Collapse simulation of a typical super-tall RC frame-core tube building exposed to extreme fire

The previous fire accidents proofed that reinforced concrete (RC) structures may experience progressive collapse subjected to extreme fires. In consequence, the study on the extreme fire-induced progressive collapse of RC structures is important for the safety of buildings. However, limited study has been performed on the extreme fire-induced progressive collapse of super-tall buildings. In this work, a finite element (FE) model and the corresponding elemental deactivation technology is proposed to simulate the extreme fire-induced progressive collapse of a typical super-tall RC frame-core tube building. The simulation discovered that the collapse of the building is initiated by the flexural failure of perimeter columns because of the thermal expansion of the floor system. The mechanism that discovered can provide a reference for related research of the fire safety of RC buildings

LLM-FuncMapper: Function Identification for Interpreting Complex Clauses in Building Codes via LLM

As a vital stage of automated rule checking (ARC), rule interpretation of regulatory texts requires considerable effort. However, interpreting regulatory clauses with implicit properties or complex computational logic is still challenging due to the lack of domain knowledge and limited expressibility of conventional logic representations. Thus, LLM-FuncMapper, an approach to identifying predefined functions needed to interpret various regulatory clauses based on the large language model (LLM), is proposed. First, by systematically analysis of building codes, a series of atomic functions are defined to capture shared computational logics of implicit properties and complex constraints, creating a database of common blocks for interpreting regulatory clauses. Then, a prompt template with the chain of thought is developed and further enhanced with a classification-based tuning strategy, to enable common LLMs for effective function identification. Finally, the proposed approach is validated with statistical analysis, experiments, and proof of concept. Statistical analysis reveals a long-tail distribution and high expressibility of the developed function database, with which almost 100% of computer-processible clauses can be interpreted and represented as computer-executable codes. Experiments show that LLM-FuncMapper achieve promising results in identifying relevant predefined functions for rule interpretation. Further proof of concept in automated rule interpretation also demonstrates the possibility of LLM-FuncMapper in interpreting complex regulatory clauses. To the best of our knowledge, this study is the first attempt to introduce LLM for understanding and interpreting complex regulatory clauses, which may shed light on further adoption of LLM in the construction domain

Sign structure in the square-lattice tt-t′t^\prime-JJ model and numerical consequences

Understanding the doped Mott insulator is a central challenge in condensed matter physics. This study identifies an intrinsic Berry-phase-like sign structure for the square-lattice $t$-$t'$-$J$ model with the nearest-neighbor ($t$) and next-nearest-neighbor hopping ($t'$), which could help explain the origin of the quasi-long-range superconducting and stripe phases observed through density matrix renormalization group (DMRG) calculation. We first demonstrate that the hole binding underlies both the superconducting and stripe orders, and then show that the hole pairing generically disappears once the phase-string or mutual statistics component of the sign structure is switched off in DMRG calculation. In the latter case, the superexchange interaction no longer plays a crucial role in shaping the charge dynamics, where a Fermi-liquid-like phase with small hole Fermi pockets is found. It is in sharp contrast to the large Fermi surfaces in either the stripe phase found at $t'/t0$ in the original $t$-$t'$-$J$ model on the 6-leg ladder.Comment: 13 pages, 10 figure

Research Progress of the International Carbon Tariff: A Review

Under the constraints of the target peak carbon dioxide emissions and carbon neutrality, how the international carbon tariff can be levied have become an important question for scholars and research institutions all over the world. This paper aimed to comprehensively sort the relevant literature on the Carbon Border Adjustment Mechanism from an economic perspective. Based on defining the concept connotation and extension of carbon tariff, we summarized and determined the price mechanism, institutional mechanism, and coordination mechanism of the carbon tariff, and analyzed the impact of carbon tariff on the economic environment and other fields. Further, this paper makes an international comparison of the existing reasonably operable carbon tariff, points out the focus and direction of the next research, and strives to provide valuable experience and theoretical reference for the innovative practice of building the international Carbon Border Adjustment Mechanism. Keywords: carbon tariff, border tax adjustment, connotation and extension, mechanism design, economic impac

