Splicing of concurrent upper-body motion spaces with locomotion

In this paper, we present a motion splicing technique for generating concurrent upper-body actions occurring simultaneously with the evolution of a lower-body locomotion sequence. Specifically, we show that a layered interpolation motion model generates upper-body poses while assigning different actions to each upper-body part. Hence, in the proposed motion splicing approach, it is possible to increase the number of generated motions as well as the number of desired actions that can be performed by virtual characters. Additionally, we propose an iterative motion blending solution, inverse pseudo-blending, to maintain a smooth and natural interaction between the virtual character and the virtual environment; inverse pseudo-blending is a constraint-based motion editing technique that blends the motions enclosed in a tetrahedron by minimising the distances between the end-effector positions of the actual and blended motions. Additionally, to evaluate the proposed solution, we implemented an example-based application for interactive motion splicing based on specified constraints. Finally, the generated results show that the proposed solution can be beneficially applied to interactive applications where concurrent actions of the upper-body are desired

ChatGPT impacts in programming education: A recent literature overview that debates ChatGPT responses

This paper aims at a brief overview of the main impact of ChatGTP in the scientific field of programming and learning/education in computer science. It lists, covers and documents from the literature the major issues that have been identified for this topic, such as applications, advantages and limitations, ethical issues raised. Answers to the above questions were solicited from ChatGPT itself, the responses were collected, and then the recent literature was surveyed to determine whether or not the responses are supported. The paper ends with a short discussion on what is expected to happen in the near future. A future that can be extremely promising if humanity manages to have AI as a proper ally and partner, with distinct roles and specific rules of cooperation and interaction.Comment: 16 page

Autonomous Reality Modelling for Cultural Heritage Sites employing cooperative quadrupedal robots and unmanned aerial vehicles

Nowadays, the use of advanced sensors, such as terrestrial 3D laser scanners, mobile LiDARs and Unmanned Aerial Vehicles (UAV) photogrammetric imaging, has become the prevalent practice for 3D Reality Modeling and digitization of large-scale monuments of Cultural Heritage (CH). In practice, this process is heavily related to the expertise of the surveying team, handling the laborious planning and time-consuming execution of the 3D mapping process that is tailored to the specific requirements and constraints of each site. To minimize human intervention, this paper introduces a novel methodology for autonomous 3D Reality Modeling for CH monuments by employing au-tonomous biomimetic quadrupedal robotic agents and UAVs equipped with the appropriate sensors. These autonomous robotic agents carry out the 3D RM process in a systematic and repeatable ap-proach. The outcomes of this automated process may find applications in digital twin platforms, facilitating secure monitoring and management of cultural heritage sites and spaces, in both indoor and outdoor environments

The Case for Graph-Based Recommendations

Recommender systems have been intensively used to create personalised profiles, which enhance the user experience. In certain areas, such as e-learning, this approach is short-sighted, since each student masters each concept through different means. The progress from one concept to the next, or from one lesson to another, does not necessarily follow a fixed pattern. Given these settings, we can no longer use simple structures (vectors, strings, etc.) to represent each user's interactions with the system, because the sequence of events and their mapping to user's intentions, build up into more complex synergies. As a consequence, we propose a graph-based interpretation of the problem and identify the challenges behind (a) using graphs to model the users' journeys and hence as the input to the recommender system, and (b) producing recommendations in the form of graphs of actions to be taken

Rethinking shortest path: an energy expenditure approach

Considering that humans acting in constrained environments do not always plan according to shortest path criteria; rather, they conceptually measure the path which minimises the amount of expended energy. Hence, virtual characters should be able to execute their paths according to planning methods based not on path length but on the minimisation of actual expended energy. Thus, in this paper, we introduce a simple method that uses a formula for computing vanadium dioxide (VO2) levels, which is a proxy for the energy expended by humans during various activities

Scaling k-Nearest Neighbors Queries (The Right Way)

Recently parallel / distributed processing approaches have been proposed for processing k-Nearest Neighbours (kNN) queries over very large (multidimensional) datasets aiming to ensure scalability. However, this is typically achieved at the expense of efficiency. With this paper we offer a novel approach that alleviates the performance problems associated with state of the art methods. The essence of our approach, which differentiates it from related research, rests on (i) adopting a coordinator-based distributed processing algorithm, instead of those employed over data-parallel executionengines (such as Hadoop/MapReduce or Spark), and (ii) on a way to organize data, to structure computation, and to index the stored datasets that ensures that only a very small number of data items are retrieved from the underlying data store, communicated over the network, and processed by the coordinatorfor every kNN query. Our approach also pays special attention to ensuring scalability in addition to low query processing times. Overall, kNN queries can be processed in just tens of milliseconds (as opposed to the tens of) seconds required by state of the art. We have implemented our approach, usinga NoSQL DB (HBase) as the data store, and we compare it against the state-of-the-art: the Hadoop-based Spatial Hadoop (SHadoop) and the Spark-based Simba methods. We employ different datasets of various sizes, showcasing the contributed performance advantages. Our approach outperforms the stateof the art, by 2-3 orders of magnitude, and consistently for dataset sizes ranging from hundreds of millions to hundreds of billions of data points. We also show that the key constituent performance overheads incurred during query processing (such as the number of data items retrieved from the data store, the required network bandwidth, and the processing time at the coordinator) scale very well, ensuring the overall scalability of the approach

CFD Simulation and 3D Visualization on Cultural Heritage sites: The Castle of Mytilene

This paper presents a CFD and 3D Visualization pipeline to simulate wind flow over a heritage site and then visualize the results. As case study, a coarse 3D geometry model of the Fortress of Mytilene, Lesvos island, Greece and its surrounding was generated from open access Digital Elevation Models. The CFD simulation of the air flow on the wider heritage site area was performed using the steady-state version of the in-house flow solver IBOFlow (Immersed Boundary Octree Flow Solver) developed at Fraunhofer-Chalmers Research Centre. All the simulations were completed considering the mean wind direction and wind speed during the last 22 years from actual weather data retrieved from Open Weather Map. The visualization results were achieved through Unreal Engine, using built-in visualization tools and a tailored-made plugin to visualize the air flow over the monument and on the monument’s wall. As discussed in the conclusion section, the overall process proposed in this paper can be implemented for an initial assessment of the effect of environmental parameters over any heritage site and moreover, it may form the basis for valuable assistive tool for conservators and engineers

Optimized classification predictions with a new index combining machine learning algorithms

Voting is a commonly used ensemble method aiming to optimize classification predictions by combining results from individual base classifiers. However, the selection of appropriate classifiers to participate in voting algorithm is currently an open issue. In this study we developed a novel Dissimilarity-Performance (DP) index which incorporates two important criteria for the selection of base classifiers to participate in voting: their differential response in classification (dissimilarity) when combined in triads and their individual performance. To develop this empirical index we firstly used a range of different datasets to evaluate the relationship between voting results and measures of dissimilarity among classifiers of different types (rules, trees, lazy classifiers, functions and Bayes). Secondly, we computed the combined effect on voting performance of classifiers with different individual performance and/or diverse results in the voting performance. Our DP index was able to rank the classifier combinations according to their voting performance and thus to suggest the optimal combination. The proposed index is recommended for individual machine learning users as a preliminary tool to identify which classifiers to combine in order to achieve more accurate classification predictions avoiding computer intensive and time-consuming search