Efficient techniques for soft tissue modeling and simulation

Performing realistic deformation simulations in real time is a challenging problem in computer graphics. Among numerous proposed methods including Finite Element Modeling and ChainMail, we have implemented a mass spring system because of its acceptable accuracy and speed. Mass spring systems have, however, some drawbacks such as, the determination of simulation coefficients with their iterative nature. Given the correct parameters, mass spring systems can accurately simulate tissue deformations but choosing parameters that capture nonlinear deformation behavior is extremely difficult. Since most of the applications require a large number of elements i. e. points and springs in the modeling process it is extremely difficult to reach realtime performance with an iterative method. We have developed a new parameter identification method based on neural networks. The structure of the mass spring system is modified and neural networks are integrated into this structure. The input space consists of changes in spring lengths and velocities while a "teacher" signal is chosen as the total spring force, which is expressed in terms of positional changes and applied external forces. Neural networks are trained to learn nonlinear tissue characteristics represented by spring stiffness and damping in the mass spring algorithm. The learning algorithm is further enhanced by an adaptive learning rate, developed particularly for mass spring systems. In order to avoid the iterative approach in deformation simulations we have developed a new deformation algorithm. This algorithm defines the relationships between points and springs and specifies a set of rules on spring movements and deformations. These rules result in a deformation surface, which is called the search space. The deformation algorithm then finds the deformed points and springs in the search space with the help of the defined rules. The algorithm also sets rules on each element i. e. triangle or tetrahedron so that they do not pass through each other. The new algorithm is considerably faster than the original mass spring systems algorithm and provides an opportunity for various deformation applications. We have used mass spring systems and the developed method in the simulation of craniofacial surgery. For this purpose, a patient-specific head model was generated from MRI medical data by applying medical image processing tools such as, filtering, the segmentation and polygonal representation of such model is obtained using a surface generation algorithm. Prism volume elements are generated between the skin and bone surfaces so that different tissue layers are included to the head model. Both methods produce plausible results verified by surgeons

Gallienus klasisizmi ve dönemin sanatında portrecilik anlayışı

Tez (yüksek lisans) - Anadolu ÜniversitesiAnadolu Üniversitesi, Sosyal Bilimler Enstitüsü, Arkeoloji Anabilim DalıKayıt no: 238369Roma İmparatorluk tarihinde 3. yy. imparatorlarından biri olan Gallienus’un incelendiği bu çalışmada, dönemin siyasi, ekonomik, din, sanat ve felsefe tarihi üzerinde durulmuş, birbirleriyle ilişkileri saptanmaya çalışılmıştır. Bunun yanı sıra Hellen kültürü ve Plotinus’un Roma dünyası için şekillenen Klasisizmin etkileri araştırılmış ve Klasisizmin politik amaçlar baz alınarak yaratıldığı anlaşılmıştır

Efficient techniques for soft tissue modeling and simulation

Performing realistic deformation simulations in real time is a challenging problem in computer graphics. Among numerous proposed methods including Finite Element Modeling and ChainMail, we have implemented a mass spring system because of its acceptable accuracy and speed. Mass spring systems have, however, some drawbacks such as, the determination of simulation coefficients with their iterative nature. Given the correct parameters, mass spring systems can accurately simulate tissue deformations but choosing parameters that capture nonlinear deformation behavior is extremely difficult. Since most of the applications require a large number of elements i. e. points and springs in the modeling process it is extremely difficult to reach realtime performance with an iterative method. We have developed a new parameter identification method based on neural networks. The structure of the mass spring system is modified and neural networks are integrated into this structure. The input space consists of changes in spring lengths and velocities while a "teacher" signal is chosen as the total spring force, which is expressed in terms of positional changes and applied external forces. Neural networks are trained to learn nonlinear tissue characteristics represented by spring stiffness and damping in the mass spring algorithm. The learning algorithm is further enhanced by an adaptive learning rate, developed particularly for mass spring systems. In order to avoid the iterative approach in deformation simulations we have developed a new deformation algorithm. This algorithm defines the relationships between points and springs and specifies a set of rules on spring movements and deformations. These rules result in a deformation surface, which is called the search space. The deformation algorithm then finds the deformed points and springs in the search space with the help of the defined rules. The algorithm also sets rules on each element i. e. triangle or tetrahedron so that they do not pass through each other. The new algorithm is considerably faster than the original mass spring systems algorithm and provides an opportunity for various deformation applications. We have used mass spring systems and the developed method in the simulation of craniofacial surgery. For this purpose, a patient-specific head model was generated from MRI medical data by applying medical image processing tools such as, filtering, the segmentation and polygonal representation of such model is obtained using a surface generation algorithm. Prism volume elements are generated between the skin and bone surfaces so that different tissue layers are included to the head model. Both methods produce plausible results verified by surgeons.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Çinko nanopartiküllere (Zn-Np) maruz birakilan tilapia (Oreochromis niloticus) baliğinin farkli organlarinda oksidatif stres duyarliliğinin belirlenmesi

