GSTR: Secure Multi-hop Message Dissemination in Connected Vehicles using Social Trust Model

The emergence of connected vehicles paradigm has made secure communication a key concern amongst the connected vehicles. Communication between the vehicles and Road Side Units (RSUs) is critical to disseminate message among the vehicles. We focus on secure message transmission in connected vehicles using multi_hop social networks environment to deliver the message with varying trustworthiness. We proposed a Geographic Social Trust Routing (GSTR) approach; messages are propagated using multiple hops and by considering the various available users in the vehicular network. GSTR is proposed in an application perspective with an assumption that the users are socially connected. The users are selected based on trustworthiness as defined by social connectivity. The route to send a message is calculated based on the highest trust level of each node by using the nodes social network connections along the path in the network. GSTR determines the shortest route using the trusted nodes along the route for message dissemination. GSTR is made delay tolerant by introducing message storage in the cloud if a trustworthy node is unavailable to deliver the message. We compared the proposed approach with Geographic and Traffic Load based Routing (GTLR), Greedy Perimeter Stateless Routing (GPSR), Trust-based GPSR (T_GPSR). The performance results obtained show that GSTR ensures efficient resource utilization, lower packet losses at high vehicle densities

Optimal Duration for Continuation of Statin Therapy in Bacteremic Patients

Background: Evidence suggests statins may improve survival in patients with bloodstream infections. However, there is no consensus on optimal timing and duration of exposure. Objectives: To quantify statin therapy duration associated with decreased mortality in bacteremic statin users. Methods: We conducted a case-control study using OptumClinformatics™ with matched Premier hospital data (1 October 2009–31 March 2013). Cases who died during the hospitalization were matched 1:1 to survivors on disease risk scores (DRSs). Post-admission statin therapy duration was evaluated in patients with at least 90 days of pre-admission continuous statin use. Classification and regression tree (CART) analysis was conducted to identify the optimal duration of statin continuation which provided the lowest inpatient mortality. Logistic regression was used to calculate the odds of mortality. Results: We included 58 DRS matched pairs of cases and controls: 47 patients (41%) continued statin therapy during the hospital admission, 15 (32%) cases and 32 (68%) controls. The CART analysis partitioned the continuation of statin therapy at ⩾2 days, representing lower mortality for patients who continued statins for 2 days or more and higher mortality for patients who did not continue or remained on statins for only 1 day. Inpatient mortality was 76% lower among those with at least 2 days of continued statin use (odds ratio 0.24, 95% confidence interval 0.11–0.55)

Micro-shear bond strength of different surface treatments on a polymer infiltrated ceramic network [version 1; peer review: 1 approved, 2 approved with reservations]

Background: Polymer infiltrated ceramic networks, or hybrid ceramics, are a combination of infiltrating polymerizable organic monomers into a pre-sintered porous ceramic matrix. In addition to having good mechanical properties, the polymer infiltrated ceramic network must comply with the possibility of adequate bonding to the resinous cement. The surface conditioning of this hybrid material must be carefully considered due to its organic composition and ceramic network. The purpose of this research is to evaluate the effect of hydrofluoric acid and a self-etching ceramic primer, under two different application times, on the bond strength of a polymer infiltrated ceramic network. Methods: Blocks of a polymer infiltrated ceramic network were cut to obtain sheets, and these were randomized into five groups. For the group termed AAS, airborne-particle abrasion with Al2O3 (aluminum oxide) of 50µm was used. For groups HF2 and HF6, hydrofluoric acid was used for 20 and 60 seconds respectively, and for the groups MB2 and MB6, a self-etch ceramic primer was applied for 20 and 60 seconds respectively. A silane was applied to the groups AAS, HF2, and HF6 after the treatment. After 24-hour storage in distilled water, a micro-shear bond strength test was performed using a universal mechanical testing machine. All samples were evaluated in a stereomicroscope at 40x and 50x to determine the type of failure. Results: The highest and lowest values of bond strength were reported by groups MB6 and AAS, respectively. Groups HF2, HF6, MB6, and MB2 did not report statistically significant differences. The predominant failure pattern was a mixed failure. Conclusions: With the limitations of the present investigation, the treatments of self-etching ceramic primer and hydrofluoric acid followed by silane were reported to be statistically equal at 20 and 60 seconds

Analysis and Modeling of Human Body When Exposed to Automotive Vehicle

Vibration is one of the important considerations in design. Nowadays, almost every family has the car. So, it becomes most important to study the vehicle vibrations. Analysis of human body physical model experimentally when situated in automotive vehicle. The model fabrication is done on the basis of comparing real human body parameters with human physical models used in the ISO 10068:2012 standard. This article revealed effect of vibration transferring to the specific parts of human body due to vibration transferring from Seat to Height (STH) and from Hands on steering. The focus of the present study was to determine the vibration output from fabricated model. The vibrations as input to the model are from automotive vehicles. The input verses output vibration characteristics will be useful to study effects of vibration on human health. The human body is considered as a simple spring, mass, damper system for analysis. This multi body model representative of the automotive postures found in the literature were investigated, one with and the other without a backrest support. The model was modified to suitably represent the different automotive postures with and without backrest supports, and validated by various experimental data from the published literature pertaining to the same postural conditions on the basis of the analytical study and the experimental

