Artifacts Mapping: Multi-Modal Semantic Mapping for Object Detection and 3D Localization

Geometric navigation is nowadays a well-established field of robotics and the research focus is shifting towards higher-level scene understanding, such as Semantic Mapping. When a robot needs to interact with its environment, it must be able to comprehend the contextual information of its surroundings. This work focuses on classifying and localising objects within a map, which is under construction (SLAM) or already built. To further explore this direction, we propose a framework that can autonomously detect and localize predefined objects in a known environment using a multi-modal sensor fusion approach (combining RGB and depth data from an RGB-D camera and a lidar). The framework consists of three key elements: understanding the environment through RGB data, estimating depth through multi-modal sensor fusion, and managing artifacts (i.e., filtering and stabilizing measurements). The experiments show that the proposed framework can accurately detect 98% of the objects in the real sample environment, without post-processing, while 85% and 80% of the objects were mapped using the single RGBD camera or RGB + lidar setup respectively. The comparison with single-sensor (camera or lidar) experiments is performed to show that sensor fusion allows the robot to accurately detect near and far obstacles, which would have been noisy or imprecise in a purely visual or laser-based approach.Comment: Accepted to the 11th European Conference on Mobile Robots (ECMR) 202

CARPE-ID: Continuously Adaptable Re-identification for Personalized Robot Assistance

In today's Human-Robot Interaction (HRI) scenarios, a prevailing tendency exists to assume that the robot shall cooperate with the closest individual or that the scene involves merely a singular human actor. However, in realistic scenarios, such as shop floor operations, such an assumption may not hold and personalized target recognition by the robot in crowded environments is required. To fulfil this requirement, in this work, we propose a person re-identification module based on continual visual adaptation techniques that ensure the robot's seamless cooperation with the appropriate individual even subject to varying visual appearances or partial or complete occlusions. We test the framework singularly using recorded videos in a laboratory environment and an HRI scenario, i.e., a person-following task by a mobile robot. The targets are asked to change their appearance during tracking and to disappear from the camera field of view to test the challenging cases of occlusion and outfit variations. We compare our framework with one of the state-of-the-art Multi-Object Tracking (MOT) methods and the results show that the CARPE-ID can accurately track each selected target throughout the experiments in all the cases (except two limit cases). At the same time, the s-o-t-a MOT has a mean of 4 tracking errors for each video

FollowMe: a Robust Person Following Framework Based on Re-Identification and Gestures

Human-robot interaction (HRI) has become a crucial enabler in houses and industries for facilitating operational flexibility. When it comes to mobile collaborative robots, this flexibility can be further increased due to the autonomous mobility and navigation capacity of the robotic agents, expanding their workspace and consequently, the personalizable assistance they can provide to the human operators. This however requires that the robot is capable of detecting and identifying the human counterpart in all stages of the collaborative task, and in particular while following a human in crowded workplaces. To respond to this need, we developed a unified perception and navigation framework, which enables the robot to identify and follow a target person using a combination of visual Re-Identification (Re-ID), hand gestures detection, and collision-free navigation. The Re-ID module can autonomously learn the features of a target person and use the acquired knowledge to visually re-identify the target. The navigation stack is used to follow the target avoiding obstacles and other individuals in the environment. Experiments are conducted with few subjects in a laboratory setting where some unknown dynamic obstacles are introduced.Comment: published in "2023 IEEE International Conference on Advanced Robotics and Its Social Impacts (ARSO)

Flow Cytometry as a Diagnostic Tool in the Early Diagnosis of Aggressive Lymphomas Mimicking Life-Threatening Infection

Aggressive lymphomas can present with symptoms mimicking life-threatening infection. Flow cytometry (FC) is usually recommended for the classification and staging of lymphomas in patients with organomegaly and atypical cells in effusions and blood, after the exclusion of other possible diagnoses. FC may also have a place in the initial diagnostic investigation of aggressive lymphoma. Three cases are presented here of highly aggressive lymphomas in young adults, which presented with the clinical picture of fever of unknown origin (FUO) in patients severely ill. All followed a life-threatening clinical course, and two developed the hemophagocytic syndrome (HPS), but microbiological, immunological, and morphological evaluation and immunohistochemistry (IHC) failed to substantiate an early diagnosis. FC was the technique that provided conclusive diagnostic evidence of lymphoma, subsequently verified by IHC. Our experience with these three cases highlights the potential role of FC as an adjunct methodology in the initial assessment of possible highly aggressive lymphoma presenting with the signs and symptoms of life-threatening infection, although the definitive diagnosis should be established by biopsy. In such cases, FC can contribute to the diagnosis of lymphoma, independently of the presence of HPS

Multi-physics Modelling of a Compliant Humanoid Robot

In this paper, we discuss some very important features for getting exploitable simulation results for multibody systems, relying on the example of a humanoid robot. First, we provide a comparison of simulation speed and accuracy for kinematics modeling relying on relative vs. absolute coor- dinates. This choice is particularly critical for mechanisms with long serial chains (e.g. legs and arms). Compliance in the robot actuation chain is also critical to enhance the robot safety and en- ergy efficiency, but makes the simulator more sensitive to modeling errors. Therefore, our second contribution is to derive the full electro-mechanical model of the inner dynamics of the compliant actuators embedded in our robot. Finally, we report our reasoning for choosing an appropriate contact library. The recommended solution is to couple our simulator with an open-source contact library offering both accurate and fast full-body contact modeling

