714 research outputs found
Spiking Neural P Systems with Structural Plasticity: Attacking the Subset Sum Problem
Spiking neural P systems with structural plasticity (in short,
SNPSP systems) are models of computations inspired by the function and
structure of biological neurons. In SNPSP systems, neurons can create
or delete synapses using plasticity rules. We report two families of solutions:
a non-uniform and a uniform one, to the NP-complete problem
Subset Sum using SNPSP systems. Instead of the usual rule-level nondeterminism
(choosing which rule to apply) we use synapse-level nondeterminism
(choosing which synapses to create or delete). The nondeterminism
due to plasticity rules have the following improvements from a
previous solution: in our non-uniform solution, plasticity rules allowed
for a normal form to be used (i.e. without forgetting rules or rules with
delays, system is simple, only synapse-level nondeterminism); in our uniform
solution the number of neurons and the computation steps are
reduced.Ministerio de Economía y Competitividad TIN2012-3743
Balancing the Focus of Quality Assurance Frameworks of Higher Education Institutions in Africa: A Ghanaian Context
Higher education institutions in Africa appear to be completely copying the quality assurance (QA) frameworks of developed countries instead of conceptualising their own frameworks for delivering quality higher education outcomes in Africa. Certain factors (limited funding, inadequate infrastructure, inadequate staffing, relatively low research outputs, and limited graduate employable skills) characterising higher education are peculiar to developing countries including Africa. Using a qualitative case‐study approach through interviews and document reviews, and a “PPP” conceptual framework, this study examined the foci of quality assurance frameworks of three flagship universities in Ghana. The findings indicate that the least attention is given to facilities in the quality assurance frameworks even though limited facilities pose a major challenge to the quality of higher education outcomes of the universities. The findings indicate that most attention is paid to programme areas such as teaching and learning. The results of the study recommend regular and appropriate balancing of the foci of quality assurance frameworks in the universities to enable them to give optimum attention to all key operational areas for quality outcomes
Scattering Effects of Residential Trees on Very High Frequency Radio Wave Propagation
Modeling of attenuation of Very High Frequency radio signal in residential environment can be very tedious as the channels are rarely characterized by vegetation of the same variety. This work focus on path loss measurement and attenuation modeling of the coherent scattered field intensity of VHF as it propagates through Mango and Jathropha trees. The two separate trees were illuminated uniformly with 2.15dBi dipole antenna connected to 60W transmitter while 1.7dBi short dipole connected to GSP-730 Spectrum Analyzer was used for reception. Path loss due to each canopy were estimated relative to the scattering angles. Dry-matter fraction of the leave were determined using sensitive weigh balance and corresponding effective dielectric properties of the leaves and branches peculiar to each tree were estimated using semi-empirical formula. Specific attenuation models were developed separately for the two trees relative to dielectric properties of each tree leaves and branches. The results show that path loss due to single Mango tree canopy ranges from 100dB to 140dB and that of Jathropha ranges from 95dB to 135dB. The results also show that total specific attenuation of the two trees depends on frequency, wavelength and dielectric properties of the canopies constituents Keywords: Path loss; Radio Propagation; Residential Trees; Specific Attenuation Coefficient; VHF; DOI: 10.7176/APTA/83-11 Publication date: December 30th 202
Design and Construction of Wireless Instrumentation System for Measuring Solar Module Performance Parameters
This paper presents the development of a wireless instrumentation system for accurate characterization and evaluation of solar modules performance parameters under variable atmospheric conditions. A wireless transmitter that operate at 5V (315MHz) was designed and constructed to transmit electrical parameters of three different solar panels measured via current, temperature and voltage sensors to a constructed Omni-directional receiver that is made up of inbuilt storage system. The measured electrical parameters from individual panels were evaluated in terms of their responses to variable atmospheric conditions and compared with that of manufacturer’s ratings. The results based on the plotted curves show that as individual panel temperature increases the output voltage also increases. Increase in output voltage result into increase in output current measured across the load resistor which also results into corresponding increase in output power of individual panel. The measured electrical parameters are within the manufacturer’s ratings range, except maximum output currents and maximum powers which show little differences from that of manufacturer’s ratings due to choice of load resistors used in the design which impede the free flow of current to some extent. Keywords: Design, Construction, wireless instrumentation, solar modules DOI: 10.7176/JNSR/9-10-09 Publication date:May 31st 201
Mapping the Policy Regulatory Environment of Transnational Education (TNE) in the Ghanaian Tertiary Education System
Given the critical role of public policy in TNE arrangements of countries, and the fact that TNE partnerships are growing steadily in the Ghanaian tertiary education sector, a robust and resilient public policy environment is imperative. However, the public policy environment of TNE partnerships in the tertiary education sector in Ghana is unexamined by any scientific study to guide decision on TNE partnerships in Ghanaian tertiary education institutions (TEIs). Against this backdrop, this chapter examines the level of influence of public policy frameworks on TNE partnerships in TEIs in Ghana to ignite a national discourse on TNE regulation. A multiphase mixed-method research design, informed by exploratory and explanatory sequential designs was adopted for the study. The findings reveal that TNE partnerships are an emerging concept in the Ghanaian tertiary education system with less than 20% of the over 200 TEIs engaged in TNE partnerships. More importantly, the findings indicate that the policy environment of TNE partnerships of TEIs in Ghana is not sufficiently robust because no tailor-made policy regulatory frameworks exist to regulate TNE partnerships in TEIs. To this end, the study concludes that the existing policy regulatory frameworks for the Ghanaian tertiary education system are incapable of helping the country maximise the full benefits of TNE partnerships by ensuring win-win situations for TEIs engaged in TNE partnerships. In view of this, the study recommends that the government should develop a tailor-made policy framework for regulating TNE partnerships in Ghanaian TEIs
Authorship and partnerships in health promotion research: issues of erasure, ownership and inequity in knowledge production
Earlier this year, the authors of this editorial submitted a paper to a major international health promotion conference and, after peer review, were accepted and invited to present. The presentation was titled ‘North-South Health Research Partnerships in an Unequal World’ and it presented findings from a qualitative study exploring the experiences of local health research stakeholders in Zambia with international health research collaborations. Because of funding constraints, Corbin (the one Northern partner from a high-income country) was the only author who was able to travel to attend the conference and present on behalf of the team. Because of revenue problems on the part of the conference organizers, they were forced to implement a policy which required that everyone listed in the program pay the ∼$300 USD registration fee (this was the discounted rate for low-income countries). The Zambian partners, lacking funds, were not able to pay even this discounted registration fee. So, while they did appear in the online link to the full text of the conference abstracts, their names were literally erased from their research in the official program
Everolimus plus exemestane in postmenopausal patients with HR(+) breast cancer: BOLERO-2 final progression-free survival analysis.
