Mehran Alidoost Nia

Amirhosein Sadr, Mehran Alidoost Nia

Compiler phase ordering has a strong effect on program performance. Finding an effective sequence of passes is still a difficult task because the search space is large and execution time, code size and energy consumption often conflict. Existing methods usually depend on fixed optimization levels or limited heuristics and they rarely handle multiple objectives at the same time. This paper presents MileStone, a modular framework that models compiler phase ordering as a multi-objective optimization problem. MileStone represents programs as graphs, predicts performance metrics with a graph neural network and explores pass sequences with a reinforcement-learning agent that follows user constraints. The framework also builds a self-evolving database that collects compiler transformations and improves prediction quality. Experiments on standard benchmarks show that MileStone finds strong Pareto-optimal solutions, meets energy limits more accurately than LLVM optimization levels and other related techniques. MileStone reduces execution time by up to 45 percent under the same energy budget using a multi-objective approach. The results show that MileStone provides an effective and scalable solution for multi-objective compiler phase ordering.

Melika Dastranj, Mehran Alidoost Nia, Mehdi Kargahi

The autonomous systems need to decide how to react to the changes at runtime efficiently. The ability to rigorously analyze the environment and the system together is theoretically possible by the model-driven approaches; however, the model size and timing limitations are two significant obstacles against such an autonomous decision-making process. To tackle this issue, the incremental approximation technique can be used to partition the model and only verify a partition if it is affected by the change. This paper proposes a policy-based analysis approach that finds the best partitioning policy among a set of available policies based on two proposed metrics, namely Balancing and Variation. The metrics quantitatively evaluate the generated components from the incremental approximation scheme according to their size and frequency. We investigate the validity of the approach both theoretically and experimentally via a case study on energy harvesting systems. The results confirm the effectiveness of the proposed approach.

Mehran Alidoost Nia, Eduard Babulak, Benjamin Fabian et al.

Anonymous communication systems (ACS) offer privacy and anonymity through the Internet. They are mostly free tools and are popular among users all over the world. In the recent years, anonymity applications faced many problems regarding traffic engineering methods. Even though they ensure privacy under some conditions, their anonymity will be endangered by high performance processing units. To address these issues, this study is devoted to investigating traffic-engineering methods in anonymous communication systems, and proposes an analytical view of the current issues in ACS privacy and anonymity. Our study also indicates new types of solutions for these current issues with ACS.

Mehran Alidoost Nia, Ali Sajedi, Aryo Jamshidpey

Today, all types of digital signature schemes emphasis on secure and best verification methods. Different digital signature schemes are used in order for the websites, security organizations, banks and so on to verify user's validity. Digital signature schemes are categorized to several types such as proxy, on-time, batch and so on. In this paper, different types of schemes are compared based on security level, efficiency, difficulty of algorithm and so on. Results show that best scheme depends on security, complexity and other important parameters. We tried simply to define the schemes and review them in practice.

Mehran Alidoost Nia, Aida Ghorbani, Reza Ebrahimi Atani

Anonymous cloud architecture provides secure environment for business and also e-commerce approaches. By using this type of architecture, we can propose anonymous online applications. Customers who need secure and reliable online services should pay for provided services. A big problem is electronic payment that is needed for billing customers. But customer identity should be remained anonymous during and also after payment procedure. In this paper we propose a novel and modified anonymous architecture that ensures customers that hide their identity from others. This architecture is used from common network protocols and we eliminate Tor anonymous service from architecture design space because of independency. The here is introduced scalability parameter in anonymous cloud architecture design space. After all we compare proposed architecture with other popular cloud architectures in this range and we obtain its advantages according to efficiency, security and anonymity.