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Ecoregional variations of aboveground biomass and stand structure in evergreen broadleaved forests

Journal of Forestry Research 2020年第5期31卷 1713-1722页

作者： Tran Van Do Mamoru Yamamoto Osamu Kozan Vo Dai Hai Phung Dinh Trung Nguyen Toan Thang Lai Thanh Hai Vu Thanh Nam Trieu Thai Hung Hoang Van Thang Tran Duc Manh Cao Chi Khiem Vu Tien Lam Nguyen Quang Hung Tran Hoang Quy pham Quang Tuyen Trinh Ngoc Bon Nguyen Thi Thu Phuong Ninh Viet Khuong Nguyen Van Tuan Dang Thi Hai Ha Tran Hai long Dang Van Thuyet Dang Thinh Trieu Nguyen Van Thinh Tran Anh Hai Duong Quang Trung Nguyen Van Bich Dinh Hai Dang pham Tien Dung Nguyen Huy Hoang Le Thi Hanh Phan Minh Quang Nguyen Thi Thuy Huong Hoang Thanh Son Nguyen Thanh Son Nguyen Thi Van Anh Nguyen Thi Hoai Anh pham Dinh Sam Hoang Thi Nhung Hoang Van Thanh Nguyen Huu Thinh Tran Hong Van Ho Trung Luong Bui Kieu Hung Research Institute for Sustainable Humanosphere Kyoto UniversityUjiKyotoJapan Silviculture Research Institute Vietnamese Academy of Forest SciencesNorth Tu LiemHanoiVietnam Center for Southeast Asian Studies Kyoto UniversityKyotoJapan Vietnamese Academy of Forest Sciences North Tu LiemHanoiVietnam Vietnam Administration of Forestry No.2 Ngoc HaBa DinhHanoiVietnam

Biotic and abiotic factors control aboveground biomass(AGB)and the structure of forest *** study analyses the variation of AGB and stand structure of evergreen broadleaved forests among six ecoregions of Vietnam.A data set of 1731-ha plots from 52 locations in undisturbed old-growth forests was *** results indicate that basal area and AGB are closely correlated with annual precipitation,but not with annual temperature,evaporation or hours of *** area and AGB are positively correlated with trees>30 cm *** areas surveyed(52.6%)in these old-growth forests had AGB of 100–200 Mg ha^-1;5.2%had AGB of 400–500 Mg ha^-1,and 0.6%had AGB of>800 Mg ha^-*** percent of the areas surveyed had stand densities of 300–600 ***^-1,and 64%had basal areas of 20–40 m^2 ha^-*** is an important factor influencing the AGB of old-growth,evergreen broadleaved forests in *** causing the loss of large-diameter trees(e.g.,>100 cm DBH)affects AGB but may not seriously affect stand density.

关键词： Aboveground biomass Carbon storage Climatic variables Ecoregion Edaphic variables Oldgrowth forest

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The Optimal Stopping Time for Selling an Asset When It Is Uncertain Whether the Price Process Is Increasing or Decreasing When the Horizon Is Infinite

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American Journal of Operations Research 2018年第2期8卷 82-91页

作者： Nguyen Khac Minh Nguyen Thanh Trung pham Van Khanh Thang long Institute of Mathematics and Applied Science Hanoi Vietnam Faculty of Fundamental Science Military Academy of Logistics Hanoi Vietnam

Assume that we want to shell an asset with unknown drift but known that the drift is a two value random variable, and the initial distribution can be estimated. As time goes by, this distribution is updated and base on the probability of the drift takes the small one gives us the stopping rule. Research results show that the optimal strategy to sell the asset is if the initial probability that the drift receives a small value greater than a certain threshold then liquidates the asset immediately, otherwise the asset holder will wait until the probability of the drift receives a small value passing a certain threshold, it is the optimal time to liquidate the asset.

关键词： Optimal Stopping Time Incomplete Information Probability Process

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Fabrication of patterned graphitized carbon wires using low voltage near-field electrospinning, pyrolysis, electrodeposition, and chemical vapor deposition

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Microsystems & Nanoengineering 2020年第1期6卷 1341-1352页

作者： Derosh George Adrian Garcia Quang pham Mario Ramos Perez Jufeng Deng Michelle Trang Nguyen Tuo Zhou Sergio OMartinez-Chapa Yoonjin Won Chong Liu Roger CLo Regina Ragan Marc Madou Mechanical and Aerospace Engineering University of CaliforniaIrvineUSA Chemical Engineering and Materials Science University of CaliforniaIrvineUSA Materials and Manufacturing Technology University of CaliforniaIrvineUSA School of Engineering and Sciences Tecnologico de MonterreyMonterreyMexico Mechanical Engineering Dalian University of TechnologyDalianChina Chemical Engineering California State UniversityLong BeachUSA Present address:Mechanical Engineering Centro de Ensenanza Tecnica y Superior UniversidadMexicaliMexico

