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Hybrid model to optimize object-based land cover classification by meta-heuristic algorithm:an example for supporting urban management in Ha Noi,Viet Nam

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International Journal of Digital Earth 2019年第10期12卷 1118-1132页

作者： Quang-Thanh Bui Manh Pham Van Nguyen Thi Thuy Hang Quoc-Huy Nguyen Nguyen Xuan Linh Pham Minh Hai tran anh tuan Pham Van Cu Center for Applied Research in Remote sensing and GIS(CARGIS) VNU University of ScienceHa NoiViet Nam VNU University of Science Ha NoiViet Nam Vietnam Institute of Geodesy and Cartography Ha NoiViet Nam Ministry of Education and Training Ha NoiViet Nam

This study proposed a novel object-based hybrid classification model named GMNN that combines Grasshopper Optimization Algorithm(GOA)and the multiple-class Neural network(MNN)for urban pattern detection in Hanoi,*** bands of SPOT 7 image and derivable NDVI,NDWI were used to generate image segments with associated attributes by PCI Geomatics *** segments were classified into four urban surface types(namely water,impervious surface,vegetation and bare soil)by the proposed ***,three training and validation datasets of different sizes were used to verify the robustness of this *** all tests,the overall accuracies of the classification were approximately 87%,and the Area under Receiver Operating Characteristic curves for each land cover type was ***,the performance of this model was examined by comparing several statistical indicators with common benchmark *** results showed that GMNN out-performed established methods in all comparable *** results suggested that our hybrid model was successfully deployed in the study area and could be used as an alternative classification method for urban land cover *** a broader sense,classification methods will be enriched with the active and fast-growing contribution of metaheuristic algorithms.

关键词： Urban remote sensing object-based classification neural network grasshopper optimization algorithm

Development of 24 and 59 keV Filtered Neutron Beams for Neutron Capture Experiments at Dalat Research Reactor

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World Journal of Nuclear Science and Technology 2014年第2期4卷 59-64页

作者： Pham Ngoc Son Vuong Huu Tan Phu Chi Hoa tran tuan anh Nuclear Research Institute Dalat Vietnam The University of Dalat Dalat Vietnam Vietnam Agency for Radiation and Nuclear Safety Hanoi Vietnam

External filtered neutron beams have been developed at the horizontal radial channels No. 4 of Dalat research reactor. In the material composition of the neutron filters, the primary material components of Iron, Aluminum, Nickel and Vanadium are used to obtain the mono-energetic neutron beams of 24 and 59 keV, with low level of Gamma and slow neutron background. A computer code and Monte-Carlo simulation technique were applied to optimize the filter configurations and to deduce the neutron energy distributions in the filtered beams. A hydrogen-filled proton recoil detector and the activation method with Gold foils were used to measure the neutron energy spectrum and flux of each beam at sample position. The results of experimental neutron fluxes are 6.1 × 105 and 5.3 × 105 n/cm2/s for 24 and 59 keV beams, respectively.

关键词： Research Reactor Filtered Neutron 24 keV 59 keV

Effect of Temperature Dependence on Electrical Characterization of <i>p-n</i>GaN Diode Fabricated by RF Magnetron Sputtering

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Materials Sciences and Applications 2015年第9期6卷 809-817页

作者： Thi tran anh tuan Dong-Hau Kuo Cheng-Che Li Guan-Zhang Li Department of Materials Science and Engineering National Taiwan University of Science and Technology Taiwan School of Basic Sciences Tra Vinh University Tra Vinh Vietnam

The p-n junction GaN diodes were all fabricated by sputtering technique with cermet targets for p- and n-type GaN and metal targets for electrodes. The interface of these p-n junction GaN diodes examined by high-resolution transition electron microscopy was clear and distinguishable. Lattice images identified the complete dissolution of Mg into the Ga site. At the room temperature, the diode had the turn-on voltage of 2.2 V, the leakage current of 2.2 × 10–7 A, the breakdown voltage of –6 V, the barrier height of 0.56 eV, ideality factor of 5.0 by I (current)-V (voltage) test and 5.2 derived from the Cheungs’ method, and series resistance of 560 Ω. These electrical properties were investigated at different testing temperatures from room temperature to 200°C. The temperature dependence in the I-V characteristics of the p-n diodes can be successfully explained on the basis of thermionic-emission mode.

