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Resource Allocation in Multi-User Cellular Networks:A Transformer-Based Deep Reinforcement Learning Approach
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作者 Zhao Di Zheng Zhong +2 位作者 Qin Pengfei Qin Hao Song Bin 《China Communications》 SCIE CSCD 2024年第5期77-96,共20页
To meet the communication services with diverse requirements,dynamic resource allocation has shown increasing importance.In this paper,we consider the multi-slot and multi-user resource allocation(MSMU-RA)in a downlin... To meet the communication services with diverse requirements,dynamic resource allocation has shown increasing importance.In this paper,we consider the multi-slot and multi-user resource allocation(MSMU-RA)in a downlink cellular scenario with the aim of maximizing system spectral efficiency while guaranteeing user fairness.We first model the MSMURA problem as a dual-sequence decision-making process,and then solve it by a novel Transformerbased deep reinforcement learning(TDRL)approach.Specifically,the proposed TDRL approach can be achieved based on two aspects:1)To adapt to the dynamic wireless environment,the proximal policy optimization(PPO)algorithm is used to optimize the multi-slot RA strategy.2)To avoid co-channel interference,the Transformer-based PPO algorithm is presented to obtain the optimal multi-user RA scheme by exploring the mapping between user sequence and resource sequence.Experimental results show that:i)the proposed approach outperforms both the traditional and DRL methods in spectral efficiency and user fairness,ii)the proposed algorithm is superior to DRL approaches in terms of convergence speed and generalization performance. 展开更多
关键词 dynamic resource allocation multi-user cellular network spectrum efficiency user fairness
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Hybrid Block Diagonalization Precoding for Multi-User Weighted Sum-Rate Maximization
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作者 Su Xiaofeng Jiang Yi 《China Communications》 SCIE CSCD 2024年第8期127-141,共15页
This paper studies large-scale multi-input multi-output(MIMO)orthogonal frequency division multiplexing(OFDM)communications in a broadband frequency-selective channel,where a massive MIMO base station(BS)communicates ... This paper studies large-scale multi-input multi-output(MIMO)orthogonal frequency division multiplexing(OFDM)communications in a broadband frequency-selective channel,where a massive MIMO base station(BS)communicates with multiple users equipped with multi-antenna.We develop a hybrid precoding design to maximize the weighted sum-rate(WSR)of the users by optimizing the digital and the analog precoders alternately.For the digital part,we employ block-diagonalization to eliminate inter-user interference and apply water-filling power allocation to maximize the WSR.For the analog part,the optimization of the PSN is formulated as an unconstrained problem,which can be efficiently solved by a gradient descent method.Numerical results show that the proposed block-diagonal hybrid precoding algorithm can outperform the existing works. 展开更多
关键词 block-diagonal gradient descent hybrid precoding iterative optimization MIMO-OFDM multi-user water-filling power allocation weighted sum-rate maximization
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A Shared Natural Neighbors Based-Hierarchical Clustering Algorithm for Discovering Arbitrary-Shaped Clusters
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作者 Zhongshang Chen Ji Feng +1 位作者 Fapeng Cai Degang Yang 《Computers, Materials & Continua》 SCIE EI 2024年第8期2031-2048,共18页
In clustering algorithms,the selection of neighbors significantly affects the quality of the final clustering results.While various neighbor relationships exist,such as K-nearest neighbors,natural neighbors,and shared... In clustering algorithms,the selection of neighbors significantly affects the quality of the final clustering results.While various neighbor relationships exist,such as K-nearest neighbors,natural neighbors,and shared neighbors,most neighbor relationships can only handle single structural relationships,and the identification accuracy is low for datasets with multiple structures.In life,people’s first instinct for complex things is to divide them into multiple parts to complete.Partitioning the dataset into more sub-graphs is a good idea approach to identifying complex structures.Taking inspiration from this,we propose a novel neighbor method:Shared Natural Neighbors(SNaN).To demonstrate the superiority of this neighbor method,we propose a shared natural neighbors-based hierarchical clustering algorithm for discovering arbitrary-shaped clusters(HC-SNaN).Our algorithm excels in identifying both spherical clusters and manifold clusters.Tested on synthetic datasets and real-world datasets,HC-SNaN demonstrates significant advantages over existing clustering algorithms,particularly when dealing with datasets containing arbitrary shapes. 展开更多
关键词 Cluster analysis shared natural neighbor hierarchical clustering
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Shared decision making in rural general practices:a qualitative exploration of older rural South Australians'perceived involvement in clinical consultations with doctors
