Evaluation of cybersickness in virtual reality in driving simulator

Virtual reality (VR) devices are becoming a more popular and widespread tool for learning, gaming and entertainment purposes. One of familiar problems of emerging in VR is side effect known as cybersickness, which can be a nuisance for consumers of VR content. This occurrence can be explained as visual and vestibular conflict. The problem with cybersickness lies within the fact that the body is stationary, but eyes perceive motion in virtual reality, also known as vection. Cybersickness symptoms that often occur include blurred vision, headache, vertigo, upset stomach and other. Aim of this research is to observe changes in cybersickness symptoms in two tested conditions (2D display and VR). In this paper, subjective and objective metric of evaluation regarding cybersickness in VR driving simulation are used. Subjective metric is survey and objective metric is electroencephalogram (EEG). Results of the survey indicate which symptoms of cybersickness are more pronounced during driving in virtual environment compared with classic 2D screen experience. Statistically significant difference was found for 6 variables, which include vertigo, blurred vision and headache. Objective metric showed that highest average beta wave was in VR setting, as well as beta/alpha ratio, which is associated with stress and excitement

Service e-Learning Project : State Graduation Online Demo Exam

The service e-learning project described in this paper presents the online demo exam in informatics designed as a preparatory step for the state graduation. It was created in the midst of turbulence caused by the introduction of the state graduation at the end of secondary education in Croatia. With this project we wanted to engage grammar school students in service e-learning and present them with the opportunity to design their own test materials through the collaboration with college students who are experts in the field. We also aimed to gain our own benefit of connecting the theory learned during the study with new practical experiences while at the same time helping the students to achieve at a high level in the state graduation exam. Finally, since its free available online, our project should benefit everyone who wants to test their knowledge in informatics and/or learn something new in an easy and interesting way

Uticaj postoperativne terapije laserom male snage na oseointegraciju samourezujućih implantata u bočnoj regiji gornje vilice - šestonedeljna split-mouth klinička studija

Background/Aim. Low-level laser therapy (LLLT) has been proven to stimulate bone repair, affecting cellular proliferation, differentiation and adhesion, and has shown a potential to reduce the healing time following implant placement. The aim of this clinical study was to investigate the influence of postoperative LLLT osseointegration and early success of self-tapping implants placed into low-density bone. Methods. Following the split-mouth design, self-tapping implants (n = 44) were inserted in the posterior maxilla of 12 patients. One jaw side randomly received LLLT (test group), while the other side was placebo (control group). For LLLT, a 637 nm gallium-aluminum-arsenide (GaAlAs) laser (Medicolaser 637, Technoline, Belgrade, Serbia) with an output power of 40 mW and continuous wave was used. Low-level laser treatment was performed immediately after the surgery and then repeated every day in the following 7 days. The total irradiation dose per treatment was 6.26 J/cm² per implant. The study outcomes were: implant stability, alkaline-phosphatase (ALP) activity and early implant success rate. The follow-up took 6 weeks. Results. Irradiated implants achieved a higher stability compared with controls during the entire follow-up and the difference reached significance in the 5th postoperative week (paired t-test, p = 0.030). The difference in ALP activ- ity between the groups was insignificant in any observation point (paired t-test, p > 0.05). The early implant success rate was 100%, regardless of LLLT usage. Conclusion. LLLT applied daily during the first postoperative week expressed no significant influence on the osseointegration of self- tapping implants placed into low density bone of the posterior maxilla. Placement of self-tapping macro-designed implants into low density bone could be a predictable therapeutic procedure with a high early success rate regardless of LLLT usage.Uvod/Cilj. Terapija laserom male snage (TLMS) stimuliše reparatorne sposobnosti kosti utičući na ćelijsku proliferaciju, diferencijaciju i adheziju, i ima potencijal da skrati vreme zarastanja kosti nakon ugradnje implantata. Cilj ove kliničke studije bio je da se ispita uticaj postoperativne primene TLMS na oseointegraciju i rani uspeh ugradnje samourezujućih implantata u kost male gustine. Metode. Prateći split- mouth dizajn, samourezujući implantati (n = 44) ugrađeni su u posteriorne regije gornje vilice 12 pacijenata. Slučajnim izborom, jednoj od strana vilice je dodeljena TLMS (test grupa), dok je druga strana bila placebo (kontrolna grupa). Za TLMS korišćen je galijum-aluminijum-arsenid (GaAlAs) laser (Medicolaser 637, Technoline, Beograd, Srbija) talasne dužine 637 nm, snage 40 mW, neprekidnog režima rada. Tretman laserom male snage sprovodio se neposredno po ugradnji, a zatim svakodnevno, tokom narednih sedam dana. Ukupna zračna doza po tretmanu bila je 6,26 J/cm² po implantatu. Praćeni su stabilnost implantata, aktivnost alkalne fosfataze (ALP) i procenat rane uspešnosti implantatne terapije. Period praćenja bio je šest nedelja. Rezultati. Zračeni implantati imali su veću stabilnost u odnosu na kontrolne tokom celog perioda praćenja, a statistički značajno veća stabilnost bila je u petoj postoperativnoj nedelji (t-test za vezane uzorke, p = 0.030). Razlika u aktivnosti ALP između grupa nije bila statistički značajna ni u jednoj tački posmatranja (t-test za vezane uzorke, p > 0.05). Procenat rane uspešnosti terapije implantatima bio je 100%, bez obzira na primenjenu TLMS. Zaključak. Svakodnevna primena TLMS u prvoj postoperativnoj nedelji nije pokazala značajan uticaj na oseointegraciju samourezujućih implantata u kost male gustine bočne regije gornje vilice. Primena implantata samourezujućeg makrodizajna u kosti male gustine mogla bi predstavljati predvidljivu terapijsku proceduru sa visokim procentom rane uspešnosti, bez obzira na primenjenu TLMS

