Semi-supervised learning based hybrid beamforming under time-varying propagation environments

Hybrid precoding is considered as a promising low-cost technique for millimeter wave(mm-wave)massive Multi-Input Multi-Output(MIMO)systems.In this work,referring to the time-varying propagation circumstances,with semi-supervised Incremental Learning(IL),we propose an online hybrid beamforming scheme.Firstly,given the constraint of constant modulus on analog beamformer and combiner,we propose a new broadnetwork-based structure for the design model of hybrid beamforming.Compared with the existing network structure,the proposed network structure can achieve better transmission performance and lower complexity.Moreover,to enhance the efficiency of IL further,by combining the semi-supervised graph with IL,we propose a hybrid beamforming scheme based on chunk-by-chunk semi-supervised learning,where only few transmissions are required to calculate the label and all other unlabelled transmissions would also be put into a training data chunk.Unlike the existing single-by-single approach where transmissions during the model update are not taken into the consideration of model update,all transmissions,even the ones during the model update,would make contributions to model update in the proposed method.During the model update,the amount of unlabelled transmissions is very large and they also carry some information,the prediction performance can be enhanced to some extent by these unlabelled channel data.Simulation results demonstrate the spectral efficiency of the proposed method outperforms that of the existing single-by-single approach.Besides,we prove the general complexity of the proposed method is lower than that of the existing approach and give the condition under which its absolute complexity outperforms that of the existing approach.

Tomato detection method using domain adaptive learning for dense planting environments

This study aimed to address the challenge of accurately and reliably detecting tomatoes in dense planting environments,a critical prerequisite for the automation implementation of robotic harvesting.However,the heavy reliance on extensive manually annotated datasets for training deep learning models still poses significant limitations to their application in real-world agricultural production environments.To overcome these limitations,we employed domain adaptive learning approach combined with the YOLOv5 model to develop a novel tomato detection model called as TDA-YOLO(tomato detection domain adaptation).We designated the normal illumination scenes in dense planting environments as the source domain and utilized various other illumination scenes as the target domain.To construct bridge mechanism between source and target domains,neural preset for color style transfer is introduced to generate a pseudo-dataset,which served to deal with domain discrepancy.Furthermore,this study combines the semi-supervised learning method to enable the model to extract domain-invariant features more fully,and uses knowledge distillation to improve the model's ability to adapt to the target domain.Additionally,for purpose of promoting inference speed and low computational demand,the lightweight FasterNet network was integrated into the YOLOv5's C3 module,creating a modified C3_Faster module.The experimental results demonstrated that the proposed TDA-YOLO model significantly outperformed original YOLOv5s model,achieving a mAP(mean average precision)of 96.80%for tomato detection across diverse scenarios in dense planting environments,increasing by 7.19 percentage points;Compared with the latest YOLOv8 and YOLOv9,it is also 2.17 and 1.19 percentage points higher,respectively.The model's average detection time per image was an impressive 15 milliseconds,with a FLOPs(floating point operations per second)count of 13.8 G.After acceleration processing,the detection accuracy of the TDA-YOLO model on the Jetson Xavier NX development board is 90.95%,the mAP value is 91.35%,and the detection time of each image is 21 ms,which can still meet the requirements of real-time detection of tomatoes in dense planting environment.The experimental results show that the proposed TDA-YOLO model can accurately and quickly detect tomatoes in dense planting environment,and at the same time avoid the use of a large number of annotated data,which provides technical support for the development of automatic harvesting systems for tomatoes and other fruits.

Effects of Perceived Teacher Support on Student Behavioral Engagement in the Blended Learning Environment:Learning Experience as a Mediator

Blended learning(BL)has been widely adopted to improve students’academic achievements in higher education.However,its success relies mainly on student engagement,which plays an essential role in active learning and provides a rich understanding of students’experiences.The study utilized three self-designed scales-the Teacher Support Scale,Student Engagement Scale,and Student Learning Experience Scale-to gauge and examine the impact and relationship between perceived teacher support,student behavioral engagement,and the intermediary role of learning experiences.A cohort of 899 college students undertaking the obligatory College English course through BL modes across five Chinese universities actively participated by completing a comprehensive questionnaire.The results showed significant correlations between perceived teacher support,learning experience,and behavioral engagement.Perceived teacher support significantly predicted students’behavioral engagement,with socio-affective support exerting the most substantial predictive effects.All predictive effects were partially mediated by learning experience(learning mode,online resources,overall LMS-based learning,interaction with their instructor and peers,and learning outcome).The influence of perceived teacher support on behavioral engagement differed between students who reported the most positive(vs.negative)learning experiences.Suggestions for further research are offered for consideration.

