无人机辅助物联网中基于Safe Actor-Critic的信息年龄最小化研究

无人机作为一种新的通信设备,有望在物联网数据采集、监控等业务中发挥关键作用。为保证所采集数据的时效性,利用信息年龄来衡量无人机从物联网设备接收到的数据新鲜度。通过联合优化无人机轨迹和无人机与物联网设备的关联策略以最小化信息年龄加权和,并保证无人机累积飞行能量消耗满足预算要求。由于上述问题同时受短期和长期约束条件的限制,将问题建模为受约束的马尔可夫决策过程(CMDP),并利用Safe Actor-Critic来求解。仿真结果表明,所提算法在最小化信息年龄的同时,能有效保证能量预算。

A cross-sectional study to assess medication safety,knowledge,attitude,and practices regarding nutrition and medication among pregnant women

Objective:To assess pregnant women's knowledge,attitude,and practice regarding nutrition and medication usage,analyse the prescribing pattern,and categorize them based on the Food and Drug Administration(FDA)guidelines.Methods:A cross-sectional study was conducted with 264 pregnant women in the obstetrics and gynaecology department of a tertiary care hospital from October 2022 to August 2023.A knowledge,attitude,and practice(KAP)questionnaire was prepared in English language by the researchers and validated by an expert panel consisting of 12 members.The validated questionnaire was then translated into regional languages,Kannada and Malayalam.The reliability of the questionnaire was assessed with test-retest method with a representative sample population of 30 subjects(10 subjects for each language).The subjects'knowledge,attitude,and practice were evaluated using the validated KAP questionnaire.The safety of the medication was assessed using the FDA drug safety classification for pregnancy.Results:The mean scores for nutritional and medication usage knowledge,attitude,and practice were 4.14±1.15,4.50±1.09,and 3.00±1.47,respectively.Among 30 prescribed medications,3 belong to category A(no risk in human studies),8 belong to category B(no risk in animal studies),18 belong to category C(risk cannot be ruled out)and 1 drug is not classified.A significant association was observed between medication knowledge and practice(r=0.159,P=0.010).Conclusions:Most of the study population knows the need to maintain good dietary and medication practices during pregnancy.Counselling pregnant women regarding diet and medication usage is crucial in maternal care.

A Game-Theoretic Approach to Safe Crowd Evacuation in Emergencies

Obstacle removal in crowd evacuation is critical to safety and the evacuation system efficiency. Recently, manyresearchers proposed game theoreticmodels to avoid and remove obstacles for crowd evacuation. Game theoreticalmodels aim to study and analyze the strategic behaviors of individuals within a crowd and their interactionsduring the evacuation. Game theoretical models have some limitations in the context of crowd evacuation. Thesemodels consider a group of individuals as homogeneous objects with the same goals, involve complex mathematicalformulation, and cannot model real-world scenarios such as panic, environmental information, crowds that movedynamically, etc. The proposed work presents a game theoretic model integrating an agent-based model to removethe obstacles from exits. The proposed model considered the parameters named: (1) obstacle size, length, andwidth, (2) removal time, (3) evacuation time, (4) crowd density, (5) obstacle identification, and (6) route selection.The proposed work conducts various experiments considering different conditions, such as obstacle types, obstacleremoval, and several obstacles. Evaluation results show the proposed model’s effectiveness compared with existingliterature in reducing the overall evacuation time, cell selection, and obstacle removal. The study is potentially usefulfor public safety situations such as emergency evacuations during disasters and calamities.

Risk-Informed Model-Free Safe Control of Linear Parameter-Varying Systems

This paper presents a risk-informed data-driven safe control design approach for a class of stochastic uncertain nonlinear discrete-time systems.The nonlinear system is modeled using linear parameter-varying(LPV)systems.A model-based probabilistic safe controller is first designed to guarantee probabilisticλ-contractivity(i.e.,stability and invariance)of the LPV system with respect to a given polyhedral safe set.To obviate the requirement of knowing the LPV system model and to bypass identifying its open-loop model,its closed-loop data-based representation is provided in terms of state and scheduling data as well as a decision variable.It is shown that the variance of the closedloop system,as well as the probability of safety satisfaction,depends on the decision variable and the noise covariance.A minimum-variance direct data-driven gain-scheduling safe control design approach is presented next by designing the decision variable such that all possible closed-loop system realizations satisfy safety with the highest confidence level.This minimum-variance approach is a control-oriented learning method since it minimizes the variance of the state of the closed-loop system with respect to the safe set,and thus minimizes the risk of safety violation.Unlike the certainty-equivalent approach that results in a risk-neutral control design,the minimum-variance method leads to a risk-averse control design.It is shown that the presented direct risk-averse learning approach requires weaker data richness conditions than existing indirect learning methods based on system identification and can lead to a lower risk of safety violation.Two simulation examples along with an experimental validation on an autonomous vehicle are provided to show the effectiveness of the presented approach.

