bluuebunny/crossref_metadata_2025 huggingface dataset:
Classed versus Unclassed Choropleth Maps: A Question of How Many Classes
Authors: CROMLEY ROBERT G.
Published: April 2007

The question of classed versus unclassed maps can be rephrased as a question of how many classes to use. An unclassed map has as many classes as there exist unique data values in the distribution. However, not all of these classes may be necessary if the map reader cannot discriminate among the graphic values representing unique numerical values. This paper presents an optimal classification scheme that minimizes the number of classes for a given level of value discrimination. Results show that far fewer classes than those found in an unclassed map are necessary to portray the underlying spatial structure of the data distribution. Cartes statistiques classifiées et non classifiées : combien de classes? La question qui surgit propos des cartes classifies, par opposition aux cartes non classifies, peut tre revue comme un questionnement sur le nombre de classes utiliser. Une carte non classifie a autant de classes qu'il existe de valeurs de donnes uniques dans la distribution. Par contre, toutes ces classes peuvent ne pas tre ncessaires si le lecteur de la carte ne peut pas diffrencier les valeurs graphiques reprsentant chaque valeur numrique unique. Cet article prsente un plan de classification optimal qui minimise le nombre de classes pour un niveau donn de diffrenciation de valeurs. Les rsultats montrent que, pour reprsenter la structure spatiale sous-jacente de la distribution de donnes, il faut beaucoup moins de classes que ce que l'on trouve dans une carte non classifie.
THE RELATIVE EFFECTIVENESS OF SOME COMMON GRADUATED POINT SYMBOLS IN THE PRESENTATION OF QUANTITATIVE DATA
Authors: FLANNERY JAMES JOHN
Published: April 2007

Circles with their areas varying in direct proportion to quantities represented are a common form of graduated point symbols. When so used, unfortunately, the average map reader perceives a smaller quantitative difference than intended because circle size differences are usually underestimated. An apparent size scale developed empirically fifteen years ago is claimed to eliminate the problem of consistent underestimation. More recent investigations by psychologists and cartographers support the apparent size scale. Bars communicate quantitative variation effectively when graduated in the traditional manner on a linear basis, but wedges require an apparent size scale and even then are less accurately judged. Les cercles dont la surface varie en proportion directe de la quantité à représenter constituent une forme habituelle de symbole quantitatif. Leur utilisation à cette fin, malheureusement, a pour résultat que le lecteur de la carte perçoit souvent une différence quantitative moindre que celle que l'on désire signifier parce qu'il lui est facile de sous-estimer la différence entre les dimensions des cercles. Une échelle de dimensions apparentes établie de manière empirique il y a une quinzaine d'années devait éliminer ce problème, et des études psychologiques et cartographiques récentes appuyaient cette échelle. Les traits représentent efficacement les variations de quantité lorsqu'ils sont gradués de manière conventionnelle, c'est à dire linéaire, mais les secteurs appellent une échelle de dimensions apparentes et leur ordre de grandeur est plus difficile à juger.
Getting There without Aiming at It: Women's Experiences in Becoming Cartographers
Authors: Van Den Hoonaard Will
Published: April 2007

This article presents findings from an ongoing study of gender and cartography. In this paper, I offer narratives from interviews with some 38 women cartographers from 21 countries and in 15 languages. The narratives explain how women have become interested in cartographic work, their formative years, and the distinctive twists and turns of their becoming cartographers. I also describe their identifying moments as occupational incumbents. The article is sociological in nature and uses a qualitative methodology.
GIS: MODELS OF USE AND IMPLICATIONS FOR SERVICE DELIVERY ON HIGHER EDUCATION COMPUTING CAMPUSES
Authors: Wise Stephen
Published: April 2007

The Computer Board and the Inter-University Software Committee are attempting to increase the availability of top quality GIS software in the academic sector. The intention is to recommend a product for central purchase, which will give all Higher Education institutions the opportunity to purchase commercial GIS software on extremely favourable terms. GIS has the potential to be of use to a very wide range of disciplines. In order for this potential to be realised, GIS software must be made available as part of the range of services provided and supported by the central computer services of Higher Education Institutions. A focus for discussion is provided by identifying the problems and issues of how the software is made available and how support and training are given.
RUSSIAN CARTOGRAPHY OF THE 18th CENTURY AS A SYNTHESIS OF ASTRONOMIC-GEODETIC AND GRAPHIC PROCESSES
Authors: FEL S YE
Published: April 2007

