期刊文献+
共找到861,793篇文章
< 1 2 250 >
每页显示 20 50 100
Multi-Time Scale Operation and Simulation Strategy of the Park Based on Model Predictive Control
1
作者 Jun Zhao Chaoying Yang +1 位作者 Ran Li Jinge Song 《Energy Engineering》 EI 2024年第3期747-767,共21页
Due to the impact of source-load prediction power errors and uncertainties,the actual operation of the park will have a wide range of fluctuations compared with the expected state,resulting in its inability to achieve... Due to the impact of source-load prediction power errors and uncertainties,the actual operation of the park will have a wide range of fluctuations compared with the expected state,resulting in its inability to achieve the expected economy.This paper constructs an operating simulation model of the park power grid operation considering demand response and proposes a multi-time scale operating simulation method that combines day-ahead optimization and model predictive control(MPC).In the day-ahead stage,an operating simulation plan that comprehensively considers the user’s side comfort and operating costs is proposed with a long-term time scale of 15 min.In order to cope with power fluctuations of photovoltaic,wind turbine and conventional load,MPC is used to track and roll correct the day-ahead operating simulation plan in the intra-day stage to meet the actual operating operation status of the park.Finally,the validity and economy of the operating simulation strategy are verified through the analysis of arithmetic examples. 展开更多
关键词 Demand response model predictive control multiple time scales operating simulation
下载PDF
Multi-Time Scale Optimal Scheduling of a Photovoltaic Energy Storage Building System Based on Model Predictive Control
2
作者 Ximin Cao Xinglong Chen +2 位作者 He Huang Yanchi Zhang Qifan Huang 《Energy Engineering》 EI 2024年第4期1067-1089,共23页
Building emission reduction is an important way to achieve China’s carbon peaking and carbon neutrality goals.Aiming at the problem of low carbon economic operation of a photovoltaic energy storage building system,a ... Building emission reduction is an important way to achieve China’s carbon peaking and carbon neutrality goals.Aiming at the problem of low carbon economic operation of a photovoltaic energy storage building system,a multi-time scale optimal scheduling strategy based on model predictive control(MPC)is proposed under the consideration of load optimization.First,load optimization is achieved by controlling the charging time of electric vehicles as well as adjusting the air conditioning operation temperature,and the photovoltaic energy storage building system model is constructed to propose a day-ahead scheduling strategy with the lowest daily operation cost.Second,considering inter-day to intra-day source-load prediction error,an intraday rolling optimal scheduling strategy based on MPC is proposed that dynamically corrects the day-ahead dispatch results to stabilize system power fluctuations and promote photovoltaic consumption.Finally,taking an office building on a summer work day as an example,the effectiveness of the proposed scheduling strategy is verified.The results of the example show that the strategy reduces the total operating cost of the photovoltaic energy storage building system by 17.11%,improves the carbon emission reduction by 7.99%,and the photovoltaic consumption rate reaches 98.57%,improving the system’s low-carbon and economic performance. 展开更多
关键词 Load optimization model predictive control multi-time scale optimal scheduling photovoltaic consumption photovoltaic energy storage building
下载PDF
GUARDIAN: A Multi-Tiered Defense Architecture for Thwarting Prompt Injection Attacks on LLMs
3
作者 Parijat Rai Saumil Sood +1 位作者 Vijay K. Madisetti Arshdeep Bahga 《Journal of Software Engineering and Applications》 2024年第1期43-68,共26页
