Fuzzy logic expert system for calculating the parameters of coupled numerical analysis of the fluid and thin-walled structures interaction

U radu su prikazani rezultati numeričkih proračuna interakcije fluid-struktura korišćenjem diskretizacionih numeričkih metoda - metode konačnih elemenata za proračun naponsko-deformacionog stanja zida kanala i metode konačnih zapremina za numerički proračun dinamike fluida. Na osnovu dobijenih rezultata razvijen je fazi ekspertski sistem za procenu izlaznih parametara numeričkog proračuna, prikazane su osnovne karakteristike razvijenog fazi modela i rezultati dobijeni njegovom primenom. Analizirani su uticaji tri ulazna parametra - temperature unutrašnje površine zida kanala, razlike između temperatura unutrašnje i spoljašnje površine zida i faktora koji definiše gustinu numeričkih mreža - na dva izlazna parametra: vrednost pada statičkog pritiska niz struju i vrednost maksimalnih kombinovanih Fon Misesovih napona ostvarenih u strukturi kanala za zadate uslove opterećenja. Na osnovu dobijenih rezultata vidimo da formirani fazi ekspertski sistem može sa zadovoljavajućom tačnošću biti iskorišćen za procenu posmatranih izlaznih veličina, pri znatno kraćem vremenu potrebnom za proračun i uz angažovanje resursa računarskog sistema u značajno manjem obimu.This paper deal with structural deformation of one rectangular, closed, thin walled, steel made, thermally loaded channel and influence of this deformation on the air flow through the channel, recognised as coupled fluid-structure interaction problem. The geometrically non-linear deformation of thermally loaded channel was solved using commercial finite-element analysis software ANSYS. The unsteady Navier-Stokes equations in their conservation form defining fluid flow are solved using commercial computer fluid dynamics software ANSYS CFX. A fuzzy logic-based expert system has been developed to predict some results of structural and fluid flow numerical simulation instead of directly evaluating it by a time-consuming software coupling of finite-element and computer fluid dynamics numerical analysis. Three input parameters, namely temperature of channel inner walls, difference in temperature of inner and outer surface of channel wall, and factor of mesh size, are varied while solving the fluid-structure interaction problem. A pressure drop downstream the flow was considered as a computer fluid dynamics output parameter of importance, while Von Misses maximum stresses were an finite-element analysis output parameter observed. The developed FLES can predict the results of finite-element and computer fluid dynamics analysis, a pressure drop and Von Misses maximum stresses respectively, within a reasonable accuracy limit and at lower computation cost compared to the finite-element, and CFD computer fluid dynamics packages combined into series of multi-physics analyses

Fuzzy logic expert system for calculating the parameters of coupled numerical analysis of the fluid and thin-walled structures interaction

U radu su prikazani rezultati numeričkih proračuna interakcije fluid-struktura korišćenjem diskretizacionih numeričkih metoda - metode konačnih elemenata za proračun naponsko-deformacionog stanja zida kanala i metode konačnih zapremina za numerički proračun dinamike fluida. Na osnovu dobijenih rezultata razvijen je fazi ekspertski sistem za procenu izlaznih parametara numeričkog proračuna, prikazane su osnovne karakteristike razvijenog fazi modela i rezultati dobijeni njegovom primenom. Analizirani su uticaji tri ulazna parametra - temperature unutrašnje površine zida kanala, razlike između temperatura unutrašnje i spoljašnje površine zida i faktora koji definiše gustinu numeričkih mreža - na dva izlazna parametra: vrednost pada statičkog pritiska niz struju i vrednost maksimalnih kombinovanih Fon Misesovih napona ostvarenih u strukturi kanala za zadate uslove opterećenja. Na osnovu dobijenih rezultata vidimo da formirani fazi ekspertski sistem može sa zadovoljavajućom tačnošću biti iskorišćen za procenu posmatranih izlaznih veličina, pri znatno kraćem vremenu potrebnom za proračun i uz angažovanje resursa računarskog sistema u značajno manjem obimu.This paper deal with structural deformation of one rectangular, closed, thin walled, steel made, thermally loaded channel and influence of this deformation on the air flow through the channel, recognised as coupled fluid-structure interaction problem. The geometrically non-linear deformation of thermally loaded channel was solved using commercial finite-element analysis software ANSYS. The unsteady Navier-Stokes equations in their conservation form defining fluid flow are solved using commercial computer fluid dynamics software ANSYS CFX. A fuzzy logic-based expert system has been developed to predict some results of structural and fluid flow numerical simulation instead of directly evaluating it by a time-consuming software coupling of finite-element and computer fluid dynamics numerical analysis. Three input parameters, namely temperature of channel inner walls, difference in temperature of inner and outer surface of channel wall, and factor of mesh size, are varied while solving the fluid-structure interaction problem. A pressure drop downstream the flow was considered as a computer fluid dynamics output parameter of importance, while Von Misses maximum stresses were an finite-element analysis output parameter observed. The developed FLES can predict the results of finite-element and computer fluid dynamics analysis, a pressure drop and Von Misses maximum stresses respectively, within a reasonable accuracy limit and at lower computation cost compared to the finite-element, and CFD computer fluid dynamics packages combined into series of multi-physics analyses

