The operational and safety effects of heavy duty vehicles platooning

Abstract Although researchers have studied the effects of platooning, most of the work done so far has focused on fuel consumption. There are a few studies that have targeted the impact of platooning on the highway operations and safety. This thesis focuses on the impact of heavy-duty vehicles (HDVs) platooning on highway characteristics. Specifically, this study aims at evaluating the effects of platooning of HDVs on capacity, safety, and CO2 emissions. This study is based on a hypothetical model that was created using the VISSIM software. VISSIM is a powerful simulation software designed to mimic the field traffic flow conditions. For model validity, the model outputs were compared with recommended values from guidelines such as the Highway Capacity Manual (HCM) (Transportation Research Board, 2016). VISSIM was used to obtain the simulation results regarding capacity. However, in addition to VISSIM, two other software packages were used to obtain outputs that cannot be assessed in VISSIM. MOVES and SSAM are two simulation software packages that were used for emission and safety metrics, respectively. Both software packages depended on input from VISSIM for analysis. It was found that with the presence of HDVs in the model, the capacity, the emission of CO2, and the safety of the roadway would improve positively. A capacity of 4200 PCE/h/ln could be achieved when there are enough HDVs in platoons. Furthermore, more than 3% of the traffic flow emission of CO2 reduction is possible when 100% of the HDVs used in the model are in platoons. In addition to that, a reduction of more than 75% of the total number of conflicts might be obtained. Furthermore, with the analysis of the full factorial method and the Design of Experiment (DOE) conducted by using Excel and Minitab respectively, it was possible to investigate the impact of the platoons’ factors on the highway parameters. Most of these factors affect the parameters significantly. However, the change in the desired speed was found to insignificantly affect the highway parameters, due to the high penetration rate. Keywords: VISSIM, MOVES, SSAM, COM-interface, HDVs, Platooning, Number of Conflict

Four essays on return behaviour and market microstructures: Evidence from the Saudi stock market

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.This dissertation is divided into an introductory chapter and four essays. Chapter one discusses the importance of the study and describes the development and growth of the market as well. The first part (Chapters 2 & 3) examines stock returns behaviour and trading activity around earnings announcements. The second part (Chapters 4 & 5) examines price impact asymmetry and the price effects of block trades in the market microstructure context. Each essay addresses some aspects of market microstructure and stock returns behaviour in order to aid researchers, investors and regulators to understand a market which lacks research coverage. The research provides empirical evidence on issues such as the efficiency of the market, information asymmetry, liquidity and price impact of block trades. In first part of the thesis, event study and regression analysis were used to measure the price reaction around earnings announcements and to examine trading activity, information asymmetry and liquidity. In second part the determinants of the price impact of block trades were examined with regard to trade size, market condition and time of the day effects using transaction data. Liquidity and information asymmetry issues of block trades were also studied in this part

The Impact of Government Debt on Macroeconomic Indicators: Evidence from G7 and ASEAN Countries

Government debt continues to be a critical economic policy issue, which largely affects both developed and developing countries, due to elevated level of debt. From a general viewpoint, government debt is a crucial feature of a country\u27s financial system and a major indicator that contributes to the formation of a country\u27s reputation in the international market. This paper investigates the impact of government debt on certain macroeconomic and wellbeing indicators in a group of industrialized and developing countries. That is, the study seeks to examine how government debt influences GDP per capita, domestic and foreign investment, and HDI in both G7 and ASEAN nations during the period from 1995 to 2015. While the results indicate that there is a positive relationship between government debt and macroeconomic indicators in G7 countries, the government debt of ASEAN countries has a negative impact on macroeconomic and wellbeing indicators. Some presumed causes of the different impact of the debt on G7 vs ASEAN economies is allocation effect , threshold effect , and institutional quality effect

The Impact of Power Distance and Gender on the Choice of Disagreement Strategies in Saudi Colloquial Arabic

