Abstract: Medical case retrieval (MCR) is information retrieval in a collection of medical case descriptions, where descriptions of patients' symptoms are used as queries. We apply known text retrieval techniques based on query and document expansion to this problem, and combine them with new algorithms to match queries and documents with Medical Subject Headings (MeSH). We ran comprehensive experiments to evaluate 546 method combinations on the ImageCLEF 2013 MCR dataset. Methods combining MeSH query expansion with pseudo-relevance feedback performed best, delivering retrieval performance comparable to or slightly better than the best MCR run submitted to ImageCLEF 2013.

Abstract: The actual content of endoscopic videos is typically limited to a circular area in the center of the image due to the inherent characteristics of the camera. This area is surrounded by a dark border that fills up the remainder of the rectangular image and is subject to noise. The position and size of the circle is not standardized and usually varies over time. In this paper a robust algorithm is presented that (1) classifies which parts of an endoscopic video feature a circular content area and (2) determines its exact position and size, if present. This information is useful for improving video encoding efficiency, limiting further analysis steps to the relevant area and saving ink when printing still images on findings. Our evaluation shows that the proposed method is very fast, reliable and robust. Moreover, it indicates that by exploiting this information for video encoding a considerable bitrate reduction is possible with the same visual quality.

Abstract: More and more content in various formats become available via the World Wide Web (WWW). Currently available Web browsers are able to access and interpret these contents (i.e., Web videos, text, image, and audio). These contents stimulate only senses like audition or vision. Recently, it has been proposed to stimulate also other senses while consuming multimedia content through so-called sensory effects. These sensory effects aim to enhance the ambient experience by providing effects, such as, light, wind, vibration, etc. The effects are represented as Sensory Effect Metadata (SEM) which is associated to multimedia content and is rendered on devices like fans, vibration chairs, or lamps. In this paper we present a plug-in for the Mozilla Firefox browser which is able to render such sensory effects that are provided via the WWW. Furthermore, the paper describes two user studies conducted with the plug-in and presents the results achieved.

Abstract: Time- or history-management systems are implemented in a lot of existing applications. The visited web pages in browsers, the undoing list in nearly every editor or the recorded differences in version control systems are only some examples where time-based information plays an important role. Every kind of information (no matter if we talk about the last headlines in the newspaper or the last user inputs on the workstation) without an explicit date description is nearly useless. Due this fact we are wondering why no global time axis for recording general time-based information is integrated in today’s operating systems. We will introduce a time model to record all kinds of user actions and general time-based events as well. As a second part we will analyze how the visual output system can profit from such a global time axis as well. Up to now it takes a great effort to implement animated user interfaces and so they are rarely found on today’s software market. With the global conjunction of time it is possible to generate animations automatically for every kind of information. We explore the ways of using the time dimension for information presentation (for timely and not timely information as well). We will evaluate these so-called 4D user interfaces1 and introduce a programming model to take advantage of the time-dimension in multiple ways.

Abstract: The visualization of temporal information should not be seen as a special case. A lot of applications take already advantage of the time factor (e.g. capturing user events) but nearly all of them implement this feature completely proprietary. So why do we not embed the time as a ”first class citizen” in today’s operating systems that every application can use time based operations in an unified way. Such an invention would not only improve and standardize the capturing of temporal events but it would be of benefit for a temporal visualization system too. Within a 3D visualization space and a global time axis we introduce a printf4D() 1 method. With this method it is possible to display images, videos, text strings or any other kinds of information in an automatically animated way. As a first proposal we demonstrate this function in a ”flow of information” metaphor where information-objects are not displayed all at once but in a flowing manner over a certain period of time. Additionally we will show that printf4D() is not limited to temporal data. It can be extended automatically to any kind of static information.

Abstract: An adaptive multimedia proxy is presented which provides (1) caching, (2) filtering, and (3) media gateway functionalities. The proxy can perform media adaptation on its own, either relying on layered coding or using transcoding in the decompressed domain. A cost model is presented which incorporates user requirements, terminal capabilities, and video variations in one formula. Based on this model, the proxy acts as a general broker of different user requirements and of different video variations. This is a first step towards What You Need is What You Get (WYNIWYG) video services, which deliver videos to users in exactly the quality they need and are willing to pay for. The MPEG-7 and MPEG-21 standards enable this in an interoperable way. A detailed evaluation based on a series of simulation runs is provided.

Abstract: The DAHL project aimed at demonstrating some of the research achievements at ITEC by extending anexisting web application with content-based search mechanisms and an adaptive streaming environment for video data. The search is based on MPEG-7 descriptions of video data, and video retrieval uses an MPEG-4 conforming adaptive streaming server and player, which allows to adapt the video stream dynamically to client capabilities, user preferences, and available network bandwidth. This report describes the design, implementation, and integration work done in the DAHL project.

Abstract: We argue for the need of a tool that is able to provide QoS aware server applications with accurate information about current as well as predicted network characteristics. To address this issue, we present the design and evaluation of DANEF - a system that is able to estimate, process and forecast bottleneck bandwidth, available bandwidth, delay, jitter and loss of a certain path. Active measurements are performed by sending small ICMP packet trains and forecasts are performed by applying fast allgorithms that need only small initialization sets. The accuracy of the measurements is achieved by applying an efficient and innovative filtering mechanism, the correctness of the forecasts is achieved by dynamically selecting the best fitting forecast model and by considering the forecast error of previous samples. Our evaluation has shown that DANEF's measurement results are significantly more precise than those yield by the 5 most widely used tools called Bprobe, Cprobe, Pathload, Pathchar and Network Weather Service.

