DISTANCE-based clustering methods categorize samples by optimizing a global criterion, finding ellipsoid clusters with roughly equal sizes. In contrast, density-based clustering techniques form clusters with arbitrary shapes and sizes by optimizing a local criterion. Most of these methods have several hyper-parameters, and their performance is highly dependent on the hyper-parameter setup. Recently, a Gaussian Density DISTANCE (GDD) approach was proposed to optimize local criteria in terms of DISTANCE and density properties of samples. GDD can find clusters with different shapes and sizes without any free parameters. However, it may fail to discover the appropriate clusters due to the interfering of clustered samples in estimating the density and DISTANCE properties of remaining unclustered samples. Here, we introduce Adaptive GDD (AGDD), which eliminates the inappropriate effect of clustered samples by adaptively updating the parameters during clustering. It is stable and can identify clusters with various shapes, sizes, and densities without adding extra parameters. The DISTANCE metrics calculating the dissimilarity between samples can affect the clustering performance. The effect of different DISTANCE MEASUREMENTS is also analyzed on the method. The experimental results conducted on several well-known datasets show the effectiveness of the proposed AGDD method compared to the other well-known clustering methods.

Background/Objective: Normal values for CT orbital MEASUREMENTS, which appear in reference books, may not be applicable to the Iranian population. The purpose of this study was to determine normal values in an Iranian population and compare them with published standards. Patients and Methods: Orbital CT scans from adults were studied from March 2003 to June 2005. The scans had been ordered for complaints unrelated to craniofacial and orbital abnormalities, and in all of them, the presence of any pathology of the bones, globe and orbit were excluded. Four hundred CT scans (134 females, 266 males, mean age 36.9±16.7 years) were studied. Results: The normal interorbital DISTANCE at the posterior border of the frontal process of the maxilla measured from 1.8 to 3.5 cm (mean 2.30) in men and 1.5 to 3.2 cm (mean 2.17) in women (p<0.01). At the level of orbital equator, the mean interorbital DISTANCE was 2.46 cm in women (range 1.7-3.2) and 2.65 cm in men (range 2-3.4) (p<0.01). Compared with the corresponding values of interorbital standards, all these MEASUREMENTS were smaller. Conclusion: Normal values of orbital MEASUREMENTS are smaller and more varied in Iranian population and these values must be used when interpreting CT scans of the orbit.      

Background & Aim: There are several methods for determination of occlusal vertical dimension. The vertical dimension of rest position, interocclusal DISTANCE and closest speaking space are two important methods. The purpose of this study was comparison the variability of interocclusal DISTANCE and closest speaking space in denture wearers.Method &Materials: The subjects were 34 edentulous patients (18 males & 16 females with mean age of 56) who had received complete dentures in the prosthodontics department of Isfahan dental school. They had good residual ridges. The dentures had correct clinical vertical dimension with 1-2mm overjet and 0.5 -1mm overbite. There was no evidence of neuromuscular and TMJ problems. The TOM guage was used for measuring the vertical dimension of rest position and «S» position.Results: The results showed that the mean and standard deviation of interocclusal DISTANCE were smaller than closest speaking space. Paired T-test and Levene's test were used for statistical analysis. There was a statistically difference between interocclusal DISTANCE and closest speaking space, so the interocclusal DISTANCE was less variable than closest speaking space (P<0.05).Conclusion: The closest speaking space during S position is affected by the occlusion, vertical and horizontal overlap of anterior teeth. These factors are up to dentist's judgement in complete denture and can influence the variability of vertical dimension of S position. Because of this variability it is recommended to use several methods for determining of vertical dimension.

Introduction: The aim of the present study was to determine and compare the accuracy of MEASUREMENTS of CEJ-to-alveolar crest (AC) DISTANCE in periapical conventional and digital radiographs corrected for attenuation and visual response.Materials and Methods: Sixty-three interproximal bone sites adjacent to posterior teeth with different amounts of horizontal bone loss in dried human mandibles were selected in the present experimental study. The CEJ-AC DISTANCEs in the mandibles were assessed and employed as gold standard. Periapical and digital radiographs (parallel technique) were exposed with the CCD sensor and E-speed films. Digital radiographs were processed with Dental Eye program to correct for attenuation and visual response. The CEJ-AC DISTANCEs were assessed on conventional and corrected digital radiographs. The results of the two radiographic MEASUREMENTS were compared with gold standard by paired t-test. Pearson’s correlation coefficient for the two radiographic MEASUREMENTS was calculated with gold standard (a=0.05).Results: The accuracy of CEJ-AC DISTANCE MEASUREMENTS on conventional and digital radiographs was estimated to be 86%. Pearson’s correlation coefficient between the gold standard and MEASUREMENTS on conventional (r=0.90) and digital radiographs (r=0.92) indicated strong correlation between the gold standard and the two radiographic MEASUREMENTS (p value >0.001).Conclusion: Digital radiographs corrected for x-ray attenuation and visual response are comparable to conventional radiographs in accuracy for MEASUREMENTS of CEJ-AC DISTANCE.