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作者 Mohammad Hamiduzzaman Noore Siddiquee +4 位作者 Harry James Gaffney Frances Barraclough Aziz Rahman Jennene Greenhill Vicki Flood 《Global Health Journal》 2024年第3期140-146,共7页
Background:Shared decision-making(SDM)implementation is a priority for Australian health systems,including general practices but it remains complex for specific groups like older rural Australians.We initiated a quali... Background:Shared decision-making(SDM)implementation is a priority for Australian health systems,including general practices but it remains complex for specific groups like older rural Australians.We initiated a qualitative study with older rural Australians to explore barriers to and facilitators of SDM in local general practices.Methods:We conducted a patient-oriented research,partnering with older rural Australians,families,and health service providers in research design.Participants who visited general practices were purposively sampled from five small rural towns in South Australia.A semi-structured interview guide was used for interviews and reflexive thematic coding was conducted.Results:Telephone interviews were held with 27 participants.Four themes were identified around older rural adults’involvement in SDM:(1)Understanding of"patient involvement";(2)Positive and negative outcomes;(3)Barriers to SDM;and(4)Facilitators to SDM.Understanding of patient involvement in SDM considerably varied among participants,with some reporting their involvement was contingent on the“opportunity to ask questions”and the“treatment choices”offered to them.Alongside the opportunity for involvement,barriers such as avoidance of cultural care and a lack of continuity of care are new findings.Challenges encountered in SDM implementation also included resource constraints and time limitations in general practices.Rural knowledge of general practitioners and technology integration in consultations were viewed as potential enablers..Conclusion:Adequate resources and well-defined guidelines about the process should accompany the implementation of SDM in rural general practices of South Australia.Innovative strategies by general practitioners promoting health literacy and culturally-tailored communication approaches could increase older rural Australians'involvement in general. 展开更多
关键词 General practices shared decision making Olderrural Australians Patient involvement South Australia
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A study on the influencing factors of rural tourism promoting households'shared prosperity in Yinan County of Shandong Province
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作者 YU Feng XIE Ai-liang 《Ecological Economy》 2024年第1期72-84,共13页
This study examines the influencing factors of rural tourism in promoting shared prosperity among households,using the case study of Yinan County in Shandong province,China.The research aims to provide insights into t... This study examines the influencing factors of rural tourism in promoting shared prosperity among households,using the case study of Yinan County in Shandong province,China.The research aims to provide insights into the economic benefits experienced by low-income households in the context of rural tourism development.Based on field research conducted from April 8,2023,to May 17,2023,including interviews and site visits,the study constructs an evaluation index system to assess the influencing factors.Through expert scoring and the application of a weighted set-valued mathematical statistical model,the importance and quantification of each factor are determined.The results indicate that the current stage of promoting shared prosperity through rural tourism in Yinan County is primarily influenced by the scale of tourist consumption of external visitors.This factor outweighs others such as the participation capacity and willingness of low-income households,the capacity of investment enterprises,and the policies and financial allocation of the local government.The findings emphasize the significance of external visitor spending and highlight the need to address the obstacles faced by low-income households in accessing economic benefits.The evaluation index system and measurement model presented in this study offer a scientific basis for assessing and improving the income situation of low-income households in rural tourism development initiatives.However,it is crucial to note that the importance of these influencing factors may evolve with the lifecycle of the tourism destination.Future research should include long-term tracking and consider a broader range of indicators to deepen our understanding of their mechanisms and significance.Furthermore,alternative approaches and theories may provide valuable perspectives for further exploration in this field. 展开更多
关键词 rural tourism households shared prosperity influencing factors economic benefits
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Youth Exchange“Harmony for Shared Prosperity”
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《Contemporary World》 2024年第3期F0003-F0003,共1页
Contemporary World Magazine,which is affiliated to the International Department of the CPC Central Committee(IDCPC),held an exchange act ivi ty themed on“Harmony for Shared Prosperity”in Beijing on May 7,2024.
