| 1. |
- Gustavsson, Andreas, 1982-
(författare)
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Static Execution Time Analysis of Parallel Systems
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The past trend of increasing processor throughput by increasing the clock frequency and the instruction level parallelism is no longer feasible due to extensive power consumption and heat dissipation. Therefore, the current trend in computer hardware design is to expose explicit parallelism to the software level. This is most often done using multiple, relatively slow and simple, processing cores situated on a single processor chip. The cores usually share some resources on the chip, such as some level of cache memory (which means that they also share the interconnect, e.g., a bus, to that memory and also all higher levels of memory). To fully exploit this type of parallel processor chip, programs running on it will have to be concurrent. Since multi-core processors are the new standard, even embedded real-time systems will (and some already do) incorporate this kind of processor and concurrent code.A real-time system is any system whose correctness is dependent both on its functional and temporal behavior. For some real-time systems, a failure to meet the temporal requirements can have catastrophic consequences. Therefore, it is crucial that methods to derive safe estimations on the timing properties of parallel computer systems are developed, if at all possible.This thesis presents a method to derive safe (lower and upper) bounds on the execution time of a given parallel system, thus showing that such methods must exist. The interface to the method is a small concurrent programming language, based on communicating and synchronizing threads, that is formally (syntactically and semantically) defined in the thesis. The method is based on abstract execution, which is itself based on abstract interpretation techniques that have been commonly used within the field of timing analysis of single-core computer systems, to derive safe timing bounds in an efficient (although, over-approximative) way. The thesis also proves the soundness of the presented method (i.e., that the estimated timing bounds are indeed safe) and evaluates a prototype implementation of it.
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| 2. |
- Gustavsson, Andreas, 1982-
(författare)
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Static Timing Analysis of Parallel Systems Using Abstract Execution
- 2014
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The Power Wall has stopped the past trend of increasing processor throughput by increasing the clock frequency and the instruction level parallelism.Therefore, the current trend in computer hardware design is to expose explicit parallelism to the software level.This is most often done using multiple processing cores situated on a single processor chip.The cores usually share some resources on the chip, such as some level of cache memory (which means that they also share the interconnect, e.g. a bus, to that memory and also all higher levels of memory), and to fully exploit this type of parallel processor chip, programs running on it will have to be concurrent.Since multi-core processors are the new standard, even embedded real-time systems will (and some already do) incorporate this kind of processor and concurrent code.A real-time system is any system whose correctness is dependent both on its functional and temporal output. For some real-time systems, a failure to meet the temporal requirements can have catastrophic consequences. Therefore, it is of utmost importance that methods to analyze and derive safe estimations on the timing properties of parallel computer systems are developed.This thesis presents an analysis that derives safe (lower and upper) bounds on the execution time of a given parallel system.The interface to the analysis is a small concurrent programming language, based on communicating and synchronizing threads, that is formally (syntactically and semantically) defined in the thesis.The analysis is based on abstract execution, which is itself based on abstract interpretation techniques that have been commonly used within the field of timing analysis of single-core computer systems, to derive safe timing bounds in an efficient (although, over-approximative) way.Basically, abstract execution simulates the execution of several real executions of the analyzed program in one go.The thesis also proves the soundness of the presented analysis (i.e. that the estimated timing bounds are indeed safe) and includes some examples, each showing different features or characteristics of the analysis.
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| 3. |
- Gustavsson, Andreas, 1982-
(författare)
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An Efficient Approach for Detecting Moving Objects and Deriving Their Positions and Velocities
- 2020
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Ingår i: Advances in Intelligent Systems and Computing. - Cham : Springer International Publishing. ; , s. 293-313
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Konferensbidrag (refereegranskat)abstract
- Well-functioning autonomous robot solutions heavily rely on the availability of fast and correct navigation solutions. The presence of dynamic/moving objects in the environment poses a challenge because the risk of collision increases. In order to derive the best and most foreseeing re-routing solutions for cases where the planned route suddenly involves the risk of colliding with a moving object, the robot's navigation system must be provided with information about such objects' positions and velocities. Based on sensor readings providing either 2-dimensional polar range scan or 3-dimensional point cloud data streams, we present an efficient and effective method which detects objects in the environment and derives their positions and velocities. The method has been implemented, based on the Robot Operating System (ROS), and we also present an evaluation of it. It was found that the method results in good accuracy in the position and velocity calculations, a small memory footprint and low CPU usage requirements.
