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Now showing 1 - 10 of 79
  • Article
    Citation - WoS: 21
    Citation - Scopus: 23
    Best Proximity Points of Generalized Almost Ψ-Geraghty Contractive Non-Self
    (Springer international Publishing Ag, 2014) Aydi, Hassen; Karapinar, Erdal; Erhan, Inci M.; Salimi, Peyman
    In this paper, we introduce the new notion of almost psi-Geraghty contractive mappings and investigate the existence of a best proximity point for such mappings in complete metric spaces via the weak P-property. We provide an example to validate our best proximity point theorem. The obtained results extend, generalize, and complement some known fixed and best proximity point results from the literature.
  • Article
    Citation - WoS: 13
    Citation - Scopus: 14
    The Existence of Optimal Approximate Solution Theorems for Generalized Α-Proximal Contraction Non-Self Mappings and Applications
    (Springer international Publishing Ag, 2013) Karapinar, Erdal; Sintunavarat, Wutiphol
    In this paper, we investigate the sufficient conditions to find a best proximity point for a certain class of non-self mappings. It is well known that optimization problems can be transformed to the problems of the existence of a best proximity point. Hence, improvement in the best proximity point theory implicitly develops the theory of optimization. Our presented results generalize, extent and improve various well-known results on the topic in the literature. In particular, we consider some applications of our results to the best proximity point theorems on a class of metric spaces endowed with an arbitrary binary relation which involves the partially ordered metric spaces.
  • Conference Object
    Citation - WoS: 1
    A Statistical Analysis of Process Abnormalities in Slab Casting
    (Springer international Publishing Ag, 2018) Keskinkilic, Ender
    Continuous casting of slabs is conducted with two successive steel flows: first from ladle to tundish, then from tundish to mold. There are certain process abnormalities related to ladle, tundish and mold. For example, change of submerged entry nozzle (SEN) is the one encountered during steel flow from tundish to mold. Tundish exchange is the abnormality taking place due to replacement of processed tundish with the new one at rest. Another example is the flow of steel from ladle to tundish without a ladle shroud. In this study, a statistical analysis was conducted related to the process abnormalities in slab casters of a steel plant. Slab surface defects observed in slab yard was incorporated in this analysis.
  • Article
    Citation - WoS: 13
    Citation - Scopus: 18
    On the existence of fixed points that belong to the zero set of a certain function
    (Springer international Publishing Ag, 2015) Karapinar, Erdal; O'Regan, Donal; Samet, Bessem
    Let T : X -> X be a given operator and F-T be the set of its fixed points. For a certain function phi : X -> [0,infinity), we say that F-T is phi-admissible if F-T is nonempty and F-T subset of Z(phi), where Z(phi) is the zero set of phi. In this paper, we study the phi-admissibility of a new class of operators. As applications, we establish a new homotopy result and we obtain a partial metric version of the Boyd-Wong fixed point theorem.
  • Review
    Citation - WoS: 3
    Citation - Scopus: 9
    An Empirical Evaluation of Software Quality Assurance Practices and Challenges in a Developing Country: a Comparison of Nigeria and Turkey
    (Springer international Publishing Ag, 2016) Sowunmi, Olaperi Yeside; Mısra, Sanjay; Misra, Sanjay; Fernandez-Sanz, Luis; Crawford, Broderick; Soto, Ricardo; Mısra, Sanjay; Computer Engineering; Computer Engineering
    Background: The importance of quality assurance in the software development process cannot be overemphasized because its adoption results in high reliability and easy maintenance of the software system and other software products. Software quality assurance includes different activities such as quality control, quality management, quality standards, quality planning, process standardization and improvement amongst others. The aim of this work is to further investigate the software quality assurance practices of practitioners in Nigeria. While our previous work covered areas on quality planning, adherence to standardized processes and the inherent challenges, this work has been extended to include quality control, software process improvement and international quality standard organization membership. It also makes comparison based on a similar study carried out in Turkey. The goal is to generate more robust findings that can properly support decision making by the software community. The qualitative research approach, specifically, the use of questionnaire research instruments was applied to acquire data from software practitioners. Results: In addition to the previous results, it was observed that quality assurance practices are quite neglected and this can be the cause of low patronage. Moreover, software practitioners are neither aware of international standards organizations or the required process improvement techniques; as such their claimed standards are not aligned to those of accredited bodies, and are only limited to their local experience and knowledge, which makes it questionable. The comparison with Turkey also yielded similar findings, making the results typical of developing countries. The research instrument used was tested for internal consistency using the Cronbach's alpha, and it was proved reliable. Conclusion: For the software industry in developing countries to grow strong and be a viable source of external revenue, software assurance practices have to be taken seriously because its effect is evident in the final product. Moreover, quality frameworks and tools which require minimum time and cost are highly needed in these countries.
