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Evaluating different levels of information on the calibration of building energy simulation models

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Building Simulation 2024年第4期17卷 657-676页

作者： Siyu Cheng Zeynep Duygu Tekler Hongyuan Ji Wenxin Li Adrian Chong Department of the Built Environment College of Design and EngineeringNational University of Singapore4 Architecture DriveSingapore117566Singapore School of Civil Engineering and Architecture Chongqing University of Science and TechnologyChongqing401331China School of Energy and Environment Southeast UniversityNanjing210096China

A poorly calibrated model undermines confidence in the effectiveness of building energy simulation, impeding the widespread application of advanced energy conservation measures (ECMs). Striking a balance between information-gathering efforts and achieving sufficient model credibility is crucial but often obscured by ambiguities. To address this gap, we model and calibrate a test bed with different levels of information (LOI). Beginning with an initial model based on building geometry (LOI 1), we progressively introduce additional information, including nameplate information (LOI 2), envelope conductivity (LOI 3), zone infiltration rate (LOI 4), AHU fan power (LOI 5), and HVAC data (LOI 6). The models are evaluated for accuracy, consistency, and the robustness of their predictions. Our results indicate that adding more information for calibration leads to improved data fit. However, this improvement is not uniform across all observed outputs due to identifiability issues. Furthermore, for energy-saving analysis, adding more information can significantly affect the projected energy savings by up to two times. Nevertheless, for ECM ranking, models that did not meet ASHRAE 14 accuracy thresholds can yield correct retrofit decisions. These findings underscore equifinality in modeling complex building systems. Clearly, predictive accuracy is not synonymous with model credibility. Therefore, to balance efforts in information-gathering and model reliability, it is crucial to (1) determine the minimum level of information required for calibration compatible with its intended purpose and (2) calibrate models with information closely linked to all outputs of interest, particularly when simultaneous accuracy for multiple outputs is necessary.

关键词： calibration building energy simulation(BES) energy conservation measure(ECM) level of information field measurements

Fast Bayesian optimization of Needle-in-a-Haystack problems using zooming memory-based initialization (ZoMBI)

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npj Computational Materials 2023年第1期9卷 1543-1555页

作者： Alexander E.Siemenn Zekun Ren Qianxiao Li Tonio Buonassisi Department of Mechanical Engineering Massachusetts Institute of TechnologyCambridgeMAUSA Department of Electrical and Computer Engineering Singapore-MIT Alliance for Research and TechnologySingaporeSingapore Xinterra SingaporeSingapore Department of Mathematics National University of SingaporeSingaporeSingapore Institute for Functional Intelligent Materials National University of SingaporeSingaporeSingapore

Needle-in-a-Haystack problems exist across a wide range of applications including rare disease prediction,ecological resource management,fraud detection,and material property optimization.A Needle-in-a-Haystack problem arises when there is an extreme imbalance of optimum conditions relative to the size of the ***,current state-of-the-art optimization algorithms are not designed with the capabilities to find solutions to these challenging multidimensional Needle-in-a-Haystack problems,resulting in slow convergence or pigeonholing into a local *** this paper,we present a Zooming Memory-Based Initialization algorithm,entitled ZoMBI,that builds on conventional Bayesian optimization principles to quickly and efficiently optimize Needle-in-a-Haystack problems in both less time and fewer *** ZoMBI algorithm demonstrates compute time speed-ups of 400×compared to traditional Bayesian optimization as well as efficiently discovering optima in under 100 experiments that are up to 3×more highly optimized than those discovered by similar methods.

关键词： optimization problems extreme

UBP12/UBP13-mediated deubiquitination of salicylic acid receptor NPR3 suppresses plant immunity

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Molecular Plant 2023年第1期16卷 232-244页

作者： Yu Zhou Su-Hyun Park Nam-Hai Chua Temasek Life Sciences Laboratory National University of Singapore1 Research LinkSingapore 117604Singapore Disruptive&Sustainable Technologies for Agricultural Precision Singapore-MIT Alliance for Research and Technology1 CREATE WaySingapore 138602Singapore

