检索结果-内蒙古大学图书馆

Online Learning Models for Vehicle Usage Prediction During COVID-19

学校读者我要写书评

暂无评论

arXiv 2022年

作者： Lindroth, Tobias Svensson, Axel Akerblom, Niklas Pourabdollah, Mitra Chehreghani, Morteza Haghir Volvo Car Corporation Torslanda GöteborgSE-405 31 Sweden The Department of Computer Science and Engineering Chalmers University of Technology GöteborgSE-412 96 Sweden

Today, there is an ongoing transition to more sustainable transportation, for which an essential part is the switch from combustion engine vehicles to battery electric vehicles (BEVs). BEVs have many advantages from a sustainability perspective, but issues such as limited driving range and long recharge times slow down the transition from combustion engines. One way to mitigate these issues is by performing battery thermal preconditioning, which increases the energy efficiency of the battery. However, to optimally perform battery thermal preconditioning, the vehicle usage pattern needs to be known, i.e., how and when the vehicle will be used. This study attempts to predict the departure time and distance of the first drive each day using online machine learning models. The online machine learning models are trained and evaluated on historical driving data collected from a fleet of BEVs during the COVID-19 pandemic. Additionally, the prediction models are extended to quantify the uncertainty of their predictions, which can be used to decide whether the prediction should be used or dismissed. Based on our results, the best-performing prediction models yield an aggregated mean absolute error of 2.75 hours when predicting departure time and 13.37 km when predicting trip distance. Copyright © 2022, The Authors. All rights reserved.

关键词： COVID-19

Branch-and-bound for the precedence constrained generalized traveling salesman problem (extended abstract) 13

学校读者我要写书评

暂无评论

Branch-and-bound for the precedence constrained generalized ...

13th International Symposium on Combinatorial Search, SoCS 2020

作者： Salman, Raad Ekstedt, Fredrik Damaschke, Peter Fraunhofer-Chalmers Research Centre for Industrial Mathematics Göteborg41288 Sweden Department of Computer Science and Engineering Chalmers University of Technology Göteborg41296 Sweden

The use of incentives to promote Technical Debt management

学校读者我要写书评

暂无评论

arXiv 2021年

作者： Besker, Terese Martini, Antonio Bosch, Jan Computer Science and Engineering Software Engineering Chalmers University of Technology Göteborg Sweden University of Oslo Programming and Software Engineering Oslo Norway

Context: When developing software, it is vitally important to keep the level of technical debt down since it is well established from several studies that technical debt can, e.g., lower the development productivity, decrease the developers' morale, and compromise the overall quality of the software. However, even if researchers and practitioners working in today's software development industry are quite familiar with the concept of technical debt and its related negative consequences, there has been no empirical research focusing specifically on how software managers actively communicate and manage the need to keep the level of technical debt as low as possible. Objective: This study aims to understand how software companies give incentives to manage Technical Debt. This is done by exploring how companies encourage and reward practitioners for actively keeping the level of technical debt down and whether the companies use any forcing or penalizing initiatives when managing technical debt. Method: In a first step, this paper reports the results of both an online survey provided quantitative data from 258 participants and interviews with 32 software practitioners. In a second step, this study set out to specifically provide a detailed assessment of additional and in-depth analysis of Technical Debt management strategies based on an encouraging mindset and attitude from both managers and technical roles to understand how, when and by whom such strategy is adopted in practice. Results: Our findings show that having a Technical Debt management strategy (specially based on encouragement) can significantly impact the amount of Technical Debt in the software. Conclusion: The result indicates that there is considerable unfulfilled potential to influence how software practitioners can further limit and reduce Technical Debt by adopting a strategy based explicitly on an encouraging mindset from managers where they also specifically dedicate time and resources for Technical De