Constructive systems of fully reinforced lightweight concrete bridges

This paper deals with the possibility of using fully reinforced lightweight concrete systems in the bridge structures. Fully reinforced lightweight concrete systems are composed of a steel reinforcement skeleton with the main bearing capacity and lightweight concrete body as a secondary bearing material for a local and global stabilisation. Two examples are given in this paper; the example of a grill-shaped overpass over four spans and a box girder bridge over three spans. Lightweight concrete deck slab is reinforced with a grill-shaped reinforcement made of welded R trusses in two perpendicular directions. The reinforcement of the lightweight main girders, cross girders and walls of the lightweight box girder is designed as, at least, one truss with X-shaped diagonals

UNAPREĐENJE KONCEPTA PODRIJETLA MARKE PUTEM OBRNUTOG UČINKA ZEMLJE PODRIJETLA: SLUČAJ GENERACIJE Z

Product origin dispersion around the world in today’s globalized market has aroused interest in depicting brand origin in more detail, the latter being considered a more distinctive cue of product origin. Due to the fact that the impact of product origin location on product evaluation has already been established many times, the purpose of this paper is to offer new insights into the less researched, reverse country of origin effect. More specifically, this paper deals with the impact of product attitude on the evaluation of brand origin, latter being viewed through the brand’s country image and cultural background. Since this research is an exploratory one by nature, the PLS-SEM methodology was utilized, while the data collection was done through a questionnaire, through which 154 students from two Croatian universities belonging to generation Z completed the questionnaire successfully. The results point that brand attitude mediates the impact of product attitude on brand origin, implying that brand managers have to pay even more attention to product development strategies today, since favorable consumers’ product and brand attitudes can have a spillover effect on the image of an entire country. The results of this research point to several practical implications for brand managers. The first is the fact that each product in a brand’s portfolio must be optimal, as respondents showed that product attitudes influences brand attitudes directly. Brand managers need to keep in mind that consumers’ product attitudes can be a whole set of triggers for thinking about the origin of a particular brand and forming attitudes toward the origin of that brand based on their own experiences or product perceptions. Finally, the results suggest not only that product attitude influences the components of brand origin, but also that products that reflect the values of their origin help to build a favourable image of brand origin. This paper gives a broader perspective to the country of origin effect studies, but also contributes to further brand origin conceptualization by observing the brand origin framework through both country and culture of brand origin.Raspršenost podrijetla proizvoda diljem svijeta na današnjem globaliziranom tržištu pobudila je zanimanje za detaljnijim razrađivanjem podrijetla marke, pri čemu se ono smatra razlikovnim znakom podrijetla proizvoda. S obzirom na činjenicu da je utjecaj lokacije podrijetla proizvoda na ocjenjivanje proizvoda već mnogo puta utvrđen, svrha ovog rada je ponuditi nove uvide u manje istraženi, obrnuti učinak zemlje podrijetla. Konkretnije, ovaj se rad bavi utjecajem stava o proizvodu na ocjenu podrijetla marke, gdje se posljednje promatra kroz imidž zemlje i kulturnu pozadinu marke. Budući da je ovo istraživanje eksplorativnog karaktera, korištena je PLS-SEM metodologija, dok je prikupljanje podataka obavljeno putem anketnog upitnika kojeg su uspješno ispunila 154 studenta dvaju hrvatskih sveučilišta, a koji pripadaju generaciji Z. Rezultati pokazuju da stav o marki posreduje utjecaj stava o proizvodu na podrijetlo marke, što implicira da vodstvo marke u današnje vrijeme mora još više pozornosti posvetiti strategijama razvoja proizvoda, obzirom da povoljni stavovi potrošača o proizvodu i marki mogu imati učinak prelijevanja na imidž cijele zemlja. Rezultati ovog istraživanja ukazuju na nekoliko praktičnih implikacija za vodstvo marke. Prva je činjenica da svaki proizvod u portfelju marke mora biti optimalan, iz razloga što su ispitanici pokazali da stavovi o proizvodu izravno utječu na stavove o marki. Vodstvo marke treba imati na umu da stavovi potrošača o proizvodu mogu predstavljati čitav niz okidača za razmišljanje o podrijetlu određene marke i formiranje stavova o podrijetlu te marke na temelju vlastitih iskustava ili percepcije o proizvodu. Konačno, rezultati sugeriraju ne samo da stav o proizvodu utječe na komponente podrijetla marke, već i da proizvodi koji odražavaju vrijednosti svog podrijetla pomažu u izgradnji povoljnog imidža podrijetla marke. Ovaj rad daje širu perspektivu studijama učinka zemlje podrijetla, ali i doprinosi daljnjoj konceptualizaciji podrijetla marke promatrajući okvir podrijetla marke kroz zemlju i kulturu podrijetla marke

