Автоматическое регулирование частоты и перетоков мощности. Анализ и теоретическое исследование процессов

В работе произведен обзор теоретических сведений в области регулирования частоты и мощности в ЭЭС. Регулирование частоты и мощности в объединенной ЭЭС, моделирование с использованием программных комплексов.The paper reviews theoretical information in the field of frequency and power regulation in electric power systems (EPS). Regulation of frequency and power in the united electric power system (EPS), modeling using software complexes

Acting as Expected:Global Leadership Preferences and the Pursuit of an Integrated Supply Chain

While research has extensively explored the potential benefits companies gain with integrated supply chains, the topic of why some companies are better at pursuing supply chain integration (SCI) is relatively under‐examined. We take the perspective that SCI is associated with preferred forms of leadership using leadership preference derived from path–goal logic. By combining global data sources, we examine the relationships among leadership style preferences, internal integration (i.e., between sales and purchasing) programs, and external integration (i.e., supplier side) programs. Our country‐level results challenge the assumption that the choice to pursue internal and external integration has similar origins. Specifically, while collaborative‐style leadership preferences relate to internal integration programs, societies preferring individualistic‐style leaders will be predisposed toward external integration programs. Our study’s contribution is in the novel use of theories on leadership to explain variations in approaches toward supply chain integration

Ground vegetation monitoring in Swiss forests: comparison of survey methods and implications for trend assessments

At Swiss long-term forest ecosystem research sites, ground vegetation was assessed during the period 1994-2003/2008 following two approaches: (1) visual assessment of the cover of species occurring in sixteen 1m2 quadrats, distributed over a 43 × 43m area, and (2) phytosociological relevés in concentric circular plots of 30, 200, and 500m2. We first compared the two approaches with respect to diversity assessment. The number of species recorded in the 16 quadrats was in general higher than in the 30m2 plot and it represented 42% to 108% of the number of species recorded in the 500m2 plot. In a second step, we tested whether any temporal trends were apparent. In a few cases, a decrease or increase in Landolt's mean indicator values for light, nitrogen availability, soil pH, soil moisture, or temperature was found to be significant. However, these changes were usually restricted to one approach or one area. The only clear trend was detected in an unmanaged former coppice beech stand, for which all survey approaches indicated canopy closure. At another site, vegetation reacted to the local opening of the canopy following windthrow. In a third step, we compared the leaf area index (LAI), measured with an LAI-2000 instrument (Licor, Inc.) over each quadrat, with the indicator value of the vegetation for light (L). Within a site, there was no clear relationship between LAI and L values per quadrat. In contrast, across all sites, the relationship between LAI and L, averaged per site for all available years, was highly significan

Investigating the Effects of Daily Inventory Record Inaccuracy in Multichannel Retailing

Inventory record inaccuracy (IRI) challenges multichannel retailers in fulfilling both brick-and-mortar and direct channel demands from their distribution centers. The nature and damaging effects of IRI largely go unnoticed because retailers assume daily IRI remains stable over time within the replenishment cycle. While research shows that a high level of IRI is damaging, in reality the level of IRI can change every day. We posit that daily IRI variation increases the uncertainty in the system to negatively affect inventory and service levels. Our research uses data collected daily from a multichannel retailer to ground a discrete-event simulation experiment. Going beyond testing just the level of IRI, we evaluate daily IRI variation\u27s impact on operating performance. What we find in our empirical data challenges extant assumptions regarding the characteristics of IRI. In addition, our simulation results reveal that daily IRI variation has a paradoxical effect: it increases inventory levels while also decreasing service levels. Moreover, we also reveal that brick-and-mortar and direct channels are impacted differently. Our findings show that assumptions and practices that ignore daily IRI variation need revising. For managers, we demonstrate how periods of multiday counting help assess their daily IRI variation and indicate what the causes may be

Ashes of oxyfuel- and air-fired pulverised fuel combustion processes - mineralogical characterisation and long-term modification

