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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
981

Storskalig agil transformation - En fallstudie på Skatteverket

Olsson, Ossian, Sammy, Joulak January 2022 (has links)
En dynamisk och komplex omvärld ställer allt större krav på förnyelse och organisatorisk anpassning. I många organisationer har agila arbetssätt blivit populära. Storskaliga agila transformationer kan dock i praktiken vara svåra att genomföra. Dessutom kan agilitet och en hierarkisk organisationsstruktur vara svåra att kombinera. Studiens syfte är att söka kunskap om förutsättningar som påverkar en storskalig agil transformation inom en statlig myndighet. För studiens analysmodell identifierades initialt, med grund i tidigare forskning inom organisatorisk förändring, tre utmaningar och fem framgångsfaktorer. Studiens empiriska material bygger på sju intervjuer med anställda på Skatteverket. Baserat på studiens resultat kompletterades analysmodellen med två utmaningar och två framgångsfaktorer specifika för Skatteverkets transformation. Studiens resultat visade att utmaningarna decentraliserad utveckling, arbete med värdeströmmar och synkronisering av styrning har varit framträdande. Motstånd till förändring och uppföljningsmetodik ansågs inte ha varit reella. Framgångsfaktorerna pilotstudie, stöd från ledningen, utbildning och coachning, kulturanpassning, eldsjälar och införandestrategi ansågs ha varit viktiga för Skatteverket. Vision och kommunikation ansågs inte ha varit av större betydelse. / In our dynamic and complex world organizations are facing an increased demand for renewal and flexibility. Many organizations now shift to becoming agile. Large scale agile transformations are however difficult to practically implement. Moreover, combining hierarchical organizational structures and agile ways of working might be challenging. The aim of this study is to seek knowledge about which conditions that are affecting large scale agile transformations within a state agency. Three challenges and five success factors were identified for the model of analysis based on previous research within the field organizational transformation. Data was gathered through seven interviews with employees at Skatteverket. Based on the result of the study two new challenges and two new success factors were added to the model of analysis. The results show that decentralized development, value streams and synchronization of management have been prominent challenges for Skatteverket. Resistance to change and follow-up methodology were not as evident. The success factors pilot study, support from management, education and coaching, adaptation of culture, agile enthusiasts and implement strategy have been important for Skatteverket. Vision and communication were not as important.
982

Hardware-Efficient WDM/SDM Network : Smart Resource Allocation with SDN Controller / Maskinvarueffektivt WDM / SDM-nätverk : Smart resursallokering med SDN-controller

