UAV-assisted data collection for wireless sensor networks with dynamic working modes

Wireless Sensor Network(WSN)is a cornerstone of Internet of Things(IoT)and has rich application scenarios.In this work,we consider a heterogeneous WSN whose sensor nodes have a diversity in their Residual Energy(RE).In this work,to protect the sensor nodes with low RE,we investigate dynamic working modes for sensor nodes which are determined by their RE and an introduced energy threshold.Besides,we employ an Unmanned Aerial Vehicle(UAV)to collect the stored data from the heterogeneous WSN.We aim to jointly optimize the cluster head selection,energy threshold and sensor nodes’working mode to minimize the weighted sum of energy con-sumption from the WSN and UAV,subject to the data collection rate constraint.To this end,we propose an efficient search method to search for an optimal energy threshold,and develop a penalty-based successive convex approximation algorithm to select the cluster heads.Then we present a low-complexity iterative approach to solve the joint optimization problem and discuss the implementation procedure.Numerical results justify that our proposed approach is able to reduce the energy consumption of the sensor nodes with low RE significantly and also saves energy for the whole WSN.

Design and optimization of fluid lubricated bearings operated with extreme working performances——a comprehensive review

Fluid lubricated bearings have been widely adopted as support components for high-end equipment in metrology,semiconductor devices,aviation,strategic defense,ultraprecision manufacturing,medical treatment,and power generation.In all these applications,the equipment must deliver extreme working performances such as ultraprecise movement,ultrahigh rotation speed,ultraheavy bearing loads,ultrahigh environmental temperatures,strong radiation resistance,and high vacuum operation,which have challenged the design and optimization of reliable fluid lubricated bearings.Breakthrough of any related bottlenecks will promote the development course of high-end equipment.To promote the advancement of high-end equipment,this paper reviews the design and optimization of fluid lubricated bearings operated at typical extreme working performances,targeting the realization of extreme working performances,current challenges and solutions,underlying deficiencies,and promising developmental directions.This paper can guide the selection of suitable fluid lubricated bearings and optimize their structures to meet their required working performances.

Relationship between physical activity and specific working memory indicators of depressive symptoms in university students

BACKGROUND The detection rate of depression among university students has been increasing in recent years,becoming one of the main psychological diseases that endangers their physical and mental health.According to statistics,self-harm and suicide,for which there is no effective intervention,are the second leading causes of death.AIM To explore the relationship between different elements and levels of physical activity and college students’depression-symptom-specific working memory indicators.METHODS Of 143 college students were analyzed using the Beck Depression Self-Rating Scale,the Physical Activity Rating Scale,and the Working Memory Task.RESULTS There was a significant difference between college students with depressive symptoms and healthy college students in completing verbal and spatial working memory(SWM)tasks correctly(all P<0.01).Physical Activity Scale-3 scores were significantly and positively correlated with the correct rate of the verbal working memory task(r=0.166)and the correct rate of the SWM task(r=0.210)(all P<0.05).There were significant differences in the correct rates of verbal and SWM tasks according to different exercise intensities(all P<0.05)and different exercise durations(all P<0.05),and no significant differences in the correct rates of verbal and SWM tasks by exercise frequency(all P>0.05).CONCLUSION An increase in physical exercise among college students,particularly medium-and high-intensity exercise and exercise of 30 min or more,can improve the correct rate of completing working memory tasks.

A Review on Technologies for the Use of CO2 as a Working Fluid in Refrigeration and Power Cycles

The use of carbon dioxide as a working fluid has been the subject of extensive studies in recent years, particularly in the field of refrigeration where it is at the heart of research to replace CFC and HCFC. Its thermodynamic properties make it a fluid of choice in the efficient use of energy at low and medium temperatures in engine cycles. However, the performance of transcritical CO2 cycles weakens under high temperature and pressure conditions, especially in refrigeration systems;On the other hand, this disadvantage becomes rather interesting in engine cycles where CO2 can be used as an alternative to the organic working fluid in small and medium-sized electrical systems for low quality or waste heat sources. In order to improve the performance of systems operating with CO2 in the field of refrigeration and electricity production, research has made it possible to develop several concepts, of which this article deals with a review of the state of the art, followed by analyzes in-depth and critical of the various developments to the most recent modifications in these fields. Detailed discussions on the performance and technical characteristics of the different evolutions are also highlighted as well as the factors affecting the overall performance of the systems studied. Finally, perspectives on the future development of the use of CO2 in these different cycles are presented.

