HVAC operations play a significant role among various driving factors to improve energy performance of buildings. Extensive researches have been conducted on the design efficiencies and control strategies of HVAC system, but very few focused on the impacts of its operational faults on the building energy efficiency. Modeling and simulation of operational faults can lead to better understandings...

On-line monitoring is a useful technique for ensuring system reliability. By continuously supervising the system’s operation, a wide range of problems, such as physical defects, transient faults and design errors, can be detected. A monitor M∗’s behavior can be viewed as an abstraction of the target system M’s behavior, and can be represented by a homomorphic mapping from M to M∗. We present a ...

We developed an accurate, efficient and flexible modeling method for the steady-state and transient analysis of grid-connected superconducting synchronous machines. On the one hand, the machine flux linkages and electromagnetic torque as function of operational parameters are obtained from static finite element analysis and stored in lookup tables. On the other hand, the machine is represented ...

earthquake ground-motions show significant variability in both spectral and temporal characteristics. procedures to generalize and predict strong ground motions may be generally divided into three main disciplines: numerical techniques based on a kinematic source description, empirical attenuation models, and semi-empirical stochastic models. numerous studies have shown that, in the near-fault ...

The aim of this work was to delineate the prospects of podiform-type chromite by staged factor analysis and geochemical mineralization prospectivity index in Balvard area, SE Iran. The stream sediment data and fault density were used as the exploration features for prospectivity modeling in the studied area. In this regard, two continuous fuzzified evidence layers were generated and integrated ...

Fault trees show which joint components' faults mean system faults. Fault trees can often be used to determine dependability parameters of systems. Here it is shown that i) binary decision diagrams (BDDs) can also be used to calculate system mean failure frequency, ii) modeling dynamics of fault trees does not always mean Markov modeling, iii) a deeper understanding of interrelations between s-...

The automatic modeling of fault tree for nuclear power safety I&C configuration is designed to meet the requirements of reducing the workload and improving the traceability during the nuclear power safety I&C system reliability assessment work. To complete the fault tree automatic modeling, the Visio Automation software technology is used to analyze the topology of the nuclear power safety I&C ...

in this paper, single, bi-layered and three-layered tube hydroforming processes were numerically simulated using the finite element method. it was found that the final bulges heights resulted from the models were in good agreement with the experimental results. three types of modeling were kept with the same geometry, tube material and process parameters to be compared between the obtained hydr...

[1] We investigate the rupture process of the 1999 Chi-Chi, Taiwan, earthquake using extensive near-source observations, including three-component velocity waveforms at 36 strong motion stations and 119 GPS measurements. A three-plane fault geometry derived from our previous inversion using only static data [Ji et al., 2001] is applied. The slip amplitude, rake angle, rupture initiation time, a...