Elastica-based strain energy functions for soft biological tissue

Continuum strain energy functions are developed for soft biological tissues that possess long fibrillar components. The treatment is based on the model of an elastica, which is our fine scale model, and is homogenized in a simple fashion to obtain a continuum strain energy function. Notably, we avoid solving the full fourth-order, nonlinear, partial differential equation for the elastica by resorting to other assumptions, kinematic and energetic, on the response of the individual, elastica-like fibrils.Comment: To appear in J. Mech. Phys. Solid

EXPLORING PRE-SERVICE MATHEMATICS TEACHERS’ UNDERSTANDINGS OF COUNTABILITY AND INFINITY IN WEBQUEST BASED LEARNING ENVIRONMENT

Infinity concept is difficult to understand because of its nature. Even if the concept of infinity doesn’t directly take part in mathematics curriculum, it takes place on many topics such as lines, planes, sets, irrational numbers, limit, differentiation, and integration. The present study examined pre-service mathematics teachers’ understandings of infinity and countability concepts in WebQuest based learning environment. Twenty-nine pre-service teachers participated at the study. Data were collected through a questionnaire developed by the researchers and semi-structured interviews. Qualitative data were analyzed by using phenomenology research method. The findings of this study revealed that pre-service teachers generally defined infinite sets as the sets whose elements continue infinitely. They inclined to define countable sets as bounded sets, finite sets, and the sets with known elements. Whereas most of the students stated countable finite sets and countable infinite sets were existent, they also expressed uncountable finite sets and uncountable infinite sets were non-existent. They used natural numbers set as an example for the countable infinite sets. This research presented some implications for teacher education programme in the light of obtained findings.  Article visualizations

Eşyönsüz Mikro Yapıya Sahip Kalp Dokusundaki Büyümenin Modellenmesi Üzerine

Konferans Bildirisi -- Teorik ve Uygulamalı Mekanik Türk Milli Komitesi, 2013Conference Paper -- Theoretical and Applied Mechanical Turkish National Committee, 2013Bu çalışma eşyönsüz mikro yapıya sahip kalp dokusunda meydana gelen fizyolojik ve patolojik büyümenin modellenmesi için geliştirilen genel bir kinematik yaklaşımı konu almaktadır. Bu amaçla, şekil değiştirme gradyanı çarpımsal olarak elastik şekil değiştirme gradyanı ve büyüme tensörlerine parçalanmıştır. Büyümenin yönü kalp dokusunun mikro yapısı tarafından kontrol edilirken, büyümenin miktarı skalar büyüme değişkeni ile belirlenmektedir. Bu büyüme değişkeninin zamanla değişimini de hipertrofinin tipine göre değişen büyüme kriteri ve onun sınırlandırılmış çarpanı tarafından kontrol edilmektedir. Büyüme tensörü elde edildikten sonra şekil değiştirme gradyanının elastik kısmı hesaplanır. Bu tensör cinsinden ifade edilmiş olan serbest enerji fonksiyonundan Doyle-Ericksen formülü yardımı ile Kirchhoff gerilme tensörü elde edilir. Anahtar Kelimeler: Biyomekanik, Kalp Mekaniği, Büyüme, HipertrofiThis work is concerned with the generalized kinematic framework for finite growth in cardiac tissue. For this purpose, the deformation gradient is multiplicatively decomposed into an elastic part and a growth part. This naturally brings about an incompatible intermediate growth configuration. While the direction of growth is dictated by the architecture of the cardiac tissue, the amount of growth is determined by a scalar growth field whose evolution is governed by a corresponding disease-dependent growth criterion function and its bounded coefficient. Once the growth tensor is known, the elastic part of the deformation gradient, which directly enters the orthotropic energy storage function, can be readily obtained and the relevant stress tensor is determined through the Doyle-Ericksen formula. Keywords: Biomechanics, Cardiac Mechanics, Growth, Hypertroph

Virtual Heart Models: Multi-Physics Approaches to Computational Cardiology (VHEART)

