256 research outputs found
Co-detection of micro seismic activity as early warning of gravitational slope failure
We developed a new strategy for Disaster Risk Reduction for gravitational
slope failure: We propose a simple method for real-time early warning of
gravity-driven failures that considers and exploits both the heterogeneity of
natural media and characteristics of acoustic emissions attenuation. This
method capitalizes on co-detection of elastic waves emanating from micro-cracks
by a network of multiple and spatially distributed sensors. Event co-detection
is considered as surrogate for large event size with more frequent co-detected
events marking imminence of catastrophic failure. In this study we apply this
method to a steep rock glacier / debris slope and demonstrate the potential of
this simple strategy for real world cases, i.e. at slope scale. This low cost,
robust and autonomous system provides a well adapted alternative/complementary
solution for Early Warning Systems.Comment: 11 pages, 8 figure
The Time-Triggered Wireless Architecture
Wirelessly interconnected sensors, actuators, and controllers promise greater flexibility, lower installation and maintenance costs, and higher robustness in harsh conditions than wired solutions. However, to facilitate the adoption of wireless communication in cyber-physical systems (CPS), the functional and non-functional properties must be similar to those known from wired architectures. We thus present Time-Triggered Wireless (TTW), a wireless architecture for multi-mode CPS that offers reliable communication with guarantees on end-to-end delays among distributed applications executing on low-cost, low-power embedded devices. We achieve this by exploiting the high reliability and deterministic behavior of a synchronous transmission based communication stack we design, and by coupling the timings of distributed task executions and message exchanges across the wireless network by solving a novel co-scheduling problem. While some of the concepts in TTW have existed for some time and TTW has already been successfully applied for feedback control and coordination of multiple mechanical systems with closed-loop stability guarantees, this paper presents the key algorithmic, scheduling, and networking mechanisms behind TTW, along with their experimental evaluation, which have not been known so far. TTW is open source and ready to use: https://ttw.ethz.ch
The Time-Triggered Wireless Architecture (Artifact)
This artifact contains a stable version of all the data and source code required to reproduce or replicate the results presented in The Time-Triggered Wireless Architecture.
One GitHub repository serves as main hub for all information related to the artifact. The README file contains detailed instructions for
- Running the TTnet model
- Compiling and running TTnet
- Running the TTW scheduler
- Reproducing the data processing
