191 research outputs found
Measurement of Velocity and Concentration Profiles of Pneumatically Conveyed Particles in a Square-Shaped Pipe Using Electrostatic Sensor Arrays
Cross-sectional measurement of particle velocity and concentration in a pneumatic conveying pipe is desirable for the characterisation of particle flow dynamics and determination of particle mass flow rate. In this study, an inner-inserted electrostatic sensor array consisting of nine pairs of electrodes is implemented to measure the cross-sectional velocity and concentration profiling of particles over the whole cross section in a square-shaped pipe. Experimental tests were conducted on both vertical and horizontal pipe sections on a test rig under dilute conditions with different air velocities and particle mass flow rates. Test results show that the slope-shaped particle concentration profile changes to an arch-shaped one when the particles flow from a horizontal pipe to a vertical one. The particle velocity profile is arch-shaped in both vertical and horizontal pipes. A comparative study of cross-sectional mean particle velocity and concentration measured by the developed electrostatic sensor arrays is conducted
Multi-view Fuzzy Representation Learning with Rules based Model
Unsupervised multi-view representation learning has been extensively studied
for mining multi-view data. However, some critical challenges remain. On the
one hand, the existing methods cannot explore multi-view data comprehensively
since they usually learn a common representation between views, given that
multi-view data contains both the common information between views and the
specific information within each view. On the other hand, to mine the nonlinear
relationship between data, kernel or neural network methods are commonly used
for multi-view representation learning. However, these methods are lacking in
interpretability. To this end, this paper proposes a new multi-view fuzzy
representation learning method based on the interpretable Takagi-Sugeno-Kang
(TSK) fuzzy system (MVRL_FS). The method realizes multi-view representation
learning from two aspects. First, multi-view data are transformed into a
high-dimensional fuzzy feature space, while the common information between
views and specific information of each view are explored simultaneously.
Second, a new regularization method based on L_(2,1)-norm regression is
proposed to mine the consistency information between views, while the geometric
structure of the data is preserved through the Laplacian graph. Finally,
extensive experiments on many benchmark multi-view datasets are conducted to
validate the superiority of the proposed method.Comment: This work has been accepted by IEEE Transactions on Knowledge and
Data Engineerin
Recent progress in Ti-based nanocomposite anodes for lithium ion batteries
Studying on the anode materials with high energy densities for next-generation lithium-ion batteries (LIBs) is the key for the wide application for electrochemical energy storage devices. Ti-based compounds as promising anode materials are known for their outstanding high-rate capacity and cycling stability as well as improved safety over graphite. However, Ti-based materials still suffer from the low capacity, thus largely limiting their commercialized application. Here, we present an overview of the recent development of Ti-based anode materials in LIBs, and special emphasis is placed on capacity enhancement by rational design of hybrid nanocomposites with conversion-/ alloying-type anodes. This review is expected to provide a guidance for designing novel Ti-based materials for energy storage and conversion. Keywords: lithium-ion batteries (LIBs) anode titania lithium titanateNational Natural Science Foundation (China) (51472137)National Natural Science Foundation (China) (51772163
Denevil: Towards Deciphering and Navigating the Ethical Values of Large Language Models via Instruction Learning
Large Language Models (LLMs) have made unprecedented breakthroughs, yet their
increasing integration into everyday life might raise societal risks due to
generated unethical content. Despite extensive study on specific issues like
bias, the intrinsic values of LLMs remain largely unexplored from a moral
philosophy perspective. This work delves into ethical values utilizing Moral
Foundation Theory. Moving beyond conventional discriminative evaluations with
poor reliability, we propose DeNEVIL, a novel prompt generation algorithm
tailored to dynamically exploit LLMs' value vulnerabilities and elicit the
violation of ethics in a generative manner, revealing their underlying value
inclinations. On such a basis, we construct MoralPrompt, a high-quality dataset
comprising 2,397 prompts covering 500+ value principles, and then benchmark the
intrinsic values across a spectrum of LLMs. We discovered that most models are
essentially misaligned, necessitating further ethical value alignment. In
response, we develop VILMO, an in-context alignment method that substantially
enhances the value compliance of LLM outputs by learning to generate
appropriate value instructions, outperforming existing competitors. Our methods
are suitable for black-box and open-source models, offering a promising initial
step in studying the ethical values of LLMs
Modulation of Excited State Property Based on Benzo[a, c]phenazine Acceptor: Three Typical Excited States and Electroluminescence Performance
Throwing light upon the structure-property relationship of the excited state properties for next-generation fluorescent materials is crucial for the organic light emitting diode (OLED) field. Herein, we designed and synthesized three donor-acceptor (D-A) structure compounds based on a strong spin orbit coupling (SOC) acceptor benzo[a, c]phenazine (DPPZ) to research on the three typical types of excited states, namely, the locally-excited (LE) dominated excited state (CZP-DPPZ), the hybridized local and charge-transfer (HLCT) state (TPA-DPPZ), and the charge-transfer (CT) dominated state with TADF characteristics (PXZ-DPPZ). A theoretical combined experimental research was adopted for the excited state properties and their regulation methods of the three compounds. Benefiting from the HLCT character, TPA-DPPZ achieves the best non-doped device performance with maximum brightness of 61,951 cd m−2 and maximum external quantum efficiency of 3.42%, with both high photoluminescence quantum efficiency of 40.2% and high exciton utilization of 42.8%. Additionally, for the doped OLED, PXZ-DPPZ can achieve a max EQE of 9.35%, due to a suppressed triplet quenching and an enhanced SOC
Angle-Uniform Parallel Coordinates
We present angle-uniform parallel coordinates, a data-independent technique
that deforms the image plane of parallel coordinates so that the angles of
linear relationships between two variables are linearly mapped along the
horizontal axis of the parallel coordinates plot. Despite being a common method
for visualizing multidimensional data, parallel coordinates are ineffective for
revealing positive correlations since the associated parallel coordinates
points of such structures may be located at infinity in the image plane and the
asymmetric encoding of negative and positive correlations may lead to
unreliable estimations. To address this issue, we introduce a transformation
that bounds all points horizontally using an angle-uniform mapping and shrinks
them vertically in a structure-preserving fashion; polygonal lines become
smooth curves and a symmetric representation of data correlations is achieved.
We further propose a combined subsampling and density visualization approach to
reduce visual clutter caused by overdrawing. Our method enables accurate visual
pattern interpretation of data correlations, and its data-independent nature
makes it applicable to all multidimensional datasets. The usefulness of our
method is demonstrated using examples of synthetic and real-world datasets.Comment: Computational Visual Media, 202
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
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