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Institute
Modern distributed computing frameworks and domain-specific languages provide a convenient and robust way to structure large distributed applications and deploy them on either data center or edge computing environments. The current systems suffer however from the need for a complex underlay of services to allow them to run effectively on existing Internet protocols. These services include centralized schedulers, DNS-based name translation, stateful load balancers, and heavy-weight transport protocols. In contrast, ICN-oriented remote invocation methodologies provide an attractive match for current distributed programming languages by supporting both functional programming and stateful objects such as Actors. In this paper we design a computation graph representation for distributed programs, realize it using Conflict-free Replicated Data Types (CRDTs) as the underlying data structures, and employ RICE (Remote Method Invocation for ICN) as the execution environment. We show using NDNSim simulations that it provides attractive benefits in simplicity, performance, and failure resilience.
We present some results on integrating computing with networking so as to optimize the placement of workloads within a distributed network. We describe INCA, an In-Network Computing Architecture that allows clients to request functions that are then instantiated at a place within the network that attempts to meet both the QoE constraints of the application and the incentives of the operator of the network. We have implemented INCA, including network monitoring capability as well as a function placement optimization capability. In our evaluation, INCA demonstrates the benefit of a joint optimization of the networking and computing aspects.
In this poster, we discuss design options for a LoRaWAN and LoRa transmission system to employing Information-Centric Networking (ICN). ICN has been successfully applied to LoWPAN scenarios and can provide many benefits with respect to object-based security, performance, disruption tolerance and usability. Our findings indicate that the current LoRaWAN MAC layer is impractical for an ICN request-response with caching. We present ideas for a new MAC layer that harmonizes the long-range LoRa radios with ICN.
Wind turbines are constantly exposed to wind gusts, dirt particles, and precipitation. Depending on the site, surface defects on rotor blades emerge from the first day of operation on. While erosion increases quickly with time, even small defects can affect the performance of the wind turbine due to nonlinear interaction. Consequently, there is a demand for a remote and easily applicable condition monitoring method for rotor blades that is capable of detecting surface defects at an early stage. In this work it is analyzed if infrared thermography (IRT) can meet these requirements by visualizing differences in the thermal transport and the corresponding surface temperature of the wall-bounded flow.Firstly, a validation of the IRT method against stereoscopic particle image velocimetry measurements is performed comparing both types of experimental results for the boundary layer of a flat plate. Then, the main characteristics of the flow in the wake of generic surface defects on different types of lifting surfaces are studied both experimentally and numerically: temperature gradients behind protruding surface defects on a flat plate and a DU 91-W2-250 profile are studied by means of IRT. The same is done with the wall shear stress from RANS simulations of a wind turbine blade. It is consistently observed both in the experiments and the simulations that turbulent wedges are formed on the flow downstream of generic surface defects. These wedges provide valuable information about the kind of defect that generates them. At last, experimental and numerical performance measures are taken into account for evaluating the aerodynamic impact of surface defects on rotor blades. We conclude that the IRT method is a suitable remote condition and performance monitoring technique for detecting surface defects on wind turbines at an early stage.
For three different wind propulsion technologies, the energy saving potential of sea going cargo vessels are discussed: a kite, a Flettner rotor and a Dynarig-sail. The energy saving potential can be increased significantly if the route can be optimized when using a wind assisted ship propulsion. The increase of travelling time due to a route adoption is within the frame of the commonly accepted uncertainty in supply chains and can be limited or adjusted in the route optimization software as a parameter. The calculated saving potential depends on several parameters: the considered wind propulsion system, the route, the kind of ship (bulker, multipurpose carrier, tanker), as well as the ship speed and the weather. The cost-effectiveness of the installation of a wind propulsion system strongly depends on the fuel price, the ship speed and the international policy concerning the ship emissions.
To address climate change, innovative ships with alternative propulsion systems must be developed to reduce greenhouse gas emissions. One option is to use additional wind propulsion systems, which encounter additional resistance due to drift and rudder forces. After calculating the sail forces, changing the locations of the aerodynamic centre of pressure of the sails and the centre of lateral resistance on the hull depending on the ship’s speed and drift angle has a significant influence. The aim of this research is to show how the drift and rudder angles and the corresponding forces can be calculated using methods from Skogman, Wagner, Bertram, Lewis, and Larsson. The drift calculation methods are validated using the results from tank towing model tests in oblique flow with a traditional sailing vessel and a multi-purpose vessel. A comparison of theoretically calculated and measured drift forces as well as the prediction of the drift angle by Skogman’s method show good agreement when the pressure points are close enough to each other. Additionally, the methods for calculating the rudder forces by Bertram, Lewis, and Larsson are sufficient for use in further investigations.
EyeMRTK: A Toolkit for Developing Eye Gaze Interactive Applications in Virtual and Augmented Reality
(2019)
For head mounted displays, like they are used in mixed reality applications, eye gaze seems to be a natural interaction modality. EyeMRTK provides building blocks for eye gaze interaction in virtual and augmented reality. Based on a hardware abstraction layer, it allows interaction researchers and developers to focus on their interaction concepts, while enabling them to evaluate their ideas on all supported systems. In addition to that, the toolkit provides a simulation layer for debugging purposes, which speeds up prototyping during development on the desktop.
For the introduction of new automated driving functions, the systems need to be verified extensively. A scenario-driven approach has become an accepted method for this task. But to verify the functionality of an automated vehicle in the simulation in a certain scenario such as a lane change, relevant characteristics of scenarios need to be identified. This, however, requires to extract these scenarios from real-world drivings accurately. For that purpose, this work proposes a novel framework based on a set of unsupervised learning methods to identify lane-changes on motorways. To represent various types of lane changes, the maneuver is split up into primitive driving actions with an Hidden Markov Model and Divisive Hierarchical Clustering. Based on this, lane change maneuvers are identified using Dynamic-Time-Warping. The presented framework is evaluated with a real-world test drive and compared to other baseline methods. With a f1 score of 98.01\% in lane-change identification, the presented approach shows promising results.
Applying Task-centric Holistic Teaching Approach in Education of Industrial Cyber Physical Systems
(2020)
In order to meet the increasing demand for industrial cyber physical systems, highly qualified professionals are required who possess both excellent professional knowledge and skills as well as soft skills. The interdisciplinarity of industrial cyber physical systems makes teaching the necessary skill challenging. The approach known from the education of software engineering, in which students form a team to develop a software product, is not sufficient. There is also a lack of soft skills, which are often seen as key success factors for engineering projects. To close the existing gaps in education of industrial cyber-physical systems engineering, the task-centric holistic agile teaching approach (T-CHAT) is proposed. This approach will be implemented in a newly developed curriculum for industrial cyber physical systems at the ITMO University St. Petersburg, Russia. It focuses on teaching of both technical and soft skills.