40 research outputs found
Törtrendű deriváltak integrálása nemlineáris rendszerek Ăşj lágy számĂtási eljárásokon alapulĂł adaptĂv szabályozásával = Integration of Fractional Order Derivatives in the Adaptive Control of Nonlinear Systems on the Basis of Novel Soft Computing Techniques
A projektben speciális, "Single Input - Single Output" rendszerekre hasonlĂł háromszögeken alapulĂł adaptĂv fixpont transzformáciĂłs szabályozĂłt dolgoztunk ki Ă©s alkalmaztunk nemlineáris paradigmákra (Ball-Beam System, polimerizáciĂłs reakciĂł, hidraulikus munkahenger). A következĹ‘ lĂ©pĂ©s e mĂłdszer robusztus változatának kidolgozása, majd "Multiple Input - Multiple Output" rendszerekre valĂł kĂ©tfĂ©le általánosĂtása volt. A frakcionális deriváltak Caputo fĂ©le alakjábĂłl numerikus közelĂtĂ©ssel bevezettĂĽk a frakcionális derivált három paramĂ©teres változatát Ă©s a "kezdeti Ă©rtĂ©k" helyett a "kezdeti törtĂ©net" fogalmát. Megmutattuk, hogy ez disszipatĂv Ă©s gerjedĹ‘ rendszerek modellezĂ©sĂ©re is alkalmas. E deriváltat felhasználtuk egĂ©sz rendű rendszerek szabályozásának javĂtására Ă©s hipotetikus frakcionális rendszerek modellezĂ©sĂ©re. Kimutattuk, hogy az általunk javasolt adaptĂv szabályozĂł e rendszerekre nehĂ©zsĂ©g nĂ©lkĂĽl alkalmazhatĂł. AdaptĂv szabályozásunkat kĂĽlönfĂ©le egĂ©sz Ă©s törtrendű rendszerek szabályozására alkalmaztuk szimuláciĂłval. SzĂ©les körű szimuláciĂłs vizsgálatokkal kimutattuk a legtipikusabb, Lyapunov fĂĽggvĂ©nyt használĂł adaptĂv mĂłdszerek hiányosságait. VĂ©gĂĽl ezek kikĂĽszöbölĂ©sĂ©re kidolgoztuk a "Model Reference Adaptive Control" szabályozĂłk Ăşj változatát, amely Lyapunov direkt mĂłdszere helyett robusztus fixpont transzformáciĂłval működik. | In the project special adaptive controllers were proposed for "Single Input - Single Output" systems. It applies similar triangles for formulating the control law. It was successfully applied for nonlinear paradigms as the Ball-Beam System, a polymerization reaction, and a hydraulic cylinder. In the next step the robust version of this method was elaborated, it was generalized for "Multiple Input - Multiple Output" systems in two different ways. Via numerically approximating Caputo's definition of fractional order (FO) systems a three parameters, finite memory generalization of the FO derivatives was proposed with the concept of the "preceding history" instaed of the "initial conditions". It was shown that it can be used for modeling stable dissipative and unstable systems, too. The new fractional derivative was utilized for improving the adaptive control elaborated for integer order systems, and for modeling the fractional order systems. It was shown that the fixed point transformations based control can easily be applied for the adaptive control of such hypothetical systems. Our method was applied for various integer and fractional order systems via simulations. The most important deficiencies of the most popular adaptive methods using Lyapunov's direct method were pointed out. To eliminate these deficiencies a novel approach was elaborated for the "Model Reference Adaptive Control" in which Lyapunov's method is replaced by robust fixed point transformation
Tumor Volume Estimation and Quasi- Continuous Administration for Most Effective Bevacizumab Therapy
Bevacizumab is an exogenous inhibitor which inhibits the biological activity of human VEGF. Several studies have investigated the effectiveness of bevacizumab therapy according to different cancer types but these days there is an intense debate on its utility. We have investigated different methods to find the best tumor volume estimation since it creates the possibility for precise and effective drug administration with a much lower dose than in the protocol.We have examined C38 mouse colon adenocarcinoma and HT-29 human colorectal adenocarcinoma. In both cases, three groups were compared in the experiments. The first group did not receive therapy, the second group received one 200 ÎĽg bevacizumab dose for a treatment period (protocol-based therapy), and the third group received 1.1 ÎĽg bevacizumab every day (quasi-continuous therapy). Tumor volume measurement was performed by digital caliper and small animal MRI. The mathematical relationship between MRI-measured tumor volume and mass was investigated to estimate accurate tumor volume using caliper-measured data. A two-dimensional mathematical model was applied for tumor volume evaluation, and tumor- and therapy-specific constants were calculated for the three different groups. The effectiveness of bevacizumab