scholarly journals User-Adaptive Brake Assist System for Rolling Walkers

2021 ◽  
Vol 33 (4) ◽  
pp. 911-918
Author(s):  
Tetsuya Hirotomi ◽  
Keyword(s):  
Older Adults ◽  
Young Adults ◽  
Walking Speed ◽  
Risk Of Falling ◽  
Weighting Method ◽  
Distance Weighting ◽  
Mobility Aids ◽  
Brake Assist ◽  
Inverse Distance ◽  
Improve Stability

Rolling walkers are popular mobility aids for older adults. A rolling walker usually has two swivel front wheels and two non-swivel rear wheels. It is designed to improve stability while walking and reduce the risk of falling. However, a considerable number of users have come close to or experienced falling. We developed a user-adaptive brake assist system for the walker. In the system, the usage of a walker is modeled in combination with the walking speed and the distance from the walker to the user. A brake pattern is generated based on usage data interpolated using the inverse distance weighting method. The pattern is referenced to activate brakes with the corresponding strength while walking. The applicability was confirmed by analyzing the walking data of two older adults, and the usability was positively evaluated in experiments with seven young adults wearing elderly simulation suits.

scholarly journals Spatial Distribution of Soil Nutrients in Farmland in a Hilly Region of the Pearl River Delta in China Based on Geostatistics and the Inverse Distance Weighting Method

Agriculture ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 50
Author(s):  
Rumi Wang ◽  
Runyan Zou ◽  
Jianmei Liu ◽  
Luo Liu ◽  
Yueming Hu
Keyword(s):  
Spatial Distribution ◽  
Pearl River Delta ◽  
Pearl River ◽  
Weighting Method ◽  
Farmland Protection ◽  
The Pearl River Delta ◽  
Hilly Region ◽  
Distance Weighting ◽  
The Pearl River ◽  
Inverse Distance

Soil nutrients are essential factors that reflect farmland quality. Nitrogen, phosphorus, and potassium are essential elements for plants, while silicon is considered a “quasi-essential” element. This study investigated the spatial distribution of plant nutrients in soil in a hilly region of the Pearl River Delta in China. A total of 201 soil samples were collected from farmland topsoil (0–20 cm) for the analysis of total nitrogen (TN), available phosphorus (AP), available potassium (AK), and available silicon (ASi). The coefficients of variation ranged from 47.88% to 76.91%. The NSRs of TN, AP, AK, and ASi were 0.15, 0. 07, 0.12, and 0.13, respectively. The NSRs varied from 0.02 to 0.20. All variables exhibited weak spatial dependence (R2 < 0.5), except for TN (R2 = 0.701). After comparing the prediction accuracy of the different methods, we used the inverse distance weighting method to analyze the spatial distribution of plant nutrients in soil. The uniform spatial distribution of AK, TN overall showed a trend of increasing from northeast to southwest, and the overall spatial distribution of AP and ASi showed that the northeast was higher than the southwest. This study provides support for the delimitation of basic farmland protection areas, the formulation of land use spatial planning, and the formulation of accurate farmland protection policies.

scholarly journals Evaluation of an inverse distance weighting method for patching daily and dekadal rainfall over the Free State Province, South Africa

Water SA ◽  
2016 ◽  
Vol 42 (3) ◽  
pp. 466 ◽  
Author(s):  
Mokhele Edmond Moeletsi ◽  
Zakhele Phumlani Shabalala ◽  
Gert De Nysschen ◽  
Sue Walker
Keyword(s):  
South Africa ◽  
Inverse Distance Weighting ◽  
Free State ◽  
Weighting Method ◽  
Free State Province ◽  
Distance Weighting ◽  
Inverse Distance

scholarly journals Increasing Efficiency of Field Water Re-Injection during Water-Flooding in Mature Hydrocarbon Reservoirs: A Case Study from the Sava Depression, Northern Croatia

2020 ◽  
Vol 12 (3) ◽  
pp. 786 ◽  
Author(s):  
Tomislav Malvić ◽  
Josip Ivšinović ◽  
Josipa Velić ◽  
Jasenka Sremac ◽  
Uroš Barudžija
Keyword(s):  
Water Injection ◽  
Inverse Distance Weighting ◽  
Hydrocarbon Reservoirs ◽  
Water Flooding ◽  
Injection Wells ◽  
Weighting Method ◽  
Hydrocarbon Production ◽  
Recovery Method ◽  
Distance Weighting ◽  
Inverse Distance

