| 347681. |
- Soutukorva, Åsa, et al.
(författare)
-
Metodhandledning i samhällsekonomiskkonsekvensanalysKulturmiljön i miljömålsarbetetRapport från Riksantikvarieämbetet 2008:2
- 2008
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Denna metodhandledning handlar om hur det går till attgöra en samhällsekonomisk konsekvensanalys av åtgärdersom kan behöva vidtas för att nå miljökvalitetsmål(miljömål) med bäring på kulturmiljön. Analysmetodensom beskrivs är generell och kan avse en godtyckligkulturmiljö. Målgruppen för metodhandledningen ärframför allt handläggare som utför konsekvensanalyser avkulturmiljön men även andra som vill få en större förståelseför vad en samhällsekonomisk konsekvensanalys är förnågot och hur kopplingen mellan kulturmiljövärdenoch ekonomi kan se ut. Ett syfte med rapporten är attden ska vara användbar även för personer som intehar expertkunskaper i nationalekonomi. Den juridiskabakgrunden till metodhandledningen är bland annatbestämmelserna i miljöbalken som syftar till en hållbarutveckling, vilket innebär att nuvarande och kommandegenerationer tillförsäkras en hälsosam och god miljö.Efter en allmän bakgrundsbeskrivning följer enintroduktionmeden kort genomgång av konsekvensanalysisyfte att ge läsaren en känsla om analysens beståndsdelar.Denna metodhandledning gäller för samhällsekonomiskkonsekvensanalys. Det speciella med en sådan konsekvensanalysär att den har en ambition att uttrycka konsekvenseri samhällsekonomiska termer (nyttorochkostnader)och så långt det är möjligt göra detta i monetäraenheter.Kvantifiering och monetarisering av nyttor somkan kopplas till kulturmiljön är ett tämligen outforskatområde och ett viktigt fokus i rapporten är att diskuteraetablerade miljövärderingsmetoder samt deras användbarhetför värdering av kulturmiljön. Förutom värderingsmetoderpresenteras i introduktionsdelen även andraviktiga begrepp som används inom kostnads-nyttoanalysoch kostnadseffektivitetsanalys.
|
|
| 347682. |
|
|
| 347683. |
|
|
| 347684. |
- Souza, Abel, PhLic. 1986-, et al.
(författare)
-
A HPC Co-Scheduler with Reinforcement Learning
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- High Performance Computing (HPC) datacenters process thousands of diverse applications, supporting many scientific and business endeavours. Although users understand minimum coarse resource job requirements such as amounts of CPUs and memory, internal infrastructural utilization data and system dynamics are often visible only to cluster operators. Besides that, due to increased complexity, heuristically tweaking a batch system is even today a very challenge task. When combined with applications profiling, infrastructural data enables improvements to job scheduling, while creating space to improve Quality-of-Service (QoS) metrics such as queue waiting times and total execution times. Targeting improvements in utilization and throughput, in this paper we evaluate and propose a novel Reinforcement Learning co-scheduler algorithm that combines capacity utilization with application performance profiling. We first profile a running application by assessing its resource utilization and progress by means of a forest of decision trees, enabling our algorithm to understand the application’s resource capacity usage. We then use this information to estimate how much capacity from this ongoing allocation can be allocated for co-scheduling additional applications. Because estimations may go wrong, our algorithm has to learn and evaluate when co-scheduling decisions results in QoS degradation, such as application slowness. To overcome this, we devised a co-scheduling architecture and a handful metric to help minimizing performance degradation, enabling improvements on utilization of up to 25% even when the cluster is experiencing high demands, with 10% average queue makespan reductions when experiencing low loads.Together with the architecture, our algorithm forms the base of an application-aware co-scheduler for improved datacenter utilization and minimal performance degradation.
