57 research outputs found

    Performance Comparison of Design Optimization and Deep Learning-based Inverse Design

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    Surrogate model-based optimization has been increasingly used in the field of engineering design. It involves creating a surrogate model with objective functions or constraints based on the data obtained from simulations or real-world experiments, and then finding the optimal solution from the model using numerical optimization methods. Recent advancements in deep learning-based inverse design methods have made it possible to generate real-time optimal solutions for engineering design problems, eliminating the requirement for iterative optimization processes. Nevertheless, no comprehensive study has yet closely examined the specific advantages and disadvantages of this novel approach compared to the traditional design optimization method. The objective of this paper is to compare the performance of traditional design optimization methods with deep learning-based inverse design methods by employing benchmark problems across various scenarios. Based on the findings of this study, we provide guidelines that can be taken into account for the future utilization of deep learning-based inverse design. It is anticipated that these guidelines will enhance the practical applicability of this approach to real engineering design problems

    Genomic and Virulence Characterization of Intrauterine Pathogenic Escherichia coli With Multi-Drug Resistance Isolated From Cow Uteri With Metritis

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    Metritis is a major disease in dairy cows causing animal death, decrease of birth rate, milk production, and economic loss. Antibiotic treatment is generally used to treat such disease but has a high failure rate of 23–35%. The reason for the treatment failure remains unclear, although antibiotic resistance is postulated as one of factors. Our study investigated the prevalence of extended spectrum ÎČ-lactamase (ESBL) producing bacteria in uterine samples of cows with metritis and characterized the isolated intrauterine pathogenic Escherichia coli (IUPEC) strains using whole genome sequencing. We found that the cows with metritis we examined had a high percentage of ESBL producing IUPEC with multi-drug resistance including ceftiofur which is commonly used for metritis treatment. The ESBL producing IUPEC strains harbored versatile antibiotic resistance genes conferring resistance against 29 antibiotic classes, suggesting that transmission of these bacteria to other animals and humans may lead to antibiotic treatment failure. Furthermore, these strains had strong adhesion and invasion activity, along with critical virulence factors, indicating that they may cause infectious diseases in not only the uterus, but also in other organs and hosts

    Formal Modeling and Verification of Motor Drive Software for Networked Motion Control Systems

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    Abstract: This paper presents a model-based approach to the design and verification of motor drive software for networked motion control systems. We develop a formal model for an Ethernetbased motion system, where, using timed automata, we describe the concurrent and synchronized behaviors of the components, i.e., motion controller, motor drives, and communication links. The drive, in particular, is modeled in enough detail to accurately reflect the software implementation used in a real drive. We use the design of multitasked drive software with fixed-priority preemptive scheduling. With UPPAAL model checking, we verify the precision and accuracy of the rendered motion in terms of the requirements on the actuation delay at each drive and the actuation deviation between different drives, respectively. The analysis results demonstrate the benefits of our model-based approach in the safety verification and design space exploration of motor drive software. We show that it is possible to verify deadlock freeness and real-time schedulability in an early design phase. And, for varying number of drives and size of messages, we can successfully determine the combination of task periods that leads to the best precision and accuracy

    Analysis of spike protein variants evolved in a novel in vivo long-term replication model for SARS-CoV-2

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    IntroductionThe spectrum of SARS-CoV-2 mutations have increased over time, resulting in the emergence of several variants of concern. Persistent infection is assumed to be involved in the evolution of the variants. Calu-3 human lung cancer cells persistently grow without apoptosis and release low virus titers after infection.MethodsWe established a novel in vivo long-term replication model using xenografts of Calu-3 human lung cancer cells in immunodeficient mice. Virus replication in the tumor was monitored for 30 days and occurrence of mutations in the viral genome was determined by whole-genome deep sequencing. Viral isolates with mutations were selected after plaque forming assays and their properties were determined in cells and in K18-hACE2 mice.ResultsAfter infection with parental SARS-CoV-2, viruses were found in the tumor tissues for up to 30 days and acquired various mutations, predominantly in the spike (S) protein, some of which increased while others fluctuated for 30 days. Three viral isolates with different combination of mutations produced higher virus titers than the parental virus in Calu-3 cells without cytopathic effects. In K18-hACE2 mice, the variants were less lethal than the parental virus. Infection with each variant induced production of cross-reactive antibodies to the receptor binding domain of parental SARS-CoV-2 S protein and provided protective immunity against subsequent challenge with parental virus.DiscussionThese results suggest that most of the SARS-CoV-2 variants acquired mutations promoting host adaptation in the Calu-3 xenograft mice. This model can be used in the future to further study SARS-CoV-2 variants upon long-term replication in vivo

    Self-Leadership and Innovative Behavior: Mediation of Informal Learning and Moderation of Social Capital

