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A Federated Learning Framework with Blockchain-Based Auditable Participant Selection
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作者 Huang Zeng Mingtian Zhang +1 位作者 Tengfei Liu Anjia Yang 《Computers, Materials & Continua》 SCIE EI 2024年第6期5125-5142,共18页
Federated learning is an important distributed model training technique in Internet of Things(IoT),in which participant selection is a key component that plays a role in improving training efficiency and model accurac... Federated learning is an important distributed model training technique in Internet of Things(IoT),in which participant selection is a key component that plays a role in improving training efficiency and model accuracy.This module enables a central server to select a subset of participants to performmodel training based on data and device information.By doing so,selected participants are rewarded and actively perform model training,while participants that are detrimental to training efficiency and model accuracy are excluded.However,in practice,participants may suspect that the central server may have miscalculated and thus not made the selection honestly.This lack of trustworthiness problem,which can demotivate participants,has received little attention.Another problem that has received little attention is the leakage of participants’private information during the selection process.We will therefore propose a federated learning framework with auditable participant selection.It supports smart contracts in selecting a set of suitable participants based on their training loss without compromising the privacy.Considering the possibility of malicious campaigning and impersonation of participants,the framework employs commitment schemes and zero-knowledge proofs to counteract these malicious behaviors.Finally,we analyze the security of the framework and conduct a series of experiments to demonstrate that the framework can effectively improve the efficiency of federated learning. 展开更多
关键词 Federated learning internet of things participant selection blockchain auditability PRIVACY
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Problems and Countermeasures to Improve Clinical Trial Participants’Compensation Rights in China
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作者 Yang Xiuqiao Wen Ping +2 位作者 Lin Hong Chen Wenhuan Chen Yuwen 《Asian Journal of Social Pharmacy》 2024年第1期58-63,共6页
Objective To discuss the problems existing in the compensation of Chinese clinical trial participants and propose some suggestions for improving their rights.Methods The literature related to the participants’right t... Objective To discuss the problems existing in the compensation of Chinese clinical trial participants and propose some suggestions for improving their rights.Methods The literature related to the participants’right to compensation at home and abroad was searched to study the inadequacy of the compensation right for clinical trial participants in China from four aspects:insurance system,principle of attribution,legal relationship and compensation regulations.Then,some suggestions to improve the participants’right to compensation were proposed.Results and Conclusion China lacks clear legal norms for participants’right to compensation.There are problems such as unclear insurance rules and compensation rules,unclear contractual relationships between parties to clinical trials,and no laws and regulations to rely on for attribution and compensation.China should issue regulatory guidelines related to the right to compensation of participants in clinical trials,so that all parties in clinical trials can have rules to follow if there is the occurrence of injury,which can better protect the rights and interests of the participants. 展开更多
关键词 clinical trial participant compensation right
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How Do the Participant Relations Affect Adjacency Pairs?