关键词 Prosper HARMONY shared
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Joint Management of Shared Resources, Issues and Conflicts of the Nso and Oku Tribes in the Ngongbaa Montane Forest Area, NWR of Cameroon
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作者 Jean-Louis Tatah Elvis Kah 《Natural Resources》 2024年第6期149-172,共24页
Wherever people live together in or near homelands that harbour joint natural resources such as forest, water, minerals, oil etc., they must collaborate, co-exist and share these resources irrespective of their geneti... Wherever people live together in or near homelands that harbour joint natural resources such as forest, water, minerals, oil etc., they must collaborate, co-exist and share these resources irrespective of their genetic, social, cultural, and political peculiarities. This is not always the case when self-interest, ethnic divisions, elitist politics, economic interest and power tussle set in. The Nso and Oku people who reside in the Ngongbaa Forest area constitute an example of joint management of resources where at one period, their relationship over the management of the Oku Mountain Forest was cordial and at another, the relationship became conflictive. This study was designed to study the influence of the KIFP forest management policies on the Nso indigenous forest Management system in Ngongbaa Forest, and its implications. The data collected for the study was secured through the administration of a questionnaire to residents of 10 villages adjacent to the Ngongbaa Forest, and forest users who carried out livelihood activities there between 1963 and 2015. These forest user groups include beekeepers, rat trappers, grazers, mushroom gatherers, ground honey/tree honey harvesters, carvers, etc. The investigation also extended to the traditional leaders of Nso and Oku who are in charge of the land tenure systems. The findings show that the Oku Mountain Forest is jointly owned by the Nso and Oku people. The Nso own the eastern half of the forest known as Ngongbaa Forest while the Oku own the western half, known as the Kilum Forest. The cordial relationship that existed between these people ensured the conservation of the forest. But the conflicts that later set in, especially due to the creation of the Kilum Mountain Forest Project in 1987 later changed to the Kilum Ijim Forest Project (KIFP) in 1992 sidelined the local communities which was contrary to the dispositions of the new Cameroon forest law enacted in 1994. Thus, the indigenous conservation practices became ignored which the local population never digested well. This seriously jeopardized the wellbeing of the forest in general. 展开更多
关键词 CONFLICT Joint Management shared Resources Ngongbaa Kilum CONSERVATION
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An Exploration of the Three Dimensions and Epochal Strengths of Building a Human Community With a Shared Future
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作者 Jiang Ruibing Liu Zongling 《Contemporary Social Sciences》 2024年第3期120-138,共19页
The idea of a human community with a shared future was proposed by the Communist Party of China(CPC)Central Committee with Comrade Xi Jinping at its core for the future development of human beings to face up to the mo... The idea of a human community with a shared future was proposed by the Communist Party of China(CPC)Central Committee with Comrade Xi Jinping at its core for the future development of human beings to face up to the most important question in today's world:“What is happening to the world and what should we do?”It profoundly answers the question of the world,history,and the times.The theory of a human community with a shared future is an innovative theory with a multidimensional formation logic that guides humanity toward continually seeking common interests and values.This paper dives into the profound motivations behind building a human community with a shared future from historical,cultural,and practical dimensions and analyzes its epochal value from both domestic and international perspectives.This not only helps exert China's role in the international community,contributing Chinese strength to the construction of a peaceful,stable,and prosperous human society,but also enhances the influence of the idea of a human community with a shared future in the international community,accelerating the building of a human community with a shared future that considers the legitimate concerns of all countries,and aiding in solving the crises facing the world. 展开更多
