Reinforcement Learning Solution for Unit Commitment Problem Considering Minimum Start Up and Shut Down Times

Unit Commitment Problem (UCP) in power system refers to the problem of determining the on/ off status of generating units that minimize the operating cost during a given time horizon. Since various system and generation constraints are to be satisfied while finding the optimum schedule, UCP turns to be a constrained optimization problem in power system scheduling. Numerical solutions developed are limited for small systems and heuristic methodologies find difficulty in handling stochastic cost functions associated with practical systems. This paper models Unit Commitment as a multi stage decision making task and an efficient Reinforcement Learning solution is formulated considering minimum up time /down time constraints. The correctness and efficiency of the developed solutions are verified for standard test systems

Effects of different tillage treatments on labile soil organic matter pools and stabilization processes

An improved understanding of soil organic carbon (Corg) dynamics in interaction with the mechanisms of soil structure formation is important in terms of sustainable agriculture and reduction of environmental costs of agricultural ecosystems. However, information on physical and chemical processes influencing formation and stabilization of water stable aggregates in association with Corg sequestration is scarce. Long term soil experiments are important in evaluating open questions about management induced effects on soil Corg dynamics in interaction with soil structure formation. The objectives of the present thesis were: (i) to determine the long term impacts of different tillage treatments on the interaction between macro aggregation (>250 µm) and light fraction (LF) distribution and on C sequestration in plots differing in soil texture and climatic conditions. (ii) to determine the impact of different tillage treatments on temporal changes in the size distribution of water stable aggregates and on macro aggregate turnover. (iii) to evaluate the macro aggregate rebuilding in soils with varying initial Corg contents, organic matter (OM) amendments and clay contents in a short term incubation experiment. Soil samples were taken in 0-5 cm, 5-25 cm and 25-40 cm depth from up to four commercially used fields located in arable loess regions of eastern and southern Germany after 18-25 years of different tillage treatments with almost identical experimental setups per site. At each site, one large field with spatially homogenous soil properties was divided into three plots. One of the following three tillage treatments was carried in each plot: (i) Conventional tillage (CT) with annual mouldboard ploughing to 25-30 cm (ii) mulch tillage (MT) with a cultivator or disc harrow 10-15 cm deep, and (iii) no tillage (NT) with direct drilling. The crop rotation at each site consisted of sugar beet (Beta vulgaris L.) - winter wheat (Triticum aestivum L.) - winter wheat. Crop residues were left on the field and crop management was carried out following the regional standards of agricultural practice. To investigate the above mentioned research objectives, three experiments were conducted: Experiment (i) was performed with soils sampled from four sites in April 2010 (wheat stand). Experiment (ii) was conducted with soils sampled from three sites in April 2010, September 2011 (after harvest or sugar beet stand), November 2011 (after tillage) and April 2012 (bare soil or wheat stand). An incubation study (experiment (iii)) was performed with soil sampled from one site in April 2010. Based on the aforementioned research objectives and experiments the main findings were: (i) Consistent results were found between the four long term tillage fields, varying in texture and climatic conditions. Correlation analysis of the yields of macro aggregate against the yields of free LF ( ≤1.8 g cm-3) and occluded LF, respectively, suggested that the effective litter translocation in higher soil depths and higher litter input under CT and MT compensated in the long term the higher physical impact by tillage equipment than under NT. The Corg stocks (kg Corg m−2) in 522 kg soil, based on the equivalent soil mass approach (CT: 0–40 cm, MT: 0–38 cm, NT: 0–36 cm) increased in the order CT (5.2) = NT (5.2) < MT (5.7). Significantly (p ≤ 0.05) highest Corg stocks under MT were probably a result of high crop yields in combination with reduced physical tillage impact and effective litter incorporation, resulting in a Corg sequestration rate of 31 g C-2 m-2 yr-1. (ii) Significantly higher yields of macro aggregates (g kg-2 soil) under NT (732-777) and MT (680-726) than under CT (542-631) were generally restricted to the 0-5 cm sampling depth for all sampling dates. Temporal changes on aggregate size distribution were only small and no tillage induced net effect was detectable. Thus, we assume that the physical impact by tillage equipment was only small or the impact was compensated by a higher soil mixing and effective litter translocation into higher soil depths under CT, which probably resulted in a high re aggregation. (iii) The short term incubation study showed that macro aggregate yields (g kg-2 soil) were higher after 28 days in soils receiving OM (121.4-363.0) than in the control soils (22.0-52.0), accompanied by higher contents of microbial biomass carbon and ergosterol. Highest soil respiration rates after OM amendments within the first three days of incubation indicated that macro aggregate formation is a fast process. Most of the rebuilt macro aggregates were formed within the first seven days of incubation (42-75%). Nevertheless, it was ongoing throughout the entire 28 days of incubation, which was indicated by higher soil respiration rates at the end of the incubation period in OM amended soils than in the control soils. At the same time, decreasing carbon contents within macro aggregates over time indicated that newly occluded OM within the rebuilt macro aggregates served as Corg source for microbial biomass. The different clay contents played only minor role in macro aggregate formation under the particular conditions of the incubation study. Overall, no net changes on macro aggregation were identified in the short term. Furthermore, no indications for an effective Corg sequestration on the long term under NT in comparison to CT were found. The interaction of soil disturbance, litter distribution and the fast re aggregation suggested that a distinct steady state per tillage treatment in terms of soil aggregation was established. However, continuous application of MT with a combination of reduced physical tillage impact and effective litter incorporation may offer some potential in improving the soil structure and may therefore prevent incorporated LF from rapid decomposition and result in a higher C sequestration on the long term.

