Effects of heterogeneity on bank efficiency scores

Bank efficiency estimates often serve as a proxy of managerial skill since they quantify sub-optimal production choices. But such deviations can also be due to omitted systematic differences among banks. In this study, we examine the effects of heterogeneity on bank efficiency scores. We compare different specifications of a stochastic cost and alternative profit frontier model with a baseline specification. After conducting a specification test, we discuss heterogeneity effects on efficiency levels, ranks and the tails of the efficiency distribution. We find that heterogeneity controls influence both banks’ optimal costs and profits and their ability to be efficient. Differences in efficiency scores are important for more than only methodological reasons. First, different ways of accounting for heterogeneity result in estimates of foregone profits and additional costs that are significantly different from what we infer from our general specification. Second, banks are significantly re-ranked when their efficiency is estimated with a specification other than the preferred, general specification. Third, the general specification gives the most reliable estimates of the probability of distress, although differences to the other specifications are low.     

Stochastic optimization for blending problem in brass casting industry

A critical process in brass casting is blending of the raw materials in a furnace so that the specified metal ratios are satisfied. The uncertainties in raw material compositions may cause violations of the specification limits and extra cost. In this study, we proposed a chance-constrained stochastic programming approach for blending problem in brass casting industry to handle the statistical variations in raw material compositions. The proposed approach is a non-linear mathematical model that is solved global optimally by using GAMS/BARON solver. An application has been performed in MKEK brass factory in Kırıkkale, Turkey and the solution of the application has been compared with alternative solution approaches based on cost and specification violation risk conditions. This comparison demonstrates that the proposed model is the most effective solution approach for managing stochastic uncertainties in blending problems and successfully can be used other industries such as alloy steel or secondary aluminum production.     

A deterministic linear optimization model for allocating schools to zones

This paper presents a deterministic linear optimization model to support decisions on optimal allocation of schools to zones, its characterization and assignment of students, maximizing the social benefits of school owners and students. Students are assumed to show a multi-attribute behaviour, considering as important not only location, as is usual in the literature, but also quality of education and infrastructure, school costs and other attributes. There is heterogeneity of supply and demand. Students are classified by place of residence and socio-economic characteristics. Schools can be private, subsidized or free municipal ones. The model developed is applied to data of one of the municipalities of Santiago. The results obtained under different scenarios tend to confirm the expected demand's behaviour. This model could be used to guide decisions of both school owners or municipalities as well as students towards an equilibrium closer to a social optimum.     

AN ENCOMPASSING APPROACH TO MODELING FISHERY DYNAMICS: MODELING DYNAMIC NONLINEAR SYSTEMS

Uncertainty about the nature and significance of nonlinearities and the manner in which dynamics affect future realizations makes model specification the most difficult aspect of modeling dynamic systems. By interpreting several popular fishery models as subcases of a nesting dynamic Taylor series approximation, we isolate the specification differences between these models in a way that accounts for commonalities. On the argument that the differences due to alternative nonlinear forms are likely to be small compared to more mundane considerations such as delay difference and general dynamic lag specification, we propose an alternative model that uses the terms from the first order approximation common to all models combined with a data-based determination of the appropriate lags using the methods of state space time series analysis. Finally, the success of the alternative models is judged in an application to Pacific halibut data.     

MODELING AND MEASURING PRODUCTION PROCESSES FOR A MULTI‐SPECIES FISHERY: ALTERNATIVE TECHNICAL EFFICIENCY ESTIMATES FOR THE NORTHERN SPAIN HAKE FISHERY

ABSTRACT. The economic performance of fisheries is difficult to measure, due to the importance of (multi‐species) biological dynamics, property rights and regulatory issues affecting fishermen's behavior and efficiency. However, an understanding of performance patterns is essential for enhancing the economic and biological viability of fisheries. In this paper we estimate and evaluate alternative primal stochastic approaches to modeling and measuring technical efficiency for the Northern Spain hake fishery. We then compare the resulting efficiency measures to identify variations in their potential interpretation, and application to policy guidance. We find that multi‐output models are more theoretically and empirically justifiable than aggregate output production function models, and provide additional policy‐relevant insights, but that relative production and efficiency estimates are not sub‐stantively affected by model specification.     

Economic manufacturing quantity,optimum process mean,and economic specification limits setting under the rectifying inspection plan

Economic manufacturing quantity, process mean, and specification limits setting are three important methods for the inventory and quality control problems. In the imperfect production system, we usually consider the manufacturing quantity for reducing the inventory cost, determine the process level for reducing the production cost, and select the specification limits for screening the products. In this paper, we propose the above integrated model based on the application of rectifying inspection plan for obtaining maximum expected total profit of product. The asymmetric quadratic quality loss function is adopted for measuring the product quality. The sensitivity analyses of parameters are provided for illustration.     

