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直流阻容式电压互感器用于直流输电谐波电压测量的研究

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电工电能新技术 2015年第3期34卷 54-60页

作者： nguyen phuc Huy 韩民晓华北电力大学电气与电子工程学院北京102206

谐波问题的分析与控制是保证高压直流输电系统正常运行的重要内容。为了寻找最适当的测量方法,需要对电压谐波测量进行深入研究。直流电压互感器(DCVt)是测量直流输电系统电压的重要设备。本文介绍与分析了阻容式直流电压互感器的主要... 详细信息

谐波问题的分析与控制是保证高压直流输电系统正常运行的重要内容。为了寻找最适当的测量方法,需要对电压谐波测量进行深入研究。直流电压互感器(DCVt)是测量直流输电系统电压的重要设备。本文介绍与分析了阻容式直流电压互感器的主要组件的特性,如同轴电缆、A/D与D/A转换器、光耦合器,详细分析了分压器的对地杂散电容对电压互感器频率响应的影响,非理想状态下元器件对测量误差的影响。理论分析指出选择一个合适的并联电阻的电容可以减小分压器对地杂散电容的影响,并且可选择精密电阻和电容来减少测量误差。实验结果表明,阻容式直流电压互感器适合直流谐波电压测量,而且测量误差小于0.2%,可达到10k Hz的频率带宽。

关键词：高压直流输电谐波谐波电压测量直流电压测量直流阻容式电压互感器阻容分压器频率响应

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加密图像中的数据隐藏

加密图像中的数据隐藏

作者： nguyen tHANH phuc（阮成福）华南理工大学

学位级别：硕士

近年来,随着互联网、移动设备、云计算和社交网络等技术的巨大进步,大量的数据在网络上存储和传输。数据的拥有者们只需要很少的代价,就可以将他们的数据委托存储在云端,并享受着方便的数据管理服务。而在这大量的委托存储数据中,具有... 详细信息

近年来,随着互联网、移动设备、云计算和社交网络等技术的巨大进步,大量的数据在网络上存储和传输。数据的拥有者们只需要很少的代价,就可以将他们的数据委托存储在云端,并享受着方便的数据管理服务。而在这大量的委托存储数据中,具有隐私信息的图片占据了很大一部分。正因如此,这类具有个人隐私信息或者商业信息的图片的安全性要求迫在眉睫。在这类问题中,加密技术是一种最常见的解决方法,但是加密后的图片非常不便于分享和管理。为了满足管理上的需求,诸如拥有者、存储位置和时间戳等,辅助信息常常伴随着加密后的图片一起存储,而这些辅助信息往往对原始内容并没有什么影响。基于以上的观察,本论文将研究在加密图像中嵌入秘密信息的方法。在加密图像中嵌入秘密信息需要满足以下的要求:安全性、可逆性、可分离性和容量等。大多数已存在的方法并不能很好的满足以上提到的几个特性。为了解决这个问题,本文提出了一种新颖的加密域图像隐写方法。基于加密前预留空间框架,一幅原始图像先被分成两个部分,然后各自进行XOR和AES加密,从而提供安全性保证。在加密和预留空间的处理过程中使用差分扩展和奇偶转换来满足加密域可逆隐写的几个要求。同时,在加密图像中将会使用一种新颖的嵌入方法来嵌入辅助信息,该方法基于通过使用秘密像素点最低位隐藏信息的LSB技术。我们可以从嵌有秘密信息的加密图像中准确提取出秘密信息或者无失真地还原图像,信息提取和图像加密两个过程是可分离的。换句话说,只要拥有解密密钥和提取密钥,接收者可以先提取后解密或者先解密后提取。新方法的一个特别的特性就是只要拥有解密密钥,就可以直接将加密隐写后的图像还原,不需要提取出秘密信息(跟以前的其他算法不一样的)。我们还通过实验证明了本文提出的加密域可逆隐写方法拥有很大的嵌入容量。在Windows系统上,我们用C#语言实现了提出的方法,并在两个常见的图像数据库上进行了大量的实验。实验结果表明了所提出方法的有效性。同时,嵌入容量可以达到0.3 bpp或者更高,高于其他相关工作。另外,对应的PSNR值在可接受范围内(对于Lena图像,当嵌入率为0.2 bpp时,第一种方法的PSNR值为33.09 dB,第二种方法的PSNR值为58.12 dB)。最后,通过理论分析验证了所提出的方法的安全性、可逆性和可分离性。

关键词：数据隐藏加密图像可逆可分离高容量

the trade-Off Between Performance and Security of Virtualized trusted Execution Environment on Android

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Computer Systems Science & Engineering 2023年第9期46卷 3059-3073页

作者： thien-phuc Doan Ngoc-tu Chau Jungsoo Park Souhwan Jung Soongsil University Seoul06978Korea

