Another look at delineation of uniform pavement sections based on falling weight deflectometer deflections data

2016 ◽  
Vol 43 (1) ◽  
pp. 40-50 ◽  
Author(s):  
Syed Waqar Haider ◽  
Sudhir Varma
Keyword(s):  
Structural Condition ◽  
Mean Difference ◽  
Falling Weight Deflectometer ◽  
Pavement Surface ◽  
State Highway ◽  
Practical Standpoint ◽  
The Mean ◽  
Mean Differences ◽  
Falling Weight ◽  
Local Variability

The large amount of data commonly used to characterize the pavement surface and structural conditions offer a challenge to practitioners making decisions about the representative value of a particular parameter for design. While a large number of observations along the length of a road allow a better quantification of the expected value and variance of a parameter, basing a design on an average parameter along the project length will typically be uneconomical and less reliable. Therefore, pavement surface and structural condition data along a project length needs to be delineated into uniform sections. The design can be performed individually for each of these uniform sections to achieve economy without compromising reliability level. This paper documents delineation methods that explicitly address the problem of segmentation of measurement series obtained from Falling weight deflectometer deflections. Modifications in the existing American Association of State Highway and Transportation Officials (AASHTO) delineation procedure were incorporated to address the mean differences and the local variability. The results of delineation show that the AASHTO methodology ignores the local variations along the project length which may not be valid from a practical standpoint while designing rehabilitation or preservation strategies. The inclusion of restrictions on mean difference and section length resulted in better delineation than the AASHTO method but it could be sensitive to local variations of the deflections within a section. The delineation approach can handle the local deflection variations within a section if appropriate constraints on the local variations are imposed. The results from the delineation of field deflections showed that the restrictions on mean difference, minimum section length, and location variability are vital to delineate the project length into appropriate homogenous sections which can be different from each other from both statistical and practical viewpoints.

Application of Traffic Speed Deflectometer for Network-Level Pavement Management

2018 ◽  
Vol 2672 (40) ◽  
pp. 348-359 ◽  
Author(s):  
Shivesh Shrestha ◽  
Samer W. Katicha ◽  
Gerardo W. Flintsch ◽  
Senthilmurugan Thyagarajan
Keyword(s):  
Surface Condition ◽  
Structural Condition ◽  
Pavement Management ◽  
Falling Weight Deflectometer ◽  
Pavement Management System ◽  
State Highway ◽  
Structural Evaluation ◽  
Traffic Speed ◽  
State Highway Agencies ◽  
Falling Weight

In this paper, the traffic speed deflectometer (TSD), a device used for network level structural evaluation, is assessed. TSD testing was performed in nine states on a total of 5,928 miles (some repeated) during three time periods: November 2013, May to July 2014, and June to September 2015. This paper presents (1) the results of repeatability and comparison of the TSD with the falling weight deflectometer (FWD), (2) the results of the comparison of TSD measurements with typical pavement management system (PMS) data, and (3) an approach that can be implemented by State Highway Agencies (SHAs) to incorporate indices derived from TSD data into their PMS decision-making process. The results show that repeated TSD measurements follow similar trends and the TSD measurements and FWD measurements on the same pavement sections follow similar trends as well. Comparing TSD measurements with PMS surface condition data confirmed that the TSD provided valuable information about the structural condition of the tested pavement sections that cannot be derived from the already available pavement surface condition as part of an agency’s PMS. An example of how TSD information can be used to refine the triggered maintenance treatment category as part of a network-level PMS analysis is presented for a roughly 75-mile section of I-81 south in Virginia.

Evaluation of inverted pavement by structural condition indicators from falling weight deflectometer

2022 ◽  
Vol 319 ◽  
pp. 125991
Author(s):  
Xi Jiang ◽  
Jay Gabrielson ◽  
Baoshan Huang ◽  
Yun Bai ◽  
Pawel Polaczyk ◽  
...  
Keyword(s):  
Structural Condition ◽  
Falling Weight Deflectometer ◽  
Condition Indicators ◽  
Falling Weight

scholarly journals Agreement between Original and Rasch-Approved Neck Disability Index

2020 ◽  
Author(s):  
ZE LU ◽  
Joy C. MacDermid ◽  
Goris Nazari
Keyword(s):  
Neck Pain ◽  
Neck Disability Index ◽  
Secondary Data ◽  
Study Data ◽  
Mean Difference ◽  
Patient Status ◽  
Alternate Forms ◽  
The Mean ◽  
Mean Differences ◽  
Neck Disability

