Domain randomization is a widely adopted technique in deep reinforcement learning(DRL)to improve agent generalization by exposing policies to diverse environmental conditions.This paper investigates the impact of diff...Domain randomization is a widely adopted technique in deep reinforcement learning(DRL)to improve agent generalization by exposing policies to diverse environmental conditions.This paper investigates the impact of different reset strategies,normal,non-randomized,and randomized,on agent performance using the Deep Deterministic Policy Gradient(DDPG)and Twin Delayed DDPG(TD3)algorithms within the CarRacing-v2 environment.Two experimental setups were conducted:an extended training regime with DDPG for 1000 steps per episode across 1000 episodes,and a fast execution setup comparing DDPG and TD3 for 30 episodes with 50 steps per episode under constrained computational resources.A step-based reward scaling mechanism was applied under the randomized reset condition to promote broader state exploration.Experimental results showthat randomized resets significantly enhance learning efficiency and generalization,with DDPG demonstrating superior performance across all reset strategies.In particular,DDPG combined with randomized resets achieves the highest smoothed rewards(reaching approximately 15),best stability,and fastest convergence.These differences are statistically significant,as confirmed by t-tests:DDPG outperforms TD3 under randomized(t=−101.91,p<0.0001),normal(t=−21.59,p<0.0001),and non-randomized(t=−62.46,p<0.0001)reset conditions.The findings underscore the critical role of reset strategy and reward shaping in enhancing the robustness and adaptability of DRL agents in continuous control tasks,particularly in environments where computational efficiency and training stability are crucial.展开更多
Human orofacial clefts (OFCs) are congenital anomalies that result from the breakdown of normal mechanisms that regulate the formation of the human face. They could be syndromic or non-syndromic, with a global inciden...Human orofacial clefts (OFCs) are congenital anomalies that result from the breakdown of normal mechanisms that regulate the formation of the human face. They could be syndromic or non-syndromic, with a global incidence of 1:700 per live births. Environmental and genetic factors are thought to play various roles in the aetiology of OFCs. This study seeks to establish the diversity, distribution and pattern of inheritance of OFCs as well as environmental and other risk factors associated with OFCs in a Ghanaian population. A family-based, descriptive cross-sectional study that employed an interview-based survey questionnaire was used to obtain information from 467 families with history of OFCs. We employed chi-square statistics to analyse the data and used graphs to interpret the data. All previously reported subphenotypes of OFCs were observed by the present study. Clinically, about 12% of clefts in the study population were syndromic. The most common syndromic forms observed were Pierre Robin Sequence, cleft-with-club foot abnormalities and Van der Woude Syndrome. Only about 5% of clefts in the study cohort were familial. The study also established that lower level of education of parents, poverty, late antenatal care and dietary folate deficiency are major environmental factors associated with clefts in the Ghanaian population. In conclusion, OFCs are non-randomly distributed in Ghana and folate deficiency could likely be a source of genetic mutations and “epimutations” that cause OFCs, since folate is essential for DNA methylation, replication and repair as well as histone modification.展开更多