关键词： p-n GaN Diode I-V Measurement Barrier Height Leakage Current Cheungs’ Method

Characteristics of Filtered Neutron Beam Energy Spectra at Dalat Reactor

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World Journal of Nuclear Science and Technology 2014年第2期4卷 96-102页

作者： tran tuan anh Pham Ngoc Son Vuong Huu Tan Pham Dinh Khang Phu Chi Hoa Nuclear Research Institute Dalat Vietnam The University of Dalat Dalat Vietnam Vietnam Agency for Radiation and Nuclear Safety Hanoi Vietnam

Filtered neutron technique was applied for producing quasi-monoenergetic neutron beams of 24 keV, 54 keV, 133 keV and 148 keV at the horizontal neutron channel No. 4 of the Dalat Nuclear Research Reactor. The study on physical characteristics of these beam lines has been carried out for efficient applications in neutron capture experiments. The filtered neutron spectrum of each beam has been simulated by Monte-Carlo method and experimentally measured by a gas-filled protonrecoil spectrometer. The neutron fluxes of these filtered beams were measured by the activation technique with standard foils of 197Au, using a high efficient HPGe digital gamma-ray spectrometer.

关键词： Neutron Filter Proton-Recoil

Material and Device Developments of p/n Ⅲ-Nitrde Thin Films made by Low-Temperature Sputtering

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Material and Device Developments of p/n Ⅲ-Nitrde Thin Films...

An Efficient Differential Evolution for Truss Sizing Optimization Using AdaBoost Classifier

第二届海峡两岸功能材料科技与产业峰会（2015）

作者： Dong-Hau Kuo Thi tran anh tuan Cheng-Che Li Wei-Chun Yen Department of Materials Science and Engineering "National Taiwan University of Science and Technology"

GaN and In GaN layers have been deposited by metal-organic vapor deposition(MOCVD)and molecular beam *** MOCVD,In GaN films grown at 550-900 oC use trimethylindium(TMIn),trimethylgallium(TMGa),and NH as reaction precursors and N as carrier *** high capital cost and process temperature and the utilization of dangerous precursors are the major concerns of MOCVD process.p-Ga N films grown at 1000

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Computer Modeling in Engineering & Sciences 2023年第1期134卷 429-458页

作者： tran-Hieu Nguyen anh-tuan Vu Hanoi University of Civil Engineering Hanoi100000Vietnam

Design constraints verification is the most computationally expensive task in evolutionary structural optimization due to a large number of structural analyses thatmust be *** a surrogatemodel to approximate the behavior of structures instead of the exact structural analyses is a possible solution to tackle this ***,most existing surrogate models have been designed based on regression *** paper proposes a novel method,called CaDE,which adopts a machine learning classification technique for enhancing the performance of the Differential Evolution(DE)*** proposed method is separated into two *** the first optimization stage,the original DE is implemented as usual,but all individuals produced in this phase are stored as inputs of the training *** on design constraints verification,these individuals are labeled as“safe”or“unsafe”and their labels are saved as outputs of the training *** collecting enough data,an AdaBoost model is trained to evaluate the safety state of *** model is then used in the second stage to preliminarily assess new individuals,and unpromising ones are rejected without checking design *** method reduces unnecessary structural analyses,thereby shortens the optimization *** benchmark truss sizing optimization problems are solved using the proposed method to demonstrate its *** obtained results show that the CaDE finds good optimal designs with less structural analyses in comparison with the original DE and four other DE *** reduction rate of five examples ranges from 18 to over 50%.Moreover,the proposed method is applied to a real-size transmission tower design problem to exhibit its applicability in practice.

