Structural Adjustment of Oasis Agriculture in Xinjiang

Abstract

Xinjiang's oasis agriculture has made enormous strides over past decades. Structural adjustment of oasis agriculture sector has promoted production diversification. Xinjiang's oasis agriculture sector is entering a new era. The era means more adjustments in oasis agricultural and rural economic structure so as to realize the sustainable development of agriculture. By summing and analyzing the main problems in Xinjinag's oasis agricultural structure, such as raising farmer's income, industry structure within agriculture, rural urbanization, pressure coming from market, agricultural environment degradation, puts forward the thinking, director and countermeasures to adjust oasis agricultural structure.     

A hybrid approach using AHP–TOPSIS–entropy methods for sustainable ranking of structural materials

Nowadays, many countries are looking towards sustainability as a goal because our world has limited resources and serious environmental impacts. In the construction industry, the process of sustainable selection of structural material is considered one of the keys to achieve more sustainable construction. In this paper, the theories of decision making are utilised to develop an approach for evaluation and ranking the structural materials over their total life based on sustainability criteria using multi-attribute decision-making methods. One of them is Analytical Hierarchy Process which is utilised to build the problem hierarchical structure and assign weights of the predetermined sustainable factors. The other is Technique for Order Preference by Similarity to the Ideal Solution which is utilised to rank the structural materials within both each material life cycle phase and the complete material life cycle phases. The third is the concept of entropy by Shannon to evaluate the weight factor for each phase of material life cycle. The proposed approach presents an objective, systematic and comprehensive method for the sustainable ranking of materials that links between the structural element design and the sustainable selection of materials.     

成渝产业带产业结构的相似性及其结构转换力分析

利用数据方差，相关系数和相似系数指标对成渝产业带这一长江上游具有重要地位的经济区域进行了产业和结构特征分析。从产业部门相对变动的总体方差看，第一产业在国内生产总值中的份额变动幅度最大，即第一产业在国内生产总值的比重元首衡性最弱，第三产业次之，第二产业最小；     

Using structural equation modeling to investigate relationships among ecological variables

Structural equation modeling is an advanced multivariate statistical process with which a researcher can construct theoretical concepts, test their measurement reliability, hypothesize and test a theory about their relationships, take into account measurement errors, and consider both direct and indirect effects of variables on one another. Latent variables are theoretical concepts that unite phenomena under a single term, e.g., ecosystem health, environmental condition, and pollution (Bollen, 1989). Latent variables are not measured directly but can be expressed in terms of one or more directly measurable variables called indicators. For some researchers, defining, constructing, and examining the validity of latent variables may be the end task of itself. For others, testing hypothesized relationships of latent variables may be of interest. We analyzed the correlation matrix of eleven environmental variables from the U.S. Environmental Protection Agency's (USEPA) Environmental Monitoring and Assessment Program for Estuaries (EMAP-E) using methods of structural equation modeling. We hypothesized and tested a conceptual model to characterize the interdependencies between four latent variables-sediment contamination, natural variability, biodiversity, and growth potential. In particular, we were interested in measuring the direct, indirect, and total effects of sediment contamination and natural variability on biodiversity and growth potential. The model fit the data well and accounted for 81% of the variability in biodiversity and 69% of the variability in growth potential. It revealed a positive total effect of natural variability on growth potential that otherwise would have been judged negative had we not considered indirect effects. That is, natural variability had a negative direct effect on growth potential of magnitude –0.3251 and a positive indirect effect mediated through biodiversity of magnitude 0.4509, yielding a net positive total effect of 0.1258. Natural variability had a positive direct effect on biodiversity of magnitude 0.5347 and a negative indirect effect mediated through growth potential of magnitude –0.1105 yielding a positive total effects of magnitude 0.4242. Sediment contamination had a negative direct effect on biodiversity of magnitude –0.1956 and a negative indirect effect on growth potential via biodiversity of magnitude –0.067. Biodiversity had a positive effect on growth potential of magnitude 0.8432, and growth potential had a positive effect on biodiversity of magnitude 0.3398. The correlation between biodiversity and growth potential was estimated at 0.7658 and that between sediment contamination and natural variability at –0.3769.     

