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We evaluate the performance of optical network designs using relatively few switch nodes at which wavelength conversion and electronic regeneration is possible. A simple heuristic for placing the fewest such nodes to reach a given blocking probability is based on the ranked frequency of shortest-path routes transiting each node. This strategy is found to be(More)
—We consider a slotted WDM packet switch with limited-range wavelength converters. The performance of this switch is studied using simulations with various types of data traffic. Results show that the slotted WDM packet switch with a small range of wavelength conversion capability can achieve a performance close to that of a switch with the full range of(More)
We propose and investigate three connection admission control policies for the establishment of label switched paths (LSPs) in IP/MPLS over optical networks. We show that the policy of establishing LSPs first in the optical layer achieves a better blocking performance. We examine the effect of the number of add/drop ports of optical cross-connects (OXCs) on(More)
Keywords: Scale-free network Imperfect immunization Epidemic threshold Average outbreak size Degree-correlated SIR a b s t r a c t Scale-free networks are prone to epidemic spreading. To provide cost-effective protection for such networks, targeted immunization was proposed to selectively immunize the hub nodes. In many real-life applications, however, the(More)
Due to the impairments in optical fiber transmission, regeneration is needed in certain intermediate nodes for some lengthy lightpaths. This kind of optical networks is called translucent optical networks. Spare transceivers in the optical nodes can be used for regeneration. The problem of maximizing the number of established connections (NEC) in the(More)
The problem of how to upgrade translucent optical networks is studied in this paper. This study is motivated by the cost advantage of not having network nodes fully equipped with transceivers in the beginning of network deployment but adding transceivers as and when it is necessary. A novel heuristic algorithm for the selection of nodes to upgrade (by(More)
Twenty-four patients with increased skeletal:renal uptake ratios of 99mTc-methylene diphosphonate were studied. Increased uptake was central in metastatic prostate carcinoma, peripheral in hematologic disorders, and heterogeneous in Paget disease and fibrous dysplasia. There was no discernible redistribution of skeletal uptake in patients with renal(More)
The diagnosis of thoracic actinomycosis is readily made when the patient presents with the constellation of poor oral hygiene, pulmonary infiltrates, empyema, sinus tracts, and osteomyelitis of the ribs. However, in the absence of rib and chest wall involvement, the disease may be overlooked. Three cases of primary pulmonary actinomycosis are presented(More)
Hypoalbuminemia is a surrogate of malnutrition in patients with end-stage renal disease undergoing chronic dialysis and commonly improves with prescription of adequate nutrition and dialysis. Nevertheless, some patients remain hypoalbuminemic for poorly understood reasons. We tested the hypotheses that chronic dialysis patients who remain hypoalbuminemic(More)
Cholescintigraphy, ultrasonography, and contrast cholangiography were compared in 60 patients. Among those having abdominal pain but no biliary disease or jaundice, cholescintigraphy was normal in 14/14, ultrasound in 10/13, and cholangiography in 13/14. Jaundice due to hepatocellular disease was correctly distinguished from complete biliary obstruction by(More)