scholarly journals A Low-Cost Digital Colorimetry Setup to Investigate the Relationship between Water Color and Its Chemical Composition

Sensors ◽  
2021 ◽  
Vol 21 (20) ◽  
pp. 6699
Author(s):  
Ruosha Zeng ◽  
Chris M. Mannaerts ◽  
Zhehai Shang

Developments in digital image acquisition technologies and citizen science lead to more water color observations and broader public participation in environmental monitoring. However, the implications of the use of these simple water color indices for water quality assessment have not yet been fully evaluated. In this paper, we build a low-cost digital camera colorimetry setup to investigate quantitative relationships between water color indices and concentrations of optically active constituents (OACs). As proxies for colored dissolved organic matter (CDOM) and phytoplankton, humic acid and algae pigments were used to investigate the relationship between water chromaticity and concentration. We found that the concentration fits an ascending relationship with xy chromaticity values and a descending relationship with hue angle. Our investigations permitted us to increase the information content of simple water color observations, by relating them to chemical constituent concentrations in observed waters.

2019 ◽  
Author(s):  
Nikki Theofanopoulou ◽  
Katherine Isbister ◽  
Julian Edbrooke-Childs ◽  
Petr Slovák

BACKGROUND A common challenge within psychiatry and prevention science more broadly is the lack of effective, engaging, and scale-able mechanisms to deliver psycho-social interventions for children, especially beyond in-person therapeutic or school-based contexts. Although digital technology has the potential to address these issues, existing research on technology-enabled interventions for families remains limited. OBJECTIVE The aim of this pilot study was to examine the feasibility of in-situ deployments of a low-cost, bespoke prototype, which has been designed to support children’s in-the-moment emotion regulation efforts. This prototype instantiates a novel intervention model that aims to address the existing limitations by delivering the intervention through an interactive object (a ‘smart toy’) sent home with the child, without any prior training necessary for either the child or their carer. This pilot study examined (i) engagement and acceptability of the device in the homes during 1 week deployments; and (ii) qualitative indicators of emotion regulation effects, as reported by parents and children. METHODS In this qualitative study, ten families (altogether 11 children aged 6-10 years) were recruited from three under-privileged communities in the UK. The RA visited participants in their homes to give children the ‘smart toy’ and conduct a semi-structured interview with at least one parent from each family. Children were given the prototype, a discovery book, and a simple digital camera to keep at home for 7-8 days, after which we interviewed each child and their parent about their experience. Thematic analysis guided the identification and organisation of common themes and patterns across the dataset. In addition, the prototypes automatically logged every interaction with the toy throughout the week-long deployments. RESULTS Across all 10 families, parents and children reported that the ‘smart toy’ was incorporated into children’s emotion regulation practices and engaged with naturally in moments children wanted to relax or calm down. Data suggests that children interacted with the toy throughout the duration of the deployment, found the experience enjoyable, and all requested to keep the toy longer. Child emotional connection to the toy—caring for its ‘well-being’—appears to have driven this strong engagement. Parents reported satisfaction with and acceptability of the toy. CONCLUSIONS This is the first known study investigation of the use of object-enabled intervention delivery to support emotion regulation in-situ. The strong engagement and qualitative indications of effects are promising – children were able to use the prototype without any training and incorporated it into their emotion regulation practices during daily challenges. Future work is needed to extend this indicative data with efficacy studies examining the psychological efficacy of the proposed intervention. More broadly, our findings suggest the potential of a technology-enabled shift in how prevention interventions are designed and delivered: empowering children and parents through ‘child-led, situated interventions’, where participants learn through actionable support directly within family life, as opposed to didactic in-person workshops and a subsequent skills application.


