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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 “Balcı” aspir (Carthamus tinctorius l.) çeşidinin in vitro sürgün uçlarının mikroçoğaltımı ve köklendirilmesi üzerine oksin ve sitokininlerin etkisi(Yüzüncü Yıl Üniversitesi, 2018-12-31) Akbaş, Filiz; Hamidi Birecikli, AtikeBu çalışmada, linoleik tipte olan Balcı aspir çeşidinin, mikroçoğaltımı ve köklendirilmesi üzerine bazı sitokinin (BAP ve Kin) ve oksinlerin (NAA ve IAA) etkisi incelenerek in vitro çoğaltım protokolünün geliştirilmesi amaçlanmıştır. Başlangıç materyali olarak, in vitro koşullarda çimlendirilen olgun tohumlardan elde edilen steril fidelerin sürgün uçları kullanılmıştır. Sürgün uçları mikroçoğaltım için, BAP ve Kin’in farklı konsantrasyonlarının (0.0, 0.5, 1.0, 2.0 ve 4.0 mg/L) bulunduğu MS besi ortamında kültüre alınmıştır. Elde edilen sürgünler köklendirme aşamasında farklı NAA ve IAA (0.0, 0.5, 1.0 ve 2.0 mg/L) konsantrasyonlarını içeren MS besi ortamına transfer edilmiştir. BAP konsantrasyonları arasında en iyi sürgün çoğaltımı, eksplant başına 5.33 adet sürgün ile 0.5 mg/L BAP’lı ortamdan elde edilirken, Kin uygulamalarında ise 3.75 adet sürgün ile 0.5 mg/L Kin ve 3.33 adet sürgün ile 4.0 mg/L Kin içeren ortamdan elde edilmiştir. Ancak BAP uygulamalarının genelinde ve 4.0 mg/L Kin uygulamasında oluşan sürgünlerde vitrifikasyon olduğu belirlenmiştir. Bu nedenle, 0.5 mg/L Kin ile desteklenmiş MS besi ortamının Balcı aspir çeşidinin in vitro sürgün çoğaltımı için en ideal ortam olduğu tespit edilmiştir. En iyi kök oluşumunun, eksplant başına 20 adet ile 2.0 mg/L NAA içeren ortamda kültüre alınan sürgünlerde olduğu saptanmıştır. Elde edilen köklü fideler torf – perlit karışımı içeren saksılara dikilerek toprağa adaptasyonu sağlanmıştır.Öğe A novel approach for extracting ideal exemplars by clustering for massive time-ordered datasets(TÜBİTAK, 2017-07-30) Ertuğrul, Ömer FarukThe number and length of massive datasets have increased day by day and this yields more complex machine learning stages due to the high computational costs. To decrease the computational cost many methods were proposed in the literature such as data condensing, feature selection, and filtering. Although clustering methods are generally employed to divide samples into groups, another way of data condensing is by determining ideal exemplars (or prototypes), which can be used instead of the whole dataset. In this study, first the efficiency of traditional data condensing by clustering approach was confirmed according to obtained accuracies and condensing ratios in 9 different synthetic or real batch datasets. This approach was then improved to be employed in time-ordered datasets. In order to validate the proposed approach, 23 different real time-ordered datasets were used in experiments. Achieved mean RMSEs were 0.27 and 0.29 by employing the condensed (mean condensed ratio was 97.17%) and the whole datasets, respectively. Obtained results showed that higher accuracy rates and condensing ratios were achieved by the proposed approach.Öğe Ahmet Mithat Efendi’nin ilk romanlarında Mısır ve Mısırlılar(Atatürk Üniversitesi, 2011-06) Korkmaz, FerhatAhmet Mithat Efendi, Şemsettin Sami’den sonra ikinci telif romanı yazan Türk romancısıdır. Osmanlı Devleti açısından 18. Yüzyıldan itibaren başlayan Mısır sorunu, 19. Yüzyılda özellikle Kavalalı Mehmet Ali Paşa döneminde en karmaşık halini alır. 1517’de fethedilen; ancak 1882’de Osmanlı Devleti’nin elinden çıkan Mısır bu ilk romancılarımızın ilgisini çekmiş ve Tanzimat dönemi romanlarında bu ülkeye ait kimi konular işlenmiştir. Tanzimat romanında Mısır coğrafyası mekân olarak kullanılmış, roman yazarları ise romanlarının kimi bölümlerini Mısır, Mısırlılar veyahut Mısır’daki meselelere ayırmıştır. Ahmet Mithat Efendi de bir Tanzimat romancısı olarak Mısır konusuna bîgâne kalmamıştır. Onun romanlarını Osmanlı ülkesinin yaşayan halklarının siyasi, ekonomik, coğrafi, sosyal, psikolojik ve kültürel tarihi olarak değerlendirdiğimizden makalemizde, Ahmet Mithat Efendi’nin romanlarında Mısır coğrafyası ve Mısırlılar ele alınmıştırÖğe Enantioselevtive compexation of chiral lariat crown ethers and chiral primary alkylamonum perchlorates(Turkish Journal Chemistry, 2011-02-01) Aral, Tarık; Köylü, Mehmet Zafer; Kocakaya, Şafak Özhan; Karakaplan, Mehmet; Hoşgören, HalilIn order to investigate the enantiomeric recognition abilities toward 2 chiral alkylammonium perchlorates (AmI, AmII) by 1 H-NMR titration method in CDCl 3, 4 chiral lariat ethers 8-11 with a (p-methoxyphenoxy) methyl flexible side arm were used. The most effective enantiomeric recognition was obtained by LCEs 9 and 11 toward AmII, by KR /KS 6.58 and KS /KR 6.63, respectively. The effect of macroring size, subunit of macroring, and side arm appeared to have strong influence on the binding ability of these alkylammonium ions.