Heart disease is the number one cause of death in industrialized nations. Despite the broad class of treatment techniques such as medication, surgery and tissue-engineered therapies, heart disease remains to be one of the most frequent, disabling, and life-threatening diseases. In Europe it accounts for almost half of overall annual mortality rate. In the European Union (EU) alone, cardiovascular disease causes over 2 million deaths per year. The cost of cardiovascular disease to the EU economy is €192 billion per year. As opposed to the traditional trial-and-error based therapies, a systematic, personalized simulation-aided approach offers a great potential for understanding, diagnosing, and treating heart failure through the sound understanding of functional and structural changes in the infarcted tissue and the computational tools of multi-scale solid mechanics. The proposed research aims: (1) to develop multi-scale models of computational cardiac electrophysiology, (2) to model the fully coupled electromechanics of the heart through a novel micro-structurally based kinematic approach, (3) to couple the electromechanical computational tool with the ionic models of cardiac electrophysiology, (4) to employ the new multi-scale tools of computational cardiology to explore the underlying complex mechanisms of heart diseases and thereby guide personalized cardiac therapies. The anticipated outcomes are: (A) a multi-scale computational electrophysiological tool that incorporates multi-physics ionic models in the implicit bidomain framework, (B) a better understanding of underlying physiological reasons for electrophysiological cardiac disease such as arrhythmia, left and right bundle blocks, (C) a novel, micro-structurally based, computationally efficient, modular electromechanical computational tool, (D) a virtual test environment for the patient-specific optimization of cardiac therapies and surgical procedures.EU, Funded under :FP7-PEOPLE-2011-CI

A WebQuest Example for Mathematics Education

AbstractIn this research a WebQuest that can be used in mathematics education is prepared. It was designed to teach coordinate system to seventh grade students in an entertaining way. The prepared WebQuest is published in mathematicswebquest.sitemynet.com web site. The aim of this project is to increase the effectiveness of learning process and enrich the course visually and provide interaction of students. Literature survey method is used in the research. The emergence of WebQuest, preparation process, design steps, important points for effective usage, usage of it in Turkey, advantages & disadvantages and limitations of the system are indicated. The history of WebQuest in Turkey, teacher and student perspectives are also implied in the study. The general view defends that this kind of activities can make a positive contribution on affective and cognitive abilities of learning environments. On the other hand, when the existing structure of studies taken into consideration, some negative situations about the technical deficiencies and teacher/student competence are observed

Enhanced Machine Learning Techniques for Early HARQ Feedback Prediction in 5G

We investigate Early Hybrid Automatic Repeat reQuest (E-HARQ) feedback schemes enhanced by machine learning techniques as a path towards ultra-reliable and low-latency communication (URLLC). To this end, we propose machine learning methods to predict the outcome of the decoding process ahead of the end of the transmission. We discuss different input features and classification algorithms ranging from traditional methods to newly developed supervised autoencoders. These methods are evaluated based on their prospects of complying with the URLLC requirements of effective block error rates below $10^{-5}$ at small latency overheads. We provide realistic performance estimates in a system model incorporating scheduling effects to demonstrate the feasibility of E-HARQ across different signal-to-noise ratios, subcode lengths, channel conditions and system loads, and show the benefit over regular HARQ and existing E-HARQ schemes without machine learning.Comment: 14 pages, 15 figures; accepted versio

