Číslo 4
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Browsing Číslo 4 by Subject "C38"
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- ItemKeystroke Dynamics Authentication Using a Small Number of Samples(Technická Univerzita v Liberci, ) Čapek, Jan; Hub, Miloslav; Ekonomická fakultaThe verification of a person’s identity is very important in today’s information society, especially in e-commerce systems and directly affects user account management and administration. Although present e-commerce systems use many modern sophisticated methods of authentication, large numbers of e-commerce systems use passwords for this purpose incessantly. However, passwords are not considered be too secure because users usually do not adhere to security policies for creating and managing theirs passwords. This problem can be solved by security policies that require the user to change the password frequently, select a completely new password, and structure the password, which places additional demands on the user. The solution is a two-factor authentication where a user needs to know the right password and at the same time, he must write this password in the correct way. Indeed, many different methods for keystroke dynamics authentication exist nowadays, but unfortunately, many of them need a large number of samples to create a stable template and therefore it is impossible use them in systems whose security policy requires frequent password change. The authors suggest a completely new method for these purposes that is enough stable even with a small number of measurements to create a template. This proposed method of keystroke dynamics authentication is validated and results are compared with existing methods both over the own dataset and the existing reference datasets. The authors believe that the proposed method will simplify the management and administration of user accounts as well as their security.
- ItemTargeting of Online Advertising Using Logistic Regression(Technická Univerzita v Liberci, ) Šoltés, Erik; Táborecká-Petrovičová, Janka; Šipoldová, Romana; Ekonomická fakultaRecently, the internet became the dominant medium in marketing and comparing the development of expenditures into advertising indicates the dominance of online advertising will be inevitably stronger. Internet advertising compared to traditional media advertising has plenty of advantages hence online marketing exhibits a huge expansion in recent era. To fully utilize the potential of online marketing, it is necessary to effectively target activities of relevant internet users with the real presumption they will purchase promoted products or services. The paper is focused on demographic targeting by the mean of logistic regression models. Explanatory variables in presented application are arising from affinities of internet webpages visited by particular users and areas of their interests that are identified from their online behaviour. Our paper provides binomial logistic mode whose role is to predict the gender of internet user and multinomial logistic model constructed for the estimation of age category the user may be assigned to. The only variables exploited in the model by the mean of stepwise regression are variables with significant influence. The impact of particular factors is quantified via odds ratios that are used for the identification of areas of interests typical for women, men and for considered age categories. The paper demonstrates how it is possible to utilise estimated logistic models for the estimation of probabilities that the internet user is from a target group – in our case, women aged 25–44 years old. Prediction quality of models is assessed by the set of classification measures arising from confusion matrix that is generally acceptable in machine learning. Presented analyses are conducted in statistical software SAS Enterprise Guide on data provided from the real advertising campaign. More than 160,000 statistical units enabled the confirm results gained on training dataset of a relatively huge validation dataset.