378 research outputs found
ESP for Biotechnology Purposes in Serbian Higher Education: the Skills Required and Blended Learning Environment
Biotechnology engineering is a complex domain that explores the use of living systems and organisms to develop products or any technological application that uses biological systems and living organisms to make or modify products or processes for specific use in the production of raw food, feed, and food processing. English as a foreign language in biotechnology engineering reflects the complexity in terms of content knowledge, language skills, and strategies characteristic of biotechnology. The article focuses on the knowledge and skills a biotechnology engineer should acquire with the emphasis on communicative language ability in English as a foreign language for specific purposes, as well as on the gains and obstacles of a blended learning language environment from the perspective of a Serbian higher education setting. Additionally, small-scale research was carried out to examine the potential differences in the levels of biotechnology undergraduate students\u27 communicative language ability in two language learning environments - blended language learning and face-to-face language instruction in prepandemic and pandemic times. The obtained results indicate that blended learning instruction during the pandemic enhanced the students\u27 communication skills in English for biotechnology purposes
Cellular and Wi-Fi technologies evolution: from complementarity to competition
This PhD thesis has the characteristic to span over a long time because while working on it, I was working as a research engineer at CTTC with highly demanding development duties. This has delayed the deposit more than I would have liked. On the other hand, this has given me the privilege of witnessing and studying how wireless technologies have been evolving over a decade from 4G to 5G and beyond.
When I started my PhD thesis, IEEE and 3GPP were defining the two main wireless technologies at the time, Wi-Fi and LTE, for covering two substantially complementary market targets. Wi-Fi was designed to operate mostly indoor, in unlicensed spectrum, and was aimed to be a simple and cheap technology. Its primary technology for coexistence was based on the assumption that the spectrum on which it was operating was for free, and so it was designed with interference avoidance through the famous CSMA/CA protocol. On the other hand, 3GPP was designing technologies for licensed spectrum, a costly kind of spectrum. As a result, LTE was designed to take the best advantage of it while providing the best QoE in mainly outdoor scenarios.
The PhD thesis starts in this context and evolves with these two technologies. In the first chapters, the thesis studies radio resource management solutions for standalone operation of Wi-Fi in unlicensed and LTE in licensed spectrum. We anticipated the now fundamental machine learning trend by working on machine learning-based radio resource management solutions to improve LTE and Wi-Fi operation in their respective spectrum. We pay particular attention to small cell deployments aimed at improving the spectrum efficiency in licensed spectrum, reproducing small range scenarios typical of Wi-Fi settings.
IEEE and 3GPP followed evolving the technologies over the years: Wi-Fi has grown into a much more complex and sophisticated technology, incorporating the key features of cellular technologies, like HARQ, OFDMA, MU-MIMO, MAC scheduling and spatial reuse. On the other hand, since Release 13, cellular networks have also been designed for unlicensed spectrum. As a result, the two last chapters of this thesis focus on coexistence scenarios, in which LTE needs to be designed to coexist with Wi-Fi fairly, and NR, the radio access for 5G, with Wi-Fi in 5 GHz and WiGig in 60 GHz. Unlike LTE, which was adapted to operate in unlicensed spectrum, NR-U is natively designed with this feature, including its capability to operate in unlicensed in a complete standalone fashion, a fundamental new milestone for cellular. In this context, our focus of analysis changes. We consider that these two technological families are no longer targeting complementarity but are now competing, and we claim that this will be the trend for the years to come.
