3,748 research outputs found
Model-Free Reconstruction of Capacity Degradation Trajectory of Lithium-Ion Batteries Using Early Cycle Data
Early degradation prediction of lithium-ion batteries is crucial for ensuring
safety and preventing unexpected failure in manufacturing and diagnostic
processes. Long-term capacity trajectory predictions can fail due to cumulative
errors and noise. To address this issue, this study proposes a data-centric
method that uses early single-cycle data to predict the capacity degradation
trajectory of lithium-ion cells. The method involves predicting a few knots at
specific retention levels using a deep learning-based model and interpolating
them to reconstruct the trajectory. Two approaches are used to identify the
retention levels of two to four knots: uniformly dividing the retention up to
the end of life and finding optimal locations using Bayesian optimization. The
proposed model is validated with experimental data from 169 cells using
five-fold cross-validation. The results show that mean absolute percentage
errors in trajectory prediction are less than 1.60% for all cases of knots. By
predicting only the cycle numbers of at least two knots based on early
single-cycle charge and discharge data, the model can directly estimate the
overall capacity degradation trajectory. Further experiments suggest using
three-cycle input data to achieve robust and efficient predictions, even in the
presence of noise. The method is then applied to predict various shapes of
capacity degradation patterns using additional experimental data from 82 cells.
The study demonstrates that collecting only the cycle information of a few
knots during model training and a few early cycle data points for predictions
is sufficient for predicting capacity degradation. This can help establish
appropriate warranties or replacement cycles in battery manufacturing and
diagnosis processes
Compressible Boundary Layer Predictions at High Reynolds Number using Hybrid LES/RANS Methods
Simulations of compressible boundary layer flow at three different Reynolds numbers (Re(sub delta) = 5.59x10(exp 4), 1.78x10(exp 5), and 1.58x10(exp 6) are performed using a hybrid large-eddy/Reynolds-averaged Navier-Stokes method. Variations in the recycling/rescaling method, the higher-order extension, the choice of primitive variables, the RANS/LES transition parameters, and the mesh resolution are considered in order to assess the model. The results indicate that the present model can provide good predictions of the mean flow properties and second-moment statistics of the boundary layers considered. Normalized Reynolds stresses in the outer layer are found to be independent of Reynolds number, similar to incompressible turbulent boundary layers
Simultaneous deletion of floxed genes mediated by CaMKIIa-Cre in the brain and in male germ cells: application to conditional and conventional disruption of Go-alfa
The Cre/LoxP system is a well-established approach to spatially and temporally control genetic inactivation. The calcium/calmodulin-dependent protein kinase II alpha subunit (CaMKIIα) promoter limits expression to specific regions of the forebrain and thus has been utilized for the brain-specific inactivation of the genes. Here, we show that CaMKIIα-Cre can be utilized for simultaneous inactivation of genes in the adult brain and in male germ cells. Double transgenic Rosa26+/stop-lacZ::CaMKIIα-Cre+/Cre mice generated by crossing CaMKIIα-Cre+/Cre mice with floxed ROSA26 lacZ reporter (Rosa26+/stop-lacZ) mice exhibited lacZ expression in the brain and testis. When these mice were mated to wild-type females, about 27% of the offspring were whole body blue by X-gal staining without inheriting the Cre transgene. These results indicate that recombination can occur in the germ cells of male Rosa26+/stop-lacZ::CaMKIIα-Cre+/Cre mice. Similarly, when double transgenic Gnao+/f::CaMKIIα-Cre+/Cre mice carrying a floxed Go-alpha gene (Gnaof/f) were backcrossed to wild-type females, approximately 22% of the offspring carried the disrupted allele (GnaoΔ) without inheriting the Cre transgene. The GnaoΔ/Δ mice closely resembled conventional Go-alpha knockout mice (Gnao−/−) with respect to impairment of their behavior. Thus, we conclude that CaMKIIα-Cre mice afford recombination for both tissue- and time-controlled inactivation of floxed target genes in the brain and for their permanent disruption. This work also emphasizes that extra caution should be exercised in utilizing CaMKIIα-Cre mice as breeding pairs.Fil: Choi, Chan-Il. Ajou University. School of Medicine; Corea del SurFil: Yoon, Sang-Phil. Ajou University. School of Medicine; Corea del SurFil: Choi, Jung-Mi. Ajou University. School of Medicine; Corea del SurFil: Kim, Sung-Soo. Ajou University. School of Medicine; Corea del SurFil: Lee, Young-Don. Ajou University. School of Medicine; Corea del SurFil: Birnbaumer, Lutz. National Institute of Environmental Health Sciences; Estados Unidos. Pontificia Universidad Católica Argentina "Santa María de los Buenos Aires". Instituto de Investigaciones Biomédicas. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas; ArgentinaFil: Suh-Kim. Haeyoung. Ajou University. School of Medicine; Corea del Su
Ionothermal Synthesis of Metal-Organic Framework
