检索结果-内蒙古大学图书馆

36th Jahrestagung der Gesellschaft fur Informatik e.V. (GI): Informatik fur Menschen, INFORMATIK 2006

作者： Urbanski, Stephan Handte, Marcus Schiele, Gregor Rothermel, Kurt Distributed Systems Department Institute of Parallel and Distributed Systems Universität Stuttgart Universitätsstr. 38 70569 Stuttgart Germany

ISBN: (纸本)9783885791874

Pervasive Computing envisions seamless computing support for users while performing their everyday tasks. Many of these tasks are hard to capture by the notion of a single application as their requirements on computing support vary over time. To ease the development of applications for such tasks, we have designed an application model for process-oriented pervasive applications, called Sentient Processes, and a supporting middleware system implementing the flow control for processes. In this paper, we show the capabilities of the Sentient Process model to capture everyday user tasks by the example of a process supporting a student in managing his classes during a term.

关键词： Ubiquitous computing

来源：评论

学校读者我要写书评

暂无评论

Enhancing Data Trustworthiness in Explorative Analysis: An Interactive Approach for Data Quality Monitoring

引用

SN Computer Science 2024年第5期5卷 465页

作者： Behringer, Michael Hirmer, Pascal Villanueva, Alejandro Rapp, Jannis Mitschang, Bernhard Institute for Parallel and Distributed Systems University of Stuttgart Universitätsstr. 38 Stuttgart 70569 Germany

The volume of data to be analyzed has increased tremendously in recent years. In order to extract knowledge from this data, domain experts gain new insights with the help of graphical analysis tools for explorative analyses. Here, the reliability and trustworthiness of an exploratory analysis is determined by the quality of the underlying data. Existing approaches require manual testing to ensure data quality which is often neglected. This research aims to introduce a novel interactive approach for seamlessly integrating data quality considerations into the process of explorative data analysis conducted by domain experts. We derive requirements, conduct an extensive literature review, and develop an approach that efficiently combines stakeholders’ strengths, allowing unobtrusive data quality integration in interactive analysis. Our approach enhances trustworthiness due to unobtrusive monitoring of data quality within the context of explorative data analysis. Domain experts gain insights more reliably, bridging the gap between technical requirements and domain expertise. In conclusion, our research presents a promising solution for improving the reliability and trustworthiness of explorative data analysis, especially for domain experts who may lack technical knowledge. By seamlessly integrating data quality into the analytical process, we empower domain experts to extract valuable insights from the ever-increasing volume of data, thereby advancing the field of data-driven decision-making. © The Author(s) 2024.

关键词： Data Quality Data Mashups Explorative Data Analysis Human-in-the-Loop

来源：评论

学校读者我要写书评

暂无评论

Efficient capturing of environmental data with mobile RFID readers 09

Efficient capturing of environmental data with mobile RFID r...

引用

2009 10th International Conference on Mobile Data Management: systems, Services and Middleware, MDM 2009

作者： Weinschrott, Harald Dürr, Frank Rothermel, Kurt Institute of Parallel and Distributed Systems Universitätsstraße 38 70569 Stuttgart Germany

ISBN: (纸本)9780769536507

In this paper we introduce a novel scenario for environmental sensing based on the combination of simple and cheap RFID-based sensors and mobile devices like mobile phones with integrated RFID readers. We envision a system that exploits the availability of these devices to cooperatively read sensors installed in the environment, and transmit the data to a server infrastructure. To achieve quality requirements and efficiency in terms of communication cost and energy consumption, this paper presents several algorithms for coordinating update operations. First, mobile nodes form an ad-hoc network for the cooperative management of requested update times to meet the desired update interval and to avoid redundant sensor reading and collisions during read operations. Second, besides this decentralizedcoordination algorithm, we also show a complementary algorithm that exploits infrastructure based coordination. By extensive simulations we show that our algorithms allow for autonomous operation and achieve a high quality of sensor updates where nearly 100% of the possible updates are performed. Moreover, the algorithms achieve a very high energy efficiency allowing for several hundred hours of operation assuming a typical battery of a mobile phone. © 2009 IEEE.

关键词： Cellular telephones

来源：评论

学校读者我要写书评

暂无评论

Schedule Processes, not VCPUs 13

Schedule Processes, not VCPUs

引用

4th Asia-Pacific Workshop on systems, APSys 2013

作者： Song, Xiang Shi, Jicheng Chen, Haibo Zang, Binyu School of Software Institute of Parallel and Distributed Systems Shanghai Jiao Tong University China

