10,903 results on '"Karras, A"'
Search Results
2. Perturb-and-Revise: Flexible 3D Editing with Generative Trajectories
- Author
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Hong, Susung, Karras, Johanna, Martin-Brualla, Ricardo, and Kemelmacher-Shlizerman, Ira
- Subjects
Computer Science - Computer Vision and Pattern Recognition - Abstract
The fields of 3D reconstruction and text-based 3D editing have advanced significantly with the evolution of text-based diffusion models. While existing 3D editing methods excel at modifying color, texture, and style, they struggle with extensive geometric or appearance changes, thus limiting their applications. We propose Perturb-and-Revise, which makes possible a variety of NeRF editing. First, we perturb the NeRF parameters with random initializations to create a versatile initialization. We automatically determine the perturbation magnitude through analysis of the local loss landscape. Then, we revise the edited NeRF via generative trajectories. Combined with the generative process, we impose identity-preserving gradients to refine the edited NeRF. Extensive experiments demonstrate that Perturb-and-Revise facilitates flexible, effective, and consistent editing of color, appearance, and geometry in 3D. For 360{\deg} results, please visit our project page: https://susunghong.github.io/Perturb-and-Revise., Comment: Project page: https://susunghong.github.io/Perturb-and-Revise
- Published
- 2024
3. Edify Image: High-Quality Image Generation with Pixel Space Laplacian Diffusion Models
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NVIDIA, Atzmon, Yuval, Bala, Maciej, Balaji, Yogesh, Cai, Tiffany, Cui, Yin, Fan, Jiaojiao, Ge, Yunhao, Gururani, Siddharth, Huffman, Jacob, Isaac, Ronald, Jannaty, Pooya, Karras, Tero, Lam, Grace, Lewis, J. P., Licata, Aaron, Lin, Yen-Chen, Liu, Ming-Yu, Ma, Qianli, Mallya, Arun, Martino-Tarr, Ashlee, Mendez, Doug, Nah, Seungjun, Pruett, Chris, Reda, Fitsum, Song, Jiaming, Wang, Ting-Chun, Wei, Fangyin, Zeng, Xiaohui, Zeng, Yu, and Zhang, Qinsheng
- Subjects
Computer Science - Computer Vision and Pattern Recognition ,Computer Science - Machine Learning - Abstract
We introduce Edify Image, a family of diffusion models capable of generating photorealistic image content with pixel-perfect accuracy. Edify Image utilizes cascaded pixel-space diffusion models trained using a novel Laplacian diffusion process, in which image signals at different frequency bands are attenuated at varying rates. Edify Image supports a wide range of applications, including text-to-image synthesis, 4K upsampling, ControlNets, 360 HDR panorama generation, and finetuning for image customization.
- Published
- 2024
4. Fashion-VDM: Video Diffusion Model for Virtual Try-On
- Author
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Karras, Johanna, Li, Yingwei, Liu, Nan, Zhu, Luyang, Yoo, Innfarn, Lugmayr, Andreas, Lee, Chris, and Kemelmacher-Shlizerman, Ira
- Subjects
Computer Science - Computer Vision and Pattern Recognition - Abstract
We present Fashion-VDM, a video diffusion model (VDM) for generating virtual try-on videos. Given an input garment image and person video, our method aims to generate a high-quality try-on video of the person wearing the given garment, while preserving the person's identity and motion. Image-based virtual try-on has shown impressive results; however, existing video virtual try-on (VVT) methods are still lacking garment details and temporal consistency. To address these issues, we propose a diffusion-based architecture for video virtual try-on, split classifier-free guidance for increased control over the conditioning inputs, and a progressive temporal training strategy for single-pass 64-frame, 512px video generation. We also demonstrate the effectiveness of joint image-video training for video try-on, especially when video data is limited. Our qualitative and quantitative experiments show that our approach sets the new state-of-the-art for video virtual try-on. For additional results, visit our project page: https://johannakarras.github.io/Fashion-VDM., Comment: Accepted to SIGGRAPH Asia 2024
- Published
- 2024
5. SHRINK: Data Compression by Semantic Extraction and Residuals Encoding
- Author
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Sun, Guoyou, Karras, Panagiotis, and Zhang, Qi
- Subjects
Computer Science - Distributed, Parallel, and Cluster Computing - Abstract
The distributed data infrastructure in Internet of Things (IoT) ecosystems requires efficient data-series compression methods, along with the ability to feed different accuracy demands. However, the compression performance of existing compression methods degrades sharply when calling for ultra-accurate data recovery. In this paper, we introduce SHRINK, a novel highly accurate data compression method that offers a higher compression ratio and also lower runtime than prior compressors. SHRINK extracts data semantics in the form of linear segments to construct a compact knowledge base, using a dynamic error threshold that it adapts to data characteristics. Then, it captures the remaining data details as residuals to support lossy compression at diverse resolutions as well as lossless compression. As SHRINK identifies repeated semantics, its compression ratio increases with data size. Our experimental evaluation demonstrates that SHRINK outperforms state-of-art methods with an up to threefold improvement in compression ratio., Comment: 11 pages
- Published
- 2024
6. Multirotor Nonlinear Model Predictive Control based on Visual Servoing of Evolving Features
- Author
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Aspragkathos, Sotirios N., Rousseas, Panagiotis, Karras, George C., and Kyriakopoulos, Kostas J.
- Subjects
Computer Science - Robotics ,Electrical Engineering and Systems Science - Systems and Control - Abstract
This article presents a Visual Servoing Nonlinear Model Predictive Control (NMPC) scheme for autonomously tracking a moving target using multirotor Unmanned Aerial Vehicles (UAVs). The scheme is developed for surveillance and tracking of contour-based areas with evolving features. NMPC is used to manage input and state constraints, while additional barrier functions are incorporated in order to ensure system safety and optimal performance. The proposed control scheme is designed based on the extraction and implementation of the full dynamic model of the features describing the target and the state variables. Real-time simulations and experiments using a quadrotor UAV equipped with a camera demonstrate the effectiveness of the proposed strategy.