To enable the research in these multi-RAT scenarios, another fundamental result of this PhD thesis, besides the scientific contributions, is the release of high fidelity models for LTE and NR and their coexistence with Wi-Fi and WiGig to the ns-3 open-source community. ns-3 is a popular open-source network simulator, with the characteristic to be multi-RAT and so naturally allows the evaluation of coexistence scenarios between different technologies. These models, for which I led the development, are by academic citations, the most used open-source simulation models for LTE and NR and havereceived fundings from industry (Ubiquisys, WFA, SpiderCloud, Interdigital, Facebook) and federal agencies (NIST, LLNL) over the years.Aquesta tesi doctoral tĂ© la caracterĂstica d’allargar-se durant un llarg perĂode de temps ja que mentre treballava en ella, treballava com a enginyera investigadora a CTTC amb tasques de desenvolupament molt exigents. Això ha endarrerit el dipositar-la mĂ©s del que m’haguĂ©s agradat. D’altra banda, això m’ha donat el privilegi de ser testimoni i estudiar com han evolucionat les tecnologies sense fils durant mĂ©s d’una dècada des del 4G fins al 5G i mĂ©s enllĂ . Quan vaig començar la tesi doctoral, IEEE i 3GPP estaven definint les dues tecnologies sense fils principals en aquell moment, Wi-Fi i LTE, que cobreixen dos objectius de mercat substancialment complementaris. Wi-Fi va ser dissenyat per funcionar principalment en interiors, en espectre sense llicència, i pretenia ser una tecnologia senzilla i barata. La seva tecnologia primĂ ria per a la convivència es basava en el supòsit que l’espectre en el que estava operant era de franc, i, per tant, es va dissenyar simplement evitant interferències a travĂ©s del famĂłs protocol CSMA/CA. D’altra banda, 3GPP estava dissenyant tecnologies per a espectres amb llicència, un tipus d’espectre costĂłs. Com a resultat, LTE estĂ dissenyat per treure’n el mĂ xim profit alhora que proporciona el millor QoE en escenaris principalment a l’aire lliure. La tesi doctoral comença amb aquest context i evoluciona amb aquestes dues tecnologies. En els primers capĂtols, estudiem solucions de gestiĂł de recursos de radio per a operacions en espectre de Wi-Fi sense llicència i LTE amb llicència. Hem anticipat l’actual tendència fonamental d’aprenentatge automĂ tic treballant solucions de gestiĂł de recursos de radio basades en l’aprenentatge automĂ tic per millorar l’LTE i Wi-Fi en el seu espectre respectiu. Prestem especial atenciĂł als desplegaments de cèl·lules petites destinades a millorar la eficiència d’espectre llicenciat, reproduint escenaris de petit abast tĂpics de la configuraciĂł Wi-Fi. IEEE i 3GPP van seguir evolucionant les tecnologies al llarg dels anys: El Wi-Fi s’ha convertit en una tecnologia molt mĂ©s complexa i sofisticada, incorporant les caracterĂstiques clau de les tecnologies cel·lulars, com ara HARQ i la reutilitzaciĂł espacial. D’altra banda, des de la versiĂł 13, tambĂ© s’han dissenyat xarxes cel·lulars per a espectre sense llicència. Com a resultat, els dos darrers capĂtols d’aquesta tesi es centren en aquests escenaris de convivència, on s’ha de dissenyar LTE per conviure amb la Wi-Fi de manera justa, i NR, l’accĂ©s a la radio per a 5G amb Wi-Fi a 5 GHz i WiGig a 60 GHz. A diferència de LTE, que es va adaptar per funcionar en espectre sense llicència, NR-U estĂ dissenyat de forma nativa amb aquesta caracterĂstica, inclosa la seva capacitat per operar sense llicència de forma autònoma completa, una nova fita fonamental per al mòbil. En aquest context, el nostre focus d’anĂ lisi canvia. Considerem que aquestes dues famĂlies de tecnologia ja no estan orientades cap a la complementarietat, sinĂł que ara competeixen, i afirmem que aquesta serĂ el tendència per als propers anys. Per permetre la investigaciĂł en aquests escenaris multi-RAT, un altre resultat fonamental d’aquesta tesi doctoral, a mĂ©s de les aportacions cientĂfiques, Ă©s l’alliberament de models d’alta fidelitat per a LTE i NR i la seva coexistència amb Wi-Fi a la comunitat de codi obert ns-3. ns-3 Ă©s un popular simulador de xarxa de codi obert, amb la caracterĂstica de ser multi-RAT i, per tant, permet l’avaluaciĂł de manera natural d’escenaris de convivència entre diferents tecnologies. Aquests models, pels quals he liderat el desenvolupament, sĂłn per cites acadèmiques, els models de simulaciĂł de codi obert mĂ©s utilitzats per a LTE i NR i que han rebut finançament de la indĂşstria (Ubiquisys, WFA, SpiderCloud, Interdigital, Facebook) i agències federals (NIST, LLNL) al llarg dels anys.Esta tesis doctoral tiene la caracterĂstica de extenderse durante mucho tiempo porque mientras trabajaba en ella, trabajaba como ingeniera de investigaciĂłn en CTTC con tareas de desarrollo muy exigentes. Esto ha retrasado el depĂłsito más de lo que me hubiera gustado. Por otro lado,
gracias a ello, he tenido el privilegio de presenciar y estudiar como las tecnologĂas inalámbricas
han evolucionado durante una década, de 4G a 5G y más allá.
