Leistungsverstärker für den Einsatz in energiesparsamer Informations- und Kommunikationstechnik

Thematisch eingebettet in das Forschungsgebiet der energiesparsamen Informations- und Kommunikationstechnik (IKT), beschäftigt sich diese Dissertation mit dem Entwurf und der Analyse von Leistungsverstärkern (LV) für drahtlose Übertragungssysteme. Die Arbeit konzentriert sich einerseits auf den asymmetrischen Doherty-Leistungsverstärker (DPA), welcher in einem Ausgangsleistungs-Backoff (OBO) von mehr als 6 dB einen zusätzlichen Ef fizienzhochpunkt aufweist. Andererseits wird die Topologie des geschalteten inversen Klasse-E Verstärkers beleuchtet, der sich durch einen theoretischen Wirkungsgrad von 100 % auszeichnet und daher für den Einsatz in energiesparsamer IKT von besonderem Interesse ist. Das Breitbandverhalten des DPA wird zur Optimierung der Leistungseffizienz (PAE) theoretisch analysiert. Hierbei wird der Einfluss der charakteristischen Impedanz des Impedanzinverters (IT) im Main-Pfad untersucht. Daran anknüpfend werden drei asymmetrische Sub-6 GHz DPA mit unterschiedlichen IT entworfen. Labormessung ergeben eine maximale PAE zwischen 52 % und 63 % bei einer Ausgangsleistung von 41 dBm bis 42 dBm, was für einen derartigen LV mit einer Mittenfrequenz oberhalb von 3 GHz den höchsten Wert im Vergleich zum Stand der Technik darstellt. Neben diesem diskreten Aufbau werden zwei weitere integrierte asymmetrische DPA-Designs in Galliumnitrid (GaN) bzw. Siliziumgermanium (SiGe) vorgestellt. Für den GaN-DPA mit Chebyshev-Anpassnetzwerk wird in der Messung eine abweichende Phasenlage zwischen Peak- und Main-Pfad detektiert, die nachträglich durch Bonddrahtmodifikation auf dem Chip verbessert wird. Der Schaltkreis erreicht eine hohe PAE im OBO von 34 % bis 54 %. Der dritte Entwurf untersucht einen zweistufigen asymmetrischen DPA in SiGe, der auf einer Analyse des WLAN-Standards bei 60 GHz basiert. Diese Analyse ergibt ein Verhältnis von maximaler zu mittlerer Ausgangsleistung (PAPR) von 8 dB. Der LV erreicht im Frequenzbereich von 59 GHz bis 67 GHz den vergleichsweise höchsten Leistungsgewinn von 22 dB. Die inverse Klasse-E Topologie wird als Ausgangsstufe in einem polaren Vektormodulator mit niedriger Versorgungsspannung verwendet. Eine theoretische Analyse der Topologie zeigt, dass die für einen effizienten Betrieb erforderlichen Induktivitäten geringer sind als beim klassischen Klasse-E Verstärker. Der daraus resultierende geringere Bedarf an Chipfläche macht diese Topologie besonders für stark skalierte CMOS-Prozesse interessant. Es werden zwei integrierte Schaltkreise (IC) in 45 nm bzw. 22 nm CMOS entworfen. Das Prinzip des Vektormodulators wird mit dem in 45 nm gefertigten IC getestet. Zur Steigerung der Ausgangsleistung auf bis zu 19,3 dBm wird die Topologie in eine neuartige inverse Klasse-E Gegentaktstufe überführt. Die kompakte Schaltung zeichnet sich durch eine hohe relative Bandbreite von 70,5 % aus. Neben den rein schaltungstechnischen Inhalten der Arbeit wird in einer kollaborativen Studie das Reduktionspotential von Treibhausgasemissionen durch IKT untersucht. Ziel ist der interdisziplinäre Brückenschlag zwischen Umwelt- und Ingenieurwissenschaften, um die ganzheitliche Sichtweise auf das Thema energieeffizienter IKT zu erweitern. Am Beispiel deutscher Konferenzreisen für das Jahr 2030 wird anhand einer Szenarioanalyse gezeigt, dass die deutschen CO2-Emissionen durch den Einsatz neuartiger 2D/3D-Videokonferenzsysteme jährlich um bis zu 20, 51 MtCO2e gesenkt werden könnten. Dies entspräche rund 2,7 % der gesamtdeutschen Emissionen. In diesem Teil der Arbeit werden mögliche Chancen des IKT-Beitrags zur Erreichung der Klimaziele deutlich. Unklar bleibt allerdings, ob es zu Rebound-Effekten kommt und wie Ressourcenbedarf und Recycling der Technologie in Zukunft nachhaltig gestaltet werden können