- Published
- 2024
7. Mining Path Association Rules in Large Property Graphs (with Appendix)
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Sasaki, Yuya and Karras, Panagiotis
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Computer Science - Databases ,Computer Science - Artificial Intelligence - Abstract
How can we mine frequent path regularities from a graph with edge labels and vertex attributes? The task of association rule mining successfully discovers regular patterns in item sets and substructures. Still, to our best knowledge, this concept has not yet been extended to path patterns in large property graphs. In this paper, we introduce the problem of path association rule mining (PARM). Applied to any \emph{reachability path} between two vertices within a large graph, PARM discovers regular ways in which path patterns, identified by vertex attributes and edge labels, co-occur with each other. We develop an efficient and scalable algorithm PIONEER that exploits an anti-monotonicity property to effectively prune the search space. Further, we devise approximation techniques and employ parallelization to achieve scalable path association rule mining. Our experimental study using real-world graph data verifies the significance of path association rules and the efficiency of our solutions.
- Published
- 2024
8. SWARM-SLR -- Streamlined Workflow Automation for Machine-actionable Systematic Literature Reviews
- Author
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Wittenborg, Tim, Karras, Oliver, and Auer, Sören
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Computer Science - Digital Libraries ,Computer Science - Software Engineering - Abstract
Authoring survey or review articles still requires significant tedious manual effort, despite many advancements in research knowledge management having the potential to improve efficiency, reproducibility, and reuse. However, these advancements bring forth an increasing number of approaches, tools, and systems, which often cover only specific stages and lack a comprehensive workflow utilizing their task-specific strengths. We propose the Streamlined Workflow Automation for Machine-actionable Systematic Literature Reviews (SWARM-SLR) to crowdsource the improvement of SLR efficiency while maintaining scientific integrity in a state-of-the-art knowledge discovery and distribution process. The workflow aims to domain-independently support researchers in collaboratively and sustainably managing the rising scholarly knowledge corpus. By synthesizing guidelines from the literature, we have composed a set of 65 requirements, spanning from planning to reporting a review. Existing tools were assessed against these requirements and synthesized into the SWARM-SLR workflow prototype, a ready-for-operation software support tool. The SWARM-SLR was evaluated via two online surveys, which largely confirmed the validity of the 65 requirements and situated 11 tools to the different life-cycle stages. The SWARM-SLR workflow was similarly evaluated and found to be supporting almost the entire span of an SLR, excelling specifically in search and retrieval, information extraction, knowledge synthesis, and distribution. Our SWARM-SLR requirements and workflow support tool streamlines the SLR support for researchers, allowing sustainable collaboration by linking individual efficiency improvements to crowdsourced knowledge management. If these efforts are continued, we expect the increasing number of tools to be manageable and usable inside fully structured, (semi-)automated literature review workflows., Comment: This preprint has not undergone peer review (when applicable) or any post-submission improvements or corrections
- Published
- 2024
- Full Text
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9. An autoencoder for compressing angle-resolved photoemission spectroscopy data
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Agustsson, Steinn Ymir, Haque, Mohammad Ahsanul, Truong, Thi Tam, Bianchi, Marco, Klyuchnikov, Nikita, Mottin, Davide, Karras, Panagiotis, and Hofmann, Philip
- Subjects
Condensed Matter - Materials Science ,Computer Science - Machine Learning - Abstract
Angle-resolved photoemission spectroscopy (ARPES) is a powerful experimental technique to determine the electronic structure of solids. Advances in light sources for ARPES experiments are currently leading to a vast increase of data acquisition rates and data quantity. On the other hand, access time to the most advanced ARPES instruments remains strictly limited, calling for fast, effective, and on-the-fly data analysis tools to exploit this time. In response to this need, we introduce ARPESNet, a versatile autoencoder network that efficiently summmarises and compresses ARPES datasets. We train ARPESNet on a large and varied dataset of 2-dimensional ARPES data extracted by cutting standard 3-dimensional ARPES datasets along random directions in $\mathbf{k}$. To test the data representation capacity of ARPESNet, we compare $k$-means clustering quality between data compressed by ARPESNet, data compressed by discrete cosine transform, and raw data, at different noise levels. ARPESNet data excels in clustering quality despite its high compression ratio.
- Published
- 2024
10. The European Seaborne Empires: From the Thirty Years' War to the Age of Revolutions by Gabriel Paquette (review)
- Author
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Karras, Alan L.
- Published
- 2020
11. Smugglers, Brothels, and Twine: Historical Perspectives on Contraband and Vice in North America’s Borderlands ed. by Elaine Carey and Andrae M. Marak (review)
- Author
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Karras, Alan L.
