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Skotnes, Harald; Hartvigsen, Gunnar; Johansen, Dag (Research report; Forskningsrapport, Sep-1994)[+][-]
Abstract: Advances in computing power and graphics have increased the use of graphics in weather forecasting. This includes 3D animation sequences and geographical information systems. The paper addresses the main problems and presents preliminary results of the visualization of atmospheric models in conjunction with the underlying topography. The goal is among others to make a sort of 3D satellite pictures that present the weather described by the gridpoints in an atmospheric model, i.e., the weather of tomorrow. URI: http://hdl.handle.net/10037/401 File(s) in this item: 1
report.pdf (50.11Kb) -
Sudmann, Nils P.; Johansen, Dag (Research report; Forskningsrapport, 2000)[+][-]
Abstract: In this paper we will show that it is possible to combine mobile agent technology with existing non-mobile data mining applications. The motivation for this is the advantage mobile agents offer in moving the computation closer to the data in a distributed system. This can save bandwidth and increase performance when the data is condensed as a result of data mining. URI: http://hdl.handle.net/10037/357 File(s) in this item: 1
report.pdf (70.91Kb) -
Marzullo, Keith; Johansen, Dag; Lauvset, Kåre J. (Research report; Forskningsrapport, 1998)[+][-]
Abstract: We devise a mobile agent middleware architecture for supporting distributed applications in a wide-area network. The architecture provides a structural framework for functional components that are needed to support mobile agents in asymmetric networking environments. URI: http://hdl.handle.net/10037/363 File(s) in this item: 1
report.pdf (88.72Kb) -
Khalaila, Ahmad; Eliassen, Frank (Research report; Forskningsrapport, Apr-1997)[+][-]
Abstract: A large class of linear recursive queries compute the bill-of-materials of database relations.This paper presents a novel algorithm that computes the bill-of-materials of its argument's (database) relation. The algorithm uses a special join operation that accumulates the cost of composite parts, without constructing the transitive closure of the argument relation, thus saving time and space. We argue that this algorithm outperforms existent algorithms in the order of the diameter of the graph represented in the argument relation. This is made possible by exploiting knowledge of the level each tuple of the argument relation belongs to. Moreover, this algorithm in contrast to transitive closure based processing, produces data at a very early stage of the processing which renders it suitable for pipelined distributed data processing. URI: http://hdl.handle.net/10037/368 File(s) in this item: 1
report.pdf (249.6Kb) -
Johansen, Dag; Marzullo, Keith; Lauvset, Kåre J. (Research report; Forskningsrapport, 06-Oct-2000)[+][-]
Abstract: This paper presents a generic software architecture for large-scale distributed applications where mobile agents are an integral part. We have devised this architecture through completion of a series of mobile agent systems and associated applications over the last 8 years. URI: http://hdl.handle.net/10037/403 File(s) in this item: 1
report.pdf (185.9Kb) -
Renesse, Robbert van; Johansen, Dag; Schneider, Fred B. (Research report; Forskningsrapport, Jun-1995)[+][-]
Abstract: This report briefly introduces TACOMA Version 1.0. This distributed system supports agents, computations that can roam the internet. The report presents the TACOMA project, the computational model, how to get started, and the basic TACOMA abstractions. URI: http://hdl.handle.net/10037/382 File(s) in this item: 1
report.pdf (129.2Kb) -
Dahle, Peter (Master thesis; Mastergradsoppgave, 15-Jun-2007)[+][-]
Abstract: Several actors are involved in all layers the handset architecture, from hardware producers to service providers, and the numbers are raising. Lack of collaboration amongst these actors across and within layers has led to a complex development-process of services and applications, which in turn leads to difficult use of such applications and services. In this thesis we took a closer look at the mobile phone, examined challenges surrounding development and use of services on mobile phones, and found initiatives by actors to handle these challenges. This knowledge was used to design and implement a solution to handle identified challenges. The solution involves using the UICC as the main application platform and container of state, with the possibility to deploy handset-specific parts of an application on the handset. Standardized tools on the handset give UICC-applications the means to communicate with external processes and users. In addition the network operator is given an important role to administrate and adapt applications on the UICC as services change communication technology and application standard. The designed architecture facilitates more widespread development and use of services on the mobile handset. The architecture is realizable through current platforms and standards. By implementing a simulation and subset of our design on a handset the design was substantiated. URI: http://hdl.handle.net/10037/1136 File(s) in this item: 2
thesis.pdf (2.060Mb)thesis.zip (2.343Mb) -
Blair, Gordon S.; Yang, Jie; Andersen, Anders (Research report; Forskningsrapport, 2005)[+][-]
