Effect Of Target Position Research Articles

The effect of target position on Al plasma characteristics induced by a 355 nm nanosecond laser in the presence of an external non-uniform magnetic field

In this work, the effect of target position on Al plasma characteristics induced by a 355 nm nanosecond laser in the presence of an external non-uniform magnetic field was investigated by using the optical emission spectroscopy and fast imaging. The time-resolved spectra were recorded at various sample positions within the magnetic field at different time delays. It was observed that all spectral lines emitted from the Al ions or neutral atoms were enhanced in the presence of the magnetic field, and the emission intensity reached its maximum peak at delay time of 150 ns for Al II 281.6 nm and delay time of 600ns for Al I 394.6 nm. At the early stage of plasma plume expansion, the plasma plume front at M position is longer than that of at B position. As the delay time increasing, under the confinement of magnetic pressure, the plasma plume fronts for two position are near same. The observed differences in emission intensity at the various positions were attributed to the curvature and gradient of the magnetic field.

Endogenous and Exogenous Attention in Alzheimer Type of Dementia: Effect of Target Position

Endogenous attention (EnA) is an ability in goal-driven processes, controlled by top-down mechanisms and exogenous attention (ExA) is an ability in stimulus-driven processes, controlled by bottomup mechanisms. In the present research, it was aimed to investigate in Alzheimer's disease (AD) the EnA and ExA processes in relation to target position (right/left) by using the Spatial Cueing Paradigm (SCP). The study was conducted with the participants of 65-90 year age range, consisting of 14 female and 14 male (n=28) participants diagnosed with AD and 12 female and 12 male (n=24) healthy volunteers as controls. The group variable (AD, Control) was tested on the intergroup basis; and the attention type (EnA, ExA), trial type (valid /VT+ and invalid/ VT-) and the target position (left/right) variables were tested on the intra-subject basis (within subject design). Two separate factorial ANOVAs were conducted for mean reaction time and accuracy measures obtained from SCP. In comparison to the control group, the AD group participants gave slow and wrong reactions to stimuli for EnA and ExA. The AD group responses were faster in the VT+s and more accurate in the VT-s to stimuli on the left as compared to those on the right; and the responses of AD patients to the stimuli on the left as compared to those on the right was more accurate in VT-s under ExA condition. AD causes impairment of EnA and ExA. Faster reactions by AD participants to the target on the left in VT+s and more accurate reactions to the target on the left in VT-s are in agreement with reports in the literature on the lateralization of visual-spatial attention (VSA) in the right hemisphere. In this study, also in agreement with previous reports, lateralization in AD was noted in favour of the stimuli on the left in ExA.

Target visibility under mesopic vision using a driving simulator

Small target visibility is widely used to evaluate the quality of road lighting. It provides a link between lighting design and driving performance. However, it is based on a strong simplification of the driving task using psychophysical data from laboratory conditions. Using a driving simulator to mimic the real driving environment, the impact of driving workload on target detection performance in mesopic vision conditions has been evaluated. The target visibility level is studied with and without driving workload together with different luminance contrasts and target positions, with reference to the small target visibility scenario. The results show that the driving workload significantly reduces the target detection performance. Consequently, the visibility level value for driving conditions should be much higher (visibility level ≥21) than some currently recommended ones (visibility level = 7) to achieve the same detection rates. Effects of target position and contrast are found in a way consistent with the literature. In addition, results indicate that the small target visibility model used for road lighting is limited and needs to be improved for a reliable prediction of visual performance with driving workload.

The Effect of Target Position on the Accuracy of Cervical-Spine-Rotation Active Joint-Position Sense

Context:The cervical spine can be divided into upper and lower units, each making a different contribution to the magnitude of rotation and proprioception. However, few studies have examined the effect of the cervical-rotation positions on proprioception.Objective:To compare cervical-spine rotation active joint-position sense (AJPS) near midrange of motion (mid-ROM; 30°) and near end-ROM (60°).Design:Cross-sectional study.Setting:Human performance research laboratory.Participants:53 military helicopter pilots (age 28.4 ± 6.2 y, height 175.3 ± 9.3 cm, weight 80.1 ± 11.8 kg).Main Outcome Measures:A motion-analysis system was used to record cervical-rotation kinematics. Subjects sat in a chair wearing a headband and blindfold. First, they actively rotated the head right or left to a target position (30°/60°), with real-time verbal cues provided by the tester. Subjects held the target position for 5 s and then returned to the start position. After this, they replicated the target position as closely as possible. Five trials were performed in both directions to both target positions (R30/R60/L30/L60). Order of direction/position was randomized. The difference between target and replicated positions was calculated and defined as absolute error (AE), and the mean of 5 trials was used for analyses. Wilcoxon signed-ranks tests were used to compare AJPS at the different target positions (P < .0125 with Bonferroni adjustments).Results:End-ROM AEs were significantly more accurate than mid-ROM AEs (P = .001).Conclusion:Cervical-spine-rotation AJPS is more accurate near end-ROM than mid-ROM. Both target positions should be used to examine cervical-spine-rotation AJPS of both the upper and lower units.

