| 1. |
- Iwaya, Leonardo H, et al.
(författare)
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Mobile health in emerging countries : a survey of research initiatives in Brazil.
- 2013
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Ingår i: International Journal of Medical Informatics. - : Elsevier BV. - 1386-5056 .- 1872-8243. ; 82:5, s. 283-298
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To conduct a comprehensive survey of mobile health (mHealth) research initiatives in Brazil, discussing current challenges, gaps, opportunities and tendencies.METHODS: Systematic review of publicly available electronic documents related to mHealth, including scientific publications, technical reports and descriptions of commercial products. Specifically, 42 projects are analyzed and classified according to their goals. This analysis considers aspects such as security features provided (if any), the health condition that are focus of attention, the main providers involved in the projects development and deployment, types of devices used, target users, where the projects are tested and/or deployed, among others.RESULTS: The study shows a large number (86%) of mHealth solutions focused on the following categories: health surveys, surveillance, patient records and monitoring. Meanwhile, treatment compliance, awareness raising and decision support systems are less explored. The main providers of solutions are the universities (56%) and health units (32%), with considerable cooperation between such entities. Most applications have physicians (55%) and Community Health Agents (CHAs) (33%) as targeted users, the latter being important elements in nation-wide governmental health programs. Projects focused on health managers, however, are a minority (5%). The majority of projects do not focus on specific diseases but rather general health (57%), although solutions for hearth conditions are reasonably numerous (21%). Finally, the lack of security mechanisms in the majority of the surveyed solutions (52%) may hinder their deployment in the field due to the lack of compliance with general regulations for medical data handling.CONCLUSION: There are currently many mHealth initiatives in Brazil, but some areas have not been much explored, such as solutions for treatment compliance and awareness raising, as well as decision support systems. Another research trend worth exploring refers to creating interoperable security mechanisms, especially for widely explored mHealth categories such as health surveys, patient records and monitoring. Challenges for the expansion of mHealth solutions, both in number and coverage, include the further involvement of health managers in the deployment of such solutions and in coordinating efforts among health and research institutions interested in the mHealth trend, possibly exploring the widespread presence of CHAs around the country as users of such technology.
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| 2. |
- Barros, B M, et al.
(författare)
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Classifying Security Threats in Cloud Networking
- 2015
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Ingår i: Proceedings of the 5th International Conference on Cloud Computing and Services Science. - : SciTePress. - 9789897581045 ; , s. 214-220
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Konferensbidrag (refereegranskat)abstract
- A central component of managing risks in cloud computing is to understand the nature of security threats. The relevance of security concerns are evidenced by the efforts from both the academic community and technological organizations such as NIST, ENISA and CSA, to investigate security threats and vulnerabilities related to cloud systems. Provisioning secure virtual networks (SVNs) in a multi-tenant environment is a fundamental aspect to ensure trust in public cloud systems and to encourage their adoption. However, comparing existing SVN-oriented solutions is a difficult task due to the lack of studies summarizing the main concerns of network virtualization and providing a comprehensive list of threats those solutions should cover. To address this issue, this paper presents a threat classification for cloud networking, describing threat categories and attack scenarios that should be taken into account when designing, comparing, or categorizing solutions. The classification is based o n the CSA threat report, building upon studies and surveys from the specialized literature to extend the CSA list of threats and to allow a more detailed analysis of cloud network virtualization issues.
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| 3. |
- Esmaeili, M., et al.
(författare)
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Optical properties of GaN/AlGaN QW nanostructures with different well and barrier widths
- 2007
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Ingår i: Journal of Physics. - : IOP Publishing. - 0953-8984 .- 1361-648X. ; 19:35
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Tidskriftsartikel (refereegranskat)abstract
- Optical properties of wurtzite AlGaN/GaN quantum well (QW) structures grown by molecular-beam epitaxy (MBE) and metal-organic chemical vapor deposition (MOCVD) on c-plane sapphire substrates have been investigated by means of photoluminescence (PL) and time-resolved photoluminescence (TRPL) at low temperature. The PL spectra exhibit a blue-shifted emission of GaN/AlGaN QW nanostructures by decreasing the barrier width, in contrast to the arsenide system (Pabla A S et al 1993 Appl. Phys. Lett. 63 752). This behavior is attributed to a redistribution across the samples of the huge built-in electric field (several hundreds of kV cm(-1)) induced by the polarization difference between wells and barriers. The trend of the barrier width dependence of the internal polarization field is reproduced by using simple electrostatic arguments. In addition, the effect of well width variation on the optical transition and decay time of GaN multiple quantum wells (MQWs) have been investigated, and it has been shown that the screening of the piezoelectric field and the electron-hole separation are strongly dependent on the well thickness and have a profound effect on the optical properties of the GaN/AlGaN MQWs. The time-resolved PL spectra of 3 nm well MQWs reveal that the spectral peak position shifts toward lower energies as the decay time increases and becomes red-shifted at longer decay times.
