Sharif Digital Repository

FlexRay communication protocol is expected to become the de-facto standard for distributed safety-critical systems. This paper classifies the effects of transient single bit-flip fault injections into the FlexRay communication controller. In this protocol, when an injected fault is activated, this may result in one or more error types, i.e.: Boundary violation, Conflict, Content, Freeze, Synchronization, Syntax, and Invalid frame. To study the activated faults, a FlexRay bus network, composed of four nodes, was modeled by Verilog HDL; and a total of 135,600 transient faults was injected in only one node, called the target node. The results show that only 9,342 of the faults (about 6.9%) were... 

Fire is a potential hazard in public transportation facilities such as subways or road tunnels due to its contribution to high number of deaths. To provide an insight into fire development behavior in tunnels which can serve as the basis for emergency ventilation design, model-scale railcar fire is explored numerically in this research. Fire growth and its spread are investigated by analyzing the HRR curve as the representative of fire behavior in different stages. Fire development has been predicted through a new approach using an Arrhenius-based pyrolysis model, established to predict the decomposition behavior of solid flammable materials exposed to heat flux. Using this approach,... 

Accidents involving falls and falling objects (group I) are highly frequent accidents in the construction industry. While being hit by a vehicle, electric shock, collapse in the excavation and fire or explosion accidents (group II) are much less frequent, they make up a considerable proportion of severe accidents. In this study, multiple-correspondence analysis, decision tree, ensembles of decision tree and association rules methods are employed to analyse a database of construction accidents throughout Iran between 2007 and 2011. The findings indicate that in group I, there is a significant correspondence among these variables: time of accident, place of accident, body part affected, final... 

Traffic safety policies are still conventionally ranked on financial and environmental criteria in developing countries, yet the equity concept can be advantageously used as an integral part of the process of traffic safety policy making. Equity in transportation is defined as how appropriately and equally the impacts of transportation are distributed among different types of users. The main contribution of this research is to introduce traffic safety equity in transportation policy making. The authors advocate for a modeling framework that considers traffic safety equity as a focal point. The analytical network process overcomes the drawbacks of data intensive models that are so difficult... 

Underground gas pipelines are one of the vital parts of each country which surface blasts can break down such pipelines, making destructive explosions and threatening the safety of neighborhood structures and people. In this paper, to enhance the safety of these lines, response of a buried 56-inch diameter high pressure natural gas pipeline to a surface blast was numerically investigated. Besides, the effects of: i) explosive mass, ii) pipeline thickness, iii) burial depth and iv) concrete protective layer on pipeline deformation were parametrically studied. To simulate the problem according to actual explosion events, geometries were modeled in real scales, pipeline properties were... 

Deep excavation in urban areas can cause instability problems due to significant settlement at the ground surface and large movements at the excavation facing walls. One of the most popular methods used to stabilise these excavations is utilising soil-nailing method. This method has also been widely used to stabilise natural slopes and earth retaining structures. Because of the complexity involved in the mechanism of this stabilising system due to interacting effects of the soil, nails, grout and shotcrete, numerical modelling with high accuracy should be used to analyse the behaviour of the soil-nailed walls. Considering all aspects of soil-structure interaction in the present research, a... 

Performing maneuvers such as braking and lane changing can hinder the occurrence of a crash. The driver tends to escape from the crash occurrence or reduce its severity by doing the maneuver, so finding the factors affecting this type of maneuver can help the driver to react better. This work aims to discover the effect of distraction-related factors on the performance of a crash avoidance maneuver. In order to pave the way for a more thorough comprehension of this matter, variables related to the characteristics of the driver, road, crash, vehicle, and environmental properties are also considered in the analysis. The used data is based on General Estimate System 2010 dataset, a dataset... 