Robotica ◽  
2021 ◽  
pp. 1-19
Author(s):  
Shengjie Wang ◽  
Kun Wang ◽  
Chunsong Zhang ◽  
Jian S Dai

Abstract A kinetostatic approach applied to the design of a backflip strategy for quadruped robots is proposed in this paper. Inspired by legged animals and taking the advantage of the leg workspace, this strategy provides an optimal design idea for the low-cost quadruped robots to achieve self-recovery after overturning. Through kinetostatic and energy analysis, a four-stepped backflip strategy based on the selected rotation axis with minimum energy is proposed, with a process of selection, lifting, rotating, and protection. The kinematic factors that affect the backflip are investigated, along with the relationship between the design parameters of the leg and trunk being analyzed. At the end of this paper, the strategy is validated by a simulation and experiments with a prototype called DRbot, demonstrating that the strategy endows the robot a strong self-recovery ability in various terrains.


2021 ◽  
pp. 1-15
Author(s):  
PHUC VAN PHAN

Public governance and income inequality relationship is complex and debatable. This paper examines the extent to which the quality of local governance affects inequality in Vietnam spanning the 2006–2016 period. I apply a generalized method of moments (GMM) estimators to a dynamic panel data extracted from the Vietnam’s provincial competitiveness index and the Vietnam household living standard surveys. The findings are that there is a positive inequality — corruption link but no statistically significant correlation coefficient between the overall level of governance and income disparity. The study, therefore, suggests that the Vietnamese Government at all levels should consider both more effective legal practices and economic low-cost solutions to mitigate corruption.


2019 ◽  
Vol 13 (1) ◽  
pp. 47-61
Author(s):  
Guenther Retscher ◽  
Jonathan Kleine ◽  
Lisa Whitemore

Abstract More and more sensors and receivers are found nowadays in smartphones which can enable and improve positioning for Location-based Services and other navigation applications. Apart from inertial sensors, such as accelerometers, gyroscope and magnetometer, receivers for Wireless Fidelity (Wi-Fi) and GNSS signals can be employed for positioning of a mobile user. In this study, three trilateration methods for Wi-Fi positioning are investigated whereby the influence of the derivation of the relationship between the received signal strength (RSS) and the range to an Access Points (AP) are analyzed. The first approach is a straightforward resection for point determination and the second is based on the calculation of the center of gravity in a triangle of APs while weighting the received RSS. In the third method a differential approach is employed where as in Differential GNSS (DGNSS) corrections are derived and applied to the raw RSS measurements. In this Differential Wi-Fi (DWi-Fi) method, reference stations realized by low-cost Raspberry Pi units are used to model temporal RSS variations. In the experiments in this study two different indoor environments are used, one in a laboratory and the second in the entrance of an office building. The results of the second and third approach show position deviations from the ground truth of around 2 m in dependence of the geometrical point location. Furthermore, the transition between GNSS positioning outdoors and Wi-Fi localization indoors in the entrance area of the building is studied.


Sensors ◽  
2021 ◽  
Vol 21 (21) ◽  
pp. 7410
Author(s):  
Ruey-Ching Twu ◽  
Kai-Hsuan Li ◽  
Bo-Lin Lin

A low-cost polyethylene terephthalate fluidic sensor (PET-FS) is demonstrated for the concentration variation measurement on fluidic solutions. The PET-FS consisted of a triangular fluidic container attached with a birefringent PET thin layer. The PET-FS was injected with the test liquid solution that was placed in a common path polarization interferometer by utilizing a heterodyne scheme. The measured phase variation of probe light was used to obtain the information regarding the concentration change in the fluidic liquids. The sensor was experimentally tested using different concentrations of sodium chloride solution showing a sensitivity of 3.52 ×104 deg./refractive index unit (RIU) and a detection resolution of 6.25 × 10−6 RIU. The estimated sensitivity and detection resolutions were 5.62 × 104 (deg./RIU) and 6.94 × 10−6 RIU, respectively, for the hydrochloric acid. The relationship between the measured phase and the concentration is linear with an R-squared value reaching above 0.995.


2017 ◽  
Vol 12 (7) ◽  
pp. 864-871
Author(s):  
Homero Gustavo Ferrari ◽  
Leonardo H.D. Messias ◽  
Ivan G.M. Reis ◽  
Claudio A. Gobatto ◽  
Filipe A.B. Sousa ◽  
...  

