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Application of a Neural Network Technique for Prediction of the Water Quality Index in the Dong Nai River, Vietnam

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Journal of Environmental Science and Engineering(B) 2016年第7期5卷 363-370页

作者： nguyen Hien Than Che dinh Ly Pham Van Tat nguyen Ngoc Thanh Department of Natural Resources Management Institute of Environment and Resources Vietnam National University HCMC 700000 Vietnam Faculty of Science and Technology Hoa Sen University HCMC 700000 Vietnam Institute of Environmental Science Engineering and Management Industrial University of rio Chi Minh City 700000 Vietnam

Recent trends in environmental management of water resource have enlarged the demand for predicting techniques that can provide reliable, efficient and accurate water quality. In this case study, the authors applied the Artificial Neural Networks （ANN） to estimate the water quality index on the Dong Nai River flowing through Dong Nai and Binh Duong provinces. The information and data including 10 water quality parameters of the Dong Nai River at 23 monitoring stations were collected during the recorded time period from 2010 to 2014 to build water quality prediction models. The results of the study demonstrated that the Water Quality Index （WQI） forecasted with GRNN was very significant and had high correlation coefficient （R2 = 0.974 and p = 0.0） compared to the real values of the WQI. Moreover, the ANN models provided better predicted values than the multiple regression models did.

关键词： Artificial Neural Networks water quality forecast water quality prediction.

Full-Filling Subcarrier Power Allocation in OFDMA-Based Cognitive Radio Systems

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Wireless Engineering and Technology 2014年第1期5卷 11-18页

作者： Tuan Le Van Hieu dinh Chi Kinh nguyen Viet Hieu nguyen Thanh Authority of Radio Frequency Management Hanoi Viet Nam School of Electrical and Electronic Engineering Nanyang Technological University Singapore City Singapore University of Engineering and Technology Hanoi Viet Nam

When implementing an appropriate windowing, the interference from a Cognitive Radio (CR) system to licensed systems (primary users) will be significantly reduced. Consequently, power allocated to subcarriers can be increased, especially subcarriers having far spectral distance to primary user bands can be allocated full of its maximum possible power. In this paper, we propose a new class of sub-optimal subcarrier power allocation algorithm that significantly reduces complexity of OFDMA-based CR systems. Two sub-optimal proposals, called Pre-set Filling Range (PFR) and Maximum Filling Range (MFR) are studied. Investigations show that this new power allocating algorithm allows CR systems obtain high throughput while retaining low complexity.

关键词： Cognitive Radio Windowing Power Allocation Full Filling

不同围岩条件下偏压隧道初期支护优化设计研究——以鹤大高速公路回头沟隧道为例

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不同围岩条件下偏压隧道初期支护优化设计研究——以鹤大高速公路...

作者： nguyen dinh HOAN（阮庭环）吉林大学

学位级别：硕士

由于偏压隧道的复杂性,通过工程类比法设计出的初期支护在实际工程的施工和运营期间出现了许多问题,因此对于地形偏压隧道的初期支护结构有必要进行深入的研究、优化设计。本文结合在建隧道的浅埋偏压段,通过资料调研、理论分析和数值... 详细信息

由于偏压隧道的复杂性,通过工程类比法设计出的初期支护在实际工程的施工和运营期间出现了许多问题,因此对于地形偏压隧道的初期支护结构有必要进行深入的研究、优化设计。本文结合在建隧道的浅埋偏压段,通过资料调研、理论分析和数值模拟对偏压隧道的初期支护体系提出锚杆长度、锚杆间距和喷混凝土厚度的优化设计。本文采用MIDAS/GTS/NX有限元数值模拟软件建立二维数值模型,根据原设计方案与《公路隧道设计规范》(JTG D70-2004)设计出锚杆长度、间距以及喷射混凝土层厚度的各个工况,进行模拟分析研究,最终结合工程经济性做出优化设计。通过研究得出以下成果:1.根据回头沟隧道工程地质条件,几何参数和围岩的物理力学特性建立了相应的数值模拟模型,利用数值方法对偏压隧道初期支护进行了模拟分析。给出了各设计工况产生的隧道特征位移、衬砌轴应力与弯矩、围岩塑性区、锚杆轴力等,并对其进行研究分析。最终给出回头沟隧道IV级和V级围岩条件下初期支护的优化设计方案。2.分析比较了埋深为5m,10m,15m,地表倾角为15°,30°,45°各组合条件下,隧道不同初期支护设计的支护效果,通过比较塑性区分布情况以及围岩压力,周围位移,衬砌受力,可知:(1)对于偏压隧道,埋深和地表倾角均会影响到隧道初期支护的受力,因此要综合考虑隧道的埋深和地表倾角。(2对于偏压隧道,采用非对称的支护结构设计较对称设计更为合理。3.依据优化方案,对该隧道的施工进行指导,保障其安全与稳定。