The Influence of Information Technology Investment on the Organizational Performance:The Moderating Role of External Environment

In the information era,enterprises can enhance organizational performance through advanced information technology.Based on the resource-based view,this paper examines the mechanism by which information technology(IT)investment influences organizational performance,with the external environment as a moderating variable.Using 265 valid samples collected from agricultural enterprises in Shandong province,this study conducts an empirical test through partial least squares structural equation modeling.The results demonstrate that IT investment has a significant positive effect on organizational performance,and the external environment significantly moderates the relationship between IT investment and organizational performance.This research contributes to a deeper understanding of the relationship between IT investment and organizational performance,enriches resource-based theory,expands the research framework on IT investment,and offers guidance for enterprises seeking sustainable growth.

Toward real-world deployment of machine learning for health care:External validation,continual monitoring,and randomized clinical trials

1|OVERVIEW.Machine learning(ML)has been increasingly used for tackling various diagnostic,therapeutic,and prognostic tasks owing to its capability to learn and reason without explicit programming[1].Most developed ML models have had their accuracy proven through internal validation using retrospective data.However,external validation using retrospective data,continual monitoring using prospective data,and randomized controlled trials(RCTs)using prospective data are important for the translation of ML models into real-world clinical practice[2].

The Use of Virtual Learning Environment in Chinese Higher Education

The paper analyzes the current condition of the use of virtual learning environment(VLE) in Zhejiang University of Chinese Medicine. It is indicated that students show a positive attitude toward this technology, but the use of it fails to meet students' perception. In light of this, recommendations are made with a view to enhance the use of VLE.

On Improving the Classroom Environment of English Learning in College

This paper, firstly, acknowledges the importance of classroom environment and the problems existing in the college English classroom. And then, it offers some ways of improving the classroom environment which is very critical to evaluate educational programs and curriculum and provides guidance to teachers who are eager to boost their classroom teaching.

Current Situation and Future Development of“Affordance”in College English Learning Environment in Information Age

With the increasing development of economy and society,the 21st century will surely become an era of rapid development of information technology.Based on the macro and micro levels of education in China,this paper introduces the"affordance theory"to analyze and discuss the current situation of College English learning environment in China,and puts forward new goals and principles to promote the future development of College English learning environment in order to better promote its effective transformation.

Study on the Ubiquitous English Learning Environment in Vocational Colleges

Ubiquitous learning is a new type of learning method with rich learning concepts and educational significance. The study of ubiquitous learning began in 1991, and has experienced three stages of gestation, start-up and formation and development.After entering the 21 st century, new technologies and new ideas have emerged endlessly. The change in learning methods has led to the flip of classroom teaching, and ubiquitous learning has become more known as the pace of social development. The current higher vocational education presents the characteristics of disjointed education content, misaligned learning roles, and single teaching form. The integration of ubiquitous learning environment into vocational education teaching is a new direction for the development of vocational education.

PD-type iterative learning control for nonlinear time-delay system with external disturbance

The PD-type iterative learning control design of a class of affine nonlinear time-delay systems with external disturbances is considered. Sufficient conditions guaranteeing the convergence of the n-norm of the tracking error are derived. It is shown that the system outputs can be guaranteed to converge to desired trajectories in the absence of external disturbances and output measurement noises. And in the presence of state disturbances and measurement noises, the tracking error will be bounded uniformly. A numerical simulation example is presented to validate the effectiveness of the proposed scheme.

Research on Application of Metacognitive Strategy in English Listening in the Web-based Self-access Learning Environment

Metacognitive strategies are regarded as advanced strategies in all the learning strategies.This study focuses on the application of metacognitive strategies in English listening in the web-based self-access learning environment(WSLE) and tries to provide some references for those students and teachers in the vocational colleges.

