Comparison of PI Controllers Designed for the Delay Model of TCP/AQM Networks

Cataloged from PDF version of article.One of the major problems of communication networks is congestion. In order to address this problem in TCP/IP networks, Active Queue Management (AQM) scheme is recommended. AQM aims to minimize the congestion by regulating the average queue size at the routers. To improve upon AQM, recently, several feedback control approaches were proposed. Among these approaches, PI controllers are gaining attention because of their simplicity and ease of implementation. In this paper, by utilizing the fluid-flow model of TCP networks, we study the PI controllers designed for TCP/AQM. We compare these controllers by first analyzing their robustness and fragility. Then, we implement these controllers in ns-2 platform and conduct simulation experiments to compare their performances in terms of queue length. Taken together, our results provide a guideline for choosing a PI controller for AQM given specific performance requirements. (C) 2013 Elsevier B.V. All rights reserved

Digital competences in research: creativity and entrepreneurship as essential predictors for teacher training

The first purpose of this study was to analyse the digital research competences of higher education teaching staff, depending on whether the level of creativity of the teacher to initiate new research projects and their level of entrepreneurial spirit was low/good. Following, it was analysed whether the use of different emerging technologies significantly affect the digital skills of teachers in research work; and to know in what order the use of these emerging technologies or the combination of several of them affect the digital competences of teachers. A ex post facto design was used with a sample of 1740 Higher Education teachers. Digital skills were measured using the instrument of Guillén-Gámez et al. (Educ Inf Technol 10.1007/s10639- 023-11895-2, 2023). The levels of creativity and entrepreneurship were analyzed with dichotomous variables from a 10-point Likert scale (less than 7 points-low level, greater than or equal to 7-good level). The results showed that, although teachers possessed an adequate level of digital research skills, this could vary depending on transversal skills such as creativity and entrepreneurship, with large differences when these skills were at a basic level. Furthermore, depending on whether teachers had research experience in XR technology, cryptocurrencies, facial authentication systems, wearables or robotics, amongst others, this significantly affected the level of digital competence in research. The added value of this study lies on the one hand, in the fact that there are hardly any studies that analyse this subject; and on the other hand, the implications that this could have for institutions to launch training initiatives for their teaching staff in emerging technologies, as well as in transversal competences in any disciplinary fiel

Repeat Purchase intentions: Exploring the perceived values of Locally-made Hand-Woven Bags in Lagawe, Ifugao, Philippines

Purpose: Purchase behavior is a significant consideration for consumers when choosing and evaluating various products. Perceived values influencing repurchase intention are critical since these are the major inputs used by marketing managers to estimate future extra sales and develop strategies to influence consumers' repurchasing behavior. As a result, this study studied the perceived value of locally-made hand-woven bags and the repurchase intentions of consumers in Ifugao, Philippines, which also serves as the foundation for offering interventions to raise the possibility of purchasing a local product. Design/methodology/approach: The quantitative research method's descriptive-correlational research design with the use of a validated survey instrument was utilized to gather data from 202 real buyers and users of Ifugao weave bags in the three municipalities of Ifugao, namely Kiangan, Hingyon, and Lagawe. Using SPSS, data was counted, handled, and analyzed using mean, standard deviation, and Pearson-r correlation. Findings: The findings demonstrated that local weave bags have functional, experiential, cultural, aesthetics, and social values, which all influence their repurchase intention. All of the characteristics observed had a moderate to a high relationship with repurchase intent. Practical Implications: Nonetheless, marketing methods to develop Ifugao weave bags in the Philippines that integrate these criteria may have a high likelihood of success in retaining existing customers and attracting new markets

Homomorphic encryption and some black box attacks

This paper is a compressed summary of some principal definitions and concepts in the approach to the black box algebra being developed by the authors. We suggest that black box algebra could be useful in cryptanalysis of homomorphic encryption schemes, and that homomorphic encryption is an area of research where cryptography and black box algebra may benefit from exchange of ideas

Following the lead of Barack Obama, CNN, and Ashton Kutcher: Police departments’ use of Twitter

An increasing number of police departments are using Twitter to communicate with the public. As with any emerging communications technology, there is considerable variation in the usage of this medium. This study reports the results of a content analysis designed to determine how police departments are using Twitter

Growth and Immune Response of Pond-Reared Giant Freshwater Prawn Macrobrachium osenbergii Post Larvae Fed Diets Containing Chlorella vulgaris

