Akusztikai célú anyagok dinamikai tulajdonságainak kutatása = Dynamic properties of materials for sound insulation in buildings

A téma középpontjában az akusztikai célú anyagok dinamikai tulajdonságának, illetve viselkedésének kutatása állt. A munkának alapvetően három célja volt. Az egyik cél az volt, hogy új ismereteket szerezzünk az akusztikai célú viszkoelasztikus anyagok dinamikai tulajdonságainak frekvenciafüggéséről, különös tekintettel a nagyfrekvenciás tartományra. Ennek eredményeként arra az új megállapításra jutottunk, hogy a viszkoelasztikus anyagok komplex rugalmassági modulusa nagyfrekvencián nem korlátos növekedést is mutathat. Igazoltuk, hogy ez a nagyfrekvenciás viselkedés összhangban van az általános érvényű Kramers-Krönig diszperziós összefüggésekkel. A kutatás másik céljának megfelelően kidolgoztunk egy új anyagmodellt, amely elsősorban a kis veszteségű anyagok esetében alkalmas a dinamikai tulajdonságok frekvenciafüggésének matematikai leírására. A kutatás harmadik célja a viszkoelasztikus anyagok komplex Poisson száma veszteségi része - az ú.n. Poisson veszteségi tényező értékének a meghatározása volt. Ennek során igazoltuk, hogy a Poisson veszteségi tényező az anyag energiaelnyelő képességén kívül a dinamikai Poisson számtól is függ. Új elméleti összefüggéseket dolgoztunk ki, amelyek lehetővé teszik a Poisson veszteségi tényező meghatározását a nyírási veszteségi tényező és a dinamikai Poisson szám ismeretében. Az összefüggések érvényességét kísérleti adatokkal is igazoltuk. Kutatási eredményeinket a szakma rangos, nemzetközi folyóirataiban, illetve fórumain közöltük. | The dynamic elastic and damping properties of solid materials used for sound and vibration control were in focus of this research work. The research project basically had three aims. The first aim was to investigate the frequency dependences of dynamic properties of viscoelastic materials with special respect to the high frequency range. As a result of investigations it has been found that the complex modulus of elasticity of viscoelastic materials may exhibit unbounded increase at high frequencies. It has been proved that the unbounded high frequency behaviour is in agreement with the Kramers-Kronig dispersion relations. The second aim of the project was to search for material models to describe mathematically the dynamic behaviour of materials used for acoustical purposes. A new model has been developed which is able to describe the dynamic behaviour of solid materials experienced over a certain frequency range. The third research aim was to determine the Poisson's loss factor of solid viscoelastic materials. It has been proved that the magnitude of the Poisson?s loss factor is proportional to the damping in viscoelastic material, moreover it is dependent on the dynamic Poisson?s ratio too. New theoretical relationships have been found which enable one to determine the Poisson?s loss factor from knowledge of the shear loss factor and the dynamic Poisson's ratio. The theoretical results have been verified with experimental data

Three-dimensional virtual refocusing of fluorescence microscopy images using deep learning

Three-dimensional (3D) fluorescence microscopy in general requires axial scanning to capture images of a sample at different planes. Here we demonstrate that a deep convolutional neural network can be trained to virtually refocus a 2D fluorescence image onto user-defined 3D surfaces within the sample volume. With this data-driven computational microscopy framework, we imaged the neuron activity of a Caenorhabditis elegans worm in 3D using a time-sequence of fluorescence images acquired at a single focal plane, digitally increasing the depth-of-field of the microscope by 20-fold without any axial scanning, additional hardware, or a trade-off of imaging resolution or speed. Furthermore, we demonstrate that this learning-based approach can correct for sample drift, tilt, and other image aberrations, all digitally performed after the acquisition of a single fluorescence image. This unique framework also cross-connects different imaging modalities to each other, enabling 3D refocusing of a single wide-field fluorescence image to match confocal microscopy images acquired at different sample planes. This deep learning-based 3D image refocusing method might be transformative for imaging and tracking of 3D biological samples, especially over extended periods of time, mitigating photo-toxicity, sample drift, aberration and defocusing related challenges associated with standard 3D fluorescence microscopy techniques.Comment: 47 pages, 5 figures (main text

