Estimation of P{X < Y} for gamma exponential model

In this paper, we estimate probability P{X < Y} when X and Y are two independent random variables from gamma and exponential distribution, respectively. We obtain maximum likelihood estimator and its asymptotic distribution. We perform some simulation study

Upravljanje rizicima unit-linked životnog osiguranja

Osnovna karakteristika unit-linked životnog osiguranja ogleda se u specifičnosti ulaganja sredstava, koje je direktno vezano za vrednost investicione jedinice određenog investicionog fonda. Prednost unit-linked osiguranja, sa aspekta osiguravača, sastoji se u prenošenju rizika investiranja na osiguranika. Sa aspekta osiguranika, ovo osiguranje omogućuje, sa jedne strane, slobodu izbora nivoa zaštite, a sa druge strane, slobodu ulaganja sredstava rezerve, odnosno izbor investicionog fonda u koji će ta sredstva biti investirana, u skladu sa stepenom averzije prema riziku. Iako unit-linked osiguranje može doneti veće prinose u odnosu na tradicionalne proizvode životnog osiguranja, pri nepovoljnoj investicionoj klimi mogu biti ostvareni značajni gubici. Iz navedenih razloga, veoma je važno sagledati prednosti i nedostatke ovog vida osiguranja, sa aspekta politike investiranja, posebno u uslovima globalne finansijske krize. Tema dobija na aktuelnosti izmenom Zakona o osiguranju, kojom se omogućuje uvođenje navedenog novog proizvoda životnog osiguranja u Srbiji. Stoga je veoma značajno blagovremeno identifikovati rizike koji su povezani sa ovim vidom osiguranja, kako bi bile definisane adekvatne metode upravljanja tim rizicima

Mathematics and music game in the function of child’s social and emotional development

The paper presents empirical research, aiming to present the extent to which the application of the concrete mathematical and musical play contributes to the child’s social and emotional development. The research was conducted in two international schools in Belgrade, using the play titled ‘Musical Monkeys’ and in collaboration with the Music-Math team from Mexico who are the creators of the mentioned game. The results have shown that this kind of approach in working with children encourages activity and engagement, self-confidence, empathy, team work, integrity, tolerance and enthusiasm, while requiring and encouraging collaboration and constructive communication, cooperation and respect among students in the process of solving a set of mathematical and/ or musical tasks. The obtained results confirm that the children established connection between the mathematical and musical segments involving a high level of emotional and social skills – collaboration, communication, empathy, enthusiasm, commitment, curiosity for the game and felt benefits of team work, tolerance and respect while solving the given educational tasks

Analiza razvoja i okluzalne karakteristike u primarnoj denticiji kod ispitanika sa i bez zbijenosti trajnih zubi

