936 research outputs found
On the Two-user Multi-carrier Joint Channel Selection and Power Control Game
In this paper, we propose a hierarchical game approach to model the energy
efficiency maximization problem where transmitters individually choose their
channel assignment and power control. We conduct a thorough analysis of the
existence, uniqueness and characterization of the Stackelberg equilibrium.
Interestingly, we formally show that a spectrum orthogonalization naturally
occurs when users decide sequentially about their transmitting carriers and
powers, delivering a binary channel assignment. Both analytical and simulation
results are provided for assessing and improving the performances in terms of
energy efficiency and spectrum utilization between the simultaneous-move game
(with synchronous decision makers), the social welfare (in a centralized
manner) and the proposed Stackelberg (hierarchical) game. For the first time,
we provide tight closed-form bounds on the spectral efficiency of such a model,
including correlation across carriers and users. We show that the spectrum
orthogonalization capability induced by the proposed hierarchical game model
enables the wireless network to achieve the spectral efficiency improvement
while still enjoying a high energy efficiency.Comment: 31 pages, 13 figures, accepted in IEEE Transactions on Communication
Menstrual Cycle and Physical Effort
In addition to affecting the sexual organs in women, ovarian hormones have a wide impact on processes related to metabolism, water and electrolyte balance, thermoregulation, and redox balance. Differences in the estradiol and progesterone concentrations during the follicular and luteal phases, as well as the increase in the concentration of these hormones under the influence of physical exercise, may cause a different course of exercise response in women depending on the phase of menstrual cycle. Estrogens affect the metabolism of women by reducing the rate of gluconeogenesis and glycogenolysis and, at the same time, by increasing the share of lipids in covering energy requirements. Progesterone affects respiratory system parameters causing, among others, an increase in pulmonary ventilation. The resultant antagonistic action of progesterone and estradiol is the effect on thermoregulatory mechanisms. Increased estradiol concentration at the low progesterone concentration level causes water and electrolyte retention. In turn, an increased level of progesterone leads to loss of water and sodium, causing a decrease in the volume of plasma during the postovulatory phase of the menstrual cycle. The processes described above are related to metabolic changes affecting the ability to perform physical efforts
A Game Theoretic Analysis for Energy Efficient Heterogeneous Networks
Smooth and green future extension/scalability (e.g., from sparse to dense,
from small-area dense to large-area dense, or from normal-dense to super-dense)
is an important issue in heterogeneous networks. In this paper, we study energy
efficiency of heterogeneous networks for both sparse and dense two-tier small
cell deployments. We formulate the problem as a hierarchical (Stackelberg) game
in which the macro cell is the leader whereas the small cell is the follower.
Both players want to strategically decide on their power allocation policies in
order to maximize the energy efficiency of their registered users. A backward
induction method has been used to obtain a closed-form expression of the
Stackelberg equilibrium. It is shown that the energy efficiency is maximized
when only one sub-band is exploited for the players of the game depending on
their fading channel gains. Simulation results are presented to show the
effectiveness of the proposed scheme.Comment: 7 pages, 3 figures, in Wiopt 201
Primary Sclerosing Cholangitis (PSC) in Children
Primary sclerosing cholangitis (PSC) is a chronic liver disease of unknown aetiology affecting extrahepatic and/or intrahepatic bile ducts causing its inflammation and fibrosis with most frequent consequences including biliary cirrhosis and liver failure. The incidence of PSC in children and adolescents is 0.2 per 100,000 children per year, when in adults the reported incidence is higher and equals 0.5 to 1 in 100,000 individuals per year. PSC is more common among men and boys. The diagnosis is usually established in the second decade of life in the paediatric population with the mean age of diagnosis of 13.8 years. Many studies point out a strong correlation between IBD and PSC, especially ulcerative colitis. The prevalence of IBD among children with PSC diagnosis varies from 60 to 99%; however, the incidence of PSC is about 12% in patients with ulcerative colitis and fluctuates about 2–5% in Crohn’s disease diagnosed patients. Clinical symptoms are present in approximately half of cases and they are unspecific in many of them. Elevated liver enzymes and biochemical markers of cholestasis are sometimes the only signs of PSC. Gold standard for PSC diagnosis is magnetic resonance cholangiopancreatography (MRCP) as a non-invasive procedure comparing to endoscopic retrograde cholangiopancreatography (ERCP) which is also used in some cases. The aim of the study was to review the risk factors, clinical symptoms, diagnostic methods and treatment of paediatric patients with primary sclerosing cholangitis
Liver Changes in the Course of Cystic Fibrosis
Liver damage observed in cystic fibrosis is a complicated process comprised of fibrogenesis, inflammation, remodeling, apoptosis, and cholestasis. Complexity of processes which take place in the liver and bile ducts in the course of this disease are not clearly defined. Changes in the liver are observed in 5–20% of patients with diagnosed cystic fibrosis; however they can increase mortality, shorten time of life, and deteriorate quality of life. The aim of the chapter was to review the risk factors, clinical symptoms, diagnostic methods, and treatment of liver changes in the course of cystic fibrosis
Evaluation or perfusion and thermal parameters of skiin tissue using cold provocation and thermographic measurements
Measurement of the perfusion coefficient and thermal parameters of skin tissue using dynamic thermography is presented in this paper. A novel approach based on cold provocation and thermal modelling of skin tissue is presented. The measurement was performed on a person’s forearm using a special cooling device equipped with the Peltier module. The proposed method first cools the skin, and then measures the changes of its temperature matching the measurement results with a heat transfer model to estimate the skin perfusion and other thermal parameters. In order to assess correctness of the proposed approach, the uncertainty analysis was performed
The determination of steric purity of amines and amino acids gas chromatography and mass spectrometry
Amines and amino acids have been condensed with a mixture of N-TFA-R-prolyl chloride and N-TFA-S-(1-^H)-prolyl chloride and the resulting four diastereoisomers have been separated by Gas Chromatography into two peaks. The amount of each diastereoisomer formed was then determined by Chemical Ionisation Mass Spectrometry. The steric purity of the enantiomeric mixtures was calcuated from these values and the calculated values were always found to be within 5% of the expected values
Book Review: A History of the American Constitution. by Daniel A. Farber & Suzanna Sherry.
Book review: A History of the American Constitution. By Daniel A. Farber & Suzanna Sherry. St. Paul, Minn.: West Publishing. 1990. Pp. xxii, 458. Reviewed by: William M. Wiecek
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