From Linked Data to Relevant Data -- Time is the Essence

The Semantic Web initiative puts emphasis not primarily on putting data on the Web, but rather on creating links in a way that both humans and machines can explore the Web of data. When such users access the Web, they leave a trail as Web servers maintain a history of requests. Web usage mining approaches have been studied since the beginning of the Web given the log's huge potential for purposes such as resource annotation, personalization, forecasting etc. However, the impact of any such efforts has not really gone beyond generating statistics detailing who, when, and how Web pages maintained by a Web server were visited.Comment: 1st International Workshop on Usage Analysis and the Web of Data (USEWOD2011) in the 20th International World Wide Web Conference (WWW2011), Hyderabad, India, March 28th, 201

Interpretable Prediction of Urban Mobility Flows with Deep Neural Networks as Gaussian Processes

The ability to understand and predict the flows of people in cities is crucial for the planning of transportation systems and other urban infrastructures. Deep-learning approaches are powerful since they can capture non-linear relations between geographic features and the resulting mobility flow from a given origin location to a destination location. However, existing methods cannot quantify the uncertainty of the predictions, limiting their interpretability and thus their use for practical applications in urban infrastructure planning. To that end, we propose a Bayesian deep-learning approach that formulates deep neural networks as Gaussian processes and integrates automatic variable selection. Our method provides uncertainty estimates for the predicted origin-destination flows while also allowing to identify the most critical geographic features that drive the mobility patterns. The developed machine learning approach is applied to large-scale taxi trip data from New York City

Self-organization of Nodes using Bio-Inspired Techniques for Achieving Small World Properties

In an autonomous wireless sensor network, self-organization of the nodes is essential to achieve network wide characteristics. We believe that connectivity in wireless autonomous networks can be increased and overall average path length can be reduced by using beamforming and bio-inspired algorithms. Recent works on the use of beamforming in wireless networks mostly assume the knowledge of the network in aggregation to either heterogeneous or hybrid deployment. We propose that without the global knowledge or the introduction of any special feature, the average path length can be reduced with the help of inspirations from the nature and simple interactions between neighboring nodes. Our algorithm also reduces the number of disconnected components within the network. Our results show that reduction in the average path length and the number of disconnected components can be achieved using very simple local rules and without the full network knowledge.Comment: Accepted to Joint workshop on complex networks and pervasive group communication (CCNet/PerGroup), in conjunction with IEEE Globecom 201

A Self-Organization Framework for Wireless Ad Hoc Networks as Small Worlds

Motivated by the benefits of small world networks, we propose a self-organization framework for wireless ad hoc networks. We investigate the use of directional beamforming for creating long-range short cuts between nodes. Using simulation results for randomized beamforming as a guideline, we identify crucial design issues for algorithm design. Our results show that, while significant path length reduction is achievable, this is accompanied by the problem of asymmetric paths between nodes. Subsequently, we propose a distributed algorithm for small world creation that achieves path length reduction while maintaining connectivity. We define a new centrality measure that estimates the structural importance of nodes based on traffic flow in the network, which is used to identify the optimum nodes for beamforming. We show, using simulations, that this leads to significant reduction in path length while maintaining connectivity.Comment: Submitted to IEEE Transactions on Vehicular Technolog

Achieving Small World Properties using Bio-Inspired Techniques in Wireless Networks

It is highly desirable and challenging for a wireless ad hoc network to have self-organization properties in order to achieve network wide characteristics. Studies have shown that Small World properties, primarily low average path length and high clustering coefficient, are desired properties for networks in general. However, due to the spatial nature of the wireless networks, achieving small world properties remains highly challenging. Studies also show that, wireless ad hoc networks with small world properties show a degree distribution that lies between geometric and power law. In this paper, we show that in a wireless ad hoc network with non-uniform node density with only local information, we can significantly reduce the average path length and retain the clustering coefficient. To achieve our goal, our algorithm first identifies logical regions using Lateral Inhibition technique, then identifies the nodes that beamform and finally the beam properties using Flocking. We use Lateral Inhibition and Flocking because they enable us to use local state information as opposed to other techniques. We support our work with simulation results and analysis, which show that a reduction of up to 40% can be achieved for a high-density network. We also show the effect of hopcount used to create regions on average path length, clustering coefficient and connectivity.Comment: Accepted for publication: Special Issue on Security and Performance of Networks and Clouds (The Computer Journal