关键词 a human community with a shared future historical dimension cultural dimension practical dimension epochal strength
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Enablers and barriers of implementing shared governance in nursing departments:a case study from the United Arab Emirates
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作者 Siboj Kurup Anne Paula Manalastas Jayzafer Ciruelas 《Frontiers of Nursing》 2024年第4期415-426,共12页
Objective:The literature provides evidence about the positive impact of shared governance implementation in nursing departments and units,as well as on several aspects of nursing practice,including nurse empowerment,e... Objective:The literature provides evidence about the positive impact of shared governance implementation in nursing departments and units,as well as on several aspects of nursing practice,including nurse empowerment,engagement,well-being,job satisfaction,retention,and positive outcomes in direct patient care.Accordingly,many nursing departments of United Arab Emirates(UAE)hospitals have implemented shared governance in their units.However,the success of implementation varies among these hospitals.Therefore,the study aimed to explore the progress of shared governance implementation in hospitals,identify the enablers and inhibitors of implementing the model,and produce a recommendation to help the nursing departments of hospitals to overcome challenges and accelerate the implementation process.Methods:The study used an inductive,qualitative case-study research method and semi-structured in-depth interviews with a purposive sample of 15 nurses working in various units in a tertiary hospital in UAE.The authors used a thematic data analysis approach to find the results.Results:The results identified immediate manager understanding and support as a significant enabler and lack of senior management support,nurses'attitudes and behaviors,and time as the main barriers.The study highlights that nurses are positive and enthusiastic about improving the current situation of shared governance by providing several suggestions and strategies.Conclusions:The study highlights that senior nursing managers should re-evaluate shared governance implementation and modify the strategies accordingly. 展开更多
关键词 NURSING nurses PARTICIPATORY LEADERSHIP shared governance UAE
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Shared-nothing并行事务数据库系统中规则的挖掘与更新算法 被引量:3
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作者 朱玉全 陈耿 +1 位作者 宋余庆 孙志挥 《小型微型计算机系统》 CSCD 北大核心 2003年第8期1499-1502,共4页
关联规则是数据挖掘中的一个重要研究内容 .本文提出了 Shared- nothing并行事务数据库系统 (简称SNPDBS)中一种快速的关联规则挖掘算法 SNPMAR,并考虑当最小支持度发生变化后 SNPDBS中关联规则的高效更新问题 ,提出了一种有效的关联规... 关联规则是数据挖掘中的一个重要研究内容 .本文提出了 Shared- nothing并行事务数据库系统 (简称SNPDBS)中一种快速的关联规则挖掘算法 SNPMAR,并考虑当最小支持度发生变化后 SNPDBS中关联规则的高效更新问题 ,提出了一种有效的关联规则更新算法 SNPIUA. 展开更多
关键词 数据挖掘 关联规则 shared—nothing 并行事务数据库系统 增量式更新
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Bi-level model for shared parking decision-making based on parking lot assignment simulation 被引量:7
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作者 冉江宇 过秀成 +1 位作者 唐亮 张晔 《Journal of Southeast University(English Edition)》 EI CAS 2011年第3期322-327,共6页
