No-cointegration test based on fractional differencing: Some Monte Carlo results

This paper examines the use of the t-statistic in the Geweke–Porter-Hudak regression for the estimation of the fractional differencing parameter as a test for cointegration. The critical values of the test statistic are estimated using Monte Carlo methods. The results confirm that the test will over-reject the null hypothesis of no cointegration if the standard-normal critical values are used. The estimated critical values are generally robust to the nuisance parameters in the autoregressive or moving average specification of the error process of the component time series. Exceptions occur when the dependent variable in the cointegration regression follows an autoregressive process with a large positive parameter or a moving average process with a large negative parameter.     

从入藏路线的书写看19世纪法国对中国藏族地区的殖民想象——以法国人旅藏游记为中心

文章以19世纪中后期法国人旅藏游记文本为基点,以各文本均强调的“入藏路线”为引子,在19世纪中后期中法关系的历史背景下,论述了19世纪法国对藏族地区想象性的殖民意图。在较少的关于法国同中国藏族地区交往史的研究中,这是一个值得关注的重要内容。     

Operational research in Indian defence

The paper gives an outline of the areas of Operational Research (OR) where work in the Defence Department in India has been successful, even though it has not been fully implemented due to certain reservations on the part of the users and some limitations of OR scientists. There is an ad hoc quality in the decision making of the customer, and no large scale OR models are available which give a total effect of defence spending on social measures and human resources development. OR would be able to contribute to a balanced spending on defence in developing countries, if effort were made to analyse defence problems in the wider context. The author was formerly Director of Scientific Evaluation, Ministry of Defence, India.     

Oncology phase II proof‐of‐concept studies with multiple targets: Randomized controlled trial or single arm?

For oncology drug development, phase II proof‐of‐concept studies have played a key role in determining whether or not to advance to a confirmatory phase III trial. With the increasing number of immunotherapies, efficient design strategies are crucial in moving successful drugs quickly to market. Our research examines drug development decision making under the framework of maximizing resource investment, characterized by benefit cost ratios (BCRs). In general, benefit represents the likelihood that a drug is successful, and cost is characterized by the risk adjusted total sample size of the phases II and III studies. Phase III studies often include a futility interim analysis; this sequential component can also be incorporated into BCRs. Under this framework, multiple scenarios can be considered. For example, for a given drug and cancer indication, BCRs can yield insights into whether to use a randomized control trial or a single‐arm study. Importantly, any uncertainty in historical control estimates that are used to benchmark single‐arm studies can be explicitly incorporated into BCRs. More complex scenarios, such as restricted resources or multiple potential cancer indications, can also be examined. Overall, BCR analyses indicate that single‐arm trials are favored for proof‐of‐concept trials when there is low uncertainty in historical control data and smaller phase III sample sizes. Otherwise, especially if the most likely to succeed tumor indication can be identified, randomized controlled trials may be a better option. While the findings are consistent with intuition, we provide a more objective approach.     

Friends' influences on young people's aggression risk

Just as a young person's earlier aggression is likely to predispose later aggression, the person's friends may also play a role in the predisposition. For the latter, however, theory and research have not been consistently supportive. To clarify the personal and friends' influences, the present study analyzed data from 1746 Hong Kong Chinese pupils (i.e., 4th to 7th graders). The data included direct measures of friends nominated by the pupils. Results show that association with friends did not affect aggression risk. Friend aggression had a very weak but statistically significant effect on aggression risk, when the friend was the first nominated friend or reciprocally nominated friend. This effect was higher when the pupil had higher aggression before. The weak and conditional effects of friend aggression suggest that friendship had little direct influence on the child's aggression.     

Chebyshev Inequality with Estimated Mean and Variance

Chebyshev's inequality is investigated when the population mean and variance are estimated from a sample. The necessary modification to the inequality is simple and is actually valid when (a) the population moments do not exist and (b) the sample is exchangeably distributed. The latter case would include, for example, a sample taken without replacement from a finite population and the independent and identically distributed case.     

Long‐term continuous clients and their needs: a New Zealand analysis

National New Zealand data (2002) indicate that 27% of gambling clients remain in treatment for longer than 12 months. This research retrospectively analysed data from long‐term continuous, re‐admitted and brief therapy clients. The data were obtained from a national database and were analysed quantitatively and qualitatively. Results indicated that relevant differences between long‐term continuous and other clients occurred in ethnicity and clinic location. The latter was confounded by the number of clinics versus clients. The average age of long‐term continuous clients was 43 years; 5–6 years older than other clients; however, this marginally failed to reach a level of statistical significance. The results led to the proposal of two alternative models of therapy for clients with gambling problems: (a) a six‐session capsule model and (b) an inductive, open‐ended model (with regular review component). Further research is required to test the efficacy of these models.     

藏族文化与20世纪初的法国文学创作

同英国一样,19世纪的法国也同中国藏族地区有相当的历史交往,藏族文化通过传教士、冒险家、旅行者、外交官、藏族文化研究者等不同职业的人得以在法国传递。到世界局势动荡的20世纪初,法国出现了一些与藏族文化相关的文学创作,自此藏族文化以象征性的形式进入到法国人的意识中,这是长期以来法国接受藏族文化的一个结果,同时也反映出法国人对藏族文化的认识和理解进入了一个新的发展阶段。     

A stakeholder perspective on process improvement behaviours: delivering the triple bottom line in SMEs

Abstract

The primary focus of operations management is to add value through operational processes. Considerable attention has been given to using process improvement (PI) techniques to reduce costs and time, in order to develop a competitive advantage for the wider organization. However, this narrow definition of value at times overlooks the triple bottom line (TBL) which can result in a number of unintended consequences, specifically issues related to environmental and social measures of performance. To address this, a stakeholder theory lens will be used to analyze PI activities within the context of small and medium-sized enterprises. The TBL will be used to complement the stakeholder perspective, to interpret the benefits that are realized from PI activities. This article highlights both the direct benefits from PI as well as more indirect benefits realized by involving a selection of salient stakeholders in PI. It will show how a developed view of PI can provide an important mechanism for delivering improvements to a firm’s TBL. The work concludes by highlighting the contributions made to both PI practice and stakeholder theory, while acknowledging the need for more research on PI, both from a stakeholder perspective and how it impacts a firm’s TBL.     

Use of a case study in sequencing/scheduling research

This paper describes a study of an industrial sequencing/scheduling problem. The study contains the definition of the problem, data requirements and examination of solution technique. Definition of the problem is discussed from the aspect of uniqueness of the specific system. Discussion of data requirements includes availability and accuracy, while examination of solution technique considers limitation of time, computer capacity, etc., as well as the possibility of imbedding available algorithms into the solution procedure. Conclusions are presented relative to the use of the case study approach in sequencing/scheduling research.