125 research outputs found
Pseudo Picard Operators On Generalized Metric Spaces
No full textAltun, Ishak/0000-0002-7967-0554; Samet, Bessem/0000-0002-6769-3417In this paper, we present a new class of pseudo Picard operators in the setting of generalized metric spaces introduced recently in [M. JLELI AND B. SAMET: A generalized metric space and related fixed point theorems, Fixed Point Theory Appl., (2015) 2015:61]. An example is provided to illustrate the main result.Deanship of Scientific Research at King Saud UniversityDeanship of Scientific Research at King Saud University [RGP-237]The second author extends his appreciation to the Deanship of Scientific Research at King Saud University for funding this work through research group No RGP-237
An extension of Assad-Kirk's fixed point theorem for multivalued nonself mappings
No full textAltun, Ishak/0000-0002-7967-0554In the present paper, taking into account the recent developments on the theory of fixed point, we give some fixed point results for multivalued nonself mappings on complete metrically convex metric spaces. Our main result properly includes the famous Assad-Kirk fixed point theorem for nonself mappings. Also, we provide a nontrivial example which shows the motivation for such investigations of multivalued nonself contraction mappings.TUBITAKTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK)The authors are grateful to the referees because their suggestions contributed to improve the paper. The second author would like to thank TUBITAK for their financial supports during his PhD studies
Fixed point theorems for Ćirić-type strong almost contractions on partial metric spaces
No full textBerinde, Vasile/0000-0002-3677-795X; Altun, Ishak/0000-0002-7967-0554; Berinde, Vasile/0000-0002-3677-795XIn the present paper we prove some fixed point theorems for A dagger iriA double dagger-type strong almost contractions on partial metric spaces. We also give an illustrative example.Romanian Ministry of Education and Research [PN-II-RU-TE-2011-3-239]The authors are grateful to the referees because their suggestions contributed to improve the paper. The second author research was supported by the Grant PN-II-RU-TE-2011-3-239 of the Romanian Ministry of Education and Research
Characterizations of partial metric completeness in terms of weakly contractive mappings having fixed point
No full textWe characterize both complete and 0-complete partial metri
c spaces in terms
of weakly contractive mappings having a fixed point. Our resu
lts extend
a well-known characterization of metric completeness due t
o
Suzuki
and
Takahashi
to the partial metric frameworkThe authors are grateful to the referees because their suggestions contributed to improve the paper. The second named author thanks the support of the Ministry of Science and Innovation of Spain, grant MTM2009-12872-C02-01.Altun, I.; Romaguera Bonilla, S. (2012). Characterizations of partial metric completeness in terms of weakly contractive mappings having fixed point. Applicable Analysis and Discrete Mathematics. 6(2):247-256. https://doi.org/10.2298/AADM120322009AS2472566
Caristi's type mappings on complete partial metric spaces
No full text[EN] We introduce a new type of Caristi's mapping on partial metric spaces and show that a partial metric space is complete if and only if every Caristi mapping has a fixed point. From this result we deduce a characterization of bicomplete weightable quasi-metric spaces. Several illustrative examples are given.The third author thanks the support of the Spanish Ministry of Science and Innovation, grand MTM2009-12872-C02-01.Acar, Ö.; Altun, I.; Romaguera Bonilla, S. (2013). Caristi's type mappings on complete partial metric spaces. Fixed Point Theory. 14(1):3-10. https://riunet.upv.es/handle/10251/56874S31014
Caristi's Type Mappings On Complete Partial Metric Spaces
No full textAltun, Ishak/0000-0002-7967-0554We introduce a new type of Caristi's mapping on partial metric spaces and show that a partial metric space is complete if and only if every Caristi mapping has a fixed point. From this result we deduce a characterization of bicomplete weightable quasi-metric spaces. Several illustrative examples are given.Spanish Ministry of Science and InnovationSpanish Government [MTM2009-12872-C02-01]The third author thanks the support of the Spanish Ministry of Science and Innovation, grand MTM2009-12872-C02-01
A stationary point theorem for multivalued θ-contractions
No full textAltun, Ishak/0000-0002-7967-0554This paper is mainly devoted to a positive answer, with a new aspect, of the problem considered by Hanc, er et al. in [11] concerning multivalued version of theta - contraction which have been recently introduced by Jleli and Samet [15]. Considering delta - distance between two bounded subsets of a metric space, we provide a stationary point results for multivalued theta - contractions.TUBITAK (The Scientific and Technological Research Council of Turkey)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK)The authors were grateful to the reviewers for useful suggestions which improve the contents of this paper. The first author would like to thank TUBITAK (The Scientific and Technological Research Council of Turkey) for their financial supports during his PhD studies
Selçuk Altun'un romanlarında kültürel kaynaklar