This paper introduces a novel multi-tiered defense architecture to protect language models from adversarial prompt attacks. We construct adversarial prompts using strategies like role emulation and manipulative assist... This paper introduces a novel multi-tiered defense architecture to protect language models from adversarial prompt attacks. We construct adversarial prompts using strategies like role emulation and manipulative assistance to simulate real threats. We introduce a comprehensive, multi-tiered defense framework named GUARDIAN (Guardrails for Upholding Ethics in Language Models) comprising a system prompt filter, pre-processing filter leveraging a toxic classifier and ethical prompt generator, and pre-display filter using the model itself for output screening. Extensive testing on Meta’s Llama-2 model demonstrates the capability to block 100% of attack prompts. The approach also auto-suggests safer prompt alternatives, thereby bolstering language model security. Quantitatively evaluated defense layers and an ethical substitution mechanism represent key innovations to counter sophisticated attacks. The integrated methodology not only fortifies smaller LLMs against emerging cyber threats but also guides the broader application of LLMs in a secure and ethical manner. 展开更多
关键词 Large Language models (LLMs) Adversarial Attack Prompt Injection Filter Defense Artificial Intelligence Machine Learning CYBERSECURITY
下载PDF
Aquaporin-4-IgG-seropositive neuromyelitis optica spectrum disorders:progress of experimental models based on disease pathogenesis
4
作者 Li Xu Huiming Xu Changyong Tang 《Neural Regeneration Research》 SCIE CAS 2025年第2期354-365,共12页
Neuromyelitis optica spectrum disorders are neuroinflammatory demyelinating disorders that lead to permanent visual loss and motor dysfunction.To date,no effective treatment exists as the exact causative mechanism rem... Neuromyelitis optica spectrum disorders are neuroinflammatory demyelinating disorders that lead to permanent visual loss and motor dysfunction.To date,no effective treatment exists as the exact causative mechanism remains unknown.Therefore,experimental models of neuromyelitis optica spectrum disorders are essential for exploring its pathogenesis and in screening for therapeutic targets.Since most patients with neuromyelitis optica spectrum disorders are seropositive for IgG autoantibodies against aquaporin-4,which is highly expressed on the membrane of astrocyte endfeet,most current experimental models are based on aquaporin-4-IgG that initially targets astrocytes.These experimental models have successfully simulated many pathological features of neuromyelitis optica spectrum disorders,such as aquaporin-4 loss,astrocytopathy,granulocyte and macrophage infiltration,complement activation,demyelination,and neuronal loss;however,they do not fully capture the pathological process of human neuromyelitis optica spectrum disorders.In this review,we summarize the currently known pathogenic mechanisms and the development of associated experimental models in vitro,ex vivo,and in vivo for neuromyelitis optica spectrum disorders,suggest potential pathogenic mechanisms for further investigation,and provide guidance on experimental model choices.In addition,this review summarizes the latest information on pathologies and therapies for neuromyelitis optica spectrum disorders based on experimental models of aquaporin-4-IgG-seropositive neuromyelitis optica spectrum disorders,offering further therapeutic targets and a theoretical basis for clinical trials. 展开更多
关键词 AQUAPORIN-4 experimental model neuromyelitis optica spectrum disorder PATHOGENESIS
下载PDF
Exploiting fly models to investigate rare human neurological disorders
5
作者 Tomomi Tanaka Hyung-Lok Chung 《Neural Regeneration Research》 SCIE CAS 2025年第1期21-28,共8页
