311 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
Recycling of textile wastes produced in a textile business by a green approach
No full textFen Bilimleri Enstitüsü, Lif ve Polimer Mühendisliği Ana Bilim DalıDünyada ve Türkiye'de önemli sanayi kollarından biri olan tekstil sektörü, enerji yoğun prosesleri ve oluşturduğu atıklar ile çevresel çalışmaların yoğunlaştırıldığı alanlardan biri haline gelmiştir. Tekstil üretiminin temel hammaddelerinden biri olan pamuk, tüm yaşam döngüsü boyunca önemli çevresel etkilere sahip doğal bir elyaftır. Bu çevresel etkilerin minimize edilmesinde en etkili yöntemlerden biri ise, geri kazanımdır. Pamuğun çevresel etkilerini azaltmanın yanında doğal esaslı ve değerli bir hammadde olması, maliyetler açısından da geri kazanım konusunda giderek daha da önemli bir elyaf haline gelmiştir. Bu çalışmada; bir işletmede %100 pamuk iplik üretimi gerçekleştirilen ring üretim prosesleri takibi yapılarak, prosesler boyunca oluşan telef bölgelerinden numuneler alınmıştır. Alınan numunelerin öncelikli olarak ön deneme çalışmaları ile karakteristik elyaf özellikleri belirlenmiştir. Elde edilen veriler ışığında OE-Rotor ve ring iplik eğirme sistemlerinde üretim denemeleri gerçekleştirilmiş ve ipliklerin performans özellikleri incelenmiştir. Daha sonraki adımda ise; dokuma kumaş üretimleri gerçekleştirilerek, kumaşların performans özellikleri test edilmiştir. Ayrıca teleflerden geri dönüşüm iplik üretim prosesleri takip edilerek, telef geri kazanım metotlarının Yaşam döngü değerlendirmesi (YDD) analizi yapılmış ve çevresel etki değerlendirmeleri gerçekleştirilmiştir. Türkiye'de tekstil atıkları uzun yıllardır geri kazanılmaktadır ve bu konuda önemli bir bilgi alt yapısı da mevcuttur. Ancak Türkiye'deki pamuk geri kazanım sektörünün en önemli sorunları ise, kalın ve düşük kalitede, katma değeri düşük iplik üretimi ve ürün çeşitliliğinin az olmasıdır. Dünyada son yıllarda telef/atık geri kazanımı yeni bir boyut kazanmış ve atıklardan yüksek katma değerli ürün eldesi önem kazanmıştır. Gerçekleştirilen bu çalışma, daha ince ve kaliteli iplik ve ürün üretimi için diğer araştırma ve geliştirme çalışmalarına ışık tutacaktır.The textile industry is one of the most important industries in the world and Turkey, energy has become one of the areas where intensive work with the intensification of environmental processes and the waste it generates. Cotton, one of the basic raw materials of textile production, is a natural fiber with significant environmental impact throughout the entire life cycle. One of the most effective methods to minimize these environmental effects is recovery. In addition to reducing the environmental impact of cotton, it has become an increasingly important fiber in terms of costs as well as being a natural and valuable raw material. In this study; the ring production processes in which 100% cotton yarn production was carried out in one operation were taken and samples were taken from the waste regions formed during the processes. Preliminary trials and characteristic fiber properties of the receiving samples were determined primarily. Experiments on production of OE-Rotor and ring spinning systems were performed and the performance characteristics of yarns were investigated. In the next step; woven fabrics were produced and the performance characteristics of the fabrics were tested. In addition, recycling yarn production processes were followed from the waste, life cycle assessment (LCA) analysis of waste recovery methods was performed and environmental impact assessments were carried out. Textile waste recovered in Turkey for many years and the infrastructure is an important information on this subject is also available. But the most important problems of the cotton sector recovery in Turkey, thick and of low qualit, added value is less than the lower yarn production and product variety. In recent years, waste/waste recovery has gained a new dimension in the world and the acquisition of high value-added products from wastes has gained importance. This study will shed light on other and development for more fine and high quality yarn and product production
Some Fixed-Point Theorems for Multivalued Monotone Mappings in Ordered Uniform Space
No full text We use the order relation on uniform spaces defined by Altun and Imdad (2009) to prove some new fixed-point and coupled fixed-point theorems for multivalued monotone mappings in ordered uniform spaces.</p
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
Büyük veri kullanılarak raf yerinin konumlandırılması
No full textABSTRACT: Big data practices and related to this allocation of the right shelf place in supermarkets is a new approaches; for retailers searching for new ways to sell their products through the various kinds of stores, categories. In order to have successful sales and profit maximization, companies have to focus on the right shelf place, that supermarket chains and suppliers are racing to answer these days. It is believed that there are products relationship matrix that may have an influence on consumers on different categories, and these are relational and locational factors. This research was made in order to identify the best shelf place allocations for the supplier to replace product categories that have an effect on increasing sales performance. The results were obtained through current sales analysis, what are the actual sales in reality and comparing what could be much more if our big data model applies to change shelf place, and all these applications resulted to show very clearly that this analysis does help is increasing the total number of sales. Although big data helps us to find the right shelf place location for products for categories, but in terms of more profitable products supermarkets focus on the advantage of profit maximization when they decide to choose right shelf place.ÖZET: Bu tezin temel amacı, süpermarketlerdeki büyük veri uygulamalarıyla raf yeri performansının ölçülmesi, doğru lokasyonun büyük dataya bakılarak tespit edilmesi ve diğer şubeler ile karşılaştırılması; yeni metodlarla ürünler, mağazalar, kategoriler ve müşterilerin satın alma süreçlerini büyük dataya bağlı olarak ürün yerleşiminde ulaşılabilecek maksimum verimliliğe çıkartılmasıdır. Başarılı satış süreci ve kar maksimizasyonu elde etmek için süpermarket zincirleri ve tedarikçiler doğru ürünü, doğru raf yerinde, doğru zamanda yerleştirmelidir. Bu tezde, yazar kasalardan gelen ham data, ürün ilişkisi matrisinin tüketiciler için farklı kategoriler üzerinde etkisi olduğunu gösteriyor ve bu etkilerin ilişkisel ve konumsal faktörler olduğunu tespit ediyoruz. Bu araştırma, satış performansını arttırmada etkisi olan ürünün yer seçimi, tedarikçi ürün kategorileri için en uygun raf yeri tahsislerini belirlemek amacıyla yapılmıştır. Sonuçlar şu anki satış analiziyle, gerçek satışların ne olduğu üzerinden büyük veri modelimiz kullanılarak raf yerini değiştirmek için maksimum performas gösteren şubelere bakarak uygulandığında, açık ve net satışı arttıran sonuçlar elde edilmiştir. Elbetteki bu veriler bize ürünler için mağazadaki ideal lokasyonu göstersede, ancak supermarketler raf seçimi yaparken kar marjı doğrultusunda ürünleri satışa çıkarmaktadırlar
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
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