|
|
| 347685. |
- Souza, Abel, PhLic. 1986-
(författare)
-
Autonomous resource management for high performance datacenters
- 2020
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Over the last decade, new applications such as data intensive workflows have hit an inflection point in wide spread use and influenced the compute paradigm of most scientific and industrial endeavours. Data intensive workflows are highly dynamic and adaptable to resource changes, system faults, and by also allowing approximate solutions into their models. On the one hand, these dynamic characteristics require processing power and capabilities originated in cloud computing environments, and are not well supported by large High Performance Computing (HPC) infrastructures. On the other hand, cloud computing datacenters favor low latency over throughput, deeply contrasting with HPC, which enforces a centralized environment and prioritizes total computation accomplished over-time, ignoring latency entirely. Although data handling needs are predicted to increase by as much as a thousand times over the next decade, future datacenters processing power will not increase as much.To tackle these long-term developments, this thesis proposes autonomic methods combined with novel scheduling strategies to optimize datacenter utilization while guaranteeing user defined constraints and seamlessly supporting a wide range of applications under various real operational scenarios. Leveraging upon data intensive characteristics, a library is developed to dynamically adjust the amount of resources used throughout the lifespan of a workflow, enabling elasticity for such applications in HPC datacenters. For mission critical environments where services must run even in the event of system failures, we define an adaptive controller to dynamically select the best method to perform runtime state synchronizations. We develop different hybrid extensible architectures and reinforcement learning scheduling algorithms that smoothly enable dynamic applications into HPC environments. An overall theme in this thesis is extensive experimentation in real datacenters environments. Our results show improvements in datacenter utilization and performance, achieving higher overall efficiency. Our methods also simplify operations and allow the onboarding of novel types of applications previously not supported.
|
|
| 347686. |
- Souza, Ana Carolina Almeida
(författare)
-
Transmedia experiences in the Magic Kingdom theme park : Branding, space, and (un)sustainability at Disney
- 2022
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Beyond being just a medium that supports other media, the contemporary theme park is a complex space that brings together material and symbolic features of different user-producer relationships. Although robust, the theme park is scarcely investigated, especially as an autonomous and potentially adaptable media for the maintenance of transmedia dynamics.Based on this perception, the question that guides the research is as follows: in what way are transmediatic experiences outlined in theme parks, and to what extent does the relationship between space, brands and sustainability singularise the notion of transmediality?To this end, we centred the research on the user-producer relationship from a conceptual triangulation between branding, space and sustainability. These three elements are articulated around the notion of transmedia experience, which considers the individuality of each user experience. In this proposal, we identified transmediatic experiences driven by cognitive and affective aspects directly affected by the embedded engagement that the users had with the space and the brand.To develop this theoretical-methodological perspective, we elected the Magic Kingdom (MK) as the empirical object of the dissertation. This choice is directly related to the proposed triangulation since MK is the world's most popular theme park, and also because it belongs to a consolidated brand in the entertainment market: Disney. Moreover, MK turned 50 years old in 2021, a longevity that indicates a close relationship of the space with the very history of Disney as a brand. The MK park is also considered an icon of the experience economy, which makes it a particularly fertile ground to observe and analyse the types of transmedia experiences that arise through the user-producer relationship in this space.The research, exploratory in nature, is methodologically grounded on the concept of rhizome, articulating cartography and scales in order to map, characterise and analyse the user-producer experiential relationship. To select the research corpus, we opted for digital data collection and employed snowball and purposive sampling methods. Thus, we selected media content produced by the Disney brand and by its users which could highlight the different territories created, destroyed, maintained and modified in the theme park space.Our guiding question led us to the discovery of a complex transmediatic relationship between user-producer which, when mediated by the MK theme park, preserves the Disney brand, making it long-lasting and, in this sense, sustainable. At the same time, the user-producer relationship shows how subjectivities (re)parameterise Magic Kingdom's space and compose other forms of approaching sustainability (from a social, economic, and environmental point of view), including in terms of what is unsustainable and contradictory in this relationship.
