| 1. |
|
|
| 2. |
- Andersson, Ulf
(författare)
-
Betalkort : Slutrapport
- 1980
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Idén till Universalkort uppkom för cirka tre år sedan, som en följd av ett examensarbete med namnet "ID- kort med minne". Där undersöktes möjligheten att placera ett nonvolatilt minne på ett kort. Fortsättningen på det projektet beskrivs kort under rubriken ”Existerande hårdvarusystem”.Utvecklingen av Betal- och Universalkortsidén har sedan dess bedrivits i samarbete med personal på Institutionen för Systemteknik inom ämnesområdet informationsteori vid LiTH. Jag vill rikta ett varmt tack till dessa och speciellt till Rolf Blom , Robert Forchheimer och Ingemar Ingemarsson för deras bidrag till arbetet.
|
|
| 3. |
- Fahlander, Olov
(författare)
-
Hemligheten bakom datorgenererad musik
- 1980
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Föredraget kommer av utrymmesskäl att ganska summariskt behandla möjligheterna till musikalisk ljudsyntes med digitala metoder främst med tanke på ”personal computing”. Vissa utvikningar utöver detta är oundvikliga och föredraget har därför mer karaktären av översikt snarare än en mer detaljerad genomgång av speciella metoder. Några konkreta exempel på hårdvarulösningar har dock redovisats och därutöver hänvisas till ett antal referenser som för den intresserade kan ge en mer detaljerad förståelse .Föredraget är uppdelat på tre huvudgrupper: Klang syntes, interaktion och komposition, där det förstnämnda ges mest utrymme. Enligt min personliga uppfattning ligger dock dom intressanta spörsmålen inom det sistnämnda området och det är antagligen här de största in satserna i framtiden kommer att göras, när väl hårdvaruutvecklingen mognat tillräckligt.Det kan nämnas i detta sammanhang att forskningen inom områden som dessa för ett mycket tynande liv, trots att musikindustrin, framtidens stora avnämare för dess resultat, omsätter svindlande summor över hela världen . I Europa är det främst i Paris vid IRCAM som en satsning av betydelse sker. De amerikanska universiteten har annars svarat för den främsta utvecklingen. Detta områdes stora popularitet ]land hobbymänniskor bevisas av att det numera utkommer en specialtidskrift ”Computer music journal” med fyra nummer per år samt att artiklar inom området är mycket vanliga i hobbytidskrifter som ”Byte” och liknande.
|
|
| 4. |
- Lindeberg, Tony, 1964-
(författare)
-
Scale-space for discrete images
- 1989
-
Ingår i: Scandinavian Conference on Image Analysis. ; , s. 1098-1107
-
Konferensbidrag (refereegranskat)abstract
- This article addresses the formulation of a scale-space theory for one-dimensional discrete images. Two main subjects are treated:Which linear transformations remove structure in the sense that the number of local extrema (or zero-crossings) in the output image does not exceed the number of local extrema (or zero-crossings) in the original image?How should one create a multi-resolution family of representations with the property that an image at a coarser level of scale never contains more structure than an image at a finer level of scale?We propose that there is only one reasonable way to define a scale-space for discrete images comprising a continuous scale parameter, namely by (discrete) convolution with the family of kernels T(n; t) = e^{-t} I_n(t),, where $I_n$ are the modified Bessel functions of integer order. Similar arguments applied in the continuous case uniquely lead to the Gaussian kernel.Some obvious discretizations of the continuous scale-space theory are discussed in view of the results presented. An important result is that scale-space violations might occur in the family of representations generated by discrete convolution with the sampled Gaussian kernel.
|
|
| 5. |
- Nygren, Sven
(författare)
-
En studie av kryptering vid satellitkommunikation
- 1982
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Stormakterna övervakar varandra och den övriga världen med hjälp av ett stort antal spionsatelliter. Det finns många olika typer av rent militära satelliter, men även alla . .normalt civila satelliter som lämnar information som kan vara av taktisk eller strategisk betydelse och måste betraktas som militära i en konfliktsituation. Som exempel på dessa "halvmilitära" satelliter kan nämnas; vädersatelliter, telesatelliter, navigationssatelliter och fjärranalyserande satelliter typ LANDSAT….
|
|
| 6. |
- Maguire Jr., Gerald Q.
(författare)
-
Looking back at PACS attempts—what has happened since PACS I
- 1986
-
Ingår i: Pictorial information systems in medicine : [proceedings of the NATO Advanced Study Inst. on Pictorial Information Systems in Medicine held in Braunlage FRG, August 27 - September 7, 1984]. - 3540139214 - 0387139214 ; , s. 391-399
-
Konferensbidrag (refereegranskat)
|
|
| 7. |
|
|
| 8. |
- Eriksson, Lars-Henrik, et al.
(författare)
-
A programming calculus based on partial inductive definitions (with an introduction to the theory of partial inductive definitions)
- 1988. - 1
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- We present a general framework (a programming calculus) for the specification, verification and synthesis of programs. The underlying programming paradigm is similar in spirit to logic programming but based on the theory of partial inductive definitions instead of predicate logic. Within this framework we give criteria for the correctness of programs and outline a methodology for using these criteria to perform verifications and syntheses. The programming calculus permits us to use an arbitrary specification language, as long as this language itself can be defined within our framework. The program language is based on partial inductive definitions. Such definitions can be regarded as sets of an extension to Horn clauses of logic, so traditional logic (pure Prolog) programs are included as a special case. Since the theory of partial inductive definitions is not widely known, we include an introduction to it. This introduction can also be read by itself, without any interest in the programming calculus.
|
|
| 9. |
- Olsson, Pelle, et al.
