraging
physical transformations for enhancing NN performance
Serum Neopterin and Procalcitonin Levels in Relationship with Pediatric Burn Wound Infections
Infection and septic complications in burn patients can be monitored by procalcitonin (PCT) and neopterin plasma values. The aim of the study was to investigate serum neopterin and PCT levels with WBC (white blood cell) and CRP (C-reactive protein) levels in patient group (PG) and healthy control group (HCG) and to investigate the relationship of these markers with burn wound infections (BWI). As the PG, 23 patients between 0–12 ages and up to 30% Total Body Surface Area (TBSA) burned and 15 HCG were included. PCT, neopterin, WBC, and CRP results on the first, the seventh, the fourteenth and the 21st day have been compared. During the follow-up period, 11 patients with BWI and 12 patients without BWI were classified as infected and non-infected patients, respectively. PCT and neopterin levels were detected higher in patients with BWI but no significant difference were present. Also, PCT and neopterin levels within the first 24 hours following the burn were detected higher in PG than HCG. CRP and WBC levels were detected high due to burn trauma. PCT and neopterin levels were increased in patients with BWI. PCT levels were increased during the pre-infectious period, while neopterin levels increased during the post-infectious period
Cardiovascular disease, chronic kidney disease, and diabetes mortality burden of cardiometabolic risk factors from 1980 to 2010: A comparative risk assessment
Background: High blood pressure, blood glucose, serum cholesterol, and BMI are risk factors for cardiovascular diseases and some of these factors also increase the risk of chronic kidney disease and diabetes. We estimated mortality from cardiovascular diseases, chronic kidney disease, and diabetes that was attributable to these four cardiometabolic risk factors for all countries and regions from 1980 to 2010. Methods: We used data for exposure to risk factors by country, age group, and sex from pooled analyses of population-based health surveys. We obtained relative risks for the effects of risk factors on cause-specific mortality from meta-analyses of large prospective studies. We calculated the population attributable fractions for each risk factor alone, and for the combination of all risk factors, accounting for multicausality and for mediation of the effects of BMI by the other three risks. We calculated attributable deaths by multiplying the cause-specific population attributable fractions by the number of disease-specific deaths. We obtained cause-specific mortality from the Global Burden of Diseases, Injuries, and Risk Factors 2010 Study. We propagated the uncertainties of all the inputs to the final estimates. Findings: In 2010, high blood pressure was the leading risk factor for deaths due to cardiovascular diseases, chronic kidney disease, and diabetes in every region, causing more than 40% of worldwide deaths from these diseases; high BMI and glucose were each responsible for about 15% of deaths, and high cholesterol for more than 10%. After accounting for multicausality, 63% (10·8 million deaths, 95% CI 10·1-11·5) of deaths from these diseases in 2010 were attributable to the combined effect of these four metabolic risk factors, compared with 67% (7·1 million deaths, 6·6-7·6) in 1980. The mortality burden of high BMI and glucose nearly doubled from 1980 to 2010. At the country level, age-standardised death rates from these diseases attributable to the combined effects of these four risk factors surpassed 925 deaths per 100 000 for men in Belarus, Kazakhstan, and Mongolia, but were less than 130 deaths per 100 000 for women and less than 200 for men in some high-income countries including Australia, Canada, France, Japan, the Netherlands, Singapore, South Korea, and Spain. Interpretation: The salient features of the cardiometabolic disease and risk factor epidemic at the beginning of the 21st century are high blood pressure and an increasing effect of obesity and diabetes. The mortality burden of cardiometabolic risk factors has shifted from high-income to low-income and middle-income countries. Lowering cardiometabolic risks through dietary, behavioural, and pharmacological interventions should be a part of the global response to non-communicable diseases. Funding: UK Medical Research Council, US National Institutes of Health. © 2014 Elsevier Ltd
EPIdemiology of Surgery-Associated Acute Kidney Injury (EPIS-AKI) : Study protocol for a multicentre, observational trial
More than 300 million surgical procedures are performed each year. Acute kidney injury (AKI) is a common complication after major surgery and is associated with adverse short-term and long-term outcomes. However, there is a large variation in the incidence of reported AKI rates. The establishment of an accurate epidemiology of surgery-associated AKI is important for healthcare policy, quality initiatives, clinical trials, as well as for improving guidelines. The objective of the Epidemiology of Surgery-associated Acute Kidney Injury (EPIS-AKI) trial is to prospectively evaluate the epidemiology of AKI after major surgery using the latest Kidney Disease: Improving Global Outcomes (KDIGO) consensus definition of AKI. EPIS-AKI is an international prospective, observational, multicentre cohort study including 10 000 patients undergoing major surgery who are subsequently admitted to the ICU or a similar high dependency unit. The primary endpoint is the incidence of AKI within 72 hours after surgery according to the KDIGO criteria. Secondary endpoints include use of renal replacement therapy (RRT), mortality during ICU and hospital stay, length of ICU and hospital stay and major adverse kidney events (combined endpoint consisting of persistent renal dysfunction, RRT and mortality) at day 90. Further, we will evaluate preoperative and intraoperative risk factors affecting the incidence of postoperative AKI. In an add-on analysis, we will assess urinary biomarkers for early detection of AKI. EPIS-AKI has been approved by the leading Ethics Committee of the Medical Council North Rhine-Westphalia, of the Westphalian Wilhelms-University Münster and the corresponding Ethics Committee at each participating site. Results will be disseminated widely and published in peer-reviewed journals, presented at conferences and used to design further AKI-related trials. Trial registration number NCT04165369
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