146 research outputs found
Planlanmış Davranış Teorisine Göre “Güvenli Laboratuvar Kullanımını Gerçekleştirme Ölçeği” Geliştirme Çalışması
Bu çalışmanın amacı fen bilimleri öğretmenlerinin güvenli laboratuvar kullanımını gerçekleştirme davranış amaçlarını tespit etmek için planlanmış davranış teorisine göre geçerli ve güvenilir bir ölçek geliştirmektir. Literatür taraması yapıldıktan sonra hazırlanan 6 açık uçlu soru, 46 fen bilimleri öğretmeni ve 87 fen bilimleri öğretmen adayına uygulanmıştır.10 bölümden oluşan ve toplam 96 maddelik taslak ölçek 7li likert tipinde hazırlanmıştır. Ölçek Ankara ilinde Milli Eğitim Bakanlığına bağlı okullarda görev yapan 110 fen bilimleri öğretmeni ve Hacettepe Üniversitesinde eğitim gören 190 fen bilimleri öğretmen adayı toplam 300 kişiye uygulanmıştır. Yapılan faktör analizi sonucunda ölçeğin 6 faktörlü bir yapıya sahip olduğu ve 84 maddeden oluştuğu tespit edilmiştir. Ölçeğin bütünü için Cronbach-Alpha iç tutarlılık katsayısı 0.961, davranışsal inançlar alt boyutunda 0.974, Normatif inançlar alt boyutunda 0.957 ve Kontrol inançları boyutunda 0.915dir.Tüm bu bulgular ölçeğin geçerli ve tatmin edici düzeyde güvenirliğe sahip olduğuna göstermektedir
Analysis and Improvement of Tools and Methods Used in GraphQL Query Building Process
Günümüzde yaşanan teknolojik gelişmeler, İnternete bağlanan toplam cihaz tür ve sayısında büyük bir artışa yol açmıştır. Sunucu makineler daha fazla istek almaya başlamış hem ağ trafiği hem de sunucu yanıt süresi olumsuz etkilenmiştir. Bu sorunları çözmek için Facebook tarafından 2015 yılında duyurulan GraphQL teknolojisi tek bir istekle birden fazla tablo, koleksiyon veya veri tabanına erişim sağlayarak toplu veri sorgulama ve değiştirmeye imkân vermektedir. Bu sayede cihaz başına düşen istek sayısı ve cihazların belleklerinde tutulacak veri boyutu azalır. Ancak GraphQL yeni bir teknoloji olduğundan henüz kod geliştirme sürecini yöneten ve kolaylaştıran araçlar tam olarak gelişmemiştir. Sunucu kısmında sorguları oluşturmak ve çalıştırmak için önemli miktardaki kodun elle yazılması gerekmektedir. Bu da yazılım geliştiricilere önemli bir iş yükü oluşturmaktadır. Bu çalışmada GraphQL sorgu geliştirme süreci, bu süreci kolaylaştırmak veya otomatikleştirmek için kullanılan araçlar, bu araçların kullandığı yöntemler ve sorgu geliştirme maliyetleri analiz edilmiştir. Bu maliyeti azaltmak için kodları otomatik oluşturan bir yöntem önerilmiş ve bu yöntemi kullanan bir araç geliştirilmiştir. Geliştirilen yöntemin etkinliği diğer yöntemlerle karşılaştırılmış, sayısal olarak incelenmiş ve yazılımcıları önemli miktardaki kodu tekrar yazmaktan kurtararak zamandan tasarruf sağladığı görülmüştürNowadays, as a result of developing technology, increasing device diversity, and the total number of devices connected to the Internet, servers have started to receive more requests adversely affecting both network traffic and server response time. For eliminating these problems, in 2015, Facebook announced GraphQL technology allowing multiple tables, collections, or databases can be accessed instantly via a single request and a single answer. Therefore, the number of requests per device and the size of the data to be kept in the memory of the devices is reduced significantly. However, it is necessary to write code manually to create and run the GraphQL queries on the server part due to the lack of adequate code management and automation tools. Thus, it creates an additional workload for the developer. In this study, we have analyzed the tools used to automate or facilitate the query development process of GraphQL and compared the cost of query development. A new method and tool for generating GraphQL queries have been developed and its effectiveness has been compared to other methods and evaluated quantitively. The results show that the developers save time by avoiding the burden of writing many lines of code
Optimum design of purlin systems used in steel roofs
In this study, one existing purlin system which is used in steel roof is optimized by taking into account less cost and bearing maximum load via developed software. This software runs with firefly algorithm which is one of the recent stochastic search techniques. One of the metaheuristic techniques, so-called firefly algorithm imitates behaviors of natural phenomena. Behaviors and communications of firefly are inspired by this algorithm. In optimization algorithm, steel sections, distance between purlins, tensional diagonal braces are determined as design variables. Design loads are taken into account by considering TS498-1997 (Turkish Code) in point of place where structure will be built, outside factors and used materials. Profile list in TS910 is used in selection stage of cross sections of profile. Constraints of optimization are identified in accordance with bending stress, deformation and shear stress in TS648. Design variables of optimization are selected as discrete variables so as to obtain applicable results. Developed software is tested on existing real sample so; it is evaluated with regard to design and performance of algorithm
Protective effects of cordycepin on the histopathological changes and oxidative stress induced by hepatic ischemia/reperfusion in rats
Aim: To investigate the effects of cordycepin on the histopathological changes and oxidative stress induced by hepatic ischemia/reperfusion (I/R) in rats.