Cocoa agroforestry systems vs. monocultures under conventional and organic management - results from tropical Bolivia

Cocoa is one of the most important export commodities for many developing countries and provides income for millions of smallholders. The expansion of cocoa production has resulted in habitat destruction, biodiversity loss, and soil degradation. The prevalent cocoa production systems worldwide are conventional monoculture full sun systems. Agroforestry systems are argued to be a viable strategy for sustainable cocoa production. However, data-based information on advantages and limitations of different cocoa production systems is limited. Pairwise comparisons on the long-term performance of cocoa monocultures and agroforestry systems under conventional and organic management are inexistent. FiBL is pioneering to fill this knowledge gap with a unique long-term field trial in tropical Bolivia established in 2008. The trial consists of six treatments: two monocultures (MONO CONV/ORG) and two agroforestry system (AF CONV/ORG) under conventional and organic management, one organic successional agroforestry system (SAFS) with dynamic shade management, and a fallow of the same age serving as a reference for biodiversity and soil fertility studies. The treatments are representative for current cocoa production systems of smallholders. Parameters regularly assessed include canopy openness, cocoa stem diameter and bean yield, pests and diseases, soil fertility, carbon stocks, economic data and biodiversity. Five years after planting, results showed significantly shorter tree circumference (18% and 33%) in AF systems and SAFS, respectively, compared to MONO systems. Tree circumference correlated strongly with cocoa bean yield, and highest bean yields were recorded in MONO CONV as expected. Additional products like banana/plantain, cassava, pineapple, etc. were harvested in AF systems and SAFS, which may compensate for lower cocoa yield in the first years. First results indicate that disease incidences were higher in MONO systems compared to AF and SAFS. Future research will investigate cocoa performance after the establishment phase and thus provide indications on the long-term sustainability of the different systems

Cocoa in Full-sun Monocultures vs. Shaded Agroforestry Systems under Conventional and Organic Management in Bolivia

Cocoa is a crucial export commodity for many developing countries and provides income for millions of smallholders. However, cocoa cultivation has resulted in habitat destruction, biodiversity loss and soil degradation. While much of the world’s cocoa is produced in arguably unsustainable full-sun monoculture systems, shaded agroforestry systems may be an alternative for sustainable cocoa production. However, data-based information on advantages and limitations of different cocoa production systems are limited and pairwise comparisons on the long-term performance of cocoa monocultures and agroforestry systems under conventional and organic management are literally inexistent. The Research Institute of Organic Agriculture (FiBL) is pioneering to fill this knowledge gap with a unique long term field trial in tropical Bolivia. The trial was established in 2008 and consists of six systems: two monocultures (MONO CONV/ORG) and two agroforestry systems (AF CONV/ORG) under conventional and organic management, one successional agroforestry system (SAFS, organic only) with dynamic shade management, and a fallow system of the same age serving as a reference for biodiversity and soil fertility studies. The systems aim to represent current smallholder cocoa farmers’ practices. Parameters such as the tree development, yield of cocoa and by-crops, incidences of pests and diseases, soil fertility, carbon stocks, nutrient balances, economic data and biodiversity are regularly assessed. Five years after planting, results showed significantly shorter tree circumference (18% and 33 %) in AF systems and SAFS, respectively, compared to MONO systems. Tree circumference correlated strongly with cocoa dry bean yield which was, as expected, highest in MONO CONV (603 kg ha−1). By-crops such as plantain, cassava, pineapple, etc. were harvested in AF systems and SAFS, which may compensate for lower cocoa yields in the first years. Future research will investigate cocoa performance after the establishment phase and thus provide indications on the long-term sustainability of the different systems

Depressive symptoms evaluated by the Calgary Depression Scale for Schizophrenia (CDSS): Genetic vulnerability and sex effects

The present study compares the occurrence of depressive symptoms evaluated by the Calgary Depression Scale for Schizophrenia (CDSS) in patients of Multiplex (MS) and Simplex Schizophrenia families (SS). The Positive and Negative Syndrome Scale (PANSS) was used to evaluate psychopathology. A total of 206 paranoid schizophrenia patients were studied according DSM-IV criteria. The Family Interview for Genetic Studies (FIGS) was used to study the families. A result in the FIGS for a positive family history of schizophrenia was referred as MS (patients); its lack as SS (patients). CDSS scores were compared among MS and SS patients and possible sex differences intra- and inter-groups were explored. In the analysis of our sample (30) 19% of the total persons with schizophrenia group was depressed. The depressive symptoms measured by the CDSS were higher in females and the MS males group. Males from MS group showed more depressive symptoms than males from SS group. No differences with females from both groups were found. Findings in this study underscore the importance of gender and family history in understanding the heterogeneity of schizophrenia. This study suggests proved that sex and familiar history is an important point for studying depressive symptoms.Fil: Martín Reyes, Migdyrai. No especifíca;Fil: Mendoza, Raúl. No especifíca;Fil: Domínguez, Mayelín. No especifíca;Fil: Caballero, Antonio. No especifíca;Fil: Bravo, Tania Marta. No especifíca;Fil: Díaz, Thais. No especifíca;Fil: Gerra, Seidel. No especifíca;Fil: Ibañez, Agustin Mariano. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Diego Portales; ChileFil: Ruiz-Linares, Andres. University College London; Estados Unido

