Frequency-Domain Analysis of Linear Time-Periodic Systems

In this paper, we study convergence of truncated representations of the frequency-response operator of a linear time-periodic system. The frequency-response operator is frequently called the harmonic transfer function. We introduce the concepts of input, output, and skew roll-off. These concepts are related to the decay rates of elements in the harmonic transfer function. A system with high input and output roll-off may be well approximated by a low-dimensional matrix function. A system with high skew roll-off may be represented by an operator with only few diagonals. Furthermore, the roll-off rates are shown to be determined by certain properties of Taylor and Fourier expansions of the periodic systems. Finally, we clarify the connections between the different methods for computing the harmonic transfer function that are suggested in the literature

Managing Alaska’s Coastal Development: State Review of Federal Oil and Gas Lease Sales

Contention for shared cache resources has been recognized as a major bottleneck for multicores—especially for mixed workloads of independent applications. While most modern processors implement instructions to manage caches, these instructions are largely unused due to a lack of understanding of how to best leverage them. This paper introduces a classification of applications into four cache usage categories. We discuss how applications from different categories affect each other's performance indirectly through cache sharing and devise a scheme to optimize such sharing. We also propose a low-overhead method to automatically find the best per-instruction cache management policy. We demonstrate how the indirect cache-sharing effects of mixed workloads can be tamed by automatically altering some instructions to better manage cache resources. Practical experiments demonstrate that our software-only method can improve application performance up to 35% on x86 multicore hardware.Coder-mpUPMAR

Fokus 2015: Die Millenniums-Entwicklungsziele – Magna Charta der Globalisierung? Eine Zwischenbilanz – 5 Jahre nach der UN-Millenniumserklärung. Dokumentation der gleichnamigen Konferenz am 25. Januar 2005 in Berlin

The purpose of this paper is to explore how sustainable competitive advantage is generated in two Swedish best practice companies that successfully exploit logistics as a source for competitive advantage. Using a theoretical framework based on the resource-based view of the firm, this research elaborates on the links between operational and dynamic logistics capabilities and sustainable competitive advantage. The findings conclude that a sustainable competitive advantage is based on a combination of efficient and effective logistics operations and well-functioning, adjusted, in-house-developed IT systems. This operational capability is in turn sustained through five dynamic capabilities: managerial knowledge and presence, cross-functional teamwork, control, learning and supply chain relationships.  This is an electronic version of an article published in:Erik Sandberg and Mats Abrahamsson, Logistics capabilities for sustainable competitive advantage, 2011, International Journal of Logistics, (14), 1, 61-75.International Journal of Logistics is available online at informaworldTM: http://dx.doi.org/10.1080/13675567.2010.551110Copyright: Taylor & Francishttp://www.tandf.co.uk/journals/default.as

The effect of selection systems on the community of vascular plants

The utilization of the Swedish forest as a natural resource has intensified during the last decade, which has led to an increase in disturbances on the forest ecosystems as a result of clear cutting. The effect of forestry on species richness and species composition has a large impact on how well the biodiversity and ecological communities can function. The interest for continuous cover forestry has increased, especially for selection system, but studies examining the effect that this has on biodiversity is limited. This study seeks to increase the knowledge on how selection systems affect the biodiversity among vascular plants in the field layer, with extra focus on the key species bilberry (Vaccinium myrtillus L.). This was measured through different biodiversity indexes: Species richness, Shannon-Wiener index, community evenness and the abundance of bilberry. The study took place on six sites in central Sweden and was consisted of an inventory in 2013, selective felling 2014, followed by a second inventory in 2018. Each site consisted of two adjacent areas: a control where no measure was taken, and one where selective felling was conducted. The study found no difference between the cut areas and the controls. The results indicate that selection systems can be seen as a suitable alternative to the more common rotation forestry system, regarding conservation of biodiversity. More studies are needed to examine the long-term effects of selective felling systems to be able to conclude how it effects biodiversity. The studies should preferably be more extensive and conducted on a larger time scale.Nyttjandet av den svenska skogen som naturresurs har ökat det senaste århundrandet, vilket har lett till ökade störningar i skogsekosystem till följd av trakthyggesbruket. Skogsbrukets påverkan på artrikedom och artsammansättning har stor betydelse för biodiversitet och ekosystemfunktioner. Intresset för hyggesfria skogsskötselsystem, främst i form av blädningsbruk, har ökat. Studier om blädningsbrukets påverkan på biodiversitet är få och det saknas tydlig forskning om dess effekter. Denna studie söker att ge en ökad förståelse för hur blädningsbruk påverkar biodiversiteten hos kärlväxtsamhällen i fältskiktet, med fokus på nyckelarten blåbär (Vaccinium myrtillus, L.). Detta studerades genom olika diversitetsindex; Species richness, Shannon-Wiener index, Community evenness, samt förekomsten av blåbär. Studien utfördes på sex lokaler i Mellansverige genom en första inventering år 2013, följt av blädning år 2014, samt en andra inventering år 2018. Samtliga lokaler utgjordes av två parceller, en försöksyta som blädades samt en kontrollyta där ingen åtgärd utfördes. Studien fann ingen skillnad på blädningsytorna gentemot kontrollytorna. Resultatet indikerade att blädningsbruk kan ses som ett bra alternativ till det vanligare trakthyggesbruket, med avseende på bevarande av biologisk mångfald. För att med säkerhet kunna dra slutsatser kring blädningsbrukets påverkan på biodiversiteten på längre sikt krävs mer omfattande studier som sträcker sig över en längre tidshorisont

