481 research outputs found

    Analysis and Modeling Experiment Performance Parameters of Routing Protocols in MANETs and VANETs

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    In this paper, a framework for experimental parameters in which Packet Delivery Ratio (PDR), effect of link duration over End-to-End Delay (E2ED) and Normalized Routing Overhead (NRO) in terms of control packets is analyzed and modeled for Mobile Ad-Hoc NETworks (MANETs) and Vehicular Ad-Hoc NETworks (VANETs) with the assumption that nodes (vehicles) are sparsely moving in two different road. Moreover, this paper contributes the performance comparison of one Proactive Routing Protocol; Destination Sequenced Distance vector (DSDV) and two reactive protocols; DYnamic Source Routing (DSR) and DYnamic MANET On-Demand (DYMO). A novel contribution of this work is enhancements in default versions of selected routing protocols. Three performance parameters; PDR, E2ED and NRO with varying scalabilities are measured to analyze the performance of selected routing protocols with their original and enhanced versions. From extensive simulations, it is observed that DSR outperforms among all three protocols at the cost of delay. NS-2 simulator is used for simulation with TwoRayGround propagation model to evaluate analytical results

    On an Empirical Definition of Money for Pakistan

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    In the realm of monetary economics, the question of the appropriate definition of money is both crucial and controversial. Various definitions of money offered by monetary economists differ widely. While narrowly defined money consists of currency and demand deposits only. other broader definitions of money include a host of other assets as well. The choice of the most appropriate monetary aggregate is an empirical issue and needs to be settled empirically. In the literature a number of methods are available for defining money empirically. To mention only two of them, Meltzer (1963) and Laidler (1966) consider that definition o f money the most appropriate which gives the most stable demand function for money while Chetty (1969), Moroney and Wilberatte (1976), Boughton (1981) and Husted and Rush (1984) infer their definition of money on the basis of the degree of substitutability between narrowly defined money and other financial assets. Although the two methods are closely linked, the latter has the advantage of providing a direct measure of the degree of substitutability between various financial assets and also allows for defining money as a sort of weighted average of these assets based on this substitutability rather than a simple-sum aggregation

    Program Synthesis with Best-First Bottom-Up Search

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    Cost-guided bottom-up search (BUS) algorithms use a cost function to guide the search to solve program synthesis tasks. In this paper, we show that current state-of-the-art cost-guided BUS algorithms suffer from a common problem: they can lose useful information given by the model and fail to perform the search in a best-first order according to a cost function. We introduce a novel best-first bottom-up search algorithm, which we call Bee Search, that does not suffer information loss and is able to perform cost-guided bottom-up synthesis in a best-first manner. Importantly, Bee Search performs best-first search with respect to the generation of programs, i.e., it does not even create in memory programs that are more expensive than the solution program. It attains best-first ordering with respect to generation by performing a search in an abstract space of program costs. We also introduce a new cost function that better uses the information provided by an existing cost model. Empirical results on string manipulation and bit-vector tasks show that Bee Search can outperform existing cost-guided BUS approaches when employing more complex domain-specific languages (DSLs); Bee Search and previous approaches perform equally well with simpler DSLs. Furthermore, our new cost function with Bee Search outperforms previous cost functions on string manipulation tasks.Comment: Published at the Journal of Artificial Intelligence Research (JAIR

    Contrast-Induced Nephropathy in Patients Undergoing Percutaneous Coronary Intervention

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    Contrast Induced Nephropathy (CIN) is a feared complication of numerous radiological procedures that expose patients to contrast media. The most notorious of these procedures is percutaneous coronary intervention (PCI). Not only is this a leading cause of morbidity and mortality, but it also adds to increased costs in high risk patients undergoing PCI. It is thought to result from direct cytotoxicity and hemodynamic challenge to renal tissue. CIN is defined as an increase in serum creatinine by either ≥0.5 mg/dL or by ≥25% from baseline within the first 2-3 days after contrast administration, after other causes of renal impairment have been excluded. The incidence is considerably higher in diabetics, elderly and patients with pre-existing renal disease when compared to the general population. The nephrotoxic potential of various contrast agents must be evaluated completely, with prevention as the mainstay of focus as no effective treatment exists. The purpose of this article is to examine the pathophysiology, risk factors, and clinical course of CIN, as well as the most recent studies dealing with its prevention and potential therapeutic interventions, especially during PCI. The role of gadolinium as an alternative to iodinated contrast is also discussed