关键词： Software design

Cell-Free Massive MIMO for URLLC: A Finite-Blocklength Analysis

学校读者我要写书评

暂无评论

arXiv 2022年

作者： Lancho, Alejandro Durisi, Giuseppe Sanguinetti, Luca The Department of Electrical Engineering and Computer Science Massachusetts Institute of Technology CambridgeMA02139 United States The Department of Electrical Engineering Chalmers University of Technology Gothenburg41296 Sweden The Dipartimento di Ingegneria dell'Informazione University of Pisa Pisa56122 Italy

We present a general framework for the characterization of the packet error probability achievable in cell-free Massive multiple-input multiple output (MIMO) architectures deployed to support ultra-reliable low-latency (URLLC) traffic. The framework is general and encompasses both centralized and distributed cell-free architectures, arbitrary fading channels and channel estimation algorithms at both network and user-equipment (UE) sides, as well as arbitrary combining and precoding schemes. The framework is used to perform numerical experiments on specific scenarios, which illustrate the superiority of cell-free architectures compared to cellular architectures in supporting URLLC traffic in uplink and downlink. Also, these numerical experiments provide the following insights into the design of cell-free architectures for URLLC: i) minimum mean square error (MMSE) spatial processing must be used to achieve the URLLC targets;ii) for a given total number of antennas per coverage area, centralized cell-free solutions involving single-antenna access points (APs) offer the best performance in the uplink, thereby highlighting the importance of reducing the average distance between APs and UEs in the URLLC regime;iii) this observation applies also to the downlink, provided that the APs transmit precoded pilots to allow the UEs to estimate accurately the precoded channel. Copyright © 2022, The Authors. All rights reserved.

关键词： Mean square error

Are we ready for beyond-application high-volume data? The Reeds robot perception benchmark dataset

学校读者我要写书评

暂无评论

arXiv 2021年

作者： Benderius, Ola Berger, Christian Blanch, Krister Department of Mechanics and Maritime Sciences Chalmers University of Technology Sweden Department of Computer Science and Engineering University of Gothenburg Sweden

This paper presents a dataset, called Reeds, for research on robot perception algorithms. The dataset aims to provide demanding benchmark opportunities for algorithms, rather than providing an environment for testing applicationspecific solutions. A boat was selected as a logging platform in order to provide highly dynamic kinematics. The sensor package includes six high-performance vision sensors, two long-range lidars, radar, as well as GNSS and an IMU. The spatiotemporal resolution of sensors were maximized in order to provide large variations and flexibility in the data, offering evaluation at a large number of different resolution presets based on the resolution found in other datasets. Reeds also provides means of a fair and reproducible comparison of algorithms, by running all evaluations on a common server backend. As the dataset contains massive-scale data, the evaluation principle also serves as a way to avoid moving data unnecessarily. It was also found that naive evaluation of algorithms, where each evaluation is computed sequentially, was not practical as the fetch and decode task of each frame would not scale well. Instead, each frame is only decoded once and then fed to all algorithms in parallel, including for GPU-based algorithms. © 2021, CC BY.

关键词： Decoding

Wind Comfort Analysis Using an Immersed Boundary Method for Early-Stage Building Design

学校读者我要写书评

暂无评论

SSRN

SSRN 2024年

作者： Mitkov, Radostin Hunger, Franziska Pantusheva, Mariya Naserentin, Vasilis Gösta, Alexander Mark, Andreas Petrova-Antonova, Dessislava Logg, Anders GATE Institute Sofia University "St. Kliment Ohridski" Sofia1113 Bulgaria Fraunhofer-Chalmers Centre for Industrial Mathematics Computational Engineering and Design Chalmers Science Park GothenburgSE-412 88 Sweden Department of Mathematical Sciences Chalmers University of Technology GothenburgSE-412 969 Sweden Department of Electrical and Computer Engineering Aristotle University of Thessaloniki ThessalonikiGR- 54124 Greece RISE - Research Institutes of Sweden Architecture and spatial planning Drottning Kristinas Väg 61 StockholmSE-114 28 Sweden Liljewall Arkitekter Odinsplatsen 1 GothenburgSE-411 02 Sweden