Novi lekovi u terapiji osteoporoze - pregled 2. i 3. - faze kliničkih istraživanja

Osteoporosis is a chronic disease with increasing incidence that predominantly occurs in female population. There are evidences that bisphosphonates, selective estrogen receptor modulators, denosumab, teriparatide and strontium renalate, prevent vertebral fractures while alendronate, risedronate, zoledronic acid, denosumab and strontium renalate prevent hip fractures. Although these drugs are effective in osteoporosis treatment, their use is limited by their side-effects and low-adherence. The aim of this review article was to compare efficacy of new drugs for osteoporosis currently in phase 2 and 3 clinical trials. After reviewing 57 articles available on PubMed and Scopus databases that evaluated efficacy of osteoporosis medications, 10 papers, that fulfilled the review criteria, were selected for the analysis. Finally, the efficacy of five drugs was compared. Efficacy was evaluated by the values of bone mineral density (BMD) and bone turnover markers (BTM). In all the analyzed articles the BMD increased and changes of BTM were noted. The highest increase of lumbar BMD from the baseline values was achieved after six months of subcutaneous application of 20 μg/day teriparatide (11.3%). The lowest increase of BMD in the same region was recorded after six months of risedronate therapy 100 mg per os once monthly (2.1%). From ten selected articles, only one has reported data about fracture risk.Osteoporoza je hronična bolest koja je sve više zastupljena i to pretežno kod osoba ženskog pola. Postoje dokazi da bisfosfonati, selektivni modulatori estrogenskih receptora, denosumab, teriparatid i stroncijum ranelat mogu da preveniraju prelom kuka. Iako su ovi lekovi efikasni u lečenju osteoporoze, njihova upotreba je ograničena usled ispoljavanja neželjenih reakcija, a time i postojanja niske adherencije bolesnika. Cilj ovog preglednog rada bio je upoređivanje efikasnosti novih lekova za lečenje osteoporoze koji su trenutno u 2. i 3. fazi kliničkih istraživanja. Nakon pregleda 57 originalnih radova koji su imali za cilj da pokažu efikasnost lekova u lečenju osteoporoze, dostupnih na PubMed i Scopus bazi, za analizu je odabrano 10 radova koji su zadovoljili kriterijume za pretraživanje. Na kraju analize, poređena je efikasnost pet lekova. Efikasnost je evaluirana na osnovu vrednosti mineralne koštane gustine (BMD) i koštanih markera (BTM). Povećanje BMD vrednosti i promene u vrednostima BTM zabeležene su u svim radovima. Najveće povećanje BMD (za 11,3%) lumbalnog skeletnog regiona postignuto je nakon šestomesečne subkutane terapije teriparatidom u dozi 20 μg dnevno. Najmanje povećanje BMD (za 2,1%) istog skeletnog regiona zabeleženo je nakon šestomesečne per os terapije risedronatom u dozi od 100 mg jednom mesečno. Od deset analiziranih studija, samo je jedna prikazala podatke o riziku od frakture

Validation of the osteoporosis quality of life questionnaire QUALEFFO-41 for the Serbian population