关键词：偏压隧道初期支护不同围岩级别优化设计

Assessing the Vulnerability of Agricultural Production Activities in the Coastal Area of Thua Thien Hue Province, Vietnam by GIS Analysis Tools

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Journal of Geoscience and Environment Protection 2019年第5期7卷 116-130页

作者： nguyen Hoang Son Dao dinh Cham Phan Anh Hang nguyen Trong Quan nguyen Thanh Hoan University of Education Hue University Hue Vietnam Institute of Geography Vietnam Academy of Science and Technology Hanoi Vietnam Graduate University of Science and Technology Vietnam Academy of Science and Technology Hanoi Vietnam University of Science Hue University Hue Vietnam

Using Geography Information System (GIS) tools and remote sensing data in assessing the level of vulnerability of agricultural production activities in the coastal area has become more efficient in the recent years. This research has identified the sensitivity index (S) (including the traffic access index;the impact of residential areas;the impacts of industrial zones;the community dependence level), exposure index (E) (the sea level rises to 2100;the temperature change to 2100), the adaptable capacity index (AC) (slope;morphology), thereby synthesizing the vulnerability index (V). Based on the indexes to calculate vulnerability, the high to very high vulnerability area is 37,081.44 ha, accounting for 68.09%;the average vulnerability level is 15,286.49 ha, accounting for 28.07%;the low to very low vulnerability level with an area is 2087.82 ha, accounting for 3.84% of the total area. With a high and very high vulnerability accounting for 68.09%, there will be great influences on the lives of resident in the area, especially agricultural production.

关键词： Vulnerability Indexes GIS Tools Agricultural Production Activity Coastal Areas

The Changes of Water Quality in Space and Time in the Mekong River, Bassac River and Adjacent Waterways

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Journal of Life Sciences 2014年第6期8卷 481-488页

作者： Luu Duc Dien Ma Tu Lan nguyen dinh Hung Research Institute for Aquaculture No. 2 116 Nguyen Dinh Chieu Street District 1 Hochiminh City 70000 Vietnam

Catfish （Pangasianodon hypophthalmus） farming along Mekong river and Bassac river depends heavily on water quality of the two rivers, whereas water quality of these rivers are affected by the waste of aquaculture activities, agricultural production, industrial and municipal waste. This report analyzes the monitoring data on Mekong river, Bassac river and adjacent waterways in the period of 2011-2012, focusing on parameters of organic pollution to assess the current quality of these two rivers. Based on the results, the water quality in the river-head was generally better than in the middle and at the end of the river, and the quality of water of the Mekong river was better than Bassac river. In terms of time, water quality in July was considered the best in all the basins. At adjacent natural rivers and canals, ammonia levels increased and exceeded the Vietnamese standard in April, and BOD values were also much higher compared to two major rivers. The results of the model also showed that the levels of pollution index of the Mekong and Bassac river were very low （1.33 and 1.47）, and the values （Y） in the canals were higher （1.63-1.67） but still in permitted level. Therefore, the water quality of the Mekong and Bassac river in the period 2011-2012 was generally still quite good.

关键词： Bassac river catfish Mekong river model water quality.

越南高中德育问题及对策研究 ——以河内市高中学校为例

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越南高中德育问题及对策研究 ——以河...

作者： nguyen dinh HOA（阮庭和）西南大学

学位级别：硕士

如今,道德教育计划已经在学生不同教育阶段予以实施。在学前阶段,它是道德行为的教育;在中学阶段,它是道德课程的教育;在高中阶段,它是公民教育。在学校的道德教育仍然被视为避免部分学生道德退化的一个重要方面。但教材过于依赖理论,... 详细信息

如今,道德教育计划已经在学生不同教育阶段予以实施。在学前阶段,它是道德行为的教育;在中学阶段,它是道德课程的教育;在高中阶段,它是公民教育。在学校的道德教育仍然被视为避免部分学生道德退化的一个重要方面。但教材过于依赖理论,与现实缺乏联系,缺少软技能,未能显著形成学生的个性。道德教育项目繁重,因此学生很难记忆和集中注意力。在高中,公民道德教育教材尚未彻底地改变,导致学生缺乏正确的道德习惯,在其心里中没有形成一个标志,使他们成为社会的弱势群体。正值青春期的高中生,他们处在生理和心理同时发展的阶段,这是一段从青少年到成人的过渡期。这个阶段是学生积极参与社会生活,从而形成公民素质的时期,也是学校教育学生在社会关系中保持善良,宽容,慷慨和教育伦理的时期。需要为学生搭建一个健康的平台让他们找到有效的生活方式。在社会和学校,特别是在家庭和班级,创造良好的教育环境,使学生成为有良好道德的人。为了研究收集信息,笔者已经对不同背景的人进行了问卷调查。他们包括家长,教师,学生等。对德育的问卷调查进行了设计并得到了455人的答案:（1）河内高中德育现状的评价;（2）发现学校与家庭和社会之间的联系重要性;（3）提出一个包含课外课程活动的道德教育计划,将学校与家庭和社会联系在一起。通过对高中思想品德教育现状的评价与研究,进行数据分析,与越南国家教育的现实相结合。我们可以看到:除了学校的德育课之外,还应该举办其他活动,让学生参与并开阔他们的眼界。但是组织什么样的活动?如何组织这些活动?这是许多人需要思考的问题。学校可以与家庭和社会密切配合以组织课外课程活动。但是如何协调这些力量,如何加强与家庭和社会的联系?这也是许多人的问题。从自己的知识和经验出发,结合他人的问题和建议,笔者已经尝试通过课外的课程活动设计一个道德教育计划。在这项计划中,笔者已经证实了在为高中生实施道德教育过程中的课外活动的必要性,并选择了20个适合高中生的活动。同时也提出了步骤和措施:组织这些活动;将学校与家庭和社会联系在一起;加强他们之间的联系;评估过程和结果的联系。所有的步骤和措施都是基于教育法、合作原则,以及在社区中的责任共担。这个项目具有适当的步骤和措施,希望能对国家未来一代的培养有合理的贡献。