The purpose of this study was to examine the potential impact of power distance and gender on the choice of disagreement strategies by speakers of Saudi colloquial Arabic (henceforth “SCA”) in same- and cross-gender interactions. A Discourse Completion Test (DCT) consisting of three situations reflecting the three different combinations of power status (high-low, low-high, and equal) was used to collect the data. To have a comprehensive account of the impact of gender, four groups of participants (Male®Male, Male®Female, Female®Female and Female®Male) were included. Each group consisted of 40 participants. The collected data were compared and analyzed using Maíz-Arévalo’s (2014) taxonomy of disagreement strategies. The data analysis revealed two patterns; firstly, when there was no power distance between interlocuters or when the speaker expressing disagreement had a higher power position than the addressee, gender appeared to have an impact on the choice of disagreement strategies by the speakers of SCA. When disagreeing with the same gender, both male and female speakers of SCA tended to use strong disagreement strategies but mitigated disagreement strategies when disagreeing with the other gender; and secondly, when the speaker expressing disagreement had a lower power position than the addressee, the gender of either the speaker or the addressee did not seem to have an impact on the choice of disagreement strategies. In this pattern, power appeared to be the decisive factor which both male and female speakers of SCA tended to use in mitigated disagreement strategies regardless of the gender of the addressee

Proactive detection of DDOS attacks in Publish-Subscribe networks

Information centric networking (ICN) using architectures such as Publish-Subscribe Internet Routing Paradigm (PSIRP) or Publish-Subscribe Internet Technology (PURSUIT) has been proposed as an important candidate for the Internet of the future. ICN is an emerging research area that proposes a transformation of the current host centric Internet architecture into an architecture where information items are of primary importance. This change allows network functions such as routing and locating to be optimized based on the information items themselves. The Bloom filter based content delivery is a source routing scheme that is used in the PSIRP/PURSUIT architectures. Although this mechanism solves many issues of today’s Internet such as the growth of the routing table and the scalability problems, it is vulnerable to distributed denial-of-service (DDoS) attacks. In this paper, we present a new content delivery scheme that has the advantages of Bloom filter based approach while at the same time being able to prevent DDoS attacks on the forwarding mechanism. Our security analysis suggests that with the proposed approach, the forwarding plane is able to resist attacks such as DDoS with very high probabilit

Culture in the design of mHealth UI:An effort to increase acceptance among culturally specific groups

Purpose: Designers of mobile applications have long understood the importance of users’ preferences in making the user experience easier, convenient and therefore valuable. The cultural aspects of groups of users are among the key features of users’ design preferences, because each group’s preferences depend on various features that are culturally compatible. The process of integrating culture into the design of a system has always been an important ingredient for effective and interactive human computer interface. This study aims to investigate the design of a mobile health (mHealth) application user interface (UI) based on Arabic culture. It was argued that integrating certain cultural values of specific groups of users into the design of UI would increase their acceptance of the technology. Design/methodology/approach: A total of 135 users responded to an online survey about their acceptance of a culturally designed mHealth. Findings: The findings showed that culturally based language, colours, layout and images had a significant relationship with users’ behavioural intention to use the culturally based mHealth UI. Research limitations/implications: First, the sample and the data collected of this study were restricted to Arab users and Arab culture; therefore, the results cannot be generalized to other cultures and users. Second, the adapted unified theory of acceptance and use of technology model was used in this study instead of the new version, which may expose new perceptions. Third, the cultural aspects of UI design in this study were limited to the images, colours, language and layout. Practical implications: It encourages UI designers to implement the relevant cultural aspects while developing mobile applications. Originality/value: Embedding Arab cultural aspects in designing UI for mobile applications to satisfy Arab users and enhance their acceptance toward using mobile applications, which will reflect positively on their lives.</p

An Enhanced Source Location Privacy based on Data Dissemination in Wireless Sensor Networks (DeLP)

open access articleWireless Sensor Network is a network of large number of nodes with limited power and computational capabilities. It has the potential of event monitoring in unattended locations where there is a chance of unauthorized access. The work that is presented here identifies and addresses the problem of eavesdropping in the exposed environment of the sensor network, which makes it easy for the adversary to trace the packets to find the originator source node, hence compromising the contextual privacy. Our scheme provides an enhanced three-level security system for source location privacy. The base station is at the center of square grid of four quadrants and it is surrounded by a ring of flooding nodes, which act as a first step in confusing the adversary. The fake node is deployed in the opposite quadrant of actual source and start reporting base station. The selection of phantom node using our algorithm in another quadrant provides the third level of confusion. The results show that Dissemination in Wireless Sensor Networks (DeLP) has reduced the energy utilization by 50% percent, increased the safety period by 26%, while providing a six times more packet delivery ratio along with a further 15% decrease in the packet delivery delay as compared to the tree-based scheme. It also provides 334% more safety period than the phantom routing, while it lags behind in other parameters due to the simplicity of phantom scheme. This work illustrates the privacy protection of the source node and the designed procedure may be useful in designing more robust algorithms for location privac