96 research outputs found

    Microgrids: Studies on Generalization and Protection

    Get PDF
    Bu çalışmada akıllı ağların en önemli güç katmanı uygulamaları olan dağıtık üretim ve mikro ağlar, uygulama kolaylığı sağlaması amacıyla genelleştirilmeye çalışılmıştır. Öncelikle genelleştirilmiş dağıtık üreteç modeli ve kaynakları belirlendikten sonra alçak gerilim yerleşim alanlarında yenilenebilir enerji kaynaklarının yaygın olarak kullanımına olanak sağlayan bir mikro ağ yapısı ve dağıtım otomasyon mimarisi önerilmiştir. Önerilen felsefe yenilenebilir kaynakların mevcut dağıtım şebekelerine asgari maliyetle entegrasyonunu sağlayacak şekilde tasarlanmıştır. Çalışmadaki amaç yenilenebilir kaynakların yaygın kullanımıyla birlikte ortaya çıkan durumda akıllı ağlarda yenilenebilir kaynakların entegrasyonu konusunda standart bir uygulama prensibi sağlamaktır

    Participatory design to lower the threshold for intelligent support authoring

    Get PDF
    One of the fundamental aims of authoring tools is to provide teachers with opportunities to configure, modify and generally appropriate the content and pedagogical strategies of intelligent systems. Despite some progress in the field, there is still a need for tools that have low thresholds in terms of the users’ technical expertise. Here, we demonstrate that designing systems with lower entry barrier can potentially be achieved through co-design activities with non-programmers and carefully observing novices. Following an iterative participatory co-design cycle with teachers who have little or no programming expertise, we reflect on their proposed enhancements. Our investigations focus on Authelo, an authoring tool that has been designed primarily for Exploratory Learning Objects, but we conclude the paper by providing transferable lessons, particularly the strong preference for visual interfaces and high-level pedagogical predicates for authoring analysis and feedback rules

    Calvarial bone defects in ovariectomised rats treated with mesenchymal stem cells and demineralised freeze-dried bone allografts

    Get PDF
    Background: The aim of the study was to investigate the ability of a combination of bone marrow mesenchymal stem cells (BM-MSCs) with and without demineralised freeze-dried bone allografts (DFDBAs) to induce bone regeneration incalvarial defects in ovariectomised rats.Materials and methods: Critical size defects were filled with a combination of DFDBAs and BM-MSCs or BM-MSCs alone. Eight weeks after calvarial surgery, the rats were sacrificed. The samples were analysed histologically and immunohistochemically.Results: No difference was observed in vascularisation between groups C1 (animals with cranial defect only, control group) and O1 (animals with cranial defect only, ovariectomy group). Intramembranous ossification was observed at a limited level in groups C2 (animals with cranial defect with MSCs, control group) and O2 (animals with cranial defect with MSCs, ovariectomy group) compared to C1 and O1. In group C3 (animals with DFDBAs with MSCs, control group), the fibrous structures of the matrix became compact as a result of a bone graft having been placed in the cavity, but in group O3 (animals with DFDBAs with MSCs, ovariectomy group), the fibrous tissue was poorly distributed between the bone grafts for the most parts.Conclusions: We conclude that the insertion of BM-MSCs enhances bone healing; however, the DFDBA/BM-MSC combination has little effect on overcoming impaired bone formation in ovariectomised rats

    The Semileptonic BB to K1(1270,1400)K_1(1270,1400) Decays in QCD Sum Rules

    Get PDF
    We analyze the semileptonic rare decays of BB meson to K1(1270)K_{1} (1270) and K1(1400)K_{1} (1400) axial vector mesons. The BK1(1270,1400)+B\to K_{1} (1270,1400) \ell^+ \ell^- decays are significant flavor changing neutral current decays of the BB meson. These decays are sensitive to the new physics beyond SM, since these processes are forbidden at tree level at SM. These decays occurring at the quark level via bs+b\to s \ell^+ \ell^- transition, also provide new opportunities for calculating the CKM matrix elements VbtV_{bt} and VtsV_{ts}. In this study, the transition form factors of the BK1(1270,1400)+B\to K_{1} (1270,1400) \ell^+ \ell^- decays are calculated using three-point QCD sum rules approach. The resulting form factors are used to estimate the branching fractions of these decays.Comment: 18 pages, 7 figures, version to appear in JP

