This study introduces a fault diagnosis algorithm based on particle filtering for open-cycle liquid-propellant rocket engines (LPREs). The algorithm serves as a model-based method for the startup ...process, accounting for more than 30% of engine failures. Similar to the previous fault detection and diagnosis (FDD) algorithm for the startup process, the algorithm in this study is composed of a nonlinear filter to generate residuals, a residual analysis, and a multiple-model (MM) approach to detect and diagnose faults from the residuals. In contrast to the previous study, this study makes use of the modified cumulative sum (CUSUM) algorithm, widely used in change-detection monitoring, and a particle filter (PF), which is theoretically the most accurate nonlinear filter. The algorithm is confirmed numerically using the CUSUM and MM methods. Subsequently, the FDD algorithm is compared with an algorithm from a previous study using a Monte Carlo simulation. Through a comparative analysis of algorithmic performance, this study demonstrates that the current PF-based FDD algorithm outperforms the algorithm based on other nonlinear filters.
We propose a fault detection and diagnosis (FDD) method for liquid-propellant rocket engine tests during startup transient based on deep learning. A numerical model describing the startup transient ...for the hot-firing test of the rocket engine allows to simulate normal and abnormal situations caused by various types of faults. Datasets containing potential fault types during the engine startup have been constructed using the numerical model to train deep neural networks targeting. Actual hot-firing ground test data of a liquid rocket have been used to determine the input parameters of the model and validate the simulation results. A numerical case study on FDD for the ground operation of an open-cycle liquid-propellant rocket engine demonstrates the effectiveness of the proposed method compared to the traditional red-line cutoff.
•Fault detection and diagnosis (FDD) is important during rocket engine startup.•We propose a deep neural network approach for this type of FDD.•A comprehensive engine model is derived to generate representative training data.•The model is validated using real data from hot-fire tests in normal/faulty cases.•The trained networks provide realistic, fast, and accurate FDD results.
Obesity and metabolic disorders caused by alterations in lipid metabolism are major health issues in developed, affluent societies. Adipose tissue is the only organ that stores lipids and prevents ...lipotoxicity in other organs. Mature adipocytes can affect themselves and distant metabolism‐related tissues by producing various adipokines, including adiponectin and leptin. The engulfment adaptor phosphotyrosine‐binding domain‐containing 1 (GULP1) regulates intracellular trafficking of glycosphingolipids and cholesterol, suggesting its close association with lipid metabolism. However, the role of GULP1 in adipocytes remains unknown. Therefore, this study aimed to investigate the function of GULP1 in adipogenesis, glucose uptake, and the insulin signaling pathway in adipocytes. A 3T3‐L1 cell line with Gulp1 knockdown (shGulp1) and a 3T3‐L1 control group (U6) were established. Changes in shGulp1 cells due to GULP1 deficiency were examined and compared to those in U6 cells using microarray analysis. Glucose uptake was monitored via insulin stimulation in shGulp1 and U6 cells using a 2‐NBDG glucose uptake assay, and the insulin signaling pathway was investigated by western blot analysis. Adipogenesis was significantly delayed, lipid metabolism was altered, and several adipogenesis‐related genes were downregulated in shGulp1 cells compared to those in U6 cells. Microarray analysis revealed significant inhibition of peroxisome proliferator‐activated receptor signaling in shGulp1 cells compared with U6 cells. The production and secretion of adiponectin as well as the expression of adiponectin receptor were decreased in shGulp1 cells. In particular, compared with U6 cells, glucose uptake via insulin stimulation was significantly decreased in shGulp1 cells through the disturbance of ERK1/2 phosphorylation. This is the first study to identify the role of GULP1 in adipogenesis and insulin‐stimulated glucose uptake by adipocytes, thereby providing new insights into the differentiation and functions of adipocytes and the metabolism of lipids and glucose, which can help better understand metabolic diseases.