  • Conference Object
    Citation - WoS: 2
    The Limit q-bernstein Operators With Varying q
    (Springer international Publishing Ag, 2019) Almesbahi, Manal Mastafa; Ostrovska, Sofiya; Turan, Mehmet
    [No Abstract Available]
  • Book Part
    Citation - WoS: 15
    Citation - Scopus: 15
    Comparison of Hematopoietic and Spermatogonial Stem Cell Niches From the Regenerative Medicine Aspect
    (Springer international Publishing Ag, 2018) Kose, Sevil; Yersal, Nilgun; Onen, Selin; Korkusuz, Petek
    Recent advances require a dual evaluation of germ and somatic stem cell niches with a regenerative medicine perspective. For a better point of view of the niche concept, it is needed to compare the microenvironments of those niches in respect to several components. The cellular environment of spermatogonial stem cells' niche consists of Sertoli cells, Leydig cells, vascular endothelial cells, epididymal fat cells, peritubular myoid cells while hematopoietic stem cells have mesenchymal stem cells, osteoblasts, osteoclasts, megacaryocytes, macrophages, vascular endothelial cells, pericytes and adipocytes in their microenvironment. Not only those cells', but also the effect of the other factors such as hormones, growth factors, chemokines, cytokines, extracellular matrix components, biomechanical forces (like shear stress, tension or compression) and physical environmental elements such as temperature, oxygen level and pH will be clarified during the chapter. Because it is known that the microenvironment has an important role in the stem cell homeostasis and disease conditions, it is crucial to understand the details of the microenvironment and to be able to compare the niche concepts of the different types of stem cells from each other, for the regenerative interventions. Indeed, the purpose of this chapter is to point out the usage of niche engineering within the further studies in the regenerative medicine field. Decellularized, synthetic or non-synthetic scaffolds may help to mimic the stem cell niche. However, the shared or different characteristics of germ and somatic stem cell microenvironments are necessary to constitute a proper niche model. When considered from this aspect, it is possible to produce some strategies on the personalized medicine by using those artificial models of stem cell microenvironment.
  • Conference Object
    Citation - WoS: 27
    Citation - Scopus: 41
    Ux Professionals' Definitions of Usability and Ux - a Comparison Between Turkey, Finland, Denmark, France and Malaysia
    (Springer international Publishing Ag, 2017) Rajanen, Dorina; Clemmensen, Torkil; Iivari, Netta; Inal, Yavuz; Rizvanoglu, Kerem; Sivaji, Ashok; Roche, Amelie
    This paper examines the views of user experience (UX) professionals on the definitions of usability and UX, and compares the findings between countries and within different socio-cultural groups. A mixed-method analysis was employed on data gathered on 422 professionals through a survey in Turkey, Finland, Denmark, France, and Malaysia. Usability appears to be an established concept, respondents across all countries agreeing on the importance of the ISO 9241-11 definition. There is also a tendency that UX professionals attach organizational perspective to usability. UX professionals diverge when defining UX, and there are systematic differences related to socio-cultural conditions. UX professionals in Finland and France incline more towards the definition highlighting the experiential qualities, when compared to Turkey and Malaysia that incline towards the definition reflecting the ease of use, utility, attractiveness, and degree of usage. Further research should address the implications of the diverse meanings and contexts of usability and UX.
  • Article
    Citation - WoS: 28
    Citation - Scopus: 33
    Coincidence Point Theorems in Quasi-Metric Spaces Without Assuming the Mixed Monotone Property and Consequences in g-metric Spaces
    (Springer international Publishing Ag, 2014) Roldan-Lopez-de-Hierro, Antonio-Francisco; Karapinar, Erdal; de la Sen, Manuel
    In this paper, we present some coincidence point theorems in the setting of quasi-metric spaces that can be applied to operators which not necessarily have the mixed monotone property. As a consequence, we particularize our results to the field of metric spaces, partially ordered metric spaces and G-metric spaces, obtaining some very recent results. Finally, we show how to use our main theorems to obtain coupled, tripled, quadrupled and multidimensional coincidence point results.
  • Conference Object
    Citation - WoS: 1
    Citation - Scopus: 1
    Disseminating the Use of Sustainable Design Principles Through Architectural Competitions
    (Springer international Publishing Ag, 2018) Toprak, Gizem Kucak
    Sustainable architectural designs have become current issue, as in other disciplines, in architecture since 1970s because of these reasons, oil shock, global warming, to be consumed natural resources, get further away from the nature. Putting into practice and increase of awareness of sustainable architectural designs become a important topic 2000s in Turkey. It's hard to reach clear information about how much designs are carried into practice. Obtaining energy efficiency certificate for new buildings has become obligatory since 1 January 2011 and it's determined that 450,815 buildings have this certificate. But this certificate evaluates energy performance of buildings only. In fact, process of sustainable design cannot be evaluated by just energy performance analysis. Efficiently use of energy, water, building land and environment, relationship with environment and buildings, benefit/damage analysis in urban area, increase of user comfort in building come into prominence. 425 buildings obtained LEED certificate that make a comprehensive investigation. As it seen, the numbers, used above, show us, it's necessary that sustainable design principles must be disseminated and the methods, are been used, must be evaluated. This work tackles architectural competitions as a method for developing and disseminating sustainable design principles. Architectural competitions are not only didactic but also developer and independent design platform which all architects can join. The results are reached the large masses over draw up a contract, design process, evaluating the projects and discussion platform, colloquium. So that the establishment, designers, the jury and the other participants are involved in an interaction. Architectural competitions can used for development, evaluation, discussion and dissemination of sustainable design principles. The aim of this work is that evaluating how to tackle "sustainability" as a term in competitions, in 2010s and in accordance with the results, offering suggestions for disseminating the use of sustainable design principles with competitions also.