A sinusoidal grating can be viewed as a series of light and dark bars. Here we measure the contrast discrimination thresholds for light and dark bars individually, and find that the contrast discrimination thresholds for the whole sinusoid can be explained as ideal summation of the light and dark bar thresholds. We propose a model for light bar, dark bar, and sinusoidal contrast discrimination ...

statement of the problem: the stability of orthodontic treatment depends on preserving the patient’s pretreatment arch form and arch size during and after treatment. purpose: this investigation was aimed to study the size and shape of iranian mandibular dental arch and evaluate the correlation of their average dental arch with commercially available preformed rectangular nickel-titanium arch wi...

intra-oral appliances such as transpalatal arch and nance appliance fail to resist against forces that tend to loosen the anchorage. the infirmity arises due to the long lever arm and the mesial force that is perpendicular to the long axis of the appliance. the butterfly arch is presented here as an intra-oral appliance that withstands the mesially directed forces with a mechanism that puts str...

conclusions according to our results, these clinical measurements would provide valid information regarding the structure of the medial longitudinal arch. patients & methods clinical measurements of arch index (ai) and foot posture index (fpi) were performed on 40 subjects (18 boys and 22 girls), aged from 5 to 7 years referred to adabian rehabilitation center, kermanshah, iran. the study was c...

For optimization of real-world arch dams, it is unavoidable to consider two or more conflicting objectives. This paper employs two multi-objective differential evolution algorithms (MoDE) in combination of a parallel working MATLAB-APDL code to obtain a set of Pareto solutions for optimal shape of arch dams. Full dam-reservoir interaction subjected to seismic loading is considered. A benchmark ...