Bibliografie tematiche / Dispersion management

Indice

Articoli di riviste
Tesi
Libri
Capitoli di libri
Atti di convegni
Rapporti di organizzazioni

Letteratura scientifica selezionata sul tema "Dispersion management"

Autore: Grafiati

Pubblicato: 4 giugno 2021

Ultima modifica: 25 maggio 2024

Cita una fonte nei formati APA, MLA, Chicago, Harvard e in molti altri stili

Scegli il tipo di fonte:

Consulta la lista di attuali articoli, libri, tesi, atti di convegni e altre fonti scientifiche attinenti al tema "Dispersion management".

Accanto a ogni fonte nell'elenco di riferimenti c'è un pulsante "Aggiungi alla bibliografia". Premilo e genereremo automaticamente la citazione bibliografica dell'opera scelta nello stile citazionale di cui hai bisogno: APA, MLA, Harvard, Chicago, Vancouver ecc.

Puoi anche scaricare il testo completo della pubblicazione scientifica nel formato .pdf e leggere online l'abstract (il sommario) dell'opera se è presente nei metadati.

Articoli di riviste sul tema "Dispersion management"

Berntson, Anders, and Boris A. Malomed. "Dispersion management with filtering." Optics Letters 24, no. 8 (April 15, 1999): 507. http://dx.doi.org/10.1364/ol.24.000507.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Porsezian, Kuppusamy, Ramanathan Ganapathy, Akira Hasegawa, and Vladimir N. Serkin. "Nonautonomous Soliton Dispersion Management." IEEE Journal of Quantum Electronics 45, no. 12 (December 2009): 1577–83. http://dx.doi.org/10.1109/jqe.2009.2027819.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Turitsyn, Sergei K., Vladimir K. Mezentsev, and Elena G. Shapiro. "Dispersion-Managed Solitons and Optimization of the Dispersion Management." Optical Fiber Technology 4, no. 4 (October 1998): 384–452. http://dx.doi.org/10.1006/ofte.1998.0271.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Dombi, Péter, Péter Rácz, Miklós Lenner, Volodymyr Pervak, and Ferenc Krausz. "Dispersion management in femtosecond laser oscillators with highly dispersive mirrors." Optics Express 17, no. 22 (October 23, 2009): 20598. http://dx.doi.org/10.1364/oe.17.020598.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Leo, Annalisa De, and Nicoletta Tambroni, Alessandro Stocchino. "EXPERIMENTAL STUDY OF LAGRANGIAN MIXING IN WEAKLY DISSIPATIVE TIDAL CHANNELS." Coastal Engineering Proceedings, no. 37 (September 1, 2023): 33. http://dx.doi.org/10.9753/icce.v37.management.33.

Testo completo

Abstract (sommario):

Estuaries are extremely dynamic environments, allowing wildlife to grow in a wide variety of ecosystems because of the interaction of masses of water with different characteristics. In particular, coastal bays and estuaries are characterized by flows driven by hydraulic unbalance such as baroclinic pressure gradients, river inflows and wind stresses, and tidal waves. Here, following a reductionist approach, we examine dispersion processes in a physical model of a tidal channel bounded by an inlet mouth, with tides as the dominant forcing. The presence of a tidal inlet can generate macro-vortices that during a tidal cycle may influence the momentum and mass transport on relatively large distances (Awaji et al. (1980), Awaji (1982), Branyon et al. (2022)). Moreover, tides tend to produce non-monotonic particle velocity correlation leading to possible particle looping trajectories that also reflect on a looping character of the Lagrangian integral time scales, differently from the classical statistically steady or homogeneous turbulence (Enrile et al. (2019)). Our goal is to examine the dispersion regimes by means of two-dimensional velocity measurements at the free surface reproduced in a large-scale physical model as a starting point for Lagrangian analysis. We show how the presence of a tidal inlet generates complex flow patterns depending on the character of the forcing tides. Furthermore, the mixed nature of tides may be crucial to dispersion processes, as it enhances the ability of the flow to transport mass in the direction of the main flow.

Gli stili APA, Harvard, Vancouver, ISO e altri

de Silva, Harindra, Steven Sapra, and Steven Thorley. "Return Dispersion and Active Management." Financial Analysts Journal 57, no. 5 (September 2001): 29–42. http://dx.doi.org/10.2469/faj.v57.n5.2479.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Sackley, William H. "Return Dispersion and Active Management." CFA Digest 32, no. 2 (May 2002): 92–93. http://dx.doi.org/10.2469/dig.v32.n2.1094.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Zharnitsky, Vadim, Emmanuel Grenier, Christopher K. R. T. Jones, and Sergei K. Turitsyn. "Stabilizing effects of dispersion management." Physica D: Nonlinear Phenomena 152-153 (May 2001): 794–817. http://dx.doi.org/10.1016/s0167-2789(01)00213-5.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Shi, Guifeng, Jianfei Sun, and Rui Luo. "Geographic dispersion and earnings management." Journal of Accounting and Public Policy 34, no. 5 (September 2015): 490–508. http://dx.doi.org/10.1016/j.jaccpubpol.2015.05.003.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Atai, Javid, and Boris A. Malomed. "Stabilized scheme for dispersion management." Journal of the Optical Society of America B 17, no. 7 (July 1, 2000): 1134. http://dx.doi.org/10.1364/josab.17.001134.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Più fonti

Tesi sul tema "Dispersion management"

Perutz, Mark A. (Mark Andrew). "An investigation of price dispersion in Internet auctions." Thesis, Massachusetts Institute of Technology, 2000. http://hdl.handle.net/1721.1/9195.

