138 research outputs found
Investigating Scene Understanding for Robotic Grasping: From Pose Estimation to Explainable AI
In the rapidly evolving field of robotics, the ability to accurately grasp and manipulate objectsâknown as robotic graspingâis a cornerstone of autonomous operation. This capability is pivotal across a multitude of applications, from industrial manufacturing automation to supply chain management, and is a key determinant of a robot's ability to interact effectively with its environment. Central to this capability is the concept of scene understanding, a complex task that involves interpreting the robot's environment to facilitate decision-making and action planning. This thesis presents a comprehensive exploration of scene understanding for robotic grasping, with a particular emphasis on pose estimation, a critical aspect of scene understanding.
Pose estimation, the process of determining the position and orientation of objects within the robot's environment, is a crucial component of robotic grasping. It provides the robot with the necessary spatial information about the objects in the scene, enabling it to plan and execute grasping actions effectively. However, many current pose estimation methods provide relative pose compared to a 3D model, which lacks descriptiveness without referencing the 3D model. This thesis explores the use of keypoints and superquadrics as more general and descriptive representations of an object's pose. These novel approaches address the limitations of traditional methods and significantly enhance the generalizability and descriptiveness of pose estimation, thereby improving the overall effectiveness of robotic grasping.
In addition to pose estimation, this thesis briefly touches upon the importance of uncertainty estimation and explainable AI in the context of robotic grasping. It introduces the concept of multimodal consistency for uncertainty estimation, providing a reliable measure of uncertainty that can enhance decision-making in human-in-the-loop situations. Furthermore, it explores the realm of explainable AI, presenting a method for gaining deeper insights into deep learning models, thereby enhancing their transparency and interpretability.
In summary, this thesis presents a comprehensive approach to scene understanding for robotic grasping, with a particular emphasis on pose estimation. It addresses key challenges and advances the state of the art in this critical area of robotics research. The research is structured around five published papers, each contributing to a unique aspect of the overall study
Novel Approaches for Nondestructive Testing and Evaluation
Nondestructive testing and evaluation (NDT&E) is one of the most important techniques for determining the quality and safety of materials, components, devices, and structures. NDT&E technologies include ultrasonic testing (UT), magnetic particle testing (MT), magnetic flux leakage testing (MFLT), eddy current testing (ECT), radiation testing (RT), penetrant testing (PT), and visual testing (VT), and these are widely used throughout the modern industry. However, some NDT processes, such as those for cleaning specimens and removing paint, cause environmental pollution and must only be considered in limited environments (time, space, and sensor selection). Thus, NDT&E is classified as a typical 3D (dirty, dangerous, and difficult) job. In addition, NDT operators judge the presence of damage based on experience and subjective judgment, so in some cases, a flaw may not be detected during the test. Therefore, to obtain clearer test results, a means for the operator to determine flaws more easily should be provided. In addition, the test results should be organized systemically in order to identify the cause of the abnormality in the test specimen and to identify the progress of the damage quantitatively
Play Among Books
How does coding change the way we think about architecture? Miro Roman and his AI Alice_ch3n81 develop a playful scenario in which they propose coding as the new literacy of information. They convey knowledge in the form of a project model that links the fields of architecture and information through two interwoven narrative strands in an âinfinite flowâ of real books
Antennas and Propagation
This Special Issue gathers topics of utmost interest in the field of antennas and propagation, such as: new directions and challenges in antenna design and propagation; innovative antenna technologies for space applications; metamaterial, metasurface and other periodic structures; antennas for 5G; electromagnetic field measurements and remote sensing applications
EVOLUTION OF THE SUBCONTINENTAL LITHOSPHERE DURING MESOZOIC TETHYAN RIFTING: CONSTRAINTS FROM THE EXTERNAL LIGURIAN MANTLE SECTION (NORTHERN APENNINE, ITALY)
Our study is focussed on mantle bodies from the External Ligurian ophiolites, within the Monte Gavi and Monte Sant'Agostino areas. Here, two distinct pyroxenite-bearing mantle sections were recognized, mainly based on their plagioclase-facies evolution. The Monte Gavi mantle section is nearly undeformed and records reactive melt infiltration under plagioclase-facies conditions. This process involved both peridotites (clinopyroxene-poor lherzolites) and enclosed spinel pyroxenite layers, and occurred at 0.7â0.8 GPa. In the Monte Gavi peridotites and pyroxenites, the spinel-facies clinopyroxene was replaced by Ca-rich plagioclase and new orthopyroxene, typically associated with secondary clinopyroxene. The reactive melt migration caused increase of TiO2 contents in relict clinopyroxene and spinel, with the latter also recording a Cr2O3 increase. In the Monte Gavi peridotites and pyroxenites, geothermometers based on slowly diffusing elements (REE and Y) record high temperature conditions (1200-1250 °C) related to the melt infiltration event, followed by subsolidus cooling until ca. 900°C. The Monte Sant'Agostino mantle section is characterized by widespread ductile shearing with no evidence of melt infiltration. The deformation recorded by the Monte Sant'Agostino peridotites (clinopyroxene-rich lherzolites) occurred at 750â800 °C and 0.3â0.6 GPa, leading to protomylonitic to ultramylonitic textures with extreme grain size reduction (10â50 Îźm). Compared to the peridotites, the enclosed pyroxenite layers gave higher temperature-pressure estimates for the plagioclase-facies re-equilibration (870â930 °C and 0.8â0.9 GPa). We propose that the earlier plagioclase crystallization in the pyroxenites enhanced strain localization and formation of mylonite shear zones in the entire mantle section. We subdivide the subcontinental mantle section from the External Ligurian ophiolites into three distinct domains, developed in response to the rifting evolution that ultimately formed a Middle Jurassic ocean-continent transition: (1) a spinel tectonite domain, characterized by subsolidus static formation of plagioclase, i.e. the Suvero mantle section (Hidas et al., 2020), (2) a plagioclase mylonite domain experiencing melt-absent deformation and (3) a nearly undeformed domain that underwent reactive melt infiltration under plagioclase-facies conditions, exemplified by the the Monte Sant'Agostino and the Monte Gavi mantle sections, respectively. We relate mantle domains (1) and (2) to a rifting-driven uplift in the late Triassic accommodated by large-scale shear zones consisting of anhydrous plagioclase mylonites.
