115 research outputs found
RMSE-ELM: Recursive Model based Selective Ensemble of Extreme Learning Machines for Robustness Improvement
Extreme learning machine (ELM) as an emerging branch of shallow networks has
shown its excellent generalization and fast learning speed. However, for
blended data, the robustness of ELM is weak because its weights and biases of
hidden nodes are set randomly. Moreover, the noisy data exert a negative
effect. To solve this problem, a new framework called RMSE-ELM is proposed in
this paper. It is a two-layer recursive model. In the first layer, the
framework trains lots of ELMs in different groups concurrently, then employs
selective ensemble to pick out an optimal set of ELMs in each group, which can
be merged into a large group of ELMs called candidate pool. In the second
layer, selective ensemble is recursively used on candidate pool to acquire the
final ensemble. In the experiments, we apply UCI blended datasets to confirm
the robustness of our new approach in two key aspects (mean square error and
standard deviation). The space complexity of our method is increased to some
degree, but the results have shown that RMSE-ELM significantly improves
robustness with slightly computational time compared with representative
methods (ELM, OP-ELM, GASEN-ELM, GASEN-BP and E-GASEN). It becomes a potential
framework to solve robustness issue of ELM for high-dimensional blended data in
the future.Comment: Accepted for publication in Mathematical Problems in Engineering,
09/22/201
MS23D: A 3D Object Detection Method Using Multi-Scale Semantic Feature Points to Construct 3D Feature Layer
Lidar point clouds, as a type of data with accurate distance perception, can
effectively represent the motion and posture of objects in three-dimensional
space. However, the sparsity and disorderliness of point clouds make it
challenging to extract features directly from them. Many studies have addressed
this issue by transforming point clouds into regular voxel representations.
However, these methods often lead to the loss of fine-grained local feature
information due to downsampling. Moreover, the sparsity of point clouds poses
difficulties in efficiently aggregating features in 3D feature layer using
voxel-based two-stage methods. To address these issues, this paper proposes a
two-stage 3D detection framework called MS3D. In MS3D, we utilize
small-sized voxels to extract fine-grained local features and large-sized
voxels to capture long-range local features. Additionally, we propose a method
for constructing 3D feature layer using multi-scale semantic feature points,
enabling the transformation of sparse 3D feature layer into more compact
representations. Furthermore, we compute the offset between feature points in
the 3D feature layer and the centroid of objects, aiming to bring them as close
as possible to the object's center. It significantly enhances the efficiency of
feature aggregation. To validate the effectiveness of our method, we evaluated
our method on the KITTI dataset and ONCE dataset together
Lithium-salt mediated synthesis of a covalent triazine framework for highly stable lithium metal batteries
A new strategy for the synthesis of a covalent triazine framework (CTFâ1) was introduced based on the cyclotrimerization reaction of 1,4âdicyanobenzene using lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) under ionothermal conditions. LiTFSI not only served as a catalyst, but also facilitated the in situ generation and homogeneous distribution of LiF particles across the framework. The hierarchical structure resulting upon integration of CTFâLiF onto an airlaidâpaper (AP) offered unique features for lithium metal anodes, such as lithiophilicity from CTF, interface stabilization from LiF, and sufficient lithium storage space from AP. Based on this synergistic effect, the APâCTFâLiF anode exhibited stable cycling performance even at a current density of 10â
mAâcmâ
PV-SSD: A Projection and Voxel-based Double Branch Single-Stage 3D Object Detector
LIDAR-based 3D object detection and classification is crucial for autonomous
driving. However, inference in real-time from extremely sparse 3D data poses a
formidable challenge. To address this issue, a common approach is to project
point clouds onto a bird's-eye or perspective view, effectively converting them
into an image-like data format. However, this excessive compression of point
cloud data often leads to the loss of information. This paper proposes a 3D
object detector based on voxel and projection double branch feature extraction
(PV-SSD) to address the problem of information loss. We add voxel features
input containing rich local semantic information, which is fully fused with the
projected features in the feature extraction stage to reduce the local
information loss caused by projection. A good performance is achieved compared
to the previous work. In addition, this paper makes the following
contributions: 1) a voxel feature extraction method with variable receptive
fields is proposed; 2) a feature point sampling method by weight sampling is
used to filter out the feature points that are more conducive to the detection
task; 3) the MSSFA module is proposed based on the SSFA module. To verify the
effectiveness of our method, we designed comparison experiments
The decay property of the as the state
In this paper, the new particle discovered by the LHCb
Collaboration is identified to be the state. We study
its strong decays with the combination of the Bethe-Salpeter method and the
