98 research outputs found
The emerging legal framework for private sector development in Viet Nam's transitional economy
No full textA major objective of Viet Nam's transition to a market economy has been to reactivate the private sector in a mixed economy. Several new laws have been introduced in the past five years to implement this policy and to create an enabling environment for the private sector. The author reviews some of the more important laws and regulations that affect Viet Nam's private sector activities, including laws on real property, intellectual property, companies, domestic investment, foreign investment, bankruptcy, contracts, and dispute resolution. Anti-monopoly law has not yet been introduced in Viet Nam. The issue of competition is addressed in the context of trade law, the relative roles of the state and private sector, and restrictions in company law. These areas all establish the foundation of a legal framework for a market economy. The author concludes that Viet Nam's legal framework, like China's, is still influenced by ideology, which causes problems in such areas as private ownership of real property and with such fundamental legal concepts as"due process of law."It is noted that the private sector is constrained by the lack of an independent judiciary, the absence of private land ownership, other uncertainties in property law that limit the develpoment of financial markets, and the inherent bias of the system in favor of the state sector (and collective ownership). Also noted is a law-abiding attitude, equally important to development has been slow to develop. The author goes on to point out that the foreign investment process is too complicated, and its company law too restrictive. A first priority should be to strreamline regulations, as well as liberalize trade policy and increase efforts in privatization of state enterprises. In this respect the author notes that export processing zones may be a useful interim instrument to attract foreign investment but should be phased out over time. More important in the long term is a good investment climate resting on a strong legal foundation.Legal Products,Environmental Economics&Policies,Banks&Banking Reform,Municipal Housing and Land,Municipal Financial Management,Environmental Economics&Policies,Banks&Banking Reform,Municipal Housing and Land,Legal Products,Municipal Financial Management
Development of HR information system and related business processes
No full textTato diplomová práce se zabývá personálním informačním systémem SAP SuccessFactors a jeho rozvojem ve vybraném podniku. Práce popisuje implementaci rozšíření systému SAP SuccessFactors o nástroj pro správu pozic, tzv. Position Management. Cílem práce je rozvoj personálního informačního systému ve vybraném podniku. Dílčími cíli jsou následně analýza stávajícího stavu ve vybraném podniku, popis implementace rozšíření a popis změn v personálních procesech. Pro dosažení těchto cílů bylo využito metodiky Design Science Research. V teoretické části diplomové práce je blíže specifikováno fungování řízení lidských zdrojů v souladu s informačními technologiemi. V praktické části je provedena analýza a popsána samotná implementace rozšíření Position Management.This diploma thesis discusses HR information system SAP SuccessFactors and its development in a selected company. The thesis describes the implementation of the extension of the SAP SuccessFactors system with a tool for position management. The primary goal of the work is the development of HR information system in a selected company. The partial goals are then the analysis of the current state in the selected company, a description of the implementation of the extension and a description of changes in HR processes. To achieve these goals, the methodology of Design Science Research was used. The theoretical part of the thesis describes the human resource management and its usage of information technology. The practical part analyzes and describes the implementation of the Position Management extension
Environmental Performance Evaluation at Urban Roundabouts
No full textTransformation toward greener, healthier and safer management of urban mobility demand is needed soon. Smart tools are available to assess the impact of new infrastructural projects and road facilities also from an environmental point of view. In this pilot study pollutant emissions at a sample of urban roundabouts were estimated employing the Vehicle Specific Power methodology which needs second-by-second speed profiles both gathered in the field and simulated in AIMSUN. The versatility of the micro-simulation model for a calibration aimed at improving accuracy of the emissions estimates was tested in order to ensure that second-by-second trajectories experienced in the field properly reflected the simulated speed-time profiles. The results confirmed the feasibility of the smart approach that integrates the use of fieldobserved and simulated data to estimate emissions at urban roundabouts. It is also revealed friendly in collecting information via smartphone and in the subsequent data analysis, and provided new opportunities for a large-scale data collection through a digital communit
6His-tagged Recombinant Human Cytoglobin Deactivates Hepatic Stellate Cells and Inhibits Liver Fibrosis by Scavenging Reactive Oxygen Species
