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Learning outcomes in electronic courses often involve objectives that require hands-on experience in a laboratory environment. Thus, transforming such a course to be suited for distance learning might prove problematic. Using video lectures is possible but deprives the students of the ability to experiment on their own. The aim of this thesis was to mitigate the problem by developing an affordable platform providing the basic functionality of standard laboratory equipment designed for easy distribution. The resulting hardware is able to produce an 8 Vpp output signal in the range of 1 Hz to 100 kHz with a high level of accuracy both in terms of voltage level and frequency. The signal may be applied to a circuit and analyzed using two analog input channels, displaying the results on the screen of a computer connected with a USB cable. The hardware interaction is performed using a graphical interface developed to function on all major operating systems and provide a user-friendly environment. Some interference were experienced on high frequencies but we believe that the problems can be fixed with a minor redesign of the circuit board. The evaluation shows that the performance is within the specified requirements and after testing some of the typical use cases the system is concluded to be sufficient for the intended purposes.

Real time video streaming over wireless network is an increasingly important and attractive service to the mobile users. Video streaming involves a large amount of data to be transmitted in real time, while wireless channel conditions may vary from time to time. It is hard to guarantee a reliable transmission over the wireless network, where the parameters specifying the transmissions are; bandwidth, packet loss, packet delays, and outage times. The quality of the video is affected negatively when network packets are lost, and the mobile users may notice some sudden stop during the video playing; the picture is momentarily frozen, followed by a jump from one scene to a totally different one. The main objective of this thesis is to provide a smooth video playback in the mobile device over unreliable networks with a satisfactory video quality. Three different techniques are proposed to achieve this goal. The first technique will stream duplicate gray scale frames over multichannels, if there is lost frames in one channel it can be recovered from another channel. In the second technique, each video frame will be split into sub-frames. The splitted sub-frames will be streamed over multichannels. If there is a missing sub-frame during the transmission a reconstruction mechanism will be applied in the mobile device to recreate the missing sub-frames. In the third technique, we propose a time interleaving robust streaming (TIRS) technique to stream the video frames in different order. The benefit of that is to avoid the losses of a sequence of neighbouring frames. A missing frame from the streaming video will be reconstructed based on the surrounding frames. The mean opinion score (MOS) metric is used to evaluate the video quality. The experienced quality of a video is subject to the personal opinion, which is the only goal to satisfy the average human watching the contents of the video.

Software has, for better or worse, become a core component in the structured management and manipulation of vast quantitates of information, and is therefore central to many crucial services and infrastructures. However, hidden among the various benefits that the inclusion of software may bring is the potential of unwanted and unforeseen interactions, ranging from mere annoyances all the way up to full-blown catastrophes. Overcoming adversities of this nature is a challenge shared with other engineering ventures, and there are many developed strategies that work towards eliminating various kinds of disturbances, assuming that it is possible to apply such strategies correctly. One approach in this regard, is to accept some anomalous behaviors as mere facts of life and make sure that the situations experienced are dealt with in an expeditious manner, while at the same time trying to discover, implement and improve safe-guards that can lessen adverse consequences in the event of future problems; in short, to embed resilience. The work described in this thesis explores the foundations of software resilience, and thus covers the main resilience-enabling mechanisms, along with supporting tools, techniques and methods used to embed resilience. These instruments are dissected and analyzed from the perspective of stakeholders that have to operate on pre-existing, critical, large and heterogeneous subjects that are to some extent already up and running at the point of instrumentation. Finally, in the course of describing this subject, the thesis describes a demonstrator environment for self-healing activities in a partially damaged power grid, its construction details and the initial results of the study conducted in this environment.

