Asynchronous,Iterative, and Parallel Procedures for Solving the Weighted-Region Least Cost Path Problem

A family of local, asynchronous, iterative, and parallel procedures (LAIPPs) are described. These procedures are designed to find least cost paths (LCPs) in bounded regions of the plane that have been partitioned into triangular subregions. The unit cost of traversing a given subregion is uniform within the subregion, but varies between subregions. In the case of one-dimensional chains of triangles, the procedures are guaranteed to converge to a global LCP. Although the procedures are guaranteed to terminate, we have so far been unable to prove, in the general case of a two-dimensional triangulation, that the procedures always terminate in admissible paths. Extensive experimental investigations, however, have revealed convergence to admissible paths in all cases examined. While counterexamples are constructed to prove that the procedures may converge to the local rather than global LCPs, convergence to the global LCP was found to occur in nearly all of our experimental investigations. The computational complexity of the procedures, as measured by the number of iterations required for convergence, was found experimentally to be independent of the size of the domain in which the paths lay, and to be slightly greater than linear in the Euclidian length of the paths. The complexity was also found to depend on the cost structure of the domain. Such LAIPPs appear to be promising procedures for both application and further investigation. In particular, the question of convergence is an interesting problem.     

Microstructural,chemical and isotopic evidence for the origin of late neolithic leather recovered from an ice field in the Swiss Alps

Archaeological leather samples recovered from the ice field at the Schnidejoch Pass (altitude 2756 m amsl) in the western Swiss Alps were studied using optical, chemical molecular and isotopic (δ¹³C and δ¹⁵N of the bulk leather, and compound-specific δ¹³C analyses of the organic-solvent extracted fatty acids) methods to obtain insight into the origin of the leather and ancient tanning procedures. For comparison, leathers from modern native animals in alpine environment (red deer, goat, sheep, chamois, and calf/cow) were analyzed using the same approach. Optical and electron microscopically comparisons of Schnidejoch and modern leathers showed that the gross structure (pattern of collagen fibrils and intra-fibrils material) of archaeological leather had survived essentially intact for five millennia. The SEM studies of the hairs from the most important archaeological find, a Neolithic leather legging, show a wave structure of the hair cuticle, which is a diagnostic feature for goatskins. The variations of the bulk δ¹³C and δ¹⁵N values, and δ¹³C values of the main fatty acids are within the range expected for pre-industrial temperate C₃ environment. The archaeological leather samples contain a mixture of indigenous (from the animal) and exogenous plant/animal lipids. An important amount of waxy n-alkanes, n-alkan-1-ols and phytosterols (β-sitosterol, sitostanol) in all samples, and abundant biomarker of conifers (nonacosan-10-ol) in the legging leathers clearly indicate that the Neolithic people were active in a subalpine coniferous forest, and that they used an aqueous extract of diverse plant material for tanning leather.     

Borderless sport? Imagining and organising bicycle racing in Belgium, 1869–1914: between transnational dynamics and national aspirations

From the 1860s onwards, the new sport of bicycle racing engendered transnational flows of ideas, practices and performers. However, national actors and sensitivities always remained present. In interaction with these transnational flows they shaped national identity in this sport, as the Belgian case shows. Belgium was a site of cross-border interaction for racing from early on. Nevertheless, actors like the Belgian cycling press or national cycling union also continuously tried to construct a ‘national’ racing culture. French and British influences were especially crucial here, as Belgian actors were continuously torn between both in determining their position in the amateur–professional question or in the International Cycling Association. France and Britain thus functioned as ‘significant others’ in the shaping of ‘national’ Belgian racing, a process often complicated by the transnational activities of other, commercially motivated actors like cycling tracks or racers themselves. In competition, too, the discourses of the Belgian press on racers Hubert Houben and Robert Protin celebrated their ‘small nation’ and its success against and differences from its bigger neighbours. The Belgian orientation on French racing eventually became dominant, and proved to be crucial to the resurrection of the sport in Belgium after a period of crisis around 1900.     