Analiza programa specijalističke izobrazbe iz oftalmologije

The aim of the study was to perform qualitative and quantitative analysis of residency curriculum in ophthalmology. A structured anonymous questionnaire was distributed to 73 medical doctors who were at least on the second year of their residency training in ophthalmology or young ophthalmologists with maximum 4 years of experience. The questionnaire consisted of 52 questions covering every segment of education from the current Protocol for Residency Education of Health Care Professionals in Ophthalmology. Forty-two (58%) doctors answered the questionnaire. Qualitative analysis showed that most of the procedures were mastered by residents. Diagnostic and/or examination procedures were mastered better than surgical and/or interventional procedures. Quantitative analysis showed that the majority of residents failed to reach the prescribed number of surgical procedures. Thirty-three (79%) participants were not satisfied with the current residency curriculum. Although residents mastered most of the prescribed procedures, current residency curriculum is far from being perfect and needs improvements. We think that objective assessment tools for monitoring the progress and competencies of residents during their residency training need to be developed.Cilj rada bio je provesti kvalitativnu i kvantitativnu analizu programa specijalističkog usavršavanja iz oftalmologije metodom anonimne ankete. O anonimnoj anketi obaviještena su ukupno 73 doktora medicine koji su bili najmanje na drugoj godini specijalizacije iz oftalmologije, odnosno oftalmolozi s maksimalno 4 godine specijalističkog staža. Anketa se sastojala od 52 pitanja vezana uza sve dijelove izobrazbe iz aktualnog Pravilnika o specijalističkom usavršavanju zdravstvenih djelatnika iz oftalmologije. Anketu su ispunila 42 (58%) doktora. Kvalitativna analiza pokazala je kako je većina predviđenih zahvata uspješno svladana za vrijeme specijalizacije. Dijagnostički zahvati i/ili razne metode pregleda svladani su bolje nego kirurški i/ili interventni postupci. Prema kvantitativnoj analizi većina specijalizanata nije ispunila predviđeni broj kirurških zahvata. Trideset troje (78%) sudionika nije zadovoljno trenutnim programom specijalističkog usavršavanja. Dakle, premda su specijalizanti ovladali većinom predviđenih zahvata, sadašnji program specijalističkog usavršavanja daleko je od savršenog i potrebna su poboljšanja. Smatramo da je potrebno razviti kvalitetne metode za objektivnu procjenu napretka i kompetentnosti specijalizanata za vrijeme specijalizacije