- Reproducing the plot
Π’ΡΠ°Π½ΡΡΠΎΡΠΌΠ°ΡΠΈΡ ΡΠΎΡΠΌ Π·Π°Π½ΡΡΠΎΡΡΠΈ Π² ΡΡΠ»ΠΎΠ²ΠΈΡΡ ΡΠΈΡΡΠΎΠ²ΠΈΠ·Π°ΡΠΈΠΈ ΡΠΊΠΎΠ½ΠΎΠΌΠΈΠΊΠΈ
ΠΠΊΡΡΠ°Π»ΡΠ½ΠΎΡΡΡ ΡΠ΅ΠΌΡ Π΄ΠΈΡΡΠ΅ΡΡΠ°ΡΠΈΠΎΠ½Π½ΠΎΠ³ΠΎ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΡ ΠΎΠ±ΡΡΠ»ΠΎΠ²Π»Π΅Π½Π° ΡΠ°Π΄ΠΈΠΊΠ°Π»ΡΠ½ΡΠΌΠΈ ΡΠ΅Ρ
Π½ΠΎΠ»ΠΎΠ³ΠΈΡΠ΅ΡΠΊΠΈΠΌΠΈ ΠΈΠ·ΠΌΠ΅Π½Π΅Π½ΠΈΡΠΌΠΈ, ΠΌΠ΅Π½ΡΡΡΠΈΠΌΠΈ ΡΡΡΡΠΎΠΉΡΡΠ²ΠΎ ΠΆΠΈΠ·Π½ΠΈ ΠΈ ΡΠΎΡΠΈΠ°Π»ΡΠ½ΡΠ΅ ΠΎΡΠ½ΠΎΡΠ΅Π½ΠΈΡ. ΠΠ°ΡΡΡΠ°Π±Π½ΡΠ΅ ΠΈΠ·ΠΌΠ΅Π½Π΅Π½ΠΈΡ ΠΏΡΠΎΠΈΡΡ
ΠΎΠ΄ΡΡ Π² ΡΡΠ΅ΡΠ°Ρ
ΡΡΡΠ΄Π° ΠΈ Π·Π°Π½ΡΡΠΎΡΡΠΈ Π½Π°ΡΠ΅Π»Π΅Π½ΠΈΡ. Π’ΡΠ°Π½ΡΡΠΎΡΠΌΠ°ΡΠΈΡ ΡΠΎΡΠΌ Π·Π°Π½ΡΡΠΎΡΡΠΈ ΠΈΠ·ΠΌΠ΅Π½ΡΠ΅Ρ ΡΡΠ°Π΄ΠΈΡΠΈΠΎΠ½Π½ΠΎ ΡΠ»ΠΎΠΆΠΈΠ²ΡΡΡΡΡ ΡΡΡΡΠΊΡΡΡΡ Π·Π°Π½ΡΡΠΎΡΡΠΈ Π½Π°ΡΠ΅Π»Π΅Π½ΠΈΡ, ΡΠΏΠΎΡΠΎΠ±ΡΡΠ²ΡΠ΅Ρ ΡΡΠΈΠ»Π΅Π½ΠΈΡ ΠΌΠΎΠ±ΠΈΠ»ΡΠ½ΠΎΡΡΠΈ ΡΡΡΠ΄ΠΎΠ²ΡΡ
ΡΠ΅ΡΡΡΡΠΎΠ², ΡΠ°ΡΠΏΡΠ΅Π΄Π΅Π»Π΅Π½ΠΈΠ΅ ΠΊΠΎΡΠΎΡΡΡ
ΠΏΡΠΎΠΈΡΡ
ΠΎΠ΄ΠΈΡ ΠΏΠΎΠ΄ Π²ΠΎΠ·Π΄Π΅ΠΉΡΡΠ²ΠΈΠ΅ΠΌ ΡΠΊΠ»Π°Π΄ΡΠ²Π°ΡΡΠ΅ΠΉΡΡ ΠΊΠΎΠ½ΡΡΠ½ΠΊΡΡΡΡ Π½Π° ΠΌΠ΅ΠΆΠ΄ΡΠ½Π°ΡΠΎΠ΄Π½ΠΎΠΌ ΠΈ Π½Π°ΡΠΈΠΎΠ½Π°Π»ΡΠ½ΡΡ
ΡΡΠ½ΠΊΠ°Ρ
. Π ΡΠ°ΠΌΠΊΠ°Ρ
ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΡ Π±ΡΠ»ΠΈ ΠΏΡΠΎΠ°Π½Π°Π»ΠΈΠ·ΠΈΡΠΎΠ²Π°Π½Ρ ΠΏΡΠΎΠ±Π»Π΅ΠΌΡ ΠΈ ΡΠΈΡΠΊΠΈ, Ρ ΠΊΠΎΡΠΎΡΡΠΌΠΈ ΡΡΠ°Π»ΠΊΠΈΠ²Π°Π΅ΡΡΡ ΠΏΡΠ΅Π΄ΠΏΡΠΈΡΡΠΈΠ΅ ΠΏΡΠΈ ΠΏΠ΅ΡΠ΅Π²ΠΎΠ΄Π΅ ΡΠΎΡΡΡΠ΄Π½ΠΈΠΊΠΎΠ² Π½Π° Π΄ΠΈΡΡΠ°Π½ΡΠΈΠΎΠ½Π½ΡΠΉ ΡΠ΅ΠΆΠΈΠΌ ΡΠ°Π±ΠΎΡΡ. Π ΠΈΡΠΎΠ³Π΅ ΠΏΡΠ΅Π΄ΡΡΠ°Π²Π»Π΅Π½ ΠΊΠΎΠΌΠΏΠ»Π΅ΠΊΡ ΡΠ΅ΠΊΠΎΠΌΠ΅Π½Π΄Π°ΡΠΈΠΉ, ΠΏΠΎ ΠΏΡΠ΅Π΄ΠΎΡΠ²ΡΠ°ΡΠ΅Π½ΠΈΡ ΠΏΡΠΎΠ±Π»Π΅ΠΌ, ΠΌΠΈΠ½ΠΈΠΌΠΈΠ·Π°ΡΠΈΠΈ ΡΠΈΡΠΊΠΎΠ² ΠΈ ΠΎΠΏΡΠΈΠΌΠΈΠ·Π°ΡΠΈΠΈ ΡΠ°ΡΡ
ΠΎΠ΄ΠΎΠ².The relevance of the topic of the dissertation research is due to radical technological changes that change the structure of life and social relations. Major changes take place in the spheres of labor and employment of the population. The transformation of forms of employment alters the traditionally formed structure of the employment of the population, contributes to the increase in the mobility of labor resources, the distribution of which is influenced by the emerging conjuncture in international and national markets. The study analyzed the problems and risks faced by the company when transferring employees to a remote mode of operation. As a result, a set of recommendations is presented to prevent problems, minimize risks and optimize costs
Heterologous Expression, Purification, and Biochemical Characterization of Ξ±-Humulene Synthase from Zingiber zerumbet Smith
The Ξ±-humulene synthase from Zingiber zerumbet Smith was expressed as a polyhistidine-tagged protein in an E. coli BL21(DE3) strain. Induction time and inductor (isopropyl-Ξ²-D-thiogalactopyranoside) concentration were optimized. The enzyme was successfully purified directly from cell lysate by NTA affinity column chromatography and careful selection of coordinated metal ion and imidazole elution conditions. Bioactivity assays were conducted with the natural substrate farnesyl diphosphate (FDP) in a two-phase system with in situ extraction of products. The conversion of FDP to Ξ±-humulene (~94.5 %) and Ξ²-caryophyllene (~5.5 %) could be monitored by gas chromatography-flame ionization detection (GC-FID). Optimal pH and temperature as well as kinetic parameters KM and kcat were determined using a discontinuous kinetic assay. The final publication is available at Springer via http://dx.doi.org/10.1007/s12010-015-1888-4.EFRE/ZW-8-8013094
