Use of tilt sensing equipment for monitoring long-term bridge movement

1991 ◽  
Vol 18 (6) ◽  
pp. 1033-1046 ◽  
Author(s):  
Terry J. Wipf
Keyword(s):  
Key Words ◽  
Reference Point ◽  
Structural Engineering ◽  
Field Tests ◽  
Measurement Instruments ◽  
Time Period ◽  
Long Time ◽  
Time Periods ◽  
Tilt Sensors

Accurate monitoring of long-term movements in bridges can be difficult primarily because of the relatively long time period over which the movements occur and inadequate instrumentation and technique. A stable reference point for measurements is difficult to obtain over these long time periods. Two bridges were monitored for long-term structural movement; the results are presented here. Instrumentation including temperature transducers and tilt sensors placed on and near piers determined the pier movement. The results of the study indicate that a superstructure expansion pier on one of the bridges monitored actually behaved as a fixed pier. The equipment used in the study, including data acquisition components and tilt sensors, proved reliable and accurate. Key words: bridges, girder, field tests, foundations, measurement instruments, piers, structural engineering.

scholarly journals Characterizing and Correcting Phase Biases in Short-Term, Multilooked Interferograms

2021 ◽  
Author(s):  
Yasser Maghsoudi ◽  
Andy Hooper ◽  
Tim Wright ◽  
Homa Ansari ◽  
Milan Lazecky
Keyword(s):  
Ground Cover ◽  
Short Term ◽  
Western Turkey ◽  
Time Period ◽  
Interferometric Phase ◽  
Common Strategy ◽  
Long Time ◽  
Phase Bias ◽  
Time Periods

Interferometric Synthetic Aperture Radar (InSAR) is widely used to measure deformation of the Earth’s surface over large areas and long time periods. A common strategy to overcome coherence loss in long-term interferograms is to use multiple multilooked shorter interferograms, which can cover the same time period but maintain coherence. However, it has recently been shown that using this strategy can introduce a bias (also referred to as “fading signals”) in the interferometric phase, particularly over vegetated areas. We isolate the signature of the phase bias by constructing daisy chain sums of short-term interferograms covering identical 1-year time periods, but using interferograms of different time spans. This shows that the shorter interferograms are more affected by this phenomenon and that different ground cover types are affected differently. We, propose a method for correcting the phase bias, based on the assumption that the bias in an interferogram is linearly related to the sum of the bias in shorter interferograms spanning the same time. We tested the algorithm over a study area in western Turkey by comparing average velocities against results from a phase linking approach that has been shown to be rather insensitive to the phase bias. Our corrected velocities agree well with those from phase linking approach. Our approach can be applied to global compilations of short-term interferograms and offer the possibility of accurate long-term velocities without a requirement for coherence in long-term interferograms.

scholarly journals Are stock returns an inflation hedge for the UK? Evidence from a wavelet analysis using over three centuries of data

2018 ◽  
Vol 23 (3) ◽  
Author(s):  
Aviral Kumar Tiwari ◽  
Juncal Cunado ◽  
Rangan Gupta ◽  
Mark E. Wohar
Keyword(s):  
South Africa ◽  
Wavelet Analysis ◽  
Stock Returns ◽  
Time Period ◽  
Inflation Rates ◽  
The Us ◽  
Long Time ◽  
Time Periods ◽  
The Uk ◽  
The Relationship

Abstract This paper analyzes the relationship between stock returns and the inflation rates for the UK over a long time period (February 1790–February 2017) and at different frequencies, by employing a wavelet analysis. We also compare the results for the UK economy with those for the US and two developing countries (India and South Africa). Overall, our results tend to suggest that, while the relationship between stock returns and inflation rates varies across frequencies and time periods, there is no evidence of stock returns acting as an inflation hedge, irrespective of whether we look at the two developed or the two developing markets in our sample.

The remote results of laser destruction of proliferating colloidal goiter

2016 ◽  
Vol 22 (1) ◽  
pp. 7-9
Author(s):  
Yu. K Aleksandrov ◽  
Vasiliy I. Semikov ◽  
V. A Kudachkov ◽  
E. I Sokolova
Keyword(s):  
Thyroid Gland ◽  
Connective Tissue ◽  
Morphological Analysis ◽  
Nodular Goiter ◽  
Early Time ◽  
Follicular Epithelium ◽  
Time Period ◽  
Time Periods ◽  
Tissue Structures

The article presents the remote results (time-period more than 1 year) of application of percutaneous laser destruction in treatment of nodular goiter in 164 patients. The reliable decreasing of dimensions and size of nodular formations of thyroid gland in early time-periods with continuation of regression during a year is established. In the following, slight regression was marked during 3,5-5 years. The morphological analysis established that in remote time-periods after percutaneous laser destruction of nodular proliferating colloid goiter the destroyed follicular epithelium and colloid are replaced by connective tissue structures with large amount of collagen guaranteeing long-term predictive result.

