4,280 research outputs found
Auslander-Reiten triangles and Grothendieck groups of triangulated categories
We prove that if the Auslander-Reiten triangles generate the relations for
the Grothendieck group of a Hom-finite Krull-Schmidt triangulated category with
a (co)generator, then the category has only finitely many isomorphism classes
of indecomposable objects up to translation. This gives a triangulated converse
to a theorem of Butler and Auslander-Reiten on the relations for Grothendieck
groups. Our approach has applications in the context of Frobenius categories.Comment: 9 pages. Final version, accepted for publication in Algebr.
Represent. Theor
High efficiency IMPATT diodes for 60 GHz intersatellite link applications
Intersatellite links are expected to play an increasingly important role in future satellite systems. Improved components are required to properly utilize the wide bandwidth allocated for intersatellite link applications around 60 GHz. IMPATT diodes offer the highest potential performance as solid state power sources for a 60 GHz transmitter. Presently available devices do not have the desired power and efficiency. High efficiency, high power IMPATT diodes for intersatellite link applications are being developed by NASA and other government agencies. The development of high efficiency 60 GHz IMPATT diodes by NASA is described
A Fluorescent Probe at the Active Site of Alpha Chymotrypsin
Spectrofluorimetric analysis of mobility and polarity of active sites of alpha chymotrypsi
Holocene forest development and tree-limit changes in Ridalen, in the RĂžros mountains
Holocene forest development, tree migration and tree-line fluctuations have been reconstructed from peat sequences, derived from two study localities situated along an altitudinal transect between the north boreal and low alpine zone in the mountain region of the RÞros area. The local-scaled reconstructions are based on pollen analysis, stomata and megafossil findings. Additionally, an attempt to reconstruct the climate history has been made by the use of the indicator species approach. The reconstructions have further been compared to other palaeoecological studies in adjacent regions to Ridalen, in order to deduce regional patterns for the Holocene vegetation and climate. A pioneer flora dominated at the LervahÄ mire at 770 m a.s.l. under relatively warm and dry conditions in early Holocene until ca. 10,500 cal. years BP. A rather coeval local presence of tree-birch (Betula pubescence) and pine (Pinus sylvestris) has been recorded at ca. 10,100 cal. years BP. Pine expanded rapidly thereafter, becoming the dominating tree in the Ridalen region until ca. 8,000-7,400 cal. years BP. Alnus grew locally in moister habitats at the LervahÄ mire from ca. 9,200 cal. years BP and reached its maximum abundance around 7,400- 7,100 cal. years BP, after which a sub-alpine birch forest established at Reinskaret. In the cooler and moister period subsequent to ca. 5,000 cal. years BP the sub-alpine birch forest reached the LervahÄ mire. Picea increased in abundance in regional forests after ca. 2,700 cal. years BP. In the period after ca. 3,700 cal. years BP, pine only grew as scattered individuals at 770 m a.sl. Tree-birch no longer grew at the Reinskaret locality after ca. 2,000 cal. years BP. The time of deglaciation could not be inferred for the area since the oldest layers could not be properly dated. Nevertheless, the stratigraphical sequence from the LervahÄ mire is assumed to represent maximum the last ca. 11,500 years. The tree that first established in the study region is still uncertain.Master i Biologi - Biodiversitet, evolusjon og ÞkologiMAMN-BIODIBIODI
Sammenhengen mellom kursen pÄ amerikanske dollar og oljepris : en teoretisk og empirisk analyse
BÄde oljepris og kursen pÄ amerikanske dollar er individuelt blitt underlagt detaljerte analyser
gjennom de senere Är, men det eksisterer etter min kjennskap fÄ analyser pÄ sammenhengen
mellom dem. Det kan derfor vÊre mye informasjon Ä hente ved Ä se nÊrmere pÄ dette. I denne
oppgaven har jeg tatt for meg en teoretisk og empirisk analyse av sammenhengen mellom
oljepris og kursen pÄ amerikanske dollar i perioden 1984-2008, samt for delperiodene 1984-
