6,135 research outputs found
Fault tolerant decentralized H∞ control for symmetric composite systems
This note discusses a class of large-scale systems composed of symmetrically interconnected identical subsystems. We consider the decentralized H∞ control design problem and study the fault tolerance of the resulting system. By exploiting the special structure of the systems, a sufficient condition for the existence of a decentralized H∞ controller is derived. Moreover, for the nominal case as well as for contingent situations characterized by control channel failures, the poles and the H∞-norm of the closed-loop system can be calculated easily based on certain systems of reduced dimensions. Consequently, the tolerance to actuator failure can be easily tested.published_or_final_versio
Mapping the gene for aroma in rice(Oryza sativa L.) by bulk segregation analysis via RAPD markers
The sensory qualities of food such as aroma, taste, and texture are the most important criteria for distinguishing Basmati type rices from non-Basmati types. To map the gene(s) controlling aroma, bulked segregant analysis (BSA) using Random Amplified Polymorphic DNA (RAPD) markers was applied in an F2/F3 population of Basmati 370 (aromatic) and IR36 (non-aromatic). DNA samples from homozygous aromatic and homozygous non-aromatic plants identified on the basis of progeny tests were bulked and used for BSA. A total of 550 random primers were used and the primers, AG8 and AN1, produced polymorphism between aromatic and non-aromatic types. Association of AG8-AR, AN1-AR1, and AN1-AR2 with a gene for aroma was determined by surveying F2 individuals. The three RAPD markers AG8-AR, AN1-AR1, and AN1-AR2 were found to be linked to the gene for aroma with a distance of 6.9, 8.9 and 16.4 cM, respectively. Southern analysis with AG8-AR as a probe with 125 F2 individuals confirmed linkage between AG8-AR and the gene for aroma. AG8-AR was mapped on chromosome 8 flanked by two tightly linked markers, RZ617 and RG978, at 2.1 and 1.7 cM distances, respectively, indicating that this gene in Basmati 370 is located on chromosome 8
Introducing a framework to assess newly created questions with Natural Language Processing
Statistical models such as those derived from Item Response Theory (IRT)
enable the assessment of students on a specific subject, which can be useful
for several purposes (e.g., learning path customization, drop-out prediction).
However, the questions have to be assessed as well and, although it is possible
to estimate with IRT the characteristics of questions that have already been
answered by several students, this technique cannot be used on newly generated
questions. In this paper, we propose a framework to train and evaluate models
for estimating the difficulty and discrimination of newly created Multiple
Choice Questions by extracting meaningful features from the text of the
question and of the possible choices. We implement one model using this
framework and test it on a real-world dataset provided by CloudAcademy, showing
that it outperforms previously proposed models, reducing by 6.7% the RMSE for
difficulty estimation and by 10.8% the RMSE for discrimination estimation. We
also present the results of an ablation study performed to support our features
choice and to show the effects of different characteristics of the questions'
text on difficulty and discrimination.Comment: Accepted at the International Conference of Artificial Intelligence
in Educatio
Development of 〈110〉 texture in copper thin films
Author name used in this publication: C. H. Woo2001-2002 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe
Recommended from our members
A factorial Bayesian copula framework for partitioning uncertainties in multivariate risk inference
National Key Research and Development Plan; Natural Sciences Foundation of China; Natural Science and Engineering Research Council of Canad
A coupled ensemble filtering and probabilistic collocation approach for uncertainty quantification of hydrological models
Natural Science Foundation of China (Nos. 51190095 and 51225904) and the Program for Innovative Research Team in University (IRT1127)
Recommended from our members
Collided with COVID-19 Pandemic, the 2020 Yangtze Flood Is Exceptionally Severe
