A Media Access Control Protocol for Wireless Adhoc Networks with Misbehaviour Avoidance

The most common wireless Medium Access Control (MAC) protocol is IEEE 802.11. Currently IEEE 802.11 standard protocol is not resilient for many identified MAC layer attacks, because the protocol is designed without intention for providing security and with the assumption that all the nodes in the wireless network adhere to the protocol. However, nodes may purposefully show misbehaviours at the MAC layer in order to obtain extra bandwidth con-serve resources and degrade or disrupt the network performance. This research proposes a secure MAC protocol for MAC layer which has integrated with a novel misbehaviour detection and avoidance mechanism for Mobile Ad Hoc Networks (MANETs). The proposed secure MAC protocol the sender and receiver work collaboratively together to handshakes prior to deciding the back-off values. Common neighbours of the sender and receiver contributes effectively to misbehaviours detection and avoidance process at MAC layer. In addition the proposed solution introduces a new trust distribution model in the network by assuming none of the wireless nodes need to trust each other. The secure MAC protocol also assumes that misbehaving nodes have significant levels of intelligence to avoid the detectio

Project risk management for community-based post-disaster housing reconstruction project

Indonesia is a highly disaster prone country, particularly to earthquakes. In the last decade, Indonesia has been hit by three large earthquakes; Aceh in December 2004, Yogyakarta in May 2006, and West Sumatra in September 2009. These earthquakes have created considerable losses to Indonesian communities, lead to 130,000 fatalities, US$10.3 billions economic losses, and 500,000 of heavily damaged houses. The massive housing reconstruction has been found to be the most problematic sector of housing reconstruction programme. Although community-based post-disaster housing reconstruction project (CPHRP) has been implemented, nevertheless the outcome was still overshadowed by the delay in delivery, cost escalation, unexpected quality, and community dissatisfaction. The implementation of good practice of project risk management in construction industry is expected to enhance the success of CPHRP. Accordingly, this study aims to develop a risk management model for community-based post-disaster housing reconstruction approach. In order to achieve the aim and objective of the research, multiple case studies is selected as research strategies. This study implements the sequential mixed method application, started with semi-structure interview and followed by questionnaire survey as the primary method. Content analysis was used to analyse qualitative data, whilst descriptive and inferential statistics were deployed to analyse quantitative data. This study reveals the importance of the understanding on community-based approach in post-disaster housing reconstruction. Four highly significant advantages of CPHRP have been discovered, with ‘create sense of ownership’ of beneficiaries to the project as the most significant advantage. It was also found that the psychological advantage of CPHRP is more dominant compare to the construction advantage. Further, the risk assessment has discovered some high risk events during the pre-construction stage of CPHRP. The most affected project objective by them is project time completion. Risk response document has also been proposed. Moreover, this study found twelve critical success factors (CSFs) of CPHRP, with the highest CSFs is ‘transparency and accountability’. With careful attention on the above findings, it is expected the success of the implementation of CPHRP can be increase

Analysis of DoS Attacks at MAC Layer in Mobile Adhoc Networks

—Wireless network security has received tremendous attention due to the vulnerabilities exposed in the open communication medium. The most common wireless Medium Access Control (MAC) protocol is IEEE 802.11, which assumes all the nodes in the network are cooperative. However, nodes may purposefully misbehave in order to disrupt network performance, obtain extra bandwidth and conserve resources. These MAC layer misbehaviours can lead to Denial of Service (DoS) attacks which can disrupt the network operation. There is a lack of comprehensive analysis of MAC layer misbehaviour driven DoS attacks for the IEEE 802.11 protocol. This research studied possible MAC layer DoS attack strategies that are driven by the MAC layer malicious/selfish nodes and investigates the performance of the IEEE 802.11 protocol. Such DoS attacks caused by malicious and selfish nodes violating backoff timers associated with the protocol. The experimental and analytical approach evaluates several practical MAC layer backoff value manipulation and the impact of such attacks on the network performance and stability in MANETs. The simulation results show that introducing DoS attacks at MAC layer could significantly affect the network throughput and data packet collision rate. This paper concludes that DoS attacks with selfish/malicious intend can obtain a larger throughput by denying well-behaved nodes to obtain deserved throughput, also DoS attacks with the intend of complete destruction of the network can succee

Effect of soil parameter uncertainty on seismic response of buried segmented pipeline

Pipelines are important lifeline facilities spread over a large area and they generally encounter a range of seismic hazards and different soil conditions. The seismic response of a buried segmented pipe depends on various parameters such as the type of buried pipe material and joints, end restraint conditions, soil characteristics, burial depths, and earthquake ground motion, etc. This study highlights the effect of the variation of geotechnical properties of the surrounding soil on seismic response of a buried pipeline. The variations of the properties of the surrounding soil along the pipe are described by sampling them from predefined probability distribution. The soil-pipe interaction model is developed in OpenSEES. Nonlinear earthquake time-history analysis is performed to study the effect of soil parameters variability on the response of pipeline. Based on the results, it is found that uncertainty in soil parameters may result in significant response variability of the pipeline

Resilient Misbehaviour Detection MAC Protocol (MD-MAC) for Distributed Wireless Networks