关键词： Structural optimization machine learning surrogate model differential evolution AdaBoost classifier

Likelihood of Innovative Construction Techniques to Build Disaster Resilience for Vernacular Housing in the Highland of Central Vietnam

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Journal of Civil Engineering and Architecture 2012年第10期6卷 1392-1398页

作者： tran tuan anh School of Architecture and Design RMIT University Melbourne 3001 Australia Faculty of Architecture College of Sciences Hue University Hue 8454 Vietnam

Disaster mitigation for marginal communities has become one of the most significant development goals of the 21st century. Vietnam has been reported one of the five most vulnerable nations in the world to climate change and so serves as a useful case study in developing appropriate housing solutions after disasters. In addition, some local communities in remote mountainous areas of Vietnam still keep strong vernacular traditions in their housing, especially the typical timber house-on-stilt, which need intense consideration before employing any new techniques of disaster mitigation on them. Perceptions on how to develop a sustainable housing solution for such communities, therefore, is still controversial with very few useful options developed to date. The paper investigates the existing unsafe conditions of traditional houses of a local community in the central highland of Vietnam, exposed to natural disasters, together with an identification of several traditional features of this housing that would be needed to preserve in future construction. Some important gaps of these traditional houses in terms of disaster risk reduction are then displayed to show opportunities where new construction techniques have a high possibility to perform against extreme climate events.

关键词：传统民居建筑技术越南灾难高地韧性创新极端气候事件

Object Detection in Remote Sensing Images Using Picture Fuzzy Clustering and MapReduce

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Computer Systems Science & Engineering 2022年第12期43卷 1241-1253页

作者： tran Manh tuan tran Thi Ngan Nguyen Tu Trung Faculty of Computer Science and Engineering Thuyloi University175 Tay SonDong DaHanoi010000Vietnam

In image processing, one of the most important steps is image segmentation. The objects in remote sensing images often have to be detected in order toperform next steps in image processing. Remote sensing images usually havelarge size and various spatial resolutions. Thus, detecting objects in remote sensing images is very complicated. In this paper, we develop a model to detectobjects in remote sensing images based on the combination of picture fuzzy clustering and MapReduce method (denoted as MPFC). Firstly, picture fuzzy clustering is applied to segment the input images. Then, MapReduce is used to reducethe runtime with the guarantee of quality. To convert data for MapReduce processing, two new procedures are introduced, including Map_PFC and Reduce_*** formal representation and details of two these procedures are presented in thispaper. The experiments on satellite image and remote sensing image datasets aregiven to evaluate proposed model. Validity indices and time consuming are usedto compare proposed model to picture fuzzy clustering model. The values ofvalidity indices show that picture fuzzy clustering integrated to MapReduce getsbetter quality of segmentation than using picture fuzzy clustering only. Moreover,on two selected image datasets, the run time of MPFC model is much less thanthat of picture fuzzy clustering.

关键词： Remote sensing images picture fuzzy clustering image segmentation object detection MapReduce

Spherical Fuzzy WASPAS-based Entropy Objective Weighting for International Payment Method Selection

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Computers, Materials & Continua 2022年第7期72卷 2055-2075页

作者： Phi-Hung Nguyen Thanh-tuan Dang Kim-anh Nguyen Hong-anh Pham Faculty of Business FPT UniversityHanoi100000Vietnam Department of Business Management National Taipei University of TechnologyTaipei1068Taiwan Department of Industrial Engineering and Management National Kaohsiung University of Science and TechnologyKaohsiung80778Taiwan

In international trade,exporters prefer to receive payments as quickly as possible,and importers want to make payments as late as *** this respect,the payment field,an essential condition for trade transactions,also represents the positions of exporters and importers *** addition,there are many cases in which various variables must be considered rather than only one specific variable representatively affecting payment,particularly in the case of import-export Small and Medium-Sized Enterprises(SMEs)from emerging countries.A selection of proper payment methods can be categorized as a Multi-Criteria Decision-Making(MCDM)***,this study aims to propose a novel and efficient Spherical Fuzzy Weighted Aggregated Sum Product Assessment based Entropy Objective Weighting method(SF-EW and WASPAS-SF)to evaluate international payment methods with uncertain ***,SF-EW model is applied to determine the relative weights of critical ***,international payment method alternatives are prioritized by the WASPAS-SF *** essential factors for four international payment methods are proposed based on experts’opinions and the existing literature.A real-world case study from Vietnamese import-export SMEs is presented to validate the applicability of the proposed *** results indicated that“Characteristics of payment method(PA)”had the most significant impact on international payment method *** comparison,“Letters of Credit(L/C)”was the most reliable payment method with the highest ranking available to international ***,a sensitivity analysis was performed to examine the validity and robustness of the proposed decision support ***,this study could contribute to international payment services and in the context of globalization and international trade.

关键词： International payment Vietnam MCDM spherical fuzzy theory entropy WASPAS