No abstract

Existing traffic control systems are mostly deployed in private wired networks. With the development of wireless technology, vehicles and infrastructure devices will be connected through wireless communications, which might open a new door for cyberattackers. It is still not clear what types of cyberattacks can be performed through infrastructure-to-infrastructure and vehicle-to-infrastructure communications, whether such attacks can introduce critical failure to the system, and what the impacts are of cyberattacks on traffic operations. This paper investigates the vulnerability of traffic control systems in a connected environment. Four typical elements, including signal controllers, vehicle detectors, roadside units, and onboard units, are identified as the attack surfaces. The paper mainly focuses on attacking actuated and adaptive signal control systems by sending falsified data, which is considered as an indirect but realistic attack approach. The objective of an attacker is to maximize system delay with constraints such as budget and attack intensity. Empirical results show that different attack scenarios result in significant differences in delay, and some ineffective attacks may even improve the system performance. Simulation results from a real-world corridor show that critical intersections, which have a higher impact on network performance, can be identified by analyzing the attack locations. Identification of such intersections can be helpful in designing a more resilient transportation network.

Graphical documentation is often characterized as an effective aid in program understanding. However, it is an open question exactly which types of graphical documentation are most suitable for which types of program understanding tasks (and in which specific usage contexts). The Unified Modeling Language (UML) is the de facto standard for modeling modern software applications. This paper describes an experiment to assess the qualitative efficacy of UML diagrams in aiding program understanding. The experiment had participants analyze a series of UML diagrams and answer a detailed questionnaire concerning a hypothetical software system. Results from the experiment suggest that the UML's efficacy in support of program understanding is limited by factors such as ill-defined syntax and semantics, spatial layout, and domain knowledge.

Graphical documentation is often characterized as an effective aid in program understanding. However, it is an open question exactly which types of graphical documentation are most suitable for which types of program understanding tasks (and in which specific usage contexts). The Unified Modeling Language (UML) is the de facto standard for modeling modern software applications. This paper describes an experiment to assess the qualitative efficacy of UML diagrams in aiding program understanding. The experiment had participants analyze a series of UML diagrams and answer a detailed questionnaire concerning a hypothetical software system. Results from the experiment suggest that the UML's efficacy in support of program understanding is limited by factors such as ill-defined syntax and semantics, spatial layout, and domain knowledge.

A significant barrier to the use of Web services is the problem of testing them. One of the solutions to deal with the problem lies in the ability to simulate the usage of the services. Requests must be generated and responses must be validated automatically in a fast and reliable manner. To accomplish this goal, we have developed a tool called WSDLTest. WSDLTest is part of a larger complex tool set -DataTest -for generating and validating system test data. The architecture and functionality of this tool, as well as the experience gained from using it, are presented.