Academic literature on the topic 'Power pattern synthesis'

Array synthesis with embedded element patterns is a problem of great practical importance. In this paper, an array pattern synthesis method using scalable alternating projection and proximal splitting is proposed which considers the scaling invariance property of design specifications and constraints for the amplitudes of pattern and excitation. Under the framework of alternating projection, the scalable pattern and excitation constraint sets are first defined. Then the scalable pattern projection and iterative procedure for optimum pattern scaling factor are studied in detail. For the scalable excitation projection, it is designed as the solution to a constrained weighted least mean squares optimization, which can be solved by an effective forward-backward splitting iterative process. Finally, the selection of the weighted matrix and computational complexity are discussed briefly. Several typical linear and planar synthesis examples with or without the embedded element patterns are provided to demonstrate the effectiveness and power of the proposed method.

The problem of linear antenna construction synthesize is first formulated and solved. Linear antenna consists of antenna array (AR) and power divider (PD). Linear omnidirectional AR with cosecant pattern is synthesized using partial-beam method. Beam-forming scheme for this antenna is based on two directional unequal splitters. The article proposes itera-tive method considering AR and beam-forming scheme mutual effect in terms of scattering matrix. Synthesis results demonstrate rapid convergence of the process and provide optimal pattern.

2010/2011
The material presented in this thesis is the result of the Ph.D. activity carried on between January 2009 and December 2012 at the Ph.D. school in Information Engineering of the University of Trieste. After a brief introduction on the involved topics, the final objective of this thesis is that of presenting the original results, consisting in the development of power pattern synthesis algorithms for arbitrary antenna arrays including, in particular, arrays for satellite applications. Since the earlier satellite missions of last century, satellite communication systems have received growing attention due to the opportunities they offer and their greater flexibility with respect to alternative solutions adopting other media, such as, for example, fiber optic cables. The enormous spread of satellites, for both military and civilian applications, has been achieved thanks to the experienced technological progress, which has allowed an increase of satellite capacities. The need of constantly increasing the capacity of commercial communications satellites resulted in the continuing evolution of the antenna systems onboard the satellites. The business environment has driven the architecture of satellites' systems towards more efficiency and cost consciousness while at the same time, providing flexible access to a growing diversity of services and customers. Antennas that provide a multiplicity of frequency reuse coverage beams through either spatial or polarization isolation have been developed, resulting in the evolution of satellite antennas from a simple omnidirectional dipole to multiple-beam, dual-polarized configurations with frequency reuse between the beams for increased capacity. These requirements translate into high-gain, high-efficiency antennas with low side-lobe levels and excellent polarization purity. Moreover, since new requirements are often determined after the satellite is operational, antennas adjustable to produce a wide variety of radiation patterns have become popular. These are the so-called multiple-beam antennas, which can adjust their radiation coverage areas according to new demands. Multiple-beam antennas are currently being used for direct-broadcast satellites, personal communication satellites, military communication satellites, and high-speed Internet applications. High-gain multiple-beam antenna systems usually take one of three generic forms: lens, reflector or direct radiating array. Thus, arrays of antennas can be used in multiple-beam systems either to feed other types of antennas, or directly as radiating structures. The material of this thesis is mainly related to the synthesis algorithms for antenna arrays. In particular, many analytical and numerical techniques for the power pattern synthesis of antenna arrays have been carefully studied and analyzed. Some of them are suitable only for linear or rectangular arrays, the others for arrays of more complicated geometries. Furthermore, it is extremely important, for power synthesis techniques in satellite applications, to be able to consider additional constraints. These typically are the phase-only reconfigurability of the radiated beams, the control of the cross-polar patterns, which allows the polarization re-use and/or the control of the cross-polar interference, the dynamic range ratio reduction which comports simpler feeding networks and lower mutual coupling between array elements, and the near-field reduction, which allows to take into account the antennas operating environment. A numerical iterative algorithm has been developed during the Ph.D. school in Information Engineering, suitable for arrays of arbitrary geometry, thus including sparse and conformal arrays, which are often used in satellite applications. The algorithm allows to solve the power pattern synthesis problem, which is an inherently non linear problem. The solution is achieved using the alternating projections algorithm, which is a numerical iterative technique for finding a point of the intersection between two sets. It will be seen that the projections method has previously already been applied to problems of image processing and also in the antenna pattern synthesis. However, the results and the computational burden are strongly related to the projection operators, which in turn, strictly depend on the definition of the adopted distance, thus on the definition of the sets adopted in the formulation of the problem. Thus, the main originality of the developed algorithms consists in an extremely advantageous definition of the sets involved in the solving scheme, which, along with the adopted distance, allow an easy evaluation of the projection operators and thus a simple solving procedure. The thesis is organized as follows. Chapter 1 introduces the satellite antennas, analyzing some solutions adopted in the past. Particular attention is devoted to multiple-beam antennas (MBAs) and in particular to arrays of antennas, which can constitute the feeding system of reflector MBAs, or which can be used as direct radiating antennas themselves. Chapter 2 presents analytical and numerical methods of power pattern synthesis for antenna arrays proposed in the literature. First, the classical analytical methods, suitable for linear arrays of equally spaced elements are presented. Then, numerical iterative methods are analyzed. Attention is devoted to both deterministic and stochastic algorithms. A section is dedicated to the near-field constraint, due to its importance in practical real applications. In fact, taking into account the effect of the antenna operating environment is of fundamental importance: obstacles or mounting platforms, as well as other electronic devices located in proximity of the antenna, may strongly degrade the radiated far-field pattern. Then, Chapter 3 presents the developed algorithm. Precisely, the evolution is described from a synthesis algorithm suitable for arbitrary phase-only reconfigurable arrays to a powerful algorithm for phase-only antenna arrays, including several additional constraints, such as the dynamic range ratio reduction, the cross-polar pattern synthesis and the near-field reduction. Moreover, in its final form, the algorithm also allows to minimize the power radiated in the side-lobe regions of both the co- and cross-polar patterns and the electric energy stored in the near-field region of interest. Numerical results validating the effectiveness of the proposed algorithm are presented in Chapter 4 and the conclusions are summarized in Chapter 5. Finally, the appendix mathematically describes the classical alternating projections method and the genetic algorithms, which have been used as global optimization algorithms for comparison purposes.
