Modern Societal Impulses and their Nordic Manifestations : On Emancipation and Constraint in Societal Development

The 1980s and the early 1990s have proved to be an important turning point in the history of the Nordic welfare states. After this breaking point, the Nordic social order has been built upon a new foundation. This study shows that the new order is mainly built upon new hierarchies and control mechanisms that have been developed consistently through economic and labour market policy measures. During the post-war period Nordic welfare states to an increasing extent created equality of opportunity and scope for agency among people. Public social services were available for all and the tax-benefit system maintained a level income distribution. During this golden era of Nordic welfare state, the scope for agency was, however, limited by social structures. Public institutions and law tended to categorize people according to their life circumstances ascribing them a predefined role. In the 1980s and 1990s this collectivist social order began to mature and it became subject to political renegotiation. Signs of a new social order in the Nordic countries have included the liberation of the financial markets, the privatizing of public functions and redefining the role of the public sector. It is now possible to reassess the ideological foundations of this new order. As a contrast to widely used political rhetoric, the foundation of the new order has not been the ideas of individual freedom or choice. Instead, the most important aim appears to have been to control and direct people to act in accordance with the rules of the market. The various levels of government and the social security system have been redirected to serve this goal. Instead of being a mechanism for redistributing income, the Nordic social security system has been geared towards creating new hierarchies on the Nordic labour markets. During the past decades, conditions for receiving income support and unemployment benefit have been tightened in all Nordic countries. As a consequence, people have been forced to accept deteriorating terms and conditions on the labour market. Country-specific variations exist, however: in sum Sweden has been most conservative, Denmark most innovative and Finland most radical in reforming labour market policy. The new hierarchies on the labour market have co-incided with slow or non-existent growth of real wages and with a strong growth of the share of capital income. Slow growth of real wages has kept inflation low and thus secured the value of capital. Societal development has thus progressed from equality of opportunity during the age of the welfare states towards a hierarchical social order where the majority of people face increasing constraints and where a fortunate minority enjoys prosperity and security.