|
|
| 347687. |
- Souza, Abel Pinto Coelho de, 1986-
(författare)
-
Application-aware resource management for datacenters
- 2018
-
Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- High Performance Computing (HPC) and Cloud Computing datacenters are extensively used to steer and solve complex problems in science, engineering, and business, such as calculating correlations and making predictions. Already in a single datacenter server, there are thousands of hardware and software metrics – Key Performance Indicators (KPIs) – that individually and aggregated can give insight in the performance, robustness, and efficiency of the datacenter and the provisioned applications. At the datacenter level, the number of KPIs is even higher. The fast growing interest on datacenter management from both public and industry together with the rapid expansion in scale and complexity of datacenter resources and the services being provided on them have made monitoring, profiling, controlling, and provisioning compute resources dynamically at runtime into a challenging and complex task. Commonly, correlations of application KPIs, like response time and throughput, with resource capacities show that runtime systems (e.g., containers or virtual machines) that are used to provision these applications do not utilize available resources efficiently. This reduces datacenter efficiency, which in term results in higher operational costs and longer waiting times for results.The goal of this thesis is to develop tools and autonomic techniques for improving datacenter operations, management and utilization, while improving and/or minimizing impacts on applications performance. To this end, we make use of application resource descriptors to create a library that dynamically adjusts the amount of resources used, enabling elasticity for scientific workflows in HPC datacenters. For mission critical applications, high availability is of great concern since these services must be kept running even in the event of system failures. By modeling and correlating specific resource counters, like CPU, memory and network utilization, with the number of runtime synchronizations, we present adaptive mechanisms to dynamically select which fault tolerant mechanism to use. Likewise, for scientific applications we propose a hybrid extensible architecture for dual-level scheduling of data intensive jobs in HPC infrastructures, allowing operational simplification, on-boarding of new types of applications and achieving greater job throughput with higher overall datacenter efficiency.
|
|
| 347688. |
- Souza, Domingos, 1954-
(författare)
-
Harvesting of Saphenous Vein for Coronary Artery Bypass Grafting : An Improved Technique that Maintains Vein Wall Integrity and Provides a High Early Patency Rate
- 2002
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The primary aim of this thesis was to modify saphenous vein (SV) harvesting technique and evaluate its clinical importance. A new "no touch" (NT) technique of SV preparation was developed where the vein is harvested with a pedicle of surrounding tissue, which protects the vein from spasm therefore obviating the need for distension.Firstly, a prospective randomised study in 156 patients who underwent coronary artery bypass grafting was done to compare this new "no touch" technique to two others, the conventional (C) and the intermediate (I) techniques. A morphological study of the endothelium showed an endothelial integrity of 97% in NT vessels while about half of endothelial surface of veins harvested by the other two techniques was devoid of endothelium. At angiographic follow up, the patency for NT was 95.4%, 88.9% for grafts in group C and 86.2% for grafts in group I. A statistically significant difference in patency rate was found between the NT group and group C (p=0.025) and the poorest result was observed in group I.Secondly, the immunohistochemistry assessment using CD31-antibody confirmed a better-preserved endothelium for NT vessels. Putative NOS was identified by NADPH-diaphorase histochemistry and autoradiographic localization of [3H] L-nitroarginine (NOARG) binding. NADPH staining was almost continuous on the luminal aspect and was also present in the intact adventitia of NT vessels, which was markedly reduced in conventionally harvested veins. Autoradiographic analysis of specific NOARG binding showed greater binding in the no-touch vessels, confirming the histochemistry results. All three NOS isoforms were identified in the media of SV grafts. In NT, NOS I was abundant in adventitial nerves; NOS II was found in adventitial vasa vasorum and NOS III was associated with endothelial cells lining both the vessel lumen and microvessels within the adventitia.In conclusion, this study demonstrated that the endothelial integrity and NOS activity are better maintained when using the no-touch technique for vein graft harvesting. The vasorelaxant and thromboresistent activities of NO may be responsible for the reduced venospasm and improved early patency rates observed. Furthermore, the mechanical properties provided by the cushion of surrounding tissue in grafts harvested by NT technique may contribute to the observed high patency rate.