Objective:Acute ischemic stroke(AIS)is characterized by high morbidity and high mortality.In recent years,complementary and alternative medicine has gradually been widely accepted and applied.At present,traditional Ch...Objective:Acute ischemic stroke(AIS)is characterized by high morbidity and high mortality.In recent years,complementary and alternative medicine has gradually been widely accepted and applied.At present,traditional Chinese medicine therapy and standard treatments are used for the treatment of AIS.Xingnao-Jianshen prescriptions(XNJS)is an effective prescription for the clinical treatment of AIS,but there is a lack of large-scale clinical evidence to confirm its clinical efficacy.Therefore,our team designed this protocol to evaluate the initial therapeutic effect of XNJS.Methods:The protocol for a non-randomized controlled trial is designed in which 72 eligible patients will be allocated to one of two groups.The control group(n=36)will receive standard treatment for AIS,the test group(n=36)will receive XNJS and standard treatment.Patients will be recruited after stroke onset and will receive the intervention continuously over 10±1 days,with a follow-up period of 90 days.The primary outcome will be the change in the NIHSS,BI,mRS scores.All outcome measures will be assessed at inception,after the intervention(10±1 days),and at the follow-up(90 days).The results will be disseminated to the public through peerreviewed journals and academic conferences.Discussion:The study will provide evidence of the preliminary effects.展开更多
Objective： To evaluate the effect and safety of acupuncture therapy on patients with moderate to severe allergic rhinitis. Methods： A non-randomized controlled design was used to compare between the acupuncture grou...Objective： To evaluate the effect and safety of acupuncture therapy on patients with moderate to severe allergic rhinitis. Methods： A non-randomized controlled design was used to compare between the acupuncture group and the medication group. The acupuncture group received 8-week acupuncture therapy, and the medication group received budesonide nasal spray with cetirizine tablets for 8 weeks. The clinical symptoms and signs were analyzed before treatment, at 4 and 8 weeks after the start of treatment, and at 12 weeks after the end of treatment. Furthermore, the clinical efficacy and safety indicators were compared between the two groups. Results： A total of 76 participants consisting of 38 in each of the two groups were enrolled. The scores of each clinical symptom and sign, including sneezing, runny nose, stuffy nose, nasal itching, and turbinate edema, and the total scores decreased over time in both groups （all P〈0.05）; and no difference was found in the scores between the two groups （P〉0.05）. There was no statistically significant difference in the effective rates of the acupuncture group at 4 and 8 weeks after the start of treatment as well as at 12-week follow-up compared with those of the medication group （83.3% vs. 91.2%, and 94.4 % vs. 85.3%; and 80.6 % vs. 82.4%, all P〉0.05）. Experimental items including blood routine, urine routine, aspartate transaminase, alanine aminotransferase, urea nitrogen and creatinine were all in the normal reference ranges during the treatment in the acupuncture group. Conclusions： Acupuncture therapy has a comparable effect to the medication treatment on patients with moderate to severe allergic rhinitis, and it is safe with no severe adverse effects.展开更多
