Propagation inside buildings suffer from large shadowing and high multipath effects. This is a serious problem for Wireless Local Area Network (WLAN) systems. OFDM has a high multipath tolerance and this paper shows how this can be used to overcome the problems due to shadowing. OFDM allows a base station to transmit and receive the same signal at the same frequency from multiple locations, at ...

Scaffolding and shadowing techniques have been shown to improve language learners’ reading comprehension. However, little attention has been paid to the comparative effectiveness of these techniques. This study investigated the effect of three selected scaffolding techniques (peer scaffolding, distributed scaffolding, and reciprocal scaffolding) versus three types of shadowing (complete shadowi...

Partial shadowing has been identified as a main cause for reducing energy yield of grid-connected photovoltaic systems. The impact of the applied system configuration on the energy yield of partially shadowed arrays has been widely discussed. Nevertheless, there is still much confusion especially regarding the optimal grade of modularity for such systems. A 5-kWp photovoltaic system was install...

This paper describes the use of a building database and a three-dimensional formulation of the Fresnel-Kirchoff diffraction theory to compute the shadowing by buildings in the general situation where diffraction can occur by building edges of both horizontal and vertical orientation. The storage format of buildings in a geographi_c information systems database is described. An algorithm is pres...

Cognitive Radios require sensing to detect the presence of Primary Users in a frequency band. Sensing is hampered by shadowing, multi-path and penetration loss through buildings. Hence an individual radio must be designed to be highly sensitive to overcome these signal variations. In this paper we investigate cooperative sensing, where Cognitive Radios use sensing results from other Cognitive R...

We propose to use wireless sensor networks to assess the accuracy and application of Digital Surface Models (DSM) for the study of shadowing and solar radiation over the built environment. Using the ability of sensor network data to provide information about solar radiation and predicting the exact time of the day that the Sun starts radiating a sensor, a comparative study and statistical analy...

In this paper, some properties of the periodic shadowing are presented. It is shown that a homeomorphism has the periodic shadowing property if and only if so does every lift of it to the universal covering space. Also, it is proved that continuous mappings on a compact metric space with the periodic shadowing and the average shadowing property also have the shadowing property and then are chao...

Traffic sign recognition is a difficult task if aim is at detecting and recognizing signs in images captured from unfavorable environments. Complex background, weather, shadow, and other lighting-related problems may make it difficult to detect and recognize signs in the rural as well as the urban areas. Two major problems exist in the whole detection process. Road signs are frequently occluded...

In this paper, the new concept of non-autonomous iterated function system is introduced and also shown that non-autonomous iterated function system IFS(f_(1,∞)^0,f_(1,∞)^1) is topologically transitive for the metric space of X whenever the system has average shadowing property and its minimal points on X are dense. Moreover, such a system is topologically transitive, whenever, there is a point ...