The greek avant- garde cinema

The subject of this dissertation is the Greek avant- garde cinema, which constitutes the Greek paradigm of the international avant- garde cinema. It examines the so- called ‘avant- garde’ or ‘experimental’ films, which not only deviate from established narrative conventions, but dismiss them consciously, partially or altogether. They are made by Greek directors who either worked within the Greek film production framework or have lived and worked abroad in different cultural and historical contexts, but maintain Greek elements in the core of their work. This research attempts to offer a clear and substantiated composition of the previously vague aesthetic field known as the Greek avant- garde cinema, which it chooses to redefine as Greek non- narrative cinema. The alternative term it suggests is in no way ideal in any sense, but at least it proposes a tangible criterion by which the specific cinematic field can be composed. The goals of the dissertation are to provide a concrete body of non- narrative films, to examine them under the related theory, to show and compare modes of work as well as thematic and stylistic traits among filmmakers, and provide an analytical reading of each film. The chronological structure forms a first broad historical evolution of the field, while the individual chapters for each director provide an in-depth look to each one’s contribution to it. Since the 1960s, taken as the starting point of the field in Greece, until the early 2000s, the thesis specifies well- known directors and relatively unknown ones as non- narrative artists and redresses theoretical and historiographical misconceptions that have kept the field from being properly examined, organized and appreciated.Η εργασία έχει θέμα την ελληνική κινηματογραφική πρωτοπορία, που αποτελεί το ελληνικό παράδειγμα της διεθνούς κινηματογραφικής πρωτοπορίας. Εξετάζει τις λεγόμενες ‘πρωτοποριακές’ ή ‘πειραματικές’ ταινίες, οι οποίες δεν αποκλίνουν απλώς από τις καθιερωμένες και δημοφιλείς αφηγηματικές κι αναπαραστατικές συμβάσεις, αλλά τις απορρίπτουν συνειδητά σε μεγάλο βαθμό ή εντελώς, εξερευνώντας και διευρύνοντας τις εκφραστικές δυνατότητες του κινηματογραφικού μέσου μακριά από την αφήγηση. Είναι σκηνοθετημένες από δημιουργούς ελληνικής καταγωγής που εργάστηκαν μέσα στα γεωγραφικά όρια του ελληνικού κράτους και στις συνθήκες του εγχώριου πλαισίου κινηματογραφικής παραγωγής. Εκτός απ’ αυτούς όμως, στην εργασία περιλαμβάνονται Έλληνες σκηνοθέτες του εξωτερικού, οι οποίοι ακόμη κι αν ανήκουν σε διαφορετικά εθνικο- ιστορικά πλαίσια, διατηρούν την ελληνικότητα στο επίκεντρο των προβληματισμών και των αναζητήσεών τους- στοιχείο αποφασιστικό για τη συμπερίληψή τους στην εργασία. Η εργασία επιχειρεί μια σαφώς οριοθετημένη και τεκμηριωμένη πρόταση για τη συγκρότηση του αισθητικού πεδίου γνωστότερου ως ελληνική κινηματογραφική πρωτοπορία ή ελληνικός πειραματικός κινηματογράφος, το οποίο επιλέγει να επαναπροσδιορίσει ως ελληνικό μη- αφηγηματικό κινηματογράφο. Ο εναλλακτικός όρος που προτείνει, παρότι σε καμία περίπτωση απόλυτος ή ιδανικός, αποτελεί ένα ξεκάθαρο κριτήριο βάσει του οποίου γίνεται δυνατή η επιλογή ταινιών για τη σύσταση του πεδίου από την αρχή, ο ακριβής προσδιορισμός μιας χρονικής έναρξης, καθώς κι ο σχηματισμός ενός εξελικτικού διαγράμματός του μέσα στον χρόνο. Στόχοι της μελέτης υπήρξαν η συγκρότηση του σώματος του μη- αφηγηματικού κινηματογράφου, η επεξεργασία του με τη βοήθεια της διεθνούς θεωρίας, η ανάδειξη του τρόπου δουλειάς των καλλιτεχνών και των κύριων χαρακτηριστικών του έργου τους, οι μεταξύ τους συγκλίσεις, αποκλίσεις και πιθανές ομαδοποιήσεις, καθώς κι η αναλυτική ερμηνευτική προσέγγιση των ταινιών. Η χρονολογική οργάνωση επέτρεψε την απόδοση της ιστορικής εξέλιξης του είδους, κι η δευτερεύουσα οργάνωση κατά σκηνοθέτη τη διατύπωση μιας ευκρινούς εικόνας για συμβολή της καθεμιάς και του καθένα στη σύνθεση του είδους. Η έρευνα συμπληρώνει τους ήδη γνώριμους τίτλους γνωστών δημιουργών, αναδεικνύει καινούρια ονόματα σε παλιότερες και νεότερες περιόδους, κι αποκαθιστά εννοιολογικές κι ιστορικές παρερμηνείες που μέχρι τώρα εμπόδιζαν την κατανόηση του είδους υπό μελέτη

