957 research outputs found
Multi-Scalar-Tensor Equivalents for Modified Gravitational Actions
A general scheme of constructing scalar-tensor equivalents to modified
gravitational actions are studied using the algebra of exterior differential
forms and the first order formalism that allows an independent connection and
coframe. By introducing appropriate constraints on the connection,
pseudo-Riemannian cases as well as non-Riemannian cases are discussed for
various gravitational models. The issue of the dynamical degree of freedom for
the resulting scalar fields is discussed at the level of the field equations.
Explicit scalar-tensor equivalents for gravitational models based on
models, the quadratic curvature lagrangians and the models involving the
gradients of the scalar curvature are presented. In particular, explicit ST
equivalence for gravitational lagrangians popular in some cosmological models
are constructed.Comment: V1:17 pages in two column format, revtex; V2: 19 pages, an appendix
and references added, published versio
Wireless model-based predictive networked control system over cooperative wireless network
Owing to their distributed architecture, networked control systems (NCSs) are proven to be feasible in scenarios where a spatially distributed feedback control system is required. Traditionally, such NCSs operate over real-time wired networks. Recently, in order to achieve the utmost flexibility, scalability, ease of deployment, and maintainability, wireless networks such as IEEE 802.11 wireless local area networks (LANs) are being preferred over dedicated wired networks. However, conventional NCSs with event-triggered controllers and actuators cannot operate over such general purpose wireless networks since the stability of the system is compromised due to unbounded delays and unpredictable packet losses that are typical in the wireless medium. Approaching the wireless networked control problem from two perspectives, this work introduces a practical wireless NCS and an implementation of a cooperative medium access control protocol that work jointly to achieve decent control under severe impairments, such as unbounded delay, bursts of packet loss and ambient wireless traffic. The proposed system is evaluated on a dedicated test platform under numerous scenarios and significant performance gains are observed, making cooperative communications a strong candidate for improving the reliability of industrial wireless networks
An Analysis of Iraq's Pre-import Inspection, Testing & Certification Program: A’WOT Analysis
AbstractThe Pre-import Inspection, Testing and Certification program became an important factor to get a market share in Iraq. Verification of Conformity (VoC) of products before shipment to Iraq was started in May 2011 by Iraqi government. The objectives of this program are; protection of consumers and environment, assurance of conformity, transparency in commercial activities and releasing goods faster at Iraqi customs with the appropriate certificate of conformity. After several months of preparation, today this program is being executed actively for countries all over the world that wants to export in Iraq. In this study, an analysis of Iraq's new pre-import inspection, testing and certification program is tried to determine by A’WOT hybrid multi-criteria method. A’WOT is a combination of the Strengths, Weaknesses, Opportunities and Threats (SWOT) analysis and Analytic Hierarchy Process (AHP). As a result of this study, possible risks and solutions of the program are pointed out
Accelerated Corrosion Behaviors of Zn, Al AND Zn/15Al Coatings on a Steel Surface
Zn, Al and Zn/15Al coatings can be produced in optimum conditions by the twin wire arc (TWEA) spraying technique. The
coatings are used for corrosion protection in a variety of industrial applications. In this study, the accelerated corrosion behavior
of Zn, Al and Zn/15Al coatings on a steel surface during the salt-spray testing period was investigated. The surfaces of steel
coupons were coated with Zn, Al and Zn/15Al using the TWEA spray-deposition system. The corrosion test was performed in a
chloride atmosphere in a salt-spray test for over 2000 h. The corrosion of samples is assessed as the ratio of the corroded area of
the specimens. The salt-spray test results showed that Al and Zn/15Al coatings have a better corrosion resistance than Zn
coatings
Kvaliteta usluge konvencionalnih i islamskih banaka u Turskoj
Purpose – The aim of this research study is to determine and compare the service quality of conventional and Islamic banks in Turkey.
Design/Methodology/Approach – Stratified sampling method was used to select the sample of respondents for the survey. The data collection phase was carried out online via Google forms and data obtained from 524 participants was used for the analysis. A revised SERVQUAL scale for the banking sector was employed in the research.
