This article proposes a control strategy based on the finite control set model predictive control (FCS-MPC) for a single-stage buck-boost (SSBB) rectifier. The proposed FCS-MPC requires the reference ...of parallel inductor current in the SSBB, which can be generated by two steps. First, the dc output voltage error is applied to a proportional-integral (PI) controller, which generates the grid current reference. Then, the grid current error is applied to a proportional-resonant (PR) regulator, which generates the reference of the parallel inductor current. Finally, the control of parallel inductor current is achieved by the proposed method, which evaluates possible switching states. Considering the charging and discharging states of the parallel inductor, the number of switching states is reduced from six to three by eliminating the redundant options. The effectiveness of the proposed controller is investigated experimentally on the built prototype. The results are obtained to prove that the proposed control of the dc output voltage and grid current together with unity input power factor are achieved in steady-state and transients under load and grid voltage variations. Furthermore, the performance of the proposed controller is tested under parameter mismatch. The execution times of the proposed controller with six and reduced (three) switching states are compared in this article to further demonstrate the correctness of the proposed approach.
In the partition of unity (PU)-based methods, the global approximation is built by multiplying a partition of unity by local approximations. Within this framework, high-order approximations are ...achieved by directly adopting high-order polynomials as local approximations, and therefore nodes along sides or inside elements, which are usually adopted in the conventional finite element methods, are no more required. However, the PU-based approximation constructed in this way may suffer from rank deficiency due to the linear dependence of the global degrees of freedom. In this paper, the origin of the rank deficiency in the PU-based approximation space is first dissected at an element level, and then an approach to predict the rank deficiency for a mesh is proposed together with the principle of the increase of rank deficiency. Finally, examples are investigated to validate the present approach. The current work indicates such a fact that the rank deficiency is an unrelated issue to the nullity of the global matrix. It can be resolved in its own manner.
The demonstrated square‐planar Pt(II)‐complex has reduced triplet‐triplet quenching and therefore a near unity quantum yield in the neat thin film. A non‐doped phosphorescent organic light‐emitting ...diode (PhOLED) based on this emitter achieves (31.1 ± 0.1)% external quantum efficiency without any out‐coupling, which shows that a non‐doped PhOLED can be comparable in efficiency to the best doped devices with very complicated device structures.
RESUMO Este artigo analisa os primeiros estudos de Erich Auerbach sobre Dante Alighieri, produzidos na década de 1920, de modo a salientar as rivalidades teóricas e políticas que atravessavam o ...ambiente acadêmico em que ele estava inserido. Dentre as tendências interpretativas que se estabeleceram após a Primeira Guerra Mundial sublinha-se a busca pela relevância atual da Divina comédia para a sociedade alemã. Por um lado, essa inclinação fundamentou leituras ufanistas e racialistas de Dante, e por outro, embasou a defesa da unidade da cultura europeia que, em alguma medida, seu poema permitiria vislumbrar. Os textos de Auerbach situam-se no segundo grupo, posto que, nos versos dantescos, para além da orientação teórica de sua reflexão sobre a literatura, ele teria encontrado o sentido do seu envolvimento no mundo enquanto filólogo europeu.
ABSTRACT This article analyses Erich Auerbach’s early studies on Dante Alighieri in the 1920s, and highlights the theoretical and political rivalries that characterized the academic environment in which he worked. It also underlines the search for the relevance of The Divine Comedy for German society among the interpretative trends that were established after the First World War. On the one hand, this disposition was used as the basis for chauvinistic and racialist readings of Dante’s work; on the other, it supported the defense of a unified European culture that his poem would allow to glimpse. Auerbach’s texts exemplify the second category because, beyond his theoretical reflections on literature, he found in Dante’s verses the meaning of his involvement in the world as a European philologist.
RESUMEN Este artículo analiza los primeros estudios de Erich Auerbach sobre Dante de Alighieri, producidos en la década de 1920, de modo de destacar las rivalidades teóricas y políticas que atravesaban el ambiente académico en que este estaba inmerso. Dentro de las tendencias interpretativas que se establecieron después de la I Guerra Mundial se destaca la búsqueda por la relevancia actual de la Comedia para la sociedad alemana. Por un lado, esa inclinación fundamentó lecturas vanagloriosas y racistas de Dante, y por otro, basó la defensa de la unidad de la cultura europea que, en cierta medida, su poema permitiría vislumbrar. Los textos de Auerbach se sitúan en el segundo grupo, puesto que, en los versos dantescos, además de la orientación teórica de su reflexión sobre la literatura, él habría encontrado el sentido de su envolvimiento en el mundo como filólogo europeo.
There's a common line of reasoning which supposes that the phenomenal unity of conscious experience is grounded in a mind-like simple subject. To the contrary, Mādhyamika Buddhist philosophers ...beginning with Śrīgupta (seventh-eighth century) argue that any kind of mental simple is incoherent and thus metaphysically impossible. Lacking any unifying principle, the phenomenal unity of conscious experience is instead an unfounded illusion. In this paper, I present an analysis of Śrīgupta's 'neither-one-nor-many argument' against mental simples and show how his line of reasoning is driven by a set of implicit questions concerning the nature of and relation between consciousness and its intentional object. These questions not only set the agenda for centuries of intra-Buddhist debate on the topic, but they are also questions to which any defender of unified consciousness or a simple subject of experience arguably owes responses.
A series of Cu-ZrO2 catalysts prepared by a co-precipitation method were studied for the hydrogenation of levulinic acid to give gamma -valerolactone (GVL). The effects of a range of catalyst ...preparation parameters, namely molar Cu/Zr ratio, calcination temperature and the ageing time of the precipitates, were systematically investigated. The molar Cu/Zr ratio was found to have a strong influence on the BET surface area of the material leading to a high activity for catalysts prepared with a Cu/Zr molar ratio of unity. Using this molar ratio the calcination temperature was varied from 300 degree C to 800 degree C, the material calcined at 400 degree C showed the highest activity. Increasing the ageing time used in the catalyst preparation identified 6 h as the optimum to achieve the highest activity for LA conversion. Based on characterisation of all materials we conclude that the active Cu species is present in only low concentration suggesting that it should be possible to produce a catalyst of high activity with much lower Cu content.
A modified hierarchical control structure for distributed generation (DG) in microgrid is applied in accordance to the recommendations by the IEEE Std. 1676. In the inverter control layer, a ...generalized control algorithm is developed to enable the DGs to operate in all three modes (i.e., grid-forming, grid-feeding, and grid-supporting modes) with a single control structure, facilitating the seamless transition between the operating modes. This feature is obtained by designing the multiloop controller in the inverter control layer using inverse plant modeling techniques so that the dynamics of the inverter and the LC filter are fully compensated, virtually transforming the controlled DG in the unity gain from the application layer perspective. Thus, effects of disturbances associated with the mode transitions are thus fully eliminated. The effectiveness of the proposed control algorithm is validated by numerical simulations and hardware-in-the-loop experiments. The results show that the DGs can fulfill the tasks defined in the system control layer with fast dynamics, desired accuracy, and good transient behavior.
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