Deep excavation in urban areas can cause instability problems due to significant settlement at the ground surface and large movements at the excavation facing walls. One of the most popular methods used to stabilise these excavations is utilising soil-nailing method. This method has also been widely used to stabilise natural slopes and earth retaining structures. Because of the complexity involved in the mechanism of this stabilising system due to interacting effects of the soil, nails, grout and shotcrete, numerical modelling with high accuracy should be used to analyse the behaviour of the soil-nailed walls. Considering all aspects of soil-structure interaction in the present research, a... 

Petroleum contamination of soil is a serious problem throughout the oil producer countries. Vegetation may play an important role in the biodegradation of toxic organic chemicals in soil. For petroleum compounds, the presence of rhizosphere micro flora may accelerate biodegradation of the contaminants. In a greenhouse study, petroleum contaminated soil were treated using phytoremediation . The C/N ratios and microbial populations were assessed in the beginning and the end of trials. The results showed that Puccinellia distance could tolerate the harsh condition of the soils. As MPN increases, C/N ratios decrease among trials. N, as a nutrient, had effects on both microbial populations and... 

For a given multicast network problem, there are different solutions. Sometimes some links of a network may be removed by failure and then we will be encountered with link failure in the network. Therefore, one of the objectives of selecting a specific network code solution among different options is to increase the robustness provided by this solution against such failure. In this paper we extend the definition of the minimal subtree graph and replace it with a new definition of minimal subgraph and use it as a basis of a faster method with lower complexity for finding a static network code resistant against all solvable link failure patterns of a network. ©2008 IEEE  

Vulnerabilities are now part of all software systems. To handle vulnerabilities, many approaches have been proposed till now. Many of these approaches try to analyze vulnerabilities based on model checking techniques. However, the models used in these approaches handle authorized and unauthorized rules separately. This basically cause in weaker modeling abilities and consequently weaker vulnerability analysis. From authorized and unauthorized rules, we mean those emanated from access control model and those originated from vulnerabilities respectively. Currently, a new general graph-based protection system concentrating on vulnerabilities called VGBPS is proposed to overcome the mentioned... 

Nowadays "as everywhere in the world", so much attention is drawn to performing safety and HSE management rules in Iran. Considering the long life of oil and it's relevant industries in Iran (since 1908, first oil well in Middle East, Masjid Soleyman), many units with more than 50 years old are still in operation. This situation posed special problems in performing safety and HSE regulations that some of them are communal among these units. This paper reveals the result of industrial projects, collecting numerous technical checklists in such units and author's experiences in recent years in Iran, which is aimed to announce some of these major problems and also present solutions for them  

Deep excavation in urban areas can cause instability problems due to significant settlement at the ground surface and large movements at the excavation facing walls. One of the most popular methods used to stabilise these excavations is utilising soil-nailing method. This method has also been widely used to stabilise natural slopes and earth retaining structures. Because of the complexity involved in the mechanism of this stabilising system due to interacting effects of the soil, nails, grout and shotcrete, numerical modelling with high accuracy should be used to analyse the behaviour of the soil-nailed walls. Considering all aspects of soil-structure interaction in the present research, a... 

Endurance Time (ET) method is a new dynamic procedure that has been recently developed for seismic safety evaluation of structures. This method is based on the comparison of seismic response of new-designed or existing structures under intensifying ET records with the pre-assigned damage index. Also this method can efficiently reproduce the seismic responses of the structures excited by scaled earthquakes that are required in time history analysis by the codes. In this paper, first general idea of this new method is described and then is applied to evaluate the seismic safety of a cylindrical steel storage tank under multidirectional excitations. It is shown that the ET method can predict... 

Today, managing an organization is concerned with many problems. Adopting proper strategies can promote an organization's survival. This study aimed at developing an appropriate HSSE Strategy for regional operation associated companies of Iran National Gas Company (INGS) using SWOT analysis. The analysis of the strengths, weaknesses, opportunities, and threats of HSSE was carried out and according to the results suitable strategies were recommended. In this regard, senior and junior managers, supervisors, and experts active in regional operation associated companies of Iran National Gas Company participated in SWOT analysis from HSSE angle. Then, they selected the most applicable SWOT...