We herein report a high-resolution nanopatterning method using low voltage electromechanical spinning with a rotating collector to obtain aligned graphitized micro and nanowires for carbon nanomanufacturing.A small wire diameter and a small inter-wire spacing were obtained by controlling the electric field,the spinneret-to-collector distance,the pyrolysis parameters,the linear speed of the spinneret,the rotational speed of the *** a simple scaling analysis,we show how the straightness and the diameter of the wires can be controlled by the electric field and the distance of the spinneret to the collector.A small inter-wire spacing,as predicted by a simple model,was achieved by simultaneously controlling the linear speed of the spinneret and the rotational speed of the *** drying of the polymer nanowires enabled the facile fabrication of suspended wires over various *** polyacrylonitrile wires were carbonized using standard stabilization and pyrolysis to obtain carbon *** carbon nanowires with a diameter of<50 nm were *** also established a method for making patterned,highly graphitized structures by using the aforementioned carbon wire structures as a template for chemical vapor deposition of *** patterning technique offers high throughput for nano writing,which outperforms other existing nanopatterning techniques,making it a potential candidate for large-scale carbon nanomanufacturing.

关键词： nanowires carbon field

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Impacts of Exchange Rate Volatility and FDI on Technical Efficiency—A Case Study of Vietnamese Agricultural Sector

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American Journal of Operations Research 2015年第4期5卷 317-325页

作者： Nguyen Khac Minh pham Van Khanh Nguyen Viet Hung Economics and Management Faculty Thang Long University Hanoi Vietnam Institute of Economics and Corporate Group Hanoi Vietnam Faculty of Economics National Economics University Hanoi Vietnam

The objective of this research is to examine impacts of exchange rate volatility and FDI on efficiency of the Vietnamese agricultural sector at the provincial level for the period 1998-2011. Due to the characteristic of high uncertainty in agricultural production, the chance-constrained programming model would be used to estimate efficiency of the agricultural production sector. In order to study impacts of exchange rate volatility and FDI, we employ the two-stage model. In the first stage, we use the chance-constrained programming model to measure technical efficiency and ARIMA model to quantify exchange rate volatility. In the second stage, we use the fixed effect model to evaluate impacts of exchange rate volatility and FDI on efficiency of agricultural production in poor and rich provinces. The estimated results show that fluctuation in exchange rate volatility would reduce efficiency in agricultural production but FDI has an insignificant impact on the efficient production in Vietnam agricultural sector.

关键词： Chance-Constrained Programming DEA Exchange Rate Volatility FDI Technical Efficiency

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Super Efficiency and Misallocation: Evidence from Vietnamese Electric-Computer Industry

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American Journal of Operations Research 2018年第2期8卷 63-81页

作者： Nguyen Khac Minh pham Van Khanh Nguyen Thi Phuong Thang long Institute of Mathematics and Applied Science Hanoi Vietnam Faculty of Economics and Management Thang Long University Hanoi Vietnam

Misallocation means that the source is not distributed efficiently. This leads to an important question of how the relationship between misallocation and efficiency is (see [1]). The purpose of this study is to address the empirical relationship between misallocation and efficiency in the electric and computer industry in Vietnam during the 2005-2015 periods. To do this, we built a model that allowed us to evaluate the impact of misallocation and other factors on efficiency. The slack-based measured efficiency (SBM) model (Tone [2]), and the super-efficient model (Tone [3]) are used to estimate the firms’ efficiency. The approach of Hsieh and Klenow [4] is used to measure misallocation in the study area. Estimated results of the model about the relationship between misallocation and efficiency show that the variable representing the misallocation has a negative sign and statistical significance in all models. In other words, the misallocation negatively affects efficiency. The bigger the misallocation, the lower the efficiency.

关键词： Misallocation Super-Efficient Slack-Based Measured Efficiency

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Spectrally　Adjustable　Picosecond　Dye　Laser　Pulses　Generated　with　Nanosecond　Nitrogen　Lasers

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Chinese Journal of Lasers 1995年第5期 385-392页

作者： Nguyen Dai Hung pham long Dinh Van Trung Nguyen Van Tien Le Hoang Hai and Nguyen Ha (Institute of Material sciences.Vietnam National Centre for Sciences and Technology.Nghia Do,TuLiem,Hanoi,Vietnam)

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ＳｐｅｃｔｒａｌｌｙＡｄｊｕｓｔａｂｌｅＰｉｃｏｓｅｃｏｎｄＤｙｅＬａｓｅｒＰｕｌｓｅｓＧｅｎｅｒａｔｅｄｗｉｔｈＮａｎｏｓｅｃｏｎｄＮｉｔｒｏｇｅｎＬａｓｅｒｓＮｇｕｙｅｎＤａｉＨｕｎｇ；ＰｈａｍＬｏｎｇ；ＤｉｎｈＶａｎＴｒｕｎｇ；ＮｇｕｙｅｎＶａ...

