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Öğe Investigation of plasma arc cutting parameters with type-2 fuzzy set and system(De Gruyter, 2013-10) Çelik, Yahya Hışman; Özek, Cebeli; Bulut Özek, MüzeyyenThe objective of the present study was it to design a type-2 fuzzy set and system in order to predict surface roughness and hardness depending on the parameters (material thickness, cutting speed, arc voltage and current) of the plasma arc cutting process of S235JR sheet materials. Therefore, some experimental studies were conducted. The experimentally determined data were used to describe the type-2 fuzzy set and system. Type-2 fuzzy set and system was found to be usefull to predict surface roughnes and hardness. According to the obtained values, the best surface roughness and the values closest to the hardness of the raw material were obtained at 1500 mm/min cutting speed, 8 mm material thickness, 115 V arc voltage and 80 A current.Öğe An exergy analysis of a concentric tube heat exchanger using hBN-water nanofluids(Inder Science Publishers, 2021) Budak Ziyadanoğulları, Neşe; Perçin, SüleymanThis study investigated the effects of using nanofluids prepared with hexagonal boron nitride (hBN) nanoparticles on the thermal performance and pressure drop of a concentric tube heat exchanger. Experiments were carried out with water-hBN nanofluids for stable, dispersed, 0.01%, 0.1% and 1% volume concentrations, at different flow rates and Reynolds numbers under parallel and counter-flow conditions. When the experimental results were examined, the exergy loss was higher in the parallel-flow heat exchanger compared to the counter-flow heat exchanger. The highest exergy loss value was obtained for distilled water at the highest Reynolds number (Re = 8,700) for parallel flow operation at 170 W. The exergy loss of water at the highest Reynolds number (Re = 8,700) for parallel flow operation increased by 15.7%, 24.8% and 49.8% for hBN-water concentrations of 0.01%, 0.1% and 1%, respectively. Exergy loss of water at the highest Reynold number (Re = 8,700) for counter flow operation increased by 11.3%, 17.3% and 29.2% for hBN-water concentrations of 0.01%, 0.1% and 1%, respectively. When evaluating the exergy analysis of the system, exergy losses due to pressure drops were negligible for both flows (parallel and counter).Öğe A novel approach for spam email detection based on shifted binary patterns(Wiley-Blackwell, 2016-01-11) Kaya, Yılmaz; Ertuğrul, Ömer FarukAdvances in communication allow people flexibility to communicate in various ways. Electronic mail (email) is one of the most used communication methods for personal or business purposes. However, it brings one of the most tackling issues, called spam email, which also raises concerns about data safety. Thus, the requirement of detecting spams is crucial for keeping the users safe and saving them from the waste of time while tackling those issues. In this study, an effective approach based on the probability of the usage of the characters that has similar orders with respect to their UTF-8 value by employing shifted one-dimensional local binary pattern (shifted-1D-LBP) was used to extract quantitative features from emails for spam email detection. Shifted-1D-LBP, which can be described as an ordered set of binary comparisons of the center value with its neighboring values, is a content-based approach to spam detection with low-level information. To validate the performance of the proposed approach, three benchmark corpora, Spamassasian, Ling-Spam, and TREC email corpuses, were used. The average classification accuracies of the proposed approach were 92.34%, 92.57%, and 95.15%, respectively. Analysis and promising experimental results indicated that the proposed approach was a very competitive feature extraction method in spam email filtering.Öğe Türkistan’dan Tunceli’ye kurban inancı(Geleneksel Yayıncılık, 2017) Arslan, YusufToplumdan topluma kurbana yüklenen anlam, kurban kesim şekli, kurban sunuları değişiklik gösterse de, çoğunlukla her dinde ve gelenekte kurban, günahlardan arınma, tövbe, şükür gibi amaçlarla yapılmaktadır. 