Testo completo

Abstract (sommario):

Thesis (M.B.A.)--Massachusetts Institute of Technology, Sloan School of Management, 2000. Also available online on DSpace at MIT. Includes bibliographical references (leaf 37). It can be observed that in consumer-to-consumer on-line auctions, there is a strong degree of price dispersion, even in liquid markets with a large number of bids per auction item. This Thesis research strives to quantify such dispersion and present explanations for the key findings on the nature of price dispersion in on-line auctions of like goods: Although contrary to common sense and public opinion, I found no significant correlation of winning bid price with feedback rating. This is true for low, medium-high and high value goods and for both new and used goods. This observation holds for all ranges of feedback ratings. Of all of the other variables of an auction listing: (shipping costs, amount of opening bid, number of bids, accepted payment types, picture in listing, and the use of reserve prices), only picture in listing and use of reserve prices are correlated with winning bid price. This observation holds for all types of goods examined. However, correcting for these variables does not significantly reduce price dispersion. The majority of the dispersion in winning bid prices of same-good auctions can be explained by the unique ability of the on-line auction process to obtain the reservation prices of buyers in the market, through its use of maximum bid amounts and proxy bidding. An auction winning bid curve for a good can be constructed by aggregating the winning bid prices of all auctions of that good over a period of time. The downward sloping and isoelastic nature of this curve can be explained in part by the downward sloping demand curve for that good, made up by the range of premiums buyers are willing to pay in order to increase their chances of winning the auction, and getting the item sooner. The exact shape of the curve can be further explained and in fact reconstructed by an examination of the statistics of grouping bids in auctions. Arbitrage to take advantage of the dispersion of winning bid prices can be shown to be possible, and in theory it appears to be surprisingly profitable. This suggests that on-line auction markets are only weakly market efficient. Several explanations were explored as to why arbitrage has not been pursued, thereby eliminating the observed dispersion. These explanations include the unseen non-monetary transaction and arbitrage costs, the level of sophistication necessary to capitalize on opportunities, and the persisting immaturity of the consumer-to-consumer on-line auction market. by Mark Andrew Perutz. M.B.A.

Gli stili APA, Harvard, Vancouver, ISO e altri

O'Leary, Michael Boyer 1969. "Geographic dispersion in teams : its history, experience, measurement, and change." Thesis, Massachusetts Institute of Technology, 2002. http://hdl.handle.net/1721.1/16883.

Testo completo

Abstract (sommario):

Thesis (Ph. D.)--Massachusetts Institute of Technology, Sloan School of Management, 2002. Vita. Includes bibliographical references. This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections. This thesis begins with the simple argument that geographic dispersion has gone surprisingly unexamined despite its role as the domain-defining construct for geographically dispersed teams (a.k.a. "virtual teams"). The last few years have seen slow but steady growth in field studies of such teams, but our understanding of geographic dispersion and the role it plays in work is stillquite limited. The thesis attempts to open the "black box" of geographic dispersion, show that it is far from a new phenomenon in organizations, understand the ways in which it is experienced, propose ways in which it can be measured, and understand the effects of doing work at increasing degrees of dispersion. It does so through three studies which combine qualitative and quantitative methods, and draw on archival, survey, observational, and interview data. Study 1 uses rich archival data covering more than two centuries (1670-1950) of the life of one firm - i.e., the Hudson's Bay Company - to understand its far-flung managers' experience of dispersion. It shows that the managers experienced their dispersion through a combination of coordination, communication, isolation, and control challenges. It also serves as a "typifier," showing that modem "virtual" teams have deep historical roots. Study 2 proposes a multi-dimensional definition of dispersion, including spatial-temporal distance and configuration, as well as a series of new measures to capture those dimensions. It explores the measures and their relationship to communications frequency in a sample of 115 dispersed project teams from a Fortune 500 company. (cont.) Study 3 is based on field research with nine geographically dispersed internal consulting teams in a large, national humanitarian aid organization. It follows them from the inception to the completion of their work and compares two teams in detail. One team was moderately dispersed and one was a pilot for a more fully dispersed approach to the internal consulting projects. It finds that perceptions about timing and dispersion differ from more objective measures like those in Study 2. It also shows how dispersion is a challenge for team boundaries and calls for more attention to the weighting of different team effectiveness criteria. Keywords: geographic dispersion, teams, virtual teams, effectiveness, communications, history. by Michael Boyer O'Leary. Ph.D.

Gli stili APA, Harvard, Vancouver, ISO e altri

Gajadharsingh, Asshvin. "Étude de solitons en dispersion management (DM) au moyen des moments d'ordre deux." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/MQ60720.pdf.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

He, Yangbo. "Sodic Soil Swelling and Dispersion and their Implications for Water Movement and Management." Diss., North Dakota State University, 2014. https://hdl.handle.net/10365/27543.

Testo completo

Abstract (sommario):