- Published
- 2019
12. Guiding a Diffusion Model with a Bad Version of Itself
- Author
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Karras, Tero, Aittala, Miika, Kynkäänniemi, Tuomas, Lehtinen, Jaakko, Aila, Timo, and Laine, Samuli
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Computer Science - Computer Vision and Pattern Recognition ,Computer Science - Artificial Intelligence ,Computer Science - Machine Learning ,Computer Science - Neural and Evolutionary Computing ,Statistics - Machine Learning - Abstract
The primary axes of interest in image-generating diffusion models are image quality, the amount of variation in the results, and how well the results align with a given condition, e.g., a class label or a text prompt. The popular classifier-free guidance approach uses an unconditional model to guide a conditional model, leading to simultaneously better prompt alignment and higher-quality images at the cost of reduced variation. These effects seem inherently entangled, and thus hard to control. We make the surprising observation that it is possible to obtain disentangled control over image quality without compromising the amount of variation by guiding generation using a smaller, less-trained version of the model itself rather than an unconditional model. This leads to significant improvements in ImageNet generation, setting record FIDs of 1.01 for 64x64 and 1.25 for 512x512, using publicly available networks. Furthermore, the method is also applicable to unconditional diffusion models, drastically improving their quality., Comment: NeurIPS 2024
- Published
- 2024
13. KG-EmpiRE: A Community-Maintainable Knowledge Graph for a Sustainable Literature Review on the State and Evolution of Empirical Research in Requirements Engineering
- Author
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Karras, Oliver
- Subjects
Computer Science - Software Engineering - Abstract
In the last two decades, several researchers provided snapshots of the "current" state and evolution of empirical research in requirements engineering (RE) through literature reviews. However, these literature reviews were not sustainable, as none built on or updated previous works due to the unavailability of the extracted and analyzed data. KG-EmpiRE is a Knowledge Graph (KG) of empirical research in RE based on scientific data extracted from currently 680 papers published in the IEEE International Requirements Engineering Conference (1994-2022). KG-EmpiRE is maintained in the Open Research Knowledge Graph (ORKG), making all data openly and long-term available according to the FAIR data principles. Our long-term goal is to constantly maintain KG-EmpiRE with the research community to synthesize a comprehensive, up-to-date, and long-term available overview of the state and evolution of empirical research in RE. Besides KG-EmpiRE, we provide its analysis with all supplementary materials in a repository. This repository contains all files with instructions for replicating and (re-)using the analysis locally or via executable environments and for repeating the research approach. Since its first release based on 199 papers (2014-2022), KG-EmpiRE and its analysis have been updated twice, currently covering over 650 papers. KG-EmpiRE and its analysis demonstrate how innovative infrastructures, such as the ORKG, can be leveraged to make data from literature reviews FAIR, openly available, and maintainable for the research community in the long term. In this way, we can enable replicable, (re-)usable, and thus sustainable literature reviews to ensure the quality, reliability, and timeliness of their research results., Comment: Accepted for publication at the 32nd IEEE International Requirements Engineering conference (RE) 2024
- Published
- 2024
14. Robust Reward Placement under Uncertainty
- Author
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Petsinis, Petros, Zhang, Kaichen, Pavlogiannis, Andreas, Zhou, Jingbo, and Karras, Panagiotis
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Computer Science - Multiagent Systems ,Computer Science - Social and Information Networks - Abstract
We consider a problem of placing generators of rewards to be collected by randomly moving agents in a network. In many settings, the precise mobility pattern may be one of several possible, based on parameters outside our control, such as weather conditions. The placement should be robust to this uncertainty, to gain a competent total reward across possible networks. To study such scenarios, we introduce the Robust Reward Placement problem (RRP). Agents move randomly by a Markovian Mobility Model with a predetermined set of locations whose connectivity is chosen adversarially from a known set $\Pi$ of candidates. We aim to select a set of reward states within a budget that maximizes the minimum ratio, among all candidates in $\Pi$, of the collected total reward over the optimal collectable reward under the same candidate. We prove that RRP is NP-hard and inapproximable, and develop $\Psi$-Saturate, a pseudo-polynomial time algorithm that achieves an $\epsilon$-additive approximation by exceeding the budget constraint by a factor that scales as $O(\ln |\Pi|/\epsilon)$. In addition, we present several heuristics, most prominently one inspired by a dynamic programming algorithm for the max-min 0-1 KNAPSACK problem. We corroborate our theoretical analysis with an experimental evaluation on synthetic and real data., Comment: Accepted for publication in IJCAI 2024
- Published
- 2024
15. ReliK: A Reliability Measure for Knowledge Graph Embeddings
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Egger, Maximilian K., Ma, Wenyue, Mottin, Davide, Karras, Panagiotis, Bordino, Ilaria, Gullo, Francesco, and Anagnostopoulos, Aris
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Computer Science - Social and Information Networks - Abstract
Can we assess a priori how well a knowledge graph embedding will perform on a specific downstream task and in a specific part of the knowledge graph? Knowledge graph embeddings (KGEs) represent entities (e.g., "da Vinci," "Mona Lisa") and relationships (e.g., "painted") of a knowledge graph (KG) as vectors. KGEs are generated by optimizing an embedding score, which assesses whether a triple (e.g., "da Vinci," "painted," "Mona Lisa") exists in the graph. KGEs have been proven effective in a variety of web-related downstream tasks, including, for instance, predicting relationships among entities. However, the problem of anticipating the performance of a given KGE in a certain downstream task and locally to a specific individual triple, has not been tackled so far. In this paper, we fill this gap with ReliK, a Reliability measure for KGEs. ReliK relies solely on KGE embedding scores, is task- and KGE-agnostic, and requires no further KGE training. As such, it is particularly appealing for semantic web applications which call for testing multiple KGE methods on various parts of the KG and on each individual downstream task. Through extensive experiments, we attest that ReliK correlates well with both common downstream tasks, such as tail or relation prediction and triple classification, as well as advanced downstream tasks, such as rule mining and question answering, while preserving locality.
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- 2024
16. Seed Selection in the Heterogeneous Moran Process
- Author
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Petsinis, Petros, Pavlogiannis, Andreas, Tkadlec, Josef, and Karras, Panagiotis
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Computer Science - Data Structures and Algorithms ,Computer Science - Computational Complexity ,Computer Science - Social and Information Networks ,Quantitative Biology - Populations and Evolution - Abstract
The Moran process is a classic stochastic process that models the rise and takeover of novel traits in network-structured populations. In biological terms, a set of mutants, each with fitness $m\in(0,\infty)$ invade a population of residents with fitness $1$. Each agent reproduces at a rate proportional to its fitness and each offspring replaces a random network neighbor. The process ends when the mutants either fixate (take over the whole population) or go extinct. The fixation probability measures the success of the invasion. To account for environmental heterogeneity, we study a generalization of the Standard process, called the Heterogeneous Moran process. Here, the fitness of each agent is determined both by its type (resident/mutant) and the node it occupies. We study the natural optimization problem of seed selection: given a budget $k$, which $k$ agents should initiate the mutant invasion to maximize the fixation probability? We show that the problem is strongly inapproximable: it is $\mathbf{NP}$-hard to distinguish between maximum fixation probability 0 and 1. We then focus on mutant-biased networks, where each node exhibits at least as large mutant fitness as resident fitness. We show that the problem remains $\mathbf{NP}$-hard, but the fixation probability becomes submodular, and thus the optimization problem admits a greedy $(1-1/e)$-approximation. An experimental evaluation of the greedy algorithm along with various heuristics on real-world data sets corroborates our results., Comment: Accepted for publication in IJCAI 2024
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- 2024
17. Applying Guidance in a Limited Interval Improves Sample and Distribution Quality in Diffusion Models
- Author
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Kynkäänniemi, Tuomas, Aittala, Miika, Karras, Tero, Laine, Samuli, Aila, Timo, and Lehtinen, Jaakko
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Computer Science - Computer Vision and Pattern Recognition ,Computer Science - Artificial Intelligence ,Computer Science - Machine Learning ,Computer Science - Neural and Evolutionary Computing ,Statistics - Machine Learning - Abstract
Guidance is a crucial technique for extracting the best performance out of image-generating diffusion models. Traditionally, a constant guidance weight has been applied throughout the sampling chain of an image. We show that guidance is clearly harmful toward the beginning of the chain (high noise levels), largely unnecessary toward the end (low noise levels), and only beneficial in the middle. We thus restrict it to a specific range of noise levels, improving both the inference speed and result quality. This limited guidance interval improves the record FID in ImageNet-512 significantly, from 1.81 to 1.40. We show that it is quantitatively and qualitatively beneficial across different sampler parameters, network architectures, and datasets, including the large-scale setting of Stable Diffusion XL. We thus suggest exposing the guidance interval as a hyperparameter in all diffusion models that use guidance., Comment: NeurIPS 2024
- Published
- 2024
18. The Global Atlantic: 1400–1900 by Christoph Strobel (review)
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Karras, Alan L.
