Damage detection in bridges under moving loads based on subspace projection residuals

This paper proposes a data-driven method using subspace projection residual of the responses to identify the damage locations in bridges subjected to moving loads. In this method, a moving window with a certain length determined by the sampling frequency and the fundamental frequency of the measured responses is used to cut out the acceleration responses of the bridge subjected to a moving vehicle. The characteristic subspaces of the windowed signals are subsequently extracted to calculate the local damage index using the subspace projection residual. When the window moves to the damage location, the orthogonality between the active subspace of the damaged state and the null subspace of the healthy state is invalid, which leads to a relatively large projection residual that can be used to localize the damage. To improve the reliability of the proposed approach, a one-side upper confidence limit is introduced. A simply supported beam bridge subjected to a moving mass is simulated to verify the effectiveness of the proposed method. Numerical results indicate that the proposed approach can accurately localize the single and multiple damages, even when the responses are smeared with a significant noise. Experimental tests conducted on a steel beam bridge model also demonstrate the performance and accuracy of the proposed approach. The results demonstrate that the proposed method can localize the damage even with a small number of sensors, indicating the method has a good and promising performance for practical engineering applications.

Investigation of surface morphology of thin metal films with magnetic layers Fe-Cr-Co

Films containing layers of dispersion-hardening alloys (LDHA) based on the Fe-Cr-Co system were obtained by magnetron sputtering. LDHA acquire the properties of film permanent magnets after a single-stage «fast» high-vacuum annealing. Bulk materials acquire such properties only after many hours of multi-stage heat treatment. The film samples acquire these properties in tens of seconds. The morphology of their surface was studied to determine the origin of the coercive force of film samples. The surface morphology was studied using high resolution scanning electron microscopy and atomic force microscopy. We studied two compositions that, in bulk, have a different tendency to form many phases during crystallization. In magnetron sputtering, the alloy in which a multiphase state is easily formed is polycrystalline. The antipode alloy in magnetron sputtering is realized in an amorphous state. After annealing, both alloys are in a polycrystalline state. Electron microscopic examination showed that as a result of annealing, crystallites are formed with a large projection onto the substrate plane, which grow due to the nearest neighbors. Moreover, these crystallites have not only a large area, but also a height. After annealing, both alloys are in a polycrystalline state. Electron microscopic examination showed that as a result of annealing, crystallites are formed with a large projection onto the substrate plane, which grow due to the nearest neighbors. Moreover, these crystallites have not only a large area, but also a height. What is determined by atomic force microscopy. High crystallites are also faceted. This may indicate that the composition of these crystallites differs from the composition of the surrounding layer, which may be the reason for the increase in coercive force as a result of annealing.

A new species of the genus Sulcohumpacris Yin, Yin et Cao, 2017 (Orthoptera, Acridoidea, Pamphagidae) from China

A new species of the genus Sulcohumpacris Yin, Yin et Cao, 2017 i.e. Sulcohumpacris wuanensis sp. nov. is described in this paper from China. The new species is similar to Sulcohumpacris hebeiensis Yin, Yin et Cao, 2017 but differs from latter by median keel of pronotum cut by hind sulcus slightly, tegmen of male cover 2/3 tympanum, length of Krauss’ organ 1.8 times of width in female, apex of subgenital plate of male point, cercus of male narrow at base, lower margin of Epiphallus with large projection in the middle and hind knee of female not curved at lower margin. Type specimens are deposited in the College of Life Sciences, Hebei University, Baoding, China.

SHIP SAFETY AT HAZARDOUS SITUATIONS ON EXAMPLES OF ANTI-DEFECT PROTECTION SIMULATOR

The paper presents a deployment of a simulator of Ship Anti-defect Protection (SAP) as a modern method of training the crews of service ships of the Polish Navy on anti-defect countermeasures. Ship’s safety is a complex question of many aspects. For instance, making the proper decisions and following the binding rules depends on the sea experience and training, whereas the process of training takes place both at sea cruises and at training centres. The paper deals with the questions of warship’s safety when a fire starts in various places of the ship. Identification of defects and their types, and methods and tools for their repair are described. The SAP simulator was built by using modern computer technologies and a large projection screen being a section of a cylindrical surface.