North Dakota has over 1.9 million ha of sodium-affected soils, influencing water movement and crop production. This dissertation consists of four studies examining different aspects of sodic soils. The first study surveys sodium adsorption ratio (SAR) methods to determine which is the most reliable. The second and third studies investigate the dispersion and swelling functions of sodic soils. The final study examines field spatial distribution of Na in order to propose management strategies. Analytical approaches for converting alternative to standard approaches are needed. The SAR was determined from many non-standard techniques. One hundred soils were used, SARe and 1:5 soil/water SAR1:5 determined using shaking, stirring, and a USDA-NRCS method were compared. Three of the methods influenced the SAR1:5 values. Electrical conductivity (EC), SAR, and Ca/Mg ratios influence dispersion. Three pure clay minerals (montmorillonite, kaolinite and illite) were pretreated by variable Na and cation ratios and absorbance was determined using spectrophotometer for dispersion. Calcium-Mg ratios across the same SAR did not influence clay dispersion. Dispersion increased with higher SAR and reduced EC whereas no dispersion for kaolinite. Swelling is associated with hydration of clays, which forces clay tactoids to separate. Four soil series from North Dakota field sites were used. To assess swelling, field capacity (FC) was used as proxy. The study found that soil Na and soluble salt concentrations were two important chemical factors influencing FCW. The FCW increases with increased SAR and lower levels of EC. These results indicate that maintaining an EC level above 4 dS m-1 may mitigate swelling, which is an issue considered in tile drainage. Over- and under-application of amendments in sodic soils was studied in a 8.1 ha sodic soil field. At each site, samples were taken from two depths; electromagnetic (EM38) and elevation readings were done. Elevation was significantly correlated with soil variables except for Na%. The EM38 was reliable to express soil EC and was correlated with Na% and dispersion. Therefore, conducting the EM38 and RTK may allow site-specific management of Na. Improved knowledge of sodic soils dispersion, swelling, and field distribution will benefit researchers and farmers in managing their fields. NRCS Conservation Innovation Grant China Scholarship Council North Dakota Water Resources Research Institute

Gli stili APA, Harvard, Vancouver, ISO e altri

Docherty, Andrew Engineering UNSW. "Collision induced timing shifts in wavelength-division-multiplexed optical fiber communications systems." Awarded by:University of New South Wales. Engineering, 2004. http://handle.unsw.edu.au/1959.4/19337.

Testo completo

Abstract (sommario):

Long distance repeaterless optical fiber communications systems are currently used to transmit most internet and telephone information worldwide. The growth of photonic telecommunications technology has produced systems with very high bit-rate per fiber, but this still falls short of its potential capacity. Currently systems that are able to transmit even higher bit-rates are being developed utilizing dense wavelength-division-multiplexing (WDM) to maximally utilize the bandwidth potential of optical fibers. One of the most important factors that limits the bit-rate achievable in a such a WDM optical communications system is the cross-talk between channels caused by pulse collisions. In this thesis a consistent mathematical theory is used to analyze the frequency and timing shifts caused collisions between two WDM channels. This theory is applied to the systems currently most promising for next-generation photonic telecommunications; the dispersion managed (DM) soliton and 'quasi-linear' systems. Self-contained formulae are obtained which accurately predict the timing shifts suffered in these systems with a wide range of parameters. These formulae require an order of magnitude less computational time that direct numerical simulations. Several mathematical techniques are introduced to obtain computationally efficient formulae for complete and incomplete collisions in both systems. For complete collisions we use the Poisson sum transform to change the calculation to a sum in the Fourier domain. For incomplete collisions we use asymptotic integration to obtain approximate formulae. For quasi-linear systems we simplify the Laplace method even further to obtain elementary formulae. We show that using a combination of these methods the timing shift for incomplete and complete collisions in a wide range of system configurations can be obtained in comparatively small computational times. We find that for systems with small DM map strength the timing shift from widely separated channels is significant. For quasi-linear systems with large DM map strength this is negligable and the timing shift decreases with the square of the channel frequency separation. We also find the timing shift from closely spaced channels is higher for quasi-linear systems than for DM soliton systems operating at the same average dispersion.

Gli stili APA, Harvard, Vancouver, ISO e altri

Raubenheimer, Heidi. "Managing portfolio managers : the impacts of market concentration, cross-sectional return dispersion and restrictions on short sales." Thesis, Stellenbosch : Stellenbosch University, 2012. http://hdl.handle.net/10019.1/20266.

Testo completo

Abstract (sommario):

Thesis (PhD)--Stellenbosch University, 2012. The impacts on the active management of investment portfolios of a) market concentration, b) cross-sectional return dispersion and c) restrictions on short sales are explored in this thesis. The context is the fund sponsor’s management of their investment managers in a South African equity investment environment. Some of the findings here are developed analytically and some make use of multiple simulated investment views and their corresponding optimal portfolio solutions to document the size and nature of the inefficiencies that are created by these three factors. The cross-sectional volatility of asset returns in an investment universe represents a carrying capacity for active risk taking: the higher the cross-sectional volatility, the greater the opportunity for active risk taking. Cross-sectional volatility is shown to be an important consideration when setting active risk targets. It is shown that, to remain efficient, active risk should be reduced during periods of low cross-sectional dispersion and vice versa. The sensitivity of active risk estimates to changes in the cross-sectional dispersion of their investment universe is demonstrated and sponsors should therefore exercise caution when reacting to changes in the active risk estimates of their funds. Cross-sectional volatility is shown to be time-varying and is related to similarly varying dispersion in realised fund returns. The ex post performance of competing portfolio managers therefore require correction for this heteroscedasticity and an effective weighted adjustment is recommended. Active managers can only fully express their views in an environment where their mandated conditions accommodate their conviction and level of risk taking. The short sale restriction is shown to be materially binding when applied to a concentrated benchmark such as the ALSI where only a few of the stocks comprise most of the total investment weight. The more concentrated the benchmark and the higher the active risk target, the wider the distribution of individual asset weights in the portfolio will be and the more binding the weighting constraints will be. It is shown that constraints on short positions are more binding on assets with small weightings in the benchmark illustrating the asymmetrical sub-optimal effect of these constraints when they are applied uniformly across the investment opportunity set. It is argued that requiring long-only managers to increase their active positions and/or active risk in a concentrated investment environment further constrains them in their ability to express their best investment view and increases their competitive disadvantage relative to unconstrained funds taking similar risk. The research presented in this thesis measures the nature and size of the impacts of the market concentration, cross sectional return dispersion and restrictions on short sales that are implied by the investment mandate on the quality of the investment portfolio, providing analysis and techniques which can inform and improve the quality of the relationship between fund sponsor and fund manager. The more appropriate the investment mandate and the monitoring of the fund’s performance subject to this mandate, the more effective the manager’s risk-taking on behalf of their investors will be. This is the principle that this research aims to serve.