Chaminda Alocious, Hannan Xiao, B. Christianson, 'Resilient Misbehaviour Detection MAC Protocol (MD-MAC) for Distributed Wireless Networks' paper presented at the 2016 IEEE Wireless Communications and Networking Conference (IEEE WCNC). Doha, Qatar. 3-6 April 2016Wireless network security requirements are becoming more important and critical. The modern network security architectures require more attention to provide security in each network layer. This will require understanding of protocol vulnerabilities in existing protocol architectures. However, providing security requirements are not just limited to confidentiality and integrity, also availability and fairness are important security elements. IEEE 802.11 MAC protocol is one of the most common standard in modern day networks and has been designed without a consideration for providing security protection at MAC layer. IEEE 802.11 assumes all the nodes in the network are cooperative. However, nodes may purposefully misbehave in order to obtain extra bandwidth, conserve resources and disrupt network performance. This research proposes a Misbehaviour Detection MAC protocol (MD-MAC) to address the problematic scenarios of MAC layer misbehaviours, which takes a novel approach to detect misbehaviours in Mobile Adhoc Networks (MANETs). The MD-MAC modifies the CSMA/CA protocol message exchange and uses verifiable backoff value generation mechanism with an incorporated trust model which is suitable for distributed networks. The MD-MAC protocol has been implemented and evaluated in ns2, simulation results suggest that the protocol is able to detect misbehaving wireless nodes in a distributed network environment

Building Disaster Resilience within the Emirati Energy Sector through a Comprehensive Strategic Mitigation Plan

Disasters, both natural and man-made, have been occurring with increasing frequency and effect in recent decades in many countries around the world. Such threats have been shown to result in a loss of life, property and income and all of which have an impact on the country’s socio-economic structure and geo-political positioning. The UAE is steadily adapting its policies and practices to manage any potential disaster, whether natural or man-made. However, evidently the UAE is exposed and vulnerable to tectonic activity from a number of sources and yet there is little in the form of seismic detection, protection, resistance or design for some of the newest and tallest structures in the world. The paper highlights the importance of the strategic mitigation planning for disaster resilience within the Emirati Energy sector. It discusses the issue of disaster globally and then specifically with regards to the UAE, forming a critical analysis on crisis and its management. A broad literature review of the problems readily associated within the discourse is undertaken so that the definition, classification and the application of the disaster and its management cycle are appropriately contextualised in regards to the Emirati problem. The window of opportunity that the UAE has for improvement is emphasised by the findings of this paper

Vulnerability of the Emirati Energy Sector for Disaster: A Critical Review

Infrastructure in all its forms is a valuable asset and vulnerable to any natural or manmade hazard. The protection of infrastructure is thus one of the most important and difficult tasks for any government. The energy sector dominates in the UAE and consists of various assets - electricity, oil and natural gas that are geographically dispersed and connected by systems and networks. The protection of these systems and assets and within the energy sector especially, the safeguarding of oil and gas infrastructure from any and all internal and external threats should become top priority in the UAE. Threats to geopolitical and economic stability that need to be considered and prepared for include tectonic activity, climate change, nuclear energy, terrorism and war. This paper explores the disaster vulnerability of the Emirati energy sector with specific focus on Abu Dhabi and Dubai cities. It is based on secondary data, taken from various academic and professional sources, and primary data from a questionnaire survey administered on site at two electricity-generating plants in Abu Dhabi and Dubai. Forty questionnaires were distributed and 35 were returned back- 20 Abu Dhabi and 15 Dubai. Oil and gas sectors were identified as the most vulnerable energy sources in both Abu-Dhabi and Dubai. Risk from terrorism was thought to be the greatest hazard with every single respondent choosing it. This was despite the fact that respondents believe it to be one of the threats that the energy sector is prepared for

Assessment of recycled concrete aggregates for road base and sub-base

Population increase and economic developments can lead to construction as well as demolition of infrastructures such as buildings, bridges, roads, etc and used concrete is the main waste product of them. Recycling of waste concrete to obtain the recycled concrete aggregates (RCA) for base and/or sub-base materials in road construction is a foremost application to be promoted to gain economical and sustainable benefits. As the mortar, bricks, glass and asphalt present in different constituents in RCA, it exhibits inconsistent properties and performance. In this study, six different types of RCA samples were subjected classification tests such as particle size distribution, plasticity, compaction test and California Bearing Ratio (CBR). Results were compared with those of the standard road materials used in Queensland, Australia and found that ‘RM1-100/RM3-0’ and ‘RM1-80/RM3-20’ samples are sitting in the margin of the minimum required specifications of base materials while others are lower than that

Risk Assessment on Community-Based Post-Disaster Housing Reconstruction Project

Risk management method has been acknowledged to be an important factor to achieve the project objectives in the construction industry. However, its implementation on community-based post-disaster housing reconstruction is hardly found. Accordingly, the objective of this paper is to assess high risk events that affect time completion of community-based post-disaster housing reconstruction project (CPHRP). Three most recent and most severe areas affected by earthquake and tsunami in Indonesia were chosen as case study locations: Aceh (2004), Yogyakarta (2006) and West Sumatra (2009). Questionnaire survey was selected as data collection method and emailed to respondents to assess the probability of occurrence of particular event and its impact on time completion. The response rate was considered as very satisfactory (79%) with sixty five questionnaires were categorized as valid. Result shows that twenty events can be categorised as high risk and are mostly originated from government