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布隆迪生土建筑教室的设计与建造：被动式教室原型的生土建筑模式

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布隆迪生土建筑教室的设计与建造：被动式教室原型的生土建筑模式

作者： Ntwari Hugues yannick（亚尼克）天津大学

学位级别：硕士

为了争取到2030年为所有儿童和年轻人提供优质教育,并实现联合国可持续发展目标(Sustainable Development Goals,SDGs),在撒哈拉以南非洲的许多国家中,布隆迪一直在努力建设充足和负担得起的教育基础设施,特别是在其80%人口居住的农村... 详细信息

为了争取到2030年为所有儿童和年轻人提供优质教育,并实现联合国可持续发展目标(Sustainable Development Goals,SDGs),在撒哈拉以南非洲的许多国家中,布隆迪一直在努力建设充足和负担得起的教育基础设施,特别是在其80%人口居住的农村地区。一项研究表明布隆迪当地社区的许多学校或教室因建造不当导致大多数学校建筑不舒适、不安全或不耐用。这在一定程度上是因为缺乏资金、缺乏足够的专业知识和缺乏合适的建筑材料。生土建筑(Cob)是一种古老的建筑技术,这种建筑在中东和西非地区很常见,特别是在炎热和干旱的气候下更适合。生土材料是沙和粘土的混合物,还混合了稻草和水作为砌筑或夯筑的建筑材料。本文探讨了生土建筑作为一种新型的教室建筑原型的应用潜力,重点研究了热带气候条件下生土建筑的建造技术和物理性能。这项研究结合了理论文献综述、案例研究、基于绩效的原型教室建筑设计和对可行的被动式设计策略,如采光、通风等的计算模拟,以提高原型生土教室建筑的热工环境性能,并期望为在布隆迪实施生土教室建设提供实用指南。通过文献综述,确定了生土建筑的一般组成、物理性能、力学性能和湿热性能,并对孟加拉国、巴基斯坦和贝宁农村地区的生土建筑案例进行了分,以确定墙壁、天花板到屋顶的合适材料和施工技术。在考虑被动式设计策略的基础上,通过对生土教室的自然通风、天然采光、被动式降温、制冷负荷等室内外环境性能的量化分析,结果表明:为实现有效的穿堂风通风,应鼓励南向和北向开窗,应考虑适当加大开窗,以获得更好的采光体验,同时结合开窗应考虑适当的遮阳,尤其是西立面。此外,在冷负荷和热负荷模拟过程中观察到生土教室在室内热性能和能耗降低方面表现更好。通过以上研究得出结论:如果设计和实施得当,利用充足的当地材料,高质量的生土建筑有可能在布隆迪农村社区的教室建筑中应用,可满足建造负担得起、性能舒适的教室的要求。

关键词：普及型初等教育教室原型生土建筑生土建构技术被动式设计策略布隆迪

高温合金热生长陶瓷薄膜在压应力作用下的脱落特性研究

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高温合金热生长陶瓷薄膜在压应力作用下的脱落特性研究

第十五届全国高技术陶瓷学术年会

作者：齐育红 Philippe Lours yannick LeMaoult 大连海事大学交通与物流工程学院材料科学与工程系 Research Centre on Tools Materials & ProcessesEcole des Mines

本文采用CCD监测技术和红外监测技术,实时监测PM2000 Fe-Cr-Al合金氧化物陶瓷薄膜在受到热冲

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多点地质统计学在储层相建模中的应用

断块油气田 2015年第6期22卷 760-764页

作者：刘超谢传礼 yannick Tepinhi 汪磊中国石油大学(北京)石油工程学院北京102249 中国石化胜利油田分公司河口采油厂山东东营257051

针对渤南油田五六区沙三段4砂组2小层(Es342)储层砂体形态弯曲、分叉、砂体规模与展布变化大的特点,利用多点地质统计学建模法对研究层位进行沉积微相模拟。在该区密集井网区精细地层研究的基础上,统计扇三角洲前缘水下分流河道与河口... 详细信息

