Ketil Danielsen

• Husakou, Anatol; Hvattum, Lars Magnus; Danielsen, Ketil & Hoff, Arild (2020). An application of the multi-depot heterogeneous fixed fleet open vehicle routing problem. International Journal of Advanced Operations Management (IJAOM). ISSN 1758-938X. 12(2), p. 142–155. doi: 10.1504/IJAOM.2020.108262. Full text in Research Archive Show summary

  This work describes an application of a multi-depot heterogeneous fixed fleet open vehicle routing problem. A contractor owns a fleet of vehicles with different capacities and running costs. The fleet is used to transport craftsmen from their homes to assigned project sites and back, with some of the craftsmen appointed as drivers while others are passengers. An optimisation model is described that enables the contractor to minimise the transportation costs, and a computational study shows that the model can be solved to optimality for realistically sized instances using a standard mixed-integer programming solver. A variant of the problem is also considered, where the assignment of craftsmen to projects is not fixed a priori. For this variant, several simple heuristic rules are investigated to generate project assignments, and computational results show that they are able to find improved assignments. Keywords: mixed integer programming, assignment, transportation

• Jæger, Bjørn & Danielsen, Ketil (2006). On rerouting in MPLS based networks. WSEAS Transactions on Communications. ISSN 1109-2742. 5(10), p. 2024–2030. Show summary

  In this paper we consider the problem of rerouting after a failure in MPLS based networks. MPLS technology enables scalable VPNs and end-to-end QoS over the Internet which requires efficient fault recovery in presence of link or node failures. A major factor on network performance in connection oriented packet switched networks is the transient congestion that results from restored Label Switched Paths trying to retransmit packets lost since the failure. We focus on the step in the restoration process where new recovery paths are selected, and we discuss various strategies for picking paths in order to reduce the transient effects on network performance after a failure. We present results from a simulation-based performance study of four routing algorithms. The results show that using dedicated fault recovery routing algorithms can improve MPLS-network performance after a failure compared to steady state algorithms.

• Molka-Danielsen, Judith Ann & Danielsen, Ketil (2000). Pricing and admissions policies for IP networks. Telektronikk. ISSN 0085-7130. 96(2), p. 59–67. Show summary

  Resource reservation systems are becoming an important tool as network providers are beginning to offer multimedia support, virtual leased lines and private networks over packetswitched internetworks. Policy-controlled access to the reservation system is necessary, but may fail to capture the immediate needs of the user. Market-based access control offers an alternative to policy-based control, where requests are admitted based on the current willingness to pay for reservation service. It is important to discover the level of value these market-based access controls offer to customer. Do these market-based mechanisms improve the customer perceived quality of service (QoS) over simple policy-based access such as first-come first-serve queuing? In this study, we examine several admission policies using market-based access controls. Our study seeks to attain whether value improvements over policy-based admission mechanisms could be obtained using market-based access control mechanisms such as auctions and reservation options. We have implemented a market-based admissions system that use bids and an auction-based admission rule to determine which customers gain access to network resources. We also have studied the use of a rule that prevents the preemption of network resources once they are gained.

• Danielsen, Ketil; Jæger, Bjørn & Molka-Danielsen, Judith (1998). Kvalitetsgarantier for multimediatjenester. Unitnytt. ISSN 1504-8403.
• Danielsen, Ketil & Weiss, Martin B. H. (1997). User control and IP allocation. In McKnight, Lee W. & Bailey, Joseph P. (Ed.), Internet economics. MIT Press. ISSN 0-262-13336-9. p. 305–321.
• Danielsen, Ketil & Weiss, Martin B. H. (1996). Real-time end user input to the network link sharing problem. In Emstad, Peder J.; Helvik, Bjarne Emil & Myskja, Arne H. (Ed.), The Thirteenth Nordic Teletraffic Seminar, NTS-13 : Trondheim, Norway, August 20-22, 1996. NTNU : department of telematics. ISSN 82-993980-0-2. p. 305–312.

