TY - JOUR A1 - Friedrich, Tobias A1 - Katzmann, Maximilian A1 - Krohmer, Anton T1 - Unbounded Discrepancy of Deterministic Random Walks on Grids JF - SIAM journal on discrete mathematics N2 - Random walks are frequently used in randomized algorithms. We study a derandomized variant of a random walk on graphs called the rotor-router model. In this model, instead of distributing tokens randomly, each vertex serves its neighbors in a fixed deterministic order. For most setups, both processes behave in a remarkably similar way: Starting with the same initial configuration, the number of tokens in the rotor-router model deviates only slightly from the expected number of tokens on the corresponding vertex in the random walk model. The maximal difference over all vertices and all times is called single vertex discrepancy. Cooper and Spencer [Combin. Probab. Comput., 15 (2006), pp. 815-822] showed that on Z(d), the single vertex discrepancy is only a constant c(d). Other authors also determined the precise value of c(d) for d = 1, 2. All of these results, however, assume that initially all tokens are only placed on one partition of the bipartite graph Z(d). We show that this assumption is crucial by proving that, otherwise, the single vertex discrepancy can become arbitrarily large. For all dimensions d >= 1 and arbitrary discrepancies l >= 0, we construct configurations that reach a discrepancy of at least l. KW - deterministic random walk KW - rotor-router model KW - single vertex discrepancy Y1 - 2018 U6 - https://doi.org/10.1137/17M1131088 SN - 0895-4801 SN - 1095-7146 VL - 32 IS - 4 SP - 2441 EP - 2452 PB - Society for Industrial and Applied Mathematics CY - Philadelphia ER - TY - GEN A1 - Stojanovic, Vladeta A1 - Trapp, Matthias A1 - Richter, Rico A1 - Döllner, Jürgen Roland Friedrich T1 - A service-oriented approach for classifying 3D points clouds by example of office furniture classification T2 - Web3D 2018: Proceedings of the 23rd International ACM Conference on 3D Web Technology N2 - The rapid digitalization of the Facility Management (FM) sector has increased the demand for mobile, interactive analytics approaches concerning the operational state of a building. These approaches provide the key to increasing stakeholder engagement associated with Operation and Maintenance (O&M) procedures of living and working areas, buildings, and other built environment spaces. We present a generic and fast approach to process and analyze given 3D point clouds of typical indoor office spaces to create corresponding up-to-date approximations of classified segments and object-based 3D models that can be used to analyze, record and highlight changes of spatial configurations. The approach is based on machine-learning methods used to classify the scanned 3D point cloud data using 2D images. This approach can be used to primarily track changes of objects over time for comparison, allowing for routine classification, and presentation of results used for decision making. We specifically focus on classification, segmentation, and reconstruction of multiple different object types in a 3D point-cloud scene. We present our current research and describe the implementation of these technologies as a web-based application using a services-oriented methodology. KW - Indoor Models KW - 3D Point Clouds KW - Machine KW - Learning KW - BIM KW - Service-Oriented Y1 - 2018 SN - 978-1-4503-5800-2 U6 - https://doi.org/10.1145/3208806.3208810 SP - 1 EP - 9 PB - Association for Computing Machinery CY - New York ER - TY - GEN A1 - Schneider, Oliver A1 - Shigeyama, Jotaro A1 - Kovacs, Robert A1 - Roumen, Thijs Jan A1 - Marwecki, Sebastian A1 - Böckhoff, Nico A1 - Glöckner, Daniel Amadeus Johannes A1 - Bounama, Jonas A1 - Baudisch, Patrick T1 - DualPanto BT - a haptic device that enables blind users to continuously interact with virtual worlds T2 - UIST '18: Proceedings of the 31st Annual ACM Symposium on User Interface Software and Technology N2 - We present a new haptic device that enables blind users to continuously track the absolute position of moving objects in spatial virtual environments, as is the case in sports or shooter games. Users interact with DualPanto by operating the me handle with one hand and by holding on to the it handle with the other hand. Each handle is connected to a pantograph haptic input/output device. The key feature is that the two handles are spatially registered with respect to each other. When guiding their avatar through a virtual world