Induced soliton ejection from a continuous-wave source waveguided by an optical pulse-soliton train

It has been established for some time that high-power pump can trap a probe beam of lower intensity that is simultaneously propagating in a Kerr-type optical medium, inducing a focusing of the probe with the emergence of modes displaying solitonic properties. To understand the mechanism by which such self-sustained modes are generated, and mainly the changes on probe spectrum induced by the cross-phase-modulation effect for an harmonic probe trapped by a multiplex of temporal pulses, a linear equation (for the probe) and a nonlinear Schr\"odinger equation (for the pump) both coupled by a cross-phase-modulation term, are considered simultaneously. In general the set of coupled probe-pump equations is not exactly tractable at any arbitrary value of the ratio of the cross-phase to the self-phase modulation strengths. However, for certain values of this ratio, the probe modulation wavector develops into |n,l\textgreater {\it quantum states} involving $2n+1$ soliton-shaped eigenfunctions which spectral properties can be characterized unambiguously. Solutions of the probe equation give evidence that the competition between the self-phase and cross-phase modulations leads to a broadband spectrum, with the possibility of a quasi-continuum of soliton modes when the cross-phase-modulation coupling is strong enough.Comment: 15 pages, 27 figure

Incompatibility boundaries for properties of community partitions

We prove the incompatibility of certain desirable properties of community partition quality functions. Our results generalize the impossibility result of [Kleinberg 2003] by considering sets of weaker properties. In particular, we use an alternative notion to solve the central issue of the consistency property. (The latter means that modifying the graph in a way consistent with a partition should not have counterintuitive effects). Our results clearly show that community partition methods should not be expected to perfectly satisfy all ideally desired properties. We then proceed to show that this incompatibility no longer holds when slightly relaxed versions of the properties are considered, and we provide in fact examples of simple quality functions satisfying these relaxed properties. An experimental study of these quality functions shows a behavior comparable to established methods in some situations, but more debatable results in others. This suggests that defining a notion of good partition in communities probably requires imposing additional properties.Comment: 17 pages, 3 figure

Liabilities of Regional Foreignness and the Use of Firm Level and Country Level Data

We are pleased that Dunning et al. (2006) have provided macro (country) level data demonstrating the increased internationalization of many nations over the past decade. We also appreciate their findings lending support to our perspective on the regional nature of world business. Our work was based solely on micro (firm) level data, see Rugman and Verbeke (2004a). Both country level data and firm level data have methodological problems which we attempt to reconcile in this comment. We also address the broader conceptual issues of how to interpret country level versus firm level data.Regional strategy, home region bound firm-specific advantages, liability of regional foreignness, methodology

A Perspective on Regional and Global Strategies of Multinational Enterprises

It is widely accepted that multinational enterprises (MNEs) are the key drivers of globalization. The ultimate test to assess the level of globalization is the actual penetration of markets across the globe, especially in the broad ‘triad’ markets of NAFTA, the European Union and Asia. Yet, data on the activities of the 500 largest MNEs reveal that very few actually operate globally. For 320 of the 380 for which geographic sales data are available, an average of 80.3% of their total sales are in their home region of the triad. This means that the world’s largest firms are not global, but regionally based in terms of breadth and depth of market coverage. Globalization thus reflects a special, and rather unusual, outcome of doing international business, and regional strategies are more relevant than global ones. This has important implications for various strands of mainstream international business research, as well as for the broader managerial debate on the design of optimal strategies and governance structures for MNEs.Semi-globalization, regional strategy triad, value chain, firm specific advantages, localization, global strategy

Regional Transnationals and Triad Strategy

In this paper, we address the geographic distribution of sales of some of the world’s largest multinational enterprises (MNEs), with a focus on the share of each leg of the ‘Triad’ (the North-American Free Trade Agreement or NAFTA-zone, the European Union - E.U., and Asia) in these firms’ overall sales. Our view is that a firm has achieved global corporate success only if it is able to earn a balanced regional distribution of sales. Only high actual sales across the globe, especially in the wealthy and technologically advanced triad regions, demonstrate both strong firm-level capabilities at the supply side to market products and services worldwide, and a high willingness of sophisticated consumers at the demand side, to pay for the firm’s output. With respect to the supply side, we develop a new conceptual framework, which distinguishes among the global, regional and national loci of MNE decision-making, as well as the global, regional and national levels of product standardization. Our main point is that the regional dimension is important for many firms, because it is a geographic level where many important decisions are made, and where product standardization may be appropriate. We then identify the twenty MNEs with the highest foreign-to-total (F/T) sales ratios in the UNCTAD list of most internationalized companies in terms of foreign asset base that are also Fortune 500 firms. For this set of large, highly internationalized companies, we measure the distribution of their sales across triad regions. We find that only three of these firms actually have a substantial portion of their sales across all three legs of the triad. The other MNEs are either bi-regional, host-region oriented or home-triad region oriented. In other words, the empirical evidence reveals that even these highly internationalized MNEs do not have a balanced global distribution of sales. We further elaborate on this empirical finding by investigating whether a regional component can be identified in twelve specific cases of MNE strategy, building upon our new framework.globalization, regionalization, triad, transnational enterprises, triad home-base, regional, global, bi-regional, Wal-Mart