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作者 张宝国 《海外英语》 2010年第12X期2-4,共3页
This paper will briefly discuss the issue of how different participant relations affect adjacency pairs in conversation analysis.In terms of the affects or influence on adjacency pairs,this article only places its foc... This paper will briefly discuss the issue of how different participant relations affect adjacency pairs in conversation analysis.In terms of the affects or influence on adjacency pairs,this article only places its focus on the ways how the first pair part (FPP) and second pair part (SPP) in conversation are relevant to each other.As for the final result,the data back up such conclusions:in conversation between acquaintance /friends,family members,and as such,the relevance are built up either directly or indirectly.However,in conversation between strangers,this relevance seems to be constructed only directly. 展开更多
关键词 participant relation ADJACENCY PAIRS RELEVANCE direct or indirect
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Association between Free Triiodothyronine Levels and Peripheral Arterial Disease in Euthyroid Participants 被引量:5
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作者 WANG Po DU Rui +8 位作者 LIN Lin DING Lin PENG Kui XU Yu XU Min BI Yu Fang WANG Wei Qing NING Guang LU Jie Li 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2017年第2期128-133,共6页
This current cross-sectional study investigates the relationship between thyroid hormones and peripheral artery disease (PAD) among euthyroid Chinese population aged 40 years and above. Serum free triiodothyronine ... This current cross-sectional study investigates the relationship between thyroid hormones and peripheral artery disease (PAD) among euthyroid Chinese population aged 40 years and above. Serum free triiodothyronine (FT3), free thyroxin (FT4), thyroid-stimulating hormone (TSH), and thyroid antibodies were measured. 展开更多
关键词 PAD Association between Free Triiodothyronine Levels and Peripheral Arterial Disease in Euthyroid participants TPOAb HDL SBP LDL TSH FPG
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Practical Quantum Private Query with Classical Participants 被引量:1
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作者 Min Xiao Di-Fang Zhang 《Chinese Physics Letters》 SCIE CAS CSCD 2019年第3期9-13,共5页
Quantum key distribution(QKD)-based quantum private query(QPQ) is a practical application of QKD, which relaxes the security condition of perfectly concealing a private query to a cheating-sensitive strategy. We propo... Quantum key distribution(QKD)-based quantum private query(QPQ) is a practical application of QKD, which relaxes the security condition of perfectly concealing a private query to a cheating-sensitive strategy. We propose a QPQ protocol based on the delegated QKD scheme(DQKD-based QPQ), in which two almost ‘classical' clients(data user and database owner) can establish a 1-out-of-N oblivious key with the help of a cloud server with full quantum ability. Concretely, the two classical participants in the DQKD-based QPQ only need to access the quantum channel and reorder qubits, and the costly quantum operations, quantum state preparation and measurement are outsourced to a full quantum server in the cloud without leaking participants' privacy. The proposed protocol not only provides a cloud-based framework of QKD-based QPQ, but also obtains better security by a real-time security check, which can protect the security of the database and user against all potential attacks even if the quantum server is assumed to be a powerfully untrusted adversary. 展开更多
关键词 QKD PRIVATE QUERY participantS
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A Decision Model for Selecting Participants in Supply Chain 被引量:1
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作者 ZHOU Shui ying, CHEN Rong qiu School of Management, Huazhong University of Science & Technology, Wuhan, Hubei 430079, China 《Journal of Shanghai University(English Edition)》 CAS 2001年第4期341-344,共4页
In order to satisfy the rapid changing requirements of customers, enterprises must cooperate with each other to form supply chain. The first and the most important stage in the forming of supply chain is the selection... In order to satisfy the rapid changing requirements of customers, enterprises must cooperate with each other to form supply chain. The first and the most important stage in the forming of supply chain is the selection of participants. The article proposes a two staged decision model to select partners. The first stage is the inter company comparison in each business process to select high efficiency candidate based on inside variables. The next stage is to analyse the combination of different candidates in order to select the most perfect partners according to a goal programming model. 展开更多
关键词 supply chain goal programming participantS
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Charged Multiplicity Density and Number of Participant Nucleons in Relativistic Nuclear Collisions
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作者 SABen-Hao CAIXu 《Communications in Theoretical Physics》 SCIE CAS CSCD 2003年第2期212-218,共7页