Experimental study on pressure distribution and flow coefficient of globe valve

In this study, the pressure distribution and flow coefficient of a globe valve are investigated with a series of experiments conducted in a flow test loop. The experiments are performed on a three-inch model test valve from an eight-inch ANSI (American National Standards Institute) B16.11-Class 2500# prototype globe valve with various pump speeds and full range of valve openings. Both inherent and installed flow characteristics are measured, and the results show that the flow coefficient depends not only on the valve geometry and valve opening but also on the Reynolds number. When the Reynolds number exceeds a certain value, the flow coefficients are stable. In addition, the pressures at different positions in the upstream and the downstream of the valve are measured and compared with recommendation per ANSI/ISA-75.01 standard. The results show that, in single-phase flow, the discrepancies in pressure between different measurement locations within close range of 10 nominal diameter from the valve are inconsiderable

Self-Organization of Wireless Ad Hoc Networks as Small Worlds Using Long Range Directional Beams

We study how long range directional beams can be used for self-organization of a wireless network to exhibit small world properties. Using simulation results for randomized beamforming as a guideline, we identify crucial design issues for algorithm design. Subsequently, we propose an algorithm for deterministic creation of small worlds. We define a new centrality measure that estimates the structural importance of nodes based on traffic flow in the network, which is used to identify the optimum nodes for beamforming. This results in significant reduction in path length while maintaining connectivity.Comment: Accepted to Joint workshop on complex networks and pervasive group communication (CCNet/PerGroup), in conjunction with IEEE Globecom 201

Proposal of Strength Formula and Type Development of Composite Mega Column to Beam Connections with T-shaped Stiffener

[EN] As buildings are becoming larger, demand for mega-sized composite columns (over 1-meter diameter) is increased. We have developed and commercialized welded built-up CFT column (ACT Column I) since 2005 which are structurally stable and economical using cold-formed steel with rib. However, there has a limit in size of cross section (618 X 618mm) by a fabrication facilities. And due to charateristics of closed cross section, there has a limit to construction of connection of moment frame. Composite mega column (ACT Column II) has same concept of forming closed cross section. But in order to enlarge cross sectional size, thick plate is inserted between cold-formed steels. Since composite mega column can control thickness and width of thick plate, steel or composite beams can be directly attached to the connection. In this study, we propose strength formula of composite mega column to beam connections with T-shaped stiffener as internal diaphragm and verified through finite element analysis and simple tensile experiment.Lee, JH.; Kim, SH.; Kim, BK.; Yom, KS.; Choi, SM. (2018). Proposal of Strength Formula and Type Development of Composite Mega Column to Beam Connections with T-shaped Stiffener. En Proceedings of the 12th International Conference on Advances in Steel-Concrete Composite Structures. ASCCS 2018. Editorial Universitat Politècnica de València. 465-473. https://doi.org/10.4995/ASCCS2018.2018.7016OCS46547

Bubble formation in globe valve and flow characteristics of partially filled pipe water flow

Air bubble entrainment is a phenomenon that can significantly reduce the efficiency of liquid motion in piping systems. In the present study, the bubble formation mechanism in a globe valve with 90% water fraction flow is explained by visualization study and pressure oscillation analysis. The shadowgraph imaging technique is applied to illustrate the unsteady flow inside the transparent valve. This helps to study the effect of bubbles induced by the globe valve on pressure distribution and valve flow coefficient. International Society of Automation (ISA) recommends locations for measuring pressure drop of the valve to determine its flow coefficient. This paper presents the comparison of the pressures at different locations along with the upstream and the downstream of the valve with the values at recommended positions by the ISA standard. The results show that in partially filled pipe flow, the discrepancies in pressure between different measurement locations in the valve downstream are significant at valve openings less than 30%. The aerated flow induces the oscillation in pressure and flow rate, which leads to the fluctuation in the flow coefficient of the valve. The flow coefficients have a linear relationship with the Reynolds number. For the same increase of Reynolds number, the flow coefficients grow faster with larger valve openings and level off at the opening of 50%