期刊文献+
共找到271,198篇文章
< 1 2 250 >
每页显示 20 50 100
基于修正RMR分级法的金属矿山岩体稳定性分析
1
作者 刘震 《科技创新与应用》 2024年第11期143-146,共4页
焦家金矿寺庄矿区正逐步进入深部采矿,目前中深部采场存在稳固性较差的情况。结合寺庄矿区实际工程中地温、地下水及地应力的影响,对RMR分类法修正改进,提出IRMR分类法作为寺庄矿区岩体质量评级的方法。结果表明,主采的2号和7号矿体,从-... 焦家金矿寺庄矿区正逐步进入深部采矿,目前中深部采场存在稳固性较差的情况。结合寺庄矿区实际工程中地温、地下水及地应力的影响,对RMR分类法修正改进,提出IRMR分类法作为寺庄矿区岩体质量评级的方法。结果表明,主采的2号和7号矿体,从-280~-450 m深度大部分矿体为稳固性中等的Ⅲ岩体,仅部分区域存在稳固性较差的Ⅳ岩体。从IRMR法和RMR法结果对比中可以发现,大部分分级结果一致,仅一处工程IRMR分级为Ⅳ,结果更加合理。 展开更多
关键词 金属矿山 rmr Irmr 稳定性分析 质量评级
下载PDF
Fluorinated semi-interpenetrating polymer networks for enhancing the mechanical performance and storage stability of polymer-bonded explosives by controlling curing and phase separation rates
2
作者 Chao Deng Huihui Liu +1 位作者 Yongping Bai Zhen Hu 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第8期58-66,共9页
Herein, the effect of fluoropolymer binders on the properties of polymer-bonded explosives(PBXs) was comprehensively investigated. To this end, fluorinated semi-interpenetrating polymer networks(semiIPNs) were prepare... Herein, the effect of fluoropolymer binders on the properties of polymer-bonded explosives(PBXs) was comprehensively investigated. To this end, fluorinated semi-interpenetrating polymer networks(semiIPNs) were prepared using different catalyst amounts(denoted as F23-CLF-30-D). The involved curing and phase separation processes were monitored using Fourier-transform infrared spectroscopy, differential scanning calorimetry, a haze meter and a rheometer. Curing rate constant and activation energy were calculated using a theoretical model and numerical method, respectively. Results revealed that owing to its co-continuous micro-phase separation structure, the F23-CLF-30-D3 semi-IPN exhibited considerably higher tensile strength and elongation at break than pure fluororubber F2314 and the F23-CLF-30-D0 semi-IPN because the phase separation and curing rates matched in the initial stage of curing.An arc Brazilian test revealed that F23-CLF-30-D-based composites used as mock materials for PBXs exhibited excellent mechanical performance and storage stability. Thus, the matched curing and phase separation rates play a crucial role during the fabrication of high-performance semi-IPNs;these factors can be feasibly controlled using an appropriate catalyst amount. 展开更多
关键词 Semi-interpenetrating polymer networks FLUOROPOLYMER Curing rate Phase separation rate Polymer-bonded explosives
下载PDF
Rock Mass Quality Rating Based on the Multi-Criteria Grey Metric Space
3
作者 Miloš Gligoric Zoran Gligoric +3 位作者 Saša Jovanovic Suzana Lutovac Dragan Pamucar Ivan Jankovic 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第9期2635-2664,共30页
Assessment of rock mass quality significantly impacts the design and construction of underground and open-pit mines from the point of stability and economy.This study develops the novel Gromov-Hausdorff distance for r... Assessment of rock mass quality significantly impacts the design and construction of underground and open-pit mines from the point of stability and economy.This study develops the novel Gromov-Hausdorff distance for rock quality(GHDQR)methodology for rock mass quality rating based on multi-criteria grey metric space.It usually presents the quality of surrounding rock by classes(metric spaces)with specified properties and adequate interval-grey numbers.Measuring the distance between surrounding rock sample characteristics and existing classes represents the