Active-Device Losses in Resonant Power Converters: A Case Study with Class-E Inverters

Author(s):  
Nirmana Perera ◽  
Remco van Erp ◽  
Jessy Ancay ◽  
Armin Jafari ◽  
Elison Matioli
2014 ◽  
Vol 6 (1) ◽  
pp. 20-34 ◽  
Author(s):  
Stephan Sigg ◽  
Shuyu Shi ◽  
Yusheng Ji

The authors consider two untackled problems in RF-based activity recognition: the distinction of simultaneously conducted activities of individuals and the recognition of gestures from purely time-domain-based features. Recognition is based on a single antenna system. This is important for the application in end-user devices which are usually single-antenna systems and have seldom access to more sophisticated, e.g. frequency-based features. In case studies with software defined radio nodes utilised in an active, device-free activity recognition (DFAR) system, the authors observe a good recognition accuracy for the detection of multiple simultaneously conducted activities with two and more receive devices. Four gestures and two baseline situations are distinguished with good accuracy in a second case study.


2018 ◽  
Vol 223 ◽  
pp. 01016
Author(s):  
Mattison S. Siri ◽  
David S. Cochran

Here, the step-by-step design procedure for a Class E amplifier is presented. An existing Class E amplifier system is described using a systems architecture approach. The design decomposition for the case study is written so that Physical Solutions (PSs; equivalent to Design Parameters) are in terms of component parameters (such as frequency or capacitance). Coupling issues are found to arise given constraints on transistor use. The design decomposition is altered to reflect the case where an amplifier is required to power a specific load. A discussion of transistor failure enables a design procedure to be developed by observing path-dependent coupling. The design procedure is tested through the design of a real amplifier. The designed amplifier is built and its performance measured.


Author(s):  
Jose R. Perez-Cisneros ◽  
M. Nieves Ruiz ◽  
M. Lobeira ◽  
C. Branas ◽  
J. de Mingo ◽  
...  

2016 ◽  
Vol 4 (1) ◽  
pp. 20
Author(s):  
Anastasia Endah Anastika Dewi ◽  
Mukminan Mukminan

<p class="E-JOURNALTitle">Penelitian ini bertujuan untuk: (1) Mendapatkan bukti-bukti otentik implementasi pendekatan saintifik, (2) Menilai kesesuaian pendekatan saintifik. (3) Menemukan faktor-faktor penghambat dan pendukung implementasi pendekatan saintifik pada pembelajaran  IPS di <em>middle grade</em> SD Tumbuh 3 Kota Yogyakarta. Penelitian ini merupakan penelitian kualitatif menggunakan desain studi kasus. Hasil penelitian menunjukkan: (1) Implementasi pendekatan saintifik meliputi sudah sesuai kurikulum dan, pelaksanaan sesuai tahapan pendekatan saintifik, penilaian belum sesuai penilaian otentik, tindak lanjut sudah sesuai. (2) Penerapan pendekatan saintifik pada pembelajaran IPS untuk siswa <em>middle grade</em> sesuai dengan perkembangan berfikir dan proses belajar siswa. (3) Faktor pendukung pendekatan saintifik adalah: kepala sekolah, guru yang profesional, iklim sekolah yang kondusif, sarana dan prasarana yang lengkap. Faktor penghambatnya adalah: sistem penerimaan siswa tidak transparan, ada beberapa peserta didik belum bisa membaca dan menulis, instrumen penilaian tidak sesuai, dan jam pembelajaran yang terbatas dan guru tidak membatasi bobot cakupan materi sesuai dengan tingkat perkembangan berpikir siswa.</p><p class="E-JOURNALAbstrakKeywords"><strong>Kata kunci</strong>: implementasi, pendekatan saintifik, middle grade, IPS</p><p class="E-JOURNALTitleEnglish"> </p><p class="E-JOURNALTitleEnglish"><strong>IMPLEMENTATION OF SCIENTIFIC APPROACH IN SOCIAL STUDIES INSTRUCTION AT MIDDLE GRADE OF SD TUMBUH 3 KOTA YOGYAKARTA</strong></p><p class="E-JOURNALTitleEnglish"><strong>Abstract</strong></p><p class="E-JOURNALAbstractBodyEnglish">This study aims to: (1) Getting authentic proof of scientific approach implementation (2) Asses the scientific approach appropriateness in social studies, (3) to find some factors that become the barriers and the proponents of the scientific approach implementation in social studies instruction in middle grade. This study is a qualitative research which uses case study design. The results of this reasearch are as follows: (1) The scientific approach implementation ranges from, the planning aspect has already been appropriate, the implementation aspect has already been good, the assessment aspect has not been appropriate to the approach used, the follow-up aspect has been carried out based on the students' need. (2) Scientific approach in for middle-grade age has already been appropriate,(3) The supporting factors are: a good headmaster, professional teache, The conductive school climate, the complete facilities and infrastructures. The inhibiting factors are: the non-transparent admission system, students who have not been able to read and write, the inappropriate assessment, and  limited schedule of social studies the teacher do not limit the range of Social Studies material based on student’s cognitive development stage.</p><strong>Keywords</strong>: implementation, scientific approach, middle grade, social studies


Electronics ◽  
2021 ◽  
Vol 10 (19) ◽  
pp. 2344
Author(s):  
Martin Kjær ◽  
Huai Wang ◽  
Frede Blaabjerg

The reliability of power converters has been extensively examined in terms of component- and converter level. However, in case of multiple generation units, the evaluation of the performance of power systems requires system-level modeling. This paper aims to merge the prior art of reliability modeling of power converters with the adequacy evaluation of power systems through an extensive design and evaluation analysis of a microgrid based case study. The methodology proposed in the paper integrates the device-level analysis into the domain of the conventional power system reliability analysis while outlining the steps needed to deal with non-exponential distributed failures of power electronic-based generation units. A replacement policy of the power electronic-based units is adopted by means of evaluating the system risk of not supplying system loads, and, finally, an approach on how to ensure a desired replacement frequency is outlined.


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