Rare neurological diseases,while individually are rare,collectively impact millions globally,leading to diverse and often severe neurological symptoms.Often attributed to genetic mutations that disrupt protein functio... Rare neurological diseases,while individually are rare,collectively impact millions globally,leading to diverse and often severe neurological symptoms.Often attributed to genetic mutations that disrupt protein function or structure,understanding their genetic basis is crucial for accurate diagnosis and targeted therapies.To investigate the underlying pathogenesis of these conditions,researchers often use non-mammalian model organisms,such as Drosophila(fruit flies),which is valued for their genetic manipulability,cost-efficiency,and preservation of genes and biological functions across evolutionary time.Genetic tools available in Drosophila,including CRISPR-Cas9,offer a means to manipulate gene expression,allowing for a deep exploration of the genetic underpinnings of rare neurological diseases.Drosophila boasts a versatile genetic toolkit,rapid generation turnover,and ease of large-scale experimentation,making it an invaluable resource for identifying potential drug candidates.Researchers can expose flies carrying disease-associated mutations to various compounds,rapidly pinpointing promising therapeutic agents for further investigation in mammalian models and,ultimately,clinical trials.In this comprehensive review,we explore rare neurological diseases where fly research has significantly contributed to our understanding of their genetic basis,pathophysiology,and potential therapeutic implications.We discuss rare diseases associated with both neuron-expressed and glial-expressed genes.Specific cases include mutations in CDK19 resulting in epilepsy and developmental delay,mutations in TIAM1 leading to a neurodevelopmental disorder with seizures and language delay,and mutations in IRF2BPL causing seizures,a neurodevelopmental disorder with regression,loss of speech,and abnormal movements.And we explore mutations in EMC1 related to cerebellar atrophy,visual impairment,psychomotor retardation,and gain-of-function mutations in ACOX1 causing Mitchell syndrome.Loss-of-function mutations in ACOX1 result in ACOX1 deficiency,characterized by very-long-chain fatty acid accumulation and glial degeneration.Notably,this review highlights how modeling these diseases in Drosophila has provided valuable insights into their pathophysiology,offering a platform for the rapid identification of potential therapeutic interventions.Rare neurological diseases involve a wide range of expression systems,and sometimes common phenotypes can be found among different genes that cause abnormalities in neurons or glia.Furthermore,mutations within the same gene may result in varying functional outcomes,such as complete loss of function,partial loss of function,or gain-of-function mutations.The phenotypes observed in patients can differ significantly,underscoring the complexity of these conditions.In conclusion,Drosophila represents an indispensable and cost-effective tool for investigating rare neurological diseases.By facilitating the modeling of these conditions,Drosophila contributes to a deeper understanding of their genetic basis,pathophysiology,and potential therapies.This approach accelerates the discovery of promising drug candidates,ultimately benefiting patients affected by these complex and understudied diseases. 展开更多
关键词 ACOX1 Drosophila melanogaster GLIA lipid metabolism model organisms NEUROINFLAMMATION neurologic disorders NEURON rare disease VLCFA
下载PDF
A promising approach for quantifying focal stroke modeling and assessing stroke progression:optical resolution photoacoustic microscopy photothrombosis
6
作者 Xiao Liang Xingping Quan +6 位作者 Xiaorui Geng Yujing Huang Yonghua Zhao Lei Xi Zhen Yuan Ping Wang Bin Liu 《Neural Regeneration Research》 SCIE CAS 2025年第7期2029-2037,共9页
