Genetic Algorithms in Real-Time Imprecise Computing

This article describes the use of genetic algorithms in real-time systems that employ the imprecise computation paradigm. In real-time systems, the focus is on ensuring that a set of tasks each complete within their deadlines. Faults may occur in the computation or the environment that can cause missed deadlines. That is why the idea of using partial results, when exact ones cannot be produced within the deadline, has been introduced. This idea has been formalized using the concepts of anytime algorithms and imprecise computation and specific techniques have been developed for designing programs which can produce partial results and for developing systems that can support imprecise computation techniques. Genetic algorithms are methods that can be, without any adaptation, used in an imprecise computation system. They produce a solution that bears a certain measure of reliability. During the process of their execution, this solution is constant ly improving. They can be used as a part of a real-time system, especially for optimizing tasks where the classical algorithms are not applicable or its computational time proves to be too expensive

Određivanje lomne žilavosti konstrukcijskih ljepila prilikom odljepljivanja u modu-I pomoću testa dvostruke konzole

Double cantilever beam (DCB) test is the most commonly used test for determining the fracture resistance of structural adhesive joints in mode-I debonding. Test specimens are composed of two equal plates that are glued together, and then exposed to the opening load causing crack propagation along the bonded surface. During the experiment, loadline displacement, applied force and crack length are measured continuously. Using these data, the fracture toughness of the adhesive can be computed by the procedure given in the relevant ISO standard (BS ISO 25217:2009). The calculations are based on simple beam theory and linear elastic fracture mechanics (LEFM) equations. In this paper, we will present the standard method for performing a DCB test and the method for data processing required to obtain the adhesive fracture toughness, i.e. the critical energy release rate. Experiments are performed for SikaPower® 4720 adhesive, applied with controlled thickness between the aluminium plates (adherends). After the curing period recommended by the adhesive manufacturer, DCB specimens with piano hinges are loaded by a tensile-testing machine. Loading is applied in the displacement-control mode because when the crack starts to propagate, the applied load drops. Using the optical measurement system GOM Aramis, complete displacement field is recorded during the experiment. Displacement field is then used to obtain the actual load-line displacement of the adherends (different than the one recorded on the tensile-testing machine grips) and the position of the crack tip. After syncing the measurements from different devices, fracture toughness for the adhesive is determined and a statistical analysis performed.Test dvostruke konzole (eng. Double Cantilever Beam (DCB) test) je najčešće korišteni test za izračun lomne žilavosti u modu I kod konstrukcijskih lijepljenih spojeva. Testni uzorci se sastoje od dvije jednake pločice koje se prvo međusobno zalijepe, a zatim izlože opterećenju, što uzrokuje širenje pukotine duž ljepila. Tijekom eksperimenta kontinuirano se mjeri pomak, sila i duljina pukotine. Koristeći ove podatke, lomna žilavost ljepila se može izračunati prema postupcima navedenim u odgovarajućem ISO standardu (BS ISO 25217: 2009). Proračuni se temelje na jednostavnoj grednoj teoriji i linearno-elastičnoj mehanici loma. U ovom radu predstavit ćemo standardnu metodu za izvođenje DCB testa, a potom i metodu obrade podataka potrebnu za izračun lomne žilavosti, što odgovara kritičnoj promjeni oslobođene energije (eng. Critical Energy Release Rate). Eksperimenti su izvedeni za ljepilo SikaPower® 4720, s kontroliranom debljinom ljepila između aluminijskih pločica. Nakon razdoblja stvrdnjavanja prema preporuci proizvođača ljepila, DCB uzorci su preko zglobnog prihvata šarkama opterećeni vlačnom silom s kidalice. Opterećenje na kidalici se nanosi kontrolom pomaka, tako da pri monotonom povećanju pomaka najprije imamo povećanje opterećenja, a kada se pukotina počne širiti, naneseno opterećenje pada. Koristeći optički mjerni sustav GOM Aramis, tijekom eksperimenta mjereno je polje pomaka, koje je onda korišteno za mjerenje stvarnog pomaka aluminijskih pločica (umjesto onog zabilježenog na kidalici) i položaja vrha pukotine. Nakon sinkronizacije mjerenja različitih uređaja određena je lomna žilavost ljepila i izvršena statistička analiza rezultata

