QOS Multimedia Multicast Routing: A Component Based Primal Dual Approach

The QoS Steiner Tree Problem asks for the most cost efficient way to multicast multimedia to a heterogeneous collection of users with different data consumption rates. We assume that the cost of using a link is not constant but rather depends on the maximum bandwidth routed through the link. Formally, given a graph with costs on the edges, a source node and a set of terminal nodes, each one with a bandwidth requirement, the goal is to find a Steiner tree containing the source, and the cheapest assignment of bandwidth to each of its edges so that each source-to-terminal path in the tree has bandwidth at least as large as the bandwidth required by the terminal. Our main contributions are: (1) New flow-based integer linear program formulation for the problem; (2) First implementation of 4.311 primal-dual constant factor approximation algorithm; (3) an extensive experimental study of the new heuristics and of several previously proposed algorithms

Factors that Undermine International Students’ Decision to Choose China as Work Destination: An Exploratory Study

Recently, China has become one of the top leading destinations in Asia and fifth global host destination for international students from across the globe. Unlike the developed countries, China is not an attractive work destination for those global students graduating from Chinese universities. This study aims to explore the determinants of de-motivation for international students to choose China as work destination. This research  leads  to  expand  the  understanding of  the  various  elements  that  support students’  decision  with  regards  to  choosing  a  study  destination. The questionnaires were distributed personally at international students’ dormitories of various universities in Wuhan to ensure the highest response. The results shows that 64 percent responded that Chinese economy is growing but 74 percent of the respondents mentioned that they do not want to stay for seeking jobs after graduation and 80 percent of the respondents were not to start their own business in China. One of the reasons was that majority of students was legally bound to go back to their countries after graduation as they were on scholarships. Policy suggestions will be directed in the light of these results. This research also, exploring that contribution of growing countries as not only senders, but also recipients of international students. Keywords: de-motivation, international graduates, work destinatio

Methods of synthesis of hydrogels … A review

AbstractHydrogels are being investigated recently for the bioactive molecules (in particular pharmaceutical proteins) controlled release, such as matrices, and for the living cells encapsulation. Biodegradable nature of hydrogels has created much interest for drug delivery systems. The original three-dimensional structure disintegrates into nontoxic substances to ascertain an excellent biocompatibility of the gel. Chemical cross-linking is the highly resourceful method for the formation of hydrogels having an excellent mechanical strength. Cross-linkers used in hydrogel preparation should be extracted from the hydrogels before use due to their reported toxicity. Physically cross-linked methods for preparation of hydrogel are the alternate solution of cross-linker toxicity

The effects of using variable lengths for degraded signal acquisition in GPS receivers

The signal acquisition in GPS receivers is the first and very crucial process that may affect the overall performance of a navigation receiver. Acquisition program initiates a searching operation on received navigation signals to detect and identify the visible satellites. However, signal acquisition becomes a very challenging task in a degraded environment (i.e, dense urban) and the receiver may not be able to detect the satellites present in radio-vicinity, thus cannot estimate an accurate position solution. In such environments, satellite signals are attenuated and fluctuated due to fading introduced by Multipath and NLOS reception. To perform signal acquisition in such degraded environments, larger data accumulation can be effective in enhancing SNR, which tradeoff huge computational load, prolonged acquisition time and high cost of receiver. This paper highlights the effects of fading on satellite signal acquisition in GPS receiver through variable data lengths and SNR comparison, and then develops a statistical relationship between satellite visibility and SNR. Furthermore it also analyzes/investigates the tradeoff between computation load and signal data length

An alkali catalyzed trans-esterification of rice bran, cottonseed and waste cooking oil

In this research work, biodiesel production by trans-esterification of three raw materials including virgin and used edible oil and non edible oil has been presented. A two step method following acidic and alkali catalyst was used for non edible oil due to the unsuitability of using the straight alkaline-catalyzed trans-esterification of high FFA present in rice bran oil. The acid value after processing for rice bran, cottonseed and waste cooking oil was found to be 0.95, 0.12 and 0.87 respectively. The influence of three variables on percentage yield i.e., methanol to oil molar ratio, reaction temperature and reaction time were studied at this stage. Cottonseed oil, waste cooking oil and rice bran oil showed a maximum yield of 91.7%, 84.1% and 87.1% under optimum conditions. Fuel properties of the three biodiesel satisfied standard biodiesel fuel results

Ependymal tumors with oligodendroglioma like clear cells: Experience from a tertiary care hospital in Pakistan

Background: Ependymal tumors with oligodendroglioma like clear cells have never been reported from Pakistan. We aimed to see the features and outcomes of this rare entity.Methods: It was retrospective cohort conducted at the Department of Neurosurgery, Aga Khan University from 2003 to 2013. The medical records and radiology of patients with proven histopathology were reviewed. Analysis was done on SPSS 20.Results: Eleven cases of ependymal tumors with clear cells were found, which equated to 1.5% of the total tumor burden in 11 years. The median age was 49 years. Most common presenting symptom was headache 54.5%. Out of 11 patients, 9 patients had a supratentorial tumor. Magnetic resonance imaging showed hypointense signals on T1 and hyperintense signals on T2-weighted images in all cases. Contrast enhancement was found in 9 patients (77.8%), necrosis and hemorrhage was found in 4 (36%) and 3 (27%) patients, respectively. Immunohistochemistry showed glial fibrillary acidic protein and epithelial membrane antigen positivity in all cases. Ki-67 showed high proliferative index in 6 patients. According to the World Health Organization grading of ependymal tumors, 2 patients had Grade II tumors, and 9 patients had Grade III tumors with clear cells. Gross total resection was achieved in 6 (54.5%) and subtotal resection in 5 patients (45.4%). Recurrence was observed in 9 patients. Six patients died of the disease. Median progression-free survival and overall survival was 8 months and 10 months, respectively.Conclusion: Ependymal tumors with clear cells presented more commonly in Grade III lesions and were more aggressive in behavior with poorer outcome compared to similar studies

A Review on Anticancer Potential of Nitric Oxide

Nitrous oxide (NO) is a free radical gas which performs various physiological and pathological processes in body. NO is produced by different enzymatic pathways and plays role in homeostasis. Over past years, NO has emerged as a molecule of interest in many ailments including cancer. But its role in cancer is still controversy. It can display dose-dependant anticancer therapy on one hand and induce procancer properties on the other hand. But as compared to conventional treatments, NO proved better tumor cell resistance. This review mentions dichotomous nature of NO that may encourage future research assessing the role of NO in cancer prevention and treatment either as a single agent or in combination with other antineoplastic compounds

A Novel Low-Temperature Thermal Desalination Technology Using Direct-Contact Spray Method

Due to the emerging water crisis, the global desalination capacity has been expanding exponentially in the past few decades, leading to substantial amount of primary energy consumption. Therefore, the exploration of energy-efficient desalination processes and alternative energy sources has been the subject of great research interests. The spray-assisted low-temperature desalination (SLTD) system is a novel method for desalination that enables efficient renewable energy utilization. It works on the direct-contact spray evaporation/condensation mechanism and uses only hollow chambers. The merits include enhanced heat and mass transfer, lower initial and operational costs, and reduced scaling and fouling issues. This chapter presents a study on the SLTD system driven by sensible heat sources. The working principle of the system will be introduced first. Then a thermodynamic analysis will be presented to obtain the freshwater productivity under different design and operational conditions. Additionally, the energy utilization level will be quantified to highlight the energy wastage when operating with sensible heat sources. Afterward, the system configuration will be modified to maximize the utilization of sensible heat sources and promote productivity. Finally economic viability of the modified design will be evaluated