Research in psychology and neurology shows that both body and mind are involved when experiencing emotions (Damasio 1994, Davidson et al. 2003). People are also very physical when they try to communicate their emotions. Somewhere in between beings consciously and unconsciously aware of it ourselves, we produce both verbal and physical signs to make other people understand how we feel. Simultaneously, this production of signs involves us in a stronger personal experience of the emotions we express. Emotions are also communicated in the digital world, but there is little focus on users' personal as well as physical experience of emotions in the available digital media. In order to explore whether and how we can expand existing media, we have designed, implemented and evaluated /eMoto/, a mobile service for sending affective messages to others. With eMoto, we explicitly aim to address both cognitive and physical experiences of human emotions. Through combining affective gestures for input with affective expressions that make use of colors, shapes and animations for the background of messages, the interaction "pulls" the user into an /affective loop/. In this thesis we define what we mean by affective loop and present a user-centered design approach expressed through four design principles inspired by previous work within Human Computer Interaction (HCI) but adjusted to our purposes; /embodiment/ (Dourish 2001) as a means to address how people communicate emotions in real life, /flow/ (Csikszentmihalyi 1990) to reach a state of involvement that goes further than the current context, /ambiguity/ of the designed expressions (Gaver et al. 2003) to allow for open-ended interpretation by the end-users instead of simplistic, one-emotion one-expression pairs and /natural but designed expressions/ to address people's natural couplings between cognitively and physically experienced emotions. We also present results from an end-user study of eMoto that indicates that subjects got both physically and emotionally involved in the interaction and that the designed "openness" and ambiguity of the expressions, was appreciated and understood by our subjects. Through the user study, we identified four potential design problems that have to be tackled in order to achieve an affective loop effect; the extent to which users' /feel in control/ of the interaction, /harmony and coherence/ between cognitive and physical expressions/,/ /timing/ of expressions and feedback in a communicational setting, and effects of users' /personality/ on their emotional expressions and experiences of the interaction.

In our daily lives we communicate emotions not only in face-to-face situations, but also in the digital world. When communicating emotions to other people we are not always aware of exactly what we are expressing. Emotions are communicated not only by the actual words we say, but through physical expressions like gestures, body posture and tone of voice. Designing for emotional expressivity requires a design that can capture the characteristics of emotions as well as the subjective experiences. This design should also mirror the communicative reality that we live in and open up for personality, context and situation to be expressed. In order to explore emotional communication in the digital world we have designed, implemented and evaluated eMoto, a mobile service for sending text messages that can be enhanced with emotional content. In this thesis we will present a detailed description of the design process, including user studies, leading to the design of the emotional expressivity in the eMoto prototype. Through the use of a body movement analysis and a dimensional model of emotion experiences, we arrived at the final design. The service makes use of the sub-symbolic expressions; colours, shapes and animations, for expressing emotions in an open-ended way. The results from the user studies show that the use of these sub-symbolic expressions can work as a foundation to use as a creative tool, but still allowing for the communication to be situated. The inspiration taken from body movements proved to be very useful as a design input. From the design process and the user studied we have extracted four desirable qualities when designing for emotional expressivity: to consider the media specific qualities, to provide cues of emotional expressivity building on familiarity, to be aware of contradictions between the modalities, and to open for personal expressivity. Incorporating these qualities open up for more expressivity when designing within this area. The actual design process is itself another example that can be used as inspiration in future designs aiming at emotional expressivity.

As the computer screen is replacing the book as the dominant medium for communication (Kress, 2003), questions about how meaning is constituted by the multimodal interaction of different media (including music) is becoming increasingly important in contemporary research of pedagogy, sociology and media studies. The overall aim with this licentiate thesis is to explore musical narrative functions as they appear in multimedia such as film and computer games. The thesis is based on three publications. Publication 1 proposes a classification of musical narrative functions, with 6 narrative classes(the Emotive, Informative, Descriptive, Guiding, Temporal and Rhetorical classes) and 11 categories. The relational interplay of music with contextual factors is emphasized. Publication 2 describes the design of a software tool, REMUPP (Relations Between Musical Parameters and Perceived Properties), to be used for experimental studies of musical expression. REMUPP is used for real time alteration of musical expression, by the manipulation of musical parameters such as tempo, harmony, rhythm, articulation, etc. Publication 3 describes a quasi-experiment using REMUPP, where a group of young participants (12-13 years old) were given the task of adapting musical expression – by manipulating 7 parameters – to make it fit 3 visual scenes shown on a computer screen. They also answered a questionnaire asking about their musical backgrounds and habits of listening to music, watching movies and playing computer games. Numerical data from the manipulations were analyzed statistically with regards to the preferred values of the musical parameters in relation to the different visual scenes. The results indicated awareness and knowledge about codes and conventions of musical narrative functions, and were to some degree affected by the participants’ gender, musical backgrounds and media habits. / Audio Games Design