The author, a specialist in Russian cartography of the 18th century, discusses the causes, dimensions, and results of cartographic and geodetic progress from the pre-Petrine to the post-Petrine era. He cites the inauguration of scientific expeditions and systematic research, the circulation of geographical questionnaires, the scientific training of cadres, the development of an accurate mathematical foundation with astronomically-determined control points, the transition from "sketch and interview" surveying to instrument surveying with triangulation, levelling, and traversing, the devising of new projections, the tackling of the problem of generalization, the introduction of non-perspective symbols and hachures, the gradual simplification of the map's external design, the transition from manuscript maps of small areas to copper-engraved maps of the whole country, the publication of numerous maps and atlases with diverse content and various uses, and the enlistment of cartographic science to solve practical state tasks and to promote economic development. L'auteur, un spécialiste de la cartographie russe du XVIIIe siècle, traite des causes, des dimensions et des résultats des progrès effectués dans les domaines de la cartographie et de la géodésie, de l'époque antérieure à Pierre le Grand à l'époque postérieure à son règne. Il traite du début des expéditions scientifiques et de la recherche systématique, de la distribution de questionnaires géographiques, de la préparation scientifique des cadres de l'armée, de l'élaboration d'une base mathématique appropriée avec des repères choisis grâce à l'astronomie, de la transition de l'étape des relevés faits au moyen "d'esquisses et d'entrevues" à celle des relevés faits au moyen d'instruments et de la triangulation, du nivellement et du levé par intersection, de l'invention de nouveaux planisphères, de la solution du problème de la généralisation, de l'introduction de symboles et de hachures non perspectifs, de la simplification graduelle de la ligne de la carte, du passage de la carte manuscrite de régions limitées à la carte de tout le pays gravée sur cuivre, de la publication de plusieurs cartes et atlas au contenu divers et aux usages variés et de l'utilisation de la science géographique pour résoudre des problèmes pratiques qui se posent à l'Etat et pour promouvoir l'expansion économique.
MANUSCRIPT MAPS IN LATE IMPERIAL CHINA
Authors: CHANG SEN-DOU
Published: April 2007

This paper, based on collections of Oriental maps in the Library of Congress and in the British Museum, describes the cartographic characteristics of manuscript maps made in late Imperial China and evaluates their role in cartographic history in a world perspective. Chinese manuscript maps were constructed by local authorities in great numbers for various administrative, water control, military, and ideological purposes. While Chinese cartographers seemed quite content with much limited planimetric information, they devoted their efforts almost entirely to the perfection of symbolization and the visual effectiveness of map design for its own artistic value. Chinese maps were oriented in a few peculiar ways to serve functional and ideological needs. Pictorial map symbols which were so elaborately designed reflected a good deal of Chinese perception of physical and cultural features in various periods. The distortion and exaggeration of many planimetric features on these maps were associated with certain institutional and cosmological beliefs.
The Utopian Potential of GIS
Authors: Warren Stacy
Published: April 2007

Lively debate has surrounded the emergence of geographic information systems (gis) as a formidable presence in both intellectual and applied geographic circles. Earlier discourses that polarized gis into two mutually exclusive camps — neutral, objective tool vs. positivist, theoretically corrupt weapon — have more recently been tempered through the infusion of conceptual vantage points such as feminist theory and theories of science as socially constructed practice. The widening array of uses to which gis is now put, including everything from missile sitings and gerrymandering to movements for social and environmental justice, make it even more imperative to situate gis inquiry within broader frameworks that can encompass the richly contradictory cultural, political, and economic landscapes of technology. In this paper, I home in on a case study of a local, fledgling public participation gis (ppgis) effort in order to understand gis as part of the longer trajectory of people's struggles with and against the machine within industrial capitalism. Specifically, I draw from utopian studies to propose that gis can be seen as a contemporary manifestation of the utopian impulse, where technology is both the problem and, when inserted into more emancipatory social settings, the potential cure. The loosely organized collection of people working locally to use gis, in small and often disconnected ways, to interfere in the fabric of industrial (and post-industrial) capitalism in fact represents a utopian undertaking to confront geographically specific problems and create the "better life in the better place."
A New Approach for the Simplification of Contours
Authors: Gökgöz Türkay , Selçuk Mehmet
Published: April 2007

The requirements for the simplification of contours are explained, and existing approaches for the generalization (i.e., simplification and smoothing) of contours are briefly summarized. Skeleton lines (i.e., drainage and ridge lines) are supposed to provide information for the determination of characteristic parts of contours. Characteristic points are automatically determined during the process of deriving skeleton lines from contours in accordance with the method developed by Aumann, Ebner, and Tang (1991). Three widely used algorithms for the simplification of contours - nth point, distance tolerance, and Douglas-Peucker - are examined. They are analysed with respect to the retention of characteristic parts of contours, based on case studies. Finally, the algorithms are modified in such a way as to consider the determined characteristic points. A new simplification criterion is included in the algorithms, ensuring that they retain the characteristic parts of contours.
Cartographic Results Of The General Survey Of Russia 1766–1861
Authors: TSVETKOV M. A.
Published: April 2007

The late author (1875–1960), who specialized in the historical geography and mapping of forests, describes the atlases, maps, plans, and notes produced by the General Survey of thirty-five provinces of European Russia in the last half of the 18th and the first half of the 19th century. He discusses the purpose, administration, coverage, and duration of the survey and the content, value, and location of the resultant maps and notes, almost all of which have survived in unpublished form in various Soviet archives. Their value for historical geographers is illustrated by several excerpts.
Color Stereoscopic Effect Cartography
Authors: EYTON J RONALD
Published: April 2007

