| Many mathematical solutions to certain classes of optimal control problems, particularly problems which give rise tòchattering controls', make some physically unrealistic assumptions in order to solve the problems. These solutions often ignore the cost of changing control and thus fail to give physically realistic results due to the physical reality of this cost in many applications. When thi...

We analyze changes in the structure of a concept lattice corresponding to a context resulting from a given context with a known concept lattice by removing exactly one incidence. We identify the set of concepts affected by the removal and show how they can be used for computing concepts in the new concept lattice. We present algorithms for incremental computation of the new concept lattice, wit...

Navigation through the web, colloquially known as “surfing”, is one of the main activities of users during web interaction. When users follow a navigation trail they often tend to get disoriented in terms of the goals of their original query and thus the discovery of typical user trails could be useful in providing navigation assistance. Herein we give a theoretical underpinning of user navigat...

In this paper, a new composite rough set model is proposed to process incomplete composite information with criteria and regular attributes. Following that, some strategies for incrementally updating approximations of composite rough sets when adding or removing some objects are discussed and the corresponding incremental algorithms are designed. Several numerical examples illustrate the feasib...

The physical infrastructure of the power systems, including the high-voltage transmission towers and lines as well as the poles and wires for power distribution at a lower voltage level, is critical for the resilience of the community to avoid power outages under the extreme weather related loads. In the current engineering practices, single circuit lattice steel towers linked by transmission l...

background: the present study aims to evaluate the cost-effectiveness of dynamic interspinous spacer (coflex®) and static spacer (x-stop ®) compared to laminectomy (lami) in patients with lumbar spinal stenosis.   methods: a decision-analysis model was developed to estimate the cost-effectiveness. the effectiveness parameters were obtained from a systematic literature review in relevant databas...

The present work is aimed at assessing the impact of strong column-weak beam (SCWB) criterion on seismic performance of optimally designed steel moment frames. To this end, different SCWB ratios are considered for steel special moment resisting frame (SMRF) structures and performance-based design optimization process is implemented with the aid of an efficient metaheuristic. The seismic collaps...