Satellite communication networks have been evolving from standalone networks with ad-hoc infrastructures to possibly interconnected portions of a wider Future Internet architecture. Experts belonging to the fifth-gene...Satellite communication networks have been evolving from standalone networks with ad-hoc infrastructures to possibly interconnected portions of a wider Future Internet architecture. Experts belonging to the fifth-generation(5 G) standardization committees are considering satellites as a technology to integrate in the 5 G environment. Software Defined Networking(SDN) is one of the paradigms of the next generation of mobile and fixed communications. It can be employed to perform different control functionalities, such as routing, because it allows traffic flow identification based on different parameters and traffic flow management in a centralized way. A centralized set of controllers makes the decisions and sends the corresponding forwarding rules for each traffic flow to the involved intermediate nodes that practically forward data up to the destination. The time to perform this process in integrated terrestrial-satellite networks could be not negligible due to satellite link delays. The aim of this paper is to introduce an SDN-based terrestrial satellite network architecture and to estimate the mean time to deliver the data of a new traffic flow from the source to the destination including the time required to transfer SDN control actions. The practical effect is to identify the maximum performance than can be expected.展开更多
This article is about the problem of optimizing of the capital structure of the concrete firm and about the possibility to use the passive way of optimizing of this capital structure on the basis of the so-called Bran...This article is about the problem of optimizing of the capital structure of the concrete firm and about the possibility to use the passive way of optimizing of this capital structure on the basis of the so-called Branch standards. Branch standards are defined as some average indebtedness that the firms are trying to follow. There are a lot of theories available, but the final process of optimizing of the capital structure of the concrete firm is very complicated and it is necessary to cope with a lot of application problems. Besides Traditional theory, none of the further theories offer some concrete recommended optimal indebtedness. For that reason, the possibility to optimize the capital structure based on the passive way is represented besides other things by the so-called Branch standards. The aim of this article is to judge if it is possible to identify this average indebtedness in different branches and in different countries. The hypothesis was stated that it is possible only in selected branches in selected countries. The research is realized in the six selected branches： Railroads, Beverages, Steel, Paper Production, Tobacco, and Electrical Equipment in the Czech Republic and in USA. Data for the years 2008-2016 were obtained from the system Albertina Data at the University of Economics in Prague and from the web pages of Prof. Aswath Damodaran in USA. There were identified so-called Branch standards in the Czech Republic for the branches Railroads 45%, Beverages 50%, Tobacco 50%, and Electrical Equipment 40%. There are also identified so-called Branch standards in USA for the branches Railroads 40% and Paper Production 40%-50%. For the branch Paper Production in the Czech Republic and for the branch Beverages in USA were identified ranges of 40%-45% and 40%-50% respectively. The so-called Branch standards were not stated for the branch Steel in both countries and for the branches Tobacco and Electrical Equipment in USA. The values were verified by the data for the year 2016 and the so-called Branch standards were confirmed excluding the branch Steel in both countries and the branches Tobacco and Electrical Equipment in the US.展开更多
This paper considers accounting regulation research from a structuration and cultural perspective. Therefore, accounting regulation research spans over three spheres of enquiry： （1） an accounting focus of standard-...This paper considers accounting regulation research from a structuration and cultural perspective. Therefore, accounting regulation research spans over three spheres of enquiry： （1） an accounting focus of standard-setting; （2） a cultural analysis in an empirical context; and （3） the use of a research methodology drawn from Anthony Giddens＇ structuration theory. In such approach, accounting regulation research analyzes the accounting regulation actors drawing upon the cultures in their standard-setting actions and interactions, referring to Giddens＇ three structural properties of meaning, power, and morality. The integration of these three spheres of enquiry is not entirely original. A few prior studies have similar combinations： Although they stress the uses and consequences of accounting systems in producing and reproducing organizational culture and negotiating meaning at the organizational level, this paper chooses the research approach of contextual analysis of accounting systems at more macro-societal and cultural levels. This different research interest and design provides this paper with its distinguishable characteristic from the prior similar studies.展开更多