using the me handle, spatial registration enables users to track moving objects by having the device guide the output hand. This allows blind players of a 1-on-1 soccer game to race for the ball or evade an opponent; it allows blind players of a shooter game to aim at an opponent and dodge shots. In our user study, blind participants reported very high enjoyment when using the device to play (6.5/7). KW - Haptics KW - force-feedback KW - accessibility KW - blind KW - visually impaired KW - gaming Y1 - 2018 SN - 978-1-4503-5948-1 U6 - https://doi.org/10.1145/3242587.3242604 SP - 877 EP - 887 PB - Association for Computing Machinery CY - New York ER - TY - JOUR A1 - Mendling, Jan A1 - Weber, Ingo A1 - van der Aalst, Wil A1 - Brocke, Jan Vom A1 - Cabanillas, Cristina A1 - Daniel, Florian A1 - Debois, Soren A1 - Di Ciccio, Claudio A1 - Dumas, Marlon A1 - Dustdar, Schahram A1 - Gal, Avigdor A1 - Garcia-Banuelos, Luciano A1 - Governatori, Guido A1 - Hull, Richard A1 - La Rosa, Marcello A1 - Leopold, Henrik A1 - Leymann, Frank A1 - Recker, Jan A1 - Reichert, Manfred A1 - Reijers, Hajo A. A1 - Rinderle-Ma, Stefanie A1 - Solti, Andreas A1 - Rosemann, Michael A1 - Schulte, Stefan A1 - Singh, Munindar P. A1 - Slaats, Tijs A1 - Staples, Mark A1 - Weber, Barbara A1 - Weidlich, Matthias A1 - Weske, Mathias A1 - Xu, Xiwei A1 - Zhu, Liming T1 - Blockchains for Business Process Management BT - Challenges and Opportunities JF - ACM Transactions on Management Information Systems N2 - Blockchain technology offers a sizable promise to rethink the way interorganizational business processes are managed because of its potential to realize execution without a central party serving as a single point of trust (and failure). To stimulate research on this promise and the limits thereof, in this article, we outline the challenges and opportunities of blockchain for business process management (BPM). We first reflect how blockchains could be used in the context of the established BPM lifecycle and second how they might become relevant beyond. We conclude our discourse with a summary of seven research directions for investigating the application of blockchain technology in the context of BPM. KW - Blockchain KW - business process management KW - research challenges Y1 - 2018 U6 - https://doi.org/10.1145/3183367 SN - 2158-656X SN - 2158-6578 VL - 9 IS - 1 SP - 1 EP - 16 PB - Association for Computing Machinery CY - New York ER - TY - JOUR A1 - Wang, Cheng A1 - Yang, Haojin A1 - Meinel, Christoph T1 - Image Captioning with Deep Bidirectional LSTMs and Multi-Task Learning JF - ACM transactions on multimedia computing, communications, and applications N2 - Generating a novel and descriptive caption of an image is drawing increasing interests in computer vision, natural language processing, and multimedia communities. In this work, we propose an end-to-end trainable deep bidirectional LSTM (Bi-LSTM (Long Short-Term Memory)) model to address the problem. By combining a deep convolutional neural network (CNN) and two separate LSTM networks, our model is capable of learning long-term visual-language interactions by making use of history and future context information at high-level semantic space. We also explore deep multimodal bidirectional models, in which we increase the depth of nonlinearity transition in different ways to learn hierarchical visual-language embeddings. Data augmentation techniques such as multi-crop, multi-scale, and vertical mirror are proposed to prevent over-fitting in training deep models. To understand how our models "translate" image to sentence, we visualize and qualitatively analyze the evolution of Bi-LSTM internal states over time. The effectiveness and generality of proposed models are evaluated on four benchmark datasets: Flickr8K, Flickr30K, MSCOCO, and Pascal1K datasets. We demonstrate that Bi-LSTM models achieve highly competitive performance on both caption generation and image-sentence retrieval even without integrating an additional mechanism (e.g., object detection, attention model). Our experiments also prove that multi-task learning is beneficial to increase model generality and gain performance. We also demonstrate the performance of transfer learning of the Bi-LSTM model significantly outperforms previous methods on the Pascal1K dataset. KW - Deep learning KW - LSTM KW - multimodal representations KW - image captioning KW - mutli-task learning Y1 - 2018 U6 - https://doi.org/10.1145/3115432 SN - 1551-6857 SN - 1551-6865 VL - 