Size Of Individual Elements Research Articles

The value of the human auricle for its identification

The purpose of the study is the possibility of a more complete use of the signs of the structure of the auricle in the identification of a person. The authors conducted a comparative study of the morphological features of the elements of the human auricle in an artistic image and a profile photograph by comparing the same-name features. If images are presented for identification that do not fully reproduce the face of a person, or images in profile, then identification can be difficult. It is noted that the signs of the structure of the auricle for identification are still clearly insufficiently used, although it is in this perspective (in profile) that such signs of the structure of the auricle as the degree of protrusion and the size of individual elements are displayed. The significant role of the auricle as an object of identification in profile mapping of the human head is substantiated.

Perceived group size is determined by the centroids of the component elements.

To accomplish the deceptively simple task of perceiving the size of objects in the visual scene, the visual system combines information about the retinal size of the object with several other cues, including perceived distance, relative size, and prior knowledge. When local component elements are perceptually grouped to form objects, the task is further complicated because a grouped object does not have a continuous contour from which retinal size can be estimated. Here, we investigate how the visual system solves this problem and makes it possible for observers to judge the size of perceptually grouped objects. We systematically vary the shape and orientation of the component elements in a two-alternative forced-choice task and find that the perceived size of the array of component objects can be almost perfectly predicted from the distance between the centroids of the component elements and the center of the array. This is true whether the global contour forms a circle or a square. When elements were positioned such that the centroids along the global contour were at different distances from the center, perceived size was based on the average distance. These results indicate that perceived size does not depend on the size of individual elements, and that smooth contours formed by the outer edges of the component elements are not used to estimate size. The current study adds to a growing literature highlighting the importance of centroids in visual perception and may have implications for how size is estimated for ensembles of different objects.

Precise nanoscale temperature mapping in operational microelectronic devices by use of a phase change material

The microelectronics industry is pushing the fundamental limit on the physical size of individual elements to produce faster and more powerful integrated chips. These chips have nanoscale features that dissipate power resulting in nanoscale hotspots leading to device failures. To understand the reliability impact of the hotspots, the device needs to be tested under the actual operating conditions. Therefore, the development of high-resolution thermometry techniques is required to understand the heat dissipation processes during the device operation. Recently, several thermometry techniques have been proposed, such as radiation thermometry, thermocouple based contact thermometry, scanning thermal microscopy, scanning transmission electron microscopy and transition based threshold thermometers. However, most of these techniques have limitations including the need for extensive calibration, perturbation of the actual device temperature, low throughput, and the use of ultra-high vacuum. Here, we present a facile technique, which uses a thin film contact thermometer based on the phase change material Ge_2 Sb_2 Te_5, to precisely map thermal contours from the nanoscale to the microscale. Ge_2 Sb_2 Te_5 undergoes a crystalline transition at hbox {T}_{{g}} with large changes in its electric conductivity, optical reflectivity and density. Using this approach, we map the surface temperature of a nanowire and an embedded micro-heater on the same chip where the scales of the temperature contours differ by three orders of magnitude. The spatial resolution can be as high as 20 nanometers thanks to the continuous nature of the thin film.

Success Rates of Recovering Teeth and Infant-Sized Bones Dispersed among Leaf Litter

Previous research (Pokines et al. 2018) examined the success rates of search through leaf litter for older juvenile- to adult-sized bones in a New England forest environment. Individual element size class had a significant effect upon recovery rate. Using the same experimental conditions, the present research examined the recovery rates for infant-sized bones and adult-sized teeth. Ten simulated outdoor scenes were sown with dispersed, skeletonized, infant-sized pig (Sus scrofa) bones of different types and pig teeth comparable in size to adult human. Processing was executed through a hand-and-knee crawl while picking through and collecting all leaf litter by hand and then emptying it onto a tarp, where the effects of searching the same leaf litter twice were examined. Recovery rates from primary search ranged from 62.4% to 74.7% per trial with an overall rate of 68.8%, which was significantly lower than the overall recovery rate of 76.7% for the previous research. Secondary search recovered an additional 17.9% of bone, leading to an overall recovery rate of 86.7%. Teeth were recovered through primary search at an overall rate of 38.0%, with an additional 12.0% recovered through secondary search. Significant differences in recovery rate for the infant-sized remains based upon bone size were noted. Forensic archaeologists are cautioned that full recovery cannot be assumed in these situations. Careful primary searching by hand combined with secondary searching may mitigate the loss of evidence in some situations and should be considered for forensic search protocols, especially where infant skeletal remains are suspected to be present.

