scholarly journals Low Cost Method Of Turbidity Estimation Using A Smartphone Application In Cirebon Waters, Indonesia

Author(s):  
Khalid Al-Ghifari ◽  
Susanna Nurdjaman ◽  
Brian Dika Praba P Cahya ◽  
Syarifudin Nur

Coastal conditions are closely related to the conditions of rivers and estuaries in the region and changes in the river condition caused by human activities will affect water turbidity. Rivers discharge which carries suspended materials and pollution to the sea have an important role in affecting Cirebon Water turbidity. The aim of this study is to estimate the turbidity using a smartphone application called HydroColor. The study data are obtained in September 2020. This study used Horiba U-10 and HydroColor as a method used to obtain the turbidity data of Cirebon Water. HydroColor is an advancement of technology that can be used to estimate water turbidity. Estimation method using HydroColor is a low-cost method because it only requires a gray card and a HydroColor that is available for iOS and Android for free. HydroColor uses a camera on a smartphone as a 3-band radiometer and produces reflectance values measured by HydroColor. Horiba U-10 data is used as in-situ data and is used to compared to HydroColor data to obtain a correlation between the two data. The results show that the correlation of HydroColor data with in-situ data is 0.91 and HydroColor tends to produce lower turbidity values than in-situ.  

Author(s):  
Juan Carlos Laso Bayas ◽  
Linda See ◽  
Hedwig Bartl ◽  
Tobias Sturn ◽  
Mathias Karner ◽  
...  

There are many new land use and land cover (LULC) products emerging yet there is still a lack of in-situ data for training, validation, and change detection purposes. The LUCAS (Land Use Cover Area frame Sample) survey is one of the few authoritative in-situ field campaigns, which takes place every three years in European Union member countries. More recently, a study has considered whether citizen science and crowdsourcing could complement LUCAS survey data, e.g., through the FotoQuest Austria mobile app and crowdsourcing campaign. Although the data obtained from the campaign were promising when compared with authoritative LUCAS survey data, there were classes that were not well classified by the citizens, and the photographs submitted through the app were not always of sufficient quality. For this reason, in the latest FotoQuest Go Europe 2018 campaign, several improvements were made to the app to facilitate interaction with the citizens contributing and to improve their accuracy in LULC identification. In addition to extending the locations from Austria to Europe, a change detection component (comparing land cover in 2018 to the 2015 LUCAS photographs) was added, as well as an improved LC decision tree and a near real-time quality assurance system to provide feedback on the distance to the target location, the LULC classes chosen and the quality of the photographs. Another modification was the implementation of a monetary incentive scheme in which users received between 1 to 3 Euros for each successfully completed quest of sufficient quality. The purpose of this paper is to present these new features and to compare the results obtained by the citizens with authoritative LUCAS data from 2018 in terms of LULC and change in LC. We also compared the results between the FotoQuest campaigns in 2015 and 2018 and found a significant improvement in 2018, i.e., a much higher match of LC between FotoQuest Go Europe and LUCAS. Finally, we present the results from a user survey to discuss challenges encountered during the campaign and what further improvements could be made in the future, including better in-app navigation and offline maps, making FotoQuest a model for enabling the collection of large amounts of land cover data at a low cost.


2021 ◽  
Vol 1 ◽  
pp. 901-910
Author(s):  
Henrikke Dybvik ◽  
Christian Kuster Erichsen ◽  
Martin Steinert

AbstractWe developed a wearable experimental sensor setup featuring multimodal EEG+fNIRS neuroimaging applicable for in situ experiments of human behavior in interaction with technology. A low-cost electroencephalography (EEG) was integrated with a wearable functional Near-Infrared Spectroscopy (fNIRS) system, which we present in two parts. Paper A provide an exhaustive description of setup infrastructure, data synchronization process, a procedure for usage, including sensor application, and ensuring high signal quality. This paper (Paper B) demonstrate the setup';s usability in three distinct use cases: a conventional human-computer interaction experiment, an in situ driving experiment where participants drive a car in the city and on the highway, and an ashtanga vinyasa yoga practice in situ. Data on cognitive load from highly ecologically valid experimental setups are presented, and we discuss lessons learned. These include acceptable and unacceptable artefacts, data quality, and constructs possible to investigate with the setup.


