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Abstract Numerous occupant behavior models, typically stochastic ones, have been built to quantify the effect of occupants on building energy simulation, which however are supposed to go through a rigorous validation, or evaluation process to claim that they are qualified to be used in the application. Current contributions relevant with occupant behavior modeling in literature have been resorting to statistical metrics rather than those orienting on their application, causing the disputation in interpreting the accuracy of the occupant behavior models when they are actually used in simulation. Furthermore, the stochasticity of occupant behavior models necessitates statistical evaluation of the model accuracy, instead of the comparison between actual data and a single-run simulated data. This paper proposes a methodological framework for model evaluation from an application-oriented perspective, with lighting behavior as a case study. The metrics for evaluating lighting behavior models are identified according to different application scenarios, while the comparison between the measurement and simulation is done by introducing the statistical hypothesis testing. Analogous analyses on other behaviors can be conducted in the future, which altogether would foster more rigor and application significance in occupant behavior model evaluation. [ABSTRACT FROM AUTHOR]

Occupant behavior is a major contributing factor to building energy consumption. Large discrepancies might occur when occupants with diverse types in terms of behavior patterns reside in an identical building. Moreover, it is vital to derive several kinds of typical occupant behavior that represent the assemblage of occupants in a simplified way as the reference for building designers and energy policy makers. This paper presents a preliminary research on occupant behavior categorization through the building energy simulation, where some typical occupant air-conditioning behavior patterns use in Chengdu, China have been derived from a large-scale questionnaire survey based on the energy consumption levels. These typical occupant behavior patterns could be used as the context for an overview of building energy in a community, as well as the evaluation of building energy-saving technology where occupants are involved. Further efforts are required in the algorithm of dividing occupant behavior into typical patterns, the validation of the classification results, and the analysis of other behaviors. [ABSTRACT FROM AUTHOR]

Occupants are involved in a variety of activities in buildings, which drive them to move among rooms, enter or leave a building. In this study, occupancy is defined at four levels and varies with time: (1) the number of occupants in a building, (2) occupancy status of a space, (3) the number of occupants in a space, and (4) the space location of an occupant. Occupancy has a great influence on internal loads and ventilation requirement, thus building energy consumption. Based on a comprehensive review and comparison of literature on occupancy modeling, three representative occupancy models, corresponding to the levels 2–4, are selected and implemented in a software module. Main contributions of our study include: (1) new methods to classify occupancy models, (2) the review and selection of various levels of occupancy models, and (3) new methods to integrate these model into a tool that can be used in different ways for different applications and by different audiences. The software can simulate more detailed occupancy in buildings to improve the simulation of energy use, and better evaluate building technologies in buildings. The occupancy of an office building is simulated as an example to demonstrate the use of the software module. [ABSTRACT FROM AUTHOR]

Fatigue‐induced clip fractures are the most common type of damage in railway systems, and they are exacerbated by rail corrugation. This research investigated the development of rail corrugation through long‐term measurements and examined the impact of rail corrugation on the fatigue life of e‐clips using a finite element model. The examination included different corrugation wavelengths, namely, short‐pitch corrugation (SPC), long‐pitch corrugation (LPC), and a new form of corrugation called superposed SPC and LPC. The results showed that increasing corrugation amplitude reduces an e‐clip's fatigue life and alters the region in the clip where fatigue damage occurs. A short corrugation wavelength shortens fatigue life. On railway tracks with superposed SPC and LPC, a significant increase in LPC amplitude sharply reduces a clip's fatigue life, even under minuscule SPC amplitude. Effective measures are proposed to prolong the fatigue life of e‐clips subjected to the effects of rail corrugation. [ABSTRACT FROM AUTHOR]

The central role of occupants for achieving energy savings in residential buildings is increasingly recognised. Simulation programmes able to take into account occupant behaviour are considered to be powerful tools for bridging the gap between the predicted and the actual energy consumption for new buildings. Nevertheless, the majority of residential buildings that will constitute the housing stock in 2050 have already been built today, therefore occupant behaviour and building simulation tools need to be fully exploited for supporting the renovation of existing housing stock. The aim of this paper is to explore the role of occupant behaviour modelling in supporting decision-makers dealing with the design of renovation strategies for residential buildings. An Italian multi-family public housing building is assumed as case study to estimate the influence of three dimensions linked with occupant behaviour – management of the thermostat, management of the heating system, variation of building characteristics – on energy heating consumption. The results show that, while the occupant behaviour influences the heating loads up to 1/3 in case of high level of building retrofit, the less the building is renovated, the higher is the behavioural impact in absolute terms of energy reduction. Therefore, in order to be effective, renovation strategies are required to design appropriate informative instruments at an early stage to support behaviour changes towards responsible energy consumption. [ABSTRACT FROM AUTHOR]