Working condition recognition of sucker rod pumping system based on 4-segment time-frequency signature matrix and deep learning

High-precision and real-time diagnosis of sucker rod pumping system(SRPS)is important for quickly mastering oil well operations.Deep learning-based method for classifying the dynamometer card(DC)of oil wells is an efficient diagnosis method.However,the input of the DC as a two-dimensional image into the deep learning framework suffers from low feature utilization and high computational effort.Additionally,different SRPSs in an oil field have various system parameters,and the same SRPS generates different DCs at different moments.Thus,there is heterogeneity in field data,which can dramatically impair the diagnostic accuracy.To solve the above problems,a working condition recognition method based on 4-segment time-frequency signature matrix(4S-TFSM)and deep learning is presented in this paper.First,the 4-segment time-frequency signature(4S-TFS)method that can reduce the computing power requirements is proposed for feature extraction of DC data.Subsequently,the 4S-TFSM is constructed by relative normalization and matrix calculation to synthesize the features of multiple data and solve the problem of data heterogeneity.Finally,a convolutional neural network(CNN),one of the deep learning frameworks,is used to determine the functioning conditions based on the 4S-TFSM.Experiments on field data verify that the proposed diagnostic method based on 4S-TFSM and CNN(4S-TFSM-CNN)can significantly improve the accuracy of working condition recognition with lower computational cost.To the best of our knowledge,this is the first work to discuss the effect of data heterogeneity on the working condition recognition performance of SRPS.

Positive Effect of Transcranial Direct Current Stimulation on Visual Verbal Working Memory in Patients with Attention-Deficit/Hyperactivity Disorder

Background: Working memory is an executive function that plays an important role in many aspects of daily life, and its impairment in patients with attention-deficit/hyperactivity disorder (ADHD) affects quality of life. The dorsolateral prefrontal cortex (DLPFC) has been a good target site for transcranial direct current stimulation (tDCS) due to its intense involvement in working memory. In our 2018 study, tDCS improved visual-verbal working memory in healthy subjects. Objective: This study examines the effects of tDCS on ADHD patients, particularly on verbal working memory. Methods: We conducted an experiment involving verbal working memory of two modalities, visual and auditory, and a sustained attention task that could affect working memory in 9 ADHD patients. Active or sham tDCS was applied to the left DLPFC in a single-blind crossover design. Results: tDCS significantly improved the accuracy of visual-verbal working memory. In contrast, tDCS did not affect auditory-verbal working memory and sustained attention. Conclusion: tDCS to the left DLPFC improved visual-verbal working memory in ADHD patients, with important implications for potential ADHD treatments.

The Impact of the Digital Economy on Rural Residents’Working Hours:Mechanisms and Empirical Evidence

The rapid development of the digital economy has provided a new impetus for rural residents to extend their working hours.Based on the data collected by the China Labor-force Dynamics Survey(CLDS)in 2014,2016,and 2018,this paper measured the development level of the digital economy in China from the perspectives of internet development and digital financial inclusion,and tested the mechanisms of how the digital economy affected rural residents’working hours.The results showed that the digital economy extended rural residents’working hours by expanding information channels and enhancing human capital,and this mechanism was affected by heterogeneity in rural residents’educational background,age,and social capital.Building on these findings,this paper holds that to increase rural residents’income by extending their working hours and achieving common prosperity for all,it is necessary to expand the opportunities for rural residents to participate in skills training and promote their accumulation of human capital.

Feasibility of Synchronously Straightening Working Line of Adjacent Open-cast Mines

Taking Heidaigou Open-cast Mine and Haerwusu Open-cast Mine in Zhungeer mining area as the research objects,this paper deeply analyzes the current mining status of the two mines.Based on the existing working line length,mining technology,transportation system,equipment configuration,transportation access and many other factors,it systematically discusses the feasibility of straightening the working line of adjacent open-cast mines.Through in-depth theoretical analysis,it establishes the mathematical model of impact indicators and cost calculation,and it is concluded that the work line straightening can be technically achieved.However,from the perspective of economic benefits,straightening the working line does not show obvious advantages.