Method: Forty male Wistar rats were randomly divided into 4 groups as group I (sham, n=10), group II (control, n=10), group III (I/R-untreated, n=10) and group IV (I/R-cordycepin, n=10). Liver ischemia was induced for 30 min then reperfusion was allowed for 1 h. At the end of the experiment, liver specimens and blood samples were taken for histopathological and antioxidant evaluations, and biochemical analysis.
Results: The levels of IL6, IL-1β, and TNFα in the serum and liver tissues were higher in the I/R-untreated group compared to the I/R-cordycepin treated group. In the I/R-cordycepin group, serum MDA levels were decreased compared with the I/R-untreated group. The I/R-cordycepin treated group showed an increase in TAS levels, and a decrease in TOS levels compared with I/R-untreated group. The histopathological injury score were significantly lower in the I/R-cordycepin treated group compared to the I/R-untreated group. In the I/R-untreated group, the integrity of the hepatocyte cell lines deteriorated. Mononuclear inflammatory cells infiltrated the parenchyma regions, the sinuses dilated and there was diffuse congestion Preoperative treatment with cordycepine reduced histopathological abnormalities.
Conclusion: Cordycepin has demonstrated significant hepatoprotective effects against I/R injury induced in rats through TAS elevation and reduction of TOS, MDA and proinflammatory cytokines
Analysis and investigation of different advanced control strategies for high-performance induction motor drives
Induction motor (IM) drives have received a strong interest from researchers and industry particularly for high-performance AC drives through vector control method. With the advancement in power electronics and digital signal processing(DSP), high capability processors allow the implementation of advanced control techniques for motor drives such as model predictive control (MPC). In this paper, design, analysis and investigation of two different MPC techniques applied to IM drives; themodel predictive torque control (MPTC) and model predictive current control (MPCC) are presented. The two techniques are designed in Matlab/Simulink environment and compared interm of operation in different operating conditions. Moreover, a comparisonof these techniques with field-oriented control (FOC) and direct torque control (DTC) is conducted based on simulation studies with PI speed controller for all control techniques. Based on the analysis, the MPC techniques demonstrates a better result compared with the FOC and DTC in terms of speed, torque and current responses in transient and steady-state conditions
The Mediating Effect of Blockchain Technology on the Cryptocurrency Purchase Intention
Cryptocurrencies, enabling secure digital asset transfers without a central
authority, are experiencing increasing interest. With the increasing number of
global and Turkish investors, it is evident that interest in digital assets
will continue to rise sustainably, even in the face of financial fluctuations.
However, it remains uncertain whether consumers perceive blockchain
technology's ease of use and usefulness when purchasing cryptocurrencies. This
study aims to explain blockchain technology's perceived ease of use and
usefulness in cryptocurrency purchases by considering factors such as quality
customer service, reduced costs, efficiency, and reliability. To achieve this
goal, data were obtained from 463 participants interested in cryptocurrencies
in different regions of Turkey. The data were analyzed using SPSS Process Macro
programs. The analysis results indicate that perceived ease of use and
usefulness mediate the effects of customer service and reduced costs,
efficiency, and security on purchase intention
Does Ozone Administration Have a Protective Effect Against Cisplatininduced Histological Changes in Rat Testis?
Objective:We investigated the protective and therapeutic effects of ozone therapy (OT) on cisplatin (CP)-induced testicular damage.Materials and Methods:Thirty healthy adult male Wistar rats were divided into five groups consisting of 6 animals each: 1) control, 2) CP, 3) OT, 4) OT + CP and 5) CP + OT groups. Histopathological findings, Johnsen scores, thiobarbituric acid-reactive substances (TBARS), glutathione (GSH), superoxide dismutase (SOD), catalase, and GSH peroxidase (GPx) levels were evaluated.Results:CP caused a significant decrease in testicular weight and Johnsen score compared to the control group. In addition, TBARS level was significantly higher, whereas GSH, SOD, catalase and GPx levels were significantly lower in the CP group when compared to the control group. Pre- and post-CP OT significantly increased GSH, SOD, catalase and GPx levels and decreased TBARS level. Also, testicular weight and Johnsen score were increased with OT.Conclusion:The present study showed that OT is protective against CP-induced testicular damage. OT may be beneficial to patients who underwent CP chemotherapy
Worker deaths: A regional autopsy study
Amaç: Uluslararası Çalışma Örgütü’ne göre her 15 saniyede bir 153 işçi iş kazası geçirmekte ve bir işçi iş kazaları veya hastalıklar nedeniyle
ölmektedir. Dünyada her gün 6.300 insan iş kazaları veya işle ilişkili hastalıklar nedeniyle ölmektedir.