The fact that crowding appears in a larger number of cases for the first time during the replacement of teeth does not exclude the possibility o f an earlier appearance o f certain indicators, on the basis of which a future malocclusion could be predicted. In order to verify the stated hypothesis we decided to extract the factors which could be relevant to the development of crowding by means of analysis o f qualitative and quantitative characteristics o f primary dentition and by means of the evaluation o f the influence o f each individual feature on the spatial conditions in permanent dentition. The sample consisted o f 76 examinees o f both sexes which were longitudinally surveyed throughout eight years. For each examinee the following characteristics were registered and evaluated: existence o f primatical diastemas in the lower jaw, degree o f abrasion, existence and degree o f physiological diastemas in the upper jaw, condition o f equidistal planes, sagital interrelation determined by canines, overbite, transversal interrelation and overjet. After 8 years the examinees were divided into the group with crowding (51) and the group without crowding (25). The data were processed by the SAS software, for each group individually and compared mutually. The established hypothesis regarding the existence o f early symptoms relevant to the emergence o f crowding of permanent teeth has received only partial confirmation in the conducted survey. From the findings analyzed it follows that the appearance o f crowding is in the relation with the lack o f physiological diastemas; the absence or early closure o f the primatical diastema; the early loss o f equidistal plane and caries or extraction o f primary teeth. A more favorable prognosis in preventing the appearance o f crowding can be assigned to bigger physiological diastemas, the persistence of equidistal planes, the presence of primatical diastemas and intact primary teeth.Činjenica da se kompresija u većem broju slučajeva prvi put pojavljuje za vrijeme mjene zubi, ne isključuje mogućnost ranije pojave određenih indikatora, na temelju kojih bi se mogla predvidjeti buduća anomalija. S ciljem provjere navedene hipoteze odlučili smo odrediti faktore koji bi mogli biti relevantni za razvoj kompresije i to analizom kvalitativnih i kvantitativnih karakteristika mliječne denticije i evaluacijom utjecaja svakog pojedinog obilježja na prostorne uvjete u trajnoj denticiji. Uzorak se sastojao od 76 ispitanika oba spola koji su longitudinalno praćeni kroz osam godina. Svakom ispitaniku vrednovane su slijedeće karakteristike: postojanje primatnih dijastema u donjoj čeljusti, stupanj abrazije, postojanje i stupanj fizioloških dijastema u gornjoj čeljusti, stanje ekvidistalne ravnine, sagitalni odnos određen na očnjacima, dubina prijeklopa, transverzalni odnos i incizalna stepenica. Nakon osam godina ispitanici su podijeljeni u grupe sa (51) i bez kompresije (25), provedena je gnatometrijska analiza, a dobi-veni rezultati obrađeni su SAS programskom podrškom za svaku grupu posebno te međusobno uspoređeni. Hipoteza o postojanju ranih simptoma koji bi bili važni za nastanak kompresije u trajnoj denticiji samo je djelomično potvrđena ovom studijom. Analizom rezultata slijedi da je pojava kompresije povezana s nepostojanjem fizioloških dijastema, odsutnošću ranog zatvaranja primatnih dijastema, ranim gubitkom ekvidistalne ravnine, te karijesom i ekstrakcijom mliječnih zubi. Bolja prognoza može se očekivati ako su prisutne veće fiziološke dijasteme, ako perzistira ekvidistalna ravnina, ako postoje primatne dijasteme i ako su mliječni zubi intaktni

A comparative analysis of oral health in mentally retarded and normal children

Ispitivanjem je utvrđena razlika u frekvenciji karijesa kod mentalno nedovoljno razvijene djece i zdrave, utjecaj MNR na intenzitet karijesa, razlika u broju zuba i korelacija »stupnja MNR i gingivoparodontnih oboljenja. Pregledano je 119 umjereno, teško i profundno mentalno nedovoljno razvijene djece. Utvrđeno je da postoji značajna razlika u prevalenciji karijesa kod teško mentalno nedovoljno razvijene i zdrave djece, intenzitet karijesa pada sa stupnjem MNR, hipodoncija raste s mentalnom nerazvijenošću, a također i oboljenja oralne sluznice.This study was undertaken to find the differences in the prevalence of caries between mentally retarded and normal children, as well as the effect of mental retardation on the severity of teeth and the correlation between the degree of mental retardation and gingivoperiodontal diseases. A group of 119 children with moderate, severe of profound mental retardation were examined. A significant difference in the prevalence of caries was recorded between a subgroup of severely retarded children and normal children. The severity of caries was found to decline, and hypodontia and oral mucosa diseases to increase with the degree of mental retardation