Text Difficulty,Working Memory Capacity and Mind Wandering During Chinese EFL Learners’Reading

This experimental study investigated how text difficulty and different working memory capacity(WMC)affected Chinese EFL learners’reading comprehension and their tendency to engage in task-unrelated thoughts,that is,mind wandering(MW),in the course of reading.Sixty first-year university non-English majors participated in the study.A two-factor mixed experimental design of 2(text difficulty:difficult and simple)×2(WMC:high/large and low/small)was employed.Results revealed that 1)the main and interaction effects of WMC and text difficulty on voluntary MW were significant,whereas those on involuntary MW were not;2)while reading the easy texts,the involuntary MW of high-WMC individuals was less frequent than that of low-WMC ones,whereas while reading the difficult ones,the direct relationship between WMC and involuntary MW was not found;and that 3)high-WMC individuals had a lower overall rate of MW and better reading performance than low-WMC individuals did,but with increasing text difficulty,their rates of overall MW and voluntary MW were getting higher and higher,and the reading performance was getting lower and lower.These results lend support to WM theory and have pedagogical implications for the instruction of L2 reading.

Analysis of Air Exchange System Influence on Thermal and Concentration Modes in the Local Working Area under Radiant Heating Conditions

One of the effective options for energy saving in terms of heat costs for the formation of routine thermal conditions of working areas of large-sized industrial premises is the replacement of traditional convective(water)heating systems with systems,the main part of which are gas infrared emitters.But the mass introduction of such systems based on emitters was held back until recently by the lack of scientific and technical foundations for ensuring not only the routine thermal conditions of local working areas,but also ensuring acceptable concentrations of carbon dioxide,which is formed during the operation of a gas emitter.Solving the latter problem by the method of experimental selection of heating and air exchange modes is practically impossible due to the multivariate nature of possible solutions to this problem.Therefore,the purpose of the work is to analyze the results of theoretical studies of the possibility of ensuring an acceptable level of carbon dioxide concentrations in local working areas during the operation of gas infrared emitters and an air exchange system.Numerical modeling of heat and mass transfer processes under such conditions was performed in a fairly wide range of the main significant factors:air flow rate in the air exchange system from 0.01 to 0.04 kg/s,the position of the air inlet and outlet channels relative to the radiator and the local workplace(height from 0.3 to 4.1 m).It was found that by varying the numerical values of these factors,it is possible to ensure carbon dioxide concentrations in the local working area within the permissible limits of up to 1400 ppm.

Child Abdominal Trauma Due to Attack of Cattles While Working on Farms in Burkina Faso

Introduction: Cattle are strong animals very often used in agriculture in rural Africa. Unpredictable in their behavior, they regularly inflict injuries to farmers, some of whom are children in rural Africa. Objective: The purpose of this study was to describe the clinical, therapeutic and evolutionary aspects of abdominal trauma caused by bovidae to children on farms in Burkina Faso. Patients and Method: This is a descriptive study covering the period from January 2014 through December 2016 and was conducted in the General Surgery Unit of the Tenkodogo Regional Hospital in Burkina Faso. It included all patients under the age of 17, victims of abdominal trauma by cattle on farms. Result: A total of 68 patients were identified, which is 3% of all patients under 17 admitted to the service during the same period. The average age of patients was 10.5 years, with a standard variation of 3.6 years. The majority (73.5%) of the patients were boys. The main lesional mechanisms found were horn strokes (88.2%). We noted 35 eviscerations without visceral perforation, 15 intestinal perforations, 6 hepatic wounds and 5 splenic wounds. In 7 cases, there were non-penetrating wounds. All patients underwent surgical intervention under anesthesia. The average length of hospital was 6 days. Two deaths were recorded, making a mortality rate of 3%. Conclusion: Abdominal traumas of the child by attack of cattle are frequent during farm works in rural Burkina Faso. The injuries are sometimes serious. Wearing protective equipment for children should be considered during farm work.

Relevance of epidemiology data in trauma management

Trauma is a major cause of morbidity and mortality across the globe accounting for significant health burden.Relevance of trauma care revolves round prevention,planning and execution of safety regulations.Acquisition of the actual data regarding the type of trauma,affected age group,timings of trauma occurrence,involved part of the body constitute the initial steps in the building of the composite overview of the epidemiology of trauma.In succession,would be the measures directed towards avoidance of trauma and capacity building of trauma center.

