TOBB ETU GCRIS Database
Not a member yet
9778 research outputs found
Sort by
The Effect of the Distance Between the End Point of the Osteotomy and the Lateral Cortex on the Lateral Cortical Hinge Fracture in Medial Opening-Wedge High Tibial Osteotomy
No full textBackground The purpose of this study was to compare the effects of different distances between the end point of the osteotomy and the lateral cortex on the risk of lateral cortical fracture in the medial opening-wedge high tibial osteotomy (MOWHTO) procedure. Methods Eighteen synthetic tibia models were used. Saw cuts were performed on the test models (n=6 for all groups). Wedge gap distance and wedge opening load were evaluated using compression tests. Findings The mean maximum gap distance without a lateral cortical fracture was 19.90 mm in Group 5, 15.49 mm in Group 10, and 11.23 mm in Group 15. The differences between Group 5 and Group 10, Group 5 and Group 15, and Group 10 and Group 15 were statistically significant. The mean load just before the fracture was 13.24 N in Group 5, 18.31 N in Group 10, and 26.16 N in Group 15. The difference between Group 5 and Group 15 was statistically significant. No significant difference was observed between Group 10 and both Group 5 and Group 15. Interpretation As the end point of the osteotomy is brought gradually closer to the lateral cortex, wider gaps can be opened without a lateral cortical fracture. Thus, higher angle corrections can be achieved more safely by bringing the end point of the osteotomy closer to the lateral cortex, which should be preferred to reduce the risk of a lateral cortical hinge fracture during the MOWHTO procedure, from a clinical viewpoint. © 202
The Effect of Model-Based Telephone Counseling on Hba1c and Self-Management for Individuals With Type 2 Diabetes: a Randomized Controlled Trial
No full textAims: This study was conducted to examine the effect of telephone counseling based on the Information, Motivation, Behavioral Skills (IMB) Model on HbA1c and self-management in patients with type 2 diabetes mellitus (T2DM). Methods: This study was conducted between January 2019 and September 2019 with a total of 63 (31 interventions, 32 controls) T2DM patients. The intervention group was followed-up for a total of 12 weeks, after 45?60 min of patient training based on IMB, a weekly reminder message and a phone call every two weeks. No intervention was made to the control group. Data were collected at the beginning of the study and at the end of the 12th week. The data were obtained using a Patient Information Form, the Type 2 Diabetes Self-Efficacy Scale, the Diabetes Self-Management Questionnaire (DSMQ), the Perceived Diabetes Self Management Scale (PDSMS) and glycemic control (HbA1c). Results: Participants were on average 54 years old and the majority were female (58.1%). According to the results of the covariance analysis (ANCOVA), there was a statistically significant difference between the pre-post-test HbA1c (F:13.589; p 0.001), weight (F:32.176; p 0.001) and systolic blood pressure (F:7.109; p = 0.01). However, there was no significant difference in diastolic blood pressure between the intervention and control groups (F:2.686; p = 0.106). Also, after three months of follow-up, self-efficacy (F:26.632; p 0.001), self-management (F:44.487; p 0.001) and self-management perceptions (F:71.132; p 0.001) were significantly higher in the intervention group. Conclusion: The researchers concluded that telephone counseling based on the IMB model could be a suitable method to improve glycemic control and self-care behaviors in patients with type 2 diabetes. © 2021 Primary Care Diabetes EuropeWe thank all participants for their participation in this study
Postfusion Effect on Pullout Strength of Pedicle Screws With Expandablepeek Shell and Conventional Screws
No full text/0000-0002-8241-8771The pullout performance of various pedicle screws after artificial fusion process was investigated in this study. Normal, cannulated (cemented), novel expandable and normal (cemented) pedicle screws were tested. Polyurethane foams (Grade 10 and Grade 40) produced by casting method were used as test materials. The instrumentation of pedicle screws has been carried out with production of foams, simultaneously. For cemented pedicle screws, 3D models were prepared with respect to the anteriosuperior and oblique radiographs by using PMMA before casting procedure. Pullout tests were performed in an Instron 3369 testing device. Load versus displacement graph was recorded and the ultimate force was defined as the pullout strength sustained before failure of screw. As expected, the pullout strengths of pedicle screws in postfusion are higher than before fusion. Pullout strengths increased significantly by artificial fusion in Grade 10 foams compared to Grade 40 foams. Additionally, while the pullout strengths of normal, cannulated and novel expandable pedicle screws increased by artificial fusion, cemented normal pedicle screws had lower pullout values than before fusion in Grade 40 foams. When the cemented normal pedicle screws are excluded, other screws have almost similar pullout strength level. On the other hand, the pedicle screws have different increasing behaviour also, there is no correlation between each other. As a result, the novel expandable pedicle screws can be used instead of normal and cannulated ones due to their performances in non-cemented usage