Recent rapid industrial development in the Korean Peninsula has increased the impacts of meteorological disasters on marine and coastal environments. In particular, marine fog driven by summer cold ...water masses can inhibit transport and aviation; yet a lack of observational data hinders our understanding of this phenomena. The present study aimed to analyze the differences in cold water mass formation according to sea surface temperature (SST) resolution and its effects on the occurrence and distribution of sea fog over the Korean Peninsula from June 23–July 1, 2016, according to the Weather Research and Forecasting model. Data from the Final Operational Model Global Tropospheric Analyses were provided at 1° and 0.25° resolutions and NOAA real-time global SST (RTG-SST) data were provided at 0.083°. While conventional analyses have used initial SST distributions throughout the entire simulation period, small-scale, rapidly developing oceanic phenomena (e.g., cold water masses) lasting for several days act as an important mediating factor between the lower atmosphere and sea. RTG-SST was successful at identifying fog presence and maintained the most extensive horizontal distribution of cold water masses. In addition, it was confirmed that the difference in SST resolution led to varying sizes and strengths of the warm pools that provided water vapor from the open sea area to the atmosphere. On examining the horizontal water vapor transport and the vertical structure of the generated sea fog using the RTG-SST, water vapors were found to be continuously introduced by the southwesterly winds from June 29 to 30, creating a fog event throughout June 30. Accordingly, high-resolution SST data must be input into numerical models whenever possible. It is expected that the findings of this study can contribute to the reduction of ship accidents via the accurate simulation of sea fog.
Mobile energy storage devices (MESDs) operate as medium- or large-sized batteries that can be loaded onto electric trucks and connected to charging stations to provide various ancillary services for ...distribution grids. This article proposes a new strategy for MESD operation, in which their power outputs and paths are co-optimally scheduled to minimize the total energy loss in both power and transportation networks. The distances moved by MESDs and time at different locations are modeled using a set of linear equations, considering the time-varying traffic flow. The linear transit model is integrated with linearized constraints to support the reliable operation of the distribution grid. In particular, an optimal scheduling problem is formulated considering the maximum limits on incremental variations in bus voltages and line power flows for active and reactive power outputs of MESDs. A mixed-integer linear programming solver can be readily applied to the optimization problem, ensuring the global optimality of the solution. Simulation case studies are carried out under various power and transportation network conditions. The results of these case studies confirm that the proposed strategy using MESDs is effective in reducing total energy losses, compared to conventional methods using stationary batteries and plug-in electric vehicles.
Although inflammation is a host defense mechanism, chronic inflammation mediates several diseases, including cancer, allergy, asthma, and autoimmune diseases, and reportedly, it is associated with a ...60% mortality rate. There are several reports on the anti-inflammatory effects of Curcuma longa and Allium hookeri. However, although they can be used as culinary materials and have biological effects, they are not effective anti-inflammatory agents. In this study, we evaluated the synergic effect of C. longa and A. hookeri in order to confirm the possibility of a new anti-inflammatory agent. Based on cell viability and cytokine analyses, the appropriate ratio of C. longa and A. hookeri was confirmed using an air pouch animal model. Then, the anti-inflammatory effect of C. longa and A. hookeri co-treatment was evaluated by measuring the immune cell count and cytokines in the exudate and by comparing the morphological changes and cytokines in inflamed skin samples. Additionally, we evaluated the NF-κB/COX-2 pathway and iNOS levels. The active constituents detected in C. longa were demethoxycurcumin and bisdemethoxycurcumin, and that detected in A. hookeri was methylsulfonylmethane. An in vitro assessment determined the appropriate drug ratio as 3:7. In a carrageenan-induced inflammatory model, co-treatment effectively suppressed inflammatory cytokines, including IFN-γ, IL-1β, IL-6, IL-13, and IL-17, and recovered inflammation-related morphological changes in the skin. The anti-inflammatory effect of the co-treatment was mediated through the NF-κB/COX-2 pathway and iNOS inhibition. We concluded that co-treatment with C. longa and A. hookeri synergistically inhibited inflammation via the NF-κB/COX-2/iNOS pathway.
: The effect of light on melatonin biosynthesis was examined in detached rice (Oryza sativa cv. Asahi) leaves during the senescence process. The detached leaves were exposed to senescence treatment ...either in constant darkness or in constant light, and subjected to HPLC analysis for melatonin and its precursors. Higher melatonin levels were detected in rice leaves under constant light while very low levels were observed in constant darkness. Levels of the melatonin intermediates, tryptamine, serotonin, and N‐acetylserotonin significantly decreased in the dark compared to those in the light. Furthermore, relative mRNA levels of melatonin biosynthetic genes and their corresponding proteins decreased accordingly in constant darkness. The most striking difference between constant light and dark was observed in levels of the protein tryptamine 5‐hydroxylase. These results suggest that melatonin biosynthesis during senescence is dependent on light signals in rice leaves, contrary to the response found in animals.