借助外力 让感觉升华为思维——基于“Working Model”对2023年新课标卷第6题的拓展分析

“Working Model”是一个物理仿真模拟平台,可直观展示动力学中的物理过程和运动图像,形成真实的感觉。该平台可用于辅助教学,帮助学生通过感觉、知觉、记忆、想象、思维等认知过程来理解和掌握物理概念和规律。以2023年新课标卷第6题为切入点,结合近三年全国高考真题为例,探讨借助外力将感觉升华为思维的可能性,通过对“Working Model”的拓展分析提出一种新的思维模式,旨在帮助学生通过直观刺激和辅助工具将感觉体验转化为深度思考和创新思维。并通过理论分析和实证研究,探讨这种思维模式的实施方法、可行性和效果,为教育教学和认知科学领域的研究提供新的思路和启示。

利用Working Model模拟探究普适性的杠杆平衡条件

学生在学习杠杆平衡条件后,通常会对真实情境中的杠杆平衡条件的普适性产生疑问.通过对Working Model软件的学习,建立杠杆模型、科学推理、提出猜想、设计实验、收集与分析数据等,深度经历科学探究的过程,学生不仅能收获知识和实验探究的能力,还能够促进其质疑创新等核心素养的发展.

Return to work in young and middle-aged colorectal cancer survivors:Factors influencing self-efficacy,fear,resilience,and financial toxicity

BACKGROUND Return to work(RTW)serves as an indication for young and middle-aged colorectal cancer(CRC)survivors to resume their normal social lives.However,these survivors encounter significant challenges during their RTW process.Hence,scientific research is necessary to explore the barriers and facilitating factors of returning to work for young and middle-aged CRC survivors.AIM To examine the current RTW status among young and middle-aged CRC survivors and to analyze the impact of RTW self-efficacy(RTW-SE),fear of progression(FoP),eHealth literacy(eHL),family resilience(FR),and financial toxicity(FT)on their RTW outcomes.METHODS A cross-sectional investigation was adopted in this study.From September 2022 to February 2023,a total of 209 participants were recruited through a convenience sampling method from the gastrointestinal surgery department of a class A tertiary hospital in Chongqing.The investigation utilized a general information questionnaire alongside scales assessing RTW-SE,FoP,eHL,FR,and FT.To analyze the factors that influence RTW outcomes among young and middle-aged CRC survivors,Cox regression modeling and Kaplan-Meier survival analysis were used.RESULTS A total of 43.54%of the participants successfully returned to work,with an average RTW time of 100 days.Cox regression univariate analysis revealed that RTW-SE,FoP,eHL,FR,and FT were significantly different between the non-RTW and RTW groups(P<0.05).Furthermore,Cox regression multivariate analysis identified per capita family monthly income,job type,RTW-SE,and FR as independent influencing factors for RTW(P<0.05).CONCLUSION The RTW rate requires further improvement.Elevated levels of RTW-SE and FR were found to significantly increase RTW among young and middle-aged CRC survivors.Health professionals should focus on modifiable factors,such as RTW-SE and FR,to design targeted RTW support programs,thereby facilitating their timely reintegration into mainstream society.

Incorporating red blanket protocol within code crimson:Streamlining definitive trauma care amid the chaos

The care of a patient involved in major trauma with exsanguinating haemorrhage is time-critical to achieve definitive haemorrhage control,and it requires coordinated multidisciplinary care.During initial resuscitation of a patient in the emergency department(ED),Code Crimson activation facilitates rapid decisionmaking by multi-disciplinary specialists for definitive haemorrhage control in operating theatre(OT)and/or interventional radiology(IR)suite.Once this decision has been made,there may still be various factors that lead to delay in transporting the patient from ED to OT/IR.Red Blanket protocol identifies and addresses these factors and processes which cause delay,and aims to facilitate rapid and safe transport of the haemodynamically unstable patient from ED to OT,while minimizing delay in resuscitation during the transfer.The two processes,Code Crimson and Red Blanket,complement each other.It would be ideal to merge the two processes into a single protocol rather than having two separate workflows.Introducing these quality improvement strategies and coor-dinated processes within the trauma framework of the hospitals/healthcare systems will help in further improving the multi-disciplinary care for the complex trauma patients requiring rapid and definitive haemorrhage control.

