295 research outputs found
Global-Scale Resource Survey and Performance Monitoring of Public OGC Web Map Services
One of the most widely-implemented service standards provided by the Open
Geospatial Consortium (OGC) to the user community is the Web Map Service (WMS).
WMS is widely employed globally, but there is limited knowledge of the global
distribution, adoption status or the service quality of these online WMS
resources. To fill this void, we investigated global WMSs resources and
performed distributed performance monitoring of these services. This paper
explicates a distributed monitoring framework that was used to monitor 46,296
WMSs continuously for over one year and a crawling method to discover these
WMSs. We analyzed server locations, provider types, themes, the spatiotemporal
coverage of map layers and the service versions for 41,703 valid WMSs.
Furthermore, we appraised the stability and performance of basic operations for
1210 selected WMSs (i.e., GetCapabilities and GetMap). We discuss the major
reasons for request errors and performance issues, as well as the relationship
between service response times and the spatiotemporal distribution of client
monitoring sites. This paper will help service providers, end users and
developers of standards to grasp the status of global WMS resources, as well as
to understand the adoption status of OGC standards. The conclusions drawn in
this paper can benefit geospatial resource discovery, service performance
evaluation and guide service performance improvements.Comment: 24 pages; 15 figure
Determination of interfacial heat transfer coefficient and its application in high pressure die casting process
In this paper, the research progress of the interfacial heat transfer in high pressure die casting (HPDC) is reviewed. Results including determination of the interfacial heat transfer coefficient (IHTC), influence of casting thickness, process parameters and casting alloys on the IHTC are summarized and discussed. A thermal boundary condition model was developed based on the two correlations: (a) IHTC and casting solid fraction and (b) IHTC peak value and initial die surface temperature. The boundary model was then applied during the determination of the temperature field in HPDC and excellent agreement was found
Associations between polygenic risk, negative symptoms, and functional connectome topology during a working memory task in early-onset schizophrenia
Working memory (WM) deficit in schizophrenia is thought to arise from a widespread neural inefficiency. However, we do not know if this deficit results from the illness-related genetic risk and influence the symptom burden in various domains, especially in patients who have an early onset illness. We used graph theory to examine the topology of the functional connectome in 99 subjects (27 early-onset schizophrenia (EOS), 24 asymptomatic siblings, and 48 healthy subjects) during an n-back task, and calculated their polygenic risk score (PRS) for susceptibility to schizophrenia. Linear regression analysis was used to test associations of the PRS, clinical symptoms, altered connectomic properties, and WM accuracy in EOS. Indices of small-worldness and segregation were elevated in EOS during the WM task compared with the other two groups; these connectomic aberrations correlated with increased PRS and negative symptoms. In patients with higher polygenic risk, WM performance was lower only when both the connectomic aberrations and the burden of negative symptoms were higher. Negative symptoms had a stronger moderating role in this relationship. Our findings suggest that the aberrant connectomic topology is a feature of WM task performance in schizophrenia; this relates to higher polygenic risk score as well as higher burden of negative symptoms. The deleterious effects of polygenic risk on cognition are played out via its effects on the functional connectome, as well as negative symptoms
Alleviating the Long-Tail Problem in Conversational Recommender Systems
Conversational recommender systems (CRS) aim to provide the recommendation
service via natural language conversations. To develop an effective CRS,
high-quality CRS datasets are very crucial. However, existing CRS datasets
suffer from the long-tail issue, \ie a large proportion of items are rarely (or
even never) mentioned in the conversations, which are called long-tail items.
As a result, the CRSs trained on these datasets tend to recommend frequent
items, and the diversity of the recommended items would be largely reduced,
making users easier to get bored.