Cuando comencé mi tesis doctoral, IEEE y 3GPP estaban definiendo las dos principales
tecnologĂas inalámbricas en ese momento, Wi-Fi y LTE, cumpliendo dos objetivos de mercado
sustancialmente complementarios. Wi-Fi fue diseñado para funcionar principalmente en
interiores, en un espectro sin licencia, y estaba destinado a ser una tecnologĂa simple y barata.
Su tecnologĂa primaria para la convivencia se basaba en el supuesto en que el espectro en
el que estaba operando era gratis, y asà fue diseñado simplemente evitando interferencias a
travĂ©s del famoso protocolo CSMA/CA. Por otro lado, 3GPP estaba diseñando tecnologĂas
para espectro con licencia, un tipo de espectro costoso. Como resultado, LTE está diseñado
para aprovechar el espectro al máximo proporcionando al mismo tiempo el mejor QoE en
escenarios principalmente al aire libre.
La tesis doctoral parte de este contexto y evoluciona con estas dos tecnologĂas. En los
primeros capĂtulos, estudiamos las soluciones de gestiĂłn de recursos de radio para operaciĂłn
en espectro Wi-Fi sin licencia y LTE con licencia. Anticipamos la tendencia ahora fundamental
de aprendizaje automático trabajando en soluciones de gestión de recursos de radio para
mejorar LTE y funcionamiento deWi-Fi en su respectivo espectro. Prestamos especial atenciĂłn
a las implementaciones de células pequeñas destinadas a mejorar la eficiencia de espectro
licenciado, reproduciendo los tĂpicos escenarios de rango pequeño de la configuraciĂłn Wi-Fi.
IEEE y 3GPP siguieron evolucionando las tecnologĂas a lo largo de los años: Wi-Fi
se ha convertido en una tecnologĂa mucho más compleja y sofisticada, incorporando las
caracterĂsticas clave de las tecnologĂas celulares, como HARQ, OFDMA, MU-MIMO, MAC
scheduling y la reutilización espacial. Por otro lado, desde la Release 13, también se han
diseñado redes celulares para espectro sin licencia. Como resultado, los dos Ăşltimos capĂtulos
de esta tesis se centran en estos escenarios de convivencia, donde LTE debe diseñarse para
coexistir con Wi-Fi de manera justa, y NR, el acceso por radio para 5G con Wi-Fi en 5 GHz
y WiGig en 60 GHz. A diferencia de LTE, que se adaptĂł para operar en espectro sin licencia,
NR-U está diseñado de forma nativa con esta función, incluyendo su capacidad para operar
sin licencia de forma completamente independiente, un nuevo hito fundamental para los
celulares. En este contexto, cambia nuestro enfoque de análisis. Consideramos que estas dos
familias tecnológicas ya no tienen como objetivo la complementariedad, sino que ahora están
compitiendo, y afirmamos que esta será la tendencia para los próximos años.
Para permitir la investigaciĂłn en estos escenarios de mĂşltiples RAT, otro resultado fundamental
de esta tesis doctoral, además de los aportes cientĂficos, es el lanzamiento de modelos de alta
fidelidad para LTE y NR y su coexistencia con Wi-Fi y WiGig a la comunidad de cĂłdigo
abierto de ns-3. ns-3 es un simulador popular de red de cĂłdigo abierto, con la caracterĂstica
de ser multi-RAT y asĂ, naturalmente, permite la evaluaciĂłn de escenarios de convivencia
entre diferentes tecnologĂas. Estos modelos, para los cuales liderĂ© el desarrollo, son por citas
académicas, los modelos de simulación de código abierto más utilizados para LTE y NR y
han recibido fondos de la industria (Ubiquisys, WFA, SpiderCloud, Interdigital, Facebook) y
agencias federales (NIST, LLNL) a lo largo de los años.Postprint (published version
A Guide for Reading and Using online Resources
The development of the information society and information technology gave rise to
new opportunities for learning and challenged established practices considering how
teaching and learning should be organized. Yet, until recently, much of the learning
materials were protected by propriety rights and not reachable without passwords. The open
educational resource (OER) movement aims to encourage and enable freely sharing content.