A method for displaying autostereoscopic maps based on a phenomenon known as the color stereoscopic effect is presented. The technique involves coding the map in a spectral sequence of colors with the result that the short wavelength colors (blue, cyan, green) appear further from the eye (lower elevation) than the long wavelength colors (yellow, orange, red) which appear closer to the eye (higher elevation). A black raster contour overlay enhances the depth effect and a smaller contour interval creates a greater perception of relief. The use of fluorescent inks to print the map produces a display with bright, pure colors and enhances the color stereoscopic effect. A continuous spectral color coding scheme increases the realization of the three-dimensional form in the stereo image. Hillshaded overlays, with and without contours, cued the color stereoscopic effect and produced easily perceived depth in the maps.
CARTOGRAPHIC TECHNIQUES FOR MAPPING SEA ICE
Authors: BLACK W. A.
Published: April 2007

La cartographie de la glace de mer dans le Golfe du Saint-Laurent entraîne des difficultés particulières, car les vents, les marées, les courants et la température influent sur la croissance et la distribution des champs de glace. Ceux-ci ont fait l'objet d'un relevé aérien exécuté tous les dix jours en coopération avec l'ARC, par temps clair. Les caractéristiques des champs de glace, telles que concentration, inclinaisons, limites, chaînes de pression et type de la glace, ont été reportées sur des ébauches au millionième. Pour utiliser efficacement ces données, un système de classification a été mis au point; il indique graphiquement les types de glaces et les concentrations des champs de glace. Un schéma partiel superposéaux graphiques apporte des renseignements supplémentaires. Les cartes définitivesont été exécutées à l'echelle de 35 milles au pouce.
Data Intermediation and Beyond: Issues for Web-Based PPGIS
Authors: WONG SIDNEY , CHUA YANG LIANG
Published: April 2007

This article explores the implications of moving public participation GIS (PPGIS) onto the World Wide Web. It discusses the potential benefits and impediments of using the Web for PPGIS application; it then uses a PPGIS project developed solely on the Web as a case study to illustrate various issues such projects may face. It finds that the cost-benefit calculus in this transition is ambivalent: whereas some costs decrease, other threshold costs actually increase. Moving PPGIS to the Web will not undermine the traditional intermediation role of PPGIS but, rather, diversify it. The Web helps attract "occasional users" to use GIS; however, this creates new challenges for PPGIS providers, who used to work with defined clients and must now cultivate client support to anonymous clients. The Web has greatly improved connectivity and data access, which, in turn, promote collaboration among geographic and non-geographic information providers. In this context, the Web increases awareness of integrating non-geographic information such as local knowledge into GIS operations. The article concludes that Web technology alone is not sufficient to enhance the capability of every community group and resident to use GIS, to change the reality that GIS is a specialized skill, or to significantly level the unequal socio-economic or political relationships that hinder participation in distressed communities.
Professional Training As A Factor In The Proliferation Of GIS Applications
Authors: Dymon U T E J
Published: April 2007

Highly trained technicians and knowledgeable professional conceptualizations are two complementary ingredients necessary for effective applications of Geographic Information Systems. This study focuses on the kind of background and professional training required of the users and how they currently apply GIS. Results of a survey of two hundred users in Massachusetts, United States, reveal mat the majority do not possess formal training in the technique but developed the necessary skills on the job. Based on the length of their experience with GIS, two groups of users, the computer science experts and the planner/managers, emerged from the survey data. While the majority of these users are satisfied with their mastery of their respective systems, many users indicated that they needed between three and six months to become proficient in operating a GIS. Numerous cases of failures in attempts to implement a GIS were also cited by users. Deux ingrdients complmentaires sont ncessaires pour une application efficace des systmes d'information gographique (SIG): des techniciens hautement forms et des conceptualisations professionnelles savantes. Cette tude se concentre sur la nature de la formation professionnelle requise chez les usagers ainsi que la manire d'appliquer couramment les SIG. Les rsultats d'une enquªte auprs de deux cents usagers au Massachussets, aux Etats-Unis, rvlent que la majorit d'entre eux ne possdent pas de formation spcifique dans la technique, mais ont dvelopp les habilets ncessaires en cours d'emploi. Sur la base de la dure de leur exprience aves les SIG, deux groupes d'usagers sont ressortis des rsultats de l'enquªte: les experts en informatique et le groupe des gestionnaires-planificateurs. Alors que la majorit de ces usagers sont satisfaits de leur ma®trise de leurs systmes respectifs, plusieurs ont indiqu qu'ils avaient eu besoin de trois   six mois pour se sentir   l'aise dans l'opration d'un SIG. Certains usagers ont aussi racont de nombreux cas d'chec lors de certaines tentatives d'implantation d'un SIG.
The Public Cartographic Labor Process in the United States: Rationalization Then and Now
Authors: McHAFFIE P H
Published: April 2007