Gli stili APA, Harvard, Vancouver, ISO e altri

Blachetta, Marie [Verfasser]. "Dispersion von Marketingaktivitäten in Business-to-Business Unternehmen : Merkmale, Messung, Einflussfaktoren und Auswirkungen / Marie Blachetta." Berlin : Freie Universität Berlin, 2020. http://d-nb.info/1215099401/34.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Van, Reenen Reenen James. "An empirical investigation into cross-sectional return dispersion on the South African equity market." Thesis, Stellenbosch : Stellenbosch University, 2013. http://hdl.handle.net/10019.1/85655.

Testo completo

Abstract (sommario):

Thesis (MComm)--Stellenbosch University, 2013. ENGLISH ABSTRACT: This study examines the role of cross-sectional return dispersion in portfolio management by examining two topics. To begin with, the study considers why return dispersion changes over time. Given the influence of return dispersion on active portfolio return opportunity, it is important for managers to understand why return dispersion changes over time. For a sample of South African listed shares over the period June 1996 to December 2011, univariate time-series analysis reveals significant serial correlation in return dispersion which may be modelled using ARMA (1, 1) and GARCH (1, 1) processes. Further analysis within a rational economic framework reveals that return dispersion is countercyclical to aggregate economic activity and related to both local and foreign economic uncertainty. The study then considers the relationship between return dispersion and the return to investment strategies. If substantial association between return dispersion and any investment strategy exists, then it is possible for managers and fund sponsors to augment an understanding of when active return opportunity is high with strategies for exploiting return opportunities. Continuing within the rational economic framework, the study uses Spearman‟s rank correlation coefficients to show a significant positive relationship between return dispersion and the value premium. In aggregate, these findings suggest that it is possible for South African investors to understand why return dispersion changes over time, as well as how to take advantage of changes in return dispersion. AFRIKAANSE OPSOMMING: Hierdie studie ondersoek die rol van opbrengsverspreiding oor die kruissnit van „n mark in portefeuljebestuur deur twee onderwerpe te bestudeer. Eerstens bestudeer die studie hoekom opbrengsverspreiding oor tyd verander. Gegewe die invloed van opbrengsverspreiding op aktiewe beleggingsgeleentheid is dit belangrik vir bestuurders om te verstaan hoekom opbrengsverspreiding oor tyd verander. Vir „n steekproef van Suid Afrikaanse aandele oor die periode Julie 1996 tot Desember 2011 dui enkelvoudige tydreeks analise aan dat opbrengsverspreiding beduidende outokorrelasie het, waar die outokorrelasie beskryf word deur ARMA (1, 1) en GARCH (1, 1) prosesse. Verdere analise binne „n rasionele ekonomiese raamwerk dui daarop dat opbrengsverspreiding kontra-siklies aan makro-ekonomiese aktiwiteit is en verwant is aan beide plaaslike en buitelandse ekonomiese onsekerheid. Die studies ondersoek daarna die verhouding tussen opbrengsverspreiding en die opbrengs van beleggings strategieë. Indien daar „n noemenswaardige verhouding is tussen opbrengsverspreiding en enige beleggings strategie, dan kan bestuurders beter oordeel watter strategieë hoë opbrengste lewer wanneer beleggingsgeleenthede hoog is. Die studie hou binne „n rasionele ekonomiese raamwerk en gebruik Spearman se rang-orde korrelasie koeffisiënte om „n beduidende positiewe verwantskap tussen opbrengsverspreiding en die opbrengs van die waardepremie aan te dui. As „n geheel dui hierdie bevindinge daarop aan dat dit moontlik is vir Suid-Afrikaanse beleggers om te verstaan hoekom opbrengsverspreiding oor tyd verander asook hoe om voordeel uit die verwantskappe te trek.

Gli stili APA, Harvard, Vancouver, ISO e altri

Rezk, Rasha Saber Mahmoud. "Exploring the constraining influence of product attributes on value network configuration and dispersion." Thesis, University of Cambridge, 2015. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.708854.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Klingebiel, Sandro. "Picosecond pump dispersion management and jitter stabilization in a petawatt-scale few-cycle OPCPA system." Diss., Ludwig-Maximilians-Universität München, 2013. http://nbn-resolving.de/urn:nbn:de:bvb:19-159662.

Testo completo

Abstract (sommario):