Using an experimental approach, the researchers investigated the wear of a skateboard according to different profile contact lines. A high-speed current-carrying test machine was used to simulate underground railway operational conditions and obtain parameters such as the coefficient of friction, arc discharge energy, temperature increase, current-carrying efficiency, and offline rate of friction pairs comprising a skateboard and contact lines with varying profiles. The researchers analysed the impact of experimental parameters on skateboard wear matched with the different contact lines, as well as the wear mechanism of the skateboard. The experimental results revealed the following order for the total skateboard wear when matched with different contact lines: oblique contact line > pitted contact line > normal contact line. For the total skateboard wear with oblique contact line, the electrical wear of the skateboard predominantly contributed to the overall wear. Across all experiments, the total skateboard wear when matched with the oblique and pitted contact lines reached 10.291 g and 5.537 g, respectively, which was approximately 3.232 and 1.739 times the wear observed when matched with the normal contact line (3.184 g). With other experimental parameters held constant, the skateboard wear was directly proportional to current and sliding velocity, but inversely proportional to the normal load. The effect of sliding velocity on skateboard wear, arc energy, offline rate, etc., was less significant than the impact of current and normal load, especially at low speeds. [ABSTRACT FROM AUTHOR]

Hypertension is a common chronic disease, which leads to cardio-cerebrovascular diseases, and its prevalence is increasing. The cyclic adenosine monophosphate (cAMP)-protein kinase A (PKA) pathway participates in multiple cardiovascular diseases. Phosphodiesterase (PDE) 4 has been shown to regulate PKA activity via cAMP specific hydrolysis. However, whether PDE4-cAMP-PKA pathway influences hypertension remains unknown. Herein, we reveal that PDE4D (one of PDE4 isoforms) expression is upregulated in the aortas of experimental hypertension induced by angiotensin II (Ang II). Furthermore, knockout of Pde4d in mouse smooth muscle cells (SMCs) attenuates Ang II-induced hypertension, arterial wall media thickening, vascular fibrosis and vasocontraction. Additionally, we find that PDE4D deficiency activates PKA-AMP-activated protein kinase (AMPK) signaling pathway to inhibit myosin phosphatase targeting subunit 1 (MYPT1)-myosin light chain (MLC) phosphorylation, relieving Ang II-induced SMC contraction in vitro and in vivo. Our results also indicate that rolipram, a PDE4 inhibitor, may be a potential drug for hypertension therapy. Fan, Hou et al. investigate the role of phosphodiesterase (PDE) 4 and the PDE4-cAMP-PKA pathway on hypertension, reporting that PDE4D is upregulated in hypertension induced by angiotensin II. The authors also show that Pde4d knockout in mouse SMCs attenuates Ang II-induced hypertension and implicate AMPK signalling and MYPT1-MLC phosphorylation in Ang II-induced SMC contraction. [ABSTRACT FROM AUTHOR]

Uncertainty analysis in building energy assessment has become an active research field because a number of factors influencing energy use in buildings are inherently uncertain. This paper provides a systematic review on the latest research progress of uncertainty analysis in building energy assessment from four perspectives: uncertainty data sources, forward and inverse methods, application of uncertainty analysis, and available software. First, this paper describes the data sources of uncertainty in building performance analysis to provide a firm foundation for specifying variations of uncertainty factors affecting building energy. The next two sections focus on the forward and inverse methods. Forward uncertainty analysis propagates input uncertainty through building energy models to obtain variations of energy use, whereas inverse uncertainty analysis infers unknown input factors through building energy models based on energy data and prior information. For forward analysis, three types of approaches (Monte Carlo, non-sampling, and non-probabilistic) are discussed to provide sufficient choices of uncertainty methods depending on the purpose and specific application of a building project. For inverse analysis, recent research has concentrated more on Bayesian computation because Bayesian inverse methods can make full use of prior information on unknown variables. Fourth, several applications of uncertainty analysis in building energy assessment are discussed, including building stock analysis, HVAC system sizing, variations of sensitivity indicators, and optimization under uncertainty. Moreover, the software for uncertainty analysis is described to provide flexible computational environments for implementing uncertainty methods described in this review. This paper concludes with the trends and recommendations for further research to provide more convenient and robust uncertainty analysis of building energy. Uncertainty analysis has been ready to become the mainstream approach in building energy assessment although a number of issues still need to be addressed. [ABSTRACT FROM AUTHOR]

