TFUZZY-OF: a new method for routing protocol for low-power and lossy networks load balancing using multi-criteria decision-making

The internet of things (IoT) based on a network layer perspective includes low-power and lossy networks (LLN) that are limited in terms of power consumption, memory, and energy usage. The routing protocol used in these networks is called routing over low-power and lossy networks (RPL). Therefore, the IoT networks include smart objects that need multiple routing for their interconnections which makes traffic load balancing techniques indispensable to RPL routing protocol. In this paper, we propose a method based on fuzzy logic and the technique for the order of prioritization by similarity to the ideal solution (TOPSIS) as a well-known multi-criteria decision-making method to solve the load balancing problem by routing metrics composition. For this purpose, a combination of both link and node routing metrics namely hop count, expected transmission count, and received signal strength indicator is used. The results of simulations show that this method can increase the quality of services in terms of packet delivery ratio and average end-to-end delay

MHD Natural Convection and Radiation over a Flame in a Partially Heated Semicircular Cavity Filled with a Nanofluid

The numerical analysis of MHD-free convective heat transfer and its interaction with the radiation over a heated flame inside a porous semicircular cavity loaded with SWCNTs–water nanofluid was explored for the very first time in the present work. The two circular arcs of the upper wall of the enclosure were preserved at a constant cold temperature, whereas the middle region of it was considered adiabatic. The midland region of the lower wall was heated partially, while other regions were also assumed adiabatic. An internal hot flame was included inside the cavity, while the cavity was exposed to a magnetic field. The results were illustrated for Hartmann number (0 ≤ Ha ≤ 100), Rayleigh number (104 ≤ Ra ≤ 106), heated region length (0.1 ≤ L ≤ 0.3), solid volumetric fraction (0 ≤ φ ≤ 0.04), Darcy number (10−3 ≤ Da ≤ 10−5) and radiation parameter (0 ≤ Rd ≤ 1). It was found that decreasing L is the best option for enhancing natural convection. Moreover, it was noted that (Nuout) is directly proportion to (Ra), (ϕ), (Rd) and (Da) increase. In contrast, it was in reverse proportion to (Ha). Furthermore, the results showed that augmentation of about (4%) and a decrement of (56.55%) are obtained on the average (Nu) on the heated length by increasing the radiation and the Hartmann number, respectively. Moreover, raising the radiation number from (0 to 1) causes an augmentation of about (73%) in the average (Nu) of the heated flame. Results also indicated that increasing the Hartmann number will cause a decrement of about (82.4%) of the maximum velocity profile in the vertical direction

Helicobacter pylori Infection and Development of Gastric Cancer a 10-Year Follow-up Population-Based Study in a High Incidence Area

Backgrounds & Aim: H. pylori (HP) infection is the most important etiology of gastric cancer (GC) in the world but it causes GC in only a minority of those infected .Eradication of HP can decrease the development of GC only in the subgroup of HP infected subjects without precancerous lesions. Strategies of HP eradication is still not well defined in countries with high mortality rates secondary to GC with almost universal HP infection in adults. The aim of the present study was to investigate the predictors of GC in an adult population with almost universal HP infection in an area with highest rate of gastric cancer in the world. Methods: 1011 healthy subjects 40 years and older, permanent residents of Ardabil and Meshkinshahr districts in northwest Iran, were randomly selected and enrolled in an endoscopic screening study during 2000 to 2001 year. Data on demographics and potential risk factors were collected using a well-structured questionnaire. Upper gastrointestinal endoscopy with multiple biopsy sampling was performed to detect HP infection and endoscopic precancerous lesions.Participants have been followed up until 2011. During followup period data on the occurrence of GC, mortality, and cause of death were obtained from cancer and death registries, and when neccessary by direct contacting to participants, and their families. The cumulative incidence and person-time incidence rate were calculated. The effect of other risk factors in addition to H. pylori infection on the risk of GC development were estimated by fitting multivariate hazard model using Cox proportional regression analysis, and were presented as hazard ratio (HR) and corresponding 96% confidence interval (95%CI). Results: During 10-year follow up, 36 participants (3.6%) developed GC yielding an incidence rate of 3.6 per 1000 person-years. The significant risk factors of GC included age over 50 (HR 4.8; 95%CI 1.4-16.2), a positive family history of stomach cancer (6.4; 3.1-13.1), smoking (5.7; 2.5-12.6), gastric atrophy (2.3; 1.0-5.1), intestinal metaplasia (4.5; 2.3-8.9) and presence of gastric ulcer (4.8; 1.9-11.5). Joint presence of precancerous lesion and one of the other risk factors significantly increased risk of stomach cancer as (46.5; 10.8-98.6) for a positive family history of stomach cancer; (27.6; 6.5-116.4) for smoking and (25.1; 16.3-105.3) for age>50. Conclusion: Combining the information on family history, lifestyle risk factors and the type of precancerous lesion may be helpful in order to identify high risk HP infected patients who need more intensive surveillance for early detection of GC. Key words: Stomach cancer, Precancerous lesions, Risk factors, H. pylori, Ardabil,Iran