Outdoor Robot Navigation Based on View-Based Global Localization and Local Navigation

A hierarchical mobile robot simultaneous localization and mapping (SLAM) method that allows us to obtain accurate maps of large environments is proposed. The local map level is composed of a set of local metric feature maps that are guaranteed to be statistically independent. The global level is a topological graph whose arcs are labeled with the relative location between local maps. An estimation of these relative locations is maintained with local map alignment algorithm, and more accurate estimation is calculated through a global minimization procedure using the loop closure constraint. The local map is built with Rao-Blackwellised particle filter (RBPF). The particle filter is used to extend the path posterior by sampling new poses that integrate the current observation which drastically reduces the uncertainty about the robot pose. The landmark position estimation and update is also implemented through Kalman filter. Omnidirectional vision mounted on the robot tracks the 3D natural point landmarks, which are structured with matching Scale Invariant Feature Transform (SIFT) feature pairs. The matching for multi-dimension SIFT features is implemented with a KD-Tree. Experimental results on real robot in a medium size, real indoor environment show the practicality and efficiency of our proposed method.

This paper considers the real-time navigation and obstacle avoidance of mobile robots in complex environments. A novel local environment perception and navigation framework for mobile robot navigation based on the elevation information is proposed. A local elevation map is introduced to perceive and map obstacles in the local environment. Calculating obstacles’ heights and shapes by local elevation maps, the terrain traversability of the surrounding environment of a robot is determined, and a two-dimensional local occupancy grid map for robot path planning and navigation in local environment is generated. The effectiveness of our approach is validated experimentally through real-time navigation and obstacle avoidance in the artificial environment. The experimental results show that using the proposed framework, a mobile robot can safely reach its target position while avoiding the non-crossable area. For indoor mobile robots with limited computing power, in complex environments, it could provides more safe navigation and path-planning.

Disaster risk management (DRM) is undergoing noteworthy changes, reflecting the broader shifts in global and local levels of governance. At the global level two significant changes are of interest: (1) the shift from monolithic structures of global governance to a wide range of organizations that can be brought together for specific purposes and (2) the emergence of a globalized system of DRM, with technological, organizational, and institutional capacities enhancing DRM’s ability as a unit in near real time across the globe. At the local level there is an increase in ability to govern and develop creative solutions for complex problems that follow rapid urbanization. The importance of getting the global–local interface to work in tandem has been highlighted by recent hazard events, such as the 2011 Tohoku Earthquake and Tsunami. From a broad view of global and local shifts, a strategic role is becoming clearer at the national level for enhancing the relationships between the global and local levels. Through the influence of a globalized system of DRM, the local level can significantly improve its capacity without the heavy investment that might have been required to develop these capacities in isolation. One key to achieving this is a diffusion of DRM higher education, supported by an enhanced system of information flow.

The recent rise of jihadist movements in West Africa, including Boko Haram in the Lake Chad region and Al-Qaeda in the Islamic Maghreb and its affiliates in the Sahel-Saharan region, has puzzled many observers. The easy spread of the jihadist ideology, the jihadist movements’ success in massively recruiting followers among local populations as well as their ability to conquer and administer territories, are unprecedented in the region’s contemporary history. This paper sheds light on the factors and processes that contribute to the emergence of these movements. It argues that the phenomenon of jihadist insurgencies in West Africa emerges as a result of a series of processes at the global, local, and individual level. At the global level, there is the formation and dissemination of the global ideology of jihadism, conceptualised by Muslim activists and scholars based on a particular understanding of Islam and the challenges that are facing contemporary Muslim societies. At the local level, the appropriation of jihadist ideologies by “Muslim activists” who then use it to formulate a discourse which taps into local social and political demands in order to mobilise followers, is key. For a wide range of reasons, certain regions of Africa have experienced weakened state capacity and increased local conflict, and it is in these areas that jihadist insurgencies have emerged. At the individual level, the process by which African individuals decide to enrol in jihadist groups include ideological, situational, and strategic motivations, and these have all been facilitated by deteriorating conditions of life in marginalised areas.

