Perhaps the most significant development in coal mine ground control during the last century was the introduction of roof bolting during the late 1940’s and 1950’s. From an engineering standpoint, roof bolts are inherently more effective than the wood timbers they replaced. Roof bolts promised to dramatically reduce the number of roof fall accidents, which then claimed hundreds of lives each ye...

this study was conducted to rank the broiler farms based on buildings, installations and equipment and its effect on production factors. to determine the contribution of each factor in ranking of farms, a multi-criteria decision analysis (saw) was used. data of 108 broilers were recorded in specific forms and the amount of investment per broiler was calculated for individual factors. to calcula...

The Very Large Array has been used at 8.3 GHz in the DnC and CnB array configurations to carry out an H92α recombination line study (at 8.3 GHz) of the ionized gas in the Arched Filaments H II complex, which defines the western edge of the Galactic center Radio Arc. The Arched Filaments consist of a series of curved filamentary ridges which extend over 9×6 (22 × 16 pc) and are intersected in tw...

considering current population rate and ratio of non renewable energies in countries' annual energy diagram which lead to increase of pollutions reeked from and irreparable effects on living environment, there will be an energy and living environment crisis in close future. so there are two main approaches that should be considered in countries' future program: change of construction ...

Urban green roofs are discussed as a local climate adaptation measure to limit surface warming and increase evaporative cooling by vegetation in urban environments. A five month measurement campaign was conducted to observe surface and air temperatures as well as dewfall dynamics and amounts on an urban green and co-located bitumen roof. Measurements were performed in the period from August to ...

Building reconstruction is one of the most difficult and important 3D modelling problems for urban environment. In this paper, we develop an approach using minimum number of basic geometric elements to reconstruct the buildings. The basic element is a number of unstructured 3D points representing the topological identity of a building roof. Such point primitives can be measured by human or comp...

This paper presents a model-based approach for 3-D building reconstruction unstructured distinct points. The data structure of a building is an unstructured roof point cloud digitized by operators. Constructive Solid Geometry (CSG) model is applied in our approach for a complex roof which can be decomposed into three types of primitive models. The primitive model is represented as a tree. The l...

This paper compares the paradigms of LiDAR and aerophotogrammetry in the context of building extraction and briefly discusses a photogrammetric strategy for refining building roof polyhedrons previously extracted from LiDAR data. In general, empirical and theoretical studies have confirmed that LiDAR methodologies are more suitable in extracting planar roof faces and ridges of the roof, whereas...

This paper presents a data-driven method for automatic building reconstruction from raw airborne laser scanner data. The method utilises a TIN-structure that is calculated into the point cloud. The parameters of every TIN-mesh are mapped into a 3D trianglemesh parameter space, which is then analysed using a cluster analysis technique. By analysing the clusters, significant roof planes are deriv...

In view of the problems associated with poor stability coal walls, slide and leakage top-coal at tunnel excavation working face under a soft extra-thick roof, surrounding rock must be strengthened. The theoretical analysis pressure, numerical simulation other methods were comprehensively used to study coal-wall-slicing mechanism. Given characteristics combined supporting technology “coal wall w...