Semi-parametric modelling of temperature records

A range of instrumental and proxy temperature records are examined semi-parametrically, using empirical densities and quantile autoregressions containing a unit root, to assess the extent of non-stationarity and the presence of global warming trends. Only the instrumental records covering the last century and a half show any evidence of non-stationarity, but the trend behaviour of these series remains elusive.     

On- and offline detection of structural breaks in thermal spraying processes

We investigate and develop methods for structural break detection, considering time series from thermal spraying process monitoring. Since engineers induce technical malfunctions during the processes, the time series exhibit structural breaks at known time points, giving us valuable information to conduct the investigations. First, we consider a recently developed robust online (also real-time) filtering (i.e. smoothing) procedure that comprises a test for local linearity. This test rejects when jumps and trend changes are present, so that it can also be useful to detect such structural breaks online. Second, based on the filtering procedure we develop a robust method for the online detection of ongoing trends. We investigate these two methods as to the online detection of structural breaks by simulations and applications to the time series from the manipulated spraying processes. Third, we consider a recently developed fluctuation test for constant variances that can be applied offline, i.e. after the whole time series has been observed, to control the spraying results. Since this test is not reliable when jumps are present in the time series, we suggest data transformation based on filtering and demonstrate that this transformation makes the test applicable.     

我国大城市农产品批发市场交易的演进趋势——以北京为例

以北京市为例,剖析了大城市农产品批发市场交易的演进趋势:批发交易的方式,将继续以面对面的对手交易为主,以拍卖交易为辅;交易方式的创新非常活跃,新兴交易方式不断涌现;批发市场的交易辐射力将进一步增强,交易空间日益郊区化,并进一步向集群化方向发展。     

修学旅游初论

学旅游源远流长,种类繁多,正成为当前“国民休闲旅游计划”的重要举措和重点项目之一。就修学旅游的历史溯源、含义、构成要素、功能和特性、分类、发展现状和趋势等进行研究,提出修学旅游是升级的旅游产品,代表着旅游发展的某种未来形态,不仅具有旅游经济意义,而且具有文化和教育意义,对国民素质建设和文化旅游经济建设意义重大,应该大力开发和推广。     

农村合作经济的发展态势

农业生产的生物性、地域的分散性、规模的不均匀性与劳动成果的不确定性的存在 ,决定了农业的家庭经营 ,农村合作经济提高了农业经营的组织化程度。社会经济发展、结构变动及科学技术进步 ,又导致农村合作经济制度随之演进     

Public relations in the new millennium: Towards a synoptic view of fifteen years of research in Public Relations Review in the 21st century (2000–2014)

This text is part of a broader project that seeks to examine the field of Public Relations from the systematic study of scientific production published in the main academic journal of the specialty: Public Relations Review (ISSN 0363–8111). From an analysis of the content of all the papers (n = 1037) published in this journal during 15 years, between 2000 and 2014, the authors, topics, universities, professional networks, countries, objectives, questions, hypotheses, methodologies, techniques, theories and type of applied research have been examined. The main authors, universities and countries with the highest productivity are identified, as well as the dominant topics in the field and their evolution over time, among others important issues, in order to contribute to an overview of the past, present and future of public relations research from what was addressed in the journal during the first fifteen years of the XXI century. It concludes with suggestions for future research.     

The increasing importance of friends: Changes in core discussion network composition in post-communist Hungary between 1997 – 2015

In order to detect changes in social connectivity, we examined evolutions in the personal network structure by analyzing over-time trends in the composition of the population’s core discussion networks on four cross-sectional, nationally representative surveys between 1997 and 2015, in the era of post-communism, in Hungary. There has been a very significant change; in fact, a reversal of trends regarding the composition of the core discussion networks (CDNs) concerning kin and non-kin ties over the past decades. Our data suggest that friendship ties gained more importance. There seems to be a generation-specific aspect of the change: young people include family ties less often than older people and this effect strengthens over time. Women still have a higher ratio of kin ties compared to men and this effect does not change significantly during the analyzed period.     

Alternative diff-in-diffs estimators with several pretreatment periods

This paper deals with the identification of treatment effects using difference-in-differences estimators when several pretreatment periods are available. We define a family of identifying nonnested assumptions that lead to alternative difference-in-differences estimators. We show that the most usual difference-in-differences estimators imply equivalence conditions for the identifying nonnested assumptions. We further propose a model that can be used to test multiple equivalence conditions without imposing any of them. We conduct a Monte Carlo analysis and apply our approach to several recent papers to show its practical relevance.     

Extending the pursuit of flow (lean) management to encompass sales,general and administrative functions

Abstract

Operations management tends to be treated independent of other business functions—the silo syndrome. In this article, we call for operations management (OM) to broaden its perspective by strengthening linkages with other functions of the business, thereby to realize competitive advantages and strategic integration, as well as to avoid resource misallocation. The issues involved are presented and tested by examining the effects of intermeshing sales, general and administrative (SG&A) expenditures with customer-centred flow manufacturing, the latter being measured by system inventory as surrogate for customer lead time. In doing so, we designate trends in total inventory as the independent variable—representative of a dominant target of flow/lean management—and trends in SG&A expenditures as the output variable. The research tasks are enabled by inventory and SG&A data being widely available in companies’ audited financial statements. Such hard data offers methodological and validation advantages over, say, opinion-based survey research. The research adds bulk to existing flow/lean management theory and can be helpful in inducing primary business functions (e.g. OM, finance, sales and marketing) and sub-functions (such as SG&A and management accounting) to engage in cross-functional efforts in the cause of flow-oriented process improvement and company competitiveness.     

19与20世纪中国文学思潮比较论

:2 0世纪中国文坛思潮迭起 ,呈现出夸张的显泛化的态势 ,而 1 9世纪中国文学思潮则体现着潜隐性特征 ,原因是 2 0世纪中国经过了规模浩大的反传统运动 ,在普遍反传统的文化语境中 ,在西方现代思潮的强烈冲击和导引下 ,极容易形成思潮的泛滥 ,而 1 9世纪中国文人虽然也思维活跃 ,酝酿着各种思潮 ,但大多囿于传统的规范 ,甚至碍于自己的身份 ,往往使运作中的或酝酿中的思潮呈潜隐状态。由于这两个世纪基本上都面临内忧外患的严峻局势 ,中国文坛都涌动着现实主义文学主潮 ,不过 1 9世纪流行的是以古典文化为价值依托的古典现实主义 ,而 2 0世纪是以西方文化为参照的宽泛的现实主义