The authors analyse the process of water re-injection in the hydrocarbon reservoirs/fields in the Upper Miocene sandstone reservoirs, located in the western part of the Sava Depression (Croatia). Namely, this is the “A” field with “L” reservoir that currently produces hydrocarbons using a secondary recovery method, i.e., water injection (in fact, re-injection of the field waters). Three regional reservoir variables were analysed: Porosity, permeability and injected water volumes. The quantity of data was small for porosity reservoir “L” and included 25 points; for permeability and injected volumes of water, 10 points each were measured. This study defined selection of mapping algorithms among methods designed for small datasets (fewer than 20 points). Namely, those are inverse distance weighting and nearest and natural neighbourhood. Results were tested using cross-validation and isoline shape recognition, and the inverse distance weighting method is described as the most appropriate approach for mapping permeability and injected volumes in reservoir “L”. Obtained maps made possible the application of the modified geological probability calculation as a tool for prediction of success for future injection (with probability of 0.56). Consequently, it was possible to plan future injection more efficiently, with smaller injected volumes and higher hydrocarbon recovery. Prevention of useless injection, decreasing number of injection wells, saving energy and funds invested in such processes lead to lower environmental impact during the hydrocarbon production.

Changes in the Dynamic Stability of Walking in Active Healthy Older Adults Independent of Changes in Walking Speed

2008 ◽  
Author(s):  
Hyun Gu Kang ◽  
Jonathan B. Dingwell
Keyword(s):  
Older Adults ◽  
Young Adults ◽  
Dynamic Stability ◽  
Walking Speed ◽  
Age Groups ◽  
Leg Strength ◽  
Age Related ◽  
Increased Risk ◽  
Risk Of Falls ◽  
Walking Speeds

Older adults commonly walk slower, which many believe helps improve their walking stability. However, they remain at increased risk of falls. We investigated how differences in age and walking speed independently affect dynamic stability during walking, and how age-related changes in leg strength and ROM affected this relationship. Eighteen active healthy older and 17 younger adults walked on a treadmill for 5 minutes each at each of 5 speeds (80–120% of preferred). Local divergence exponents and maximum Floquet multipliers (FM) were calculated to quantify each subject’s responses to small inherent perturbations during walking. These older adults exhibited the same preferred walking speeds as the younger subjects (p = 0.860). However, these older adults still exhibited greater local divergence exponents (p&lt;0.0001) and higher maximum FM (p&lt;0.007) than young adults at all walking speeds. These older adults remained more unstable (p&lt;0.04) even after adjusting for declines in both strength and ROM. In both age groups, local divergence exponents decreased at slower speeds and increased at faster speeds (p&lt;0.0001). Maximum FM showed similar changes with speed (p&lt;0.02). The older adults in this study were healthy enough to walk at normal speeds. However, these adults were still more unstable than the young adults, independent of walking speed. This greater instability was not explained by loss of leg strength and ROM. Slower speeds led to decreased instability in both groups.

scholarly journals A POD-selective inverse distance weighting method for fast parametrized shape morphing

2018 ◽  
Vol 117 (8) ◽  
pp. 860-884 ◽  
Author(s):  
Francesco Ballarin ◽  
Alessandro D'Amario ◽  
Simona Perotto ◽  
Gianluigi Rozza
Keyword(s):  
Inverse Distance Weighting ◽  
Weighting Method ◽  
Shape Morphing ◽  
Distance Weighting ◽  
Inverse Distance

scholarly journals Stumbling Over Obstacles in Older Adults Compared to Young Adults

2005 ◽  
Vol 94 (2) ◽  
pp. 1158-1168 ◽  
Author(s):  
A. M. Schillings ◽  
Th. Mulder ◽  
J. Duysens
Keyword(s):  
Older Adults ◽  
Young Adults ◽  
Age Groups ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
Risk Of Falling ◽  
Leg Muscles ◽  
Long Latency Responses ◽  
Long Latency ◽  
Movement Strategies

