scholarly journals Red de sensores de humedad y temperatura de bajo costo

Author(s):  
Luis Manuel Mendoza-Pinto ◽  
María Jesús Espinosa-Trujillo ◽  
Jesús Humberto Peet-Manzón

This article presents the development of a low cost network of wireless sensors that use an open source hardware platform, consisting of an ESP8266 and a digital temperature-humidity sensor to measure the parameters in an area determined by the range of the sensor. The general development of the system includes the use of open source software to receive information through the network. Tests of sensor effectiveness were performed at three different points in an air-conditioned area. The first sensor was placed outside the area, the second in the middle and the last one at the exit of the air conditioning. The results obtained allowed to know the behavior of temperature and humidity in the area and the effectiveness of the sensor network to measure the variables, the results of the measurements are presented in detail. Because the system is highly scalable, inexpensive and easy to build compared to other systems, it is a good choice for a wide variety of applications.

2016 ◽  
Vol 12 (04) ◽  
pp. 27 ◽  
Author(s):  
Caroline Porto Antonio ◽  
João Paulo Lima ◽  
João Bosco Alves ◽  
Juarez Bento Silva ◽  
José Pedro Simão

This paper presents an educational tool based on open source software and low cost hardware to supplement science teaching, merging concepts of remote experiment, virtual worlds and virtual learning environment. Using an avatar, students can move around in an enriched environment and access a remote microscope that enables visualization of plant parts and interaction with the available samples.


2021 ◽  
Author(s):  
Fabio Calefato ◽  
Marco Aurelio Gerosa ◽  
Giuseppe Iaffaldano ◽  
Filippo Lanubile ◽  
Igor Fabio Steinmacher

Abstract Several Open-Source Software (OSS) projects depend on the continuity of their development communities to remain sustainable. Understanding how developers become inactive or why they take breaks can help communities prevent abandonment and incentivize developers to come back. In this paper, we propose a novel method to identify developers’ inactive periods by analyzing the individual rhythm of contributions to the projects. Using this method, we quantitatively analyze the inactivity of core developers in 18 OSS organizations hosted on GitHub. We also survey core developers to receive their feedback about the identified breaks and transitions. Our results show that our method was effective for identifying developers’ breaks. About 94% of the surveyed core developers agreed with our state model of inactivity; 71% and 79% of them acknowledged their breaks and state transition, respectively. We also show that all core developers take breaks (at least once) and about a half of them (~ 45%) have completely disengaged from a project for at least one year. We also analyzed the probability of transitions to/from inactivity and found that developers who pause their activity have a ~ 35 to ~ 55% chance to return to an active state; yet, if the break lasts for a year or longer, then the probability of resuming activities drops to ~ 21–26%, with a ~ 54% chance of complete disengagement. These results may support the creation of policies and mechanisms to make OSS community managers aware of breaks and potential project abandonment.


2021 ◽  
Vol 64 (10) ◽  
pp. 85-93
Author(s):  
Jihoon Lee ◽  
Gyuhong Lee ◽  
Jinsung Lee ◽  
Youngbin Im ◽  
Max Hollingsworth ◽  
...  

Modern cell phones are required to receive and display alerts via the Wireless Emergency Alert (WEA) program, under the mandate of the Warning, Alert, and Response Act of 2006. These alerts include AMBER alerts, severe weather alerts, and (unblockable) Presidential Alerts, intended to inform the public of imminent threats. Recently, a test Presidential Alert was sent to all capable phones in the U.S., prompting concerns about how the underlying WEA protocol could be misused or attacked. In this paper, we investigate the details of this system and develop and demonstrate the first practical spoofing attack on Presidential Alerts, using commercially available hardware and modified open source software. Our attack can be performed using a commercially available software-defined radio, and our modifications to the open source software libraries. We find that with only four malicious portable base stations of a single Watt of transmit power each, almost all of a 50,000-seat stadium can be attacked with a 90% success rate. The real impact of such an attack would, of course, depend on the density of cellphones in range; fake alerts in crowded cities or stadiums could potentially result in cascades of panic. Fixing this problem will require a large collaborative effort between carriers, government stakeholders, and cellphone manufacturers. To seed this effort, we also propose three mitigation solutions to address this threat.


Author(s):  
Antor Mahamudul Hashan ◽  
Abdullah Haidari ◽  
Srishti Saha ◽  
Titas Paul

Due to the rapid development of technology, the use of numerically controlled machines in the industry is increasing. The main idea behind this paper is computer-aided design (CAD) based low-cost computer numerical control 2D drawing robot that can accurately draw complex circuits, diagrams, logos, etc. The system is created using open-source hardware and software, which makes it available at a low cost. The open-source LibreCAD application has been used for computer-aided design. Geometric data of a CAD model is converted to coordinate points using the python-based F-Engrave application. This system uses the Arduino UNO board as a signal generator of the universal g-code sender without compromising the performance. The proposed drawing robot is designed as a low-cost robot for educational purposes and aims to increase the student's interest in robotics and computer-aided design (CAD) skills to the next level. The drawing robot structure has been developed, and it meets the requirements of low cost with satisfactory experimental results.


2012 ◽  
pp. 26-40
Author(s):  
Bhasker Mukerji ◽  
Ramaraj Palanisamy

The popularity of Open Source Software (OSS) in developing countries is quiet evident from its widespread adoption across government departments and public sector organizations. The use of OSS saves economic resources of cash starved countries, provides an opportunity to promote e-government, and to utilize their resources in other sectors. Many developing countries have a large pool of skilled developers who can modify the source code of the OSS at a very low cost. Many governments in developing and developed countries have switched to OSS which probably encourages others to follow the trend. It was not possible to follow the adoption trend in all the developing countries but the usage of OSS in countries like India, Brazil, and Venezuela provides us an insight. The successful adoption of OSS requires thorough analysis of its advantages as well as the issues associated with it. This chapter will provide an overview of OSS, characteristics of OSS developers, and their motivation to volunteer by contributing in OSS projects, followed by the advantages and issues associated with OSS.


2019 ◽  
Vol 5 (12) ◽  
pp. 88
Author(s):  
Kazuo Katoh

As conventional fluorescence microscopy and confocal laser scanning microscopy generally produce images with blurring at the upper and lower planes along the z-axis due to non-focal plane image information, the observation of biological images requires “deconvolution.” Therefore, a microscope system’s individual blur function (point spread function) is determined theoretically or by actual measurement of microbeads and processed mathematically to reduce noise and eliminate blurring as much as possible. Here the author describes the use of open-source software and open hardware design to build a deconvolution microscope at low cost, using readily available software and hardware. The advantage of this method is its cost-effectiveness and ability to construct a microscope system using commercially available optical components and open-source software. Although this system does not utilize expensive equipment, such as confocal and total internal reflection fluorescence microscopes, decent images can be obtained even without previous experience in electronics and optics.


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