基于DEA方法的企业标准化效益评价

标准化产生的最主要效果是它的经济性。企业实施标准化的效益如何,怎样对其进行准确、客观的评价,是企业管理者和标准化工作者关注的重要问题之一。本文在分析了DEA方法及其特点的基础上,借助此方法,对企业标准化的有效性进行评价。并探讨了此方法对企业标准化效益评价的可行性和优越性,同时指出评价中应注意的重要问题。     

TFT-LCD industry performance analysis and evaluation using GRA and DEA models

In this study we propose a four-stage approach, which includes data envelopment analysis, Malmquist productivity index (MPI), entropy method and grey relation analysis (GRA), to investigate the operational performance of six thin film transistor liquid crystal display (TFT-LCD) companies in Taiwan during 2009–2012. The input variables are fixed assets, operating expenses, R&D expenses and number of employees, while the output variables are cash flow and net sales. The empirical results showed that companies AUO and HannStar could increase their operation efficiency by improving their VRS efficiency and scale efficiency. When using the MPI model to measure the productivity changes for these TFT-LCD companies, we found that the technology changes in most of the companies are downward tendencies during 2009–2012 except for Ampire. Thus, not only could the proposed GRA with entropy weights evaluate the current performances of each firm effectively, it can also predict their future performances.     

DEA cross-efficiency aggregation method based upon Shannon entropy

Existing approaches for DEA cross-efficiency evaluation are mainly focused on the calculation of cross-efficiency matrix but pay little attention to the aggregation of the efficiencies in the cross-efficiency matrix. The most widely used approach is to aggregate the efficiencies in each row or column in the cross-efficiency matrix with equal weights into an average cross-efficiency score for each Decision Making Unit (DMU) and view it as the overall performance measurement of the DMU. This paper focuses on the aggregation process of the efficiencies in the cross-efficiency matrix and proposes the use of Shannon entropy for cross-efficiency aggregation. In the study, we propose an entropy model to generate a set of weights for aggregating and determining the ultimate cross-efficiency instead of the traditional average cross-efficiency. We prove that the set of weight is a unique global optimal solution which can reflect the goodness of this method. Finally, two examples of a flexible manufacturing system and 27 industrial robots are illustrated to examine the validity of the proposed method.     

Optimal scheduling for police patrol duties

ABSTRACT

In recent years, governmental agencies have issued various types of information about criminal activity. The police department can strengthen crime prevention in high-crime areas by mapping hotspots. However, a shortage of manpower can make it difficult to set up adequate patrol schedules. To overcome this lack of systematic planning, this study utilizes a mathematical programming method to construct both individual and integrated planning models designed to satisfy practical patrol requirements in individual areas and to consider the integration of patrol areas through coordination between police stations, with the objective of minimizing total officer patrol time. To evaluate the performance of both models, a case study is examined and sensitivity analysis is performed based upon real data obtained from a local police department. The results show that the integrated planning model significantly outperforms the individual planning model. These models and results can be useful references for police patrol planning.     

Hazard based models for freeway traffic incident duration

Assessing and prioritising cost-effective strategies to mitigate the impacts of traffic incidents and accidents on non-recurrent congestion on major roads represents a significant challenge for road network managers. This research examines the influence of numerous factors associated with incidents of various types on their duration. It presents a comprehensive traffic incident data mining and analysis by developing an incident duration model based on twelve months of incident data obtained from the Australian freeway network. Parametric accelerated failure time (AFT) survival models of incident duration were developed, including log-logistic, lognormal, and Weibul—considering both fixed and random parameters, as well as a Weibull model with gamma heterogeneity. The Weibull AFT models with random parameters were appropriate for modelling incident duration arising from crashes and hazards. A Weibull model with gamma heterogeneity was most suitable for modelling incident duration of stationary vehicles. Significant variables affecting incident duration include characteristics of the incidents (severity, type, towing requirements, etc.), and location, time of day, and traffic characteristics of the incident. Moreover, the findings reveal no significant effects of infrastructure and weather on incident duration. A significant and unique contribution of this paper is that the durations of each type of incident are uniquely different and respond to different factors. The results of this study are useful for traffic incident management agencies to implement strategies to reduce incident duration, leading to reduced congestion, secondary incidents, and the associated human and economic losses.     