Study of the biological behavior of caspases in hepatocellular carcinoma cells

Background: Hepatocellular carcinoma (HCC) is the fifth most common malignancy in the world and is estimated to cause approximately half a million deaths annually. Octreotide, a somatostatin analogue, has been used to treat inoperable hepatocellular carcinoma. Clinical trials have demonstrated a survival benefit of patients with inoperable HCC treated with octreotide, but also negative studies have been published and recently criticized. Several reports indicate, also, that octreotide inhibits the proliferation and induces apoptosis of HCC cells in vitro The mechanisms of apoptosis induction however are not well understood.. Moreover, clinical observations suggest that ursodeoxycholate (UDCA) may protect from hepatocellular carcinoma in cirrhotic patients. Increased apoptosis of malignant cells is a candidate mechanism. Decreased apoptosis of cholangiocytes has been proposed as a mechanism for the favourable effect of UDCA in primary biliary cirrhosis.Aims: 1) To investigate the role of octreotide on cellular proliferation, apoptosis and caspases activities of HepG2 carcinoma cells. 2) To investigate the effects of different concentrations of UDCA on HepG2 cell proliferation, apoptosis and caspases activities.Methods: We studied the occurrence of cellular proliferation, apoptosis and the possible internal caspase-mediated apoptosis pathway involved, after treatment of HepG2 carcinoma cells with octreotide, in comparison with the apoptosis caused by TNF-alpha. We, also, studied the apoptotic features and the caspases activities, after treatment of HepG2 cells with different concentrations of UDCA alone or in combination with TNF-alpha. Activities of caspase-3, caspase-9, caspase-8 and caspase-2 were studied, while apoptosis was investigated through detection of DNA fragmentation and through identification of apoptotic cells with the Annexin-V/PI flow cytometric method.Results: Cellular proliferation was decreased, after treatment of HepG2 cells with octreotide or TNF-alpha alone but, in contrast to TNF-alpha, octreotide decreased proliferation only at concentration of 10-8M, while lower concentrations increased proliferation. Early and late apoptosis were significantly increased with both substances. Octreotide significantly increased caspase-3, caspase-8 and caspase-2 activity. TNF-alpha significantly increased only caspase-2. UDCA significantly inhibits cell proliferation only at high concentrations, but increases apoptosis at low concentrations and protects from apoptosis at higher concentrations. TNF-alpha induced DNA fragmentation is potentiated by UDCA, but flow cytometry indicates protection from early apoptosis and increase in cell survival by low and intermediate UDCA concentrations. UDCA differentially activates initiator and effector caspases in different concentrations.Conclusions: Our results support the induction of a caspase-mediated apoptotic pathway by octreotide in hepatocellular carcinoma cells, implicating both the receptor-mediated and the mitochondrial-apoptotic pathway. The correlation of specific apoptotic, caspase-mediated pathways, with the expression of sst receptors in HCC cells, need more investigation, to better define and clarify the intracellular mechanisms of the antiproliferative effects of octreotide. Also, our findings indicate that measurements of serum octreotide levels may be important, at least in clinical trials, to verify optimal therapeutic drug concentrations. Moreover, our data demonstrate that the effect of UDCA on caspase activation and apoptosis of HepG2 cells is concentration-dependent and activation of the caspase cascade is not always translated into increased apoptosis. Serum levels of UDCA should be possibly monitored and dosage of the drug adjusted according to the required effect

The Compliant Joint Toolbox for MATLAB: An Introduction with Examples

This article presents the Complianhis Compliant Joint Toolbox for the modeling, simu lation, and controller development of compliant robot actuators. The object-oriented toolbox is written in MATLAB/Simulink. In a few lines of code, it can batch-generate ready-to-use joint actuator model classes from multiple parameter sets, in corporating a variety of nonlinear dynamics effects

A Conceptual Framework for Economic Analysis of Different Law Enforcement Drones

The widespread use of drones in various fields has initiated a discussion on their cost-effectiveness and economic impact. This article analyzes in detail a methodological evaluation framework for the levelized cost of drone services for law enforcement purposes. Based on the data availability, we compared two vehicles: Phantom 4 Pro and Thunder-B. Moreover, we calculated their levelized costs per surveillance time and trip distance. Our approach helps users calculate the real costs of their vehicles’ services and produce equations for rapid estimations. We observed economies of scale for time and distance and showed differentiations per aircraft capacity. Furthermore, using the produced equations, we formulated a case study and compared the costs in a 4 km area constantly monitored by the two types of drones to support the best vehicle selection. We found that the Phantom 4 Pro costs less than the Thunder-B drone, for example. Thus, we demonstrate how, by applying this methodology beforehand, decision makers can select the most appropriate vehicle for their needs based on cost. Cost research estimations will improve UAV use and will help policymakers include UAV technology in crime prevention programs, especially when more data are available