Experimental study of depth-limited open-channel flows over a gravel bed

Laboratory experiments of depth-limited open-channel flows over a gravel bed were conducted in the study. Two gravel patches with identical individual element size and different lengths (3.81m and 7.5m) were tested. The depth-limited uniform flow regime with relative submergence Sr (=D/ks) ranging from 2.68 to 5.94 was produced by adjusting the tailgate weir. The velocity profiles were measured by using both an ultra-sound velocity profiler (UVP) and an acoustic Doppler velocimeter (ADV). The conventional methods used to determine the zero-plane displacement and estimate the bed shear velocity were then reviewed and compared. The measured double-averaged (DA) velocity profiles were found to fit well with the log law and defect law with a non-universal Karman constant κ. κ-value remains nearly constant and in the range from 0.2 to 0.3 for the long patch (LP) cases and κ-values are scattered within a wider range from 0.3 to 0.5 for the short patch (SP) cases. While the Br-value in log law remains constant and equal to 8.5 for LP cases, the Br-value was found to decrease with the increase of the dimensionless roughness height ks+ for SP cases. The streamwise turbulence intensity distributions were found to be independent on the patch length and agree well with the available experimental data in the intermediate region and wall region. The Manning resistance coefficient and Darcy–Weisbach friction factor were analyzed. The κ-value decreases to 0.22 for the fitting of the logarithmic flow resistance law under small relative submergence. The value of the integration constant Ar in the logarithmic law falls within the normal range between 3.25 and 6.25.

Obligatory averaging in mean size perception.

The perception of ensemble characteristics is often regarded as an antidote to an established bottleneck in focused attention and working memory, both of which appear to be limited in capacity to a few objects only. In order to test the associative law of summation, observers were asked to estimate the mean size of four circles relative to a reference circle. When there was no time to scrutinize each individual circle, observers discriminated the mean size difference identically, irrespective of whether the same summary size increment or decrement was added to or subtracted from the size of only one, two, or all four circles. Since observers judged the size of individual circles, the position of which was indicated after they were displayed, considerably less accurately than the mean size of the four circles, it is very unlikely that explicit knowledge of the size of the individual elements is the basis of mean size judgments. The sizes of individual elements were pooled together in an obligatory manner before size information had reached awareness. The processing of size information seems to be largely constrained to only one measure at a time, with a preference for mean size rather than the individual measures from which it is assembled.

An analysis of the influence of the color rendition of images reconstructed from full-color computer-generated Fourier-transform holograms

The color rendition of an image reconstructed from a color computer-generated Fourier hologram (CCGFH) is both a basic and an important issue in the field of holography. In this study, CCGFHs are encoded with the Burch encoding algorithm and then loaded onto a spatial light modulator for optical reconstruction. The influence of the color rendition of the reconstructed images has been analyzed primarily through experiments. The experimental results show that the individual element size used in encoding the CCGFH is inversely proportional to both the size and the central location of the reconstructed images, whereas the wavelength of the monochromatic light used in optical reconstruction is proportional. Some parameters related to the spectrum, such as different transmittances, half-widths of the three primary color filters and different sensitivity levels to the three primary colors of the complementary metal–oxide–semiconductor (CMOS), affect the color rendition of the reconstructed image. A method for correcting color aberration in reconstructed images is proposed. Using this method, the influence of the wavelength can be corrected by stretching the reconstructed image to an appropriate size and the influence of the spectrum can be corrected by equalizing the spectral sensitivity levels of the CMOS. The color rendition of the reconstruction is improved significantly using the method. The proof-of-principle experiments demonstrate that the method is effective and feasible.