目的:采用网状Meta分析系统评价不同非侵入性神经调控技术对孤独症谱系障碍儿童的康复疗效。方法:系统检索中国知网、维普网、万方数据知识服务平台、中国生物医学文献数据库、Pub Med、Web of Science、Cochrane Library、Embase数据库...目的:采用网状Meta分析系统评价不同非侵入性神经调控技术对孤独症谱系障碍儿童的康复疗效。方法:系统检索中国知网、维普网、万方数据知识服务平台、中国生物医学文献数据库、Pub Med、Web of Science、Cochrane Library、Embase数据库,选择不同非侵入性神经调控技术改善孤独症谱系障碍的随机对照试验,检索时限为各数据库建库至2025年1月,由2名研究者独立进行文献筛选、数据提取并对纳入的研究进行质量评价,应用Stata 18.0软件对数据进行网状Meta分析。结果:共纳入32个随机对照试验,涉及8种干预方式。网状Meta分析结果显示,在常规康复训练的基础上,在改善孤独症行为量表评分方面,虚拟现实技术效果最佳[SMD=-12.55,95%CI(-20.85,-4.25),P<0.05],其次为θ爆发式磁刺激[SMD=-11.34,95%CI(-20.94,-1.74),P<0.05]、重复经颅磁刺激[SMD=-9.28,95%CI(-12.80,-5.77),P<0.05]、神经反馈技术[SMD=-8.75,95%CI(-15.26,-2.23),P<0.05];在儿童孤独症评定量表评分方面,虚拟现实技术改善效果最为显著[SMD=-6.36,95%CI(-9.61,-3.11),P<0.05],其次为重复经颅磁刺激[SMD=-5.98,95%CI(-9.46,-2.51),P<0.05]、神经反馈技术[SMD=-4.63,95%CI(-9.14,-0.13),P<0.05]、经皮神经电刺激[SMD=-4.14,95%CI(-5.73,-2.55),P<0.05];在孤独症治疗评估量表评分方面,神经反馈技术改善效果最显著[SMD=-16.44,95%CI(-24.10,-8.78),P<0.05],其次为虚拟现实技术[SMD=-14.09,95%CI(-22.45,-5.73),P<0.05]、重复经颅磁刺激[SMD=-12.06,95%CI(-16.45,-7.68),P<0.05]、经皮神经电刺激[SMD=-10.58,95%CI(-20.44,-0.72),P<0.05]、经颅直流电刺激[SMD=-9.75,95%CI(-18.62,-0.88),P<0.05]。结论:当前证据表明,在常规康复训练基础上,不同非侵入性神经调控技术对孤独症谱系障碍的改善效果存在差异。虚拟现实技术在改善孤独症行为量表和儿童孤独症评定量表评分方面表现出最佳效果,而神经反馈技术在孤独症治疗评估量表评分方面的改善效果最为显著。受纳入研究数量和质量的限制,上述结论尚待更多高质量研究予以验证。展开更多
目的:通过网状Meta分析整合直接与间接证据,比较不同非侵入性脑刺激技术及参数对帕金森病患者步态和平衡功能的影响,并排序最佳干预方案。方法:检索CNKI、万方、维普、CBM、PubMed、Cochrane图书馆、EMbase和Web of Science数据库,筛选...目的:通过网状Meta分析整合直接与间接证据,比较不同非侵入性脑刺激技术及参数对帕金森病患者步态和平衡功能的影响,并排序最佳干预方案。方法:检索CNKI、万方、维普、CBM、PubMed、Cochrane图书馆、EMbase和Web of Science数据库,筛选有关非侵入性脑刺激改善帕金森病患者步态和平衡障碍的随机对照试验,检索时限截止到2025-06-16。对纳入的研究进行数据提取,采用RevMan 5.4.1软件和Stata 17.0软件进行统计学处理。结果:①纳入47篇研究,共2767例患者,试验组1399例、对照组1368例;②传统Meta分析结果显示,高频重复经颅磁刺激可以降低统一帕金森病评定量表第三部分(UPDRSⅢ)评分、冻结步态问卷(FOG-Q)评分,缩短起立-行走计时试验(TUGT)时间,增加步长,改善步速,提高Berg平衡量表评分,且均优于常规治疗(P<0.05);经颅直流电刺激可以降低冻结步态问卷评分、缩短起立-行走计时试验时间,增加步长,改善步速,提高Berg平衡量表评分,且均优于常规治疗(P<0.05);低频重复经颅磁刺激可以降低统一帕金森病评定量表第三部分评分,与常规治疗比较有显著性差异(P<0.05);3种脑刺激方法对于步频的改善均无统计学意义(P>0.05),受限于研究数量少,需进一步验证;③网状Meta分析结果显示(以下排序均基于间接比较),在降低统一帕金森评定量表第三部分评分方面:高频重复经颅磁刺激选择初级运动皮质区(M1)+背外侧前额叶皮质区(DLPFC)双侧靶点联合刺激的累积概率排序最高(95.2%),在初级运动皮质区上刺激排序次之(72.5%);在缩短起立-行走计时试验时间方面:高频重复经颅磁刺激在背外侧前额叶皮质区刺激的累积概率排序最高(85.5%),在初级运动皮质区上刺激排序次之(69.0%);在改善步速方面:高频重复经颅磁刺激在背外侧前额叶皮质区的累积概率排序最高(92.5%),在初级运动皮质区上刺激排序次之(76.7%);在提高Berg平衡量表评分方面:高频重复经颅磁刺激在初级运动皮质区上刺激的累积概率排序最高(79.9%),经颅直流电刺激在小脑上刺激排序次之(79.8%);④GRADE证据质量评价结果显示,统一帕金森评定量表第三部分、冻结步态问卷评分、起立-行走计时试验、步长证据等级为中级,步速、步频、Berg平衡量表评分为低级。结论:不同类型非侵入性脑刺激都可以改善帕金森病患者的步态和平衡功能。背外侧前额叶皮质区靶向的高频重复经颅磁刺激对步态功能的改善优于初级运动皮质(中等证据),而初级运动皮质靶向的高频重复经颅磁刺激对平衡功能的改善优于小脑靶向的经颅直流电刺激(低级证据)。展开更多
在实际工作过程中,电动挖掘机所承受的载荷往往表现出显著的非平稳随机特性,导致电动挖掘机电池包振动现象十分复杂,从而直接影响电池包的安全、可靠运行。针对这一问题,探究了复杂工况下电动挖掘机所承受的路面激励、柱塞泵压力脉动激...在实际工作过程中,电动挖掘机所承受的载荷往往表现出显著的非平稳随机特性,导致电动挖掘机电池包振动现象十分复杂,从而直接影响电池包的安全、可靠运行。针对这一问题,探究了复杂工况下电动挖掘机所承受的路面激励、柱塞泵压力脉动激励和冲击激励特性,分析了各种激励下的振动传递路径,建立了电动挖掘机电池包的动力学模型,揭示了非平稳随机激励下电池包的振动特性,并通过实例进行了分析和验证。研究表明,基于小波变换及灰狼优化-变分模态分解(Grey Wolf Optimization-Variational Mode Decomposition,GWO-VMD)信号分析算法对路面激励信号进行重构,能够较好地反映路面激励特性;行驶工况下电动挖掘机所承受的路面激励具有显著的非平稳特性;在路面激励等非平稳随机激励作用下,电动挖掘机电池包产生复杂多变的振动,其动态响应的功率谱密度随时间变化显著,具有明显的非平稳随机特性。研究工作为电动挖掘机电池包的安全、可靠运行提供了一定的参考。展开更多
