Improvement of agility and sustainability: A case study in an Indian rotary switches manufacturing organisation

Increasing competition has been forcing the modern manufacturing organisations to adopt advanced manufacturing paradigms. Agile Manufacturing (AM) is an advanced manufacturing paradigm that enables an organisation to survive in the competitive business environment. Agility is the performance measure of AM practices. Simultaneously, modern business organisations are forced to evolve environmental friendly products. Sustainability is regarded as an important concept for survival by the modern organisations. In this context, agility and sustainability are regarded as performance measures for contemporary organisations. This paper reports a case study which has been carried out in an Indian rotary switches manufacturing organisation. The candidate product is the knob of rotary switch. Initially Computer Aided Design (CAD) has been used to digitalise the baseline model. Keeping the baseline model as reference, five new knob models have been evolved. Then the sustainability analysis has been carried out to determine the environmental impact of the knob models. The analysis results indicated that the proposed knob models possess minimal environmental impact. The conduct of case study has lead to an inference that there is a significant improvement of agility and sustainability in the design and development of knob of rotary switch.     

Statistical forecast models for daily air particulate iron and lead concentrations for Madrid,Spain

Statistical models that estimate the daily concentrations of air-particulate Fe and Pb (which are linked to natural and anthropogenic sources, respectively) in a semi-urban area of Madrid, Spain, have been specified. State-space modeling, coupled with Kalman filtering, and Box-Jenkins (transfer function and ARIMA) modeling has been used. Wind speed, which is related to the atmospheric diffusion, has been selected as an exogenous variable for the state-space and transfer function models. The adaptive state-space models do not seem to perform significantly better than the transfer function models but clearly do better than ARIMA models. One-day-lagged wind s̀peed and the persistence were the most important inputs for the proposed Fe and Pb concentration models. However, the predictions of daily Fe particle concentration appears to be better than those of Pb. The performance of the adaptive state-space models suggests that this kind of modeling can be suitable for particulate matter air quality forecasting.     

Model-Based Tampering for Improved Process Performance—An Application to Grinding of Shafts

This paper presents the model-based tampering (MBT) methodology to address performance degradation in complex nonlinear processes. MBT involves characterizing the dynamics of a process through experiments to derive nonlinear stochastic differential equation (n-SDE) models that can accurately and compactly represent a process, and using these models to dynamically compensate for the effects of process degradation on the performance. This research has yielded a new method to derive n-SDE models of complex processes through a signal-based reconstruction of Fokker-Planck equations.MBT was applied to control surface finish during cylindrical grinding of shafts of air bearings used in aircraft environmental control systems (ECS)—a core competency of Honeywell. It has been shown that n-SDE models help capture patterns in process outputs that cannot be captured using any simpler models, and that MBT reduces the surface finish variation by 62% over the current industry practice.     

非点源污染模型AnnAGNPS在三峡库区林农复合小流域模拟效果评定

应用连续农业非点源污染AnnAGNPS模型(Annualized AGricultural NonPoint Source Model)模拟三峡库区林农复合小流域的径流、泥沙和营养物输出,以2003年和2004年的小流域观测数据对模型分别进行校准和验证,并以统计参量决定系数(R2)、Nash-Sutcliffe效率系数(E)和相对误差(VE)对模拟结果进行评定.结果表明,径流量模型模拟结果误差在可接受范围之内,模型校准期模拟值VE值为5.0%(R2=0.93,p<0.05),验证期内模型VE值为6.7%(R2=0.90,p<0.05);与径流模拟比较,泥沙模拟结果精度较低,校准期内模型VE值为15.1%(R2=0.63,p<0.05),验证期内模型VE值为26.7%(R2=0.59,p<0.05);次降水较小,产生径流和泥沙较少时,模型模拟值则偏高,反之则偏低.氮输出模拟决定系数R2值0.68(p<0.05),略高于磷输出模拟决定系数(R2=0.65,p<0.05).模型对径流输出的模拟精度高于对泥沙和营养物的输出模拟.在三峡库区农林复合小流域应用AnnAGNPS模型模拟农业非点源污染输出满足流域管理要求.     