Openness in Teachers’ Digital Competence Frameworks: Looking for the Open Educator

There has been a wide variety of definitions of digital competence, from early narrow and technology-focused explanations to more recent attempts , such as the one by Ferrari (2013), who describes it as a complex concept encompassing a wide set of skills, attitudes and knowledge when performing tasks with Information and Communication Technologies (ICT). Furthermore, there have been various different attempts to describe teachers’ digital competence, as the literature review by McGarr and McDonagh (2019) demonstrates. These authors evidence that models either depict teachers’ digital competence in diverse taxonomies of areas and dimensions, or as a hierarchical and progressive evolution from low to high levels of awareness and ability. They observe that openness does not have a presence in most of the taxonomic models and thus they propose openness as a dimension of their four-part model, under the label of attitudes. In this current work, we analyse international and national teachers’ digital competence frameworks and review whether openness has been included in them, and, if so, how it is described. In the case of frameworks that offer a model of increasing performance, we observe the levels at which open-related concepts appear. An initial review of the frameworks by the European Commission, UNESCO, ISTE (US) and INTEF (Spain) indicates that ‘openness’ typically does not constitute a dimension in itself and tends to appear at intermediate and high levels of teachers’ digital competence, except from the UNESCO framework, where access to OER (Open Educational Resources) is present already at the lowest level. In this paper we reflect on the need for international and national frameworks of teacher professional development to boost openness: in particular, for open educational practices to be included at lower levels of teachers’ pre-service and in-service professional education. We argue that becoming an open educator requires both the development of the dispositions associated with reflective practice and the confidence to challenge neo-liberal educational assumptions in order to embrace participatory, equitable and open educational practices from the early stages of the development of teachers’ digital competence. References Ferrari, A. (2013) ‘DIGCOMP: A Framework for Developing and Understanding Digital Competence in Europe‘, Luxembourg: Publications Office of the European Union. Available at: https://publications.jrc.ec.europa.eu/repository/bitstream/JRC83167/lb-na-26035-enn.pdf McGarr, O. & McDonagh, A. (2019) ‘Digital Competence in Teacher Education‘, Output 1 of the Erasmus+ funded Developing Student Teachers’ Digital Competence (DICTE) project. Available at: https://dicte.oslomet.no/ Tur, Gemma; Marín, Victoria I.; Havemann, Leo; Keefer, Jeffrey; Marsh, J. Dawn; Nascimbeni, Fabio; Crump, Helen; Baker, Nick and García Vallejo, Mari Cruz (2018). Open Education as a threshold concept in Teacher Education: a theoretical framework for further research. In: OER18: Open to All, 18-19 Apr 2018, Bristol. http://oro.open.ac.uk/58239/ Tur, G., Havemann, L., Marsh, D., Keefer, J. M., & Nascimbeni, F. (2020). Becoming an open educator: towards an open threshold framework. Research in Learning Technology, 28. https://doi.org/10.25304/rlt.v28.233

Systemwide Clinical Ultrasound Program Development: An Expert Consensus Model.

Clinical ultrasound (CUS) is integral to the practice of an increasing number of medical specialties. Guidelines are needed to ensure effective CUS utilization across health systems. Such guidelines should address all aspects of CUS within a hospital or health system. These include leadership, training, competency, credentialing, quality assurance and improvement, documentation, archiving, workflow, equipment, and infrastructure issues relating to communication and information technology. To meet this need, a group of CUS subject matter experts, who have been involved in institution- and/or systemwide clinical ultrasound (SWCUS) program development convened. The purpose of this paper was to create a model for SWCUS development and implementation

Inicijalno otkrivena simptomatska metastaza u hipofizu u bolesnika s karcinomom prostate pjenušavih stanica: određivanje sigurne i efikasne terapije