Objective: The purpose of this study was to evaluate health education using videos and leaflets for preconception care (PCC) awareness among adolescent females up to six months after the health education. Methods: The...Objective: The purpose of this study was to evaluate health education using videos and leaflets for preconception care (PCC) awareness among adolescent females up to six months after the health education. Methods: The subjects were female university students living in the Kinki area. A longitudinal survey was conducted on 67 members in the intervention group, who received the health education, and 52 members in the control group, who did not receive the health education. The primary outcome measures were knowledge of PCC and the subscales of the Health Promotion Lifestyle Profile. Surveys were conducted before, after, and six months after the intervention in the intervention group, and an initial survey and survey six months later were conducted in the control group. Cochran’s Q test, Bonferroni’s multiple comparison test, and McNemar’s test were used to analyze the knowledge of PCC data. The Health Awareness, Nutrition, and Stress Management subscales of the Health Promotion Lifestyle Profile were analyzed by paired t-test, and comparisons between the intervention and control groups were performed using the two-way repeated measures analysis of variance. Results: In the intervention group of 67 people, the number of subjects who answered “correct” for five of the nine items concerning knowledge of PCC increased immediately after the health education (P = 0.006) but decreased for five items from immediately after the health education to six months later (P = 0.043). In addition, the number of respondents who answered “correct” for “low birth weight infants and future lifestyle-related diseases” (P = 0.016) increased after six months compared with before the health education. For the 52 subjects in the control group, there was no change in the number of subjects who answered “correct” for eight out of the nine items after six months. There was also no increase in scores for the Health Promotion Lifestyle Profile after six months for either the intervention or control group. Conclusion: Providing health education about PCC using videos and leaflets to adolescent females was shown to enhance the knowledge of PCC immediately after the education.展开更多
The security of information transmission and processing due to unknown vulnerabilities and backdoors in cyberspace is becoming increasingly problematic.However,there is a lack of effective theory to mathematically dem...The security of information transmission and processing due to unknown vulnerabilities and backdoors in cyberspace is becoming increasingly problematic.However,there is a lack of effective theory to mathematically demonstrate the security of information transmission and processing under nonrandom noise(or vulnerability backdoor attack)conditions in cyberspace.This paper first proposes a security model for cyberspace information transmission and processing channels based on error correction coding theory.First,we analyze the fault tolerance and non-randomness problem of Dynamic Heterogeneous Redundancy(DHR)structured information transmission and processing channel under the condition of non-random noise or attacks.Secondly,we use a mathematical statistical method to demonstrate that for non-random noise(or attacks)on discrete memory channels,there exists a DHR-structured channel and coding scheme that enables the average system error probability to be arbitrarily small.Finally,to construct suitable coding and heterogeneous channels,we take Turbo code as an example and simulate the effects of different heterogeneity,redundancy,output vector length,verdict algorithm and dynamism on the system,which is an important guidance for theory and engineering practice.展开更多
基金supported by the Deputyship for Research&Innovation,Ministry of Education in Saudi Arabia(Project No.MoE-IF-UJ-R2-22-04220773-1).