Extreme Learning Machine-Based Thermal Model for Lithium-Ion Batteries of Electric Vehicles under External Short Circuit

External short circuit(ESC)of lithium-ion batteries is one of the common and severe electrical failures in electric vehicles.In this study,a novel thermal modelis developed to capture the temperature behavior of batteries under ESC conditions.Experiments were systematically performed under different battery initial state of charge and ambient temperatures.Based on the experimental results,we employed an extreme learming machine(ELM)-based thermal(ELMT)model to depict battery temperature behavior under ESC,where a lumped-state thermal model was used to replace the activation function of conventional ELMs.To demonstrate the effectiveness of the proposed model,wecompared the ELMT model with a multi-lumped-state thermal(MLT)model parameterized by thegenetic algorithm using the experimental data from various sets of battery cells.It is shown that the ELMT model can achieve higher computa-tional efficiency than the MLT model and better fitting and prediction accuracy,where the average root mean squared error(RMSE)of the fitting is 0.65℃ for the ELMT model and 3.95℃ for the MLT model,and the RMES of the prediction under new data set is 3.97℃ for the ELMT model and 6.11℃ for the MLT model.

Engagement in clinical learning environment among nursing students: Role of nurse educators

Student engagement in a clinical learning environment is a vital component in the curricula of pre-licensure nursing students, providing an opportunity to combine cognitive, psychomotor, and affective skills. This paper is significant in Arab world as there is a lack of knowledge, attitude and practice of student involvement in the new clinical learning environment. The purpose of this review article is to describe the experiences and perspectives of the nurse educator in facilitating pre-licensure nursing students’ engagement in the new clinical learning environment. The review suggests that novice students prefer actual engagement in clinical learning facilitated through diversity experiences, shared learning opportunities, student-faculty interaction and active learning. They expressed continuous supervision, ongoing feedback, interpersonal relationship and personal support from nurse educators useful in the clinical practice. However, the value of this review lies in a better understanding of what constitutes quality clinical learning environment from the students’ perspective of engagement in evidence-based nursing, reflective practice, e-learning and simulated case scenarios facilitated by the nurse educators. This review is valuable in planning and implementing innovative clinical and educational experiences for improving the quality of the clinical teaching-learning environment.

Impact of light-weight external thermal insulation materials on building surrounding thermal environment in summer

The method for calculating wall surface heat storage coefficient was introduced,and the coefficients of several common walls with light-weight external thermal insulation materials and the traditional solid clay brick wall were calculated.In order to study the impact of light-weight external thermal insulation materials,a contrasting experiment was carried out between an external insulated room and an uninsulated room in August,2010,in Chongqing,China.The result shows that outside surface heat storage coefficient of the insulated wall is much less than that of the traditional wall.However,during sunny time,the surface temperature of external walls of the insulated room is obviously higher than that of the uninsulated room.In different orientations,due to different amounts of solar radiation and being irradiated in different time,the contrasting temperature difference(CTD) appears different regularity.In a word,using light-weight external thermal insulation materials has a negative impact on building surrounding thermal environment and people's health.Finally,some suggestions on how to eliminate the impact,such as improving the surface condition of the building envelop,and plating vertical greening,are put forward.

Investigating Affordance in Technology-Enriched Language Learning Environment Through Exploring Students’Perezhivanija

Preceding works tend to explicate affordance through supposing what is happening here and now.They seldom relate it to actual social,diachronic activities,such as foreign language learning.To tackle this issue,this study explores how students actualize affordances in technology-enriched language learning environment(TELLE)by examining their perezhivanija(lived and emotional experience),a term borrowed from sociocultural theory.Because an individual’s social life is a developing process or a perezhivanie2,it is necessary to base the research in a dynamic development of language learning to figure out how the affordances are actualized.Narrative interviews were adopted to collect data from three Chinese college students who learn English as a foreign language in a Northeastern university in China.The results showed that due to the students’different past perezhivanija in English learning,their present interpretations of the perceived affordances in TELLE varied.This influenced hugely in their actions taken during their English learning in college to actualize the affordances.The findings indicated that the actualization of affordances is historical,dynamic and developmental instead of static.It does not lie in the autonomy of the students or the teachers,but in the institutional and cultural legitimacy of technology use in student’s social life.The paper contributes to the application of affordance theory in foreign language learning and provides implications to language teaching practice in TELLE.