- Published
- 2018
- Full Text
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19. Autonomous microARPES
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Agustsson, Steinn Ymir, Jones, Alfred J. H., Curcio, Davide, Ulstrup, Søren, Miwa, Jill, Mottin, Davide, Karras, Panagiotis, and Hofmann, Philip
- Subjects
Condensed Matter - Materials Science ,Computer Science - Machine Learning - Abstract
Angle-resolved photoemission spectroscopy (ARPES) is a technique used to map the occupied electronic structure of solids. Recent progress in X-ray focusing optics has led to the development of ARPES into a microscopic tool, permitting the electronic structure to be spatially mapped across the surface of a sample. This comes at the expense of a time-consuming scanning process to cover not only a three-dimensional energy-momentum ($E, k_z, k_y$) space but also the two-dimensional surface area. Here, we implement a protocol to autonomously search both $\mathbf{k}$- and real space in order to find positions of particular interest, either because of their high photoemission intensity or because of sharp spectral features. The search is based on the use of Gaussian process regression and can easily be expanded to include additional parameters or optimisation criteria. This autonomous experimental control is implemented on the SGM4 micro-focus beamline of the synchrotron radiation source ASTRID2.
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- 2024
- Full Text
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20. EUGENE: Explainable Unsupervised Approximation of Graph Edit Distance
- Author
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Bommakanti, Aditya, Vonteri, Harshith Reddy, Ranu, Sayan, and Karras, Panagiotis
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Computer Science - Machine Learning - Abstract
The need to identify graphs having small structural distance from a query arises in biology, chemistry, recommender systems, and social network analysis. Among several methods to measure inter graph distance, Graph Edit Distance (GED) is preferred for its comprehensibility, yet hindered by the NP-hardness of its computation. State-of-the-art GED approximations predominantly employ neural methods, which, however, (i) lack an explanatory edit path corresponding to the approximated GED; (ii) require the NP-hard generation of ground-truth GEDs for training; and (iii) necessitate separate training on each dataset. In this paper, we propose an efficient algebraic unsuper vised method, EUGENE, that approximates GED and yields edit paths corresponding to the approx imated cost, while eliminating the need for ground truth generation and data-specific training. Extensive experimental evaluation demonstrates that the aforementioned benefits of EUGENE do not come at the cost of efficacy. Specifically, EUGENE consistently ranks among the most accurate methods across all of the benchmark datasets and outperforms majority of the neural approaches.
- Published
- 2024
21. Organizing Scientific Knowledge From Energy System Research Using the Open Research Knowledge Graph
- Author
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Karras, Oliver, Göpfert, Jan, Kuckertz, Patrick, Pelser, Tristan, and Auer, Sören
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Computer Science - Digital Libraries - Abstract
Engineering sciences, such as energy system research, play an important role in developing solutions to technical, environmental, economic, and social challenges of our modern society. In this context, the transformation of energy systems into climate-neutral systems is one of the key strategies for mitigating climate change. For the transformation of energy systems, engineers model, simulate and analyze scenarios and transformation pathways to initiate debates about possible transformation strategies. For these debates and research in general, all steps of the research process must be traceable to guarantee the trustworthiness of published results, avoid redundancies, and ensure their social acceptance. However, the analysis of energy systems is an interdisciplinary field as the investigations of large, complex energy systems often require the use of different software applications and large amounts of heterogeneous data. Engineers must therefore communicate, understand, and (re)use heterogeneous scientific knowledge and data. Although the importance of FAIR scientific knowledge and data in the engineering sciences and energy system research is increasing, little research has been conducted on this topic. When it comes to publishing scientific knowledge and data from publications, software, and datasets (such as models, scenarios, and simulations) openly available and transparent, energy system research lags behind other research domains. According to Schmitt et al. and Nie{\ss}e et al., engineers need technical support in the form of infrastructures, services, and terminologies to improve communication, understanding, and (re)use of scientific knowledge and data., Comment: 1. NFDI4Energy Conference
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- 2024
22. The Costs of Straw in Germany: Development of Regional Straw Supply Costs between 2010 and 2020
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Karras, Tom and Thrän, Daniela
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- 2024
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23. Analyzing and Improving the Training Dynamics of Diffusion Models
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Karras, Tero, Aittala, Miika, Lehtinen, Jaakko, Hellsten, Janne, Aila, Timo, and Laine, Samuli
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Computer Science - Computer Vision and Pattern Recognition ,Computer Science - Artificial Intelligence ,Computer Science - Machine Learning ,Computer Science - Neural and Evolutionary Computing ,Statistics - Machine Learning - Abstract
Diffusion models currently dominate the field of data-driven image synthesis with their unparalleled scaling to large datasets. In this paper, we identify and rectify several causes for uneven and ineffective training in the popular ADM diffusion model architecture, without altering its high-level structure. Observing uncontrolled magnitude changes and imbalances in both the network activations and weights over the course of training, we redesign the network layers to preserve activation, weight, and update magnitudes on expectation. We find that systematic application of this philosophy eliminates the observed drifts and imbalances, resulting in considerably better networks at equal computational complexity. Our modifications improve the previous record FID of 2.41 in ImageNet-512 synthesis to 1.81, achieved using fast deterministic sampling. As an independent contribution, we present a method for setting the exponential moving average (EMA) parameters post-hoc, i.e., after completing the training run. This allows precise tuning of EMA length without the cost of performing several training runs, and reveals its surprising interactions with network architecture, training time, and guidance.