Predicted and measured concentrations of traffic carbon monoxide over Delhi

Carbon monoxide concentration due to vehicular traffic in urban Delhi has been computed by using an analytical dispersion model (IITCO), Pollution Episodic Model (PEM) and Intersection Midblock Model (IMM). While IITCO has been developed in IIT, the other two are operational models in the U.S.A. Computations from models are compared with observations collected at ITO, Janpath, Nazafgarh and Townhall. On-site measurements of CO are taken by using real time analyzers and meteorological parameters are obtained from a micrometeorological tower at IIT Delhi. The model results compare well with observations. The performance of IITCO is compared with PEM and IMM and found to be quite satisfactory. The diurnal variation of concentration is also found to be in good agreement with the diurnal variation of traffic volume.     

降雨时间分辨率对SWAT水文模拟的影响

分别基于13个雨量站的日降雨量和小时降雨量,在率水流域建立SWAT（Soil and Water Assessment Tool）水文模型,对基于不同降雨时间分辨率的SWAT模型进行独立的参数率定和验证,在此基础上分析降雨时间分辨率对率水流域SWAT模拟性能的影响.结果表明,降雨输入的时间分辨率对率水流域SWAT模型的水文模拟性能有显著影响.小时降雨输入SWAT模型的纳什系数（NSE）和决定系数（R²）在率定期分别为0.89、0.90,在验证期分别为0.86、0.88,均显著高于日降雨输入SWAT模型对应的模型评价统计量值.究其原因,小时降雨输入SWAT模型对于峰值流量的模拟要明显优于日降雨输入SWAT模型.建议应在不同气候与自然环境条件的流域内开展类似的降雨时间分辨率对水文模型模拟性能的影响研究.     

降雨时间分辨率对SWAT水文模拟的影响

分别基于13个雨量站的日降雨量和小时降雨量,在率水流域建立SWAT（Soil and Water Assessment Tool）水文模型,对基于不同降雨时间分辨率的SWAT模型进行独立的参数率定和验证,在此基础上分析降雨时间分辨率对率水流域SWAT模拟性能的影响.结果表明,降雨输入的时间分辨率对率水流域SWAT模型的水文模拟性能有显著影响.小时降雨输入SWAT模型的纳什系数（NSE）和决定系数（R²）在率定期分别为0.89、0.90,在验证期分别为0.86、0.88,均显著高于日降雨输入SWAT模型对应的模型评价统计量值.究其原因,小时降雨输入SWAT模型对于峰值流量的模拟要明显优于日降雨输入SWAT模型.建议应在不同气候与自然环境条件的流域内开展类似的降雨时间分辨率对水文模型模拟性能的影响研究.     

生物滴滤净化VOCs进展

生物滴滤净化挥发性有机污染物技术是近年来发展起来的一项新技术。介绍了生物滴滤技术的研究现状 ,包括净化机理 ,可以净化的污染物 ,起降解作用的微生物和它们需要的环境条件 ,及生物滴滤模型。目前生物滴滤技术在以下几方面需要完善和发展 :提高微生物的降解能力 ,改进生物滴滤填料 ,完善生物滴滤模型和开展实际废气的应用研究。     

北京市空气质量动态统计预报系统

简要介绍了北京市空气质量动态统计预报系统的构成、特点,以及所采用的线性回归模型LRM,分类判别树CART模型,CART与LRM结合的模型,动态统计预报模型DSM,多点预报模型MPDSM 5种预报模型,分析了不同预报模型的特点和性能.所建立的动态统计预报模型DSM有良好的预报性能,减小了在高污染季节的预报误差;多点空气质量动态预报模型也具有较好的预报性能.      

厌氧附着膜膨胀床(AAFEB)反应器稳态运行的过程动力学

从AAFEB反应器运行工况特点和全混合活性污泥动力学的理论出发,建立了AAFEB反应器稳态运行的过程动力学模型。并作了动力学模型参数估值、灵敏度分析,模型检验,以及运行参数影响的动力学模拟.     

