Level repulsion is associated with exceptional points which are square root singularities of the energies as functions of a (complex) interaction parameter. This is also valid for resonance state energies. Using this concept it is argued that level anticrossing (crossing) must imply crossing (anticrossing) of the corresponding widths of the resonance states. Further, it is shown that an encircl...

Travels within the city are done in different ways, by vehicle or on foot. Thus, inevitably, a part of the travel is always done on foot. Since intersections as traffic nodes are determinant factor in transportation network capacity, any disruption in them leads to severe reduction in network capacity. Unfortunately, pedestrian behavior has received little attention in Iran. While this is a ver...

Englacial layer velocity can provide insights on the vertical-velocity structure of ice sheets. We present a repeat-pass interferometric approach that allows estimation vertical englacial using radar sounder data. In contrast to ground-based sensors, airborne data potentially be used estimate continental scale. When merged with horizontal surface and numerical models, support 3-D analysis flow ...

Two simple and rapid spectrophotometric methods were developed for the determination of two binary mixtures: moxifloxacin hydrochloride (MFH) with ketorolac tromethamine (KTM) and ciprofloxacin hydrochloride (CFH) with dexamethasone sodium phosphate (DSP). The first method, zero-crossing derivative spectrophotometry, depends on measuring the second derivative peak and trough values at 304 nm an...

We have designed and tested a one-dimensional 64 pixel, analog CMOS VLSI chip which localizes intensity edges in real-time. This device exploits on-chip photoreceptors and the natural ltering properties of resistive networks to implement a scheme similar to and motivated by the Diierence of Gaussians (DOG) operator proposed by Marr and Hildreth (1980). Our chip computes the zero-crossings assoc...

We revisit the calculation of analytic derivative couplings for configuration interaction singles (CIS), and derive and implement these couplings for its spin-flip variant for the first time. Our algorithm is closely related to the CIS analytic energy gradient algorithm and should be straightforward to implement in any quantum chemistry code that has CIS analytic energy gradients. The additiona...

During obstacle crossing, a minimal vertical distance between foot and obstacle (toe clearance) has to be preserved to avoid tripping. This study analyzed the control of an obstacle crossing task as a reaching motion with the foot when visual information was unavailable to blind and sighted participants. A major difference with upper limb reaching is that the lower limb task has to be integrate...

Recently, we have shown that the differential properties of the surfaces represented by 3D volumic images can be recovered using their partial derivatives. For instance, the crest lines can be characterized by the first, second and third partial derivatives of the grey levrl function I(x,y,z) . This paper deals with the following points : the computation of the partial derivatives of an image c...

We have designed and tested a one-dimensional 64 pixel, analog CMOS VLSI chip which localizes intensity edges in real-time. This device exploits on-chip photoreceptors and the natural filtering properties of resistive networks to implement a scheme similar to and motivated by the Difference of Gaussians (DOG) operator proposed by Marr and Hildreth (1980). Our chip computes the zero-crossings as...