597 research outputs found
A NOVEL MODEL AND TOOL FOR ENERGY RENOVATION PLANNING IN FRENCH RESIDENTIAL BUILDINGS AND DISTRICTS
International audienceEnergy renovation of existing buildings is important for energy consumption reduction. In fact, it attracted the interest of governments in several countries for its effectiveness (e.g., 38% consumption reduction by 2020 predicted in France). To achieve such rates, major incentivizing measures were taken by governments to facilitate the funding of energy-oriented renovation projects for final users (e.g., households, communities). Despite all these efforts, a lot of obstacles are yet to be overcome like the lack of interest and involvement of the population, the lack of understanding of the economic equation for renovation, unawareness of governmental aids and support. In fact, most of the population does not fully understand the long-term investment benefits of renovation and look at short term-centered benefits. By taking this into account, the aim of our study is to design, develop and implement a simulation model and decision-making tool to assist final users. The first objective of this tool is to shed the light on the advantages and the benefits of renovation to achieve a maximum awareness. To this end, we studied and highlighted three types of incentives: economical, ecological and comfort. The second objective is related to the technical aspects of the project, where users simulate one or several renovations with different characteristics such as insulation materials, space heater, glazing type. Based on the selected parameters, users will be provided with the cost of renovation works, and achievable yearly savings (energy, money, CO2, etc.). Consequently, the user can make the right decision that suits his needs
POST OCCUPANCY EVALUATION OF ADAPTIVELY REUSED BUILDINGS: CASE STUDY OF AN OFFICE BUILDING IN SAUDI ARABIA
On modeling and real-time simulation of a robust adaptive controller applied to a multicellular power converter
Introduction. This paper describes the simulation and the robustness assessment of a DC-DC power converter designed to interface a dual-battery conversion system. The adopted converter is a Buck unidirectional and non-isolated converter, composed of three cells interconnected in parallel and operating in continuous conduction mode. Purpose. In order to address the growing challenges of high switching frequencies, a more stable, efficient, and fixed-frequency-operating power system is desired. Originality. Conventional sliding mode controller suffers from high-frequency oscillation caused by practical limitations of system components and switching frequency variation. So, we have explored a soft-switching technology to deal with interface problems and switching losses, and we developed a procedure to choose the high-pass filter parameters in a sliding mode-controlled multicell converter. Methods. We suggest that the sliding mode is controlled by hysteresis bands as the excesses of the band. This delay in state exchanges gives a signal to control the switching frequency of the converter, which, in turn, produces a controlled trajectory. We are seeking an adaptive current control solution to address this issue and adapt a variable-bandwidth of the hysteresis modulation to mitigate nonlinearity in conventional sliding mode control, which struggles to set the switching frequency. Chatter problems are therefore avoided. A boundary layer-based control scheme allows multicell converters to operate with a fixed-switching-frequency. Practical value. Simulation studies in the MATLAB / Simulink environment are performed to analyze system performance and assess its robustness and stability. Thus, our converter is more efficient and able to cope with parametric variation.Вступ. У статті описується моделювання та оцінка надійності силового перетворювача постійного струму, призначеного для взаємодії із системою перетворення з двома батареями. Прийнятий перетворювач є односпрямованим і неізольованим перетворювачем Бака, що складається з трьох паралельно з’єднаних між собою осередків, що працюють в режимі безперервної провідності. Мета. Для вирішення проблем, пов’язаних з високими частотами перемикання, потрібна більш стабільна, ефективна система живлення з фіксованою частотою. Оригінальність. Звичайний регулятор ковзного режиму страждає від високочастотних коливань, викликаних практичними обмеженнями компонентів системи та зміною частоти перемикання. Отже, ми дослідили технологію м’якого перемикання для вирішення проблем інтерфейсу та комутаційних втрат, а також розробили процедуру вибору параметрів фільтра верхніх частот у багатоосередковому перетворювачі зі ковзним режимом. Методи. Ми припускаємо, що ковзний режим управляється смугами гістерезису як надлишками смуги. Ця затримка обміну станами дає сигнал управління частотою перемикання перетворювача, який, своєю чергою, створює керовану траєкторію. Ми шукаємо рішення для адаптивного керування струмом, щоб вирішити цю проблему і адаптувати гістерезисну модуляцію зі змінною смугою пропускання для пом’якшення нелінійності у звичайному ковзному режимі керування, яке щосили намагається встановити частоту перемикання. Таким чином вдається уникнути проблем із деренчанням. Схема керування на основі прикордонного шару дозволяє перетворювачам з кількома осередками працювати з фіксованою частотою перемикання. Практична цінність. Імітаційне моделювання у середовищі MATLAB/Simulink виконується для аналізу продуктивності системи та оцінки її надійності та стабільності. Таким чином, наш перетворювач ефективніший і здатний справлятися зі зміною параметрів
Survey on relational database watermarking techniques
