We characterize graphs that have intersection representations using unit intervals with open or closed ends such that all ends of the intervals are integral in terms of infinitely many minimal forbidden induced subgraphs. Furthermore, we provide a quadratic-time algorithm that decides if a given interval graph admits such an intersection representation.

An undirected graph G = (V, E) is a probe split graph if its vertex set can be partitioned into two sets, N (nonprobes) and P (probes) where N is independent and there exists E′ ⊆ N ×N such that G′ = (V, E ∪ E′) is a split graph. Recently Chang et al. gave an O(V (V +E)) time recognition algorithm for probe split graphs. In this article we give O(V 2 +V E) time recognition algorithms and charac...

A method for recognition of Persian handwritten digits based on characterization loci and mixture of experts is proposed. This method utilizes the characterization loci, as the main feature. In the classification stage of our proposed method the mixture of experts are applied. This recognition method is applied to Farsi hand-written digits in the HODA database. The experimental results support ...

Recently Postnikov gave a combinatorial description of the cells in a totallynonnegative Grassmannian. These cells correspond to a special class of matroids called positroids. We prove his conjecture that a positroid is exactly an intersection of permuted Schubert matroids. This leads to a combinatorial description of positroids that is easily computable. The main proof is purely combinatorial,...

Once viewed simply as a reservoir for carbon storage, lipids are no longer cast as bystanders in the drama of biological systems. The emerging field of lipidomics is driven by technology, most notably mass spectrometry, but also by complementary approaches for the detection and characterization of lipids and their biosynthetic enzymes in living cells. The development of these integrated tools p...

We report simultaneous measurements of the permeability and effective porosity of oil-reservoir rock cores using one-dimensional NMR imaging of the penetrating flow of laser-polarized xenon gas. The permeability result agrees well with industry standard techniques, whereas effective porosity is not easily determined by other methods. This NMR technique may have applications to the characterizat...

There is growing interest in using seismic attenuation for reservoir characterization. We measure limestone samples in the laboratory to analyze attenuation and elastic moduli as a function of frequency from 3 Hz to ultrasonic. We observe that there is a positive correlation between bulk modulus dispersion and permeability. We also measure different modes of attenuation and find that the attenu...

Hepatocyte specific contrast agents including gadoxetic acid and gadobenate dimeglumine are very useful to diagnose various benign and malignant focal hepatic lesions and even helpful to estimate hepatic functional reservoir. The far delayed phase image referred to as the hepatobiliary phase makes the sensitivity of detection for malignant focal hepatic lesions increased, but specificity of mal...

Advanced seismic techniques such as prestack inversion or azimuthal analysis are now routinely adopted for quantitative reservoir characterization of rock properties and fracture indicators, however the quality of the input seismic data is critical to such advanced analyses. Frequency content, random and coherent noise, amplitude-preserving processing and gather flatness must be addressed at th...

In this paper we solve the dividend optimization problem for a corporation or a financial institution when the managers of the corporation are facing (regulatory) implementation delays. We consider several cash reservoir models for the firm including two mean-reverting processes, OrnsteinUhlenbeck and square-root processes. We provide our solution via a new characterization of the value functio...