core of this study.The Gromov-Hausdorff distance is an especially useful discriminant function,i.e.,a classifier to calculate these distances,and assess the quality of the surrounding rock.The efficiency of the developed methodology is analyzed using the Mean Absolute Percentage Error(MAPE)technique.Seven existing methods,such as the Gaussian cloud method,Discriminant method,Mutation series method,Artificial neural network(ANN),Support vector machine(SVM),Grey wolf optimizer and Support vector classification method(GWO-SVC)and Rock mass rating method(RMR)are used for comparison with the proposed GHDQR method.The share of the highly accurate category of 85.71%clearly indicates compliance with actual values obtained by the compared methods.The results of comparisons showed that the model enables objective,efficient,and reliable assessment of rock mass quality. 展开更多
关键词 Rock mass rating MULTI-CRITERIA class metric space interval-grey numbers
下载PDF
基于RMR系统的气侵工况下井底压力控制
4
作者 张杰 余胜 +4 位作者 王芷桁 李鑫 孙瑞涛 张文镇 杨智均 《中国科技论文》 CAS 北大核心 2023年第1期1-9,共9页
为了更有效地控制钻井过程中的井底压力,确保钻井安全,以气液两相流理论为基础,建立了无隔水管海底泵举升(riserless mud recovery,RMR)系统在气侵工况下的井底压力计算模型。提出了3种流量调节方法,对流量调节后的井底压力变化过程进... 为了更有效地控制钻井过程中的井底压力,确保钻井安全,以气液两相流理论为基础,建立了无隔水管海底泵举升(riserless mud recovery,RMR)系统在气侵工况下的井底压力计算模型。提出了3种流量调节方法,对流量调节后的井底压力变化过程进行了动态模拟。结果表明:调节循环流量为30、40、50 L/s时,15 min时刻井底压力下降幅度分别为0.62、1.37、1.70 MPa;调节海底泵出口流量至17、20、23 L/s时,地层压力分别在10、11、14 min时刻得到平衡;增大钻井泵出口流量至32 L/s,调节海底泵出口流量为26、27 L/s时,地层压力分别在13.1、14.0 min时刻得到平衡。通过对数据进行拟合,得到了循环流量和海底泵出口流量与井底压力之间的关系方程,并形成了RMR系统在气侵工况下控制井底压力时的流量调节方法。 展开更多
关键词 rmr系统 气侵 流量调节 井底压力恒定
下载PDF
考虑采动影响的ACI-RMR法矿山巷道围岩质量分级研究 被引量:7
5
作者 葛伟杰 刘艳章 +3 位作者 秦绍兵 黄诗冰 肖一鸣 单梁 《有色金属工程》 CAS 北大核心 2023年第9期121-129,共9页
为了充分反映矿山开采过程中开采扰动对巷道围岩质量的影响,在传统岩体质量分级RMR法的基础上引入巷道埋深、巷道存续时间、巷道高跨比、巷道间柱宽度和分段高度等5个采动影响指标,构建采动影响巷道围岩质量分级指标体系。引入拉格朗日... 为了充分反映矿山开采过程中开采扰动对巷道围岩质量的影响,在传统岩体质量分级RMR法的基础上引入巷道埋深、巷道存续时间、巷道高跨比、巷道间柱宽度和分段高度等5个采动影响指标,构建采动影响巷道围岩质量分级指标体系。引入拉格朗日乘子法耦合层次分析法(AHP)和CRITIC法对各指标进行组合赋权,将该组合权重导入理想点法(IPM)构建考虑采动影响的AHP-CRITIC-IPM改进RMR法(ACI-RMR法),将ACI-RMR法应用于某金属矿山进路巷道围岩质量分级并与RMR法分级结果进行对比。结果表明:部分测点的ACI-RMR法分级结果较RMR法分级结果出现等级降低或相同等级评分值下降的情况,结合工程实际证明ACI-RMR法较RMR法更能反映开采扰动对巷道围岩质量的影响,为矿山安全生产与设计提供参考。 展开更多
关键词 采动影响 ACI-rmr 层次分析法 组合赋权 理想点法
下载PDF
Coal mine roof rating(CMRR),rock mass rating(RMR)and strata control:Carborough Downs Mine,Bowen Basin,Australia 被引量:4
6
作者 Martin Brook Bruce Hebblewhite Rudrajit Mitra 《International Journal of Mining Science and Technology》 SCIE EI CSCD 2020年第2期225-234,共10页
The rock mass rating(RMR)has been used across the geotechnical industry for half a century.In contrast,the coal mine roof rating(CMRR)was specifically introduced to underground coal mines two decades ago to link geolo... The rock mass rating(RMR)has been used across the geotechnical industry for half a century.In contrast,the coal mine roof rating(CMRR)was specifically introduced to underground coal mines two decades ago to link geological characterization with geotechnical risk mitigation.The premise of CMRR is that strength properties of mine roof rock are influenced by defects typical of coal measures stratigraphy.The CMRR has been used in longwall pillar design,roof support methods,and evaluation of extended cuts,but is rarely evaluated.Here,the RMR and CMRR are applied to a longwall coal mine.Roof rock mass classifications were undertaken at 67 locations across the mine.Both classifications showed marked spatial variability in terms of roof conditions.Normal and reverse faulting occur across the mine,and while no clear relationships exist between rock mass character and faulting,a central graben zone showed heterogeneous rock mass properties,and divergence between CMRR and RMR.Overall,the CMRR data fell within the broad envelope of results reported for extended cuts at Australian and U.S.coal mines.The corollary is that the CMRR is useful,and should not be used in isolation,but rather as a component of a strata control programme. 展开更多
