Areas Of Difficult Access Research Articles

Geographic isolation and learning: Evidence from rural schools in Colombia

Rural schools are usually behind in terms of learning, and this could be partly related to geographical isolation. We explore this hypothesis, assessing the causal effect of the distance between schools, towns, and State capitals on elementary school test scores. We use granular administrative records from Colombia and estimate spatial regression discontinuity models. Results indicate that the distance to both towns and State capitals negatively affect students test scores. The differences in educational inputs, such as teachers education attainment and contract stability, partly explain these gaps. A program providing monetary incentives to teachers in difficult access areas fails to attenuate the isolation effect.

Development of a Low-Cost Automated Hydrological Information System for Remote Areas in Morelia, Mexico

Measurement of meteorological variables is essential to assess and analyze extreme events, such as droughts and floods, and even more so when the purpose is to generate early warnings of such natural phenomena. Nowadays, several mechanisms can estimate climatic variables like precipitation and temperature. However, no device measures precipitation values in real-time and at a low-cost, much less are these installed in remote areas of difficult access. Therefore, an Automated Hydrological Information System was developed based on low-cost meteorological stations with two communication protocols, Wi-Fi and GSM. The devices are equipped with a self-sustainable power supply, including a solar panel and energy storage that can last for up to three cloudy days. The precipitation, temperature, and relative humidity values are sent to a database, where they are then processed and displayed on a web page, accessible for download. Users can easily access the data from an official application that redirects them to the website without the need for a computer or a mobile browser. Warning systems are feasible due to the use of IoT services such as ThingSpeak and Ubidots. Ultimately, they allow the analysis of information and immediately send alerts if it exceeds the tolerance ranges.

Estimación de propiedades eléctricas del subsuelo usando GPR e inversión de onda completa: un caso de estudio en Colombia

A method of Full Waveform Inversion on GPR data for the estimation of subsurface electrical properties such as relative permittivity and conductivity is proposed in this paper. The GPR radar antenna used for subsurface data acquisition is a B-scan acquisition and it operates at a center frequency of 400 MHz. B-scan acquisitions are a challenge in the subsurface parameter estimation process due to lack of illumination. In addition, B-scan acquisitions are more sensitive to the starting point in estimating subsurface parameters in comparison to multiple offset acquisitions. However, despite the challenges, this type of acquisition is used because it allows portability in areas of difficult access and quick data collection, reducing processing times and costs. In this work, Full Waveform Inversion with cost function constraints was evaluated to estimate subsurface relative permittivity and conductivity using B-scan acquisitions. The proposed methods were evaluated using data collected in a study area located in Mogotes, Santander, Colombia. From the results obtained, it can be concluded that the use of regularization in the inversion process gives smoother subsurface models, also preserving discontinuities. In addition, the incoherent noise in the data is reduced by Gaussian regularization, allowing a better interpretation of the study area.

Monitoring and Modelling of Sediment Flushing : A Review

With ever decreasing potential for suitable new dam sites, sustainable use of existing water reservoirs is of paramount importance. In absence of appropriate measures, reservoir storage is continually reduced due to sedimentation. One option to remove sediment deposits is hydraulic flushing. During the flushing operation, bottom outlets are open and water and sediment released. Whether flushing successfully removes sediment depends on a number of factors, such as bottom outlets capacity, reservoir shape and water availability. Modelling is often used to assess viability of flushing for sediment management in the reservoir, as well as to design the operations and optimize their scheduling. One-dimensional numerical models are preferred for long term simulations, assessments on of a large number of scenarios, and optimization studies. Two- and three-dimensional numerical models and physical models can be used, each on their own or in combination as hybrid models, to understand local scouring near the gates and other details of operation. Monitoring of flushing operations can help improving their efficiency while at the same time limit downstream impacts. General monitoring of the reservoir and its catchment can help understanding the sedimentation problem and thus facilitate preparation of efficient sediment management strategies. Live monitoring of sediment concentrations is possible with modern equipment though not without challenges, and reservoir survey can be performed faster. Earth observation techniques are also an attractive option, allowing to monitor large areas and areas of difficult access, as well as to provide historical information going back several decades. This paper reviews monitoring and modelling approaches published in the literature, as well as presents some previously unpublished analyses.