The petawatt field synthesizer (PFS) is a high-power optical parametric chirped-pulse amplification (OPCPA) system under development, which aims at generating fewcycle pulses with high energies of several Joule. The availability of light pulses with these unique parameters will enable an efficient generation of even shorter attosecond pulses with significantly higher photon flux than achievable today [1]. Not only the real-time observation, but also the control of charge transfer in molecular systems will become feasible for the first time [2]. The technique for realizing the ambitious PFS specifications is short-pulse pumped OPCPA in mm-thin crystals. The reduced crystal thickness allows for ultra-broadband amplification. The pump-pulse duration is reduced to a picosecond—compared to 100 ps to nanosecond pump-pulse duration in conventional high power OPCPA systems. The shortened pulse duration facilitates higher pump intensities whereby an efficient amplification in the mm-thin crystals is achieved. The demonstration of this novel scheme in the PFS project will allow its use in the extreme light infrastructure (ELI)[3]—a pan-European high-power laser project. Based on the PFS technology for the front end, the ELI will generate exawatt peakpower pulses and therefore facilitate the study of laser-matter interaction in an unprecedented intensity range [4]. This work describes the CPA-aspects of a suitable chirped pulse amplification (CPA) pump laser for the PFS OPCPA system. The diode-pumped Yb:YAG amplifiers up to an energy of 300 mJ (at 1030 nm) are presented in combination with the dispersion management. The application of spectral-amplitude shaping in conjunction with an Yb:glass amplifier with broader bandwidth than Yb:YAG enables an unprecedented bandwidth of 3.5nm in the Yb:YAG amplifier at this energy level. Simulations show that a similar bandwidth can be maintained for the full amplifier system. The pulses with 200 mJ could be compressed to 900 fs, close to the transform limit. Later changes in the stretcher increase the bandwidth more and compression down to 740 fs is demonstrated. To date, these are the highest peak power pulses generated in Yb:YAG. For the application as OPCPA pump, the so generated pulses are frequency doubled in a DKDP crystal. Another key aspect of this work is the synchronization of the OPCPA pump and signal pulses. In spite of optical synchronization of both pulses, a large timing fluctuation between these pulses is measured at the first OPCPA stage. The high accuracy jitter measurement setup and a series of measurements, which showed that the stretcher/compressor setup is the main source of jitter, are presented. Theoretical investigations yield that the optical delay in a compressor is orders of magnitude more sensitive to angle changes compared to free space propagation. This makes the stretcher and compressor extremely sensitive for timing jitter caused by turbulent air or mechanical instabilities. This novel insight helped us to significantly reduce the jitter to 100 fs and to demonstrate the feasibility of the PFS concept with first broad-band OPCPA experiments. Das PFS OPCPA System befindet sich zurzeit im Aufbau und zielt darauf ab, ultrakurze Lichtpulse mit wenigen optischen Zyklen und einigen Joule Pulsenergie zu erzeugen. Wenn Lichtpulse mit diesen einzigartigen Parametern verfügbar werden, können kürzere Attosekundenpulse mit höherer Effizienz und deutlich höherem Photonenfluss als bisher generiert werden [1]. Die Anwendung der so erzeugten Attosekundenpulse könnte erstmalig die Beobachtung in Echtzeit und die Kontrolle von Ladungsübergängen in Molekularen Systemen ermöglichen [2]. Die Technik, um die PFS Spezifikationen zu erreichen ist OPCPA mit mm dünnen Kristallen, gepumpt mit kurzen Pulsen. Die reduzierte Kristalldicke ermöglicht ultra-breitbandige Verstärkung. Die Pumppulsdauer ist dabei auf eine Pikosekunde reduziert, im Vergleich zu 100 ps bis Nanosekunden Pulsdauer in konventionellen Hochleistungs-OPCPA Systemen. Dies ermöglicht höhere Pumpintensitäten, wodurch eine effiziente Verstärkung in den kurzen Kristallen gewährleistet wird. Die Demonstration dieses neuartigen Verstärkungsschemas innerhalb des PFS Projektes erlaubt dessen Nutzung in ELI[3]—einem gesamt-europäische Laser Projekt. Basierend auf der PFS-Technologie für das Frontend wird ELI Lichtpulse mit Exawatt Spitzenleistung generieren, wodurch Laser-Materie-Wechselwirkung in einem bis dahin unerreichten Intensitätsbereich untersucht werden kann [4]. Diese Arbeit beschreibt die Entwicklung eines geeigneten CPA Pumplasers für das PFS OPCPA-System. Die diodengepumpten YB:YAG Verstärker bis zu einer Energie von 300 mJ (bei 1030 nm) werden in Kombination mit dem Dispersionsmanagement präsentiert. Die Anwendung von spektralem Amplitudenformen in Verbindung mit einem breitbandigen Verstärker ermöglicht eine bis dahin unerreichte Bandbreite von 3.5nm in Yb:YAG bei diesem Energieniveau. Simulationen zeigen, dass ähnliche Bandbreiten für das vollständige Verstärkersystem erreicht werden können. Die Pulse mit 200 mJ wurden auf 900 fs (nah am Transformlimit) komprimiert. Spätere Veränderungen im Strecker führen zu einer vergrößerten Bandbreite, wodurch eine Kompression auf 740 fs ermöglicht wurde. Aktuell ist dies die höchste Pulsspitzenleistung, die je in Yb:YAG generiert wurde. Für die Anwendung als OPCPA Pumpe werden die so generierten Pulse in einem DKDP Kristall frequenzverdoppelt. Ein weiterer Schwerpunkt dieser Arbeit ist die Synchronisation der OPCPA Pumpund Signalpulse. Trotz optischer Synchronisation beider Pulse wurde eine große zeitliche Schwankung zwischen diesen Pulsen am Ort der ersten OPCPA Stufe gemessen. Der Messaufbau wird vorgestellt und eine Reihe von Messungen zeigt, dass der Strecker/Kompressor des Pumplasers die Hauptursache der zeitlichen Schwankungen von einigen hundert Femtosekunden ist. Theoretische Untersuchungen ergeben, dass der Strecker und Kompressor extrem sensitiv sind für zeitliche Schwankungen, die durch Turbulenzen in Luft oder durch instabile mechanische Komponenten hervorgerufen werden können. Diese neue Einsicht hat geholfen, diese Schwankungen auf 100 fs zu reduzieren und die Machbarkeit des PFS Konzeptes mit ersten breitbandigen OPCPA Experimenten zu demonstrieren.

Gli stili APA, Harvard, Vancouver, ISO e altri

Più fonti

Libri sul tema "Dispersion management"

Włodzimierz, Czernuszenko, Rowiński Paweł M, and Instytut Geofizyki (Polska Akademia Nauk), eds. Water quality hazards and dispersion of pollutants. New York: Kluwer Academic Publishers, 2005.