4000 yıllık bir tarihe sahip olan Türklerin gelenekleri incelendiğinde, kurban kesme ritüelinin eskiden beri sürdürüldüğü anlaşılmaktadır. İslamiyet’e dâhil olduktan sonra Türklerin kurban ritüellerinde bazı değişimler yaşanmıştır. Bazı ritüeller uygulamadan kalkarken bazıları yaşatılmıştır. Örneğin, eski Türklerde kurbanların başında gelen at, İslamiyet ile birlikte yerini koç, koyun, keçi, sığır gibi hayvanlara bırakmış ve at kurban etme geleneği unutulmuştur. Bununla birlikte, Şaman ayinlerinde kurban kesilmesi, mum yakılması geleneğinin Alevilerin cem ritüeli vesilesiyle olduğu gibi yaşatıldığı görülmektedir. Günümüzde, Aleviler arasında, eski Türk gelenek, görenek ve dinine ait motifler canlı şekilde izlenebilmektedir. Örneğin, Aleviler İslam’ı benimsemiş olmalarına karşın, İslam ile beraber eski Türklerin şaman/kam inancı, kopuz eşliğinde ibadet etme, sema, kadın/erkek bir arada ibadet etme, atalar kültü, dağ, ağaç ve nehirlere kutsallık atfetme biçimindeki inançlarını terk etmemişlerdir. İbadet dillerini de olduğu şekliyle, yani Türkçe olarak korumuşlardır. Alevilerin kurban ritüelleri, kimi değişimlere uğramışsa da, eski Türklerdeki birçok ritüeli bünyesinde korumuştur ve Aleviler yüzyıllardır eski Türk geleneklerindeki şekliyle kurbanlarını kesmişlerdir. Bu makalede, eski Türklerdeki kurban ritüelleriyle Tunceli Alevilerinin halk inançlarındaki kurban ritüeli karşılaştırılmış, benzerliklerin tespitine çalışılmıştır. Araştırma, nitel araştırma yöntemine göre gerçekleştirilmiştir. Araştırmanın verileri, 2015-2016 yıllarında Tunceli ve ilçelerinde, ziyaret yerlerinde yapılan yüz yüze mülakatlardan elde edilmiştir. Toplam görüşmeci sayısı sekiz olup görüşmeciler Tunceli il nüfusuna kayıtlıdır. Araştırmanın verileri, eski Türklerin kurban pratikleri ile Tunceli Alevilerinin kurban pratiklerinin dayandığı ortak bir geleneksel temel yapı olduğunu göstermiştir. Bir başka ifadeyle, Alevilerin kurban sunu/sungusu pratiklerinde, eski Türk geleneklerinin önemli oranda korunmuş olduğu anlaşılmıştır.Öğe PID controller design for controlling integrating processes with dead time using generalized stability boundary locus(IFAC Secretariat, 2018) Atiç, Serdal; Çökmez, Erdal; Peker, Fuat; Kaya, İbrahimThis paper proposes a method so that all PID controller tuning parameters, which are satisfying stability of any integrating time delay processes, can be calculated by forming the stability boundary loci. Processes having a higher order transfer function must first be modeled by an integrating plus first order plus dead time (IFOPDT) transfer function in order to apply the method. Later, IFOPDT process transfer function and the controller transfer function are converted to normalized forms to obtain the stability boundary locus in (KKcT, KKc(T2 / Ti)), (KKcT, KKcTd) and (KKc(T2/Ti), KKcTd) planes for PID controller design. PID controller parameter values achieving stability of the control system can be determined by the obtained stability boundary loci. The advantage of the method given in this study compared with previous studies in this subject is to remove the need of re-plotting the stability boundary locus as the process transfer function changes. That is, the approach results in somehow generalized stability boundary loci for integrating plus time delay processes under a PID controller. Application of the method has been clarified with examples.Öğe An analysis of sport managers' work stress levels in various variables(Horizon Research Publishing, 2018-12) Kılınç, Zühal; Dinçer, NevzatThis paper was conducted to measure the psychological and psychosomatic symptoms related with the sport managers’ work stress in public sector and federations. In this research, total 185 sport managers including 31 sport managers from the Central Organization of Sport General Directorate, 113 sport managers from the provincial organization, 41 sport managers from the Independent Sport Federations were included. The relevant managers were applied the work stress scale developed by Houso and Rizzo (1972). According to the results of the research, as sport managers get older, the averages of work stress seem to increase. In younger sport managers, the averages of work stress were found to be lower. When the participant sport managers’ education levels improve, their work stress points fall down. In the first period of service of sport managers, the averages of work stress were high, in next years they went down over time.Öğe Temperature dependent electrical transport in Al/Poly(4-vinyl phenol)/ p -GaAs metal-oxide-semiconductor by sol-gel spin coating method(Hindawi, 2016-03-10) Özden, Şadan; Tozlu, Cem; Pakma, OsmanDeposition of poly(4-vinyl phenol) insulator layer is carried out by applying the spin coating technique onto p-type GaAs substrate so as to create Al/poly(4-vinyl phenol)/p-GaAs metal-oxide-semiconductor (MOS) structure. Temperature was set to 80-320 K while the current-voltage (I-V) characteristics of the structure were examined in the study. Ideality factor (n) and barrier height (φ b) values found in the experiment ranged from 3.13 and 0.616 eV (320 K) to 11.56 and 0.147 eV (80 K). Comparing the thermionic field emission theory and thermionic emission theory, the temperature dependent ideality factor behavior displayed that thermionic field emission theory is more valid than the latter. The calculated tunneling energy was 96 meV.