From The Global Warming to Global Chaos

Risk of conflict between states in the international relations does not arise only from the struggle for power and sovereignty. Obstacle of access to vital resources and natural disasters also create potential cause of conflict. It is undeniable fact that while prosperity and wealth bring peace and tranquility to societies, poverty and famine paves the way for conflict. Climate changes which cause major problems we face now are also seen as a result of global warming. The most basic needs and life conditions for people are being threatened by drought, wildfires, hurricanes and floods caused by the global warming in these days. It is not possible for any country to solve the problems caused by global warming alone therefore full international cooperation is required in this regard. However many governments do not still believe everything explained by scientists about the global warming is real or too much important. On the other hand, the economic and political competitions among states make them be reluctant in order to take necessary steps for the common goal. Scientists has insistently warning that an increase in temperature 1,5° C above the pre industrial level would cause irreversible dramatic changes on earth. Moreover, situation would get worse when the feedback effect of existing greenhouse gases in the atmosphere is amplified and we will experience more and more bad effects of the global warming. Considering this dangerous situation, under the leadership of the UN, international initiatives continue to stop global warming since 1992. However, these efforts seem too far from successful yet. The clear acceptance of this failure was made by the UN Secretary General Antonio Guterres at the COP27 conference held in Egypt on 6 November 2022. As the Secretary General said that "we are in the fight of our lives and we are losing". It is not a realistic attitude to place all hopes on the success of an absolute international cooperation and sit back in fighting against the global warming. It is necessary that governments have to take all their own measures with this regard in advance. Considering climate anomalies which we are currently experiencing will get worse and unpreventable, states have to manage to adapt to climate challenges and must increase their resilience to cope with this reality. Otherwise, global warming may turn into a global chaos that cannot be overcomed and controlled. Keywords: Global Warming, Climate Change, Kyoto Protocol, National Security, Drought DOI: 10.7176/IAGS/97-04 Publication date:December 31st 202

Sensory enhancement of peripheral vision

More than 99% of the visual information is sampled by peripheral vision. Despite covering the majority of the visual field, the peripheral vision offers lower visual resolution than the fovea, that is responsible from gathering high resolution information from the central visual field. Although visual sensitivity changes drastically across the retina as a function of eccentricity, our visual experiences appear to be homogeneous. This apparent visual homogeneity is achieved by our visual system striving to optimize information gathering and minimize biological costs. To this end, the visual system uses various heuristics stemming from priors and expectations while dividing the labor of gathering information between available sensory systems. The aim of this dissertation is to provide an account of how various sensory mechanisms support peripheral vision. Particularly, in three studies, it investigated how peripheral vision and the execution of peripheral tasks are supported by transsaccadic learning and prediction, neural feedbacks providing additional processing resources, and supplementary information from other senses. Study I investigated how transsaccadic learning and object predictions of familiar objects supports peripheral vision. Through transsaccadic learning the visual system associates how the appearance of an object or a feature change from periphery to fovea. Using these object specific associations visual system generates predictions about these objects and how they would look like at different eccentricities. In addition, through lifelong experience on how object appearance changes as a function of eccentricity, the visual system could generate predictions even for novel objects. However, it was unclear whether object specific predictions reserved for familiar objects provide an advantage over general predictions that are also available for novel objects in visual tasks. Study I addressed this question in two experiments where observers unknowingly familiarized with a subset of the objects by performing a sham task that required them to make saccades to these objects. On the following day, they either performed a peripheral-foveal matching or transsaccadic change detection task with familiarized and novel objects. We found that the presence of familiar objects improved the performance in both tasks by providing more precise object specific predictions from previous peripheral-foveal associations that generalize across the visual hemifields. Thus, Study I shows that object specific predictions unique to familiar objects provide additional