Sustainability analysis and resource management for wireless mesh networks with renewable energy supplies

 There is a growing interest in the use of renewable energy sources to power wireless networks in order to mitigate the detrimental effects of conventional energy production or to enable deployment in off-grid locations. However, renewable energy sources, such as solar and wind, are by nature unstable in their availability and capacity. The dynamics of energy supply hence impose new challenges for network planning and resource management. In this paper, the sustainable performance of a wireless mesh network powered by renewable energy sources is studied. To address the intermittently available capacity of the energy supply, adaptive resource management and admission control schemes are proposed. Specifically, the goal is to maximize the energy sustainability of the network, or equivalently, to minimize the failure probability that the mesh access points (APs) deplete their energy and go out of service due to the unreliable energy supply. To this end, the energy buffer of a mesh AP is modeled as a G/G/1(/N) queue with arbitrary patterns of energy charging and discharging. Diffusion approximation is applied to analyze the transient evolution of the queue length and the energy depletion duration. Based on the analysis, an adaptive resource management scheme is proposed to balance traffic loads across the mesh network according to the energy adequacy at different mesh APs. A distributed admission control strategy to guarantee high resource utilization and to improve energy sustainability is presented. By considering the first and second order statistics of the energy charging and discharging processes at each mesh AP, it is demonstrated that the proposed schemes outperform some existing state-of-the-art solutions.

Combining ganglion cell topology and data of patients with glaucoma to determine a structure-function map

PURPOSE<div>To introduce techniques for deriving a map that relates visual field locations to optic nerve head (ONH) sectors and to use the techniques to derive a map relating Medmont perimetric data to data from the Heidelberg Retinal Tomograph.<br /><br />METHODS<br />Spearman correlation coefficients were calculated relating each visual field location (Medmont M700) to rim area and volume measures for 10&deg; ONH sectors (HRT III software) for 57 participants: 34 with glaucoma, 18 with suspected glaucoma, and 5 with ocular hypertension. Correlations were constrained to be anatomically plausible with a computational model of the axon growth of retinal ganglion cells (Algorithm GROW). GROW generated a map relating field locations to sectors of the ONH. The sector with the maximum statistically significant (P &lt; 0.05) correlation coefficient within 40&deg; of the angle predicted by GROW for each location was computed. Before correlation, both functional and structural data were normalized by either normative data or the fellow eye in each participant.<br /><br />RESULTS<br />The model of axon growth produced a 24-2 map that is qualitatively similar to existing maps derived from empiric data. When GROW was used in conjunction with normative data, 31% of field locations exhibited a statistically significant relationship. This significance increased to 67% (z-test, z = 4.84; P &lt; 0.001) when both field and rim area data were normalized with the fellow eye.<br /><br />CONCLUSIONS<br />A computational model of axon growth and normalizing data by the fellow eye can assist in constructing an anatomically plausible map connecting visual field data and sectoral ONH data.</div>

Patient safety and gaps management by registered nurses

Patient safety is a global imperative aimed at reducing the incidence and impact of preventable adverse events in healthcare. This study has demonstrated how effective nursing surveillance and successful everyday nursing performance can bridge &lsquo;gaps&rsquo; in the system of care, mitigate errors, and protect patients from suffering otherwise preventable harm.

Alcohol misuse interventions in the workplace: a systematic review of workplace and sports management alcohol interventions

Alcohol misuse has been linked to negative organizational outcomes, including reduced productivity and increased absenteeism. Additionally, media reports have focused on alcohol misuse within sporting organizations. Given the paucity of research evaluating alcohol misuse interventions in professional sporting organizations, two systematic literature searches were conducted. Review one examined alcohol interventions in the workplace, and Review two included sport as a search term. Resultant papers demonstrated four categories of workplace alcohol interventions; brief, web based, psychosocial, and random drug and alcohol testing. Brief interventions were prevalent, yielding largely non-significant results. Review two studies evaluated a community sporting intervention, which adopted an ecological, multi-level approach, yielding significant improvements in alcohol consumption, drink-driving, and club profitability. Brief interventions in workplaces were ineffective, and no brief interventions were found in elite sporting organizations. However, community sporting interventions showed promising results. Ongoing evaluation of alcohol interventions in professional sporting organizations are recommended.

