644 research outputs found
Urbanisation and health in China.
China has seen the largest human migration in history, and the country's rapid urbanisation has important consequences for public health. A provincial analysis of its urbanisation trends shows shifting and accelerating rural-to-urban migration across the country and accompanying rapid increases in city size and population. The growing disease burden in urban areas attributable to nutrition and lifestyle choices is a major public health challenge, as are troubling disparities in health-care access, vaccination coverage, and accidents and injuries in China's rural-to-urban migrant population. Urban environmental quality, including air and water pollution, contributes to disease both in urban and in rural areas, and traffic-related accidents pose a major public health threat as the country becomes increasingly motorised. To address the health challenges and maximise the benefits that accompany this rapid urbanisation, innovative health policies focused on the needs of migrants and research that could close knowledge gaps on urban population exposures are needed
コンプトン散乱を用いた、広域高分解能ガンマ線画像計測装置の開発
学位の種別: 課程博士審査委員会委員 : (主査)東京大学教授 高橋 浩之, 東京大学教授 松崎 浩之, 東京大学准教授 中島 義和, 東京大学准教授 大野 雅史, 放射線医学総合研究所チームリーダー 山谷 泰賀University of Tokyo(東京大学
Fault Diagnosis of Rotating Machinery Bearings Based on Improved DCNN and WOA-DELM
A bearing is a critical component in the transmission of rotating machinery. However, due to prolonged exposure to heavy loads and high-speed environments, rolling bearings are highly susceptible to faults, Hence, it is crucial to enhance bearing fault diagnosis to ensure safe and reliable operation of rotating machinery. In order to achieve this, a rotating machinery fault diagnosis method based on a deep convolutional neural network (DCNN) and Whale Optimization Algorithm (WOA) optimized Deep Extreme Learning Machine (DELM) is proposed in this paper. DCNN is a combination of the Efficient Channel Attention Net (ECA-Net) and Bi-directional Long Short-Term Memory (BiLSTM). In this method, firstly, a DCNN classification network is constructed. The ECA-Net and BiLSTM are brought into the deep convolutional neural network to extract critical features. Next, the WOA is used to optimize the weight of the initial input layer of DELM to build the WOA-DELM classifier model. Finally, the features extracted by the Improved DCNN (IDCNN) are sent to the WOA-DELM model for bearing fault diagnosis. The diagnostic capability of the proposed IDCNN-WOA-DELM method was evaluated through multiple-condition fault diagnosis experiments using the CWRU-bearing dataset with various settings, and comparative tests against other methods were conducted as well. The results indicate that the proposed method demonstrates good diagnostic performance
Interpretable Knowledge Tracing via Response Influence-based Counterfactual Reasoning
Knowledge tracing (KT) plays a crucial role in computer-aided education and
intelligent tutoring systems, aiming to assess students' knowledge proficiency
by predicting their future performance on new questions based on their past
response records. While existing deep learning knowledge tracing (DLKT) methods
have significantly improved prediction accuracy and achieved state-of-the-art
results, they often suffer from a lack of interpretability. To address this
limitation, current approaches have explored incorporating psychological
influences to achieve more explainable predictions, but they tend to overlook
the potential influences of historical responses. In fact, understanding how
models make predictions based on response influences can enhance the
transparency and trustworthiness of the knowledge tracing process, presenting
an opportunity for a new paradigm of interpretable KT. However, measuring
unobservable response influences is challenging. In this paper, we resort to
counterfactual reasoning that intervenes in each response to answer
\textit{what if a student had answered a question incorrectly that he/she
actually answered correctly, and vice versa}. Based on this, we propose RCKT, a
novel response influence-based counterfactual knowledge tracing framework. RCKT
generates response influences by comparing prediction outcomes from factual
sequences and constructed counterfactual sequences after interventions.