Abstract: It is becoming clear that modern middleware platforms must provide both deploy-time configuration and run-time reconfiguration to accommodate rapid changing requirements and also to be able to operate in dynamic environments. J2EE is a key example of a middleware architecture that supports enterprise applications via its Enterprise JavaBeans (EJB) component model. EJB provides limited configurability in terms of a fixed set of non-functional middleware services at deployment-time (via a declarative deployment descriptor). However, EJB along with other related enterprise architectures generally do not provide enough support for re-configuration or evolution. At best, there is limited support in some platforms for replacing or updating particular services. This paper discusses the design of configurable and re-configurable middleware architecture and also the key role of separation of concerns for such platforms. The paper also describes the Arctic Beans component model which uses the Composition Filters model to capture such concerns and also support their safe composition.The paper also explains how this model can be used to construct an Arctic Beans container, in the style of EJB. The main contribution of the paper is to demonstrate that adaptable middleware platform can be developed using separation of concern technologies, specifically the composition filters model. URI: http://hdl.handle.net/10037/396 File(s) in this item: 1
report.pdf (335.0Kb) -
Eriksen, Dan Peder (Master thesis; Mastergradsoppgave, 01-Jun-2007)[+][-]
Abstract: With the emergence of the internet and e-commerce in the 90’s new common problems arose when developing applications that span the internet. These common problems include among others scalability, robustness, networking, database usage and heterogeneity. Software developers creating internet applications saw themselves reinventing the wheel repeatedly. This lead to the creation of middleware systems that aimed to solve these common problems. This thesis will present Argos which uses a different way of building middleware systems. Argos is able to provide tailored, flexible and extensible middleware support using reflection, dependency injection, Java Management Extensions (JMX) notifications and hot deployment. The result is a platform capable of tackling domain specific challenges. It provides rapid development of feature rich applications for managing and processing information. Argos has gone through thorough testing proving production stability. URI: http://hdl.handle.net/10037/1138 File(s) in this item: 1
thesis.pdf (1.599Mb) -
Arild, Ronny; Stabell-Kulø, Tage (Research report; Forskningsrapport, 18-Jan-1999)[+][-]
Abstract: A distributed file repository is described. It supports interaction between different machines used by a single user, as well as between users that share data. Files can be replicated and consistency will be maintained, or files can be shipped (copied) to a remote site. As with more traditional systems, the servers are trusted not to leak information. However, the rôle servers play is not as much the hub in the system. In particular, users are in charge of delegating acccess to files. For flexibility, delegations might take place outside of the realm of the system proper; by any means available to the users. Users can delegate access rights to local and remote users, including remote users in other domains. ACLs are used to maintain local access control; capabilities are used to access remote files. These capabilities are valid within epochs, but are immediately revoked when being used, thus being valid at-most-once. In essence, we have realized a flexible infrastructure where users can implement their own security policy. URI: http://hdl.handle.net/10037/360 File(s) in this item: 1
report.pdf (261.1Kb) -
Evertsen, Martin Hætta (Master thesis; Mastergradsoppgave, Jun-2010)[+][-]
Abstract: People love to take images, but are not so willing to annotate the images af-terwards with relevant tags. Manually tagging images is both subjective (dependent on annotator) and time consuming. It would be nice if the tag-ging process could be done automatically. A requirement for effective searching and retrieval of images in rapid growing online image databases is that each image has accurate and useful annotation. This thesis shows that automatic tagging of images with relevant tags is possible by using a combination of the capture location, the date/time when the image was captured and an image category. The use of image categories (together with location and date/time) ensures that many relevant tags are returned and restrict the occurrence of noisy tags to a very low level despite using a noisy image database (Flickr). Other methods used for further re-stricting noise are to restrict usage of more than one image from same user (as basis for tagging the query image) and a dynamic approach for using many images when possible, and fewer images when not many relevant im-ages are found. The designed system is able to tag an image as long as there are a sufficient number of geo-referenced and already tagged images that is relevant for the query image available on Flickr. The query image must also have been geo-referenced and it is assumed that the user provides an image category. Im-ages are processed based on which category the images belongs to, i.e. an image is processed with the best method to handle images belonging to that specific category. In short, this means that images of objects or places are processed differently than images from events. The evaluation of the system indicates that usage of image categories is very helpful when tagging images. The system finds more relevant tags and fewer noisy tags than baseline systems using only location. It also performs good compared to a system using both location and content-based image analysis. URI: http://hdl.handle.net/10037/2633 File(s) in this item: 1