Abstract Background: Given the high prevalence of neck pain, the neck disability index (NDI) has been used to evaluate patient status and treatment outcomes. Modified versions were proposed as solutions to measurement deficits in the NDI. However, the original 10-item NDI was scored out of 50 and is still the most frequently administered version. Examining the extent of agreement between traditional and Rasch-based versions using Bland-Altman (B&A) plots will inform our understanding of score differences that might rise from using different versions. Therefore, the objective of current study was to describe the extent of agreement between different versions of NDI.Methods: The current study was a secondary data analysis. The study data was compiled from two prospectively collected data sources. We performed a comprehensive literature search to identify Rasch approved NDI within four databases including Embase, Medline, PubMed, and Google Scholar. Alternate forms and scorings were compared to each other and to the standard NDI. We graphed B&A plots and calculated the mean difference and the 95% limits of agreement (LoA; ±1.96 times the standard deviation).Results: Two Rasch approved alternative versions (8 vs 5 items) were identified from 303 screened publications. We analyzed data from 201 (43 males and 158 females) patients attending community clinics for neck pain. We found that the mean difference was approximately 10% of the total score between the 10-item and 5-item (-4.6 points), whereas the 10-item versus 8-item and 8-item versus 5-item had smaller mean differences (-2.3 points). The B&A plots displayed wider 95% LoA for the agreement between 10-item and 8-item (LoA: -12.0, 7.4) and 5-item (LoA: -14.9, 5.8) compared with the LoA for the 8-item and 5-item (LoA: -7.8, 3.3). Conclusion: Two Rasch-based NDI solutions (8 vs 5 items) which differ in number of items and conceptual construction are available to provide interval level scoring. They both provide scores that are substantially different from the ordinal NDI, which does not provide interval level scoring. Smaller differences between the two Rasch solutions exist and may relate to the items included. Due to the size and unpredictable nature of the bias between measures, they should not be used interchangeably.

PERBANDINGAN RUMUS JOHNSON DAN RUMUS RISANTO DALAM MENENTUKAN TAKSIRAN BERAT JANIN PADA IBU HAMIL DENGAN BERAT BADAN BERLEBIH

2020 ◽  
Vol 5 (2) ◽  
pp. 24-27
Author(s):  
Leo Jumadi Simanjuntak ◽  
Patrick Anando Simanjuntak
Keyword(s):  
Birth Weight ◽  
Mode Of Delivery ◽  
Mean Difference ◽  
Fetal Weight ◽  
P Value ◽  
Cross Sectional ◽  
Care Workers ◽  
The Mean ◽  
Mean Differences ◽  
Estimated Fetal Weight