Findings and implications – The study found service quality expectations of bank customers to be very high, with neither bank type satisfying the expectations of their customers. While conventional banks satisfied 81.2% of their customer expectations, with that proportion falling to 77.8% in the case of Islamic banks, the perception of service quality by customers was found to be higher for conventional banks than for Islamic banks. Especially in the last 20 years, Islamic banking in Turkey has developed at an extremely fast pace. Turkey has become a highly attractive market, particularly for foreign banks focused on Islamic banking. However, although Turkey is a Muslim country, there is not a high preference for Islamic banking. The most important reason behind this is the quality of service offered by the country’s Islamic banks to their customers. This study has demonstrated that the service quality of Turkish banks is unsatisfactory and that improvements to service quality especially by Islamic banks are required, more so than for conventional banks. This research study provides companies seeking to enter the Turkish banking sector with the necessary steps to satisfy the service quality expectations of Turkish customers.
Limitations – The main limitations of this study are related to the timeframe and data collection. As service perception changes over time, the service quality of banks can be better evaluated through long-term data collection. This research focused on Turkish banks only, so its results cannot be generalized outside Turkey.
Originality – Although certain studies have investigated the service quality of banks in Turkey, no study in the literature has compared the quality of service of conventional and Islamic banks.Svrha – Cilj je istraživanja utvrditi i usporediti kvalitetu usluge konvencionalnih i islamskih banaka u Turskoj.
Metodološki pristup – Pri odabiru uzorka korištena je metoda stratificiranog uzorkovanja. U istraživanju je uporabljena za bankarski sektor prilagođena SERVQUAL ljestvica. Prikupljanje podataka provedeno je online putem Google obrasca, a za analizu su korišteni podatci prikupljeni od 524 ispitanika.
Rezultati i implikacije – Uočeno je da su očekivanja kvalitete usluge korisnika usluga banke vrlo visoka te da obje vrste banaka ne ispunjavaju njihova očekivanja. Dok su konvencionalne banke uspjele zadovoljiti 81.2 % očekivanja korisnika, kod islamskih banaka taj omjer pada na 77.8 %. Utvrđeno je i da je percepcija kvalitete usluge korisnika viša kod konvencionalnih nego kod islamskih banaka. U posljednjih 20 godina u Turskoj se islamsko bankarstvo vrlo brzo razvija. Turska je postala vrlo atraktivno tržište, posebno za inozemne banke usmjerene na islamsko bankarstvo. No, iako je Turska muslimanska zemlja, preferiranje islamskih banaka nije visoko. Najvažniji razlog za takvu situaciju temelji se na kvaliteti usluge koju islamske banke nude svojim korisnicima. Istraživanje je pokazalo da kvaliteta usluge banaka u Turskoj nije zadovoljavajuća, a kvalitetu usluge više od konvencionalnih banaka posebno bi trebale poboljšati islamske banke. Istraživanje posebno pomaže poduzećima koja razmišljaju o ulasku na tursko bankarsko tržište da bi se vidjelo što je potrebno poduzeti za zadovoljavanje očekivanja turskih korisnika od kvalitete usluge.
Ograničenja – Glavna ograničenja istraživanja vezana su uz vremenski okvir i prikupljanje podataka. Percepcija usluge mijenja se s vremenom, tako da se kvaliteta usluge banaka može bolje ocijeniti dugotrajnijim prikupljanjem podataka. Istraživanje je ograničeno na turske banke pa su i rezultati procijenjeni samo za Tursku.