针对渤南油田五六区沙三段4砂组2小层(Es342)储层砂体形态弯曲、分叉、砂体规模与展布变化大的特点,利用多点地质统计学建模法对研究层位进行沉积微相模拟。在该区密集井网区精细地层研究的基础上,统计扇三角洲前缘水下分流河道与河口坝砂体长、宽定量数据,结合储层地质知识库的研究,确立不同微相的平面形态与空间组合特征,依此建立定量训练图像。在此基础上,利用SNESIM算法对研究区扇三角洲前缘进行沉积微相模拟。模拟结果表明,利用多点地质统计方法,能够很好地模拟出扇三角洲前缘水下分流河道与河口坝的空间形态特征,得到符合地质意义的沉积微相模型。研究区密集井网的定量研究和训练图像的建立,可以丰富地质知识库,为类似地区利用多点地质统计学进行储层相建模时训练图像的建立提供指导。

关键词：多点地质统计学训练图像密井网区储层地质知识库扇三角洲前缘渤南油田五六区

Design of New Optogenetic Sinusoidal Probe:Optical and Mechanical Simulation

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Design of New Optogenetic Sinusoidal Probe:Optical and Mecha...

作者： Bouget Maxime yannick Joseph 上海交通大学

学位级别：硕士

经过数年对神经电极微尺寸技术的研究,研究人员期望获得对神经组织更小的侵入性伤害,但是现在微尺寸技术对降低植入‘损伤的性能改善已经触及了机械损伤的极限。最近一些新的电极形状设计（正弦型形状）为减小电极植入的侵入性伤害、提... 详细信息

经过数年对神经电极微尺寸技术的研究,研究人员期望获得对神经组织更小的侵入性伤害,但是现在微尺寸技术对降低植入‘损伤的性能改善已经触及了机械损伤的极限。最近一些新的电极形状设计（正弦型形状）为减小电极植入的侵入性伤害、提高电极记录性能开辟了新的可能性。本文旨在继续探索这种新的电极设计方法,并使其适应最新的神经组织刺激技术:光遗传学技术。本文的目标是找到导光性能良好的柔性形状。首先开展设计可行性研究:形状、材料和制作工艺。在形状和制作工艺层面主要遵循已经发表的有关正弦型电极的结论。这部分还要求必须为光学导向器找到具有良好柔韧性、生物相容性和适宜折射率的芯/包层材料。出于以上考虑,研究中放弃了将Parylene-C/Parylene-N组合作为芯/包层材料的选择。其次,使用两种不同的方法进行光学仿真:光束和光线追踪方法。结果显示了不同的形状参数对光传导的影响。由此,选择了若干组光传导性能较好的形状设计。最后,将在光学仿真软件中找到的各种形状进行力学仿真,得到表征其柔韧性的数据,将其与正弦型电极的侵入性数据进行比较。由于研究中保持了与正弦型电极相同的全局性设计,可以得出新设计电极的侵入性伤害的结论。本文最后得出了一组光学正弦型电极的形状参数、机械和光学特征,理论上可以在改善长期植入电极的植入损伤与记录性能。

关键词：神经探针正弦形光遗传学光学模拟机械模拟

Hardware Architecture of Polyphase Filter Banks Performing Embedded Resampling for Software-Defined Radio Front-Ends

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ZTE Communications 2012年第1期10卷 54-62,70页

作者： Mehmood Awan yannick Le Moullec Peter Koch Fred Harris Technology Platforms Section Dept. of Electronic Systems Aalborg University Dept. of Electrical & Computer Engineering San Diego State University