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    As the business environment is rapidly changing, interest in the innovation of organizational members is accelerating. Therefore, this study investigated how individual-level resources, particularly self-leadership, affect workers’ innovative behavior. Many studies have emphasized that employee initiative can lead to job performance at the individual level and organizational performance improvement. Self-leadership is a spontaneous and an active behavior, or mindset, defined as the ability to lead an individual in challenging situations characterized by learned behaviors that can be augmented by training. It is of interest to many researchers and practitioners. Further, we tested the mediation of informal learning, another individual-level resource, in this relationship and the moderation of social capital, a social resource, in the mediation. We analyzed the responses of 551 employees of South Korean companies using Model 6 and 14 of PROCESS Macro. The results revealed that self-leadership positively influenced workers’ innovative behavior, and informal learning mediated this relationship. We also confirmed that social capital strengthened the positive mediating effect of informal learning. This study empirically verifies the role of self-leadership, informal learning, and social capital as the determinants of innovative behavior and expands the discussion on leadership by highlighting the significance of self-leadership as opposed to traditional leadership approaches

    The Equity of Health Care Spending in South Korea: Testing the Impact of Publicness

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    This paper examined the important organizational and managerial factors of publicness for the equity of health care. The extent of organizational publicness was measured with key independent variables such as ownership, evaluation, and accreditation. The dependent variable was measured by three equity indicators for patients under medical care and veterans care: financial inequity, social equity, and overall equity. We analyzed unbalanced panel data with 328 general hospitals between 2008 and 2012. We performed panel analysis with fixed and random effects. Our findings illustrate that government ownership is significantly associated with differences in equity indicators. Government owned hospitals show the better performance for equity than nonprofit and individually owned hospitals do. Compared to nonprofit and individually owned hospitals, government owned hospitals have a higher share of medical payment bills and health care spending for the disadvantaged but a lower proportion of out-of-pocket payment. Government evaluation is also significantly related to better equity performance. There are, however, significantly negative interactions between hospital government ownership and the size of medical payment bills. We found a significant tendency that the more medical payments, the less responsiveness to the equity of health care in government owned hospitals. Future research in hospital performance is required to consider not only sectoral differences but also the negative proclivity of public hospitals that shrink health care services for the poor. Further research is also expected to explore what sectoral identities and behaviors across public, nonprofit, and private hospitals influence the level of equity or inequity in health care

    Fabrication of Micro-Patterned Chip with Controlled Thickness for High-Throughput Cryogenic Electron Microscopy

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    © 2022 JoVE Journal of Visualized Experiments.A major limitation for the efficient and high-throughput structure analysis of biomolecules using cryogenic electron microscopy (cryo-EM) is the difficulty of preparing cryo-EM samples with controlled ice thickness at the nanoscale. The silicon (Si)-based chip, which has a regular array of micro-holes with graphene oxide (GO) window patterned on a thickness-controlled silicon nitride (SixNy) film, has been developed by applying microelectromechanical system (MEMS) techniques. UV photolithography, chemical vapor deposition, wet and dry etching of the thin film, and drop-casting of 2D nanosheet materials were used for mass-production of the micro-patterned chips with GO windows. The depth of the micro-holes is regulated to control the ice thickness on-demand, depending on the size of the specimen for cryo-EM analysis. The favorable affinity of GO toward biomolecules concentrates the biomolecules of interest within the micro-hole during cryo-EM sample preparation. The micro-patterned chip with GO windows enables high-throughput cryo-EM imaging of various biological molecules, as well as inorganic nanomaterials.11Nsciescopu

    A Study on the Field Applicability of Intermittent Irrigation in Protected Cultivation Using an Automatic Irrigation System

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    The demand for efficient water use and automatic systems has been increasing due to the frequent drought damage to crops as a result of climate change, the shortage of water resources in rural areas, and the aging of farmers. The existing automatic irrigation systems reduce the amount of labor required for irrigation and maintain soil moisture. However, the irrigation threshold criteria are user-determined as opposed to being automated according to input objectives such as improving crop productivity and saving water. In this study, an algorithm that could automatically determine suitable soil moisture according to a database and an automatic irrigation system with intermittent irrigation for efficient water use were developed. An experiment was then conducted on the productivity of crops for protected cultivation according to the application of the system. As the frequency domain reflectometry (FDR) sensor used in this system measured the volumetric water content of the soil, the soil moisture tension corresponding with the set value was converted into the volumetric water content using a regression equation. The process of intermittent irrigation was defined by using the moisture movement modeling of Hydrus 2D to reduce water loss on the soil surface and allow moisture to penetrate the soil unobstructed. An experimental field of a tomato farm was divided into empirical manual and controlled automatic irrigation plots. A total of 97.3% of the soil moisture values in the −33 kPa-controlled automatic irrigation plot and 96.6% of the soil moisture values in the −25 kPa-controlled automatic irrigation plot were within each set range during the first cropping season. During the second cropping season, a total of 94.8% of the soil moisture values in the −33 kPa-controlled automatic irrigation plot was within the set range. Compared with the empirical manual irrigation plot, the water productivity in the first cropping season was 113.9% in the −33 kPa-controlled automatic irrigation plot and 106.3% in the −25 kPa-controlled automatic irrigation plot. In the second cropping season, the water productivity was 117.3% in the −33 kPa-controlled automatic irrigation plot. Therefore, an automatic irrigation system applied with intermittent irrigation could be critical to increasing agricultural production and improving water-use efficiency
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