41 research outputs found
Increasing the Semantic Similarity of Object-Oriented Domain Models by Performing Behavioral Analysis First
The main goal of any object-oriented analysis (OOA) method is to produce a model that aids in understanding and communicating knowledge about a modeled domain. A higher degree of similarity among independently produced domain models provides an indication of how well the domain was understood by the different analysts, i. e. , more similar models indicate a closer and a more common understanding of a domain. A common understanding is of critical importance for effective knowledge communication and sharing. The core of any OOA method is discovering and understanding concepts and their relationships in a domain. The main artifact produced by an OOA method is a domain model of the domain. A domain model often serves as the main source of design concepts during objectoriented design (OOD). This thesis evaluates two OOA methods by comparing the degree of similarity of the resulting domain models. In particular, this work compares the semantic similarity of domain models extracted from use cases by specification of sequence diagrams and then domain models, and
specification of unified use case statecharts and then domain models.
The thesis makes case studies out of the application of the first method to 31 instances of large Voice-over-IP (VoIP) system and its information management system (IMS) and to 3 small elevator systems, and out of the application of the second method to 46 instances of the same large VoIP system and its IMS and to 12 instances of a medium-sized elevator system. From an analysis of data from these case studies, the thesis concludes that there is an increase of 10% in the semantic similarity of domain models produced using the second method, but at the cost of less than or equal to 25% more analysis time
Time to Bribe: Measuring Block Construction Market
With the emergence of Miner Extractable Value (MEV), block construction
markets on blockchains have evolved into a competitive arena. Following
Ethereum's transition from Proof of Work (PoW) to Proof of Stake (PoS), the
Proposer Builder Separation (PBS) mechanism has emerged as the dominant force
in the Ethereum block construction market.
This paper presents an in-depth longitudinal study of the Ethereum block
construction market, spanning from the introduction of PoS and PBS in September
2022 to May 2023. We analyze the market shares of builders and relays, their
temporal changes, and the financial dynamics within the PBS system, including
payments among builders and block proposers -- commonly referred to as bribes.
We introduce an MEV-time law quantifying the expected MEV revenue wrt. the time
elapsed since the last proposed block. We provide empirical evidence that
moments of crisis (e.g. the FTX collapse, USDC stablecoin de-peg) coincide with
significant spikes in MEV payments compared to the baseline.
Despite the intention of the PBS architecture to enhance decentralization by
separating actor roles, it remains unclear whether its design is optimal.
Implicit trust assumptions and conflicts of interest may benefit particular
parties and foster the need for vertical integration. MEV-Boost was explicitly
designed to foster decentralization, causing the side effect of enabling
risk-free sandwich extraction from unsuspecting users, potentially raising
concerns for regulators
Security for Complex Cyber-Physical and Industrial Control Systems: Current Trends, Limitations, and Challenges
Today’s society relies upon the smooth and secure functioning of the mission-critical infrastructures and their services. Much of this critical infrastructure relies on the complex cyber-physical systems and the industrial control systems. In recent years, securing these two types of systems has been a top priority due to a significant increase in number of attacks. Most of these systems are often several decades old, and they were developed without significant consideration of the security requirements. As such, there is an urgent need to protect these cyber-physical and industrial systems from external vulnerabilities. In this paper, we present a survey of the cyber-physical and industrial control systems, and explore the possibility and necessity for security of such systems. We discuss the various types of cyber-physical and industrial control systems currently being used, assess the vulnerabilities of such systems, discuss the literature on the cyber-physical and industrial control systems, and examine some works that propose security standards and models for these types of systems
City.Net IES: A sustainability-oriented energy decision support system
A city's energy system processes, as well as the interactions of the energy system with other systems in a city are imperative in creating a comprehensive energy decision support system due to the interdependencies between critical segments of the system. City.Net is a sustainability-oriented decision support system that represents the energy, water, waste, transportation and building systems in a city while taking into consideration the integration and interdependencies that exist between these systems. This paper, which is focused on the integrated energy infrastructure system of a sustainable city, builds on the previous work which employs hierarchical decomposition and multi-domain formulation for the design of complex sustainable systems. The City.Net energy system encompasses the generation, transmission, distribution and consumption of energy in different forms, in several domains and at diverse scales in a city. Also, the interactions of the energy system with other aforementioned systems are incorporated in City.Net. The result is a scalable and flexible energy decision support system which can be simulated and used as a sustainability-analysis tool, encompassing environmental, social and economic sustainability
Time to Bribe: Measuring Block Construction Market
With the emergence of Miner Extractable Value (MEV), block construction markets on blockchains have evolved into a competitive arena. Following Ethereum\u27s transition from Proof of Work (PoW) to Proof of Stake (PoS), the Proposer Builder Separation (PBS) mechanism has emerged as the dominant force in the Ethereum block construction market.
This paper presents an in-depth longitudinal study of the Ethereum block construction market, spanning from the introduction of PoS and PBS in September 2022 to May 2023. We analyze the market shares of builders and relays, their temporal changes, and the financial dynamics within the PBS system, including payments among builders and block proposers---commonly referred to as bribes. We introduce an MEV-time law quantifying the expected MEV revenue wrt. the time elapsed since the last proposed block. We provide empirical evidence that moments of crisis (e.g. the FTX collapse, USDC stablecoin de-peg) coincide with significant spikes in MEV payments compared to the baseline.
Despite the intention of the PBS architecture to enhance decentralization by separating actor roles, it remains unclear whether its design is optimal. Implicit trust assumptions and conflicts of interest may benefit particular parties and foster the need for vertical integration. MEV-Boost was explicitly designed to foster decentralization, causing the side effect of enabling risk-free sandwich extraction from unsuspecting users, potentially raising concerns for regulators
Agile architecture recovery
any required final revisions, as accepted by my examiners. I understand that my thesis may be made electronically available to the public. ii Many software development projects start with an existing code base that has to be tightly inte-grated into a new system. In order to make a robust system that will achieve the desired business goals, developers must be able to understand the architecture of the old code base and its ratio-nale. This thesis presents a lightweight approach for the recovery of software architecture. The main goal of the approach is to provide an efficient way for architecture recovery that works on small to mid-sized software systems, and gives a useful starting point on large ones. The emphasis of the process is on the use of well established development techniques and tools, in order to minimize adoption costs and maximize the return on investment. iii For my mom, dad, and siste
AUTHOR’S DECLARATION FOR ELECTRONIC SUBMISSION OF A THE-
I hereby declare that I am the sole author of this thesis. This is a true copy of the thesis, including any required final revisions, as accepted by my examiners. I understand that my thesis may be made electronically available to the public. ii The main goal of any object-oriented analysis (OOA) method is to produce a model that aids in understanding and communicating knowledge about a modeled domain. A higher degree of similarity among independently produced domain models provides an indication of how well the domain was understood by the different analysts, i.e., more similar models indicate a closer and a more common understanding of a domain. A common understanding is of critical importance for effective knowledge communication and sharing. The core of any OOA method is discovering and understanding concepts and their relationships in a domain. The main artifact produced by an OOA method is a domain model of the domain. A domain model often serves as the main sourc