Thesis (M.S.) -- Worcester Polytechnic Institute. / Keywords: TDOA; indoor geolocation; TOA. Includes bibliographical references (p.55).

Dissertation (Ph.D.) -- Worcester Polytechnic Institute. / Keywords: OFDM; signal structure; CDMA; FDMA; indoor geolocation. Includes bibliographical references (p 390-408).

Dissertation (Ph.D.) -- Worcester Polytechnic Institute. / Keywords: localization; indoor geolocation; indoor radio channel. Includes bibliographical references (p. 120-125).

Η κινητή τηλεφωνία και το διαδίκτυο έχουν φέρει επανάσταση στην επικοινωνία και τον τρόπο ζωής των ανθρώπων. Ένας ολοένα αυξανόμενος αριθμός κινητών τηλεφώνων και άλλων κινητών συσκευών επιτρέπουν στους ανθρώπους να έχουν πρόσβαση στο διαδίκτυο οπουδήποτε βρίσκονται και όποτε θέλουν. Οι υπηρεσίες αυτές εστιάζουν στην αξιοποίηση της γεωγραφικής θέσης που παρέχει το σύστημα GPS παρέχοντας επιπλέον στον χρήστη πληροφορίες για τις υπηρεσίες που αφορούν την γεωγραφική θέση του και την περιοχή γύρω του. Στην εργασία αυτή οι βασισμένες στη θέση υπηρεσίες συνδυάζονται με τεχνικές παροχής συστάσεων και υλοποιείται μια πρότυπη εφαρμογή παροχής συστάσεων για χρήστες κινητών τηλεφώνων σχετικά με φωτογραφίες περιοχών του ενδιαφέροντος τους. Ο χρήστης θεωρείται μέλος ενός κοινωνικού δικτύου και οι συστάσεις που του παρέχονται βασίζονται στην ομοιότητα του χρήστη με τα μέλη του δικτύου του. Οι συστάσεις προκύπτουν από τον υπολογισμό της ομοιότητας του χρήστη με κάθε φίλο του, βάσει ενός συνόλου φωτογραφιών που έχουν βαθμολογήσει και οι δύο. Ο βαθμός ομοιότητας του χρήστη υπολογίζεται με το συντελεστή συσχέτισης του Pearson. Τα άτομα που ικανοποιούν μια καθορισμένη τιμή ομοιότητας αποτελούν τους συμβούλους του χρήστη. Οι φωτογραφίες που παρουσιάζει η εφαρμογή στους χρήστες καθορίζονται από τις βαθμολογίες των συμβούλων για τις φωτογραφίες που δεν έχει βαθμολογήσει ο χρήστης. Στο πλαίσιο της εργασίας περιγράφεται η αρχιτεκτονική που εξυπηρετεί εφαρμογές αυτού του είδους. Επίσης υλοποιείται μια πρότυπη εφαρμογή με την οποία συστήνονται στο χρήστη φωτογραφίες που έχουν βαθμολογήσει οι φίλοι του. / Telecommunications and network technologies have made a revolution in communication and the way people live. The growing number of mobile phones and other mobile devices allows people have access to internet whenever and wherever they are. These services are concentrated in the utilization of geographic position provided by GPS system giving also information about services related with user’s position and the area around him. In this work location based services are combined with recommendation techniques to implement a standard application which provides recommendations to mobile devices users related to photographs from areas which may users are interested in. User is considered as a member of a social network and recommendations provided to him are based on the similarity the user has with other members of his network. Recommendations derive from user to user similarity calculation, on basis of photographs that both users have rate. User’s degree of similarity is calculated with Pearson’s correlation coefficient. Users that satisfy a certain value of similarity constitute the consultants of a user. The photographs presented to users by the application are specified by consultants’ ratings for the photographs that user has not rated. In the context of this work the architecture that serves such applications is described. It is also implemented a standard application which recommends users with photographs that his fellows have rated.