2000 og 2001-2008, da for Ä se om det har skjedd et skille rundt Är 2000. Jeg har ogsÄ
analysert om det eksisterer noen forskjell pÄ kort og lang sikt. BÄde med hensyn til en
sammenheng fra USD til oljepris og fra oljepris til USD er den teoretiske analysen lite
opplĂžftende. Konklusjonen for de fleste kanalene en sammenheng kan virke gjennom er at de
enten ikke er gjeldende, eller at de er svakt til stede, men ustabile. Under den empiriske
analysen har jeg benyttet meg av kausalitetsanalyser for den kortsiktige sammenhengen. For
den langsiktige sammenhengen har jeg benyttet meg av kointegrasjons- sammen med ECMog
kausalitetsanalyser. Jeg har ikke funnet empirisk stĂžtte for at det eksisterer en sammenheng
i noen av de tre periodene, 1984-2008, 1984-2000 og 2001-2008, hverken pÄ kort eller lang
sikt
The weekend's impact on Norwegian government bond volatility
The objective of this thesis is to explore how the weekend affects the general trading day in the Norwegian government bond market in the period 2000 - 2015. The empirical analysis consists of closing prices based on seven different government bonds traded on the Oslo Stock Exchange. When comparing the weekend variance with identical calendar and trading time, the results reflected a deviation from the Calendar-Time Hypothesis and a consistency with the Trading-Time Hypothesis. The Trading-Time Hypothesis is found be the best describing price behaviour for bonds with lesser than five years to maturity.
These results cause evident implications for Value at Risk analysis. When approaching the Calendar-Time Hypothesis in favour of acknowledging the weekendâs effect on volatility, the results lead to a risk overestimation during the weekend and risk underestimation during weekdays. The Trading-Time Hypothesis is generally a better fit, where the over- and underestimations are relatively centred around zero. The same implications apply for option valuation in the Norwegian government bond market. When approaching the Calendar-Time Hypothesis in favour of acknowledging the weekendâs effect on volatility, the results lead to a pricing overvaluation during the weekend and pricing undervaluation during weekdays. In terms of percentage over- and undervaluation, out-of-the-money options show a stronger sensitivity to misinterpret the weekendâs volatility compared to in-the-money options. The significance of this misinterpretation decreases as maturity increases and almost completely vanish after one year.Denne masterutredningen undersĂžker hvorvidt helgen pĂ„virker handledager i det norske
markedet for statsobligasjoner i lÞpet av perioden 2000-2015. Den empiriske analysen bestÄr
av close priser fra syv ulike statsobligasjoner som handles pÄ Oslo BÞrs. NÄr variansen over
helgen sammenlignes med identisk kalender- og handletid, viser resultatet et avvik fra
Kalendertid Hypotesen og en tilnĂŠrming til Handletid Hypotesen. Handletid Hypotesen blir
sett pÄ som best beskrivende for prisutviklingen til obligasjoner med mindre enn fem Är til
forfall.
Disse resultatene skaper tydelige utfordringer for Value at Risk analyse. En tilnĂŠrming til
Kalendertid Hypotesen, som positivt anerkjenner helgens pÄvirkning pÄ volatilitet i
ukedagene, resulterer i en overestimering av risiko over helgen og en underestimering av
risiko i ukedager. Handletid Hypotesen gir en bedre risiko beskrivelse, hvor over- og
underestimeringen av risiko er relativt sentrert rundt null. De samme utfordringene gjelder for
opsjonsprising i det norske markedet for statsobligasjoner. En tilnĂŠrming til Kalendertid
Hypotesen, med sin anerkjennelse av helgens pÄvirkning pÄ volatilitet i ukedagene, resulterer
i en overprising over helgen og en underprising i ukedager. NĂ„r det gjelder prosentvis overog
underprising, sÄ viser out-of-the-money opsjoner en mye stÞrre sensitivitet enn in-themoney
opsjoner, i forhold til feiltolking av helgens pÄvirkning pÄ volatilitet i ukedagene.
Betydningen av denne feiltolkningen reduseres nÄr lÞpetiden Þker og er nesten helt borte etter
et Ă„r.M-Ă
Cotton import to Norway 1835-1920. Import, industrialization and globalization.
Historie mastergradsoppgaveHIS350MAHF-HISMAHF-LĂH
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