To investigate the mechanisms underlying the onset and progression of ischemic stroke,some methods have been proposed that can simultaneously monitor and create embolisms in the animal cerebral cortex.However,these me... To investigate the mechanisms underlying the onset and progression of ischemic stroke,some methods have been proposed that can simultaneously monitor and create embolisms in the animal cerebral cortex.However,these methods often require complex systems and the effect of age on cerebral embolism has not been adequately studied,although ischemic stroke is strongly age-related.In this study,we propose an optical-resolution photoacoustic microscopy-based visualized photothrombosis methodology to create and monitor ischemic stroke in mice simultaneously using a 532 nm pulsed laser.We observed the molding process in mice of different ages and presented age-dependent vascular embolism differentiation.Moreover,we integrated optical coherence tomography angiography to investigate age-associated trends in cerebrovascular variability following a stroke.Our imaging data and quantitative analyses underscore the differential cerebrovascular responses to stroke in mice of different ages,thereby highlighting the technique's potential for evaluating cerebrovascular health and unraveling age-related mechanisms involved in ischemic strokes. 展开更多
关键词 AGE-DEPENDENT cerebral cortex ischemic stroke mouse model optical coherence tomography angiography photoacoustic microscopy PHOTOTHROMBOSIS vascular imaging
下载PDF
Reduced mesencephalic astrocyte-derived neurotrophic factor expression by mutant androgen receptor contributes to neurodegeneration in a model of spinal and bulbar muscular atrophy pathology
7
作者 Yiyang Qin Wenzhen Zhu +6 位作者 Tingting Guo Yiran Zhang Tingting Xing Peng Yin Shihua Li Xiao-Jiang Li Su Yang 《Neural Regeneration Research》 SCIE CAS 2025年第9期2655-2666,共12页
Spinal and bulbar muscular atrophy is a neurodegenerative disease caused by extended CAG trinucleotide repeats in the androgen receptor gene,which encodes a ligand-dependent transcription facto r.The mutant androgen r... Spinal and bulbar muscular atrophy is a neurodegenerative disease caused by extended CAG trinucleotide repeats in the androgen receptor gene,which encodes a ligand-dependent transcription facto r.The mutant androgen receptor protein,characterized by polyglutamine expansion,is prone to misfolding and forms aggregates in both the nucleus and cytoplasm in the brain in spinal and bulbar muscular atrophy patients.These aggregates alter protein-protein interactions and compromise transcriptional activity.In this study,we reported that in both cultured N2a cells and mouse brain,mutant androgen receptor with polyglutamine expansion causes reduced expression of mesencephalic astrocyte-de rived neurotrophic factor.Overexpressio n of mesencephalic astrocyte-derived neurotrophic factor amelio rated the neurotoxicity of mutant androgen receptor through the inhibition of mutant androgen receptor aggregation.Conversely.knocking down endogenous mesencephalic astrocyte-derived neurotrophic factor in the mouse brain exacerbated neuronal damage and mutant androgen receptor aggregation.Our findings suggest that inhibition of mesencephalic astrocyte-derived neurotrophic factor expression by mutant androgen receptor is a potential mechanism underlying neurodegeneration in spinal and bulbar muscular atrophy. 展开更多
关键词 androgen receptor mesencephalic astrocyte-derived neurotrophic factor mouse model NEURODEGENERATION neuronal loss neurotrophic factor polyglutamine disease protein misfolding spinal and bulbar muscular atrophy transcription factor
下载PDF
An Application of a Multi-Tier Data Warehouse in Oil and Gas Drilling Information Management 被引量:2
8
作者 张宁生 王志伟 《Petroleum Science》 SCIE CAS CSCD 2004年第4期1-5,共5页