- Published
- 2023
24. Modulation of naïve mesenchymal stromal cells by extracellular vesicles derived from insulin-producing cells: an in vitro study
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Gabr, Mahmoud M., El-Halawani, Sawsan M., Refaie, Ayman F., Khater, Sherry M., Ismail, Amani M., Karras, Mary S., Magar, Raghda W., Sayed, Shorouk El, Kloc, Malgorzata, Uosef, Ahmed, Sabek, Omaima M., and Ghoneim, Mohamed A.
- Published
- 2024
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25. Slow vibrational relaxation drives ultrafast formation of photoexcited polaron pair states in glycolated conjugated polymers
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Pagano, Katia, Kim, Jin Gwan, Luke, Joel, Tan, Ellasia, Stewart, Katherine, Sazanovich, Igor V., Karras, Gabriel, Gonev, Hristo Ivov, Marsh, Adam V., Kim, Na Yeong, Kwon, Sooncheol, Kim, Young Yong, Alonso, M. Isabel, Dörling, Bernhard, Campoy-Quiles, Mariano, Parker, Anthony W., Clarke, Tracey M., Kim, Yun-Hi, and Kim, Ji-Seon
- Published
- 2024
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26. Overwintering West Nile virus in active Culex pipiens mosquito populations in Greece
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Balatsos, Georgios, Beleri, Stavroula, Tegos, Nikolaos, Bisia, Marina, Karras, Vasileios, Zavitsanou, Evangelia, Papachristos, Dimitrios P., Papadopoulos, Nikos T., Michaelakis, Antonios, and Patsoula, Eleni
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- 2024
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27. Taking a 'Whole' Classroom Perspective: Theorizing Classroom Typologies Using a Video-Based Observational Protocol
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Juliana E. Karras, Guadalupe L. Hernández, Patricia Cabral, Stephanie Nguyen, and Carola Suárez-Orozco
- Abstract
Inspired by a "whole child" framing, the current study takes a "whole classroom" perspective to consider classroom practice. Study aims included: (1) presenting a systematic video-based observational coding strategy to concurrently consider practice domains that have implications for learning--cognitive instruction, classroom management, and teacher-student relational interactions; (2) identifying distinct and interrelated classroom typologies based upon this coding strategy. The framework was developed through coding and analysis of 58 purposively sampled urban 4th-9th grade classrooms from the Measures of Effective Teaching study. Analyses revealed three overarching typologies: task-focused (52%), low stimulation (43%), and optimal (5%). We conclude by discussing implications for urban education.
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- 2024
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28. Tisagenlecleucel utilisation and outcomes across refractory, first relapse and multiply relapsed B-cell acute lymphoblastic leukemia: a retrospective analysis of real-world patterns.
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Barsan, Valentin, Li, Yimei, Prabhu, Snehit, Baggott, Christina, Nguyen, Khanh, Pacenta, Holly, Phillips, Christine, Rossoff, Jenna, Stefanski, Heather, Talano, Julie-An, Moskop, Amy, Baumeister, Susanne, Verneris, Michael, Myers, Gary, Karras, Nicole, Cooper, Stacy, Qayed, Muna, Satwani, Prakash, Krupski, Christa, Keating, Amy, Fabrizio, Vanessa, Chinnabhandar, Vasant, Kunicki, Michael, Curran, Kevin, Mackall, Crystal, Laetsch, Theodore, Schultz, Liora, and Hermiston, Michelle
- Subjects
CAR T cells ,CD19 CAR T cells ,Commercial CAR ,First relapse ,Immunotherapy ,Pediatric oncology ,Real-world analysis ,Tisagenlecleucel - Abstract
BACKGROUND: Tisagenlecleucel was approved by the Food and Drug Administration (FDA) in 2017 for refractory B-cell acute lymphoblastic leukemia (B-ALL) and B-ALL in ≥2nd relapse. Outcomes of patients receiving commercial tisagenlecleucel upon 1st relapse have yet to be established. We aimed to report real-world tisagenlecleucel utilisation patterns and outcomes across indications, specifically including patients treated in 1st relapse, an indication omitted from formal FDA approval. METHODS: We conducted a retrospective analysis of real-world tisagenlecleucel utilisation patterns across 185 children and young adults treated between August 30, 2017 and March 6, 2020 from centres participating in the Pediatric Real-World CAR Consortium (PRWCC), within the United States. We described definitions of refractory B-ALL used in the real-world setting and categorised patients by reported Chimeric Antigen Receptor (CAR) T-cell indication, including refractory, 1st relapse and ≥2nd relapse B-ALL. We analysed baseline patient characteristics and post-tisagenlecleucel outcomes across defined cohorts. FINDINGS: Thirty-six percent (n = 67) of our cohort received tisagenlecleucel following 1st relapse. Of 66 evaluable patients, 56 (85%, 95% CI 74-92%) achieved morphologic complete response. Overall-survival (OS) and event-free survival (EFS) at 1-year were 69%, (95% CI 58-82%) and 49%, (95% CI 37-64%), respectively, with survival outcomes statistically comparable to remaining patients (OS; p = 0.14, EFS; p = 0.39). Notably, toxicity was increased in this cohort, warranting further study. Interestingly, of 30 patients treated for upfront refractory disease, 23 (77%, 95% CI 58-90%) had flow cytometry and/or next-generation sequencing (NGS) minimum residual disease (MRD)-only disease at the end of induction, not meeting the historic morphologic definition of refractory. INTERPRETATION: Our findings suggested that tisagenlecleucel response and survival rates overlap across patients treated with upfront refractory B-ALL, B-ALL ≥2nd relapse and B-ALL in 1st relapse. We additionally highlighted that definitions of refractory B-ALL are evolving beyond morphologic measures of residual disease. FUNDING: St. Baldricks/Stand Up 2 Cancer, Parker Institute for Cancer Immunotherapy, Virginia and D.K. Ludwig Fund for Cancer Research.