(författare)
-
Boundary Modifications of the Dissipation Operators for the Three–Dimensional Euler Equations
- 1989
-
Ingår i: Journal of Scientific Computing. - 0885-7474 .- 1573-7691. ; 4:2, s. 159-195
-
Tidskriftsartikel (refereegranskat)abstract
- Explicit methods for the solution of fluid flow problems are of considerable interest in supercomputing. These methods parallelize well. The treatment of the boundaries is of particular interest with respect to both the numeric behavior of the solution and the computational efficiency. We have solved the three-dimensional Euler equations for a twisted channel using second-order, centered difference operators, and a three-stage Runge-Kutta method for the integration. Three different fourth-order dissipation operators were studied for numeric stabilization: one positive definite, one positive semidefinite, and one indefinite. The operators only differ in the treatment of the boundary. For computational efficiency all dissipation operators were designed with a constant bandwidth in matrix representation, with the bandwidth determined by the operator in the interior. The positive definite dissipation operator results in a significant growth in entropy close to the channel walls. The other operators maintain constant entropy. Several different implementations of the semidefinite operator obtained through factoring of the operator were also studied. We show the difference both in convergence rate and robustness for the different dissipation operators, and the factorizations of the operator due to Eriksson. For the simulations in this study one of the factorizations of the semidefinite operator required 70%–90% of the number of iterations required by the positive definite operator. The indefinite operator was sensitive to perturbations in the inflow boundary conditions. The simulations were performed on a 8,192 processor Connection Machine system CM-2. Full processor utilization was achieved, and a performance of 135 Mflops/sec in single precision was obtained. A performance of 1.1 Gflops/sec for a fully configured system with 65,536 processors was demonstrated.
|
|
| 10. |
- Andersson, Peter
(författare)
-
Informationsteknologi i organisationer : bestämningsfaktorer och mönster
- 1989
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Researchers in this field have placed different emphasis on the structural constraints visa- vis the freedom of the actors. An awareness that IT is a social construction does not necessarily mean that some individual actor or actor entity can perform freely. An inflexible, tightly structured social situation can considerably limit the action space. Actors are hemmed in by "objective" circumstances, ie, a rather closely controlled situation established by other actors, and which is apparently unyielding in the face of technological decisions.By creating a perspective that addresses both structural and actor aspects, this study attempts a holistic understanding which will lay bare the probable dialectic process between the changeable and the nonchangeable. This aspiration to comprehend the whole, when viewed against the complex character of the subject, calls for an understanding oriented approach.The study at hand deals with the choice of information technology in organizations, with special focus on automatic data processing (ADP) for administrative purposes. Its main aim is to improve an understanding of factors that determine the choice of ADP technology in organizations.The empirical section of the work at hand consists of two case studies and an overview study. The case studies, which concern two extensive ADP projects, are emphasized. The purpose of these two projects was to raise the degree of computerization and to choose both a configuration and degree of uniformity. In both cases however the configuration turned out to be the most critical issue. One concerned the administration of social insurance in Sweden, Rationalisering av den allmänna försäkringens administration (Rationalization of the Swedish social insurance administration), hereafter called the RAFA project. The other case study, referred to here as the FFV study, deals with an administrative system for the manufacturing sector of the FFV Group The overview study, called the Norrköping study, deals mainly with the technological level and the ADP configuration in a wide spectrum of organizations. The level and the configuration are viewed against an overarching organizational structure, the worksite placement of qualified ADP staff, the line of business and the size of the firm. The study consists of an opinion poll and three delimited secondary studies.In the initial stage of each project, rational motives dominated. These were founded on cost and effect assessments and on developments in the field of computer science. From a structural viewpoint, investments in computers seemed self-evident; efficiency goals were paramount. However, an ADP undertaking entails not only rationalization in the conventional sense, it also brings to the ideational aspects inherent in the organization. While ADP technology was believed necessary, it became, in the preplanning and argumentation phase, a means of projecting socially determined concepts and goals. An ADP solution was sought which would combine the latest innovations in computer science with the dominant actors' organizational ideas.The dominant actors at FFV were for the most part newly appointed managers, imprinted with other organizational ideals and relationships than those characterizing FFV. The choice stood between a departure from company tradition by selecting a solution based on local minicomputers, or expanding the existing centralized main frame facility. The critics were specialists who had taken part in the design of the existing configuration. At FFV, the structural determinants had to be toned down in favor of the deliberate performance of the dominant actors. In the RAF A case, the opposite was true. The critics wanted a certain change of existing circumstances, while the dominant actors sought to preserve status quo and its underlying ideas. In the RAF A case, ADP thus became a cementing force rather than the catalyst.The Norrkoping study clearly indicates that the direction and size of an enterprise has primary importance for how much the computers are used. The ADP configuration appearance varies mainly with the organizational relationships. This is true for the placement of ADP staff and the overall structure of the organization. The main tendency is that the configuration reflects the relationships in an organization. This supports the view in the case studies that proximity to and control of the ADP has a major organizational value.
|
|