文摘Domain randomization is a widely adopted technique in deep reinforcement learning(DRL)to improve agent generalization by exposing policies to diverse environmental conditions.This paper investigates the impact of different reset strategies,normal,non-randomized,and randomized,on agent performance using the Deep Deterministic Policy Gradient(DDPG)and Twin Delayed DDPG(TD3)algorithms within the CarRacing-v2 environment.Two experimental setups were conducted:an extended training regime with DDPG for 1000 steps per episode across 1000 episodes,and a fast execution setup comparing DDPG and TD3 for 30 episodes with 50 steps per episode under constrained computational resources.A step-based reward scaling mechanism was applied under the randomized reset condition to promote broader state exploration.Experimental results showthat randomized resets significantly enhance learning efficiency and generalization,with DDPG demonstrating superior performance across all reset strategies.In particular,DDPG combined with randomized resets achieves the highest smoothed rewards(reaching approximately 15),best stability,and fastest convergence.These differences are statistically significant,as confirmed by t-tests:DDPG outperforms TD3 under randomized(t=−101.91,p<0.0001),normal(t=−21.59,p<0.0001),and non-randomized(t=−62.46,p<0.0001)reset conditions.The findings underscore the critical role of reset strategy and reward shaping in enhancing the robustness and adaptability of DRL agents in continuous control tasks,particularly in environments where computational efficiency and training stability are crucial.
文摘Human orofacial clefts (OFCs) are congenital anomalies that result from the breakdown of normal mechanisms that regulate the formation of the human face. They could be syndromic or non-syndromic, with a global incidence of 1:700 per live births. Environmental and genetic factors are thought to play various roles in the aetiology of OFCs. This study seeks to establish the diversity, distribution and pattern of inheritance of OFCs as well as environmental and other risk factors associated with OFCs in a Ghanaian population. A family-based, descriptive cross-sectional study that employed an interview-based survey questionnaire was used to obtain information from 467 families with history of OFCs. We employed chi-square statistics to analyse the data and used graphs to interpret the data. All previously reported subphenotypes of OFCs were observed by the present study. Clinically, about 12% of clefts in the study population were syndromic. The most common syndromic forms observed were Pierre Robin Sequence, cleft-with-club foot abnormalities and Van der Woude Syndrome. Only about 5% of clefts in the study cohort were familial. The study also established that lower level of education of parents, poverty, late antenatal care and dietary folate deficiency are major environmental factors associated with clefts in the Ghanaian population. In conclusion, OFCs are non-randomly distributed in Ghana and folate deficiency could likely be a source of genetic mutations and “epimutations” that cause OFCs, since folate is essential for DNA methylation, replication and repair as well as histone modification.
基金Changchun Science and Technology Development Project(No.21ZGM32)Natural Science Foundation of Jilin Province(No.20200201412JC).All funds conflict-free.
文摘Objective:Acute ischemic stroke(AIS)is characterized by high morbidity and high mortality.In recent years,complementary and alternative medicine has gradually been widely accepted and applied.At present,traditional Chinese medicine therapy and standard treatments are used for the treatment of AIS.Xingnao-Jianshen prescriptions(XNJS)is an effective prescription for the clinical treatment of AIS,but there is a lack of large-scale clinical evidence to confirm its clinical efficacy.Therefore,our team designed this protocol to evaluate the initial therapeutic effect of XNJS.Methods:The protocol for a non-randomized controlled trial is designed in which 72 eligible patients will be allocated to one of two groups.The control group(n=36)will receive standard treatment for AIS,the test group(n=36)will receive XNJS and standard treatment.Patients will be recruited after stroke onset and will receive the intervention continuously over 10±1 days,with a follow-up period of 90 days.The primary outcome will be the change in the NIHSS,BI,mRS scores.All outcome measures will be assessed at inception,after the intervention(10±1 days),and at the follow-up(90 days).The results will be disseminated to the public through peerreviewed journals and academic conferences.Discussion:The study will provide evidence of the preliminary effects.