Former President Nelson Mandela, Bono, Peter Gabriel and other superstars stood together on the stage at Greenpoint Stadium in Cape Town in front of billions of television viewers around the world, watching the “46664” music extravaganza in support of the fight against AIDS in Africa. AIDS is clearly a global pandemic and responses to it have inevitably been on a global scale. At the same time, the disease has highly localised aspects to it. AIDS activists have had to address both the global dimensions and the local specificities of this epidemic. This article focuses on new conceptions and arenas of civic action promoted by a Cape Townbased AIDS activist group, the Treatment Action Campaign (TAC), and the new forms of citizenship that emerge from their engagement with AIDS treatment policy. TAC is an example of a “new” social movement that has constructed its own arenas of action and spaces of participation in response to state-driven AIDS policies. Unlike the formal, hierarchical structure and conventional class politics and Marxism of the “old” political and labour movements, TAC, like other new social movements, draws on grassroots, bottom-up, network based modes of organisation that operate simultaneously in local, national and global spaces (Touraine 1981; Melucci 1989). While it is problematic to assert a strict divide between “old” and “new” social movements, organisations such as TAC have introduced tactical and organisational innovations that take advantage of the increased global reach and instantaneity of the media, the Internet, email and other circuits of telecommunications (Cohen and Rai 2000; Wasserman 2003). While TAC speaks to audiences well beyond the border of the nation– state, its main objective has been to lobby and pressurise the South African government to provide AIDS treatment. TAC has been forced to address a wide range of issues at global, national and local levels: it has tackled the global pharmaceutical industry in the media, the courts and the streets; it has fought discrimination against HIV-positive people in schools, hospitals and at the workplace; it has challenged AIDS dissident science in South Africa and abroad; and taken the government to court for refusing to provide prevention of mother-to-childtransmission treatment (PMTCT) programmes in public health facilities. In addition to these high profile activities, TAC has also launched AIDS literacy campaigns in black townships throughout South Africa challenging AIDS myths, silence, denial and misinformation (see Robins, forthcoming). This article shows how these diverse TAC activities and interventions have contributed towards creating new political spaces for engagement at local, national and global levels. TAC relies both on transnational advocacy networks and grassroots mobilisation in ways that are similar to modes of activism that are increasingly described as ‘globalisation from below’ or ‘grassroots globalisation’ (Appadurai, 2002a). TAC also provides examples of organisational practices that cut across institutional and noninstitutional spaces, and that are capable of generating multiple relations to the state. In doing

In this study, we propose an improved view-based navigation method for obstacle avoidance and evaluate the effectiveness of the proposed method in actual environments existing obstacles. The proposed method is able to estimate the position and the rotation of a mobile robot, even if the mobile robot strays from a recording path for avoiding obstacles. In order to achieve this, ego-motion was employed to the view-based navigation. The ego-motion is calculated from SURF points between a current view and a recorded view by using a Kinect sensor. In conventional view-based navigations, it is difficult to generate other paths to avoid obstacles. By using the proposed method, it is expected that a mobile robot plans flexible paths and avoids persons and objects in actual environments. From experiments performed in an indoor environment, we evaluated the measurement accuracy of the proposed method, and confirmed the feasibility of the proposed method for actual robot navigation.

In this paper, a graph-based hierarchical SLAM framework is proposed which ensures not only the high-speed operation of graph-based SLAM, but also feasibility of large-scale 3D map building. Both local and global level graph-based SLAM will be operated. They can be concurrently implemented in different computing units but must maintained communication which is called as a session. During each session, local level SLAM will create a pose-graph containing trajectory for mobile robot and information for local maps. To avoid communication congestion, raw density point cloud of each pose-node will be reduced into a sparser one by voxel grid filtering. When a session is closed, duo-graph strategy is executed to guarantee the consistency between successive local map. To associate massive local map information and closing loops in large-scale environment, graph-based algorithm will also be implemented in global level SLAM.Two experiments are carried out in the real indoor environment. In the first experiment, SLAM process is greatly accelerated in this framework by distributing the whole SLAM task into different level SLAM entities: local level SLAM operated on robot and global on laptop. It shows that this framework is scalable and it can be implemented in CS(Client-Server) model. Second experiment is conducted in our biggest work office around which we control the robot traverse for three times. It demonstrates that this framework can simultaneously keep fast graph-based SLAM in local-end and generate consistent and convergent 3D map in global-end SLAM process.KeywordsPoint CloudMobile RobotSuper NodeGraph OptimizationCurrent SessionThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Although considerable attention has been given to the definition of topic from both a global and local level, most of this work has been done entirely from the perspective of researchers. We examined perceptions of global and local topic change from the point of view of conversation participants. The results indicate that participants readily agree on points of topic change at the global level, but demonstrate relatively little agreement at the local level. These results were discussed in terms of the current debate over global versus local topic definition as well as other implications for future research.

