Sökning: "time scale"

Visar resultat 16 - 20 av 3002 avhandlingar innehållade orden time scale.

1. 16. Cross-scale mechanisms and adaptation strategies in Small-Scale Fisheries

   Författare :Blanca González-Mon; Maja Schlüter; Beth Fulton; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Small-Scale fisheries; networks; agent-based modelling; trade; migration; mobility; diversification; Sustainability Science; vetenskap om hållbar utveckling;

   Sammanfattning : Small-Scale Fisheries (SSF) are increasingly facing shocks and changes that affect their capacity to provide food and maintain the livelihoods of millions of people who depend on fishing activities. At the same time, SSF influence and are influenced by interactions across scales, where interdependencies between different places are increasingly evident. LÄS MER

3. 17. Time-Frequency Analysis in Attosecond Spectroscopy

   Författare :Marcus Isinger; Atomfysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Attosecond; Spectroscopy; Time-Frequency; High-order harmonic generation; Rabitt; Interferometry;

   Sammanfattning : This thesis deals with ultrafast dynamics of electronic processes in rare gas atoms. The processes we explore include photoemission, where we time the emission of electrons moving away from the atomic core following ionization by a photon; and auto-ionization, where the atom spontaneously releases an electron wave-packet following photo-excitation. LÄS MER

4. 18. Asynchronous Algorithms for Large-Scale Optimization : Analysis and Implementation

   Författare :Arda Aytekin; Mikael Johansson; Panagiotis K. Patrinos; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; convex optimization; optimization; asynchronous algorithms; algorithms; parallel algorithms; large-scale; big data; Electrical Engineering; Elektro- och systemteknik;

   Sammanfattning : This thesis proposes and analyzes several first-order methods for convex optimization, designed for parallel implementation in shared and distributed memory architectures. The theoretical focus is on designing algorithms that can run asynchronously, allowing computing nodes to execute their tasks with stale information without jeopardizing convergence to the optimal solution. LÄS MER

5. 19. Adolescent mental health : time trends and validity of self-report measures

   Författare :Ida Blomqvist; Eva Henje; Inga Dennhag; Anne Hammarström; Lotte Haverman; Umeå universitet; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Adolescent; classical test theory; computer adaptive testing; cross-sectional; differential item functioning; graded response model; item banks; item response theory; measurement invariance; mental health; Patient-Reported Outcomes Measurement Information System; Reynolds Adolescent Depression Scale second edition; self-report measures; time trends; barn- och ungdomspsykiatri; Child and Youth Psychiatry;

   Sammanfattning : Background: Studies of time trends of adolescent self-reported mental health suggest an increase of mental health symptoms globally. Unfortunately, several studies within the field have methodological problems, such as short time-period between measurements and different mental health measures over time. LÄS MER

7. 20. Large-Scale Land Acquisitions as a Driver of Socio-Environmental Change : From the Pixel to the Globe

   Författare :Emma Johansson; Institutionen för naturgeografi och ekosystemvetenskap; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Land system sience; socio-environmental change; telecoupling; scale; co-production of knowledge; participatory art project; network science; blue and green water; Africa; Land grabbing; Remote sensing;

   Sammanfattning : A major challenge of our time is to sustainably produce food and other goods for a growing global population, without putting additional pressures on land and water resources and local people’s quality of life. Large-scale agriculture has brought many benefits to humanity in terms of food production but has also caused multiple sustainability challenges, including land and water degradation, deforestation, and biodiversity loss in areas of production. LÄS MER