Professional Development in CTE Data Driven Methods: Development of a Research-Based Intervention

An initial survey conducted by the authors in 2009 determined the amount and type of preparation career technical educators (CTE) had regarding the use of assessment data for program and instructional improvement; this survey was the basis for development of an intervention for teachers on interpretation of assessment data for improvement of classroom instruction. The intervention, titled Career and Technical Educators Using a Data Driven Improvement Model or CTEDDI, was developed and successfully piloted in five states during spring semester 2010; the results of the pilot study have been used to revise the materials and process to produce a professional development program to help CTE educators improve their data skills and instruction

On a initial value problem arising in mechanics

We study initial value problem for a system consisting of an integer order and distributed-order fractional differential equation describing forced oscillations of a body attached to a free end of a light viscoelastic rod. Explicit form of a solution for a class of linear viscoelastic solids is given in terms of a convolution integral. Restrictions on storage and loss moduli following from the Second Law of Thermodynamics play the crucial role in establishing the form of the solution. Some previous results are shown to be special cases of the present analysis

Evolution of KChIP2 Gene Function is Localized Within the Core Promoter and 5’ UTR

Plan des Kaufs der A. Voemelschen Buchhandlung, Leipzi

Becoming IELTS Examiners: Demystifying Native-Speakerism in the Area of English Language Testing

The field of English language teaching (ELT) has long been a fertile soil for native-speakerism where the native English teachers (NESTs) enjoy the privilege to be crowned as the ideal teachers of the language.  Such belief is ingrained in all aspects of ELT including English language testing such as in International English language Testing System (IELTS), where the presence of non-native English examiners is extremely rare. Departing from this phenomenon, this study, conducted as a narrative case study, embarked to counter such claim by looking into the professional credentials and experiences of three non-native English teachers (NNESTs) who, against all odds, become official IELTS examiners in Indonesia. The data of the study were gathered through interviews and analyzed using thematic analysis. The findings show that the participants develop native-like level of fluency as the result of their investment in developing English skills through engaging in English mediated communication, interactions and learning in private English language institutions (PELIs). Moreover, their success is also attributed to their international teaching certificates which opened doors for them to compete with NESTs. Thus, this study seeks to inspire NNESTs to continuously develop their teaching credentials and to boost their confidence as legitimate teachers of English.Pengajaran bahasa Inggris telah lama menjadi lahan subur bagi ideology native-speakerism; penutur asli Bahasa Inggris menikmati hak istimewa sebagai guru bahasa Inggris yang ideal. Keyakinan tersebut telah mendarah daging dalam semua aspek ELT termasuk tes bahasa Inggris seperti di International English Language Testing System (IELTS), di mana kehadiran penguji bahasa Inggris yang bukan penutur asli Bahasa Inggris masih sangat jarang ditemui. Karena fenomena tersebut, penelitian ini, dilakukan sebagai studi kasus naratif, bermaksud untuk mempertanyakan klaim tersebut dengan melihat kredensial profesional dan pengalaman tiga guru bahasa Inggris bukan penutur asli yang, dengan segala perjuangannya dalam melawan segala rintangan, untuk menjadi penguji IELTS resmi di Indonesia. Data penelitian dikumpulkan melalui wawancara dan dianalisisa menggunakan analisis tematik. Temuan menunjukkan bahwa para peserta penelitian mengembangkan tingkat kefasihan seperti penutur asli sebagai hasil dari investasi mereka dalam mengembangkan keterampilan bahasa Inggris melalui penggunaan Bahasa Inggris dalam komunikasi, interaksi social dan pembelajaran di lembaga bahasa Inggris. Selain itu, keberhasilan mereka juga tidak terlepas dari sertifikat pengajaran internasional yang mereka dapatkan yang telah memberikan kesempatan bagi mereka untuk bersaing dengan NEST. Oleh karena itu, penelitian ini bertujuan untuk menginspirasi NNEST untuk terus mengembangkan kredensial mengajar mereka dan meningkatkan kepercayaan diri mereka sebagai guru bahasa Inggris yang sah