基金Supported by the Key Project of Zhejiang Province Pharmaceutical Administration,China(No.2010ZZ001)Key Disciplines in Integrative Medicine of Zhejiang Province,China(No.2012-XK-A04)
文摘Objective： To evaluate the effect and safety of acupuncture therapy on patients with moderate to severe allergic rhinitis. Methods： A non-randomized controlled design was used to compare between the acupuncture group and the medication group. The acupuncture group received 8-week acupuncture therapy, and the medication group received budesonide nasal spray with cetirizine tablets for 8 weeks. The clinical symptoms and signs were analyzed before treatment, at 4 and 8 weeks after the start of treatment, and at 12 weeks after the end of treatment. Furthermore, the clinical efficacy and safety indicators were compared between the two groups. Results： A total of 76 participants consisting of 38 in each of the two groups were enrolled. The scores of each clinical symptom and sign, including sneezing, runny nose, stuffy nose, nasal itching, and turbinate edema, and the total scores decreased over time in both groups （all P〈0.05）; and no difference was found in the scores between the two groups （P〉0.05）. There was no statistically significant difference in the effective rates of the acupuncture group at 4 and 8 weeks after the start of treatment as well as at 12-week follow-up compared with those of the medication group （83.3% vs. 91.2%, and 94.4 % vs. 85.3%; and 80.6 % vs. 82.4%, all P〉0.05）. Experimental items including blood routine, urine routine, aspartate transaminase, alanine aminotransferase, urea nitrogen and creatinine were all in the normal reference ranges during the treatment in the acupuncture group. Conclusions： Acupuncture therapy has a comparable effect to the medication treatment on patients with moderate to severe allergic rhinitis, and it is safe with no severe adverse effects.
文摘目的:通过网状Meta分析整合直接与间接证据,比较不同非侵入性脑刺激技术及参数对帕金森病患者步态和平衡功能的影响,并排序最佳干预方案。方法:检索CNKI、万方、维普、CBM、PubMed、Cochrane图书馆、EMbase和Web of Science数据库,筛选有关非侵入性脑刺激改善帕金森病患者步态和平衡障碍的随机对照试验,检索时限截止到2025-06-16。对纳入的研究进行数据提取,采用RevMan 5.4.1软件和Stata 17.0软件进行统计学处理。结果:①纳入47篇研究,共2767例患者,试验组1399例、对照组1368例;②传统Meta分析结果显示,高频重复经颅磁刺激可以降低统一帕金森病评定量表第三部分(UPDRSⅢ)评分、冻结步态问卷(FOG-Q)评分,缩短起立-行走计时试验(TUGT)时间,增加步长,改善步速,提高Berg平衡量表评分,且均优于常规治疗(P<0.05);经颅直流电刺激可以降低冻结步态问卷评分、缩短起立-行走计时试验时间,增加步长,改善步速,提高Berg平衡量表评分,且均优于常规治疗(P<0.05);低频重复经颅磁刺激可以降低统一帕金森病评定量表第三部分评分,与常规治疗比较有显著性差异(P<0.05);3种脑刺激方法对于步频的改善均无统计学意义(P>0.05),受限于研究数量少,需进一步验证;③网状Meta分析结果显示(以下排序均基于间接比较),在降低统一帕金森评定量表第三部分评分方面:高频重复经颅磁刺激选择初级运动皮质区(M1)+背外侧前额叶皮质区(DLPFC)双侧靶点联合刺激的累积概率排序最高(95.2%),在初级运动皮质区上刺激排序次之(72.5%);在缩短起立-行走计时试验时间方面:高频重复经颅磁刺激在背外侧前额叶皮质区刺激的累积概率排序最高(85.5%),在初级运动皮质区上刺激排序次之(69.0%);在改善步速方面:高频重复经颅磁刺激在背外侧前额叶皮质区的累积概率排序最高(92.5%),在初级运动皮质区上刺激排序次之(76.7%);在提高Berg平衡量表评分方面:高频重复经颅磁刺激在初级运动皮质区上刺激的累积概率排序最高(79.9%),经颅直流电刺激在小脑上刺激排序次之(79.8%);④GRADE证据质量评价结果显示,统一帕金森评定量表第三部分、冻结步态问卷评分、起立-行走计时试验、步长证据等级为中级,步速、步频、Berg平衡量表评分为低级。结论:不同类型非侵入性脑刺激都可以改善帕金森病患者的步态和平衡功能。背外侧前额叶皮质区靶向的高频重复经颅磁刺激对步态功能的改善优于初级运动皮质(中等证据),而初级运动皮质靶向的高频重复经颅磁刺激对平衡功能的改善优于小脑靶向的经颅直流电刺激(低级证据)。
文摘在实际工作过程中,电动挖掘机所承受的载荷往往表现出显著的非平稳随机特性,导致电动挖掘机电池包振动现象十分复杂,从而直接影响电池包的安全、可靠运行。针对这一问题,探究了复杂工况下电动挖掘机所承受的路面激励、柱塞泵压力脉动激励和冲击激励特性,分析了各种激励下的振动传递路径,建立了电动挖掘机电池包的动力学模型,揭示了非平稳随机激励下电池包的振动特性,并通过实例进行了分析和验证。研究表明,基于小波变换及灰狼优化-变分模态分解(Grey Wolf Optimization-Variational Mode Decomposition,GWO-VMD)信号分析算法对路面激励信号进行重构,能够较好地反映路面激励特性;行驶工况下电动挖掘机所承受的路面激励具有显著的非平稳特性;在路面激励等非平稳随机激励作用下,电动挖掘机电池包产生复杂多变的振动,其动态响应的功率谱密度随时间变化显著,具有明显的非平稳随机特性。研究工作为电动挖掘机电池包的安全、可靠运行提供了一定的参考。