Yöntem: Adli Tıp Kurumu Trabzon Grup Başkanlığı Morg İhtisas Dairesi’nde, 2011-2015 yılları arasında otopsisi yapılan, ölüm nedeni iş kazasına
bağlanan olguların adli tahkikat evrakları ve otopsi raporları geriye dönük olarak incelendi.
Bulgular: Toplam 112 işçi ölümünden 111’inin (%99,1) erkek, 1’inin (%0,9) kadın olduğu tespit edildi. Yaşları 18 ile 64 yıl arasında değişmekteydi.
Olguların iş kollarına göre dağılımı incelendiğinde 61 (%54,5) olgunun inşaat sektöründe ve 12 (%10,7) olgunun enerji sektöründe çalıştığı
tespit edildi. İş kazalarının 34 (%30,4) olguda yüksekten düşme, 19 (%17) olguda elektrik çarpması nedeniyle gerçekleştiği belirlendi. Yapılan
otopsilerde 44 (%39,3) olguda kafatası kemik kırıkları, 22 (%19,6) olguda göğüs kafesi kırıkları vardı. Histopatolojik incelemelerde, 13 (%11,6)
olguda kalp-damar patolojileri ve 20 (%17,9) olguda akciğerlerde ödem ve kanama bulundu.
Sonuç: Ulusal iş kazası istatistikleriyle de uyumlu olarak, bu çalışmanın sonuçlarına göre, ilk sırada inşaat sektörü bulunmaktadır. Ölüm nedeni
olarak ise yüksekten düşmeye bağlı genel beden travmaları, elektrik çarpmaları ve iş makinesi kazaları öne çıkmaktadır.Objective: According to the International Labor Organization, 153 workers are injured and one worker dies because of occupational accidents
or diseases every 15 seconds. Every day, 6,300 people die due to occupational accidents or work-related diseases in the world.
Methods: Forensic investigation documents and autopsy reports of patients who were autopsied between 2011 and 2015 at the Forensic
Medicine Department of Morgue Specialization in Trabzon Group Presidency and whose causes of death were related to occupational accidents
were examined retrospectively.
Results: It was determined that 111 (99.1%) were male and 1 (0.9%) were female from a total of 112 worker deaths. Their ages ranged between 18
and 64 years. When the distribution of cases by business types was analyzed, it was determined that 61 (54.5%) cases worked in the construction
sector and 12 (10.7%) in the energy sector. It was determined that work accidents occurred due to falling from height in 34 (30.4%) cases and
electric shock in 19 (17%) cases. There were skull bone fractures in 44 (39.3%) cases and rib cage fractures in 22 (19.6%) cases during autopsies. In
histopathological examinations, there were cardiovascular pathologies in 13 (11.6%) cases, edema and bleeding in the lungs in 20 (17.9%) cases.
Conclusion: According to the results of this study, construction sector took place on the top, which is consistent with the national work accident
statistics. As a cause of death, general body traumas due to falling from high, electric shocks and work machine accidents come to the fore
Fuzzy Membership Functions Tuning For Speed Controller Of Induction Motor Drive: Performance Improvement.
Fuzzy logic controller (FLC) has gained high interest in the field of speed control of machine drives in both academic and industrial communities. This is due to the features of FLC of handling non-linearity and variations. FLC system consists of three main elements: scaling factors (SFs), membership functions (MFs), and rule-base. Fuzzy MFs can be designed with different types and sizes. For induction motor (IM) speed control, (3x3), (5x5) and (7x7) MFs are the most used MFs sizes, and normally designed based on symmetrical distribution. However, changing the width and peak position of MFs design enhance the performance. In this paper, tuning of MFs of FLC speed control of IM drives is considered. Considering (3x3), (5x5) and (7x7) MFs sizes, the widths and peak positions of these MFs are asymmetrically distributed to improve the performance of IM drive. Based on these MFs sizes, the widths and peak positions are moved toward the origin (zero), negative and positive side that produces a controller less sensitive to the small error variations. Based on simulation and performance evaluations, improvement of 5% in settling time (Ts), 0.5% in rise time and 20% of steady-state improvement achieved with the tuned MFs compared to original MFs
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