Enhanced Memory-Safe Linux Security Modules (eLSMs) for Improving Security of Docker Containers for Data Centers

The adoption of Docker containers has revolutionized software deployment by providing a lightweight and efficient way to isolate applications in data centers. However, securing these containers, especially when handling sensitive data, poses significant challenges. Traditional Linux Security Modules (LSMs) such as SELinux and AppArmor have limitations in providing fine-grained access control to files within containers. This paper presents a novel approach using eBPF (extended Berkeley Packet Filter) to implement a LSM that focuses on file-oriented access control within Docker containers. The module allows the specification of policies that determine which programs can access sensitive files, providing enhanced security without relying solely on the host operating system’s major LSM.

A Dual-Task Learning Approach for Bearing Anomaly Detection and State Evaluation of Safe Region

Predictive maintenance has emerged as an effective tool for curbing maintenance costs,yet prevailing research predominantly concentrates on the abnormal phases.Within the ostensibly stable healthy phase,the reliance on anomaly detection to preempt equipment malfunctions faces the challenge of sudden anomaly discernment.To address this challenge,this paper proposes a dual-task learning approach for bearing anomaly detection and state evaluation of safe regions.The proposed method transforms the execution of the two tasks into an optimization issue of the hypersphere center.By leveraging the monotonicity and distinguishability pertinent to the tasks as the foundation for optimization,it reconstructs the SVDD model to ensure equilibrium in the model’s performance across the two tasks.Subsequent experiments verify the proposed method’s effectiveness,which is interpreted from the perspectives of parameter adjustment and enveloping trade-offs.In the meantime,experimental results also show two deficiencies in anomaly detection accuracy and state evaluation metrics.Their theoretical analysis inspires us to focus on feature extraction and data collection to achieve improvements.The proposed method lays the foundation for realizing predictive maintenance in a healthy stage by improving condition awareness in safe regions.

Study on the Safety and Prevention Technology of Coal Mining under the River in Xingyuan Coal Mine

Coal mining-induced surface subsidence poses significant ecological and infrastructural challenges, necessitating a comprehensive study to ensure safe mining practices, particularly in underwater conditions. This project aims to address the extensive impact of coal mining on the environment, infrastructure, and overall safety, focusing on the Shigong River area above the working face. The study employs qualitative and quantitative analyses, along with on-site engineering measurements, to gather data on crucial parameters such as coal seam characteristics, roof rock lithology, thickness, water resistance, and structural damage degree. The research encompasses a multidisciplinary approach, involving mining, geology, hydrogeology, geophysical exploration, rock mechanics, mine surveying, and computational mathematics. The importance of effective safety measures and prevention techniques is emphasized, laying the foundation for research focused on the Xingyun coal mine. The brief concludes by highlighting the potential economic and social benefits of this project and its contribution to valuable experience for future subsea coal mining.

Smart materials for safe lithium-ion batteries against thermal runaway

In recent years,the new energy storage system,such as lithium ion batteries(LIBs),has attracted much attention.In order to meet the demand of industrial progress for longer cycle life,higher energy density and cost efficiency,a quantity of research has been conducted on the commercial application of LIBs.However,it is difficult to achieve satisfying safety and cycling performance simultaneously.There may be thermal runaway(TR),external impact,overcharge and overdischarge in the process of battery abuse,which makes the safety problem of LIBs more prominent.In this review,we summarize recent progress in the smart safety materials design towards the goal of preventing TR of LIBs reversibly from different abuse conditions.Benefiting from smart responsive materials and novel structural design,the safety of LIBs can be improved a lot.We expect to provide a comprehensive reference for the development of smart and safe lithium-based battery materials.

Application and Effect Evaluation of the Integrated“5A and 3+3”Management Model in the Safe Medication Use for Chemotherapy Patients

Objective:To explore the application and effect evaluation of the integrated“5A and 3+3”management model in ensuring safe medication use for chemotherapy patients.Methods:A total of 100 intravenous chemotherapy patients admitted to the oncology department of Shaanxi Provincial People’s Hospital were randomly divided into two groups using a random number list method.Both groups received conventional nursing management during chemotherapy,while the study group additionally received the integrated“5A and 3+3”safety management model.The nursing intervention effects between the two groups were compared.Results:After the intervention,the study group showed higher levels of self-management ability,compliance,and nursing satisfaction compared to the control group.The overall incidence of adverse events during hospitalization was lower in the study group,with statistically significant differences(P<0.05).The knowledge scores of medical staff in the study group,related to the prevention and treatment of chemotherapy drug side effects,daily symptom management,and daily life management,were higher than those in the control group,with statistically significant differences(P<0.05).Conclusion:Implementing the integrated“5A and 3+3”model in the safe medication management of intravenous chemotherapy patients can effectively enhance patients’self-management abilities and compliance,improve medical staff’s ability to safely administer chemotherapy drugs,reduce adverse events caused by chemotherapy,and increase patient satisfaction.