    Extrapleural hydatid disease of chest: a case of recurrent hydatid disease

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    Hydatid disease is a parasitic infestation by a tapeworm of the genus Echinococcus. We present the case of 34-year-old female who complained of chest pain and had a past history of hydatid cyst resection four times in last 15 years. She was found to have extrapleural hyatid cysts of chest that were removed via thoracotomy. The patient fully recovered and experienced an uneventful follow-up

    Rhabdomyosarcoma embryonal type: in a three and a half year old girl

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    Rhadomyosarcoma is the most common tumour of the soft tissues in infants and children. We report a case of a 3 1/2 year old girl who presented with a swelling over the neck. Swelling was diagnosed as Rhabdomyosarcoma (embryonal type). Tumour mass was found to be unresectable initially. The patient was subjected to multiple courses of checmotherapy, which shrunk the tumour significantly. There was simultaneous development of cystic lesions in upper lobe of right lung. Excision of the remnant rhabdomyosarcoma mass and biopsy of right lung with cystectomy of right upper lobe cystic lesion was performed. The patient fully recovered and experienced an uneventful 6 months of follow-up

    Chylopericardium--a rare complication after ventricular septal defect repair

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    Chylopericardium is a rare complication of cardiac surgery. It may be caused by a lesion in the thoracic duct or its tributaries or by thrombosis in the confluence of the jugular and left subclavian veins, obstructing the drainage of the thoracic duct. The treatment may be conservative or surgical, depending on the duration and on the volume of the effusion. We report the case of a 1 1/2 year-old male, who, in the late postoperative period of VSD repair, was hospitalized with low-grade fever and breathlessness for one week due to the presence of chylopericardium. The clinical findings and treatment performed are discussed

    Extensive primary malignant thymoma involving pericardium, pleura, diaphragm and lungs--a case report

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    Malignant thymoma is an extremely rare entity. According to a study, the annual incidence of malignant thymoma was estimated to be 0.15 per 100,000 person-years. We present the case of a 42-year-old female who came to us with a Type AB, Masaoka stage III malignant (invasive) thymoma with widespread involvement of the mediastinum

    Prenatal Diagnosis of Maternal Serum from Mothers Carrying β-thalassemic Fetus

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    Background Current study focused on discovering protein biomarkers from the maternal serum of β-thalassemic trait mothers carrying the normal fetus and β-thalassemic major fetus. Method Serum samples from β-thalassemic trait mothers carrying major (N=5) and normal fetuses (N=5) were studied. IVS1-5 thalassemia mutation was common among β-thalassemic trait mothers who were carrying homozygous β-thalassemic fetus (IVS1-5/ IVS1-5 mutation) or normal fetus (no mutation). We employed two-dimensional gel electrophoresis and mass spectrometric analysis to explore differentially expressed maternal serum proteins from thalassemia carrier couples having the same β-thalassemia mutation. Western blotting was performed for one of the identified proteins to validate our data. Results Ten proteins were identified in maternal serum of β-thalassemic trait mothers carrying the β-thalassemic major fetus and normal fetus. Among these, Serotransferrin, Haptoglobin, Alpha-1 anti-trypsin (A1AT), Apo-lipoprotein A1, and Fibrinogen-beta chain were found to be up-regulated in mothers carrying major fetuses and are known to be associated with pregnancy-related disorders. The expression of A1AT was validated through western blotting. Conclusion Proteins identified in the current study from maternal serum are reported to contribute to hereditary disorders. We suggest that these can serve as putative screening markers for non-invasive prenatal diagnosis in β-thalassemic pregnancies
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