support to the peripheral vision and execution of peripheral tasks. Study II investigated a neural feedback mechanism that allows peripheral information to be processed in the fovea retinotopic cortex and supports peripheral discrimination. The support of the foveal-feedback mechanism in peripheral discrimination can be impaired when a foveal input is presented asynchronously with peripheral targets. However, it was not clear whether the peripheral object information has to compete with the foveal input for the same neural resources, or if it is masked by it. Study II tested both explanations with a peripheral letter discrimination using both novel and familiar characters. Crucially, we manipulated the spatial frequency compositions of the foveal noise. Thus, if the foveal noise is masking the foveal-feedback, we would expect the efficiency of the foveal noises to vary depending on the amount of shared spatial frequency with the peripheral characters. Alternatively, if foveal noise is competing with the foveal-feedback, we would expect a more general effect of foveal noise independent from how they are similar to the peripheral characters. We found that low spatial frequency foveal noise was more effective at impairing the peripheral discrimination of both familiar and novel characters, indicating a frequency specific masking of foveal-feedback. We follow-up this result with a control experiment where the low and medium spatial frequency noises were presented overlappingly with the peripheral and foveal characters. As anticipated, we found that low frequencies were more effective at masking peripheral characters than medium frequencies while the opposite pattern was true for the foveal characters. Additionally, behavioral oscillation analyses suggested that the masking of foveal-feedback is periodic at around 5 Hz. Thus, Study II shows that the peripheral discrimination of both novel and familiar objects is supported by a foveal-feedback mechanism that periodically processes peripheral information and subjects to masking. Study III investigated how imprecise peripheral information can be combined with sensory information from other modalities. More specifically, virtual and augmented reality applications are promising for augmenting user performance and experience by providing supplementary information across senses. However, one major bottleneck for these applications is to supplement information within a tight spatiotemporal window across different sensory modalities. Therefore, if and how spatiotemporally incongruent information from different sources is an important theoretical question with direct implications. Study III addressed this question by testing how imprecise peripheral information can be combined with supplementary tactile information when they are spatially and temporally incongruent. Using a custom-built setup, observers performed visual displacement judgments with or without spatially or temporally incongruent or congruent tactile displacement cues. Using their performance in the visual only condition, we modeled how observers combine visual and tactile information in the visuotactile conditions. We found that the combination weights systematically shifted towards tactile cues under temporal incongruency compared to congruency condition. In contrast, spatial incongruency altered how visual and tactile information are combined and hinted possible individual differences in cue combination strategies. Thus, the weighting of visual and tactile information is modulated and altered by spatial and temporal incongruency which might have important consequences for multisensory applications. Nevertheless, Study III suggests that despite large temporal and spatial incongruencies tactile cues can supplement peripheral visual information. In three studies, this dissertation seeks to understand how peripheral vision is supported by diverse neural and sensory mechanisms. In particular, peripheral vision is supported by precise object associations for familiar objects that are acquired through transsaccadic learning. These familiar object associations benefit peripheral matching and transsaccadic change detection by providing more precise peripheral to foveal and foveal to peripheral predictions than the general predictions available also for novel objects. Regardless of their familiarity, the peripheral discrimination of objects is also supported by a foveal-feedback mechanism that periodically processes peripheral object information in the foveal retinotopic areas. However, the processing of peripheral information is prone to masking by delayed foveal inputs with matching spatial frequency composition as the peripheral object. On the other hand, supplementary tactile information can be combined with imprecise peripheral information despite spatiotemporal incongruencies. However, while temporal incongruencies shift the weighting of visual and tactile information, spatial incongruencies can alter combination strategies differently across different individuals. In conclusion, these sensory interactions between peripheral vision and other sensory mechanisms support peripheral vision and offer better peripheral estimates for performing various tasks