No full textSelçuk Altun, (d. 1950) 2000’li yılların başlarıyla birlikte eser vermeye başlamış bir romancıdır. Yazarın hâlihazırda 10 tane romanı bulunmaktadır. Anlatıcılarını bilgili, kültürlü, estetik zevki gelişmiş kişiler olarak tasarladığından romanları kültürel açıdan zengin bir hal almıştır. Bu durum ise yazarın romanlarındaki kültürel kaynaklara yönelik bir çalışma gerçekleştirmemizi sağlamıştır. Çalışma, üç ana bölümden oluşmaktadır. İlk bölümde Selçuk Altun’un yaşamı, yapıtları verilmiş ve romancılığı irdelenmiştir. İkinci bölüm; kültür sözcüğünün kökeninin nereden geldiğinin açıklandığı, sözcük anlamının zamanla yaşadığı değişiklere değinildiği ve son olarak felsefe, antropoloji, sosyoloji ve edebiyat dünyasındaki kişilerin kültür kavramıyla ilgili yaptığı tanımlamaların verildiği bölümdür. Bu tanımlamalardan hareketle Selçuk Altun’un romanlarındaki kültürel kaynakların hangi başlıklar altında incelenmesi gerektiğine karar verilmiştir. Üçüncü bölümde Selçuk Altun’un romanlarındaki kültürel kaynaklar sanat, bilim ve diğer kültürel kaynaklar çatısı altında incelenmiştir. İlk olarak sanat başlığı altında yazarın romanlarında yer alan edebiyat, resim, müzik, heykel, mimari ve sinema ile ilgili ögeler hakkında bilgi verilmiş ve bu ögelerin Selçuk Altun’un romanlarındaki konumuna değinilmiştir. İkinci olarak bilim başlığı altında Selçuk Altun’un romanlarındaki arkeolojik ve tarihsel unsurlar incelenmiştir. Yapıtlarında ülkemizdeki arkeolojik eser hırsızlığının önüne geçilememesini eleştirmiştir. Böylece romanlarında arkeolojik eserler de yer almıştır. Sanat bölümündekine benzer bir yolla arkeolojik eserler hakkında da bilgi verilmiştir. Bilim başlığı altında arkeolojik eserlerden sonra tarihî olaylar incelenmiştir. Çalışmada yalnızca kültür tarihini etkileyen tarihî hadiseler sanat bölümündeki yol izlenerek ele alınmıştır. Üçüncü bölümün son alt başlığında Selçuk Altun’un romanlarında yer alan dinsel ögeler, kütüphaneler ve müzeler sıralanmış ve sonuç bölümüne geçilmiştir. Bu bölümde yazarın hangi amaçla romanlarını kültürel açıdan zengin kıldığı açıklanmıştır.Mr. Selçuk Altun (b.1950) is a novelist who published his first book in the begining of the year 2000. As of the year 2021, he already have written 10 novels. Since he fictionalised his narratorial charactors as intelligent, highbrowed people of having aesthetic pleasure, the literary and artistry contents are very rich in his works. This being the case, a study have been carried out with reference to the cultural resources of which were given high coverage in the author’s books. This study is comprised of 3 sections. In the first section information about his life and books has been given and novelism worked though. The root of the word ‘’culture’’and the changes of its meaning in time have been explained in section two as well as have been given different definitions of ‘’culture’’ that had been make by some intellectuals of societies of philosophy, antropology, sociology and literature on the basis of this definitions it has been decided on which titles the cultural resources would be examined. In section three, the cultural resources that were mentioned in Mr. Altun’s novels have been analysed under the titles of art, science, and others firstly, some information about literature, art, music, sculpture, architecture and cinema has been given with references to the stand points of such within the novels. Secondly archeological and historical elements under the title of ‘’science’’ have been examined. The author critised the failure to prevent smuggling of historical artifacts giving knowledge of some of those in his novels. Historical events that had influenced the cultural history were considered in a similar way as done under title ‘’art’’. Under the last subtitle of section three religious items, libraries and museums have been listed in reference to same that had been mentioned in the author’s novels. In the conclusion, the reasons of author’s fictionalising his novels very intensively on cultural elements has been explained
Yüksek performanslı betonun basınç dayanımının farklı makine öğrenimi algoritmaları ile tahmin edilmesi
No full textCompressive strength of concrete is influenced by various factors including the amount and properties of concrete components, age, environmental conditions and experimental conditions. Machine learning algorithms are emerging as an alternative method for determining the compressive strength of concrete which is one of its most critical properties. In this study six different machine learning models were employed to predict the compressive strength of high-performance concrete using an open dataset of 1030 samples. Additionally the impact of incorporating newly derived features into the existing dataset on the prediction process was examined. The contribution of these new features to the performance of the algorithms was evaluated and the algorithms yielding the best results were analyzed. According to the results XGBoost and LightGBM demonstrated the best performance in terms of prediction accuracy and computational efficiency. Moreover, adding two new features to the dataset improved the predictive accuracy of the employed machine learning algorithmsBetonun basınç dayanımı, beton bileşenlerinin miktarları ve özellikleri, yaşı, ortam koşulları, deneysel koşullar gibi birçok faktörden etkilenmektedir. Betonun en önemli özelliği olan basınç dayanımının belirlenmesi amacıyla makine öğrenimi algoritmaları alternatif bir yöntem olarak kullanılmaktadır. Bu çalışmada, yüksek performanslı betonun basınç dayanımını tahmin etmek amacıyla 1030 satırlık açık veri seti üzerinde altı farklı makine öğrenimi modeli kullanılmıştır. Ayrıca mevcut veri setine türetilen yeni öznitelikler ilave edilerek betonun basınç dayanımını tahmin etme süreçlerindeki etkileri incelenmiştir. Bu bağlamda yeni özniteliklerin algoritmaların performansına olan katkısı değerlendirilmiş ve hangi algoritmaların en iyi sonuçları verdiği analiz edilmiştir. Elde edilen sonuçlara göre doğru tahmin etme yeteneği ve süre açısından en iyi sonucu XGBoost ve LightGBM algoritmaları göstermiştir. Buna ilaveten, veri setine iki yeni öznitelik daha eklenmesi kullanılan makine öğrenimi algoritmalarının doğru tahmin etme yeteneğini arttırmıştır