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| 4. |
- Gustavsson, Andreas, 1982-, et al.
(författare)
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Timing Analysis of Parallel Software Using Abstract Execution
- 2014
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Ingår i: VERIFICATION, MODEL CHECKING, AND ABSTRACT INTERPRETATION. - Berlin, Heidelberg : SPRINGER-VERLAG BERLIN. - 9783642540134 ; , s. 59-77, s. 59-77
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Konferensbidrag (refereegranskat)abstract
- A major trend in computer architecture is multi-core processors. To fully exploit this type of parallel processor chip, programs running on it will have to be parallel as well. This means that even hard real-time embedded systems will be parallel. Therefore, it is of utmost importance that methods to analyze the timing properties of parallel real-time systems are developed. This paper presents an algorithm that is founded on abstract interpretation and derives safe approximations of the execution times of parallel programs. The algorithm is formulated and proven correct for a simple parallel language with parallel threads, shared memory and synchronization via locks.
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| 5. |
- Gustavsson, Martin, et al.
(författare)
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Kollektivbiografi och korrespondensanalys
- 2018. - 1
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Ingår i: Metod. - Lund : Studentlitteratur AB. - 9789144107943 ; , s. 241-273
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 6. |
- Gustavsson, Martin, 1966-, et al.
(författare)
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Kollektivbiografi och korrespondensanalys
- 2022. - 2
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Ingår i: Metod. - Lund : Studentlitteratur AB. - 9789144154176 ; , s. 265-297
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 7. |
- Gustavsson, Martin, et al.
(författare)
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Länsteatrarnas ekonomiska handlingsutrymme : Intäkter, utgifter och personal 1980–2015
- 2017
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Rapporten redovisar hur länsteatrarnas inkomster, utgifter och personalstyrka har förändrats mellan 1980 och 2015, en period som präglats av tre olika kulturpolitiska reformer (sjösatta 1974, 1996 och 2009).I ett bakgrundsavsnitt diskuteras bristen på bra kulturstatistik. Obrutna serier med statistik som sträcker sig över olika kulturpolitiska perioder har saknats. För att kunna jämföra länsteatrarnas ekonomiska förhållanden under perioder märkta av olika kulturpolitiska ideal har statistik därför samlats in från olika arkiv och skarvats ihop för hela den nämnda 35-årsperioden.Rapportens första undersökande del visar att det har skett en resursmässig förstärkning av länsteatrarna över tid (mätt med konsumentprisindex). Utvecklingen har dock varit ojämn. Den följer bredare trender i samhällsekonomin. Den genomsnittliga länsteaterns intäkter ökade markant mellan 1980 och 1990 (1974 års kulturpolitiska epok), minskade påtagligt mellan 1990 och 1996 (90-talets ekonomiska kris), ökade kraftigt mellan 1996 och 2005 (1996 års kulturpolitiska era), minskade noterbart mellan 2005 och 2012 (det sena 00-talets ekonomiska kris) och ökade något mellan 2012 och 2015 (2009 års kulturpolitiska period). Vi visade också att de genomsnittliga utgifternas utveckling följer samma typ av cykliska förlopp som de genomsnittliga intäkternas.Rapportens andra del studerade finansieringens effekter på kärnverksamheten, exemplifierad av personalstyrkans storlek och sammansättning. Länsteatrarnas största utgiftspost utgörs av personalkostnader. För att undersöka om lönekostnadsutvecklingen undergrävt uppräkningen av de offentliga anslagen justerades beloppen med olika löneindex. Nu blev ett motsatt utvecklingsscenario synligt. Istället för den trendmässiga – förvisso försiktiga och periodvisa – ökningen av intäkterna som visades när anslagen räknades om med konsumentprisindex minskade anslagen över tid när de justerades med löneindex. Den genomsnittliga länsteatern kan inte i dag, trots den måttliga resursförstärkningen de senaste åren, köpa lika mycket personal som i början av undersökningsperioden.I en separat delstudie visade vi även att antalet arbetade timmar av anställd ”konstnärlig” personal på teatrarna minskade över tid, medan antalet årsverken för ”administrativ” personal ökade något.I en avslutande delstudie ställdes följdfrågor om personalsituationen. Vi visade på den något paradoxala situationen att länsteatrarna – trots lägre köpkraft (mätt med löneindex) och färre ersatta arbetstimmar utförda av anställd konstnärlig personal (årsverken) – lyckats enrollera fler personer. En delförklaring till denna utveckling ligger i att länsteatrarna under de senaste tio åren alltmer börjat befolkas av visstidsoch korttidsanställd personal (med A-skattsedel) och frivilliga eller ofrivilliga företagare (med F- och FA-skattsedel).