The cartographic labor process has remained relatively unexamined by cartographic historians. The entry of 'scientific management' into the realm of public cartographic production under the auspices of the U.S. Geological Survey presents a striking illustration of the rationalization of production procedures as the result of technological change. In particular, the adoption of contours as a method of representing terrain and the introduction of aerial photography and photogrammetry into the labor process shed light on the technological restructuring of the 1970s and 1980s. Le processus de travail cartographique a subi relativement peu d'examens de la part des historiens cartographiques. L'apparition de la 'gestion scientifique' dans le domaine de la production cartographique publique, sous les auspices des Levés géologiques des États-Unis, présente une illustration frappante de la rationalisation des procédures de production comme résultat de changement technologique. En particulier, l'adoption des courbes de niveau pour représenter le terrain et l'introduction de la photographie aérienne et de la photogrammétrie dans le processus de travail ont levé le voile sur la restructuration technologique des années 1970 et 1980.
EARLY FRENCH MAPPING OF THE WESTERN INTERIOR OF CANADA: A VIEW FROM HUDSON BAY
Authors: RAY ARTHUR J
Published: April 2007

This article examines three hitherto unpublished French maps of the western interior of Canada which were apparently drafted sometime between 1724 and 1741. Investigation reveals that these maps were based largely upon the information supplied by Nicolas Jérémie, who was an important officer at Fort Bourbon (York Factory) under the French. The maps constitute a cartographic style which is quite distinct from those that have already been identified. Furthermore, they allow us to retrace the steps involved in their construction from initial sketch drawing to final map copy. Finally, they provide a better picture of the geography of the region than do most other maps which were drawn during the early 18th century.
An Examination Of Techniques For Reformatting Digital Cartographic Data / Part 2: The Vector-To-Raster Process
Authors: Peuquet Donna J
Published: April 2007

Current graphic devices suitable for high-speed computer input and output of cartographic data are tending more and more to be raster-oriented, such as the rotating drum scanner and the color raster display. However, the majority of commonly used manipulative techniques in computer-assisted cartography and automated spatial data handling continue to require that the data be in vector format. This situation has recently precipitated the requirement for very fast techniques for converting digital cartographic data from raster to vector format for processing, and then back into raster format for plotting. The current article is the second part of a two-part paper that examines the state of the art in these conversion techniques. In Part 1, algorithms to perform all phases of the raster-to-vector process were outlined and compared. This paper outlines and compares algorithms to perform each phase of the vector-to-raster process. Methods for combining these algorithms into an efficient, integrated process are presented; they are followed by a discussion of the raster-to-vector conversion process as a whole including commonalities, methods for improving the overall process, and directions for future research.
Exploring the Quality of Enumeration-Area Data with Graphic Scripts
Authors: MONMONIER MARK
Published: April 2007

Awareness of uncertainty and variability is essential for the reliable use of geographic data tabulated for census tracts, counties, and other enumeration areas. Users of census information and other primary areal-unit data commonly ignore errors inherent in questionnaire design and census enumeration. And these users further increase uncertainty for themselves and their readers through classification, aggregation, derivative measurements, and other data-compression techniques. This secondary uncertainty calls for programmed graphic seqeuences, known as 'graphic scripts', designed both to reveal variation hidden by analytical techniques and to identify likely blunders in the primary data. Graphics scripts can force an analyst or audience to look at different perspectives provided by complementary measures, to consider how classification affects the stability of a numerical result, and to explore the effects of temporal and spatial aggregation. This paper uses a series of hypothetical screen snapshots to demonstrate how a graphic script addressing these issues can heighten an analyst's awareness of the variation, reliability, and meaningfulness of census results and other aggregated data reported by enumeration area.
THE EDUCATIONAL CHALLENGES OF A NEW CARTOGRAPHY
Authors: TAYLOR D R F
Published: April 2007

This paper argues that the major technological and socio-economic changes of the 'information revolution' are so extensive that if cartography is to play a role then the development of an entirely new cartography is necessary. The paper discusses the extent and nature of a new cartography and argues that education in cartography will have to change if the challenge is to be met.
PRIMITIVE CARTOGRAPHY IN THE MARSHALL ISLANDS
Authors: WISE DONALD A
Published: April 2007