EEG Correlations during a Working Memory Task with Emotional Stimuli in Girls with Post-Traumatic Stress Disorder Secondary to Sexual Abuse

Survivors of Child Sexual Abuse (CSA) can develop Post-Traumatic Stress Disorder (PTSD), alterations in the prefrontal cortex, changes in electroencephalographic (EEG) activity, and lower performance on working memory tasks. The aim of this study was to characterize brain electrical correlations in girls with PTSD secondary to CSA during a working memory task based on recognizing emotional facial stimuli. Girls aged 8 - 16 years old were evaluated: 12 with PTSD secondary to CSA, and 12 healthy girls with no history of abuse. EEG activity during a working memory task with emotional stimuli was recorded, and the inter- and intra-hemispheric correlations that assessed the functional connectivity among different cortical regions were analyzed. The PTSD group showed lower performance than controls on the working memory task while watching happy faces, while the EEG of this group showed greater intrahemispheric correlation among frontal areas and between frontal and posterior cortical regions. Also, the PTSD group had lower interhemispheric correlations between posterior temporal areas. The higher intrahemispheric correlation in the PTSD group could indicate that those girls used more brain areas when performing the task, likely because it required greater effort. The lower inter-posterior temporal correlation could be attributed to a reduction of the corpus callosum.

Current role of extracorporeal membrane oxygenation for the management of trauma patients:Indications and results

Extracorporeal membrane oxygenation(ECMO)has emerged as a vital circulatory life support measure for patients with critical cardiac or pulmonary conditions unresponsive to conventional therapies.ECMO allows blood to be extracted from a patient and introduced to a machine that oxygenates blood and removes carbon dioxide.This blood is then reintroduced into the patient’s circulatory system.This process makes ECMO essential for treating various medical conditions,both as a standalone therapy and as adjuvant therapy.Veno-venous(VV)ECMO primarily supports respiratory function and indicates respiratory distress.Simultaneously,veno-arterial(VA)ECMO provides hemodynamic and respiratory support and is suitable for cardiac-related complications.This study reviews recent literature to elucidate the evolving role of ECMO in trauma care,considering its procedural intricacies,indications,contraindications,and associated complications.Notably,the use of ECMO in trauma patients,particularly for acute respiratory distress syndrome and cardiogenic shock,has demonstrated promising outcomes despite challenges such as anticoagulation management and complications such as acute kidney injury,bleeding,thrombosis,and hemolysis.Some studies have shown that VV ECMO was associated with significantly higher survival rates than conventional mechanical ventilation,whereas other studies have reported that VA ECMO was associated with lower survival rates than VV ECMO.ECMO plays a critical role in managing trauma patients,particularly those with acute respiratory failure.Further research is necessary to explore the full potential of ECMO in trauma care.Clinicians should have a clear understanding of the indications and contraindications for the use of ECMO to maximize its benefits in treating trauma patients.

基于Working Model 2D运动仿真的机构设计

介绍了基于Working Model 2D运动仿真的机构设计。该文利用该软件对四杆机构进行运动仿真和运动分析,结合Excel实现凸轮机构的凸轮轮廓线的设计并作运动仿真。此软件简单易学,仿真过程形象直观,为机构设计提供了一个极好的工具。

Working Paper推进学术研究作用的实证研究——以金融经济领域为例

Working Paper(WP)是一类特殊的参考文献,它通常不是正式出版的论文,但常常又是最新学术思想和方法的载体,它对学术研究的推进作用是一个值得探讨的问题。本文以现代金融经济领域为研究对象,采用文献计量的方法对这个问题进行了实证研究。采用的样本为JFE杂志1998年1月至2007年10月刊登的559篇论文。设计了6个指标对WP的学术促进作用进行了统计分析。建立了三个经济计量模型分析了互联网等电子手段带来的文献传播速度加快是否促进了WP文献的学术影响。关键结论有:在现代金融经济研究领域,WP在全部参考文献的占比大约为1/10,时间影响长度大约为3.5年,互联网等手段促进了WP的使用,但没有带来增长速度的剧烈提高。