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Article Citation - WoS: 3Citation - Scopus: 4On the Fixed Points of Iterative Contractive Mappings Defined Via Implicit Relation(Taylor & Francis Ltd, 2021) Aksoy, Umit; Erhan, Inci M.; Fulga, Andreea; Karapinar, ErdalIn this paper, we consider an implicit relation to generalize iterative fixed point results in the literature in the context of metric spaces. We conclude that several existing results are immediate consequences of our main results.Article Citation - WoS: 8Citation - Scopus: 15Identification of Linear Handling Models for Road Vehicles(Taylor & Francis Ltd, 2008) Arikan, K. B.; Unlusoy, Y. S.; Korkmaz, I.; Celebi, A. O.This study reports the identification of linear handling models for road vehicles starting from structural identifiability analysis, continuing with the experiments to acquire data on a vehicle equipped with a sensor set and data acquisition system, and ending with the estimation of parameters using the collected data. The model structure originates from the well-known linear bicycle model that is frequently used in handling analysis of road vehicles. Physical parameters of the bicycle model structure are selected as the unknown parameter set that is to be identified. Global identifiability of the model structure is analysed, in detail, and concluded according to various available sensor sets. Physical parameters of the bicycle model structure are estimated using prediction error estimation method. Genetic algorithms are used in the optimisation phase of the identification algorithm to overcome the difficulty in the selection of initial values for parameter estimates. Validation analysis of the identified model is also presented. The identified model is shown to track the system response successfully.Article On the Injectivity With Respect To q of the Lupas q-transform(Taylor & Francis Ltd, 2024) Yilmaz, Ovgue Gurel; Ostrovska, Sofiya; Turan, Mehmet; Gurel Yilmaz, OvguThe Lupas q-transform has first appeared in the study of the Lupas q-analogue of the Bernstein operator. Given 0 < q < 1 and f is an element of C[0, 1], the Lupas q-transform is defined by Lambda(q)(f; x) Pi(infinity)(k=0) 1/1 + q(k)x Sigma(k=0)f(1 - q(k))q(k(k-1)/2)x(k)/(1 - q)(1 - q(2)) center dot center dot center dot (1 - q(k)), x >= 0. During the last decades, this transform has been investigated from a variety of angles, including its analytical, geometric features, and properties of its block functions along with their sums. As opposed to the available studies dealing with a fixed value of q, the present work is focused on the injectivity of Lambda(q) with respect to parameter q. More precisely, the conditions on f such that equality Lambda(q)(f; x) = Lambda(r)(f; x); x >= 0 implies q = r have been established.Article Citation - WoS: 8Citation - Scopus: 10Biomechanical Effects of Two Different Collar Implant Structures on Stress Distribution Under Cantilever Fixed Partial Dentures(Taylor & Francis Ltd, 2011) Meric, Gokce; Erkmen, Erkan; Kurt, Ahmet; Eser, Atilim; Ozden, Ahmet UtkuObjective. The purpose of the study was to compare the effects of two distinct collar geometries of implants on stress distribution in the bone around the implants supporting cantilever fixed partial dentures (CFPDs) as well as in the implant-abutment complex and superstructures. Materials and methods. The three-dimensional finite element method was selected to evaluate the stress distribution. CFPDs which was supported by microthread collar structured (MCS) and non-microthread collar structured (NMCS) implants was modeled; 300 N vertical, 150 N oblique and 60 N horizontal forces were applied to the models separately. The stress values in the bone, implant-abutment complex and superstructures were calculated. Results. In the MCS model, higher stresses were located in the cortical bone and implant-abutment complex in the case of vertical load while decreased stresses in cortical bone and implant-abutment complex were noted within horizontal and oblique loading. In the case of vertical load, decreased stresses have been noted in cancellous bone and framework. Upon horizontal and oblique loading, a MCS model had higher stress in cancellous bone and framework than the NMCS model. Higher von Mises stresses have been noted in veneering material for NMCS models. Conclusion. It has been concluded that stress distribution in implant-supported CFPDs correlated with the macro design of the implant collar and the direction of applied force.Article Enhancing Machining Efficiency and Sustainability of Ti-6Al-4V Through Minimum Quantity Lubrication With Ester-Based Oils(Taylor & Francis Ltd, 2025) Namlu, Ramazan Hakki; Kavut, Kuebra; Tom, Hanife GulenTi-6Al-4 V is known as difficult-to-cut due to its low thermal conductivity and high chemical reactivity. While cutting fluids aid lubrication and reduce friction, Conventional Cutting Fluids (CCF) have high consumption, limited efficiency gains and negative environmental and health effects. Therefore, there is an ongoing search for more sustainable alternatives to CCF that do not adversely affect machining performance. Minimum Quantity Lubrication (MQL), which delivers compressed air - oil aerosol, has emerged as a promising solution by drastically reducing fluid use and associated risks. Selecting the right MQL fluid is key to optimising machining performance. This study evaluates MQL fluids based on polyol and polymeric esters for Ti-6Al-4 V machining and compares their performance with CCF. Cutting forces, surface roughness and topography are examined. Results show that MQL reduces cutting forces up to 21.7% and surface roughness up to 57.6% compared to CCF, with more uniform surface topography. Among MQL oils, polymeric esters perform better than polyol esters, with a reduction in cutting force up to 14.6% and surface roughness up to 47.7%. High viscosity indexed polymeric esters showed the best overall performance due to their thermal stability. Moreover, according to the sustainability assessment analysis polymeric esters were identified as the most sustainable option.Article Citation - WoS: 2Citation - Scopus: 2Finite Element Analysis of Stress Distribution on Modified Retentive Tips of Bar Clasp(Taylor & Francis Ltd, 2012) Oyar, P.; Soyarslan, C.; Can, G.; Demirci, E.This study used finite element analysis to evaluate