Oblique Target Research Articles

Numerical Prediction of the Impact Fracture of a Projectile Through Oblique Target

Numerical Prediction of the Impact Fracture of a Projectile Through Oblique Target

Thermal Imaging and Biometrical Thermography of Humpback Whales

Determining species distributions through time and space remains a primary challenge in cetacean science and conservation. For example, many whales migrate thousands of kilometers every year between remote seasonal habitats along migratory corridors that cross major shipping lanes and intensively harvested fisheries creating a dynamic spatial and temporal context that conservation decisions must take into account. Technological advances enabling automated whale detection have the potential to dramatically improve our knowledge of when and where whales are located, presenting opportunities to help minimize adverse human-whale interactions. Using thermographic data we show that near-horizontal (i.e. high zenith angle) infrared images of humpback whale (Megaptera novaeangliae) blows, dorsal fins, flukes and rostrums record similar magnitude brightness temperature anomalies relative to the adjacent ocean surface. Our results demonstrate that these anomalies are similar in both low latitude and high latitude environments despite a ~16°C difference in ocean surface temperature between study areas. We show that these similarities occur in both environments due to emissivity effects associated with oblique target imaging, rather than differences in cetacean thermoregulation. The consistent and reproducible brightness temperature anomalies we report provide important quantitative constraints that will help facilitate the development of transient temperature anomaly detection algorithms in diverse marine environments. Thermographic videography coupled with laser range finding further enables calculation of whale blow velocity, demonstrating that biometrical measurements are possible for near-horizontal datasets that otherwise suffer from emissivity effects. The thermographic research we present creates a platform for the delivery of 3 important contributions to cetacean conservation: 1) non-invasive species-level identifications based on whale blow shapes and velocities recorded by infrared videography; 2) reduced ship-strike rates through automated thermographic cetacean detection systems deployed in high traffic areas; 3) monitoring the spatial and temporal distributions of endangered animals in remote habitats.

Re-examining the factor structure and psychometric properties of the Mini-Mental Adjustment to Cancer Scale in a sample of 364 Chinese cancer patients.

The Mini-Mental Adjustment to Cancer Scale (Mini-MAC) is widely used to evaluate cancer patients' psychological responses. Validation studies of the scale have shown methodological shortcomings and inconsistency in the factor solutions. The aim of this study was to examine the factor structure and psychometric properties of the Mini-MAC. A large sample of 364 Chinese patients with breast or colorectal cancer completed the Mini-MAC and psychosocial measures (general health, perceived stress, anxiety, and depression). Exploratory factor analyses examined the relative fit of two- to six-factor models using robust weighted least square estimation and oblique target rotation. Convergent validity was evaluated via correlations between the Mini-MAC factor scores and the psychosocial outcomes. The five-factor model showed the best model fit and largely replicated the original Mini-MAC's helpless/hopeless (HH), anxious preoccupation (AP), fighting spirit (FS), fatalism (FA), and cognitive avoidance (CA) subscales. The five factors had acceptable reliability (Cronbach's α = 0.67-0.88) and 4-month test-retest reliability (r = 0.45-0.64). HH, AP, and CA were positively associated with the psychosocial outcomes (r = 0.19-0.60). Modest and negative correlations were found between the psychosocial outcomes and FS and FA. The results support the Mini-MAC's original five-factor structure with satisfactory reliability and convergent validity. The results demonstrate that the Mini-MAC is a valid measure for assessing psychological responses in cancer patients.

Orientation is different: Interaction between contour integration and feature contrasts in visual search

Salient items usually capture attention and are beneficial to visual search. Jingling and Tseng (2013), nevertheless, have discovered that a salient collinear column can impair local visual search. The display used in that study had 21 rows and 27 columns of bars, all uniformly horizontal (or vertical) except for one column of bars orthogonally oriented to all other bars, making this unique column of collinear (or noncollinear) bars salient in the display. Observers discriminated an oblique target bar superimposed on one of the bars either in the salient column or in the background. Interestingly, responses were slower for a target in a salient collinear column than in the background. This opens a theoretical question of how contour integration interacts with salience computation, which is addressed here by an examination of how salience modulated the search impairment from the collinear column. We show that the collinear column needs to have a high orientation contrast with its neighbors to exert search interference. A collinear column of high contrast in color or luminance did not produce the same impairment. Our results show that orientation-defined salience interacted with collinear contour differently from other feature dimensions, which is consistent with the neuronal properties in V1.