Il materiale presentato in questa tesi è il risultato dell'attività svolta durante il dottorato tra gennaio 2009 e dicembre 2012 presso la scuola di dottorato in ingegneria dell'informazione dell'università di Trieste. Dopo una breve introduzione sugli argomenti trattati, l'obiettivo ultimo della tesi è quello di presentare i risultati originali che consistono nello sviluppo di algoritmi di sintesi di potenza per antenne a schiera di geometria arbitraria tra le quali, in particolare, schiere per applicazioni satellitari. Fin dalle prime missioni spaziali del secolo scorso, le comunicazioni satellitari hanno ricevuto attenzione crescente grazie alle opportunità che offrono e alla loro maggior flessibilità rispetto a soluzioni alternative che utilizzano altri sistemi, come ad esempio i cavi in fibra ottica. Grazie agli sviluppi tecnologici avvenuti, che hanno reso possibile un aumento delle capacità dei satelliti, si è sperimentata una vasta diffusione di satelliti per applicazioni militari e civili. La necessità di aumentare costantemente la capacità dei satelliti per comunicazioni commerciali ha comportato una continua evoluzione delle antenne da satellite. L'ambiente commerciale ha spinto l'architettura dei sistemi satellitari verso una miglior consapevolezza di efficienza e costi consentendo, allo stesso tempo, un accesso flessibile a un sempre maggior numero di servizi e di utenti. Sono state sviluppate antenne che consentono una molteplicità di fasci con riutilizzo della frequenza grazie ad isolamento spaziale o di polarizzazione. Questo ha generato un'evoluzione delle antenne da satellite dal semplice dipolo omnidirezionale ad antenne a fascio multiplo, con alto guadagno, alta efficienza, bassi lobi laterali ed elevata purezza di polarizzazione. Inoltre, poichè nuove necessità spesso emergono una volta che il satellite è già operativo, si sono diffuse antenne da satellite configurabili in modo da poter produrre diversi diagrammi di radiazione. Queste sono le così dette antenne riconfigurabili, che possono modificare le regioni coperte in base a nuove necessità. Antenne a fascio multiplo vengono usate correntemente in trasmissioni dirette via satellite, satelliti per comunicazioni personali, satelliti per comunicazioni militari e applicazioni Internet ad alta velocità. I sistemi di antenne a fascio multiplo ad elevato guadagno generalmente sono di uno dei seguenti tre tipi: lenti, riflettori o antenne a schiera. Dunque le antenne a schiera si possono trovare nelle applicazioni satellitari sia come strutture per alimentare altri tipi di antenne, sia come strutture radianti direttamente. Il materiale presentato in questa tesi è principalmente legato agli algoritmi di sintesi per antenne a schiera. In particolare, sono stati attentamente studiati e analizzati diversi metodi, analitici e numerici, per la sintesi di potenza di antenne a schiera. Alcuni di questi sono applicabili solo a schiere lineari o rettangolari, altri a schiere di geometria più complicata. Inoltre, è estremamente importante per gli algoritmi di sintesi di potenza di schiere per applicazioni satellitari essere in grado di considerare vincoli addizionali. Questi tipicamente sono la riconfigurabilità del fascio tramite controllo di sola fase, il controllo del diagramma cross-polare, che permette di ottenere il riutilizzo di polarizzazione e/o di controllare l'interferenza cross-polare, la riduzione della dinamica, che permette l'utilizzo di reti di alimentazione più semplici e un abbassamento del mutuo accoppiamento tra gli elementi della schiera, e la riduzione del campo vicino, che permette di tener conto dell'ambiente in cui opera l'antenna. Durante il dottorato è stato sviluppato un algoritmo numerico iterativo per schiere di geometria arbitraria, perciò comprese le schiere sparse e conformi, spesso impiegate in applicazioni satellitari. L'algoritmo permette di risolvere il problema (intrinsicamente non lineare) di sintesi di potenza. La soluzione è ottenuta mediante l'impiego del metodo delle proiezioni succesive, un metodo numerico iterativo per trovare un punto nell'intersezione tra due insiemi. Tale metodo è stato usato in passato in problemi di elaborazione delle immagini e anche in problemi di sintesi di antenne a schiera. Ciononostante, i risultati e il carico computazionale sono direttamente legati ai proiettori, che a loro volta sono strettamente dipendenti dalla definizione della distanza adottata, dunque degli insiemi coinvolti nel problema. Perciò, la principale originalità degli algoritmi sviluppati consiste in una definizione degli insiemi estremamente vantaggiosa in quanto, assieme alla scelta della distanza, permette di valutare facilmente i proiettori e perciò permette di ottenere una procedura di soluzione semplice. La tesi è organizzata come segue. Il primo capitolo introduce le antenne da satellite analizzando alcune soluzioni utilizzate in passato. Particolare attenzione è rivolta alle antenne a fascio multiplo e in particolare alle antenne a schiera, che possono costituire il sitema di alimentazione di antenne a riflettore multifascio o che possono esse stesse essere usate come elementi radianti. Il secondo capitolo presenta metodi analitici e numerici per la sintesi di potenza per antenne a schiera proposti in letteratura. Dapprima vengono presentati i metodi analitici classici, validi per schiere lineari di elementi equispaziati. Successivamente vengono analizzati i metodi numerici iterativi, sia stocastici, sia deterministici. Una sezione a parte è dedicata al vincolo sul campo vicino, vista la grande importanza che riveste nelle applicazioni pratiche. Infatti è di fondamentale importanza tener conto degli effetti dell'ambiente in cui l'antenna opera in quanto ostacoli o strutture di montaggio, così come altri apparati elettronici in prossimità dell'antenna, possono causare forti interferenze e degradare notevolmente il diagramma di campo lontano. Il capitolo 3 presenta gli algoritmi sviluppati. Precisamente, viene delineata l'evoluzione da un algoritmo di sintesi di potenza per schiere riconfigurabili di geometria arbitraria con controllo si sola fase, a un potente algoritmo di sintesi di sola fase con diversi vincoli addizionali, quali la riduzione della dinamica, la sintesi del fascio cross-polare e la riduzione del campo vicino. Inoltre, nella sua forma finale, l'algoritmo permette di minimizzare la potenza irradiata nelle regioni di lobi laterali di entrambi i diagrammi, co- e cross- polare, e l'energia immagazzinata nella regione di campo vicino presa in considerazione. I risultati numerici che provano l'efficacia del metodo sono presentati nel capitolo 4 e le conclusioni sono riassunte nel capitolo 5. Infine, l'appendice descrive matematicamente il classico metodo delle proiezioni successive e gli algoritmi genetici, che sono stati scelti come termine di paragone tra gli algoritmi di ottimizzazione globale.
XXIV Ciclo
1983

