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Optimal Pricing Strategies in Cognitive Radio Networks with Heterogeneous Secondary Users and Retrials
Get PDFIn a cognitive radio (CR) system, excessive access services for secondary users (SUs) lead to a substantial increase in congestion and the retrial phenomenon, both of which degrade the performance of CR networks, especially in overload conditions. This paper investigates the price-based spectrum access control policy that characterizes the network operator\u27s provision to heterogeneous and delay-sensitive SUs through pricing strategies. Based on shared-use dynamic spectrum access (DSA), the SUs can occupy the dedicated spectrum without degrading the operations of primary users (PUs). The service to transmission of SUs can be interrupted by an arriving PU, while the interrupted SUs join a retrial pool called an orbit, later trying to use the spectrum to complete the service. In the retrial orbit, the interrupted SU competes fairly with other SUs in the orbit. Such a DSA mechanism is formulated as a retrial queue with service interruptions and general service times. Regarding the heterogeneity of delay-sensitive SUs, we consider two cases: the delay-sensitive parameter follows a discrete distribution and a continuous distribution, respectively. In equilibrium, we find that the revenue-optimal price is unique, while there may exist a continuum of equilibria for the socially optimal price. In addition, the socially optimal price is always not greater than the revenue-optimal price, and thus the socially optimal arrival rate is not less than the revenue-optimal one, which is contrary with the conclusion, i.e., the socially optimal and revenue-optimal arrival rates are consistent, drawn in the literature for homogeneous SUs. Finally, we present numerical examples to show the effect of various parameters on the operator\u27s pricing strategies and SUs\u27 behavior
Symbolically Annihilating Female Police Officer Capabilities: Cultivating Gendered Police Use of Force Expectations
Get PDFThis first step cultivation analysis examines the quantity, temporal dynamics, and stance of muni-cipal police officer use of force depictions based on the gender of the officer. The 112 theatri-cally released films that comprise the core cop film genre were systematically identified. Subsequently, a population of 468 police use of force scenes was identified to serve as the units of analysis for this study. Findings revealed male officer use of force scenes appeared across all 40 years of films. Female officer use of force scenes, however, were highly restricted to specific films, years, and often dwarfed by male scenes within films. Lone female officer use of force scenes saw their highest representation in the 1980s but declined in the 1990s and 2000s, becoming increasingly dependent on a male officer’s presence. Implications of such patterns are discussed as well as potential second step cultivation studies
Freeman Honors Newsletter, Spring 2019 Issue
Get PDFSpring 2019 Newsletterhttps://digitalscholarship.tsu.edu/freeman_honors/1003/thumbnail.jp
Maritime Environmental Violations Within Nigeria & Its Impacts
Get PDFThe maritime industry contributes its own fair share of pollution within Nigerian ports and communities by way of crude oil spills and inappropriate waste management facilities. This spills often occur on wetlands needed for commercial maritime activities and economic survival by local inhibitors. The inadequate disposal of ship waste by privately owned waste management facilities can lead to the encouragement of illicit disposal of waste and ballast into the sea before registering into ports and terminals. Such waste can introduce toxic and noxious liquids into waters affecting marine lifeforms and indirectly, local communities. as a result of such incident, a negative impact can be seen in public health, fishing communities, agriculture and economic benefits. A feasible solution to minimizing maritime environmental pollution would be to use an alternative power source for ships when stationed at port, creation of laws and emergency funds designed to protect the environment and develop government-controlled waste management reception facilities
Circulating obesity-driven biomarkers are associated with risk of clear cell renal cell carcinoma: A two-stage, case-control study
Get PDFObesity is one of modifiable risk factors for clear cell renal cell cancer (ccRCC). We aim to identify the association between obesity-driven biomarkers and ccRCC risk. This is a retrospective, two-phase, case-control study involving 682 cases and 733 controls. Obesity-driven biomarkers [gastric inhibitory polypeptide (GIP), C-peptide, insulin, resistin, adipsin, peptide YY, pancreatic polypeptide, interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), plasminogen activator inhibitor-1, monocyte chemoattractant protein 1, lipocalin2, leptin, adiponectin] were measured using the Milliplex method. Multivariate logistic regression was used to assess the associations between biomarkers and ccRCC risk. Results revealed that GIP, C-peptide, IL-6 and TNF-α levels were consistently distinct between cases and controls. These markers were significantly associated with ccRCC risk in both phases (except C-peptide). In the combined population, compared with individuals with low levels of the biomarkers, individuals with high level of GIP [odds ratio (OR) = 0.52, 95% confidence interval (CI): 0.40-0.67] had lower risk, whereas individuals with high levels of C-peptide (OR = 1.46, 95% CI: 1.15-1.87), IL-6 (OR = 2.20, 95% CI: 1.50-3.22), TNF-α (OR = 1.90, 95% CI: 1.49-2.43) had significantly higher risk. Stratified analysis showed consistent associations with ccRCC risk in most subgroups (P \u3c 0.05). The risk score based on the IL-6, TNF-α and GIP was positively associated with ccRCC risk in a dose-response manner (P for trend = 2.18E-13). Data from The Cancer Genome Atlas indicate that insulin signaling, IL-6 signaling and TNF-α signaling were enhanced in tumors. Collectively, our study demonstrates the integrative effect of insulin resistance and inflammation in ccRCC development, which may elucidate the basis of association between obesity and carcinogenesis. Further confirmation in prospective cohort studies are warranted for clinical applications in prevention and precision medicine of ccRCC