ISBN: (纸本)9781450323161

Multiprocessor virtual machines expose underlying abundant computing resources to applications. This, however, also worsens the double scheduling problem where the hypervisor and a guest operating system will both do the CPU scheduling. Prior approaches try to mitigate the semantic gap between the two levels of schedulers by leveraging hints and heuristics, but only work in a few specific cases. This paper argues that instead of scheduling virtual CPUs (vCPUs) in the hypervisor layer, it is more beneficial to dynamically increase and decrease the vCPUs according to available CPU resources when running parallel workloads, while letting the guest operating system to schedule vCPUs to processes. Such a mechanism, which we call vCPU ballooning (VCPU-Bal for short), may avoid many problems inherent in double scheduling. To demonstrate the potential benefit of VCPU-Bal, we simulate the mechanism in both Xen and KVM by assigning an optimal amount of vCPUs for guest VMs. Our evaluation results on a 12-core Intel machine show that VCPU-Bal can achieve a performance speedup from 1.5% to 57.9% on Xen and 8.2% to 63.8% on KVM. Copyright 2013 ACM.

关键词： Program processors

来源：评论

学校读者我要写书评

暂无评论

Online trajectory data reduction using connection-preserving dead reckoning 5

Online trajectory data reduction using connection-preserving...

引用

5th International ICST Conference on Mobile and Ubiquitous systems: Computing, Networking and Services, MobiQuitous 2008

作者： Lange, Ralph Dürr, Frank Rothermel, Kurt Institute of Parallel and Distributed Systems Universitätsstraße 38 Stuttgart70569 Germany

ISBN: (纸本)9789639799219

Moving objects databases (MODs) store objects' trajectories by spatiotemporal polylines that approximate the actual movements given by sequences of sensed positions. Determining such a polyline with as few vertices as possible under the constraint that it does not deviate by more than a certain accuracy bound - from the sensed positions is an algorithmic problem known as trajectory reduction. A specific challenge is online trajectory reduction, i.e. continuous reduction with position sensing in realtime. This particularly is required for moving objects with embedded position sensors whose movements are tracked and stored by a remote MOD. In this paper, we present Connection-preserving Dead Reckoning (CDR), a new approach for online trajectory reduction. It outperforms the existing approaches by 30 to 50%. CDR requires the moving objects to temporally store some of the previously sensed positions. Although the storage consumption of CDR generally is small, it is not bounded. We therefore further present CDRM whose storage allocation and execution time per position fix can be adjusted and limited. Even with very limited storage allocations of less than 1 kB CDRM outperforms the existing approach by 20 to 40%. Copyright © 2008 ICST.

关键词： Trajectories

来源：评论

学校读者我要写书评

暂无评论

Scalable processing of trajectory-based queries in space-partitioned moving objects databases 08

Scalable processing of trajectory-based queries in space-par...

引用

16th ACM SIGSPATIAL International Conference on Advances in Geographic Information systems, ACM GIS 2008

作者： Lange, Ralph Dürr, Frank Rothermel, Kurt Institute of Parallel and Distributed Systems Universitätsstraße 38 70569 Stuttgart Germany

ISBN: (纸本)9781605583235

Space-partitioned Moving Objects Databases (SP-MODs) allow for the scalable, distributed management of large sets of mobile objects' trajectories by partitioning the trajectory data to a network of database servers. Processing a spatio-temporal query q therefore requires efficiently routing q to the servers storing the affected trajectory segments. With a coordinate-based query - like a spatio-temporal range query - the relevant servers are directly determined by the queried range. However, with trajectory-based queries - like retrieving the distance covered by a certain object during a given time interval - the relevant servers depend on actual movement of the queried object. Therefore, efficient routing mechanisms for trajectory-based queries are an important challenge in SP-MODs. In this paper, we present the distributed Trajectory Index (DTI) that allows for such efficient query routing by creating an overlay network for each trajectory. We further present an enhanced index called DTI+S. It accelerates the processing of queries on aggregates of dynamic attributes, like the maximum speed during a time interval, by augmenting DTI with summaries of trajectory segments. Our simulations with a network of 1000 database servers show that DTI+S can reduce the overall processing time by more than 98%. © 2008 ACM.

关键词： Trajectories

来源：评论

学校读者我要写书评

暂无评论

Mobile context-aware systems - Linking the physical and digital world

引用

6th International Workshop on Advanced parallel Processing Technologies, APPT 2005

作者： Rothermel, Kurt Institute of Parallel and Distributed Systems Centre of Excellence Nexus Universität Stuttgart Germany

ISBN: (纸本)3540296395

The rapid miniaturisation and decline in prices of computer, communication and sensor technology give rise to a number of interesting developments, such as multifunctional mobile devices, sensor platforms embedded into everyday things, and sensor nodes organised in a wireless network. Those systems can capture and process sensory data and communicate this information to other peers in their proximity or to an existing server infrastructure. The sensory data are fed into spatio-temporal models of the physical world, which build the basis for the promising class of context-aware applications. Based on these developments it can be anticipated that there will be billions of sensor systems in our physical environment near future. Consequently, we envision most of the future applications to be context-aware, sharing highly dynamic digital world models offered by a large number of content providers. Obviously, the realisation of this vision will cause a number of both technological and social challenges. Some of these challenges are subject to the research of Nexus, a Centre of Excellence established at University of Stuttgart in the year 2003. In this talk, we present the vision and objectives of Nexus. Moreover, we will discuss some aspects of scaleable context management. © Springer-Verlag Berlin Heidelberg 2005.