Structure of Ni<sub>80</sub>Fe<sub>20</sub> Films Deposited on SiO<sub>2</sub>/Si(100) by Direct Current Magnetron Sputtering System with the Oblique Target

About 300nm-thick Ni80Fe20 films were deposited on SiO2/Si (100) substrates at 300 K and 673 K in 1.2 Pa and 0.8 Pa Ar gas by a direct current (DC) magnetron sputtering system with the oblique target. The films grown at 300 K have a predominate [11 crystal orientation in the growth direction whereas those deposited at 673 K grow mainly with a [11 crystalline orientation in the growth direction. All the films have a columnar structure. The grain size increases with increasing deposition temperature. The films grown at 673 K are dense compared with those grown at 300 K. The film deposited at 673 K in 0.8 Pa Ar has the lowest resistivity.

Salient stimuli capture attention and action

Reaction times in a visual search task increase when an irrelevant but salient stimulus is presented. Recently, the hypothesis that the increase in reaction times was due to attentional capture by the salient distractor has been disputed. We devised a task in which a search display was shown after observers had initiated a reaching movement toward a touch screen. In a display of vertical bars, observers had to touch the oblique target while ignoring a salient color singleton. Because the hand was moving when the display appeared, reach trajectories revealed the current selection for action. We observed that salient but irrelevant stimuli changed the reach trajectory at the same time as the target was selected, about 270 ms after movement onset. The change in direction was corrected after another 160 ms. In a second experiment, we compared manual selection of color and orientation targets and observed that selection occurred earlier for color than for orientation targets. Salient stimuli support faster selection than do less salient stimuli. Under the assumption that attentional selection for action and perception are based on a common mechanism, our results suggest that attention is indeed captured by salient stimuli.

Structure and magnetic properties of Fe films with pyramid-like nanostructures deposited by oblique target direct current magnetron sputtering

Fe thin films were deposited by oblique target direct current magnetron sputtering on Si (100) and (111) substrates. The structure, surface morphology and magnetic properties of the thin films were characterized using X-ray diffraction, field emission scanning electron microscopy, and superconducting quantum interference device magnetometer, respectively. The results reveal that the structure of the as-deposited Fe thin films is body-centered cubic with the preferential [110] crystalline orientation. A pyramid-like nanostructure with sharp tip was formed on the surfaces of Fe thin films under appropriate sputtering power. Formation of the pyramid-like nanostructure is mainly owed to the enhancement of atomic mobility and the bombardment effect with increasing of sputtering power. Meanwhile, the crystalline orientation of Si substrate and the intrinsic stress in the films are expected to have little contribution to the formation of the pyramid-like nanostructure. The magnetic anisotropy was found in the as-deposited Fe thin films, and varies with the thickness of the Fe thin films. As the film thickness increases from 604 to 1,786 nm, the magnetic anisotropy field and the uniaxial anisotropy constant increase from 3.8 to 5.6 kOe, and from 0.4 × 106 to 1.1 × 106 erg/cm3, respectively, which indicates that besides magnetocrystalline anisotropy, stress induced anisotropy and shape anisotropy also exist in the as-deposited Fe thin films.

SECM imaging of latent fingerprints developed by deposition of Al-doped ZnO thin film

A novel vacuum metal deposition (VMD) based technique has been efficiently employed for the visualization of latent fingerprints on glass and plastic substrates. Al-doped ZnO thin film (ZAO) was deposited on the bare surface and the valleys between the fingerprint ridges by direct current magnetron sputtering with the oblique target, which yielded normal development of latent fingerprints. The enhanced results of latent fingerprints have been photographed with good contrast by a conventional digital camera. Additionally, an electrochemical method, scanning electrochemical microscopy (SECM), has also been successfully applied to the image acquisition of a latent fingerprint developed on the glass surface due to its superb sensitivity toward the small variation of the conductivities at the substrate surface. The SECM image of a latent fingerprint on glass substrate provided good contrast between valleys and ridges and micrometer-scale resolution images of fingerprints under wet conditions by using ferrocene methanol as a redox mediator to detect the topology of the fingerprint deposits in constant-height feedback mode.