关键词 Rock mass classification ROOF strength Coal MINE CMRR rmr BOWEN Basin
下载PDF
基于钻孔数据库和RMR法的露天矿非均匀性岩体质量参数表征及应用
7
作者 王圆文 丘永富 +4 位作者 杨天鸿 邓文学 李华 张紫瑞 刘洋 《金属矿山》 CAS 北大核心 2023年第6期192-199,共8页
露天矿边坡岩体质量评价对于边坡稳定性分析及开采方案设计具有重大意义,一般主要是分岩组、分区域选择代表性测点进行岩体质量分级,结合Hoek-Brown等经验方法确定岩体力学参数,这些经验方法精度低,误差大,且未充分利用实测数据,因此深... 露天矿边坡岩体质量评价对于边坡稳定性分析及开采方案设计具有重大意义,一般主要是分岩组、分区域选择代表性测点进行岩体质量分级,结合Hoek-Brown等经验方法确定岩体力学参数,这些经验方法精度低,误差大,且未充分利用实测数据,因此深入挖掘矿山实测的地质钻孔资料从中提取岩体结构信息进行岩体质量评价具有现实的工程意义。以司家营和研山铁矿西帮为研究对象,通过结构面半自动识别得到不同区域表面结构面信息;根据矿山含有钻孔岩芯描述文字的工程地质钻孔资料,采用3DMine建立地质钻孔数据库,建立基于钻孔编录的定量评价指标体系,从文字描述中提取评价参数,结合地质统计学方法,建立基于RMR法的非均匀性岩体力学参数块体模型,实现了精细化岩体质量分级表征。研究表明:从浅部到深部坡表结构面的节理体密度越来越小,RMR值呈现上升趋势,说明西帮浅部到深部岩体质量越来越好,确保了后期西帮深部的安全开采,为边坡加陡及最终开采境界边坡的稳定性分析提供了参考依据。 展开更多
关键词 岩体质量评价 钻孔数据库 地质统计学 rmr块体模型
下载PDF
RMR分类在坝基岩体中的应用——基于巴基斯坦某水电站实例分析 被引量:1
8
作者 胡剑峰 张学东 +2 位作者 顾明刚 董晓阳 张震 《华北自然资源》 2023年第3期69-73,共5页
RMR分类法目前多用于海外项目中的岩体分类,主要通过6个参数的赋分计算,加和得到RMR分值,根据RMR分值对岩体进行分类,为设计提供相关地质参数。文章结合巴基斯坦某水电站实例,对RMR分类法的具体应用进行解释说明;通过与Q分类法、水电规... RMR分类法目前多用于海外项目中的岩体分类,主要通过6个参数的赋分计算,加和得到RMR分值,根据RMR分值对岩体进行分类,为设计提供相关地质参数。文章结合巴基斯坦某水电站实例,对RMR分类法的具体应用进行解释说明;通过与Q分类法、水电规范法进行对比,分析3种分类方法的差异与适用条件,以便满足不同工程的实际需求。 展开更多
关键词 rmr分类法 因子参数 参数建议值 水电规范法 Q分类法
下载PDF
基于N阶多项式回归方程的RMR分级方法优化 被引量:1
9
作者 吕冠颖 刘畅 +1 位作者 何环莎 郭泽洋 《矿冶》 CAS 2023年第4期6-11,共6页
为解决RMR岩体质量分级方法单一评价因素在某一特定强度值或完整性指标附近评分结果会呈现阶梯状突变的问题。利用N阶多项式回归方程,对RMR岩体质量分级体系中单轴抗压强度、点载荷强度、钻孔RQD指标和节理间距与评分体系之间的关系进... 为解决RMR岩体质量分级方法单一评价因素在某一特定强度值或完整性指标附近评分结果会呈现阶梯状突变的问题。利用N阶多项式回归方程,对RMR岩体质量分级体系中单轴抗压强度、点载荷强度、钻孔RQD指标和节理间距与评分体系之间的关系进行了非线性连续拟合,在此基础上优化了原评价体系。结果表明:优化后的RMR岩体质量分级方法消除了原评价体系中的局部突变,使评价结果具有连续性、客观性和现场适用性,该方法已为多个矿山的岩体质量工作评价提供了更为科学、准确的技术支撑和依据。 展开更多
关键词 岩体质量评价 rmr N阶多项式回归 优化研究
下载PDF
Prediction of rock mass rating using fuzzy logic and multi-variable RMR regression model 被引量:11
10
作者 Jalalifar H. Mojedifar S. Sahebi A.A. 《International Journal of Mining Science and Technology》 SCIE EI 2014年第2期237-244,共8页
Rock mass rating system (RMR) is based on the six parameters which was defined by Bieniawski (1989) [1]. Experts frequently relate joint and discontinuities and ground water conditions in linguistic terms with rou... Rock mass rating system (RMR) is based on the six parameters which was defined by Bieniawski (1989) [1]. Experts frequently relate joint and discontinuities and ground water conditions in linguistic terms with rough calculation. As a result, there is a sharp transition between two modules which create doubts. So, in this paper the proposed weights technique was applied for linguistic criteria. Then by using the fuzzy inference system and the multi-variable regression analysis, the accurate RMR is predicted. Before the performing of regression analysis, sensitivity analysis was applied for each of Bieniawski parameters. In this process, the best function was selected among linear, logarithmic, exponential and inverse func- tions and finally it was applied in the regression analysis for construction of a predictive equation. From the constructed regression equation the relative importance of the input parameters can also be observed. It should be noted that joint condition was identified as the most important effective parameter upon RMR. Finally, fuzzy and regression models were validated with the test datasets and it was found that the fuzzy model predicts more accurately RMR than reression models. 展开更多