BackgroundMore and more Cas9 variants with higher specificity are developed to avoid the off-target effect, which brings a significant volume of experimental data. Conventional machine learning performs poorly on these datasets, while the methods based on deep learning often lack interpretability, which makes researchers have to trade-off accuracy and interpretability. It is necessary to develop a method that can not only match deep learning-based methods in performance but also with good interpretability that can be comparable to conventional machine learning methods.ResultsTo overcome these problems, we propose an intrinsically interpretable method called AttCRISPR based on deep learning to predict the on-target activity. The advantage of AttCRISPR lies in using the ensemble learning strategy to stack available encoding-based methods and embedding-based methods with strong interpretability. Comparison with the state-of-the-art methods using WT-SpCas9, eSpCas9(1.1), SpCas9-HF1 datasets, AttCRISPR can achieve an average Spearman value of 0.872, 0.867, 0.867, respectively on several public datasets, which is superior to these methods. Furthermore, benefits from two attention modules—one spatial and one temporal, AttCRISPR has good interpretability. Through these modules, we can understand the decisions made by AttCRISPR at both global and local levels without other post hoc explanations techniques.ConclusionWith the trained models, we reveal the preference for each position-dependent nucleotide on the sgRNA (short guide RNA) sequence in each dataset at a global level. And at a local level, we prove that the interpretability of AttCRISPR can be used to guide the researchers to design sgRNA with higher activity.

Heterogeneous computing is one of the future directions of HPC. Task scheduling in heterogeneous computing must balance the challenge of optimizing the application performance and the need for an intuitive interface with the programming run-time to maintain programming portability. The challenge is further compounded by the varying data communication time between tasks. This paper proposes RANGER, a hardware-assisted task-scheduling framework. By integrating RISC-V cores with accelerators, the RANGER scheduling framework divides scheduling into global and local levels. At the local level, RANGER further partitions each task into fine-grained subtasks to reduce the overall makespan. At the global level, RANGER maintains the coarse granularity of the task specification, thereby maintaining programming portability. The extensive experimental results demonstrate that RANGER achieves a $$12.7\times $$ performance improvement on average, while only requires $$2.7\%$$ of area overhead.

Textile composites are known to have improved out-of-plane properties and impact resistance. However, detailed analysis of textile composites is very difficult to perform due to the geometric complexity. In the present study, a practical computational procedure based on a global/local finite element method was developed for detailed analysis of textile composites. This procedure utilizes two problem levels: global and local levels. At the global level, an initial global solution was obtained using a coarse global mesh. At the local level, a small portion of the textile composite was modeled with a refined local mesh. For the global analysis, macroelements were used since the use of effective engineering properties are not in general accurate for the larger microstructural scale found in textile composites. Results indicated that the failure behavior of plain weave textile composites was sensitive to the fiber bundle waviness. The initial failure mode was the fiber bundle separation when the waviness ratio was large while it was the fiber bundle fracture when the waviness ratio was small. It was also found that the stress distributions near the free surface were different from those inside. The stress level was much higher inside than near the free surface. However, the boundary region was shallow and was limited to the outer-most layer.