This paper presents recent naval applications of the SWENSE （Spectral Wave Explicit Navier-Stokes Equations） approach implemented for the first time with high order fully unstructured schemes and an efficient level-...This paper presents recent naval applications of the SWENSE （Spectral Wave Explicit Navier-Stokes Equations） approach implemented for the first time with high order fully unstructured schemes and an efficient level-set method to capture free surface flows around realistic hull geometries. Numerical simulations in waves and/or viscous flows still lead generally to very large CPU times because of grid requirements to ensure a good propagation of incident waves in the meshed part of the fluid domain that makes unreachable any hull design optimization process in an industrial context. Furthermore, even if the SWENSE method clearly shows promising results in an academic context in both regular and irregular waves, the most recent publications still highlight several issues that remain unresolved up to now, e.g. poor scalability, diffusive wake pattern, non-versatile structured mesh approaches and only very few validation test cases are carried out on Wigley or DTMB 5415 hulls. In order to overcome those numerical difficulties and get an in-depth validation of the method on several cases in realistic wave conditions, a two and a half years＇ research project has been achieved involving several steps, starting by a set of dedicated model test experiments later used as reference for the validation of the method. The CFD commercial code ANANASTM used and developed in this research program is presented and validated in detail. The use of high order schemes on unstructured grids in combination with these SWENSE method and level-set approach offer to the maritime industry an innovative and state of the art method to achieve unequaled accuracy, low computation time and some unique advantages such as, amongst others, the end of the numerical wave propagation problems. The results of the validation were pleasing and can be considered as acceptable in general, with some challenges remaining to the solyed. Results obtained indicate that an optimization processes in waves in realistic conditions is now affordable in an industrial context.展开更多
Today, energy saving is one of the main objectives for engineers. In the case of mobile applications, energy can be saved by two different ways： decreasing the total masse of the system and increasing the efficiency ...Today, energy saving is one of the main objectives for engineers. In the case of mobile applications, energy can be saved by two different ways： decreasing the total masse of the system and increasing the efficiency of the overall system. This paper presents two optimization strategies to design a predefined multichannel structure of a boost converter which is dedicated to a solar airplane and used to interface PV panels and the battery system. The first strategy is a multi-criterion method that is able to trace the dependency between the converter＇s efficiency and its power density through the intermediary of the Pareto front. The second method, a mono-criterion approach, maximizes efficiency while respecting the constraint imposed on power density. The mono-criterion method that is applied to maximizing the European efficiency criterion showed that an increase in the number of channels enhanced the quantity of energy collected over a day by increasing the power density of the converter. At the end of the paper, the optimal design calculated was built to give an example of the result obtained by this design methodology. The results of the efficiency measurements made on a realized prototype are presented in this paper.展开更多
With new requirements proposed for technical standards work under the new circumstances,the article combining with the practice of Wuhan Iron and Steel Company Limited(WISCO)points out that enterprises must improve th...With new requirements proposed for technical standards work under the new circumstances,the article combining with the practice of Wuhan Iron and Steel Company Limited(WISCO)points out that enterprises must improve the work pattern of standards development and revision,and strengthen the standards implementation management and product quality supervision,so that technical standards can serve as a bridge between technologies and industrialization,support the industrial upgrading and structural optimization,create conditions for promoting trade and unify the market and provides means for global competition,helping enterprises to better cope with the increasing market competition.展开更多
This paper develops Davis technology acceptance model by adding two criteria of e-readiness assessment. For small and medium size enterprises, the paper evaluates the credit of developed model in studying the efficien...This paper develops Davis technology acceptance model by adding two criteria of e-readiness assessment. For small and medium size enterprises, the paper evaluates the credit of developed model in studying the efficient factors in internet technology acceptance, which is one of the most applicable communication tools in e-commerce. The added factors, taken from models and means of e-readiness assessment, are ＂existing information technology infrastructures＂ as well as ＂organization＇s training＂. The authors study 45 small and medium size enterprises in the city of Tehran, which are active in information technology products and services. Using Lisrel structural equation modelling, it is shown that there is a meaningful relationship between the added factors and the variables indicating internet network usage. Therefore, the better factors of e-readiness assessment lead to the higher acceptance level of electronic communication tools in e-commerce.展开更多
文摘Satellite communication networks have been evolving from standalone networks with ad-hoc infrastructures to possibly interconnected portions of a wider Future Internet architecture. Experts belonging to the fifth-generation(5 G) standardization committees are considering satellites as a technology to integrate in the 5 G environment. Software Defined Networking(SDN) is one of the paradigms of the next generation of mobile and fixed communications. It can be employed to perform different control functionalities, such as routing, because it allows traffic flow identification based on different parameters and traffic flow management in a centralized way. A centralized set of controllers makes the decisions and sends the corresponding forwarding rules for each traffic flow to the involved intermediate nodes that practically forward data up to the destination. The time to perform this process in integrated terrestrial-satellite networks could be not negligible due to satellite link delays. The aim of this paper is to introduce an SDN-based terrestrial satellite network architecture and to estimate the mean time to deliver the data of a new traffic flow from the source to the destination including the time required to transfer SDN control actions. The practical effect is to identify the maximum performance than can be expected.