Doprinos – Iako postoje prethodna istraživanja o kvaliteti usluge banaka u Turskoj, ne postoji istraživanje koje uspoređuje kvalitetu usluge konvencionalnih i islamskih banaka
Noncontact lateral-force gradient measurement on Si(111)-7×7 surface with small-amplitude off-resonance atomic force microscopy
In this work, the authors report on a quantitative investigation of lateral-force gradient and lateral force between a tungsten tip and Si(111)-(7×7) surface using combined noncontact lateral-force microscopy and scanning tunneling microscopy. Simultaneous lateral-force gradient and scanning tunneling microscopy images of single and multiatomic step are obtained. In our measurement, tunnel current is used as feedback. The lateral-stiffness contrast has been observed to be 2.5 N/m at a single atomic step, in contrast to 13 N/m at a multiatomic step on Si (111) surface. They also carried out a series of lateral stiffness-distance spectroscopy, which show a sharp increase in tip-surface interaction stiffness as the sample is approached toward the surface
A study on technology management process: the parts and components suppliers in the Turkish automotive industry
This paper summarizes part of an empirical study on technology management process in the Turkish automotive parts and components industry. In this study, technology management practices in the Turkish automotive parts and components suppliers' sector are described and evaluated. Practices, techniques, and approaches are proposed to improve the level of technology management so as to turn technology into a competitive weapon. The investigation is organized within the framework of a process model for technology management that consists of technology identification, selection, acquisition, exploitation, protection, and abandonment. A comprehensive questionnaire addressing all phases of this process is developed and the results of 21 companies are presented
Cylindrically Symmetric Vacuum Solutions in Higher Dimensional Brans-Dicke Theory
Higher dimensional, static, cylindrically symmetric vacuum solutions with and
without a cosmological constant in the Brans-Dicke theory are presented. We
show that, for a negative cosmological constant and for specific values of the
parameters, a particular subclass of these solutions include higher dimensional
topological black hole-type solutions with a flat horizon topology. We briefly
extend our discussion to stationary vacuum and vacuum solutions.Comment: V3: Published Versio
Tourmaline nanoparticles doped polyvinylidene fluoride (PVDF) nanofibers
The aim of this work is to produce tourmaline (TM) doped polyvinylidene fluoride (PVDF) nano-composite fibers. TM-containing PVDF nanofibers were produced via a horizontally located electrospinning unit. N,N-dimethylformamide (DMF) and acetone were used as solvents. The amount of PVDF or PVDF/TM in the polymer solution was 20 wt.%. PVDF was dissolved in DMF in presence of heat by using a magnetic stirrer while TM powder was dispersed in Acetone in absence of heat by using an ultrasonic stirrer. These two solutions were then mixed for TM/PVDF nanocomposite fiber production. Pristine PVDF nanofibers were also electrospun as control samples. Produced nano-surfaces were analyzed under scanning electron microscopy (SEM), Fourier-transform Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD). Voltage generation capacities were investigated by recording the voltage outputs of samples under an applied rotational impact. The peak voltage produced by the TM doped PVDF nanocomposite fibers was higher than the PVDF nanofibers. © 2019, Kauno Technologijos Universitetas. All rights reserved.NKUBAP.06This work was supported by Scientific Research Projects Coordination Unit of Tekirdag Namik Kemal University. “Project number NKUBAP.06.GA.17.093
Relationship Between Xanthine Oxidoreductase Activity and BRCA1 Levels in Patients with Stage IIIA and IIIB Non-Small Cell Lung Cancer Being Treated with Neoadjuvant Chemotherapy
Objective: Lung cancer is the leading cause of cancer-related death worldwide. Treatment in locally advanced non-small cell lung cancer (NSCLC) is heterogeneous. The cure rates after complete surgical resections are not as good as expected. A better understanding of the biology of NSCLC might allow the selection of appropriate treatment. Only a few studies have been carried out on the prognostic value of xanthine oxidoreductase (XOR) and BRCA1 in lung cancer. Material and Methods: In this study, 35 patients with stage IIIA and stage IIIB of NSCLC were included. They were operated in Baskent Ankara and Adana hospitals and received neoadjuvant chemotherapy. The regular follow-up of all the patients was done in Baskent University Medical Oncology, Thoracic Surgery Department. The clinical and histopathological parameters (age, gender, stage, smoking history, performance status, and neoadjuvant chemotherapy), along with the immunohistochemical study of BRCA1 and XOR staining, were examined, and correlated with survival outcomes. Results: Median overall survival time was reported as 38.5 months, and 5-year survival rate was 33%. The presence of BRCA1 was positively associated with shorter overall survival in stage III lung cancer patients, who were followed up with the neoadjuvant platinum-based chemotherapy regime (p<0.05). There was no relation between XOR activity and overall survival outcomes. Conclusion: BRCA1-positive status might be prognostic in patients with Stage IIIA and IIIB of NSCLC
- …