Now showing items 301-320 of 415

    • Dynamically loading mobile/cloud assemblies 

      Pettersen, Robert; Johansen, Håvard D.; Valvåg, Steffen Viken; Johansen, Dag (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-07-20)
      Distributed applications that span mobile devices, computing clusters, and cloud services, require robust and flexible mechanisms for dynamically loading code. This paper describes lady: a system that augments the .net platform with a highly reliable mechanism for resolving and loading assemblies, and arranges for safe execution of partially trusted code. Key benefits of lady are the low latency and ...
    • Telemedicine Services for the Arctic: A systematic review 

      Woldaregay, Ashenafi Zebene; Walderhaug, Ståle; Hartvigsen, Gunnar (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-06-28)
      Background: Telemedicine services have been successfully used in areas where there are adequate infrastructures such as reliable power and communication lines. However, despite the increasing number of merchants and seafarers, maritime and Arctic telemedicine have had limited success. This might be linked with various factors such as lack of good infrastructure, lack of trained onboard personnel, ...
    • Using satellite execution to reduce latency for mobile/cloud applications 

      Pettersen, Robert; Valvåg, Steffen; Kvalnes, Åge Andre; Johansen, Dag (Peer reviewed; Journal article; Tidsskriftsartikkel, 2016-02-03)
      We demonstrate a practical way to reduce latency for mobile .NET applications that interact with cloud services, without disrupting application architectures. We provide a programming abstraction for location-independent code, which has the potential to execute either locally or at a satellite execution environment in the cloud, where other cloud services can be accessed with low latency. This ...
    • Gender differences in the association between grip strength and mortality in older adults: results from the KORA-age study 

      Arvandi, Marjan; Strasser, Barbara; Meisinger, Christa; Volaklis, Konstantinos; Gothe, Raffaella Matteucci; Siebert, Uwe; Ladwig, Karl Heinz; Grill, Eva; Horsch, Alexander; Laxy, Michael; Peters, Annette; Thorand, Barbara (Journal article; Tidsskriftartikkel; Peer reviewed, 2016-11-30)
      Background: Reduced muscular strength in the old age is strongly related to activity impairment and mortality. However, studies evaluating the gender-specific association between muscularity and mortality among older adults are lacking. Thus, the objective of the present study was to examine gender differences in the association between muscular strength and mortality in a prospective population-based ...
    • GreenBST: Energy-efficient concurrent search tree 

      Umar, Ibrahim; Anshus, Otto; Ha, Hoai Phuong (Conference object; Konferansebidrag, 2016-08-09)
      Like other fundamental abstractions for energy-efficient com- puting, search trees need to support both high concurrency and fine- grained data locality. However, existing locality-aware search trees such as ones based on the van Emde Boas layout (vEB-based trees), poorly support concurrent (update) operations while existing highly-concurrent search trees such as the non-blocking binary search ...
    • On the performance and energy efficiency of the PGAS programming model on multicore architectures 

      Lagraviere, Jeremie Alexandre Emilien; Langguth, Johannes; Sourouri, Mohammed; Ha, Hoai Phuong; Cai, Xing (Journal article; Tidsskriftartikkel; Peer reviewed, 2016-09-15)
    • Access control protocol with node privacy in wireless sensor networks 

      Kumar, Pardeep; Gurtov, Andrei; Iinatti, Jari; Sain, Mangal; Ha, Hoai Phuong (Journal article; Tidsskriftartikkel; Peer reviewed, 2016-11-15)
      For preventing malicious nodes joining wireless sensor networks (WSNs), an access control mechanism is necessary for the trustworthy cooperation between the nodes. In addition to access control, recently, privacy has been an important topic regarding how to achieve privacy without disclosing the real identity of communicating entities in the WSNs. Based on elliptic curve cryptography, in this paper, ...
    • Secure and scalable statistical computation of questionnaire data in R 

      Yigzaw, Kassaye Yitbarek; Michalas, Antonis; Bellika, Johan Gustav (Journal article; Tidsskriftartikkel; Peer reviewed, 2016-08-12)
      Collecting data via a questionnaire and analyzing them while preserving respondents' privacy may increase the number of respondents and the truthfulness of their responses. It may also reduce the systematic differences between respondents and non-respondents. In this paper, we propose a privacy- preserving method for collecting and analyzing survey responses using secure multi-party computation. The ...
    • Implementing and optimizing a Sparse Matrix-Vector Multiplication with UPC 

      Lagraviere, Jeremie Alexandre Emilien; Prugger, Martina; Einkemmer, Lukas; Langguth, Johannes; Ha, Hoai Phuong; Cai, Xing (Research report; Forskningsrapport, 2016)
      Programmability and performance-per-watt are the major challenges of the race to Exascale. In this study we focus on Partitioned Global Address Space (PGAS) languages, using UPC as a particular example. This category of parallel languages provides ease of programming as a strong advantage over the classic Message Passing Interface(MPI). PGAS has also advantages compared to classic shared memory ...
    • Enforcing Privacy Policies with Meta-Code 