One of the earliest forms of primitive cartography was the stick chart used by the natives of the Marshall Islands. There are two schools of thought among scholars concerning primitive man's ability to develop such an expertise in navigation and map making. Modern studies tend to support the thesis that the Marshallese had the knowledge to make deliberate voyages using the art of navigation and stick charts to make precision landfalls. Three types of stick charts were developed – mattang, meddo and rebbelib. One type was used for training purposes and the other two types were charts of different scales to cover varying areas of the Marshall Islands. Three replicas of stick charts in the Library of Congress cartographic collections are briefly described and illustrated. L'une des premières formes de la cartographie primitive fut la carte marine faite de bâtons et de coquillages, employée par les indigènes des îles Marshall. Il existe deux écoles de pensée parmi les érudits en ce qui concerne l'aptitude de l'homme primitif à développer une telle maîtrise de la navigation et de la cartographie. Les études modernes tendent à soutenir la thèse suivant laquelle les habitants des îles Marshall avaient les connaissances voulues pour effectuer délibérément des voyages en employant l'art de la navigation et les cartes marines faite de bâtons faire des atterrissages de précision. Trois genres de ces cartes marines ont été mis au point; mattong, meddo, et rebbelib. Un genre était utilisé pour la formation et les deux autres étaient des cartes à différentes échelles qui couvraient diverses régions des îles Marshall. Trois répliques de ces cartes marines, qui font partie des collections cartographiques de la Bibliothèque du Congrès, sont décrites brièvement et illustrées.
THE EFFECTS OF CLASS INTERVAL SYSTEMS ON CHOROPLETH MAP CORRELATION
Authors: OLSON JUDY
Published: April 2007

The correlation between a pair of distributions is often measured with the product-moment correlation coefficient, r. But the choropleth maps of the same distributions may be more alike or less alike than that coefficient would indicate. The degree to which map likeness corresponds to the correlation between the data before mapping is affected by the class interval method used. Using rank correlation (Kendall's t) to measure the map correlation and drawing data from normal distributions, it is found that: (1) there is a mathematically expressible curvilinear relationship between the product-moment correlation and the expected map correlation; (2) this relationship appears to remain identical regardless of class interval system; (3) the standard deviation about the expected values does vary from one class interval system to another. Smaller standard deviations are associated with increased numbers of observations within each variable and with increased numbers of intervals. For a given r value, number of observations, and number of intervals, systems with more nearly equal numbers of observations in each category have smaller standard deviations.
A Framework For Temporal Geographic Information
Authors: LANGRAN GAIL , CHRISMAN NICHOLAS R
Published: April 2007

This paper defines the critical components of cartographic time and compares temporal and spatial topologies. Because time is topologically similar to space, spatial data structuring principles can be adapted to temporal data. We present three conceptualizations of temporal geographic information and select one as the most promising basis for a temporal geographic information system. This conceptualization creates a spatial composite of all geometric information (at all times), where each object has an attribute history distinct from that of its neighbors.
USING COMPUTER DEMONSTRATORS AND TUTORS IN GIS TEACHING: LESSONS FROM THE DEVELOPMENT OF GEOGRAPHICAL INFORMATION SYSTEMS TUTOR
Authors: Raper Jonathan
Published: April 2007

With the rapid growth in the use of GIS has come an acute skills shortage. Whilst traditional techniques of education and training based on courses at various levels are being widely exploited, there is special potential in GIS for the use of demonstrators and tutors. Such Computer Aided Learning (CAL) tools offer an effective way of putting across the graphical concepts which are vital to GIS as well as offering an attractive form of self-paced study. This paper discusses the contribution of CAL tools to GIS education and offers a short history of the techniques. A case study of the Geographical Information Systems Tutor (GIST) development is used to illustrate the educational and technical issues behind the creation and use of such a tool.
REFINING LEGEND VALUES FOR PROPORTIONAL CIRCLE MAPS
Authors: DOBSON MICHAEL W
Published: April 2007

Much research has been generated concerning the minimization of size judgment errors which occur during the reading of maps symbolized with proportional circles. However, unwise selection of legend values may inhibit the transformation of information and render the map ineffective as a graphic display. Criteria for selecting legend values are discussed and an iterative optimization technique is proposed as a method of selecting the numerical values to be symbolized in the legend.
Tactual Maps And Graphics/Some Implications For Our Study Of Visual Cartographic Communication
Authors: CASTNER HENRY W
Published: April 2007

This paper considers some of the implications for thinking about mapping in the visual area when considering the limitations and problems that arise for tactual map users and for the designers of graphics for the blind. A suggestion is made as to how the Canadian Cartographic Association might facilitate a Canadian effort in fostering the continuation of the momentum initiated at the 1st International Symposium on Maps and Graphics for the Visually Handicapped held in Washington, D.C, in March, 1983. L'article traîte des implications de la conception des cartes pour les voyants lorsqu'on considère les limites et les problèmes qui confrontent les utilisateurs de cartes tactiles et les concepteurs de graphiques a l'usage des aveugles. On suggère une façon par laquelle l'Association canadienne de cartographie pourrait faciliter un effort du Canada en vue d'encourager la poursuite du mouvement qui a pris naissance en mars 1983, a Washington, lors du premier symposium international des cartes et graphiques pour les handicapés visuels.
Creation Of A Satellite Image Map Of Illinois / A Case Study Of technology Transfer And Linkage
Authors: DAHLDERG RICHARD E , LUMAN DONALD E , STOHR CHRISTOPHER J
Published: April 2007