Mapping of mudflats with UAV images in La Bocana de Iscuandé, Colombian Pacific coast

Conservation planning for marine-coastal environments requires updated and detailed maps; the aim of this work is to generate detailed maps for two mudflats in the Iscuandé River Delta (Bocana de Iscuandé) in the Colombian Pacific Coast (Department of Nariño). These are important areas for fauna, especially migratory shorebirds. To address this problem, this study investigated the use of unmanned aerial vehicles (UAVs) as an alternative for collecting detailed mapping information in areas of difficult access using photogrammetric methodsand a geographic information system (GIS). UAV images were used to generate maps with a high level of detail at a scale of 1:10,000 that include detailed information about environments such as mudflats and mangroves which had not been mapped before. UAVs are a practical tool for mapping places where weather and access conditions hinder the use of satellite images or conventional aerial photography. They are also useful for mapping areas with high temporal and spatial variability, such as mudflats, where other platforms may not reveal their short-term dynamics. Our results show that this technique has a high potential for mapping such environments, and reveal that the Iscuandé mudflats aremaintained by a relative equilibrium between the ebb and flow of waves and tides, and are also influenced by the local climate. This type of application provides critical data for conservation and management strategies of areas with great ecological importance.

Propriedades de concreto auto-adensável contendo cinzas volantes

Self-compacting concrete is a high performance concrete with excellent rheological properties that can be spread in areas of difficult access. Selfcompacting concrete requires a high consumption of cement production, which has a negative effect on the environmental aspect, since the production of cement releases significant amounts of CO2. This study aims analysis the influence of the substitution (20 and 40% by weight) of Portland cement by fly ash on the selfcompacting concrete properties in the fresh state (spreading, workability, passing ability - J-ring test, viscosity - V-funnel test) and hardened (compressive strength).The passing ability was proved more effective to the mixture with 20% of replacement. To the viscosity, control concrete had lower flow time in V-funnel. The compressive strength results at 28 days showed a reduction of 9.5% for concrete with 20% fly ash and 77.0% for concrete with 40% fly ash compared to the control concrete.

IoT-based drinking water quality measurement: systematic literature review

Sustainable development throughout the world depends on several factors such as the economy, quality education, agriculture, industry, among others, but the environment is one of the most important. Industrialization and new land use plans have caused the proliferation of pollutants in water resources, which poses a serious public challenge. As outlined in the sustainable development goals (SDGs), innovative water quality monitoring methods are needed to ensure access to water, sustainable management and sanitation. In this sense, technologies are sought that contribute to the development and implementation of groundwater and surface water quality monitoring systems in real time, so that their parameters can be evaluated through descriptive analysis, in rural populations and areas of difficult access. Nowadays, the internet of things (IoT) and the development of modern sensors are more used, so this research reviews the latest technologies to monitor and evaluate water quality using the potential and possibilities of the IoT. The main contribution of this article is to present an overview of the state of the art of IoT applications and instrumentation for water quality monitoring, focusing on the latest innovations, in order to identify interesting and challenging areas that can be explored in future research.