Expenditure on wells constitute a significant part of the operational costs for a petroleum enterprise, where most of the cost results from drilling. This has prompted drilling departments to continuously look for wa... Expenditure on wells constitute a significant part of the operational costs for a petroleum enterprise, where most of the cost results from drilling. This has prompted drilling departments to continuously look for ways to reduce their drilling costs and be as efficient as possible. A system called the Drilling Comprehensive Information Management and Application System (DCIMAS) is developed and presented here, with an aim at collecting, storing and making full use of the valuable well data and information relating to all drilling activities and operations. The DCIMAS comprises three main parts, including a data collection and transmission system, a data warehouse (DW) management system, and an integrated platform of core applications. With the support of the application platform, the DW management system is introduced, whereby the operation data are captured at well sites and transmitted electronically to a data warehouse via transmission equipment and ETL (extract, transformation and load) tools. With the high quality of the data guaranteed, our central task is to make the best use of the operation data and information for drilling analysis and to provide further information to guide later production stages. Applications have been developed and integrated on a uniform platform to interface directly with different layers of the multi-tier DW. Now, engineers in every department spend less time on data handling and more time on applying technology in their real work with the system. 展开更多
关键词 drilling information management multi-tier data warehouse information processing application system
下载PDF
Multi-Tier数据库应用程序及在Delphi中的实现 被引量:3
9
作者 杨滨生 李伟 夏胜利 《昆明冶金高等专科学校学报》 CAS 2002年第4期22-27,共6页
介绍了多层数据库应用程序的基本原理及其在Delphi中的实现技术,并以其在学分制教务管理系统开发的程序为原型,通过实例讲述在Delphi中实现Multi-Tier技术的步骤和要点。
关键词 multi-tier 数据库应用程序 DELPHI 教务管理 学分制
下载PDF
Delphi中Multi-Tier结构的应用浅析
10
作者 章丽平 朱莉 +2 位作者 左博新 付晶 汪艺 《计算机与现代化》 2004年第1期24-26,共3页
Multi Tier结构是目前分布式系统的主要应用结构,本文首先对传统的Two Tier结构数据库和Multi Tier结构数据库系统进行了比较,然后以三层数据库应用系统为例介绍Multi Tier结构应用的构建过程,并以一个实例加以说明。
关键词 DELPHI multi-tier结构 数据库系统 数据模块 应用程序
下载PDF
使用Multi-Tier技术架构Web应用系统
11
作者 左博新 朱莉 +1 位作者 章丽平 付晶 《计算机与现代化》 2004年第9期44-46,共3页
Web系统目前被广泛应用于Internet/Intranet,随着网络的发展,传统的CGI/ISAPI标准结构已不能满足需要,本文介绍了Delphi的InternetExpress和DatabasePooling等Multi Tier技术,通过对CGI/ISAPI结构与InternetExpress结构的比较,介绍使用I... Web系统目前被广泛应用于Internet/Intranet,随着网络的发展,传统的CGI/ISAPI标准结构已不能满足需要,本文介绍了Delphi的InternetExpress和DatabasePooling等Multi Tier技术,通过对CGI/ISAPI结构与InternetExpress结构的比较,介绍使用InternetExpress技术结合MST(MicrosoftTransactionServer)构建基于Web的三层结构系统的架构过程。并以开发实例加以说明。 展开更多
关键词 multi-tier WEB应用系统 CGI/ISAPI DELPHI Internet EXPRESS Database Pooling ISAPI
下载PDF
采用STAMP-24Model的多组织事故分析
12
作者 曾明荣 秦永莹 +2 位作者 刘小航 栗婧 尚长岭 《安全与环境学报》 CAS CSCD 北大核心 2024年第7期2741-2750,共10页
安全生产事故往往由多组织交互、多因素耦合造成,事故原因涉及多个组织。为预防和遏制多组织生产安全事故的发生,基于系统理论事故建模与过程模型(Systems-Theory Accident Modeling and Process,STAMP)、24Model,构建一种用于多组织事... 安全生产事故往往由多组织交互、多因素耦合造成,事故原因涉及多个组织。为预防和遏制多组织生产安全事故的发生,基于系统理论事故建模与过程模型(Systems-Theory Accident Modeling and Process,STAMP)、24Model,构建一种用于多组织事故分析的方法,并以青岛石油爆炸事故为例进行事故原因分析。结果显示:STAMP-24Model可以分组织,分层次且有效、全面、详细地分析涉及多个组织的事故原因,探究多组织之间的交互关系;对事故进行动态演化分析,可得到各组织不安全动作耦合关系与形成的事故失效链及管控失效路径,进而为预防多组织事故提供思路和参考。 展开更多
关键词 安全工程 系统理论事故建模与过程模型(STAMP) 24model 多组织事故 原因分析
下载PDF
基于改进24Model-ISM-SNA建筑工人不安全行为关联路径研究
13
作者 赵平 刘钰 +1 位作者 靳丽艳 王佳慧 《工业安全与环保》 2024年第7期37-40,共4页
建筑施工现场环境复杂,为有效控制不安全行为发生,基于行为安全“2-4”模型对360份具有代表性的建筑安全事故调查报告进行分析,提取出22个不安全行为的主要影响因素。利用灰色关联分析方法(GRA)改进的集成ISM-SNA模型,将不安全行为风险... 建筑施工现场环境复杂,为有效控制不安全行为发生,基于行为安全“2-4”模型对360份具有代表性的建筑安全事故调查报告进行分析,提取出22个不安全行为的主要影响因素。利用灰色关联分析方法(GRA)改进的集成ISM-SNA模型,将不安全行为风险因素划分为表层、过渡层与深层,然后对风险因素进行可视化分析、中心度分析及凝聚子群分析,揭示了各致因因素间的关联关系和传导路径。结果表明,建筑工人不安全行为影响因素可划分成7级3阶的多级递阶结构,安全意识、现场监管、外部环境是建筑工人不安全行为的关键影响因素,同时现场监管和隐患排查到位能有效降低不安全行为的发生。 展开更多
关键词 建筑工人 不安全行为 24model 解释结构模型(ISM) 社会网络分析(SNA)
下载PDF
基于24Model的地铁内涝事故原因分析与评估
14
作者 张江石 胡馨月 +3 位作者 侯轩 李泳暾 李梓萌 高进东 《安全与环境工程》 CAS CSCD 北大核心 2024年第6期111-117,共7页
为降低地铁内涝事故灾害风险,基于事故致因“2-4”模型,分析了地铁内涝事故致灾因子,采用层次分析法构建了地铁内涝事故原因分析指标体系,确定了各风险因子的权重,并利用模糊综合评价法对地铁内涝事故进行了定量评估,识别出关键的影响... 为降低地铁内涝事故灾害风险,基于事故致因“2-4”模型,分析了地铁内涝事故致灾因子,采用层次分析法构建了地铁内涝事故原因分析指标体系,确定了各风险因子的权重,并利用模糊综合评价法对地铁内涝事故进行了定量评估,识别出关键的影响因素。结果表明:地铁内涝事故一级指标中不安全动作与物态因素最重要,其中影响最大的指标包括擅自更改建筑设计、未按照要求检查水位情况、未及时排水、出入口不符合防汛标准等因素;习惯性不安全行为的权重位居第二,表明该指标因素较为重要,同时安全管理体系得分位居第二,表明该指标因素较易发生。对关键指标采取防范措施,可有效降低风险,从而减少地铁内涝事故的发生。 展开更多