A note on DEA models in technology selection: an improvement of Karsak and Ahiska's approach

This paper introduces a compact form for the maximum value of the non-Archimedean in Data Envelopment Analysis (DEA) models applied for the technology selection, without the need to solve a linear programming (LP). Using this method the computational performance the common weight multi-criteria decision-making (MCDM) DEA model proposed by Karsak and Ahiska (International Journal of Production Research, 2005, 43(8), 1537–1554) is improved. This improvement is significant when computational issues and complexity analysis are a concern.     

基于DEA的评价模型及其输入输出指标确定

产品包装方案的评价是一个多目标规划问题.应用数据包络分析原理(DEA),通过对包装设计方案的横向比较,构建产品包装方案的评价模型.采用两步法对评价模型求解,首先对输入变量进行比例收缩(或对输出变量进行比例扩张),求出各方案的相对效率;然后计算各方案每项指标的松弛变量.结合包装行业的特点,将越小越好的指标作为输入指标、越大越好的指标作为输出指标,建立了相应的输入输出指标体系.     

Exceptional condition of police enforcement: Driving speeds during the police strike

In February 1976, the Finnish police went on strike for about two weeks and drivers very soon knew that no or only little traffic surveillance was made in the country. Driving speeds were studied before, during, and after the strike. Only a slight increase was found in the mean speed, during the strike, but the percentage of gross speed violations (exceeding the speed limit at least 10 km/h) was increased by 50–100% and the standard deviation of speeds was increased by about 20% suggesting that the accident risk was increased, too. Additionally, car drivers' response to a “suspicious-looking” car parked on a side road changed during the strike so that drivers no more decreased the speed when seeing such a car.     

三参数区间交叉效率DEA评价方法

基于交叉效率概念,遵循自评与互评相结合的原则,提出三参数区间交叉效率DEA评价方法。运用不同的赋权策略,获得用最优效率值、最劣效率值和最可能效率值描述的决策单元三参数区间交叉效率值。该效率值能更全面合理地反映决策单元效率值可能的取值情况和实际评价问题的特点,利用三角模糊数期望值排序方法可以对该效率值进行比较排序。算例说明该方法具有可行性和有效性。     

Mechanistic procedure for parameter determination of multiplicative decomposition based constitutive models

By exploiting the Clausius–Planck local energy dissipation inequality, a large strain, three-dimensional constitutive model has been developed for the monotonic and cyclic response prediction of various asphaltic materials. The model consists of a Zener non-linear, visco-elastic component acting in series with a stress dependent viscous component. A novel computational scheme has been developed for solution of the coupled system of equations expressing the interdependent response of these two in series components. An explicit, mechanistic, parameter determination procedure is presented for the laboratory determination of all necessary model parameters. Examples of model parameter determination and utilisation for prediction of the response of a recycled asphalt mix and a stone mastic asphalt mix are presented.     

基于DEA的供应商选择方法研究

考虑到现有方法的局限性,本文通过应用锥比率的C^2WH模型给出了不需要预先给定权重但可以体现决策者偏好的供应商选择方法。并应用这种方法对某型号零件的供应商的选择问题进行了研究。最后给出了在应用该方法进行供应商选择时,一些特殊情形的处理方法。     

Risk based probabilistic pavement deterioration prediction models for low volume roads

Accurate prediction of pavement performance is important for efficient management of road infrastructure. Pavement performance prediction models developed for low-volume roads are mainly based on deterministic approach. The deterministic prediction models are inadequate to completely capture the deterioration mechanism. Uncertainties may occur in pavement behaviour under changing traffic loads and environment conditions, which may not be realistically represented by deterministic model. The objective of this paper is to develop pavement deterioration prediction models by probabilistic approach, for various distresses observed on low-volume roads in the state of Kerala in India, with the help of existing deterministic models. The major distresses observed on low-volume roads were ravelling, pothole and edge failure. Load-associated distresses were rarely observed on these roads as the maximum cumulative standard axle observed was only one million standard axle (msa). Hence, lack of proper drainage and construction quality (CQ) could be attributed as the major reasons for the pavement deterioration. Progression of deterioration of pavements with age has been studied and the intensity of distresses along with corresponding probabilities was arrived at. The distresses predicted by probabilistic models were compared with those predicted by deterministic models and the actual distress values observed in the field. The prediction models were validated using Mean Absolute Percentage Error, a statistical method for accuracy measurement of forecasting models. A risk analysis was then conducted to select the critical percentile value for each type of distress corresponding to varying pavement age. A sensitivity analysis was also carried out to study the effect of pavement age and CQ on the progression of pavement deterioration.     