Rail corrugation is a common form of damage in subway tracks. This paper presents the results of a 1.5-year study of track wear at two sites on the Chengdu Metro. Findings revealed the appearance of corrugation with a 30 mm main wavelength near the middle of the curve on the low rail of a 350 m radius track. As the subway's operating hours extended, the corrugation expanded toward the transition curves, and the wavelength changed. Conversely, no rail corrugation was seen on the rails of a 610 m radius curved track. A finite element model of the wheelset–rail system was established based on friction-induced self-excited vibration (FSV), and complex eigenvalue and instantaneous dynamic analysis methods were employed on the model to predict corrugation. Results showed that the increased elasticity modulus of the rail pad and baseplate pad could restrain long-pitch corrugation, and matching the material parameter of the pads reasonably reduced the frequency of short-pitch corrugation (SPC). In addition, the lack of corrugation on the 610 m radius track was studied, with results showing that the creep forces at the interface were not saturated. Thus, no FSV occurred, and no corrugation arose. • Long-term tracking of corrugation on the rails of a 350 m and 610 m radius track. • Corrugation position and wavelength changed as the subway's operating accumulated. • Friction-induced self-excited vibration was the leading cause of rail corrugation. • Vibrational interference of guiding wheelsets causes the change of corrugation. • Increasing the elastic modulus of pads can inhibit long-pitch corrugation. [ABSTRACT FROM AUTHOR]

More than 30% of the total primary energy in the world is consumed in buildings. It is crucial to reduce building energy consumption in order to preserve energy resources and mitigate global climate change. Building performance simulations have been widely used for the estimation and optimization of building performance, providing reference values for the assessment of building energy consumption and the effects of energy-saving technologies. Among the various factors influencing building energy consumption, occupant behavior has drawn increasing attention. Occupant behavior includes occupant presence, movement, and interaction with building energy devices and systems. However, there are gaps in occupant behavior modeling as different energy modelers have employed varied data and tools to simulate occupant behavior, therefore producing different and incomparable results. Aiming to address these gaps, the International Energy Agency (IEA) Energy in Buildings and Community (EBC) Programme Annex 66 has established a scientific methodological framework for occupant behavior research, including data collection, behavior model representation, modeling and evaluation approaches, and the integration of behavior modeling tools with building performance simulation programs. Annex 66 also includes case studies and application guidelines to assist in building design, operation, and policymaking, using interdisciplinary approaches to reduce energy use in buildings and improve occupant comfort and productivity. This paper highlights the key research issues, methods, and outcomes pertaining to Annex 66, and offers perspectives on future research needs to integrate occupant behavior with the building life cycle. [ABSTRACT FROM AUTHOR]

Occupant behavior is now widely recognized as a major contributing factor to uncertainty of building performance. While a surge of research on the topic has occurred over the past four decades, and particularly the past few years, there are many gaps in knowledge and limitations to current methodologies. This paper outlines the state-of-the-art research, current obstacles and future needs and directions for the following four-step iterative process: (1) occupant monitoring and data collection, (2) model development, (3) model evaluation, and (4) model implementation into building simulation tools. Major themes include the need for greater rigor in experimental methodologies; detailed, honest, and candid reporting of methods and results; and development of an efficient means to implement occupant behavior models and integrate them into building energy modeling programs. [ABSTRACT FROM AUTHOR]

The seasonal cycle of growth and regression in the prostate gland of wild ground squirrel provide a unique research model to understand the morphological changes of prostate glands. Our previous studies showed that the local production of dihydrotestosterone could affect the morphology and function of the prostate gland in either an autocrine or paracrine manner. In the present study, we attempted to gain more insight into this process by investigating the expression of key factors implicated in cell proliferation, apoptosis, and the cell cycle, including mechanistic target of rapamycin (mTOR), cyclin-D2, p21, p27 and retinoblastoma 1 (pRB). Morphological and histological observations confirmed that the prostate increased significantly in both size and weight during the breeding season. Positive immunostaining for proliferating cell nuclear antigen (PCNA) was mainly localized to the prostate epithelial cells during the breeding season, which is significantly higher in the prostate gland during the breeding season (2470 ± 81/mm2) than that in the nonbreeding season (324 ± 54/mm2). However, there was no significant difference in the prostate gland when compared between the breeding and nonbreeding seasons, with regards to TUNEL staining. Moreover, cell cycle regulators were mainly localized to the epithelial cells, including mTOR, cyclin-D2, p21, p27 and pRB. the immunostaining of mTOR and cyclin D2 were stronger during the breeding season, whereas the immunostaining of p27 and pRB were stronger during the nonbreeding season. The mRNA expression levels of mTOR, cyclin D2, and PCNA, were higher during the breeding season while those of p27 and p21 were higher during the nonbreeding season. Collectively, this study profiled the distinct expression pattern of key cell cycle regulators throughout the breeding and nonbreeding seasons. Collectively, these factors may play important roles in regulating the seasonal growth and regression of the prostatic epithelium in the wild ground squirrel. Unlabelled Image • Cell proliferation in the prostate epithelium increased during the breeding season. • Apoptosis remained unchanged in the prostate during distinct reproductive periods. • Epithelial cells were immunopositive for cyclin D2, mTOR, p27, p21 and pRB. • mTOR and cyclin D2 mRNA increased in the prostate during the breeding season. • p21 and p27 gene expression was reduced in the prostate during the breeding season. [ABSTRACT FROM AUTHOR]