Global deforestation revisited: The role of weak institutions

Linking weak governance and forest degradation has received increasing attention in scientific and political spheres. Deforestation remains a global matter as a major agent of greenhouse gas (GHG) emissions, for endangering the lives of several plant and animal species, and for triggering political disputes involving land tenure and rural violence. Political factors are acknowledged to have a direct impact on forest resources management. Corruption and weak governance are able to deflect policies to private interests, and encourage illegal logging and unlawful allowances to forest degradation even in protected areas. However, the effects of corruption and weak institutions in forest management are still uncertain. This paper offers empirical-based evidence about the relationship between institutional factors and forest cover conversion. The role of weak institutions is explored by employing a logistic model of recent high-resolution global remote sensing data from the European Space Agency (ESA) Climate Change Initiative Land Cover (CCI-LC) from 1992 and 2015. We assess the cross-country associations of the Corruption Perception Index (CPI) and the World Bank Government Effectiveness (GE) index while controlling for physiographic and structural variables. Results are robust and show, as expected, that difficult access areas pose considerable barriers to forest conversion, and regions of high agricultural suitability are more likely to be converted from forests to agricultural fields. Furthermore, higher government effectiveness with stronger political enforcement, policy design, and lower corruption perception are significantly related to a lower probability of deforestation. Further elaborating governance and corruption indicators with emphasis on forest management/conservation can potentially improve the accuracy of local and cross-country quantitative land use studies. Our findings support the continuous understanding of weak institutions in deforestation debates. The paper highlights the need to fight corruption and to build strong institutions into effective policy strategies.

A survey on the process of knowledge representation of the small banana farmers (Musa spp.) in Mangaratiba, RJ

The banana, the world's most widely produced and commercialized fruit, is grown in all tropical regions of the world, being strongly present in local businesses and subsistence crops serving as an important source of nutrients for the poorest populations. In the state of Rio de Janeiro it is commonly found in hillside and difficult access areas, where most other crops would not be able to settle and, because of this, is grown with inadequate management or insufficient, resulting in low productivity in the areas of Rio de Janeiro. The objective of the present work is to carry out a survey of smallholder information from the Vale do Rio Sahy Association in Mangaratiba, RJ, to enable the representation of knowledge in this domain. From the data collected in this research, it was realized that producers have been engaged in this activity for a long time. However, it was found that the knowledge used to production is extremely tacit, without systematization. The variety of banana species (Musa spp.) grown in the production area of the association's small farmers. The knowledge transfer process knowledge to the knowledge base of an expert system is called knowledge acquisition, where it involves extract all the knowledge from the source of the specialists to systematically represent in a coded form the domain information in an appropriate medium. It was observed, even if preliminarily, that this knowledge are not represented in a database for consultation. Thus, there is a need to define human expertise or producers capable of representing in a technological way data that can be conveniently accessed for Problem solving. In view of the evidence presented in the research, the use of representation of human knowledge (small local producers) to feed and train the system according to the domain presented. Thus, enabling the prototype to help understand climate and soil variables and collaborate in decision making.

KAJIAN TINGKAT PARTISIPASI, TRANSPARANSI DAN AKUNTABILITAS PENGELOLAAN DANA OTONOMI KHUSUS PAPUA BERDASARKAN TIPOLOGI WILAYAH

Objective of the Study is to identify planning and financial management problem which are sourced from Papua's Special Autonomy Fund for education and health services in mountainous areas, difficult access areas and easy access areas. The approach used in this study is a case study which is one of the qualitative research approaches using inductive logic process. The scope of the study area is divided into three regions, namely easy access plains, coastal lowlands and difficult access, and mountains. Samples were taken according to the typology of district areas, namely: (a) the mountainous region : Jayawijaya, Tolikara, and Mountains, (b) difficult access of coastal areas: Asmat regency, Yapen Islands, Keerom, (c) easy access plains areas : District Supiori, Merauke and Jayapura. Furthermore, 1 district and 2 villages were taken from each district. The samples were taken from each district in accordance with the studies that may represent the locus of social organization, executives and legislative those are SKPD and hospitals. While for the sample of villages/urban population were taken representatively from elementary school, junior high school and Health Center. And for the study of individual locus that represent the population are teachers, doctors, health workers, traditional leaders, religious leaders, and households are all Papuans so that the sample in this study amounted to 598 people. In this case, statistical descriptive analysis tool is used. This study found that the Management which is not optimal in 3 areas are Reporting and Internal Control. Activities funded by the special autonomy fund did not inform freely to the public. During this time the local government did not involve teachers, medical personnel and Papua native communities to do the planning, implementation and monitoring of spending special autonomy funds. During these activities are carried out by SKPD which is financed by the special autonomy funds are not openly communicated to all those in need: easy access areas, difficult access areas, and mountainous areas. At the planning stage, programs and activities funded by Autonomy funds are not transparent. The only real activity that is known by society is Respek (villages’ strategic planning development). Many activities where the source of activity and funds are still unknown by teachers, medical personnel, and the public. According to the society (sample), the management of special autonomy funds is not accountable. The local government is necessary to disseminate the activities that use special autonomy funds, as well as formal and informal information to the public about the activities that used special autonomy funds. All stakeholders need to be involved to participate in the management system of special autonomy fund. Musrembang format that has been carried out needs to be done properly.Keyword : Participation, Transparency, Accountability, Special Autonomy Funds