关键词： dye laser spectrotemporal selection laser smooth pulse UV laser

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Comparison of Sensory Characteristics of Green Tea Produced in Thai Nguyen and Phu Tho Province, Vietnam

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Journal of Food Science and Engineering 2014年第2期4卷 107-114页

作者： Dang Thi Minh Luyen Ha duyen Tu Philippe Lebailly Nguyen duy Thinh Tu Viet Phu Department of Quality Management School of Biotechnology and Food Technology Hanoi University of Science and TechnologyHanoi 10000 Vietnam Department of Agricultural Sciences University of Liege Gembloux 5030 Belgium

Green tea is a popular product with a high consumption in Vietnam. Moreover, green tea produced in Tan Cuong commune, Thai Nguyen province, has long been recognized for its superior quality to those coming from other regions of the country. This study aims at comparing the tea from Thai Nguyen and Phu Tho and finding out if the difference can be identified through sensory analysis. Two products picked from Tan Cuong, Thai Nguyen province, and two others from Phu Ho district, Phu Tho province were evaluated by a trained panel of 12 judges （11 women and 1 man）. The sensory evaluation of the dry tea （11 descriptors） was carried out separately from the brewed tea （21 descriptors） and brewed leaf （five descriptors） using an unstructured intensity scale （10 cm）. Statistic analyses have shown differences between regions in all three groups of attributes： dry leaf, liquor and brewed leaf.

关键词： Green tea sensory analysis.

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Prediction of human microRNA hairpins using only positive sample learning

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Journal of Biomedical Science and Engineering 2008年第2期1卷 141-146页

作者： Dang Hung Tran Tho Hoan pham Kenji Satou Tu Bao Ho Hanoi National University of Education Japan Advanced Institute of Science and Technology

MicroRNAs(miRNA) are small molecular non-coding RNAs that have important roles in the post-transcriptional mechanism of animal and plant. They are commonly 21-25 nucleotides (nt) long and derived from 60-90 nt RNA hairpin structures, called miRNA hairpins. A larger num-ber of sequence segments in the human genome have been computationally identified with such 60-90 nt hairpins, however a majority of them are not miRNA hairpins. Most computational meth-ods so far for predicting miRNA hairpins were based on a two-class classifier to distinguish between miRNA hairpins and other sequence segments with hairpin structures. The difficulty of these methods is how to select hairpins as negative examples of miRNA hairpins in the classifier-training datasets, since only a few miRNA hairpins are available. Therefore, their classifier may be mis-trained due to some false negative examples of the training dataset. In this paper, we introduce a one-class support vector machine (SVM) method to predict miRNA hair-pins among the hairpin structures. Different from existing methods for predicting miRNA hairpins, the one-class SVM model is trained only on the information of the miRNA class. We also illus-trate some examples of predicting miRNA hair-pins in human chromosomes 10, 15, and 21, where our method overcomes the above disad-vantages of existing two-class methods.

关键词： MicroRNA Hairpin One-class SVM

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Exploring the Staging Patterns of MNC Entry to New Markets:The Resource Leverage Approach

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Journal of Business Administration Research 2021年第3期4卷 1-16页

作者： Tung-Shan Liao ThịNgọc duy Trần Thi Thuy Dung pham College of Management Yuan Ze UniversityTaoyuan CityTaiwanChina Foreign Trade University Ho Chi Minh CityVietnam

This study aims at providing explanations for how MNCs(multinational companies)proceed with their manipulation of resources and competencies in the entry process to a foreign *** an increasing extent,such processes perform as a staging process of resource *** study identifies three stages,using the multiple case study incorporating grounded theory:the initial stage,the adaptive intensification stage,and the advantage persistence *** the initial stage,an MNC’s entry decision tends to be based on the resource replication mode of resource leverage;the resource exploitation mode of resource leverage is used mainly in the adaptive intensification stage,and the resource exploration mode is used in the advantage persistence *** study suggests that these resource leverage modes incorporating their microfoundations can be viewed as a set of potential measurements for examining MNCs'dynamic capabilities in the entry process to a new host market.

关键词： MNC entry Staging processes Dynamic capabilities view Resource leverage Grounded theory

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Surface PEGylation of hollow mesoporous silica nanoparticles via aminated intermediate

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Progress in Natural Science:Materials International 2019年第6期29卷 612-616页

作者： Thi Ngoc Tram Nguyen Diem-Huong Nguyen-Tran long Giang Bach Tran Hoang Du Truong Ngoc Thuy Trang Le Dai Hai Nguyen Tra Vinh University Institute of Applied Materials Science Vietnam Academy of Science and Technology Graduate University of Science and Technology Vietnam Academy of Science and Technology Nguyen Tat Thanh University 5. Institute of Research and Development Duy Tan University

A hybrid of organic/inorganic system, hollow mesoporous silica nanoparticles functionalized with poly(ethylene glycol), was synthesized in the presence of coupling agent and aminated ends. Doxorubicin(DOX) was used as a model drug to evaluate the effect of PEGylation on the loading capacity and release pattern of the *** with transmission electron microscopy(TEM) and scanning electron microscopy(SEM), X-ray diffraction(XRD), nitrogen adsorption-desorption, thermogravimetric analysis(TGA) and Fourier transformed infrared(FTIR) confirmed the PEG conjugation, as well as the amorphous mesoporous nature of the synthesized particles. Due to the capping effect of PEG molecules over the pores in the silica structure, the synthesized system was able to retain higher amount of cargo and establish a controlled manner when releasing.

关键词： Hollow mesoporous silica nanoparticles mPEG PEGylation Surface modification

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