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| 8. |
- Gustavsson, Martin, 1966-, et al.
(författare)
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The Social Closure of the Cultural Elite : The Case of Artists in Sweden, 1945–2004
- 2020
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Ingår i: Researching Elites and Power. - Cham : Springer. - 9783030451752 - 9783030451745 - 9783030451776 ; , s. 223-239
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Bokkapitel (refereegranskat)abstract
- This chapter identifies and analyses elites in a social domain where formal positions of power are few and far between – using the fine arts as an example – by combining Weberian closure theory with Pierre Bourdieu's concept of ‘fields’. Based on a database of more than 14,000 artists, active during the period of 1945–2008, an elite group of 627 is identified. When their social origins are analysed, a first main result of the inquiry is that this aesthetic elite is strikingly similar to other elites who are defined through formal positions of power: the elite are disproportionally drawn from the upper tiers of society. A second main result is that the recruitment to leading – informal – positions in the Swedish field of art displays a process of social closure. Over time, the elite are increasingly populated by individuals with origins in the ‘intellectual’ or ‘cultural’ fractions of the middle and upper classes.
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| 9. |
- Gustavsson, Martin
(författare)
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The social history of a capitalist class : wealth holders in Stockholm, 1914-2006
- 2018. - 1
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Ingår i: New Directions in Elite Studies. - Oxon/New York : Routledge. - 9781138059191 - 9781315163796 ; , s. 177-197
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Bokkapitel (refereegranskat)abstract
- This chapter focuses on the core of the Swedish capitalist class, owners of ‘large-scale’ capital, during 1914-2006. For investigating this class, a key assumption in the works of Marx and Weber is utilized: the dominant capitalist class of property holders is internally divided. It contains “active” members (engaged in the production and circulation of goods) as well as “thinking” members (engaged in the production and circulation of ideas); it contains “entrepreneurs” (producing new capital) as well as “rentiers” (living off inherited capital).One result is that a large portion of the wealthiest individuals are professionally active in other fields than the economic field, i.e. in other positions than as leaders of large capitalist corporations. This pattern in the social composition of the capitalist class has been remarkably stable during the twentieth century, unaffected by economic crises as well as the emergence of the Swedish Social Democratic welfare state. Another result is that the proportion of rentiers is greater in the thinking fraction than within the active fraction. The results illustrate the need to combine research on economic elites and studies of the reproduction of the top stratum of the capitalist class.
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| 10. |
- Melldahl, Andreas, 1982-
(författare)
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Utbildningens värde : Fördelning, avkastning och social reproduktion under 1900-talet
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis focuses on changes in the value of educational capital over time. Taking as a point of departure Pierre Bourdieu’s notion of a multidimensional social space, the thesis examines how this value is affected when educational assets—through the democratization of education—are becoming more widespread across this space (i.e. the population).The studies are based on datasets from Statistics Sweden, comprising the complete censuses of 1960 to 1990, LISA-registers, and registers of wealth and income. Different approaches are employed: the use of the Gini-coefficient to catch changes in the distribution of education; comparative models to investigate cohorts at different points in time; and specific multiple correspondence analysis to study the distribution of several assets simultaneously. Three aspects are explored: the distributions, returns, and uses of education. Firstly, while there is a steady increase in the average number of years of schooling, there is a different pattern in the development of the distribution of education. Three phases were distinguished: one of increasing levels of inequality, one of decreasing inequality, and one in which the inequality levelled out. Secondly, the returns of education have diminished as far as economic gains are concerned, causing a fracture between different social generations, at the same time as the returns in a wider social sense have remained relatively stable. However, the relative stability hides crucial discrepancies. Groups with the lowest level of education are further marginalized and distances between ‘economic’ and ‘cultural’ groups are growing. Thirdly, in their modes of using the educational system, there are glaring differences between the economic elite and the cultural elite, although both utilize prestigious educational institutions as sites of social reproduction. The fundamental difference consists in that exclusive educational strategies are not as necessary to the dominant fraction of the economic elite. Their children are able to choose more freely among the offers of higher education. The paradoxical development of the value of education is that while the absolute value of educational capital has decreased in general, the differences in relative value persist.
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