“Empire is a state of mind” – Imagining Eurasia in Russia –

Työssäni tarkastelen venäläistä neo-euraasianistista liikettä ja tapoja joilla liikkeen aktivistit rakentavat Euraasiasta yhtenäistä kokonaisuutta ja imperiumia. Keskeisiä tutkimuskysymyksiäni ovat: Mikä imperiumi on ja mitkä ovat sen keskeisiä motivaatioita ja teemoja? Kuinka imperiumin idea rakentuu tai käsitetään ja tämän voi tulkita? Minkälaisia seurauksia voi tulkita heidän tavallaan Euraasia nähdä olevan? Materiaalina käytän haastatteluja, jotka on kerätty Moskovassa keväällä 2008, ja liikkeen kirjallisia tuotoksia (lehdet ja Internet -sivut). Neo-euraasianistisella liikkeellä tarkoitan tässä työssä Kansainvälistä Euraasianistista liikettä (Meždunarodnoe Evrazijskoe Dviženie) ja sen alahaaraa Euraasianistista Nuorisoliittoa (Evrazijskij Sojuz Molodëži). Liike perustettiin virallisesti 2003, mutta rakentaa vahvasti historiallista yhteyttä 1930 -luvun klassiseen eurasianismiin. Tämän lisäksi sen diskurssissa on paljon neuvostoliittolaisia, fasistisia, uuskonservatiivisia ja nationalistisia piirteitä. Liikkeen johtohahmo on filosofi-geopoliitikko Alexandr Dugin. Työn tausta-ajatuksena minua kiinnostaa etenkin nk. älymystön tai intelligenttien vaikutus nationalismiin tai sosiaalisia ryhmiä määrittelevien diskurssien kehitykseen ja muutokseen.Tarkastelen materiaalia diskurssianalyyttisesta näkökulmasta. Näen diskurssianalyysin sen tutkimisena, miten sosiaalista todellisuutta tuotetaan erilaisissa sosiaalisissa käytännöissä. Samalla näiden diskurssien tutkiminen, foucautlaisen perinteen myötä, tarkastelee kriittisesti niiden tuottamia (aktualisoituneita sekä potentiaalisia) valtasuhteita. Käytän työssäni myös Benedict Andersonin kuvitellun yhteisön (imagined communities) käsitettä, joka auttaa hahmottamaan tapaa, jolla tutkimuskohteeni rakentavat imperiumia yhteisönä. Aktivistien puheessa imperiumi (imperiâ) tulee esiin pääasiallisesti positiivisesti ja ”heidän omanaan,” kun taas termi imperialismi (imperializm) pääosin negatiivisena, liittyen etenkin keskeisenä vihollisena pidettyihin Yhdysvaltoihin. Esiin nousee monta toisiinsa liittyvää teemaa, jotka jaottelen viideksi pääteemaksi. Näistä tarkastelen lähemmin imperiumia ”kaikkien kansojen hyväntekijänä (poliittinen puoli)”, ulkoisen voiman lähteenä (historiallis-geopoliittinen puoli) sekä kollektiivisen subjektin luojana (imperialistis-nationalistinen puoli). Pyrin kontekstualisoimaan diskurssin ja tarkastelemaan tapoja, joilla se ammentaa motiiveja myös historiallis-kulttuurisista tavoista hahmottaa aluetta ja sen asukkaita. Käsittelen myös kansan, kansakunnan, etnoksen ja nationalismin käsitteitä ja sitä, miten ne nousevat neo-eurasianistisessa diskursissa esiin. Imperiaalisen nationalismin (imperskij nacionalizm) käsite auttaa ymmärtämään niitä tapoja, jolla liike tekee sekä pesäeroa nationalismiin että samalla hyödyntää monia nationalistisen diskurssin perusteemoja. Eräs liikkeen diskurssin keskeisistä eroista niin sanottuun nationalismin valtavirtaan on ”kansakunnan (naciâ)” käsitteen vahva negatiivinen konnotaatio. Sen vastakohtana esiin nostetaan vahvasti kansan (narod) käsite. Samalla kuitenkin etnisen venäläisen (russkij) käsitettä käytetään tavallista laajemmin ja kattavammin kuin tavallisesti, ja ennen kaikkea Venäjä nousee imperiumin keskeisimmäksi tekijäksi. Euraasialaiseen imperiumiin liitetyistä positiivistista mielikuvista käsittelen tarkemmin monikansallisuuden ja kansojen kodin ideaa, joka nousee mielestäni huomattavaksi retoriseksi taustaksi kaikessa materiaalissa. Tähän liittyy vahvasti myös saman teeman sivujuonne, eli imperiumin ”vapauttava” rooli. Tulkitsen, että liikkeen imperiumi -diskurssilla on instrumentaalinen luonne: se legitimoi aktivistien vaatimuksia varsinkin entisen Neuvostoliiton alueen suhteen. ”Euraasialaisen kansan” ajatus toimii mahdollisena Euraasiaa yhteisenä tekijänä ”Neuvostokansan” tilalla. Sen taustalla materiaalistani päätellen siintävät kuitenkin enemmänkin Venäjä ja venäläis -spesifit vaateet kuin koko Euraasia. Pohdin myös kansakunnan (nation) hyljeksimisen syitä ja käsitteen sopivuutta Venäjälle, kuten myös venäläisyyden käsitteiden kerrostuneisuutta. Kokonaisuudessaan imperiumi tuli esiin abstraktina, utopistisena ja ”totaalisena” kokonaisuutena.