Background: Estimated fetal weight (EFW) is important to determine mode of delivery. The use of estimated fetal weight based on fundal height has been widely used, but the use on overweight mothers is still limited. Objectives: This study aimed to compare the Johnson’s and Risanto’s formula in estimating fetal weight on overweight mothers. Method: The design used was cross-sectional, conducted at Mitra Sejati, Herna, and Methodist Sussana Wesley hospital on November 2019 until January 2020. Mann-Whitney test was used to compare EFW mean differences between Johnson’s and Risanto’s to actual birth weight. Paired t-test was used to compare EFW mean differences between Johnson’s and Risanto’s. Results: There were 103 overweight pregnant mothers fulfilling study criteria. The BMI mean was 31,26 ± 5l,54 kg/m2. Both Johnson’s and Risanto’s formula had no significant mean difference compare to actual birth weight, of 332,45 gram on Johnson’s (p value = 0,070) and 298,57 gram on Risanto’s (p value = 0,863). The mean difference between Risanto’s formula and actual birth weight was significantly lower than Johnson’s (mean difference = 33,88 gram, p value = 0,01). Conclusions: EFW measurement using Johnson’s and Risanto’s formula based on fundal height can be applied and used properly by health care workers. Risanto’s formula was more accurate to estimate fetal weight than Johnson’s in overweight mothers.   Latar belakang: Menentukan taksiran berat janin (TBJ) adalah penting bagi penolong persalinan untuk menentukan jenis persalinan. Pengukuran TBJ menggunakan tinggi fundus uterus merupakan metode yang banyak digunakan, namun penggunaan pada ibu hamil dengan berat badan berlebih masih terbatas. Tujuan: Penelitian ini bertujuan membandingkan rumus Johnson dan rumus Risanto dalam menentukan TBJ pada ibu hamil dengan berat badan berlebih. Metode: Desain penelitian adalah potong lintang, data diambil di RSU Mitra Sejati, RSU Herna, dan RSU Methodist Sussana Wesley pada November 2019 – Januari 2020. Dilakukan uji Mann-Whitney untuk membandingkan perbedaan rerata TBJ dengan rumus Johnson dan Risanto dengan berat badan lahir. Uji-t berpasangan digunakan untuk membandingkan perbedaan rerata TBJ dengan rumus Johnson dan Risanto. Hasil: Didapatkan 103 ibu hamil yang memenuhi kriteria penelitian dengan rerata IMT 31,26 ± 5l,54 kg/m2. Terdapat perbedaan rerata TBJ rumus Johnson dan rumus Risanto dibandingkan berat badan lahir sebesar 332,45 gram dan 298,57 gram. Tidak terdapat perbedaan rerata bermakna antara penghitungan TBJ menggunakan rumus Johnson dengan berat badan lahir (p = 0,070) dan rumus Risanto dengan berat badan lahir (p = 0,863). Perbedaan selisih TBJ Risanto dengan berat badan lahir lebih rendah dibandingkan selisih TBJ Johnson dengan berat badan lahir, yaitu sebesar 33,88 gram dan bermakna secara statistik (p = 0,01). Kesimpulan: Pengukuran TBJ menggunakan rumus Johnson dan rumus Risanto dapat diterapkan dan digunakan dengan baik oleh tenaga medis. Rumus Risanto memiliki tingkat ketepatan yang lebih baik dibandingkan rumus Johnson dalam menentukan TBJ pada ibu hamil dengan berat badan berlebih.

scholarly journals Transcutaneous Bilirubin Measurements Can Be Used to Measure Bilirubin Levels during Phototherapy

2018 ◽  
Vol 2018 ◽  
pp. 1-5 ◽  
Author(s):  
Saad Abdullah Alsaedi
Keyword(s):  
Prospective Observational Study ◽  
Serum Bilirubin ◽  
Linear Regression Analysis ◽  
Mean Difference ◽  
Total Serum ◽  
Term Infants ◽  
Transcutaneous Bilirubin ◽  
Term Newborns ◽  
The Mean ◽  
Mean Differences

Objective. To determine whether transcutaneous bilirubin measurements (TcB) before and during phototherapy taken from covered skin during phototherapy correlate with total serum bilirubin (TSB) levels.Study Design. In this prospective observational study, healthy term newborns who required TSB measurements were included. TcB measurements were taken from the forehead before starting and during phototherapy using the BiliChek device. Before starting phototherapy, part of the forehead was covered. Blood for TSB measurement was collected within 5 minutes of TcB measurements. Correlations and mean differences between TcB and TSB before and during phototherapy were calculated.Result. Paired TSB and TcB measurements before and during phototherapy in 151 newborns were performed. The mean gestational age was 38.8 weeks and birth weight was 3.1 kg; 53% were male. Before starting phototherapy, TSB and TcB were183.8±41.6and 190.5 ± 43 μmol/l, respectively. During phototherapy, TSB and TcB were191.8±39.4and187.8±45.3 μmol/l, respectively. Linear regression analysis showed a significant correlation between TcB and TSB before starting phototherapy and during phototherapy (r: 0.85;p<0.001andr: 80.0;p<0.001), respectively. Before starting phototherapy, the mean difference between TSB and TcB was6.2±23.2 μmol/l, with a 95% CI of −39.3 to 51.7 μmol. During phototherapy, the mean difference was −2.8±23.5 μmol/l, with a 95% CI of −48.9 to 43.3 μmol/l.Conclusion. TcB measurements from covered skin in jaundiced term infants during phototherapy correlate with TSB and can be used to monitor bilirubin levels during phototherapy.

scholarly journals Experimental continuously reinforced concrete pavement parameterization using nondestructive methods

2016 ◽  
Vol 9 (2) ◽  
pp. 263-274
Author(s):  
L. S. Salles ◽  
J. T. Balbo
Keyword(s):  
Reinforced Concrete ◽  
Load Transfer ◽  
Structural Condition ◽  
Concrete Pavement ◽  
Pavement Performance ◽  
Falling Weight Deflectometer ◽  
Matching Process ◽  
Load Transfer Efficiency ◽  
Falling Weight ◽  
The University