- Published
- 2023
29. Conclusion
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Karras, Jana, Rodi, Michael, Series Editor, Schäfer-Stradowsky, Simon, Series Editor, and Karras, Jana
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- 2024
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30. Description of Results
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Karras, Jana, Rodi, Michael, Series Editor, Schäfer-Stradowsky, Simon, Series Editor, and Karras, Jana
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- 2024
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31. Country Reports and their Comparative Analysis
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Karras, Jana, Rodi, Michael, Series Editor, Schäfer-Stradowsky, Simon, Series Editor, and Karras, Jana
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- 2024
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32. Possible Solutions
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Karras, Jana, Rodi, Michael, Series Editor, Schäfer-Stradowsky, Simon, Series Editor, and Karras, Jana
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- 2024
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33. Research Methodology
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Karras, Jana, Rodi, Michael, Series Editor, Schäfer-Stradowsky, Simon, Series Editor, and Karras, Jana
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- 2024
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34. Introduction
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Karras, Jana, Rodi, Michael, Series Editor, Schäfer-Stradowsky, Simon, Series Editor, and Karras, Jana
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- 2024
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35. EU Regulative Framework
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Karras, Jana, Rodi, Michael, Series Editor, Schäfer-Stradowsky, Simon, Series Editor, and Karras, Jana
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- 2024
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36. Current State of Research in Defined Area from Energy Efficiency Point of View
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Karras, Jana, Rodi, Michael, Series Editor, Schäfer-Stradowsky, Simon, Series Editor, and Karras, Jana
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- 2024
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37. Decentralized Algorithms for Efficient Energy Management over Cloud-Edge Infrastructures
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Karras, Aristeidis, Karras, Christos, Giannoukou, Ioanna, Giotopoulos, Konstantinos C., Tsolis, Dimitrios, Karydis, Ioannis, Sioutas, Spyros, Goos, Gerhard, Founding Editor, Hartmanis, Juris, Founding Editor, Bertino, Elisa, Editorial Board Member, Gao, Wen, Editorial Board Member, Steffen, Bernhard, Editorial Board Member, Yung, Moti, Editorial Board Member, Chatzigiannakis, Ioannis, editor, and Karydis, Ioannis, editor
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- 2024
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38. Algorithmic Aspects of Distributed Hash Tables on Cloud, Fog, and Edge Computing Applications: A Survey
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Karras, Aristeidis, Karras, Christos, Schizas, Nikolaos, Sioutas, Spyros, Zaroliagis, Christos, Goos, Gerhard, Founding Editor, Hartmanis, Juris, Founding Editor, Bertino, Elisa, Editorial Board Member, Gao, Wen, Editorial Board Member, Steffen, Bernhard, Editorial Board Member, Yung, Moti, Editorial Board Member, Chatzigiannakis, Ioannis, editor, and Karydis, Ioannis, editor
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- 2024
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39. An Adaptive, Energy-Efficient DRL-Based and MCMC-Based Caching Strategy for IoT Systems
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Karras, Aristeidis, Karras, Christos, Karydis, Ioannis, Avlonitis, Markos, Sioutas, Spyros, Goos, Gerhard, Founding Editor, Hartmanis, Juris, Founding Editor, Bertino, Elisa, Editorial Board Member, Gao, Wen, Editorial Board Member, Steffen, Bernhard, Editorial Board Member, Yung, Moti, Editorial Board Member, Chatzigiannakis, Ioannis, editor, and Karydis, Ioannis, editor
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- 2024
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40. Universal inverse modeling of point spread functions for SMLM localization and microscope characterization
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Liu, Sheng, Chen, Jianwei, Hellgoth, Jonas, Müller, Lucas-Raphael, Ferdman, Boris, Karras, Christian, Xiao, Dafei, Lidke, Keith A., Heintzmann, Rainer, Shechtman, Yoav, Li, Yiming, and Ries, Jonas
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- 2024
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41. Decoding the interplay between genetic and non-genetic drivers of metastasis
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Karras, Panagiotis, Black, James R. M., McGranahan, Nicholas, and Marine, Jean-Christophe
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- 2024
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42. Divide and Conquer the EmpiRE: A Community-Maintainable Knowledge Graph of Empirical Research in Requirements Engineering
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Karras, Oliver, Wernlein, Felix, Klünder, Jil, and Auer, Sören
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Computer Science - Software Engineering ,Computer Science - Digital Libraries - Abstract
[Background.] Empirical research in requirements engineering (RE) is a constantly evolving topic, with a growing number of publications. Several papers address this topic using literature reviews to provide a snapshot of its "current" state and evolution. However, these papers have never built on or updated earlier ones, resulting in overlap and redundancy. The underlying problem is the unavailability of data from earlier works. Researchers need technical infrastructures to conduct sustainable literature reviews. [Aims.] We examine the use of the Open Research Knowledge Graph (ORKG) as such an infrastructure to build and publish an initial Knowledge Graph of Empirical research in RE (KG-EmpiRE) whose data is openly available. Our long-term goal is to continuously maintain KG-EmpiRE with the research community to synthesize a comprehensive, up-to-date, and long-term available overview of the state and evolution of empirical research in RE. [Method.] We conduct a literature review using the ORKG to build and publish KG-EmpiRE which we evaluate against competency questions derived from a published vision of empirical research in software (requirements) engineering for 2020 - 2025. [Results.] From 570 papers of the IEEE International Requirements Engineering Conference (2000 - 2022), we extract and analyze data on the reported empirical research and answer 16 out of 77 competency questions. These answers show a positive development towards the vision, but also the need for future improvements. [Conclusions.] The ORKG is a ready-to-use and advanced infrastructure to organize data from literature reviews as knowledge graphs. The resulting knowledge graphs make the data openly available and maintainable by research communities, enabling sustainable literature reviews., Comment: Accepted for publication at the 17th ACM/IEEE International Symposium on Empirical Software Engineering and Measurement (ESEM 2023)
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- 2023
43. A Metadata-Based Ecosystem to Improve the FAIRness of Research Software
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Kuckertz, Patrick, Göpfert, Jan, Karras, Oliver, Neuroth, David, Schönau, Julian, Pueblas, Rodrigo, Ferenz, Stephan, Engel, Felix, Pflugradt, Noah, Weinand, Jann M., Nieße, Astrid, Auer, Sören, and Stolten, Detlef
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Computer Science - Software Engineering - Abstract
The reuse of research software is central to research efficiency and academic exchange. The application of software enables researchers with varied backgrounds to reproduce, validate, and expand upon study findings. Furthermore, the analysis of open source code aids in the comprehension, comparison, and integration of approaches. Often, however, no further use occurs because relevant software cannot be found or is incompatible with existing research processes. This results in repetitive software development, which impedes the advancement of individual researchers and entire research communities. In this article, the DataDesc ecosystem is presented, an approach to describing data models of software interfaces with detailed and machine-actionable metadata. In addition to a specialized metadata schema, an exchange format and support tools for easy collection and the automated publishing of software documentation are introduced. This approach practically increases the FAIRness, i.e., findability, accessibility, interoperability, and so the reusability of research software, as well as effectively promotes its impact on research.