Effects of grassland conversion and tillage intensities on soil microbial biomass, residues and community structure

Agricultural intensification has a strong impact on level of soil organic matter (SOM), microbial biomass stocks and microbial community structure in agro-ecosystems. The size of the microbial necromass C pool could be about 40 times that of the living microbial biomass C pool in soils. Due to the specificity, amino sugar analysis gives more important information on the relative contribution of fungal and bacterial residues to C sequestration potential of soils. Meanwhile, the relationship between microbial biomass and microbial necromass in soil and its ecological significance on SOM are not fully understood and likely to be very complex in grassland soils. This thesis focuses on the effects of tillage, grassland conversion intensities and fertilisation on microbial biomass, residues and community structure. The combined analyses of microbial biomass and residue formation of both fungi and bacteria provided a unique opportunity to study the effect of tillage, grassland conversion and fertilisation on soil microbial dynamics. In top soil at 0-30 cm layer, a reduction in tillage intensity by the GRT and NT treatments increased the accumulation of saprotrophic fungi in comparison with the MBT treatment. In contrast, the GRT and NT treatments promoted AMF at the expense of saprotrophic fungi in the bottom soil layer at 30-40 cm depth. The negative relationship between the ergosterol to microbial biomass C ratio and the fungal C to bacterial C ratio points to the importance of the relationship between saprotrophic fungi and biotrophic AMF for tillage-induced changes in microbial turnover of SOC. One-season cultivation of winter wheat with two tillage events led to a significant loss in SOC and microbial biomass C stocks at 0-40 cm depth in comparison with the permanent grassland, even 5 years after the tillage event. However, the tillage induced loss in microbial biomass C was roughly 40% less in the long-term than in the short-term of the current experiment, indicating a recovery process during grassland restoration. In general, mould board tillage and grassland conversion to maize monoculture promoted saprotrophic fungi at the expense of biotrophic AMF and bacteria compared to undisturbed grassland soils. Slurry application promoted bacterial residues as indicated by the decreases in both, the ergosterol to microbial biomass C ratio and the fungal C to bacterial C ratio. In addition, the lost microbial functional diversity due to tillage and maize monoculture was restored by slurry application both in arable and grassland soils. I conclude that the microbial biomass C/S ratio can be used as an additional indicator for a shift in microbial community. The strong relationships between microbial biomass and necromass indices points to the importance of saprotrophic fungi and biotrophic AMF for agricultural management induced effects on microbial turnover and ecosystem C storage. Quantitative information on exact biomass estimates of these two important fungal groups in soil is inevitably necessary to understand their different roles in SOM dynamics.

