Minimizing uncertainty in complete automation of Douglas-Peucker Algorithm for geospatial mapping

It is qualitatively evident that the greater the map scale change, the greater the optimal distance threshold of the Douglas-Peucker Algorithm, which is used in polyline simplification. However, no specific quantitative relationships between them are known by far, causing uncertainties in complete automation of the algorithm. To fill this gap, the current paper constructs quantitative relationships based on the spatial similarity theories of polylines. A quantitative spatial similarity relationship model was proposed and evaluated by setting two groups of control experiments and taking <C, T> as coordinates. In order to realize the automatic generalization of the polyline, we verified whether these quantitative relationships could be fitted using the same function with the same coefficients. The experiments revealed that the unary quadratic function is the best, whether the polylines were derived from different or the same geographical feature area(s). The results also show that using the same optimal distance threshold is unreasonable to simplify all polylines from different geographical feature areas. On the other hand, the same geographical feature area polylines could be simplified using the same optimal distance threshold. The uncertainties were assessed by evaluating the automated generalization results for position and geometric accuracy perspectives using polylines from the same geographic feature areas. It is demonstrated that in addition to maintaining the geographical features, the proposed model maintains the shape characteristics of polylines. Limiting the uncertainties would support the realization of completely automatic generalization of polylines and the construction of vector map geodatabases.

Glacial kettles as archives of early human settlement along the Northern Rocky Mountain Front

The Northern Rocky Mountain Front (hereafter Northern Front) is a prominent geographic feature in archaeological models of human dispersal in the terminal Pleistocene and Early Holocene of North America. Testing those models has been arduous because of local geomorphological factors that tend to obliterate or otherwise limit access to archaeological finds of relevant age. In this paper, we present well-stratified archaeological and environmental records dating back to 14,000–13,000 cal yr BP from the site of Billy Big Spring (Blackfeet Indian Reservation, Montana), located on a glacial kettle, a type of landform that has been largely ignored by regional archaeological research to date. Findings from Billy Big Spring show the continuous use of the Northern Front foothills throughout the major climatic and environmental disturbances of the Early Holocene, and possibly the terminal Pleistocene as well. As such, Billy Big Spring contributes to refining several archaeological models of early settlement of the Northern Front, particularly those that posit differential use of foothills versus plains settings during the midst of the Holocene Thermal Maximum. The record at Billy Big Spring also suggests that kettles, regardless of physiographic setting, provide a yet unsuspected and unsampled potential for preserving high-quality and easily accessible early archaeological and paleoenvironmental records.

Tracing The Shapes of Multimodal Rhetoric: Showing the Epistemic Powers of Visualization

This visual essay seeks to substantiate and illustrate the tenet that formal–structural elements in graphic design carry rhetorical functions. Based on a National Geographic feature article, the authors demonstrate methods for ‘measuring’ layout, colour and typography, and show the results in infographic visualizations. At the same time, the study showcases the epistemic value of these visualizations. The perspective adopted puts the double-page centre-stage.

NoSQL STANDARD AND APPROACH FOR GEOSPATIAL DATABASE COLLECTION

Industry of geospatial information requires a proper standard which can adapt the user requirements in parallel with the technological improvements over time. Geospatial database is an essential end product that can be used as an input to the Decision Support System. The aforementioned important role can be defined as a main indicator for effectiveness and efficiency of the provision of geospatial data and information. Standard is fundamental especially in a situation where there are so many available technologies and infrastructures on the market. Defining a robust and reliable standard and mechanism to derive the geospatial database is a main key for the successful production of the national geospatial database. NoSQL databases use a different approach to represent the storing mechanism which is generally in a form of relational structured tables. The main difference is related with the flexible model, component and storing mechanism which must not be structured in a tabular and relational way. This paper discusses geospatial database standards by using the NoSQL approach that will be implemented in order to adopt the Indonesian Geographic Feature Catalogues. The implementation of the standard in an operational stage of the geodatabase production can provide the alternative solution in competition with the traditional Relational Data Base Management System approach. Especially in the era of big data and crowd sourcing with a lot of variety in the data structure nowadays, NoSQL raises as an alternative solution to accommodate and utilize its advantages in an applicative way but still selective for the portrayal purposes.

The Accessibility Level of Balikpapan Botanical Garden According to Public Transportation Routes (Balikpapan Botanical Garden Development Concept)

East Kalimantan Government had proposed to expand its tourism division, therefore Balikpapan Botanical Garden has to attract tourist to visit. Accessibility has certain degree of effect to affect visitor trip to certain area. Accessibility is a key feature to evaluating transportation system. Measuring accessibility involving how to measure distance from one point to another as the metric. Providing transport accessibility is an essential element of tourist infrastructure development. The analysis method used in this paper is buffer analysis. This method consists of identifying area surrounding geographic feature. It involving generates buffer around existing geographic feature, then identifying feature whether it locates inside or outside the boundary of the buffer. Balikpapan Botanical Garden had medium accessibility. The nearest collector street from Balikpapan Botanical Garden already have public transportation route. Hotels and Balikpapan Botanical Garden were connected via public transportation route. drawback that affect Balikpapan Botanical Garden accessibility was the distance from public transportation stop point to Balikpapan Botanical Gate may less ideal for pedestrian. The trip took about 35 minutes on foot as far as 2.8 kilometres.