Models of Dispersal and Diversification

Ecology and evolutionary biology is the study of life on this planet. One of the many methods applied to answering the great diversity of questions regarding the lives and characteristics of individual organisms, is the utilization of mathematical models. Such models are used in a wide variety of ways. Some help us to reason, functioning as aids to, or substitutes for, our own fallible logic, thus making argumentation and thinking clearer. Models which help our reasoning can lead to conceptual clarification; by expressing ideas in algebraic terms, the relationship between different concepts become clearer. Other mathematical models are used to better understand yet more complicated models, or to develop mathematical tools for their analysis. Though helping us to reason and being used as tools in the craftmanship of science, many models do not tell us much about the real biological phenomena we are, at least initially, interested in. The main reason for this is that any mathematical model is a simplification of the real world, reducing the complexity and variety of interactions and idiosynchracies of individual organisms. What such models can tell us, however, both is and has been very valuable throughout the history of ecology and evolution. Minimally, a model simplifying the complex world can tell us that in principle, the patterns produced in a model could also be produced in the real world. We can never know how different a simplified mathematical representation is from the real world, but the similarity models do strive for, gives us confidence that their results could apply. This thesis deals with a variety of different models, used for different purposes. One model deals with how one can measure and analyse invasions; the expanding phase of invasive species. Earlier analyses claims to have shown that such invasions can be a regulated phenomena, that higher invasion speeds at a given point in time will lead to a reduction in speed. Two simple mathematical models show that analysis on this particular measure of invasion speed need not be evidence of regulation. In the context of dispersal evolution, two models acting as proof-of-principle are presented. Parent-offspring conflict emerges when there are different evolutionary optima for adaptive behavior for parents and offspring. We show that the evolution of dispersal distances can entail such a conflict, and that under parental control of dispersal (as, for example, in higher plants) wider dispersal kernels are optimal. We also show that dispersal homeostasis can be optimal; in a setting where dispersal decisions (to leave or stay in a natal patch) are made, strategies that divide their seeds or eggs into fractions that disperse or not, as opposed to randomized for each seed, can prevail. We also present a model of the evolution of bet-hedging strategies; evolutionary adaptations that occur despite their fitness, on average, being lower than a competing strategy. Such strategies can win in the long run because they have a reduced variance in fitness coupled with a reduction in mean fitness, and fitness is of a multiplicative nature across generations, and therefore sensitive to variability. This model is used for conceptual clarification; by developing a population genetical model with uncertain fitness and expressing genotypic variance in fitness as a product between individual level variance and correlations between individuals of a genotype. We arrive at expressions that intuitively reflect two of the main categorizations of bet-hedging strategies; conservative vs diversifying and within- vs between-generation bet hedging. In addition, this model shows that these divisions in fact are false dichotomies.

Urban ecosystem services at the plant-soil interface

Continuing urbanization is a crucial driver of land transformation, having widespread impacts on virtually all ecosystems. Terrestrial ecosystems, including disturbed ones, are dependent on soils, which provide a multitude of ecosystem services. As soils are always directly and/or indirectly impacted through land transformation, land cover change causes soil change. Knowledge of ecosystem properties and functions in soils is increasing in importance as humans continue to concentrate into already densely-populated areas. Urban soils often have hampered functioning due to various disturbances resulting from human activity. Innovative solutions are needed to bring the lacking ecosystem services and quality of life to these urban environments. For instance, the ecosystem services of the urban green infrastructure may be substantially improved through knowledge of their functional properties. In the research forming this thesis, the impacts of four plant species (Picea abies, Calluna vulgaris, Lotus corniculatus and Holcus lanatus) on belowground biota and regulatory ecosystem services were investigated in two different urban soil types. The retention of inorganic nitrogen and phosphorus in the plant-soil system, decomposition of plant litter, primary production, and the degradation of polycyclic aromatic hydrocarbons (PAHs) were examined in the field and under laboratory conditions. The main objective of the research was to determine whether the different plant species (representing traits with varying litter decomposability) will give rise to dissimilar urban belowground communities with differing ecological functions. Microbial activity as well as the abundance of nematodes and enchytraeid worm biomass was highest below the legume L. corniculatus. L. corniculatus and the grass H. lanatus, producing labile or intermediate quality litter, enhanced the proportion of bacteria in the soil rhizosphere, while the recalcitrant litter-producing shrub C. vulgaris and the conifer P. abies stimulated the growth of fungi. The loss of nitrogen from the plant-soil system was small for H. lanatus and the combination of C. vulgaris + P. abies, irrespective of their energy channel composition. These presumably nitrogen-conservative plant species effectively diminished the leaching losses from the plant-soil systems with all the plant traits present. The laboratory experiment revealed a difference in N allocation between the plant traits: C. vulgaris and P. abies sequestered significantly more N in aboveground shoots in comparison to L. corniculatus and H. Lanatus. Plant rhizosphere effects were less clear for phosphorus retention, litter decomposition and the degradation of PAH compounds. This may be due to the relatively short experimental durations, as the maturation of the plant-soil system is likely to take a considerably longer time. The empirical studies of this thesis demonstrated that the soil communities rapidly reflect changes in plant coverage, and this has consequences for the functionality of soils. The energy channel composition of soils can be manipulated through plants, which was also supported by the results of the separate meta-analysis conducted in this thesis. However, further research is needed to understand the linkages between the biological community properties and ecosystem services in strongly human-modified systems.

