Benefits and Challenges of Model-based Software Engineering: Lessons Learned based on Qualitative and Quantitative Findings

Even though Model-based Software Engineering (MBSwE) techniques and Autogenerated Code (AGC) have been increasingly used to produce complex software systems, there is only anecdotal knowledge about the state-of-thepractice. Furthermore, there is a lack of empirical studies that explore the potential quality improvements due to the use of these techniques. This paper presents in-depth qualitative findings about development and Software Assurance (SWA) practices and detailed quantitative analysis of software bug reports of a NASA mission that used MBSwE and AGC. The missions flight software is a combination of handwritten code and AGC developed by two different approaches: one based on state chart models (AGC-M) and another on specification dictionaries (AGC-D). The empirical analysis of fault proneness is based on 380 closed bug reports created by software developers. Our main findings include: (1) MBSwE and AGC provide some benefits, but also impose challenges. (2) SWA done only at a model level is not sufficient. AGC code should also be tested and the models and AGC should always be kept in-sync. AGC must not be changed manually. (3) Fixes made to address an individual bug report were spread both across multiple modules and across multiple files. On average, for each bug report 1.4 modules, that is, 3.4 files were fixed. (4) Most bug reports led to changes in more than one type of file. The majority of changes to auto-generated source code files were made in conjunction to changes in either file with state chart models or XML files derived from dictionaries. (5) For newly developed files, AGC-M and handwritten code were of similar quality, while AGC-D files were the least fault prone

On Factors That Influence User Interactions with Social Media Spam: Empirical Exploration Based on a Survey and Experiment

This thesis explores various factors that influence whether or not users of social media platforms will interact with spam. The research is based on using survey and experimental approaches. The survey looked at several spam related behaviors: ability to identify spam, tendency to interact with spam, and tendency to report spam. In total 256 responses were analyzed, which were collected by an online survey system. Results of the survey show that education about spam did not correlate with changes in behavior, even when users reported that the education had an effect on them. Several other factors, commonly thought to be related to interaction with spam, such as technical background, also showed little correlation to spam related behaviors. It was also found that users tend to have similar behaviors for social media spam and email spam. The experiment involved sending mock spam messages to Facebook, LinkedIn, and Twitter users. 1,200 messages per social media platform were sent. The factors studied were: social media platform, message content, matching the message content to the sending profile, and method of selecting message content. The experimental results showed that overall the highest interaction rate was on Twitter and the lowest was on Facebook. Matching the sender\u27s profile to the content of the messages sent and matching the content of spam to recipient interests did not lead to higher interaction rates than randomly selected messages and sending profiles. Additionally, news related spam distributed on Twitter was most effective in tricking users

The Out-of-Network Benefit: Problems and Policy Solutions

Health insurance plans that include coverage for out-of-network providers are common and have the potential to reduce health care costs and even improve quality. Yet, consumers may be exposed to significant unexpected and unreasonable out-of-pocket costs due to lack of accurate information on network participation, nontransparent out-of-pocket costs, inadequate provider networks, involuntary use of out-of-network emergency care, and use of out-of-network providers at in-network hospitals. Although the Affordable Care Act and some states provide some consumer protections, these may not be adequate

Introducing Primary Care Telephone Visits: An Urban Safety-Net Community Clinic Experience

Background: Telephone consultation is widely used in primary care and can provide an effective and efficient alternative for the in-person visit. Gouverneur Health, a safety-net primary care practice in New York City serving a predominately immigrant population, evaluated the feasibility and physician and patient acceptability of a telephone visit initiative in 2015. Measures: Patient and physician surveys, and physician focus groups. Results: Though only 85 of 270 scheduled telephone visits (31%) were completed, 84% of patients reported being highly satisfied with their telephone visit. Half of physicians opted to participate in the pilot. Among participating physicians, all reported they were able to communicate adequately and safely care for patients over the telephone. Conclusions: Participating patients and physicians in a linguistically and culturally diverse urban safety-net primary care clinic were highly satisfied with the use of telephone visits, though completion of the visits was low. Lessons learned from this implementation can be used to expand access and provision of high-quality primary care to other vulnerable populations

Water activity and temperature effects on mycotoxin production by Alternaria alternata on a synthetic tomato medium

Alternaria spp. have been reported to be the most frequent fungal species invading tomatoes. Certain species, in particular the most common one, A. alternata, are capable of producing several mycotoxins in infected plants and in agricultural commodities. Alternariol (AOH), alternariol monomethyl ether (AME), and tenuazonic acid (TA) are some of the main Alternaria mycotoxins that can be found as contaminants of food. The objective of this study was to determine the effect of water activity (aw, 0.904, 0.922, 0.954, and 0.982) and temperature (6, 15, 21 and 35°C) on mycotoxin production on a synthetic tomato medium of a cocktail inoculum of five strains of A. alternata isolated from tomato fruits affected by Blackmould. The optimum AOH production occurred at 0.954 aw after 28days of incubation at 21°C. A temperature of 21°C was the most favourable for AOH synthesis at all aw levels. The maximum concentration of AME was determined at 0.954 aw and 35°C. The optimum conditions for TA accumulation were 0.982 aw and 21°C. At the 0.904 aw no growth or germination was registered at 6°C and 15°C over the whole incubation period. At 21°C and 35°C growth occurred slowly but none of the toxins were detected at this aw level. In general, high aw levels were favourable for mycotoxin production. None of the other toxins was detected at quantifiable levels at 6°C after the whole incubation period. A storage temperature of 6°C or below could be considered as safe for tomato fruits and high moisture tomato products (aw>0.95), in relation with Alternaria toxins. The results obtained here could be extrapolated to evaluate the risk of spoilage in tomato fruits and tomato products caused by this pathogen.Fil: Pose, Graciela Noemi. Universidad Nacional de Quilmes; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Patriarca, Andrea Rosana. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Orgánica; ArgentinaFil: Kyanko, V.. Universidad Nacional de Quilmes; ArgentinaFil: Pardo, Alejandro Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes; ArgentinaFil: Fernández Pinto, Virginia Elena. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Orgánica; Argentin