The focus of our work was the mineralogical analysis of ashes obtained from the combustion of soft brown coal (93.4 % huminite, 4.2 % liptinite, 0.8 % inertinite, 1.6 % pyrite and quartz; detectable amounts of Ca, Fe, Na, K, Mg, Al, Si, S, Cl in the macerals) from the open mine site Welzow-Süd in Lower Lusatia (East Germany). The combustion process was achieved in the Atmospheric Pulverized Fuel Combustion Rig (KSVA) of the Institute of Combustion and Power Plant Technology (IFK), formerly Institute of Process Engineering and Power Plant Technology (IVD) at Universität Stuttgart in air and in the oxyfuel mode. Such ashes, which form during the combustion (oxyfuel process) for power production, were characterised with the methods of polarising microscopy, X-ray diffractometry, electron microprobe analysis and carbon/water-analytics and compared with ashes from the conventional combustion process in air

Catalytic Methods for Direct Access to Chiral High-Added-Value Products

This account summarizes the activities of the first three years of our young research group working in the field of homogeneous asymmetric catalysis

Computerbasierte Erfassung von Fremdsprachenkompetenzen im Unterricht der Primarstufe: Bericht zum Projekt „Erfassung von Entwicklungsprofilen im frühen schulischen Fremdsprachenlernen“

Le projet « Recensement des profils de développement dans le cadre de l’apprentissage précoce des langues étrangères à l’école » fait partie du programme de recherche 2012-2015 du Centre scientifique de compétence sur le plurilinguisme (CSP). Son objectif était de contribuer à créer, dans le cadre de l’enseignement des langues étrangères à l’école primaire (de la troisième à la sixième), une culture d’évaluation à la fois informatisée et orientée sur l’apprentissage grâce au développement d’instruments adaptés à la vérification des compétences. Les travaux de développement se sont inspirés du concept de la progression des apprentissages (learning progressions), surtout appliqué en didactique des sciences naturelles, où il constitue souvent la base des programmes, de l’enseignement et de l’évaluation.The project “Mapping developmental profiles in early language learning at school” is part of the research programme 2012-2015 of the Research Centre on Multilingualism. The overall objective of the project was to develop adequate instruments to assess language competence and thus contribute to a learning- oriented and computer-assisted assessment culture in foreign language instruction at primary schools (third to sixth class). To develop these instruments, the general work processes were guided by the notion of learning progressions, which are frequently used as the basis for developing curricula, teaching and conducting assessments in (most commonly) the natural sciences.Das Projekt „Erfassung von Entwicklungsprofilen im frühen schulischen Fremdsprachenlernen“ ist Teil des Forschungsprogramms 2012-2015 des Wissenschaftlichen Kompetenzzentrums für Mehrsprachigkeit (KFM). Das Ziel bestand darin, durch die Entwicklung von geeigneten Instrumenten zur Kompetenzerfassung einen Beitrag zu einer lernorientierten und gleichzeitig computerunterstützten Beurteilungskultur im Fremdsprachenunterricht an Primarschulen (dritte bis sechste Klasse) zu leisten. Die Entwicklungsarbeiten orientierten sich an der Idee von Lernprogressionen (learning progressions), mit der vor allem in der Didaktik der Naturwissenschaften als Grundlage für Curricula, Unterricht und Beurteilung gearbeitet wird.Il progetto sui ”profili di sviluppo nell’apprendimento delle lingue straniere nella scuola elementare” rientra nel programma di ricerca 2012-2015 del Centro scientifico di competenza per il plurilinguismo. Attraverso l’elaborazione di strumenti idonei al rilevamento di competenze si è voluto fornire, nell’ambito dell’insegnamento delle lingue straniere nella scuola elementare (dal terzo al sesto anno), un contributo a una cultura della valutazione che sia orientata all’apprendimento e che si affidi al contempo all’ausilio di mezzi informatici. Il lavoro di elaborazione era incentrato sulle progressioni di apprendimento (learning progressions), un concetto sovente applicato ai programmi, alle lezioni e alle valutazioni nella didattica delle scienze naturali