thesis.pdf (2.347Mb) -
Arntzen, Ingar Mæhlum (Master thesis; Mastergradsoppgave, 02-Dec-2009)[+][-]
Abstract: This thesis describes the design and implementation of a proxy client for a chain replicated storage system. URI: http://hdl.handle.net/10037/2361 File(s) in this item: 1
thesis.pdf (2.632Mb) -
Pettersen, Ørjan (Master thesis; Mastergradsoppgave, 25-Jun-2010)[+][-]
Abstract: This thesis covers the design, implementation and evaluation of a configuration tool for process oriented Unmanned Aerial Vehicle (UAV) programming. In addition it will examine if and how a process network can be used to control sensors and communication channels on an UAV in flight. NORUT-IT is currently developing a sensor platform based on UAVs. The mission computer software they have at the moment have room for improvement when it comes down to issues regarding routing and prioritizing between available network connections. One issue that has been identified is not being able to route between multiple available networks. They have to predefine which network connection the UAV should use to connect to the ground station when it is in flight. It will use this connection the entire flight even if a faster and/or cheaper network connection is available in some areas of the mission. Together with this issue, having a platform with a number of sensors working together, will be challenging to configure and might require programming skills to some degree to set up correctly. Communicating sequential processing(CSP) have properties that can help in building concurrent, reliable and scalable programs. By using CSP and a process configuration tool, the complexity of configuring the mission computer of an UAV can be reduced. The implementation will demonstrate a tool that are believed to be intuitive and will lower the challenge of configuring a process network intended to control the sensors and communication channels on an UAV. The process network creator tool have a graphical interface and a collection of premade CSP processes. It will also have the ability to convert the graphical representation of the process network into a running CSP process. URI: http://hdl.handle.net/10037/2722 File(s) in this item: 1
thesis.pdf (3.511Mb) -
Hansen, Christer Andre (Master thesis; Mastergradsoppgave, 18-May-2010)[+][-]
Abstract: Accessing route information should be easy. Today, most collective transport companies distribute timeta- bles online as electronic documents and in paper format. These solutions are outdated and cumbersome to use. However, systems have been built to make the task of finding route information easy, and to replace these formats. Most of these systems, still, have limitations. They rely on users knowing the name of the bus stops, and the destination is left out when finding information. In this thesis we present a system that is able to find travel alternatives based on two parameters, the user’s current location and the destination. Successful tests and experiments have proved that our system can be useful for people that does not know the following; the name of the bus stops, where the bus stops are located, what route to use, and where to get of the bus. We also suggest an architecture where our system is integrated as part of a personal cloud. URI: http://hdl.handle.net/10037/2604 File(s) in this item: 1
thesis.pdf (7.253Mb) -
Hanssen, Øyvind (Research report; Forskningsrapport, Dec-2005)[+][-]
Abstract: In this report we define the semantics of a language for dynamic QoS expressions which can be evaluated at run-time for conformance. We define how expressions can be constructed from atomic expressions termed ’basic profiles’ using composition operators. Two such operators are defined: The sum ( ’+’ ) which corresponds to simple conjunction and component-sum (’Å’) which assume that the operands denote properties of separate environments and therefore must be satisfied separately. Based on those, algorithms for conformance checking any pair of expressions can be developed. Concrete models are typically defined for specific application domains, they define the basic profile space and explicitly establishes conformance relationships between basic profiles. These are essentially sets of axioms from which we can infer conformance. Description: Publisert desember 2005, oppdatert februar 2006 / Published December 2005, updated February 2006 URI: http://hdl.handle.net/10037/383 File(s) in this item: 1
report.pdf (265.9Kb) -
Skadsem, Marte Karidatter (Master thesis; Mastergradsoppgave, 08-Jun-2006)[+][-]
