objective value

The objective value of 240 conducted scenarios.</p

Incremental calibration of seat selection preferences in agent-based simulations of public transport scenarios

The calibration of agent-based pedestrian simulation models requires empirical data. To avoid cost-intensive real-world experiments, human-in-the-loop simulations can be applied in which simulated pedestrians interact with human-controlled agents. However, the experiment results may be unrealistic if the human participants are presented with agents acting according to an uncalibrated model. We propose an incremental calibration approach that aims to address the circular dependency between the behaviour of human and simulated pedestrians. By incrementally adapting the parameters of the simulated agents to match the behaviour of the human participants, we aim to gradually approach a realistic interaction. We evaluate our approach using the simulation of the boarding procedure of a public transport vehicle in 2D and virtual reality experiments. The calibration results are compared with those gathered from a traditional non-incremental calibration. Our results indicate the feasibility of our approach and highlight the necessity for future research on efficient simulation model calibration.National Research Foundation (NRF)Accepted versionThis work was financially supported by the Singapore National Research Foundation under its Campus for Research Excellence And Technological Enterprise (CREATE) programme. The authors would like to extend their gratitude to their colleagues Dr Henriette Cornet and Goran Marinkovic in the Design for Autonomous Mobility group at TUMCREATE for the permission to use their vehicle layout

A Virtual Crack-Based Numerical Manifold Approach to Crack Initiation, Propagation and Coalescence in Granite

International audienc

A passenger model for simulating boarding and alighting in spatially confined transportation scenarios

Crowd simulation has been widely used as a tool to demonstrate the behavior of passengers on public transport. A simulation model allows researchers to evaluate the platform or interior designs without involving real-world experimentation. In this paper, we propose a passenger model to measure the effect of different public transport vehicle layouts on the required time for boarding and alighting. We first model a low level collision avoidance behavior based on an extended social force model aiming at simulating human interactions in confined spaces. The model introduces a mechanism to emulate rotation behavior while avoiding complex geometric computations and is calibrated to experimental data. The model also allows agents to perform collision prediction in low density environments. Strategical behavior of passengers is modeled according to the recognition-primed decision paradigm and combined with the collision avoidance model. We validate our model against real-world experiments from the literature, demonstrating deviations of less than 6%. In a case study, we evaluate the boarding and alighting times required by three autonomous vehicle interior layouts proposed by industrial designers in both low-density and high-density scenarios.This work was financially supported by the Singapore National Research Foundation under its Campus for Research Excellence And Technological Enterprise (CREATE) program

Time-dependent virtual crack model of rock with application to slope stability

International audienceTime-dependent deformation of rock involves the continuous to discontinuous deformation of joints, cracks, holes, and other defects under long-term stress conditions. Thus, it is of great significance to investigate the correlation between internal crack propagation in rock and external time-dependent damage and failure of rock to better understand the long-term stability of engineering rock mass. Here, we put forward a time-dependent virtual crack model to achieve the entire continuous-discontinuous time-dependent deformation progress of rock from the microscopic to the macroscopic scale. Simulated stress-strain curves for granite, including the mode of failure (axial splitting and Brazilian splitting), agree well with experimental data. We also used the virtual crack model to study the stability of one of the slopes of the Xiaowan Hydropower Station (China). The simulation results indicate that the weakly disturbed zone is the potential sliding surface, and that the deformation of the slope is similar to in-situ measurements. In the model, the vertical displacement decreased by 500 mm in 180 days and the axial strain rate decreased from 25 mm/d to zero, suggested that the slope is currently stable

Modification of BCLX pre-mRNA splicing has antitumor efficacy alone or in combination with radiotherapy in human glioblastoma cells

Abstract Dysregulation of anti-apoptotic and pro-apoptotic protein isoforms arising from aberrant splicing is a crucial hallmark of cancers and may contribute to therapeutic resistance. Thus, targeting RNA splicing to redirect isoform expression of apoptosis-related genes could lead to promising anti-cancer phenotypes. Glioblastoma (GBM) is the most common type of malignant brain tumor in adults. In this study, through RT-PCR and Western Blot analysis, we found that BCLX pre-mRNA is aberrantly spliced in GBM cells with a favored splicing of anti-apoptotic Bcl-xL. Modulation of BCLX pre-mRNA splicing using splice-switching oligonucleotides (SSOs) efficiently elevated the pro-apoptotic isoform Bcl-xS at the expense of the anti-apoptotic Bcl-xL. Induction of Bcl-xS by SSOs activated apoptosis and autophagy in GBM cells. In addition, we found that ionizing radiation could also modulate the alternative splicing of BCLX. In contrast to heavy (carbon) ion irradiation, low energy X-ray radiation-induced an increased ratio of Bcl-xL/Bcl-xS. Inhibiting Bcl-xL through splicing regulation can significantly enhance the radiation sensitivity of 2D and 3D GBM cells. These results suggested that manipulation of BCLX pre-mRNA alternative splicing by splice-switching oligonucleotides is a novel approach to inhibit glioblastoma tumorigenesis alone or in combination with radiotherapy