PolySimp: A Tool for Polygon Simplification Based on the Underlying Scaling Hierarchy

Map generalization is a process of reducing the contents of a map or data to properly show a geographic feature(s) at a smaller extent. Over the past few years, the fractal way of thinking has emerged as a new paradigm for map generalization. A geographic feature can be deemed as a fractal given the perspective of scaling, as its rough, irregular, and unsmooth shape inherently holds a striking scaling hierarchy of far more small elements than large ones. The pattern of far more small things than large ones is a de facto heavy tailed distribution. In this paper, we apply the scaling hierarchy for map generalization to polygonal features. To do this, we firstly revisit the scaling hierarchy of a classic fractal: the Koch Snowflake. We then review previous work that used the Douglas–Peuker algorithm, which identifies characteristic points on a line to derive three types of measures that are long-tailed distributed: the baseline length (d), the perpendicular distance to the baseline (x), and the area formed by x and d (area). More importantly, we extend the usage of the three measures to other most popular cartographical generalization methods; i.e., the bend simplify method, Visvalingam–Whyatt method, and hierarchical decomposition method, each of which decomposes any polygon into a set of bends, triangles, or convex hulls as basic geometric units for simplification. The different levels of details of the polygon can then be derived by recursively selecting the head part of geometric units and omitting the tail part using head/tail breaks, which is a new classification scheme for data with a heavy-tailed distribution. Since there are currently few tools with which to readily conduct the polygon simplification from such a fractal perspective, we have developed PolySimp, a tool that integrates the mentioned four algorithms for polygon simplification based on its underlying scaling hierarchy. The British coastline was selected to demonstrate the tool’s usefulness. The developed tool can be expected to showcase the applicability of fractal way of thinking and contribute to the development of map generalization.

An Evaluation Model of Level of Detail Consistency of Geographical Features on Digital Maps

This paper proposes a method to evaluate the level of detail (LoD) of geographic features on digital maps and assess their LoD consistency. First, the contour of the geometry of the geographic feature is sketched and the hierarchy of its graphical units is constructed. Using the quartile measurement method of statistical analysis, outliers of graphical units are eliminated and the average value of the graphical units below the bottom quartile is used as the statistical LoD parameter for a given data sample. By comparing the LoDs of homogeneous and heterogeneous features, we analyze the differences between the nominal scale and actual scale to evaluate the LoD consistency of features on a digital map. The validation of this method is demonstrated by experiments conducted on contour lines at a 1:5K scale and artificial building polygon data at scales of 1:2K and 1:5K. The results show that our proposed method can extract the scale of features on maps and evaluate their LoD consistency.

Sovereign Rights on the Extended Continental Shelf: The Case of the Nicaraguan Rise in the Western Caribbean

In 2016, the International Court of Justice (ICJ) ruled on Colombia’s preliminary objections to Nicaragua’s claim over the extended continental shelf in the Western Caribbean, which forms part of a submarine geographic feature known as the ‘Nicaraguan Rise’. This article recalls the long-standing Nicaragua–Colombia conflict over islands and maritime zones and analyses the 2012 and 2016 ICJ decisions with respect to the correlation between the distance and natural prolongation criteria. The article also addresses the role of the Commission on the Limits of the Continental Shelf in delimitation, and concludes by discussing the geopolitical consequences of the future ICJ ruling concerning the delimitation of the extended continental shelf.

INTELLIGENT SERVICE PUSH METHOD BASED ON ACTIVE GEOGRAPHIC PERCEPTION

In view of the lack of consideration of user behavior motives in traditional personalized precision service systems, the accuracy of service content is not high.In order to solve this problem, research on personalized accurate service push method based on active geographic perception. By constructing a geographic feature information model, get the characteristics of the user's destination in real time, and then infer the user's behavioral motivation. Focusing on active geographic awareness technology and personalized precision service methods, the concept, principle, process and key technologies of active geographic sensing are studied, determined the main research content of active geographic perception and the relationship. Then analyze and discuss the construction method of active geographic awareness architecture, developed a geographic feature content system and studied its extraction and weight calculation methods. By the way, according to the characteristics of active geo-sensing, an active awareness API conforming to high efficiency and real-time is designed. Then explored the personalized accurate service push method based on active geographic perception,designed three processes of geographic awareness, service retrieval and service push, a service retrieval and delivery method is proposed. Finally, a personalized precise service system based on active geographical perception is designed. By adding geographic features to the personalized precision service, it can make up for the lack of service personalization and lack of precision caused by ignoring user motivation, which provides a new idea for more accurate and personalized service push.