Additionally, we introduce maximization and inference techniques to leverage
accumulated influences from different past responses, further improving the
model's performance and credibility. Extensive experimental results demonstrate
that our RCKT method outperforms state-of-the-art knowledge tracing methods on
four datasets against six baselines, and provides credible interpretations of
response influences.Comment: ICDE'24 (fixing a few typos). Source code at
https://github.com/JJCui96/RCKT. Keywords: knowledge tracing, interpretable
machine learning, counterfactual reasoning, artificial intelligence for
educatio
A Design for a Lithium-Ion Battery Pack Monitoring System Based on NB-IoT-ZigBee
With environmental issues arising from the excessive use of fossil fuels, clean energy has gained widespread attention, particularly the application of lithium-ion batteries. Lithium-ion batteries are integrated into various industrial products, which necessitates higher safety requirements. Narrowband Internet of Things (NB-IoT) is an LPWA (Low Power Wide Area Network) technology that provides IoT devices with low-power, low-cost, long-endurance, and wide-coverage wireless connectivity. This study addresses the shortcomings of existing lithium-ion battery pack detection systems and proposes a lithium-ion battery monitoring system based on NB-IoT-ZigBee technology. The system operates in a master-slave mode, with the subordinate module collecting and fusing multi-source sensor data, while the master control module uploads the data to local monitoring centers and cloud platforms via TCP and NB-IoT. Experimental validation demonstrates that the design functions effectively, accomplishing the monitoring and protection of lithium-ion battery packs in energy storage power stations
Multiple measurements on the cosmic curvature using Gaussian process regression without calibration and a cosmological model
In this letter, we propose an improved cosmological model-independent method
to measure cosmic curvature, combining the recent measurements of transverse
and line-of-sight directions in the baryon acoustic oscillations (BAO) with
cosmic chronometers (CC) datasets. Considering that the CC dataset is discrete
and includes only 32 measurements, we apply Gaussian process (GP)
regression to fit the CC dataset and reconstruct them. Our methodology, which
does not need the calibration or selection of any cosmological model, provide
multiple measurements of spatial curvature () at different redshifts
(depending on the redshift coverage of BAO dataset). For combination of all BAO
data, we find that the constraint result on cosmic curvature is
with observational uncertainty.
Although the measured is in good agreement with zero cosmic
curvature within 1 confidence level, our result revels the fact of a
closed universe. More importantly, our results show that the obtained
measurements are almost unaffected by different priors of the Hubble
constant. This could help solve the issue of the Hubble tension that may be
caused by inconsistencies in the spatial curvature between the early and late
universes.Comment: 12 pages, 2 figures, welcome to comment, submitted to Physics Letters
FedDCT: A Dynamic Cross-Tier Federated Learning Scheme in Wireless Communication Networks
With the rapid proliferation of Internet of Things (IoT) devices and the
growing concern for data privacy among the public, Federated Learning (FL) has
gained significant attention as a privacy-preserving machine learning paradigm.
FL enables the training of a global model among clients without exposing local
data. However, when a federated learning system runs on wireless communication
networks, limited wireless resources, heterogeneity of clients, and network
transmission failures affect its performance and accuracy. In this study, we
propose a novel dynamic cross-tier FL scheme, named FedDCT to increase training
accuracy and performance in wireless communication networks. We utilize a
tiering algorithm that dynamically divides clients into different tiers
according to specific indicators and assigns specific timeout thresholds to
each tier to reduce the training time required. To improve the accuracy of the
model without increasing the training time, we introduce a cross-tier client
selection algorithm that can effectively select the tiers and participants.
Simulation experiments show that our scheme can make the model converge faster
and achieve a higher accuracy in wireless communication networks
Case report: Gouty renal abscess and gouty sacroiliitis associated with genetic variants of a young woman
Gout is a form of inflammatory arthritis characterized by the deposition of monosodium urate (MSU) crystals in the joints, resulting from a disorder in purine metabolism. It occurs more frequently in men than in women prior to menopause and is rare in young women. Gout can lead to various health complications, with many patients experiencing a significant burden of chronic kidney disease (CKD) and joint deformities. The development of gout is influenced by a complex interplay of genetic, environmental, and lifestyle factors, with elevated serum MSU levels serving as a key risk factor for its onset. However, only 10% of individuals with hyperuricemia go on to develop clinical gout, and several susceptibility loci are associated with the condition. Here, we present a case of a young woman with gouty sacroiliitis and gouty nephropathy linked to susceptibility loci
- …