Satellite image maps offer users a wealth of timely information but confront them with difficult interpretation tasks. The 'Satellite Image Map of Illinois' was produced in a university environment which fostered experimentation in the integration of image map and legend. The high costs of Landsat Thematic Mapper data and scarce resources for digital mosaicking led to a lower cost alternative of photomechanical mosaicking. Participation of nine entities was required to bring together the concepts, resources and technology needed to produce this satellite image map.
Geographic Logic In Line Generalization
Authors: JENKS GEORGE F
Published: April 2007

The logical problems faced by a geographer who generalizes linear symbols on a map are the same whether traditional or computer methods are used. One must recognize that there are a great many lines on the earth's surface, some of which were created by natural processes while others result from the economic, political or social activities of man. Geographic logic requires that these earth lines, when plotted on a map, should be recognizable representations in terms of symbolization and shape. Furthermore, geographers must understand that the generalization process shortens the length of linear symbols and moves them in geographic space. Critical or characteristic points should be selected so that the flow and position of the line is maintained. Le géographe qui généralise les symboles linéaires d'une carte affronte des problèmes logiques identiques, que les méthodes, utilisées soient traditionnelles ou automatisées. Nombreuses sont ces lignes qui parcourent la surface du globe : certaines sont issues de processus naturels alors que d'autres proviennent des activités économiques, politiques ou sociales de l'humanité. Selon la logique du géographe, ces lignes au sol doivent être représentées fidèlement sur la carte en termes de symbolisation et de forme. De plus, le géographe doit comprendre que le processus de généralisation raccourcit l'étendue des symboles linéaires et les déplace dans l'espace géographique. Il convient donc de choisir des points critiques ou caractéristiques afin que la position et l'enchaînement d'une ligne soient préservés.
Live Hypernarrative and Cybercartography: You Are Here, Now
Authors: Greenspan Brian , Dormann Claire , Caquard Sébastien , Eaket Chris , Biddle Robert
Published: April 2007

This article explores some of the potentialities of narration in the context of cybercartography. We have developed a new kind of dynamic or “live” form of hypernarrative, in which the content and structure of stories is determined by live information. This system would ultimately allow the creation of hypermedia narratives capable of mining public databases on the fly in order to customize and integrate narrative material appropriate to the user's particular temporal and geospatial context. Unlike other forms of hypermedia, a live hypertext narrative can actually be different every time it is read. More akin to an improvised performance than to a recorded one, a live hypertext changes depending on where and when it is accessed, and on what is happening in the world and on the Web. Live hypertext thus presents a new development in the history of writing that challenges our inherited notions of the stability, fixity, and even authority of printed text. The role of live data and the spatial and temporal aspects of the data suggest strong connections to cybercartographic environments. Not only are the same data sets relevant to both hypernarrative and cybercartography, but the nature of the hypernarrative shows new possibilities for cartographic environments. In particular, narrative and end-user navigation in a story show new ways of involving users, a key principle of cybercartography.
LAND-WATER DIFFERENTIATION IN BLACK AND WHITE CARTOGRAPHY
Authors: HEAD C GRANT
Published: April 2007

The author postulates that in the reading of maps, particularly thematic ones, the rapid, clear, and unambiguous interpretation of the dichotomy of land and water areas is highly important, for it is this differentiation that is most clearly related to readers' "mental maps." Despite the variety of means that cartographers use to accomplish this differentiation, we still know little about readers' reactions. Sample representations of a range of these techniques were used as stimulii in psychological testing with groups of cartographically-naive university students to learn, for each representation tested, its degree of ambiguity and its aesthetic value. The reactions indicated a wide spectrum of interpretations – from misinterpretation to complete ambiguity to correct and unambiguous interpretation; aesthetic values also varied markedly.
MENTAL MAPS AT A GLOBAL SCALE
Authors: MULLER JEAN-CLAUDE
Published: April 2007

Various groups of students at the University of Alberta were asked to rank a series of cities according to their longitudinal and latitudinal relative positions. The results show considerable errors in the perceived positioning of some cities. Some of these errors reflect expected mental distortions, such as the perceived latitude of Europe with respect to North America, but others are more surprising, such as the western shift of South America or the southern shift of Africa. Analysis also shows that all groups, including geographers, perceived most relative positionings of cities in the same way. An explanation of some of the mental distortions in spatial relations is attempted.
CLASS INTERVAL SYSTEMS ON MAPS OF OBSERVED CORRELATED DISTRIBUTIONS
Authors: OLSON JUDY
Published: April 2007

The degree to which choropleth maps accurately reflect product-moment correlation between sets of data depends upon the statistical distributions of the data and the system by which they are divided into class intervals. Comparing results for observed distributions with earlier results for normal distributions, it is found that: (1) the expected values of rank correlations between maps (given the product-moment correlation between the data sets) appear to be similar regardless of class interval method and regardless of whether data are normal or not; (2) class intervals based on standard deviation units have relatively smaller degrees of variation about expected values when observed data are being compared, while quantiles have small variations on the normal data (quantiles being a special case of standard deviations in that situation); and (3) the choice of interval system remains important for higher numbers of observations when observed, rather than normal, data are being considered.
An Eighteenth-Century Cosmographic Globe from India
Authors: SCHWARTZBERG JOSEPH E
Published: April 2007