An almost general theory of mean size perception

A general explanation for the observer's ability to judge the mean size of simple geometrical figures, such as circles, was advanced. Results indicated that, contrary to what would be predicted by statistical averaging, the precision of mean size perception decreases with the number of judged elements. Since mean size discrimination was insensitive to how total size differences were distributed among individual elements, this suggests that the observer has a limited cognitive access to the size of individual elements pooled together in a compulsory manner before size information reaches awareness. Confirming the associative law of addition means, observers are indeed sensitive to the mean, not the sizes of individual elements. All existing data can be explained by an almost general theory, namely, the Noise and Selection (N&S) Theory, formulated in exact quantitative terms, implementing two familiar psychophysical principles: the size of an element cannot be measured with absolute accuracy and only a limited number of elements can be taken into account in the computation of the average size. It was concluded that the computation of ensemble characteristics is not necessarily a tool for surpassing the capacity limitations of perceptual processing.

Attending to One of Many: When Infants are Surprisingly Poor at Discriminating an Item's Size

Despite a prevailing assumption in the developmental literature that changes in continuous quantities (i.e., surface area, duration) are easier to detect than changes in number, very little research has focused on the verity of this assumption. The few studies that have directly examined infants’ discriminations of continuous extent have revealed that infants discriminate the duration of a single event and the area of a single item with similar levels of precision (Brannon et al., 2006; vanMarle and Wynn, 2006). But what about when items are presented in arrays? Infants appear to be much worse at representing the cumulative surface area compared to the numerosity of an array (Cordes and Brannon, 2008a), however this may be due to a noisy accumulation process and not a general finding pertaining to representations of the extent within an array. The current study investigates how well infants detect changes in the size of individual elements when they are presented within an array. Our results indicate that infants are less sensitive to continuous properties of items when they are presented within a set than when presented in isolation. Specifically we demonstrate that infants required a fourfold change in item size to detect a change when items were presented within a set of homogeneous elements. Rather than providing redundant cues that aided discrimination, presenting a set of identical elements appeared to hamper an infant's ability to detect changes in a single element's size. In addition to providing some of the first evidence to suggest that the presence of multiple items may hinder extent representations, these results provide converging lines of evidence to support the claim that, contrary to popular belief, infants are better at tracking number than continuous properties of a set.

Modelling the statistical processing of visual information

Recent psychophysical investigations showed that humans have the ability to compute the mean size of a set of visual objects. The investigations suggest that the visual system is able to form an overall, statistical representation of a set of objects, while the information about individual members of the set is lost. We proposed a neural model that computes the mean size of a set of similar objects. The model is a feedforward, two-dimensional neural network with three layers. Computer simulations showed that the presented model of statistical processing is able to form abstract numerical representation and to compute the mean size independently from the visual appearance of objects. This is achieved in a fast, parallel manner without serial scanning of the visual field. The mean size is computed indirectly by comparing the total activity in the input layer and in the third layer. Therefore, the information about the size of individual elements is lost. An extended model is able to hold statistical information in the working memory and to handle the computation of the mean size for surfaces with empty interiors.

High electric-field-induced strain of Pb(Mg1/3Nb2/3)O 3 -PbTiO 3 crystals and their application in multilayer actuators

Electric-field-induced strain behavior of differently oriented and componential (1-x)Pb(Mg1/3Nb2/3)O3xPbTiO3 (PMNT) crystals was investigated. An optimum composition range (29%≤x≤31%) of 〈001〉-oriented PMNT crystals was ascertained for multilayer actuator applications, which exhibited high-strain and low-hysteresis behavior. The rhombohedral (monoclinic)–tetragonal phase-transition behavior in PMNT single crystals is dependent on their thermal and electric history, which markedly impacts on the strain performance of the crystals. In contrast to PZT-SF (doped PZT ceramics) multilayer actuators, the strain values for 20-layer PMNT actuators with individual element sizes of 6×6×0.3 mm3 are larger by more than five times at 20 kV/cm (0.373% compared to 0.072%), and 23-μm displacements can been achieved. Against 40-N load, the displacements are decreased to 20.2 μm.