The engulfment adaptor phosphotyrosine‐binding domain containing 1 (GULP1) is an adaptor protein involved in the engulfment of apoptotic cells via phagocytosis. Gulp1 was first found to promote the ...phagocytosis of apoptotic cells by macrophages, and its role in various tissues, including neurons and ovaries, has been well studied. However, the expression and function of GULP1 in bone tissue are poorly understood. Consequently, to determine whether GULP1 plays a role in the regulation of bone remodeling in vitro and in vivo, we generated Gulp1 knockout (KO) mice. Gulp1 was expressed in bone tissue, mainly in osteoblasts, while its expression is very low in osteoclasts. Microcomputed tomography and histomorphometry analysis in 8‐week‐old male Gulp1 KO mice revealed a high bone mass in comparison with male wild‐type (WT) mice. This was a result of decreased osteoclast differentiation and function in vivo and in vitro as confirmed by a reduced actin ring and microtubule formation in osteoclasts. Gas chromatography‐mass spectrometry analysis further showed that both 17β‐estradiol (E2) and 2‐hydroxyestradiol levels, and the E2/testosterone metabolic ratio, reflecting aromatase activity, were also higher in the bone marrow of male Gulp1 KO mice than in male WT mice. Consistent with mass spectrometry analysis, aromatase enzymatic activity was significantly higher in the bone marrow of male Gulp1 KO mice. Altogether, our results suggest that GULP1 deficiency decreases the differentiation and function of osteoclasts themselves and increases sex steroid hormone‐mediated inhibition of osteoclast differentiation and function, rather than affecting osteoblasts, resulting in a high bone mass in male mice. To the best of our knowledge, this is the first study to explore the direct and indirect roles of GULP1 in bone remodeling, providing new insights into its regulation.
To examine whether melatonin‐rich plants can defend against oxidative stress, we subjected melatonin‐rich transgenic (MRT) rice plants to the singlet‐oxygen‐generating herbicide butafenacil. Both MRT ...and transgenic control (TC; expressing the vector only) rice seeds germinated and grew equally well in continuous dark on half‐strength Murashige and Skoog (MS) medium containing 0.1 μm butafenacil. However, after transferring the seedlings to light, the TCs rapidly necrotized, whereas the MRT seedlings showed resistant phenotypes. Seven‐day‐old MRT seedlings treated with 0.1 μm butafenacil were resistant to the herbicide and contained high chlorophyll levels and low malondialdehyde and hydrogen peroxide contents compared with the TCs. As they did before the herbicide treatment, the MRT plants also produced much more melatonin after the herbicide treatment than the TCs. In addition, the MRT plants exhibited higher superoxide dismutase and catalase activities before and after the herbicide treatment compared with the TCs. This is the first report showing that MRT plants exhibit resistance against a peroxidizing herbicide that acts by generating reactive oxygen species (ROS) that kill plants. This result indicates that melatonin scavenges ROS efficiently in vivo in the transgenic plants, leading to oxidative stress resistance.
We conducted regional scale CO2 simulations using the Weather Research and Forecasting model (WRF) coupled with the Vegetation Photosynthesis and Respiration Model (VPRM). We contrasted simulated ...concentrations with column, ground and aircraft observations during the Korea-United States Air Quality (KORUS-AQ) 2016 field campaign. Overall, WRF-VPRM slightly underestimates CO2 concentrations at ground and column monitoring sites, but it significantly underestimates at an inland tower measurement site, especially within the stable (nocturnal) boundary layer in nighttime. The model successfully captures the airborne vertical profiles but showed a large offset within the planetary boundary layer (PBL) in the areas surrounding Seoul and around the Taeahn point source emissions in the west coastal area of the Korean Peninsula. A case study flight intended to capture Chinese influence observed no clear signals of long-range transport of CO2, due mainly to the much larger magnitude of background CO2 concentrations. The calculated Net Ecosystem Exchange (NEE) with flux measurements at a tower site in the South Korean Peninsula has also been evaluated comparing with CO2 flux measurements at a flux tower site, resulting in the underestimation by less than a factor of 1.
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