Communication system has a key position in smart grid (SG). Smooth operation among different functional blocks of smart grid, i.e. generation, transmission, distribution, utility, and consumers require reliable and efficient exchange of information. Hybrid architecture in smart grid, in the form of Advanced Metering Infrastructure (AMI) consists of gateways/access points and smart meters. AMI network facilitates consumers to take benefits of real-time pricing, demand side management, load scheduling and upgrading the software updates through access points to multiple smart meters without visiting every place. Information sharing can take place in the shape of readings from meters to AMI, from meters to utility and from AMI to utility. This information exchange is either scheduled, on-demand or in the form of mass transfer. Information exchange in the form of time of use (TOU) and real-time pricing also occurs from utility to meters. Broadcasting is one possible solution in these scenarios for information exchange. Data broadcasting in AMI networks can be achieved using many wired and wireless communication technologies including Zigbee, Wireless LAN, Powerline Communication (PLC), WiMAX 802.16, Cellular, and Digital Subscriber Lines (DSL). But these technologies either have limited range or can be used for licensed users only. For these reasons, Cognitive Radio Networks (CRNs) are one possible solution that provides large data transmission utilizing available spectrum resources from licensed and unlicensed bands. Broadcasting is challenging in CRNs due to Licensed/Primary User (PU) activity, availability of multiple channels, and channel diversity. Therefore, PU protection must be provided at all cost and data transmission should be quick and reliable for a smooth operation. In this thesis, two novel reliable schemes are proposed, i.e., PRobability-based Broadcasting scheme for CR-based Smart Grid (PRB-CRSG) and Area-based Broadcasting scheme for CR-based Smart Grid (ARB-CRSG) specifically designed for AMI networks. These schemes provide reliable data to smart meters with sufficient PU protection. Both these schemes have been compared with two flooding techniques, i.e., "Key Policy Attribute Based Encryption" (KP-ABE) and "Key Management Scheme" (KMS). Simulation in NS-2 validates these schemes as a viable solution in cognitive radio-based smart grid systems.
The Quran describes itself as a book of guidance. Sura l-Baqarah, verse (67) states: قَالَ أعُوْذُ بِاللّٰہِ اأنْ أَکُوْنَ مِنَ الْجَھِلِیْنَ۔He said, "I seek refuge in Allah from being among the ignorant. "The Qur'an does not render a coordinated description of the universe Creation and how it will end. In lieu of a continuous story of creation and cease, there are verses dispersed all over the Quran which deal with certain aspects of the universe’s Creation and end. These scattered verses provide information on the sequential events marking its development with varying degrees of detail. The primary objective of this paper is to analyze the Quranic Concept of Universe. The idea of steady state by Hermann Bondi, Thomas Gold, and Fred Hoyle (1948) suggests that this universe is created with big bang, it is expanding and it would be the same, always static, always contracting or always expanding with no end. This is in contrast with the pulsating theory of the accelerating expansion will result in weak gravity which will cause the universe to contract. When this contraction will condense everything back into one single point, this rapid compression will lead to another explosion (often referred to as mini big bang). As a result of which the universe will start expanding again. Hence it results in a pulsating universe in which there is alternate expansion and contraction of universe.
Background: Chronic subdural haematomas (CSDH) are a commonly encountered neurosurgical problem with no consensus on the optimal treatment strategy. The successful treatment of CSDH remains a major problem with only 64-89% having complete neurological resolution with surgery alone and up to 26% of patients developing persistent bleeding requiring further surgery. The use of corticosteroids as an adjunct to surgery in CSDH may improve outcomes. The evidence for this is unclear and practice is divided among neurosurgeons worldwide. Objective: To compare the incidence of satisfactory resolution between patients with chronic subdural haematoma undergoing surgery who received dexamethasone pre and postoperatively for 6 weeks versus patients who received a placebo for the same period. Study Design: Multi-centre, double blind randomized placebo-controlled trial. Setting: The Aga Khan University Hospital, Nairobi and The Nairobi Hospital. Methods: Fifty-three patients undergoing burrhole surgery for chronic subdural haematoma were randomized into 2 groups (control and intervention group) using a computer-generated table of numbers. Results: The two groups had similar baseline characteristics in terms of age, gender, location of haematoma, initial Glasgow Coma Scale and location of haematoma. The mean age was 57.6 years (SD 12.9). Males comprised 88.6% percent of the patients while females comprised 11.3%. One patient in the dexamethasone arm died during the study. At the end of 6 weeks, there was a statistically significant difference in satisfactory radiological resolution between patients in the dexamethasone arm (89.3%) compared to the placebo arm (56%) (p=0.0034). Participants in the dexamethasone arm were 65.3% times more likely to have resolution of the haematoma (Relative Risk 1.6593 (95% CI 1.15 to 2.38); Fishers Exact p value = 0.0034. The Number needed to treat was 2.7. There was no significant difference between neurological outcomes in both groups (p= 0.611). There was poor correlation between neurological and radiological resolution with 77% of participants having unsatisfactory radiological resolution, having good neurological scores. A total of 7 out of 52 (13.2%) participants experienced complications, 6 (21.4%) of these were in the dexamethasone arm and 1 (4%) in the placebo arm. 6 of these participants had high blood glucose, while 1 had urosepsis requiring hospitalization. All 4 participants who required a second operation were in the placebo arm. Conclusion: The present data provides Level 2 evidence that use of dexamethasone as an adjunct to surgery in the management of CSDH improves radiological outcomes. There is a significant benefit indicated by a number needed to