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.

Delay-dependent Criteria for Robust Stability of Uncertain Switched Hopfield Neural Networks

This paper deals with the problem of delay-dependent robust stability for a class of switched Hopfield neural networks with time-varying structured uncertainties and time-varying delay. Some Lyapunov-KrasoVskii functionals are constructed and the linear matrix inequality （LMI） approach and free weighting matrix method are employed to devise some delay-dependent stability criteria which guarantee the existence, uniqueness and global exponential stability of the equilibrium point for all admissible parametric uncertainties. By using Leibniz-Newton formula, free weighting matrices are employed to express this relationship, which implies that the new criteria are less conservative than existing ones. Some examples suggest that the proposed criteria are effective and are an improvement over previous ones.

Work Condition and Health at a Body Paint Workshop in Conakry

Context: Working conditions in the car repair sector are difficult in general. This leads to health risk factors for inexperienced staff. In the bodywork painting workshop, the staff seemed less interested in the risks probably due to negligence or by lack of knowledge. This work aimed to describe the working conditions and their impact on the workers’ health in a workshop of bodywork painting in Conakry. Material and Methods: This was a cross-sectional study over 06 months (from July 01, 2021, to December 31, 2021). Were included the bodybuilders-painters, the painters and the bodybuilders. The data was collected during an interview. We analysed the personal data of the workers, the physical environment factors (lighting, noise, etc.) and, the clinical manifestations felt by the workers. Results: The average age was 37 years extenting from 18 to 54 years and, they were all men. Over 80% of workers were exposed to more than 1000 lux and, 78.2% of workers were exposed to the vibratory intensity level of the cordless drill > 2.5 m/s2. The most frequent symptoms were back pain, headache, itchy eyes, and numbness of fingers and hands. The analysis of working conditions and clinical manifestations showed a significant relationship between the level of illumination and the tingling eyes (p = 0.0007), the vibratory intensity of the drill and the numbness of fingers and hands (p = 0.01). This study revealed that some of the complaints cited are related to the working conditions. Conclusion: Working conditions in a bodywork paint workshop are occupational risk factors that become dangerous if they are unknown. A longitudinal study on the assessment of working conditions could better enlighten us on this phenomenon.

Prognostic value of cachexia defined by the Asian Working Group for Cachexia criteria in patients with gastric cancer

Background:The Asian Working Group for Cachexia(AWGC)criteria are newly proposed diagnostic standards specifically designed for Asian populations.This research focused on validating the predictive value of the AWGC criteria for assessing the prognosis and medical burden of patients with gastric cancer.Methods:Cox proportional hazards analysis was conducted to evaluate the association between cachexia and overall survival.Logistic regression analysis was used to assess whether there was an independent association between cachexia and the 90-day mortality,the length of stay and the quality of life.Harrell’s concordance index was utilized to demonstrate the discriminative ability of different diagnostic criteria for cachexia.Results:AWGC-defined cachexia was an independent risk factor for a reduced overall survival in patients(HR=1.397,95%CI=1.209–1.615,P<0.001).The predictive accuracy of the AWGC criteria was markedly superior to that of the Fearon criteria(χ2=39.025 vs 13.877).Compared with Fearon standards,the AWGC criteria offered a 2.9%enhancement in clinical benefit(0.029,95%CI=0.048–0.008,P=0.005).Logistic regression analysis showed that only AWGC-defined cachexia was an independent risk factor for 90-day mortality(OR=2.142,95%CI=1.397–3.282,P<0.001)and prolonged hospitalization(OR=1.958,95%CI=1.587–2.416,P<0.001)in patients with gastric cancer,whereas cachexia defined by the Fearon criteria was not.Patients with AWGC-defined cachexia exhibited significant reductions in physical function,role function,emotional function,cognitive function,social functioning,and overall quality-of-life scores.Conversely,cachectic patients showed higher levels of fatigue,nausea and vomiting,pain,dyspnea,sleep disturbance,appetite loss,constipation,and financial difficulties.A multivariate logistic regression showed that patients with AWGC-defined cachexia had a 126.1%increased risk of impaired quality of life(OR=2.261,95%CI=1.859–2.749,P<0.001).Conclusions:The AWGC criteria are an effective tool for predicting adverse survival outcomes,90-day mortality,a prolonged hospital stay,and poorer quality of life in patients with gastric cancer.