In this study some of the first row transition metal oxides were transformed to metal sulfides by new solid gas reaction system. Transition metal sulfides have wide application area in industry and technology. Several techniques are known for the production of metal sulfides. Such as reactions between metal or metal oxide with H2S, precipitation in several liquid medium, reaction between metal and sulfur in closed vessel, chemical vapor deposition (CVD) technique. These techniques will have some disadvantages
for example, reactants are rarely available or expensive materials, their production systems are complicated and hard to set up these systems, products contain oxygen or hydrogen or corresponding metal sulfate as impurities. In our new sulfidizing system the reactants are metal oxides, carbon and SO2. These materials can be found easily. Especially, SO2 usage in this system is a big advantage of giving possibility of usage the hazardous waste product of SO2 in industry. The sulfidizing gas mixture was obtained by passing SO2 over activated carbon at 750 OC in a vertical tubular furnace. The obtained gas contains, mainly, CS2, CO and COS. The sulfidizing reactions took place in the horizontal tubular furnace at 450OC-1250 OC. The duration of the reaction, (three hours), and flow rate (60ml/min) of the SO2 gas were kept constant. The products were examined by X-ray powder diffraction and Raman scattering spectroscopy. All examined metal oxides were transformed to metal sulfides by sulfidizing gas mixture successfully. Ti3S5 was obtained from TiO2. Cr2S3 was obtained from Cr2O3. MnS (Alabandite) was obtained from MnO2. FeS and Fe1-xS (Pyrrhotite) were obtained from Fe2O3. Co9S8 (Cobaltpentlandite) and CoS (Jaipurite) were obtained from Co3O4. NiS was obtained from NiO. Cu7.2S, Cu1.6S (Calcocite-Q), Cu1.81S, Cu7S4 (Anilite) Cu9S5 (Digenite), Cu8S5 (Geerite) were obtained from CuO, ZnS was obtained from ZnO. The electrical conductivity character of each product obtained by sulfidizing reaction was analyzed in the temperature range of 77 K-300 K. Titanium sulfide, cobalt sulfide and nickel sulfide showed metallic conductivity, cupper sulfide and iron sulfide showed semiconductor behavior in this temperature range.