Effects of Target Position on Direct Initiation of Detonation using Laser Ablation

Effects of Target Position on Direct Initiation of Detonation using Laser Ablation

Improving on Human’s Movement Time Model for Pointing Task - Introducing the Target Position Factor into Fitts’ Law

The experiments were aimed at determining the effect of target position on movement time when performing a target pointing movement task. 21 subjects performed pointing movements with 72 conditions of various target position. The movement time data were collected. It was shown that the starting point position and target position greatly affect the movement time. As a result, the movement times were not explained satisfactorily by the conventional Fitts’ model. The conventional model was improved by introducing the target position factor into. Compared with the conventional Fitts’ model, the new model could describe the data better, both in term of contribution value (r2) and the standard error of the residual between the predicted value by model fit and the measured movement time.

Effect of Target Position and Target Task on Judge Sensitivity to Felt Rapport

Effect of Target Position and Target Task on Judge Sensitivity to Felt Rapport

The Effect of Target Position and Tactual Recognition Field Size on Touch Bias

Past studies have shown that touchscreen display angles other than those that perpendicularly bisect the operator's line of sight cause the operator to touch slightly below the target. The amount of bias created from this misjudgment fluctuates according to the target's position on the screen. Additionally, the percentage of touches that activate a specific target varies according to the size of the tactual recognition field. This study sought to match three square tactual recognition field sizes with the amount of touch bias occurring in each location. The results showed that although bias differed according to location, the tactual recognition fields did not vary enough in size, nor were they large enough to find a significant difference between them in the number of touches captured according to the location of the target. The tactual recognition field that optimally captures responses varies in size over display position and is non-square in shape.

Effect of Target Position and Target Task on Judge Sensitivity to Felt Rapport

The present studies investigated the effects of target context on judge sensitivity to target felt rapport. The results suggest that judge sensitivity may be increased by: (a) positioning the target to the judge's left so that the judgment task may benefit from the specialization of the right hemisphere for processing nonverbal behavior, and (b) assigning targets to a task unconstrained by social norms that allows for more spontaneous and revealing target behavior. These results have major implications for the way that interpersonal sensitivity and rapport research is conducted and for understanding interpersonal perception in everyday life.

Diameter Control in the Formation of Single-Wall Carbon Nanotubes

ABSTRACTSingle-wall carbon nanotubes (SWNTs) have been synthesized by laser ablation of Ni/Co catalyzed graphite target at 1200°C in argon gas. Raman spectroscopy has been used to study the effect of target position in the furnace and flow rate of argon gas on the diameter distribution of SWVNTs. It was found that yield of smaller diameter SWNTs relatively increases as target is placed away from the hot zone of the furnace. The relative yield of smaller diameter SWNTs decreases with increase in flow rate of the argon gas.

Effect of target position on the sequential organization of processing stages

In order to study the organization of processing stages taking place in a choice reaction time (RT) situation, the three following experimental variables were manipulated: (1) S-R compatibility; (2) movement direction; and (3) time uncertainty, these variables being known to influence distinct information processing stages. Both behavioural (RT and movement time, MT) and electrophysiological (N200 and P300 latencies) indices of processing time were analysed. All three experimental variables showed significant, additive effects on RT. Only the preparatory period had a significant effect on N200 and on P300 latencies. These results support the construction of a serial model. Furthermore, the analysis of the time intervals between electrophysiological and behavioural indices allows one to infer the relative order of the different stages in this model, as follows: motor pre-initiation, motor pre-programming, response selection and programming, and motor initiation.

Effect of target position and size on adaptive sensitivity of the surround mechanism of cat retinal ganglion cells.

The spatial distribution of the surround's adaptive sensitivity was assessed in the receptive fields of cat retinal ganglion cells. The results provide evidence that the surrounds adaptive sensitivity is higher in the center of the receptive field of Y-cells than X-cells.