Time-based Concept Research Articles

A residence time-based concept for modeling and analyzing the impact of diffusion on auto-ignition processes with thermal stratification

A meticulous definition of the residence time (also referred to as the fluid age) in the context of auto-ignition in a thermally stratified gas has demonstrated that the age can be considered as a level-set function, which allows the tracking of a self-ignition front propagating. In order to avoid the difficulty of defining the boundary and initial conditions for this age, which can be seen as fluid birth, a normalized age is introduced. Meticulous derivation of the equation revealed additional terms related to the scalar dissipation rates and the gradient in the composition space of the auto-ignition delay. To validate this model equation, two canonical configurations were proposed: one representing a hot spot self-igniting with significant thermal diffusion and the other where a self-ignition front propagates at an almost constant speed. The analysis, based on the normalized age of the particles, reveals the impact of thermal diffusion on the acceleration or deceleration of particle aging. In certain instances, a particle rejuvenation mechanism through thermal diffusion has been identified. Furthermore, this work demonstrates the capacity of the normalized residence time field to map transitions between auto-ignition and laminar flame. Finally, the different cases studied were classified in an auto-ignition/diffusion diagram based on three non-dimensional characteristic numbers, which highlighted five combustion regimes.

A Framework to Detect and Classify Time-based Concept Drift

A Framework to Detect and Classify Time-based Concept Drift

Varieties of Temporalization

This article calls attention to the outstanding conceptual work related to time that the historical research and writing imply. The starting point is an overview of the disciplines dedicated to time studies in the recent theory of history: the metaphysics of natural time, the (classical and the new) metaphysics of historical time, the regimes of historicity, and the historiographical regimes. According to these disciplines, four varieties of temporalization, with which historians have been dealing currently, are categorized and discussed: the chronological-historical, the substantive, the quasi-substantive, and the historically experienced temporalization (and its narrative representation). This categorial structure, specially the quasi-substantive temporalization, assigns epistemic unity to the so-called new metaphysics of time and allows the classification of time-based concepts which are instrumentalized by historians. In order to demonstrate the consistency of the categories that this article proposes, some concepts concerning Koselleck’s theory of time (nature-like patterns of repetition, diachronic-synchronic layers of time, contemporaneity of the noncontemporaneous) will be studied as cases that illustrate the way a theorist combines different temporalizations to conceive of a theory of historical time that deals with the treatment of the temporal experience and the writing of history which integrate historians’ practice.

A free-running, time-based readout method for particle detectors

For the EndoTOFPET-US experiment, the TOFPET ASIC has been developed as a front-end chip to read out data from silicon photomultipliers (SiPM) [1]. It introduces a time of flight information into the measurement of a PET scanner and hence reduces radiation exposure of the patient [2]. The chip is designed to work with a high event rate up to 100 kHz and a time resolution of 50 ps LSB. Using two threshold levels, it can measure the leading edge of the event pulse precisely while successfully suppressing dark counts from the SiPM. This also enables a time over threshold determination, leading to a charge measurement of the signal's pulse.The same, time-based concept is chosen for the PASTA chip used in the PANDA experiment. This high-energy particle detector contains sub-systems for specific measurement goals. The innermost of these is the Micro Vertex Detector, a silicon-based tracking system. The PASTA chip's approach is much like the TOFPET ASIC with some differences. The most significant ones are a changed amplifying part for different input signals as well as protection for radiation effects of the high-radiation environment. Apart from that, the simple and general concept combined with a small area and low power consumption support the choice for using this approach.

Optimization of the Maintenance Program of Elevating Equipment Using Risk Assessment

Maintenance program for elevating equipments is basically done in time-based concept. Inspection periods are determined for each item which is composed of plural parts; however, this inspection interval is based on experiences and does not have clear scientific backgrounds. In order to rationalize the maintenance program, the application of available data such as failure reports given by customers, and inspection data reported at periodical maintenance is extremely important. Unfortunately, this information is not necessarily utilized sufficiently at this moment. In this research, we try to quantify a risk by calculating failure rates and harm severities of each maintenance item. When calculating the failure rate, we use a statistical method and take “interruption data” into consideration to make up for the lack of data. When defining the harm severities, we evaluate the suspension time caused by the failure of . Finally, by multiplying the failure rate and the harm severity, we quantify a risk which matches maintenance executer's sense, and develop the method of optimizing the maintenance program based on risk.

PS28 リスク評価に基づいた建築設備保全計画の最適化

The maintenance program for building equipments is basically done in time-based concept. The inspection periods are determined for each item which is composed of plural parts; however, this inspection interval is determined on experience-basis and its background is not necessarily clear. In order to rationalize the maintenance program, the application of available data such as failure reports given by customers, and inspection data reported at periodical maintenance is extremely important. Unfortunately, this information is not necessarily utilized sufficiently at this moment. In this research, we try to quantify risk by calculating failure rate of each maintenance item using statistical method and by defining consequence accompanied by failure. Finally, we develop the method of optimizing the maintenance program based on risk.

Britain as a container: immigration metaphors in the 2005 election campaign

This article explores how metaphors contribute to the formation of legitimacy in right-wing political communication on immigration policy in the 2005 British election campaign. It investigates the role played by metaphors in the formation of right-wing political legitimacy and the differences in how metaphor is used by the far and centre-right. The two main types identified are ‘natural disaster’ metaphors - predominantly relating to fluids - and ‘container’ metaphors concerning a build up of pressure within or outside a container. These two types are related through the notion of a bounded area protecting what is within from external danger. The container metaphor is persuasive in political communication because it merges a fourth dimension of time with spatially based concepts of two or three dimensions. It implies that controlling immigration through maintaining the security of borders (a spatially-based concept) will ensure control over the rate of social change in Britain (a time-based concept). It also heightens emotional fears associated with the penetration of a container.

A time-based approach towards cortical functions: neural mechanisms underlying dynamic aspects of information processing before and after postontogenetic plastic processes

Under the assumptions that the entire temporal structure of neuron responses carries significant information and that single cell receptive fields (RFs) and representational maps (RMs) typify representative stages of cortical processing, dynamical properties of RFs and RMs were investigated in three modalities. The resulting time-dependent receptive fields and representational maps are interpreted as specific adaptations to processing of inherently time-variant signals. Based on experimental data about latency differences observed within different hierarchically organized areas of sensory pathways, a time-based concept of temporal distributed processing (TDP) across subcortical and cortical substrates is presented that accounts for dynamic aspects of cortical processing. The high percentage of simultaneously activated neurons makes it rather unlikely that proceeding stages wait until the end of the processing of a previous one. This lack of wait-states is the key feature of the TDP-scheme which poses special emphasis on late response components. To provide sufficient flexibility to slow changing conditions in the environment and individual performance requirements, postontogenetic plastic adaptive processes are assumed to act within this scenario by directly effecting the response dynamics thus altering the entire interareal interactions.