Development and environmental improvements of plastics for hydrophilic catheters in medical care: an environmental evaluation

Single-use medical devices have been under close scrutiny for several years, especially the choice of plastic materials. Many different requirements such as medical safety, treatment functionality and efficiency, environmental performance, etc. have to be fulfilled. Today, the most commonly used materials for hydrophilic urinary catheters are polyvinylchloride (PVC) and thermoplastic polyurethane (TPU). In this research study, these two materials' environmental performance was evaluated. In light of the knowledge gained in that study a new plastic material for use in urinary catheters was developed. The aim of the development of this new material was to design a high performance material with superior environmental performance. The newly developed plastic material is a polyolefin-based elastomer. The ecological environmental performance of the new material was evaluated and compared to the existing plastic materials. The study focused exclusively on the choice of plastic materials and their ecological environmental performance.The analysis has been performed using a system perspective and a life cycle assessment (LCA) methodology. The functional unit has been set to the treatment of one patient during one year. The results from the LCA models have been presented both in terms of direct inventory data, such as energy use and formed emissions, and in terms of the results from four different impact assessment methods. Analysis of the results based on direct inventory data, i.e. common inventory results such as energy resource uses and emissions of CO₂, NO_x and SO₂ show an overall better environmental performance for the new polyolefin-based elastomer compared to the existing PVC and TPU plastic materials. The normalization and weighting steps in the analyzes have indicated the importance of energy resource uses and global warming as indicator for the environmental performance even if other impact categories also can play a role. In the environmental impact assessment, the polyolefin-based elastomer showed a clearly better environmental performance than the TPU material. Compared to PVC plastic material the new polyolefin-based elastomer showed an almost equivalent environmental performance. This can be mainly explained by the different materials' energy use. The new material has thus also shown to be an environmentally good alternative to PVC if a PVC-free material is requested. Basing the plastic formula, on simple bulk plastics with low energy use in the production of single-use medical devices, has been shown to be a successful method of producing high quality products with superior environmental performance.     

Effects of magnetic field and rotary tool on EDM performance

In this work, the effects of tool rotation and various intensities of external magnetic field on electrical discharge machining (EDM) performance have been studied. Experimental trials divided into three regimes of low energy regime, middle energy regime and high energy regime. The influences of process parameters were investigated on main outputs of material removal rate (MRR) and surface roughness (SR). In order to correlate the input parameters and output values two mathematical models were developed to predict the MRR and SR according to variations of discharge energy, magnetic field intensity and tool rotational speed. Results indicated that the applying a rotational magnetic field around the machining gap improves the MRR and SR. Combination of rotational magnetic field and rotary electrode increases the machining performance, in comparison of previous conditions. This is due to better flushing debris from machining gap. This work introduces a new method for improving the machining performance, in cost and time points of view.     

人工神经网络模型在水质预警中的应用研究进展

水质预警模型是大数据时代构建环境智能决策与管理体系的关键技术.近年来,水质自动化监测能力的提升以及测管协同对环境模型的强烈需求,激发了研究人员探索新的建模方法并努力提高模型预测性能.其中,人工神经网络(Artificial Neural Network, ANN)模型发展迅速.本文综述了3大类ANN模型的发展历史和模型结构特点,梳理了ANN模型在水质数据软测量、数据异常检测和时间序列预测等方面的研究进展,归纳了一般建模流程、技术建议和常用的模型性能指标,发现ANN模型的应用依赖于监测数据质量,存在模型可解释性差、模型运行硬件资源要求较高等不足,提出未来水质预警模型的研发思路和重点,需要加快推进水环境监测技术与预警模型的协同发展和业务化应用,通过多种应用场景检验实现技术迭代,形成大数据驱动的水质在线监测-智能预警-应急管理支撑体系,助力我国环境治理能力现代化.     