Compact semiconductor light-emitting diodes for dynamic imaging of neuronal circuitry

We describe the use of compact green light-emitting diodes (LEDs) for fluorescence optical imaging and demonstrate this for dynamic recording from cultured neurons. The efficient gallium-nitride-based LEDs have individual element sizes comparable to typical biological cells and are operated in proximity illumination mode for individual neurons. As periodic arrays, and with direct electrical control of each LED, a spatially periodic multicellular target can be induced to fluoresce in a predesigned spatiotemporal sequence, thereby providing a new approach to dynamic recording of small neural circuits.

Families of short interspersed elements in the genome of the oomycete plant pathogen, Phytophthora infestans

The first known families of tRNA-related short interspersed elements (SINEs) in the oomycetes were identified by exploiting the genomic DNA sequence resources for the potato late blight pathogen, Phytophthora infestans. Fifteen families of tRNA-related SINEs, as well as predicted tRNAs, and other possible RNA polymerase III-transcribed sequences were identified. The size of individual elements ranges from 101 to 392 bp, representing sequences present from low (1) to highly abundant (over 2000) copy number in the P. infestans genome, based on quantitative PCR analysis. Putative short direct repeat sequences (6–14 bp) flanking the elements were also identified for eight of the SINEs. Predicted SINEs were named in a series prefixed infSINE (for infestans-SINE). Two SINEs were apparently present as multimers of tRNA-related units; four copies of a related unit for infSINEr, and two unrelated units for infSINEz. Two SINEs, infSINEh and infSINEi, were typically located within 400 bp of each other. These were also the only two elements identified as being actively transcribed in the mycelial stage of P. infestans by RT-PCR. It is possible that infSINEh and infSINEi represent active retrotransposons in P. infestans. Based on the quantitative PCR estimates of copy number for all of the elements identified, tRNA-related SINEs were estimated to comprise 0.3% of the 250 Mb P. infestans genome. InfSINE-related sequences were found to occur in species throughout the genus Phytophthora. However, seven elements were shown to be exclusive to P. infestans.

High electric-field-induced strain of Pb(Mg 1/3Nb 2/3)O 3–PbTiO 3 crystals in multilayer actuators

An optimum composition range (29%≤ x≤31%) of 〈001〉 oriented (1− x)Pb(Mg 1/3Nb 2/3)O 3– xPbTiO 3(PMNT) crystals was ascertained for multilayer actuator applications, which exhibited high-strain and low-hysteresis behavior. A −1.5 kV/cm negative E-field can be applied to PMNT ferroelectric samples with low hysteresis. Forty layer actuators with individual element sizes of 7×7×0.7 mm 3 were fabricated under identical processing conditions using two different materials: (1) single crystal PMNT and (2) commercial PZT-SF ceramics. Under free-load conditions, 48 μm displacements can been achieved in PMNT actuators at electric fields ranging from −1.5 to 10 kV/cm, which is more than twice the displacement of the PZT-SF actuators driven from −10 to 10 kV/cm. Under 4 kg loading, the displacements in PMNT stain actuators are decreased to 42.5 μm.

Soft X-ray resonant scattering: An element-specific tool to characterize patterned arrays of nanomagnets

The authors have demonstrated the use of soft X-ray resonant scattering as an element-specific tool for characterizing the structure and magnetic properties of a rectangular array of nanomagnets. The periodicity and the size of individual elements of an array of Co dots were determined by measuring the intensities of a large number of diffraction orders and comparing them to model calculations performed within the framework of Fraunhoffer diffraction theory. Element-specific hysteresis loops along both the easy and hard axis of the array were measured by tuning the incident energy to the Co L/sub 3/ absorption edge.