Hidas K., Borghini G., Tommasi A., Zanetti A. & Rampone E. 2021. Interplay between melt infiltration and deformation in the deep lithospheric mantle (External Liguride ophiolite, North Italy). Lithos 380-381, 105855
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Change and continuity in the Organisation for the Prohibition of Chemical Weapons
The Organisation for the Prohibition of Chemical Weapons (OPCW) has long been reflecting on how to prevent the âre-emergence of chemical weaponsâ as the verification of the destruction of declared stockpiles continues to approach completion. To deal with this shift in emphasis, a functional rebalancing of activities and resources will likely be required as the OPCW seeks to ensure that the implementation of the Chemical Weapons Convention remains relevant and effective in future operating environments.
Despite much expert attention, studies that explore and characterise the nature of change within the OPCW are scarce, resulting in gaps in our knowledge regarding the different actors involved, and how processes of change unfold. This stems from ontological and theoretic positions embedded within some mainstream approaches used to examine international organisations, which often treat secretariats as bureaucratic âblack boxesâ, characterising change as the product of state machinations. Moreover, change is often treated as episodic and exceptional, arising from deliberate and controlled efforts.
Drawing on archival research at the Sussex-Harvard Information Bank and participant observation within the OPCW, this thesis investigates how our understanding of changing within the OPCW can be enhanced if we treat the Secretariat as a purposive actor involved in these processes. This enhanced understanding enables a deeper exploration of what change looks like and how it unfolds, providing insights that can support contemporary development.
The thesis uses culture theories to present a unique assessment of the Secretariat through the interaction between formal/official and informal/unofficial cultural manifestations. This gives the Secretariat character, opening the black box and allowing its role in changing to be considered. Then, inspired by the work of Andrew Pettigrew, an analytical framework based on a process metaphysics ontology is employed to examine processes of changing. Three longitudinal case studies are used to examine these processes in response to perceived challenges posed by chemical terrorism and non-state actors. This reveals how States Parties and the Secretariat co-create through long-run processes of change and continuity. Evidence for taking seriously the role of bureaucratic bodies in organisational development is presented, exploring how agency can be variously conceived of, and how changing often tends to be multiplicitious and not confined to a single category.
The thesis has theoretical implications. Approaches that arbitrarily ignore particular actors within (international) organisations should be treated with caution, and where possible inclusivity should be sought. Mainstream theories about change tend to be similarly exclusive, prioritising or prescribing a particular form or type of change. This thesis has demonstrated that a variety of forms of changing can co-exist, suggesting that expanding organisational change approaches might be fruitful. An important insight to emerge is that bureaucracies tend toward dysfunction rather than the ideal-type, and using cultural approaches can open up new spaces for examining relationships between structure and agency across different levels, and bring new dimensions to our understanding of secretariats.