委内瑞拉，奥里诺科河上的探险

奥里诺科河是亚马逊河上一条光涌的逆流，更是一段有关虔诚的传教士和印第安土著人的古老故事。     

Particle size distribution of lithic assemblages and taphonomy of Palaeolithic sites

Lithic debris derived from knapping and used tools can be assimilated to simple sedimentary particles that may undergo size sorting when exposed to geomorphic processes such as streamflow or overland flow. Sorting can be identified by comparing the size distribution of archaeological assemblages to that of experimental core reduction sequences. A new database including different types of raw material (mainly flint and quartzite) and Palaeolithic debitage (blade, Levallois, discoid, on anvil, and shaping) has been built for this purpose. Palaeoeskimo data have also been added to illustrate microlithic industries. For all the debitages and raw materials, the particle size of knapping products >2 mm in width fits with a power-law distribution and shows only minor fluctuations, the range of which is always <15% between experiments (all steps of the chaîne opératoire included up to the final tool). A lithic assemblage derived from block/core knapping or blank/preform production will display a particle size distribution close to the experimental distributions if not subsequently modified. Modifications may originate either from sedimentary processes or from anthropogenic factors. To help distinguishing amongst these, data on the impact of both water flows on sedimentary particles or experimental assemblages, and anthropogenic processes such as importation-exportation (of core, preforms or finished tools) or uneven spatial distribution of the different steps in core reduction and tool production within a site, are reviewed. By contrast to anthropogenic modifications, sedimentary processes are generally typified by strong impoverishment in or selective accumulation of fine-grained (<10 mm) artefacts together with a low intra-site variability (spatial homogenization) or a downslope size trend. Archaeological case studies taken from French Palaeolithic site are then detailed. Evidence for lithic redistribution implies that care should be taken in archaeological site analysis since sorting may impact significantly the initial techno-typological balance of the assemblage.     

Impacts of Market Liberalization on Regulatory Network: A Longitudinal Analysis of the Swiss Telecommunications Sector

This article looks at the reconfiguration of the regulatory actors' network, as induced by the liberalization and reregulation processes in utility sectors. It investigates the changes in governance structures and patterns of collaborative ties between actors resulting from these processes. Applying stochastic actor‐oriented modeling (SAOM) to data on the liberalization of the Swiss telecommunications sector over two decades, we test whether and to what extent structural changes driven by liberalization and reregulation express themselves through network effects, that is, through changing patterns of interactions between political authorities, regulators, regulatees, and interest groups. Our empirical tests highlight a rearrangement of the regulatory network and a reorganization of relational patterns around new actors, such as the sector‐specific regulatory agency, coregulators, and new operators.     

The creative industries: conflict or collaboration? An analysis of the perspectives from which policymakers,art organizations and creative organizations in the creative industries are acting

This paper compares and contrasts the instruments and values formulated in the creative industries policies of three peripheral municipalities of between 150,000 and 220,000 inhabitants in the Netherlands (Groningen, Arnhem and Eindhoven) with the needs of the creative industries itself. The needs of the creative industries have been empirically researched by conducting an online survey (n = 556) and twelve in-depth interviews with professionals from different types of organizations in the creative industries. In this study, the theoretical framework of Boltanski, Thévenot and Chiapello is used in the analysis of policy documents, the outcomes of the online survey, and the in-depth interviews in order to uncover differences and similarities in perspectives from which art organizations, creative organizations and policymakers are acting in the creative industries.     

A new approach to sexual diagnosis in past populations. Practical adjustments from Van Vark's procedure

Determination of sex is a key aspect in the study of past populations. Bias in skeletal sexing is well known, however, and depends upon the completeness of the skeletal remains and the representativeness of reference samples. In order to correct these difficulties, the authors propose practical adjustments to Van Vark's well‐known procedure. Two fundamental aspects are considered to reduce the bias of sex allocation. First, we propose to increase the effectiveness of sexing during the first step (primary diagnosis only from the pelvic bone). Second, to improve the final step (secondary diagnosis from the extra‐pelvic skeleton), we consider posterior probabilities as essential. These two practical adjustments are successfully tested in a sample of known sex and lead to a classification with 94.5% accuracy. These results significantly improve sex determination in archaeological samples and therefore contribute to a better understanding of past populations. Copyright © 1999 John Wiley & Sons, Ltd.