The Prediction of Industrial Mail-Survey Response Rates

Mail-survey response rates and their prediction are important issues for researchers. The conceptual differences between industrial and most non-industrial populations raised doubt about the applicability of the Heberlein and Baumgartner model for the prediction of industrial mail-survey response rates. A test of their model using data from industrial mail-survey studies revealed a low level of predictive ability. A new model, based upon a linear logit specification and data from industrial populations, was developed and validated using a hold-out sample. The results suggested that the model based upon the new specification was superior to the simple linear alternative. The model identified a number of variables which were associated with response rates from industrial populations, and allows researchers to test and refine alternative survey designs.     

A general framework for multiresponse optimization problems based on goal programming

Setting of process variables to meet a required specification of quality characteristic (or response variable) in a process, is one of the common problems in the process quality control. But generally there are more than one quality characteristics in the process and the experimenter attempts to optimize all of them simultaneously. Since response variables are different in some properties such as scale, measurement unit, type of optimality and their preferences, there are different approaches in model building and optimization of MRS problems.     

Location of Preventive Health Care Facilities

This paper is focused on the problem of locating preventive health care facilities. The aim is to maximize participation to prevention programs. We assume that distance is a major determinant of participation and people would go to the closest facility for preventive health care. Each facility is required to have more than a predetermined number of clients because of the direct relationship between volume and quality of preventive services. We provide a mathematical formulation and present alternative solution approaches for this new location problem. We report on computational performance of the proposed methods in locating public health centers in Fulton County, Georgia and mammography screening centers in Montreal, Quebec.     

Inquiry Learning of High School Students Through a Problem‐Based Environmental Health Science Curriculum

The purpose of this study was to examine the degree to which high school students improved their inquiry capabilities in relation to scientific literacy through their experience of a problem‐based environmental health science curriculum. The two inquiry capabilities studied were scientific questioning and approaches to inquiry into their own questions. A total of 129 high school students taught by two teachers in one school wrote responses to environmental health issues at the beginning and at the end of a 10‐week long inquiry curriculum. An additional group of 46 students of one of the two teachers learned an alternative curriculum and participated as a comparison group. The students using the inquiry curriculum performed significantly better than those using the alternative curriculum in posing active inquiry questions and generating hypothesis‐driven approaches to inquiry into their questions. The inquiry curriculum students also improved significantly from the pretest to the posttest in both measures of inquiry capacity. Among the students who were less prepared for inquiry in the beginning, 68% improved inquiry‐questioning capability, while among the students who were more prepared for inquiry, 36% improved in generating hypotheses‐driven approaches. Implications for curriculum design and implementation were provided along with further research suggestions.     

微积分全英语教学模式探讨——以电子科技大学格拉斯哥学院课程Calculus(微积分)为例

电子科技大学格拉斯哥学院电子信息工程专业是电子科技大学与英国格拉斯哥大学的联合办学项目,Calculus(微积分)课程是大一学生的一门重要的基础课程,该课程采用全英语教学.全英语教学是目前我国高水平办学的教学模式之一,在教材选择、课程大纲、授课模式上都有其独特性.为了更有效地提高该课程的教学质量和教学效果,本文对微积分全英语教学的现状、价值意义、存在问题、教学模式等方面进行探讨,并对存在的主要问题给出了一些具体的方案.     

Nonparametric estimation of returns to scale in the public sector with an application to the provision of educational services

Nonparametric programming models have been developed to measure technical efficiency and scale economies. The programming models used for public sector applications, however, are based on standard private sector production theory. In the public sector environmental variables have a significant impact on the provision of public services. Without controlling for these environmental factors point estimates of efficiency and returns to scale will be biased. This paper extends nonparametric methods to allow measurement of returns to scale in the provision of public services. The method is applied to the provision of educational services in New York State school districts for illustrative purposes.     

Screening location strategies to reduce exchange rate risk

A firm that markets its products and services world-wide may face significant financial risk due to exchange rate fluctuations unless it maintains an international sourcing/production network. Thus, the firm must evaluate various sourcing/production network designs. The selection of the appropriate design is not straight-forward since decisions are made in an environment of uncertainty and involve multiple time periods. We propose a two-phase approach to screen various alternative designs (configurations) utilizing a number of criteria, and illustrate it using a popular Harvard Business School case. As by-products, we introduce a new criterion for making a pairwise stochastic comparison of alternatives and demonstrate the value of maintaining excess geographically-dispersed production capacity.     

Lead time management

In intermittent production systems, job shops, manufacturing lead times are often long and variable, yet only about 10% is due to the actual processing time. This is a major difficulty in planning production. Two alternative approaches exist for determining planning values for manufacturing lead times to use in production planning and control systems. The first is to treat them as independent uncontrollable variables. It is then a forecasting problem with the emphasis on minimising the impact of the forecasting errors. The second approach puts the emphasis on control and attempts to manage the average lead times to match pre-determined norms. This article reviews and compares these two approaches. It concludes that the second is the most appropriate but that it requires a close cooperation between the production and marketing functions of the firm. This is best achieved by regarding the firm as a hierarchical chain of backlogs connected by input/output relations.     