Nowadays,with the significant growth of the mobile market,security issues on the Android Operation System have also become an urgent *** execution environment(tEE)technologies are considered an option for satisfying the inviolable property by taking advantage of hardware ***,for Android,tEE technologies still contain restrictions and *** first issue is that non-original equipment manufacturer developers have limited access to the functionality of hardware-based *** issue of hardware-based tEE is the cross-platform *** every mobile device supports different tEE vendors,it becomes an obstacle for developers to migrate their trusted applications to other Android devices.A software-based tEE solution is a potential approach that allows developers to customize,package and deliver the product *** by that idea,this paper introduces a VtEE model,a software-based tEE solution,on Android *** research contributes to the analysis of the feasibility of using a virtualized tEE on Android devices by considering two metrics:computing performance and *** experiment shows that the VtEE model can host other software-based tEE services and deliver various cryptography tEE functions on theAndroid *** security evaluation shows that adding the VtEE model to the existing Android does not addmore security issues to the traditional ***,this paper shows applicable solutions to adjust the balance between computing performance and security.

关键词： Mobile security trusted execution model virtualized trusted execution environment hypervisor

Inferences on the Difference of two Proportions: A Bayesian Approach

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Open Journal of Statistics 2017年第1期7卷 1-15页

作者： thu Pham-Gia nguyen Van thin Phan phuc Doan Department of Mathematics and Statistics Université de Moncton New Brunswick Canada Faculty of Mathematics and Computer Science Hochiminh University of Science Ho Chi Minh Vietnam

Let π=π1-π2 be the difference of two independent proportions related to two populations. We study the test H0:π≥0 against different alternatives, in the Bayesian context. the various Bayesian approaches use standard beta distributions, and are simple to derive and compute. But the more general test H0:π≥η, with η>0, requires more advanced mathematical tools to carry out the computations. these tools, which include the density of the difference of two general beta variables, are presented in the article, with numerical examples for illustrations to facilitate comprehension of results.

关键词： Proportion Convolution Normal Beta Bayesian Critical Value Appell’s Function

Estimation of Waste Generation and Recycling Potential from traditional Market: A Case Study in Hue City, Vietnam

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Journal of Environmental Protection 2015年第4期6卷 308-320页

作者： Yasuhiro Matsui Do thi thu trang nguyen phuc thanh Graduate School of Environmental and Life Science Okayama University Okayama Japan Hitachi Zosen Corp Osaka Japan

this study was conducted to provide a detailed description of waste generation and characteristics from a traditional market in Hue city, located in central Vietnam. the authors conducted a waste generation survey and a waste composition survey for 309 stalls/vendors in five markets by 17 business categories for 10 consecutive days. the waste generation rates by stall/vendor and by floor area were assessed in three waste categories: general waste, recyclable, and food residues. the general waste that would be sent to a landfill site was classified into 10 physical categories and 77 sub-categories. For general waste, food waste accounted for the largest part, followed by plastic and grass. By multiplying the waste generation rate by stall/vendor by the total number of stall/vendors in 23 markets, the authors estimated the total amounts of general waste, recyclable, food residue and total waste by business category. the total waste generated from market was 17.0 tons/day, of which 4.6 tons (27.1%) were collected by pig farmers for feeding livestock and 0.6 tons (3.6%) were sold to the recycling market. the composting potential accounted for 55.2% of total waste generation from the traditional market in Hue. the recycling potential accounted for 5.1%. the total disposal amount sent to the landfill site would be reduced from 69.2% to 8.8% of the total. the 95% confidence interval (CI) of total waste amount from 23 markets was also estimated using Monte Carlo simulation based on the mean and standard error of the waste generation rate. the range of 95% CI was 14.9 - 18.9 tons/day.

关键词： traditional Market Recycling Potential Composting Potential

Heuristic Scheduling of Job Orders in a Build-to-Order Manufacturing System

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Computer Systems Science & Engineering 2022年第3期40卷 1059-1072页

作者： Chia-Nan Wang Chien-Chang Chou Yu-Chi Chung nguyen Ky phuc Phan Vanthanh nguyen Viet tinh nguyen Department of Industrial Engineering and Management National Kaohsiung University of Science and TechnologyKaohsiung80778Taiwan Department of Shipping technology National Kaohsiung University of Science and TechnologyKaohsiung80778Taiwan Faculty of Industrial Engineering and Management International UniversityHo Chi Minh City70000Vietnam Faculty of Commerce Van Lang UniversityHo Chi Minh City70000Vietnam

With the continuous development of technology,traditional manual work has been becoming more and more *** large or medium-sized companies have applied Enterprise Resource Planning(ERP)software into their business and production ***,since many small firms cannot afford ERP because of its expensive cost,they often still employ manual work for the same tasks this software resolves,especially for *** paper aims to provide a possible solution for small businesses to try automated scheduling and discover whether it can help *** are two main ways to make this determination:a mathematical model and a heuristic model,which are suitable for assessing low-and medium-sized workloads,*** case study was carried out in a small domestic interior furniture company,particularly in scheduling for their customized products in two-stage flow ***,they produce according to the sequence of customers’***,when we applied these supportive tools with batch-processing machines,they experienced enhanced production performance due to diminishing setup time for distinctive items and a more streamlined arrangement of job *** changes were implemented for some small companies that do not use many production stages and have a suitable number of jobs and *** this method were applied to larger demands,it would need further improvement and development to become a complete tool that can perform like a part of an ERP system.

