This study analyzes the impact of an instructor on the students' engagement using learning analytics approach by tracking one university's log data of teaching and learning activities in a web-based ...learning platform. Based on the tracking data and theoretical analysis, this study builds a teaching and learning interaction activity model to show how the instructor's course preparation and assistance activities affect different dimensions of student engagement activities and the relationship between these activities. The results reveal that an instructor's course preparation is significantly positively related to the students' viewing activities, while instructor's guidance and assistance has a significant impact on the students' completing learning tasks. The study also indicates that the students' viewing activities have a direct positive influence on their completing learning tasks activities. Students' completing learning tasks exert direct positive influence on their interaction for learning, while their viewing activities have an indirect impact on their interaction activities.
This open access book provides related theories, methods, strategies, and practical cases for implementing education reform through blended learning in curriculum, program, and institutions in the ...digital age. It sums up the research and practice achievements of blended learning from different research teams, involving more than 20 experts from educational technology, higher education, vocational education, and education management over the past 20 years. This book recommends relevant policies of blended learning to international organizations and governments in various countries, provides systematic solutions for administrators in institutions to promote educational reform via blended learning, and serves as a reference book for instructors, researchers, and relevant enterprise practitioners.
This is an open access book. It draws from relevant theories and approaches to teachers’ professional development (TPD) and innovative and inspiring TPD practices in higher education. It first lays a ...solid foundation for the rest of the book, through critiquing prevalent theories, approaches, and teaching competency frameworks guiding TPD in higher education, and defining the key concepts related to TPD. The book then develops a standard framework and assessment instrument of teaching competencies as well as ways of using this framework by institutions, departments at different levels, and individual teachers. It also proposes strategies for improving teachers’ teaching competencies by reviewing what has been achieved to date in TPD in terms of national-level policies and strategies, institutional-level interventions, and teachers’ self-directed professional development. Finally, it also presents case studies of typical practices in TPD in different countries.
Fault diagnosis can improve the safety and reliability of diesel engines. An end-to-end method based on a multi-attention convolutional neural network (MACNN) is proposed for accurate and efficient ...diesel engine fault diagnosis. By optimizing the arrangement and kernel size of the channel and spatial attention modules, the feature extraction capability is improved, and an improved convolutional block attention module (ICBAM) is obtained. Vibration signal features are acquired using a feature extraction model alternating between the convolutional neural network (CNN) and ICBAM. The feature map is recombined to reconstruct the sequence order information. Next, the self-attention mechanism (SAM) is applied to learn the recombined sequence features directly. A Swish activation function is introduced to solve "Dead ReLU" and improve the accuracy. A dynamic learning rate curve is designed to improve the convergence ability of the model. The diesel engine fault simulation experiment is carried out to simulate three kinds of fault types (abnormal valve clearance, abnormal rail pressure, and insufficient fuel supply), and each kind of fault varies in different degrees. The comparison results show that the accuracy of MACNN on the eight-class fault dataset at different speeds is more than 97%. The testing time of the MACNN is much less than the machine running time (for one work cycle). Therefore, the proposed end-to-end fault diagnosis method has a good application prospect.
Engine fault detection is conducive to improving equipment reliability and reducing maintenance costs. In practical scenarios, high-quality data is difficult to obtain. Usually, only single-sensor ...data is available. This paper proposes a fault detection method combining Variational Mode Decomposition (VMD) and Random Forest (RF). At first, the spectral energy distribution is obtained by decomposing and statistic the engine data of multiple working conditions. Based on the spectral energy distribution, the overall optimal mode number was identified, and the quadratic penalty term was optimized using SNR. The improved VMD (IVMD) improves mode aliasing and iterative efficiency and unifies feature dimensions. Decomposition of real signals demonstrates the effectiveness. The paper designs a feature vector composed of seven types of attributes, including unit bandwidth energy, center frequency, maximum singular value and so on. The feature vector is then fed to RF for classification. Features are selected in order of importance to classification to improve the training efficiency. By comparing with various algorithms, the proposed method has higher accuracy and faster training efficiency in single-speed, multi-speed and cross-speed single-sensor data diagnosis. The results show that the method has application prospects with little training data and low hardware requirements.
By applying the properties of the unique classical solution to the singular boundary value problem on half line −
p″(
s)=
g(
p(
s)),
p(
s)>0,
s∈(0,∞),
p(0)=0,lim
s→∞
p′(
s)=
b⩾0, and constructing the ...new comparison functions, they show the existence and the optimal global estimates of solutions to singular nonlinear Dirichlet problems
−
Δu=k(x)g(u),u>0,x∈Ω,u|
∂Ω=0
, where
Ω is a bounded domain with smooth boundary in
R
N
;
g(
s) is nonincreasing and positive in
(0,
∞),
∫
1
∞
g(t)
dt<∞
and
lim
s→0
+
g(s)=+∞;k∈C
α(Ω)
is positive in
Ω, and may be singular or zero on the boundary.
This paper is concerned with the boundary value problems y″+λ(yp−yq)=0 and y(−1)=y(1)=0, where p>q>−1 and λ>0 is a positive parameter. We discuss the existence of positive solutions and give a ...complete study.
This paper is concerned with the exact number of positive solutions for boundary value problems
(
|
u
′
|
p
−
2
u
′
)
′
+
λ
f
(
u
)
=
0
and
u
(
−
1
)
=
u
(
1
)
=
0
, where
p
>
1
and
λ
>
0
is a ...positive parameter. We consider the case in which the nonlinearity
f
changes sign from positive to negative on
(
0
,
∞
)
. For example,
f
(
u
)
=
u
α
−
u
β
where
β
>
α
>
−
∞
.
This paper deals with the uniqueness of positive radial solutions to Dirichlet problems on annular domains in
R
n
,
n
⩾
3
. As an application we can obtain the results to equation
Δ
u
+
u
p
−
α
1
u
−
...α
0
=
0
, where
p
>
1
,
α
1
⩾
0
,
α
0
⩾
0
and
α
1
+
α
0
>
0
.
In this article we use Leray–Schauder degree to consider the existence of nonnegative radially symmetric solution for the nonlinear elliptic equation
M
λ
,
Λ
±
(
D
2
y
)
+
f
(
|
x
|
,
y
)
=
0
in
B
R
...,
y
=
0
on
∂
B
R
, where
M
λ
,
Λ
±
denotes the Pucci's extremal operators with parameters
0
<
λ
⩽
Λ
and
B
R
is the ball of radius
R in
R
N
,
N
⩾
3
. As an application we can obtain the results to equation
M
λ
,
Λ
±
(
u
)
+
u
p
−
u
q
=
0
, where
1
<
p
<
p
∗
±
and
0
<
q
<
p
.
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