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| 4. |
- Simplício, M A, et al.
(författare)
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Method and Apparatus for Securing a Connection in a Communications Network
- 2015
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Patent (populärvet., debatt m.m.)abstract
- A method of securing a session between a Network Application Function, NAF, and a User Equipment, UE, connected to a network. The NAF is assigned a NAF identifier, NAF_id, using the Generic Bootstrapping Architecture, GBA, or a similar architecture and a shared secret is established between the UE and the NAF (S7.1). An application request containing a bootstrapping transaction identifier is sent to the NAF from the UE (S7.2) and an authentication request comprising the bootstrapping transaction identifier, the NAF_id, and information derived from the shared secret is sent to a Bootstrapping Server Function, BSF, from the NAF (S7.4). The BSF and the UE determine a NAF key, Ks_NAF, by using a modified parameter in place of or in addition to an original parameter in a key derivation function, the modified parameter being derived from the shared secret and the original parameter of the key derivation function (S7.5). This NAF key is transmitted from the BSF to the NAF (S7.6) and used to secure communications between the NAF and the UE (S7.7). Also provided are apparatus to act as a NAF, UE, and BSF in the method above.
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| 5. |
- Simplício, M A, Jr, et al.
(författare)
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SecourHealth : a delay-tolerant security framework for mobile health data collection.
- 2015
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Ingår i: IEEE journal of biomedical and health informatics. - 2168-2194 .- 2168-2208. ; 19:2, s. 761-772
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Tidskriftsartikel (refereegranskat)abstract
- Security is one of the most imperative requirements for the success of systems that deal with highly sensitive data, such as medical information. However, many existing mobile health solutions focused on collecting patients' data at their homes that do not include security among their main requirements. Aiming to tackle this issue, this paper presents SecourHealth, a lightweight security framework focused on highly sensitive data collection applications. SecourHealth provides many security services for both stored and in-transit data, displaying interesting features such as tolerance to lack of connectivity (a common issue when promoting health in remote locations) and the ability to protect data even if the device is lost/stolen or shared by different data collection agents. Together with the system's description and analysis, we also show how SecourHealth can be integrated into a real data collection solution currently deployed in the city of Sao Paulo, Brazil.
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| 6. |
- Esmaeili, M., et al.
(författare)
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Photoluminescence study of MOCVD-grown GaN/AlGaN MQW nanostructures : Influence of Al composition and Si doping
- 2007
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Ingår i: Nanotechnology. - : IOP Publishing. - 0957-4484 .- 1361-6528. ; 18:2
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Tidskriftsartikel (refereegranskat)abstract
- A detailed study of low-temperature photoluminescence (PL) in GaN/AlGaN multiple quantum well (MQW) nanostructures has been reported. We have investigated the effect of Si doping and Al content on PL spectra and PL decay time of these structures. The temperature dependence of radiative as well as non-radiative lifetimes have been evaluated between 2K and room temperature for different Si doping. We found that radiative recombination at higher temperatures even up to RT is stronger in the doped sample, compared to the undoped one. Hole localization in GaN/AlGaN MQWs with different compositions of Al is demonstrated via PL transient decay times and LO phonon coupling. It is found that there is an increasing of the decay time at the PL peak emission with increasing Al composition. For the undoped sample, a non-exponential PL decay behaviour at 2K is attributed to localized exciton recombination. A slight upshift in QWs PL peak with increasing Al composition is observed, which is counteracted by the expected rise of the internal QW electric field with increasing Al. The localization energies have been evaluated by studying the variation of the QW emission versus temperature and we found out that the localization energy increases with increasing Al composition. © IOP Publishing Ltd.