Background: Vertebral fractures could lead to reduced physical, social and mental functioning, and loss of personal independence. Therefore, during the treatment of osteoporosis, it has become necessary to examine the changes in everyday functioning, well-being and health related quality of life (HRQOL). To that effect, this study aims to translate, culturally adapt, and validate the Serbian version of Quality of Life Questionnaire of the European Foundation for Osteoporosis (QUALEFFO-41) for patients with vertebral fractures. Methods: Nine female patients with osteoporosis participated in the pre-validation study. A validation, case-control study included two groups of female patients: one that consisted of 50 female patients with osteoporosis, and with at least one vertebral fracture, and another one that consisted of 50 control patients with osteoporosis but without fractures. They completed the QUALEFFO-41 and the EuroQol group questionnaire with five dimensions (EQ-5D) twice within a month. The validation study examined internal consistency, concurrent validity, test-retest reliability, sensitivity and specificity. Results: During the pre-validation study, three of the items in the QUALEFFO-41 were slightly changed. Afterwards, during the validation study, the statistically significant differences (adjusted for: age, duration of menopause, current employment and marital status) in the mean values of all domains and total scores between the groups were noted. For the case group, the internal consistency of the QUALEFFO-41 domains and of total questionnaire was above 0.70. The test-retest reliability was tested by the intraclass correlation coefficients (ICC) that were in range 0.87 - 0.96 for the case, and 0.15 - 0.83 for the control group. Correlations between the total scores of the QUALEFFO-41 and the EQ-5D health state value, for both groups were negative and statistically significant (r = -0.78, p lt 0.001 and r = -0.73, p lt 0.001, respectively). The QUALEFFO-41 had a better prediction of the value of HRQOL of cases compared to the generic questionnaire EQ-5D (the AUC difference was 0.099, p = 0.013). Conclusions: The Serbian QUALEFFO-41 version is reliable, valid, sensitive and predictive for examinations of HRQOL in patients with prevalent vertebral fractures and can be used in further studies

Assessment Results of Fluid-Structure Interaction Numerical Simulation Using Fuzzy Logic

A fuzzy approximation concept is applied in order to predict results of coupled computational structure mechanics and computational fluid dynamics while solving a problem of steady incompressible gas flow through thermally loaded rectangular thin-walled channel. Channel wall deforms into wave-type shapes depending on thermal load and fluid inlet velocity inducing the changes of fluid flow accordingly. A set of fluid-structure interaction numerical tests have been defined by varying the values of fluid inlet velocity, temperature of inner and outer surface of the channel wall, and numerical grid density. The unsteady Navier-Stokes equations are numerically solved using an element-based finite volume method and second order backward Euler discretization scheme. The structural model is solved by finite element method including geometric and material non-linearities. The implicit two-way iterative code coupling, partitioned solution approach, were used while solving these numerical tests. Results of numerical analysis indicate that gravity and pressure distribution inside the channel contributes to triggering the shape of deformation. In the inverse problem, the results of fluid-structure interaction numerical simulations formed a database of input variables for development fuzzy logic based models considering downstream pressure drop and maximum stresses as the objective functions. Developed fuzzy models predicted targeting results within a reasonable accuracy limit at lower computation cost compared to series of fluid-structure interaction numerical calculations. Smaller relative difference were obtained when calculating the values of pressure drop then maximal stresses indicating that transfer function influence on output values have to be additionally investigated

Locus of control, negative live events and psychopathological symptoms in collectivist adolescents

This document is the authors’ version of the final accepted manuscript, published online 21.10.2019 by Personality and Individual Differences. - Correspondence concerning this article should be addressed to Prof. Paulo Moreira, Instituto de Psicologia e de Ciências da Educação, Universidade Lusíada, Rua de Moçambique 21 e 71, Porto 4100-348, Portugal. Email: [email protected] current research trend is the identification of psychosocial variables that moderate and/or mediate the association between stressors and psychopathological symptoms. Research has shown Locus of Control (LoC) is a key cognitive component of this psychological process in adolescents from individualist cultures. It is unclear whether this finding can be generalized to collectivist adolescents given that LoC is argued to be a culturally relative construct. The study examined the moderating and mediating effects of LoC on the relationship between negative events and psychopathological symptoms (anxiety and depressive symptoms) in adolescents from collectivist countries (n = 2800). Consistent with prior research, negative life events and external LoC were associated with more psychopathological symptoms. Unlike past studies with samples from individualist countries, the study did not produce clear evidence that LoC moderated or mediated this relationship. Results are discussed in terms of cultural differences in the (un)desirability of external control