Effects of tillage intensity on soil C, N, and P pools with different stability

Es ist bekannt, dass die Umsatzdynamik der organischen Substanz von der Bodenbearbeitungsintensität abhängt. Bis jetzt sind nur wenige Daten zum Einfluss der Bearbeitungsintensität und des Zwischenfruchtanbaus auf C-, N-, und P-Dynamik im Ober- (0-5 cm Tiefe) und Unterboden (5-25 cm Tiefe) von Lössböden verfügbar. Hauptziele dieser Arbeit waren die (i) Quantifizierung des Einflusses von verschiedenen langzeitig durchgeführten Bearbeitungssystemen auf labile, intermediäre, und passive C- und N-Pools; (ii) Quantifizierung des Einflusses dieser Systeme auf P-Fraktionen mit unterschiedlicher Verfügbarkeit für die Pflanzenaufnahme; (iii) Quantifizierung des Einflusses des Zwischenfruchtanbaus in Verbindung mit einer unterschiedlichen Einarbeitungstiefe der der Zwischenfrüchte auf mineralisierbares C und N. Die Ergebnisse des 1. und 2. Teilexperiments basieren auf Untersuchungen von 4 Langzeitfeldexperimenten (LFE) in Ost- und Süddeutschland, die zwischen 1990 und 1997 durch das Institut für Zuckerrübenforschung angelegt wurden. Jedes LFE umfasst 3 Bearbeitungssysteme: konventionelle Bearbeitung (CT), reduzierte Bearbeitung (RT) und Direktsaat (NT). Die Ergebnisse des 3. Teilexperiments basieren auf einem Inkubationsexperiment. Entsprechend den Hauptfragestellungen wurden folgende Untersuchungsergebnisse beschrieben: (i) Im Oberboden von NT wurden höhere labile C-Vorräte gefunden (C: 1.76 t ha-1, N: 166 kg ha-1), verglichen mit CT (C: 0.44 t ha-1, N: 52 kg ha-1). Im Gegensatz dazu waren die labile- C-Vorräte höher im Unterboden von CT mit 2.68 t ha-1 verglichen zu NT mit 2 t ha-1 und RT mit 1.87 t ha-1. Die intermediären C-Vorräte betrugen 73-85% der gesamten organischen C-Vorräte, intermediäre N-Vorräte betrugen 70-95% des Gesamt-N im Ober- und Unterboden und waren vielfach größer als die labilen und passiven C- und N-Vorräte. Nur im Oberboden konnte ein Effekt der Bearbeitungsintensität auf die intermediären N-Pools mit höheren Vorräten unter NT als CT festgestellt werden. Die passiven C- und N-Pools waren eng mit den mineralischen Bodeneigenschaften verbunden und unabhängig vom Bearbeitungssystem. Insgesamt hat sich gezeigt, dass 14 bis 22 Jahre durchgängige Direktsaatverfahren nur im Oberboden zu höheren labilen C- und N-Vorräten führen, verglichen zu konventionellen Systemen. Dies lässt eine tiefenabhängige Stärke der Dynamik der organischen Bodensubstanz vermuten. (ii) Die Konzentration des Gesamt-P (Pt) im Oberboden war höher in NT (792 mg kg-1) und ~15% höher als die Pt-Konzentration in CT (691 mg kg 1). Die Abnahme der Pt-Konzentration mit zunehmender Bodentiefe war höher in NT als in CT. Dies gilt auch für die einzelnen P-Fraktionen, ausgenommen der stabilsten P-Fraktion (residual-P). Generell hatte das Bearbeitungssystem nur einen kleinen Einfluss auf die P-Konzentration mit höheren Pt-Konzentrationen in Böden unter NT als CT. Dies resultiert vermutlich aus der flacheren Einarbeitung der Pflanzenreste als in CT. (iii) Im Zwischenfruchtexperiment war der Biomassezuwachs von Senf am höchsten und nimmt in der Reihenfolge ab (oberirdischer Ertrag in t / ha): Senf (7.0 t ha-1) > Phacelia (5.7 t ha-1) > Ölrettich (4.4 t ha-1). Damit war potentiell mineralisierbares C und N am höchsten in Böden mit Senfbewuchs. Kumulative CO2- und N2O-Emissionen während der Inkubation unterschieden sich nicht signifikant zwischen den Zwischenfruchtvarianten und waren unabhängig von der Verteilung der Pflanzenreste im Boden. Die kumulativen ausgewaschenen mineralisierten N (Nmin)-Vorräte waren in den brachliegenden Böden am höchsten. Die Nmin-Vorräte waren 51-72% niedriger in den Varianten mit Zwischenfrucht und Einarbeitung verglichen zur Brache. In den Varianten ohne Einarbeitung waren die Nmin-Vorräte 36-55% niedriger verglichen zur Brache. Dies weißt auf einen deutlichen Beitrag von Zwischenfrüchten zur Reduzierung von Nitrat-Auswaschung zwischen Winter und Frühjahr hin. Insgesamt führte reduzierte Bearbeitung zu einer Sequestrierung von C und N im Boden und der Zwischenfruchtanbau führte zu reduzierten N-Verlusten. Die P-Verfügbarkeit war höher unter Direktsaat verglichen zur konventionellen Bearbeitung. Diese Ergebnisse resultieren aus den höheren Konzentrationen der OS in den reduzierten, als in den konventionellen Systemen. Die Ergebnisse zeigen deutlich das Potential von reduzierter Bearbeitung zur Sequestrierung von intermediärem C und N zur Reduzierung von klimarelevanten Treibhausgasen. Gleichzeitig steigen die Konzentrationen an pflanzenverfügaren P-Gehalten. Zwischenfrüchte führen auch zu einem Anstieg der C- und N-Vorräte im Boden, offensichtlich unabhängig von der Zwischenfruchtart.