Comparative study on the characteristics of network and continuous Ni films

Ni films were deposited on anodic aluminum oxide (AAO) and SiO2/Si(100) substrates at 300K by direct current magnetron sputtering with the oblique target. The film thickness was 80nm, 160nm and 260nm. The films grown on AAO substrates have a network structure while those deposited on SiO2/Si(100) substrates are continuous. The network film consists of granules and is formed by granule connection. The granule consists of many fine grains. The granule size increases with increasing film thickness. The 80nm-thick network film has a honeycomb-like structure. The continuous films grow with a columnar structure and the transverse size of columnar grains increases with increasing film thickness. All the network films show a Ni(111) diffraction peak while the 160nm- and 260nm-thick continuous films exhibit the Ni(111) and Ni(200) diffraction peaks. The network films have higher coercivity and residual magnetization ratio compared with the continuous films. The coercivity and the residual magnetization ratio increase with increasing film thickness for the network films while they are almost independent of the film thickness for the continuous films. A temperature dependence of the resistance within 5–200K reveals that the 80nm-thick network Ni film exhibits markedly a minimal resistance at about 40K. A logarithmic temperature dependence of the conductance is verified at temperatures below 40K. The temperature coefficient of resistance is smallest for the 80nm-thick network film and is largest for the 260nm-thick continuous film.

Long-Range, Pattern-Dependent Contextual Effects in Early Human Visual Cortex

The standard view of neurons in early visual cortex is that they behave like localized feature detectors. Here we demonstrate that processing in early visual areas goes beyond feature detection by showing that neural responses are greater when a feature deviates from its context compared to when it does not deviate from its context. Using psychophysics, fMRI, and electroencephalography methodologies, we measured neural responses to an oriented Gabor ("target") embedded in various visual patterns as defined by the relative orientation of flanking stimuli. We first show using psychophysical contrast adaptation and fMRI that a target that differs from its context results in more neural activity compared to a target that is contained within an alternating sequence, suggesting that neurons in early visual cortex are sensitive to large-scale orientation patterns. Next, we use event-related potentials to show that orientation deviations affect the earliest sensory components of the target response. Finally, we use forced-choice classification of "noise" stimuli to show that we are more likely to "see" orientations that deviate from the context. Our results suggest that early visual cortex is sensitive to global patterns in images in a way that is markedly different from the predictions of standard models of cortical visual processing.

Structural, electrical and photoluminescence properties of ZnO:Al network films grown on nanochannel Al2O3 substrates by direct current magnetron sputtering with an oblique target

ZnO:Al network films were grown on nanochannel Al2O3 substrates at 300K by direct current magnetron sputtering with an oblique target. The film thicknesses are 60nm, 160nm and 190nm. The holes of the network films diminish with increasing film thickness. For the 60-nm thick film, the network is formed by connecting grains. For the 160-nm and 190-nm thick films, however, the network is formed by connecting granules. The granules consist of many small grains. All the network films have a wurtzite structure. The 60-nm and 160-nm thick network films mainly have a [101] orientation in the film growth direction while the 190-nm thick network film grows with a random crystallographic orientation. A temperature dependence of the resistance within 160–300K reveals that the network films exhibit a semiconducting behavior and their carrier transport mechanism is thermally activated band conduction. Room temperature photoluminescence spectra for wavelengths between 300nm and 700nm reveal a violet emission centered at 405nm for the 60-nm thick network film and a blue emission centered at 470nm for both the 160-nm and the 190-nm thick network films. Annealing decreases the resistivity of the network film.

Structural, electrical and magnetic properties of Fe network films grown on nanochannel Al2O3 substrates by direct current magnetron sputtering with the oblique target

Fe films were deposited on nanochannel Al2O3 substrates at 300K by direct current magnetron sputtering with the oblique target. The film thickness is 100nm, 120nm, 175nm and 325nm. All the films consist of granules and grow with a network structure. The network structure is formed by granule connection. The granule consists of many fine grains. The granule size increases with increasing film thickness. The transverse width of the granule gradually widens along the film growing direction. The 120nm-thick film has a honeycomb-like network structure. The network films have a resistivity of about 7×10−5Ωm. A temperature dependence of the resistivity within 1.5–200K reveals that the Fe network films exhibit a minimal resistivity at about 30K. A logarithmic temperature dependence of the conductance is verified at temperatures below 30K. The 100nm-thick film exhibits the weakest magnetocrystalline anisotropy and magnetic uniaxial anisotropy. The 120nm-thick film has the lowest coercivity.