Öğe Application and comparative performance analysis of PSO and ABC algorithms for optimal design of multimachine power system stabilizers(Gazi Üniversitesi, 2016-06-20) Ekinci, SerdarThis paper presents the application and performance comparison of PSO and ABC optimization techniques, for multi-objective design of power system stabilizers (PSSs) in the multi-machine power system. The design objective is to improve the power system stability. The PSSs parameters tuning problem is converted to an optimization problem with the time domain-based objective function and both PSO and ABC optimization techniques are used to search for optimal stabilizers parameters. The optimized stabilizers are tested on multi-machine electric power system subjected to different disturbances. The performance of both optimization techniques in terms of computational time, convergence rate and solution quality is compared. The eigenvalue analysis, nonlinear timedomain simulation results, critical clearing times and some performance indices studies are introduced and compared in order to demonstrate the effectiveness of both optimization techniques in designing stabilizers, to enhance the dynamic stability of the system. What is more, the potential and superiority of the ABC algorithm over the PSO algorithm are verified.Öğe A new record and three little-known Eupithecia Curtis species from Turkey (Lepidoptera: Geometridae)(TÜBİTAK, 2017-05-23) Seven, ErdemIn this paper, Eupithecia opistographata Dietze, 1906 is reported as new for the fauna of Turkey, and three rare species (E. brunneata Staudinger, 1900; E. dearmata Dietze, 1904; and E. marasa Wehrli, 1932) are presented as second records on the basis of specimens collected in the mountainous areas of Siirt Province and Şirvan District, southeastern Turkey. The adults and the male genitalia of the species are illustrated.Öğe A fast feature selection approach based on extreme learning machine and coefficient of variation(TÜBİTAK, 2017-07-30) Ertuğrul, Ömer Faruk; Tağluk, Mehmet EminFeature selection is the method of reducing the size of data without degrading their accuracy. In this study, we propose a novel feature selection approach, based on extreme learning machines (ELMs) and the coefficient of variation (CV). In the proposed approach, the most relevant features are identified by ranking each feature with the coefficient obtained through ELM divided by CV. The achieved accuracies and computational costs, obtained with the use of features selected via the proposed approach in 9 classification and 26 regression benchmark data sets, were compared to those obtained with all features, as well as those obtained with the features selected by a wrapper and a filtering method. The achieved accuracy values obtained with the proposed approach were generally higher than when using all features. Furthermore, high feature reduction ratios were obtained with the proposed approach, including the achieved feature reduction ratios in epilepsy, liver, EMG, shuttle, and abalone. Stock data sets were 90.48%, 90%, 70.59%, 66.67%, 75%, and 77.78%, respectively. This approach is an extremely fast process that is independent of the employed machine-learning methods.Öğe Interface effects of annealing temperatures in Al/HfO2/p-Si (MIS) structures(Gazi Üniversitesi, 2017-09-20) Özden, Şadan; Pakma, OsmanIn this study, Al/HfO2/p-Si (MIS) structures were prepared by using the sol-gel method for three different annealing temperatures. The current-voltage (I-V) and capacitance-voltage (C-V) characteristics of these structures were investigated by taking into consideration the effect of the interfacial insulator layer and surface states (Nss) at room temperature. All of the structures showed non-ideal I-V behaviour with ideality factor (n) in the range between 2.35 and 4.42 owing to interfacial insulator layer and surface states. The values of Nss and barrier height (fb) for three samples were calculated. The values of n and Nss ascend with increasing the insulator layer thickness (δ) while the values of fb decreases.
