146 research outputs found
A Survey on Cooperation for VDTN
Vehicular Delay-Tolerant Networks (VDTNs) are composed of mobile nodes (vehicles) that communicate with each other wirelessly and using store carry and forward paradigm to forward data despite intermittent connectivity. There are major challenges in establishing effective communications between nodes in Vehicular Ad Hoc Networks (VANETs). In them the systems are subject to wireless interference and disconnections, thus hindering the availability and reliability of source-destination connections. Another major problem arises when VANETs are sparse, causing excessive retransmissions and delays due to long periods without maintaing connection between pair of vehicles. This article reviews the literature related to Vehicular Delay Tolerant Network with focus on Cooperation. It starts by examining definitions of some of the fields of research in VDTN. An overview of VDTN with cooperative networks is presente
Cooperation for Vehicular Delay Tolerant Network
This article reviews the literature related to Vehicular Delay Tolerant Network with focus on Cooperation. It starts by examining definitions of some of the fields of research in VDTN. An overview of VDTN with cooperative networks is presented
Security Policies and Mechanisms for Vehicular Delay Torlant Network
This article revision the literature related to Vehicular Delay Tolerant Network with focus on Cooperation. It starts by examining definitions of some of the fields of research in VDTN on security policies. An overview of VDTN on security policies cooperative networks is presented. A security policy is a high-level specification of the security properties that a given system should possess. It is a means for designers domain experts and implementers to communicate with each other, and a blueprint that drives a project from design through implementation and validation. We offer a survey of the most significant security policy models in the literature showing security may mean very different things in different contexts and we review some of the mechanisms used to implement a gievn security policy
Colorectal carcinoma, preoperative evaluation by spiral computed tomography
Objectives: To assess the capability of spiral computed tomography (CT) scan in preoperative evaluation of colorectal carcinoma (CRC).Methods: A cross sectional study on 52 patients with recent histopathologic diagnosis of CRC was conducted over a period of one year at the Aga Khan University Hospital, Karachi. All these patients underwent spiral CT with oral and intravenous contrast administration. Surgery was subsequently done in all cases and surgical specimens were sent for detailed pathologic analysis. The radiologic findings on the CT scans were compared with the pathological findings.Results: The results proved that spiral CT had 60% sensitivity and 83% specificity for assessment of local spread of disease, 66% sensitivity and 76% specificity for the evaluation of lymph nodal metastases and 89% sensitivity and 94% specificity for hepatic metastases. In all the cases, the visualized tumour growth with wide zone of resection and regional nodal chains were surgically removed. It was however, the distant metastases which made a difference to the type of curative or palliative surgery planned and in this study spiral CT had 92% accuracy for detection of hepatic metastases.CONCLUSION: With technological advances and improvement in imaging protocols the results for local tumor spread are expected to improve, however based on the accuracy in detecting hepatic metastases in clinically unsuspected patients, this study proves that spiral CT has a significant role in preoperative evaluation and subsequent management of CRC
N-Cyclohexyl-4-methyl-N-propylbenzenesulfonamide
The title compound, C16H25NO2S, is a sulfonamide derivative with the substitution of propyl and cyclohexyl groups at the N atom. The least-squares plane through all six C atoms of the cyclohexyl ring forms a dihedral angle of 58.88 (12)° with the toluene ring. No hydrogen-bonding interactions are present in the crystal structure
Impact of Foreign Direct Investment (FDI) on GDP: A Case Study from Pakistan
This research study is related to FDI and GDP and the main aim of this research study is to validate the relationship between them. Foreign direct investment (FDI) is considered as a growth accelerating component that has received a great attention in developed countries even in developing and less developed countries during recent years. Now FDI has greater importance in closed economy. FDI benefits any economy in terms of technology, skilled labor and skills transfer to the host countries. For data collection, 30 year data from 1983 to 2012 was collected and the cobb-Douglas Production function is used to test the relationship. Our research variables are Gross Capital Formation (K), Labor (L), Health Expenditure (H), FDI and openness to trade in export oriented economy (OP*FDI). We have followed the Bhagwati’s hypothesis that was: FDI has greater impact on GDP in the export oriented economy. For data analysis, we have examined the descriptive statistics, correlation and regression model. For this we incorporate the production function in regression model. In brief, our results show that there is a positive relationship between FDI and GDP in Pakistan. But, Pakistan has not sufficient flow of FDI during past decades. And main point to consider which is evident through statistics and results is that there is greater impact of FDI in the open trade policy regimes. It is also concluded that FDI impact may be situation and culture related. So, the extent of FDI economic benefits cannot be predicted
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