RJMCMC based Text Placement to Optimize Label Placement and Quantity

International audienceLabel placement is a tedious task in map design, and its automation has long been a goal for researchers in cartography, but also in computational geometry. Methods that search for an optimal or nearly optimal solution that satisfies a set of constraints, such as label overlapping, have been proposed in the literature. Most of these methods mainly focus on finding the optimal position for a given set of labels, but rarely allow the removal of labels as part of the optimization. This paper proposes to apply an optimization technique called Reversible-Jump Markov Chain Monte Carlo that enables to easily model the removal or addition during the optimization iterations. The method, quite preliminary for now, is tested on a real dataset, and the first results are encouraging

Challenges in creating a 3D participatory platform for urban development ::a case study

This paper aims at underling difficulties regarding the establishment of citizen engagement processes. The specificity of citizen engagement processes lies in their evolution over time where objectives, constraints, and latitudes of a given project influence the relevance of the tools offered to citizens. Three categories of urban projects (trans-urban, major metropolitan, architectural design) have been described. These classes range from a local space with short deadlines to a regional space spread over several decades. Furthermore, the use of 3D platforms for a broad public is influenced by the users’ preferences, perception, and expertise. Throughout this study, major challenges that have been experienced during the design a 3D participatory platform are identified. They range from the issues of implementing adequate tools according to the project (temporal and spatial scalability), the participation forms (passive, consultative or interactive), to the difficulties of convincing the authorities to use new bottom-up methods. Finally, a conceptual framework for the creation of a 3D participatory platform has been introduced. It can be summarized by three major steps: (1) Meeting the needs of a decision maker, (2) Designing the participation tool in accordance with the context, (3) Translating collected raw data in order to respond to the initial request

Auto-filtering validation in citizen science biodiversity monitoring ::a case study

Data quality is the primary concern for researchers working on citizen science projects. The collected data by citizen science participants are heterogeneous and therefore must be validated. There are several validation approaches depending on the theme and objective of the citizen science project, but the most common approach is the expert review. While expert validation is essential in citizen science projects, considering it as the only validation approach can be very difficult and complicated for the experts. In addition, volunteers can get demotivated to contribute if they do not receive any feedback regarding their submissions. This project aims at introducing an automatic filtering mechanism for a biodiversity citizen science project. The goals of this project are to first use an available historical database of the local species to filter out the unusual ones, and second to use machine learning and image recognition techniques to verify if the observation image corresponds with the right species type. The submissions that does not successfully pass the automatic filtering will be flagged as unusual and goes through expert review. The objective is on the one hand to simplify validation task by the experts, and on the other hand to increase participants’ motivation by giving them real-time feedback on their submissions. Finally, the flagged observations will be classified as valid, valid but uncommon, and invalid, and the observation outliers (rare species) can be identified for each specific region

Are city features influencing the behavior of photographers ? ::an analysis of geo-referenced photos shooting orientation

Every day millions of social media users upload information as texts, pictures or likes. These online posts are nowadays mainly uploaded via a smartphone, that adds automatically complementary pieces of information such as the device’s location and orientation. This additional material is valuable for public services, and can be used to reinforce knowledge provided by typical methods. This study aims to inquire this additional material to observe the influence of city features on public behavior. A semi-automated workflow is introduced to combine two large datasets: the flickR geo-referenced photos (associated with their shooting orientation) and the OpenStreetMap streets’ network. The study is conducted in the city of Lausanne, Switzerland. This workflow promotes a novel approach to download, filter, compute and visualize large cluttered datasets. The investigations showed a significant difference between South/North photos’ orientation with a South dominance. Furthermore, the photographs’ orientation appears to be related to the street network, or city elements (such as remarkable buildings, fountains) only at a local scale; no connection was established at a larger scale. These results can be useful in urban planning for the diagnosis of a public place practice by its users (i.e., residents, tourists, etc.). An improved diagnosis promotes a better knowledge of a public space’s remarkable elements (by their attractiveness or unsightliness), easing the decision on conservation or transformation of these elements. Other applications are also outlined, notably in the touristic sector or the landscape preservation

E-guerrilla 3D participation ::approach, implementation, and usability study

Typical urban participatory approaches engage citizens through lengthy sessions far from the area under transformation by an urban project. Several issues result from these settings of involvement including the mobilization of similar individuals, overwhelming participatory codes, or a gap between the affected urban landscape and the location of the session. This study introduces a modern approach that leverages the use of 3D web applications to address some of the critical challenges of popular participatory sessions. The developed approach, named e-guerrilla 3D participation, is based on five dimensions: immediate participation, ease of use, flexibility, place-based engagement, and immersivity. A prototype complying with these five dimensions was implemented in this study. The prototype promotes an in situ engagement where all the users (without distinction) of a public area can explore a future urban project and get involved within minutes. A usability study conducted with 26 expert and non-expert participants investigated the prototype through a fictive scenario. The findings demonstrate a positive outcome in terms of participatory results that are identifiable with the prototype (highlighting the controversial elements of the projects) and encourage feedback collected during a survey and interview. The usability study suggests key aspects that should be considered to improve the design of participatory sessions and their interactive mediums (or tools), such as realism, affordance, incentive, and purpose. The promising participatory approach (and prototype), which was unpacked step-by-step in this study, does not replace typical practices but could help to complement them by reaching a non-selected and broader public; hence leading to the design of more inclusive participatory approaches