administration was examined by statistical analysis.In the case of C38 adenocarcinoma, protocol-based treatment did not result in significantly smaller tumor volume compared to the no treatment group; however, there was a significant difference between untreated mice and mice who received quasi-continuous therapy (p = 0.002). In the case of HT-29 adenocarcinoma, the daily treatment with one-twelfth total dose resulted in significantly smaller tumors than the protocol-based treatment (p = 0.038). When the tumor has a symmetrical, solid closed shape (typically without treatment), volume can be evaluated accurately from caliper-measured data with the applied two-dimensional mathematical model.Our results provide a theoretical background for a much more effective bevacizumab treatment using optimized administration
Wearable Devices in Health Monitoring from the Environmental towards Multiple Domains: A Survey
The World Health Organization (WHO) recognizes the environmental, behavioral, physiological, and psychological domains that impact adversely human health, well-being, and quality of life (QoL) in general. The environmental domain has significant interaction with the others. With respect to proactive and personalized medicine and the Internet of medical things (IoMT), wearables are most important for continuous health monitoring. In this work, we analyze wearables in healthcare from a perspective of innovation by categorizing them according to the four domains. Furthermore, we consider the mode of wearability, costs, and prolonged monitoring. We identify features and investigate the wearable devices in the terms of sampling rate, resolution, data usage (propagation), and data transmission. We also investigate applications of wearable devices. Web of Science, Scopus, PubMed, IEEE Xplore, and ACM Library delivered wearables that we require to monitor at least one environmental parameter, e.g., a pollutant. According to the number of domains, from which the wearables record data, we identify groups: G1, environmental parameters only; G2, environmental and behavioral parameters; G3, environmental, behavioral, and physiological parameters; and G4 parameters from all domains. In total, we included 53 devices of which 35, 9, 9, and 0 belong to G1, G2, G3, and G4, respectively. Furthermore, 32, 11, 7, and 5 wearables are applied in general health and well-being monitoring, specific diagnostics, disease management, and non-medical. We further propose customized and quantified output for future wearables from both, the perspectives of users, as well as physicians. Our study shows a shift of wearable devices towards disease management and particular applications. It also indicates the significant role of wearables in proactive healthcare, having capability of creating big data and linking to external healthcare systems for real-time monitoring and care delivery at the point of perception
An extended information system success model for mobile learning usage in Saudi Arabia universities
The emergence of 4G networks allows m-learning to be attractive for educational systems. Mobile devices have the potential to enhance accessibility and efficiency distribution of educational materials and information. Developing countries, especially in the Middle East, lag behind as they face difficulties in the adoption and use of m-learning. Previous researches stated that the studies in the success of m-learning are still insufficient in developing countries, particularly in Saudi Arabia where the number of students involved in m-learning also constitutes low percentages. Nine factors that influence the success of m-learning are incorporated and evaluated into a research model. A quantitative approach was used, where questionnaires were sent to three universities in KSA. The contributing factors and the relationships between them were evaluated using a Structural Equation Modelling technique. The research revealed that information quality, user satisfaction (US), trust in technology, attitude, organisation support, trust in organisation, and the net benefits of m-learning positively influence m-learning usage. In addition, the results confirmed that user satisfaction is positively affected by system quality (SEQ), service quality (SQ), and net benefits (NB) of using (U) the system. The results also showed that there is a significant relationship between NB and US for m-learning technology. This study extends the previous research by providing a conceptual model for the successful execution of m-learning services in universities. This mediating effect of US explains the impact of independent variables (IQ, SEQ, SQ) on U. It also examined the mediating effect of U in explaining the influence of US on the NB using m-learning services. The findings of this study are valuable as input for the Ministry of Higher Education and practitioners concerned with successful m-learning services. This study constructed a new model to enhance the mobile learning usage among students in universities
