Planet bearing vibration signals are complex and non-stationary owing to the time-varying vibration transmission path from fault point to accelerometers. In addition, due to the influence of speed ...and load variation, planetary gearboxes often operate under varying conditions, which causes the acquired vibration signals to be nonlinear. These seriously degrade the performance of the RUL prediction methods. Moreover, there are only few training samples for the RUL prediction of planet bearings. To address these problems, an RUL prediction method of planet bearings using conditional deep recurrent generative adversarial network (C-DRGAN) and action discovery (AD) is presented. First, gated recurrent unit neural network is integrated with conditional generative adversarial network to construct the C-DRGAN, which extracts fault features from nonlinear and non-stationary signals so as to realize the RUL prediction of planet bearings under small samples and varying conditions. Then, the training algorithm based on AD is employed to train the C-DRGAN to enhance convergence speed and reduce training time. Finally, a multiple linear regression classifier is utilized to predict the RUL of planet bearings. The performance of the presented method is validated through an accelerated fatigue life experiment of planet bearings. Experimental analyses demonstrate that this method possesses strong processing adaptability to nonlinear and non-stationary signals and obtains excellent performance under small samples.
In this paper, we mainly study the fractional Choquard systems with a local perturbation under the mass constraints:
(
-
Δ
)
s
u
=
λ
1
u
+
(
I
α
∗
|
u
|
2
α
,
s
∗
)
|
u
|
2
α
,
s
∗
-
2
u
+
μ
1
|
u
|
...p
-
2
u
+
β
r
1
|
u
|
r
1
-
2
u
|
v
|
r
2
in
R
N
,
(
-
Δ
)
s
v
=
λ
2
v
+
(
I
α
∗
|
v
|
2
α
,
s
∗
)
|
v
|
2
α
,
s
∗
-
2
v
+
μ
2
|
v
|
q
-
2
v
+
β
r
2
|
v
|
r
2
-
2
v
|
u
|
r
1
in
R
N
,
‖
u
‖
L
2
(
R
N
)
2
=
a
1
2
and
‖
v
‖
L
2
(
R
N
)
2
=
a
2
2
,
where
(
-
Δ
)
s
u
is the fractional Laplacian,
I
α
(
x
)
is the Riesz potential,
0
<
α
<
min
{
N
,
4
s
}
,
and
N
>
2
s
,
s
∈
(
0
,
1
)
,
λ
1
,
λ
2
∈
R
N
are unknown constants, which will appear as Lagrange multipliers,
μ
1
,
μ
2
,
β
,
a
1
,
a
2
>
0
,
r
1
,
r
2
>
1
,
p
,
q
and
r
1
+
r
2
∈
(
2
+
4
s
N
,
2
s
∗
.
2
s
∗
=
2
N
N
-
2
s
is the fractional critical Sobolev exponent and
2
α
,
s
∗
=
2
N
-
α
N
-
2
s
is the fractional Hardy–Littlewood–Sobolev critical exponent. Firstly, if
p
,
q
and
r
1
+
r
2
<
2
s
∗
,
we obtain the existence of positive normalized solution when
β
is big enough. Then, for the case of
p
=
q
=
r
1
+
r
2
=
2
s
∗
,
we may obtain the nonexistence of positive normalized solution.
With recent developments in the infrastructure of smart meters and smart grid, more electric power data is available and allows real-time easy data access. Modeling individual home appliance loads is ...important for tasks such as non-intrusive load disaggregation, load forecasting, and demand response support. Previous methods usually require sub-metering individual appliances in a home separately to determine the appliance models, which may not be practical, since we may only be able to observe aggregated real power signals for the entire-home through smart meters deployed in the field. In this paper, we propose a model, named Explicit-Duration Hidden Markov Model with differential observations (EDHMM-diff), for detecting and estimating individual home appliance loads from aggregated power signals collected by ordinary smart meters. Experiments on synthetic data and real data demonstrate that the EDHMM-diff model and the specialized forward-backward algorithm can effectively model major home appliance loads.
•The PSR index system for evaluating urban ecological civilization (UEC) is developed.•An integrated analysis framework is proposed to evaluate the level and obstacle factor of UEC.•Responsiveness is ...critical shortcomings factors affecting the construction of UEC.•The obstacle factor restricting the level of UEC in 13 cities in Jiangsu Province are identified.
Conducting urban ecological civilization (UEC) evaluation and identifying its key obstacle factors will help to formulate regionally differentiated ecological civilization promotion paths. From three dimensions of “pressure-state-response” (PSR) and four aspects of “Economy-Resources-Environment-Society”(ERES), this paper constructs an extended PSR index system of UEC to reflect the interactive relationship between humans and nature, and integrates the exponential variable weight (EVW) method, technique for order preference by similarity to an ideal solution (TOPSIS) model and obstacle degree (OD) model to evaluate and diagnose the regional differences and obstacle factors of UEC in Jiangsu Province. The results show that the performance of UEC in each city shows an increasing trend during the inspection period, but there are significant regional differences. The performance of UEC construction in Jiangsu Province has improved year by year, but the increase in its response index is relatively small, indicating that the response capacity of UEC in Jiangsu Province needs to be strengthened urgently, and its fundamental lies in reversing the GDP-oriented performance evaluation model. The key obstacles to the construction of UEC vary depending on the uneven regional development, but there are some common obstacles in the construction of UEC, such as clean energy investment, urban residents’ water supply, foreign capital utilization, land resource protection, population education quality, etc. It is recommended that local governments improve the top-level system design of UEC construction, avoid a one-size-fits-all governance model, and adopt differentiated ecological civilization control measures according to local conditions.