To deliver a reliable communication service it is essential for the network operator to manage how traffic flows in the network. The paths taken by the traffic is controlled by the routing function. Traditional ways of tuning routing in IP networks are designed to be simple to manage and are not designed to adapt to the traffic situation in the network. This can lead to congestion in parts of the network while other parts of the network is far from fully utilized. In this thesis we explore issues related to optimization of the routing function to balance load in the network. We investigate methods for efficient derivation of the traffic situation using link count measurements. The advantage of using link counts is that they are easily obtained and yield a very limited amount of data. We evaluate and show that estimation based on link counts give the operator a fast and accurate description of the traffic demands. For the evaluation we have access to a unique data set of complete traffic demands from an operational IP backbone. Furthermore, we evaluate performance of search heuristics to set weights in link-state routing protocols. For the evaluation we have access to complete traffic data from a Tier-1 IP network. Our findings confirm previous studies who use partial traffic data or synthetic traffic data. We find that optimization using estimated traffic demands has little significance to the performance of the load balancing. Finally, we device an algorithm that finds a routing setting that is robust to shifts in traffic patterns due to changes in the interdomain routing. A set of worst case scenarios caused by the interdomain routing changes is identified and used to solve a robust routing problem. The evaluation indicates that performance of the robust routing is close to optimal for a wide variety of traffic scenarios. The main contribution of this thesis is that we demonstrate that it is possible to estimate the traffic matrix with good accuracy and to develop methods that optimize the routing settings to give strong and robust network performance. Only minor changes might be necessary in order to implement our algorithms in existing networks.

Recent advances in information and communication technologies have made the development and operation of complex disease surveillance systems technically feasible, and many systems have been proposed to interpret diverse data sources for health-related signals. Implementing these systems for daily use and efficiently interpreting their output, however, remains a technical challenge. This thesis presents a method for understanding disease surveillance systems structurally, examines four existing systems, and discusses the implications of developing such systems. The discussion is followed by two papers. The first paper describes the design of a national outbreak detection system for daily disease surveillance. It is currently in use at the Swedish Institute for Communicable Disease Control. The source code has been licenced under GNU v3 and is freely available. The second paper discusses methodological issues in computational epidemiology, and presents the lessons learned from a software development project in which a spatially explicit micro-meso-macro model for the entire Swedish population was built based on registry data.

As the amount of data in todays Internet is growing larger, users are exposed to too much information, which becomes increasingly more difficult to comprehend. Publish/subscribe systems leverage this problem by providing loosely-coupled communications between producers and consumers of data in a network. Data consumers, i.e., subscribers, are provided with a subscription mechanism, to express their interests in a subset of data, in order to be notified only when some data that matches their subscription is generated by the producers, i.e., publishers. Most publish/subscribe systems today, are based on the client/server architectural model. However, to provide the publish/subscribe service in large scale, companies either have to invest huge amount of money for over-provisioning the resources, or are prone to frequent service failures. Peer-to-peer overlay networks are attractive alternative solutions for building Internet-scale publish/subscribe systems. However, scalability comes with a cost: a published message often needs to traverse a large number of uninterested (unsubscribed) nodes before reaching all its subscribers. We refer to this undesirable traffic, as relay overhead. Without careful considerations, the relay overhead might sharply increase resource consumption for the relay nodes (in terms of bandwidth transmission cost, CPU, etc) and could ultimately lead to rapid deterioration of the system’s performance once the relay nodes start dropping the messages or choose to permanently abandon the system. To mitigate this problem, some solutions use unbounded number of connections per node, while some other limit the expressiveness of the subscription scheme. In this thesis work, we introduce two systems called Vitis and Vinifera, for topic-based and content-based publish/subscribe models, respectively. Both these systems are gossip-based and significantly decrease the relay overhead. We utilize novel techniques to cluster together nodes that exhibit similar subscriptions. In the topic-based model, distinct clusters for each topic are constructed, while clusters in the content-based model are fuzzy and do not have explicit boundaries. We augment these clustered overlays by links that facilitate routing in the network. We construct a hybrid system by injecting structure into an otherwise unstructured network. The resulting structures resemble navigable small-world networks, which spans along clusters of nodes that have similar subscriptions. The properties of such overlays make them an ideal platform for efficient data dissemination in large-scale systems. The systems requires only a bounded node degree and as we show, through simulations, they scale well with the number of nodes and subscriptions and remain efficient under highly complex subscription patterns, high publication rates, and even in the presence of failures in the network. We also compare both systems against some state-of-the-art publish/subscribe systems. Our measurements show that both Vitis and Vinifera significantly outperform their counterparts on various subscription and churn scenarios, under both synthetic workloads and real-world traces. / CNS