ABSTRACT Four continuously reinforced concrete pavement (CRCP) sections were built at the University of São Paulo campus in order to analyze the pavement performance in a tropical environment. The sections short length coupled with particular project aspects made the experimental CRCP cracking be different from the traditional CRCP one. After three years of construction, a series of nondestructive testing were performed - Falling Weight Deflectometer (FWD) loadings - to verify and to parameterize the pavement structural condition based on two main properties: the elasticity modulus of concrete (E) and the modulus of subgrade reaction (k). These properties estimation was obtained through the matching process between real and EverFE simulated basins with the load at the slab center, between two consecutive cracks. The backcalculation results show that the lack of anchorage at the sections end decreases the E and k values and that the longitudinal reinforcement percentage provides additional stiffness to the pavement. Additionally, FWD loadings tangential to the cracks allowed the load transfer efficiency (LTE) estimation determination across cracks. The LTE resulted in values above 90 % for all cracks.

scholarly journals Interpolation by means of Given Differences (Central-Difference Notation)

1932 ◽  
Vol 3 (1) ◽  
pp. 1-5
Author(s):  
W. F. Sheppard
Keyword(s):  
Mean Difference ◽  
Stirling Formula ◽  
Central Difference ◽  
Difference Formula ◽  
Group A ◽  
The Mean ◽  
The Difference ◽  
Mean Differences ◽  
Group B

Formulae of interpolation in terms of given central differences might be regarded as falling into two groups, A and B. In group A, the simplest cases are those in which each given difference is one of the two which in the difference table lie nearest to the preceding given difference; the differences are all natural differences (i.e., are not mean differences), and are all expressed in the centraldifference notation. Any such formula can be a central-difference formula for a certain range of the variable: but that is a matter with which we are only incidentally concerned. What I have to do is to examine the formula as determined by the series of differences given. I have then to see how the formula is affected when an ordinary difference is replaced by a mean difference. This brings us to group B, which comprises two formulae only: the Newton-Stirling formula, which expresses the required quantity in terms of a tabulated value and its central differences; and the Newton-Bessel formula, which expresses it in terms of the mean of two tabulated values and the central differences of this mean.

Assessment of Falling Weight Deflectometer Data for Stabilized Flexible Pavements

2000 ◽  
Vol 1709 (1) ◽  
pp. 19-25 ◽  
Author(s):  
Alexander K. Appea ◽  
Imad L. Al-Qadi
Keyword(s):  
Resilient Modulus ◽  
Ground Truth ◽  
Monitoring And Evaluation ◽  
Structural Condition ◽  
Base Layer ◽  
Falling Weight Deflectometer ◽  
Structural Capacity ◽  
Pavement Monitoring ◽  
Aggregate Base ◽  
Falling Weight

Backcalculation of pavement moduli through the utilization of the falling weight deflectometer (FWD) is used for pavement monitoring and evaluation. The performance and structural condition of nine flexible pavement test sections built in Bedford County, Virginia, have been monitored over the past 5 years using FWD. The nine sections include three groups with aggregate base layer thicknesses of 100, 150, and 200 mm, respectively. Sections 1, 4, and 7 are control, whereas Sections 2, 5, 8 and 3, 6, 9 are stabilized with geotextiles and geogrids, respectively. The FWD testing used five double-load drops ranging from 26.5 to 58.9 kN. The deflection basins obtained from the testing have been analyzed using the ELMOD backcalculation program to find the pavement structural capacity and to detect changes in the aggregate resilient modulus. The analysis shows a reduction in the backcalculated resilient modulus of the 100-mmthick base layer. The reduction was 33 percent over 5 years for the nonstabilized section compared with the geosynthetically stabilized section. The reduction in base layer resilient modulus may have resulted from subgrade fine migration into this layer as confirmed by excavation. The study confirms the effectiveness of using woven geotextile as a separator in a pavement system built over weak subgrade. This supports the continuous rutting measurements and ground truth excavation conducted in late 1997.

scholarly journals The efficacy of analgesics in controlling orthodontic pain: a systematic review and meta-analysis

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Caiqi Cheng ◽  
Tian Xie ◽  
Jun Wang
Keyword(s):  
Analgesic Effect ◽  
Orthodontic Treatment ◽  
Meta Analysis ◽  
Mean Difference ◽  
Controlled Trials ◽  
Cochrane Central Register ◽  
Analgesic Effects ◽  
Orthodontic Pain ◽  
The Mean ◽  
Mean Differences