The energy and centrality dependencies of charged particle pseudorapidity density in relativistic nuclear collisions were studied using a hadron and string cascade model, JPCIAE. Both the relativistic experimental da... The energy and centrality dependencies of charged particle pseudorapidity density in relativistic nuclear collisions were studied using a hadron and string cascade model, JPCIAE. Both the relativistic experimental data and the PHOBOS and PHENIX Au+Au data at RHIC energy could be fairly reproduced within the framework of JPCIAE model and without retuning the model parameters. The predictions for collisions at the LHC energy were also given. We computed the participant nucleon distributions using different methods. It was found that the number of participant nucleons is not a well defined variable both experimentally and theoretically. Thus it may be inappropriate to use the charged particle pseudorapidity density per participant pair as a function of the number of participant nucleons for distinguishing various theoretical models. 展开更多
关键词 charged multiplicity pseudorapidity density number of participant nucleons string fragmentation JPCIAE model
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Safety at Work of Participants in the Railway Transport of Dangerous Goods
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作者 Jasmin Hodzic Safet Kalac Denis Lukac 《Chinese Business Review》 2018年第8期404-410,共7页
The transport of dangerous goods always represents a potential risk to life,human health,property,and environmental protection.For this reason and in order to preserve the lives and health of the participants in the t... The transport of dangerous goods always represents a potential risk to life,human health,property,and environmental protection.For this reason and in order to preserve the lives and health of the participants in the transport process,adequate protection measures must be taken before,during,and after the transport of dangerous goods.Since the railway itself is a recipient of dangerous goods that are essential for its own operation,and is also a carrier of large quantities of various dangerous goods,these measures are of paramount importance.This paper examines,from a point of view of the protection of lives and health of the participants in the transport process and the safe transport of dangerous goods,the conditions of shipment and transport of dangerous goods,the obligations of the participants,and the essential ways for their proper handling.Proper application of safety at work prevents impromptu and indolent attitude in transporting dangerous goods,thus contributing to protection of people lives and health.Finally,this paper includes preventive measures and basic principles for implementation of safety at work in the transport of dangerous goods. 展开更多
关键词 DANGEROUS GOODS RAILWAY transport HEALTH and SAFETY participantS
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Analysis of the Differences in Expenditure Levels of Participants at the 2014 Asian Basketball League in Ho Chi Minh City
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作者 Lam Quang Thanh Nguyen Hoang Mirth Thuan Nguyen Thanh Tu 《Journal of Sports Science》 2016年第6期377-382,共6页
Research focuses on studying the economic impacts of 2014 Asian Basketball League in Ho Chi Minh City (hereinaiter referred as ABL 2014) with respect to direct expenditure of all types of participants, including org... Research focuses on studying the economic impacts of 2014 Asian Basketball League in Ho Chi Minh City (hereinaiter referred as ABL 2014) with respect to direct expenditure of all types of participants, including organizers, coaches/athletes, journalists/communicators, audiences, etc. Research was implemented with 920 subjects, including 48 members of the organizing committee, 56 coaches/athletes, 800 audiences and 16 members of journal and media teams. 展开更多
关键词 DIFFERENCES level of expenditure participants.
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The Dilemmas of Using Covert and Overt Participant Observation in Qualitative Research: Effects and Strategies
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作者 付祥芝 《海外英语》 2015年第19期206-208,共3页
Participant observation is often applied in qualitative research to help researchers obtain the overall,useful data,which will lead researchers to gain the knowledge that the academia tries to.However,different levels... Participant observation is often applied in qualitative research to help researchers obtain the overall,useful data,which will lead researchers to gain the knowledge that the academia tries to.However,different levels of participant observation,mainly the covert and overt participant observation,have aroused heated discussions among scholars.Field researchers are faced with many problems when doing research,such as whether they should be a covert participant observer or an overt one;what the research will get when they are in different roles and etc.In order to solve those problems,this article tries to provide some effective methods to field researchers,especially to the new ones.This article mainly talks about two types of participant observation:covert and overt participant observation;tries to explore the issues caused by them and the strategies to help researchers deal with such issues.Finally,in qualitative research,when faced with different fieldworks,researchers should adapt themselves to choosing participant roles flexibly and appropriately. 展开更多
关键词 covert participant OBSERVATION overt participant OBSERVATION EFFECTS STRATEGIES
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Two NGO-Run Youth-Centers in Multicultural, Socially Deprived Suburbs in Sweden—Who Are the Participants?
