101 research outputs found
A Survey on the Application of Game Teaching Method in English Teaching of Primary School: A Case Study of a Primary School in Our Local City
The game based teaching method is specifically aimed at assisting English teaching, communicating in English, and widely used in English classrooms or extracurricular activities. Compared with Chinese, primary school students lack a certain language environment for English learning and do not have a true understanding of English learning. Therefore, English teachers should use games to mobilize students’ enthusiasm for learning, and follow the basic principle of “happy teaching” to adapt to students’ development. However, there are still many problems with game teaching methods in English teaching. This thesis wants to explore the current situation of the application of games in English teaching and research its countermeasures, so that more front-line teachers can benefit from it.This study is based on Piaget’s cognitive development theory and happiness education theory. By using the methods of questionnaire survey and interview, this paper delves into the current application status, existing problems, and cause analysis of game teaching methods in primary school English classrooms. And the study summarized the shortcomings of current primary school English teachers in the application of classroom game teaching methods.It is found that the main problems are: in ordinary classes, the use of game-based teaching methods is still relatively limited; students’ game goals are unclear and cannot be applied to practice; the class is chaotic; and all students cannot participate in the game.The study suggests that the teacher enrich the theoretical knowledge of game teaching methods and strengthen their application. Schools can provide training for teachers at appropriate times, or regularly order publications or books related to games. Teachers can also learn more from successful game application cases to improve the application ability of game teaching methods. For the student group, research suggests that students clarify the purpose of games and enable them to understand the true intention of the teacher in using games in the classroom. Secondly, it is necessary to strengthen students’ classroom discipline.Through in-depth exploration of the practice of game teaching methods in primary school English classrooms, it has reference value for primary school English teachers to correctly and effectively implement game teaching methods, and has profound significance for better implementing game teaching methods in primary school English classrooms
Channel Estimation for Ambient Backscatter Communication Systems with Massive-Antenna Reader
Ambient backscatter, an emerging green communication technology, has aroused
great interest from both academia and industry. One open problem for ambient
backscatter communication (AmBC) systems is channel estimation for a
massive-antenna reader. In this paper, we focus on channel estimation problem
in AmBC systems with uniform linear array (ULA) at the reader which consists of
large number of antennas. We first design a two-step method to jointly estimate
channel gains and direction of arrivals (DoAs), and then refine the estimates
through angular rotation. Additionally, Cramer-Rao lower bounds (CRLBs) are
derived for both the modulus of the channel gain and the DoA estimates.
Simulations are then provided to validate the analysis, and to show the
efficiency of the proposed approach.Comment: 5 figures, submitted to IEEE Transactions on Vehicular Technology, 29
March, 201
XVTP3D: Cross-view Trajectory Prediction Using Shared 3D Queries for Autonomous Driving
Trajectory prediction with uncertainty is a critical and challenging task for
autonomous driving. Nowadays, we can easily access sensor data represented in
multiple views. However, cross-view consistency has not been evaluated by the
existing models, which might lead to divergences between the multimodal
predictions from different views. It is not practical and effective when the
network does not comprehend the 3D scene, which could cause the downstream
module in a dilemma. Instead, we predicts multimodal trajectories while
maintaining cross-view consistency. We presented a cross-view trajectory
prediction method using shared 3D Queries (XVTP3D). We employ a set of 3D
queries shared across views to generate multi-goals that are cross-view
consistent. We also proposed a random mask method and coarse-to-fine
cross-attention to capture robust cross-view features. As far as we know, this
is the first work that introduces the outstanding top-down paradigm in BEV
detection field to a trajectory prediction problem. The results of experiments
on two publicly available datasets show that XVTP3D achieved state-of-the-art
performance with consistent cross-view predictions.Comment: 11 pages, 6 figures, accepted by IJCAI 2
Ray-Based Statistical Propagation Modeling for Indoor Corridor Scenarios at 15 GHz
According to the demands for fifth-generation (5G) communication systems, high frequency bands (above 6 GHz) need to be adopted to provide additional spectrum. This paper investigates the characteristics of indoor corridor channels at 15 GHz. Channel measurements with a vector network analyzer in two corridors were conducted. Based on a ray-optical approach, a deterministic channel model covering both antenna and propagation characteristic is presented. The channel model is evaluated by comparing simulated results of received power and root mean square delay spread with the corresponding measurements. By removing the impact of directional antennas from the transmitter and receiver, a path loss model as well as small-scale fading properties for typical corridors is presented based on the generated samples from the deterministic model. Results show that the standard deviation of path loss variation is related to the Tx height, and placing the Tx closer to the ceiling leads to a smaller fluctuation of path loss
Joint Design of Access and Backhaul in Densely Deployed MmWave Small Cells
With the rapid growth of mobile data traffic, the shortage of radio spectrum
resource has become increasingly prominent. Millimeter wave (mmWave) small
cells can be densely deployed in macro cells to improve network capacity and
spectrum utilization. Such a network architecture is referred to as mmWave
heterogeneous cellular networks (HetNets). Compared with the traditional wired
backhaul, The integrated access and backhaul (IAB) architecture with wireless
backhaul is more flexible and cost-effective for mmWave HetNets. However, the
imbalance of throughput between the access and backhaul links will constrain
the total system throughput. Consequently, it is necessary to jointly design of
radio access and backhaul link. In this paper, we study the joint optimization
of user association and backhaul resource allocation in mmWave HetNets, where
different mmWave bands are adopted by the access and backhaul links.