Background:Among other aspects, aerobic fitness is indispensable for performance in slalom canoe.Purpose:To propose the maximal-lactate steady-state (MLSS) and critical-force (CF) tests using a tethered canoe system as new strategies for aerobic evaluation in elite slalom kayakers. In addition, the relationship between the aerobic parameters from these tests and the kayakers’ performances was studied.Methods:Twelve male elite slalom kayakers from the Brazilian national team participated in this study. All tests were conducted using a tethered canoe system to obtain the force records. The CF test was applied on 4 d and analyzed by hyperbolic (CFhyper) and linear (CFlin) mathematical models. The MLSS intensity (MLSSint) was obtained by three 30-min continuous tests. The time of a simulated race was considered the performance index.Results:No difference (P < .05) between CFhyper (65.9 ± 1.6 N) and MLSSint (60.3 ± 2.5 N) was observed; however, CFlin (71.1 ± 1.7 N) was higher than MLSSint. An inverse and significant correlation was obtained between MLSSint and performance (r = –.67, P < .05).Conclusion:In summary, MLSS and CF tests on a tethered canoe system may be used for aerobic assessment of elite slalom kayakers. In addition, CFhyper may be used as an alternative low-cost and noninvasive method to estimate MLSSint, which is related with slalom kayakers’ performance.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Hsiu-Fen Lin

PurposeBy extending the existing service quality dimensions and reflecting the low-cost carriers (LCCs) context, the purpose ot this study aims to develop the research model to examine whether passenger satisfaction mediates the relationship between service quality and behavioral intentions of LCCs across low- and high-experience passengers.Design/methodology/approachData collected from 320 passengers (180 for low-experience passengers and 140 for high-experience passengers) to test the research model. The partial least square structural equation modeling approach was used to perform the path modeling and multi-group analysis.FindingsThe results confirm that passenger satisfaction mediates the relationship between four service quality constructs (tangible features, service reliability, quality of personnel and online ticketing service) and behavioral intentions (repurchase and recommendation intentions) for both low- and high-experience passengers. However, convenient flight schedule has a significant influence on passenger satisfaction only for low-experience passengers.Practical implicationsThe results of multi-group analysis indicated that passenger satisfaction exerts stronger effect on recommendation intentions for low-experience passengers. LCCs managers' priority should be placed on providing satisfying service experiences to less experienced passengers. Improved passenger satisfaction through superior service quality motivates low-experience passengers to recommend LCCs, thus increasing the positive word-of-mouth promotion.Originality/valueTheoretically, this study is first considering both low- and high-experience LCCs passenger perceptions to examine how passenger satisfaction mediates the relationship between service quality and post-purchase intentions. From the managerial perspective, the findings can provide useful management insights into developing multi-faceted strategies that allow LCCs firms to restore passenger confidence and retain their repurchase intentions.


1998 ◽  
Vol 14 (03) ◽  
pp. 202-213
Author(s):  
Clifford J. Mugnier

A problem in modular shipbuilding is the lack of a reliable, low-cost method of obtaining and utilizing dimensional control in 3D. Photogrammetry has been successfully used as a tool for this application, but because of the large number of systematic errors associated with film-based cameras, only very large shipyards are using it. Recently, developments in Charge Coupled Device (CCD) imaging arrays for cameras have allowed some success in applying photogrammetric techniques dimensional control Mainstream photogrammetric software and hardware configurations have been expensive and complicated. Digital camera systems and computers were purchased and programmed to tie existing inexpensive software packages with Geometric Dilution of Control (GDOP) error propagation analysis, originally designed for topographic mapping, into a tool for production shipyard fabrication dimensional control.


2012 ◽  
Vol 3 (3) ◽  
pp. 15-26
Author(s):  
Noriyasu Yamamoto ◽  
Toshihiko Wakahara

To provide a low-cost and simple user attestation method, the authors previously proposed a method with strong authentication using the digital camera of a cellular phone. This method used 2D color code, and as such, there are some process costs like create and decode 2D color code. In this paper, the authors present an improved attestation system using a cellular phone and 2D color code. They compare the performance of the encryption methods and the efficiency of the proposed attestation method, which is confirmed using an experimental prototype system.


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