Silver nanoparticle-doped zirconia capillaries for enhanced bacterial filtration
Membrane clogging and biofilm formation are the most serious problems during water filtration. Silver nanoparticle (Agnano) coatings on filtration membranes can prevent bacterial adhesion and the initiation of biofilm formation. In this study, Agnano are immobilized via direct reduction on porous zirconia capillary membranes to generate a nanocomposite material combining the advantages of ceramics being chemically, thermally and mechanically stable with nanosilver, an efficient broadband bactericide for water decontamination. The filtration of bacterial suspensions of the fecal contaminant Escherichia coli reveals highly efficient bacterial retention capacities of the capillaries of 8 log reduction values, fulfilling the requirements on safe drinking water according to the U.S. Environmental Protection Agency. Maximum bacterial loading capacities of the capillary membranes are determined to be 3 Γ 109 bacterial cells/750 mm2 capillary surface until back flushing is recommendable. The immobilized Agnano remain accessible and exhibit strong bactericidal properties by killing retained bacteria up to maximum bacterial loads of 6 Γ 108 bacterial cells/750 mm2 capillary surface and the regenerated membranes regain filtration efficiencies of 95β100%. Silver release is moderate as only 0.8% of the initial silver loading is leached during a three-day filtration experiment leading to average silver contaminant levels of 100 ΞΌg/L
Temporally Consistent Snow Cover Estimation from Noisy, Irregularly Sampled Measurements
We propose a method for accurate and temporally consistent surface classification in the presence of noisy, irregularly sampled measurements, and apply it to the estimation of snow coverage over time. The input imagery is extremely challenging, with large variations in lighting and weather distorting the measurements. Initial snow cover estimations are obtained using a Gaussian Mixture Model of color. To achieve a temporally consistent snow cover estimation, we use a Markov Random Field that penalizes rapid fluctuations in the snow state, and show that the penalty term needs to be quite large, resulting in slow reactivity to changes. We thus propose a classifier to separate good from uninformative images, which allows to use a smaller penalty term. We show that the incorporation of domain knowledge to discard uninformative images leads to better reactivity to changes in snow coverage as well as more accurate snow cover estimations
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