No full textMultiscale modeling of adsorption-transport-mechanical coupling in coal gas reservoirs : enhanced recovery by CO₂ injection
No full textLe gaz de charbon est une ressource énergétique dont l'exploitation peut être accélérée par injection de gaz carbonique (CO₂) combinant ainsi production de méthane (CH₄) et stockage du gaz carbonique produit par sa combustion. La structure du réservoir est considérée comme un milieu à double porosité avec des fractures naturelles (cleats) et une matrice contenant une phase solide et des nanopores (de taille inférieure à 2 nm) où le gaz est stocké par adsorption sur la paroi solide. Le CO₂ est plus facilement adsorbé que le CH₄. Un modèle théorique multiéchelle combinant adsorption, transport et poromécanique du réservoir est développé. À la plus petite échelle, les molécules de gaz sont considérées comme des sphères dures interagissant par un potentiel de Lennard-Jones. Une nouvelle méthode numérique utilise la théorie de la fonctionnelle de densité (DFT) et la théorie fondamentale de la mesure (FMT) pour calculer la distribution des densités moléculaires d'un mélange de gaz pour une géométrie quelconque des nanopores. La paroi solide exerce un potentiel extérieur répulsif à très courte distance et attractif à plus grande distance sur les molécules de gaz. À partir des distributions moléculaires des gaz, la force de solvatation exercée par la phase fluide sur la surface des nanopores est calculée précisément. La méthode de l'homogénéisation asymptotique permet de passer de l'échelle du nanopore à l'échelle microscopique et d'obtenir la réponse de la matrice de charbon. Le modèle poroélastique de Biot est modifié par la force de solvatation qui agit comme le principal facteur gouvernant le gonflement ou la contraction de la matrice. Les équations moyennes de conservation de la masse des deux gaz (CH₄ et CO₂) dans la matrice prennent en compte les phénomènes d'adsorption caractérisés par des coefficients de partition et une diffusion effective de type Knudsen. Une seconde homogénéisation vise à obtenir la loi macroscopique à l'échelle du réservoir en combinant le réseau de cleats et la matrice solide. Le contact à l'interface matrice-cleats est caractérisé par la loi hyperbolique de Barton-Bandis qui modifie la rigidité effective ainsi que la perméabilité du réservoir. Après homogénéisation, le réservoir est un milieu hétérogène et anisotrope du fait de la structure des cleats et de la variation spatiale de la pression du fluide. Une équation moyenne macroscopique pour la diffusion des gaz dans la matrice et le transport gaz-eau dans les cleats est développée en considérant l'échange de masse entre la matrice et les cleats gouverné par l'approximation de Warren et Root. Des simulations numériques démontrent la corrélation cruciale entre les distributions de pression de gaz, l'ouverture des cleats et la rigidité du réservoir. L'injection de CO₂ améliore significativement la production de CH₄. Elle permet le stockage souterrain de CO₂ contribuant à réduire les émissions de gaz à effet de serre.Coal seam gas is an energy resource whose exploitation can be enhanced by injectingcarbon dioxide (CO₂), thus combining the production of methane (CH₄) and the storage of carbon dioxide produced by its combustion. The structure of the reservoir is considered to be a double-porosity medium with natural fractures (cleats) and a matrix containing a solid phase and nanopores (less than 2 nm in size) where the gas is stored by adsorption on the solid wall. CO₂ is more easily adsorbed than CH₄. A multiscale theoretical model combining adsorption, transport and reservoir poro-mechanics is developed. At the smallest scale, the gas molecules are considered as hard spheres interacting through a Lennard-Jones potential. A new numerical method uses Density Functional Theory (DFT) and Fundamental Measure Theory (FMT) to calculate the distribution of molecular densities of a mixture of gases for any nanopore geometry. The solid wall exerts an external potential that is repulsive at very short distances and attractive at longer distances on the gas molecules. From the molecular distributions of the gases, the solvation force exerted by the fluid phase on the surface of the nanopores is precisely calculated. The asymptotic homogenization method is performed to upscale the nanopore-scale model and to obtain the response of the coal matrix at the microscale. The Biot poroelastic model is modified by the solvation force, which acts as the main factor governing matrix swelling or contraction. The average mass conservation equations for the two gases (CH₄ and CO₂) in the matrix take into account adsorption phenomena characterized by partition coefficients and an effective Knudsen-type diffusion. A second homogenization aims at obtaining the macroscopic law at the reservoir scaleby combining the cleats network and the solid matrix. The joint stiffness at the matrix-cleats interface is characterized by the hyperbolic Barton-Bandis law, which modifies the effective stiffness and the permeability of the reservoir. After homogenization, the reservoir is a heterogeneous and anisotropic medium due to the structure of the cleats and the spatial variation of the fluid pressure. A macroscopic average equation for gas diffusion in the matrix and gas-water transport in the cleats is developed by considering the mass exchange between the matrix and the cleats governed by the Warren and Root approximation. Numerical simulations illustrate the crucial correlation between gas pressure distributions, cleat opening and reservoir stiffness. CO₂ injection significantly improves CH₄ production and enables a underground storage of CO₂, which contributes to reducing green-house gas emissions