      Johansen, Håvard; Birrell, Eleanor; Van Renesse, Robbert; Schneider, Fred B.; Stenhaug, Magnus; Johansen, Dag (Konferansebidrag; Conference object, 2015)
      This paper proposes a mechanism for expressing and enforcing security policies for shared data. Security policies are expressed as stateful meta-code operations; meta-code can express a broad class of policies, including access-based policies, use-based policies, obligations, and sticky policies with declassification. The meta-code is interposed in the filesystem access path to ensure policy ...
    • Lessons learned from 25 years with telemedicine in Northern Norway 

      Hartvigsen, Gunnar; Pedersen, Steinar (Book; Bok, 2015)
    • Appendix E Telemedisinske løsninger i maritime operasjoner og redningstjeneste 

      Woldaregay, Ashenafi Zebene; Hartvigsen, Gunnar; Walderhaug, Ståle (Research report; Forskningsrapport, 2016)
      Folk som jobber i maritime miljø har ikke enkel tilgang til sentrale helsetjenester, og det gjelder spesielt for sjøfolk som arbeider i arktiske områder. Selv om telemedisin har vært en suksess på land, har telemedisin kun i begrenset grad blitt tatt i bruk til havs. Dette skyldes blant annet fravær av gode kommunikasjonsløsninger, dårlige værforhold, store avstander og lange perioder utenfor ...
    • Digital Chronofiles of Life Experience 

      Gurrin, Cathal; Johansen, Håvard; Sødring, Thomas; Johansen, Dag (Chapter; Bokkapittel, 2015-02-28)
      Technology has brought us to the point where we are able to digitally sample life experience in rich multimedia detail, often referred to as lifelogging. In this paper we explore the potential of lifelogging for the digitisation and archiving of life experience into a longitudinal media archive for an individual. We motivate the historical archive potential for rich digital memories, enabling ...
    • Data-intensive computing infrastructure systems for unmodified biological data analysis pipelines 

      Bongo, Lars Ailo; Pedersen, Edvard; Ernstsen, Martin (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-11-18)
      Biological data analysis is typically implemented using a deep pipeline that combines a wide array of tools and databases. These pipelines must scale to very large datasets, and consequently require parallel and distributed computing. It is therefore important to choose a hardware platform and underlying data management and processing systems well suited for processing large datasets. There are many ...
    • Kvik: three-tier data exploration tools for flexible analysis of genomic data in epidemiological studies 

      Fjukstad, Bjørn; Olsen, Karina Standahl; Jareid, Mie; Lund, Eiliv; Bongo, Lars Ailo (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-03-30)
      Kvik is an open-source system that we developed for explorative analysis of functional genomics data from large epidemiological studies. Creating such studies requires a significant amount of time and resources. It is therefore usual to reuse the data from one study for several research projects. Often each project requires implementing new analysis code, integration with specific knowledge bases, ...
    • Description of spatio-temporal gait parameters in elderly people and their association with history of falls: Results of the population-based cross-sectional KORA-Age study 

      Thaler-Kall, Kathrin; Peters, Annette; Thorand, Barbara; Grill, Eva; Autenrieth, Christine S.; Horsch, Alexander; Meisinger, Christa (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-03-25)
      Background: In this epidemiological study we described the characteristics of spatio-temporal gait parameters among a representative, population-based sample of 890 community-dwelling people aged 65 to 90 years. In addition, we investigated the associations between certain gait parameters and a history of falls in study participants. <p>Methods: In descriptive analyses spatio-temporal gait parameters ...
    • Towards Consent-Based Lifelogging in Sport Analytic 

      Johansen, Håvard; Gurrin, Cathal Gerard; Johansen, Dag (Chapter; Bokkapittel, 2015)
      Lifelogging is becoming widely deployed outside the scope of solipsistic self quantification. In elite sport, the ability to utilize these digital footprints of athletes for sport analytic has already become a game changer. This raises privacy concerns regarding both the individual lifelogger and the bystanders inadvertently captured by increasingly ubiquitous sensing devices. This paper describes ...
    • Fireflies: A Secure and Scalable Membership and Gossip Service 

      Johansen, Håvard; Van Renesse, Robbert; Vigfusson, Ymir; Johansen, Dag (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-06)
      An attacker who controls a computer in an overlay network can effectively control the entire overlay network if the mechanism managing membership information can successfully be targeted. This article describes Fireflies, an overlay network protocol that fights such attacks by organizing members in a verifiable pseudorandom structure so that an intruder cannot incorrectly modify the membership views ...
    • DeltaTree: A Locality-aware Concurrent Search Tree 

      Umar, Ibrahim; Anshus, Otto; Ha, Hoai Phuong (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-06-15)
      Like other fundamental abstractions for high-performance computing, search trees need to support both high concurrency and data locality. However, existing locality-aware search trees based on the van Emde Boas layout (vEB-based trees), poorly support concurrent (update) operations. We present DeltaTree, a practical locality-aware concurrent search tree that integrates both locality-optimization ...