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作者 Susanna Geidne Ingela Fredriksson +1 位作者 Koustuv Dalal Charli Eriksson 《Health》 2015年第9期1158-1174,共17页
Objective: Leisure-time is an important part of young people’s lives. One way to reduce social differences in health is to improve adolescents’ living conditions, for example by enhancing the quality of after-school... Objective: Leisure-time is an important part of young people’s lives. One way to reduce social differences in health is to improve adolescents’ living conditions, for example by enhancing the quality of after-school activities. Multicultural, socially deprived suburbs have less youth participation in organized leisure-time activities. This study explores who the participants are at two NGO-run youth-centers in multicultural, socially deprived suburbs in Sweden and whether socio-demographic, health-related, and leisure-time factors affect the targeted participation. Methods: The study can be seen as an explanatory mixed-methods study where qualitative data help explain initial quantitative results. The included data are a survey with youth (n = 207), seven individual interviews with staff, and six focus-groups interviews with young people at two youth-centers in two different cities. Results and Conclusions: The participants in the youth-centers are Swedish born youths having foreign-born parents who live with both parents, often in crowded apartments with many siblings. Moreover they feel healthy, enjoy school and have good contact with their parents. It seems that strategies for recruiting youths to youth-centers have a large impact on who participates. One way to succeed in having a more equal gender and ethnicity distribution is to offer youth activities that are a natural step forward from children’s activities. The youth-centers’ proximity is also of importance for participation, in these types of neighborhoods. 展开更多
关键词 Youth-Center LEISURE-TIME Participation SUBURBS NGO
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Athletic Participation and Academic Achievement of High School Students: A Longitudinal Study of Athletic and Non-Athletic Participants
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作者 Robert F.McCarthy 《Journal of International Education and Practice》 2019年第2期37-44,共8页
The majority of extant research studies have established that high school students’athletic participation is positively associated with several educational outcomes,including academic performance.However,the effect o... The majority of extant research studies have established that high school students’athletic participation is positively associated with several educational outcomes,including academic performance.However,the effect of long-term athletic participation on academic performance remains unclear.Using a longitudinal data of 220 students from a high school in eastern Massachusetts of the United States,this study has revealed that athletic participants in this school started with a statistically significant higher GPA than non-participants in the first year of study,and have continued to be higher in the following two years,lag behind significantly,however,in academic achievement growth from their nonparticipation counterparts.The results of the study call for thoughtful decision-making regarding sports programs and athletic policies,proper guidance and adequate support for athletes and an optimal sport-academic culture in American high schools. 展开更多
关键词 High School Athletic Participation Academic Achievement Zero-sum Perspective Developmental Perspectivel
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Participant Heterogeneity of Systemic Scleroderma Interventional Trials Worldwide
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作者 Li-Qing Shi Shi-Hang Zhou +6 位作者 Ping-Lang Ruan Bo Zhang Yue Xin Cheng Zhao Xu Yao Jing-Ru Tian Qian-Jin Lu 《International Journal of Dermatology and Venereology》 CSCD 2024年第2期99-107,共9页
Objective:Heterogeneity of participants in clinical trials distorts intervention efficacy.However,factors associated with participant heterogeneity in randomized clinical trials(RCTs)focusing on systemic sclerosis(SSc... Objective:Heterogeneity of participants in clinical trials distorts intervention efficacy.However,factors associated with participant heterogeneity in randomized clinical trials(RCTs)focusing on systemic sclerosis(SSc)are not clear.We conducted this systematic review to establish normative standards for future research and help develop management guidelines.Methods:Three databases and 4 registries were searched to identify characteristics of SSc RCTs across different countries.Risk of bias was assessed by the Cochrane Collaboration’s tool and logistic regression was performed to calculate crude and adjusted odds ratios.Results:In total,261 trials met our inclusion criteria.The quality of SSc RCTs worldwide was relatively poor,with no trend of improvement in recent years,and only 12.2%were ranked as having a low risk of bias.Trials with a low risk of bias