Ionothermal synthesis employs ionic liquids for synthesis of metal organic frameworks (MOFs) as solvent and template. The cations and anions of ionic liquids may be finely adjusted to produce a great variety of reaction environments and thus frameworks. Organisation of the structures synthesised from related ionic liquid combinations give rise to provocative chemical trends that may be used to predict future outcomes. Further analysis of their structures is possible by reducing the complex framework to its underlying topology, which by itself brings more precision to prediction. Through reduction, many seemingly different, but related classes of structures may be merged into larger groups and provide better understanding of the nanoscopic structures and synthesis conditions that gave rise to them. Ionothermal synthesis has promised to enable us to effectively plan the synthesis ahead for a given purpose. However, for its promise to be kept, several difficult limitations must be overcome, including the inseparable cations from the solvent that reside in the framework pore
Radar-based nowcasting by combining centroid tracking and motion vector of convective storm
Póster presentado en: 3rd European Nowcasting Conference, celebrada en la sede central de AEMET en Madrid del 24 al 26 de abril de 2019
Metal/graphene sheets as p-type transparent conducting electrodes in GaN light emitting diodes
We demonstrate the use of graphene based transparent sheets as a p-type current spreading layer in GaN light emitting diodes (LEDs). Very thin Ni/Au was inserted between graphene and p-type GaN to reduce contact resistance, which reduced contact resistance from similar to 5.5 to similar to 0.6 Omega/ cm(2), with no critical optical loss. As a result, LEDs with metal-graphene provided current spreading and injection into the p-type GaN layer, enabling three times enhanced electroluminescent intensity compared with those with graphene alone. We confirmed very strong blue light emission in a large area of the metal-graphene layer by analyzing image brightness.open281
Implementation fidelity of the Systems for Person-Centered Elder Care (SPEC): a process evaluation study
Background
The Systems for Person-Centered Elder Care (SPEC), a complex intervention, was conducted to examine its effectiveness as a technology-enhanced, multidisciplinary, and integrated care model for frail older persons among ten nursing homes (NHs) in South Korea where formal long-term care has recently been introduced. The purpose of this study was to evaluate the implementation fidelity of the SPEC intervention and to identify moderating factors that influence the implementation fidelity.
Methods
This study was a process evaluation based on an evidence-based framework for implementation fidelity using a mixed-methods design. Quantitative data from consultant logbooks, NH documentations, an information and communications technology (ICT) system, and a standardized questionnaire were collected from April 2015 to December 2016 and analyzed by calculating the descriptive statistics. Semi-structured focus group interviews were held with multidisciplinary teams from the participating NHs. Qualitative data from a semi-structured questionnaire and the focus group interviews were analyzed using content analysis.
Results
The SPEC program demonstrated good implementation fidelity, and adherence to the SPEC program was strong in all aspects, such as content, coverage, frequency, and duration. Of the participating on-site coordinators, 60% reported that the SPEC model positively impacted needs assessment and the reporting system for resident care. The important facilitating factors were tailored facilitating strategies, assurance of the quality of delivery, and recruitment strategies.
Conclusion
The effectiveness of the SPEC program was driven by good implementation fidelity. The key factors of good implementation fidelity were tailored delivery of evidence-based interventions over process evaluation work, facilitating strategies, and ICT support. Larger implementation studies with a more user-friendly ICT system are recommended.
Trial registration
ISRCTN registry,
ISRCTN11972147
. Registered on 16 March 2015This work was supported by a grant from the Korea Health Technology R&D Project through the Korea Health Industry Development Institute (KHIDI), funded by the Ministry of Health and Welfare, Republic of Korea [HI13C2250]; a 2016 AXA Award funded by AXA Research Fund [900-2017006 to HK]; and the National Research Foundation of Korea funded by the Korean Government [NO.4199990514025]. The funding sources had no role in the study design; in the collection, analysis, and interpretation of the data; in the writing of the manuscript; or in the decision to submit the manuscript for publication
Designing a Data Warehouse for Cyber Crimes
One of the greatest challenges facing modern society is the rising tide of cyber crimes. These crimes, since they rarely fit the model of conventional crimes, are difficult to investigate, hard to analyze, and difficult to prosecute. Collecting data in a unified framework is a mandatory step that will assist the investigator in sorting through the mountains of data. In this paper, we explore designing a dimensional model for a data warehouse that can be used in analyzing cyber crime data. We also present some interesting queries and the types of cyber crime analyses that can be performed based on the data warehouse. We discuss several ways of utilizing the data warehouse using OLAP and data mining technologies. We finally discuss legal issues and data population issues for the data warehouse
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