我国各地区人口素质差异的主成分和聚类分析

本文利用国家统计局人口变动情况抽样调查数据，运用主要成分和聚类分析方法，揭示了１９９７年我国３０个省份（不包括西藏）的人口素质差异。首先通过人口素质指标体系确立人口素质的综合指标，在此基础上来评价各地的人口素质状况，并按其素质的高低将全国３０个省份的人口素质状况分为四大类，同时，对各省人口素质存在差异的原因进行了归纳和总结     

A multi-objective mathematical optimization model for process targeting using 100% inspection policy

The selection of the optimal process target is an important problem in production planning and quality control. Such process targeting problems are usually modeled in the literature using a single objective optimization model. In this paper multi-objective optimization is introduced in the process targeting area. The quality characteristic under consideration is normally distributed with unknown mean and known standard deviation, and has two market specification limits. 100% inspection is used as the mean of product quality control. Product satisfies the first specification limit is sold in a primary market at a regular price and products fails the first specification limit and satisfies the second one is sold in a secondary market at a reduced price. The product is reworked if it does not satisfy both specification limits. The developed multi-objective optimization model consists of three objective functions, which are to maximize profit, income and product uniformity using Taguchi quadratic function as a surrogate for product uniformity. An algorithm is proposed to obtain and rank the set of Pareto optimal points. The utility of the model has been demonstrated using a numerical example from the literature with some additional data the new model requires. Sensitivity analysis was conducted and showed that the results of the model are sensitive to changes in process variance. In addition the optimal objectives of the profit function and product uniformity are more sensitive to changes in model parameters than the income function.     

A new approach for technical efficiency estimation in multiple output production

The nonparametric technique of Data Envelopment Analysis (DEA) has been used to measure technical efficiency. This approach has proven useful because, unlike regression analyses, it allows multiple outputs and does not require a priori functional form specification. DEA does, however, require correct model specification; inclusion of inappropriate variables or omission of relevant variables leads to distortions. The purpose of this paper is to develop an alternative methodology based on canonical correlation to measure technical efficiency for multiple output production correspondences. Using simulated data, the new methodology is compared with DEA. The results indicate that the canonical regression approach outperforms DEA in most cases.     

Detecting Students' Experiences of Discontinuities Between Middle School and High School Mathematics Programs: Learning During Boundary Crossing

Transitions from middle school to high school mathematics programs can be problematic for students due to potential differences between instructional approaches and curriculum materials. Given the minimal research on how students experience such differences, we report on the experiences of two students as they moved out of an integrated, problem-based mathematics program in their middle school into a high school mathematics program that emphasized procedural fluency. We conducted an average of two interviews per year for two and a half years with participants and engaged in participant-observation at their high school. In this study, we illustrate an analytic process for detecting discontinuities between settings from participants' perspectives. We determined that students experienced a discontinuity if they reported meaningful differences between settings (frequent mention, in detail, with emphasis terms) and concurrently reported a change in attitude. Additionally, these students' experiences illustrate two opportunities to learn during boundary-crossing experiences: identification and reflection.     

Nonparametric measurement of productivity and efficiency in education

Nondiscretionary environmental inputs are critical in explaining relative efficiency differences and productivity changes in public sector applications. For example, the literature on education production shows that school districts perform better when student poverty is lower. In this paper, we extend the nonparametric approach to decompose the Malmquist Productivity Index suggested by Färe et al. (American Economic Rewiew 84:66–83, 1994) into efficiency, technological and environmental changes. The approach is applied to analyze educational production of Ohio school districts. Applying the extended approach in an analysis of the educational production of 604 school districts in Ohio, we find changes in environmental harshness are the primary drivers in productivity changes of underperforming school districts, while technical progress drives the performance of top performing school districts.     

Evolutionary computation for automatic Web service composition: an indirect representation approach

Web services have become increasingly popular in recent years, and they are especially suitable to the process of Web service composition, which is when several services are combined to create an application that accomplishes a more complex task. In recent years, significant research efforts have been made on developing approaches for performing Quality of Service -aware Web service composition. Evolutionary computing (EC) techniques have been widely used for solving this problem, since they allow for the quality of compositions to be optimised, meanwhile also ensuring that the solutions produced have the required functionality. Existing EC-based composition approaches perform constrained optimisation to produce solutions that meet those requirements, however these constraints may hinder the effectiveness of the search. To address this issue, a novel framework based on an indirect representation is proposed in this work. The core idea is to first generate candidate service compositions encoded as sequences of services. Then, a decoding scheme is developed to transform any sequence of services into a corresponding feasible service composition. Given a service sequence, the decoding scheme builds the workflow from scratch by iteratively adding the services to proper positions of the workflow in the order of the sequence. This is beneficial because it allows the optimisation to be carried out in an unconstrained way, later enforcing functionality constraints during the decoding process. A number of encoding methods and corresponding search operators, including the PSO, GA, and GP-based methods, are proposed and tested, with results showing that the quality of the solutions produced by the proposed indirect approach is higher than that of a baseline direct representation-based approach for twelve out of the thirteen datasets considered. In particular, the method using the variable-length sequence representation has the most efficient execution time, while the fixed-length sequence produces the highest quality solutions.