This chapter synthesizes findings from Bolivia, Ghana, Peru, and Zambia. It concludes that political settlements influence the relationships between resource-dependent economies and patterns of social inclusion. However, neither authoritarian, dominant leader forms of politics, nor competitive democratic politics has fostered significant economic diversification or reduced levels of resource dependence. The extractive economy does, however, influence the dynamics of national political settlements. The rents that resource extraction makes possible, and the high cost of engaging in extractive industries, induce asymmetries and create incentives for political exclusion. Colonial and post-colonial histories of resource extraction give political valence to ideas that have helped mobilize actors who have challenged relations of power and institutional arrangements. The materiality of subsoil resources has direct implications for subnational forms of holding power that can influence resource access and control. Mineral and hydrocarbon economies bring both transnational and local political actors into the constitution of national political settlements.

AbstractElectric and autonomous mobility will increasingly rely on advanced route planning algorithms. Robust testing of these algorithms is dependent on the availability of large realistic data sets. Such data sets should capture realistic time-varying traffic patterns and corresponding travel-time and energy-use predictions. Ideally, time-varying availability of charging infrastructure and vehicle-specific charging-power curves should be included in the data to support advanced planning.We contribute with a modular testbed architecture including a semi-synthetic data generator that uses a state-of-the-art traffic simulator, real traffic distribution patterns, EV-specific data, and elevation data to generate time-dependent travel-time and energy-use weights in a road-network graph. The experimental study demonstrates that the testbed can reproduce travel-time and energy-use patterns for long-distance trips similar to commercially available services.

Given that any society is endowed not only with a set of institutions but also with the particular pattern of self-reflection and self-description, postmodernity should be viewed as an epoch representing the climax of modernity and its self-refutation. Parting with traditional society, modernity represents the triumph of power-knowledge, the divorce between spheres of culture, the global social relations, the new institutions, the change in the understanding of space-time relations, the cult of the new, and the modernization process. While preserving the institutional set of modernity, the postmodern period casts into doubt the basic thought foundations of classical modernity. The horizons of the emerging cultural future should be viewed in the light of a positive synthesis of the postmodern reflexive pattern with the legacy of modernity.