A 70-day feeding trial was conducted to evaluate the efficacy of Chlorella vulgaris supplementation in diets of giant freshwater prawn (Macrobrachium rosenbergii) post larvae. Resistance of the prawns against Aeromonas hydrophila and several immune parameters (total hemocyte count and prophenoloxidase activity) were also assessed in the study. Iso-nitrogenous, iso-lipidic, and iso-caloric prawn feeds were prepared utilizing a fishmeal based positive control diet (F0) and four dietary treatments with C. vulgaris inclusion levels of 2 (F2), 4 (F4), 6 (F6), and 8 (F8) %. Post larvae of M. rosenbergii were stocked randomly (mean initial body weight of 0.39 ± 0.38 g) in fifteen net cages (8.1 m × 8.9 m with an average depth of 1 m) in an earthen pond for the assessment of growth parameters. Overall growth indices for prawn fed Chlorella containing diets were enhanced in comparison to the control treatment. Prawn fed diets with Chlorella showed significantly higher (P \u3c 0.05) prophenol oxidase activity, total hemocyte counts, and survival rates post bacterial infection. These findings demonstrated that inclusion of 4%, 6%, and 8% C. vulgaris in prawn diets provided optimal growth rates and improved immunity of the post larvae

La concesión de honores públicos a magistrados y decuriones en las ciudades de la Bética

In this work, we study the concession of public honours to magistrales and decurions in the Betica. We analyse the origin of this practice in Hispania, its function, the different types ofhonours actually conceded, the motivations for honorific distinctions, and the social groups participating in homage events. Finally, we try to place the honoured in their social, familiar, politic and economic context and, thus, elucidate the reasons for their citizen public homage.En este trabajo estudiamos la concesión de honores públicos a magistrados y decuriones de la Bética. Analizamos el origen de esta práctica en Hispania, su función, los diferentes tipos de honores concedidos, las motivaciones que dieron lugar a distinciones honorfficas y los grupos sociales participantes en los homenajes. Finalmente, intentamos insertar a los honrados en su contexto social, familiar, polftico y económico, lo que nos ayuda a comprender los motivos por los que éstos recibieron homenajes públicos ciudadanos

Highway to heaven: mammary gland development and differentiation

In recent years, the mammary gland epithelium has been shown to be a mixture of differentiated cell populations in a hierarchical relationship with their stem and progenitor cells. However, the mechanisms that regulate their cellular differentiation processes are still unclear. The identification of genes that govern stem and progenitor cell expansion, or that determine daughter cell fate, will be of crucial interest for understanding breast cancer diversity and, ultimately, improving treatment. Two recent analyses have identified some of the key genes that regulate these processes, lighting up the highway to normal mammary gland development

AM3 (Inmunoferón®) as an adjuvant to hepatitis B vaccination in hemodialysis patients

AM3 (Inmunoferón®) as an adjuvant to hepatitis B vaccination in hemodialysis patients.BackgroundPatients with end-stage renal disease (ESRD) undergoing hemodialysis have severe alterations in cell-mediated immunity (CMI) that increases their risk of contracting chronic hepatitis B virus (HBV) infection and decreases their protective responses to HBV vaccine. In an effort to improve the humoral response to an accelerated HBV vaccine protocol in these patients, the ability of an immunomodulator, AM3, to improve seroconversion was investigated.MethodsA total of 269 patients were enrolled in a multicenter trial. All patients received a DNA recombinant vaccine (40 μg HBsAg/dose/day) on days 0, 10, 21, and 90. AM3 or placebo (3 g/day) was given orally for 30 consecutive days beginning 15 days prior to the first vaccine dose. Anti-HBsAg titers were measured on days 120 and 270 after the beginning of the trial.ResultsAfter one month, 207 patients could be evaluated and 132 patients after six months. The placebo and AM3-treated groups had comparable seroconversion and protective response rates one month after the final vaccine dose. The AM3 treatment group, but not the placebo group, maintained these protective titers up to six months after the final vaccine dose. At this time, the percentage of high responders (anti-HBsAg>100 IU/L) and mean anti-HBsAg titers in the AM3 group was significantly higher than in the placebo group.ConclusionsAM3 is a safe and easily tolerated oral agent that potentiates long-term serological immunity to hepatitis B in hemodialysis patients after vaccination

Design and integration of WAAM technology and in situ monitoring system in a gantry machine

Wire arc additive manufacturing, WAAM, is a popular wire-feed additive manufacturing technology that creates components through the deposition of material layer-by-layer. WAAM has become a promising alternative to conventional machining due to its high deposition rate, environmental friendliness and cost-competitiveness. In this research work, an adaptation of a gantry machine with in-situ monitoring and a control system has been carried out, in order to expose the ability of the WAAM technology to fabricate complex-shaped parts. The retrofitting of the machine has been done in several layers called respectively hardware, control and software layers. For the validation of the implemented system, a stainless steel 316L demonstrator has been manufactured, and the required stages have been employed, including part design (CAD), process parameters selection, tool-path definition (CAM) and part manufacturing. This study has shown the feasibility of the adapted machine for additive manufacturing as a controlled process.The authors acknowledge the European Commission for support from project AMAZE (FP7-2012-NMP-ICT-FoF, project 313781) and the Basque Government for support from project EUSK-ADDI (Etorgai 2014)