一类图的点圈扩张性

本文的主要结果是：设G是2-连通图．若，则G的每个点v都在3-圈或4-圈或5-圈上，并可由此出发经过若干次1或2-扩张，最后得到Hamilton圈．     

Borda and Condorcet: Some Distance Results

This paper provides a distance based analysis of the Borda rule with respect to Condorcet’s criterion. It shows that the minimal Condorcet consistency present in the Borda rule, whenever a Condorcet winner (the alternative that wins against every other alternative in a pairwise contest) exists, disappears in the case of voting cycles. First, it is shown that for certain preference profiles the Borda winner is furthest from being a Condorcet winner. Second, it is shown that there exist preference profiles for which the Borda winner is closest from being a Condorcet loser (the alternative that loses against every other alternative in a pairwise contest).     

董仲舒的社会控制理论——循环论探讨

董仲舒的循环论是中国社会思想史上的一个里程碑。它确立了中国传统社会控制的模型,其"天人合一"和"大一统"思想丰富了中国传统文化,更重要的是对中国社会的延续起到极为重要的作用。     

一类非线性微分方程组极限环的存在性

本文研究一类非线性微分方程组极限环的存在性,得到关于极限环存在新的充分条件的定理．     

Even Cycles and Perfect Matching Problems with Side Constraints

We study two different types of graphs that contain even cycles and, possibly, some chords. The objective is to analyze some properties of these types of graphs that can be used to solve perfect matching optimization problems with side constraints. In particular, we obtain the maximum number of edges of certain classes that can occur in the solutions to the considered problems. Finally, we apply the obtained results to derive a class of valid inequalities and a possible enumerative scheme.     

川南山地黄牛放牧补饲肥育试验

本试验选用黔江县川南山地黄牛阉公牛 12头 ,随机分成 3组 (两个试验组 ,一个对照组 )进行放牧和放牧加补饲的肥育试验。经过 60d的试验 ,两个试验组 (分别补饲混合精料和补饲单一精料 )的ADG分别为 595.83g和 4 94 .17g ,比对照组的ADG 155.83g分别提高了 2 82 .36%和2 17.12 % ,肥育毛利润分别为 75.59元 /头和 53.2 4元 /头 ,比对照组的 4 6.75元 /头分别增加 2 8.84元 /头和 6.4 9元 /头。补饲混合精料组的精料增重比 ( 2 .86 1)比补饲单一精料组的精料增重比 (3.52 1)下降 18.75%。试验结果表明 ,与放牧相比 ,放牧加补饲 (尤其是补饲混合精料 )能极显著提高日增重、缩短肥育时间、增加经济效益 ,是山区农村发展牛只肥育的一种较好方式     

Growing Through Cycles

The neoclassical growth model focuses on factor accumulation as an engine of growth, while the neo-Schumpetarian growth model stresses innovation. This paper argues that these two views of growth may capture different phases of a single growth experience. In the model presented below, the balanced growth path is unstable and the economy achieves sustainable growth through cycles under an empirically plausible condition, perpetually moving back and forth between two phases. One phase is characterized by higher output growth, higher investment, no innovation, and a competitive market structure. The other phase is characterized by lower output growth, lower investment, high innovation, and a more monopolistic market structure. Both investment and innovation are essential in sustaining growth indefinitely, and yet they move in an asynchronized way; only one of them appears to play a dominant role in each phase. The economy grows faster along the cycles than along the Zunstable. balanced growth path.     

Dynamic stability: Unfolding dynamics of vicious cycles in a design firm

Paradoxes generate tensions and contradictions in organizations. In this paper, we contribute to the paradox literature by developing a complex systems approach to how organizational members experience tensions generated by the strategic intent paradox. Specifically, we focus on the unfolding dynamics of vicious cycles experienced by organizations dealing with paradox. Drawing on a case study of a design firm, we demonstrate how a vicious cycle forms through feedback loops and develops dynamic stability over time. On the basis of our findings, we develop a micro-level understanding of vicious cycles, which incorporates defence mechanisms at staff and senior management levels. Our main contribution is a theoretical model of unfolding dynamics of vicious cycles. Our model shows the importance of (1) feedback loops that underpin a vicious cycle and (2) importance of circular causality, reinforcing cycles, and micro-mechanisms in theorizing vicious cycles.     

‘Cycles of disadvantage’ revisited: young people,families and poverty across generations*

ABSTRACT

One of Andy Furlong’s abiding concerns was to show how the problems of working-class youth are often, straightforwardly, the outcome of inequalities in employment opportunities. On rarer occasions, however, this explanation fits less well. Some young people grow up in families where poverty seems more deeply embedded and inherent to those families. Here, old ideas about a cultural ‘underclass’ can be tempting to politicians and policy makers. Our qualitative research, with 20 families living in extremely deprived U.K. neighbourhoods, showed that neither a simple lack of job opportunities nor ‘cultures of worklessness’ explained why hardship persisted for them. Our argument is that circumstances which appear to fit with the idea of an inter-generational, cultural ‘underclass’, in fact, have their provenance in a semi-permanent constellation of external socio-economic pressures bearing on successive generations of families over decades. Examples did include a shared context of declining job opportunities but extended to a contracting and disciplinary Welfare State, punitive criminal justice systems, poor-quality education and the physical decline of working-class neighbourhoods. We take one example – the destructive impact of local drug markets – to uncover the complex, obscure processes that compound the disadvantage faced by working-class young adults and their families over generations.     

Investment in Facility Changeover Flexibility for Early Entry into High‐Tech Markets

A model is introduced to analyze the manufacturing‐marketing interface for a firm in a high‐tech industry that produces a series of high‐volume products with short product life cycles on a single facility. The one‐time strategic decision regarding the firm's investment in changeover flexibility establishes the link between market opportunities and manufacturing capabilities. Specifically, the optimal changeover flexibility decision is determined in the context of the firm's market entry strategy for successive product generations, the changeover cost between generations, and the production efficiency of the facility. Moreover, the dynamic pricing policy for each product generation is obtained as a function of the firm's market entry strategy and manufacturing efficiency. Our findings provide insights linking internal manufacturing capabilities with external market forces for the high‐tech and high‐volume manufacturer of products with short life cycles. We show the impact of manufacturing efficiency and a firm's ability to benefit from volume‐based learning on the dynamic pricing policy for each product generation. The results demonstrate the benefits realized by a firm that works with its manufacturing equipment suppliers to develop more efficient and flexible technology. In addition, we explore how opportunities afforded by pioneer advantage enable a firm operating a less efficient facility to realize long term competitive advantage by deploying an earlier market entry strategy.