In order to carry out comprehensive decision-making of multi-class shared parking measures within a region, a bilevel model assisting decision-making is proposed. The upper level selects parkers' average satisfaction... In order to carry out comprehensive decision-making of multi-class shared parking measures within a region, a bilevel model assisting decision-making is proposed. The upper level selects parkers' average satisfaction and the violation rate during peak hours as indices in object function, and sets probability distribution models describing dynamic parking demand of each site, the feasibility of shared parking scenarios and occupancy requirements during peak hours of each parking lot as restrictions. The simulation model in the lower level sets up rules to assign each parker in the random parking demand series to the proper parking lot. An iterative method is proposed to confirm the state of each parking lot at the start of formal simulations. Besides, two patterns linking initialization and formal simulation are presented to acquire multiple solutions. The results of the numerical examples indicate the effectiveness of the model and solution methods. 展开更多
关键词 shared parking DECISION-MAKING bi-level model SIMULATION iterative method
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Closed BER expression of multi-user DS UWB systemsin indoor fading channel 被引量:3
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作者 樊祥宁 黄勇富 毕光国 《Journal of Southeast University(English Edition)》 EI CAS 2006年第1期16-20,共5页
The bit error rate (BER) performance of multi-user direct spreading bi-phase shift keying (DSBPSK) direct impulse ultra wideband (UWB) systems is analyzed and simulated based on a statistical indoor multi-path f... The bit error rate (BER) performance of multi-user direct spreading bi-phase shift keying (DSBPSK) direct impulse ultra wideband (UWB) systems is analyzed and simulated based on a statistical indoor multi-path fading channel model. The BER of the system is theoretically derived and given in closed form, which is expressed in terms of channel parameters and system parameters such as pulse width parameter, pulse repeat period, user number and pulse waveform. With this BER expression, the effect of these parameters on the system performance can be evaluated in a uniform way. Simulation results well match the theory numerical results, and prove that the multi-access interference (MAI) of DS-BPSK UWB is a normal distribution. 展开更多
关键词 ultra wideband (UWB) direct spreading (DS) bi-phase shift keying (BPSK) multi-user fading channel performance analysis
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Adaptive resource allocation in downlink multi-user MC-CDMA systems
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作者 王俊波 陈明 王江舟 《Journal of Southeast University(English Edition)》 EI CAS 2008年第4期402-406,共5页
The joint channel and power allocation in the downlink transmission of multi-user multi-carrier code division multiple access(MC-CDMA) systems are investigated and the throughput maximization problem is considered a... The joint channel and power allocation in the downlink transmission of multi-user multi-carrier code division multiple access(MC-CDMA) systems are investigated and the throughput maximization problem is considered as a mixed integer optimization problem. For simplicity of analysis, the problem is divided into two less complex sub-problems: power allocation and channel allocation, which can be solved by a suboptimal adaptive power allocation (APA)algorithm and an optimal adaptive channel allocation (ACA) algorithm, respectively. By combining APA and ACA algorithms, an adaptive channel and power allocation scheme is proposed. The numerical results show that the proposed APA algorithm is more suitable for MC-CDMA systems than the conventional equal power allocation algorithm, and that the proposed channel and power allocation scheme can significantly improve the system throughout performance. 展开更多
关键词 code division multiple access (CDMA) multi-carriertransmission multi-user channel allocation power allocation
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Shared-nothing并行数据库系统查询优化技术 被引量:21
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作者 文继荣 陈红 王珊 《计算机学报》 EI CSCD 北大核心 2000年第1期28-38,共11页
