共查询到20条相似文献,搜索用时 317 毫秒
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轻质墙板作为一种节能型绿色建材,其建筑功能达到保温隔垫性能优良、轻质高强的要求,便于机械化施工。以粉煤灰和煤矸石为主要原料的轻质墙板,既充分利用工业废渣又保护生态环境。但由于我国建筑业长期以来使用粘土实心砖,加之装卸式建筑和毛坯房建筑模式尚未普及,因而对使用轻质墙板的需求不旺。近几年在国家墙改政策推动下,轻质墙板的使用率已上升为26%, 相似文献
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目前与钢结构住宅结构体系相配套的围护体系不完善,尤其是墙体材料问题,目前市场上墙体材料、种类及品牌不少,多数是在原有钢筋混凝土结构体系上围护材料的转型,主要分析了围护墙板体系的特点及其在钢结构住宅中的应用。 相似文献
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作为以工业化和标准化代替传统生产与施工方式的建筑类型,装配式建筑目前在土地节约、材料节约、能源节约方面具有极强优势,对实现建筑业绿色化具有推进作用。轻质墙板作为其中最关键的部件,不仅质量轻、便于施工,还具有防火、耐冲击、保温等有点。但由于发展起步较晚,各方面还不够成熟,导致在实际运用过程中还存在一些问题。从墙板类型研究着手,分析了轻质墙板在建筑施工中的主要优势,发现其能有效提升工作效率,保证建筑质量,达到绿色环保目的,文章提出按照基本流程进行安装的策略,以推动整个产业发展,促进建筑业转型升级。 相似文献
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近几年来,青岛市各种新型建材产品发展很快,利用工业废渣生产的各种砌块和墙板等,在建筑安装后,衔接部位和部分面层经常产生裂缝。这已成为建筑的几种常见病,这种现象对新型建筑材料企业、施工单位、建设单位和住宅业主都产生诸多负面影响,甚至影响新型建材企业的生产和销售及推广应用。 相似文献
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本文从新的视角,应用因子分析与聚类分析复合模型研究市场细分和市场开拓问题。首先分析因子分析与聚类分析复合模型的应用研究现状,得出该模型在市场细分中应用的可行性。然后以移动通信行业为实证研究对象,通过设计Likert五级态度量表,对刚入校的大一学生开展抽样调查,了解新市场消费者对移动通信商及其产品的认知和态度。应用因子分析对多个观测变量进行降维,在此基础上,以公共因子和因子得分为依据,应用K—Means聚类分析法对样本进行聚类和市场细分,提出对移动通信服务商选择目标市场和进行新市场开拓的策略建议。 相似文献
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针对烟草配送中心存取作业系统所存在的问题,结合烟草存取特性,构建复合式存取作业模式。研究将多层穿梭式存取设备应用于烟草配送中心存取作业,并对其进行存取能力分析,以此跟传统的立体库进行对比,探讨基于多层穿梭式存取设备的复合式存取系统所具有的优势。 相似文献
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To understand changes in individuals' opinions and attitudes, it would be best to collect data through panels. Such panels, however, often cause irritation among respondents, resulting in low response rates and low response quality. We address whether this problem can be alleviated by designing a panel survey in an alternative way. For this purpose, we perform two field studies where we measure the effects of several panel design characteristics on response rates and response quality. These characteristics include the number of waves and the time between subsequent waves, which may be either fixed or random. Our findings suggest that response rates and response quality can be improved significantly by surveying at random time intervals. It is then crucial that panel members are not informed about the dates they will be surveyed, because in this case, respondents are less likely to develop expectations as to when they will be surveyed again. The methodology we put forward can be used to improve the efficiency of a panel study by carefully calibrating the studies' panel design parameters. 相似文献
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利率按计算方法的不同可分为单利和复利,对固定时间段内,不同计息方式下利息的计算,进行分析,构造数学函数,得到利息,从而求得在不同计息方式和计息期数下本利和的求法以及用其解决了实际经济生活中的一些问题。 相似文献
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A smoothed maximum score estimator for the binary choice panel data model with an application to labour force participation 总被引:1,自引:0,他引:1
In a binary choice panel data model with individual effects and two time periods, Manski proposed the maximum score estimator based on a discontinuous objective function and proved its consistency under weak distributional assumptions. The rate of convergence is low ( N 1/3 ) and its limit distribution cannot easily be used for statistical inference. In this paper we apply the idea of Horowitz to smooth Manski's objective function. The resulting smoothed maximum score estimator is consistent and asymptotically normal with a rate of convergence that can be made arbitrarily close to N 1/2 , depending on the strength of the smoothness assumptions imposed. The estimator can be applied to panels with more than two time periods and to unbalanced panels. We apply the estimator to analyze labour force participation of married Dutch females. 相似文献
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能源紧缺是全世界特别是我国面临的一个很严峻的问题。轻质墙板的使用,是建筑节能的一项重要内容,文章介绍了一种新型的轻质墙体材料——中空内模金属网水泥隔墙。 相似文献
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Philip Hans Franses 《Statistica Neerlandica》2006,60(4):438-456
This paper reviews research issues in modeling panels of time series. Examples of this type of data are annually observed macroeconomic indicators for all countries in the world, daily returns on the individual stocks listed in the S&P500, and the sales records of all items in a retail store. A panel of time series concerns the case where the cross‐sectional dimension and the time dimension are large. Often, there is no a priori reason to select a few series or to aggregate the series over the cross‐sectional dimension. The use of, for example, a vector autoregression or other types of multivariate models then becomes cumbersome. Panel models and associated estimation techniques are more useful. Due to the large time dimension, one should however incorporate the time‐series features. And, the models should not have too many parameters to facilitate interpretation. This paper discusses representation, estimation and inference of relevant models and discusses recently proposed modeling approaches that explicitly aim to meet these requirements. The paper concludes with some reflections on the usefulness of large data sets. These concern sample selection issues and the notion that more detail also requires more complex models. 相似文献
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本文介绍了复合期权的基本概念及国内外研究情况,就复合期权理论在矿业工程投资决策中的应用进行了探讨,采用geske模型并结合实例对此进行了验证。研究表明,运用复合期权理论进行矿业工程投资决策,在某种程度上能更好地反映不确定性和管理灵活性的价值。 相似文献