Travel time measure specification by functional approximation: application of radial basis function neural networks

AbstractIn this study, in the purpose of providing a dynamic procedure for reliable travel time specification, the performance of a neural functional approximation method is analysed. The numerical analyses are carried out on the succeeding sections of a freeway segment inputting data obtained from microwave radar sensor units located successively at the cross-sections of a freeway segment of approximately 4km. Measurements on traffic variables, i.e., vehicle counts, speed, and occupancy, for the reference time periods are processed. The structure of the employed radial basis function neural networks are configured considering the data of a three-lane freeway segment obtained by succeeding sensors located in side-fired position. Travel time measures approximated by the neural models are compared with the corresponding field measurements obtained by probe vehicle. Results prove neural model's performance in representing spatiotemporal variation of flow dynamics as well as travel times. Adaptability of the proposed travel time specification procedure to real-time intelligent control systems is a possible future extension

Application of ALINEA ramp control algorithm to freeway traffic flow on approaches to Bosphorus strait crossing bridges

AbstractBeginning from the 1960ies sustainability has been being pointed out as an important criterion in development which made many countries plan sustainability originated progressing policies. The decision makers, planning to construct a third roadway bridge to connect Asia and Europe continents on to the Bosphorus in Istanbul metropolitan area, first have to evaluate the exaggerated road traffic congestion phenomenon. Before making such a non-environmentally friend decision, advanced traffic managing strategies have to be incorporated to regularize the current pattern of traffic flows on the existing road network that prevails the road based urban transport.Ramp control is an efficient strategy that has been employed to prevent recurrent traffic congestion since 1970ies. With the employment of ramp control applications, several benefits of ramp management, including i.e., the increase on the level of traffic safety, the increase on travelling speeds and consequently decrease on travelling times, the increase on the level-of-service, increase on energy consumption efficiency, decrease on environmental impacts, and increase on user satisfaction, have been experienced. The present paper aims to impose advanced traffic management schemes, specifically the ramp control, on the non-efficient utilisation of freeway approaches to existing Bosphorus bridges as an alternative to a third bridge crossing

Investigation of tooth transposition in a non-syndromic Turkish anatolian population : characteristic features and associated dental anomalies

Objective: The aims of this study were to investigate the frequency and characteristics of dental transpositions and to evaluate associated dental anomalies in a large sample of Turkish Anatolian population. Study design: A retrospective study was performed using panoramic radiographs of 6983 patients (4092 females and 2891 males) ranging in age from 12 to 27 subjected to Faculty of Dentistry at the University of Ataturk (Erzurum, Turkey) between 2005 and 2008. For each patient with tooth transposition we recorded the demographic variables (including age, sex), history of trauma, type, classification, and location of tooth transpositions, and associated dental anomalies. The Pearson chi-squared test was used to determine potential differences in the distribution of tooth transposition when stratified by gender. Results: Tooth transposition was detected in 19 subjects (0.27%), with a 2.2:1 female male ratio (P= 0.38). The most commonly observed transposition was maxillary canine-lateral incisor (60%). The frequencies of complete and incomplete transpositions were equal (10/10) and it was more common in the left side than in the right side (11/9). Of the 19 subjects, 10.5% had a peg shaped lateral incisor, 21.1% one congenitally missing tooth excluding third molar. Supernumerary tooth, impacted teeth excluding third molars, transmigrated tooth, and dilacerations were also observed. Conclusion: The frequency of tooth transposition was 0.27% in a Turkish Anatolian population and maxillary canine-lateral incisor was the most frequently observed transposition. Retained primary teeth were the most frequently observed dental anomaly in all types of tooth transposition

Prevalence and characteristics of supernumerary teeth in a non-syndrome Turkish population : associated pathologies and proposed treatment

Objective: The objectives of the present study were to investigate the prevalence and characteristics of supernumerary teeth and evaluate the associated pathologies and treatment protocol in a Turkish patient population. Study design: A retrospective study was performed using full-mouth periapical and panoramic radiographs of 3491 patients (2146 females and 1345 males) ranging in age from 12 to 25. For each patient with supernumerary teeth we recorded the demographic variables (including age, sex), number, location, position, type, and morphology of supernumerary teeth, associated pathologies or complications, and whether any treatment has been carried out. The Pearson chi-squared test was used to determine potential differences in the distribution of supernumerary teeth when stratified by gender. Results: Supernumerary teeth were detected in 42 subjects (1.2%), of which 27 were males and 15 were females with a 1.8:1 male female ratio (P<.001). The most commonly found supernumerary teeth were mesiodens (31.3%) followed by premolar (25.0%), lateral (22.9%), distomolar (14.5%), paramolar (4.2%), and canine (2.1%). Of the 48 supernumerary teeth examined, 50.0% (n=24) were conical, 81.3% (n=39) were in a vertical position, and 20.8% (n=10) were erupted. Supernumerary teeth caused rotation or displacement of the adjacent teeth in 14 cases, and the impaction of the permanent teeth in 8 cases. Conclusion: The prevalence of supernumerary teeth in our series was found to be 1.2%, the most frequent type being mesiodens. Rotation or displacement of permanent teeth was the most frequent complication caused by supernumerary teeth