Open educational resources (OER) are digitalized materials offered freely and openly for
educators, students and self-learners to use and reuse for teaching, learning and research
(Center for Educational Research and Innovation, OECD, 2007) including learning content,
software tools, and implementation resources such as open licenses.
With the development of the World Wide Web and open educational resources,
more texts are now processed on screen. Reading in online environment is often considered
as reading practice that is different to that of reading in print. A key difference between the
two kinds of reading is considered to be rooted in the nature of hypertext where presentation
of information is not linear but multi-linear affording different access routes and different
reading options.
In order to put the reading into specific context, this material has been prepared as a
short guide for reading and using online resources in the field of agriculture. Various online
resources are presented, both generally and specifically for the agriculture and related
disciplines. A guide for reading and using online resources is designed to be used by high
school teachers in the field of agriculture and related fields, and agricultural advisors in
Serbia. It can be useful for the current and future students of both agriculture and other
fields of science, and for professionals in other domains.
Printing of the guide is funded by TEMPUS project CaSA Building Capacity of
Serbian Agricultural Education to Link with Society, coordinated by University of
Belgrade, Faculty of Agriculture
A Guide for Using a Dictionary
Learning vocabulary as the building blocks for communication plays an important
role in foreign and second language learning as it is an essential component of becoming a
fluent foreign language user. Very often vocabulary learning occurs as a product of reading.
While reading, a sentence could be incomprehensible to the readers by the occurrence of a
single unknown word and the learner can consult the dictionary to understand the text.
Through regular reading the learner may remember and recognize some new words he/she
came across in his/her reading. Of course, we all should be aware that no dictionary contains
every word in the language. The sciences, medicine and technology generate a lot of words
that never make it into a dictionary; numerous foreign words that appear in English-language
contexts are left out. A great many words are invented all the time and then they simply
vanish from the record.
This material has been prepared as a guide for using various types of dictionaries with
the aim of increasing foreign/second learners’ vocabulary in English as a foreign/second
language. It is convenient for the learners of different levels of English language and
appropriate to be used in different teaching/learning environments, both in face-to-face and elearning.
A guide for using a dictionary is designed to be used by high school teachers in the
field of agriculture and related fields, and agricultural advisors in Serbia. Also, it can be
useful for the current and future students of both agriculture and other fields of science, and
for professionals in other domains.
Printing of the guide is funded by TEMPUS project CaSA Building Capacity of
Serbian Agricultural Education to Link with Society, coordinated by University of Belgrade,
Faculty of Agriculture
INFORMATION AND COMMUNICATIONS TECHNOLOGY AS A TOOL TO SUBSTITUTE IN-PERSON VISITS IN THE SERBIAN PRISON SYSTEM DURING THE COVID-19 RESTRICTIVE MEASURES
In an attempt to properly address one of the greatest challenges for prison administrations around the world facing Covid-19, namely, to ensure regular communication between the inmates and their families, the Serbian Penal Administration, supported by German NGO Help e.V, procured the ICT equipment aimed at substituting the in-person visits. The author decided to assess the impact of this pilot project on the right of inmates to communicate with their family members, exploring their attitudes and the attitudes of professionals/prison staff that work with them, to get both perspectives. The results of the research showed that the online communication ensured through the pilot project has significantly contributed to preserving contacts and family relations in the changing environment of the Covid-19 restrictive measures, although it cannot completely replace family visits based on, in-person contact. However, the research also led to some of the remaining obstacles to a wider application of this, substitutive approach, among others, concerning the lack of IT literacy and the both of inmates and their family members, and to the life in poverty and/or in remote country areas. Additionally, this research identified a remaining need for further financial investment in the IT equipment to ensure adequate frequency and duration of communication, but also the need to revise/upgrade an existing treatment approach to integrating modern technologies/IT literacy as tools to contribute to the effectiveness of inmates’ reintegration
Concept of the Detuned Primary Coupling and Model Measurements for the Radiofrequency System of the Vincy Cyclotron
Analysis of the effects of anticorruption policies in Montenegro 2012/2013 - Recommendations for improvement
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