Salicylic acid(SA),a defense hormone produced after pathogen challenge,is critical for plant *** NONEXPRESSER OF PR GENES 1(NPR1)and its paralogs NPR3 and NPR4 can bind SA and mediate SA signal ***1 functions as a transcriptional co-activator to promote defense gene expression,whereas NPR3 and NPR4 have been shown to function as negative regulators in the SA signaling *** the mechanism about NPR1 regulation has been well studied,how NPR3/NPR4 proteins are regulated in immune responses remains largely ***,we show that the stability of NPR3/NPR4 is enhanced by *** the absence of pathogen challenge,NPR3/NPR4 are unstable and degraded by the 26S proteasome,whereas the increase in cellular SA levels upon pathogen infection suppresses NPR3/NPR4 *** found that UBP12 and UBP13,two homologous deubiquitinases from a ubiquitin-specific protease subfamily,negatively regulate plant immunity by promoting NPR3/NPR4 *** genetic results further showed that UBP12/UBP13-mediated immunity suppression is partially dependent on NPR3/NPR4 *** interacting with NPR3 in the nucleus in an SA-dependent manner,UBP12 and UBP13 remove ubiquitin from polyubiquitinated NPR3 to protect it from being *** stabilization of NPR3/NPR4 promoted by UBP12/UBP13 is essential for negative regulation of basal and SA-induced immunity.

关键词： plant immunity salicylic acid NPR3 UBP12/UBP13

Secretive derived from hypoxia preconditioned mesenchymal stem cells promote cartilage regeneration and mitigate joint inflammation via extracellular vesicles

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Bioactive Materials 2023年第9期27卷 98-112页

作者： Yanmeng Yang Yingnan Wu Dahou Yang Shu Hui Neo Nurul Dinah Kadir Doreen Goh Jian Xiong Tan Vinitha Denslin Eng Hin Lee Zheng Yang Department of Orthopaedic Surgery Yong Loo Lin School of MedicineNational University of SingaporeSingapore NUS Tissue Engineering Program Life Sciences InstituteNational University of SingaporeSingapore Critical Analytics for Manufacturing Personalised-Medicine Singapore-MIT Alliance for Research and TechnologySingapore

Secretome derived from mesenchymal stem cells (MSCs) have profound effects on tissue regeneration, which could become the basis of future MSCs therapies. Hypoxia, as the physiologic environment of MSCs, has great potential to enhance MSCs paracrine therapeutic effect. In our study, the paracrine effects of secretome derived from MSCs preconditioned in normoxia and hypoxia was compared through both in vitro functional assays and an in vivo rat osteochondral defect model. Specifically, the paracrine effect of total EVs were compared to that of soluble factors to characterize the predominant active components in the hypoxic secretome. We demonstrated that hypoxia conditioned medium, as well as the corresponding EVs, at a relatively low dosage, were efficient in promoting the repair of critical-sized osteochondral defects and mitigated the joint inflammation in a rat osteochondral defect model, relative to their normoxia counterpart. In vitro functional test shows enhancement through chondrocyte proliferation, migration, and matrix deposition, while inhibit IL-1β-induced chondrocytes senescence, inflammation, matrix degradation, and pro-inflammatory macrophage activity. Multiple functional proteins, as well as a change in EVs’ size profile, with enrichment of specific EV-miRNAs were detected with hypoxia preconditioning, implicating complex molecular pathways involved in hypoxia pre-conditioned MSCs secretome generated cartilage regeneration.

关键词： Hypoxia preconditioned MSCs Secretome Extracellular vesicles Cartilage regeneration Joint inflammation

Identification of chemical compositions from“featureless”optical absorption spectra:Machine learning predictions and experimental validations

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Nano research 2023年第3期16卷 4188-4196页

作者： Tiankai Chen Jiali Li Pengfei Cai Qiaofeng Yao Zekun Ren Yixin Zhu Saif Khan Jianping Xie Xiaonan Wang Department of Chemical and Biomolecular Engineering National University of Singapore4 Engineering Drive 4Singapore 117585Singapore Department of Materials Science and Engineering National University of Singapore9 Engineering Drive 1Singapore 117575Singapore singapore-mit alliance for research and technology(SMART) 1 CREATE WaySingapore 138602Singapore Department of Chemical Engineering Tsinghua UniversityBeijing 100084China

