This study proposed a novel external replaceable energy-dissipating device (EREDD) to enhance the seismic performance of prefabricated segmental concrete filled steel tubular bridge piers (PS-CFST bridge piers), while maintaining the construction efficiency of conventional segmentally assembled prefabricated piers with dry joints. The effectiveness and applicability of EREDDs in improving the seismic performance of PS-CFST bridge piers were studied through the cyclic tests. The inelastic cyclic response of PS-CFST bridge pier specimens with different arrangements of EREDDs was experimentally examined. A detailed account of the test results was provided and discussed, including the stiffness and strength characteristics, strain distributions, residual displacements, failure patterns, as well as hysteretic response and energy dissipation capability. Particular attention was also given within the experimental assessment to investigating the effects of the inter-segmental joint opening positions for the different EREDD arrangements on the seismic response of PS-CFST bridge piers. Based on the experimental findings, an analytical approach was developed for determining the hysteretic response of the proposed PS-CFST bridge piers incorporating EREDDs, offering the basis for their design and assessment in practice. Finally, the results indicate that EREDDs could effectively improve the seismic performance of PS-CFST bridge piers and the hysteretic response could be accurately predicted by using the proposed analytical approach. In addition, EREDDs allow the damage of PS-CFST bridge piers to be concentrated within the easily replaceable component, and thereby facilitating the controlled damage. This study provides an effective method for the seismic design of PS-CFST bridge piers incorporating EREDDs.
In general, there are various recommendations for fatigue S-N curves of welded structures for design and evaluation. Most fatigue guidelines for welded structures depend on the joint type, loading mode, plate thickness, post-weld treatment, material, etc. Also, fatigue assessments of welded structures traditionally assume a high tensile residual stress level near the vulnerable weldment location. However, the level of residual stress in weldments is not always high in tension. Therefore, it is easy to be overly conservative in fatigue design and evaluation. This study proposed a pragmatic unified fatigue design and evaluation procedure incorporating the residual stress effect for welded steel structures, considering weld toe failure. The modified fatigue parameter was generated combined with the equivalent structural stress range parameter and the master S-N curve adopted by ASME BPVC VIII-2 (2007) and API 579-1/ASME FFS-1 (2007), and the residual stress effect expressed as an effective stress ratio using the fatigue strength concept. The proposed unified procedure was validated using existing fatigue test results with various residual stress levels, such as as-welded (high tensile), stress-relieved (low tensile), prestressed (compressive), and high-frequency mechanical impact treated (compressive). Therefore, the unified fatigue design and evaluation procedure for welded structures, which considers the effect of loading and residual stress level, can be effectively applied for welded steel structures using the master S-N curve by replacing the equivalent structural stress range with the modified equivalent structural stress range on the ordinate axis.
Indonesia’s accelerating digital transformation, driven by programs such as Digital ID and INA Digital, has introduced both significant opportunities and complex governance challenges as Artificial Intelligence (AI) becomes integrated into public-sector decision-making. This conceptual paper proposes a strategic governance framework for ethical AI that aligns international standards such as the OECD AI Principles, the EU AI Act, and the NIST AI Risk Management Framework with Indonesia’s institutional and regulatory environment. The study contributes to the literature by articulating a policy-oriented model operationalizing ethics, transparency, and accountability within the national digital ecosystem. It further demonstrates how anticipatory governance, multistakeholder collaboration, and adaptive regulation can be embedded through ongoing programs led by the Ministry of Communication and Digital (Komdigi), BSSN, and BRIN. By linking global frameworks with local implementation pathways, this research provides conceptual advancement and policy relevance for emerging economies seeking to institutionalize trustworthy AI governance.
This study proposed fatigue failure criteria and investigated its effectiveness to both single-sided and double-sided gusset joints through three different fatigue assessment methods: the first one is the nominal stress method; the second method is the hot spot stress method, which requires stress calculation using FEA; and the third method is the master S-N curve using the equilibrium-based structural stress method adopted by ASME BPVC VIII-2 and API 579-1/ASME FFS-1, which requires structural stress calculation using FEA. The failure criteria for welded in plane gusset joints were investigated based on loading and geometry conditions. When the proposed failure criteria were investigated using the equilibrium-based structural stress method, all fatigue data sets were consolidated within the master S-N curve, and the design S-N curve was appropriately conservative. However, nominal and/or hot spot stress-based approaches showed inconsistent trends compared to the fatigue data sets. Some applications can use rigorous failure criteria, such as finite crack sizes, rather than complete failures. The modified equilibrium-based structural stress procedure was proposedfor partial failure cases to consider the rigorous failure criteria. Once the modified procedure was applied, the partial failure data sets were mingled with the complete failure data sets. Therefore, the design S-N curve shows excellent conservatism regardless of complete or partial failures. This study shows that when the failure criteria for welded in-plane gussets were applied, the master S-N curve approach using the equilibrium-based structural stress method exhibited excellent data collapse and proper conservatism regardless of the geometry conditions andfailure criteria.
Despite the existence of the EU Common Agricultural Policy (CAP), the incomes of primary food producers in many EU countries, including Slovakia, remain below the levels of other sectors in the national economy. The bio-based economy, which relies on natural materials and resources, is gaining increasing support across Europe. It is opening new opportunities to boost the incomes of agricultural primary producers, enhance their competitiveness, and reduce production surpluses. Currently, most biorefineries use first- and second-generation technologies to produce biofuels and chemicals from crops such as corn, wheat, sugar beet, and sugar cane, as well as from microorganisms derived from plant and animal waste. The production of biofuels, biochemicals, and biopharmaceuticals from agricultural biomass varies across EU countries. Since a thriving bioeconomy depends on productive farmers, this article aims to highlight the environmental and economic efficiency of biological raw materials and their role in diversifying farm incomes, using Slovakia’s agricultural sector as a case study.
