Livia Bandici

A Comparative Study Between the Capabilities of MySQl Vs. MongoDB as a Back-End for an Online Platform

In this article we present a comparative study between the usage capabilities of MongoDB, a non-relational database, and MySQL’s usage capabilities, a relational database, as a back-end for an online platform. We will also present the advantages of using a non-relational database, namely MongoDB, compared to a relational database, namely MySQL, integrated in an online platform, which allows users to publish different articles, books, magazines and so on, and also gives them the possibility to share online their items with other people. Nowadays, most applications have thousands of users that perform operations simultaneously thus, it takes more than one operation to be executed at a time, to really see the differences between the two databases. This paper aims to highlight the differences between MySQL and MongoDB, integrated in an online platform, when various operations were executed in parallel by many users.

An improved hebbian neural network with dynamic neuronal life and relations

In the last years, artificial intelligence has been an important field as the environments in which human-made devices have to operate become more and more complex, and designing a new algorithm for each environment can be very time and resources consuming. Neural networks have been successful in a lot of applications, since the same basic implementation can be used in a virtually unlimited number of situations, by modifying the structure of the network and the tests that are used for constructing it. In this paper we present an improved hebbian neural network that has the capability of adding new neurons to it and can connect neurons using an association rule. Since the main problem in neural network design is the actual construction of the inter-neuronal relations, we try to solve this issue at least partially by allowing the network to modify itself depending on its response to different stimuli.

Applying a pattern length constraint on the FP-Growth algorithm

With the ever-growing database sizes, we have enormous quantities of data, but unfortunately we cannot use raw data in our day-to-day reasoning/decisions. We desperately need knowledge. This knowledge is in most cases in the gathered data, but the extraction of it is a very time and resources consuming operation. In this paper we propose an improvement of the FP-Growth algorithm that focuses on applying a pattern-length constraint on the FP-Growth algorithm. This is, mining only frequent patterns with their length belonging in an interval selected by the user. The algorithm with this constraint applied can be used when only patterns with specific lengths are interesting for the user. The main advantage of running the algorithm with the length limitation instead of the classic FP-Growth algorithm is that the running time of the former is smaller, thus, the required information can be obtained in a shorter time.

The effect of pulsed electric field (PEF) treatment on the quality of wine

This paper analyses the influence of applying PEF treatment to mash obtained from red grapes (Pinot Noir and Merlot) on the content of anthocyanins and chromatic properties of wines. Different mechanical and electrical parameters (the distance between the drums, the frequency, and the voltage) have been tested in order to optimize the most effective PEF treatment so that the content of bioactive compounds such as anthocyanins be as high as possible, thus obtaining colour enhancement in the wine. In the case of the tests used, the results indicate that PEF treatment (with the characteristics: the distance between the drums of 2.5 mm, the voltage of 7 kV, the frequency of 178 Hz, and the pulse duration of 150 seconds) lead to a significant increase in the content of anthocyanins and to colour enhancement in both wines. The use of PEF in the winemaking industry is a promising technology that results in obtaining high quality wines.

The use of microwave field energy in the drying process of wooden sticks

This paper addresses the concrete mode of using the energy of the microwave field in the drying process of wooden sticks used in the food industry. For the numerical analysis of the microwave field we used the COMSOL Multiphysics numerical modelling programme. The experimental measurements were performed using a multimode applicator. The aim of this paper is to present a study on the microwave field (MW) drying of wooden sticks. This method ensures significant reduction of drying times, obtaining quality products, preserving the original geometry and structure of the sticks.

Heating of nonlinear ferromagnetic bars

The periodic electromagnetic field problem in ferromagnetic nonlinear bars is solved by using the iterative method of polarization, the Fourier series decomposition at each iteration, and the harmonics of the electromagnetic field are obtained by solving the integral equation of the eddy currents. The B-H relationship of the ferromagnetic medium and the thermal parameters depends on the temperature. The density of losses results from the solution of the electromagnetic field problem. The procedure has remarkable advantages over commercial software. The numerical results are presented.

The use of the high-frequency electromagnetic field (MW) and of the pulsed electric field (PEF) for the extraction of bioactive compounds from grapes

In recent years the uses of the high-frequency electromagnetic field (MW) and of the pulsed electric field (PEF) are studied as alternative methods in winemaking for better economic efficiency and to provide high quality products, rich in bioactive compounds. The aim of our paper was to compare the two methods, MW and PEF, in terms of their applicability for the extraction of bioactive compounds from two varieties of grapes (Pinot Noir and Merlot). We also determined the antioxidant capacity of the PEF or MW treated samples, and the results were processed using multivariate analysis. Finally, we noticed that both methods are effective for the extraction of bioactive compounds, but PEF treatments determine the highest rate of extraction of bioactive compounds.

Microwave-assisted extraction as a method of improving the quality of wines

ABSTRACT The aim of this paper is to study and compare the effect of microwave-assisted extraction (MW) on the content of bioactive compounds (total phenols, flavonoids, and monomeric anthocyanins), antioxidant capacity, chromatic parameters, and sensory properties of wines derived from three varieties of grapes (Muscat Ottonel, Pinot Noir, and Merlot). The applied MW treatment resulted in a more effective extraction of bioactive compounds from grapes that were also found in a large amount in the wine compared to the untreated (control) sample. The antioxidant capacity and colour intensity of the must and wine samples was much higher compared to the control sample. The influence of MW treatment depends on the variety of grapes treated. The results indicate that MW treatment is an appropriate method to produce white and red wine through increased extraction of bioactive compounds and implicitly colour enhancement.

The bioactive compounds, antioxidant capacity, and color intensity in must and wines derived from grapes processed by pulsed electric field

ABSTRACT The aim of this work was to study the effect of pulsed electric field (PEF) treatment on the content of bioactive compounds (total phenols, total flavonoids, monomeric anthocyanin content), antioxidant capacity, color intensity (CI), and sensory quality of wines derived from three varieties of grapes (Muscat Ottonel, Pinot Noir, and Merlot). PEF treatment resulted in an increase in all bioactive compounds, and consequently, an increase in their antioxidant capacity, which was evaluated by different methods. Applying PEF treatment to red grapes resulted in obtaining wines with higher CI compared to the control sample. For a better interpretation of the results and a proper discrimination of the samples in terms of the variety of grapes and PEF treatment, multivariate analyses, such as the principal component analysis, multivariate analysis of variance, and hierarchical cluster analysis, were applied.

A system of categorization and classification based on certain criteria

This paper proposes a new system of categorization and classification using data mining techniques based on certain criteria/topics. We describe the design and implementation of proposed system that automatically categorizes a restaurant as being good or bad, using data mining techniques, based on users reviews. For this study we took a data set consisting of approximately 9,000 reviews for 2,355 restaurants in Romania. The categorization was done on four criteria/topics: food, service, prices, atmosphere, and the results are represented as a range for each topic separately.