Minimum interference routing with fast protection

One of the most effective techniques offering QoS routing is minimum interference routing. However, it is complex in terms of computation time and is not oriented toward improving the network protection level. In order to include better levels of protection, new minimum interference routing algorithms are necessary. Minimizing the failure recovery time is also a complex process involving different failure recovery phases. Some of these phases depend completely on correct routing selection, such as minimizing the failure notification time. The level of protection also involves other aspects, such as the amount of resources used. In this case shared backup techniques should be considered. Therefore, minimum interference techniques should also be modified in order to include sharing resources for protection in their objectives. These aspects are reviewed and analyzed in this article, and a new proposal combining minimum interference with fast protection using shared segment backups is introduced. Results show that our proposed method improves both minimization of the request rejection ratio and the percentage of bandwidth allocated to backup paths in networks with low and medium protection requirements

The impact of a minimum pension on old age poverty and its budgetary cost. Evidence from Latin America

This paper examines the impact on old age poverty and the fiscal cost of universal minimum oldage pensions in Latin America using recent household survey data for 18 countries. Alleviatingold age poverty requires different approach from other age groups and a minimum pension islikely to be the only alternative available. First we measure old age poverty rates for all countries.Second we discuss the design of minimum pensions schemes, means-tested or not, as wellas the disincentive effects that they are expected to have on the economic and social behavior ofhouseholds including labor supply, saving and family solidarity. Third we use the household surveysto simulate the fiscal cost and the impact on poverty rates of alternative minimum pensionschemes in the 18 countries. We show that a universal minimum pension would substantiallyreduce poverty among the elderly except in Argentina, Brazil, Chile and Uruguay where minimumpension systems already exist and poverty rates are low. Such schemes have much tobe commended in terms of incentives, spillover effects and administrative simplicity but have ahigh fiscal cost. The latter is a function of the age at which benefits are awarded, the prevailinglongevity, the generosity of benefits, the efficacy of means testing, and naturally the fiscal capacityof the country.

The Minimum core for language and literacy : knowledge, understanding and personal skills.

Guía práctica sobre lenguaje y alfabetización para profesores en formación (nivel bachillerato). Les permite identificar y desarrollar sus propias habilidades lingüísticas y de alfabetización y al mismo tiempo apoyar la evolución de los alumnos. Contiene todas las áreas claves de conocimiento, compresión y habilidades personales, además de analizar en un contexto amplio cómo el lenguaje y la alfabetización se adquieren y se desarrollan a nivel personal, social y cultural. El contenido está adaptado para la obtención de los certificados QTLS (Qualified Teacher, Learning and Skills) y ATLS (Associate Teacher, Learning and Skills).

The Minimum core for information and communication technology : knowledge, understanding and personal skills.

Guía práctica sobre tecnologías de la información y la comunicación para profesores en formación (nivel bachillerato). Les permite identificar y desarrollar sus propias habilidades tecnológicas aplicadas a la enseñanza y al mismo tiempo apoyar la evolución de los alumnos. Contiene todas las áreas claves de conocimiento, compresión y habilidades personales, además de analizar en un contexto amplio cómo las habilidades tecnológicas en información y comunicación se adquieren y se desarrollan a nivel personal, social y cultural. El contenido está adaptado para la obtención de los certificados QTLS (Qualified Teacher, Learning and Skills) y ATLS (Associate Teacher, Learning and Skills).

Are the maximum hardness and minimum polarizability principles always obeyed in nontotally symmetric vibrations?

An overview is given on a study which showed that not only in chemical reactions but also in the favorable case of nontotally symmetric vibrations where the chemical and external potentials keep approximately constant, the generalized maximum hardness principle (GMHP) and generalized minimum polarizability principle (GMPP) may not be obeyed. A method that allows an accurate determination of the nontotally symmetric molecular distortions with more marked GMPP or anti-GMPP character through diagonalization of the polarizability Hessian matrix is introduced

Comparison of speech processor MAP minimum (T) and maximum (C) levels with psychophysical thresholds and maximum acceptable loudness levels in users of the Nucleus 22 cochlear implant system

This paper discusses the Nucleus 22 cochlear implant.