1. Hierarchical learning of robotic contact policiesMihael Simonič, Aleš Ude, Bojan Nemec, 2023, izvirni znanstveni članek Povzetek: The paper addresses the issue of learning tasks where a robot maintains permanent contact with the environment. We propose a new methodology based on a hierarchical learning scheme coupled with task representation through directed graphs. These graphs are constituted of nodes and branches that correspond to the states and robotic actions, respectively. The upper level of the hierarchy essentially operates as a decision-making algorithm. It leverages reinforcement learning (RL) techniques to facilitate optimal decision-making. The actions are generated by a constraint-space following (CSF) controller that autonomously identifies feasible directions for motion. The controller generates robot motion by adjusting its stiffness in the direction defined by the Frenet–Serret frame, which is aligned with the robot path. The proposed framework was experimentally verified through a series of challenging robotic tasks such as maze learning, door opening, learning to shift the manual car gear, and learning car license plate light assembly by disassembly. Ključne besede: autonomous robot learning, learning, experience, compliance and impedance contro Objavljeno v DiRROS: 21.09.2023; Ogledov: 14; Prenosov: 7
Celotno besedilo (1,73 MB) Gradivo ima več datotek! Več... |
2. Atmosphere–cryosphere interactions during the last phase of the Last Glacial Maximum (21 ka) in the European AlpsCostanza Del Gobbo, Renato R. Colucci, Giovanni Monegato, Manja Žebre, Filippo Giorgi, 2023, izvirni znanstveni članek Povzetek: Evidence that during the Last Glacial Maximum (LGM) glaciers extended well into the piedmont plains is still identifiable in the alpine foreland as a system of well-preserved moraines. Glaciers are strongly controlled by temperature and precipitation, and therefore, they are excellent indicators of climate change. Here, we use a regional climate model (RCM) to investigate some of the physical processes sustaining Alpine glaciers during the last phase of the LGM during Greenland Stadial 2 at 21 ka. We find a predominance of convection during summer and increased southwesterly stratiform precipitation over the southern Alps when compared to pre-industrial (PI) conditions. This precipitation pattern, along with lower temperatures, determined summer snowfall extending to low elevations, with a consequent substantial drop of the equilibrium line altitude (ELA), which is consistent with the estimated LGM glacier extent. Our RCM-based estimates of 21 ka ELA at the LGM yield excellent consistency with Alpine ELA reconstructions, further demonstrating the great potential of this technique for use in palaeoclimate studies. Ključne besede: Quaternary, ice age, atmosphere, glaciers, climate change, the Alps Objavljeno v DiRROS: 19.09.2023; Ogledov: 49; Prenosov: 20
Celotno besedilo (10,56 MB) |
3. Impact of Open-Loop Systems on Groundwater Temperature in NE SloveniaSimona Adrinek, Mitja Janža, Mihael Brenčič, 2023, izvirni znanstveni članek Povzetek: To achieve sustainable and efficient use of shallow geothermal resources, it is important to understand the heat transfer in the subsurface of the planned geothermal system. In the City Municipality of Murska Sobota, NE Slovenia, the use of geothermal open-loop systems has increased in recent years. Their high spatial density raises the question of possible mutual interference between the systems. By compiling geological, hydrogeological, and thermal data, obtained from the monitoring network, fieldwork, and knowledge of regional hydrogeological conditions, we have developed a transient groundwater flow and heat transfer model to evaluate the impact of the open-loop systems on the subsurface and surrounding systems. The transient simulation showed that the thermal state in the observed area is restored over the summer, when the systems are not in operation. Also, the systems do not have significant mutual interference that would affect their efficiency. However, as interest in installing new systems in the area increases, simulations of the thermal plumes of new geothermal systems are needed to ensure sustainable and efficient use of shallow geothermal energy in the future. Ključne besede: geothermal energy, open-loop system, groundwater heat pump, intergranular aquifer, numerical modelling, thermal plume Objavljeno v DiRROS: 19.09.2023; Ogledov: 37; Prenosov: 6
Celotno besedilo (36,17 MB) |
4. |
5. |
6. |
7. |
8. |
9. |
10. |