During June to July, 2020, persistent heavy precipitation in the Yangtze River Basin (YRB) is resulting in extensive flooding, with over 158 fatalities and tremendous economic losses. This year’s disastrous flooding extreme is exceptionally different from those of other years. It contains over 1000-year return period events (for 30-day cumulative precipitation) as observed in Anhui, Guizhou and Sichuan Provinces. The mean precipitation is 308 mm in July 2020, being 54 mm higher than that of July 1998, when serious floods affected the entire Basin causing tremendous socio-economic consequences. Compared with 1998, the short-term (e.g., 1 day) precipitation in YRB did not show significant increases, while the long-term (e.g., 30 days) cumulative precipitation increases significantly. The highest observed 30-day cumulative precipitation is 1221 mm (in Anhui Province) in 2020, while the highest one in 1998 was 1028 mm (in Jiangxi Province). We thus find that this persistent heavy precipitation is the main cause of flooding in 2020. At the same time, TGR may mitigate up 43% of upstream flood, although the main contributors to this year’s YRB flood are in the middle and lower reaches. Affected by COVID-19, the number of people at risk in the threatened area are increased, and their capacities to mitigate the dual impacts of COVID-19 pandemic and flooding are hindered since (a) the flooding-caused mitigations may limit people’s ability to prevent from virus spreading, and (b) the pandemic is retaining a large amount of migrant workers being within YRB and subject to flooding impacts. Overall, our main discovery is that, although the short-term precipitation in YRB did not increase significantly in 2020, the cumulative one increased significantly in 2020.This research was supported by the Natural Sci- ence Foundation (U2040212, 52221003, 52279002, 52279003), MWR/ CAS Institute of Hydroecology, and Natural Science and Engineering Research Council of Canada. We are also very grateful for the helpful inputs from the Editor and anonymous reviewers. All information used in this research is available in the National Meteorological Science Data Center (http://data.cma.cn)
Recommended from our members
Development of a copula-based particle filter (CopPF) approach for hydrologic data assimilation under consideration of parameter interdependence
National Natural Science Foundation of China, the National Key Research and Development Plan, and the Natural Sciences and Engineering Research Council of Canad
Tocilizumab Prevents Progression of Early Systemic Sclerosis Associated Interstitial Lung Disease
OBJECTIVE: Tocilizumab has demonstrated lung function preservation in two randomized controlled trials in early systemic sclerosis (SSc). This effect has yet to be characterized in terms of quantitative radiographic lung involvement. In this post-hoc analysis, we assess tocilizumab's impact on lung function preservation, stratifying treatment arms by the degree of radiographic lung involvement. METHODS: The focuSSced trial was a phase 3, randomized placebo-controlled trial of tocilizumab in patients with SSc and progressive skin disease. Participants had baseline and serial spirometry along with high resolution chest CT at baseline and week 48. Quantitative interstitial lung disease and fibrosis were derived using computer software. We divided quantitative interstitial lung disease in mild (5-10%), moderate (>10-20%), or severe (>20%) categories. RESULTS: Of 210 participants recruited in the trial, 136 [65%] had interstitial lung disease. The majority of these participants had moderate-to-severe involvement defined by >10% lung involvement (77%). The tocilizumab arm demonstrated preservation of forced vital capacity over 48 weeks (least squared mean change in %predicted = -0.1) compared to placebo (-6.3%). For mild, moderate, and severe QILD, the mean decline in the %pFVC in the tocilizumab arm at 48 weeks were -4.1, 0.7, and 2.1, and in the placebo group were -10.0, -5.7, and -6.7, respectively. Similar treatment-related preservation findings were seen independent of fibrosis severity. CONCLUSION: Tocilizumab in early SSc- associated interstitial lung disease with progressive skin disease stabilized forced vital capacity over 48 weeks, independent of the extent of quantitative radiographic interstitial lung disease or fibrosis
Malondialdehyde level and some enzymatic activities in subclinical mastitis milk
The purpose of this study was to evaluate the changes occurring in milk malondialdehyde (MDA) level and some enzymatic activities as a result of subclinical mastitis (SCM) in dairy cows. A total of 124 milk samples were collected from 124 lactating cows from the same herd in the period between the 2nd week after calving and the 10th week postpartum. They were classified by bacterial culture and the California mastitis test (CMT) as positive were deemed to have glands with SCM, and the periodic incidence rate of SCM was 26.6%. The most common bacterial isolates from SCM cases were Staphylococcus aureus (47%) and coagulase negative Staphylococci (CNS) (27%). The mean level of MDA and activities of lactate dehydrogenase (LDH) and alkaline phosphatase (ALP) were significantly higher in SCM milk than in normal milk, while the mean activity of glutathione peroxidase (GPx) was significantly lower in SCM milk than in normal milk. There were no differences in the activities of superoxide dismutase (SOD) and aspartate aminotransferase (AST) between normal milk and SCM milk. Therefore, the measurement of milk MDA level and GPx, LDH and ALP activities, appears to be a suitable diagnostic method for identifying SCM in dairy cows.Key words: Subclinical mastitis, mastitis diagnostic, etiology, malonaldehyde (MDA), enzym
- …