Elimination of Source A and B Errors in p-Median Location Problems

The p-median problem is a powerful tool in analyzing facility location options when the goal of the location scheme is to minimize the average distance that demand must traverse to reach its nearest facility. It may be used to determine the number of facilities to site, as well as the actual facility locations. Demand data are frequently aggregated in p-median location problems to reduce the computational complexity of the problem. Demand data aggregation, however, results in the loss of locational information. This loss may lead to suboptimal facility location configurations (optimality errors) and inaccurate measures of the resulting travel distances (cost errors). Hillsman and Rhoda (1978) have identified three error components: Source A, B, and C errors, which may result from demand data aggregation. In this article, a method to measure weighted travel distances in p-median problems which eliminates Source A and B errors is proposed. Test problem results indicate that the proposed measurement scheme yields solutions with lower optimality and cost errors than does the traditional distance measurement scheme.     

Migration,Human Resource Transfers,and Development Contexts: A Logit Analysis of Venezuelan Data

This paper is concerned with the reciprocal relationship between migration and development in Third World settings. Using individual-level data for Venezuela, migration behavior is related to a person's age, educational attainment, gender, and characteristics of his/her place(s) of residence as an out-migrant, in-migrant, or stayer. Place characteristics are in terms of four groups based on employment patterns: the core, regional centers, resource frontiers, and traditional rural areas. Four questions are of concern. First, does development influence migration? All analyses indicate this is so. Second, does migration influence development? Findings are ambiguous in that places experiencing improvement in their mix of human capital lagged in the net number of persons obtained through migration whereas a gain in numbers was accompanied by deterioriation in human capital profiles. Third, was incipient polarization reversal occurring in Venezuela in the late 1960s, early 1970s? This paper departs from the usual approach by addressing this question in terms of human capital attributes instead of population aggregates. On this basis, polarization reversal is in evidence, particularly in regional centers. Finally, this study answers in the affirmative that places with different development characteristics generate migration streams differing in type, magnitude, explanation, and impact.     

Recursive Algorithm for Determination of Proximal (Thiessen) Polygons in Any Metric Space

A new and recursive algorithm for determining proximal polygons is based on quadtree concepts. The algorithm can use any distance metric, and produces a quadtree of the image of the proximal polygons. This can be converted to vector form, or be incorporated directly into a quadtree-based geographic information system, in order to solve a number of closest-point problems. The algorithm can also produce the Delaunay triangulation, which is the dual of the proximal polygons. Empirically, the running time of the algorithm is proportional to the number of centers raised to the 1.6 power.     

Culture,technology and policy in the informal sector: attention to endogenous development

243 blacksmiths in Sierra Leone were interviewed in 1984-85 in an effort to focus on both the activities and attitudes of traditional blacksmiths in the country's economy. Due to the fact of an shortage of foreign exchange with which to import and maintain equipment, agriculture using high-technology equipment accounts for less than 15% of total production. Consequently, blacksmiths are vital to the nations' survival, despite prevailing attitudes toward them. The interviews were conducted in 9 of the 12 districts in Sierra Leone. The blacksmith operates not simply in terms of producing and servicing goods; cultural values frame his position in the community. In all of West Africa, and particularly among Mende-related peoples, there historically exists a mystique surrounding a blacksmith. In some societies, blacksmiths were believed to be witches. The arguments that most likely could account for this would probably lie in the fact that the blacksmith made farm tools and weapons of war, means of survival in the community. Thus, his position was vital. Traditionally the importance of the smith's profession lies in the fact that some of the implements he fabricates and the materials he uses are believed to provide elements of social control or to have healing powers. An appreciation of the cultural significance of the blacksmith demonstrates the degree of attachment of the population to this profession as well as the context within which one could relate to possible technological changes in the trade. An attempt was made in the interview to gather some information about levels of production. The figures represent averages, and production capacity varied owing to a number of factors, including the degree of organization of the unit, the capacity of the head of the forge to keep his team busy when work was intensive, and the degree of energy and determination of an operator to get the greatest amount of work done in 1 day. The most obvious factor influencing production levels was the size of the units. Pricing of commodities and the blacksmith's services depended on a combination of factors, but, generally, in semi-urban areas, where more impersonal relationships tended to obtain, prices appeared relatively more fixed than in rural areas. All smiths interviewed complained about the increasing scarcity of scrap iron. As there is every reason to envisage a continued dependence on informal-sector production by blacksmiths, official attitudes need to take these trades more seriously.     

What can supraspecies richness tell us?

Biogeographers, ecologists, palaeontologists, and conservation managers often deal with checklists in which not all individuals have been identified to a species level, or the accuracy of species identification is questionable. Is it possible and credible to investigate species richness based on such checklists? Studies on macrofauna in the Far Eastern seas, eastern Arctic seas, and adjacent waters of the Pacific and Arctic Oceans suggest that in different habitats and for diverse taxa, species, and higher taxa richness strongly correlate with each other and increase with an expansion in the study area and sample size according to the species–area law. Such an increase is higher in the bottom zone than in the pelagic. Species and higher taxa richness also show a decrease from lower to higher latitudes, which is in line with the Humboldt–Wallace’s law. According to Willis’ law and self-similarity in the organisation of taxonomic levels, species richness can be assessed based on the genus, family, and order richness. In other words, supraspecies richness itself can tell us the same as species richness and therefore certain global patterns revealed at the species level may also be revealed at the supraspecies level. Such a concordance in general trends among richness parameters at different taxonomic levels in practice implies that species richness can be studied based on lists that lack species identifications or lists with doubtful species identification. We suggest bolder use of supraspecies richness in science and practice, discussing the disadvantages and advantages of this approach.     

Female Personifications and Masculine Forms: Gender,Armour and Allegory in the Habsburg–Valois Conflicts of Sixteenth-Century Europe

This article examines the visual and material culture of sixteenth-century elite ceremonial armours and the paradoxes inherent in using images of women to decorate them between 1525 and 1550. It argues that foreign invading forces and their allies exploited or inverted traditional gender binaries associated with the classical and humanist iconography of the Italian Renaissance, particularly its female allegorical forms, to visually signify power relationships between combatants during the Italian Wars. Rather than simply embodying masculinity, elaborate ceremonial armours with images of women are revealing of both ideals of masculinity and femininity during times of war. These portrayals were part of wider conversations about gender and power, about the strength and weaknesses of women, and, ultimately, women's inferior status to men, which were utilised in allegorical forms to make claims to authority on these elite forms of male dress.     

Port Royal, Jamaica: The archaeological problems and potential

In September 1968, one of the authors (P. Mayes), having been appointed Head of Mission by the British Ministry of Overseas Development to act as advisor to the Jamaica National Trust Commission, made recommendations which formed the basis for the establishment of the Port Royal Project. The Project is concerned with the excavation, conservation and presentation of 17th century Port Royal, which was founded in 1655 and destroyed by an earthquake in 1692 (see Fig. 1). For the purposes of archaeology the area was divided into three: the Archaeological-Historical Reserve, encompassing the protected underwater area and lands currently occupied by government facilities at the west end of Port Royal; the area in the centre of Port Royal which is protected archaeologically by modern housing and the area at the east end of Port Royal in which it was proposed that commercial expansion should be allowed on land held on lease from the Jamaican government. Work began early in 1969 in a section of this last area, which was threatened, at that time, by the construction of an hotel. This area was part of the shoal water section of sunken Port Royal (see below and Fig. 2). Since that date excavation headquarters and conservation laboratories have been established in the old naval hospital and the construction of a major museum, the first phase of the presentation programme, has begun.