A Roadmap for HEP Software and Computing R&D for the 2020s

Particle physics has an ambitious and broad experimental programme for the coming decades. This programme requires large investments in detector hardware, either to build new facilities and experiments, or to upgrade existing ones. Similarly, it requires commensurate investment in the R&D of software to acquire, manage, process, and analyse the shear amounts of data to be recorded. In planning for the HL-LHC in particular, it is critical that all of the collaborating stakeholders agree on the software goals and priorities, and that the efforts complement each other. In this spirit, this white paper describes the R&D activities required to prepare for this software upgrade.Peer reviewe

Differential cross section measurements for the production of a W boson in association with jets in proton–proton collisions at √s = 7 TeV

Measurements are reported of differential cross sections for the production of a W boson, which decays into a muon and a neutrino, in association with jets, as a function of several variables, including the transverse momenta (pT) and pseudorapidities of the four leading jets, the scalar sum of jet transverse momenta (HT), and the difference in azimuthal angle between the directions of each jet and the muon. The data sample of pp collisions at a centre-of-mass energy of 7 TeV was collected with the CMS detector at the LHC and corresponds to an integrated luminosity of 5.0 fb[superscript −1]. The measured cross sections are compared to predictions from Monte Carlo generators, MadGraph + pythia and sherpa, and to next-to-leading-order calculations from BlackHat + sherpa. The differential cross sections are found to be in agreement with the predictions, apart from the pT distributions of the leading jets at high pT values, the distributions of the HT at high-HT and low jet multiplicity, and the distribution of the difference in azimuthal angle between the leading jet and the muon at low values.United States. Dept. of EnergyNational Science Foundation (U.S.)Alfred P. Sloan Foundatio

Penilaian Kinerja Keuangan Koperasi di Kabupaten Pelalawan

This paper describe development and financial performance of cooperative in District Pelalawan among 2007 - 2008. Studies on primary and secondary cooperative in 12 sub-districts. Method in this stady use performance measuring of productivity, efficiency, growth, liquidity, and solvability of cooperative. Productivity of cooperative in Pelalawan was highly but efficiency still low. Profit and income were highly, even liquidity of cooperative very high, and solvability was good

Juxtaposing BTE and ATE – on the role of the European insurance industry in funding civil litigation

One of the ways in which legal services are financed, and indeed shaped, is through private insurance arrangement. Two contrasting types of legal expenses insurance contracts (LEI) seem to dominate in Europe: before the event (BTE) and after the event (ATE) legal expenses insurance. Notwithstanding institutional differences between different legal systems, BTE and ATE insurance arrangements may be instrumental if government policy is geared towards strengthening a market-oriented system of financing access to justice for individuals and business. At the same time, emphasizing the role of a private industry as a keeper of the gates to justice raises issues of accountability and transparency, not readily reconcilable with demands of competition. Moreover, multiple actors (clients, lawyers, courts, insurers) are involved, causing behavioural dynamics which are not easily predicted or influenced. Against this background, this paper looks into BTE and ATE arrangements by analysing the particularities of BTE and ATE arrangements currently available in some European jurisdictions and by painting a picture of their respective markets and legal contexts. This allows for some reflection on the performance of BTE and ATE providers as both financiers and keepers. Two issues emerge from the analysis that are worthy of some further reflection. Firstly, there is the problematic long-term sustainability of some ATE products. Secondly, the challenges faced by policymakers that would like to nudge consumers into voluntarily taking out BTE LEI

Search for stop and higgsino production using diphoton Higgs boson decays

Results are presented of a search for a "natural" supersymmetry scenario with gauge mediated symmetry breaking. It is assumed that only the supersymmetric partners of the top-quark (stop) and the Higgs boson (higgsino) are accessible. Events are examined in which there are two photons forming a Higgs boson candidate, and at least two b-quark jets. In 19.7 inverse femtobarns of proton-proton collision data at sqrt(s) = 8 TeV, recorded in the CMS experiment, no evidence of a signal is found and lower limits at the 95% confidence level are set, excluding the stop mass below 360 to 410 GeV, depending on the higgsino mass