LTL generalized model checking revisited

Given a 3-valued abstraction of a program (possibly generated using static program analysis and predicate abstraction) and a temporal logic formula, generalized model checking (GMC) checks whether there exists a concretization of that abstraction that satisfies the formula. In this paper, we revisit generalized model checking for linear time (LTL) properties. First, we show that LTL GMC is 2EXPTIME-complete in the size of the formula and polynomial in the model, where the degree of the polynomial depends on the formula, instead of EXPTIME-complete and quadratic as previously believed. The standard definition of GMC depends on a definition of concretization which is tailored for branching-time model checking. We then study a simpler linear completeness preorder for relating program abstractions. We show that LTL GMC with this weaker preorder is only EXPSPACE-complete in the size of the formula, and can be solved in linear time and logarithmic space in the size of the model. Finally, we identify classes of formulas for which the model complexity of standard GMC is reduced.     

Image Sharpening by Flows Based on Triple Well Potentials

Image sharpening in the presence of noise is formulated as a non-convex variational problem. The energy functional incorporates a gradient-dependent potential, a convex fidelity criterion and a high order convex regularizing term. The first term attains local minima at zero and some high gradient magnitude, thus forming a triple well-shaped potential (in the one-dimensional case). The energy minimization flow results in sharpening of the dominant edges, while most noisy fluctuations are filtered out.     

Sorption and migration of organic liquids in poly(ethylene terephthalate)

Sorption kinetics of organic liquids in amorphous poly(ethylene terephthalate) (APET) and biaxially oriented PET (BPET) were determined at 34°C. With heptane and 1,2 propanediol, no sorption or swelling was observed. Estimated diffusion coefficients based on analysis from pseudo-Fickian sorption data are 3.7 ± 1.0 × 10⁻⁹ cm²/sec for toluene sorption in APET, 12.7 ± 4.1 × 10⁻⁹ cm²/sec for benzyl alcohol in APET, 0.44 ± 0.4 × 10⁻⁹ cm²/sec for toluene in BPET, and 0.33 ± 0.4 × 10⁻⁹ cm²/sec for benzyl alcohol in BPET. Weight gain of sorbed APET samples at equilibrium was 11.4 ± 0.1% in toluene and 21.7 ± 0.8% in benzyl alcohol. BPET weight gain at equilibrium was 9.5 ± 0.1% in toluene and 13.5 ± 0.2% in benzyl alcohol. Subsequent migration of sorbed toluene from APET samples into water at 34°C was measured by gas chromatography. Migration from toluene-sorbed APET films sandwiched between virgin APET layers was two orders of magnitude less than from sorbed films placed directly in water.     

A linear time algorithm for the weighted lexicographic rectilinear 1-center problem in the plane

We present an optimal O(n) time algorithm for the weighted lexicographic rectilinear 1-center problem in the plane and prove that calculating the optimal value of the objective function requires Θ(nlogn) time.     

Cheating on Complementarity and Interference by Translational – Internal Entanglement

We show that if internal and momentum states of an interfering particle are entangled, then by measuring its internal state we may infer both path (corpuscular) and phase (wavelike) information with practically any precision, without the complementarity constraints of which-path detection. This holds also for multipath–multistate configurations, allowing large amounts of information to be stored in a single particle. We further show that highly complex particles (e.g., molecules or macroscopic bodies) subject to fields that couple (entangle) their internal and translational (momentum) states may undergo an irresversible randomization (diffusion), manifest by the disappearance of the interference pattern, as if they are subject to decoherence. Thus, translational-internal entanglement can give rise to anomalies in quantum wavepacket propagation.     

Biologische Reinigung organisch verschmutzter Abluftströme

Biological Exhaust Air Cleaning. Production and refining of oils and fats from vegetable and animal raw materials generate –sometimes to a serious extent – organically polluted exhaust gases. Relatively new compared to conventional physico-chemical methods for air purification is the conversion of undesired impurities with the help of microorganisms within the scope of Biological Exhaust Air Cleaning. Depending on the objectives one of the systems biofilter. bioscrubber or biological trickling bed reactor can be chosen. This paper describes the present state of technology and the latest developments in the field of biological air refining and elucidates working principle and potential applications of the systems mentioned above. A procedure is presented aiming at a systematic election of an optimal air refining process.     

The Effect and Reform of Water Pricing: The Israeli Experience

Water pricing in Israel led the water situation to become almost disastrous. This was true for both quantity and quality issues. This paper deals with a proposed price reform and its implication for two issues. The first is the optimal timing to switch to a backstop technology--desalinating water in this case. Economic analysis shows that combining both demand and supply management can postpone desalinization projects by more than 20 years. The second issue deals with changing the price block schedule in order to compensate farmers for a given price change. Increasing the marginal price of water to its real value damages the marginal users. The paper tries to calculate and proposes a new price block schedule that will leave the farmers as well off as they were before the change.     

Deblurring of color images corrupted by impulsive noise.

We consider the problem of restoring a multichannel image corrupted by blur and impulsive noise (e.g., salt-and-pepper noise). Using the variational framework, we consider the L1 fidelity term and several possible regularizers. In particular, we use generalizations of the Mumford-Shah (MS) functional to color images and gamma-convergence approximations to unify deblurring and denoising. Experimental comparisons show that the MS stabilizer yields better results with respect to Beltrami and total variation regularizers. Color edge detection is a beneficial by-product of our methods.