Abstract Background Patients who had gone through orthodontic treatment experienced pain and discomfort which could be the highest-ranking reason for treatment disturbance or early termination. Thus, this review aimed to assess the efficacy of analgesics on the relief of pain in orthodontic treatment. Methods A computerized literature search was conducted in the databases of EMBASE (via OVID, 1974 to 2019 Week 50), MEDLINE (via OVID, 1946 to Dec 2019), the Cochrane Central Register of Controlled Trials (CENTRAL) (December 2019). The Cochrane Collaboration’s Review Manager 5.3 software was applied in the present study. And methodological quality was evaluated by the Cochrane Risk of Bias Tool. Results We identified twelve publications including 587 patients in 19 randomized controlled trials. The results showed that the mean difference of naproxen in visual analogue scale (VAS) were − 1.45 (95% CI -2.72, − 0.19; P = .02), − 2.11 (95% CI -3.96, − 0.26; P = .03) and − 1.90 (95% CI -3.33, − 0.47; P = .009) in 2 h, 6 h and 24 h respectively. As for ibuprofen, the standard mean differences were − 1.10 (95% CI -1.49, − 0.71), − 1.63(95% CI -2.32, − 0.95) and − 1.34 (95% CI -2.12, − 0.55) at 2 h, 6 h, and 24 h, with the overall P values all < 0.001. The mean difference of acetaminophen is − 0.68, − 1.34, − 1.91 at three time points and the overall P values all < 0.01. Conclusions This meta-analysis suggests that the use of analgesics is effective for patients in controlling orthodontic pain. Ibuprofen and naproxen are both of stable analgesic effects which could peak at 6 h, while the analgesic effect of acetaminophen increases steadily from 2 h through 24 h. Compared with ibuprofen and acetaminophen, naproxen shows a stronger analgesic effect either at 2 h or 6 h, and its effect lasts to 24 h.

scholarly journals Agreement between Original and Rasch-Approved Neck Disability Index

2020 ◽  
Author(s):  
ZE LU ◽  
Joy C. MacDermid ◽  
Goris Nazari
Keyword(s):  
Neck Pain ◽  
Neck Disability Index ◽  
Secondary Data ◽  
Study Data ◽  
Mean Difference ◽  
Patient Status ◽  
High Prevalence ◽  
The Mean ◽  
Mean Differences ◽  
Neck Disability

Abstract Background: Given the high prevalence of neck pain, the neck disability index (NDI) has been used widely to evaluate patient status and treatment outcomes. Modified versions have been proposed as solutions to measurement deficits in the NDI. However, the original 10-item NDI scored out of 50 is still the commonly administered. Examining the extent of agreement between traditional and Rasch-based versions using Bland-Altman (B&A) plots will inform our understanding of score differences that might rise from using different versions. Therefore, the objective of current study was to describe the extent of agreement between different versions of NDI. Methods: The current study was a secondary data analysis where the study data was compiled from two prospectively collected data source. We performed a comprehensive literature search to identify Rasch-approved NDI within four databases including Embase, Medline, PubMed, and Google Scholar. Modified version to identify Rasch analyses which provided alternative forms and scoring. We graphed B&A plots and calculated the mean difference and the 95% limits of agreement (LoA; ±1.96 times the standard deviation). Results: Two Rasch approved alternative versions (8- and 5- item) were identified from 303 screened publications. We analyzed data from 201 (43 males and 158 females) patients attending community clinics for neck pain. We found that the mean difference was approximately 10% of the total score between the 10-item and 5-item (-4.6 points), whereas the 10-item versus 8-item and 8-item versus 5-item had smaller mean differences (-2.3 points). The B&A plots displayed wider 95% LoA for the agreement between 10-item and 8-item (LoA: -12.0, 7.4) and 5-item (LoA: -14.9, 5.8) compared with the LoA for the 8-item and 5-item (LoA: -7.8, 3.3). Conclusion: Two Rasch-based NDI solutions (8 vs 5 items) that differ in number of items and conceptual construction are available to provide interval level scoring. They both scores that are substantially different from the traditional ordinal NDI, which does not provide interval level scoring. Smaller differences between the two Rasch solutions exist and may relate to the items included. Due to the size and unpredictable nature of the bias between measures, they should not be used interchangeably.

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