In connection with the environmental problems that have become more acute at the global level, it has been recognized the need for society to take the path of sustainable development, the main principles of which are focused on a decent standard of living for each member of society, reducing the anthropogenic burden on nature and preserving the environment, including for future generations, as well as the integrated solution of environmental, social and economic issues at the global and local levels. In the process of implementing this concept, a fundamental role of culture was revealed, and a specific role of environmental culture as well, which would ensure a harmonious development of the society and the environment. In particular, it is necessary to transform the worldview, re-evaluate the values and shift the emphasis in consumption from material benefits to spiritual ones.This research is relevant because of the need to promote the principles of sustainable development in all areas of society that determine the current level of culture and civilization. This work is aimed at analyzing the potential of dance art as a source of indirect influence on the environmental consciousness and thought, reasonable attitude to nature during the environmental culture formation.Environmental culture is expressed in people’s perception of themselves as a part of nature. One of the elements of environmental culture is environmental consciousness. Having the ability to influence the emotional sphere of a person, art, in particular dance, is a useful tool for effectively perceiving environmental information and motivating environmental activities. Due to its polyfunctionality, art can aid to form the environmental identity at the level of the following components: cognitive (informational, gnostical, educational function), emotional (compensatory, suggestive one), instrumental (social-transforming function).Based on the analysis of scientific literature and some musical and choreographic works from the standpoint of the ecocentric paradigm, the article suggests that choreography in environmentally oriented performances can serve as one of the effective means of evoking empathy at the deep kinesthetic level, environmental empathy. Choreography can play the role of an emotional component in the process of forming environmental identity, which will in general contribute to the environmental consciousness formation at the individual level.

Drawing on the global debates over biofuels and fracking, this chapter develops the core theoretical approach of the book, bringing together insights from contentious politics and political economy scholarship. The chapter details three central mechanisms of mobilization: scale shifts, identity activation, and brokerage. It specifies how key elements of political economy—that is, the conditions of finance and investment, ownership and control, and trade and patterns of exchange across global and local levels—can catalyze those mechanisms of contention. This theory-building chapter brings attention to how competing narratives and strategic discourses around biofuels and fracking were constructed at the global level, through issue linkages, scientific uncertainty, and the role of key symbols in these debates. The chapter thus establishes the basis for analyzing contestation over proposals for biofuels in sub-Saharan Africa and fracking in northern North America in the chapters that follow.

While the notion of hegemonic masculinity has received a lot of attention in recent scholarship, hegemonic femininity remains largely underdeveloped. We aim to address this gap by illustrating the benefits of using the concept of hegemonic femininities in sociolinguistic scholarship. Conducting a case study on the discourse of trailing spouses in Hong Kong, we analyse hegemonic femininities at the local, regional, and global level and explore how they are interlinked with each other. Findings show how these trailing spouses often challenge and reject hegemonic femininities on the local level, but largely accept and reinforce them on the regional and global level. The specific femininities that are considered to be hegemonic are highly context-dependent, and, unlike masculinities, the hegemony of femininities is a matter of internal degree—that is, certain femininities take hegemonic status compared to other femininities but do not take a dominant position in the gender order. (Hegemonic femininities, hegemonic masculinities, trailing spouses, Hong Kong, gender order)*

An instrumental drift in the Point Target Response (PTR) parameters has been detected on the Copernicus Sentinel-3A (S3A) altimetry mission. It could have an impact on sea level rise of a few tenths of mm yr−1. In order to accurately evaluate this drift, a method for detecting global and local mean sea level relative drifts between two altimetry missions is implemented. Associated uncertainties are also accurately calculated thanks to a detailed error budget analysis. A drift on both S3A and S3B GMSL is detected with values significantly higher than expected. For S3A, the relative GMSL drift detected is 1.0 mm yr−1 with Jason-3 and 1.3 mm yr−1 with SARAL/AltiKa. For S3B, the relative GMSL drift detected is −2.2 mm yr−1 with SARAL/AltiKa and −3.4 mm yr−1 with Jason-3. The drift detected at global level does not show detectable regional variations above the uncertainty level of the proposed method. The investigations led by the altimeter experts can now explain the origin of this drift for S3A, while it is still under investigation for S3B. The ability of the implemented method to detect a sea level drift with respect to the length of the common period is also analysed. We find that the maximum detectable sea-level drift over a 5 years period is 0.3 mm yr−1 at the global scale, and 1.5 mm yr−1 at local scales (2400 km). However, these levels of uncertainty do not meet the sea-level stability requirements for climate change studies.