We study a system of coalescing random walks on the integer lattice $$ {\mathbb {Z}}^{d} in which walk is oriented d-th direction and follows certain specified rules. first geometry paths show that, almost surely, form graph consisting just one tree for dimensions d=2,3 infinitely many disjoint trees d\ge 4 . Also, there no bi-infinite path surely 2 Subsequently, we prove that d=2 diffusive sca...

background: historically open surgical drainage has been the treatment of choice for pyogenic liver abscess. the records of 54 patients with pyogenic liver abscess were reviewed to determine whether earlier diagnosis with current imaging tests and definitive treatment with antibiotics and aspiration drainage was an effective alternative to surgery. methods: the clinical features, laboratory tes...

The flow directions of the extracted drainage network are more random based on random flow model. Binary linear regression method is applied to calculate the residual value at every point, and then the normalized residuals are used to prune reasonably as the variables. The terrains are distinguished automatically according to the normalized residuals, and the local catchment area threshold is d...

Cell-to-cell surface flow paths are commonly derived from gridded digital elevation models (DEM) by choosing the direction of steepest descent to one of the eight surrounding cells. However, adequate DEMs often are not available. We developed a topography-independent method for creating gridded, land and stream drainage direction maps based on corrected vector river networks. We applied it to t...

The United States Geological Survey has been researching generalization approaches to enable multiple-scale display and delivery of geographic data. This paper presents automated methods to prune network and polygon features of the United States high-resolution National Hydrography Dataset (NHD) to lower resolutions. Feature-pruning rules, data enrichment, and partitioning are derived from know...

one of the serious problems of iran’s watersheds is soil erosion and can be considered as one of the main obstacles to achieve sustainable agricultural development and natural resources. in most countries of the world, because of absence of accurate data for the sediment erosion, deposition utilizing models to estimate erosion is inevitable. in order to apply effective management in natural res...

We present a dynamic network model to investigate the effects of capillary number and viscosity ratio on displacement patterns and fractional flow in primary drainage. This model predicts the events that are observed in the micro-model experiments, such as swelling of the wetting layers and the meniscus oscillation. Interfaces are tracked through the pore elements using a modified Poiseuille eq...

Tissue defect reconstruction using radial forearm free flap (RFFF) is a common surgical technique whose success or failure is mainly dependent on venous drainage. RFFF has two major venous outflow systems, superficial and deep vein. Drainage methods include combining both systems or using one alone. This review aims to recapitulate the vascular anatomy and network of RFFF as well as shed light ...