A pilot, multisite, randomized controlled trial of a self-directed coping skills training intervention for couples facing prostate cancer : accrual, retention, and data collection issues

PURPOSE: To examine the acceptability of the methods used to evaluate Coping-Together, one of the first self-directed coping skill intervention for couples facing cancer, and to collect preliminary efficacy data. METHODS: Forty-two couples, randomized to a minimal ethical care (MEC) condition or to Coping-Together, completed a survey at baseline and 2&nbsp;months after, a cost diary, and a process evaluation phone interview. RESULTS: One hundred seventy patients were referred to the study. However, 57 couples did not meet all eligibility criteria, and 51 refused study participation. On average, two to three couples were randomized per month, and on average it took 26 days to enrol a couple in the study. Two couples withdrew from MEC, none from Coping-Together. Only 44&nbsp;% of the cost diaries were completed, and 55&nbsp;% of patients and 60&nbsp;% of partners found the surveys too long, and this despite the follow-up survey being five pages shorter than the baseline one. Trends in favor of Coping-Together were noted for both patients and their partners. CONCLUSIONS: This study identified the challenges of conducting dyadic research, and a number of suggestions were put forward for future studies, including to question whether distress screening was necessary and what kind of control group might be more appropriate in future studies.

Newly Automated System For Integrated Assessment Of The Conditions Of Underwater Gas Pipelines

An underwater gas pipeline is the portion of the pipeline that crosses a river beneath its bottom. Underwater gas pipelines are subject to increasing dangers as time goes by. An accident at an underwater gas pipeline can lead to technological and environmental disaster on the scale of an entire region. Therefore, timely troubleshooting of all underwater gas pipelines in order to prevent any potential accidents will remain a pressing task for the industry. The most important aspect of resolving this challenge is the quality of the automated system in question. Now the industry doesn't have any automated system that fully meets the needs of the experts working in the field maintaining underwater gas pipelines. Principle Aim of this Research: This work aims to develop a new system of automated monitoring which would simplify the process of evaluating the technical condition and decision making on planning and preventive maintenance and repair work on the underwater gas pipeline. Objectives: Creation a shared model for a new, automated system via IDEF3; Development of a new database system which would store all information about underwater gas pipelines; Development a new application that works with database servers, and provides an explanation of the results obtained from the server; Calculation of the values MTBF for specified pipelines based on quantitative data obtained from tests of this system. Conclusion: The new, automated system PodvodGazExpert has been developed for timely and qualitative determination of the physical conditions of underwater gas pipeline; The basis of the mathematical analysis of this new, automated system uses principal component analysis method; The process of determining the physical condition of an underwater gas pipeline with this new, automated system increases the MTBF by a factor of 8.18 above the existing system used today in the industry.

Financial integration and public financial institutions

This article highlights the problems associated with the existence of financiai institutions owned by a State which is a member of a federation. We show that these financiai institutions allow the States to transfer deficits to the federal government. This possibility creates incentives to higher deficits at State and federal leveis, implying an inefficiently high inflation rate. The main policy implication is that stabilization policies are more difficult to be implemented in countries such as Brazil, and Argentina which allow the members of the federation to own financiai institutions. A second policy implication is that Economic Blocks such as the European Community or Mercosur should not allow regional central banks if they create a monetary authority to help the members in financiai difficulty.

Board of directors and top management team: a study on CEO relative power and financial return

