3,024 research outputs found
Optimization of depth-based routing for underwater wireless sensor networks through intelligent assignment of initial energy
Underwater Wireless Sensor Networks (UWSNs) are extensively used to explore the diverse marine environment. Energy efficiency is one of the main concerns regarding performance of UWSNs. In a cooperative wireless sensor network, nodes with no energy are known as coverage holes. These coverage holes are created due to non-uniform energy utilization by the sensor nodes in the network. These coverage holes degrade the performance and reduce the lifetime of UWSNs. In this paper, we present an Intelligent Depth Based Routing (IDBR) scheme which addresses this issue and contributes towards maximization of network lifetime. In our proposed scheme, we allocate initial energy to the sensor nodes according to their usage requirements. This idea is helpful to balance energy consumption amongst the nodes and keep the network functional for a longer time as evidenced by the results provided
Juxtaposition of micro and macro dynamics of dividend policy on stock price volatility in financial sector of Pakistan : (comparative analysis through common, fixed, random and GMM effect)
The purpose of this study is to analyze the dividend policy dynamics in context to firm specific and macroeconomic variables with stock price volatility in the financial sector of Pakistan. Panel data is used for the period 2006-2014 to identify the common, fixed, random and GMM effect. It is concluded that dividend payout ratio, market value, interest volatility and inflation volatility have positive significant correlation with price volatility. Common effect model shows that dividend payout and interest volatility has a significant positive impact on the share prices. Whereas fixed effect model is more appropriate and good fit than random effect model and model indicate that dividend payout ratio has significant positive impact and market volatility has significant negative impact on stock prices. GMM results also support the fixed and random effect outcomes with more robustness. This study significantly contributes in dividend policy decisions and elaborates the dynamic roll of micro and macro variables on stock price volatility in financial sector of Pakistan.peer-reviewe
Predictors of lymph node involvement in bladder cancer treated with radical cystectomy
Objective: To identify the clinical variables associated with prevalence of lymph node metastasis in patients with bladder cancer treated by radical cystectomy and lymphadenectomy for primary bladder cancer. Methods: Review of records of Ninety-five patients who underwent radical cystectomy and pelvic lymph node (LN) dissection during the period of 1995-2008 from a prospectively maintained database. Eighteen patients were excluded due to lack of data on the nodal status, leaving 77 evaluable patients. Associations between LN metastasis and age, gender, duration of disease, number of transurethral resection (TUR) prior to cystectomy, pathological grade and tumour stage was analyzed. Data was analyzed using the SPSS software, version 15. Statistical tests applied were independent sample t test or the Mann Whitney U test, the chi-square test and the Fischer exact test. Results: The median age of the patients was 58 years in lymph node negative group and 63 years in lymph node positive group. There were 87% males and 13% females. LN metastasis was detected in 19 (25%) patients. Mean duration of disease in LN negative patients was 537 +/- 997 days compared to 509 +/- 708 days in LN positive patients. Mean number of TUR were same in both the groups, pathological grade was not found significantly different in both groups, where as primary tumour stage was found to be significantly (p \u3c 0.05) higher in LN positive patients. Conclusions: Higher primary tumour stage at radical cystectomy is associated with higher prevalence of lymph node metastasis
Melanotic Neuroectodermal Tumour of Infancy: A Rare Brain Tumour of Childhood
Melanotic neuroectodermal tumour of infancy is a rare, mostly benign but locally aggressive tumour of neural crest cellorigin occurring in infants. The most commonly affected anatomic site is the maxilla. Such tumours of the brain and skull are very rare. We present the case of an 8 months old baby girl whose presenting complaint was a swelling in the scalp for 6 months. She was otherwise asymptomatic. CT imaging confirmed the presence of an osteolytic tumour in the anterior parasagittal skull with dural involvement. The tumour was surgically excised enbloc. The patient has been well at 2 years follow-up without any evidence of recurrence
An assessment of the contemporary threat posed by network worm malware
The cost of a zero-day network worm outbreak has been estimated to be up to US$2.6 billion. Additionally zeroday network worm outbreaks have been observed that spread at a significant pace across the global Internet, with an observed infection level of more than 90 percent of vulnerable hosts within 10 minutes. The threat posed by such fast-spreading malware is therefore significant, particularly given the fact that network operator / administrator intervention is not likely to take effect within the typical epidemiological timescale of such infections. This paper presents a classification of wormable vulnerabilities, demonstrating a method to determine if a vulnerability is wormable, and presents a survey into the cause of the reduction of worm outbreaks in recent years, as well as their viability in the future. It then goes on to explore recent wormable vulnerabilities, and points out the issues with operating system security in relation to techniques used by zero-day worms
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