Considering the non-convex and combinatorial characteristics of the
optimization problem and the dynamic nature of the mmWave link, we propose a
multi-agent deep reinforcement learning (MADRL) based scheme to maximize the
long-term total link throughput of the network. The simulation results show
that the scheme can not only adjust user association and backhaul resource
allocation strategy according to the dynamics in the access link state, but
also effectively improve the link throughput under different system
configurations.Comment: 15 page
Throughput Maximization for Intelligent Refracting Surface Assisted mmWave High-Speed Train Communications
With the increasing demands from passengers for data-intensive services,
millimeter-wave (mmWave) communication is considered as an effective technique
to release the transmission pressure on high speed train (HST) networks.
However, mmWave signals ncounter severe losses when passing through the
carriage, which decreases the quality of services on board. In this paper, we
investigate an intelligent refracting surface (IRS)-assisted HST communication
system. Herein, an IRS is deployed on the train window to dynamically
reconfigure the propagation environment, and a hybrid time division multiple
access-nonorthogonal multiple access scheme is leveraged for interference
mitigation. We aim to maximize the overall throughput while taking into account
the constraints imposed by base station beamforming, IRS discrete phase shifts
and transmit power. To obtain a practical solution, we employ an alternating
optimization method and propose a two-stage algorithm. In the first stage, the
successive convex approximation method and branch and bound algorithm are
leveraged for IRS phase shift design. In the second stage, the Lagrangian
multiplier method is utilized for power allocation. Simulation results
demonstrate the benefits of IRS adoption and power allocation for throughput
improvement in mmWave HST networks.Comment: 13 pages, 7 figures, IEEE Internet of Things Journa
Joint Optimization of Resource Allocation and User Association in Multi-Frequency Cellular Networks Assisted by RIS
Due to the development of communication technology and the rise of user
network demand, a reasonable resource allocation for wireless networks is the
key to guaranteeing regular operation and improving system performance. Various
frequency bands exist in the natural network environment, and heterogeneous
cellular network (HCN) has become a hot topic for current research. Meanwhile,
Reconfigurable Intelligent Surface (RIS) has become a key technology for
developing next-generation wireless networks. By modifying the phase of the
incident signal arriving at the RIS surface, RIS can improve the signal quality
at the receiver and reduce co-channel interference. In this paper, we develop a
RIS-assisted HCN model for a multi-base station (BS) multi-frequency network,
which includes 4G, 5G, millimeter wave (mmwave), and terahertz networks, and
considers the case of multiple network coverage users, which is more in line
with the realistic network characteristics and the concept of 6G networks. We
propose the optimization objective of maximizing the system sum rate, which is
decomposed into two subproblems, i.e., the user resource allocation and the
phase shift optimization problem of RIS components. Due to the NP-hard and
coupling relationship, we use the block coordinate descent (BCD) method to
alternately optimize the local solutions of the coalition game and the local
discrete phase search algorithm to obtain the global solution. In contrast,
most previous studies have used the coalition game algorithm to solve the
resource allocation problem alone. Simulation results show that the algorithm
performs better than the rest of the algorithms, effectively improves the
system sum rate, and achieves performance close to the optimal solution of the
traversal algorithm with low complexity.Comment: 18 page
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