Geographic social trust routing: multi-hop message dissemination in intervehicle communication systems using social trust model in geographic networks

The emergence of smart vehicles has brought up a key concern of secured communication among these connected vehicles. Vehicular adhoc networks (VANET) help communication between these vehicles and road side units (RSU) which helps improve road safety and security by warning drivers of hazards coming their way. To handle such sensitive and important data, the authenticity and trustworthiness of the data is essential. This study is about the security aspect of the connected vehicles taking into consideration the multi-hop message passing environment to deliver the message with a high level of trustworthiness. In this proposed approach, the message propagation is carried out using multi-hop considering the various available users in the network. These users are selected based on trustworthiness as defined by social connectivity. The route to send a message is calculated using the highest trust level of each node using the node’s social network connections along the path in the network. Geographic social trust routing (GSTR) works to find the closest route using the trusted nodes for message dissemination. The proposed system is made delay tolerant by the introduction of message storage in the cloud upon the unavailability of a trustworthy node to deliver the message. Index Terms— Authentication, GSTR, Multi-hop message dissemination, QoS, Social networks, Trustworthiness, VANET, Vehicular Cloud Computing

The morphology of the pulp chamber floor of permanent mandibular first and second molars in an Indian subpopulation—a descriptive cross-sectional study employing Pawar and Singh classification

Background Mandibular molars are multi-rooted teeth with a complex and strenuous root canal anatomy. Because there is relatively negligible literature describing the pulp chamber floor anatomy, predicting the exact anatomical layout and its variations is daunting. A thorough comprehension and knowledge of the same is required for efficacious endodontic treatment consequence. The purpose of this study was to characterise and ascertain the pulp chamber floor anatomy of permanent mandibular first (ManFMs) and second (ManSMs) molars in an Indian population. Methods On 2,134 extracted human mandibular first (ManFMs = 1,067) and second molars (ManSMs = 1,067), a descriptive cross-sectional investigation was executed. Cleaning and removal of hard and soft tissue debris were performed, followed by flattening the anatomical crown until the pupal architecture was uncovered. A stereomicroscope with a magnification of 4.5 magnification was used to investigate the pulpal anatomy. Statistical analysis was carried out using chi square test, with 95% confidence intervals and a p value of 0.05 considered statistically significant. Results The majority of the ManFMs showed presence of three canal orifices in 57.73%, followed by four orifices 31.31%, five orifices 8.81%, and six orifices 2.15%. For ManSMs, majorly three orifices were found in 39.83% specimens, followed by two orifices in 37.39%, four orifices in 16.31%, and single root canal orifice was observed in 6.47%. The mesio-buccal, mesio-lingual, disto-buccal, disto-lingual canal orifices exhibited round and oval shapes in both ManFMs and ManSMs. The shape was predominantly oval with a single distal canal orifice (84.25% ManFMs and 74.16% ManSMs). In ManSMs, among the single root canal orifice, 66.66% were round in shape and 33.34% were C-shaped. In ManSMs with two root canal orifices, mesially 79.44% exhibited oval and 20.56% round shape. Distally, 74.16% were oval and 25.84% were round. The shapes of the access cavities for ManFMs were rectangular in 46.67% and triangular in 53.33%. For the ManSMs, the access cavities were triangular in 39.83%, rectangular in 16.31% and non-classified (others) in 43.86% of specimen. In both ManFMs and ManSMs, the pulp chamber floor morphology was predominately Y shaped (57.73% and 39.83%) according to the Pawar and Singh classification© of pulp chamber floor anatomy. Conclusion Our study indicated that the orifices on the pulp chamber floor are arranged in a typical manner, supporting the proposed categorization. Furthermore, description of the anatomical patterns of the pulp chamber guides the clinicians in chair-side treatment decisions

An application of TOPSIS for selection of appropriate e-Governance practices to improve customer satisfaction

E-governance practices and standardization of processes are significant factors affecting the per-formance of government organizations and undertakings in India. Customer is the backbone of any organization and customer satisfaction is the key for ensuring the success. Using a multiple-criteria decision analysis method named TOPSIS, we attempt to study the impact of e-governance practices on customer satisfaction of Maharashtra Housing and Area Development Authority (MHADA). The method determines the ranking and contribution of different elements in an attempt to determine a suitable strategy for every customer segment. Results show that cus-tomers belonging to Higher Income Group (HIG) and Middle Income Group (MIG) are more satisfied with the Online Mitra Service while the customers of Lower Income Group (LIG) and Economic Weaker Section (EWS) are more inclined towards Process Standardization. In order to remove bias and obtain fairly accurate results the data were collected through questionnaire from every customer segment

Dynamics of gas bubbles in fiber suspensions

International audienc