Root system traits of Norway spruce, Scots pine, and silver birch in mixed boreal forests: an analysis of root architecture, morphology, and anatomy

The aim of this thesis was to unravel the functional-structural characteristics of root systems of Betula pendula Roth., Picea abies (L.) Karst., and Pinus sylvestris L. in mixed boreal forest stands differing in their developmental stage and site fertility. The root systems of these species had similar structural regularities: horizontally-oriented shallow roots defined the horizontal area of influence, and within this area, each species placed fine roots in the uppermost soil layers, while sinker roots defined the maximum rooting depth. Large radial spread and high ramification of coarse roots, and the high specific root length (SRL) and root length density (RLD) of fine roots indicated the high belowground competitiveness and root plasticity of B. pendula. Smaller radial root spread and sparser branching of coarse roots, and low SRL and RLD of fine roots of the conifers could indicate their more conservative resource use and high association with and dependence on ectomycorrhiza-forming fungi. The vertical fine root distributions of the species were mostly overlapping, implying the possibility for intense belowground competition for nutrients. In each species, conduits tapered and their frequency increased from distal roots to the stem, from the stem to the branches, and to leaf petioles in B. pendula. Conduit tapering was organ-specific in each species violating the assumptions of the general vascular scaling model (WBE). This reflects the hierarchical organization of a tree and differences between organs in the relative importance of transport, safety, and mechanical demands. The applied root model was capable of depicting the mass, length and spread of coarse roots of B. pendula and P. abies, and to the lesser extent in P. sylvestris. The roots did not follow self-similar fractal branching, because the parameter values varied within the root systems. Model parameters indicate differences in rooting behavior, and therefore different ecophysiological adaptations between species.

Elämää suuremmat sankarittaret : Suomalaisen teatterin elämäkerralliset taiteilijahahmot vuosina 2000 - 2010

