Security by Spatial Reference:Using Relative Positioning to Authenticate Devices for Spontaneous Interaction

Spontaneous interaction is a desirable characteristic associated with mobile and ubiquitous computing. The aim is to enable users to connect their personal devices with devices encountered in their environment in order to take advantage of interaction opportunities in accordance with their situation. However, it is difficult to secure spontaneous interaction as this requires authentication of the encountered device, in the absence of any prior knowledge of the device. In this paper we present a method for establishing and securing spontaneous interactions on the basis of emphspatial references that capture the spatial relationship of the involved devices. Spatial references are obtained by accurate sensing of relative device positions, presented to the user for initiation of interactions, and used in a peer authentication protocol that exploits a novel mechanism for message transfer over ultrasound to ensures spatial authenticity of the sender

Towards self-protecting ubiquitous systems : monitoring trust-based interactions

The requirement for spontaneous interaction in ubiquitous computing creates security issues over and above those present in other areas of computing, deeming traditional approaches ineffective. As a result, to support secure collaborations entities must implement self-protective measures. Trust management is a solution well suited to this task as reasoning about future interactions is based on the outcome of past ones. This requires monitoring of interactions as they take place. Such monitoring also allows us to take corrective action when interactions are proceeding unsatisfactorily. In this vein, we first present a trust-based model of interaction based on event structures. We then describe our ongoing work in the development of a monitor architecture which enables self-protective actions to be carried out at critical points during principal interaction. Finally, we discuss some potential directions for future work

Development of a miniature gridded ion thruster

Electric propulsion has matured to the point where it starts credibly to challenge chemical propulsion systems. The high efficiency and larger specific impulse have allowed to lower the weight of the satellites and therefore costs. Even though the thrust of an electric propulsion systems is still just a fraction of that chemical rockets, the possibility of keeping it on for months eventually gives the same amount of momentum. While CubeSat projects are getting more popular by universities only a few have developed their own miniature ion thruster. These mini thrusters have a thrust force of sub mN to few mN, but they still enable up to 100 kg almost any kind of altering to satellites orbital position and attitude. Another, issue on electric propulsion is the propellant. Xenon is most used propellant fuel in ion thrusters, but because of its high costs, it is out of the reach for many universities. This study tried tackling into those two topics and create a design of a miniature ring cusp gridded ion thruster. The study wanted to research possibilities of using 3D printing technology and this way simplify the fabrication process. The goal was to create a design which could be used as a foundation for Aalto University’s propulsion development and also enable testing of alternative propellants. The propellants studied were iodine, adamantane, and diamantane. All of them are in a solid-state at room temperature, which would be practical for storage. The design is presented at the end of the study

Supporting Device Discovery and Spontaneous Interaction with Spatial References

The RELATE interaction model is designed to support spontaneous interaction of mobile users with devices and services in their environment. The model is based on spatial references that capture the spatial relationship of a user’s device with other co-located devices. Spatial references are obtained by relative position sensing and integrated in the mobile user interface to spatially visualize the arrangement of discovered devices, and to provide direct access for interaction across devices. In this paper we discuss two prototype systems demonstrating the utility of the model in collaborative and mobile settings, and present a study on usability of spatial list and map representations for device selection

Årstiderna i Tors Park

Med utgångspunkt från ett befintligt gestaltningsförslag och en tillhörande växtlista har jag i det här arbetet undersökt de aspekter som kan beaktas för en plantering med estetiska värden under hela året. Syftet med arbetet är att lyfta betydelsen för landskapsarkitekter men även andra läsare att lära känna sitt växtmaterial för att kunna göra dynamiska växtkompositioner. Detta kandidatexamensarbete är uppdelat i tre delar. Den första delen av arbetet består av en litteraturstudie där läsaren får insyn i aspekterna form, färg och komposition. Studien visade på att växtdynamik är mest intressant att ta hänsyn till då en komposition med estetiska värden under hela året eftersträvas. Med planering och förståelse för växterna kan växtsäsongen förlängas och de estetiska värdena i offentliga rum och privata trädgårdar förhöjas. Utifrån litteraturstudien och resultatet komponerades ett nytt växtförslag för det tidigare gestaltningsförslaget. Den avslutande delen av arbetet består av diskussioner och reflektioner kring resultatet och kring de metoder som tillämpades.In this bachelor’s thesis I have examined which aspects to take into account when designing a plant proposal with seasonal interest. The aim of the study is to enlighten landscape architects, and other readers as well, to get to know their material in the making of dynamic plant combinations. This paper consists of three parts. The first part consists of a study of literature which will give the reader an introduction to the aspects of form, colour and plant combinations. The study showed that the dynamic of plants is the most interesting aspect to take into account when aesthetical values during the year are sought. With planning and a deeper understanding of plants the flowering season could be extended and the aesthetical values of private and public gardens could be enhanced. Based on the results of the study I composed a new plant proposal for an existing design. The last part of the study consists of discussions and reflections on the result and the methods that were applied