Control and analysis of a unified power flow controller

This paper presents a control scheme and comprehensive analysis for a unified power flow controller (UPFC) on the basis of theory, computer simulation and experiment. This developed theoretical analysis reveals that a conventional power feedback control scheme makes the UPFC induce power fluctuation in transient states. The conventional control scheme cannot attenuate the power fluctuation, and so the time constant of damping is independent of active and reactive power feedback gains integrated in its control circuit. This paper proposes an advanced control scheme which has the function of successfully damping out the power fluctuation. A UPFC rated at 10 kVA is designed and constructed, which is a combination of a series device consisting of three single-phase pulsewidth modulation (PWM) converters and a shunt device consisting of a three-phase diode rectifier. Although the dynamics of the shunt device are not included, it is possible to confirm and demonstrate the performance of the series device. Experimental results agree well with both analytical and simulated results and show viability and effectiveness of the proposed control scheme </p

Bank Size and Lending Relationships in Japan

Current theoretical and empirical research suggests that small banks have a comparative advantage in processing soft information and delivering relationship lending. The most comprehensive analysis of this view found using U.S. data that smaller SMEs borrow from smaller banks and smaller banks have stronger relationships with their borrowers (Berger, Miller, Petersen, Rajan, and Stein 2005) (BMPRS). We employ essentially the same methodology as BMPRS on a unique Japanese data set and obtained findings that are quite interesting from an international comparison point of view. We found like BMPRS that larger firms tend to borrow from larger banks. However, unlike BMPRS we did not find that this was because larger firms are more transparent. Together these results imply that large banks do not necessarily have a comparative advantage in extending transactions-based lending. We also found like BMPRS that smaller banks have strong relationships with their borrowers. However, we find that banking relationships in the U.S. and Japan are strong in somewhat different dimensions. Our paper clarifies these and other interesting similarities and differences between the U.S. and Japan.

Transfer learning of language-independent end-to-end ASR with language model fusion

This work explores better adaptation methods to low-resource languages using an external language model (LM) under the framework of transfer learning. We first build a language-independent ASR system in a unified sequence-to-sequence (S2S) architecture with a shared vocabulary among all languages. During adaptation, we perform LM fusion transfer, where an external LM is integrated into the decoder network of the attention-based S2S model in the whole adaptation stage, to effectively incorporate linguistic context of the target language. We also investigate various seed models for transfer learning. Experimental evaluations using the IARPA BABEL data set show that LM fusion transfer improves performances on all target five languages compared with simple transfer learning when the external text data is available. Our final system drastically reduces the performance gap from the hybrid systems.Comment: Accepted at ICASSP201

Transient analysis of a unified power flow controller and its application to design of the DC-link capacitor

This paper presents a transient analysis of a unified power flow controller (UPFC), and design of capacitance of the dc-link capacitor based on that analysis. Active power flowing out of the series device in transient states is theoretically discussed to derive what amount of electric energy the dc link capacitor absorbs or releases through the series device. As a result, it is clarified that the active power flowing out of the series device is stored in the line inductance as magnetic energy during transient states. Design of capacitance of the dc-link capacitor is also presented in this paper, based on the theoretical analysis. Experimental results obtained from a 10-kVA laboratory setup are shown to verify the analytical results.</p

Structural equation model of factors related to quality of life for community-dwelling schizophrenic patients in Japan

BACKGROUND: This study aimed to clarify how community mental healthcare systems can be improved. METHODS: We included 79 schizophrenic patients, aged 20 to 80 years, residing in the Tokyo metropolitan area who regularly visited rehabilitation facilities offering assistance to psychiatric patients and were receiving treatment on an outpatient basis. No subjects had severe cognitive disorders or were taking medication with side effects that could prevent the completion of questionnaires. Questionnaires included items related to quality of life, self-efficacy, self-esteem, psychosis based on the Behavior and Symptom Identification Scale, health locus of control, and socio-demographic factors. We performed multiple linear regression analysis with quality of life as the dependent variable and, based on covariance structural analysis, evaluated the goodness of fit of the resulting structural equations models. RESULTS: Self-efficacy, self-esteem, and degree of psychosis significantly impacted quality of life. Marital status, age, and types of medications also influenced quality of life. Multiple linear regression analysis revealed psychiatric symptoms (Behavior and Symptom Identification Scale-32 [daily living and role functioning] (Beta = −0.537, p < 0.001) and self-efficacy (Beta = 0.249, p < 0.05) to be predictors of total quality of life score. Based on covariance structural analysis, the resulting model was found to exhibit reasonable goodness of fit. CONCLUSIONS: Self-efficacy had an especially strong and direct impact on QOL. Therefore, it is important to provide more positive feedback to patients, provide social skills training based on cognitive behavioral therapy, and engage patients in role playing to improve self-efficacy and self-concept

Computational water analysis in an artificial lake: Kojima Lake case

We treat the problem of water pollution by the method of a mathematical model. We illustrate the method of analysis with Kojima Lake. We analyze in-flow and out-flow of the lake, compute numerical solutions of the governing equations of the water flow and the pollutant. The simulation leads to the conclusion concerning the figure of Kojima Lake

Different defects formation modes under sevier reducing condition in primitive cubic perovskites, BaZr1-xYxO3-x/2 and BaSn1-xYxO3-x/2

Reduction processes using metal hydride agents modify the chemical and structural properties of metal oxide crystals with different manners, depending on the host crystals and the process conditions [1]. In BaTiO3, a reduction using CaH2 leads to partial and random substitution of H-for the O2-site, which is compensated by a formal valence change of Ti4+ to Ti3+, imparting an electronic conduction [2] (Fig. 1a). In contrast, a low temperature reduction of SrFeO3 preferentially eliminates O2-at axial sites in the FeO6 octahedra without the H--incorporation to convert to SrFeO2 with a unique planner four-coordinated Fe2+ [3] (Fig. 1b). An intermediate result has been obtained in a layered perovskite, LaSrCoO4, in which H- ions are selectively incorporated in specific O2- sites to form trans-configuration of H-ions [4]. Herein, we focus on the metal hydride-reduction of BaZr1-xYxO3-x/2 (BZY) and BaSn1-xYxO3-x/2 (BSY) and relevant defect chemistry. Both system have the primitive cubic perovskite structure and are popular fast protonic conductor. The latter is related to our expectation that the H-ions are incorporated with a similar manner with the OH- formation via OOX + VO·· + CaH2 ® 2HO· + CaO. BZY and BSY powders were annealed in vacuum-sealed glass tubes containing metal hydride agents at 350-550 °C. Please click Additional Files below to see the full abstract

Are Trade Creditors Relationship Lenders?

Despite the importance of the hypothesis that trade creditors may act as relationship lenders, it has been virtually impossible to directly test this hypothesis because of a lack of data. We attempt to overcome this problem by using a relatively new Japanese database on small and midsized enterprises (SMEs) that contains information on the strength of the buyer-seller relationship. We find some evidence that trade creditors may be relationship lenders. However, we also find evidence that trade creditors may be financial statement lenders. Our results are generally quite sensitive to model specification in both our "quantity" and "terms of credit" regressions. Thus, our results can only be viewed as suggestive of the possibility that trade creditors acquire private soft information over time and use this information to set the terms of trade financing.