Electronic canopy characterization to determine structural properties is an important issue in tree crop management. Ultrasonic and optical sensors are the most used sensors for this purpose. The objective of this work was to assess the performance of an ultrasonic sensor under laboratory and field conditions in order to provide reliable estimations of DISTANCE MEASUREMENTS to apple tree canopies. To achieve this purpose, a methodology has been designed to analyze sensor performance in relation to foliage DISTANCE and to the effects of interference with adjacent sensors when working simultaneously. Results showed that the average error in DISTANCE measurement using the ultrasonic sensor in laboratory conditions was 0.64 cm. However, the increase of variability in field conditions reduced the accuracy of this kind of sensors when estimating DISTANCEs to canopies.The average error in such situations was 3.19 cm. When analyzing interferences of adjacent sensors 30 cm apart, the average error was ±14.65 cm. When adjacent sensors were placed apart by 60 cm, the average error became 6.73 cm. The ultrasonic sensor tested has been proven to be suitable to estimate DISTANCEs to the canopy in pistachio garden conditions when sensors are 60 cm apart or more and can, therefore, be used in a system to estimate structural canopy parameters in precision horticulture.

Determination of plant resistance to drought and salinity is very important for selecting the favorable plant species in rangelands. The aim of this study was to compare the salinity and drought tolerance of the two rangeland species namely puccinelia DISTANCE and Aeluropus Littoralis. In this study biomass production of these two species was also compared. The Experimental design of split-split plot in randomized block was excuted for the study. The main plots were allocated to the treatments of 7 and 14 days irrigation periods. The subplot were 4 level of salinity including 100, 150, 200 mmolar Cl.Na and normal irrigation water as control respectively. The morphological criterias such as water potential, wilting percentage of the plants and also dry biomass were evaluated in this study. In the context of plant anatomy, The density of stomata per unit area of leaves, vesicular structure, mesophyt tissues and epidermis were also investigated. The results showed that wilting percentage increased with increasing salinity and water deficit (drought). With increasing the time of drought and salinity stress, the weight of dry stem and total dry mass were decreased. The wilting percentage and reduction of total dry biomass in Aeluropus Littoralis was more than puccinelia DISTANCE. It was concluded that puccinelia DISTANCE is more resistante compare to Aeluropus Littoralis while Aeluropus Littoralis is more tolerate to salinity stress.

Background and Aims: Cephalometric MEASUREMENTS cannot be performed for screening purposes, therefore orthodontists usually have to use either photographic or anthropometric MEASUREMENTS in such occasions. Finding a valid and reliable alternative could be of great value. The purpose of this study was to evaluate the correlation between McNamara’s cephalometric unit difference and a proposed soft tissue equivalent.Materials and Methods: An anthropometric ruler was redesigned and used in this study. Soft tissue MEASUREMENTS were performed on 36 randomly selected specimens by two investigators. The soft tissue MEASUREMENTS included external auditory meatus to subnasale (Ext-Sn), external auditory meatus to soft tissue pogonion (Ext-Pog), and the difference between them (UDMA´). These MEASUREMENTS were considered as equivalents to cephalometric indices in McNamara’s anteroposterior MEASUREMENTS, including maxillary (Co-A) and mandibular (Co-Gn) unit length and their difference (UDMA), respectively.Results: All soft tissue variables had an intra-class correlation coefficient (ICC) above 0.90. There was a high and significant correlation between cephalometric and anthropometric MEASUREMENTS (P<0.01). The ICC between (Ext-Sn) and (Co-A) was 0.890, 0.869 between (Ext-Pog) and (Co-Gn), and 0.819 between UDMA´ and UDMA.Conclusion: The proposed anthropometric method showed a good correlation with cephalometric equivalents and the results show that this method could be used for screening purposes, especially when a low-cost, non-invasive method is required. However, it cannot be considered as a substitute for cephalometry in diagnostic and treatment purposes.