Best corporate governance practices published in the primers of Brazilian Securities and Exchange Commission and the Brazilian Corporate Governance Institute promote board independence as much as possible, as a way to increase the effectiveness of governance mechanism (Sanzovo, 2010). Therefore, this paper aims at understanding if what the managerial literature portraits as being self-evident - stricter governance, better performance - can be observed in actual evidence. The question answered is: do companies with a stricter control and monitoring system perform better than others? The method applied in this paper consists on comparing 116 companies in respect to the their independence level between top management team and board directors��� being that measured by four parameters, namely, the percentage of independent outsiders in the board, the separation of CEO and chairman, the adoption of contingent compensation and the percentage of institutional investors in the ownership structure ��� and their financial return measured in terms return on assets (ROA) from the latest Quarterly Earnings release of 2012. From the 534 companies listed in the Stock Exchange of Sao Paulo ��� Bovespa ��� 116 were selected due to their level of corporate governance. The title ���Novo Mercado��� refers to the superior level of governance level within companies listed in Bovespa, as they have to follow specific criteria to assure shareholders ��protection (BM&F, 2011). Regression analyses were conducted in order to reveal the correlation level between two selected variables. The results from the regression analysis were the following: the correlation between each parameter and ROA was 10.26%; the second regression analysis conducted measured the correlation between the independence level of top management team vis-��-vis board directors ��� namely, CEO relative power - and ROA, leading to a multiple R of 5.45%. Understanding that the scale is a simplification of the reality, the second part of the analysis transforms all the four parameters into dummy variables, excluding what could be called as an arbitrary scale. The ultimate result from this paper led to a multiple R of 28.44%, which implies that the combination of the variables are still not enough to translate the complex reality of organizations. Nonetheless, an important finding can be taken from this paper: two variables (percentage of outside directors and percentage of institutional investor ownership) are significant in the regression, with p-value lower than 10% and with negative coefficients. In other words, counter affirming what the literature very often portraits as being self-evident ��� stricter governance leads to higher performance ��� this paper has provided evidences to believe that the increase in the formal governance structure trough outside directors in the board and ownership by institutional investor might actually lead to worse performance. The section limitations and suggestions for future researches presents some reasons explaining why, although supported by strong theoretical background, this paper faced some challenging methodological assumptions, precluding categorical statements about the level of governance ��� measured by four selected parameters ��� and the financial return in terms of financial on assets.

International integration and long- run persistence of the GNP distribution

We use the Ramsey model of g,Towth elaborated by Bliss [1995] and Ventlira [1997] to show how international integration results in long-nm persistellce Df GNPs distribution, while allowing, under certain conditions on parameters, for convergellce during the transition. First, we pi��ovide relationships which explicitly relate, in the neighborhood of the steady-state, the magnitude of conditional convergence or divergence to the fundamentaIs of the economies. Second, we present ali analysis of the Cobb Douglas case with a broad dass of utility functions and show that there is always transitional convergenee with this technology. Third, directions for testing the Illodel against the traditional dosed-ecollomy setting are proposed. These lead to adding specific and world-wide regTessors to traditional growth regressions.

Brazilian Federal Universities : relative efficiency evaluation and data envelopment analysis

The papers aims at considering the issue of relative efficiency measurement in the context of the public sector. In particular, we consider the efficiency measurement approach provided by Data Envelopment Analysis (DEA). The application considered the main Brazilian federal universities for the year of 1994. Given the large number of inputs and outputs, this paper advances the idea of using factor analysis to explore common dimensions in the data set. Such procedure made possible a meaningful application of DEA, which finally provided a set of efficiency scores for the universities considered .

Aquaculture Research and Development as an Entry-Point and Contributor to Natural Resources and Coastal Management

Recent, fervent international dialogue concerning the existence and magnitude of impacts associated with aquaculture has had both positive and negative outcomes. Aquaculture stakeholders have become sensitized to requirements for improved environmental management of aquaculture. on the other hand, in some cases aquaculture development has been negatively affected by some of the unwarranted and unproved allegations to the detriment of the stakeholders most in need of aquaculture development (i.e., resource users, particularly the poor, who are dependent on natural resources). These resource users are targeted by, and directly influence biodiversity and conservation agendas; hence the need to understand how to gain their active participation. This discussion focuses on examples of how aquaculture research and development can be a useful tool or strategy for resource management initiatives and provide tangible positive including increased stakeholder participation and cooperation, offering alternatives to resource extraction and use in otherwise difficult or intransigent resource management conflicts.

Impact of successive sugarcane harvests and trash management practices on soil microbiological properties

Coordena����o de Aperfei��oamento de Pessoal de N��vel Superior (CAPES)