14 IS - 2 PB - Association for Computing Machinery CY - New York ER - TY - JOUR A1 - Gebser, Martin A1 - Obermeier, Philipp A1 - Otto, Thomas A1 - Schaub, Torsten H. A1 - Sabuncu, Orkunt A1 - Van Nguyen, A1 - Tran Cao Son, T1 - Experimenting with robotic intra-logistics domains JF - Theory and practice of logic programming N2 - We introduce the asprilo1 framework to facilitate experimental studies of approaches addressing complex dynamic applications. For this purpose, we have chosen the domain of robotic intra-logistics. This domain is not only highly relevant in the context of today's fourth industrial revolution but it moreover combines a multitude of challenging issues within a single uniform framework. This includes multi-agent planning, reasoning about action, change, resources, strategies, etc. In return, asprilo allows users to study alternative solutions as regards effectiveness and scalability. Although asprilo relies on Answer Set Programming and Python, it is readily usable by any system complying with its fact-oriented interface format. This makes it attractive for benchmarking and teaching well beyond logic programming. More precisely, asprilo consists of a versatile benchmark generator, solution checker and visualizer as well as a bunch of reference encodings featuring various ASP techniques. Importantly, the visualizer's animation capabilities are indispensable for complex scenarios like intra-logistics in order to inspect valid as well as invalid solution candidates. Also, it allows for graphically editing benchmark layouts that can be used as a basis for generating benchmark suites. Y1 - 2018 U6 - https://doi.org/10.1017/S1471068418000200 SN - 1471-0684 SN - 1475-3081 VL - 18 IS - 3-4 SP - 502 EP - 519 PB - Cambridge Univ. Press CY - New York ER - TY - JOUR A1 - Cabalar, Pedro A1 - Kaminski, Roland A1 - Schaub, Torsten H. A1 - Schuhmann, Anna T1 - Temporal answer set programming on finite traces JF - Theory and practice of logic programming N2 - In this paper, we introduce an alternative approach to Temporal Answer Set Programming that relies on a variation of Temporal Equilibrium Logic (TEL) for finite traces. This approach allows us to even out the expressiveness of TEL over infinite traces with the computational capacity of (incremental) Answer Set Programming (ASP). Also, we argue that finite traces are more natural when reasoning about action and change. As a result, our approach is readily implementable via multi-shot ASP systems and benefits from an extension of ASP's full-fledged input language with temporal operators. This includes future as well as past operators whose combination offers a rich temporal modeling language. For computation, we identify the class of temporal logic programs and prove that it constitutes a normal form for our approach. Finally, we outline two implementations, a generic one and an extension of the ASP system clingo. Under consideration for publication in Theory and Practice of Logic Programming (TPLP) Y1 - 2018 U6 - https://doi.org/10.1017/S1471068418000297 SN - 1471-0684 SN - 1475-3081 VL - 18 IS - 3-4 SP - 406 EP - 420 PB - Cambridge Univ. Press CY - New York ER - TY - JOUR A1 - Koumarelas, Ioannis A1 - Kroschk, Axel A1 - Mosley, Clifford A1 - Naumann, Felix T1 - Experience: Enhancing address matching with geocoding and similarity measure selection JF - Journal of Data and Information Quality N2 - Given a query record, record matching is the problem of finding database records that represent the same real-world object. In the easiest scenario, a database record is completely identical to the query. However, in most cases, problems do arise, for instance, as a result of data errors or data integrated from multiple sources or received from restrictive form fields. These problems are usually difficult, because they require a variety of actions, including field segmentation, decoding of values, and similarity comparisons, each requiring some domain knowledge. In this article, we study the problem of matching records that contain address information, including attributes such as Street-address and City. To facilitate this matching process, we propose a domain-specific procedure to, first, enrich each record with a more complete representation of the address information through geocoding and reverse-geocoding and, second, to select the best similarity measure per each address attribute that will finally help the classifier to achieve the best f-measure. We report on our experience