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- 2023
44. DreamPose: Fashion Image-to-Video Synthesis via Stable Diffusion
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Karras, Johanna, Holynski, Aleksander, Wang, Ting-Chun, and Kemelmacher-Shlizerman, Ira
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Computer Science - Computer Vision and Pattern Recognition - Abstract
We present DreamPose, a diffusion-based method for generating animated fashion videos from still images. Given an image and a sequence of human body poses, our method synthesizes a video containing both human and fabric motion. To achieve this, we transform a pretrained text-to-image model (Stable Diffusion) into a pose-and-image guided video synthesis model, using a novel fine-tuning strategy, a set of architectural changes to support the added conditioning signals, and techniques to encourage temporal consistency. We fine-tune on a collection of fashion videos from the UBC Fashion dataset. We evaluate our method on a variety of clothing styles and poses, and demonstrate that our method produces state-of-the-art results on fashion video animation.Video results are available on our project page., Comment: Project page: https://grail.cs.washington.edu/projects/dreampose/
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- 2023
45. SciKGTeX -- A LaTeX Package to Semantically Annotate Contributions in Scientific Publications
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Bless, Christof, Baimuratov, Ildar, and Karras, Oliver
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Computer Science - Digital Libraries ,Computer Science - Software Engineering - Abstract
Scientific knowledge graphs have been proposed as a solution to structure the content of research publications in a machine-actionable way and enable more efficient, computer-assisted workflows for many research activities. Crowd-sourcing approaches are used frequently to build and maintain such scientific knowledge graphs. To contribute to scientific knowledge graphs, researchers need simple and easy-to-use solutions to generate new knowledge graph elements and establish the practice of semantic representations in scientific communication. In this paper, we present a workflow for authors of scientific documents to specify their contributions with a LaTeX package, called SciKGTeX, and upload them to a scientific knowledge graph. The SciKGTeX package allows authors of scientific publications to mark the main contributions of their work directly in LaTeX source files. The package embeds marked contributions as metadata into the generated PDF document, from where they can be extracted automatically and imported into a scientific knowledge graph, such as the ORKG. This workflow is simpler and faster than current approaches, which make use of external web interfaces for data entry. Our user evaluation shows that SciKGTeX is easy to use, with a score of 79 out of 100 on the System Usability Scale, as participants of the study needed only 7 minutes on average to annotate the main contributions on a sample abstract of a published paper. Further testing shows that the embedded contributions can be successfully uploaded to ORKG within ten seconds. SciKGTeX simplifies the process of manual semantic annotation of research contributions in scientific articles. Our workflow demonstrates how a scientific knowledge graph can automatically ingest research contributions from document metadata., Comment: Accepted for publication at the ACM/IEEE Joint Conference on Digital Libraries 2023 (JCDL2023)
- Published
- 2023
46. Generative Novel View Synthesis with 3D-Aware Diffusion Models
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Chan, Eric R., Nagano, Koki, Chan, Matthew A., Bergman, Alexander W., Park, Jeong Joon, Levy, Axel, Aittala, Miika, De Mello, Shalini, Karras, Tero, and Wetzstein, Gordon
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Computer Science - Computer Vision and Pattern Recognition ,Computer Science - Artificial Intelligence ,Computer Science - Graphics - Abstract
We present a diffusion-based model for 3D-aware generative novel view synthesis from as few as a single input image. Our model samples from the distribution of possible renderings consistent with the input and, even in the presence of ambiguity, is capable of rendering diverse and plausible novel views. To achieve this, our method makes use of existing 2D diffusion backbones but, crucially, incorporates geometry priors in the form of a 3D feature volume. This latent feature field captures the distribution over possible scene representations and improves our method's ability to generate view-consistent novel renderings. In addition to generating novel views, our method has the ability to autoregressively synthesize 3D-consistent sequences. We demonstrate state-of-the-art results on synthetic renderings and room-scale scenes; we also show compelling results for challenging, real-world objects., Comment: Project page: https://nvlabs.github.io/genvs
- Published
- 2023
47. Human–Robot Interaction through Dynamic Movement Recognition for Agricultural Environments
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Vasileios Moysiadis, Lefteris Benos, George Karras, Dimitrios Kateris, Andrea Peruzzi, Remigio Berruto, Elpiniki Papageorgiou, and Dionysis Bochtis
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human–robot collaboration ,natural communication framework ,vision-based human activity recognition ,situation awareness ,Agriculture (General) ,S1-972 ,Engineering (General). Civil engineering (General) ,TA1-2040 - Abstract
In open-field agricultural environments, the inherent unpredictable situations pose significant challenges for effective human–robot interaction. This study aims to enhance natural communication between humans and robots in such challenging conditions by converting the detection of a range of dynamic human movements into specific robot actions. Various machine learning models were evaluated to classify these movements, with Long Short-Term Memory (LSTM) demonstrating the highest performance. Furthermore, the Robot Operating System (ROS) software (Melodic Version) capabilities were employed to interpret the movements into certain actions to be performed by the unmanned ground vehicle (UGV). The novel interaction framework exploiting vision-based human activity recognition was successfully tested through three scenarios taking place in an orchard, including (a) a UGV following the authorized participant; (b) GPS-based navigation to a specified site of the orchard; and (c) a combined harvesting scenario with the UGV following participants and aid by transporting crates from the harvest site to designated sites. The main challenge was the precise detection of the dynamic hand gesture “come” alongside navigating through intricate environments with complexities in background surroundings and obstacle avoidance. Overall, this study lays a foundation for future advancements in human–robot collaboration in agriculture, offering insights into how integrating dynamic human movements can enhance natural communication, trust, and safety.