Longitudinal Impacts of Gastric Bypass Surgery on Pharmacodynamics and Pharmacokinetics of Statins
No full textPurpose: Undergoing Roux-en-Y gastric bypass (RYGB) is expected to affect orally administered drug absorption. Statins are commonly prescribed to patients with obesity for the prevention of atherosclerotic cardiovascular diseases by lowering cholesterol. This is the first longitudinal prospective study on impacts of RYGB on weight loss, pharmacodynamics, and pharmacokinetics of atorvastatin, rosuvastatin, and simvastatin, and their active metabolites, up to 1-year post-surgery. Methods: Forty-six patients were recruited, five patients on atorvastatin, twelve on rosuvastatin, nine on simvastatin, and twenty on no statin. The concentrations of atorvastatin, rosuvastatin, and simvastatin with their active metabolites were monitored. Results: Mean plasma concentrations of atorvastatin and metabolites and rosuvastatin normalized by the unit dose [(nM)/(mg/kg)] decreased by 3- to 6-month post-surgery. Conversely, simvastatin and its metabolite concentrations increased up to 6-month post-surgery, then declined to preoperative levels by 1-year post-surgery. The metabolisms of atorvastatin to hydroxyl-metabolites and simvastatin to simvastatin acid were decreased after RYGB. The weight loss and PD outcomes were comparable between statin and non-statin groups suggesting the key impacts were from RYGB. The discontinuation or reduction of dose of atorvastatin or rosuvastatin post-RYGB exhibited rebounds of LDL levels in some subjects, but the rebound was not apparent with patients on simvastatin pre-surgery. Conclusion: Discontinuations of statin dosing post-RYGB require LDL monitoring and reducing the dose to half seems to have better results. Patients on statin treatment post-RYGB should be followed-up closely based on our pharmacokinetic findings, to ensure therapeutic effects of the treatment with minimal adverse effects
Quantum (q, h)-Bézier surfaces based on bivariate (q, h)-blossoming
No full textWe introduce the (q, h)-blossom of bivariate polynomials, and we define the bivariate (q, h)-Bernstein polynomials and (q, h)-Bézier surfaces on rectangular domains using the tensor product. Using the (q, h)-blossom, we construct recursive evaluation algorithms for (q, h)-Bézier surfaces and we derive a dual functional property, a Marsden identity, and a number of other properties for bivariate (q, h)-Bernstein polynomials and (q, h)-Bézier surfaces. We develop a subdivision algorithm for (q, h)-Bézier surfaces with a geometric rate of convergence. Recursive evaluation algorithms for quantum (q, h)-partial derivatives of bivariate polynomials are also derived
An Optimal Strategy for Resource Utilization in Cloud Data Centers
Get PDFCloud computing has emerged in recent years as one of the most interesting developments in technology. With the gaining popularity of cloud-based solutions, more and more applications are migrating into the Cloud and thus have highly demanding critical requirements for networking resources. Virtual technology associated with a Data Center consists of a set of servers, storage and network devices, power systems, cooling systems, etc., and makes it possible for the resource management of physical machines to be more finely tuned and thus support multiple virtual machines well. The growing challenge, however, is how to efficiently provision these resources to meet the requirements of the different qualities of service levels. This paper offers and investigates a general situation wherein a datacenter can determine the cost of using resources and a Cloud service user can decide whether it will pay the price for the resource or not for an incoming task. By establishing a Continuous-Time Markov Decision Process model for both an average reward model and a discounted expected reward model, the optimal policy of each model for admitting tasks can be verified to be a State-related control limit (threshold) policy, respectively. Further, a detailed statement and verification of the upper boundaries for such an optimal policy, and a comprehensive set of experiments on the various cases to validate this proposed solution are provided. Particularly, the machine learning method is implemented to obtain the optimal threshold values by using a feed-forward neural network model. Several numerical examples are also provided on how to derive optimal threshold values. The results offered in this paper can be easily utilized to help datacenter operate in an economically optimal way when providing different needed application services to Cloud service users
Alkalinity And Mineral Concentration Estimation In Commercial Drinking Water
Get PDFSeveral aspects of water and water quality were reviewed and investigated in this study; the effects of dehydration on human health, the role of alkalinity in drinking water, and the actual levels of alkalinity and other minerals in commercial drinking water. Hydration plays a critical role in human physical performance as well as in the prevention of chronic diseases. This experiment was conducted to determine if the level of acidity ( or alkalinity) of commercial alkaline water are truly above the normal ph levels, and to identify the salts in each type of water. Based on researches, a more alkaline distilled water has more health benefits in contrast to acidic water, or drinking water with low pH. In this experiment, the mineral content of each water was observed by using the ICPMS. Results showed that the Fiji water sample had the highest amount of calcium, potassium, magnesium and sodium present. This was followed by Alkaline 88, Niagara and lastly, distilled water. Results have shown the positive correlation between mineral content and pH level. Alkaline 88 showed the highest level of alkalinity, with an average pH of 8.26 from the conducted 3 trials. Fiji water had an average pH of 7.02, distilled water had 6.73 and lastly, Niagara had an average pH of 5.42. Niagara, being the cheapest and most popular, had a pH lower than what was put on the label, and the lowest pH of all the samples, which may be 10 to 100 times more acidic than the acceptable values