In the first decade of the 21st century, national notables were a significant theme in the Finnish theatre. The lives of artists, in particular, inspired the performances that combined historical and fictional elements. In this study, I focus on the characters of female artists in 18 Finnish plays or performances from the first decade of the 21st century. The study pertains to the field of performance analysis. I approach the characters from three points of view. Firstly, I examine them through the action of performances at the thematic level. Secondly, I concentrate on the forms of relationships between the audience and the half-historical character. Thirdly, I examine the representations of characters and their relationships to the audience using myth as a tool. I approach characters from the frame of feminist phenomenological theatre study but also combine the points of view of other traditions. As a model, I adapt the approach of the theatre researcher Bert O. States, which concentrates on the relation between a play s text and an actor, and between an actor and the public. Furthermore, I use the analysing tools of performance art in an examination of performances counted among the contemporary performance genre. The biographical plays about these artists are concentrated in the domestic sphere and take part in the conversation about the position of women in both the community and private life. They represent the heroines work, love, temptations and hardships. The artists do not carry out heroic acts, being more like everyday heroines whose lives and art were shared with the audience in an aphoristic atmosphere. In the examined performances, criticism of the heterosexual matrix was mainly conservative and the myths of female and male artists differed from each other: the woman artist was presented as a super heroine whose strength often meant sacrifices; the male artist was a weaker figure primarily pursuing his individualistic objectives. The performances proved to be a kind of documentary theatre, a hybrid of truth and fiction. Nonetheless, the constructions of subject and identity mainly represented the characters of the mythical stories and only secondarily gave a faithful rendition of the artists lives. Although these performances were addressed to the general and heterogeneous public, their audience proved to be a strictly predefined group, for which the national myths and the experience of a collective identity emerged as an important theme. The heroine characters offered the audience "safe" idols who ensured the solidity of the community. These performances contained common, shared values and gave the audience an opportunity to feel empathy and to be charmed by the confessions of well-known national characters.

Rocking response of rectangular rigid blocks under random noise base excitations

The response of a rigid rectangular block resting on a rigid foundation and acted upon simultaneously by a horizontal and a vertical random white-noise excitation is considered. In the equation of motion, the energy dissipation is modeled through a viscous damping term. Under the assumption that the body does not topple, the steady-state joint probability density function of the rotation and the rotational velocity is obtained using the Fokker-Planck equation approach. Closed form solution is obtained for a specific combination of system parameters. A more general but approximate solution to the joint probability density function based on the method of equivalent non-linearization is also presented. Further, the problem of overturning of the block is approached in the framework of the diffusion methods for first passage failure studies. The overturning of the block is deemed incipient when the response trajectories in the phase plane cross the separatrix of the conservative unforced system. Expressions for the moments of first passage time are obtained via a series solution to the governing generalized Pontriagin-Vitt equations. Numerical results illustra- tive of the theoretical solutions are presented and their validity is examined through limited amount of digital simulations.

Taloustilanteen heikkenemisestä johtuvat muutokset asuntosijoittamiseen pääkaupunkiseudulla 2008

Tutkielman tavoitteena on selvittää miten taloustaantuma vaikutti asuntosijoittamisen kiinnostavuuteen ja asuntomarkkinoilla käytävään keskusteluun vuonna 2008. Tuolloin Suomen talous taantui voimakkaasti ja nopeasti yllättäen myös ennusteita laativat asiantuntijat. Ekonomistien lausunnoista puuttui yhdenmukaisuus ja tarkkuus. Ne myös saattoivat muuttua merkittävästi lyhyellä aikavälillä. Taantumassa sijoitusviestintä on varovaista ja tarkasti muotoiltua. Sijoittajat uskovat mielellään muiden sijoittajien mielipiteitä ja käsityksiä vaikkei niiden taustalla olisikaan aina todennettua faktatietoa. Asiantuntijoiden tilastoihin halutaan uskoa vaikka niitä kohtaan koetaan epäilyksiä. Toisaalta asuntosijoittamisen kannattavuuteen ja taloudelliseen tuottoon halutaan uskoa vaikka asiantuntijat voisivat todistaa toisin. Tutkimus toteutettiin kvalitatiivisena tapaustutkimuksena jota analysoitiin Greimasin aktanttimallia mukaillen. Tutkimusaineisto koostui 14 Helsingin Sanomissa julkaistuista asuntosijoittamiseen liittyvistä artikkelista sekä 13 Taloussanomien keskustelupalstalla julkaistusta mielipidekirjoituksesta. Viestien merkityksiä käytiin läpi semioottisesti määrittelemällä eri aktanteille rooleja. Tarinassa sijoittajasubjektin objektina on asunto, jonka avulla pyritään saavuttamaan mahdollisimman suuri rahallinen tuotto. Lähettäjiä ovat muun muassa tilastojen laatijat ja sijoitusneuvojat. Kaikki optimaalisen sijoituspäätöksen tekemiseen vaikuttavat aktantit käydään tarkemmin läpi tutkimuksen loppupuolella.