Liu, Lida January 2019 (has links)
Optical networking has been developing for decades and wavelength-division multiplexing (WDM) is the main technology used to carry signals in fiber-optical communication systems. However, its development has slowed because it is approaching the Shannon limit of nonlinear fiber transmission. Researchers are looking for multi dimensional multiplexing. Space-division multiplexing (SDM) is an ideal way to scale network capacities. The capacity of WDM/SDM network could be expanded to several times the capacity of WDM network but the active hardware devices may also increase by several times. This project aims to answer a practical question: How to construct a WDM/SDM network with less hardware resource? There is no mature research about WDM/SDM network yet. Therefore, the problem can be divided into two parts: (1) how to build a WDM/SDM network and (2) how to allocate resource and compute routes in such a network to minimize hardware resources. First, this thesis proposes a WDM/SDM node which has bypass connections between different fibers and architecture on demand (AoD) to effectively decrease the number of active hardware devices within the node. Then, two types of networks were constructed: one with bypass connections in each node and another one without any bypass connections. These networks were under the control of a software defined network (SDN) controller. The controller knew the wavelength resources within the networks. Several algorithms were applied to these networks to evaluate the effect of a bypass network and to identify the desired characteristics (to find short length path and decrease the probability of spectrum fragmentation) of an algorithm suitable for a network with bypass connections. The results of applying the proposed algorithms in two networks proved that the bypass connections increased the blocking probability in small topology but did not affect the results in large topology. The results in a large-scale network with bypass network were almost the same as the results in a network without bypass connections. Thus, bypass connections are suitable for large-scale network. / Optiskt nätverk har utvecklats i årtionden och våglängdsdelningsmultiplexering (WDM) är den viktigaste tekniken som används för att bära signaler i fiberoptiska kommunikationssystem. Utvecklingen har dock minskat eftersom den närmar sig Shannon-gränsen för olinjär fiberöverföring. Forskare letar efter flerdimensionell multiplexering. Space-division multiplexing (SDM) är ett idealiskt sätt att skala nätverkskapacitet. Kapaciteten för WDM / SDM-nätverk kan utökas till flera gånger WDM-nätverkets kapacitet, men de aktiva hårdvaraenheterna kan också öka med flera gånger. Projektet syftar till att svara på en praktisk fråga: Hur konstruerar jag ett WDM / SDM-nätverk med mindre hårdvara? Det finns ingen mogen forskning om WDM / SDM-nätverk än. Därför kan problemet delas in i två delar: (1) hur man bygger ett WDM / SDM-nätverk och (2) hur man fördelar resurser och beräknar rutter i ett sådant nätverk för att minimera hårdvaruressurser. Först föreslår denna avhandling en WDM / SDM-nod som har förbikopplingsanslutningar mellan olika fibrer och arkitektur på begäran (AoD) för att effektivt minska antalet aktiva hårdvaraenheter inom noden. Sedan konstruerades två typer av nätverk: en med bypass-anslutningar i varje nod och en annan utan några bypass-anslutningar. Dessa nätverk kontrollerades av en mjukvarudefinierad nätverkskontroller (SDN). Styrenheten visste våglängdsresurserna i nätverket. Flera algoritmer applicerades på dessa nätverk för att utvärdera effekten av ett förbikopplingsnätverk och för att identifiera de önskade egenskaperna (för att hitta en kort längdväg och minska sannolikheten för spektrumfragmentering) av en algoritm som är lämplig för ett nätverk med bypass-anslutningar. Resultaten av att tillämpa de föreslagna algoritmerna i två nät visade att förbikopplingsförbindelserna ökade blockeringssannolikheten i liten topologi men inte påverkade resultaten i stor topologi. Resultaten i ett storskaligt nätverk med bypass-nätverk var nästan samma som resultaten i ett nätverk utan bypass-anslutningar. Bypassanslutningar är således lämpliga för storskaliga nätverk.
983

A Travel Time Estimation Model for Facility Location on Real Road Networks

Al Adaileh, Mohammad Ali 20 September 2019 (has links)
No description available.
984

Large-Scale Form in Chopin's Four Ballades from Sonata Theory and Phrase-Rhythmic Perspectives

Chung, Soo Kyung 22 August 2022 (has links)
No description available.
985

Tracing Systematic Factors of Lead Time Deviations : A Case Study of Large-Scale Custom-Driven Development Projects at Saab Surveillance

Wallden, William January 2023 (has links)
In a world driven by technological advancements and ever-changing consumer preferences, large-scale custom-driven development projects have emerged as the gateway to creating complex products and systems tailored to individual customer needs. Steering these projects to successful completion presents significant challenges, with lead time deviations being a key concern. This study investigates an industrial defense corporation's current product development process to examine systematic factors that negatively impact lead time. Therefore, semi-structured interviews wereconducted with eight interview persons with the primarily aim to identify and classify these systematic factors into three organizationalperspectives providing a comprehensive understanding of their implications.  These perspectives revealed how systematic factors shaped initial project planning expectations and potential consequences, based on the organization's priorities. Additionally, the study emphasizes the need for a flexible risk-reducing reactive project model to mitigate lead time deviations stemming from the company's existing project model. Lastly, the study reveals that large-scale custom-driven development projects require careful consideration of trade-offs related to multi-project management and resource allocation. Companies must make decisions regarding whether to prioritize efficent project execution or winning business deals.
986

