BINALIGNER: Aligning Binary Code for Cross-Compilation Environment Diffing

Binary diffing aims to align portions of control flow graphs corresponding to the same source code snippets between two binaries for software security analyses, such as vulnerability and plagiarism detection tasks. Previous works have limited effectiveness and inflexible support for cross-compilation environment scenarios. The main reason is that they perform matching based on the similarity comparison of basic blocks. In our work, we propose a novel diffing approach BINALIGNER to alleviate the above limitations at the binary level. To reduce the likelihood of false and missed matches corresponding to the same source code snippets, we present conditional relaxation strategies to find candidate subgraph pairs. To support a more flexible binary diffing in cross-compilation environment scenarios, we use instruction-independent basic block features for subgraph embedding generation. We implement BINALIGNER and conduct experiments across four cross-compilation environment scenarios (i.e., cross-version, cross-compiler, cross-optimization level, and cross-architecture) to evaluate its effectiveness and support ability for different scenarios. Experimental results show that BINALIGNER significantly outperforms the state-of-the-art methods in most scenarios. Especially in the cross-architecture scenario and multiple combinations of cross-compilation environment scenarios, BINALIGNER exhibits F1-scores that are on average 65% higher than the baselines. Two case studies using real-world vulnerabilities and patches further demonstrate the utility of BINALIGNER

Coupled analysis and performance evaluation of a semi-submersible floating wind turbine with active ballasting system

Semi-submersible floating offshore wind turbines (FOWTs) are susceptible to platform inclination induced by wind thrust, which amplifies motion responses, reduces power generation efficiency, and compromises structural safety. To mitigate these challenges, an active ballasting system (ABS) can be introduced to dynamically redistribute the ballast water within the platform. A fully coupled aero-hydro-servo-elastic model is developed in SESAM, where the effects of ballast water movement are represented by applying external moments to the platform. Real-time interaction between the floating structure and the active ballasting program is established via TCP communication. The program, implemented in Python, employs a PID control algorithm based on platform pitch and roll angles, while incorporating pump flow constraints. The IEA 15 MW floating wind turbine is selected as the reference model. The coupled model is validated by comparing the motion responses of the FOWT without active ballasting against published benchmarks. Additionally, computational fluid dynamics (CFD) simulations are carried out to investigate the hydrodynamic behavior of the FOWT under both upright and inclined conditions. The active ballasting system is then applied in time-domain simulations under a range of environmental conditions. Simulation results demonstrate that the average inclination is reduced to near-zero, while the mean power output is improved under identical operating scenarios

The Four Faces of Ethiopian Federalism

Ethiopian federalism has been considered ethnic federalism both in domestic scholarly and policy discussions and internationally in comparative federalism studies. I argue that Ethiopian federalism is so much more than ‘ethnic federalism’ and even more than federalism itself. Ethiopian federalism has four faces, which are unitary, federal, confederal, and ethnocratic. While its unitary feature defers the federal promises, its confederal aspect overshadows the federal spirit. Similarly, its ethnocratic institutional arrangement not only creates ‘citizens’ and ‘subjects’, but also displaces the national project of creating a federal democracy to the periphery. By taking the Ethiopian constitution and the political theory that underpins it seriously, this article demonstrates how the four faces of Ethiopian federalism have made the practice of constitutional democracy difficult in the past and how they could presumably make it more arduous in the future

Developing sustainable engineered cementitious composites with carbonated recycled concrete fines: Feasibility and engineering properties

Using carbonated recycled concrete fines (CRCF) as supplementary cementitious material is an effective way to develop sustainable engineered cementitious composites (ECC). This study systematically explored the effects of CRCF with a substitution rate up to 30 % through mechanical property tests, micromechanical analysis and microstructural characterisation, aiming to elucidate the mechanism of CRCF on ECC. Results suggest that the incorporation of CRCF reduces the mechanical properties of ECC, but a moderate amount (15 %) of CRCF-ECC still performs more than 85 % and 90 % of the tensile and compressive strengths of the reference ECC. Also, the tensile strain capacity of 15CR is increased by approximately 20 %, significantly enhancing the tensile toughness of ECC. The Jʹ b and Jtip of 15CR are approximately 10 % and 6 % higher than those of 15R, respectively. This indicates that the 15CR mixture exhibits superior Griffith crack propagation capability after the initiation of the first crack, which is also recognised as flat crack propagation capability. The incorporation of CRCF significantly improves the average pore size of ECC, mainly attributed to more calcium carbonate on the surface of CRCF, resulting in strengthening of bonding interactions with C-S-H during hydration. This results in stronger fibrematrix bonding and denser microstructure in the microscopic reaction, and in turn enhances the internal structural compactness and strengthens the mechanical properties. The effects and micro-mechanisms of CRCF on the mechanical properties of ECC were comprehensively evaluated and revealed