Structural, electrical and photoluminescence properties of ZnO:Al films grown on MgO(0 0 1) by direct current magnetron sputtering with the oblique target

ZnO:Al films were deposited on MgO(0 0 1) substrates at 300 K and 673 K by direct current magnetron sputtering with the oblique target. The Ar pressure was adjusted to 0.4 Pa and 1.2 Pa, respectively. All the films have a wurtzite structure and a c-axis orientation in the film growth direction. The films deposited at 300 K initially grow with thin columnar grains and subsequently grow with large granular grains on the thin columnar grains. However, the films grown at 673 K consist mainly of dense columnar grains perpendicular to the substrate surface. The ZnO:Al film deposited at 673 K and 0.4 Pa has the lowest resistivity, the highest free electron concentration and Hall's mobility. A temperature dependence of the resistivity within 5–300 K reveals that the films grown at 300 K exhibit a semiconducting behavior and those grown at 673 K show a metal–semiconductor transition. The carrier transport mechanism is Mott's variable range hopping in the temperature range below 90 K for all the films and thermally activated band conduction above 215 K for the films grown at 300 K. Room temperature photoluminescence spectra for wavelengths between 300 nm and 800 nm reveal mainly blue-green emissions centered at 452 nm, 475 nm and 515 nm.

Characteristics of Ni films deposited on SiO 2/Si(1 0 0) and MgO(0 0 1) by direct current magnetron sputtering system with the oblique target

280 nm-thick Ni films were deposited on SiO 2/Si(1 0 0) and MgO(0 0 1) substrates at 300 K, 513 K and 663 K by a direct current magnetron sputtering system with the oblique target. The films deposited at 300 K mainly have a [1 1 0] crystalline orientation in the film growth direction. The [1 1 0]-orientation weakens and the [1 1 1]- and [1 0 0]-orientations enhance with increasing deposition temperature. The lattice constant of the Ni films is smaller than that of the Ni bulk, except for the film grown on MgO(0 0 1) at 663 K. Furthermore, as the deposition temperature increases, the lattice constant of the films grown on the SiO 2/Si(1 0 0) decreases whereas that of the films grown on the MgO(0 0 1) increases. The films deposited at 300 K and 513 K grow with columnar grains perpendicular to the substrate. For the films deposited at 663 K, however, the columnar grain structure is destroyed, i.e., an about 50 nm-thick layer consisting of granular grains is formed at the interface between the film and the substrate and then large grains grow on the layer. The Ni films deposited at 300 K consist of thin columnar grains and have many voids at the grain boundaries. The grains become thick and the voids decrease with increasing deposition temperature. The resistivity of the film decreases and the saturation magnetization increases with increasing deposition temperature.

Structural and physical properties of ZnO:Al films grown on glass by direct current magnetron sputtering with the oblique target

ZnO:Al films were deposited on glass substrates at 300 K and 673 K by direct current magnetron sputtering with the oblique target. The Ar pressure was adjusted to 0.4 Pa and 1.2 Pa, respectively. All the films have a wurtzite structure and grow with a c-axis orientation in the film growth direction. The films grow mainly with columnar grains perpendicular to the substrate and some granular grains also exist in the films. The film deposited at 673 K and 0.4 Pa has the largest grains whereas that prepared at 300 K and 0.4 Pa consists of the smallest grains and is porous. The films exhibit an n-type semiconducting behavior at room temperature. The ZnO:Al film deposited at 673 K and 0.4 Pa has the lowest resistivity (3.40 × 10 −3 Ω cm), the highest free electron concentration (4.63 × 10 20 cm −3) and a moderate Hall mobility (4.0 cm 2 V −1 s −1). The film deposited at 300 K and 0.4 Pa has the highest resistivity and the lowest free electron concentration and Hall mobility. A temperature dependence of the resistivity reveals that the carrier transport mechanism is Mott’s variable range hopping in the temperature region below 100 K and thermally activated band conduction above 215 K. The activation energy for the film deposited at 300 K and 0.4 Pa is 41 meV and that for the other films is about 35 meV. All the films have an average optical transmittance of over 85% in the visible wavelength range. The absorption edge of the film deposited at 300 K and 0.4 Pa shifts to the longer wavelength (redshift) relative to the films prepared under the other conditions.

Orientation perception in rhesus monkeys (Macaca mulatta)

It was previously demonstrated that monkeys divide the orientation continuum into cardinal and oblique categories. However, it is still unclear how monkeys perceive within-category orientations. To better understand monkeys' perception of orientation, two experiments were conducted using five monkeys. In experiment 1, they were trained to identify either one cardinal or one oblique target orientation out of six orientations. The results showed that they readily identified the cardinal target whether it was oriented horizontally or vertically. However, a longer training period was needed to identify the oblique target orientation regardless of its degree and direction of tilt. In experiment 2, the same monkeys were trained to identify two-oblique target orientations out of six orientations. These orientations were paired, either sharing the degree of tilt, direction of tilt, or neither property. The results showed that the monkeys readily identified oblique orientations when they had either the same degree or direction of tilt. However, when the target orientations had neither the same degree nor direction of tilt, the animals had difficulty in identifying them. In summary, horizontal and vertical orientations are individually processed, indicating that monkeys do not have a category for cardinal orientation, but they may recognize cardinal orientations as non-obliques. In addition, monkeys efficiently abstract either the degree or the direction of tilt from oblique orientations, but they have difficulty combining these features to identify an oblique orientation. Thus, not all orientations within the oblique category are equally perceived.