Author(s):  
Junehyeon Ahn ◽  
Hongkwon Kim ◽  
Kangho Byun ◽  
Youngmin Lee ◽  
Donghoon Jang ◽  
...  

For an application of fine pitch Ball Grid Array (BGA) or Land Grid Array (LGA) packages, ENEPIG is a promising surface finish technology of low cost, fine pitch and easy fabrication. In this paper, we study the drop test, one of the most important items of hand held device reliability test, of ENEPIG surface finished packages. This paper focuses on the drop test performance of a bond between the main board and three kinds of packages. Those packages are designed with a daisy chain for a detection of open/short during the drop test. The main board has a bar type outline and is suitable for an In-Situ data acquisition. Drop tester is composed of a drop test unit, a high speed resistance meter and a data acquisition system (PC). JEDEC Condition B (1,500G and 0.5milliseconds duration time and half-sine pulse) in JESD22-B111 Table 1 or in JESD22-B104-C Table 1 is applied as a test condition. After the drop test, the joint geometry and the intermetallic compound (IMC) of failure samples are analyzed through the cross section method. The result shows no breaks at the solder joint of package side. All breaks, however, are originated from the solder joints of main board side. It is a significant outcome of this work to show no performance difference between ENEPIG and Electrolytic Ni/Au.


2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Zhijun Xu ◽  
Ranran Zhang ◽  
Liang Fan ◽  
Xing Han ◽  
Fang Yuan ◽  
...  

The quality of in situ data is key to calculating resistance factor of bored piles. However, it is difficult to summarize accuracy data due to various uncertainties in engineering. This paper employs the Bayesian method and mathematical statistics theory to put forward an estimation method for updating in situ data. A testing database (33 tests in noncohesive soils and 53 tests in cohesive soils) of bored piles is summarized. The model factor of bored piles is quantified as the ratio of the measured capacity to the calculated capacity. The proposed method is used to classify summarized data into three categories, which are “good data,” “general data,” and “bad data.” The “bad data” are discarded because of bad contribution to calculation, and Bayesian theory is incorporated into updating the model factor statistics. Three methods are used to calculate the reliability index and resistance factor of bored piles, and the results show that the reliability index and resistance factor are sensitive to the quality of data. Finally, the available values of resistance factors are proposed based on resistance factor design for bridge design specification, which can offer references to revision relevant specifications. The proposed method can be used to update other geotechnical data.


2019 ◽  
Vol 19 (4A) ◽  
pp. 1-15
Author(s):  
To Duy Thai ◽  
Bui Hong Long

Hydrodynamic processes in the East Sea have been studied by many Vietnamese and foreign scientists applying the models as advanced tools with low cost and spatial and temporal synchronized dataset to serve their research. However, applying the model to study variability of small and medium structures with very high resolution (a few kilometers) is still challenge for scientists. With the advantages of high quality real-time data, open source hydrodynamic model, and the support from high performance computer (HPC) systems, we have step by step studied and developed the numerical model for study on hydrodynamic fields in the East Sea. The model was validated with high resolution satellite data as well as in-situ data from the ARGO and research vessels. Initial results of the simulation are very good for the surface seawater temperature (SST) field in the East Sea.