Öğe An experimental investigation of the effect of thermophysical properties on time lag and decrement factor for building elements(Gazi University, 2020-06-01) Oktay, Hasan; Yumrutaş, Recep; Argunhan, ZekiThe time lag (TL) and decrement factor (DF) are essential for the heat storage capabilities of building elements, which strictly depend on the thermophysical properties of the elements. Many investigations are presented in literature arguing to find the influence of each thermophysical property on TL and DF by keeping the other properties constant. This study aims to investigate the effect of each property on TL and DF, utilizing relationships between the measurement values of the thermophysical properties of wall materials. Therefore, first, 132 new concrete wall samples were produced, and their thermophysical properties were tested. Secondly, TL and DF values for each building element are computed from the solution of the problem by Complex Finite Fourier Transform (CFFT) technique. Finally, a multivariate regression analysis has been performed, and the variations of each thermophysical property versus TL and DF are presented, and also the findings are compared with literature. The results show that each property alone (keeping the other properties constant) is not adequate to identify the thermal inertia and thermal performance of a wall element. Besides, 87.3 % decrease in thermal diffusivity corresponds to 6.03 h increase in the value of TL and 88.8 % decrease in value of DF; respectively, for W1 wall assembly.Öğe The effect of intrapreneurship and organizational factors on the innovation performance in hospital(Expert Projects, 2018-09) Ekingen, Erhan; Ekemen, Mehmet Ali; Yıldız, Ahmet; Korkmazer, FuatIn the context of environmental uncertainty and competition, organizations are trying to find new ways to improve their performance. The development of novelties based on innovation, especially in the service sector, is the departure point for many organizations. Intrapreneurship and organizational structure are important factors for organizations to improve the innovation performance. In this study, it is aimed to investigate whether intrapreneurship and organizational factors influence the innovation performance. The data were collected from a hospital by means of intrapreneurship scale, organizational factors scale and innovation performance scale. According to the results of Structural Equation Model analysis, intrapreneurship has positive influences on innovation performance. Organizational factors directly and indirectly affect innovation performance. Moreover, intrapreneurship has mediation effect between organizational factors and innovation performance. Lastly, Intrapreneurship enhances the effect of organizational factors on innovation performance.Öğe Finite element analysis of the stress distributions in peri-implant bone in modified and standard-threaded dental implants(Taylor & Francis, 2016-01) Topkaya, Tolga; Dündar, Serkan; Solmaz, Murat Yavuz; Yaman, Ferhan; Atalay, Yusuf; Saybak, Arif; Asutay, Fatih; Çakmak, ÖmerThe aim of this study was to examine the stress distributions with three different loads in two different geometric and threaded types of dental implants by finite element analysis. For this purpose, two different implant models, Nobel Replace and Nobel Active (Nobel Biocare, Zurich, Switzerland), which are currently used in clinical cases, were constructed by using ANSYS Workbench 12.1. The stress distributions on components of the implant system under three different static loadings were analysed for the two models. The maximum stress values that occurred in all components were observed in FIII (300 N). The maximum stress values occurred in FIII (300 N) when the Nobel Replace implant is used, whereas the lowest ones, in the case of FI (150 N) loading in the Nobel Active implant. In all models, the maximum tensions were observed to be in the neck region of the implants. Increasing the connection between the implant and the bone surface may allow more uniform distribution of the forces of the dental implant and may protect the bone around the implant. Thus, the implant could remain in the mouth for longer periods. Variable-thread tapered implants can increase the implant and bone contact.