King's College criteria and the Clichy-Villejuif criteria require adjustments for assessing acute liver failure due to yellow fever

BACKGROUND Acute liver failure(ALF)is a severe condition characterized by rapid deterioration of liver function in individuals without preexisting liver disease.Liver transplantation(LT)is the most impactful treatment.Yellow fever(YF)is an infectious disease that primarily affects the liver and has a high mortality rate.However,LT can be a viable option for treating rare cases with extensive liver involvement.However,the criteria for assessing the severity of ALF and determining the indications for transplantation have not been specifically validated for cases caused by YF.AIM To present necessary adjustments to established scoring systems for ALF secondary to YF.METHODS This was an observational,retrospective,single-center study.Fourteen consecutive patients with confirmed ALF due to YF were monitored in the intensive care unit by a specialized liver transplant team during a three-month epidemic outbreak in Brazil.During hospitalization,general supportive therapeutic measures were implemented,and the patients were regularly assessed using the King's College criteria and the Clichy-Villejuif criteria to determine the severity of liver failure.LT is considered a viable measure for patients with signs of end-stage liver failure.RESULTS Eight of 14(57%)patients developed severe neurological alterations within the first 96 hours after hospital admission.Four patients underwent emergency LT,and despite a moderate viral infection of the graft after transplantation,the 5-year survival rate was 50%.Although the King's College criteria and the Clichy-Villejuif criteria are the main scoring systems for ALF,they are insufficient for predicting the risk of mortality in this context,primarily because of low serum bilirubin levels in the final stage of the disease and significant disparities between coagulation abnormalities and patient severity.CONCLUSION To ensure good applicability in cases of YF-induced ALF,the authors suggest adaptations to the King's College and Clichy-Villejuif criteria.

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.

基于SolidWorks的导线卡线器三维建模及运动仿真

为解决导线挂线时的滑线、跑线问题,提高卡线器的设计效率,通过分析卡线器的结构和工作原理,以SKLT-60卡线器为主要研究对象,基于三维软件SolidWorks及其Motion插件,进行零件建模、虚拟装配及运动仿真,得到卡线器的夹嘴夹持力、上夹嘴运动轨迹、摇杆极限位置及滑块行程随时间的变化曲线.仿真结果表明:夹嘴夹持力、传动角及拉环行程满足设计要求.将虚拟样机技术和运动仿真技术相结合,对卡线器进行仿真分析,具有较好的模拟效果,缩短了产品开发周期,还能根据仿真结果进行结构优化,为类似设计提供了一种快捷、可靠的方法.

POST-OCCUPANCY EVALUATION OF EMPLOYEES’WORK PERFORMANCE AND SATISFACTION AS RELATED TO SUSTAINABLE DESIGN CRITERIA AND WORKSTATION TYPE

This case study investigated employees’work performance and satisfaction in relation to sustainable design criteria used to design the interior of their office building.The case study is part of ongoing research to continue testing a questionnaire for validity and reliability,which will contribute to the development of sustainable design/occupant scales relating to satisfaction and performance.A self-administered,Internet-based questionnaire was developed that reflects a set of recognized sustainable design guidelines.It was submitted to over 200 employees of a business housed in a newly built office building in a mid-western city.Generally positive results were found for employees’satisfaction with the new facility(site,building,and interior)and their performance as related to sustainable design criteria in the new facility.Dissatisfaction with acoustic and privacy conditions were found for employees of open-office workstation types(cubicles).Exploration of prior workstation types showed that moving from private offices to cubicles decreased employees’satisfaction with new cubicles compared to moving from cubicles in a prior building to cubicles in the new building,though dissatisfaction with these two criteria was found despite prior workstation type.These findings concur with other sustainable design studies and demonstrate that the questionnaire can be used by sustainable designers to document and explore design outcomes.