关键词： Mobile telecommunication systems

来源：评论

学校读者我要写书评

暂无评论

Efficient position sharing for location privacy using binary space partitioning 9th

Efficient position sharing for location privacy using binary...

引用

9th International Conference on Mobile and Ubiquitous systems: Computing, Networking and Services, MobiQuitous 2012

作者： Wernke, Marius Dürr, Frank Rothermel, Kurt Institute of Parallel and Distributed Systems Universitätsstraße 38 Stuttgart70569 Germany

ISBN: (纸本)9783642402371

Millions of users use location-based applications (LBAs) to share their positions with friends, request information from points of interest finders, or get notifications from event finders, etc. Such LBAs are typically based on location servers (LSs) managing mobile object positions in a scalable fashion. However, storing precise user positions on LSs raises privacy concerns, in particular, if LS providers are non-trusted. To solve this problem, we present PShare-BSP, a novel approach for the secure management of private user positions on non-trusted LSs. PShare-BSP splits up precise user positions into position shares and distributes them to different LSs of different providers. Thus, a compromised provider only reveals user positions with degraded precision. Nevertheless, LBAs can combine several shares from different LSs to increase their precision. PShare-BSP improves on our previous position sharing approaches [4,15,17]: It uses a deterministic share generation approach based on binary space partitioning to avoid probabilistic attacks based, for instance, on Monte Carlo simulations. Moreover, it significantly decreases the computational complexity and increases the efficiency by reducing the update costs for succeeding position updates. © institute for Computer Sciences, Social Informatics and Telecommunications Engineering 2013.

关键词： Location

来源：评论

学校读者我要写书评

暂无评论

An improvised A* algorithm for mobile robots to find the optimal path in an unknown environment with minimized search efforts 12th

引用

12th International Conference on Industrial and Engineering Applications of Artificial Intelligence and Expert systems, IEA/AIE 1999

作者： Piriyakumar, Douglas Antony Louis Levi, Paul Institute of Parallel and Distributed High-Performance Systems University of Stuttgart Stuttgart70565 Germany

ISBN: (纸本)3540660763

An Algorithm for finding the optimal path given the initial and final positions of a cylinder-shaped mobile robot with the constraint on minimizing the search efforts is presented in this paper. This algorithm is based on the well known AI strategy A ∗ to get the optimal solution always. The strategy constructs a path from the available knowledge incrementally leading to the optimal path, and at the same time without any collision with the stationary obstacles. In this process, there are discontinuous "jumps" which demand the robot to move physically through the whole path traversing all along to reach the other end of the jump. Most of the times, the robot spends more time in traversing back and forth during the process of finding the optimal path. We have developed three new techniques, namely, Petri expansion, Markovian cost function, and Retaining shortest path nodes to minimize the search efforts in finding the optimal *** have demonstrated the effectiveness of these techniques with ample examples. These three techniques always lead not only to the optimal path, but improves the search strategy by minimizing the "jumps" required. Computationally also, they reduce the number of nodes generated in the general A* algorithm. The important issue is that the incorporation of these techniques in A* is very easy with simple modifications and without any extra computational burden © Springer-Verlag Berlin Heidelberg 1999.

关键词： Mobile robots

来源：评论

学校读者我要写书评

暂无评论

Simulation software engineering: Experiences and challenges 3

Simulation software engineering: Experiences and challenges

引用

3rd International Workshop on Software Engineering for High Performance Computing in Computational Science and Engineering, SEHPCCSE 2015 - co-located with Supercomputing 2015

作者： Wagner, Stefan Pflüger, Dirk Mehl, Miriam Institute of Software Technology University of Stuttgart Germany Institute for Parallel and Distributed Systems University of Stuttgart Germany

ISBN: (纸本)9781450340120

Using software for large-scale simulations has become an important research method in many disciplines. With increasingly complex simulations, simulation software becomes a valuable assest. Yet, the quality of many simulation codes is worrying. In this paper, we want to collect and structure the challenges for a systematic simulation software engineering as a reference and the basis for further research. We describe our own experiences with developing simulation software and collaborating with non-computer-scientists. We complement our experienced challenges with a brief literature review. We structured the challenges for simulation software engineering into six areas: motivation and recognition;education and training;developer turnover;software length of life;verification, validation and debugging;and efficiency vs. maintainability. Overcoming these challenges needs efforts from research agencies, scientific computing researchers as well as software engineering researchers. © 2015 ACM.

关键词： Verification

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：