model. Its electromagnetic (EM) decay is also calculated by the
Bethe-Salpeter method within Mandelstam formalism. The strong decay widths are
{ MeV},
MeV, and the ratio . The EM decay width is
MeV. We also estimate the
total width to be 2.87 MeV, which is in good agreement with the experimental
data MeV. Since the used relativistic wave functions
include different partial waves, we also study the contributions of different
partial waves in electromagnetic decay.Comment: 17 pages, 3 figures, 3 table
Development of magnetorheological elastomers-based tuned mass damper for building protection from seismic events
This study investigated and evaluated a semi-active tuned mass damper which incorporated four multi-layered structures fabricated using magnetorheological elastomers. The four magnetorheological elastomer structures formed a square and provided the tuned mass damper variable stiffness used to track the excitation frequencies. This design not only increases the stability of the tuned mass damper but more importantly eliminates the magnetic circuit gap in a design which we used in the past because all four of the magnetic circuits used to control the magnetorheological elastomer isolators are closed circuits. In order to verify the capability of the magnetorheological elastomer-based tuned mass damper to protect a building from earthquake, extensive simulation and experimental testing were conducted. The swept sinusoidal signal and the scaled 1940 El Centro earthquake record were used to excite a scaled three-story building. Both simulation and experiment have verified that the magnetorheological elastomer-based tuned mass damper outperformed all other passive tuned mass dampers under either swept sinusoidal or seismic conditions
DETIRE: a hybrid deep learning model for identifying viral sequences from metagenomes
A metagenome contains all DNA sequences from an environmental sample, including viruses, bacteria, archaea, and eukaryotes. Since viruses are of huge abundance and have caused vast mortality and morbidity to human society in history as a type of major pathogens, detecting viruses from metagenomes plays a crucial role in analyzing the viral component of samples and is the very first step for clinical diagnosis. However, detecting viral fragments directly from the metagenomes is still a tough issue because of the existence of a huge number of short sequences. In this study a hybrid Deep lEarning model for idenTifying vIral sequences fRom mEtagenomes (DETIRE) is proposed to solve the problem. First, the graph-based nucleotide sequence embedding strategy is utilized to enrich the expression of DNA sequences by training an embedding matrix. Then, the spatial and sequential features are extracted by trained CNN and BiLSTM networks, respectively, to enrich the features of short sequences. Finally, the two sets of features are weighted combined for the final decision. Trained by 220,000 sequences of 500 bp subsampled from the Virus and Host RefSeq genomes, DETIRE identifies more short viral sequences (<1,000 bp) than the three latest methods, such as DeepVirFinder, PPR-Meta, and CHEER. DETIRE is freely available at Github (https://github.com/crazyinter/DETIRE)
Partial wave effects in the heavy quarkonium radiative electromagnetic decays
In a previous paper \cite{Bc}, it was pointed out that the wave functions of
all particles are not pure waves, besides the main partial waves, they all
contain {other partial waves}. It is very interesting to know what role these
different partial waves play in particle transitions. Therefore, by using the
Bethe-Salpeter equation method, we study the radiative electromagnetic decays
and
(). We find that for the and wave dominated states, like the
, , , and etc.,
the dominant and waves provide main and nonrelativistic contrition to
the decays; other partial waves mainly contribute to the relativistic
correction. For the states like the , ,
, and etc., they are the mixing state
dominated by wave or the mixing state dominated by wave. Large
decay widths are found in the transitions ,
, and etc.,
which may be helpful to study the missing states ,
, and .Comment: 31 pages, 19 table
AUV SLAM and experiments using a mechanical scanning forward-looking sonar
Navigation technology is one of the most important challenges in the applications of autonomous underwater vehicles (AUVs) which navigate in the complex undersea environment. The ability of localizing a robot and accurately mapping its surroundings simultaneously, namely the simultaneous localization and mapping (SLAM) problem, is a key prerequisite of truly autonomous robots. In this paper, a modified-FastSLAM algorithm is proposed and used in the navigation for our C-Ranger research platform, an open-frame AUV. A mechanical scanning imaging sonar is chosen as the active sensor for the AUV. The modified-FastSLAM implements the update relying on the on-board sensors of C-Ranger. On the other hand, the algorithm employs the data association which combines the single particle maximum likelihood method with modified negative evidence method, and uses the rank-based resampling to overcome the particle depletion problem. In order to verify the feasibility of the proposed methods, both simulation experiments and sea trials for C-Ranger are conducted. The experimental results show the modified-FastSLAM employed for the navigation of the C-Ranger AUV is much more effective and accurate compared with the traditional methods
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