基于SolidWorks二次开发的平面闸门工程图出图研究

文章以平面闸门工程图三维正向设计出图为研究目的,系统性地梳理了平面闸门三维建模和工程图出图流程及方法,提出建模原则和方式,利用SolidWorks API接口进行二次开发,解决了工程图中材料明细表和焊接切割清单统计问题,开发了金属结构专业工程图插件软件,显著提高了工程图出图效率和质量。

A Practical Approach Based on Equal Area Criteria for Stability Analysis of Weak Networks with Wind Generation Penetration

The performance of DFIG-based wind generation systems that interconnected to solid networks is well understood and prevalent in Europe and North America. However, the application of these renewable generating stations to weak network has been examined in very limited occasions. Weak networks have a range of limitations from system capacities to CFCT restrictions which would need to be well understood prior to wind energy integration. Of particular interest would be how much wind generation could be integrated into a weak network prior to increasing voltage and frequency stability issues brought about by penetration issues. This paper introduces a simple and practical approach based on the equal area criteria to investigate the stability of weak networks. Simulation results that are presented to show the proposed approach is a viable preliminary assessment tool to determine system stability on weak networks with wind power penetration.

基于微课的高职“Solid Works三维建模设计”课程教学设计

针对传统"Solid Works三维建模设计"课程教学存在的不足,结合多年实践教学经验,将微课引入"Solid Works三维建模设计"课程教学当中,有助于提升学生自主学习能力,实现分层教学,提升"Solid Works三维建模设计"课堂教学效果。

基于Cosmos/Works液压支架整架有限元分析

对适用于大倾角的液压支架优化设计技术进行研究,在对液压支架产品建立虚拟样机模型的基础上,按照MT312-2000试验标准,通过Cosmos/Works软件,主要分析支架在顶梁扭转载荷工况下的有限元分析,为支架结构的优化设计分析提供了参考。

用VB开发SolidWorks的一种简单方法

论述了用VB对SolidWorks进行二次开发的一种简单方法,该方法将信息提取技术、编程计算技术和数据库技术相结合,克服了以往编程绘图程序编写复杂的困难,实现了计算和绘图的自动化。并结合实例进行了验证。

Solid works环境下的齿轮精确三维造型设计

详细介绍了在Solid works中实现圆柱齿轮精确三维造型的方法和技巧。重点讨论了齿廓曲线的计算方法及其与齿轮加工刀具的关系,分别讨论了齿廓曲线渐开线部分和齿根过渡曲线部分的曲线方程,并编制出了齿廓曲线的计算程序。最后在Solid works中绘制出了直齿圆柱齿轮的精确三维模型。

Visual C++对Solid Works二次开发技术及应用

介绍了三维CAD系统SolidWorks的特点及其API函数,讨论了对SolidWorks进行二次开发的关键技术及系统设计,并通过实例阐述了利用VisualC++工具开发SolidWorks动态连接库DLL的步骤和编程方法,这有利于对SolidWorks进行本地化和专业化的二次开发工作,使其在我国企业中更有效地发挥作用。

基于Solid Works的水稻盘育秧用土处理机的虚拟设计

本文基于国内生产的碎土机和筛土机的原型,构思了综合碎土、筛土两种功能的水稻盘育秧用土处理机,并进行了设计。在三维CAD设计软件Solid Works环境下完成了水稻盘育秧用土处理机AN-PSJ01型整机的三维实体建模,对水稻盘育秧用土处理机的虚拟样机的设计与研究进行了有创新和有建设性的尝试,为利用虚拟样机技术研究农业机械提供了更多有益的参考。

基于COSMOS/Works的数控机床主轴箱模态分析及优化设计

在COSMOS/Works环境下创建了数控机床主轴箱有限元模型,并对其进行模态分析,获得了关心的自振频率及振型。在此基础上,定义多个结构尺寸作为设计变量,对主轴箱动态特性进行优化,结果使其基频得以明显提高,有效增强了箱体的抗振性能。计算得出了一组具有良好动态特性的结构参数,为主轴箱的结构设计提供了重要参考。

基于COSMOS/Works的带式输送机传动滚筒的有限元分析

对输送机传动滚筒受力状况做了理论分析,运用有限元分析软件COSMOS/Works对传动滚筒进行了静力分析,得出滚筒在载荷作用下的应力和变形分布规律。分析结果表明,该传动滚筒的结构设计完全满足其强度、刚度要求。

基于Solid Works环境的渐开线斜齿轮三维实体造型技术

针对目前广泛应用的SolidWorks三维软件 ,详细阐述了基于SolidWorks环境的渐开线斜齿轮三维实体造型原理及关键技术 。