粮食气味物质的提取、关键组分判别及其在储藏中的应用研究进展

粮食气味物质受粮食种类、储藏条件、储藏时间及是否受有害生物污染等多种因素影响,气味物质种类及含量能够及时反映粮食是否变质或受有害生物危害。首先,本文概述目前常用的粮食气味物质的提取和鉴定技术,总结不同状态粮食气味物质组成,发现烷烃类、酸类、醛类和醇类等物质赋予粮食特有的气味,而不同的储藏环境和粮食状态下,其气味物质存在较大差异。其次,探讨粮食中特征气味物质的分析方法,梳理粮食关键气味物质可能的代谢途径,归纳水稻和小麦中特征气味物质,其中稻谷中特征气味物质2-乙酰基-1-吡咯啉的生成机制也已得到初步确认。最后,对气味物质在粮食安全储藏领域的应用进行概述,提出深入分析、挖掘粮食气味物质数据,构建新型预测模型以快速、精准检测粮食品质将成为未来粮食气味物质研究领域的重要方向;同时,部分气味物质也被证实对粮仓中有害生物具有防控作用,将成为未来研发新型绿色储粮药剂的重要来源。

Murtagh安全诊断策略联合思维导图构建临床思维在全科教学门诊中的应用

全科教学门诊是培养住院医师规范化培训(简称住培)全科医生临床思维、提升全科诊疗能力的重要培训方法。本文用1例以乏力为主要表现的患者为教学案例,介绍全科教学门诊中采用澳大利亚著名全科医学专家John Murtagh提出的Murtagh安全诊断策略启发住培全科医生对乏力进行诊断与鉴别诊断:(1)引起乏力的常见疾病有哪些?(2)哪些重要疾病是不能忽视的?(3)乏力有什么容易被遗漏的疾病?(4)是否存在潜在的容易被掩盖的疾病?(5)患者是否有话没有说?结合病史、体格检查和实验室检查结果初步诊断为抗中性粒细胞胞浆抗体相关性血管炎引起急进性肾小球肾炎可能性大,及时转诊,肾病理检查确诊乏力的病因为抗中性粒细胞胞浆抗体相关性肾小球肾炎,取得满意疗效。带教老师基于Murtagh安全诊断策略帮助住培全科医生构建乏力鉴别、分析的系统知识框架,从而提升住培全科医生的临床逻辑思维能力和解决临床实际问题的能力;以思维导图为辅助工具,将Murtagh安全诊断策略诊断与鉴别诊断思路可视化、形象化,优化教学效果。

SAFE与SDE法对金华火腿皮下脂肪气味活性物质研究

通过溶剂辅助风味蒸发系统(SAFE)和同时蒸馏提取技术(SDE)与气相色谱-嗅闻仪-质谱联机法(GC-O-MS)结合,对已发酵18个月的金华火腿皮下脂肪气味化合物进行定性定量分析和感官评价.SAFE和SDE法分别检测并嗅闻到40种和22种气味活性化合物,对脂肪气味贡献度较大的10种关键性化合物分别是:己醛、庚醛、二异丙基二硫醚、辛醛、反-2-辛烯醛、3-甲基丁酸、反,反-2,4-癸二烯醛、γ-癸内酯、γ-十一内酯和苯乙酸.

一种描述逻辑与DL-safe规则复合逻辑中的规则抽取方法

OWL本体描述语言包含相对丰富的概念定义符,但提供的关系定义符描述能力则较差。将 OWL与规则相结合是克服这种表达能力限制的一种常用方法。Motik提出了一种可判定的方法,将SHIQ(D)描述逻辑与规则结合,所结合的规则限定在一种叫做DL-safe规则的范围内。本文提出了一种抽取DL-safe规则的方法,方法利用SHIQ(D)逻辑中的UNION定义符满足一些规则在前件中包含析取逻辑运算符的需求,从而扩展了规则的描述能力。

SAFE应用于我国股权众筹市场的前景和法律监管思路——以新时代金融供给侧结构性改革为背景

未来股权简单协议(SAFE)是一种新兴股权众筹形式,由于其能够适应高成长型初创企业的投融资需要而在美国资本市场流行。我国未来可尝试引入SAFE机制作为金融创新手段,但需要注意其内在风险。应采取积极审慎的态度,从股权众筹平台的准入和征信制度、所提供的格式合同文本、投资者的教育机制、信息披露要求等方面制定和完善相关法律法规,进行必要的监管,以严格控制其风险,尽量减少其负面影响,使其既有助于小微初创企业融资,又不致损害投资者的利益。

