The effects of open system evolution on single particle interferometry, quantum computation, and the adiabatic approximation are investigated. Single particle interferometry: Three concepts concerning completely positive maps (CPMs) and trace preserving CPMs (channels), named subspace preserving (SP) CPMs, subspace local channels, and gluing of CPMs, are introduced. SP channels preserve probability weights on given orthogonal sum decompositions of the Hilbert space of a quantum system. Subspace locality determines what channels act locally with respect to such decompositions. Gluings are the possible total channels obtainable if two evolution devices, characterized by channels, act jointly on a superposition of a particle in their inputs. It is shown that gluings are not uniquely determined by the two channels. We determine all possible interference patterns in single particle interferometry for given channels acting in the interferometer paths. It is shown that the standard interferometric setup cannot distinguish all gluings, but a generalized setup can. Quantum computing: The robustness of local and global adiabatic quantum search subject to decoherence in the instantaneous eigenbasis of the search Hamiltonian, is examined. In both the global and local search case the asymptotic time-complexity of the ideal closed case is preserved, as long as the Hamiltonian dynamics is present. In the case of pure decoherence, where the environment monitors the search Hamiltonian, it is shown that the local adiabatic quantum search performs as the classical search with scaling N, and that the global search scales like N3/2 , where N is the list length. We consider success probabilities p<1 and prove bounds on the run-time with the same scaling as in the conditions for the p → 1 limit. Adiabatic evolution: We generalize the adiabatic approximation to the case of open quantum systems in the joint limit of slow change and weak open system disturbances.

The established methodologies for studying computational complexity can be applied to the new problems posed by very large-scale integrated (VLSI) circuits. This thesis develops a ''VLSI model of computation'' and derives upper and lower bounds on the silicon area and time required to solve the problems of sorting and discrete Fourier transformation. In particular, the area A and time T taken by any VLSI chip using any algorithm to perform an N-point Fourier transform must satisfy AT2 ≥ c N2 log2 N, for some fixed c > 0. A more general result for both sorting and Fourier transformation is that AT2x = Ω(N1 + x log2x N) for any x in the range 0 < x < 1. Also, the energy dissipated by a VLSI chip during the solution of either of these problems is at least Ω(N3/2 log N). The tightness of these bounds is demonstrated by the existence of nearly optimal circuits for both sorting and Fourier transformation. The circuits based on the shuffle-exchange interconnection pattern are fast but large: T = O(log2 N) for Fourier transformation, T = O(log3 N) for sorting; both have area A of at most O(N2 / log1/2 N). The circuits based on the mesh interconnection pattern are slow but small: T = O(N1/2 loglog N), A = O(N log2 N).

Att minska energikonsumtionen inom mjukvaruutveckling är ett högst aktuellt ämne då datacenter och dataöverföringar står för 0,9% av de globala växthusgasutsläppen. Syftet med den här studien var att undersöka förhållandet mellan gröna val och standarder i system med många utvecklare. Detta har gjorts genom att undersöka hur utvecklare på Monitor ERP System AB ser på hållbarhet under utvecklingsprocessen, samt hur en algoritms tidskomplexitet och val av primitiva datatyper och datastrukturer påverkar en mjukvarulösnings energikonsumtion. Arbetet genomfördes med mixad metod och använde intervjuer och experiment som datainsamlingsmetoder. Intervjuer hölls med utvecklare på Monitor ERP System för att undersöka vad som påverkade utvecklingsprocessen och skapa en uppfattning om var gröna val kunde ta plats. Experiment genomfördes för att undersöka hur algoritmers tidskomplexitet och val av primitiva datatyper och datastrukturer påverkar energikonsumtionen i en mjukvarulösning. Resultatet från intervjuerna visade att hållbarhet inte togs in som en faktor i utveck-lingsprocessen på grund av kunskapsbrist och att prestanda var en högt prioriterad faktor. Detta kombinerades med experimentets resultat att energikonsumtionen av en mjukvarulösning berodde på programinstruktioners exekveringstid i kombination med en algoritms tidskomplexitet. Slutsatsen av arbetet är att grön mjukvaruutveckling kan tas in i system med standarder genom att skapa nya gröna standarder med fokus på prestanda och lättillgänglig sammanställning av gröna val. / Reducing the energy consumption in software development is a highly relevant subject, as data centers and data transmissions make up 0.9% of the global carbon emissions. The purpose of this study was to examine the relationship between green choices and standards in systems with many developers. This was investigated by examining how developers at Monitor ERP System AB view sustainability during the development process, as well as how an algorithm’s time complexity and choices of primitive data types and data structures influence a software solution’s energy consumption. The study was conducted using mixed method with interviews and an experiment as data collection methods. Interviews were held with developers at Monitor ERP System to determine what affected the development process and create a perception for where green choices could take place. Experiments were conducted to investigate how an algorithm’s time complexity and choices of primitive data types and data structures affect the energy consumption of a software solution.  The interview results show that sustainability was not considered during the development process due to a lack of knowledge and that performance was a heavily prioritized factor. This was combined with the experiment results that energy consumption was dependent on the execution time of program instructions in combination with an algorithm’s time complexity. The conclusion was that green software development can take place in systems with standards by creating new green standards, focusing on performance and easy access to a collection of green choices.

This work deals with scheduling problem in particular plastic production service. The solution is based on heuristic algorithms, programming languages C + +, C # and is built on the .NET framework and LINQ to XML. It provides the users with comparisons of the heuristic approach with genetic algorithms applied to production problem. All methods results are compared in relation to hand-arranged plans.

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