The most detailed of six surviving Indian cosmographic globes is a goreless, painted, papier-maché construction at the Bharat Kala Bhavan in Varanasi. Believed to be of east Indian provenance and to date from the mid-eighteenth century, the globe combines two distinct cosmographic conceptions, one each for the northern and southern hemispheres. These derive from ancient texts known as Purānas. In addition to its primarily mythic content, the globe includes a geographic section for Bhāratavarsa (India), the portion of the northern hemisphere within an arc forty-five degrees from the intersection of the prime meridian and the equator. Iconographically, the globe belongs to the Vaishnavite tradition of Hinduism. Le plus détaillé de six globes cosmographiques indiens qui subsistent est une pièce sans godet, peinte et en papier maché, que l'on retrouve au Bharat Kala Bhavan, à Varanasi. Présumé venir de l'Inde de l'est et dater du milieu du dix-huitième siècle, le globe combine deux conceptions cosmographiques distinctes, l'une pour l'hémisphère nord et l'autre pour l'hémisphère sud. Celles-ci viennent de textes anciens, appelés 'Puranas'. En plus de son contenu principalement mythique, le globe comporte une section géographique pour l'Inde ('Bharatavarsa'), soit une portion de l'hémisphère nord comprise dans un arc de quarantecinq degrés à partir de l'intersection du méridien principal et de l'équateur. Du point de vue iconographique, le globe appartient à la tradition vishnouiste de l'hindouisme.
OTTAWA N-L 18: A NEW MAP IN THE IMW SERIES
Authors: LONG D. E.
Published: April 2007

Lors d'une conférence technique des Nations-Unies tenue à Bonn en 1962, an a approuvé les spécifications revisées de la Carte internationale du Monde au millionième. Les nouvelles spécifications permettent l'emploi des techniques modernes de tracé ainsi qu'une certaine coordination avec les séries de cartes aéronautiques mondiales de l'OACI, également au millionième. La carte d'Ottawa (N.L. 18) est la première qui ait été établie au Canada selon les spécifications revisées, l'ne partie de cette carte est reproduite ici en hors-texte central. Elle illustre les signes conventionnels approuvés et montre une région-type qui pourra servir à évaluer la valeur de cette carte pour l'organisation ou comme base des cartes thématiques.
Perceptual Responses to Line Simplification in a Task-Oriented Map Analysis Experiment
Authors: WOOD CLIFFORD H.
Published: April 2007

Perceptual responses to linear simplification during the performance of a map analysis task are not well documented, even though a great deal of effort has been expended on developing and perfecting digital line simplification algorithms. It is unknown, for example, whether increasing the simplification of linear map elements will reduce the amount of visual processing necessary to satisfy specific map-analysis tasks. The partial results reported in this paper are derived from a larger map analysis experiment (Wood 1992), in which the eye-movement parameters of fixations, durations of fixations, and duration per fixation were collected while subjects scanned ninety-six test maps simplified using four different line-simplification tolerances in three different map-analysis tasks. The results of this portion of the larger task-oriented map analysis experiment indicated that different levels of linear simplification contributed neither main effects nor interaction effects in explaining variation in eye-movement parameters in two of three map-analysis tasks. The data, furthermore, revealed that progressively eliminating more map detail through line simplification had little effect on the number of fixations or durations required to complete two of the three tasks.
Parallel Pairs In Automated Cartography
Authors: CHRISTENSEN ALBERT H J
Published: April 2007

A computer procedure is presented that can be applied to various tasks in automated cartography, the common constituent being the ability to determine lines parallel to given lines of any configuration. The procedure described works in vector mode, that is, the lines are expressed as lists of coordinates. Uses of this procedure are presented and discussed for the purpose of expanding lines, line generalization, buffering and medial axis transformation. The computer procedure is outlined briefly, and comparisons are made with other techniques already reported, particularly those used in raster environments.
THE AUSTRAL CONTINENT ON 16TH CENTURY MAPS / AN ICONOLOGICAL INTERPRETATION
Authors: GILMARTIN PATRICIA
Published: April 2007

Maps can be viewed as documents from which can be interpreted various philosophical, cultural or symbolical values of the society that produced them. This premise is explored, using a set of 16th-century maps and globes as the subject of study and the art historians' iconographical method of analysis. Specifically, the representation of terra australis as an enormous landmass occupying up to one-third of the southern hemisphere is discussed in terms of its form and meaning in Renaissance culture. The argument is made that the oversized southern continent reflected the pervasive influence in that culture of classical Greco-Roman themes. Greek cosmology had assumed the existence of southern lands on philosophical and aesthetic grounds, and these principles were manifest again centuries later in maps of the Renaissance.
CARTOGRAPHIC COMMUNICATION AND GEOGRAPHIC UNDERSTANDING
Authors: GUELKE LEONARD
Published: April 2007