Long-Term Excess Mortality after Aneurysmal Subarachnoid Hemorrhage

Objective There is high case-fatality rate and loss of productive life-years related to aneurysmal subarachnoid hemorrhage (aSAH) but little data on long-term survival of SAH patients. We aim to evaluate long-term excess mortality and related risk factors after aSAH. Methods One year survivors (n=3080) after aSAH from Department of Neurosurgery in Helsinki between 1980 and 2007 were reviewed for this retrospective follow-up study. Follow-up started one year after SAH and continued until death or the end of 2008 (36 960 patient-years). Mortality and relative survival ratio (RSR) were compared with matched general population. Results After 20 years, survivors of aSAH showed 18% excess mortality compared to general population. Risk factors included: old age; poor preoperative clinical condition; conservative aneurysm treatment; multiple aneurysms; and unfavourable clinical outcome at 3 months. Conclusion Even after initially favourable recovery, patients with aSAH experience excess mortality in the long run. Cardiovascular and cerebrovascular diseases are prominent in this population.

Non-conservatively loaded stochastic columns

A new finite element method is developed to analyse non-conservative structures with more than one parameter behaving in a stochastic manner. As a generalization, this paper treats the subsequent non-self-adjoint random eigenvalue problem that arises when the material property values of the non-conservative structural system have stochastic fluctuations resulting from manufacturing and measurement errors. The free vibration problems of stochastic Beck's column and stochastic Leipholz column whose Young's modulus and mass density are distributed stochastically are considered. The stochastic finite element method that is developed, is implemented to arrive at a random non-self-adjoint algebraic eigenvalue problem. The stochastic characteristics of eigensolutions are derived in terms of the stochastic material property variations. Numerical examples are given. It is demonstrated that, through this formulation, the finite element discretization need not be dependent on the characteristics of stochastic processes of the fluctuations in material property value.

Identification of Critical Residues of the Mycobacterial Dephosphocoenzyme A Kinase by Site-Directed Mutagenesis

Dephosphocoenzyme A kinase performs the transfer of the c-phosphate of ATP to dephosphocoenzyme A, catalyzing the last step of coenzyme A biosynthesis. This enzyme belongs to the P-loop-containing NTP hydrolase superfamily, all members of which posses a three domain topology consisting of a CoA domain that binds the acceptor substrate, the nucleotide binding domain and the lid domain. Differences in the enzymatic organization and regulation between the human and mycobacterial counterparts, have pointed out the tubercular CoaE as a high confidence drug target (HAMAP database). Unfortunately the absence of a three-dimensional crystal structure of the enzyme, either alone or complexed with either of its substrates/regulators, leaves both the reaction mechanism unidentified and the chief players involved in substrate binding, stabilization and catalysis unknown. Based on homology modeling and sequence analysis, we chose residues in the three functional domains of the enzyme to assess their contributions to ligand binding and catalysis using site-directed mutagenesis. Systematically mutating the residues from the P-loop and the nucleotide-binding site identified Lys14 and Arg140 in ATP binding and the stabilization of the phosphoryl intermediate during the phosphotransfer reaction. Mutagenesis of Asp32 and Arg140 showed catalytic efficiencies less than 5-10% of the wild type, indicating the pivotal roles played by these residues in catalysis. Non-conservative substitution of the Leu114 residue identifies this leucine as the critical residue from the hydrophobic cleft involved in leading substrate, DCoA binding. We show that the mycobacterial enzyme requires the Mg2+ for its catalytic activity. The binding energetics of the interactions of the mutant enzymes with the substrates were characterized in terms of their enthalpic and entropic contributions by ITC, providing a complete picture of the effects of the mutations on activity. The properties of mutants defective in substrate recognition were consistent with the ordered sequential mechanism of substrate addition for CoaE.