scholarly journals Influence of treatment in multiple sclerosis dysability: an open, retrospective, non-randomized long-term analysis

2010 ◽  
Vol 68 (4) ◽  
pp. 511-521 ◽  
Author(s):  
Lineu Cesar Werneck ◽  
Paulo José Lorenzoni ◽  
Vitor A Radünz ◽  
Marco A.T Utiumi ◽  
Cláudia Suemi Kamoi Kay ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Disease Progression ◽  
Age Of Onset ◽  
Statistical Significance ◽  
Time Period ◽  
Disability Status ◽  
Therapeutic Procedures ◽  
Long Time ◽  
Final Score

The efficacies of immunosuppressive (IMS) and immunomodulatory (IMM) drugs for multiple sclerosis (MS) have been reported in several studies. These agents can reduce relapse rates and lesions observed by magnetic resonance imaging studies. However, the effect of these medications in disability progression over 4 years is rarely examined. OBJECTIVE: To study the disabilities associated with MS patients after a long time period and to analyze the therapeutic influence of different types of treatments in patient disease progression. METHOD: This is an open, uncontrolled, non-randomized, retrospective study of the disease progression using the Expanded Disability Status Scale (EDSS) and the Multiple Sclerosis Severity Score (MSSS) in 155 cases of MS, which were 76% female with a mean age of onset of 30.21±9.70. The follow-up period was 115.39±88.08 months (median 92, 3 to 447 months). These cases were submitted to the following 277 different therapeutic procedures: 62 without IMS or IMM therapy (SYT) (just corticosteroids), 53 with azathioprine (AZA), 53 interferon-β (IFNβ)-1b 250 µg (BET), 55 IFNβ-1a 22 µg (R22), 19 IFNβ-1a 30 µg (AVO), 15 IFNβ-1a 44 µg (R44), 15 glatiramer acetate (COP) 20 mg, and 5 cases with mitoxantrone (MIT). RESULTS: The median EDSS group was 2.00 (0 to 5.5, mean 1.89±1.52) at the onset of each treatment and 2.50 (0 to 9, mean 3.06±2.18) at the end. The median initial MSSS was 3.34 (0.25 to 9.50, mean 3.94±2.91) and the final medial was 3.90 (0.05 to 9.88, mean 4.02±2.78). The EDSS between initial and final score for the whole group had statistically significant progression, as well as for the sub-groups SYT, AZA, BET and R22. No statistically significance difference was found in the MSSS between initial and final scores in the whole group or treatment sub-groups. The variation between the initial and final EDSS and MSSS among the types of treatments found no statistical significance for any group. CONCLUSION: In this study series, no statistical difference was found in the long-term progression of disability among the IMS and IMM treated cases, nor in the cases treated only with corticosteroids.

The moire crack gauges on the crown of the Frank Slide

1990 ◽  
Vol 27 (6) ◽  
pp. 835-840 ◽  
Author(s):  
B. Kostak ◽  
D. M. Cruden
Keyword(s):  
Key Words ◽  
Measurement System ◽  
Rock Block ◽  
Reliable Measurement ◽  
Long Time ◽  
Moire Fringe ◽  
Time Periods ◽  
Moiré Fringe

Two TM71 Crack Monitors installed in a gaping crack in the crown of the Frank Slide, Alberta, have recorded movements of less than 1 mm/year. These movements are attributed to continuing dilation of the rock block field in the crown. The crack monitors' moire fringe measurement system is particularly suited to the reliable measurement of small movements over long time periods. Key words: displacements, monitoring, rock, Rockies, creep, interferometry.

Autonomous Acoustic Recording Packages (ARPs) for Long-Term Monitoring of Whale Sounds

2003 ◽  
Vol 37 (2) ◽  
pp. 13-22 ◽  
Author(s):  
Sean Wiggins
Keyword(s):  
Weather Conditions ◽  
High Data ◽  
West Antarctic ◽  
Data Capacity ◽  
Long Time ◽  
Long Term Monitoring ◽  
Time Periods ◽  
Acoustic Recording ◽  
Term Monitoring

Advancements in low-power and high-data capacity computer technology during the past decade have been adapted to autonomously record acoustic data from vocalizing whales over long time periods. Acoustic monitoring of whales has advantages over traditional visual surveys including greater detection ranges, continuous long-term monitoring in remote locations and in various weather conditions, and lower cost. An autonomous acoustic recording package (ARP) is described that uses a tethered hydrophone above a seafloor-mounted instrument frame. ARPs have been deployed to record baleen whale sounds in the Bering Sea, off the coast of southern California, near the West Antarctic Peninsula, and near Hawaii. ARP data have provided new information on the seasonal presence, abundance, call character, and patterns of vocalizing whales. Current development is underway for a broader-band, higher-data capacity system capable of recording odontocete whales, dolphins, and porpoises for long time periods.