Abstract: In this thesis we present the development of a distributed and parallel environment which offers functionality to robots to support them in their task performance. We want the environment to be a framework where students can experiment with robots, and in which we can arrange robot competitions. Our motivation for this thesis is an earlier developed robot system at our department. It was used as an instrument to demonstrate the principles and practice of distributed and high performance parallel computing. The system was used by students on advanced courses on cluster architecture and programming, and popular competitions were held in it. The old system had many infrastructure demands and had to be closed. We want to make a new system that has less infrastructure demands and more functionality. The environment has control over a certain amount of work space where the robots can operate. Within this work space, the environment offers functionality that includes context awareness, location, mapping, naming, and structured interfaces for interaction between the different components. Users can control the robots through the environment, and they assign tasks to the robots. Users can also download extensions to robots through the environment, and robots can upload data to the environment. The state of the environment, the robots and the work space is visualized on a display wall. Users can interact with this visualization and assign simple tasks through it. URI: http://hdl.handle.net/10037/1009 File(s) in this item: 1
thesis.pdf (1.883Mb) -
Andersen, Anders; Aanensen, Thomas (Research report; Forskningsrapport, 2005)[+][-]
Abstract: OOPP is a component based middleware platform with support for complex distributed applications. The main goal of OOPP is to create an expressive programming model for distributed applications where by default details are hidden for the programmer. When necessary, reflection is used to expose and sometimes modify these details. All interaction with an OOPP component are specified by its component model and a at set of well-defined interfaces. The component model specifies how a component interacts with the runtime. The set of interfaces specifies how a component interacts with other components. An OOPP application is created by combining a set of OOPP components. OOPP Studio can be used to create and manage such an application. This paper gives an overview of the OOPP programming model and discusses in more details OOPP Studio. OOPP Studio is a powerful graphical tool used to build, deploy, and manage a distributed OOPP application. URI: http://hdl.handle.net/10037/390 File(s) in this item: 1
report.pdf (210.2Kb) -
Hartvigsen, Gunnar; Johansen, Dag (Research report; Forskningsrapport, 1990)[+][-]
Abstract: Artificial intelligence applications are normally complex, demanding much computing power. This paper presents the multiagent architecture of StormCast, a distributed artificial intelligence application for severe storm forecasting. Important objectives as scaleability, robustness and reusability can be met by partitioning an ove rall task in subtasks, distribution of the subtasks on different nodes, parallel processing of the subtasks and cooperation between the subtasks. URI: http://hdl.handle.net/10037/406 File(s) in this item: 1
report.pdf (54.93Kb) -
Arntzen, Ingar Mæhlum; Johansen, Dag (Research report; Forskningsrapport, 2004)[+][-]
Abstract: This exstended abstract presents an asymmetric and programmable (extensible) approach to pervasive computing. The idea is to off-load computations from light portable clients into a back-bone of seamlessly integrated servers. This way, a user can extend and personalize his pervasive computational environment by installing computations following his trajectory throughout the day. Focus on this extended abstract is on structural issues related to the back-end servers running mobile code off-loaded from the mobile user. URI: http://hdl.handle.net/10037/374 File(s) in this item: 1
report.pdf (57.07Kb) -
Josefsen, Kent Ove (Master thesis; Mastergradsoppgave, 15-Dec-2007)[+][-]
Abstract: Web services enable businesses to deliver services via the Web. In addition, Web services can be used to improve business efficiency, because Web services can often replace manual activities in a business process. A Web service can be composed of other simpler Web services using the abstraction traditionally known as workflows. The process of controlling the correct and reliable execution of a workflow is known as workflow enactment, but it can also be referred to as Web services orchestration. A centralized approach to Web services orchestration is not an optimal solution, when considering the decentralized nature of Web services and the Internet. The problem is that a centralized workflow engine can easily become a communication and processing bottleneck as well as a central point of failure. Therefore, a decentralized approach to Web services orchestration is needed in order to overcome these obstacles. However, some decentralized approaches require static analysis of workflow specifications, which implies that resources must be allocated prior to the workflow execution. As a result, resources are wasted. In this thesis a prototype is developed to demonstrate a decentralized Web services orchestration based on continuation-passing enactment of distributed workflows. This decentralized approach does not require any pre-allocation of resources, nor is it subject to the limitations of a centralized approach. The continuation-passing mechanism involves continuations, or the reminder of the executions, which are passed along asynchronous messages for workflow enactment. URI: http://hdl.handle.net/10037/1355 File(s) in this item: 2
thesis.pdf (989.0Kb)thesis.zip (38.20Mb)
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