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| 7. |
- Kamiyama, S., et al.
(författare)
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Extremely high quantum efficiency of donor-acceptor-pair emission in N-and-B-doped 6H-SiC
- 2006
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Ingår i: Journal of Applied Physics. - : AIP Publishing. - 0021-8979 .- 1089-7550. ; 99:9
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Tidskriftsartikel (refereegranskat)abstract
- High-efficiency visible light emission in N-and-B-doped 6H-SiC epilayers was observed in photoluminescence measurements at room temperature. The orange-yellow light emission due to the recombination of donor-acceptor pairs (DAPs) has a broad spectrum with a peak wavelength of 576 nm and a full width at half maximum of 110 nm at 250 K. The high B concentration of more than 1018 cm-3 improves the emission efficiency of the DAP recombination at a high temperature. Compared with the photoluminescence spectrum of GaN at 10 K, a high quantum efficiency of 95% was estimated for the highly B-doped sample. From time-resolved photoluminescence measurements, a DAP recombination time of 5.0 ms was obtained, which is in good agreement with the calculated value by the rate equation with the assumption of a 95% internal quantum efficiency. This is quite promising as a light-emitting medium by optical pumping, as well as monolithic light sources combined with nitride-based light-emitting diodes grown on the DA-doped SiC epilayer. © 2006 American Institute of Physics.
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| 8. |
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| 9. |
- Bergman, Peder, et al.
(författare)
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Photoluminescence and electroluminescence characterization of InxGa1-x/InyGa1-yN multiple quantum well light emitting diodes
- 2002
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Ingår i: Materials Science Forum, Vols. 389-393. ; , s. 1493-1496
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Konferensbidrag (refereegranskat)abstract
- We report on a study of radiative recombination in In0.11Ga0.89N/In.0.01Ga0.99N multiple quantum wells (MQWs). The QWs were nominally undoped, while the InGaN barriers were Si doped. The MQW part is situated in the depletion field of a pn-junction structure with electrical contacts, so that both photoluminescence (PL) and electroluminescence (EL) can be studied as a function of bias. The PL and EL spectra are distinctly different, in particular at low temperatures. The spectral properties and related differences in PL decay times reflect different recombination conditions in the MQW region for the individual QWs.
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| 10. |
- Haque, Mubin U., et al.
(författare)
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Challenges in Docker Development : A Large-scale Study Using Stack Overflow
- 2020
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Ingår i: ESEM '20: Proceedings of the 14th ACM / IEEE International Symposium on Empirical Software Engineering and Measurement (ESEM). - New York, NY, USA : ACM Digital Library. - 9781450375801 ; , s. 1-11
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Konferensbidrag (refereegranskat)abstract
- Background: Docker technology has been increasingly used among software developers in a multitude of projects. This growing interest is due to the fact that Docker technology supports a convenient process for creating and building containers, promoting close cooperation between developer and operations teams, and enabling continuous software delivery. As a fast-growing technology, it is important to identify the Docker-related topics that are most popular as well as existing challenges and difficulties that developers face. Aims: This paper presents a large-scale empirical study identifying practitioners' perspectives on Docker technology by mining posts from the Stack Overflow (SoF) community. Method: A dataset of 113, 922 Docker-related posts was created based on a set of relevant tags and contents. The dataset was cleaned and prepared. Topic modelling was conducted using Latent Dirichlet Allocation (LDA), allowing the identification of dominant topics in the domain. Results: Our results show that most developers use SoF to ask about a broad spectrum of Docker topics including framework development, application deployment, continuous integration, web-server configuration and many more. We determined that 30 topics that developers discuss can be grouped into 13 main categories. Most of the posts belong to categories of application development, configuration, and networking. On the other hand, we find that the posts on monitoring status, transferring data, and authenticating users are more popular among developers compared to the other topics. Specifically, developers face challenges in web browser issues, networking error and memory management. Besides, there is a lack of experts in this domain. Conclusion: Our research findings will guide future work on the development of new tools and techniques, helping the community to focus efforts and understand existing trade-offs on Docker topics.
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