Cognitive radio (CR) is a new paradigm that utilizes the available spectrum band. The key characteristic of CR system is to sense the electromagnetic environment to adapt their operation and dynamically vary its radio operating parameters. The technique of dynamically accessing the unused spectrum band is known as Dynamic Spectrum Access (DSA). The dynamic spectrum access technology helps to mi...

Network multimedia applications require certain performance guarantees that can be provided through proper resource allocation. Allocation techniques are needed to provide these guarantees as efficiently as possible since resources are limited. This paper presents an allocation method called Dynamic Search Algorithm (DSA+). DSA+ is an on-line algorithm that dynamically adjusts the resource allo...

In this paper, a 3D semantic segmentation method is proposed, in which novel feature extraction framework introduced assembling point initial information embedding (PIIE) and dynamic self-attention (DSA)—named PIIE-DSA-net. Ideal accuracy challenging task, since the sparse, irregular disordered structure of cloud. Currently, taking into account both low-level features deep cloud more reliable w...

C-Arm CT three-dimensional (3-D) digital subtraction angiography (DSA) reconstructions cannot provide temporal information to radiologists. Four-dimensional (4-D) DSA provides a time series of 3-D volumes utilizing temporal dynamics in the two-dimensional (2-D) projections using a constraining image reconstruction approach. Volumetric limiting spatial resolution (VLSR) of 4-D DSA is quantified ...

BACKGROUND AND PURPOSE 3D computed tomographic angiography (3DCTA) has been used recently for the evaluation of intracerebral aneurysms, but it is difficult to use this technique to visualize aneurysms near the base of the skull because of the presence of bone. Subtracted 3DCTA could replace digital subtraction angiography (DSA) for evaluation of aneurysms near the base of the skull if the 2 me...

BACKGROUND AND PURPOSE High-resolution MR imaging has recently been introduced as a promising diagnostic modality in intracranial artery disease. Our aim was to compare high-resolution MR imaging with digital subtraction angiography for the characterization and diagnosis of various intracranial artery diseases. MATERIALS AND METHODS Thirty-seven patients who had undergone both high-resolution...

BACKGROUND There is growing interest in examining the simultaneous effects of multiple exposures and, more generally, the effects of mixtures of exposures, as part of the exposome concept (being defined as the totality of human environmental exposures from conception onwards). Uncovering such combined effects is challenging owing to the large number of exposures, several of them being highly co...

The introduction of digital subtraction angiography (DSA) in 1980 provided a method for real time 2D subtraction imaging. Later, 4D magnetic resonance (MR) angiography emerged beginning with techniques like Keyhole and time-resolved imaging of contrast kinetics (TRICKS) that provided frame rates of one every 5 seconds with limited spatial resolution. Undersampled radial acquisition was subseque...

BACKGROUND AND PURPOSE Endovascular reconstruction and flow diversion by using the Pipeline Embolization Device is an effective treatment for complex cerebral aneurysms. Accurate noninvasive alternatives to DSA for follow-up after Pipeline Embolization Device treatment are desirable. This study evaluated the accuracy of contrast-enhanced time-resolved MRA for this purpose, hypothesizing that co...

Today’s wireless networks are characterized by fixed spectrum assignment policy. The limited available spectrum and the inefficiency in the spectrum usage necessitate a new communication paradigm, referred to as Dynamic Spectrum Access (DSA) and cognitive radio networks. The dynamic spectrum access technology can allow unlicensed secondary systems to share the spectrum with the licensed primary...