Rapid and accurate chemical composition identification is critically important in *** it can be achieved with optical absorption spectrometry by comparing the experimental spectra with the reference data when the chemical compositions are simple,such application is limited in more complicated scenarios especially in nano-scale *** is due to the difficulties in identifying optical absorption peaks(i.e.,from“featureless”spectra)arose from the *** this work,using the ultraviolet-visible(UV-Vis)absorption spectra of metal nanoclusters(NCs)as a demonstration,we develop a machine-learningbased method to unravel the compositions of metal NCs behind the“featureless”*** implementing a one-dimensional convolutional neural network,good matches between prediction results and experimental results and low mean absolute error values are achieved on these optical absorption spectra that human cannot *** work opens a door for the identification of nanomaterials at molecular precision from their optical properties,paving the way to rapid and high-throughput characterizations.

关键词： gold nanoclusters composition identification optical absorption machine learning convolutional neural network

G protein controls stress readiness by modulating transcriptional and metabolic homeostasis in Arabidopsis thaliana and Marchantia polymorpha

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Molecular Plant 2022年第12期15卷 1889-1907页

作者： Ting-Ying Wu Shalini Krishnamoorthi Kulaporn Boonyaves Isam Al-Darabsah Richalynn Leong Alan M.Jones Kimitsune Ishizaki Kang-Ling Liao Daisuke Urano Temasek Life Sciences Laboratory SingaporeSingapore Department of Mathematics University of ManitobaWinnipegMBCanada singapore-mit alliance for research and technology SingaporeSingapore Department of Biological Sciences National University of SingaporeSingapore 117558Singapore Departments of Biology and Pharmacology University of North CarolinaChapel HillNCUSA Graduate School of Science Kobe UniversityKobeHyogo 657-8501Japan

The core G protein signaling module,which consists of Gαand extra-large Gα(XLG)subunits coupled with the Gβγdimer,is a master regulator of various stress *** this study,we compared the basal and salt stress-induced transcriptomic,metabolomic and phenotypic profiles in Gα,Gβ,and XLG-null mutants of two plant species,Arabidopsis thaliana and Marchantia polymorpha,and showed that G protein mediates the shift of transcriptional and metabolic homeostasis to stress readiness *** demonstrated that such stress readiness serves as an intrinsic protection mechanism against further stressors through enhancing the phenylpropanoid pathway and abscisic acid ***,WRKY transcription factors were identified as key intermediates of G protein-mediated homeostatic *** and mathematical model comparisons between *** and *** revealed evolutionary conservation of transcriptional and metabolic networks over land plant evolution,whereas divergence has occurred in the function of plant-specific atypical XLG *** together,our results indicate that the shifts in transcriptional and metabolic homeostasis at least partially act as the mechanisms of G protein-coupled stress responses that are conserved between two distantly related plants.

关键词： homeostatic adjustments transcriptional regulation metabolic regulation heterotrimeric G protein evolutionary conservation

Thermal energy dependent transient permittivity of epsilon-near-zero material

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Science China(Physics,Mechanics & Astronomy) 2022年第8期65卷 96-101页

作者： Heng Wang Lixun Sun Kang Du Wending Zhang SooJin Chua Guixin Li Ting Mei MOE Key Laboratory of Material Physics and Chemistry under Extraordinary Conditions and Shaanxi Key Laboratory of Optical Information TechnologySchool of Physical Science and TechnologyNorthwestern Polytechnical UniversityXi’an710129China Department of Materials Science and Engineering Southern University of Science and TechnologyShenzhen518055China Shenzhen Institute for Quantum Science and Engineering Southern University of Science and TechnologyShenzhen518055China Department of Electrical and Computer Engineering National University of SingaporeSingapore117583Singapore LEES Program Singapore-MIT Alliance for Research&Technology(SMART)Singapore138602Singapore