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• Hoff, Arild; Hvattum, Lars Magnus & Danielsen, Ketil (2021). An application of the multi-depot heterogeneous fixed fleet open vehicle routing problem.
• Jæger, Bjørn & Danielsen, Ketil (2006). Effects of rerouting after service disruption in MPLS based networks. Show summary

  This paper considers the effects of dynamic restoration routing after a failure in MPLS based networks. MPLS technology enables scalable VPNs and end-to-end QoS over the Internet which requires efficient fault recovery in presence of link or node failures. A major factor on network performance after a failure is the transient congestion that results from restored connections trying to retransmit packets lost since the failure. We focus on the importance of appropriate selection of a rerouting algorithm to control the transient congestion, and we present results from a simulation-based performance study of several routing algorithms. The results show that proper selection of fault recovery routing algorithm can improve MPLS-network performance after a failure.

• Jæger, Bjørn & Danielsen, Ketil (2006). Effects of rerouting after service disruption in MPLS based networks, Proceedings of the 6th WSEAS International Conference on Applied Informatics and Communications [CD ROM]. WSEAS Working Group on Computer Science ; WSEAS Working Group on Commu. Show summary

  This paper considers the effects of dynamic restoration routing after a failure in MPLS based networks. MPLS technology enables scalable VPNs and end-to-end QoS over the Internet which requires efficient fault recovery in presence of link or node failures. A major factor on network performance after a failure is the transient congestion that results from restored connections trying to retransmit packets lost since the failure. We focus on the importance of appropriate selection of a rerouting algorithm to control the transient congestion, and we present results from a simulation-based performance study of several routing algorithms. The results show that proper selection of fault recovery routing algorithm can improve MPLS-network performance after a failure.

• Jæger, Bjørn & Danielsen, Ketil (2004). Effect of rerouting after service disruption in MPLS based networks.
• Danielsen, Ketil (2000). RSVP pilotprosjekt.
• Danielsen, Ketil & Molka-Danielsen, Judith (1999). Admissions and preemption in auction-based reservation networks.
• Molka-Danielsen, Judith Ann & Danielsen, Ketil (1999). Pricing in admissions policy : using hold options over IP networks.
• Danielsen, Ketil (1998). Real-time auctions for network resource allocation.
• Danielsen, Ketil (1998). UNINETT RSVP pilotprosjekt.
• Danielsen, Ketil; Molka-Danielsen, Judith & Jæger, Bjørn (1998). Tester framtidas internett. Romsdals Budstikke.. ISSN 0806-5160.
• Danielsen, Ketil (1998). RSVP pilotprosjekt.
• Danielsen, Ketil; Molka-Danielsen, Judith & Jæger, Bjørn (1998). Fremtidens kommunikasjonsnettverk. In Bræin, Lasse & Hervik, Arild (Ed.), Populærvitenskapelige artikler : Forskningsdagene 98. Høgskolen i Molde. ISSN 82-90347-84-7. p. 57–59. Show summary

  Data-, tele-, internett- og TV-verdenen deler alle en drøm om å kunne tilby tjenestene ved hjelp av ett og samme fysiske nettverk. Om du hører på radio, ser på TV, surfer på Internett eller snakker i telefon, skal du kunne bruke en og samme "boks" hjemme og bare ha en ledning inn i huset ditt. Kort sagt er målet å slå sammen dagens system for enveis utsendelse av levende bilder og lyd (TV), med de toveis kommunikasjonssystem som finnes (telefonen og Internett).

• Danielsen, Ketil & Weiss, Martin B. H. (1996). Real-time end user input to the network link sharing problem.
• Danielsen, Ketil (2001). Auctions and preemptions in reservation-based computer networks. UMI Dissertation Services.
• Molka-Danielsen, Judith Ann & Danielsen, Ketil (1999). Pricing in admissions policy : using hold options over IP networks (Paper for the 27th Annual Telecommunications Policy Research Conference, Sept 25-27, 1999, Washington D.C., USA). Høgskolen i Molde. ISSN 82-7962-004-4.
• Danielsen, Ketil; Jæger, Bjørn & Molka-Danielsen, Judith Ann (1998). RSVP technology for UNINETT multimedia services : pilot project, technical tests [Kompendium]. Høgskolen i Molde.

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