Cervical musculoskeletal disorders and their relationships with personal and work-related factors among electronic assembly workers

IntroductionElectronics assembly workers are reported to have a high prevalence of musculoskeletal disorders (MSDs). This study investigated the prevalence of cervical MSDs and the complex relationships between cervical MSDs and individual, physical, psychosocial factors among electronics assembly workers. Methods: In this cross-sectional survey, self-administered questionnaires from 700 workers in electronics manufacturing workshops were analysed. Information concerning musculoskeletal symptoms, personal and work-related factors was collected. Finally, the prevalence of cervical MSDs was computed for different subgroups, and the relationships with different factors were analyzed using logistic regression and structural equation modeling (SEM). Results: The total 12 month prevalence of cervical MSDs among the survey population was 29.4%. Variables of gender, job tenure, twisting head frequently, neck flexion/extension for long time and work required to be done quickly showed significant associations with MSDs in a multivariate logistic regression (P < 0.05). The SEM analysis showed moderate and significant correlations between postural load (γ = 0.279), gender (γ = 0.233) and cervical MSDs, while there were weak but significant correlations between vibration (γ = 0.024), work stress (γ = 0.126), job tenure (γ = 0.024) and cervical MSDs. Both work stress and vibration affected the MSDs indirectly through postural load. Conclusions: The logistic regression results support previous general epidemiological MSD studies, and indicates that individual, physical, and psychosocial factors are related to cervical MSDs. The SEM provides a better approximation of the complexity of the relationship between risk factors and cervical MSDs. Improving awkward postures may be effective ways to control the influence of occupational stressors or vibration on MSDs. Practical Applications: The study is to improve prevention of MSDs among electronics assembly workers and promote their occupational health.     

基于ISM的油港集疏运作业安全风险分析

油港集疏运作业安全对油港运营安全管理至关重要。通过实地调研、访谈及问卷调查确定了油港集疏运作业安全风险因素;分析各因素间的直接影响关系,建立邻接矩阵和可达矩阵,构建了油港集疏运作业安全影响因素的解释结构模型;通过不同层级之间的关系分析,找出了油港集疏运作业过程中优先级较高的风险因素。结果表明,表层风险因素多为设备因素,中层风险因素集中于港内自身和港外环境因素,深层风险因素主要为人为因素和安全管理因素。     

基于物联网的塔式起重机安全监控系统

为减少塔式起重机事故的发生概率,顺应信息化监测技术迅速发展的行业背景,提出一套基于物联网的塔式起重机安全监控系统。首先设计塔式起重机安全监控系统架构,结合其结构特点提出传感器布置方案。然后针对结构安全和安拆作业程序安全2个方面,以国家强制性标准为依据设置监测指标、预警阈值和预警等级;最后结合实际工程项目对监控系统方案进行现场试验。研究表明:塔式起重机结构安全监测应覆盖结构应力、垂直度、风速等指标;安拆作业程序监测应覆盖顶升高度、顶升速度、套架倾角等指标;结合物联网的数据采集、传输和处理功能,可实时监控塔式起重机的结构和作业状态。     

基于TPB的通航企业事件信息自主上报意愿影响因素研究*

为探讨通航企业不安全事件信息自主上报意愿的影响因素,基于扩展计划行为理论的分析框架,采用结构方程模型和差异显著性分析,对我国通航企业170份样本数据进行分析。结果表明:企业性质、规模和成立年限显著影响企业事件信息报告行为意向。其中,国有企业行为意向显著高于民营企业,500人以上较大规模企业行为意向显著高于500人以下较小规模企业,成立3 a以上企业的行为意向显著高于成立3 a以下的企业。此外,通航企业不安全事件自主上报的行为意向直接影响因素包括行为态度、主观规范、知觉行为控制、感知成本及认知,间接影响因素是感知成本与感知收益、示范性规范与指令性规范。     

基于结构方程模型的认知性VDT作业过程解析*

为实现通过过程控制和管理提高认知性视觉显示终端（VDT）作业人员可靠性和绩效的目标,应用结构方程模型（SEM）研究作业过程表征方法。构建认知性VDT作业的信息加工过程模型,抽取13个基本认知动素（CT）,提出CT概念结构模型假设,设计外显指标测试题项,运用问卷调查样本数据构建结构方程和测量方程;对测量数据与结构方程模型的拟合度进行分析,并训练BP神经网络模式识别模型对作业过程进行还原检验。结果表明:认知性VDT作业过程模型有效,元认知控制其他12个CT的结构关系成立,认知性VDT作业过程可由包括元认知在内的13个基本CT解析。