Media coverage of 3D visual tools used in urban participatory planning

The opportunities provided by adopting digitally-generated visual tools in urban participatory planning are compelling. These visual tools can promote interactions between authorities and citizens and among citizens. However, the urban participatory practices of these tools are often described from an academic perspective, which leads to a lack of knowledge from the practitioner's outlook. This study investigates practices of 3D visual tools in applied urban projects. The applied projects were recovered from media coverage. The objective is to describe participatory projects and their adopted 3D tools with a contextual and technical lens. The findings demonstrate that 3D visuals are mostly adopted for communication with a realistic representation and limited interaction in the later stage of the project where negotiation margins are insufficient at a small and medium urban scale. A better understanding of applied practices can help to introduce guidelines that support practitioners in designing approaches that benefit from the full potential of 3D visual tools

Towards an open 3D participatory citizen debate

This paper presents a platform aiming the ease of the debate between citizens. In the early 2010’ies, governments are seeking new ways to be more accountable and transparent towards their citizens; marking a renewal in public participation. In return, citizens are eager to be heard and to use new tools based on information and communication technologies (ICT) like the web 2.0. This public’s empowerment presents some costs for the authorities who are mainly concerned with the loss of decision making power. To face those challenges, several 2D online maps have been developed to help the governments to direct and centralize citizens insights. Those previous collaborating mapping tools helped to identify the characteristics of a reliable platform: user-friendly, simple and accessible (anywhere at any time). In our implementation, we adopted the third dimension which provides numerous benefits: 1. A more effective and effortless visualization, 2. An unbiased representation of the environment, 3. The merge of the participant cognition spaces. From our past experiences, we conceptualized the actors (citizens / facilitator / transcriber) interactions and dynamics in public engagement on-site meeting. From this approach, we evaluated how the utilization of a 3D virtual environment as the support of the participation will reshape and enhance the relation synergies between the actors: 1. Centralization of the interactions within the platform, 2. Automated analysis from the gathered raw information, 3. Reachability of a larger part of the population, 4. Lightening of the participatory processes

Towards the use of a 3D virtual globe to support public participatory decision making

Today the utilization of 3D mock-ups is very common in GIScience. Since 2001, with the emergence of Google Earth, citizen have become used to virtual globes. However, a majority of applications using these technologies are still restricted to professional users. This is the case with urbanism and decision making where only static 3D scenes are shared with the public. In this paper, we describe the early results of a 3D virtual globe platform to support participatory decision making processes for urban planning. Our concept is built on the visualization of specific scenes. Context, content and design are crucial elements that need to be considered for the development of any participatory decision making tool. Our goal is the development of a web-based platform that focuses on collecting feedback from realworld citizen. The next step of this project is to utilize the platform in a real-world scenario and to evaluate the feedback from real-world citizen

Impact of digital and non-Digital urban participatory approaches on public access conditions ::an evaluation framework

The gradual institutionalization of public participation increasingly compels local authorities to partially share their power over the transformation of urban areas. The smooth running of a participatory session is based on selecting the appropriate type of interaction, or medium, which supports the local authorities to reach and interact with a targeted public. However, local authorities often appear unfamiliar with the organization of interactive sessions with the population. This article introduces an evaluation framework that focuses on the access conditions of participants to the sessions of interaction. This novel perspective aspires to assist the local authorities in their decision to adopt a participatory medium (or method of interaction). Seven dimensions are investigated to this aim, namely accessibility, availability, adequacy, affordability, acceptability, awareness, and attractiveness (the last dimension is introduced in this article). In light of two real case scenarios that occurred in Western Switzerland, the use of the access framework is investigated for two potential purposes: (1) supporting the choice of a medium for an interactive session according to the urban project’s context and the targeted public; and (2) improving future participatory approaches by assessing the representativeness of participants attending a past session in comparison to the originally targeted public

How do users interact with virtual geographic environments ? ::users’ behavior evaluation in urban participatory planning

Abstract. For the past twenty years, the adoption of Virtual Geographic Environments is thriving. This democratization is due to numerous new opportunities offered by this medium. However, in participatory urban planning these interactive 3D geovisualizations are still labeled as very advanced means, and are only scarcely used. The involvement of citizens in urban decision-making is indeed carefully planned ahead to limit off-topic feedback. A better comprehension of Virtual Geographic Environments, and more specifically of users’ strategic behaviors while interacting with this medium could enhance participants’ contributions. The users’ strategic behavior was assessed in this article through an experimental study. A total of 107 participants completed online tasks about the identification of 3D scenes’ footprints, the comparison of buildings’ heights, and the visibility of objects through the scenes. The interactions of the participants were recorded (i.e. pressed keys, pointing device interactions), as well as the camera positions adopted to complete specific tasks. The results show that: (1) users get more efficient throughout the study; (2) interruptions in 3D manipulation appear to highlight difficulties in interacting with the virtual environments; (3) users tend to centralize their positions within the scene, notably around their starting position; (4) the type of task strongly affects the behavior of users, limiting or broadening their explorations. The results of this experimental study are a valuable resource that can be used to improve the design of future urban planning projects involving Virtual Geographic Environments, e.g. with the creation of personalized 3D tools