A communications model emphasizing the transfer of information from cartographer to map user by means of the map has been widely accepted in cartography. The adoption of this model has focussed map use research on symbols and their visual characteristics. The communications model is inadequate for a complete analysis of the map, because it is concerned more with information than meaning and understanding. A fundamental objective of cartography is to enhance a map user's understanding of reality by placing information in appropriate contexts. A criterion of meaning is needed in cartography as a basis for decisions on map content. Maps showing distributions of isolated data are often failures, because such data lack an appropriate context. In assessing the effectiveness of maps as transmitters of geographic information, comparisons with graphs, tables and words are needed. A knowledge of geography is essential for cartographers concerned with adding meaning to their maps.
On-line Reporting and Mapping of Spatially Aggregated Individual Records Selected by User Queries
Authors: Cromley Ellen , Cromley Robert , Ye Yanlin
Published: April 2007

In this article, an on-line system allowing users to perform detailed queries of a database of individual records containing confidential information is described. The results of the query can be reported in table, comma-delimited file, or map format for spatial aggregates defined by the user. This system addresses some important social problems arising from the development of large digital databases of information on individuals that can be analysed using GIS, including violating privacy and confidentiality protections, profiling, and distributing multiple, unregulated copies of source databases. It also recognizes the needs of public agencies to distribute information and of individuals to have access to public information. The system is designed as an open-architecture server-side system. A database of six years' worth of injury mortality records compiled from data provided by the Connecticut Department of Public Health is developed to demonstrate the process of formulating user queries and the corresponding results. The prototype system described uses technology to address the needs of public agencies to provide access to public information in a way that ensures database integrity, protects privacy and confidentiality, and enhances access to public information.
Several Methods For Representing Discrete Data By Line Segments
Authors: MEEK D S , WALTON D J
Published: April 2007

Many algorithms for representing data by straight line segments have been published. Now that topographic maps are being digitized, these algorithms will undoubtedly have application in representing sets of data which are sampled from curved lines such as shore lines or contour lines. The major classes of such algorithms are surveyed here, and are applied to data representing contour lines taken from a topographic map. The methods are compared in speed of execution and number of line segments required.
SENSITIVITY ANALYSIS OF THE BOYCE-CLARK SHAPE INDEX
Authors: CERNY JAMES W
Published: April 2007

The Boyce-Clark shape index is one of the more common shape measures suited to cartographic analysis. It requires care, however, in the selection of the center point, number of radials, and orientation of the radials. This study shows the need to maintain consistency in procedures for selecting the center point and positioning the radials. To achieve stable results at least 16–20 radials are desirable. Probabilistic questions involving the likelihood or significance of a given index value are shown to be more difficult to answer. Le système de mesure Boyce-Clark est un des systèmes les mieux connus, adapté à l'analyse cartographique. Toutefois, une attention doit être apportée dans le choix du point central de ce système, du nombre de rayons et de leur orientation. Cette étude démontre la nécessité de maintenir une uniformité auprès des procédés afin de choisir le point central et de mettre les rayons en place. Afin d'obtenir des résultats constants, il est souhaitable d'utiliser au moins 16 à 20 rayons. Des questions portant sur la probabilité ou la signification d'une valeur donnée de l'index ne sont pas aussi faciles à démontrer.
Mountain Cartography in Slovenia
Authors: PETROVIC DUSAN
Published: April 2007

Slovenia has a hilly character, and a high percentage of the population participates in mountaineering as an outdoor sport. Mountaineering enthusiasts produced the first mountain maps. It wasn't until 1969, however, that official mountain maps were published under the auspices of the National Mountaineering Association of Slovenia. The official mountain maps were initially in high demand because topographic maps produced by the military were generally unavailable throughout Slovenia â€“ a situation that has completely changed since then. Today, the use of mountain maps is in decline because of competition from other high-quality topographic maps that are more readily available. The future viability of Slovenian mountain mapping as a separate program depends on the implementation of new technology and the development of new products that are relevant to mountaineers.
RE-DEFINING THE ROLE OF GOVERNMENT IN SURVEYS AND MAPPING / A VIEW OF EVENTS IN THE UNITED KINGDOM
Authors: McGRATH GERALD
Published: April 2007

The present state of surveying and mapping within the private sector in the United Kingdom is considered briefly. Attention is then turned to two of the British official mapping organizations for which the roots of recent or impending changes are shown to lie in the early years of the 1970s. Factors are discussed which may influence current thinking on the role of government. Three significant thrusts of the Ordnance Survey Review Committee's Report are noted prior to comment on more recent developments. The paper examines the 'Rayner scrutiny' of the Directorate of Overseas Surveys, which led the government to conclude that the size of the organization should be reduced and work transferred to the private sector.