关键词： scheduling mathematical heuristic flow shop batch-processing

Estimation of the Solid Waste Generation and Recycling Potential of the Hotel Sector: A Case Study in Hue City, Vietnam

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Journal of Environmental Protection 2018年第7期9卷 751-769页

作者： Le Hoang Son Yasuhiro Matsui Do thi thu trang nguyen phuc thanh Graduate School of Environmental and Life Science Okayama University Okayama Japan Danang University of Science and technology University of Da Nang Da Nang Vietnam New Royal Village B202 1497-1 Muramatsu Tokai Village Naka-gun Ibaraki 319-1112 Japan Hitachi Zosen Corporation Tokyo Japan

this study examined the solid waste generation and recycling potential of the hotel sector in Hue City, Vietnam. the authors conducted waste measurement, waste composition, and questionnaire surveys for 45 target hotels over ten consecutive days. the waste generation rates (WGRs) by rooms, beds, guests, and workers were assessed by hotel class using the following three waste categories, considering informal waste collection: general waste (GW), separated recyclables (SRe), and separated food residue (SFR). the 5-star hotels exhibited the highest WGR per room at 1.61 kg/room/day, while 1-star hotels exhibited the lowest per-room WGR (0.39 kg/room/day). Spearman Rank correlation test revealed that hotel class and per-room, per-bed, and per-guest WGRs were significantly positively correlated (p the major components of GW were food waste (40.9% to 57.4%), paper (10.1% to 20.3%), and plastic (10.7% to 15.5%). the recycling and composting potentials remaining in the GW were 19.3% to 38.5% and 38.0% to 57.9%, respectively. Based on the WGRs and waste composition determined in this study, the estimated total amount of waste generated was 6.88 tons/day (6.26 to 7.62 tons/day, 95% CI), of which 4.37 (64%), 2.13 (31%), and 0.38 tons/day (6%) were GW, SFR, and SRe, respectively. the recycling and composting potentials remaining in GW were 0.94 (13%) and 2.57 tons/day (37%), respectively. High-class hotels should be considered as the highest priority targets for a “reduce, reuse, recycle” (3R) promotion campaign in the future, with estimated recycling and composting potentials of 0.27 (4%) and 1.10 tons/day (16%), respectively.

关键词： Waste Generation Recycling Potential Hotel Sector Confidence Interval Estimation

Dynamics modeling and motion control for high-speed underwater vehicles using H-infinity synthesis with anti-windup compensator

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Journal of Ocean Engineering and Science 2022年第1期7卷 84-91页

作者： phuc Duc Hong Bui Sam-Sang You Hwan-Seong Kim Sang-Do Lee Department of Mechanical Engineering The University of TulsaTulsaOK 74104United States Division of Mechanical Engineering Korea Maritime and Ocean UniversityBusan 49112Republic of Korea Division of Logistics Engineering Korea Maritime and Ocean UniversityBusan 49112Republic of Korea Division of Navigation and Information System Mokpo National Maritime UniversityMokpoJeollanam-do 58628Republic of Korea

the control synthesis of a high-speed supercavitating vehicle(HSSV)faces many difficulties such as the stability,control,and maneuvering with dynamical uncertainties due to parameter perturbations,exter-nal disturbances,unmodeled dynamics,measurement noises,and actuator *** by the HSSV dynamical analysis,this paper proposes the H∞(i.e."H-infinity")robust control synthesis to gen-erate a robust low-order controller,which is intended for real implementations to ensure active control ***,the presented control scheme includes a feedback component and an anti-windup *** anti-windup synthesis is to provide system stability under actuator ***-tensive simulations show that the designed controller provides good performances with high robustness for vertical plane manoeuver while effectively eliminating planning forces,exogenous disturbances and noises as well as overcoming cavitator saturations.

关键词： Vehicle dynamics Planing force Vertical maneuver H-infinity control Anti-windup Actuator saturation

Large signal of h → μτ within the constraints of e_(i) → e_(j)γ decays in the 3-3-1 model with neutral leptons

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Chinese Physics C 2022年第12期46卷 106-125页

作者： H.t.Hung D.t.Binh H.V.Quyet Department of Physics Hanoi Pedagogical University 2Phuc YenVinh Phuc 15000Vietnam Institute of theoretical and Applied Research Duy Tan UniversityHanoi 10000Vietnam Faculty of Natural Science Duy Tan UniversityDa Nang 50000Vietnam

In the framework of the 3-3-1 model with neutral leptons,we investigate lepton-flavor-violating sources based on the Higgs mass spectrum,which has two neutral Higgs identified with the corresponding ones of the two-Higgs-doublet *** note that at the 13teV scale of the LHC,the parameter space regions satisfy the experimental limits of e_(i)→e_(j)γ*** regions depend heavily on the mixing of exotic leptons but are predicted to have large h_(1)^(0)→μτ*** also show that Br(h_(1)^(0)→μτ)can reach a value of 10^(-4).

关键词： Higgs boson electroweak interaction beyond the SM LFV decays