The stability of a tunnel face and the rationality its supporting structures are guarantees for safe construction. This paper established quantitative analysis model stability, obtained calculation formula coefficient based on silo theory surrounding rock, then realized description under condition pipe roofing support, bolting grouting support reserved core soil. Finally, discrimination optimiz...

In this paper we use the concept of resource cumulation to model various forms of computation. The space of cumulations (called a cumulator) is simply represented as a five tuple consisting of a well-founded partial order, a monoid and a volume function. The volume function is introduced to simplify reasoning about limit points and other topological properties. A specification command is a set ...

When an update to a view is requested by a user, there may be no unique way of up dating the stored relations in the database to realize the requested update. Chosing one of the alternatives for updating stored relations may not reflect the change that has actually taken place in the real world; in the presence of other derived views, the database may actually present a very wrong model of the ...

The terms "cumulative" and "cumulative effects" are becoming more widely used in environmental impact assessment. The popularity of the concept is understandable as our culture comes to recognize that solitary insults to the environment considered in isolation cannot capture the full effect of the problems now before us. But what exactly do we mean by the term "cumulative"? "Cumulative" means g...

The cumulative cyber deterrence can be seen as a concept in which increasing the weight of different means and their use increases deterrent effect on common level or selected adversaries. Cumulative may include all traditional options deterrence, active passive. Active characterized targeting specific threats actors, consisting several methods, while passive is form commonly targeted at potent...

landscape metrics quantifies structural features of the landscape. one of the advantages of these metrics is a possibility to use them in fast cumulative assessment of the development activities in the environment. in this paper, the cumulative effects of road network expansion on the tree cover of gorgan, kordkuy, aliabad townships in golestan province were investigated. to prepare the require...