Cerca il testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Division, Alberta Environmental Sciences. Comparison of meteorology elements in Alberta Environment's regional screening dispersion modelling data sets. Edmonton: Alberta Environment, Environmental Service, Environmental Sciences Division, 1999.

Cerca il testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

United States. Environmental Protection Agency. Office of Air Quality Planning and Standards. Technical Support Division and Radian Corporation, eds. Guidance on the application of refined dispersion models for hazardous/toxic air releases. Research Triangle Park, N.C: U.S. Environmental Protection Agency, Office of Air Quality Planning and Standards, 1993.

Cerca il testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Group, Alberta Alberta Environmental Protection Model Modification Task. Dispersion Modelling Modification Task Group recommendation report for the Alberta air quality guidelines. Edmonton]: Model Modification Task Group, 1999.

Cerca il testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Protection, Alberta Alberta Environmental. Dispersion modelling modification task group recommendation report for the Alberta air quality guidelines. [Edmonton: Alberta Environmental Protection], 1999.

Cerca il testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Eckman, Richard M. The Suitability of diffusion and wind-field techniques for an emergency-response dispersion model. Silver Spring, Md: U.S. Dept. of Commerce, National Oceanic and Atmospheric Administration, Environmental Research Laboratories, 1989.

Cerca il testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

J, Dobosy Ronald, and Air Resources Laboratory (U.S.), eds. The suitability of diffusion and wind-field techniques for an emergency-response dispersion model. Silver Spring, Md: U.S. Dept. of Commerce, National Oceanic and Atmospheric Administration, Environmental Research Laboratories, Air Resources Laboratory, 1989.

Cerca il testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

International Symposium on Spatial Processes and Management of Marine Populations (1999 Anchorage, Alaska). Spatial processes and management of marine populations: Proceedings of the Symposium on Spatial Processes and Management of Marine Populations, October 27-30, 1999, Anchorage, Alaska. Edited by Kruse Gordon H and Lowell Wakefield Fisheries Symposium (17th : 1999 : Anchorage, Alaska). Fairbanks, Alaska: University of Alaska Sea Grant College Program, 2001.

Cerca il testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Endowment, Virginia Environmental, Marshall University Research Corporation, West Virginia. Dept. of Environmental Protection, and Geological Survey (U.S.), eds. Traveltime and dispersion data, including associated discharge and water-surface elevation data, Kanawha River, West Virginia, 1991. Charleston, W. Va: U.S. Dept. of the Interior, U.S. Geological Survey, 1993.

Cerca il testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Egan, B. A. Dispersion in complex terrain: A report of a workshop held at Keystone, Colorado, May 17-20, 1983. Research Triangle Park, NC: U.S. Environmental Protection Agency, Atmospheric Sciences Research Laboratory, 1986.

Cerca il testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Più fonti

Capitoli di libri sul tema "Dispersion management"

Theodore, Mary K., and Louis Theodore. "Atmospheric Dispersion Modeling." In Introduction to Environmental Management, 99–104. 2nd ed. Second Edition. | Boca Raton ; London: CRC Press, 2021. | “First edition published by CRC Press 2009”—T.p. verso.: CRC Press, 2021. http://dx.doi.org/10.1201/9781003171126-12.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Brennan, James F. "Broadband fiber Bragg gratings for dispersion management." In Fiber Based Dispersion Compensation, 341–78. New York, NY: Springer New York, 2007. http://dx.doi.org/10.1007/978-0-387-48948-3_10.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Ali, Maher. "Management of Polarization-Mode Dispersion." In Transmission-Efficient Design and Management of Wavelength-Routed Optical Networks, 171–84. Boston, MA: Springer US, 2001. http://dx.doi.org/10.1007/978-1-4615-1491-6_7.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Ramachandran, Siddharth, and Man F. Yan. "Static and tunable dispersion management with higher order mode fibers." In Fiber Based Dispersion Compensation, 187–248. New York, NY: Springer New York, 2007. http://dx.doi.org/10.1007/978-0-387-48948-3_7.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Theodore, Mary K., and Louis Theodore. "Dispersion Modeling in Water Systems." In Introduction to Environmental Management, 197–202. 2nd ed. Second Edition. | Boca Raton ; London: CRC Press, 2021. | “First edition published by CRC Press 2009”—T.p. verso.: CRC Press, 2021. http://dx.doi.org/10.1201/9781003171126-23.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Schatzmann, Michael, Bernd Leitl, and Joachim Liedtke. "Dispersion in Urban Environments." In Urban Air Quality: Measurement, Modelling and Management, 249–57. Dordrecht: Springer Netherlands, 2000. http://dx.doi.org/10.1007/978-94-010-0932-4_27.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Kootstra, Freddie, Albert Pons Julia, and Frank van het Veld. "Neutral gas dispersion modeling revised." In Probabilistic Safety Assessment and Management, 3231–43. London: Springer London, 2004. http://dx.doi.org/10.1007/978-0-85729-410-4_517.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Humphries, Bob, and Tyler Abel. "Modelling the Dispersion of Pollutants: Two Case Studies." In Air Quality Management, 99–127. Dordrecht: Springer Netherlands, 2013. http://dx.doi.org/10.1007/978-94-007-7557-2_5.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

de Moraes, Carlos Gustavo V., and Remo Susanna. "Glaucomas: Pigment Dispersion Glaucoma and Angle Recession Glaucoma." In Pearls of Glaucoma Management, 345–53. Berlin, Heidelberg: Springer Berlin Heidelberg, 2009. http://dx.doi.org/10.1007/978-3-540-68240-0_45.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Jäger, Gerold, Anand Srivastav, and Katja Wolf. "Solving Generalized Maximum Dispersion with Linear Programming." In Algorithmic Aspects in Information and Management, 1–10. Berlin, Heidelberg: Springer Berlin Heidelberg, 2007. http://dx.doi.org/10.1007/978-3-540-72870-2_1.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Atti di convegni sul tema "Dispersion management"