Transparent conductive oxides exhibit attractive optical nonlinearity with ultrafast response and giant refractive index change near the epsilon-near-zero(ENZ) wavelength, originating from the intraband dynamics of conduction electrons. The optical nonlinearity of ENZ materials has been explained by using the overall-effective-mass and the overall-scattering-time of electrons in the extended Drude model. However, their response to optical excitation is yet the last building block to complete the theory. In this paper, the concept of thermal energy is theoretically proposed to account for the total energy of conduction electrons exceeding their thermal equilibrium value. The time-varying thermal energy is adopted to describe the transient optical response of indium-tin-oxide(ITO), a typical ENZ material. A spectrally-resolved femtosecond pump-probe experiment was conducted to verify our theory. By correlating the thermal energy with the pumping density, both the giant change and the transient response of the permittivity of ITO can be predicted. The results in this work provide a new methodology to describe the transient permittivities of ENZ materials, which will benefit the design of ENZ-based nonlinear photonic devices.

关键词： epsilon-near-zero optical nonlinearity transient response thermal energy hot electron indium tin oxide

维普期刊数据库

Recent progress on the mechanics of sharply bent DNA

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Science China(Physics,Mechanics & Astronomy) 2016年第8期59卷 1-8页

作者： PeiWen Cong Jie Yan Mechanobiology Institute National University of Singapore singapore-mit alliance National University of Singapore Department of Physics National University of Singapore BioSystems and Micromechanics IRG Singapore-MIT Alliance for Research and Technology Centre Centre for BioImaging Sciences National University of Singapore

Despite extensive studies on the mechanics of DNA under external constrains, such as tension, torsion, and bending, several important aspects have remained poorly understood. One biologically important example is the mechanics of DNA under sharp bending conditions, which has been debated for a decade without thorough comprehension. The debate is about the interesting phenomenon raised from a series of different experiments: sharply bent DNA has a surprisingly high apparent bending flexibility that deviates from the canonical bending elasticity of DNA. This finding has motivated various theoretical models, which mainly incorporate the excitation of mechanical defects inside severely bent DNA molecules. Here, we review the recent progress on the understanding of the mechanics of sharply bent DNA and provide our view on this important question by interrogating the theoretical foundation of these experimental measurements.

关键词： DNA 弯曲力学实验测量外部约束生物学分子内

维普期刊数据库

Full-parameter omnidirectional transformation optical devices

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National Science Review 2024年第3期11卷 92-99页

作者： Yuan Gao Yu Luo Jingjing Zhang Zhengjie Huang Bin Zheng Hongsheng Chen Dexin Ye Interdisciplinary Center for Quantum Information State Key Laboratory of Extreme Photonics and InstrumentationZJU-Hangzhou Global Scientific and Technological Innovation CenterZhejiang University School of Electrical and Electronic Engineering Nanyang Technological University CNRS-InternationalNTU-Thales research alliance Nanyang Technological University Institute of Electromagnetic Space Southeast University State Key Laboratory of Millimeter Waves Southeast University International Joint Innovation Center The Electromagnetics Academy at Zhejiang University Zhejiang University Key Laboratory of Advanced Micro/Nano Electronic Devices&Smart Systems of Zhejiang Jinhua Institute of Zhejiang UniversityZhejiang University Shaoxing Institute of Zhejiang University Zhejiang University

Transformation optics(TO) provides an unprecedented technique to control electromagnetic(EM) waves by engineering the constitutive parameters of the surrounding medium through a proper spatial transformation. In general, ideal transformation optical devices require simultaneous electric and magnetic responses along all three dimensions. To ease the practical implementation, previous studies usually made use of reduced parameters or other simplified approaches, which inevitably introduce extra reflection or unwanted phase shift. Up to today, experimental realizations of full-parameter transformation optical devices in free space are still quite limited. Here, a general design strategy is proposed to solve this *** a specific example, a full-parameter spatial-compression TO medium with constitutive parameters taking the diagonal form diag(a, a, 1/a) for the TM wave incidence was designed and realized experimentally. Such spatial-compression TO media were then applied to the implementation of an ideal omnidirectional invisibility cloak capable of concealing a large-scale object over a wide range of illumination angles. Both the simulation and experiment confirm that the cloak allows for nearly unity transmission of EM waves in the forward direction without introducing extra scattering or phase shift. This work constitutes an important stepping stone for future practical implementation of arbitrary full-parameter omnidirectional transformation optical devices.

关键词： transformation optical devices omnidirectional impedance matching full-parameter invisibility cloak