The allocation of wireless resources to many different services and service providers has resulted in a heavily fractured spectrum and inefficient use. However, new dynamic spectrum capabilities allow the recapture of this wastage. This work describes the creation of a virtual wireless network (VWN). Taking an approach based on cognitive radio techniques, the VWN allows new network services to ...

A scheme combining multichannel crosstalk resistant adaptive noise cancellation (MCRANC) algorithm and improved spectrum subtraction (ISS) algorithm is presented to enhance noise carrying speech signals. The scheme would permit locating the microphones in close proximity by virtue of using MCRANC which has the capability of removing the crosstalk effect. MCRANC would also permit canceling out n...

It is argued that the dominant subleading shape-function contributions to the endpoint region of the charged-lepton energy spectrum in B → Xu l ν decays can be related in a model-independent way to an integral over the B → Xsγ photon spectrum. The square root of the fraction of B → Xu l ν events with chargedlepton energy above E0 = 2.2GeV can be calculated with a residual theoretical uncertaint...

purpose: to evaluate residual refractive errors after cataract surgery and its determinant factors at farabi eye hospital, tehran. methods: simple random sampling was done among cataract surgery scheduled patients over a 4 year period (2003-2006). exclusion criteria were uveitis, previous intraocular surgery and ocular trauma. after applying the exclusion criteria, 423 patients were studied. le...

background: induction chemotherapy for acute lymphoblastic leukemia achieves complete remis sion in over 90% of children. it is apparent therefore that many patients in clinical remission and with out residual disease detectable by conventional light microscopy of peripheral blood or bone marrow films still harbor viable cells of the original disease mrd analysis does have a useful role to play...

We present a new study of the high latitude galactic contributions to the millimeter sky, based on an analysis of theWMAP data combined with several templates of dust emission (DIRBE/COBE and FIRAS/COBE) and gas tracers (HI and Hα). To study the IR to millimeter properties of the diffuse sky at high galactic latitude, we concentrate on the emission correlated with the HI gas. We compute the emi...

we define a new type of spectrum, called δ-approximate spectrum, of an element a in a complex unital banach algebra a and show that the δ-approximate spectrum σ_δ (a) of a is compact. the relation between the δ-approximate spectrum and the usual spectrum is investigated. also an analogue of the classical gleason-kahane-zelazko theorem is established: for each ε>0, there is δ>0 such that if ϕ is...