Qiao, Haigeng, Chuanfeng He, Jinlong Yu, Jufeng Dai, and Enze Yang. "New dispersion-decreasing dispersion management." In Lasers and Applications in Science and Engineering, edited by Kenneth L. Schepler and Dennis D. Lowenthal. SPIE, 2004. http://dx.doi.org/10.1117/12.527644.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Smith, N. J., N. J. Doran, K. J. Blow, F. M. Knox, and W. Forysiak. "Enhanced power solitons in optical fibres with strong dispersion management." In Nonlinear Guided Waves and Their Applications. Washington, D.C.: Optica Publishing Group, 1996. http://dx.doi.org/10.1364/nlgw.1996.fa.4.

Testo completo

Abstract (sommario):

The study of propagation in optical fibres with non-uniform dispersion has recently become a key topic in long haul optical communications. By using combinations of fibres with opposite sign dispersions, it is possible to construct a system which has high local dispersion at any given point, but a low path-average dispersion. This procedure strongly modifies the nonlinear transmission properties of the system compared with one constructed from uniformly low dispersion fibre, because the efficiency with which nonlinear four wave mixing processes are phase matched is substantially reduced[1, 2].

Gli stili APA, Harvard, Vancouver, ISO e altri

Barrington, S., L. Xingjun, D. Choinière, and S. Prasher. "Windbreaks for odour dispersion." In WASTE MANAGEMENT 2006. Southampton, UK: WIT Press, 2006. http://dx.doi.org/10.2495/wm060381.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Dombi, Peter, Peter Racz, Miklos Lenner, Volodymyr Pervak, and Ferenc Krausz. "Dispersion management in femtosecond laser oscillators with highly dispersive mirrors." In 11th European Quantum Electronics Conference (CLEO/EQEC). IEEE, 2009. http://dx.doi.org/10.1109/cleoe-eqec.2009.5196428.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Tempea, G., Tuan Le, M. Hofer, A. Stingl, and W. Drexler. "Dispersion management for microscope objectives." In 2005 Conference on Lasers and Electro-Optics (CLEO). IEEE, 2005. http://dx.doi.org/10.1109/cleo.2005.202359.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Garrett, L. D. "Dispersion management in optical networks." In 11th International Conference on Integrated Optics and Optical Fibre Communications. 23rd European Conference on Optical Communications IOOC-ECOC97. IEE, 1997. http://dx.doi.org/10.1049/cp:19971585.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Buck, Samuel, and Marco Galimberti. "Wavefront-tilt Correction of Laser Pulses by Angular Dispersion Management." In CLEO: Science and Innovations. Washington, D.C.: Optica Publishing Group, 2022. http://dx.doi.org/10.1364/cleo_si.2022.sf3e.3.

Testo completo

Abstract (sommario):

A new diagnostic has been tested to visualise pulse-front-tilt in ultrashort laser pulses. Dispersive mediums were rotationally controlled in an automated feedback loop in accordance to the diagnostic to successfully minimise existing angular dispersion.

Gli stili APA, Harvard, Vancouver, ISO e altri

Serkin, Vladmir N., and Akira Hasegawa. "Femtosecond soliton amplification in nonlinear dispersive traps and soliton dispersion management." In Symposium on High-Power Lasers and Applications, edited by Yehuda B. Band. SPIE, 2000. http://dx.doi.org/10.1117/12.382052.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Kaushal, Saket, and José Azaña. "Dispersion Management of Periodic Signals using On-chip Dispersive Phase Filters." In Integrated Photonics Research, Silicon and Nanophotonics. Washington, D.C.: OSA, 2021. http://dx.doi.org/10.1364/iprsn.2021.im1b.6.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Ania-Castanon, Juan D., Priscila Garcia-Fernandez, and Jose M. Soto-Crespo. "Dispersion management with fiber Bragg gratings." In Symposium on High-Power Lasers and Applications, edited by Yehuda B. Band. SPIE, 2000. http://dx.doi.org/10.1117/12.382079.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Rapporti di organizzazioni sul tema "Dispersion management"

Riggle, K. J., and J. W. Roddy. A preliminary assessment of selected atmospheric dispersion, food-chain transport, and dose-to-man computer codes for use by the DOE Office of Civilian Radioactive Waste Management. Office of Scientific and Technical Information (OSTI), February 1989. http://dx.doi.org/10.2172/6187511.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Aalto, Juha, and Ari Venäläinen, eds. Climate change and forest management affect forest fire risk in Fennoscandia. Finnish Meteorological Institute, June 2021. http://dx.doi.org/10.35614/isbn.9789523361355.