关键词 Fuzzy set Fuzzy inference system Multi-variable regression Rock mass classification
下载PDF
基于深部岩体特征的RMR法修正 被引量:1
11
作者 汪炳锋 江铃峰 《采矿技术》 2023年第5期6-11,共6页
深部工程岩体具有高地应力、高温、高渗透压等特征,“三高”的存在和复杂节理面组合会对岩体质量造成不同程度的影响。因此,使用传统RMR法进行评价时,结果难免会不准确,需要根据深部岩体特性对RMR法进行修正。通过引入高应力修正系数KS... 深部工程岩体具有高地应力、高温、高渗透压等特征,“三高”的存在和复杂节理面组合会对岩体质量造成不同程度的影响。因此,使用传统RMR法进行评价时,结果难免会不准确,需要根据深部岩体特性对RMR法进行修正。通过引入高应力修正系数KS、节理组合修正系数KJ、高温效应修正系数KT、高渗透压修正系数KP对RMR法进行修正,建立S-RMR法,并运用于白音呼布矿区的岩体质量评价。结果表明:地应力对于深部岩体质量评价结果影响最大;用修正后的RMR法评价得出的岩体质量等级有所下降,根据矿区现有的支护效果可知修正后的RMR法的评价结果更准确。 展开更多
关键词 深部岩体 岩体质量评价 rmr
下载PDF
Inflatable rock bolt bond strength versus rock mass rating (RMR): A comparative analysis of pull-out testing data from underground mines in Nevada 被引量:3
12
作者 Barnard Chase Kallu Raj R. +1 位作者 Warren Sean Thareja Rahul 《International Journal of Mining Science and Technology》 SCIE EI CSCD 2016年第1期19-22,共4页
The purpose of this paper is to establish confidence in anticipated minimum bond strength for inflatable rock bolts by comparing the bond strength to variable geotechnical conditions using the rock mass rating (RMR)... The purpose of this paper is to establish confidence in anticipated minimum bond strength for inflatable rock bolts by comparing the bond strength to variable geotechnical conditions using the rock mass rating (RMR) system. To investigate a correlation between these parameters, the minimum bond strength of pull-out tested inflatable rock bolts was compared to the RMR of the rock in which these bolts were placed. Bond strength vs. RMR plots indicate that expected minimum bond strength is positively corre- lated with RMR; however, the correlation is not strong. Cumulative percent graphs indicate that 97~; of pull-out tests result in a minimum bond strength of 3.3 and 1.7 ton/m in RMR/〉 45 and 〈45, respectively. Although lower bond strengths are more commonly encountered in low RMR ground, high bond strengths are possible as well, yielding higher variability in bond strengths in low RMR ground. Bond strength of friction bolts relies on contact between the rock bolt and drill hole. Experience in Nevada indicates that RMR is known to affect both the quality and consistency of drill holes which likely affects bond strength. Drilling and bolting in low RMR ground is more sensitive to drilling and bolting practices, and strategies for maximizing bond strength in these conditions are discussed. 展开更多
关键词 Rock mass ratingrmrRock boltPull-out testBond strength
下载PDF
Comparative Analysis of Building Rating Systems and Occupant Rating Systems
13
作者 Rana Al Kady Salah El-Haggar Ahmed El-Gendy 《Journal of Environmental Protection》 CAS 2023年第4期285-296,共12页