The pattern of malocclusion in a sample of orthodontic patients from Turkey

Objective: The objective of this study was to determine the prevalence of individual traits of malocclusion in a sample of Turkish orthodontic patients. Study design: The present study was based on the examination of dental casts, intraoral photographs and panoramic radiographs of 1507 orthodontic patients (884 females and 623 males). The relationship of the first upper and lower molars according to the Angle?s classification, overjet, overbite, crowding, spacing, posterior crossbite, scissor bite, maxillary median diastema were examined. The Pearson chi-squared and Fisher?s Exact tests were used to determine potential differences in the distribution of malocclusion when stratified by gender. Results: The study demonstrated that only 52 (3.5%) of the subjects had normal occlusion. Class I malocclusion was found in 626 (41.5%), Class II Division 1 in 435 (28.9%), Class II Division 2 in 142 (9.4%) and Class III malocclusion in 252 (16.7%) subjects of all examined. Normal overbite, normal overjet, crossbite on both sides and severe crowding in the upper dental arch were observed more frequently in females (P<.05), however, increased overbite and moderate crowding in the upper dental arch were observed more frequently in males (P<.05). Conclusion: The results of this study showed that crowding in the upper and lower dental arches in a sample of Turkish population was the most frequent of all anomalies recorded with ranges of 70.0% and 47.3%, respectively

Sensitivity function and entropy increase rates for z-logistic map family at the edge of chaos

It is well known that, for chaotic systems, the production of relevant entropy (Boltzmann-Gibbs) is always linear and the system has strong (exponential) sensitivity to initial conditions. In recent years, various numerical results indicate that basically the same type of behavior emerges at the edge of chaos if a specific generalization of the entropy and the exponential are used. In this work, we contribute to this scenario by numerically analysing some generalized nonextensive entropies and their related exponential definitions using $z$-logistic map family. We also corroborate our findings by testing them at accumulation points of different cycles.Comment: 9 pages, 2 fig

Frequency and characteristics of tooth agenesis among an orthodontic patient population

Purpose: The objectives of this study were to investigate the prevalence and characteristics of tooth agenesis and the associated skeletal morphology and arch widths in a group of Turkish patients seeking orthodontic treatment. Material and Methods: We designed a retrospective study composed of pre- and post-treatment panoramic radiographs and lateral cephalometric films of 3,341 patients (2,040 females and 1,301 males). Tooth agenesis was evaluated for hypodontia and oligodontia -excluding the third molars- from the orthopantomograms. The significance test for the differences in the skeletal morphology between hypodontia and non-hypodontia patients was performed using the Pearson chi-square and Student t-test. Results: The prevalence of tooth agenesis was 4.6 percent for the Turkish orthodontic patient population. Tooth agenesis was found more frequently in females than in males, although this difference was not statistically significant (p>0.05). The most commonly missing teeth were the maxillary lateral incisors, followed by the mandibular second premolars and mandibular central incisors. Intercanine and intermolar widths in the maxillary and mandibular arches were significantly reduced in the hypodontia group compared with the control group (p0.05). Conclusions: The prevalence of tooth agenesis was found to be 4.6 percent for the Turkish orthodontic patient population (hypodontia 4.3% and oligodontia 0.3%), and was found more frequently in females. Intercanine and intermolar widths were significantly reduced in the hypodontia group for both jaws compared with the control grou

Assessment of the prevalence and characteristics of dens invaginatus in a sample of Turkish Anatolian population

Objective: The objective of this study was to assess the prevalence and characteristics of dens invaginatus in anterior teeth and to classify the type of dens invaginatus in a sample of Turkish Anatolian population. Study design: A retrospective study was performed using full-mouth periapical and panoramic radiographs of 1012 patients. Maxillary and mandibular anterior teeth were evaluated for the presence and characteristics of dens invaginatus. Statistical evaluation of the presence of dens invaginatus related to gender was performed by the Pearson chi-squared test. Results: Dens invaginatus was observed in 13 out of 1012 subjects and in only maxillary lateral incisors. There were no periapical lesions in teeth with types I and II, whereas both of the subjects with type III had apical periodontitis at the time of referral. Males and females were almost equally affected by dens invaginatus (P= 0.98). Conclusion: The anomaly was detected in only maxillary lateral incisors with no gender difference and the most commonly observed type of dens invaginatus was type I (81.25%)