Digital watermarking has been in multimedia data use over the past years. Recently it has become applicable in relational database system not only to secure copyright ownership but also to ensure data contents integrity. Further, it is used in locating tampered and modified places. However, the watermarking relational database has its own requirements, challenges, attacks and limitations. This paper, surveys recent database watermarking techniques focusing on the importance of watermarking relational database, the difference between watermarking relational database and multimedia objects, the issues in watermarking relational database, type of attacks on watermarked database, classifications, distortion introduced and the embedded information. The comparative study shows that watermarking relational database can be an effective tool for copyright protection, tampered detection, and hacker tracing while maintaining the integrity of data contents. In addition, this study explores the current issues in watermarking relational database as well as the significant differences between watermarking multimedia data and relational database contents. Finally, it provides a classification of database watermarking techniques according to the way of selecting the candidate key attributes and tuples, distortion introduced and decoding methods used
Evaluasi Program Inisiasi Menyusu Dini oleh Bidan di Rumah Sakit Panti Wilasa Citarum Semarang
Sesuai target Millenium Development Goals (MDGs) (AKI) di Indonesia sampai 2015 adalah 102 per 100.000. Dalam rangka mengatasi masalah AKI dan AKB, Departemen Kesehatan mengeluarkan kebijakan yang mengacu kepada intervensi strategis dalam upaya safe motherhood yang salah satunya yaituInisiasi menyusu dini. Rumah Sakit Panti Wilasa Citarum Semarang merupakan Rumah Sakit Sayang Ibu dan Bayi yang melakukan program IMD. Data tahun 2010 terdapat 43,1% persalinan normal dengan IMD dan tahun 2011 sebanyak 34.6%. Berdasarkan studi pendahuluan yang dilakukan pada 3 ibu bidan diketahui bahwa 2 dari 3 pelaksana IMD belum melaksanakan IMD sesuai dengan pedoman pelaksanaan IMD dan Rumah Sakit Panti Wilasa Citarum Semarang belum melaksanakan evaluasi selama 5 tahun terakhir. Tujuan penelitian untuk mengukur pelaksanaan program IMD oleh bidan di Rumah Sakit Panti Wilasa Citarum Semarang. Penelitian dilaksanakan di ruang bersalin dengan menggunakan pendekatan kualitatif deskriptif dengan 8 informan utama dan 11 informan triangulasi. Pengumpulan data dilakukan dengan indepth interview serta teori system Azrul Azwar digunakan sebagai kerangka konsep dengan analisis data secara induktif. Dari hasil penelitian dapat disimpulkan bahwa bidan sudah cukup berkulitas dan berkompeten dalam pelaksanaan IMD, sarana dan prasarana sudah cukup baik namun tidak tersedia Klinik Laktasidan KP-ASI sebagai sarana pendukung program, IMD, perencanaan anggaran IMD sudah cukup yaitu diperoleh dari rumah sakit dan dikelola oleh TIM RSSIB, protap IMD sudah tersedia di rumah sakit dan disahkan oleh Direktur sebagai petunjuk kerja IMD, perencanaan kegiatan IMD sudah cukup baik yaitu perencanaan tenaga IMD, dana dan sarana dan prasarana. Pelaksanaan kegiatan IMD belum cukup baik, bidan tidak melaksanakan IMD sesuai dengan protap IMD, dan pengawasan dilakukan oleh TIM RSSIB yaitu melakukan monitoring pelaksanaan program IMD di ruang VK. Dapat disimpulkan bidan belum mematuhi protap IMD sehingga perlunya diberikan motivasi kepada bidan pelaksana IMD agar bidan melaksanakan IMD sesuai dengan protap IMD dan evaluasi keseluruhan program IMD oleh Rumah Sakit Panti Wilasa Citarum Semaran
MHD heat transfer in W-shaped inclined cavity containing a porous medium saturated with Ag/Al2O3 hybrid nanofluid in the presence of uniform heat generation/absorption
© 2020 by the Authors. In this paper, a 2D numerical study of natural convection heat transfer in a W-shaped inclined enclosure with a variable aspect ratio was performed. The enclosure contained a porous medium saturated with Ag/Al2O3 hybrid nanofluid in the presence of uniform heat generation or absorption under the effect of a uniform magnetic field. The vertical walls of the enclosure were heated differentially; however, the top and bottom walls were kept insulated. The governing equations were solved with numerical simulation software COMSOL Multiphysics which is based on the finite element method. The results showed that the convection heat transfer was improved with the increase of the aspect ratio; the average Nusselt number reached a maximum for an aspect ratio (AR) = 0.7 and the effect of the inclination was practically negligible for an aspect ratio of AR = 0.7. The maximum heat transfer performance was obtained for an inclination of ω = 15 and the minimum is obtained for ω = 30. The addition of composite nanoparticles ameliorated the convection heat transfer performance. This effect was proportional to the increase of Rayleigh and Darcy numbers, the aspect ratio and the fraction of Ag in the volumetric fraction of nanoparticles
Profil ganglionnaire des micro carcinomes papillaires de la thyroide
Management of papillary microcarcinomas of thyroid gland is subject to many discussions.Objective : Aim of this study: determinate lymph node status in these malignant tumors.Materials and methods : this study is about 20 cases of papillary microcarcinomas of thyroid gland, operated between 1994 and 2007,Results : Our study was about 18 women and 2 men with a middle-age of 46 years. We had found that 35% of microcarcinomas had a size higher than 0,5cm.Neck lymph node metastasis were present in 83% when the size of tumor was higher than 0,5 cm.Conclusion : Neck lymph node metastasis in micropapillary carcinomas is conditioned by many factors of which depend the therapeutic management.Keywords : Thyroid gland, papillary microcarcinoma, neck-lymph node dissection
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