To begin with, rating systems are a beneficial tool in determining the efficiency of a building’s ability to utilise its resources effectively. In this study, the two elements under comparison are the Building Rating... To begin with, rating systems are a beneficial tool in determining the efficiency of a building’s ability to utilise its resources effectively. In this study, the two elements under comparison are the Building Rating Systems (BRSs) and Occupant Rating Systems (ORSs). The main objective of this paper is to be able to examine the most commonly applied international and national BRS and ORS and, based on that, discover the possibility of developing an integration of both the BRS and ORS into one rating system. Quite simply, a BRS is a method by which buildings are assessed and given a score based on numerous features such as the efficiency of each of the services, total energy consumption, and alternate options of consumption. There are various BRSs that are implemented globally, each with its own set of criteria and specifications. Thus, based on the analysis of the benefits and drawbacks of both types of rating systems, it could be deduced that a well-rounded rating system with all technical and non-technical aspects combined would be beneficial to both the efficiency of the building as well as the building occupants’ health and well-being. 展开更多
关键词 Building rating Systems Energy Efficiency Net-Zero Buildings OCCUPANCY rating Systems Renewable Energy Technologies
下载PDF
Exploring the thermal stability of lithium-ion cells via accelerating rate calorimetry:A review
14
作者 Dongxu Ouyang Mingyi Chen +3 位作者 Jingwen Weng Kuo Wang Jian Wang Zhirong Wang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2023年第6期543-573,I0012,共32页
Given the importance of lithium-ion cell safety,a comprehensive review on the thermal stability of lithium-ion cells investigated by accelerating rate calorimetry(ARC),is provided in the present work.The operating mec... Given the importance of lithium-ion cell safety,a comprehensive review on the thermal stability of lithium-ion cells investigated by accelerating rate calorimetry(ARC),is provided in the present work.The operating mechanism of ARC is discussed first,including the usage and the reaction kinetics.Besides that,the thermal stability of the cathode/anode materials at elevated temperatures is revealed by examining the impacts of some significant factors,i.e.,the lithium content,particle size,material density,lithium salt,solvent,additive,binder and initial heating temperature.A comparison of the common cathode materials indicates that the presence of Mn and polyanion could significantly enhance the thermal stability of cathode materials,while the doping of Al also helps to restrain the reactivity.Except for their high capacity,some alloy materials demonstrate more competitive safety than traditional carbon anode materials.Furthermore,the thermal behaviors of full cells under abusive conditions are reviewed here.Due to the sensitivity of ARC to the kinetic parameters,a reaction kinetic modeling can be built on the basis of ARC profiles,to predict the thermal behaviors of cell components and cells.Herein,a shortcircuit modeling is exampled. 展开更多
关键词 Accelerating rate calorimetry Electrode materials Full cells SAFETY MODELING
下载PDF
SCIM: Incorporating secure communication and interference management in one operation
15
作者 Zhao Li Pintian Lyu +3 位作者 Jun Li Zhixian Chang Jia Liu Zheng Yan 《Digital Communications and Networks》 SCIE CSCD 2023年第2期512-522,共11页