    Internet-based, culturally sensitive, problem-solving therapy for turkish migrants with depression: Randomized controlled trial

    Get PDF
    Background: Turkish migrants living in the Netherlands have a high prevalence of depressive disorders, but experience considerable obstacles to accessing professional help. Providing easily accessible Internet treatments may help to overcome these barriers. Objective: The aim of this study was to evaluate the effectiveness of a culturally sensitive, guided, self-help, problem-solving intervention through the Internet for reducing depressive symptoms in Turkish migrants. Methods: A two-armed randomized controlled trial was conducted. The primary outcome measure was the severity of depressive symptoms; secondary outcome measures were somatic symptoms, anxiety, quality of life, and satisfaction with the treatment. Participants were assessed online at baseline, posttest (6 weeks after baseline), and 4 months after baseline. Posttest results were analyzed on the intention-to-treat sample. Missing values were estimated by means of multiple imputation. Differences in clinical outcome between groups were analyzed with a t test. Cohen's d was used to determine the between-groups effect size at posttreatment and follow-up. Results: Turkish adults (N=96) with depressive symptoms were randomized to the experimental group (n=49) or to a waitlist control group (n=47). High attrition rates were found among the 96 participants of which 42% (40/96) did not complete the posttest (6 weeks) and 62% (59/96) participants did not complete the follow-up assessment at 4 months. No significant difference between the experimental group and the control group was found for depression at posttest. Recovery occurred significantly more often in the experimental group (33%, 16/49) than in the control group (9%, 4/47) at posttest (P=.02). Because of the high attrition rate, a completers-only analysis was conducted at follow-up. The experimental group showed significant improvement in depression compared to the control group both at posttest (P=.01) and follow-up (P=.01). Conclusions: The results of this study did not show a significant effect on the reduction of depressive symptoms. However, the effect size at posttest was high, which might be an indicator of the possible effectiveness of the intervention when assessed in a larger sample and robust trial. Future research should replicate our study with adequately powered samples. © Burçin Ünlü Ince, Pim Cuijpers, Edith van 't Hof, Wouter van Ballegooijen, Helen Christensen, Heleen Riper

    Thermodynamic principles and implementations of quantum machines

    Full text link
    The efficiency of cyclic heat engines is limited by the Carnot bound. This bound follows from the second law of thermodynamics and is attained by engines that operate between two thermal baths under the reversibility condition whereby the total entropy does not increase. By contrast, the efficiency of engines powered by quantum non-thermal baths has been claimed to surpass the thermodynamic Carnot bound. The key to understanding the performance of such engines is a proper division of the energy supplied by the bath to the system into heat and work, depending on the associated change in the system entropy and ergotropy. Due to their hybrid character, the efficiency bound for quantum engines powered by a non-thermal bath does not solely follow from the laws of thermodynamics. Hence, the thermodynamic Carnot bound is inapplicable to such hybrid engines. Yet, they do not violate the principles of thermodynamics. An alternative means of boosting machine performance is the concept of heat-to-work conversion catalysis by quantum non-linear (squeezed) pumping of the piston mode. This enhancement is due to the increased ability of the squeezed piston to store ergotropy. Since the catalyzed machine is fueled by thermal baths, it adheres to the Carnot bound. We conclude by arguing that it is not quantumness per se that improves the machine performance, but rather the properties of the baths, the working fluid and the piston that boost the ergotropy and minimize the wasted heat in both the input and the output.Comment: As a chapter of: F. Binder, L. A. Correa, C. Gogolin, J. Anders, and G. Adesso (eds.), "Thermodynamics in the quantum regime - Recent Progress and Outlook", (Springer International Publishing
    corecore