Modélisation multiéchelle du couplage adsorption-transport-mécanique dans les réservoirs de gaz de charbon : récupération assistée par injection de CO₂
No full textCoal seam gas is an energy resource whose exploitation can be enhanced by injectingcarbon dioxide (CO₂), thus combining the production of methane (CH₄) and the storage of carbon dioxide produced by its combustion. The structure of the reservoir is considered to be a double-porosity medium with natural fractures (cleats) and a matrix containing a solid phase and nanopores (less than 2 nm in size) where the gas is stored by adsorption on the solid wall. CO₂ is more easily adsorbed than CH₄. A multiscale theoretical model combining adsorption, transport and reservoir poro-mechanics is developed. At the smallest scale, the gas molecules are considered as hard spheres interacting through a Lennard-Jones potential. A new numerical method uses Density Functional Theory (DFT) and Fundamental Measure Theory (FMT) to calculate the distribution of molecular densities of a mixture of gases for any nanopore geometry. The solid wall exerts an external potential that is repulsive at very short distances and attractive at longer distances on the gas molecules. From the molecular distributions of the gases, the solvation force exerted by the fluid phase on the surface of the nanopores is precisely calculated. The asymptotic homogenization method is performed to upscale the nanopore-scale model and to obtain the response of the coal matrix at the microscale. The Biot poroelastic model is modified by the solvation force, which acts as the main factor governing matrix swelling or contraction. The average mass conservation equations for the two gases (CH₄ and CO₂) in the matrix take into account adsorption phenomena characterized by partition coefficients and an effective Knudsen-type diffusion. A second homogenization aims at obtaining the macroscopic law at the reservoir scaleby combining the cleats network and the solid matrix. The joint stiffness at the matrix-cleats interface is characterized by the hyperbolic Barton-Bandis law, which modifies the effective stiffness and the permeability of the reservoir. After homogenization, the reservoir is a heterogeneous and anisotropic medium due to the structure of the cleats and the spatial variation of the fluid pressure. A macroscopic average equation for gas diffusion in the matrix and gas-water transport in the cleats is developed by considering the mass exchange between the matrix and the cleats governed by the Warren and Root approximation. Numerical simulations illustrate the crucial correlation between gas pressure distributions, cleat opening and reservoir stiffness. CO₂ injection significantly improves CH₄ production and enables a underground storage of CO₂, which contributes to reducing green-house gas emissions.Le gaz de charbon est une ressource énergétique dont l'exploitation peut être accélérée par injection de gaz carbonique (CO₂) combinant ainsi production de méthane (CH₄) et stockage du gaz carbonique produit par sa combustion. La structure du réservoir est considérée comme un milieu à double porosité avec des fractures naturelles (cleats) et une matrice contenant une phase solide et des nanopores (de taille inférieure à 2 nm) où le gaz est stocké par adsorption sur la paroi solide. Le CO₂ est plus facilement adsorbé que le CH₄. Un modèle théorique multiéchelle combinant adsorption, transport et poromécanique du réservoir est développé. À la plus petite échelle, les molécules de gaz sont considérées comme des sphères dures interagissant par un potentiel de Lennard-Jones. Une nouvelle méthode numérique utilise la théorie de la fonctionnelle de densité (DFT) et la théorie fondamentale de la mesure (FMT) pour calculer la distribution des densités moléculaires d'un mélange de gaz pour une géométrie quelconque des nanopores. La paroi solide exerce un potentiel extérieur répulsif à très courte distance et attractif à plus grande distance sur les molécules de gaz. À partir des distributions moléculaires des gaz, la force de solvatation exercée par la phase fluide sur la surface des nanopores est calculée précisément. La méthode de l'homogénéisation asymptotique permet de passer de l'échelle du nanopore à l'échelle microscopique et d'obtenir la réponse de la matrice de charbon. Le modèle poroélastique de Biot est modifié par la force de solvatation qui agit comme le principal facteur gouvernant le gonflement ou la contraction de la matrice. Les équations moyennes de conservation de la masse des deux gaz (CH₄ et CO₂) dans la matrice prennent en compte les phénomènes d'adsorption caractérisés par des coefficients de partition et une diffusion effective de type Knudsen. Une seconde homogénéisation vise à obtenir la loi macroscopique à l'échelle du réservoir en combinant le réseau de cleats et la matrice solide. Le contact à l'interface matrice-cleats est caractérisé par la loi hyperbolique de Barton-Bandis qui modifie la rigidité effective ainsi que la perméabilité du réservoir. Après homogénéisation, le réservoir est un milieu hétérogène et anisotrope du fait de la structure des cleats et de la variation spatiale de la pression du fluide. Une équation moyenne macroscopique pour la diffusion des gaz dans la matrice et le transport gaz-eau dans les cleats est développée en considérant l'échange de masse entre la matrice et les cleats gouverné par l'approximation de Warren et Root. Des simulations numériques démontrent la corrélation cruciale entre les distributions de pression de gaz, l'ouverture des cleats et la rigidité du réservoir. L'injection de CO₂ améliore significativement la production de CH₄. Elle permet le stockage souterrain de CO₂ contribuant à réduire les émissions de gaz à effet de serre