Path Planning and Control of a UAV Fleet in Bridge Management Systems

Traditional methodologies for precise inspection of bridges (pavement, beams, column cap, column, joints and inside box girder, etc.) with By-bridge equipment, Aerial Work Platform (AWP) or via ropes have several limits that can be overcome by using Unmanned Aerial Vehicles (UAVs). The constant development in this field allows us to go beyond the manual control and the use of a single UAV. In the context of inspection rules, this research provides new inputs to the multilevel approach used today and to the methods of structural inspection with drones. Today, UAV-based inspections are limited by manual and/or semi-automatic control with many restrictions on trajectory settings, especially for areas of difficult access with Global Navigation Satellite Systems (GNSS) denied that still require the intervention of a human operator. This work proposes the use of autonomous navigation with a fleet of UAVs for infrastructural inspections. Starting from a digital twin, a solution is provided to problems such as the definition of a set of reference trajectories and the design of a position controller. A workflow to integrate a generic Bridge Management System (BMS) with this type of approach is provided.

Spectral Map-Based Tool for Backhaul Rural Network Optimization and Indirect Estimation of Demographic Behaviors

In this article, both the optimization of a backhaul network and the indirect estimation of demographic behaviors from spectral analysis are proposed. Electromagnetic spectrum in 5 GHz frequency band was scanned, and graphs generation associated with the spectral map were obtained using AirView Spectrum Analyzer software incorporated into Ubiquiti devices; these devices were installed in Ovejas and Chalán municipalities as part of a rural backhaul network located in Sucre, Colombia to bridge the digital divide in rural areas. In addition to telecommunications system working frequency optimization between Almagra and La Ceiba nodes, which was configured at 5790 MHz—spectral analysis is presented as a non-traditional information source of demographic behavior, an indirect measure of population data from rural and difficult access areas. Initially, power intensity levels measured in Almagra and La Ceiba nodes based on the spectral map are presented as a tool to continuously measure the demographic behavior relating telecommunications equipment use to population density.

Tuberculosis screening indicators in indigenous population in Colombia: a mixed methods research.

This study aims to evaluate, via a mixed methods study, the implementation of the screening process for pulmonary tuberculosis (PTB) within indigenous population of the Department of Cauca, Colombia, during the 2016-2018 period. Indicators assessing the PTB screening process were elaborated and estimated. Subsequently, an evaluation of the indicators were performed based on a sampling process from health care providers of the municipalities with the highest and lowest PTB incidence and from key agents' perspective. Screening indicators were estimated and thematic analysis was performed based on the interviews conducted with key agents. Finally, a triangulation of quantitative and qualitative findings was performed. From the total population expected to have respiratory symptomatics (n = 16,711), the health care providers were able to identify 42.3% of them. Out of the individuals identified as respiratory symptomatics (n = 7,064), they were able to examine 93.2% (n = 6,585) with at least one acid-fast bacilli smear test. The reported positivity index from acid-fast bacilli smear test was 1.87%. The explanations from key agents revolved around the possibility of an overestimated targeted amount of respiratory symptomatics; insufficient personnel for the search of symptomatic individuals; high costs for the search in areas of difficult access; the need to request permissions from indigenous authorities; culturally ingrained stigma; use of traditional medicine and self-medication; and patient's personal beliefs. This study revealed barriers in the implementation of the screening process for PTB within the indigenous population from the Department of Cauca, mainly in the identifying process of the respiratory symptomatics.