查询优化是并行数据库系统的核心技术 .该文介绍作者自行研制的一个 Shared- nothing并行数据库系统PBA SE/ 2中独特的两阶段优化策略 .为了缩减并行查询优化庞大的搜索空间 ,PBASE/ 2将并行查询优化划分为顺序优化和并行化两个阶段 .... 查询优化是并行数据库系统的核心技术 .该文介绍作者自行研制的一个 Shared- nothing并行数据库系统PBA SE/ 2中独特的两阶段优化策略 .为了缩减并行查询优化庞大的搜索空间 ,PBASE/ 2将并行查询优化划分为顺序优化和并行化两个阶段 .在顺序优化阶段对并行化后的通信代价进行预先估算 ,将通信开销加入顺序优化的代价模型 ,同时对动态规划搜索算法进行了修正和扩展 ,保证了顺序优化阶段得到的最小代价计划在并行化后代价仍然最小 .并行化阶段的优化目标是实现查询工作量在系统内多种资源上的负载平衡 ,提出了资源负载平衡因子的概念 ,并且通过启发式规则、任务调度等机制保证了并行查询执行计划的优化性 . 展开更多
关键词 并行数据库系统 并行查询优化 资源负载平衡
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Flash mx2004中利用SharedObject存取本地磁盘数据 被引量:2
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作者 刘栋 张彩环 《电脑学习》 2006年第4期35-36,60,共3页
探讨了在FlashMx2004中利用共享对象实现对本地数据进行存取的原理,并且用一个实例来说明实现存取数据的具体的步骤和方法。
关键词 共享对象 sharedObjeet FLASH 存储数据 读取数据
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Optimal subcarrier allocation for cognitive radio with multi-user OFDM and distributed antenna 被引量:1
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作者 葛文栋 纪红 +1 位作者 司鹏搏 李曦 《Journal of Southeast University(English Edition)》 EI CAS 2010年第4期513-517,共5页
The subcarrier allocation problem in cognitive radio(CR)networks with multi-user orthogonal frequency-division multiplexing(OFDM)and distributed antenna is analyzed and modeled for the flat fading channel and the ... The subcarrier allocation problem in cognitive radio(CR)networks with multi-user orthogonal frequency-division multiplexing(OFDM)and distributed antenna is analyzed and modeled for the flat fading channel and the frequency selective channel,where the constraint on the secondary user(SU)to protect the primary user(PU)is that the total throughput of each PU must be above the given threshold instead of the "interference temperature".According to the features of different types of channels,the optimal subcarrier allocation schemes are proposed to pursue efficiency(or maximal throughput),using the branch and bound algorithm and the 0-1 implicit enumeration algorithm.Furthermore,considering the tradeoff between efficiency and fairness,the optimal subcarrier allocation schemes with fairness are proposed in different fading channels,using the pegging algorithm.Extensive simulation results illustrate the significant performance improvement of the proposed subcarrier allocation schemes compared with the existing ones in different scenarios. 展开更多
关键词 cognitive radio subcarrier allocation multi-user OFDM distributed antenna branch and bound algorithm implicit enumeration algorithm pegging algorithm
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一种Shared-Nothing分布式数据库的构建方法 被引量:1
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作者 龙源 郑彦 《计算机技术与发展》 2012年第10期79-82,共4页
分布式数据库能够以相对低廉的代价满足海量数据分析处理的性能需求,兼具良好的可扩展性。文中采用Shared-Nothing架构及MySQL数据库来实现分布式数据库访问层的功能架构及模块设计,提出了使用列存储机制提升分布式数据库系统查询性能... 分布式数据库能够以相对低廉的代价满足海量数据分析处理的性能需求,兼具良好的可扩展性。文中采用Shared-Nothing架构及MySQL数据库来实现分布式数据库访问层的功能架构及模块设计,提出了使用列存储机制提升分布式数据库系统查询性能的思路,包括数据存储的方法及策略。对所设计实现的系统进行了基准性能测试及扩展性能测试,结果表明,文中所实现系统相较传统列式数据库具有出色的查询性能表现,同时具有优秀的可扩展性,能够以较低的代价满足海量数据分析处理所带来的额外数据库性能提升要求。 展开更多
关键词 分布式数据库 shared—Nothing MYSQL 列存储
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安心卡引导的尊严照护干预联合SHARE模式在肿瘤患者安宁疗护中的应用
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作者 申青 《黑龙江医学》 2024年第13期1633-1636,共4页
目的:探讨和分析安心卡引导的尊严照护干预联合SHARE模式在肿瘤患者安宁疗护中的应用,为临床提供参考。方法:选取2022年1—12月郑州市第三人民医院收治的68例肿瘤患者作为研究对象。对照组(34例)采取传统的照护方法和告知模式,试验组(34... 目的:探讨和分析安心卡引导的尊严照护干预联合SHARE模式在肿瘤患者安宁疗护中的应用,为临床提供参考。方法:选取2022年1—12月郑州市第三人民医院收治的68例肿瘤患者作为研究对象。对照组(34例)采取传统的照护方法和告知模式,试验组(34例)采取安心卡引导的尊严照护方法和SHARE告知模式,比较两组患者的自尊水平、死亡态度、焦虑情绪、睡眠质量状况。结果:干预后,两组患者的自尊水平测定分数均增高,试验组的自尊水平测定分数显著高于对照组,差异有统计学意义(t=4.218,P<0.05);干预后,试验组的害怕、回避死亡态度得分显著低于对照组,自然接受、接近接受死亡态度得分显著高于对照组,差异有统计学意义(t=10.119、3.222、17.142、6.278,P<0.05);干预后,两组患者的焦虑情绪得分均降低,试验组焦虑情绪得分显著低于对照组,差异有统计学意义(t=18.739,P<0.05);干预后,两组患者的睡眠质量得分均降低,试验组睡眠质量得分显著低于对照组,差异有统计学意义(t=10.746,P<0.05);干预后,两组患者的疼痛程度得分均降低,干预后试验组疼痛程度得分显著低于对照组,差异有统计学意义(t=9.685,P<0.05)。结论:安心卡引导的尊严照护干预联合SHARE模式在肿瘤患者安宁疗护中,有利于肿瘤患者疾病治疗和身心健康发展,可供临床参考。 展开更多
关键词 安心卡 尊严照护 share模式 癌症告知 安宁疗护
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Shared and Service-oriented CNC Machining System for Intelligent Manufacturing Process 被引量:7