A Path toward Inherently Asymmetric Micromotors

Chattopadhyay, Purnesh, Heckel, Sandra, Irigon Pereira, Fabio, Simmchen, Juliane 05 March 2024 (has links)
Since the highly cited paper by Purcell postulating the “Scallop theorem” almost 50 years ago, asymmetry is an unavoidable part of micromotors. It is frequently induced by self-shadowing or self-masking, resulting in so-called Janus colloids. This strategy works very reliably, but turns into a bottleneck once up-scaling becomes important. Herein, existing alternatives are discussed and a novel synthetic pathway yielding active swimmers in a one-pot synthesis is presented. To understand the resulting mobility from a single material, the geometric asymmetry is evaluated using a python based algorithm and this process is automated in an open access tool.
987

CSAR: The Cross-Sectional Autoregression Model

Lehner, Wolfgang, Hartmann, Claudio, Hahmann, Martin, Habich, Dirk 18 January 2023 (has links)
The forecasting of time series data is an integral component for management, planning, and decision making. Following the Big Data trend, large amounts of time series data are available in many application domains. The highly dynamic and often noisy character of these domains in combination with the logistic problems of collecting data from a large number of data sources, imposes new requirements on the forecasting process. A constantly increasing number of time series has to be forecasted, preferably with low latency AND high accuracy. This is almost impossible, when keeping the traditional focus on creating one forecast model for each individual time series. In addition, often used forecasting approaches like ARIMA need complete historical data to train forecast models and fail if time series are intermittent. A method that addresses all these new requirements is the cross-sectional forecasting approach. It utilizes available data from many time series of the same domain in one single model, thus, missing values can be compensated and accurate forecast results can be calculated quickly. However, this approach is limited by a rigid training data selection and existing forecasting methods show that adaptability of the model to the data increases the forecast accuracy. Therefore, in this paper we present CSAR a model that extends the cross-sectional paradigm by adding more flexibility and allowing fine grained adaptations to the analyzed data. In this way, we achieve an increased forecast accuracy and thus a wider applicability.
988

Beam Discovery and Tracking for Mobile MIMO

Abdelrazek, Mohamed Naguib Hussein January 2022 (has links)
No description available.
989

Short-Term Traffic Prediction in Large-Scale Urban Networks

Cebecauer, Matej January 2019 (has links)
City-wide travel time prediction in real-time is an important enabler for efficient use of the road network. It can be used in traveler information to enable more efficient routing of individual vehicles as well as decision support for traffic management applications such as directed information campaigns or incident management. 3D speed maps have been shown to be a promising methodology for revealing day-to-day regularities of city-level travel times and possibly also for short-term prediction. In this paper, we aim to further evaluate and benchmark the use of 3D speed maps for short-term travel time prediction and to enable scenario-based evaluation of traffic management actions we also evaluate the framework for traffic flow prediction. The 3D speed map methodology is adapted to short-term prediction and benchmarked against historical mean as well as against Probabilistic Principal Component Analysis (PPCA). The benchmarking and analysis are made using one year of travel time and traffic flow data for the city of Stockholm, Sweden. The result of the case study shows very promising results of the 3D speed map methodology for short-term prediction of both travel times and traffic flows. The modified version of the 3D speed map prediction outperforms the historical mean prediction as well as the PPCA method. Further work includes an extended evaluation of the method for different conditions in terms of underlying sensor infrastructure, preprocessing and spatio-temporal aggregation as well as benchmarking against other prediction methods. / <p>QC 20190531</p>
990

Effects of climate and land-use change on retention of semi-natural grassland plant species : A landscape study in southern and central Sweden / Effekter av klimat och markanvändningsförändringar på hävdgynnade gräsmarksarter : En landskapsstudie i södra och mellersta Sverige