Architecture and Media
No full textThe modernization process of the Republic of Turkey in the early 1930s is one of the finest examples among various others, illustrating the role of communication media in the formation of modern societies. As is well known, new social orders require a systematic means of communicating ideas to achieve their goals. In this context, ar- chitecture and the built environment take on a new meaning as an enduring means of a new way of living to be realized, and correspondingly, turning into communica- tion tools. Similarly, during the same era in Turkey, the republican reforms and pol- icies attempted to communicate with the public through architecture. Subsequently, architecture, which also began the process of modernization, created its media. Thus, architectural and political thought did not seem to exist without being embodied in the media, because communicating ideas must be almost entirely mediated and me- diatized. In this sense, this chapter is concerned with the issue of the complex rela- tionships between architecture and media in the context of materializing ideas in early republican Turkey. To portray the issue, the instrumentality of mediums, such as architectural exhibitions, competitions, journals, books, photography, and film, in the materialization of ideas during the formative years of the country is addressed
Aerospace Structure Design Using Structural Response of a Payload Carried by Jet Fighter
No full textPurpose: The aim of this study is to evaluate the structural responses proposed by military specifications with real test conditions and also compare the effects of usage ANN predicted and military specification loads in design of aerospace structures. Theory and Methods: Vibration responses in structural design is used as PSD in the frequency domain. Loads for structural design purposes are calculated with random loads using PSD data between 20-300 Hz frequency bands. Results: An aerospace structure is designed according to the ANN predictions, military specification proposal and experimental design loads. Supports designed based on experimental and predicted loads are lighter than the support designed according to the military specification load. Conclusion: It was observed that military specification loads exhibit conservatism. This conservatism makes the aerospace structures complex and heavier. Also, more engineering effort and production cost is occurred since the loads are high with respect to real environmental conditions
Immune Mechanisms in Human Sarcoptes Scabiei (acari: Sarcoptidae) Infestations
No full textScabies is a parasitic infestation of human and animal skin caused by different strains of the itch mite, Sarcoptes scabiei. The World Health Organization (WHO) has declared scabies in human as a neglected tropical disease, and today over 200 million people worldwide are affected. The two most commonly reported clinical manifestation of the condition are ordinary (OS) and crusted scabies (CS). CS, which can lead to fatal consequences due to secondary bacterial infections, is mostly observed in immunocompromised subjects but can also, although rarely, be detected in immunocompetent individuals. Innate and adaptive immune system components are involved in protection and pathogenesis of scabies, although with some differences between OS and CS. While the cutaneous immune response is dominated by CD4(+) T-cells in OS, it is mainly mediated by CD8(+) T-cells in CS. The two clinical conditions also differ in CD4(+) T-cell-mediated immune responses with mixed T(H)1/T(H)2 (protective) and T(H)2/T(H)17 (non-protective) immunoprofiles in OS and CS, respectively. Moreover, the development of CS is associated with early immunosuppression that is followed by deleterious immune response to uncontrolled mite proliferation. However, the immune response to scabies still needs further attention due to inconsistent results in the literature. The aim of this study is to attract more attention to this area by summarizing the current literature on innate and adaptive immune responses triggered against S. scabiei mites
Analysis of Adas Radars With Electronic Warfare Perspective