Dentometrijske karakteristike ispitanika s primarnom kompresijom

A comparative study of dentometric characteristics of incisors in the upper and lower jaws was performed in on attempt to determine the role of the size of the mentioned teeth in the process of primary crowding. The study included 200 examinees (140 females and 60 males) with primary crowding and 100 eugnathic subjects (48 females and 52 males) as a control group. The sample was selected according to the following criteria: anterior crowding, completed exchange of teeth, neutral intermaxillary relationship (Angle class I), lack of other malocclusion. The age was limited to 14 years in order to avoid the possible influence of tertiary crowding. The study was carried out by means of a sliding-caliper with 1 mm precision on plaster casts of the upper and lower jaws, and the mesiodistal diameters of all the four permanent incisors in the upper and lower jaws were measured. After statistical analysis and interpretation of the results, the following was concluded: Arithmetical means of the sums of the upper incisors were considerably higher in boys, while the difference between the mean values of the sums of the lower incisors was insignificant. The subjects with crowding had significantly bigger upper but not lower incisors. One of the important factors for the occurrence of crowding were bigger incisors, especially the upper central ones, and in girls also the lower incisors. The size of the incisors should by no means be taken as the only cause o f crowding, as demonstrated by the analysis of the widths and heights o f the upper dental arch. Significantly smaller widths of dental arches in the premolar and molar regions, along with an increase in the anterior upper height were registered in the subjects with crowding. The analysis of correlations revealed only a slight association between the size o f incisors, especially the upper ones, and the widths and anterior heights of the upper dental arch, possibly indicating a very low correlation or the lack o f correlation among the factors inducing crowding, i.e. increase in the size of incisors, and a narrower and longer upper dental arch.Provedeno je usporedno istraživanje dentometrijskih odlika sjekutiča u gornjoj i donjoj čeljusti s ciljem utvrđivanja uloge veličine navedenih zubi u procesu nastajanja primarne kompresije. Istraživanje je obuhvatilo 200 ispitanika (140 ženskih i 60 muških) s primarnom kompresijom i 100 eugnatih ispitanika (48 ženskih i 52 muška) koji su poslužili kao kontrolna skupina. Odabir je učinjen prema slijedećim mjerilima: zbijeni postav sjekutiča, završena mijena zubi, neutralni međučeljusni odnos (Kl I), odsutnost neke druge ortodontske anomalije. Dob je ograničena na 14 godina, kako bi se izbjegao mogući utjecaj tercijarne kompresije. Istraživanje je provedeno pomičnom kliznom mjerkom s točnošću od 0,5 mm na sadrenim odljevima gornjih i donjih čeljusti, a izmjereni su meziodistalni promjeri svih gornjih i donjih trajnih sjekutića. Nakon provedene statističke obrade i analize rezultata, može se zaključiti slijedeće: Aritmetičke sredine suma gornjih inciziva značajno su veće u dječaka, dok razlika između spolova za prosječne vrijednosti suma donjih inciziva nije značajna. Jedan od važnih čimbenika za nastajanje »crowdinga« je povećana zubna masa sjekutića, prvenstveno gornjih srednjih, a u djevojčica i donjih inciziva. Veličina inciziva nikako se ne može uzeti kao jedini razlog za nastanak kompresije, što potvrđuje i analiza širina i dužina gornjega zubnoga niza. U ispitanika s »crowdingom« zabilježene su značajno manje širine zubnih nizova u regiji premolara i molara te povećanje prednje gornje dužine. Analiza korelacija ukazuje tek na laganu povezanost ili nepovezanost veličine inciziva sa širinama i prednjom dužinom gornjega zubnog niza. To bi moglo ukazivati na vrlo malu povezanost, odnosno nepovezanost čimbenika koji dovode do »crowdinga«, a to su veći incizivi te uži i duži gornji zubni niz

The use in grass production of clinoptilolite as an ammonia adsorbent and a nitrogen carrier

Clinoptilolite-rich tuff (NZ) from the Zlatokop deposit (Vranjska Banja, Serbia) was studied as a nitrogen carrier for grass production. The mechanism of binding ammonium cations present in aqueous solutions by NZ was examined, as well as the possibility of adsorption of ammonia released in fresh cattle manure during its fermentation. The NH4+ binding from solutions proceeded via an ion-exchange process that followed pseudo-second-order kinetics. Adsorption isotherms studied at 298-318 K followed the Freundlich isotherm equation. The NZ readily adsorbs ammonia liberated from manure and the addition of 10 wt. % of NZ to manure can preserve up to 90 % of ammonia. The potential benefit of this effect was examined in greenhouse pot experiments with Italian ryegrass (Lolium multiflorum, var. Macho) using three different types of soil (silty, clayey and sandy). The zeta potential measurements showed that the stability of their colloidal dispersions differed mutually and that the addition of NZ affected the stability and nitrogen cycling differently. All results indicated that NZ could be applied in grass production