Strengthened Monitoring of H5 Avian Influenza Viruses in External Environment in Hubei, 2018

The contamination status of H5 avian influenza viruses and distribution of subtypes of H5N1 and H5N6 in poultry-related environment of Hubei areas were investigated.Urban and rural live poultry markets,poultry farms,intensive livestock farms and other monitoring types of 103 counties in 17 cities were selected in Hubei.Wiping samples from cage surface,wiping samples from chopping board,fecal specimens and other environmental samples were collected and tested by real-time RT-PCR using primers and probes of influenza A,avian influenza of H5,N1 and N6 from December 2017 to March 2018.The avian influenza virus positive rate was compared among different monitoring sites,samples,time and regions.Totally,7132 environmental samples were collected in 1634 monitoring points with a positive rate of 2.24%.The positive rate of H5 avian influenza virus was the highest in urban and rural live poultry markets(3.44%,x^2=61.329,P<0.05)in 6 monitoring sites and wiping samples from chopping board(5.46%,x^2=67.072,P<0.05)in 6 sample types.H5N6 avian influenza viruses were detected more in eastern than western Hubei,and H5N6 avian influenza viruses were detected only in Xiangyang city of western Hubei.There were important high-risk places of human infection with H5 avian influenza virus in urban and rural live poultry markets and the poultry slaughtering plants.H5N6 has been the predominant subtype of H5 avian influenza viruses in the eastern and western Hubei and H5N6 avian influenza viruses were still present in a few areas of Hubei.Outbreaks of human H5N1 and H5N6 avian influenza remain at risk in Hubei province.

Practices of caring for nursing students: A clinical learning environment

Objective:The purpose of this study was to explore,describe and illuminate nursing students'best encounters of caring in the clinical learning environment.Caring for nursing students was emphasized and recommendations provided to enhance caring for nursing students within their clinical learning environment.Methods:Qualitative data was collected by the researcher using semi-structured individual interviews and an Appreciative Inquiry(AI)methodology.Ten second year nursing students undertaking the bridging course leading to registration as general nurses in terms of Regulation 683 of the South African Nursing Council(SANC)were purposively sampled from 3 private hospitals within the Western Cape.Data was analysed using Giorgi's method.Results:The main theme included the best and'least best'caring practices embedded in the centrality of the heart.The subthemes comprised of the nursing students'experiences of caring literacy and caring illiteracy.The second theme included the creation of best caring practices within a conducive clinical learning environment.Within this theme,the subthemes comprised of the caring attributes required in reflecting best caring practices,as well the creation of a clinical learning environment to optimise caring.Conclusions:The significance and necessity of caring for the nursing student were clearly illustrated and confirmed by participants.Caring was equated to the heart as the core to the nursing students'being.Recommendations for nursing education,management,practice and research were therefore specifically formulated to enhance caring towards nursing students.

A Multi-Agent System for Environmental Monitoring Using Boolean Networks and Reinforcement Learning

Distributed wireless sensor networks have been shown to be effective for environmental monitoring tasks,in which multiple sensors are deployed in a wide range of the environments to collect information or monitor a particular event,Wireless sensor networks,consisting of a large number of interacting sensors,have been successful in a variety of applications where they are able to share information using different transmission protocols through the communication network.However,the irregular and dynamic environment requires traditional wireless sensor networks to have frequent communications to exchange the most recent information,which can easily generate high communication cost through the collaborative data collection and data transmission.High frequency communication also has high probability of failure because of long distance data transmission.In this paper,we developed a novel approach to multi-sensor environment monitoring network using the idea of distributed system.Its communication network can overcome the difficulties of high communication cost and Single Point of Failure(SPOF)through the decentralized approach,which performs in-network computation.Our approach makes use of Boolean networks that allows for a non-complex method of corroboration and retains meaningful information regarding the dynamics of the communication network.Our approach also reduces the complexity of data aggregation process and employee a reinforcement learning algorithm to predict future event inside the environment through the pattern recognition.

Tracking Students’ Mental Engagement Using EEG Signals during an Interaction with a Virtual Learning Environment

Monitoring students’ level of engagement during learning activities is an important challenge in the development of tutoring interventions. In this paper, we explore the feasibility of using electroencephalographic signals (EEG) as a tool to monitor the mental engagement index of novice medicine students during a reasoning process. More precisely, the objectives were first, to track students’ mental engagement evolution in order to investigate whether there were particular sections within the learning environment that aroused the highest engagement level among the students, and, if so, did these sections have an impact on learners’ performance. Experimental analyses showed the same trends in the different resolution phases as well as across the different regions of the environments. However, we noticed a higher engagement index during the treatment identification phase since it aroused more mental effort. Moreover statistically significant effects were found between mental engagement and students’ performance.

An Active Language Learning Environment Created by Email Communication

The rapid development of information and communication technology in recent years is associated with a corresponding growth in interest in computer-mediated communication(CMC)-synchronous CMC and asynchronous CMC.Among asynchronous CMC,email communication has attracted more attention of researchers in the field of foreign language learning.This paper will review studies which investigate one aspect of the advantages of email communication-an active environment for foreign language learning.