IntroductionEffective treatments for hormone-receptor-positive (HR(+)) breast cancer (BC) following relapse/progression on nonsteroidal aromatase inhibitor (NSAI) therapy are needed. Initial Breast Cancer Trials of OraL EveROlimus-2 (BOLERO-2) trial data demonstrated that everolimus and exemestane significantly prolonged progression-free survival (PFS) versus placebo plus exemestane alone in this patient population.MethodsBOLERO-2 is a phase 3, double-blind, randomized, international trial comparing everolimus (10 mg/day) plus exemestane (25 mg/day) versus placebo plus exemestane in postmenopausal women with HR(+) advanced BC with recurrence/progression during or after NSAIs. The primary endpoint was PFS by local investigator review, and was confirmed by independent central radiology review. Overall survival, response rate, and clinical benefit rate were secondary endpoints.ResultsFinal study results with median 18-month follow-up show that median PFS remained significantly longer with everolimus plus exemestane versus placebo plus exemestane [investigator review: 7.8 versus 3.2 months, respectively; hazard ratio = 0.45 (95% confidence interval 0.38-0.54); log-rank P < 0.0001; central review: 11.0 versus 4.1 months, respectively; hazard ratio = 0.38 (95% confidence interval 0.31-0.48); log-rank P < 0.0001] in the overall population and in all prospectively defined subgroups, including patients with visceral metastases, [corrected] and irrespective of age. The incidence and severity of adverse events were consistent with those reported at the interim analysis and in other everolimus trials.ConclusionThe addition of everolimus to exemestane markedly prolonged PFS in patients with HR(+) advanced BC with disease recurrence/progression following prior NSAIs. These results further support the use of everolimus plus exemestane in this patient population. ClinicalTrials.gov #NCT00863655
IFRS Adoption, Reporting Incentives, and Financial Reporting Quality in Private Firms
This study examines financial reporting quality (FRQ) effects around voluntary International Financial Reporting Standards (IFRS) adoptions by German private firms across two important dimensions, earnings quality and disclosure practices. To capture differences in the motivations for IFRS adoptions, we identify four different types of IFRS adopting firms based on a comprehensive set of firm characteristics. We observe earnings quality improvements around IFRS adoptions primarily for one type of firms, which are young, fast growing and seeking access to public equity markets. Using a matched sample of private German GAAP and IFRS reporting firms, we find some evidence suggesting that IFRS also contribute to higher earnings quality. Recognizing that our earnings quality metrics are only incomplete measures of FRQ, we also compare the disclosure practices of IFRS and German GAAP firms. We find that all IFRS firm types disclose significantly more information in their financial reports and show a higher propensity to publish their financial reports voluntarily on the corporate website. Our findings indicate that failure to identify earnings quality changes around IFRS adoption cannot be automatically interpreted as IFRS adoption having no effect on the FRQ of (private) firms. Collectively, our results suggest that both incentives and accounting standards shape private firms’ FRQ
Multifunctional heterogeneous ion-exchange membranes for ion and microbe removal in low-salinity water
Here, multifunctional heterogeneous ion-exchange metal nanocomposite membranes were prepared for surface water desalination and bacterial inactivation under low-pressure (0.05 MPa) filtration conditions. Ultrafiltration (UF) heterogeneous ion exchange membranes (IEMs) were modified with different concentrations of AgNO3 and CuSO4 solutions using the intermatrix synthesis (IMS) technique to produce metal nanocomposite membranes. Scanning electron microscopy (SEM) images revealed that the metal nanoparticles (MNPs) (Ag and Cu) were uniformly distributed on the surface and the interior of the nanocomposite membranes. With increasing metal precursor solution concentration (0.01 to 0.05 mol·L−1), the metal content of Ag and Cu nanocomposite membranes increased from 0.020 to 0.084 mg·cm−2 and from 0.031 to 0.218 m·cm−2 respectively. Results showed that the hydrodynamic diameter diameters of Ag and Cu nanoparticles (NPs) increased from 62.42 to 121.10 nm and from 54.2 to 125.7 nm respectively, as the metal precursor concentration loaded increased. The leaching of metals from metal nanocomposite membranes was measured in a dead-end filtration system, and the highest leaching concentration levels were 8.72 ppb and 5.32 ppb for Ag and Cu, respectively. The salt rejection studies indicated that ionic selectivity was improved with increasing metal content. Bacterial filtration showed higher antibacterial activity for metal nanocomposite membranes, reaching 3.6 log bacterial inactivation
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