Zooming out, we first reach the various regions that compose Crete (e.g. west Crete, Mesara, north-central Crete, Malia-Lasithi zone, Mirabello Bay area, east Crete) and then the whole island itself. This is the macro-scale where settlement patterns can be observed and ‘which may see low-level exchange, competition, close affiliations; a whole range of potential scenarios, including “states”’ (Knappett 2012: 395). Further out, we might speak of the global scale, that of the supra-regional, with connections beyond the island to the Cyclades, Asia Minor, the Greek mainland, and so on. Although we have a general idea of how settlement patterns evolved during the Cretan Bronze Age (Driessen 2001; see also Bevan 2010 for an up-to-date synthesis), limitations at the micro- and meso-scale clearly also constrain our understanding of the macro-scale. Nevertheless, starting with Sir Arthur Evans (1928: 60–92), who was particularly interested in roads and how they connected specific settlements both in central and east Crete to support his view of Knossian overarching power (see also Warren 1994: 189, n.3), an interest in broader regional dynamics and top-down approaches to sociopolitical complexity was always prominent in Aegean archaeology (Cherry 1984; Renfrew 1972; Renfrew and Cherry 1986). This focus on site hierarchies has motivated a broad range of studies, from comparative material culture analysis (e.g. Knappett 1999) to surface surveys and associated tests which provided invaluable information on road networks (e.g. Müller 1991; Tzedakis et al. 1989; Tzedakis et al. 1990) and settlement distribution (for extensive bibliography and synthesis, see Driessen 2001; Whitelaw 2012). Although recent surveys clearly increase the temporal and spatial resolution of our data sets (e.g. Haggis 2005; Watrous 2012; Whitelaw, Bredaki, and Vasilakis 2006–7), they still have considerable gaps. For example, compared to central and east Crete, relatively few sites have been identified in the west of the island. This problem was recently tackled by Bevan and Wilson (2013), who devised a model for exploring settlement locations, hierarchies, and interconnections despite our incomplete dataset (see also chapters 12 and 15).

This book has explored the major methods and concepts in the field of ecophylogenetics. It has considered many of the common statistics and metrics used by ecologists when testing ecophylogenetic hypotheses at both small and large scales. The power of this approach is predicated on the assumption that phylogeny provides information on the evolutionary history of traits that cannot be inferred simply from community data. This concluding chapter reviews some of the advances that have been made in terms of predicting ecology from evolutionary patterns, combining trait and phylogenetic information, and developing a more predictive science of climate change and the biology of species invasions. It also discusses several possible trajectories for ecophylogenetic analyses in the future that will be important in moving the field forward. Finally, it looks at the benefits of a synthesis between ecology and evolution.

In this chapter a systematic investigation of impact of mechanical activation on structural, microstructural, thermal and optical properties of MgO – TiO2 nanocrystalline composite system, synthesized via high energy ball milling techniques. Williamson-Hall (W-H) plot method was employed to understand the signature of the broadening in the XRD peaks and for the estimation of crystallite size of MgO – TiO2 nanocrystalline composite system. It revealed that the peak broadening is not only due to reduced coherently diffracting domain size but also due to a significant strain distribution. The calculated strain was 9.01× 10−3 and the average crystallite sizes were 40–60 nm for 35 hours (hrs) milled powder and this result is very much consistent with transmission electron microscopy (TEM) analysis. The SAED ring pattern indicates that the phase of Mg2TiO4 - nanoparticles was polycrystalline in structure and the distance between crystalline planes was consistent with the standard pattern for a spinel Mg2TiO4 crystal structure. To analyze the lattice fringes for the 35 hrs milled samples high resolution-TEM (HR-TEM) study was carried out and the result revealed that the each particle has single crystalline structure. Morphological studies were carried out by using SEM analysis. The thermal decomposition behavior of the milled powders was examined by a thermo-gravimetric analyzer (TGA) in argon atmosphere. Also, MTO nanoparticles showed a strong absorption at ~356 nm and the band gap values ranged between 3.26-3.78 eV with an increase of milling time from 0 to 35 hr. The mechanically derived MTO nanoparticles showed promising optical properties which are suitable for commercial optoelectronic applications.

This concluding chapter raises three foundational questions to explore what is at stake, intellectually and fundamentally, in the patterns that can be discerned in children's departures across India. The first deals reflexively with the book's project itself, asking: what are the ethnographic ethics of researching, depicting, and describing runaways' suffering for academic or artistic ends, and what are the entailments of speaking for someone else, particularly a vulnerable, nearly powerless subject? The second question asks whether running away might represent a form of resistance, and if so how, and to what power. The third question situates running away in the context of world history, world history theory, and architectures of global capital and labor. These questions help frame, define, synthesize, and sediment the book's wider relevance at its end, at the point where the reader can properly take stock of the story from a rich range of angles.