NAV2V: Navigation Assisted V2V Routing Protocol for Urban Areas

Vehicular AdHoc networks (VANETs) allow connectivity in dispersed vehicle environments and other difficult access areas, where conventional network systems are not satisfactory. One of the most significant technical challenges faced in implementing VANET is designing an efficient routing protocol that can provide a reliable path between the source and destination of the information. This paper discusses a routing scheme that incorporates the control strategy for transmitting messages and Global Navigation Satellite System (GGNS) information to optimize network routing. This scheme uses geolocation information to select the best path to forward the messages. To simulate communication in real-life scenarios, we used the Simulation of Urban MObility (SUMO) and Network Simulator-version 3 (NS-3) platform to compare our proposed algorithm to the traditional routing protocols scenarios when the number of source-destination pairs varies. Our results show that the proposed NAV2V algorithm can decrease the packet loss rate, end-to-end delay, and enhance network efficiency.

AN ADAPTED UNMANNED AERIAL VEHICLE FOR ENVIRONMENTAL WATER SAMPLING

In this work an unmanned aerial vehicle (UAV) was adapted to be used as an environmental tool to collect water samples of sea, estuary, and mangrove for further analysis by gas chromatography with a mass detector (GC-MS). The sampling automated system was based on a microcontroller, a solenoid valve, and a peristaltic mini-pump that was coupled to a quadcopter UAV. The apparatus was properly calibrated to acquire 100 mL of environmental water at 4.6 min. After, the concentration of BTEX (benzene, toluene, ethylbenzene, and o, m, p-xylenes) was analyzed in laboratory using GC-MS and the BTEX concentration ranged from 0.3 to 5.0 µg L-1 with a recovery from 83.9 to 118% with a relative standard deviation lower than 7.0%. Tests of cross-contamination were performed by simultaneous sampling and laboratory blank was carried out and no contamination was found for BTEX analysis. Based on the results, the adapted UAV presented a very useful ability to collect samples in difficult access areas such as mangroves, points between rocks, corals reefs, without health risk and without impacting the fragile ecosystem being an interesting tool for environmental purposes.

Spatial quality assessment of the pedestrian's environment using online digital tools

Tourist cities, in addition to offering places of attraction, must have quality spaces, with pedestrian-oriented infrastructure to ensure comfort, safety, accessibility, among other aspects that contribute to increasing local attractiveness. However, for this to happen, it is necessary that these cities know the reality of the pedestrian-oriented infrastructure available, through accurate surveys, which can be done on site and/or through online digital tools. In this context, this paper shows results from a study on the quality of pedestrian infrastructure on an important avenue in the tourist city of Barra Bonita, a city in the Midwest of São Paulo. The methodology incorporated the use of the spatial quality index of the pedestrian environment (IQEAP), developed by TONON (2019), and the virtual tools of Google Earth and Street View. The analysis of the results showed that the evaluated area has "Regular" IQEAP and, therefore, needs improvements in aspects involving the three pedestrian environment plans aimed at the pedestrian scale. The results also show negative aspects in relation to the virtual form of data survey (technical audit), which is not very accurate due to the dates of the images, absence of precision tools, and low image resolution. However, significant positive aspects can be highlighted, such as the reduction of survey time on site (in situ), and the use of fewer financial resources. Thus, this method can facilitate the survey of data in places of difficult geographical access, dispersed, large or distant areas, and thus become an innovative and practical option.

Digital Planning on Guided Endodontics Technology.

The aim of this review is to discuss the digital planning and the use of guided technology in Endodontics. The complexity of the root canals anatomy and the challenges in the microorganism's control represent risk factors for failure after the infected root canal's treatment. Scientific improvements associated with technological advances have enabled better predictability of therapeutic procedures results. The development of efficient and modern devices provided safer root canal treatments, with shorter clinical visits and greater patient comfort. Digital endodontics incorporated different tools and developed its own, advancing even further in resolving complex cases. The faithful copy of the internal anatomy provided by the advancement of CBCT devices and software's, associated with the digital resources of 3D planning and printing, enabled the advent of guided endodontics. This technique is used at different stages of endodontic treatment, with specific indications and greater result predictability. Therefore, this study critically reviewed the potential clinical application of this guided access technique, and the operative steps for its safe performance in managing complex endodontic cases. The main indications are accessing calcified root canals, performing endodontic surgeries in difficult access areas, removing fiberglass posts, and accessing teeth with developmental anomalies. In summary, guided endodontics has been a precise strategy, effective, safe, and clinically applicable. This procedure represents incorporating technological resources and digital planning in the Endodontist clinical practice, increasing predictability to complex cases.