Sodium-ion batteries (SIBs) are one of the most promising alternatives to lithium-ion batteries (LIBs), due to the much more abundant resources of Na compared with Li in the world. Developing SIB ...technology to satisfy the increased demand for energy storage is therefore a significant task . However, one of the biggest bottlenecks is the design of high-performance and low-cost anode materials, since the graphite anode in commercial LIBs is not suitable for SIBs due to thermal dynamic issues. Hard carbon materials have been regarded as having the greatest potential as anodes in commercial SIBs owing to their excellent cost-effectiveness, but their relatively limited performance compared to the graphite in LIBs as well as the dimness of the sodium storage mechanisms still need further investigation. In this review, we summarize the progress of recent research into hard carbons for SIB applications, including the fundamentals of SIBs, sodium storage mechanisms, structures and the electrochemical performances of different types of hard carbons in SIBs and other types of sodium-based energy storage as well as the main challenges in this field. We aim to provide a general insight into hard carbons and their applications in SIBs, opening up future perspectives and possible research directions.
In the cooperative tracking task of multiple permanent magnetic maglev trains, system uncertainty, external disturbances, and collision avoidance control are issues that must be considered. ...Therefore, the cooperative tracking and collision avoidance control for train virtual coupling with external disturbances are studied. First, according to the idea of multi‐agent consensus control and active disturbance rejection control, a cooperative tracking controller based on a novel nonlinear extended state observer (NESO) is designed. Second, a collision avoidance control method based on an improved artificial potential field (APF) is designed. Finally, an improved cooperative tracking and collision avoidance control protocol is proposed, and the stability proof is given. Compared with the conventional protocol, the proposed protocol can achieve smooth coupling and high‐precision cruise while ensuring safe collision avoidance. It has the advantages of higher tracking accuracy and stronger anti‐interference performance.
To address the cooperative tracking and collision avoidance control problem for virtual coupling of permanent magnetic maglev trains with external disturbances, we propose an improved cooperative tracking and collision avoidance control protocol and its stability is demonstrated.
In this paper, we consider the following fractional Choquard–Kirchhoff equation with magnetic fields and critical exponents
M
(
u
s
,
A
2
)
(
-
Δ
)
A
s
u
+
V
(
x
)
u
=
|
x
|
-
α
∗
|
u
|
2
α
,
s
∗
...|
u
|
2
α
,
s
∗
-
2
u
+
λ
f
(
x
,
u
)
in
R
N
,
where
N
>
2
s
with
0
<
s
<
1
,
λ
>
0
,
A
=
(
A
1
,
A
2
,
…
,
A
n
)
∈
(
R
N
,
R
N
)
is a magnetic potential,
2
α
,
s
∗
=
(
2
N
-
α
)
/
(
N
-
2
s
)
is the fractional Hardy—Littlewood—Sobolev critical exponent with
0
<
α
<
2
s
,
M
(
u
s
,
A
2
)
=
a
+
b
u
s
,
A
2
with
a
,
b
>
0
,
u
∈
(
R
N
,
C
)
is a complex valued function,
V
∈
L
∞
(
R
N
)
and
f
∈
(
R
N
×
R
,
R
)
are continuous functions,
(
-
Δ
)
A
s
is a fractional magnetic Laplacian operator. Under some suitable assumptions, by applying the Nehari method and the concentration-compactness principle, we obtain the existence of ground state solutions.
A novel compact ultra-wideband (UWB) bandpass filter based on vialess vertical coplanar waveguide (CPW)/microstrip transitions is proposed, designed, fabricated and measured. The represented filter ...consists of two back-to-back hybrid microstrip/slotline transitions derived from the microstrip to CPW. Due to this coupling configuration, a smooth UWB passband response with an insertion loss <0.85 dB is achieved. Moreover, two transmission zeros at lower and upper passband edges are introduced to provide sharp selectivity. For verification, a prototype is fabricated and measured. The simulated results are in good agreement with the measured one.
In this paper, we consider a fractional Klein–Gordon–Maxwell system when the non-linearity exhibits critical growth. Under some appropriate assumptions on potential
V
, we prove the existence of ...positive ground state solutions using the Nehari method.
•Supplement POSTN weakened cytotoxicity which evoked by OGD.•POSTN protects mouse NSCs to against OGD-induced cell apoptosis.•POSTN impacts on NSCs via inhibiting p38 phosphorylation.
Promoting ...neural stem cells (NSCs) survival in the harsh niche is essential to cell replacement therapy for various central nervous system diseases. As an integral component of the extracellular matrix, Periostin (POSTN) has been shown to protect various cell types from hypoxia-ischemia damage. This study aimed to investigate the neuroprotective effects of POSTN on NSCs injury induced by oxygen and glucose deprivation (OGD). Under challenge with OGD, cell viability significantly decreased in cultured mouse NSCs, and supplement POSTN rescued cell viability in a concentration-dependent manner, as shown by CCK-8. TUNEL and propidium iodide/Hoechst staining showed that POSTN pretreatment protected NSCs against OGD-induced apoptosis. Western blot assay demonstrated that POSTN pretreatment inhibited cleavage of caspase-3 and restored the balance of Bcl-2/Bax. And pretreatment with cilengitide (an inhibitor of POSTN receptors) abolished the protective effect of POSTN. Further investigation demonstrated that supplement POSTN inhibited phosphorylation of p38 in a concentration-dependent manner. Moreover, the neuroprotective effect of POSTN was hampered by anisomycin, an activator of p38. We conclude that POSTN pretreatment in cultured mouse NSCs mitigated OGD-induced cell death, and inhibition of the p38 MAPK pathway might be one of the underlying mechanisms. Our findings may provide a novel strategy for enhancing both endogenous and exogenous NSCs survival after ischemia and hypoxia injury.
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