基于FE-SAFE对某型起重机底架疲劳寿命预估

以某型现役汽车起重机底架钢结构为研究对象,建立起重机虚拟样机模型及有限元静力学模型,分析并获得五个载荷步下的名义应力谱;基于FE-SAFE(durability analysis software for finite element models)耐久性分析软件,用多轴临界平面疲劳损伤模型,采用Brown-Miller准则建立寿命损伤模型,对底架结构的疲劳寿命进行预算。预算结果表明该型起重机底架结构工作约3 062个循环时出现肉眼可见裂纹,而其使用寿命约为70 555个工作循环。其疲劳寿命预算分析为某型现役起重机的实际设计和使用检修提供有价值的参考。

SDE与SAFE分析全脂巴氏乳挥发性成分

采用同时蒸馏萃取与溶剂辅助风味蒸发法萃取分析巴氏全脂乳的挥发性成分,用气相色谱-质谱联用(GC-MS)对挥发性成分进行了分析。结果表明同时蒸馏萃取法以二氯甲烷为萃取溶剂时鉴定出8种成分,以乙醚为萃取溶剂时鉴定出6种成分;溶剂辅助风味蒸发法鉴定出8种,两种方法共计鉴定出14种挥发性成分,其中酸类8种、醛类1种、醇类2种、酯类2种、其它类1种,其中含量较大的有己酸、辛酸、癸酸、月桂酸、肉豆蔻酸等。

SPME和SAFE结合GC-O-MS分析鲜榨西瓜汁挥发性香气成分

为比较不同萃取方式对西瓜汁风味的萃取效果,本研究采用固相微萃取(SPME)和溶剂辅助风味蒸发(SAFE)两种方法结合GC-O-MS对无籽西瓜中的挥发性香气成分进行分析。共鉴定出46种化合物,这些化合物主要包括醛类8种,烯醛类9种,醇类12种,酮类6种,呋喃2种,内酯1种,酯类2种。无籽西瓜中重要的挥发性香气成分有己醛(青草香)、6-甲基-5-庚烯-2-酮(柠檬味、苹果味)、反-6-壬烯醛(甜瓜味)、反-2-壬烯醛(甜瓜味、清香)、反,顺-2,6壬二烯醛(黄瓜味)、顺-3-壬烯-1-醇(清香、动物脂味)、反,顺-3,6-壬二烯-1-醇(黄瓜味)。SPME和SAFE对西瓜汁中关键香气成分均具有良好的萃取效果,但SPME萃取得到的化合物种类更多。

Calculation of Safe Volume of Straw Using Frank-Kamenetskii Model

[Objective] The aim was to calculate the safe straw volume using Frank- Kamenetskii Model to provide method for fire protection in forage farm. [Method] Frank-Kamenetskii Model was used to measure Tacr and improved by marginal tem- perature which was adjustable. In addition, effects of water content and density of baled straws on Tc were explored using the improved model. [Result] Size of straw bales was the key factor determining whether spontaneous combustion would occur. For baled straws with water at 15.27% and density at 285 kg/m3, Tc was 85-88 ~C and safe diameter of baled straws maximized 8.2 m. In addition, straws should be stacked from south to north （or north to south） to avoid sunshine and certain space should be kept between straw bales for heat dissipation. [Conclusion] The research is of significance for safe management of forage farm.

美国NPPS项目中SAFE^(TM)游戏场安全管理框架的分析与启示

美国游戏场安全国家项目(National Program for playground Safety,简称NPPS)旨在提高人们对游戏场安全性的认识,为儿童创设安全的游戏环境。其构建的SAFE TM游戏场安全管理框架包含监督、适当的环境、坠落铺面、设备维护4个彼此交互的基本元素。为保障SAFE TM游戏场安全管理框架的有效实施,NPPS还构建了与之相匹配的支持系统,包括符合准则和标准、评估游戏场、检查程序和课程培训四个方面。当前,我国也日益重视儿童户外游戏场地的安全,系统分析SAFE TM游戏场安全管理框架及其特点,对于我国幼儿园户外游戏场地设计与管理具有重要启示。

基于Fe-safe螺杆泵定子橡胶疲劳裂纹形成寿命预测

采油用螺杆泵橡胶定子为研究对象,通过对定子橡胶材料的进行伸张疲劳试验,建立定子橡胶的S-N曲线;对螺杆泵进行力学特性分析,确定在靠近高压腔室螺旋密封带上螺杆泵最易发生疲劳失效;利用Fe-safe对螺杆泵定子橡胶进行疲劳裂纹形成寿命进行预测研究,确定螺杆泵定子橡胶各段模型的最小疲劳裂纹形成寿命和安全系数和随腔室压力的关系,即随腔室压力升高而下降,并拟合得到橡胶定子疲劳裂纹形成寿命与腔室压力的关系式。