Fen Bilimleri Enstitüsü, Su Ürünleri Temel Bilimleri Ana Bilim DalıSon yıllarda, yeni fiziksel ve kimyasal özellikler kazandırılmış nanoparçacıkların kullanım alanları hızlı bir şekilde artmaktadır. Bu yeni materyallerin çeşitli sanayi ve endüstriyel alanlarda (gıda, tekstil, kâğıt, kimya, metal, petrol sanayisi vb.) kullanımlarının genişlemesiyle beraber akuatik ekosistemler ile ve özellikle balıklarla teması kaçınılmaz hale gelmiştir. Bu tez çalışmasında, düşük (40-60 nm) ve yüksek (60-80 nm) boyutlardaki çinko nanopartiküllerin (Zn-NP) toksisitesinin tilapia (Oreochromis niloticus) balığı üzerinde oluşturabileceği oksidatif stres yapma kapasitesi hedef dokularda (karaciğer, beyin, solungaç ve kas) biyomarkır analizlerinden toplam glutatyon (GSH) ve tiyobarbutirik asitle tepkimeye giren madde (TBARS) analizleri ile incelenmiştir. Deney süresince 1 ppm ve 10 ppm Zn nanpartikül konsantrasyonlarına maruz bırakılan gruplarda bir adet balık ölümü gözlenmiştir. In vivo etkide Zn NP konsantrasyonlarına maruz bırakılan tilapia balığında GSH seviyelerinin zamana, maruz kalma süresine, doku türüne ve partikül boyutuna bağlı olarak değişim gösterdiği, TBARS düzeyinin ise Zn NP'lün düşük ve yüksek konsantrasyonlarına maruz bırakılan tilapia dokularında kas hariç arttığı görülmüştür (p<0,05). Çalışmada elde edilen sonuçlara göre, Zn NP'lün küçük boyutunun yüksek boyuta göre daha fazla toksik olduğu ve O. niloticus dokularında her iki boyuttada oksidatif strese sebep olduğu belirlenmiştir. Anahtar Kelimeler: Zn Nanopartikül, Glutatyon, TBARS, Oksidatif Stres, Oreochromis niloticus.The area of usage of nanoparticles that gained new physical and chemical properties has been increasing rapidly in recent years. The use of new materials in various industries and industrial areas (food industry, textile industry, paper industry, chemical industry, metal industry, oil industry) has been becoming wider day by day and because of that with aquatic ecosystems, especially contact with fish has become inevitable. In this thesis study, it has been researched that how the big (60-80 nm) and small size (40-60 nm) of zinc nanoparticles (Zn-NPs) toxicity might effect the capacity of oxidative stress on tilapia fish tissues with TBARS and GSH analysis. During the experiment, only one fish mortality was observed in the group which was treated to 1 ppm and 10 ppm Zn-NPs concentration. In vivo effects, the GSH level of tilapia fish that was treated to different Zn-NPs concentration change directly with time, duration of exposure, the tissue culture and particle size and also it was observed that TBARS level increased on the tilapia fish tissues expect muscle that treated to high and low level concentration of Zn-NPs. According to the results in this study it was determined that small particle size was more toxic than big particle size of Zn-NPs and it also caused the oxidative stress on tilapia tissues with both size. Keywords: Zn Nanoparticles, Glutathione, TBARS, Oxidative Stress, Oreochromis niloticus

Perception of multigrade classes schools: sociology of personalized learning

There are many schools of multigrade classes in many cities in Turkey due to the fact that there are various reasons, from a lack of financial budget to a harsh geographic demographic condition. Nevertheless, what should not be forgotten that this schooling is neither good nor bad, or is it neutral. Rather what the important is how they are utilized and how they came to be in the present practices in order to provide particular suggestions to authorities. To achieve the desired educational outcome of effectiveness and efficiency in these schools, the teachers' perception of these schooling is one of the crucial influencers. Therefore, this study aims to investigate how candidates of classroom teachers perceive the educational practices, in particular after visiting several of multigrade classes' schools through a participatory research approach. This study actually introduces the notions of education and sociology; particularly personalized learning in which the aim of progressive education approach ought to devalue political relativism and educational centralization and to revalue educational subjectivism and humanitarian utilitarianism. Particularly, this study aims to clarify the issue of responsibility and accountability in this schooling, and why and how this personalization of progressive education would be approached by whom

Example of Erzurum regional court of justice in Turkish public administration on staff motivation and efficiency