Metastases to pituitary gland are unusual and mostly asymptomatic, presenting with local symptoms in one of ten patients, and only 3%-5% of them are of prostate origin. Here we report and evaluate the effectiveness and safety of multimodal treatment in a patient with pituitary metastasis of a prostate foamy gland carcinoma. A 78-year-old male patient presented with blurred vision and headache without a previous history of malignancy. Magnetic resonance imaging scans revealed a large sellar mass, with infiltration of the surrounding structures. Maximal trans-sphenoidal reduction of pituitary metastasis was performed, with a histologic finding of metastatic prostate foamy gland adenocarcinoma. Evaluation of the prostate specific antigen revealed a very high level (1461 ng/mL) and foamy gland carcinoma was found on prostate needle biopsy. The patient received 3Dconformal external beam radiotherapy with 6 MV photons to the sellar and parasellar region with a tumor dose of 44 Gy, followed by androgen deprivation therapy. Follow up magnetic resonance imaging done after radiotherapy showed shrinkage of the tumor process, with rapid prostate specific antigen decline to 0.3 ng/mL. The visual function was fully established and headache resolved. On the last follow up 14 months after the diagnosis, the patient was alive and free from clinical signs of disease. Tailored treatment, including limited radiotherapy in a higher palliative dose, in a patient with foamy gland symptomatic pituitary metastatic disease resulted in good local and systemic control of the disease. In older male patients with clinical and/or radiologic characteristics suggestive of metastatic pituitary disease, the prostate specific antigen test should be included as part of the work-up.Metastaze u hipofizu su vrlo rijetke, a oko 3%-5% čine metastaze s ishodištem u prostati, u većini slučajeva su asimptomatske, dok su lokalni simptomi prisutni samo u jednog od deset bolesnika. Ovim slučajem prikazujemo i procjenjujemo učinkovitost i sigurnost multimodalnog liječenja u bolesnika s metastazama u hipofizu primarnog ishodišta u karcinomu prostate pjenušavih stanica. Prikazuje se 78-godišnji muškarac bez prethodne anamneze maligne bolesti kod kojega su se pojavili simptomi zamućenog vida i glavobolje. Magnetskom rezonancom je otkrivena velika selarna masa s infiltracijom okolnih struktura. Učinjena je maksimalna transfenoidna redukcija metastaze u hipofizi te je dobiven histološki nalaz metastatskog adenokarcinoma prostate pjenušavih stanica. Otkrivena je vrlo visoka vrijednost za prostatu specifičnog antigena (1461 ng/mL) te je biopsijom prostate tankom iglom dobiven nalaz karcinoma pjenušavih stanica. Bolesnik je primio 3D-konformalnu radioterapiju vanjskim snopom s fotonima energije 6 MV na selarnu i paraselarnu regiju s tumorskom dozom od 44 Gy te je nastavio primati androgenu deprivacijsku terapiju. Kontrolna snimka magnetske rezonance pokazala je smanjenje tumorskog procesa s brzim padom za prostatu specifičnog antigena na 0,3 ng/mL. Uspostavljena je potpuna vizualna funkcija s postupnim nestankom glavobolje. Na posljednjem kontrolnom pregledu 14 mjeseci nakon postavljene dijagnoze bolesnik je živ, bez kliničkih znakova bolesti. Prilagođeno liječenje bolesnika sa simptomatskom metastatskom bolesti od karcinoma pjenušavih stanica, koje uključuje ograničenu radioterapiju u višoj palijativnoj dozi, rezultiralo je dobrom lokalnom i sistemskom kontrolom bolesti. U starijih muških bolesnika s kliničkim i/ili radiološkim osobinama sa sumnjom za metastatsku bolest u hipofizu test za prostatu specifičnog antigena trebao bi biti uključen kao dio obrade