No full textThe increasing demand in the development of autonomous driving systems makes the employment of automotive radars unavoidable. Such a motivation for the demonstration of fully-autonomous vehicles brings the challenge of secure driving under high traffic jam conditions. In this paper, we present the investigation of Advanced Driver Assistance Systems (ADAS) radars from the perspective of electronic warfare (EW). Close to real life, four ADAS jamming scenarios have been defined. Considering these scenarios, the necessary jamming power to jam ADAS radars is calculated. The required jamming Effective Radiated Power (ERP) is -2 dBm to 40 dBm depending on the jamming scenario. These ERP values are very low and easily realizable. Moreover, the effect of the jamming has been investigated on the radar detection at radar Range Doppler Map (RDM) and 2-Dimensional Constant False Alarm Rate (2D-CFAR). Furthermore, the possible jamming system requirements have been investigated. It is noted that the required jamming system will not require high-end technology. It is concluded that for the security of automotive driving, the ADAS radar manufacturer should consider the intentional jamming and related Electronic Counter Countermeasures (ECCM) features in the design of ADAS radars
Üç Boyutlu Yazicilar Kullanilarak Kisiye Özel Sternokostal Eklem İmplanti Tasarimi ve Üretimi
No full textThe sternocostal joints are the joints located in the thoracic region between the first seven ribs and the sternum. Some of the tumors, infections, and traumas occurring in the chest wall result in reconstruction of the sternum and its associated sternocostal joints. In order to enhance the patient's quality of life, sternocostal implants made of anatomical and material compatible with the tissue of the person to be used to replace the removed damaged area. Unlike the standard implants in the market, the production of implants specific to the person's condition not only reduces the risks of the surgeries but also facilitates the job of the surgeons. These implants, which are designed in computer aided technoloiges, can be turned into tangible 3-D models thanks to 3-D printer technologies, which are accepted as additive manufacturing. In this study, the production and design stages of a custom sternocostal joint implant with SLS (Selective Laser Sintering), which is a powder-based additive manufacturing method of 3-D manufacturing technologies, was examined and a new implant design was proposed. In the analysis program of a sternocostal implant made of Ti-6Al-4V material created by MDMC (Medical Design and Manufacturing Center, University of Health Sciences, Gülhane, Ankara) and implanted to the patient, finite element analysis was performed and the loads and stress values on the implant were measured. In the analysis, specific bounded conditions were created and stress, strain and deformation values on the implant were examined under the same boundary conditions in all models. According to the results, it was observed that when a CPR force is applied to the implant model integrated into the rib cage, the implant can withstand this force, and the stress results remain below the yield strength of titanium, so it does not cause permanent deformation of the implant. Some sternocostal implants designed to date in the world and in our country have been examined within the scope of the study, design differences and improvements have been made on the analyzed sternocostal implant as a result of the researches, and their analyzes have been carried out. Within these design differences, the implant was divided into three parts and the parts were combined with screws, and the results were evaluated by applying the same boundary conditions in the analysis program. According to the results of the analysis, it was observed that the stress was concentrated around the holes with the screws and the number of screws in the designs was increased, the analysis results were compared and the results were interpreted. The study is aimed to guide the sternocostal implant studies that will be designed from now on.Sternokostal eklemler, toraks bölgesinde ilk yedi kaburga ile sternum arasında yer alan eklemlerdir. Göğüs duvarında meydana gelen tümörler, enfeksiyonlar ve travmaların tedavisi sternumun ve ona bağlı sternokostal eklemlerin cerrahi olarak çıkartılması ile sonuçlanabilmektedir. Hastanın yaşamsal fonksiyonlarının devam etmesini sağlamak için çıkarılan hasarlı bölgenin yerine geçebilecek kişinin dokusu ile uyumlu malzemeden üretilmiş sternokostal implantlar kullanılabilmektedir. Pazardaki standart implantların yanı sıra kişiye özel tasarlanan implantlar ameliyatların risklerini azaltmanın yanı sıra cerrahların işini de kolaylaştırmaktadır. Bilgisayar ortamında tasarlanan kişiye özel bu implantlar eklemeli/katmanlı üretim (Additive Manufacturing) olarak kabul edilen 3 boyutlu yazıcı teknolojileri sayesinde somut hale dönüştürülebilmektedir. Bu çalışmada 3 boyutlu üretim teknolojilerinden toz esaslı eklemeli imalat yöntemi olan SLS (Seçici Lazer Sinterleme) ile kişiye özel sternokostal eklem implantının tasarım ve üretim aşamaları incelenmiştir. METÜM (Medikal Tasarım ve Üretim Merkezi, Sağlık Bilimleri Üniversitesi Gülhane Yerleşkesi, Ankara) tarafından oluşturulan ve hastaya implantasyonu gerçekleştirilen Ti-6Al-4v malzemeden üretilmiş bir sternokostal implantın analiz programında sonlu elemanlar analizi yapılmıştır. Hastaya ait tomografi görüntüleri alınarak 3 boyutlu modelleme programında göğüs kafesi modeli