关键词：德育教育联系课外活动

Directly immobilized DNA sensor for label-free detection of herpes virus

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Journal of Biomedical Science and Engineering 2009年第6期2卷 374-379页

作者： Phuong dinh Tam Mai Anh Tuan nguyen Duc Chien 不详

This paper reports the direct immobilization of deoxyribonucleic acid (DNA) sequences of Herpes simplex virus (5’–AT CAC CGA CCC GGA GAG GGA C–3’) on the surface of DNA sensor by using the cyclic voltammetric method with the presence of pyrrole. The potential was scanned from –0.7 volt to + 0.6 volt, the scanning rate was at 100mV/s. This kind of DNA sensor was developed to detect Herpes virus DNA in real samples. The FTIR was applied to verify specific binding of DNA sequence and conducting polymer, the morphology of conducting polymer doped with DNA strands was investigated by using a field emission scanning electron microscope (FE-SEM). The results showed that output signal given by coimmobilized DNA/PPy membrane sensor was better than that given by APTS immobilized membrane sensors. The sensor can detect as low as 2 nM of DNA target in real samples.

关键词： DNA Sensor Hybridization APTS

Prediction of the Local Scour at the Bridge Square Pier Using a 3D Numerical Model

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Open Journal of Applied Sciences 2014年第2期4卷 34-42页

作者： nguyen Viet Thanh Dang Huu Chung Tran dinh Nghien University of Transport and Communication Hanoi Viet Nam Vietnam Academy of Science and Technology Hanoi Viet Nam

In this paper, the problem on local scour around a single square pier was studied by using both the numerical and physical models. The numerical model for the study is FSUM based on a finite-difference method to solve the Reynolds averaged Navier-Stokes equations (RANS) and the equations for suspended sediment concentration and bed morphology. The computed result was verified through data measured in the experimental flume with a sand bed. In general, the typical features of local scour around the pier were successfully simulated by FSUM, such as stream flow, bow flow, down flow, horseshoe vortex. The comparison between the computation and experiment data shows a quite good fitness. Both numerical model and experiment results show that the maximum scour depth occurs at two front edges of the pier. Although the computed result shows a little bigger scour depth in comparison with the measurement in the physical model, it still confirms the reliability of numerical model in some measure.

关键词： Numerical Modeling Experiment Bridge Square Pier Local Scour FSUM Model

Polymeric Liquid Templating of Hierarchical Porous Films by Nanofibrillar Alginic Acid Assemblies

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Soft Nanoscience Letters 2014年第1期4卷 6-14页

作者： Thai-Hoa Tran Sy-Thang Ho Thanh-dinh nguyen Department of Chemical Engineering Laval University Quebec Canada. Department of Chemistry College of Sciences Hue University Hue Vietnam Department of Chemistry Dong Thap University Dong Thap Vietnam

Hierarchical phases of the biomaterials can be used as template to transfer their intricate organization into biomimic inorganic solids. Herein, hierarchical mesoporous silica films with aligned pores have been templated by nanofibrillar alginic acid. An aqueous suspension of the alginic acid nanofibers was prepared by treating the brown seaweeds with sodium carbonate solution and subsequent precipitation in dilute hydrochloric acid. The alginic acid nanofibers of the organize into a hierarchical aligned phase in an acetic acid-sodium acetate buffer that was used to template silica-alginic acid composite films by evaporation induced self-assembly of alkoxysilane with nanofibrillar alginic acid. Calcination of the alginic acid template afforded hierarchical mesoporous silica glasses. Carbonization of the silica-alginic acid composites and subsequent etching the silica recovered mesoporous carbon supercapacitors.

关键词： Nanofibrillar Alginic Acid Hierarchial Organization Mesoporosity Silica Films Carbon Supercapacitors