Field Measurement and Study on Overburden Fracture and Surface Subsidence Law of Solid Filling Mining under Buildings

In order to predict the surface subsidence scientifically in solid filling mining, it is necessary to establish a complete subsidence prediction model and parameter system according to the evolution law of overburden structure and strata movement characteristics. Mine pressure monitoring and borehole peeping show that the overburden in solid filling mining is mainly a bending zone with relatively complete layered structure, and the overburden only develops a certain height of fault zone near the roof, without collapse. The results show that the surface subsidence pattern of solid filling mining can still be described by probability integral model, and the parameter system of the surface subsidence prediction model based on “equivalent mining height” is further discussed. Finally, the prediction model of surface subsidence established in this paper is applied to an engineering example, and good results are achieved.

Local-Activity and Simultaneous Zero-Hopf Bifurcations Leading to Multistability in a Memristive Circuit

In this paper, we consider a memristive circuit consisting of three elements: a passive linear inductor, a passive linear capacitor and an active memristive device. The circuit is described by a four-parameter system of ordinary differential equations. We study in detail the role of parameters in the dynamics of the system. Using the existence of first integrals, we show that the circuit may present a continuum of stable periodic orbits, which arise due to the occurrence of infinitely many simultaneous zero-Hopf bifurcations on a line of equilibria located in the region where the memristance is negative and, consequently, the memristive device is locally-active. These bifurcations lead to multistability, which is a difficult and interesting problem in applied models, since the final state of a solution depends crucially on its initial condition. We also study the control of multistability by varying a parameter related to the state variable of the memristive device. All analytical results obtained were corroborated by numerical simulations.

CONSERVATIONAL ARCHITECTURE EVALUATION AND ENVIRONMENTAL CONTROL SYSTEM BASED ON LONG-TERM ENVIRONMENTAL MONITORING DATA – TAKING GUANGYUAN QIANFOYA CLIFF INSCRIPTIONS CONSERVATIONAL ARCHITECTURE ASSESSMENT AS AN EXAMPLE

The environmental monitoring data of Qianfoya Cliff Inscriptions in Guangyuan, Sichuan Province accumulated since 2014 make it possible to analyze the environmental monitoring data in and out of the Experimental Structure of the Conservational Architecture of Qianfoya Cliff Inscriptions which was built in 2016. By comparing the long long-term environmental pattern and differences between the internal and external part of the section, the results indicate that the Conservational Architecture effectively decrease the frequency of short-term sever winds, strong sunshine and extreme high and low temperatures, reduces the short short-term temperature and humidity variation range, which creates a stable microenvironment conducive to the preservation of statues without changing the long long-term environmental transformation pattern. Moreover, a parameter system for evaluating the conservational architecture, which directly related to environmental damage factors and meets the requirement of measurability and controllability, has been established and control threshold of microenvironment adjustment, which divides abnormal environment state in three levels (caution states, Pre-warning states, Warning states), has been chosen so as to quantitatively evaluate the protection effect of the experimental structure and provide data guidance for daily protection work and environmental control. Based on this parameter system and control thresholds , the total duration of warning states in Qianfoya experimental structure can be reduced by 30% compared with that outside the experimental structure , which further proves that the experimental structure plays a significant role in alleviating the main natural deterioration factors in Qianfoya cliff.

iBikeSafe: A Multi-Parameter System for Monitoring, Evaluation and Visualization of Cycling Paths in Smart Cities Targeted at Cycling Adverse Conditions

The fast transformation of the urban centers, pushed by the impacts of climatic changes and the dramatic events of the COVID-19 Pandemic, will profoundly influence our daily mobility. This resulted scenario is expected to favor adopting cleaner and flexible modal solutions centered on bicycles and scooters, especially as last-mile options. However, as the use of bicycles has rapidly increased, cyclists have been subject to adverse conditions that may affect their health and safety when cycling in urban areas. Therefore, whereas cities should implement mechanisms to monitor and evaluate adverse conditions in cycling paths, cyclists should have some effective mechanism to visualize the indirect quality of cycling paths, eventually supporting choosing more appropriate routes. Therefore, this article proposes a comprehensive multi-parameter system based on multiple independent subsystems, covering all phases of data collecting, formatting, transmission, and processing related to the monitoring, evaluating, and visualizing the quality of cycling paths in the perspective of adverse conditions that affect cyclist. The formal interactions of all modules are carefully described, as well as implementation and deployment details. Additionally, a case study is considered for a large city in Brazil, demonstrating how the proposed system can be adopted in a real scenario.

Practical Simulation Model-Based Measurement Power Factor Matlab / Simulink

Pembelajaran praktikum sangat dibutuhkan oleh mahasiswa agar dapat menerapkan dan mengintegrasikan pengetahuan serta keterampilan khusus yang telah dimiliki juga sebagai sarana untuk membuktikan teori secara ilmiah. Praktikum pengukuran power factor (pf) salah satu yang penting bagi mahasiswa program studi teknik elektro konsentrasi power system. Permasalahan timbul karena sejak pandemi, mahasiswa dibatasi bahkan dilarang untuk berkegiatan di kampus termasuk bengkel dan laboratorium. Solusi yang diusulkan adalah merancang model praktikum simulasi pengukuran pf menggunakan software Matlab/Simulink. Model praktikum harus dapat menggambarkan parameter system jaringan yang sesuai dengan praktikum laboratorium sehingga mahasiswa benar-benar dapat menerapkan dan membuktikan teori serta pengetahuan yang telah didapat. Hasil rancangan menunjukkan bahwa model praktikum berbasis Simulink dapat merepresentasikan alat praktikum sesungguhnya. Saat beban resistif nilai pf = 1. Saat beban resistif-induktif nilai pf turun berbanding terbalik dengan nilai induktansinya. Saat diberikan kompensasi dengan memasangkan kapasitor dengan nilai yang tepat nilai pf dapat naik kembali mendekati 1

Formulation of Unique Standard Protocol To Assess Degree of Deterioration in RCC Buildings

The repairs strategy adopted is replacement of damaged materials without dealing with the real problems. Many engineers unintentionally attempt treating the symptoms, instead of dealing with the cause. Such an approach may offer a quick action with minimum inconvenience to the occupants. But in this process, there is a strong possibility that the source and cause for the distress remain unattended and continue to cause problem even after the superficial repairs have been executed. If structural defects are dealt with in this fashion, it remains only as defects camouflaged beneath finishes, which gives a false sense of safety to the occupants allowing the problem to continue without getting treated. A rational approach to any repair and rehabilitation work to consider the source of the problem and the symptoms together identified on a standard scale is needed. Repairs, maintenance , rehabilitation is an integral part during life span of the structure. Neglecting or avoiding the same results in a potential loss of structure which may ultimately result in loss of human life. Structural Audit is the most commonly used parameter/system which gives a detailed structural information regarding the actual insight of the structure. There are also detailed systems available as far as repairs or rehabilitation is concerned. There is a gap which needs to be bridged between the assessment and the actual repair process. There needs to be a standard system developed which will act as a protocol regarding assessment of the degree of deterioration of the structure.