494 research outputs found
Design and analysis of a novel long-distance double tendon-sheath transmission device for breast intervention robots under MRI field
Cancer represents a major threat to human health. Magnetic resonance imaging (MRI) provides superior performance to other imaging-based examination methods in the detection of tumors and offers distinct advantages in biopsy and seed implantation. However, because of the MRI environment, the material requirements for actuating devices for the medical robots used in MRI are incredibly demanding. This paper describes a novel double tendon-sheath transmission device for use in MRI applications. LeBus grooves are used in the original transmission wheels, thus enabling the system to realize long-distance and large-stroke transmission with improved accuracy. The friction model of the transmission system and the transmission characteristics model of the novel tendon-sheath structure are then established. To address the problem that tension sensors cannot be installed in large-stroke transmission systems, a three-point force measurement method is used to measure and set an appropriate preload in the novel tendon-sheath transmission system. Additionally, experiments are conducted to verify the accuracy of the theoretical model and multiple groups of tests are performed to explore the transmission characteristics. Finally, the novel tendon-sheath transmission system is compensated to improve its accuracy and the experimental results acquired after compensation show that the system satisfies the design requirements
An information diffusion model in social networks with carrier compartment and delay
With the wide applications of the communication networks, the topic of information networks security is getting more and more attention from governments and individuals. This paper is devoted to investigating a malware propagation model with carrier compartment and delay to describe the process of malware propagation in mobile wireless sensor networks. Based on matrix theory for characteristic values, the local stability criterion of equilibrium points is established. Applying the linear approximation method of nonlinear systems, we study the existence of Hopf bifurcation at the equilibrium points. At the same time, we identify some sensitive parameters in the process of malware propagation. Finally, numerical simulations are performed to illustrate the theoretical results
Thoughts and countermeasures of establishing national modern agricultural demonstration zone ââ Take Shijiazhuang City, Hebei Province as an example
Modern agricultural demonstration area is of far-reaching significance to promote the development of modern agriculture. According to the current situation of agricultural industry development in Shijiazhuang, this paper analyzes the development conditions of establishing a national modern agricultural demonstration zone, puts forward the basic ideas, development orientation and development countermeasures of building a national modern agricultural demonstration zone, and analyzes the guarantee measures for its development, in order to build Shijiazhuang into a national modern agricultural demonstration zone
Mitigating Shortcuts in Language Models with Soft Label Encoding
Recent research has shown that large language models rely on spurious
correlations in the data for natural language understanding (NLU) tasks. In
this work, we aim to answer the following research question: Can we reduce
spurious correlations by modifying the ground truth labels of the training
data? Specifically, we propose a simple yet effective debiasing framework,
named Soft Label Encoding (SoftLE). We first train a teacher model with hard
labels to determine each sample's degree of relying on shortcuts. We then add
one dummy class to encode the shortcut degree, which is used to smooth other
dimensions in the ground truth label to generate soft labels. This new ground
truth label is used to train a more robust student model. Extensive experiments
on two NLU benchmark tasks demonstrate that SoftLE significantly improves
out-of-distribution generalization while maintaining satisfactory
in-distribution accuracy
Persistent fifth aortic arch: a comprehensive literature review
Persistent fifth aortic arch (PFAA) is an extremely rare congenital cardiovascular anomaly resulting from the failure of the fifth aortic arch to degenerate during embryonic development; it is often associated with various other cardiovascular anomalies. Despite being first reported by Van Praagh in 1969, there have been only a few individual case reports. Owing to its rarity and lack of comprehensive understanding, PFAA is often misdiagnosed or missed diagnosed during clinical. Thus, this review aimed to summarise the embryonic development, pathological classification, imaging diagnosis, and clinical treatment of PFAA to improve its overall understanding, ultimately helping in accurate diagnosis and treatment
Explainability for Large Language Models: A Survey
Large language models (LLMs) have demonstrated impressive capabilities in
natural language processing. However, their internal mechanisms are still
unclear and this lack of transparency poses unwanted risks for downstream
applications. Therefore, understanding and explaining these models is crucial
for elucidating their behaviors, limitations, and social impacts. In this
paper, we introduce a taxonomy of explainability techniques and provide a
structured overview of methods for explaining Transformer-based language
models. We categorize techniques based on the training paradigms of LLMs:
traditional fine-tuning-based paradigm and prompting-based paradigm. For each
paradigm, we summarize the goals and dominant approaches for generating local
explanations of individual predictions and global explanations of overall model
knowledge. We also discuss metrics for evaluating generated explanations, and
discuss how explanations can be leveraged to debug models and improve
performance. Lastly, we examine key challenges and emerging opportunities for
explanation techniques in the era of LLMs in comparison to conventional machine
learning models
Atomistic Conversion Reaction Mechanism of WO3 in Secondary Ion Batteries of Li, Na, and Ca
Intercalation and conversion are two fundamental chemical processes for battery materials in response to ion insertion. The interplay between these two chemical processes has never been directly seen and understood at atomic scale. Here, using inâ
situ HRTEM, we captured the atomistic conversion reaction processes during Li, Na, Ca insertion into a WO3 single crystal model electrode. An intercalation step prior to conversion is explicitly revealed at atomic scale for the first time for Li, Na, Ca. Nanoscale diffraction and abâ
initio molecular dynamic simulations revealed that after intercalation, the inserted ionâoxygen bond formation destabilizes the transitionâmetal framework which gradually shrinks, distorts and finally collapses to an amorphous W and MxO (M=Li, Na, Ca) composite structure. This study provides a full atomistic picture of the transition from intercalation to conversion, which is of essential importance for both secondary ion batteries and electrochromic devices.Das Wechselspiel zwischen Ioneninterkalation und Umwandlung des WO3âElektrodenmaterials wurde durch InâsituâTEM auf atomarer Ebene untersucht. Die Bildung von IonâSauerstoffâBindungen destabilisiert das WO3âGerĂŒst: Es schrumpft, wird verzerrt und fĂ€llt schlieĂlich zu einer amorphen Wâ und MxOâVerbundstruktur (M=Li, Na, Ca) zusammen.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/134843/1/ange201601542_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/134843/2/ange201601542.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/134843/3/ange201601542-sup-0001-misc_information.pd
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