iABACUS: A Wi-Fi-Based Automatic Bus Passenger Counting System
Since the early stages of the Internet-of-Things (IoT), one of the application scenarios that have been affected the most by this new paradigm is mobility. Smart Cities have greatly benefited from the awareness of some people’s habits to develop efficient mobility services. In particular, knowing how people use public transportation services and move throughout urban infrastructure is crucial in several areas, among which the most prominent are tourism and transportation. Indeed, especially for Public Transportation Companies (PTCs), long- and short-term planning of the transit network requires having a thorough knowledge of the flows of passengers in and out vehicles. Thanks to the ubiquitous presence of Internet connections, this knowledge can be easily enabled by sensors deployed on board of public transport vehicles. In this paper, a Wi-Fi-based Automatic Bus pAssenger CoUnting System, named iABACUS, is presented. The objective of iABACUS is to observe and analyze urban mobility by tracking passengers throughout their journey on public transportation vehicles, without the need for them to take any action. Test results proves that iABACUS efficiently detects the number of devices with an active Wi-Fi interface, with an accuracy of 100% in the static case and almost 94% in the dynamic case. In the latter case, there is a random error that only appears when two bus stops are very close to each other
Integrating Mobile Technology Quality Service, Trust and Cultural Factors Into Technology Acceptance of Mobile Learning: A Case of the Jordan Higher Education Institution
The success of mobile learning system in higher education depends a lot on the students‟ acceptance of the technology. From an early investigation, students at Jordanian higher educational institutions however are still unwilling to use mobile learning applications and services. The students‟ acceptance should be a key concern for the management of a university in considering the implementation of mobile learning system. The objective of this study is to identify the factors that influence the acceptance of mobile learning system based on the Technology Acceptance Model (TAM). A total of 500 questionnaires were distributed to five universities in Jordan, out of which 398 question-naires were returned, representing 79% response rate. Statistical techniques including bivariate correlation analyses, multiple linear and stepwise regression analyses, T-tests, and One-Way ANOVA were used. The results showed three core determinants: Culture, Trust, and Technology Service Quality as significantly influenced Perceived Usefulness and Perceived Ease of Use. Perceived Usefulness and Perceived Ease of Use moreover have significantly determined Attitude, while Perceived Usefulness and Attitude, have significantly determined users‟ Behavioral Intention. Among the five variables of culture, the study found Power Distance to be the most contributive variable, and Trust in University as the most contributive variable under the Trust factor. Meanwhile, the most contributive variable in Technology Service Quality factor is Accessibility. For the Demographic factors, the study proved that gender, mobile learning experience, and mobile internet experience have significantly influenced students‟ acceptance. Based on the results obtained, the study proposes a model of mobile learning acceptance based on TAM. A comprehensive understanding of this model will assist decision makers to enhance the acceptance of the mobile learning system among students in Jordanian higher educational institutions in the future
3rd Workshop in Symbolic Data Analysis: book of abstracts
This workshop is the third regular meeting of researchers interested in Symbolic Data Analysis. The main aim of the
event is to favor the meeting of people and the exchange of ideas from different fields - Mathematics, Statistics, Computer Science, Engineering, Economics, among others - that contribute to Symbolic Data Analysis