2020 ◽  
Author(s):  
Nengfang Chao

<p>Groundwater plays a major role in the hydrological processes driven by climate change and human activities, particularly in upper mountainous basins. The Jinsha River Basin (JRB) is the uppermost region of the Yangtze River and the largest hydropower production region in China. With the construction of artificial cascade reservoirs increasing in this region, the annual and seasonal flows are changing and affecting the water cycles. Here, we first infer the groundwater storage changes (GWSC), accounting for sediment transport in JRB, by combining the Gravity Recovery and Climate Experiment (GRACE) mission, hydrologic models and in situ data. The results indicate: (1) the average estimation of the GWSC trend, accounting for sediment transport in JRB, is 0.76±0.10 cm/year during the period 2003–2015, and the contribution of sediment transport accounts for 15%; (2) precipitation (P), evapotranspiration (ET), soil moisture change (SMC), GWSC and land water storage changes (LWSC) show clear seasonal cycles; the interannual trends of LWSC and GWSC increase, but P, runoff (R), surface water storage change (SWSC) and SMC decrease, and ET remains basically unchanged; (3) the main contributor to the increase in LWSC in JRB is GWSC, and the increased GWSC may be dominated by human activities, such as cascade damming, and climate variations (such as snow and glacier melt due to increased temperatures). This study can provide valuable information regarding JRB in China for understanding GWSC patterns and exploring their implications for regional water management.</p>


2021 ◽  
Vol 20 ◽  
pp. 160940692110296
Author(s):  
Katja Kaufmann ◽  
Corinna Peil ◽  
Tabea Bork-Hüffer

Researching people in their chaotic and complex everyday lives is challenging for researchers at any time but especially during the application of social distancing measures. In this article, we make the case for the methodical potential of mobile messengers such as WhatsApp for qualitative mobile in situ research. We exemplify the productive use of the Mobile Instant Messaging Interview (MIMI), a research method developed by Kaufmann and Peil in 2020, to study participants’ everyday life in real-time. Based on two case studies from geography and communication studies conducted during the COVID-19 pandemic, we expound our experiences in the practical application of the MIMI approach and give recommendations. We conclude that MIMIs are a low-cost, easily feasible and short-term implemented approach for research interests across disciplines and possessing great potential for exceptional circumstances like the COVID-19 pandemic. They allow direct access to the practices and experiences of people in situ and in real-time that would otherwise stay hidden and inaccessible to social sciences. The method is suitable for research projects of any size, and can be applied as part of multi- and mixed methods designs and as well for longitudinal designs. Nonetheless, the MIMIs have to be well prepared, demand smart ways of nudging participants into elaborating their responses and require careful coordination between larger teams of researchers.


Author(s):  
Jian-Shing Luo ◽  
Hsiu Ting Lee

Abstract Several methods are used to invert samples 180 deg in a dual beam focused ion beam (FIB) system for backside milling by a specific in-situ lift out system or stages. However, most of those methods occupied too much time on FIB systems or requires a specific in-situ lift out system. This paper provides a novel transmission electron microscopy (TEM) sample preparation method to eliminate the curtain effect completely by a combination of backside milling and sample dicing with low cost and less FIB time. The procedures of the TEM pre-thinned sample preparation method using a combination of sample dicing and backside milling are described step by step. From the analysis results, the method has applied successfully to eliminate the curtain effect of dual beam FIB TEM samples for both random and site specific addresses.


Author(s):  
Alexander Myasoedov ◽  
Alexander Myasoedov ◽  
Sergey Azarov ◽  
Sergey Azarov ◽  
Ekaterina Balashova ◽  
...  

Working with satellite data, has long been an issue for users which has often prevented from a wider use of these data because of Volume, Access, Format and Data Combination. The purpose of the Storm Ice Oil Wind Wave Watch System (SIOWS) developed at Satellite Oceanography Laboratory (SOLab) is to solve the main issues encountered with satellite data and to provide users with a fast and flexible tool to select and extract data within massive archives that match exactly its needs or interest improving the efficiency of the monitoring system of geophysical conditions in the Arctic. SIOWS - is a Web GIS, designed to display various satellite, model and in situ data, it uses developed at SOLab storing, processing and visualization technologies for operational and archived data. It allows synergistic analysis of both historical data and monitoring of the current state and dynamics of the "ocean-atmosphere-cryosphere" system in the Arctic region, as well as Arctic system forecasting based on thermodynamic models with satellite data assimilation.


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