scholarly journals MATHEMATICAL MODELLING OF WATER-QUALITY FOR LONG TIME PERIODS

1984 ◽  
Vol 1 (19) ◽  
pp. 207
Author(s):  
P. Huizinga
Keyword(s):  
Water Quality ◽  
Mathematical Modelling ◽  
Test Cases ◽  
Quality Model ◽  
One Dimensional ◽  
Long Time ◽  
Time Periods ◽  
Theoretical Test ◽  
Modelling Of Water Quality

This paper presents a one-dimensional dynamic water-quality model suitable for long-term application to estuaries. The computation techniques used in the model are very simple, but very good results have been obtained both for theoretical test cases and from applications to estuaries when compared with prototype measurements.

scholarly journals KINEMATIC ANALYSIS EVOLUTION OF EXTENDED LANDSLIDES: TWO CASE STUDIES FROM WESTERN GREECE

2017 ◽  
Vol 50 (2) ◽  
pp. 730
Author(s):  
K. Kavoura ◽  
S. Anagnostopoulou ◽  
K. Servou ◽  
N. Depoundis ◽  
K. Nikolakopoulos ◽  
...  
Keyword(s):  
Statistical Model ◽  
Temporal Evolution ◽  
Data Normalization ◽  
Time Period ◽  
Long Time ◽  
Triggering Factor ◽  
The Common ◽  
Western Greece ◽  
Heavy Rainfalls

Two of the most well known historical landslide occurrences are analyzed and their temporal evolution is presented. The sites of Panagopoula and Karya are often referred as the most representative cases of long term ground displacements based on inclinometer monitoring data. Regarding these cases, the heavy rainfalls constitute the main controlling (triggering) factor, while flysch is the critical landslide-prone formation which significantly contributes to landsliding. The inclinometer data through a long time period were analyzed and typical movement diagrams were compiled. A simple statistical model including data normalization through several active stages (phases) of movement is used to identify the common kinematic features as well as to estimate the velocity trend type of movement.

scholarly journals Trends in the Seaward Extent of Saltmarshes across Europe from Long-Term Satellite Data

2019 ◽  
Vol 11 (14) ◽  
pp. 1653 ◽  
Author(s):  
Marieke Liesa Laengner ◽  
Koen Siteur ◽  
Daphne van der Wal
Keyword(s):  
Satellite Data ◽  
Large Scale ◽  
Open Water ◽  
Classification Performance ◽  
Environmental Drivers ◽  
Decision Tree Classification ◽  
Time Period ◽  
Long Time ◽  
Water Level Variations

Saltmarshes provide crucial functions for flora, fauna, and humankind. Thus far, studies of their dynamics and response to environmental drivers are limited in space and time. Satellite data allow for looking at saltmarshes on a large scale and over a long time period. We developed an unsupervised decision tree classification method to classify satellite images into saltmarsh vegetation, mudflat and open water, integrating additional land cover information. By using consecutive stacks of three years, we considered trends while taking into account water level variations. We used Landsat 5 TM data but found that other satellite data can be used as well. Classification performance for different periods of the Western Scheldt was almost perfect for this site, with overall accuracies above 90% and Kappa coefficients of over 0.85. Sensitivity analysis characterizes the method as being robust. Generated time series for 125 sites across Europe show saltmarsh area changes between 1986 and 2010. The method also worked using a global approach for these sites. We reveal transitions between saltmarsh, mudflat and open water, both at the saltmarsh lower edge and interior, but our method cannot detect changes at the saltmarsh-upland boundary. Resulting trends in saltmarsh dynamics can be coupled to environmental drivers, such as sea level, tidal currents, waves, and sediment availability.

scholarly journals Retention following Two-Stage Collaborative Exams Depends on Timing and Student Performance

2019 ◽  
Vol 18 (2) ◽  
pp. ar12 ◽  
Author(s):  
James E. Cooke ◽  
Laura Weir ◽  
Bridgette Clarkston
Keyword(s):  
Student Performance ◽  
Two Stage ◽  
Course Content ◽  
High Performing ◽  
Number Of Factors ◽  
Time Period ◽  
Long Time ◽  
Course Material ◽  
Time Periods ◽  
Content Retention

Multistage collaborative exams are implemented to enhance learning and retention of course material. However, the effects of multistage collaborative exams on retention of course content are varied. These discrepancies may be due to a number of factors. To date, studies examining collaborative exams and content retention have used questions that all, or mostly, require students to select an answer, rather than generate one of their own. However, content retention can improve when students generate their own responses. Thus, we examined the effect of collaborative exams with open-ended questions on retention of course content. Retention was measured at two time periods; one relatively shortly (9 days) following a collaborative exam and another over a longer time period (23 days). Furthermore, we examined whether content retention differed for low-, mid-, or high-­performing students. Our results suggest that collaborative exams offer retention benefits at relatively long time periods between pre- and posttests, but not over shorter time periods. Retention varied across students in different performance categories. Our study, the first to use only open-ended questions, showed relatively small effects compared with studies using multiple-choice or fill-in-the-blank format, but still suggest that collaborative exams can aid in content retention.

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