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作者 LI Yao LIU Qiang +1 位作者 TONG Ronglei CUI Xiaohong 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2015年第6期1100-1108,共9页
To improve efficiency, reduce cost, ensure quality effectively, researchers on CNC machining have focused on virtual machine tool, cloud manufacturing, wireless manufacturing. However, low level of information shared ... To improve efficiency, reduce cost, ensure quality effectively, researchers on CNC machining have focused on virtual machine tool, cloud manufacturing, wireless manufacturing. However, low level of information shared among different systems is a common disadvantage. In this paper, a machining database with data evaluation module is set up to ensure integrity and update. An online monitoring system based on internet of things and multi-sensors "feel" a variety of signal features to "percept" the state in CNC machining process. A high efficiency and green machining parameters optimization system "execute" service-oriented manufacturing, intelligent manufacturing and green manufacturing. The intelligent CNC machining system is applied in production. CNC machining database effectively shares and manages process data among different systems. The prediction accuracy of online monitoring system is up to 98.8% by acquiring acceleration and noise in real time. High efficiency and green machining parameters optimization system optimizes the original processing parameters, and the calculation indicates that optimized processing parameters not only improve production efficiency, but also reduce carbon emissions. The application proves that the shared and service-oriented CNC machining system is reliable and effective. This research presents a shared and service-oriented CNC machining system for intelligent manufacturing process. 展开更多
关键词 INTELLIGENT SERVICE-ORIENTED shared DATABASE MONITOR OPTIMIZATION evaluation
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Core-based Shared Tree Multicast Routing Algorithms for LEO Satellite IP Networks 被引量:6
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作者 Cheng Lianzhen Zhang Jun Liu Kai 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2007年第4期353-361,共9页
A new core-based shared tree algorithm, viz core-cluster combination-based shared tree (CCST) algorithm and the weighted version (i.e. w-CCST algorithm) are proposed in order to resolve the channel resources waste... A new core-based shared tree algorithm, viz core-cluster combination-based shared tree (CCST) algorithm and the weighted version (i.e. w-CCST algorithm) are proposed in order to resolve the channel resources waste problem in typical source-based multicast routing algorithms in low earth orbit (LEO) satellite IP networks. The CCST algorithm includes the dynamic approximate center (DAC) core selection method and the core-cluster combination multicast route construction scheme. Without complicated onboard computation, the DAC method is uniquely developed for highly dynamic networks of periodical and regular movement. The core-cluster combination method takes core node as the initial core-cluster, and expands it stepwise to construct an entire multicast tree at the lowest tree cost by a shortest path scheme between the newly-generated core-cluster and surplus group members, which results in great bandwidth utilization. Moreover, the w-CCST algorithm is able to strike a balance between performance of tree cost and that of end-to-end propagation delay by adjusting the weighted factor to meet strict end-to-end delay requirements of some real-time multicast services at the expense of a slight increase in tree cost. Finally, performance comparison is conducted between the proposed algorithms and typical algorithms in LEO satellite IP networks. Simulation results show that the CCST algorithm significantly decreases the average tree cost against to the others, and also the average end-to-end propagation delay ofw-CCST algorithm is lower than that of the CCST algorithm. 展开更多
关键词 satellite IP networks LEO multicast routing shared tree CORE
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