In this paper, we describe resourceefficient hardware architectures for softwaredefined radio （SDR） frontends. These architectures are made efficient by using a polyphase channelizer that performs arbitrary sample rate changes, frequency selection, and bandwidth control. We discuss area, time, and power optimization for field programmable gate array （FPGA） based architectures in an Mpath polyphase filter bank with modified Npath polyphase filter. Such systems allow resampling by arbitrary ratios while simultaneously performing baseband aliasing from center frequencies at Nyquist zones that are not multiples of the output sample rate. A nonmaximally decimated polyphase filter bank, where the number of data loads is not equal to the number of M subfilters, processes M subfilters in a time period that is either less than or greater than the Mdataload ＇ s time period. We present a loadprocess architecture （LPA） and a runtime architecture （RA）（based on serial polyphase structure） which have different scheduling. In LPA, Nsubfilters are loaded, and then M subfilters are processed at a clock rate that is a multiple of the input data rate. This is necessary to meet the output time constraint of the down-sampled data. In RA, Msubfilters processes are efficiently scheduled within Ndataload time while simultaneously loading N subfilters. This requires reduced clock rates compared with LPA, and potentially less power is consumed. A polyphase filter bank that uses different resampling factors for maximally decimated, underdecimated, overdecimated, and combined upand downsampled scenarios is used as a case study, and an analysis of area, time, and power for their FPGA architectures is given. For resourceoptimized SDR frontends, RA is superior for reducing operating clock rates and dynamic power consumption. RA is also superior for reducing area resources, except when indices are prestored in LUTs.

关键词： SDR FPGA Digital Frontends Polyphase Filter Bank Embedded Resampling

Influence of Thin Water Film on Skid Resistance

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Journal of Traffic and Transportation Engineering 2014年第1期2卷 36-44页

作者： Minh-Tan Do Veronique Cerezo yannick Beautru Malal Kane IFSTTAR (French Institute of Science and Technology for Transport Development and Networks) Bouguenais 44344 France

Most of past researches on the skid resistance/road wetness relationship deal with thick water depths （〉 1 mm）. Questions remain as to the variation of skid resistance with thin water films and the transition between the dry state and the so-called ＂damp＂ or ＂humid＂ state at which the skid resistance drop can be as high as 30%-40%. This paper deals with a theoretical and experimental assessment of the friction-water depth relationship. The main objective is to estimate local water depths trapped between the tire and the road asperities and to define a so-called ＂critical＂ water depth which can be used to detect risky situations for road users. Tests are performed in laboratory. It was found that the friction-water depth curves have an inverse-S shape and present an initial constant-friction part before decreasing to a minimum value. A ＂critical＂ water depth, defined as the water depth above which the friction coefficient collapses significantly, is determined from surface texture on critical water depth is discussed. observed friction-water depth curves. Influence of test speed and

关键词： Skid resistance, water depth, microtexture.

Polyphase Filter Banks for Embedded Sample Rate Changes in Digital Radio Front-Ends

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ZTE Communications 2011年第4期9卷 3-9页

作者： Mehmood Awan yannick Le Moullec Peter Koch Fred Harris Technology Platforms Section Dept. of Electronic Systems Aalborg University Denmark Dept. of Electrical & Computer Engineering San Diego State UniversityCA USA

This paper presents efficient processing engines for software-defined radio （SDR） front-ends. These engines, based on a polyphase channelizer, perform arbitrary sample-rate changes, frequency selection, and bandwidth control. This paper presents an M-path polyphase filter bank based on a modified N-path polyphase filter. Such a system allows resampling by arbitrary ratios while performing baseband aliasing from center frequencies at Nyquist zones that are not multiples of the output sample rate. This resampling technique is based on sliding cyclic data load interacting with cyclic-shifted coefficients. A non-maximally-decimated polyphase filterbank （where the number of data loads is not equal to the number of M subfilters） processes M subfilters in a time period that is less than or greater than the M data loads. A polyphase filter bank with five different resampling modes is used as a case study for embedded resamp/ing in SDR front-ends. These modes are （i） maximally decimated, （ii） Under-decimated, （iii） over-decimated, and combined up- and down-sampling with （iv） single stride length, and （v） multiple stride lengths. These modes can be used to obtain any required rational sampling rate change in an SDR front-end based on a polyphase channelizer. They can also be used for translation to and from arbitrary center frequencies that are unrelated to the output sample rates.