Due to the broadcast nature of wireless communications,users’data transmitted wirelessly is susceptible to security/privacy threats.Meanwhile,as a result of the limitation of spectrum resources,massive wireless conne... Due to the broadcast nature of wireless communications,users’data transmitted wirelessly is susceptible to security/privacy threats.Meanwhile,as a result of the limitation of spectrum resources,massive wireless connections will incur serious interference,which may damage the efficiency of data transmission.Therefore,improving both efficiency and secrecy of data transmission is of research significance.In this paper,we propose a wireless transmission scheme by taking both Secure Communication(SC)and Interference Management(IM)into account,namely SCIM.With this scheme,an SCIM signal is generated by the legitimate transmitter(Tx)and sent along with the desired signal,so that the SCIM signal can interact with and suppress the environmental interference at the legitimate receiver(Rx).Meanwhile,the SCIM signal may interfere with the eavesdropper in the coverage of legitimate transmission so as to deteriorate the eavesdropping performance.Therefore,the secrecy of desired transmission is improved.In this way,both the transmission efficiency and privacy are enhanced.Then,by taking various transmission preferences into account,we develop different implementations of SCIM,including Interference Suppression First SCIM(ISF-SCIM),Data Transmission First SCIM(DTF-SCIM),Anti-Eavesdropping First SCIM(AEF-SCIM),and Secrecy Rate Maximization SCIM(SRM-SCIM).Our in-depth simulation results have shown the proposed methods to effectively improve the efficiency and secrecy of the legitimate transmission. 展开更多
关键词 Physical-layer security Secure communication Anti-eavesdropping Interference management Secrecy rate
下载PDF
The laparoscopic rating scale for the evaluation of working conditions for surgical treatment of super-obesity
16
作者 Oral Ospanov 《Laparoscopic, Endoscopic and Robotic Surgery》 2023年第2期78-82,共5页
In this technical note,a novel rating scale(abdominal integral index)was introduced for assessing the conditions of the working laparoscopic space based on linear measurements to select the optimal one or two-stage su... In this technical note,a novel rating scale(abdominal integral index)was introduced for assessing the conditions of the working laparoscopic space based on linear measurements to select the optimal one or two-stage surgical treatment for super-obesity.Patients with the same height and similar BMI values had different rating scale scores,reflecting different conditions of laparoscopic bariatric surgery.The rating scale helps surgeons and patients make a safe option for surgery,depending on the experience of the surgeon and technical laparoscopic conditions. 展开更多
关键词 Bariatric surgery Laparoscopic rating scale Surgical working conditions SUPER-OBESITY
下载PDF
Design of Online Vitals Monitor by Integrating Big Data and IoT
17
作者 E.Afreen Banu V.Rajamani 《Computer Systems Science & Engineering》 SCIE EI 2023年第3期2469-2487,共19页
In this work,we design a multisensory IoT-based online vitals monitor(hereinafter referred to as the VITALS)to sense four bedside physiological parameters including pulse(heart)rate,body temperature,blood pressure,and... In this work,we design a multisensory IoT-based online vitals monitor(hereinafter referred to as the VITALS)to sense four bedside physiological parameters including pulse(heart)rate,body temperature,blood pressure,and periph-eral oxygen saturation.Then,the proposed system constantly transfers these signals to the analytics system which aids in enhancing diagnostics at an earlier stage as well as monitoring after