Analiza programa specijalističke izobrazbe iz oftalmologije

The aim of the study was to perform qualitative and quantitative analysis of residency curriculum in ophthalmology. A structured anonymous questionnaire was distributed to 73 medical doctors who were at least on the second year of their residency training in ophthalmology or young ophthalmologists with maximum 4 years of experience. The questionnaire consisted of 52 questions covering every segment of education from the current Protocol for Residency Education of Health Care Professionals in Ophthalmology. Forty-two (58%) doctors answered the questionnaire. Qualitative analysis showed that most of the procedures were mastered by residents. Diagnostic and/or examination procedures were mastered better than surgical and/or interventional procedures. Quantitative analysis showed that the majority of residents failed to reach the prescribed number of surgical procedures. Thirty-three (79%) participants were not satisfied with the current residency curriculum. Although residents mastered most of the prescribed procedures, current residency curriculum is far from being perfect and needs improvements. We think that objective assessment tools for monitoring the progress and competencies of residents during their residency training need to be developed.Cilj rada bio je provesti kvalitativnu i kvantitativnu analizu programa specijalističkog usavršavanja iz oftalmologije metodom anonimne ankete. O anonimnoj anketi obaviještena su ukupno 73 doktora medicine koji su bili najmanje na drugoj godini specijalizacije iz oftalmologije, odnosno oftalmolozi s maksimalno 4 godine specijalističkog staža. Anketa se sastojala od 52 pitanja vezana uza sve dijelove izobrazbe iz aktualnog Pravilnika o specijalističkom usavršavanju zdravstvenih djelatnika iz oftalmologije. Anketu su ispunila 42 (58%) doktora. Kvalitativna analiza pokazala je kako je većina predviđenih zahvata uspješno svladana za vrijeme specijalizacije. Dijagnostički zahvati i/ili razne metode pregleda svladani su bolje nego kirurški i/ili interventni postupci. Prema kvantitativnoj analizi većina specijalizanata nije ispunila predviđeni broj kirurških zahvata. Trideset troje (78%) sudionika nije zadovoljno trenutnim programom specijalističkog usavršavanja. Dakle, premda su specijalizanti ovladali većinom predviđenih zahvata, sadašnji program specijalističkog usavršavanja daleko je od savršenog i potrebna su poboljšanja. Smatramo da je potrebno razviti kvalitetne metode za objektivnu procjenu napretka i kompetentnosti specijalizanata za vrijeme specijalizacije

Adjustment of small-span masonry arch bridges to present-day demands

U radu je dan pregled mehanizama razaranja i oštećenja zidanih svođenih mostova, metoda ispitivanja za utvrđivanje svojstava postojećih konstrukcija te konzervativnih i sofisticiranih metoda ocjenjivanja. Na temelju analiza svođenih mostova malih raspona provedenih trima konzervativnim metodama ocjenjivanja i dodatnih razmatranja učinaka pojačavanja i prilagodbe ovih mostova u njihovom vijeku trajanja suvremenim prometnim zahtjevima, razvijena je izvorna procedura preliminarnog ocjenjivanja koja sadržava tri osnovna koraka: prikupljanje podataka, ocjenjivanje svoda i ocjenjivanje kolničke ploče.An overview of deterioration mechanisms and damage to masonry arch bridges, methods for inspection of existing structures, and conservative and sophisticated assessment methods, is presented in this paper. An original preliminary assessment procedure is developed based on the analysis of small-span masonry arch bridges using three conservative assessment methods, and an additional analysis of strengthening and adjustment of these bridges during their service life to modern traffic demands. The procedure contains three basic steps: data collection, arch assessment, and deck slab assessment

Applied and research based performance indicator database for highway bridges across Europe

Publicado em "Life-cycle of engineering systems: emphasis on sustainable civil infrastructure: proceedings of the Fifth International Symposium on Life-Cycle Civil Engineering (IALCCE 2016), ISBN 978-1-138-02847-0"Structural codes provide several practical principles and application rules such as the use of protective systems for material exposed in aggressive environment, the construction detailing aimed at avoiding the initiation of degradation, the maintenance actions to be regularly performed. Each construction, during its life cycle, will face with deterioration depending on several factors such as the environmental condition, the natural aging, the quality of the material, the execution of works and the planned maintenance. Therefore, several design procedures based on the prediction of the deterioration that will likely act on the structure will be developed in the framework of the international research. In addition, performance indicators for the present and future structural conditions on deterministic and probabilistic level will be defined and determined. It is extremely important to analyse such indicators in terms of used assessment frameworks, and in terms of the quantification procedure itself.COST (European Cooperation in Science and Technology

Interaction diagrams for pier reinforcement design

U članku je prikazana analiza područja primjene postupka proračuna stupova prema Ehlersu na temelju koje su nacrtani dijagrami interakcije i uspoređeni s tzv. klasičnim dijagramima. Primijenjeni su uvjeti Eurokoda 2 o minimalnoj i maksimalnoj armaturi. Upozorava se na djelovanje momenta savijanja i tlačne sile kad Ehlersov postupak daje neadekvatnu armaturu. Određena su i dopuštena područja dijagrama interakcije prema Eurokodu 8, s obzirom na ograničenja veličine tlačne sile.The analysis of the area in which pier design according to Ehlers can be applied is presented, and the resulting interaction diagrams are compared with the so called traditional diagrams. Eurocode 2 requirements concerning minimum and maximum reinforcement are applied. The attention is drawn to the bending moment and compressive force action in cases when Ehlers procedure results in an inadequate reinforcement. Allowable interaction diagram areas are defined according to Eurocode 8, taking into account limitations with respect to the value of compressive force