Worship on Screen

Chapter 5 examines digital audiovisual worship media as nodes that serve both as extensions of congregations into the virtual realm and as sites for the creation of new networked congregations. Drawing from ethnographic field research both on and offline, this chapter argues that new digital audiovisual technologies and the avenues of online communication along which they travel not only give evangelical worshipers new ways to transmit, share, and discover worship songs; rather, they also strongly condition the practices evangelicals consider to be necessary parts of worship. Through audiovisual worship media experienced on small personal screens and large projection screens in church, conference, and concert settings, once-separate aural and visual strands of evangelical devotion are drawn together into a powerful experiential whole. The networked mode of congregating centered around these audiovisual worship experiences challenges the boundaries between public and private worship and has brought about new negotiations between individual, institutional, and industry authority.

Grasping Elapsing

An iterative series of hybrid media installations and generative, participatory performance projects, Grasping Elapsing (2003-present) attempts to show embodied thought process by creating open-ended connections among object, image, archive, digital process and word. The project is comprised of a combination of installations, performances, images created by the artist over time, images created by participants in prior and current performances/installations, live-sourced, appropriated images accessed through software, generative software that processes combinations of the above-described images, and a Twitter feed/archive. Given the highly-temporal nature of the project, it is difficult to analyze specific juxtapositions that might arise. This report will therefore mainly address the projects’ ongoing conceptual framework while referencing specific moments in time where it might be helpful for contemporary readers. The current iteration, Grasping Elapsing 3.1 is a digitally-augmented participatory performance with a “live” component of approximately twenty minutes and an indefinitely-extended digital component which is conducted online. The piece expresses a convergence of history, place and present moment through the use of digital practices and face-to-face discussion. It is conducted with an audience that, after an approximately eight-minute introduction, is invited to participate by contributing images through the use of scanning. The entire piece is enacted at a table with a large projection behind it. The artist sits at the table facing audience-participants. Throughout the performance, the artist delivers spoken-word content and participatory instructions. On the table are a laptop computer which the artist uses to improvisationally control a custom-made software application designed specifically for the performance. The application displays artist-produced, appropriated and past-and-current participant-contributed imagery, and also imagery generatively processed from combinations of all of the above-mentioned source materials. The output of this application is shown on the projection screen. Also on the table is a flatbed scanner which participants use to digitize images for contribution to the piece; scanned images are automatically added to a databank from which the application draws in real time.

Open cluster study in LAMOST DR3

In studying Galactic open clusters based on LAMOST DR3, we deliberately selected several nearby cluster, which have relatively large projection area and reliable proper motion measurements. For each cluster, we firstly determine the typical proper motion distribution profiles in the cluster-core and the outskirt region, respectively, and perform field-star decontamination on the cluster area. We then calculate kinematic membership probability for each star in the cluster area and cross-match the highly probable members with LAMOST DR3 spectral catalog. Based on enhanced signal of cluster-member radial velocity distribution emerging from the whole field, we have also obtained reliable radial velocity membership probability for each star. Finally, we perform isochrones fitting with MCMC technique to study basic properties of these cluster, including age, metallicity, and distance modulus.

The Sequential Pattern Mining Algorithm MHSP Based on MH

Pattern growth approach is an important method in sequential pattern mining. Projection database based on the method is introduced in PrefixSpan, and the PrefixSpan algorithm can solve the problem of mining sequential patterns. But relative to large projection database, the performance of PrefixSpan is affected. Inspired by the prefix-divide method and MH structure, this paper proposed a new algorithm MHSP for sequential pattern mining. Based on the real datasets, experimental results show that the performance of MHSP algorithm is more than twice as fast as PrefixSpan.