as well as single-center,single-country,or open-label trials tended to have better participant adherence than trials with a high risk of bias and multiple-center,multiple-country,or double-blind trials.Interestingly,trial registration and primary outcome definition contributed to high withdrawal.National income was also relevant;participant adherence in high-income countries,but not in upper-and lower-middle-income countries,was significantly altered by different variables.Conclusion:Overall,the risk of bias,national income,and trial design may lead to participant heterogeneity of SSc RCTs and ultimately confound the general clinical utility of the results.Trials with a rigorous design and transparent conduction protocol are crucial for obtaining unbiased data that can serve as a reference and for maintaining the fundamental repeatability of SSc RCTs. 展开更多
关键词 systemic sclerosis randomized clinical trials HETEROGENEITY participant adherence national income risk of bias
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The Chinese Reception of Western Marxism:From Wary Onlookers to Confident Participants on the World Stage
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作者 Roland Boer 《Fudan Journal of the Humanities and Social Sciences》 2024年第1期1-22,共22页
This study presents an analytic overview of forty years of study of Western Marxism by Chinese scholars.Organised into four main sections,it begins with an emphasis on the wider institutional context of this Chinese r... This study presents an analytic overview of forty years of study of Western Marxism by Chinese scholars.Organised into four main sections,it begins with an emphasis on the wider institutional context of this Chinese research.Here,I deal with the beginnings of research on Western Marxism in China and outline the two main periods of this research,which turn on the important educational reforms of 2005.The next section focuses on the initial period of research on Western Marxism,from the early 1980s to the education reforms,which may be characterised in terms of the work of“wary onlookers”writing introductions and surveys of Western Marxist scholars.The following section covers the last two decades after the 2005 education reforms.This period is of most interest,so more attention is devoted to developments during this time.It has been a time of increasingly confident participants on the world stage,who focus on core issues,realistic demands,and problem-based research.The final section concerns assessments of the limitations of Western Marxism,which have been identified through the in-depth research of the second period.In conclusion,while Western Marxism may be seen as a legitimate development of Marxism in a capitalist context,it is a tributary from the mainstream. 展开更多
关键词 Western Marxism Chinese scholarship 2005 education reforms Wary onlookers Confident global participants Mainstream and tributary
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Joint Participant Selection and Learning Optimization for Federated Learning of Multiple Models in Edge Cloud
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作者 Xinliang Wei Jiyao Liu Yu Wang 《Journal of Computer Science & Technology》 SCIE EI CSCD 2023年第4期754-772,共19页
To overcome the limitations of long latency and privacy concerns from cloud computing,edge computing along with distributed machine learning such as federated learning(FL),has gained much attention and popularity in a... To overcome the limitations of long latency and privacy concerns from cloud computing,edge computing along with distributed machine learning such as federated learning(FL),has gained much attention and popularity in academia and industry.Most existing work on FL over the edge mainly focuses on optimizing the training of one shared global model in edge systems.However,with the increasing applications of FL in edge systems,there could be multiple FL models from different applications concurrently being trained in the shared edge cloud.Such concurrent training of these FL models can lead to edge resource competition(for both computing and network resources),and further affect the FL training performance of each other.Therefore,in this paper,considering a multi-model FL scenario,we formulate a joint participant selection and learning optimization problem in a shared edge cloud.This joint optimization aims to determine FL participants and the learning schedule for each FL model such that the total training cost of all FL models in the edge cloud is minimized.We propose a multi-stage optimization framework by decoupling the original problem into two or three subproblems that can be solved respectively and iteratively.Extensive evaluation has been conducted with realworld FL datasets and models.The results have shown that our proposed algorithms can reduce the total cost efficiently compared with prior algorithms. 展开更多
关键词 edge computing federated learning(FL) participant selection learning optimization
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A Survey on Task and Participant Matching in Mobile Crowd Sensing 被引量:4
