Functional control structure model for the complex systems and its application in system safety analysis

The safety problem for the complex system is regarded as a control problem other than probability one, where the overall functional control structure model of the complex system could be configured in terms of the relationships among their functional labels. The hazards are due to the unsafe control actions (UCA), or the malfunctional control action (MCA). Meanwhile, UCA and MCA are due to the error feedback information (EFI), the error environment variables (EEV), the error state variables (ESE), the error command inputs (ECI), the error working modes (EWM), and the error process models (EPM), etc. Every function or component would be described as 10 labels, which are the input command (IC), the feedback to the upper level (FU), the control action (CA), the feedback from the lower levels (FL), the external input command (EC), the process model (PM), other related state variable (SV), the precondition (PC), the resource and the executing condition (RE) of the system, and the environment variable (EV). The aircraft wheel brake system’s control structure model is given to show its effectiveness

Becoming Christians: Prayers and subject formation in an urban church in China

Prayers in Christianity are often considered to be a theological or pastoral topic; while social scientific studies generally tend to reduce them, like prayers in other religious contexts, to the status of psychological responses bringing comfort to the practitioner, or a collective construction connected with social and cultural institutions. However, what prayer actually is, and what it means to Christians who practise it remains an open issue for further, more intensive and thorough study. Based on fieldwork in an urban church in China, this article provides some perspectives on contemporary Chinese Christians and their prayer life, attempting to elaborate its possible significance, especially in terms of subject-formation processes within these Christians. Meanwhile, this article argues that, in working towards a better understanding of Christians, it is more efficacious to take ‘Christians’ as those who are, rather than a given or acquired identity, or a status of being, engaged in a process of becoming through a practice, or set of practices, which in this case is prayer,. Moreover, in the case of this Chinese Christian church, the practise of prayer also indicates some reflections on the cultural and religious diversity of contemporary Chinese society

Strongly Coupled Electron–Phonon Dynamics in Few-Layer TiSe_2 Exfoliates

Ultrafast electron diffraction is used to probe the time-resolved dynamics in a few-layer TiSe_2 sample. At normal incidence, the suppression of the Bragg diffraction peak intensities following photoexcitation displays strongly biexponential behavior. For tilted samples, changes in the diffraction peak positions reveal coherent acoustic vibrations that are dependent on the sample thickness and that further permit a calculation of the Young’s modulus. The complex room temperature lattice dynamics observed are attributed to strong electron–phonon coupling and electron–lattice equilibration processes, which support a Jahn–Teller origin of the charge density wave behavior in TiSe_2. Additionally, the significant role that the related Kohn anomalies may play in the electron transport dynamics and transition mechanism of this material is emphasized. These results demonstrate the importance of strongly coupled electron–phonon dynamics in the relaxation of electronically excited room temperature TiSe2, which is expected to impact its applicability in optoelectronics

Delayed formation of coherent LO phonon-plasmon coupled modes in n-type and p-type GaAs measured using a femtosecond coherent control technique

Coherent control experiments using a pair of collinear femtosecond laser pulses have been carried out to manipulate longitudinal optical (LO) phonon-plasmon coupled (LOPC) modes in both p- and n-type GaAs. By tuning the interpulse separation, remarkably distinct responses have been observed in the two samples. To understand the results obtained a phenomenological model taking the delayed formation of coherent LOPC modes into account is proposed. The model suggests that the lifetime of coherent LOPC modes plays a key role and the interference of the coherent LO phonons excited successively by two pump pulses strongly affects the manipulation of coherent LOPC modes.Comment: 19 pages, 6 figures, accepted for publication in Phys. Rev.

Fractal Behavior in the Clarification Process of Cane Sugar Production

Cane sugar production is an important industrial process. One of the most important steps in cane sugar production is the clarification process, which provides high-quality, concentrated sugar syrup crystal for further processing. To gain fundamental understanding of the physical and chemical processes associated with the clarification process and help design better approaches to improve the clarification of the mixed juice, we explore the fractal behavior of the variables pertinent to the clarification process. We show that the major variables in this key process all show persistent long-range correlations, for time scales up to at least a few days. Persistent long-range correlations amount to unilateral deviations from a preset target. This means that when the process is in a desired mode such that the target variables, color of the produced sugar and its clarity degree, both satisfy preset conditions, they will remain so for a long period of time. However, adversity could happen, in the sense that when they do not satisfy the requirements, the adverse situation may last quite long. These findings have to be explicitly accounted for when designing active controlling strategies to improve the quality of the produced sugar