An improved MCDM DEA model for technology selection

This paper presents an Improved MCDM Data Envelopment Analysis (DEA) model in order to evaluate the best efficient DMUs in Advanced Manufacturing Technology (AMT). This model is capable of ranking the next most efficient DMUs after removing the previous best one.     

评价供应商的DEA方法

以制造业中采购管理为背景，讨论了供应商的评价准则，应用数据包络分析方法解决了供应商的评价问题，并在采购者对供应商有不同要求的情况下，为供应商选择问题提供了有效的技术经济分析方法。     

DEA cross-efficiency evaluation based on satisfaction degree: an application to technology selection

Data envelopment analysis (DEA) has been extended to cross-efficiency evaluation to provide better discrimination and ranking of decision-making units (DMUs). However, the non-uniqueness of optimal weights in the traditional DEA models (CCR and BCC models) has reduced the usefulness of the DEA cross-efficiency evaluation method. To solve this problem, we introduce the concept of the satisfaction degree of a DMU towards a set of optimal weights for another DMU. Then, a new DEA cross-efficiency evaluation approach, which contains a maxmin model and two algorithms, is proposed based on the satisfaction degrees of the DMUs. Our maxmin model and algorithm 1 can obtain for each DMU an optimal set of weights that maximises the least satisfaction degrees among all the other DMUs. Further, our algorithm 2 can then be used to guarantee the uniqueness of the optimal weights for each DMU. Finally, our approach is applied to a real-world case study of technology selection.     

Data based models for automobile side impact analysis and design evaluation

Occupant protection during side impacts is a very important consideration in automobile design. To ensure occupant protection. physical tests as well as simulation using analytical models are extensively used in the early phases of design. Analytical models for side impact simulation can be developed directly from the crash measurement data and the physical insight of the crash event. In this paper, uncoupled lumped parameter models for the automobile structure and the test dummy are developed based on the study of distribution of crash energy. The model parameters are estimated using a Kalman filter estimator in a constrained environment. The estimation approach is verified using simulated data as well as test data. The modeling and application of the data based model is demonstrated in the actual design environment with an example. The data based model is shown to be very useful in understanding the contribution of various components in the overall crash performance, evaluating design trade-offs and developing component level performance targets.     

一种基于振型正交化的元素型模型修正方法

在振型正交化的一阶增量摄动格式基础上,综合元素型方法的灵活特点与矩阵型方法的公式简洁的优点,提出了内部元素联系矩阵这一概念,保持了刚度矩阵和质量矩阵的物理特性和内部元素的关联性的同时,有效的降低了求解增量方程组的欠定性,而且仅用前几阶试验频率和振型就能有效的修改系统的动力特性。最后分别用前两阶和前三阶试验频率及振型修正一个楼板结构和一个平面框架结构,表明了本方法的有效性和鲁棒性     

Unification scheme for 3D surface reconstruction using physically based models

We propose a unification framework for three-dimensional shape reconstruction using physically based models. A variety of 3D shape reconstruction techniques have been developed in the past two decades, such as shape from stereopsis, from shading, from texture gradient, and from structured lighting. However, the lack of a general theory that unifies these shape reconstruction techniques into one framework hinders the effort of a synergistical image interpretation scheme using multiple sensors/information sources. Most shape-from-X techniques use an “observable” (e.g., the stereo disparity, intensity, or texture gradient) and a model, which is based on specific domain knowledge (e.g., the triangulation principle, reflectance function, or texture distortion equation) to predict the observable, in 3D shape reconstruction. We show that all these “observable–prediction-model” types of techniques can be incorporated into our framework of energy constraint on a flexible, deformable image frame. In our algorithm, if the observable does not confirm to the predictions obtained using the corresponding model, a large “error” potential results. The error potential gradient forces the flexible image frame to deform in space. The deformation brings the flexible image frame to “wrap” onto the surface of the imaged 3D object. Surface reconstruction is thus achieved through a “package wrapping” or a “shape deformation” process by minimizing the discrepancy in the observable and the model prediction. The dynamics of such a wrapping process are governed by the least action principle which is physically correct. A physically based model is essential in this general shape reconstruction framework because of its capability to recover the desired 3D shape, to provide an animation sequence of the reconstruction, and to include the regularization principle into the theory of surface reconstruction.