This paper presents a thorough exploration of wind comfort dynamics in urban environments through the application of computational fluid dynamics simulations, with a specific emphasis on the Immersed Boundary Method. The study validates the Immersed Boundary Octree Flow solver, IBOFlow, against experimental data and then simulates the flow in a real-world case study of an area in Mölndal, Sweden. The research examines the impact of varying the number of simulated wind directions on the wind comfort maps, revealing that employing 16 wind directions is a reliable balance between computational efficiency and precision. Further, the investigation delves into the implications of using a simplified building geometry as available in early-stage design, demonstrating that computational simulations can provide reliable information about the pedestrian wind comfort early in the design process. While underscoring the significance of early-stage CFD simulations in informing design decisions, the paper concludes by advocating for a holistic approach. It emphasizes the relevance of simulation testing in later design iterations, particularly as architectural details continue to be refined. © 2024, The Authors. All rights reserved.

关键词： Computational fluid dynamics

End-to-end learning of geometrical shaping maximizing generalized mutual information

学校读者我要写书评

暂无评论

End-to-end learning of geometrical shaping maximizing genera...

Optical Fiber Communication Conference, OFC 2020

作者： Gümüs, Kadir Alvarado, Alex Chen, Bin Häger, Christian Agrell, Erik Department of Electrical Engineering Eindhoven University of Technology Eindhoven Netherlands School of Computer Science and Information Engineering Hefei University of Technology Hefei China Department of Electrical Engineering Chalmers University of Technology Göteborg Sweden

GMI-based end-to-end learning is shown to be highly nonconvex. We apply gradient descent initialized with Gray-labeled APSK constellations directly to the constellation coordinates. State-of-the-art constellations in ... 详细信息

ISBN: (数字)9781943580712

ISBN: (纸本)9781943580712

关键词： Optical fibers

Bayesian paired comparison with the bpcs package

学校读者我要写书评

暂无评论

arXiv 2021年

作者： Mattos, David Issa Ramos, Érika Martins Silva Department of Computer Science and Engineering Chalmers University of Technology Gothenburg Sweden Department of Psychology University of Gothenburg Gothenburg Sweden

This article introduces the bpcs R package (Bayesian Paired Comparison in Stan) and the statistical models implemented in the package. This package aims to facilitate the use of Bayesian models for paired comparison data in behavioral research. Bayesian analysis of paired comparison data allows parameter estimation even in conditions where the maximum likelihood does not exist, allows easy extension of paired comparison models, provide straightforward interpretation of the results with credible intervals, have better control of type I error, have more robust evidence towards the null hypothesis, allows propagation of uncertainties, includes prior information, and perform well when handling models with many parameters and latent variables. The bpcs package provides a consistent interface for R users and several functions to evaluate the posterior distribution of all parameters, to estimate the posterior distribution of any contest between items, and to obtain the posterior distribution of the ranks. Three reanalyses of recent studies that used the frequentist Bradley-Terry model are presented. These reanalyses are conducted with the Bayesian models of the bpcs package, and all the code used to fit the models, generate the figures, and the tables are available in the online appendix. Copyright © 2021, The Authors. All rights reserved.

关键词： Bayesian networks

ASIC design exploration for DSP and FEC of 400-Gbit/s coherent data-center interconnect receivers

学校读者我要写书评

暂无评论

ASIC design exploration for DSP and FEC of 400-Gbit/s cohere...

Optical Fiber Communication Conference, OFC 2020

作者： Fougstedt, Christoffer Gustafsson, Oscar Bae, Cheolyong Börjeson, Erik Larsson-Edefors, Per Dept. of Computer Science and Engineering Chalmers University of Technology Gothenburg Sweden Dept. of Electrical Engineering Linköping University Linköping Sweden

We perform exploratory ASIC design of key DSP and FEC units for 400-Gbit/s coherent data-center interconnect receivers. In 22-nm CMOS, the considered units together dissipate 5 W, suggesting implementation feasibility... 详细信息

ISBN: (数字)9781943580712

ISBN: (纸本)9781943580712

关键词： Optical fibers