recovery.The core hardware of the VITALS includes commercial off-the-shelf sensing devices/medical equipment,a powerful microcontroller,a reliable wireless communication module,and a big data analytics system.It extracts human vital signs in a pre-programmed interval of 30 min and sends them to big data analytics system through the WiFi module for further analysis.We use Apache Kafka(to gather live data streams from connected sen-sors),Apache Spark(to categorize the patient vitals and notify the medical pro-fessionals while identifying abnormalities in physiological parameters),Hadoop Distributed File System(HDFS)(to archive data streams for further analysis and long-term storage),Spark SQL,Hive and Matplotlib(to support caregivers to access/visualize appropriate information from collected data streams and to explore/understand the health status of the individuals).In addition,we develop a mobile application to send statistical graphs to doctors and patients to enable them to monitor health conditions remotely.Our proposed system is implemented on three patients for 7 days to check the effectiveness of sensing,data processing,and data transmission mechanisms.To validate the system accuracy,we compare the data values collected from established sensors with the measured readouts using a commercial healthcare monitor,the Welch Allyn®Spot Check.Our pro-posed system provides improved care solutions,especially for those whose access to care services is limited. 展开更多
关键词 Big data analytics blood pressure body temperature physiological parameters pulse rate sensors SPO2
下载PDF
The Impact of Credit Ratings on Financial Performance (ROA) and Value Creation (Tobin’s Q)
18
作者 Nazário Augusto de Oliveira Leonardo Fernando Cruz Basso 《Chinese Business Review》 2023年第2期69-85,共17页
This study employs a bibliometric and systematic approach to examine the impact of credit ratings as a measure of financial performance for companies listed in the S&P 500 index.The study identified a knowledge ga... This study employs a bibliometric and systematic approach to examine the impact of credit ratings as a measure of financial performance for companies listed in the S&P 500 index.The study identified a knowledge gap as only two researches were found,one suggesting and another using credit ratings to measure financial performance.Most researches use leverage,profitability,liquidity,and Share Return measures to explain financial performance.The empirical analysis uses the data of 2,398 observations of 240 companies rated by S&P Global Ratings for the period 2009-2013,applying a Generalized Method of Moments(GMM)methodology to estimate the models due to its ability to address potential endogeneity issues.The study considers Return on Assets(ROA)and Tobin’s Q as dependent variables.It incorporates credit ratings(CRWLTA)along with variables such as Total Debt to Total Assets(TDTA),Total Shareholder Return(TSR),EBITDA Interest coverage(EBITDAICOV),Quick Ratio(QR),Altman’s Z-Score(AZS),as well as macroeconomic factors like Gross Domestic Product(GDP)growth,inflation(Consumer Price Index-CPI),and the Federal Reserve Interest Rate(FDRI)as independent variables.The study argues that credit ratings,which incorporate historical data and confidential information about companies’strategies,provide reliable forward-looking creditworthiness assessments to the market.It is supported by specialized rating agencies that employ their methodologies.However,the findings suggested that CRWLTA,had a negative relationship with Q Tobin,although it was not statistically significant,and a negative relationship with ROA that was on the verge of significance. 展开更多
