1,720,982 research outputs found
APPLICATION OF ADJUSTED PRESENT VALUE MODEL IN CASH FLOW VALUATION FOR VIETNAM's CONSTRUCTION COMPANIES
No full textCash flow always plays an important role in investment activities because of its characteristics of showing the profitability, the value and the risk that a company or a project will have and face. Moreover, considering and calculating a project’s cash flow becomes more and more complicated and difficult in a present market, including many changes, especially in construction industry where exists much more risk than other industries. Therefore, the effective cash flow valuation method is very necessary, and the aim of this study is finding a proper method to apply for Vietnam’s construction companies. Methods stated throughout this study are: Weight Average Cost of Capital (WACC), Capital Cash Flows (CCFs) and Adjusted Present Value (APV). While WACC is the method used popular in Vietnam today, CCF method is more proper than WACC method in the situation of happening the changes in capital structure. However, APV method, with its flexibility, is the most appropriate method in comparison with two other methods mentioned above. Three models will be applied for 36 construction companies listed in Vietnam’s stock market. The results are analyzed through paired samples T-Test to show that three methods will have the equivalent results in the same condition of capital structure and financing effects. However, the research proves the advantages of APV method, then suggests that this method deserves to be applied in cash flow valuation for Vietnamese firms
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Etude de la propagation d'une fissure sous chargement thermique cyclique induisant un gradient de température dans l'épaisseur
No full textThis study aims to figure out the crack growth phenomenon by thermal fatigue induced by thermal gradient through thickness of specimen. Firstly, an experimental facility has been developed: a rectangular parallelepiped specimen is subjected to thermal cycling between 350°C and 100°C; the specimen is freed to expand and contract. Two semi-circular notches (0,1mm depth and 4mm length) have been machined on the surface of the specimen. A series of interrupted tests has been carried out to characterize and quantify the crack growth in depth and surface of the pre-existing crack.Next, a three-dimensional crack growth simulation has been implemented in ABAQUS. Automation using Python was used to simulate the propagation of a crack under thermal cycling, with remeshing at crack front after each calculation step. No assumption has been taken on the crack front during the crack propagation. A comparison with test results showed very good agreement on the evolution of crack front shape and on the kinetics of propagation on the edge and the heart of pre-existing crack.An analytical approach was also developed based on the calculation of stress intensity factors (SIC). A two-dimensional approach was first introduced enabling us to better understand the influence of various thermal and geometric parameters. Finally, a three-dimensional approach, with an elliptical assumption crack shape during the propagation, leading to a prediction of crack growth on the surface and in depth which is very similar to that obtained numerically, but with computational time much lower.Cette étude vise à appréhender le phénomène de propagation de fissure par fatigue thermique induisant un gradient de température dans l'épaisseur. Dans un premier temps, un dispositif expérimental original a été mis au point, permettant de soumettre une éprouvette parallélépipédique de 304L à du cyclage thermique entre 350°C et 100°C, en l'absence de chargement mécanique. Deux entailles semi-circulaires (profondeur 0,1mm, de largeur 4mm) ont été usinées. Les essais interrompus réalisés ont permis de caractériser et quantifier la propagation de la fissure existante en surface et à coeur.Dans une deuxième partie, des calculs numériques tridimensionnels ont été effectués sous Abaqus. Une automatisation utilisant Python a permis de simuler la propagation d'une fissure sous cyclage thermique, avec remaillage en front de fissure à chaque pas de calcul. Aucune hypothèse n'a été prise sur la forme de fissure durant la propagation. Une comparaison avec les résultats d'essais montre une très bonne concordance sur l'évolution de la forme du front de fissure ainsi que sur les cinétiques de propagation au bord et à coeur.Une approche analytique a également été développée se basant sur le calcul du facteur d'intensité de contraintes (FIC). Une approche bidimensionnelle a d'abord été mise en place nous permettant de mieux comprendre l'influence de différents paramètres thermiques et géométriques. Enfin, une approche tridimensionnelle, avec une fissure demeurant elliptique pendant la propagation, a abouti à une prédiction de la propagation en largeur et profondeur de la fissure tout à fait comparable à celle obtenue numériquement, mais avec des temps de calcul bien moindres
Etude de la propagation d'une fissure sous chargement thermique cyclique induisant un gradient de température dans l'épaisseur
No full textThis study aims to figure out the crack growth phenomenon by thermal fatigue induced by thermal gradient through thickness of specimen. Firstly, an experimental facility has been developed: a rectangular parallelepiped specimen is subjected to thermal cycling between 350°C and 100°C; the specimen is freed to expand and contract. Two semi-circular notches (0,1mm depth and 4mm length) have been machined on the surface of the specimen. A series of interrupted tests has been carried out to characterize and quantify the crack growth in depth and surface of the pre-existing crack.Next, a three-dimensional crack growth simulation has been implemented in ABAQUS. Automation using Python was used to simulate the propagation of a crack under thermal cycling, with remeshing at crack front after each calculation step. No assumption has been taken on the crack front during the crack propagation. A comparison with test results showed very good agreement on the evolution of crack front shape and on the kinetics of propagation on