oluşturulmuş ve dijital ortamda hazırlanan implant modeli ile birlikte analiz programında statik analizleri gerçekleştirilmiştir. Analizde belirli sınırlı şartları oluşturulmuş ve tüm modellerde aynı sınır şartlarında implant üzerindeki stres, gerinim ve yer değiştirme (deformasyon) değerleri incelenmiştir. Elde edilen sonuçlara göre göğüs kafesine entegre edilmiş implant modeline bir CPR kuvveti uygulandığında implantın bu kuvvete dayanabildiği, stres sonuçlarının titanyumun akma dayanımının altında kaldığı dolayısıyla implantta kalıcı şekil değişikliğine sebep olmadığı görülmüştür. Ülkemizde ve dünyada günümüze kadar tasarlanmış olan bazı sternokostal implantlar çalışma dahilinde incelenmiş, yapılan araştırmalar sonucunda analizi yapılan sternokostal implant üzerinde tasarımsal farklılıklar ve iyileştirmeler yapılmıştır. Bu tasarımsal farklılıklar dahilinde implant üç parçaya ayrılmış ve parçalar vidalarla birleştirilmiş, analiz programında aynı sınır şartları uygulanarak, sonuçlar değerlendirilmiştir. Analiz sonuçlarına göre vida bulunan deliklerin etrafında stresin yoğunlaştığı görülmüş ve tasarımlardaki vida sayısı artırılarak analiz sonuçları karşılaştırılmış ve sonuçlar yorumlanmıştır. Yapılan çalışmanın bundan sonra tasarlanacak olan sternokostal implant çalışmalarına yol göstermesi amaçlanmaktadır
Dr-Strange: End-To System Design for Dram-Based True Random Number Generators
No full text28th Annual IEEE International Symposium on High-Performance Computer Architecture (HPCA) -- APR 02-06, 2022 -- ELECTR NETWORKRandom number generation is an important task in a wide variety of critical applications including cryptographic algorithms, scientific simulations, and industrial testing tools. True Random Number Generators (TRNGs) produce cryptographically secure truly random data by sampling a physical entropy source that typically requires custom hardware and suffers from long latency. To enable high-bandwidth and low-latency TRNGs on widely-available commodity devices, recent works propose hardware TRNGs that generate random numbers using commodity DRAM as an entropy source. Although prior works demonstrate promising TRNG mechanisms using DRAM, practical integration of such mechanisms into real systems poses various challenges. We identify three key challenges for using DRAM-based TRNGs in current systems: (1) generating random numbers with DRAM-based TRNGs can degrade overall system performance by slowing down concurrently-running applications due to the interference between RNG and regular memory operations in the memory controller (i.e., RNG interference), (2) this RNG interference can degrade system fairness by causing unfair prioritization of applications that intensively use random numbers (i.e., RNG applications), and (3) RNG applications can experience significant slowdown due to the high latency of DRAM-based TRNGs. To address these challenges, we propose DR-STRaNGe, an end-to-end system design for DRAM-based TRNGs that (1) reduces the RNG interference by separating RNG requests from regular memory requests in the memory controller, (2) improves fairness across applications with an RNG-aware memory request scheduler, and (3) hides the large TRNG latencies using a random number buffering mechanism combined with a new DRAM idleness predictor that accurately identifies idle DRAM periods. We evaluate DR-STRaNGe using a comprehensive set of 186 multi programmed workloads. Compared to an RNG-oblivious baseline system, DR-STRaNGe improves the performance of non-RNG and RNG applications on average by 17.9% and 25.1%, respectively. DR-STRaNGe improves system fairness by 32.1% on average when generating random numbers at a 5 Gb/s throughput. DR-STRaNGe reduces energy consumption by 21% compared to the RNG-oblivious baseline design by reducing the time spent for RNG and non-RNG memory accesses by 15.8%.IEEE,IEEE Comp Soc,Samsung,Microsoft,Sk Hynix,Furiosa,AMD,Intel,Arm,Meta,IBM,Nvidia,Kais
A Survey of Machine Learning Techniques in Structural and Multidisciplinary Optimization
No full textMachine Learning (ML) techniques have been used in an extensive range of applications in the field of structural and multidisciplinary optimization over the last few years. This paper presents a survey of this wide but disjointed literature on ML techniques in the structural and multidisciplinary optimization field. First, we discuss the challenges associated with conventional optimization and how Machine learning can address them. Then, we review the literature in the context of how ML can accelerate design synthesis and optimization. Some real-life engineering applications in structural design, material design, fluid mechanics, aerodynamics, heat transfer, and multidisciplinary design are summarized, and a brief list of widely used open-source codes as well as commercial packages are provided. Finally, the survey culminates with some concluding remarks and future research suggestions. For the sake of completeness, categories of ML problems, algorithms, and paradigms are presented in the Appendix