Abnormal crowd density estimation in aerial images based on the deep and handcrafted features fusion

Abnormal crowd analysis has always been an interesting research area since it ensures people’s safety and prevents crowd disasters in large scale events. In particular, crowd density estimation in aerial images has the advantage of monitoring open areas by covering a very large view and reaching difficult access areas. In this context, we proposed a new method for crowd density estimation in aerial images in order to detect crowded areas showing abnormal densities. The proposed method consists of two phases: an offline phase and an inference phase. The offline phase aimed to generate a crowd model using a fusion of relevant deep and handcrafted features selected via the minimum-redundancy maximum-relevance (mRMR) technique. However, in the inference phase, we made use of the already generated model to classify the aerial images patches into four classes: None, Sparse, Medium and Dense. Our main contributions lie in the fact we relied on the fusion of semantic and low-level information to encode crowd density patches, as well as, the definition of the most salient crowd features to reduce confusion between crowd density classes. The experimental evaluation of the proposed method proves the validity of these contributions as well as the effectiveness and efficiency of our method compared to the state-of-the-art reference methods.

A TDR wireless device for volumetric water content sensing

Time Domain Reflectometry (TDR) is a widely used technique to estimate the soil volumetric water content (θ) and bulk electrical conductivity (σ). This paper presents TDR-WiFi, a wireless, portable and low cost interface to ease sensing of θ and σ by connecting TDR cable tester with a smartphone. TDR-WiFi consists of a microprocessor equipped with a WiFi microcontroller (M5Stack unit) and connected to the TDR device through an RS232-TTL adapter. The M5stack firmware is programmed in MicroPython language to act as a server between the user and the TDR device through a web page accessible from any smartphone web browser. TDR-WiFi is compatible with the Campbell TDR100 device and allows storing the TDR waveforms as well as estimating θ and σ. A complementary web page for subsequent analysis of the TDR waveforms was developed and is publicly available at http://swi.csic.es/tdrwifi/. The system was satisfactorily demonstrated in laboratory and tested in the field. The field trial allowed water content measurements in a steep road slope. TDR-WiFi demonstrated to be operative in the field and it can be satisfactorily used in difficult access areas.

Singular Spectrum Analysis for Source Separation in Drone-Based Audio Recording

The usage of drones is increasingly spreading into new fields of application, ranging from agriculture to security. One of these new applications is sound recording in areas of difficult access. The challenge that arises when using drones for this purpose is that the sound of the recorded sources must be separated from the noise produced by the drone. The intensity of the noise emitted by the drone depends on several factors such as engine power, propeller rotation speed, or propeller type. Noise reduction is thus one of the greatest challenges for the next generations of unmanned aerial vehicles (UAVs) and unmanned aerial systems (UAS). Even though some advances have been made on that matter, drones still produce a considerable noise. In this article, we approach the problem of removing drone noise from single-channel audio recordings using blind source separation (BSS) techniques, and in particular, the singular spectrum analysis algorithm (SSA). Furthermore, we propose an optimization of this algorithm with a spatial complexity of <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">O</i> (nt), which is significantly lower than the naive implementation which has a spatial complexity of O(tk <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ) (where n is the number of sounds to be recovered, t is the signal length and k is the window size). The best value for each parameter (window length and number of components used to reconstruct the source) is selected by testing a wide range of values on different noise-sound ratios. Our system can greatly reduce the noise produced by the drone on said recordings. On average, after the recording has been processed by our method, the noise is reduced by 1.41 decibels.