in selecting geocoding services and discovering similarity measures for a concrete but common industry use-case. KW - Address matching KW - record linkage KW - duplicate detection KW - similarity measures KW - conditional functional dependencies KW - address normalization KW - address parsing KW - geocoding KW - geographic information systems KW - random forest Y1 - 2018 U6 - https://doi.org/10.1145/3232852 SN - 1936-1955 VL - 10 IS - 2 SP - 1 EP - 16 PB - Association for Computing Machinery CY - New York ER - TY - JOUR A1 - Koehler, Friedrich A1 - Koehler, Kerstin A1 - Deckwart, Oliver A1 - Prescher, Sandra A1 - Wegscheider, Karl A1 - Winkler, Sebastian A1 - Vettorazzi, Eik A1 - Polze, Andreas A1 - Stangl, Karl A1 - Hartmann, Oliver A1 - Marx, Almuth A1 - Neuhaus, Petra A1 - Scherf, Michael A1 - Kirwan, Bridget-Anne A1 - Anker, Stefan D. T1 - Telemedical Interventional Management in Heart Failure II (TIM-HF2), a randomised, controlled trial investigating the impact of telemedicine on unplanned cardiovascular hospitalisations and mortality in heart failure patients BT - study design and description of the intervention JF - European Journal of Heart Failure N2 - Background Heart failure (HF) is a complex, chronic condition that is associated with debilitating symptoms, all of which necessitate close follow-up by health care providers. Lack of disease monitoring may result in increased mortality and more frequent hospital readmissions for decompensated HF. Remote patient management (RPM) in this patient population may help to detect early signs and symptoms of cardiac decompensation, thus enabling a prompt initiation of the appropriate treatment and care before a manifestation of HF decompensation. Objective The objective of the present article is to describe the design of a new trial investigating the impact of RPM on unplanned cardiovascular hospitalisations and mortality in HF patients. Methods The TIM-HF2 trial is designed as a prospective, randomised, controlled, parallel group, open (with randomisation concealment), multicentre trial with pragmatic elements introduced for data collection. Eligible patients with HF are randomised (1:1) to either RPM + usual care or to usual care only and are followed for 12 months. The primary outcome is the percentage of days lost due to unplanned cardiovascular hospitalisations or all-cause death. The main secondary outcomes are all-cause and cardiovascular mortality. Conclusion The TIM-HF2 trial will provide important prospective data on the potential beneficial effect of telemedical monitoring and RPM on unplanned cardiovascular hospitalisations and mortality in HF patients. KW - Chronic heart failure KW - Telemonitoring KW - Remote patient management KW - Hospitalisation Y1 - 2018 U6 - https://doi.org/10.1002/ejhf.1300 SN - 1388-9842 SN - 1879-0844 VL - 20 IS - 10 SP - 1485 EP - 1493 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Peng, Junjie A1 - Liu, Danxu A1 - Wang, Yingtao A1 - Zeng, Ying A1 - Cheng, Feng A1 - Zhang, Wenqiang T1 - Weight-based strategy for an I/O-intensive application at a cloud data center JF - Concurrency and computation : practice & experience N2 - Applications with different characteristics in the cloud may have different resources preferences. However, traditional resource allocation and scheduling strategies rarely take into account the characteristics of applications. Considering that an I/O-intensive application is a typical type of application and that frequent I/O accesses, especially small files randomly accessing the disk, may lead to an inefficient use of resources and reduce the quality of service (QoS) of applications, a weight allocation strategy is proposed based on the available resources that a physical server can provide as well as the characteristics of the applications. Using the weight obtained, a resource allocation and scheduling strategy is presented based on the specific application characteristics in the data center. Extensive experiments show that the strategy is correct and can guarantee a high concurrency of I/O per second (IOPS) in a cloud data center with high QoS. Additionally, the strategy can efficiently improve the utilization of the disk and resources of the data center without affecting the service quality of applications. KW - IOPS KW - process scheduling KW - random I KW - O KW - small files KW - weight Y1 - 2018 U6 - https://doi.org/10.1002/cpe.4648 SN - 1532-0626 SN - 1532-0634 VL - 30 IS - 19 PB - Wiley CY - Hoboken ER -