关键词： SDR digital front-ends polyphase filter bank embedded resampling

Impact of the COVID-19 Pandemic on Patient Attendance and Trends in the Use of Medical Imaging Modalities in a Referral Hospital in the City of Douala, Cameroon

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Open Journal of Medical Imaging 2022年第1期12卷 16-24页

作者： yannick Onana Joshua Tambe Mohamadou Aminou Samuel Mbozo’o Mvondo Francis Ateba Ndongo Jean Claude Mballa Amougou Jeremie Mbo Amvene Mathurin Neossi Guena Harvey Onana Boniface Moifo Emile Telesphore Mboudou Douala Gyneco-Obstetric and Pediatric Hospital Douala Cameroon Faculty of Medicine and Biomedical Sciences of Garoua University of Ngaoundere Garoua Cameroon Faculty of Health Sciences University of Buea Buea Cameroon Faculty of Medicine and Pharmaceutical Sciences University of Douala Douala Cameroon Faculty of Sciences University of Ngaoundere Ngaoundere Cameroon Faculty of Medicine and Biomedical Sciences The University of Yaoundé 1 Yaoundé Cameroon

Introduction: The COVID-19 pandemic has led to a massive influx of patients with suspected or confirmed flu to hospitals, paradoxically leading to a decrease in the attendance for some services. This study aspired to assess the impact of the COVID-19 pandemic on the attendance of patients at the Radiology and Medical Imaging Department of a tertiary hospital in Douala, Cameroon. Materials and Methods: This was an observational, retrospective and descriptive hospital-based study. Data on patient attendance was extracted from the medical records at the Radiology Unit of Douala Gyneco-Obstetric and Pediatric Hospital (DGOPH) between the 1st of March 2019 and the 30th of August 2021. Results: There was a drop in the number of sonographies and conventional radiographies by 25.73% and 18.26% respectively during the peaks pandemic period of 2020 compared to the preceding pre-pandemic era (2019). There was a recovery in 2021 as the numbers increased. Computed tomography studies increased by 40.65% during the peak pandemic period of 2020. Conclusion: This study enables us to understand the health-seeking behavior during the COVID-19 pandemic. The increase in CT utilization during the peak period of the pandemic nevertheless required caution in order to ensure safety and to promote rational cost-effective utilization.

关键词： COVID-19 Impact Imaging Trends Radiology Department Douala

Hybrid Composite Based on Natural Rubber Reinforced with Short Fibers of the Triumfetta cordifolia/Saccharum officinarum L.: Performance Evaluation

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Journal of Minerals and Materials Characterization and Engineering 2022年第5期10卷 385-399页

作者： Abel Emmanuel Njom Armel Mewoli Marie Josette Ndengue Fabien Betene Ebanda Augustine Demze Nitidem Sandrine Biloa Otiti yannick Devario Youssi Bang Legrand Ndoumou Belinga Pierre Marcel Anicet Noah Atangana Ateba Department of Mechanical Engineering ENSET University of Douala Douala Cameroon Laboratory of Materials Mechanics Structures and Integrated Manufacturing National Advanced School of Engineering University of Yaoundé 1 Yaoundé Cameroon Laboratory of Engineering Civil and Mechanics National Advanced School of Engineering University of Yaoundé 1 Yaoundé Cameroon Laboratory of Mechanics University of Douala Douala Cameroon Mechanics and Adapted Materials Laboratory (LAMMA) ENSET Douala Cameroon

This article contributes to the development of the new class of fully biodegradable “green” composites by combining fibers (natural/bio) with biodegradable resin. The vegetable fibers (Triumfetta cordifolia and sugarcane bagasse) treated with NaOH and bleached were incorporated into a natural rubber matrix. The influence of the fiber ratio on the physical properties, tensile strength and surface hardness of the hybrid composites was analyzed. The results show that the addition of fibers in the natural rubber matrix increases the water absorption capacity but gradually reduces it with increasing fiber ratio. The hybrid composites of the NRT50-50B proportions show the best tensile strengths at 20 phr and a shore A hardness of 43.7 at 30 phr. The combination of two fibers has improved the physical and mechanical properties of the hybrid composites which can be used in engineering applications.

关键词： Hybrid Composites Triumfetta cordifolia Fiber Sugarcane Bagasse Fiber Natural Rubber Shore a Hardness