Novel Process Methodology for Uniformly Cutting Nanotubes

AbstractWe present a novel process methodology for the controlled cutting of nanotubes and other nanostructures to well-controlled lengths and sizes. The continuing increase in complexity of electronic devices, coupled with decreasing size of individual elements, are placing more stringent demands on the resolution and accuracy of fabrication patterns. The ability to fabricate on a nanometer scale guarantees a continuation in miniaturization of functional devices. Particularly interesting is the application of nanotubes' chemical and electronic properties which vary with their dimensions and structure. One realization of this process includes the use of photolithography or electron beam lithography to place protective resist patterns over the nanostructures to be cut. Those sections which are not covered by the resist pattern are removed by reactive ion etching. This is a scaleable process which permits the simultaneous cutting of many nanostructures and ensembles of nanostructures. The lengths, shapes or length distributions can be predicted from theory and thus specified for a given application requirement. Nanostructures which can be cut in this process include nanotubes, nanofibers and nanoplanes. Large scale production of nanostructures with uniform length or specific size-distribution can be used in electronic applications such as field-emission transistors, optoelectronic elements, single electron devices and sensors.

Ultrasound apparatus for three dimensional image reconstruction

This invention employs an ultrasound apparatus with a phased transducer having transmit and receive array systems to form an electronically scanned ultrasonic "pencil" beam (25) from crossed flat acoustic beams. The flat transmit beams and flat receive apertures are shaped by the arrays with size of individual elements on the order of the wavelength of a generated carrier frequency in a human body. The separation of array functions in the transmission and reception modes reducess the side lobe level and improves the noise performance. A fast method of acquisition of two dimensional images is described. This method uses a property of a dynamic focused and scanned flat acoustic beam together with the ability to shape flat synthetic receive apertures from digitized and memorized amplitude information. The same fast method of three dimensional image reconstruction is suggested, which uses an unfocused acoustic beam generated by a single transducer element together with the ability to form flat synthetic receive apertures in memory.

High-power VCSELs: single devices and densely packed 2-D-arrays

We report on vertical-cavity surface-emitting lasers (VCSELs) and laser arrays providing high output powers in the 980-nm wavelength regime. Extensive investigations on size scaling behavior of single top- and bottom-emitting devices concerning fundamental electrooptical and thermal properties show limits of attainable output characteristics. Maximum experimentally achieved continuous-wave (CW) optical output powers at room temperature are 180 and 350 mW for top- and bottom-emitting VCSELs, respectively. Detailed analysis on the thermal interaction between closely spaced elements have been carried out to describe the thermally induced power limitations of two-dimensional arrays. Fabricated heat sunk bottom-emitting arrays of 23 elements and 40-/spl mu/m aperture size of individual elements show output powers of 0.56 W CW at room temperature and 0.8 W actively cooled, resulting in 0.33 kW/cm/sup 2/ and 0.47 kW/cm/sup 2/ maximum spatially averaged optical power density, respectively.

Calculation of ultrasonic transducer signal-to-noise ratios using the KLM model

This paper describes a method for adding thermal and amplifier noise to a KLM model for a transducer element. The model is used to compare the magnitudes of various noise sources in a 5 MHz array element typical of those used for linear array imaging with and without an amplifier. Fundamental signal-to-noise ratio (SNR) issues of importance to array and amplifier designers are explored, including the effect on SNR of effective dielectric constant of the piezoelectric material, individual element size, changing the number of elements, and adding an amplifier to an element before and after a cable. SNR is considered both for the case in which the acoustic output is limited by the maximum rarefactive pressure which is considered safe for a particular application (Mechanical Index limitation) and the case in which acoustic output is limited by the maximum transmit voltage than can he delivered by the imaging system or tolerated by the transducer. It is shown that the SNR performance depends on many controllable parameters and that significant improvements in SNR can be achieved through proper design. The implications for 1.5-D and 2-D array elements are discussed.

Structural and loads analysis of a two-stage reusable manned launch system

The conceptual design of a rocket-powered, two-stage, fully reusable launch vehicle has been performed as a part of the NASA's Advanced Manned Launch System study. This paper summarizes the structural design and load analysis of this vehicle. The method used to determine the structural weights consists of generating a finite-element model for each vehicle, selecting a set of critical loading conditions, determining the loads on the model caused by those conditions, determining the model response, and changing the sizes of individual elements to obtain a safe structure. The integrated loads on the vehicle were obtained from a three-degree-of-freedom trajectory analysis.