Evidence-enabled verification for the Linux kernel

Formal verification of large software has been an elusive target, riddled with problems of low accuracy and high computational complexity. With growing dependence on software in embedded and cyber-physical systems where vulnerabilities and malware can lead to disasters, an efficient and accurate verification has become a crucial need. The verification should be rigorous, computationally efficient, and automated enough to keep the human effort within reasonable limits, but it does not have to be completely automated. The automation should actually enable and simplify human cross-checking which is especially important when the stakes are high. Unfortunately, formal verification methods work mostly as automated black boxes with very little support for cross-checking. This thesis is about a different way to approach the software verification problem. It is about creating a powerful fusion of automation and human intelligence by incorporating algorithmic innovations to address the major challenges to advance the state of the art for accurate and scalable software verification where complete automation has remained intractable. The key is a mathematically rigorous notion of verification-critical evidence that the machine abstracts from software to empower human to reason with. The algorithmic innovation is to discover the patterns the developers have applied to manage complexity and leverage them. A pattern-based verification is crucial because the problem is intractable otherwise. We call the overall approach Evidence-Enabled Verification (EEV). This thesis presents the EEV with two challenging applications: (1) EEV for Lock/Unlock Pairing to verify the correct pairing of mutex lock and spin lock with their corresponding unlocks on all feasible execution paths, and (2) EEV for Allocation/Deallocation Pairing to verify the correct pairing of memory allocation with its corresponding deallocations on all feasible execution paths. We applied the EEV approach to verify recent versions of the Linux kernel. The results include a comparison with the state-of-the-art Linux Driver Verification (LDV) tool, effectiveness of the proposed visual models as verification-critical evidence, representative examples of verification, the discovered bugs, and limitations of the proposed approach

The Changes in the urban roles of the public spaces and its impact on the future plans of Great cities centers

The Great cities center all over the world have common features in its structure, Such as The Historic district that represent the oldest part of the city, the Central Business district "CBD", the Main of public transportation networks, and many other urban components. Those mentioned urban components including Public spaces, such as the Central Parks, Main squares and pedestrians Plazas which represent the Social Activities of a great city center do not exist as the same as in the rest of the city. at the same time they have urban roles within the urban structure of the great cities center. Not only the traditional Urban role but also the new roles that appaiers according to the global changes (political, social, economical, environmental issues) in the 21 century . This paper aims to determine the new urban roles of the public spaces in the great cities center and its impact on future plans, to be applied in the developing plans. Not only on Cairo city center but also on the other world's Great cities.Our Methedology based on analyzing the structure of the Greater Cairo city center, focusing on the distributing, classification of the Public spaces and its urban characteristics. And Using the SWOT analysis to evaluate the existing Public spaces in the Greater Cairo center and its urban performance related to the new social activities.The study found that there are many urban problems about the Public spaces in Cairo city center affect its performance.Cairo center suffers from shortage of the Public spaces, considering that most of its squares designed as automobiles squares, such as the famous square of "El-Tahrir". KEY WORDS: Urban roles, Public spaces, Great Cities, Future plans

Optimizing Ozone Processing Technology for Farm-Fresh, Salmonella-Free Shell Eggs

Author Institution: Department of Food Science and Technology, The Ohio State Universit