文摘Objective: The purpose of this study was to evaluate health education using videos and leaflets for preconception care (PCC) awareness among adolescent females up to six months after the health education. Methods: The subjects were female university students living in the Kinki area. A longitudinal survey was conducted on 67 members in the intervention group, who received the health education, and 52 members in the control group, who did not receive the health education. The primary outcome measures were knowledge of PCC and the subscales of the Health Promotion Lifestyle Profile. Surveys were conducted before, after, and six months after the intervention in the intervention group, and an initial survey and survey six months later were conducted in the control group. Cochran’s Q test, Bonferroni’s multiple comparison test, and McNemar’s test were used to analyze the knowledge of PCC data. The Health Awareness, Nutrition, and Stress Management subscales of the Health Promotion Lifestyle Profile were analyzed by paired t-test, and comparisons between the intervention and control groups were performed using the two-way repeated measures analysis of variance. Results: In the intervention group of 67 people, the number of subjects who answered “correct” for five of the nine items concerning knowledge of PCC increased immediately after the health education (P = 0.006) but decreased for five items from immediately after the health education to six months later (P = 0.043). In addition, the number of respondents who answered “correct” for “low birth weight infants and future lifestyle-related diseases” (P = 0.016) increased after six months compared with before the health education. For the 52 subjects in the control group, there was no change in the number of subjects who answered “correct” for eight out of the nine items after six months. There was also no increase in scores for the Health Promotion Lifestyle Profile after six months for either the intervention or control group. Conclusion: Providing health education about PCC using videos and leaflets to adolescent females was shown to enhance the knowledge of PCC immediately after the education.
基金supported by National Key R&D Program of China for Young Scientists:Cyberspace Endogenous Security Mechanisms and Evaluation Methods(No.2022YFB3102800).
文摘The security of information transmission and processing due to unknown vulnerabilities and backdoors in cyberspace is becoming increasingly problematic.However,there is a lack of effective theory to mathematically demonstrate the security of information transmission and processing under nonrandom noise(or vulnerability backdoor attack)conditions in cyberspace.This paper first proposes a security model for cyberspace information transmission and processing channels based on error correction coding theory.First,we analyze the fault tolerance and non-randomness problem of Dynamic Heterogeneous Redundancy(DHR)structured information transmission and processing channel under the condition of non-random noise or attacks.Secondly,we use a mathematical statistical method to demonstrate that for non-random noise(or attacks)on discrete memory channels,there exists a DHR-structured channel and coding scheme that enables the average system error probability to be arbitrarily small.Finally,to construct suitable coding and heterogeneous channels,we take Turbo code as an example and simulate the effects of different heterogeneity,redundancy,output vector length,verdict algorithm and dynamism on the system,which is an important guidance for theory and engineering practice.