关键词 credit ratings financial performance risk management
下载PDF
Prediction of film ratings based on domain adaptive transfer learning
19
作者 舒展 DUAN Yong 《High Technology Letters》 EI CAS 2023年第1期98-104,共7页
This paper examines the prediction of film ratings.Firstly,in the data feature engineering,feature construction is performed based on the original features of the film dataset.Secondly,the clustering algorithm is util... This paper examines the prediction of film ratings.Firstly,in the data feature engineering,feature construction is performed based on the original features of the film dataset.Secondly,the clustering algorithm is utilized to remove singular film samples,and feature selections are carried out.When solving the problem that film samples of the target domain are unlabelled,it is impossible to train a model and address the inconsistency in the feature dimension for film samples from the source domain.Therefore,the domain adaptive transfer learning model combined with dimensionality reduction algorithms is adopted in this paper.At the same time,in order to reduce the prediction error of models,the stacking ensemble learning model for regression is also used.Finally,through comparative experiments,the effectiveness of the proposed method is verified,which proves to be better predicting film ratings in the target domain. 展开更多
关键词 prediction of film rating domain adaptive transfer component analysis(TCA) correlation alignment(CORAL) stacking
下载PDF
Aspect Level Songs Rating Based Upon Reviews in English
20
作者 Muhammad Aasim Qureshi Muhammad Asif +4 位作者 Saira Anwar Umar Shaukat Atta-ur-Rahman Muhammad Adnan Khan Amir Mosavi 《Computers, Materials & Continua》 SCIE EI 2023年第2期2589-2605,共17页
With the advancements in internet facilities,people are more inclined towards the use of online services.The service providers shelve their items for e-users.These users post their feedbacks,reviews,ratings,etc.after ... With the advancements in internet facilities,people are more inclined towards the use of online services.The service providers shelve their items for e-users.These users post their feedbacks,reviews,ratings,etc.after the use of the item.The enormous increase in these reviews has raised the need for an automated system to analyze these reviews to rate these items.Sentiment Analysis(SA)is a technique that performs such decision analysis.This research targets the ranking and rating through sentiment analysis of these reviews,on different aspects.As a case study,Songs are opted to design and test the decision model.Different aspects of songs namely music,lyrics,song,voice and video are picked.For the reason,reviews of 20 songs are scraped from YouTube,pre-processed and formed a dataset.Different machine learning algorithms—Naïve Bayes(NB),Gradient Boost Tree,Logistic Regression LR,K-Nearest Neighbors(KNN)and Artificial Neural Network(ANN)are applied.ANN performed the best with 74.99%accuracy.Results are validated using K-Fold. 展开更多
关键词 Machine learning natural language processing songs reviews:sentiment analysis songs rating aspect level sentiment analysis reviews analysis text classification MUSIC
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部