机器学习在材料服役性能预测中的应用

针对材料服役性能预测存在误差大、计算复杂、适用性差等问题,提出了基于数据挖掘的机器学习预测方法。首先阐述了机器学习的应用流程,并总结了常用模型原理及其在材料性能预测中的应用。然后采用多种机器学习模型对RPV钢的辐照性能进行预测,并通过Stacking集成方法提高了模型的预测精度。结果表明,机器学习可用于材料服役性能预测,具有较高的预测精度和可靠性。根据材料服役数据的不同特征选择合适的学习模型,同时进行模型融合和参数优化,可有效提高模型的预测精度及运算速度。     

蓝藻对重金属的生物吸附研究进展

生物吸附作为目前重金属废水处理中最有前途的方法之一,其吸附机理、吸附量影响因素、吸附模型、吸附工艺以及各种生物吸附剂的吸附特性等已被广泛研究。寻找对重金属具有特异性吸附与较强吸附能力的生物体是生物吸附领域的一个永恒课题。蓝藻是世界上分布最广的生物,本文较全面的介绍了蓝藻对重金属的吸附特性与基因工程在构建高吸附性能蓝藻方面的研究进展,并对生物吸附剂的开发应用前景作了展望。     

Roles of semivolatile and intermediate-volatility organic compounds in secondary organic aerosol formation and its implication: A review

Secondary organic aerosol(SOA) is a very important component of fine particulate matter(PM_2.5) in the atmosphere. However, the simulations of SOA, which could help to elucidate the detailed mechanism of SOA formation and quantify the roles of various precursors, remains unsatisfactory, as SOA levels are frequently underestimated. It has been found that the performance of SOA formation models can be significantly improved by incorporating the emission and evolution of semivolatile and ...     

Framework for environmental performance measurement in a Swedish public sector organization

Environmental performance measurements are an important component in strategies for achieving ecologically sustainable development. However, models and frameworks for performance measurement are primarily developed for business and may not be directly applicable to public organizations. This study aimed to contribute to the development of environmental performance measurement tools for public sector organizations by developing an appropriate framework. The study is based on a case study of the Swedish Rail Administration. The main method for data collection was focus group interviews. The proposed framework presents important features of an environmental performance measurement for the public sector and is illustrated by results from the case organization. The framework was constructed using the causal-chain framework pressure-state-response (PSR) and the management system management-by-objectives (MBO), respectively measuring and managing performance towards both strategic and operational objectives. An environmental management system serves as a toolbox, encompassing and coordinating the environmental objectives and the tools for performance measurement.     

Evaluating catchment-scale models for diffuse pollution policy support: some results from the EUROHARP project

The EU Framework V EUROHARP project evaluated the performance of a representative range of nutrient pollution tools used for policy support across a network of six representative catchments covering a north–south gradient in climate, hydrology, soils, and land use. The main objective was a detailed evaluation of model performance, strengths and weaknesses, and ranges of applicability. Model performance was assessed against measured data by an expert group. A range of models was tested and compared, including the EveNFlow model of daily flow and nitrate concentrations, and the PSYCHIC model of monthly total phosphorus loads.The outputs from the EUROHARP project have a number of important implications for the use of models to support diffuse pollution policy in the EU. The outcomes suggested that the policy support tools tested are capable of acceptable performance in modelling flows, nutrient concentrations and loads in five out of the six test catchments considered by the study. Results also demonstrated that diffuse pollution tools can be successfully applied to catchments where agricultural practices contrast markedly from those characterising the study areas underpinning the development of individual models. Such adaptability conveys significant benefits by demonstrating that some diffuse pollution tools have the flexibility required for demanding and strategic policy support purposes.     

古交矿区大气污染的模式预测及其与实测值的比较

本文采用商斯烟羽模式或变天气条件烟团模式(点源),结合ATDL模式(面源),预测了古交煤矿区域各关心位置的大气污染物(SO_2、尘等)的年均浓度,典型日浓度、最大小时浓度,并利用相关系数r、符合指数d等统计学指标与实测值作了统计比较,结果表明,模式基本可行,但计算日均浓度的体源烟团模式,其性能明显优于计算年均浓度的高斯烟羽模式。     

Accurate prediction of air quality response to emissions for effective control policy design

Designing effective control policy requires accurate quantification of the relationship between the ambient concentrations of O₃and PM_2.5and the emissions of their precursors.However,the challenge is that precursor reduction does not necessarily lead to decreases in the concentrations of O₃and PM_2.5,which are formed by multiple precursors under complex physical and chemical processes;this calls for the development of advanced model technologies to prov...