Jonsson, Malin January 2023 (has links)
Plants associated with the historical agricultural landscape are threatened. Land-use changes causing loss, fragmentation and degradation of semi-natural grassland habitats have resulted in many species becoming Red Listed. In addition, climate change favours generalist species, which risk outcompeting the specialist semi-natural grassland species. Conservation of small remnants of historical meadows and pastures left in landscapes has, on the other hand, proved to be of great importance for conservation of these species. A better understanding of how thespecies are affected by climate and land-use changes is essential for long-term and effective conservation plans and restoration measures. With this large-scale study, covering the whole of southern and central Sweden (ca 210000 km2), I investigated spatial variations in the number of retained semi-natural grassland species, and whether the proportion of retained distribution varies between species in different Red-List categories. Recently digitized data on the historical distribution of Swedish vascular plants made it possible to compare the historical and contemporary distributions of species on a large scale. Historical and current data of species distribution, climate and land use, and the presence of valuable grasslands were used to investigate the effects of changes in land use and climate on the species. Over 200 semi-natural grassland species were included in the analysis. The results showed that 34% of the seminatural grassland species in the study were Red Listed. There were spatial variations in retained distribution of species and the proportion of retained distribution varied between different Red-List categories. Species in the most critical category, CR had the lowestproportion retained distribution (median=0.39) and not Red Listed species the highest (median=0.95). The proportion of valuable semi-natural grasslands had a positive effect on retained distribution of species, while retention of open habitats had a negative effect, the lattercontradicting previous studies. Retention of species turned out not to be affected by climate change, which previous studies have suggested, but it was positively affected by a historically colder climate. The results of the study show the importance of preserving and restoring seminatural grasslands to reduce negative effects from other influencing factors, and that spatial differences in the effects are important to consider. The study underscores the need for more knowledge to understand the full impact of the threats that land-use change and climate change pose to these species. / Kärlväxter associerade till det historiska odlingslandskapet är hotade. Förändrad markanvändning med förlust, fragmentering och degradering av habitaten som resultat har lett till att ett stort antal av dessa arter numer är rödlistade. Dessutom hotas arterna ytterligare av klimatförändringar som gynnar generalistarter som då riskerar att konkurrera ut de mer specialiserade hävdgynnade gräsmarksarterna. Bevarandet av små kvarvarande ängs- och betesmarker har däremot visat sig ha stor betydelse för bevarandet av dessa arter. En ökad förståelse för hur arterna påverkas av förändringar i klimat och markanvändning är avgörande för långsiktiga och effektiva bevarandeplaner och restaureringsåtgärder. Med denna storskaliga studie över hela södra och mellersta Sverige undersöker jag spatiala variationer i antalet bevarade hävdgynnade gräsmarksarter, samt om andelen bibehållen utbredning varierar mellan arter i olika rödlistningskategorier. Nyligen digitaliserade data om svenska kärlväxters historiska utbredning gjorde det möjligt att jämföra arters historiska och nutida utbredning i stor skala. Historiska och aktuella data om arters utbredning, klimat och markanvändning, samt förekomsten av värdefulla gräsmarker användes för att undersöka effekterna av förändringar i markanvändning och klimat på hävdgynnade gräsmarksarter. Över 200 hävdgynnade gräsmarksarter inkluderades i analyserna. Resultaten visade att 34% av arterna i studien var rödlistade. Det fanns spatiala variationer i arternas bibehållna utbredningar och proportionen bibehållen utbredning varierade mellan olika rödlistningskategorier. Arter i den mest kritiska rödlistningskategorin CR hade lägst proportion bibehållen utbredning (median= 0,39), medan de ej rödlistade arterna den högsta (median=0,95). Proportionen värdefulla ängs- och betesmarker hade en positiv effekt på arters bevarade utbredning och bevarad öppen mark hade en negativ effekt, det senare i motsats till tidigare studiers resultat. Arternas bibehållna utbredning visade sig inte påverkats av klimatförändringarna, vilket tidigare studier visat på, ett historiskt kallare klimat hade däremot positiva effekter. Studiens resultat visar på vikten av att bevara och restaurera hävdpräglade marker för att minska negativa effekter från andra påverkansfaktorer och att spatiala skillnader i effekterna är viktiga att beakta. Studien understryker att mer kunskap behövs för att förstå de totala effekterna av de hot som förändrad markanvändning och klimatförändringar utgör för dessa arter.

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