Motivasyon insanı harekete geçiren, davranışlarını yönlendiren olgulardır. Verimlilik ise eldeki kaynaklarla en çok çıktıya ulaşma çabasıdır. İnsanlar fiziksel, duygusal ve düşünsel farklılıklara sahiptir. Bu durum insanların motivasyonunu etkileyen faktörlerin farklılaşmasına neden olmuştur. Bu farklılıklardan hareketle insanı harekete geçiren motivasyon faktörlerinin belirlenmesi ve ölçümü ile motivasyon faktörlerinin verimlilik üzerine etkilerine yönelik yargı özelinde literatür eksikliği bulunmaktadır. Bu çalışmanın temel amacı, yargı süreçlerinin hızlandırılması noktasında kamu personellerinin motivasyonu ve verimlilik üzerine etkilerinin araştırılmasıdır. Bu amaçla çalışma, Türk yargı sisteminde faaliyet gösteren Erzurum Bölge Adliye Mahkemesi’nde çeşitli unvanlarda görev yapan çalışanlar ile gerçekleştirilmiştir. Çalışma kapsamında anket tekniği kullanılarak çalışanların konuya ilişkin algıları ölçülmeye çalışılmıştır. Bu çerçevede teorik bilgilere yer verilerek anket sonucu elde edilen bulgular ortaya konulmuştur.Motivation is the facts that motivate the human and directs their behavior. Productivity is the effort to reach the most output with the resources available. People have physical, emotional and intellectual differences. This situation caused different factors affecting the motivation of people. Based on these differences, there is a lack of literature about the determination and measurement of motivation factors that motivate people and the effects of motivation factors on productivity. The main aim of this study is to investigate the effects of public personnel on motivation and efficiency in accelerating judicial processes. For this purpose, the study was carried out with the employees working in various titles in the Erzurum Regional Court of Justice, which operates in the Turkish judicial system. Within the scope of the study, the employees' perceptions about the subject were tried to be measured by using the survey technique. In this context, theoretical knowledge is presented and findings obtained from the survey are presented

Hibernation Period in Some Land Snail Species (Gastropoda: Helicidae): Epiphragmal Structure and Hypometabolic Behaviors

In this study, the hypometabolism behavior, epiphragm formation process, and the mineral composition of the epiphragmal structure of the Helix pomacella, Eobania vermiculata, Helix melanostoma, and Helix asemnis land snails were investigated during the hibernation period. 100 snails selected among mature individuals, 25 from each species, were collected from nature for the research. The snails were placed in four 50x50x5 cm pans containing 20-cm-deep humus soil. Snails were fed with lettuce by free feeding until the hibernation period. Hypometabolism behavior of snails that had hibernated between November and December 2018, and January and February 2019 were examined as entering the hibernation stage, hibernation stage, and leaving the hibernation stage. The ionic concentration (Calcium, Iron, and Phosphorus) of the epiphragm layer formed during the hibernation process was analyzed, its formation duration, and its degradation at the end of the hibernation period were examined. In the study, it was determined that the weight before hibernation reduced by 18-22% in all examined species (H. pomacella, E. vermiculata, H. melanostoma, and H. asemnis). The highest values in terms of epiphragm formation duration (19±0.30 days), weight (0.41±0.26 g), and thickness (0.310±0.22 mm) were determined in H. asemnis. In terms of the ionic concentration, the highest Calcium level was determined in H. asemnis (29.96±0.12 mg/g) while the highest Phosphorus level (4.02±0.20 mg/g) was determined in E. vermiculata, and the highest Iron content was found in H. pomacella (19.50±0.33 mg/g). The degradation duration of the epiphragm layer at the end of hibernation was determined the longest in E. vermiculata (7 days) whereas the shortest in H. pomacella (3 days). As a result of the present research, it was seen that the epiphragm layer is important for snails in terms of a sustainable life cycle and that the ecological tolerances of snails depend on the epiphragmal structure

FARKLI PROGRAMLARDAKİ ÖĞRETMEN ADAYLARININ ÖĞRETMENLİK MESLEĞİNE YÖNELİK TUTUMLARININ ÇEŞİTLİ DEĞİŞKENLER AÇISINDAN KARŞILAŞTIRILMASI: RİZE ÜNİVERSİTESİ ÖRNEĞİ