Testo completo

Abstract (sommario):

Forest and wildland fires are a natural part of ecosystems worldwide, but large fires in particular can cause societal, economic and ecological disruption. Fires are an important source of greenhouse gases and black carbon that can further amplify and accelerate climate change. In recent years, large forest fires in Sweden demonstrate that the issue should also be considered in other parts of Fennoscandia. This final report of the project “Forest fires in Fennoscandia under changing climate and forest cover (IBA ForestFires)” funded by the Ministry for Foreign Affairs of Finland, synthesises current knowledge of the occurrence, monitoring, modelling and suppression of forest fires in Fennoscandia. The report also focuses on elaborating the role of forest fires as a source of black carbon (BC) emissions over the Arctic and discussing the importance of international collaboration in tackling forest fires. The report explains the factors regulating fire ignition, spread and intensity in Fennoscandian conditions. It highlights that the climate in Fennoscandia is characterised by large inter-annual variability, which is reflected in forest fire risk. Here, the majority of forest fires are caused by human activities such as careless handling of fire and ignitions related to forest harvesting. In addition to weather and climate, fuel characteristics in forests influence fire ignition, intensity and spread. In the report, long-term fire statistics are presented for Finland, Sweden and the Republic of Karelia. The statistics indicate that the amount of annually burnt forest has decreased in Fennoscandia. However, with the exception of recent large fires in Sweden, during the past 25 years the annually burnt area and number of fires have been fairly stable, which is mainly due to effective fire mitigation. Land surface models were used to investigate how climate change and forest management can influence forest fires in the future. The simulations were conducted using different regional climate models and greenhouse gas emission scenarios. Simulations, extending to 2100, indicate that forest fire risk is likely to increase over the coming decades. The report also highlights that globally, forest fires are a significant source of BC in the Arctic, having adverse health effects and further amplifying climate warming. However, simulations made using an atmospheric dispersion model indicate that the impact of forest fires in Fennoscandia on the environment and air quality is relatively minor and highly seasonal. Efficient forest fire mitigation requires the development of forest fire detection tools including satellites and drones, high spatial resolution modelling of fire risk and fire spreading that account for detailed terrain and weather information. Moreover, increasing the general preparedness and operational efficiency of firefighting is highly important. Forest fires are a large challenge requiring multidisciplinary research and close cooperation between the various administrative operators, e.g. rescue services, weather services, forest organisations and forest owners is required at both the national and international level.

Gli stili APA, Harvard, Vancouver, ISO e altri

Lundgren, Jonathan, Moshe Coll, and James Harwood. Biological control of cereal aphids in wheat: Implications of alternative foods and intraguild predation. United States Department of Agriculture, October 2014. http://dx.doi.org/10.32747/2014.7699858.bard.

Testo completo

Abstract (sommario):

The overall objective of this proposal is to understand how realistic strategies for incorporating alternative foods into wheat fields affect the intraguild (IG) interactions of omnivorous and carnivorous predators and their efficacy as biological control agents. Cereal aphids are a primary pest of wheat throughout much of the world. Naturally occurring predator communities consume large quantities of cereal aphids in wheat, and are partitioned into aphid specialists and omnivores. Within wheat fields, the relative abilities of omnivorous and carnivorous predators to reduce cereal aphids depend heavily on the availability, distribution and type of alternative foods (alternative prey, sugar, and pollen), and on the intensity and direction of IG predation events within this community. A series of eight synergistic experiments, carefully crafted to accomplish objectives while accounting for regional production practices, will be conducted to explore how cover crops (US, where large fields preclude effective use of field margins) and field margins (IS, where cover crops are not feasible) as sources of alternative foods affect the IG interactions of predators and their efficacy as biological control agents. These objectives are: 1. Determine the mechanisms whereby the availability of alternative prey and plant-provided resources affect pest suppression by omnivorous and carnivorous generalist predators; 2. Characterize the intensity of IGP within generalist predator communities of wheat systems and assess the impact of these interactions on cereal aphid predation; and 3. Evaluate how spatial patterns in the availability of non-prey resources and IGP affect predation on cereal aphids by generalist predator communities. To accomplish these goals, novel tools, including molecular and biochemical gut content analysis and geospatial analysis, will be coupled with traditional techniques used to monitor and manipulate insect populations and predator efficacy. Our approach will manipulate key alternative foods and IG prey to determine how these individual interactions contribute to the ability of predators to suppress cereal aphids within systems where cover crop and field margin management strategies are evaluated in production scale plots. Using these strategies, the proposed project will not only provide cost-effective and realistic solutions for pest management issues faced by IS and US producers, but also will provide a better understanding of how spatial dispersion, IG predation, and the availability of alternative foods contribute to biological control by omnivores and carnivores within agroecosystems. By reducing the reliance of wheat producers on insecticides, this proposal will address the BARD priorities of increasing the efficiency of agricultural production and protecting plants against biotic sources of stress in an environmentally friendly and sustainable manner.

Gli stili APA, Harvard, Vancouver, ISO e altri

Steenhuis, Tammo S., Israela Ravina, Jean-Yves Parlange, Rony Wallach, and Larry D. Geohring. Improving Preferential Flow Modules by Experimentation. United States Department of Agriculture, September 1994. http://dx.doi.org/10.32747/1994.7570552.bard.

Testo completo

Abstract (sommario):

Preferential flow is the process whereby water and solutes move by preferred pathways. During preferential flow, local wetting fronts propagate to considerable depths in the soil profile, essentially bypassing the matrix pore space. Under such conditions classical methods, such as the convective-dispersive equation, for quantifying flow of water and solutes in uniform soils are not valid. This project set out to develop methods to predict fast and early breakthrough of solutes. To facilitate understanding of these processes, several field drainage studies were conducted in the United States and Israel. In both countries, solutes moved rapidly down and could be found below 1 m depth soon after application. Based on these experiments, we developed and validated a number of modules to predict the solute concentration of the preferentially moving water in the vadose zone. We also successfully simulatd the initial high solute concentration in agriculturel tile lines shortly after the chemical was applied. The understanding gained on fast transport of agri-chemicals is instrumental in developing management practices to reduce the nonpoint sources and to increase the leaching efficiency of salt affected soils.

Gli stili APA, Harvard, Vancouver, ISO e altri

Offriamo sconti su tutti i piani premium per gli autori le cui opere sono incluse in raccolte letterarie tematiche. Contattaci per ottenere un codice promozionale unico!