The thesis deals with possibilities for more precise determination of geographical position of given IP address by combination of estimates of data obtained from geolocation databases. The first part introduces the issue on theoretical level. Possibilities of network device identification, its geographical location and principles of geolocation databases are described here. After analyzing the theoretical part of this issue, the current state of application for geolocation databases is described. The next section introduces a new application which uses original software ip2geotools as a library. Using the three implemented methods for combining results (based on average, median, and cluster analysis by K-Means algorithm), the new program allows to estimate the physical location of IP address. The app is complemented with console interface and geographic data visualization on the map. In the last part, the accuracy of computational methods is validated and a detailed statistical analysis of data obtained by performing a calculation over a set of IP addresses with known geographical location of the RIPE Atlas service is performed.

This master thesis deals with methods of stations’ geolocation on the Internet, it means the estimation geographic location of unknown station, which is conected to this network. The introductory part describes the methods for determining position, which don‘t need any measeruments of the network. The next section is devoted to points, where delay is invoked, to the causes of latency in the Internet, to their types and some usual values. The following part features ways to measure delays and route, including several tools for this purpose. The penulminate section describes some chosen geolocation techniques based on RTT measurement. The final chapter is devoted to practical demonstration geolocation using the CBG method, when the delay measurement was carried out in an experimental PlanetLab network.

This thesis deals with the evaluation of the geographical location of the Internet using delay and implementating method Octant. The first part is devoted to familiarization with the principles of evaluation of the physical position of the stations on the Internet, with a focus on active methods for IP Geolocation. Here it is more space devoted to geolocation Octant algorithm and a more detailed explanation of its principles. At the end of the first part is also familiar with the experimental network PlanetLab. The second part describes the design and implementation of the program in programming language C#, which locates the searched local station with mentioned localization algorithm Octant. Description realization is accompanied by explained examples of the classes with a detailed explanation. Here are also the results of the methods on selected IP addresses of stations with known locations to detect errors or deviations of method from the actual position of searched station. At the end of this section is a comparison with other active as well as passive geolocation methods.

This master's thesis is focused on geolocation and visualization of IPv6 addresses. Several current approaches to geolocation have been discussed. Its main goal is to design geolocation database with regular updates with ability to visualize geographic location of the IPv6 address on the world map. Implemented system is gathering data about IPv6 prefixes from public Whois database. Gathered geographical addresses are mapped into coordinates by Google Maps Geocoding API. All gathered data are being saved into database together. Locations of IPv6 addresses are visualized via web-based Google Maps API. Moreover, the density mapping of IPv6 address blocks in particular countries can be visualized too.

This thesis deals with measuring transmission parameters of the Internet network, in particular latency of ping, SSH protocol and bandwidth. The thesis is divided into a theoretical and a practical part. Theoretical part describes PlanetLab network, its brief history and contemporary projects. At the same time, tools for data mining from web pages are described. These information obtained from the theoretical part are used for creating PlanetLab nodes list and for programming applications which measure the network transmission parameters. Applications, list of nodes and obtained data are attached on DVD disc.

Locating a radio transmitter is important in a number of problems such as finding radio tags, people with radios, and devices that are collecting information in an unauthorized manner. Locating a radio transmitter is inherently difficult because the radio waves of concern are not in the visible spectrum, they reflect and distort easily, and they propagate at the speed of light. A number of methods for locating transmitters are currently used, the majority of which require expensive hardware and extensive processing. This thesis presents a method of using simpler measurements to produce similar location estimates in order to augment or replace current systems. While other systems have significant advantages, the methods proposed in this thesis are advantageous because they only require easily-obtained measurements that are based on the observed power of the transmission. The research uses simulations and experiments on real-world data collected locally to demonstrate the possibility of locating a transmitter using information of this type. The conclusion is that some methods are able to compensate for the difficulties in the problem more effectively and produce useful location estimates.