Modeling the measurement uncertainty with Fuzzy approach

There are several types of uncertainty in a material characterization arisen from different sources of measurement errors, such as methodological, instrumental, and personal. As a reason of the uncertainty in material models, it is plausible to consider model parameters in an interval instead of a singleton. The probability theory is widely known method used for the consideration of uncertainties by means of a certain distribution function and confidence level concept. In this study, fuzzy logic is considered within a material characterization model to deal with the uncertainty coming from random measurement errors. Data points are treated using fuzzy numbers instead of single values to cover random measurement errors. In this context, an illustrative example, prepared with core strength-rebound hammer data obtained from a concrete structure, is solved and evaluated in detail. Results revealed that there is a potential for fuzzy logic to characterize the uncertainty in a material model arisen from measurement errors

Yabancı fenomenolojisi ve çeviribilimde yabancılaştırma sorunsalı

06.03.2018 tarihli ve 30352 sayılı Resmi Gazetede yayımlanan “Yükseköğretim Kanunu İle Bazı Kanun Ve Kanun Hükmünde Kararnamelerde Değişiklik Yapılması Hakkında Kanun” ile 18.06.2018 tarihli “Lisansüstü Tezlerin Elektronik Ortamda Toplanması, Düzenlenmesi ve Erişime Açılmasına İlişkin Yönerge” gereğince tam metin erişime açılmıştır.Çeviride her ne kadar yöntemsel olarak yabancılaştırma yöntemi ile yabancının yeri ve konumu aktarılmış olsa bile çeviride yabancının ne olduğuna veya yabancılığa dair bir ayrım yapılmamıştır. Xenoloji yabancılığın ne olduğundan öte yabancılık sorunun nasıl ortaya çıktığını göstermektedir. Çeviribilimde de xenolojik çalışma ile yabancılık sorunun tespiti mümkün olmaktadır. Çeviribilimde yabancının varlığı çeviri tanımlarında örtük bir şekilde yer almaktadır; xenoloji ile çeviri tanımlarının barındırdığı örtük yabancılık ortaya konulmuştur. Xenoloji yabancı sorununu ortaya çıkarırken yabancı fenomenolojisi ise yabancı sorununa çözüm yolları sunmaktadır. Çevirmen yabancıyı anlamadan veya yabancıyı deneyimlemeden kaynak dilden erek dile aktarım yapması mümkün değildir. Yabancı fenomenolojisi de yabancıyı anlama ve yabancı deneyiminden ortaya çıkmıştır. Ne yabancının ne de çevirinin genel geçer tek bir tanımı vardır. Yabancı fenomenolojisinin kurucusu Bernhard Waldenfels de yabancıya cevap verme ve yabancı tanımının çeşitliliğini sınırlamak adına yabancılığı üç türe ayırarak yabancılığın kendi içindeki sınırlarını da belirlemiştir. Waldenfels'in geliştirmiş olduğu yabancılık türleri çeviriye uyarlandığında sıradan yabancılık, metin türlerinde, çevirmenlerin başvuru kaynaklarında, çeviriye dair notlarda (önsöz ve dipnot gibi) görülmektedir. Metin içerisinde geçen dilsel ve kültürel farklılıklar yapısal/kültürel yabancılık olarak nitelendirilirken, çevirmenin zamansal, mekânsal, kültürel ve dilsel uzaklıktan dolayı yorumlayarak gerçekleştirdiği çeviriler ise radikal yabancılık içermektedirler. Çeviride yabancılığı temsil eden fenomenlerin başında mecazlar, dilsel varyasyonlar, kültürel semboller, başlık çevirileri, kelime ve dil oyunları yer alır. Çalışmada yabancılık sadece yabancılaştırma yönteminde değil, çeviribilimin genelinde var olduğunu gösterilmiş ve çeviribilimde xenoloji ile yabancı fenomenolojisi çalışmalarından da yararlanılarak yabancının yeri ve konumunun belirlenmesinde yeni bir bakış açısı sunmuştur.In translation studies, despite the fact that various facets of the concept of 'alien' and the 'method of alienation' had been previously defined, a clear-cut definition was not provided for its distinctive features. Xenology concerns itself more with discovering how the question of 'alienation' had emerged than with seeking to reveal what it really is. While the question of 'alienation' can be studied with xenological investigations in translation studies, an implicit definition is suggested for the existence of the 'alien'. Thus, xenology only offers to define an 'implicit alienness' through the lens of translation theory. Whereas xenology raises questions over the concept of 'alien', 'alien phenomenology' introduces a number of solutions as to how to deal with this question. Translators can not be expected to perform the act of translation from the source language into the target language, without raising their awareness regarding 'alien experience'. Alien phenomenology can, in a sense, be assumed to have developed from alien experience. Attempts to come up with a refined definition of 'alien' and 'translation' will be futile. Bernard Waldenfels, the founder of the 'phenomenology of alien', introduced a three part classification for 'alienness' in order to define its limits. When Waldenfels's 'alienness degrees' are incorporated into translation studies, 'everyday alienness' reveals itself in text types, resources that translators resort to, as well as their notes for the translation performance. While the textually defined linguistic and cultural differences are cited as structural/cultural alienness, radical alienness is referred to as a variety of challenges facing the translators due to temporal, spacial, cultural ve linguistic distance. Among the phenomena that represent alienation in translation task are metaphors, linguistic variations, cultural symbols, and puns. This study seeks to highlight that 'alienness' not only exists in the method of alienation, but also in translation studies as a whole and that the place and role of the concept of 'alien' can be valued by making use of the studies of alien phenomenology and xenology in translation studies