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作者 Yue-Yue Chen Pin Lv +2 位作者 De-Ke Guo Tong-Qing Zhou Ming Xu 《Journal of Computer Science & Technology》 SCIE EI CSCD 2018年第4期768-791,共24页
Mobile crowd sensing is an innovative paradigm which leverages the crowd, i.e., a large group of people with their mobile devices, to sense various information in the physical world. With the help of sensed informatio... Mobile crowd sensing is an innovative paradigm which leverages the crowd, i.e., a large group of people with their mobile devices, to sense various information in the physical world. With the help of sensed information, many tasks can be fulfilled in an efficient manner, such as environment monitoring, traffic prediction, and indoor localization. Task and participant matching is an important issue in mobile crowd sensing, because it determines the quality and efficiency of a mobile crowd sensing task. Hence, numerous matching strategies have been proposed in recent research work. This survey aims to provide an up-to-date view on this topic. We propose a research framework for the matching problem in this paper, including participant model, task model, and solution design. The participant model is made up of three kinds of participant characters, i.e., attributes, requirements, and supplements. The task models are separated according to application backgrounds and objective functions. Offline and online solutions in recent literatures are both discussed. Some open issues are introduced, including matching strategy for heterogeneous tasks, context-aware matching, online strategy, and leveraging historical data to finish new tasks. 展开更多
关键词 mobile crowd sensing participant selection task allocation task and participant matching
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Participant attack on the deterministic measurement-device-independent quantum secret sharing protocol 被引量:3
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作者 Yu-Guang Yang Yue-Chao Wang +4 位作者 Yong-Li Yang Xiu-Bo Chen Dan Li Yi-Hua Zhou Wei-Min Shi 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS CSCD 2021年第6期121-124,共4页
In a recent article[Gao et al.,Sci.China-Phys.Mech.Astron.63,120311(2020)],a two-receiver measurement-deviceindependent quantum secret sharing(MDI-QSS)protocol was presented.It was proven to be secure against eavesdro... In a recent article[Gao et al.,Sci.China-Phys.Mech.Astron.63,120311(2020)],a two-receiver measurement-deviceindependent quantum secret sharing(MDI-QSS)protocol was presented.It was proven to be secure against eavesdropping and generalized to the multireceiver case.However,the participant attack is a fatal threat to QSS protocols.Here,we highlight that a dishonest participant can obtain a sender’s secret message alone without introducing any detectable error,evidencing the vulnerability of the MDI-QSS protocol to the participant attack. 展开更多
关键词 quantum cryptography quantum secret sharing participant attack
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Calcium requirements for Chinese adults by cross-sectional statistical analyses of calcium balance studies: an individual participant data and aggregate data meta-regression 被引量:2
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作者 Fang Aiping Li Keji Shi Haoyu He Jingjing Li He 《Chinese Medical Journal》 SCIE CAS CSCD 2014年第24期4250-4257,共8页
Background Chinese dietary reference intakes for calcium are largely based on foreign studies. We undertook meta- regression to estimate calcium requirements for Chinese adults derived from calcium balance data in Chi... Background Chinese dietary reference intakes for calcium are largely based on foreign studies. We undertook meta- regression to estimate calcium requirements for Chinese adults derived from calcium balance data in Chinese adults. Methods We searched PubMed, Cochrane CENTRAL, and SinoMed from inception to March 5, 2014, by using a structured search strategy. The bibliographies of any relevant papers and journals were also screened for potentially eligible studies. We extracted a standardized data set from studies in Chinese adults that reported calcium balance data. The relationship between calcium intake and output was examined by an individual participant data (IPD) and aggregate data (AD) meta-regression. Results We identified 11 metabolic studies in Chinese adults within 18-60 years of age. One hundred and forty-one IPD (n=35) expressed as mg/d, 127 IPD (n=32) expressed as mg.kg body wt-l-d-1, and 44 AD (n=132) expressed as mg/d were collected. The models predicted a neutral calcium balance (defined as calcium output (Y) equal to calcium intake (C)) at intakes of 460 mg/d (Y=0.60C+183.98) and 8.27 mg.kg body wt-l.d-1 (Y=0.60C+3.33) for IPD, or 409 mg/d (Y=0.66C+139.00) for AD. Calcium requirements at upper intakes were higher than that at lower intakes in all these models. Conclusion Calcium requirement for Chinese adults 18-60 years of age approximately ranges between 400 mg/d and 500 mg/d when consuming traditional plant-based Chinese diets. 展开更多