Ankle syndesmosis: anatomy, mechanisms of injuries, diagnosis and treatment

Distalni tibiofibularni zglob odgovoran je za širinu i stabilnost takozvane zglobne viljuške gležnja koju sačinjavaju distalna tibija i distalna fibula. Prema nekim autorima tijekom uganuća gležnja u 95 % slučajeva dolazi i do ozljede ligamenta distalnog tibiofibularnog zgloba. Upravo je prepoznavanje ovih ozljeda od velike važnosti, jer se pacijenti s tim ozljedama liječe dvostruko dulje od pacijenata s ozljedama ligamentarnih struktura lateralne strane gležnja, a do povratka sportskim aktivnostima protekne i do 6 mjeseci. Standardni klinički testovi i klasične rendgenske snimke nisu često dostatni za postavljanje dijagnoze, pa je pri sumnji na ozljede sindezmoze potrebno učiniti i magnetsku rezonanciju. Način liječenja akutnih izoliranih ozljeda sindezmoze ovisi o stupnju nestabilnosti gležnja. Danas još uvijek postoje nedoumice i nesuglasja u postavljanju dijagnoze i liječenja takvih ozljeda. U ovom radu pokušali smo na sistematičan način prikazati anatomske karakteristike distalnog tibiofibularnog zgloba, ali i najnovije stavove u dijagnostici i liječenju ozljede sindezmoze.Distal tibiofibular joint is responsible for the distal crucial anatomic structure responsible for the ankle joint stability. According to some authors syndesmosis injury occurs in 95% of the lateral ankle sprain during sport activity. Syndesmotic injuries often require twice as long to return to sport as compared to isolated lateral ligament sprains and can lead to prolonged pain and disability. Clinical tests and plain radiography have limited diagnostic capacity and often MRI imaging is necessary. The treatment of the acute isolated syndesmotic injury depends on the ankle stability. Today still, there is some doubt and disagreement regarding diagnostic criteria, classification, and treatment of syndesmotic injury

Searching for Exoplanets Using a Microresonator Astrocomb

Detection of weak radial velocity shifts of host stars induced by orbiting planets is an important technique for discovering and characterizing planets beyond our solar system. Optical frequency combs enable calibration of stellar radial velocity shifts at levels required for detection of Earth analogs. A new chip-based device, the Kerr soliton microcomb, has properties ideal for ubiquitous application outside the lab and even in future space-borne instruments. Moreover, microcomb spectra are ideally suited for astronomical spectrograph calibration and eliminate filtering steps required by conventional mode-locked-laser frequency combs. Here, for the calibration of astronomical spectrographs, we demonstrate an atomic/molecular line-referenced, near-infrared soliton microcomb. Efforts to search for the known exoplanet HD 187123b were conducted at the Keck-II telescope as a first in-the-field demonstration of microcombs

Open Education as a threshold concept in Teacher Education: a theoretical framework for further research

* Threshold concept framework: A threshold concept can be considered as akin to a portal, opening up a new and previously inaccessible way of thinking about something. It represents a transformed way of understanding, or interpreting, or viewing something without which the learner cannot progress. As a consequence of comprehending a threshold concept there may thus be a transformed internal view of subject matter, subject landscape, or even worldview (Meyer and Land, 2003). Threshold concepts have been explored in many disciplines (Bradbeer, 2006) and may have a key role for the transformation of the students’ learning experience (Cousin, 2006). Since open education has implications for innovation and change (Peter and Deimann, 2013), we suggest exploring it as a threshold concept. There are five main attributes defined originally by Meyer and Land (2003) and three more have also been listed stemming from comments made by the authors (UCL, 2013): transformative, troublesome, irreversible, integrative, bounded, discursive, reconstitutive and liminal. * Openness as a threshold concept: 1. Transformative Is openness transformative for students involved in open educational practices? 2. Troublesome What difficulties do students face when being involved in open educational practices? 3. Irreversible How do students’ perceptions change when being involved in open educational practices? How do these changes impact visions of their own future professional careers? 4. Liminality How can the progressive change towards the open movement be scaffolded? How can feedback help in the construction of authentic open educational practices? 5. Discursive What kind of narrative do students involved in open educational practices develop? Does it reflect authentic construction of the open movement understanding? This is the theoretical framework for future research about openness as a threshold concept. More research is needed to obtain data that would throw light on how to address each particular attribute. This is an open call to those interested in going further in this line of research