Application of XGBoost Model for Predicting the Dynamic Response of High-Speed Railway Bridges
No full textThe dynamic response at high speed affects both the vehicles and the structures in a complex manner, especially in the railway infrastructure problems. In this study, we developed a new KD-Railway tool for analyzing the dynamic behavior of high-speed railways by using the finite element method. Then, extreme gradient boosting (XGBoost) was used to predict and better understand the dynamic response of high-speed railway bridges. The model was trained and tested using a dataset including properties and dynamic responses of 10,000 bridges generated by KD-Railway. The input variables were the bridge span length, the flexural rigidity, mass per length of the bridge, the cross-section area of bridge decks, the train speed, the damping ratio, and the HSLM train models. On the other hand, maximum vertical deflection and maximum acceleration were considered as the output parameters. The coefficients of determination (R2) for these two outputs were (0.996, 0.931, 0.977) and (0.987, 0.901, 0.962) for the training, testing, and entire dataset, respectively. The sensitivity analyses were also conducted to evaluate the importance of each input variable on the outcomes.</p
Temperature Changes on Land Surface in the Context of Urbanization in Quy Nhon City, Viet Nam
No full textQuy Nhon city is a grade 1 city situated in Binh Dinh province, in Viet Nam. Its population was 481.110 inhabitants and it had an urbanization rate of 60% in 2019, while Quy nhon population numbered just 260.000 in 2017. In order to evaluate the relationship between urban heat island and land cover, we used Landsat satellite imagery from 1990 to 2020 to classify the land cover by using the Support Vector Machine learning method (SVM). The classified results were evaluated with the test samples from the field survey. The accuracy is above 77%, which is reliable enough for use in research. To create the surface temperature layer, we used band 6 in the Landsat 5 ETM remote sensing imagery and bands 10, 11 in the Landsat 8 imagery. The results were calculated the surface temperature for the study area. The study carried out statistics of surface temperature value with land cover. The results show that Quy Nhon city has become warmer since 2005, which witnessed a significant increase, compared with roughly 4 degrees in 1996 and around 9 degrees in 1990. And the temperature in the urban land area is between 30 and 35 degrees. During this period, the classification results show that urban land has rapidly expanded. Especially from 2005 up to now, Quy Nhon city has witnessed a strong urban expansion, agricultural land, and water surface have been changed into urban land. To determine the area of urban heat islands we used the urban heat index (UHI). The results show that the heat island phenomenon increases with urbanization in the city and tends to increase over the years. This research result is a practical basis to propose suitable spatial and landscape planning solutions for the city, towards green and sustainable urban development
Energy Consumption Prediction of Residential Buildings Using Machine Learning: A Study on Energy Benchmarking Datasets of Selected Cities Across the United States
No full textEnergy consumption around the globe has been rising for many decades. A significant portion of this consumption occurs in residential buildings. Developing reliable methods to understand and predict energy use is essential in the global effort to become more sustainable. Many cities across the U.S. have mandatory energy benchmarking programs requiring large buildings to track and report their energy use. These openly available datasets have encouraged many researchers to study energy use and develop energy use prediction models. In this study, we employ Extreme Gradient Boosting, Random Forest, and Artificial Neural Network as three common Machine Learning methods to predict building energy use in eight U.S. metropolitan areas. By examining the models’ performance, we also evaluate and compare the datasets provided by the benchmarking programs and we investigate whether the openly available datasets provide adequate input variables for energy use prediction. Based on the results, suggestions are provided to enhance the datasets and further improve building energy use research.</p
Land-tenure policy reforms: Decollectivization and the Doi Moi system in Vietnam
No full textmillions fed, food security, rice, Land tenure, Land reform, Doi Moi, Decollectivization,
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