Electric vehicles : An assessment of consumer perceptions using importance-performance analysis

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A dynamic capabilities approach

peerReviewe

Importance of aviation in higher education

Author's accepted version (post-print).Available from 09/08/2020.Air transport is particularly important for countries with geographically scattered settlements, where ground transport can be time consuming. Norway is one such country, and Norwegian authorities regard aviation as a regional policy instrument; therefore, they procure unprofitable air services in rural areas. To increase human capital in rural areas, Norway has a decentralised system of Higher Education Institutions (HEIs). This paper evaluates the importance of aviation to this HEI system and estimates the welfare effects from aviation on their students and employees. We found that the number of job-related air trips completed by HEI employees is significantly higher than the average number of business trips in Norwegian enterprises. The number of air trips per HEI employee are highest in the regions furthest from the capital; as such, the welfare effects of aviation are greatest for HEIs in the most peripheral regions. To maintain the positive effect of aviation on HEIs, effective flight connections and the establishment of meeting venues where the HEIs management, airline representatives, airport management, and politicians can discuss measures to increase the benefits for HEIs and society are crucial.acceptedVersio

Public Service Obligation as a tool for implementing flight routes operated by electric aircrafts

Hovedformålet med denne rapporten er å undersøke hvilke erfaringer myndighetene kan ta med seg fra prosessen med innføring av nullutslippsfartøy i fergedriften i Norge når de gjennom kjøp av flyruter (FOT-ruter) skal legge til rette for at fly som får energien fra batterier eller andre nullutslippskilder skal kunne erstatte fly som benytter fossilt drivstoff. For å tilrettelegge for bruk av elektriske fly på disse rutene er det, basert på erfaringene fra fergeanbudene, viktig at Samferdselsdepartementet, foretar en kartlegging av strømforsyning og strømbehovet for alle flyplassene, involverer Avinor, Luftfartstilsynet og sikkerhetsmyndighetene, innleder en dialog med leverandører og underleverandører til luftfartsnæringen og starter arbeidet med utforming av nye anbudskontrakter. The main aim of this report is to investigate what experiences the authorities can draw from the recent process of introducing zero-emission vessels in ferry operations in Norway when, in purchasing air routes (PSO routes), they facilitate the replacement of aircraft powered by fossil fuels with ones that receive their energy from batteries or other zero-emission sources. In order to facilitate the use of electric aircraft on these routes, it is important that the Ministry of Transport, conducts a survey of power supply and power requirements for the airports, involves the airport owner and the safety authorities, initiates a dialogue with airlines, suppliers and subcontractors to the aviation industry and starts working on the design of new tender contracts

Research incentives and research output

Author's accepted version (post-print).This is a post-peer-review, pre-copyedit version of an article published in Higher Education. The final authenticated version is available online at: http://dx.doi.org/10.1007/s10734-018-0238-1.Available from 10/03/2019.acceptedVersio