Abstract: Universal Multimedia Access (UMA) has become a driving concept behind a significant amount of research activities. One of MPEG’s (Moving Pictures Experts Group) responses to UMA is MPEG-21 Digital Item Adaptation (DIA). In this paper we present how tools as specified within DIA (i.e., normative XML-based description formats) are applied in streaming and constrained environments enabling piece-wise multimedia content adaptation including the adaptation decision-taking process and the actual resource adaptation in a coding format-independent way. Additionally, we demonstrate how the metadata overhead imposed by DIA tools can be reduced by means of appropriate metadata encoding tools.

Abstract: The precision of the predictors used in the ADMS[1] can be determined by similarity. There are already such measures[2] given, but we do not know exactly what efficiency they have and how well they show the difference between two lists. Kendall’s tau • Spearman’s footrule • Ulam’s distance We examined the characteristics of these similarity measures and developed some more measures that fit better our needs. One of the main goals is to consider the similarity more important at the begin of list, than at the end of list. Because the clients at the begin of the list probably will request more videos. During our work we defined 20 special ordered lists with 17 elements each. We tested the different measures on these lists. We also tested the Kemeny distance, which was defined in paper[3]. We modified the Spearman’s footrule and the Ulam’s distance according to the goal defined above (the top of the list considerate with higher weight (Weighted Spearman’s footrule, Weighted Ulam’s distance). Using the already known measures we developed a more complex, mixed measure, which uses more factors when defining the similarity. Finally we compared the 7 different measures using the artificially defined lists. With using the similarity measures we can tell how good the predictors[2] work in ADMS project. We could order the predictors by goodness, testing them on a real database (the World Cup ’98 Website’s access log).

Abstract: Proxy-cache deployment in the LANs has become a current practice aimed at increasing the availability of the data while also reducing client perceived latency, reduce the load on origin servers as well as the external network bandwidth consumption. As the load increases, due to an increase in client’s requests for both cached and non-cached data, it often happens that one single proxy-cache can not handle all the incoming requests. For those situations, when request dropping and cache replacement becomes necessary, we propose an alternative, namely proxy-cache splitting. Our solution is to dynamically deploy additional proxy-caches inside the LAN, and divert towards them some of the requests addressed to the original proxy-cache(s). By doing this we can achieve even better response time, load balancing, higher availability and robustness of the service than in the case in which a single proxy-cache is used.

Abstract: We argue for the need of a tool that is able to provide QoS aware server applications with accurate information about current as well as predicted network characteristics. To address this issue, we present the design and evaluation of DANEF - a system that is able to estimate, process and forecast bottleneck bandwidth, available bandwidth, delay, jitter and loss of a certain path. Active measurements are performed by sending small ICMP packet trains and forecasts are performed by applying fast allgorithms that need only small initialization sets. The accuracy of the measurements is achieved by applying an efficient and innovative filtering mechanism, the correctness of the forecasts is achieved by dynamically selecting the best fitting forecast model and by considering the forecast error of previous samples. Our evaluation has shown that DANEF's measurement results are significantly more precise than those yield by the 5 most widely used tools called Bprobe, Cprobe, Pathload, Pathchar and Network Weather Service.

Abstract: We argue for the need of a tool that is able to provide QoS aware server applications with accurate information about current as well as predicted network characteristics. To address this issue, we present the design and evaluation of DANEF - a system that is able to estimate, process and forecast bottleneck bandwidth, available bandwidth, delay, jitter and loss of a certain path. Active measurements are performed by sending small ICMP packet trains and forecasts are performed by applying fast allgorithms that need only small initialization sets. The accuracy of the measurements is achieved by applying an efficient and innovative filtering mechanism, the correctness of the forecasts is achieved by dynamically selecting the best fitting forecast model and by considering the forecast error of previous samples. Our evaluation has shown that DANEF's measurement results are significantly more precise than those yield by the 5 most widely used tools called Bprobe, Cprobe, Pathload, Pathchar and Network Weather Service.

Abstract: Due to the increasing availability of audio/visual data on the Internet, proxy caching is gaining on importance as a performance factor. This increase is accompanied by a diversification in the end terminals, which calls for media gateways and filters. An adaptive proxy is presented which performs (1) caching, (2) filtering and (3) media gateway functionality in one. The proxy can perform media adaptation -- using transcoding -- on its own. A cost model is presented which incorporates user requirements, terminal capabilities and video variations in one formula. Based on this model, the proxy acts as a general broker of different user requirements and of different video variations. This is a first step towards "What You Need is What You Get" (WYNIWYG) video services, which deliver videos to users in exactly that quality what they need and what they want to pay for. The MPEG-7 and MPEG-21 standards enables this in an interoperable way. A detailed evaluation based on a series of measurements is provided.

Abstract: We present a possibility how to add proactive behaviour to Video-on-Demand systems. To do so we propose categorizing videos and using external information as well as observing the behaviour of our clients. We examined 23 predictor functions on artificial and real datasets using different similarity measures to compare them. Our model is quite simple; therefore some extensions are proposed at the end.

Abstract: This paper introduces a mobile agent-based infrastructure for an adaptive multimedia server enabling a dynamic migration or replication of certain multimedia applications among a set of available server nodes. It discusses the requirements from both, the server’s and the middleware’s point of view to each other and comes up with a specification and implementation of a CORBA-based interface between them.