Zinc Metal–Organic Framework for Selective Detection and Differentiation of Fe(III) and Cr(VI) Ions in Aqueous Solution

A new luminescent Zn­(II)-based metal–organic framework (MOF), [Zn₂(TPOM)­(NDC)₂]·3.5H₂O (Zn-MOF; TPOM = tetrakis­(4-pyridyloxymethylene)­methane and H₂ndc = 2,6-naphthalenedicarboxylic acid), was successfully synthesized by a hydrothermal reaction. The MOF exhibits excellent luminescence emission, and it can detect Fe­(III) and Cr­(VI) ions with high selectivity, well antiinterference performance, and short response time. In addition, Zn-MOF was selected as a parent coordination compound to encapsulate Eu³⁺ cations to obtain a Eu³⁺-incorporated sample (Eu³⁺@Zn-MOF). Subsequently, we explored the potential application of Eu³⁺@Zn-MOF as a probe for the selective sensing of Fe­(III) and Cr­(VI) ions, and it revealed that we could differentiate Fe­(III) and Cr­(VI) ions by the combination Zn-MOF and Eu³⁺@Zn-MOF. More importantly, it represents the first example of MOF-based luminescent sensors which can detect and differentiate Fe­(III) and Cr­(VI) ions selectively. And the possible sensing mechanism was discussed in detail

Associations of residential greenness exposure during early pregnancy with the risk of spontaneous abortion: the China Birth Cohort Study

Abstract Background Living in higher greenness level community has many benefits for pregnancy outcomes, however, few research have explored the relationship between greenness and spontaneous abortion (SAB). We aimed to analyze relationships between SAB and community greenness in Chinese pregnant women, and further assessed the modifying effects from air pollutants. Methods We studied 90 890 pregnant women from the China Birth Cohort Study from February 2018 to December 2021. We diagnosed SAB by certified obstetricians and gynecologists. The level of exposure to greenness during the first trimester was measured using the normalized difference vegetation index (NDVI) and the enhanced vegetation index (EVI). Particulate matter ≤ 2.5 μm (PM2.5), nitrogen dioxide (NO2) and ozone (O3) were used as proxies of ambient air pollution. Time-dependent multivariable adjusted Cox proportional hazards models, with gestational weeks as the time scale, were used to analyze the association between SAB and greenness. We additionally performed subgroup analyses stratified by age, urbanicity, research location, season of birth, temperature, humidity and air pollution levels. Results Lower SAB prevalence was related to living in greener places. A 0.1 unit increase in NDVI500m and EVI500m was significantly associated with a 12.3% (95% CI 9.9%, 15.5%) and 16.2% (95% CI 11.4%, 20.6%) lower risks of SAB, respectively. In sensitivity analysis, these relationships remained consistent. The associations were stronger among older, participants lived in the north of China and lived in places with higher PM2.5 and lower NO2 levels. Conclusions Our findings indicate significantly inverse associations between community greenness and SAB in Chinese pregnant women, especially for older and participants who live in the north of China, the PM2.5 and NO2 may modify the effects of greenness on SAB

A model-based analysis of evacuation strategies in hospital emergency departments

Evacuation planning for emergency incidents is an essential preparedness for Emergency Departments (ED) which normally contains patients with severe illness and limited mobility. However, the preparedness can be challenging due to a lack of empirical data and difficulties conducting physical drills. We propose an agent-based model to simulate the evacuation process in the EDs containing medical staff, rescuers, visitors and various types of patients. In a case study, we apply the model to a peak hour scenario of the ED of the largest hospital in Singapore. Two rescue strategies with different behavior sequences of medical staff as suggested by the practitioners are evaluated. The simulation results show that prioritizing preparation of all the patients generates less total evacuation time but leads to fewer evacuated cases in the first 20 minutes and more serious congestion compared to one-by-one transfer of individual patients.National Research Foundation (NRF)Submitted/Accepted versionThis research is supported by National Research Foundation (NRF) Singapore, GOVTECH under its Virtual Singapore program Grant No. NRF2017VSG-AT3DCM001-031