the edge and the heart of pre-existing crack.An analytical approach was also developed based on the calculation of stress intensity factors (SIC). A two-dimensional approach was first introduced enabling us to better understand the influence of various thermal and geometric parameters. Finally, a three-dimensional approach, with an elliptical assumption crack shape during the propagation, leading to a prediction of crack growth on the surface and in depth which is very similar to that obtained numerically, but with computational time much lower.Cette étude vise à appréhender le phénomène de propagation de fissure par fatigue thermique induisant un gradient de température dans l'épaisseur. Dans un premier temps, un dispositif expérimental original a été mis au point, permettant de soumettre une éprouvette parallélépipédique de 304L à du cyclage thermique entre 350°C et 100°C, en l'absence de chargement mécanique. Deux entailles semi-circulaires (profondeur 0,1mm, de largeur 4mm) ont été usinées. Les essais interrompus réalisés ont permis de caractériser et quantifier la propagation de la fissure existante en surface et à coeur.Dans une deuxième partie, des calculs numériques tridimensionnels ont été effectués sous Abaqus. Une automatisation utilisant Python a permis de simuler la propagation d'une fissure sous cyclage thermique, avec remaillage en front de fissure à chaque pas de calcul. Aucune hypothèse n'a été prise sur la forme de fissure durant la propagation. Une comparaison avec les résultats d'essais montre une très bonne concordance sur l'évolution de la forme du front de fissure ainsi que sur les cinétiques de propagation au bord et à coeur.Une approche analytique a également été développée se basant sur le calcul du facteur d'intensité de contraintes (FIC). Une approche bidimensionnelle a d'abord été mise en place nous permettant de mieux comprendre l'influence de différents paramètres thermiques et géométriques. Enfin, une approche tridimensionnelle, avec une fissure demeurant elliptique pendant la propagation, a abouti à une prédiction de la propagation en largeur et profondeur de la fissure tout à fait comparable à celle obtenue numériquement, mais avec des temps de calcul bien moindres
Inductance-Independent Discontinuous Current Mode Control with Minimized Inductor for Power Converters
Get PDF国立大学法人長岡技術科学大学博士（工学）doctoral thesi
Potential development of RORO transport in Vietnam based on possibility of reducing CO₂ by shifting from road transportation to sea transportation
No full text東京海洋大学修士学位論文 2023年度(2023年9月) 海運ロジスティクス 修士 第4144号指導教員: 渡邉豊全文公表年月日: 2024-3-1
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Inductance-Independent Discontinuous Current Mode Control with Minimized Inductor for Power Converters
No full textArticl
Etude de la propagation d'une fissure sous chargement thermique cyclique induisant un gradient de température dans l'épaisseur
No full textThis study aims to figure out the crack growth phenomenon by thermal fatigue induced by thermal gradient through thickness of specimen. Firstly, an experimental facility has been developed: a rectangular parallelepiped specimen is subjected to thermal cycling between 350°C and 100°C; the specimen is freed to expand and contract. Two semi-circular notches (0,1mm depth and 4mm length) have been machined on the surface of the specimen. A series of interrupted tests has been carried out to characterize and quantify the crack growth in depth and surface of the pre-existing crack.Next, a three-dimensional crack growth simulation has been implemented in ABAQUS. Automation using Python was used to simulate the propagation of a crack under thermal cycling, with remeshing at crack front after each calculation step. No assumption has been taken on the crack front during the crack propagation. A comparison with test results showed very good agreement on the evolution of crack front shape and on the kinetics of propagation on the edge and the heart of pre-existing crack.An analytical approach was also developed based on the calculation of stress intensity factors (SIC). A two-dimensional approach was first introduced enabling us to better understand the influence of various thermal and geometric parameters. Finally, a three-dimensional approach, with an elliptical assumption crack shape during the propagation, leading to a prediction of crack growth on the surface and in depth which is very similar to that obtained numerically, but with computational time much lower.Cette étude vise à appréhender le phénomène de propagation de fissure par fatigue thermique induisant un gradient de température dans l'épaisseur. Dans un premier temps, un dispositif expérimental original a été mis au point, permettant de soumettre une éprouvette parallélépipédique de 304L à du cyclage thermique entre 350°C et 100°C, en l'absence de chargement mécanique. Deux entailles semi-circulaires (profondeur 0,1mm, de largeur 4mm) ont été usinées. Les essais interrompus réalisés ont permis de caractériser et quantifier la propagation de la fissure existante en surface et à coeur.Dans une deuxième partie, des calculs numériques tridimensionnels ont été effectués sous Abaqus. Une automatisation utilisant Python a permis de simuler la propagation d'une fissure sous cyclage thermique, avec remaillage en front de fissure à chaque pas de calcul. Aucune hypothèse n'a été prise sur la forme de fissure durant la propagation. Une comparaison avec les résultats d'essais montre une très bonne concordance sur l'évolution de la forme du front de fissure ainsi que sur les cinétiques de propagation au bord et à coeur.Une approche analytique a également été développée se basant sur le calcul du facteur d'intensité de contraintes (FIC). Une approche bidimensionnelle a d'abord été mise en place nous permettant de mieux comprendre l'influence de différents paramètres thermiques et géométriques. Enfin, une approche tridimensionnelle, avec une fissure demeurant elliptique pendant la propagation, a abouti à une prédiction de la propagation en largeur et profondeur de la fissure tout à fait comparable à celle obtenue numériquement, mais avec des temps de calcul bien moindres
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