O debate sobre os métodos de ensino nos liceus portugueses (anos 30 a 60 do século XX)

Congresso realizado nos dias 6 a 9 de Maio de 2014, em Toluca, MéxicoA presente comunicação tem como objetivo refletir sobre os métodos de ensino, ao nível do ensino secundário, tal como são propostos e debatidos por educadores e professores em duas das grandes revistas pedagógicas consagrados a esse nível de ensino e ligadas a um importante contexto de formação de professores – o Liceu Normal de Pedro Nunes situado em Lisboa. Estamos a falar do Boletim do Liceu Normal de Lisboa Pedro Nunes (1932-1938) e de Palestra. Revista de pedagogia e cultura (1957-1973).info:eu-repo/semantics/publishedVersio

EMU Detection of a Large and Low Surface Brightness Galactic SNR G288.8-6.3

We present the serendipitous detection of a new Galactic Supernova Remnant (SNR), G288.8-6.3 using data from the Australian Square Kilometre Array Pathfinder (ASKAP)-Evolutionary Map of the Universe (EMU) survey. Using multi-frequency analysis, we confirm this object as an evolved Galactic SNR at high Galactic latitude with low radio surface brightness and typical SNR spectral index of $\alpha = -0.41\pm0.12$. To determine the magnetic field strength in SNR G288.8-6.3, we present the first derivation of the equipartition formulae for SNRs with spectral indices $\alpha>-0.5$. The angular size is 1.\!^\circ 8\times 1.\!^\circ 6 (107.\!^\prime 6 \times 98.\!^\prime 4) and we estimate that its intrinsic size is $\sim40$pc which implies a distance of $\sim1.3$kpc and a position of $\sim140$pc above the Galactic plane. This is one of the largest angular size and closest Galactic SNRs. Given its low radio surface brightness, we suggest that it is about 13000 years old.Comment: Accepted for publication in The Astrophysical Journa

Bringing the margin to the focus: 10 challenges for riparian vegetation science and management

Riparian zones are the paragon of transitional ecosystems, providing critical habitat and ecosystem services that are especially threatened by global change. Following consultation with experts, 10 key challenges were identified to be addressed for riparian vegetation science and management improvement: (1) Create a distinct scientific community by establishing stronger bridges between disciplines; (2) Make riparian vegetation more visible and appreciated in society and policies; (3) Improve knowledge regarding biodiversity—ecosystem functioning links; (4) Manage spatial scale and context-based issues; (5) Improve knowledge on social dimensions of riparian vegetation; (6) Anticipate responses to emergent issues and future trajectories; (7) Enhance tools to quantify and prioritize ecosystem services; (8) Improve numerical modeling and simulation tools; (9) Calibrate methods and increase data availability for better indicators and monitoring practices and transferability; and (10) Undertake scientific validation of best management practices. These challenges are discussed and critiqued here, to guide future research into riparian vegetation

Proizvodnja i percepcija govora

Zbornik radova okupio je 57 domaćih i inozemnih autora/ica, koji/e kroz 33 rada, iz različitih istraživačkih kutova, obrađuju recentne teme o proizvodnji i percepciji govora, te o njihovoj međuovisnosti u govornom procesu. Knjiga je posvećena profesoru Damiru Horgi povodom njegova sedamdesetog rođendana. Uz svaki rad naveden je sažetak na hrvatskom i engleskom jeziku. Zbornik je objavljen u suizdavaštvu Odsjeka za fonetiku Filozofskog fakulteta Sveučilišta u Zagrebu, Odjela za fonetiku Hrvatskoga filološkog društva i FF-pressa.Zbornik radova okupio je 57 domaćih i inozemnih autora/ica, koji/e kroz 33 rada, iz različitih istraživačkih kutova, obrađuju recentne teme o proizvodnji i percepciji govora, te o njihovoj međuovisnosti u govornom procesu. Knjiga je posvećena profesoru Damiru Horgi povodom njegova sedamdesetog rođendana. Uz svaki rad naveden je sažetak na hrvatskom i engleskom jeziku. Zbornik je objavljen u suizdavaštvu Odsjeka za fonetiku Filozofskog fakulteta Sveučilišta u Zagrebu, Odjela za fonetiku Hrvatskoga filološkog društva i FF-pressa