The biocompatibility and characterization of aromatic thermosetting copolyester
No full textThe current designs of new biomaterials for bone substitutes or scaffolds focus on achieving biocompatibility and sufficient mechanical properties. In this thesis, we investigated the biocompatibility of synthetic polymers called aromatic thermosetting copolyesters (ATSP) as potential biomaterials for bone replacements (implants). These materials are easy to manufacture and have good mechanical properties such as high tensile strength, and high wear resistance. They can be made into bulk, film, foams, and composites. In this thesis, we included all these forms and created a composite by infusing ATSP with 10wt% of hydroxyapatite (minerals of similar compositions as those found in bone). Homogenous distribution of the HA filler improves the physical properties of composite ATSP. In addition to this, having robust adhesive features with metals, high energy absorption limit, and promising tribological properties makes ATSP a strong candidate for different orthopedic implant applications.
This research extended an earlier biocompatibility study of ATSP in which direct contact of fibroblasts cells was used to study of neat ATSP and ATSP blends with ultrahigh molecular weight polyethylene (UHMWPE) for total joint arthroplasty. The results demonstrated that cells were able to attach to ATSP, and there was no indication of cell death [1]. Since these previous results looked promising, in this thesis we conducted more extensive studies of the biocompatibity of ATSP.
Chapter 1 describes the biocompatibility investigation of three different compositions (film, bulk, and foam) of neat and composite ATSP by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT assay) with human osteoblast cell line (hFOB 1.19 (ATCC® CRL 11372™)), and the results were obtained from the metabolic activity of hFOB 1.19 cells for 48 hours. The results which were either equal to or greater than 85% were accepted as non-cytotoxic, the values between 60% and 85% were defined as slightly cytotoxic, 30%– 59% were moderately cytotoxic and less than 30% were accepted severely cytotoxic. The results of metabolic activity by MTT showed that each group (film, bulk, and foam) of neat and composite ATSP samples did not demonstrate any toxicity at all concentrations (≥85%) except for neat film samples which showed slight toxicity (~75%). Overall the results for each group were consistent between neat and composite samples. Furthermore, the increase in the concentration did not change the results. The presence of HA was used to investigate the effect of HA on increasing the metabolic cell activity; however, there was no increase in cell activity with the presence of the HA.
Chapter 2 highlights the neat and composite foams that were designed to analyze the effect of biomaterial physical features, including porosity and mineral content over the bone formation by human mesenchymal stem cells differentiation. The analysis was done by alamarBlue® and RT-PCR assays. The metabolic activity results of foam samples by alamarBlue® with MSCs showed that none of the samples demonstrated any toxic effect; the metabolic activity for all samples was higher than initial metabolic activity values. All samples allowed cell proliferation and cell growth. Also, not only mineralized samples but also osteogenic media positively affected the metabolic activity because the composite samples showed high metabolic activity than neat samples on the day seven. Also, samples in osteogenic media demonstrated the high metabolic activity in comparison with sample in growth media on day seven. RT-PCR results showed that the samples in osteogenic media showed upregulated pattern for all gene expressions. It could also be interpreted that neat and mineralized samples in combination with pure osteogenic media promoted osteogenesis and allowed new bone formation.Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2020-08-01The student, Esra Altun, accepted the attached license on 2018-07-19 at 17:40.The student, Esra Altun, submitted this Thesis for approval on 2018-07-20 at 15:13.This Thesis was approved for publication on 2018-07-20 at 17:08.DSpace SAF Submission Ingestion Package generated from Vireo submission #12945 on 2018-09-27 at 11:19:39Made available in DSpace on 2018-09-27T16:34:24Z (GMT). No. of bitstreams: 2
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Previous issue date: 2018-07-20Embargo set by: Seth Robbins for item 107832
Lift date: 2020-09-27T16:34:29Z
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