Analysis of binary data for the balanced one-way classification

A test is proposed for testing the equality of proportions based on the data available from a one-way classification having t treatment conditions and n binary observations per treatment. The test statistic B is a constant multiple of the F-statistic which results when the analysis of variance procedure for the one-way classification is applied to the data and, hence, is computationally simple. The statistic B from this binary analysis of variance (BIANOVA) is distributed asymptotically as a chi-square random variable. The proposed test is uniformly more powerful than either the F-test indicated above or the Pearson chi-square test; however, the attained empirical level of significance is frequently higher than for either of these competitors and usually higher than the stated level of significance for smaller values of n (say n ≤ 20).     

A combined optimization and agent-based approach to supply chain modelling and performance assessment

The main objective of this paper is to give an example of how expert systems techniques for distributed decision-making can be combined with contemporary numerical optimization techniques for the purposes of supply chain optimization and to describe the resulting software implementation. In this paper, multi-agent modelling techniques are applied to simulate and control a simple demand-driven supply chain network system, with the manufacturing component being optimized through mathematical programming. The system measures supply chain performance and the effect of different parameters in the replenishment control system, and can be used to simulate the behaviour of a system that uses optimization for part of its decision-making. The objective of this supply chain network system is to reduce operating cost, while maintaining a high level of customer order fulfilment.     

The orbit problem is in the GapL hierarchy

The Orbit problem is defined as follows: Given a matrix A∈ℚ ^n×n and vectors x,y∈ℚ ⁿ , does there exist a non-negative integer i such that A ⁱ x=y. This problem was shown to be in deterministic polynomial time by Kannan and Lipton (J. ACM 33(4):808–821, 1986). In this paper we place the problem in the logspace counting hierarchy GapLH. We also show that the problem is hard for C₌L with respect to logspace many-one reductions.     

Integrating sustainable supply chain practices with operational performance: an exploratory study of Chinese SMEs

Abstract

With growing regulatory and market pressure to implement green practices, SMEs are facing enormous challenges to simultaneously improve operational and green performances of their supply chains. The paper aims to understand the green practices adopted by Chinese SMEs in the packaging sector in order to assess the impact of these practices in improving the operational performance. Case study-based research methodology is adopted and semi-structured interviews are conducted to collect data from seven SMEs in this study. Both in-case and cross-case analyses are performed to understand the green practices being adopted with the focus on improving the operational performance. The findings of this study indicate that although most SMEs understand the importance of green practices, they have limited knowledge to integrate these practices to improve operational performance. Integration and alignment of green activities with the operational improvement measures are identified as critical factors to develop an efficient green supply chain.     

Environmental improvement initiatives in the coal mining industry: maximisation of the triple bottom line

Abstract

Mining is an economically important industry, which faces several environmental and social challenges. Other than operational improvement activities, mining companies are increasingly paying attention to reduce greenhouse gas emissions (GHGs) and maximise social welfare to satisfy multiple stakeholders and the rise of corporate social responsible initiatives. Based on a case study analysis of coal mining companies we develop a triple bottom line (TBL) initiatives framework that provides a starting point for mining companies to develop a strategic approach to environmental improvement initiatives that can positively impact all elements of the TBL. We highlight four types of process and offset-based initiatives that are available to mining companies to reduce their GHGs, each having differential effects on elements of the TBL. Our findings suggest the importance of company-wide strategies of looking at initiatives through all rather than individual elements of the TBL. Such a strategy would provide an appropriate estimate of the costs and benefits of the initiatives and results in a balanced approach that takes care of operational improvement, reduces GHGs and improves the social welfare of people engaged in mining operations and wider society.     

Application of minque procedure to block designs

Method of minimum norm quadratic unbiased estimation (MINQUE) is applied to incomplete block designs. Simple formulae are derived for a class of designs which includes the balanced designs.