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- 2024
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48. Modulation of naïve mesenchymal stromal cells by extracellular vesicles derived from insulin-producing cells: an in vitro study
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Mahmoud M. Gabr, Sawsan M. El-Halawani, Ayman F. Refaie, Sherry M. Khater, Amani M. Ismail, Mary S. Karras, Raghda W. Magar, Shorouk El Sayed, Malgorzata Kloc, Ahmed Uosef, Omaima M. Sabek, and Mohamed A. Ghoneim
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MSCs ,Differentiation ,Insulin-producing cells ,Extracellular vesicles ,Exosomes ,Diabetes ,Medicine ,Science - Abstract
Abstract This study was to determine whether extracellular vesicles (EVs) derived from insulin-producing cells (IPCs) can modulate naïve mesenchymal stromal cells (MSCs) to become insulin-secreting. MSCs were isolated from human adipose tissue. The cells were then differentiated to generate IPCs by achemical-based induction protocol. EVs were retrieved from the conditioned media of undifferentiated (naïve) MSCs (uneducated EVs) and from that of MSC-derived IPCs (educated EVs) by sequential ultracentrifugation. The obtained EVs were co-cultured with naïve MSCs.The cocultured cells were evaluated by immunofluorescence, flow cytometry, C-peptide nanogold silver-enhanced immunostaining, relative gene expression and their response to a glucose challenge.Immunostaining for naïve MSCs cocultured with educated EVs was positive for insulin, C-peptide, and GAD65. By flow cytometry, the median percentages of insulin-andC-peptide-positive cells were 16.1% and 14.2% respectively. C-peptide nanogoldimmunostaining providedevidence for the intrinsic synthesis of C-peptide. These cells released increasing amounts of insulin and C-peptide in response to increasing glucose concentrations. Gene expression of relevant pancreatic endocrine genes, except for insulin, was modest. In contrast, the results of naïve MSCs co-cultured with uneducated exosomes were negative for insulin, C-peptide, and GAD65. These findings suggest that this approach may overcome the limitations of cell therapy.
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- 2024
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49. Slow vibrational relaxation drives ultrafast formation of photoexcited polaron pair states in glycolated conjugated polymers
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Katia Pagano, Jin Gwan Kim, Joel Luke, Ellasia Tan, Katherine Stewart, Igor V. Sazanovich, Gabriel Karras, Hristo Ivov Gonev, Adam V. Marsh, Na Yeong Kim, Sooncheol Kwon, Young Yong Kim, M. Isabel Alonso, Bernhard Dörling, Mariano Campoy-Quiles, Anthony W. Parker, Tracey M. Clarke, Yun-Hi Kim, and Ji-Seon Kim
- Subjects
Science - Abstract
Abstract Glycol sidechains are often used to enhance the performance of organic photoconversion and electrochemical devices. Herein, we study their effects on electronic states and electronic properties. We find that polymer glycolation not only induces more disordered packing, but also results in a higher reorganisation energy due to more localised π-electron density. Transient absorption spectroscopy and femtosecond stimulated Raman spectroscopy are utilised to monitor the structural relaxation dynamics coupled to the excited state formation upon photoexcitation. Singlet excitons are initially formed, followed by polaron pair formation. The associated structural relaxation slows down in glycolated polymers (5 ps vs. 1.25 ps for alkylated), consistent with larger reorganisation energy. This slower vibrational relaxation is found to drive ultrafast formation of the polaron pair state (5 ps vs. 10 ps for alkylated). These results provide key experimental evidence demonstrating the impact of molecular structure on electronic state formation driven by strong vibrational coupling.
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- 2024
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50. Overwintering West Nile virus in active Culex pipiens mosquito populations in Greece
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Georgios Balatsos, Stavroula Beleri, Nikolaos Tegos, Marina Bisia, Vasileios Karras, Evangelia Zavitsanou, Dimitrios P. Papachristos, Nikos T. Papadopoulos, Antonios Michaelakis, and Eleni Patsoula
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West Nile virus ,Overwintering ,Culex pipiens ,Biotypes ,Host searching ,Infectious and parasitic diseases ,RC109-216 - Abstract
Abstract The flavivirus West Nile Virus (WNV), which is transmitted by mosquitoes, poses a significant threat to both humans and animals, and its outbreaks often challenge public health in Europe and other continents. In recent years, there is an increasing trend of WNV incidence rates across several European countries. However, whether there is a year-round circulation or seasonal introduction has yet to be elucidated. Real-time polymerase chain reaction (PCR) identified WNV-positive Culex pipiens mosquitos in 6 out of 146 pools examined in winter 2022 that correspond to three out of the 24 study areas, located in two coastal regions units in Attica, Greece. Spatial dispersion of the six positive pools in the same region suggests a clustered circulation of WNV during the winter of 2022. This is the first study that documents the identification of WNV in Cx. pipiens populations, captured in adult traps during winter period. Our findings underscore the need to extend entomological surveillance programs to include the winter period, specifically in temperate climates and historically affected areas by WNV. Graphical Abstract
- Published
- 2024
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