|
|
| 347689. |
- Souza Dantas, Nilton
(författare)
-
Electronic structure and optical properties of PbY and SnY (Y=S, Se, and Te)
- 2007
-
Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Lead chalcogenides and tin chalcogenides and their alloys are IV−VI family semiconductors with unique material properties compared with similar semiconductors. For instance, PbY (Y = S, Se, and Te) are narrow-gap semiconductors with anomalous negative pressure coefficient and positive temperature coefficient. It is known that this behavior is related with the symmetry of wave functions in first Brillouin zone L-point, which moves the edges of valence band maximum and conduction band minimum towards each other with pressure increasing. SnTe has opposite behavior since its wavefunction symmetry is different from PbY. Therefore, by alloying PbTe and SnTe one can change and control the band gap energy and its pressure or temperature dependence. These chalcogenides alloys have therefore a huge potential in industrial low-wavelength applications and have been attracted the attention of researchers. This thesis comprises theoretical studies of PbY, SnY (Y = S, Se and Te) and the Pb1−xSnxTe alloys (x = 0.00, 0.25, 0.50, 0.75, and 1.00) by means of a first-principles calculation, using the full-potential linearized augmented plane waves method and the local density approximation. The optical properties of Pb1−xSnxTe alloys are investigated in terms of the dielectric function ε(ω) = ε1(ω) + iε2(ω). We find strong optical response in the 0.5–2.0 eV region arising from optical absorption around the LW-line of the Brillouin zone. The calculated linear optical response functions agree well with measured spectra from ellipsometry spectroscopy performed by the Laboratory of Applied Optics, Linköping University. The calculations of the electronic band-edges of the binary PbY and SnY compounds, show similar electronic structure and density-of-states, but there are differences of the symmetry of the band-edge states at and near the Brillouin zone L-point. PbY have a band gap of Eg 0.15−0.30 eV. However, SnY are zero-gap semiconductors Eg = 0 if the spin-orbit interaction is excluded. The reason for this is that the lowest conduction band and the uppermost valence band cross along the LW line. When including in PbY. Although PbY and SnY have different band-edge physics at their respective equilibrium lattice constants, the change of the band-edges with respect to cell volume is qualitatively the same for all six chalcogenides. The calculations show that the symmetry of band edge at the L-point changes when lattice constant varies and this change affects the pressure coefficient. the spin-orbit interaction a gap Eg ≈ 0.2 eV is created, and hence this gap is induced by the spin-orbit interaction. At the L-point, the conduction-band state is a symmetric state and the valence-band state is antisymmetric thereby the L-point pressure coefficient +4L−4LpEg∂∂/)L( in SnY is a positive quantity. In contrast to SnY, the PbY compounds have a band gap both when spin-orbit coupling is excluded and included; this gap is at the L-point, and the conduction-band state has and the valence-band state has symmetry, and thereby this band edge yields the characteristic negative pressure coefficient +4L−4LpEg∂∂/)L(
|
|
| 347690. |
- Souza de Almeida, Jailton, 1971-
(författare)
-
Designing and Tuning the Properties of Materials by Quantum Mechanical Calculations
- 2006
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In many materials, changes in chemical composition, pressure or temperature can induce metal to insulator transitions. It is recently observed in yttrium hydride, for example, changes from a shiny mirror (YH2) to a transparent window (YH3), which has important technological application in optical devices. We have tuned the above transition by choosing pressure instead of composition. Our predicted finding is confirmed by recent experiments and opens a new way to design optical switches.The unique role that gold plays in society is to a large extent related to the fact that it is the most noble of all metals.We have studied the noble nature of gold by choosing pressure as tool. Our prediction shows that gold transforms from a face centered cubic to an hexagonal closed packed phase above 200 GPa whereas platinum, another noble metal, does not show any phase transition up to 500 GPa. This prediction has also been confirmed by experiments suggesting that platinum is more noble than gold.The growing concern about climate change and fossil fuel availability, the direct conversion of solar irradiation into electricity appears to be an ideal alternative to conventional energy sources. Power generation by solar cells is a direct method of solar energy conversion. We report a new cubic phase of TiO2 which can be stabilized at ambient conditions. This phase has an absorption three or four orders of magnitude larger than the conventional state-of-the-art solar cell based on anatase TiO2. Therefore, we are introducing a well established material with a new structure for future generation solar cells. The same effect is also observed in cubic SnO2.Electronic and optical properties of other materials such as BexZn1-xTe, RuO2 and IrO2 are also studied in present thesis. In particular, for BexZn1-xTe, we have used composition as a tool to tune the optical properties.
|
|
