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The number and size of social networks have grown significantly as years have passed. With its 1.5 billion active users, Facebook is by far the most popular social networks on the planet. From kindergarten kids to grandparents to teenagers, Facebook attracts users of all ages, religions, personalities and social status. Facebook users are sharing their personal information, their lifestyle, their precious moments and their feelings online. In this paper, we download a set of comments from the page ‘Opposing Views’ from Facebook. These were then categorised into either a positive comment or a negative comment using the auto code feature in NVivo 11. Comments where no positive or negative sentiments are found are considered to be neutral. Out of 626 comments, 29.6% were found to contain positive sentiments while 62.0% were found to contain negative sentiments. The outcome of this work can be used by businesses to assess public reviews about their products. This will help them understand what is working and what is not. Thus, they can improve their products and respond to customer demands sufficiently quickly.

In hydrogeology, understanding the behavior of aquifers is an important issue. May it be for forecasting the availability of water on a long term or for estimating the impact of pollutants when injected at difierent regions, modeling of an aquifer is very useful for hydrogeologists. This paper gives an overlook of the difierent types of tests on a particularsite, namely the Hydrogeological Experimental Site (HES) of Poitiers (France). The aim is to show that the HES is a huge instrumented test bed allowing difierent types of experiments. Thus, system identification users can expect to gather large series of input-output datasets so as to experiment their own tools. Note that a large database exists concerning already-run tests, but what is interesting is that new experiments can be programmed so as to account for customized datasets. As a counterpart, the use of HES data should promote proper modeling of the underlying aquifer, thus contributing to the hydrological research field.

In hydrogeology, estimating aquifer permeability is an important issue. This can be useful in understanding the flow of pollutants from one area of an aquifer to another. For this aquifer analysis sake, the Hydrogeological Experimental Site of Poitiers (France) covering a limestone aquifer is an appropriate instrumented test bed enabling measurement of hydraulic responses of a series of observation wells due to a step-type pumping out excitation at a given well. Given the input-output data, black-box continous-time modeling is quite a straight forward process as shown in this paper. The aim is then to be able to use the identified parameters to classify the different wells according to how sensitive they are to the one having been excited. A correlation between black-box parameters and hydrogeological ones is then established.

This paper presents a dynamic model of a counter flow water to oil heat exchanger when all inputs (inlet temperatures of the fluids and the mass flow rates) are simultaneously varying. Although interesting results about modeling of heat exchanger by linear parameter varying (LPV) can be found in [25] , several problems remain to be solved such as the structure estimation or a proper initial MISO model for the optimization algorithms. This paper introduces a new model structure called quasi LPV model which simulates accurately the temperature and flow transients in a counter flow heat exchanger (COFHX). The quasi LPV model is compared to a realistic numerical model of a counter flow heat exchanger adjusted with the test rig heat exchanger of the University of Valenciennes in France. Comparisons indicate that the developed quasi LPV model is capable of predicting the transient performance of the heat exchangers satisfactorily.

This paper presents a vision based cart-inverted pendulum (CIP) system under a hybrid feedback configuration: the continuous cart's position measured by encoder and the delayed & sampled inverted pendulum's upper coordinates, obtained from a visual sensor. The challenge here is to stabilize the CIP from a big inclined initial angle by using a low cost CCD camera. Under this scheme, we propose a hybrid control which consists in a jumping-up (bang-bang) control and a two causal stabilization loops control: the first one (inner loop) realizes a linearization and the stabilization control of the pendulum based on an innovative piecewise continuous reduced order Luenberger observer (PCROLO) coupled with a linearization module, the second one (the outer loop) realizes a Lyapunov based control for the unstable internal system with lower dynamics than that of the pendulum. This hybrid control method is capable of balancing the CIP system within small cart's displacement. Performances issues of the proposed method are illustrated by the experimental figures and videos.

Tracheostomies are the most common procedure performed in the intensive care units for patients who need prolonged respiratory support (>21 days).

This article presents a control method to realize tracking of linear plants that deliver a delayed and sampled output. To do so, we make use of a class of piecewise functioning controller (PFC): bi-sampled controller. The use of this type of controller allows sampled tracking with a delay twice as much as that on the plant's output. Thus, we propose mathematical approach of the dynamics of our controller. We then give an adaptation of these mathematical approaches, using only the delayed and sampled output, by means of a reduced-order Luenberger observer. Computer simulation results are given so as to enhance the theoretical aspect of our method.