关键词 安全工程 地铁内涝 24model 层次分析法 模糊综合评价法
下载PDF
基于24Model-D-ISM的地铁站火灾疏散影响因素研究
15
作者 孙世梅 张家严 《中国安全科学学报》 CAS CSCD 北大核心 2024年第4期153-159,共7页
为预防地铁站火灾事故,深入了解地铁站火灾人员疏散影响因素间的内在联系与层次结构,基于第6版“2-4”模型(24Model)分析63起地铁站火灾疏散事故,充分考虑各个因素之间的交互作用,提取19个影响地铁站人员疏散的关键因素,建立地铁站火灾... 为预防地铁站火灾事故,深入了解地铁站火灾人员疏散影响因素间的内在联系与层次结构,基于第6版“2-4”模型(24Model)分析63起地铁站火灾疏散事故,充分考虑各个因素之间的交互作用,提取19个影响地铁站人员疏散的关键因素,建立地铁站火灾人员疏散影响因素指标体系;采用算子客观赋权法(C-OWA)改进决策试验与评价实验法(DEMATEL),确定地铁站火灾人员疏散的重要影响因素;在此基础上,采用解释结构模型(ISM)分析各个因素间的层次结构及相互作用路径,构建地铁站火灾人员疏散影响因素的多级递阶结构模型。研究结果表明:疏散引导、恐慌从众行为、人员拥挤为地铁站火灾人员疏散的关键影响因素;地铁站火灾人员疏散受表层因素、中间层因素、深层因素共同作用的影响,其中,疏散教育与培训、设施维护与检查、疏散预案等因素是根源影响因素,重视根源影响因素的改善有利于从本质上预防和控制事故的发生。 展开更多
关键词 “2-4”模型(24model) 决策试验与评价实验法(DEMATEL) 解释结构模型(ISM) 地铁站 火灾疏散 影响因素
下载PDF
Seismic assessment of two multi-tiered pagodas damaged by the 2015 Nepal earthquake 被引量:1
16
作者 Yohei Endo Toshikazu Hanazato 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2021年第2期453-469,共17页
A seismic assessment of two multi-tier pagodas by numerical analysis is presented herein.The Changu Narayan temple and the Kumbeshwar temple in Nepal are used as the case studies.Both pagodas are built of brick masonr... A seismic assessment of two multi-tier pagodas by numerical analysis is presented herein.The Changu Narayan temple and the Kumbeshwar temple in Nepal are used as the case studies.Both pagodas are built of brick masonry in earthen mortar,with timber columns and crossbeams.The Changu Narayan temple is a two-tier pagoda,and was seriously damaged during the 2015 Gorkha earthquake.The Kumbeshwar temple is a five-tier pagoda,and its top-tier collapsed due to the Gorkha earthquake.A seismic assessment was carried out using finite element(FE)analysis.The FE models were prepared,and dynamic identification tests and penetrometer tests were conducted.Pushover analysis and nonlinear dynamic analysis were performed as part of the seismic assessment.The main shock of the 2015 Gorkha earthquake was considered as the input accelerograms.The behavior between the two pagodas was compared with the collapse mechanisms and damage patterns observed in the actual structures.The comparison suggested common structural features of multi-tier pagodas.This study is dedicated to providing a better understanding of the seismic behavior of multi-tier pagoda-type structures and provides suggestions for their effective analysis. 展开更多
关键词 MASONRY multi-tier pagoda seismic assessment nonlinear dynamic analysis FEM analysis
下载PDF
Storage Assignment Optimization in a Multi-tier Shuttle Warehousing System 被引量:8
17
作者 WANG Yanyan MOU Shandong WU Yaohua 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2016年第2期421-429,共9页
The current mathematical models for the storage assignment problem are generally established based on the traveling salesman problem(TSP),which has been widely applied in the conventional automated storage and retri... The current mathematical models for the storage assignment problem are generally established based on the traveling salesman problem(TSP),which has been widely applied in the conventional automated storage and retrieval system(AS/RS).However,the previous mathematical models in conventional AS/RS do not match multi-tier shuttle warehousing systems(MSWS) because the characteristics of parallel retrieval in multiple tiers and progressive vertical movement destroy the foundation of TSP.In this study,a two-stage open queuing network model in which shuttles and a lift are regarded as servers at different stages is proposed to analyze system performance in the terms of shuttle waiting period(SWP) and lift idle period(LIP) during transaction cycle time.A mean arrival time difference matrix for pairwise stock keeping units(SKUs) is presented to determine the mean waiting time and queue length to optimize the storage assignment problem on the basis of SKU correlation.The decomposition method is applied to analyze the interactions among outbound task time,SWP,and