Practical implications include demonstrating how the Secretariat has contributed to organisational capacity and capability to respond to perceived challenges around chemical terrorism and non-state actors. In doing so, it provides new perspectives on how the OPCW develops. The research argues that as the OPCW functionally rebalances, attention to organisational geographies and identities will need to be part of human resource strategies, as the cultural analysis reveals areas of tension. Finally, the Secretariat are co-creators of organisational changing, and although their inputs and impacts can be hidden, indirect, or informal, this research reveals they are productive. This suggests that more evidence-based research is needed to examine the role of secretarial components in organisational changing. During times of normative stress and functional uncertainty, this must be a priority
Ecosystem mapping in the Central Arctic Ocean (CAO) during the SAS-Oden expedition
As a result of global warming, the marine ecosystem around the North Pole, the Central Arctic Ocean (CAO), is in fast transition from a permanently to a seasonally ice-covered ocean. The sea-ice loss is expected to enable summer access to the CAO for non-icebreaking ships, including fishery vessels, in the near future1. However, the lack of knowledge on the CAO ecosystem impedes any assessment of the sustainability of potential future fisheries in the CAO. Taking a precautionary approach, the EU and nine countries in October 2018 signed the Agreement to Prevent Unregulated High Seas Fisheries in the Central Arctic Ocean. This agreement entered into force in June 2021 and a.o. requires the establishment of a joint scientific program to improve the understanding of the CAO ecosystem, including mapping and monitoring. To reduce the existing lack of knowledge, 12 scientists from the EFICA Consortium participated, together with 26 other on-board scientists, in sampling and data collection of ecosystem data during the Swedish SAS-Oden expedition in summer 2021. This report describes the field work performed by the EFICA scientists using water-column acoustics, deep-sea optical observations, and fish, zooplankton, sediment otolith and eDNA sampling for targeting fish, zooplankton and mammals. Further ecosystem data (physical, chemical and biological) were collected by the EFICA scientists in collaboration with other scientists on-board. Together with this report, a metadata database containing lists of all collected samples and data that are relevant for future fish-stock modelling and assessment studies was delivered to the European Commission
Impact of Etnaâs volcanic emission on major ions and trace elements composition of the atmospheric deposition
Mt. Etna, on the eastern coast of Sicily (Italy), is one of the most active volcanoes on the planet and it is widely recognized as a big source of volcanic gases (e.g., CO2 and SO2), halogens, and a lot of trace elements, to the atmosphere in the Mediterranean region. Especially during eruptive periods, Etnaâs emissions can be dispersed over long distances and cover wide areas. A group of trace elements has been recently brought to attention for their possible environmental and human health impacts, the Technology-critical elements. The current knowledge about their geochemical cycles is still scarce, nevertheless, recent studies (Brugnone et al., 2020) evidenced a contribution from the volcanic activity for some of them (Te, Tl, and REE). In 2021, in the framework of the research project âPianeta Dinamicoâ, by INGV, a network of 10 bulk collectors was implemented to collect, monthly, atmospheric deposition samples. Four of these collectors are located on the flanks of Mt. Etna, other two are in the urban area of Catania and three are in the industrial area of Priolo, all most of the time downwind of the main craters. The last one, close to Cesarò (Nebrodi Regional Park), represents the regional background. The research aims to produce a database on major ions and trace element compositions of the bulk deposition and here we report the values of the main physical-chemical parameters and the deposition fluxes of major ions and trace elements from the first year of research. The pH ranged from 3.1 to 7.7, with a mean value of 5.6, in samples from the Etna area, while it ranged between 5.2 and 7.6, with a mean value of 6.4, in samples from the other study areas. The EC showed values ranging from 5 to 1032 ÎźS cm-1, with a mean value of 65 ÎźS cm-1. The most abundant ions were Cl- and SO42- for anions, Na+ and Ca+ for cations, whose mean deposition fluxes, considering all sampling sites, were 16.6, 6.8, 8.4, and 6.0 mg m-2 d, respectively. The highest deposition fluxes of volcanic refractory elements, such as Al, Fe, and Ti, were measured in the Etnaâs sites, with mean values of 948, 464, and 34.3 Îźg m-2 d-1, respectively, higher than those detected in the other sampling sites, further away from the volcanic source (26.2, 12.4, 0.5 Îźg m-2 d-1, respectively). The same trend was also observed for volatile elements of prevailing volcanic origin, such as Tl (0.49 Îźg m-2 d-1), Te (0.07 Îźg m-2 d-1), As (0.95 Îźg m-2 d-1), Se (1.92 Îźg m-2 d-1), and Cd (0.39 Îźg m-2 d-1). Our preliminary results show that, close to a volcanic area, volcanic emissions must be considered among the major contributors of ions and trace elements to the atmosphere. Their deposition may significantly impact the pedosphere, hydrosphere, and biosphere and directly or indirectly human health
Impact of geogenic degassing on C-isotopic composition of dissolved carbon in karst systems of Greece
The Earth C-cycle is complex, where endogenic and exogenic sources are interconnected, operating in a multiple spatial and temporal scale (Lee et al., 2019). Non-volcanic CO2 degassing from active tectonic structures is one of the less defined components of this cycle (Frondini et al., 2019). Carbon mass-balance (Chiodini et al., 2000) is a useful tool to quantify the geogenic carbon output from regional karst hydrosystems. This approach has been demonstrated for central Italy and may be valid also for Greece, due to the similar geodynamic settings. Deep degassing in Greece has been ascertained mainly at hydrothermal and volcanic areas, but the impact of geogenic CO2 released by active tectonic areas has not yet been quantified. The main aim of this research is to investigate the possible deep degassing through the big karst aquifers of Greece. Since 2016, 156 karst springs were sampled along most of the Greek territory. To discriminate the sources of carbon, the analysis of the isotopic composition of carbon was carried out. δ13CTDIC values vary from -16.61 to -0.91â° and can be subdivided into two groups characterized by (a) low δ13CTDIC, and (b) intermediate to high δ13CTDIC with a threshold value of -6.55â°. The composition of the first group can be related to the mixing of organic-derived CO2 and the dissolution of marine carbonates. Springs of the second group, mostly located close to Quaternary volcanic areas, are linked to possible carbon input from deep sources
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