Characteristics of Ni6Fe94 films deposited on SiO2/Si(100) by an oblique target co-sputtering

Ni6Fe94 films were deposited on SiO2/Si(100) substrates at room temperature by oblique target co-sputtering and then annealed in vacuum at 573 K, 673 K and 753 K for 1 h, respectively. The as-deposited and annealed films mainly have a body-centered cubic structure and a [110]-crystalline orientation in the film growth direction. The [110]-orientation of the film enhances with increasing annealing temperature. A face-centered cubic phase coexists in the body-centered cubic phase of the Ni6Fe94 films annealed at 673 K and 753 K. The as-deposited film grows with thin columnar grains and has a void network at the grain boundaries. The grain size does not change markedly with annealing temperature, whereas the voids decrease with increasing annealing temperature. Furthermore, wide and short void network is formed upon annealing. The resistivity of the film decreases with annealing temperature. The temperature coefficient of resistance of the film annealed at 753 K is larger than that of the as-deposited film. The as-deposited film shows a hard magnetization requiring a saturation field of 3.34×105 A/m. The film annealed at 753 K shows an easy magnetization characteristic and its coercivity is 2.51×104 A/m. The saturation magnetization of the film increases with annealing temperature. The as-deposited and annealed films have an isotropic magnetization characteristic.

Anisotropies in peripheral vernier acuity

Vernier acuity for short horizontal, vertical and oblique target lines was measured in many locations in the periphery of the visual field in normal human observers. In the 10 deg periphery, the average alignment threshold with oblique vernier lines in eight locations for three observers was 2.29 times higher than that with vertical and horizontal target lines. This oblique effect was found everywhere in the visual field. Similar conclusions are drawn for configurations in which the lines were replaced by just their distal endpoints, but here, additionally, performance was distinctly better when the dot pair was collinear with the fixation point, i.e. oriented radially, than when it was oriented tangentially. Both for vernier lines and for dot pairs, in all observers, horizontal configurations showed somewhat better thresholds than vertical ones. These results suggest an inherent pattern of connectivity throughout the visual field favoring processing in the cardinal orientations over the obliques, the radial over the tangential and, to a limited extent, the horizontal over the vertical.

Progress towards an analytical modelling capability for kinetic energy penetrators and complex armours

By combining the Walker-Anderson penetration model with the rod-bar impact model of Eichelberger an analytical model has been developed for semi-infinite, finite, oblique and moving plates. Tate's energy balance equation for target crater diameter is included in the model. The predicted effect of pitch angle against 0° and 60° obliquity RHA compares well with experimental data at 1.65 km/s for negative pitch angles. At high angles of positive pitch, the penetration depth into an oblique target is over-predicted. A bulging algorithm for the target face is required to represent such impact conditions accurately. Comparisons with reverse ballistic experiments at up to 2.6 km/s predict the residual rod shape and erosion quite accurately.

Smooth pursuit eye movements in patients with ocular motor nerve palsies: A preliminary report

The trajectories, velocity, and co-ordination of smooth pursuit eye movements were investigated in 30 patients with ocular motor nerve palsies (including palsies of cranial nerves III, IV and VI). The recordings of horizontal and vertical eye movements were obtained by video-oculography under monocular viewing conditions. During the recordings, horizontal, vertical, and oblique target movements of 10°/s constant velocity were presented to the subjects in succession. In contrast to normal subjects, smooth pursuit eye movements in patients with ocular nerve palsies showed considerable differences in dependence on the fixating eye. The smooth pursuit gain of the paretic eye was reduced for eye movements in the pulling plane of the paretic muscle. When viewing with the paretic eye, the tracking of the target was achieved by a series of refixation saccades, which also occurred in the occluded normal eye. Consequently, the sound eye position overshot the target. The transition from a smooth to a saccadic pursuit pattern was accompanied by a spatial deviation of the eye movement trajectories from the path of the fixation target.