LIP.The ant colony clustering algorithm is designed to determine storage partitions using clustering items.In addition,goods are assigned for storage according to the rearranging permutation and the combination of storage partitions in a 2D plane.This combination is derived based on the analysis results of the queuing network model and on three basic principles.The storage assignment method and its entire optimization algorithm method as applied in a MSWS are verified through a practical engineering project conducted in the tobacco industry.The applying results show that the total SWP and LIP can be reduced effectively to improve the utilization rates of all devices and to increase the throughput of the distribution center. 展开更多
关键词 multi-tier shuttle warehousing system storage assignment optimization open queuing network ant colony clustering algorithm
下载PDF
24Model与LCM原因因素定义对比研究 被引量:2
18
作者 袁晨辉 傅贵 +1 位作者 吴治蓉 赵金坤 《中国安全科学学报》 CAS CSCD 北大核心 2024年第1期27-34,共8页
为探究损失致因模型(LCM)原因因素定义与事故致因“2-4”模型(24Model)存在的异同和优缺点,梳理2个模型各层面原因和结果的定义,对比定义内容及其对事故原因分析等安全实务的指导作用,并以一起瓦斯爆炸事故为例加以实证分析,获得二者分... 为探究损失致因模型(LCM)原因因素定义与事故致因“2-4”模型(24Model)存在的异同和优缺点,梳理2个模型各层面原因和结果的定义,对比定义内容及其对事故原因分析等安全实务的指导作用,并以一起瓦斯爆炸事故为例加以实证分析,获得二者分析结果之间的差异。研究结果表明:LCM是首个将管理因素纳入事故致因分析的一维事件序列模型,可明确各层面原因因素的定义和因素间的逻辑关系,但部分定义存在交叉重复的问题,并没有揭示安全工作指导思想等深层次事故致因因素;24Model作为系统性事故致因模型,对各类因素的定义均以组织为主体,描述事件、事故、安全的概念内涵,划分个体安全动作、安全能力和组织安全管理体系的类别并给出含义解析,探究组织安全文化层面的问题并以32个元素体现;2个模型的事故原因分析方法均建立在对各层级原因因素定义的基础上,并适用于模型理论体系本身。 展开更多
关键词 “2-4”模型(24model) 损失致因模型(LCM) 事故致因模型 原因因素定义 对比研究
下载PDF
Delphi与Multi-tiered应用开发
19
作者 李剑宇 周伟光 +1 位作者 唐利强 杨兴萍 《湘潭师范学院学报(自然科学版)》 2002年第3期41-44,共4页
概述了数据库应用技术的发展历程。介绍了三层应用的结构及优点。以开发工具Delphi为例阐述了三层应用的工作原理与开发。
关键词 分布式数据库系统 MIDAS multi-tiered APPLICATIONS DELPHI 三层应用结构 系统开发
下载PDF
Performance Evaluation Approach for Multi-Tier Cloud Applications
20
作者 Arshdeep Bahga Vijay K. Madisetti 《Journal of Software Engineering and Applications》 2013年第2期74-83,共10页
Complex multi-tier applications deployed in cloud computing environments can experience rapid changes in their workloads. To ensure market readiness of such applications, adequate resources need to be provisioned so t... Complex multi-tier applications deployed in cloud computing environments can experience rapid changes in their workloads. To ensure market readiness of such applications, adequate resources need to be provisioned so that the applications can meet the demands of specified workload levels and at the same time ensure that service level agreements are met. Multi-tier cloud applications can have complex deployment configurations with load balancers, web servers, application servers and database servers. Complex dependencies may exist between servers in various tiers. To support provisioning and capacity planning decisions, performance testing approaches with synthetic workloads are used. Accuracy of a performance testing approach is determined by how closely the generated synthetic workloads mimic the realistic workloads. Since multi-tier applications can have varied deployment configurations and characteristic workloads, there is a need for a generic performance testing methodology that allows accurately modeling the performance of applications. We propose a methodology for performance testing of complex multi-tier applications. The workloads of multi-tier cloud applications are captured in two different models-benchmark application and workload models. An architecture model captures the deployment configurations of multi-tier applications. We propose a rapid deployment prototyping methodology that can help in choosing the best and most cost effective deployments for multi-tier applications that meet the specified performance requirements. We also describe a system bottleneck detection approach based on experimental evaluation of multi-tier applications. 展开更多
关键词 PERFORMANCE modeling Synthetic WORKLOAD BENCHMARKING multi-tier APPLICATIONS CLOUD Computing
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部