Dentometrijske karakteristike ispitanika s primarnom kompresijom

A comparative study of dentometric characteristics of incisors in the upper and lower jaws was performed in on attempt to determine the role of the size of the mentioned teeth in the process of primary crowding. The study included 200 examinees (140 females and 60 males) with primary crowding and 100 eugnathic subjects (48 females and 52 males) as a control group. The sample was selected according to the following criteria: anterior crowding, completed exchange of teeth, neutral intermaxillary relationship (Angle class I), lack of other malocclusion. The age was limited to 14 years in order to avoid the possible influence of tertiary crowding. The study was carried out by means of a sliding-caliper with 1 mm precision on plaster casts of the upper and lower jaws, and the mesiodistal diameters of all the four permanent incisors in the upper and lower jaws were measured. After statistical analysis and interpretation of the results, the following was concluded: Arithmetical means of the sums of the upper incisors were considerably higher in boys, while the difference between the mean values of the sums of the lower incisors was insignificant. The subjects with crowding had significantly bigger upper but not lower incisors. One of the important factors for the occurrence of crowding were bigger incisors, especially the upper central ones, and in girls also the lower incisors. The size of the incisors should by no means be taken as the only cause o f crowding, as demonstrated by the analysis of the widths and heights o f the upper dental arch. Significantly smaller widths of dental arches in the premolar and molar regions, along with an increase in the anterior upper height were registered in the subjects with crowding. The analysis of correlations revealed only a slight association between the size o f incisors, especially the upper ones, and the widths and anterior heights of the upper dental arch, possibly indicating a very low correlation or the lack o f correlation among the factors inducing crowding, i.e. increase in the size of incisors, and a narrower and longer upper dental arch.Provedeno je usporedno istraživanje dentometrijskih odlika sjekutiča u gornjoj i donjoj čeljusti s ciljem utvrđivanja uloge veličine navedenih zubi u procesu nastajanja primarne kompresije. Istraživanje je obuhvatilo 200 ispitanika (140 ženskih i 60 muških) s primarnom kompresijom i 100 eugnatih ispitanika (48 ženskih i 52 muška) koji su poslužili kao kontrolna skupina. Odabir je učinjen prema slijedećim mjerilima: zbijeni postav sjekutiča, završena mijena zubi, neutralni međučeljusni odnos (Kl I), odsutnost neke druge ortodontske anomalije. Dob je ograničena na 14 godina, kako bi se izbjegao mogući utjecaj tercijarne kompresije. Istraživanje je provedeno pomičnom kliznom mjerkom s točnošću od 0,5 mm na sadrenim odljevima gornjih i donjih čeljusti, a izmjereni su meziodistalni promjeri svih gornjih i donjih trajnih sjekutića. Nakon provedene statističke obrade i analize rezultata, može se zaključiti slijedeće: Aritmetičke sredine suma gornjih inciziva značajno su veće u dječaka, dok razlika između spolova za prosječne vrijednosti suma donjih inciziva nije značajna. Jedan od važnih čimbenika za nastajanje »crowdinga« je povećana zubna masa sjekutića, prvenstveno gornjih srednjih, a u djevojčica i donjih inciziva. Veličina inciziva nikako se ne može uzeti kao jedini razlog za nastanak kompresije, što potvrđuje i analiza širina i dužina gornjega zubnoga niza. U ispitanika s »crowdingom« zabilježene su značajno manje širine zubnih nizova u regiji premolara i molara te povećanje prednje gornje dužine. Analiza korelacija ukazuje tek na laganu povezanost ili nepovezanost veličine inciziva sa širinama i prednjom dužinom gornjega zubnog niza. To bi moglo ukazivati na vrlo malu povezanost, odnosno nepovezanost čimbenika koji dovode do »crowdinga«, a to su veći incizivi te uži i duži gornji zubni niz

Methods used for soil stabilization during construction of transportation facilities

U radu je dan kratak pregled konvencionalnih postupaka stabilizacije (vapno, cement) te postupaka u kojima se primjenjuju noviji proizvodi na bazi sintetičkih polimera (primjerice akrilat, polivinil acetat), encimi i biološka sredstva, ionski proizvodi, lignini, smole te ostali tipovi sredstava za stabilizaciju. Također su prikazani rezultati in situ i rezultati laboratorijskih ispitivanja tla stabiliziranog GeoCretom, jednim od novijih proizvoda dostupnih na hrvatskom tržištu.A brief overview is given of traditional stabilization procedures (lime, cement) and procedures involving the use of new synthetic-polymer based products (such as acrylate, polyvinyl acetate), enzymes and biological products, ionic products, lignins, resins, and other types of stabilization products. Results of in situ and laboratory testing of soil stabilized with GeoCreta, one of the recent products available on Croatian market, are also presented