Risk factors and in-hospital mortality in Chinese patients undergoing coronary artery bypass grafting: Analysis of a large multi-institutional Chinese database

ObjectiveThis study was undertaken to delineate outcomes and to assess risk factors for in-hospital mortality among Chinese patients undergoing coronary artery bypass grafting.MethodsFrom 2007 to 2008, a total of 9838 consecutive adult patients undergoing coronary artery bypass grafting were enrolled in the Chinese Coronary Artery Bypass Grafting Registry, which included 43 centers from 17 province-level regions in China. This registry collected information on 67 preoperative factors and 30 operative factors believed to influence in-hospital mortality. The relationship between risk factors and in-hospital mortality was evaluated by univariate and logistic regression analyses.ResultsOverall in-hospital mortality was 2.5%. Eleven risk factors were found to be significant predictors for outcome: age (continuous), body mass index (continuous), left ventricular ejection fraction (continuous), preoperative New York Heart Association functional class III or IV, chronic renal failure, extracardiac arteriopathy, chronic obstructive pulmonary disease, preoperative atrial fibrillation or flutter (within 2 weeks), preoperative critical state, other than elective surgery, and combined valve procedure. Calibration with the Hosmer-Lemeshow test was satisfactory (P = .35), and the discrimination power was good (area under the receiver operating characteristic curve, 0.81; 95% confidence interval, 0.79–0.84).ConclusionsThe risk profiles and in-hospital mortality of Chinese patients undergoing coronary artery bypass grafting were determined from data in the most up-to-date multi-institutional database. Eleven variables were demonstrated to be independent risk factors for in-hospital death after coronary artery bypass grafting

Risk factors and in-hospital mortality in Chinese patients undergoing coronary artery bypass grafting: Analysis of a large multi-institutional Chinese database

ObjectiveThis study was undertaken to delineate outcomes and to assess risk factors for in-hospital mortality among Chinese patients undergoing coronary artery bypass grafting.MethodsFrom 2007 to 2008, a total of 9838 consecutive adult patients undergoing coronary artery bypass grafting were enrolled in the Chinese Coronary Artery Bypass Grafting Registry, which included 43 centers from 17 province-level regions in China. This registry collected information on 67 preoperative factors and 30 operative factors believed to influence in-hospital mortality. The relationship between risk factors and in-hospital mortality was evaluated by univariate and logistic regression analyses.ResultsOverall in-hospital mortality was 2.5%. Eleven risk factors were found to be significant predictors for outcome: age (continuous), body mass index (continuous), left ventricular ejection fraction (continuous), preoperative New York Heart Association functional class III or IV, chronic renal failure, extracardiac arteriopathy, chronic obstructive pulmonary disease, preoperative atrial fibrillation or flutter (within 2 weeks), preoperative critical state, other than elective surgery, and combined valve procedure. Calibration with the Hosmer-Lemeshow test was satisfactory (P = .35), and the discrimination power was good (area under the receiver operating characteristic curve, 0.81; 95% confidence interval, 0.79–0.84).ConclusionsThe risk profiles and in-hospital mortality of Chinese patients undergoing coronary artery bypass grafting were determined from data in the most up-to-date multi-institutional database. Eleven variables were demonstrated to be independent risk factors for in-hospital death after coronary artery bypass grafting

Software defined intelligent building

The networks of intelligent building are usually consist of a great number of smart devices. Since many smart devices only support on-site configuration and upgrade, and communication between devices could be observed and even altered by attackers, efficiency and security are two key concerns in maintaining and managing the devices used in intelligent building networks. In this paper, the authors apply the technology of software defined networking to satisfy the requirement for efficiency in intelligent building networks. More specific, a protocol stack in smart devices that support OpenFlow is designed. In addition, the authors designed the lightweight security mechanism with two foundation protocols and a full protocol that uses the foundation protocols as example. Performance and session key establishment for the security mechanism are also discussed