Bu araştırmada, farklı programlardaki öğretmen adaylarının öğretmenlik mesleğine yönelik tutumları karşılaştırılmıştır. Çalışma, Rize Üniversitesi Eğitim Fakültesinde öğrenim gören 180 Sınıf, 101 İlköğretim Matematik, 42 Din Kültürü ve Ahlak Bilgisi, 33 Fen Bilgisi ve 30 Sosyal Bilgiler öğretmenliği programı birinci sınıf öğrencisi olmak üzere toplam 386 kişiyle gerçekleştirilmiştir. Araştırmada, Özgür (1994) tarafından geliştirilen Öğretmenlik Mesleğine Yönelik Tutum Ölçeği kullanılmıştır. Verilerin analizinde SPSS 17,0 programından yararlanılmış ve t-testi ile ANOVA kullanılmıştır. Araştırma sonucunda, tutum ölçeğinde Sosyal Bilimler (Sınıf, Din Kültürü ve Ahlak Bilgisi, Sosyal Bilgiler) alanı öğretmenlik programlarındaki öğretmen adaylarının, Fen Bilimleri(İlköğretim Matematik, Fen Bilgisi) alanındakilere göre daha yüksek puanlar aldıkları görülmüştür. Sınavsız öğrenci alan liselerden mezun olan öğretmen adaylarının, sınavla öğrenci alan liselerden mezun olanlara göre daha olumlu tutumları olduğu bulunmuştur. Ayrıca kız öğretmen adaylarının erkek öğretmen adaylarına göre öğretmenlik mesleğine yönelik daha olumlu tutumlara sahip oldukları sonucuna ulaşılmıştır. Öğretmen adaylarının öğrenim gördükleri programını tercih etme sırasına bağlı olarak ise tutum puanlarının anlamlı şekilde farklılaşmadığı ortaya çıkmıştır. Öğrencilere yapılan mesleki rehberlik çalışmalarında öğrencilerin tutumları göz ardı edilmemelidir. Ayrıca eğitim fakültelerinde öğretmenlik mesleğine ilişkin olumlu tutumlar kazandırılmasına yönelik faaliyetlerin artırılmasının yararlı olacağı düşünülmektedir

3D printed patch antenna design with coplanar waveguide feed for ultra wideband wireless communication applications

Kablosuz iletişim teknolojilerindeki gelişmeler, yüksek hızlı veri transferi için ihtiyacı artırıyor. Bu bağlamda, ultra geniş bant (UGB) teknolojisi, geniş frekans aralığında çalışabilen yeni bir kablosuz iletişim çözümü olarak öne çıkıyor. Bu teknolojinin önemli bir bileşeni olan antenlerin üretimi için ise 3D baskı teknolojisi dikkat çekiyor. Bu çalışmada, geniş bantlı kablosuz haberleşme sistemlerinde kullanılmak üzere tasarlanmış kompakt bir monopol yama antenin 3D baskı teknolojisi ile tasarımı, üretimi ve karakterizasyonu incelenmiştir. Işıyıcı olarak kullanılan üçgen bir yama, dik yamuğa benzeyen toprak düzlemlerinden oluşan eş düzlemsel dalga kılavuz beslenmiştir. Toplam boyutu 20.7×28.6 mm2 olan bu kompakt antenin üretiminde alttaş olarak 1 mm kalınlığında PLA malzemesi tercih edilmiştir. Önerilen UGB antenin yama ve toprak düzlemlerinden oluşan iletken kısımları ise bakır bant ile kaplanarak oluşturulmuştur. 2.75-13 GHz çalışma frekans aralığı ile %165 oransal bant genişliğine sahip anten çalışma bandı boyunca %83’ün üzerinde bir ışıma verimliği sunmaktadır. Maksimum kazanç değerinin 5.5 dBi olduğu 3D baskılı UGB yama anten, çok yönlü ışıma karakteristiğine de sahiptir. Ayrıca, yapılan ölçümlerle önerilen antenin ışıma performansı da doğrulanmıştır. Bu çalışma ile 3D baskı teknolojisinin yama antenlerin üretimindeki kullanılabilirliği ve tasarım esnekliği vurgulanmaktadır. Gelecekte, bu teknoloji üzerindeki çalışmaların kablosuz haberleşme sistemlerinin daha da gelişmesine katkı sağlaması beklenmektedir.Advancements in wireless communication technologies are driving the need for high-speed data transfer. In this context, ultra-wideband (UWB) technology emerges as a new wireless communication solution capable of operating over a wide frequency range. The production of antennas, an essential component of this technology, is drawing attention to 3D printing technology. This study examines the design, production, and characterization of a compact monopole patch antenna designed for use in wideband wireless communication systems using 3D printing technology. A triangular patch serving as the radiator is fed by a coplanar waveguide resembling a tapered trapezoid. This compact antenna, with a total size of 20.7×28.6 mm², utilizes PLA material with a thickness of 1 mm as the substrate. The conductive parts consisting of the patch and ground planes of the proposed UWB antenna are constructed using copper tape. With a working frequency range of 2.75-13 GHz and a 165% fractional bandwidth, the antenna provides over 83% radiation efficiency across the operating band. The antenna exhibits a maximum gain of 5.5 dBi and features omnidirectional radiation characteristics. Additionally, measurements confirm the radiation performance of the proposed antenna. This study highlights the usability and design flexibility of 3D printing technology in patch antenna production. Future research on this technology is expected to further contribute to the advancement of wireless communication systems