The chapter synthesizes the archaeological and historical evidence presented in previous chapters to interrogate the structures of early Spanish colonial urbanism with theoretical perspectives on archaeological and historical patterns at a global spatial scale. How do we explain this fervor for urban foundation and rapid expansion of Spanish American urbanism? Why were towns so crucial to Spaniards in the early decades of colonial expansion? how did this urban tradition begin, and how did it affect the lives and practice of Castilians during the middle ages and early modern period? Answers to these questions are sought at the temporal scales of the long durée or geographic time and the conjuncture or social time, and a number of interrelated factors are considered. These include spatial production and deployment of structural power derived from the historico-spatial dialectics of city founding and the implantation of ancient urban institutions as well as spatial construction and a series of symbolic beliefs about the civitas and policía.

This paper synthesises the findings of a set of country studies commissioned by the RISE Programme to explore the influence of politics and power on education sector policymaking and implementation. The synthesis groups the countries into three political-institutional contexts: Dominant contexts, where power is centred around a political leader and a hierarchical governance structure. As the Vietnam case details, top-down leadership potentially can provide a robust platform for improving learning outcomes. However, as the case studies of Ethiopia, Indonesia, Nigeria, and Tanzania illustrate, all-too-often dominant leaders’ goals vis-à-vis the education sector can veer in other directions. In impersonal competitive contexts, a combination of strong formal institutions and effective processes of resolving disagreements can, on occasion, result in a shared commitment among powerful interests to improve learning outcomes—but in none of the case studies is this outcome evident. In Peru, substantial learning gains have been achieved despite messy top-level politics. But the Chilean, Indian, and South African case studies suggest that the all-too-common result of rule-boundedness plus unresolved political contestation over the education sector’s goals is some combination of exaggerated rule compliance and/or performative isomorphic mimicry. Personalised competitive contexts (Bangladesh, Ghana, and Kenya for example) lack the seeming strengths of either their dominant or their impersonal competitive contexts; there are multiple politically-influential groups and multiple, competing goals—but no credible framework of rules to bring coherence either to political competition or to the education bureaucracy. The case studies show that political and institutional constraints can render ineffective many specialised sectoral interventions intended to improve learning outcomes. But they also point to the possibility that ‘soft governance’ entry points might open up some context-aligned opportunities for improving learning outcomes. In dominant contexts, the focus might usefully be on trying to influence the goals and strategies of top-level leadership. In impersonal competitive contexts, it might be on strengthening alliances between mission-oriented public officials and other developmentally-oriented stakeholders. In personalised competitive contexts, gains are more likely to come from the bottom-up—via a combination of local-level initiatives plus a broader effort to inculcate a shared sense among a country’s citizenry of ‘all for education’.

This paper synthesises the findings of a set of country studies commissioned by the RISE Programme to explore the influence of politics and power on education sector policymaking and implementation. The synthesis groups the countries into three political-institutional contexts: Dominant contexts, where power is centred around a political leader and a hierarchical governance structure. As the Vietnam case details, top-down leadership potentially can provide a robust platform for improving learning outcomes. However, as the case studies of Ethiopia, Indonesia, Nigeria, and Tanzania illustrate, all-too-often dominant leaders’ goals vis-à-vis the education sector can veer in other directions. In impersonal competitive contexts, a combination of strong formal institutions and effective processes of resolving disagreements can, on occasion, result in a shared commitment among powerful interests to improve learning outcomes—but in none of the case studies is this outcome evident. In Peru, substantial learning gains have been achieved despite messy top-level politics. But the Chilean, Indian, and South African case studies suggest that the all-too-common result of rule-boundedness plus unresolved political contestation over the education sector’s goals is some combination of exaggerated rule compliance and/or performative isomorphic mimicry. Personalised competitive contexts (Bangladesh, Ghana, and Kenya for example) lack the seeming strengths of either their dominant or their impersonal competitive contexts; there are multiple politically-influential groups and multiple, competing goals—but no credible framework of rules to bring coherence either to political competition or to the education bureaucracy. The case studies show that political and institutional constraints can render ineffective many specialised sectoral interventions intended to improve learning outcomes. But they also point to the possibility that ‘soft governance’ entry points might open up some context-aligned opportunities for improving learning outcomes. In dominant contexts, the focus might usefully be on trying to influence the goals and strategies of top-level leadership. In impersonal competitive contexts, it might be on strengthening alliances between mission-oriented public officials and other developmentally-oriented stakeholders. In personalised competitive contexts, gains are more likely to come from the bottom-up—via a combination of local-level initiatives plus a broader effort to inculcate a shared sense among a country’s citizenry of ‘all for education’.