Minimum weight design of fiber-reinforced laminated composite structures with maximum stress and Tsai-Wu failure criteria

In this article, a minimum weight design of carbon/epoxy laminates is carried out using genetic algorithms. New failure envelopes have been developed by the combination of two commonly used phenomenological failure criteria, namely Maximum Stress (MS) and Tsai-Wu (TW) are used to obtain the minimum weight of the laminate. These failure envelopes are the most conservative failure envelope (MCFE) and the least conservative failure envelope (LCFE). Uniaxial and biaxial loading conditions are considered for the study and the differences in the optimal weight of the laminate are compared for the MCFE and LCFE. The MCFE can be used for design of critical load-carrying composites, while the LCFE could be used for the design of composite structures where weight reduction is much more important than safety such as unmanned air vehicles.

Chance constrained uncertain classification via robust optimization

This paper studies the problem of constructing robust classifiers when the training is plagued with uncertainty. The problem is posed as a Chance-Constrained Program (CCP) which ensures that the uncertain data points are classified correctly with high probability. Unfortunately such a CCP turns out to be intractable. The key novelty is in employing Bernstein bounding schemes to relax the CCP as a convex second order cone program whose solution is guaranteed to satisfy the probabilistic constraint. Prior to this work, only the Chebyshev based relaxations were exploited in learning algorithms. Bernstein bounds employ richer partial information and hence can be far less conservative than Chebyshev bounds. Due to this efficient modeling of uncertainty, the resulting classifiers achieve higher classification margins and hence better generalization. Methodologies for classifying uncertain test data points and error measures for evaluating classifiers robust to uncertain data are discussed. Experimental results on synthetic and real-world datasets show that the proposed classifiers are better equipped to handle data uncertainty and outperform state-of-the-art in many cases.

Vertical uplift capacity of horizontal anchors

The method of characteristics coupled with a log-spiral failure surface was used to develop a theory for vertical uplift capacity of shallow horizontal strip anchors in a general c-phi soil. Uplift-capacity factors F(c), F(q) and F(gamma), for the effects of cohesion, surcharge, and density, respectively, have been established as functions of embedment ratio lambda and angle of friction phi. The extent of the failure surface at the ground has also been determined. Comparisons made with existing test results support the predictive capability of the theory, and comparisons with the analysis proposed by Meyerhof and Adams show the proposed analysis provides slightly more conservative predictions of pullout capacity.

The effect of traffic shaping in efficiently providing end-to-end performance guarantees

This paper reports new results concerning the capabilities of a family of service disciplines aimed at providing per-connection end-to-end delay (and throughput) guarantees in high-speed networks. This family consists of the class of rate-controlled service disciplines, in which traffic from a connection is reshaped to conform to specific traffic characteristics, at every hop on its path. When used together with a scheduling policy at each node, this reshaping enables the network to provide end-to-end delay guarantees to individual connections. The main advantages of this family of service disciplines are their implementation simplicity and flexibility. On the other hand, because the delay guarantees provided are based on summing worst case delays at each node, it has also been argued that the resulting bounds are very conservative which may more than offset the benefits. In particular, other service disciplines such as those based on Fair Queueing or Generalized Processor Sharing (GPS), have been shown to provide much tighter delay bounds. As a result, these disciplines, although more complex from an implementation point-of-view, have been considered for the purpose of providing end-to-end guarantees in high-speed networks. In this paper, we show that through ''proper'' selection of the reshaping to which we subject the traffic of a connection, the penalty incurred by computing end-to-end delay bounds based on worst cases at each node can be alleviated. Specifically, we show how rate-controlled service disciplines can be designed to outperform the Rate Proportional Processor Sharing (RPPS) service discipline. Based on these findings, we believe that rate-controlled service disciplines provide a very powerful and practical solution to the problem of providing end-to-end guarantees in high-speed networks.