To address this issue, this paper presents \textbf{LOT-CRS}, a novel
framework that focuses on simulating and utilizing a balanced CRS dataset (\ie
covering all the items evenly) for improving \textbf{LO}ng-\textbf{T}ail
recommendation performance of CRSs. In our approach, we design two pre-training
tasks to enhance the understanding of simulated conversation for long-tail
items, and adopt retrieval-augmented fine-tuning with label smoothness strategy
to further improve the recommendation of long-tail items. Extensive experiments
on two public CRS datasets have demonstrated the effectiveness and
extensibility of our approach, especially on long-tail recommendation.Comment: work in progres
The ecdysteroid receptor regulates salivary gland degeneration through apoptosis in Rhipicephalus haemaphysaloides
Background: It is well established that ecdysteroid hormones play an important role in arthropod development and reproduction, mediated by ecdysteroid receptors. Ticks are obligate hematophagous arthropods and vectors of pathogens. The salivary gland plays an essential role in tick growth and reproduction and in the transmission of pathogens to vertebrate hosts. During tick development, the salivary gland undergoes degeneration triggered by ecdysteroid hormones and activated by apoptosis. However, it is unknown how the ecdysteroid receptor and apoptosis regulate salivary gland degeneration. Here, we report the functional ecdysteroid receptor (a heterodimer of the ecdysone receptor [EcR] and ultraspiracle [USP]) isolated from the salivary gland of the tick Rhipicephalus haemaphysaloides and explore the molecular mechanism of ecdysteroid receptor regulation of salivary gland degeneration. Methods: The full length of RhEcR and RhUSP open reading frames (ORFs) was obtained from the transcriptome. The RhEcR and RhUSP proteins were expressed in a bacterial heterologous system, Escherichia coli. Polyclonal antibodies were produced against synthetic peptides and were able to recognize recombinant and native proteins. Quantitative real-time PCR and western blot were used to detect the distribution of RhEcR, RhUSP, and RhCaspases in the R. haemaphysaloides organs. A proteomics approach was used to analyze the expression profiles of the ecdysteroid receptors, RhCaspases, and other proteins. To analyze the function of the ecdysteroid receptor, RNA interference (RNAi) was used to silence the genes in adult female ticks. Finally, the interaction of RhEcR and RhUSP was identified by heterologous co-expression assays in HEK293T cells. Results: We identified the functional ecdysone receptor (RhEcR/RhUSP) of 20-hydroxyecdysone from the salivary gland of the tick R. haemaphysaloides. The RhEcR and RhUSP genes have three and two isoforms, respectively, and belong to a nuclear receptor family but with variable N-terminal A/B domains. The RhEcR gene silencing inhibited blood-feeding, blocked engorgement, and restrained salivary gland degeneration, showing the biological role of the RhEcR gene in ticks. In the ecdysteroid signaling pathway, RhEcR silencing inhibited salivary gland degeneration by suppressing caspase-dependent apoptosis. The heterologous expression in mammalian HEK293T cells showed that RhEcR1 interacts with RhUSP1 and induces caspase-dependent apoptosis
Applications of Electromagnetic Forming Technology at the Wuhan National High Magnetic Field Center
The research of the electromagnetic forming (EMF) technology at the Wuhan National High Magnetic Field Center (WHMFC) has focused on designing electromagnetic system for generating a more flex-ible and strong Lorentz forces acting on workpieces, and then expanding the applications of EMF technology to solve current problems in forming large-scale and complex components. In this paper, we will sum up the latest progress of EMF technology at the WHMFC in detail according to recently reported works
Development of Space-Time-Controlled Multi-Stage Pulsed Magnetic Field Forming and Manufacturing Technology at the WHMFC*
In November 2011, the Project of Basic Research of Forming by Space-Time-Controlled
Multi-Stage Pulsed Magnetic Field (Stic-Must-PMF) was supported by the National Basic
Research Program of China (973 Project, 2011.11-2016.08). It is aimed at achieving
breakthroughs in manufacturing technology to solve current problems in forming largescale
and complex sheet and tube parts and components, imposed by the limitations of
existing equipment and materials forming properties. The objective of our research group
focuses on the design principles and structural layout optimization of Stic-Must-PMF
facility. And this paper will report the development of Stic-Must-PMF forming and
manufacturing technology at the Wuhan National High Magnetic Field Center (WHMFC)
including numerical modeling, experimental setup and experimental studies
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