the retentive tips of bar clasps made from different alloys and using different designs in order to determine whether or not different materials and tip forms are suitable for bar clasp applications. Co-Cr, Ti and Type IV Au alloys were selected based on their physical and mechanical properties. The 3D finite element models of three different bar clasp retentive tip geometries prepared from Co-Cr, Ti and Type IV Au alloys were constructed using the finite element software package MSC. Marc. Analysis of a concentrated load of 5N applied to the removable partial denture approach arms in an occlusal direction was performed. Although stress distribution and localisation within bar clasps with different retentive tips were observed to be similar and were concentrated in the approach arm, stress intensities differed in all models.Article Citation - WoS: 12Citation - Scopus: 19An Ontology-Based Multi-Agent Virtual Enterprise System (omave): Part 1: Domain Modelling and Rule Management(Taylor & Francis Ltd, 2017) Sadigh, Bahram Lotfi; Unver, Hakki Ozgur; Nikghadam, Shahrzad; Dogdu, Erdogan; Ozbayoglu, A. Murat; Kilic, S. EnginNew advancements in computers and information technologies have yielded novel ideas to create more effective virtual collaboration platforms for multiple enterprises. Virtual enterprise (VE) is a collaboration model between multiple independent business partners in a value chain and is particularly suited to small and medium-sized enterprises (SMEs). The most challenging problem in implementing VE systems is ineffcient and inFLexible data storage and management techniques for VE systems. In this research, an ontology-based multi-agent virtual enterprise (OMAVE) system is proposed to help SMEs shift from the classical trend of manufacturing part pieces to producing high-value-added, high-tech, innovative products. OMAVE targets improvement in the FLexibility of VE business processes in order to enhance integration with available enterprise resource planning (ERP) systems. The architecture of OMAVE supports the requisite FLexibility and enhances the reusability of the data and knowledge created in a VE system. In this article, a detailed description of system features along with the rule-based reasoning and decision support capabilities of OMAVE system are presented. To test and verify the functionality and operation of this system, a sample product was manufactured using OMAVE applications and tools with the contribution of three SMEs.Article Citation - WoS: 252Citation - Scopus: 355Supply Chain Performance Measurement: a Literature Review(Taylor & Francis Ltd, 2010) Akyuz, Goknur Arzu; Erkan, Turan Erman; Erman Erkan, Turan; Arzu Akyuz, GoknurThis paper is intended to provide a critical literature review on supply chain performance measurement. The study aims at revealing the basic research methodologies/approaches followed, problem areas and requirements for the performance management of the new supply chain era. The review study covers articles coming from major journals related with the topic, including a taxonomy study and detailed investigation as to the methodologies, approaches and findings of these works. The methodology followed during the conduct of this research includes starting with a broad base of articles lying at the intersection of supply chain, information technology (IT), performance measurement and business process management topics and then screening the list to have a focus on supply chain performance measurement. Findings reveal that performance measurement in the new supply era is still an open area of research. Further need of research is identified regarding framework development, empirical cross-industry research and adoption of performance measurement systems for the requirements of the new era, to include the development of partnership, collaboration, agility, flexibility, information productivity and business excellence metrics. The contribution of this study lies in the taxonomy study, detailed description and treatment of methodologies followed and in shedding light on future research.Article Citation - WoS: 3Citation - Scopus: 3Inverse Spectral Problem for Finite Jacobi Matrices With Zero Diagonal(Taylor & Francis Ltd, 2015) Aydin, Ayhan; Guseinov, Gusein Sh.In this study, the necessary and sufficient conditions for solvability of an inverse spectral problem about eigenvalues and normalizing numbers for finite-order real Jacobi matrices with zero diagonal elements are established. Anexplicit procedure of reconstruction of the matrix from the spectral data consisting of the eigenvalues and normalizing numbers is given. Numerical examples and error analysis are provided to demonstrate the solution technique of the inverse problem. The results obtained are used to justify the solving procedure of the finite Langmuir lattice by the method of inverse spectral problem.Article Citation - WoS: 4Citation - Scopus: 5In Vitro Evaluation of Tooth-Colored Yttria Stabilized Zirconia Ceramics(Taylor & Francis Ltd, 2021) Akarsu, Melis Kaplan; Basar, Ahmet Ozan; Sasmazel, Hilal Turkoglu; Park, Jongee; Ozturk, AbdullahEffects of MoCl3 and NiCl2, originally incorporated as coloring agent, on the cellular response of 3 mol% yttria stabilized zirconia (3Y-TZP) ceramics was investigated. MoCl3 and NiCl2-MoCl3 incorporated, tooth-colored 3Y-TZP ceramics were produced through cold isostatic pressing at 100 MPa followed by pressureless sintering at 1450 degrees C for 2 h. Aging was performed on the sintered ceramics using distilled water in a reactor at 134 degrees C at 2.3 bar pressure for 2 h. The phases developed during different stages of processing were identified by X-ray diffraction (XRD) analysis. In vitro cell culture studies were carried out using L929 fibroblast cell line. The cell viability and proliferation studies revealed that none of the specimens showed cytotoxicity with respect to coloring. Confocal laser scanning microscope (CLSM) analyses suggested that all of the specimens exhibited good in vitro cytocompatibility. Enhancement in cell attachment, adhesion, and proliferation was observed in all specimens via scanning electron microscope (SEM) analysis. Although the coloring process did not improve the proliferation performance of the aged specimens, the incorporation of transition metals enhanced the in vitro performance of 3Y-TZP ceramics.