关键词 calcium requirement Chinese adults individual participant data aggregate data META-REGRESSION
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Network analysis of the relationships between depressive symptoms and social participation activities among Chinese older adults and its implications for nursing
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作者 Yebo Yu Hewei Min +3 位作者 Wei Pan Ping Chen Xuxi Zhang Xinying Sun 《International Journal of Nursing Sciences》 CSCD 2024年第4期465-472,I0002,共9页
Objective:Network analysis was used to explore the complex inter-relationships between social participation activities and depressive symptoms among the Chinese older population,and the differences in network structur... Objective:Network analysis was used to explore the complex inter-relationships between social participation activities and depressive symptoms among the Chinese older population,and the differences in network structures among different genders,age groups,and urban-rural residency would be compared.Methods:Based on the 2018 wave of the Chinese Longitudinal Healthy Longevity Survey(CLHLS),12,043 people aged 65 to 105 were included.The 10-item Center for Epidemiologic Studies Depression(CESD)Scale was used to assess depressive symptoms and 10 types of social participation activities were collected,including housework,tai-chi,square dancing,visiting and interacting with friends,garden work,reading newspapers or books,raising domestic animals,playing cards or mahjong,watching TV or listening to radio,and organized social activities.R 4.2.1 software was used to estimate the network model and calculate strength and bridge strength.Results:21.60%(2,601/12,043)of the participants had depressive symptoms.The total social participation score was negatively associated with depressive symptoms after adjusting for sociodemographic factors.The network of social participation and depressive symptoms showed that“D9(Inability to get going)”and“S9(Watching TV and/or listening to the radio)”had the highest strength within depressive symptoms and social participation communities,respectively,and“S1(Housework)”,“S9(Watching TV and/or listening to the radio)”,and“D5(Hopelessness)”were the most prominent bridging nodes between the two communities.Most edges linking the two communities were negative.“S5(Graden work)-D5(Hopelessness)”and“S6(Reading newspapers/books)-D4(Everything was an effort)”were the top 2 strongest negative edges.Older females had significantly denser network structures than older males.Compared to older people aged 65e80,the age group 81e105 showed higher network global strength.Conclusions:This study provides novel insights into the complex relationships between social participation and depressive symptoms.Except for doing housework,other social participation activities were found to be protective for depression levels.Different nursing strategies should be taken to prevent and alleviate depressive symptoms for different genders and older people of different ages. 展开更多
关键词 Depressive symptoms Network analysis Older adults Sex characteristics Social participation
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Low-frequency oscillation of train-network system considering traction power supply mode
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作者 Yuchen Liu Xiaoqin Lyu +1 位作者 Mingyuan Chang Qiqi Yang 《Railway Engineering Science》 EI 2024年第2期244-256,共13页
The low-frequency oscillation(LFO)has occurred in the train-network system due to the introduction of the power electronics of the trains.The modeling and analyzing method in current researches based on electrified ra... The low-frequency oscillation(LFO)has occurred in the train-network system due to the introduction of the power electronics of the trains.The modeling and analyzing method in current researches based on electrified railway unilateral power supply system are not suitable for the LFO analysis in a bilateral power supply system,where the trains are supplied by two traction substations.In this work,based on the single-input and single-output impedance model of China CRH5 trains,the node admittance matrices of the train-network system both in unilateral and bilateral power supply modes are established,including three-phase power grid,traction transformers and traction network.Then the modal analysis is used to study the oscillation modes and propagation characteristics of the unilateral and bilateral power supply systems.Moreover,the influence of the equivalent inductance of the power grid,the length of the transmission line,and the length of the traction network are analyzed on the critical oscillation mode of the bilateral power supply system.Finally,the theoretical analysis results are verified by the time-domain simulation model in MATLAB/Simulink. 展开更多
关键词 Low-frequency oscillation Train-network system Modal analysis Bilateral power supply Participation factor
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