Falls are a major problem in older adults. Many falls occur because of stumbling. The aim of the present study is to investigate stumbling reactions of older adults and to compare them with young adults. While subjects walked on a treadmill, a rigid obstacle unexpectedly obstructed the forward sway of the foot. In general, older adults used the same movement strategies as young adults (“elevating” and “lowering”). The electromyographic responses were categorized according to latencies: short-latency (about 45 ms, RP1), medium-latency (about 80 ms, RP2), and long-latency responses (about 110 ms, RP3; about 160 ms, RP4). Latencies of RP1 responses increased by about 6 ms and of RP2 by 10–19 ms in older adults compared with the young. Amplitudes of RP1 were similar for both age groups, whereas amplitudes of RP2–RP4 could differ. In the early-swing elevating strategy (perturbed foot directly lifted over the obstacle) older adults showed smaller responses in ipsilateral upper-leg muscles (biceps femoris and rectus femoris). This was related to shorter swing durations, more shortened step distances, and more failures in clearing the obstacle. In parallel, RP4 activity in the contralateral biceps femoris was enhanced, possibly pointing to a higher demand for trunk stabilization. In the late-swing lowering strategy (foot placed on the treadmill before clearing the obstacle) older adults showed lower RP2–RP3 responses in most muscles measured. However, kinematic responses were similar to those of the young. It is concluded that the changes in muscular responses in older adults induce a greater risk of falling after tripping, especially in early swing.

scholarly journals Development and evaluation of an extended inverse distance weighting method for streamflow estimation at an ungauged site

2015 ◽  
Vol 47 (2) ◽  
pp. 333-343 ◽  
Author(s):  
Muhammad Waseem ◽  
Muhammad Ajmal ◽  
Ungtae Kim ◽  
Tae-Woong Kim
Keyword(s):  
Weighted Average ◽  
Inverse Distance Weighting ◽  
General Idea ◽  
Coefficient Of Determination ◽  
Weighting Method ◽  
Ungauged Sites ◽  
Distance Weighting ◽  
Leave One Out ◽  
Mean Square Errors ◽  
Inverse Distance

In spatial interpolation, one of the most widely used deterministic methods is the inverse distance weighting (IDW) technique. The general idea of IDW is primarily based on the hypothesis that the attribute value of an ungauged site is the weighted average of the known attribute values within the neighborhood, and the ‘weights’ are merely associated with the horizontal distances between the gauged and ungauged sites. However, here we propose an extended version of IDW (hereafter, called the EIDW method) to provide ‘alternative weights’ based on the blended geographical and physiographical spaces for estimation of streamflow percentiles at ungauged sites. Based on the leave-one-out cross-validation procedure, the coefficient of determination had a value of 0.77 and 0.82 for the proposed EIDW models, M1 and M2, respectively, with low root mean square errors. Moreover, after investigating the relationship between the prediction efficiency and the distance decay parameter (C), the better performance of the M1 and M2 resulted at C = 2. Furthermore, the results of this study show that the EIDW could be considered as a constructive way forward to provide more accurate and consistent results in comparison to the traditional IDW or the dimension reduction technique-based IDW.

Application of Marine Geotechnical Investigation and Analysis Techniques in Salvage Project

2014 ◽  
Vol 1065-1069 ◽  
pp. 15-18
Author(s):  
Yong Ning An
Keyword(s):  
Mechanical Properties ◽  
New Technology ◽  
Physical And Mechanical Properties ◽  
Geotechnical Investigation ◽  
Standard Analysis ◽  
Weighting Method ◽  
Analysis Techniques ◽  
Distance Weighting ◽  
Curve Method ◽  
Inverse Distance

Marine geotechnical investigation techniques provide important support for maritime salvage project. when using the new technology of pile rooting to righting shipwrecks, marine geotechnical investigation can provide a detailed physical and mechanical properties with reasonable parameters, and then use of splines curves and inverse distance weighting method to apply parameters to each pile, then analysis of the vertical uplift and compressive bearing capacity based on API standard, analysis of the level of resistance and strain relations based on P-Y curve method, predict drivability of piles and so on.

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