文摘This article is about the problem of optimizing of the capital structure of the concrete firm and about the possibility to use the passive way of optimizing of this capital structure on the basis of the so-called Branch standards. Branch standards are defined as some average indebtedness that the firms are trying to follow. There are a lot of theories available, but the final process of optimizing of the capital structure of the concrete firm is very complicated and it is necessary to cope with a lot of application problems. Besides Traditional theory, none of the further theories offer some concrete recommended optimal indebtedness. For that reason, the possibility to optimize the capital structure based on the passive way is represented besides other things by the so-called Branch standards. The aim of this article is to judge if it is possible to identify this average indebtedness in different branches and in different countries. The hypothesis was stated that it is possible only in selected branches in selected countries. The research is realized in the six selected branches： Railroads, Beverages, Steel, Paper Production, Tobacco, and Electrical Equipment in the Czech Republic and in USA. Data for the years 2008-2016 were obtained from the system Albertina Data at the University of Economics in Prague and from the web pages of Prof. Aswath Damodaran in USA. There were identified so-called Branch standards in the Czech Republic for the branches Railroads 45%, Beverages 50%, Tobacco 50%, and Electrical Equipment 40%. There are also identified so-called Branch standards in USA for the branches Railroads 40% and Paper Production 40%-50%. For the branch Paper Production in the Czech Republic and for the branch Beverages in USA were identified ranges of 40%-45% and 40%-50% respectively. The so-called Branch standards were not stated for the branch Steel in both countries and for the branches Tobacco and Electrical Equipment in USA. The values were verified by the data for the year 2016 and the so-called Branch standards were confirmed excluding the branch Steel in both countries and the branches Tobacco and Electrical Equipment in the US.
文摘This paper considers accounting regulation research from a structuration and cultural perspective. Therefore, accounting regulation research spans over three spheres of enquiry： （1） an accounting focus of standard-setting; （2） a cultural analysis in an empirical context; and （3） the use of a research methodology drawn from Anthony Giddens＇ structuration theory. In such approach, accounting regulation research analyzes the accounting regulation actors drawing upon the cultures in their standard-setting actions and interactions, referring to Giddens＇ three structural properties of meaning, power, and morality. The integration of these three spheres of enquiry is not entirely original. A few prior studies have similar combinations： Although they stress the uses and consequences of accounting systems in producing and reproducing organizational culture and negotiating meaning at the organizational level, this paper chooses the research approach of contextual analysis of accounting systems at more macro-societal and cultural levels. This different research interest and design provides this paper with its distinguishable characteristic from the prior similar studies.
文摘This paper presents recent naval applications of the SWENSE （Spectral Wave Explicit Navier-Stokes Equations） approach implemented for the first time with high order fully unstructured schemes and an efficient level-set method to capture free surface flows around realistic hull geometries. Numerical simulations in waves and/or viscous flows still lead generally to very large CPU times because of grid requirements to ensure a good propagation of incident waves in the meshed part of the fluid domain that makes unreachable any hull design optimization process in an industrial context. Furthermore, even if the SWENSE method clearly shows promising results in an academic context in both regular and irregular waves, the most recent publications still highlight several issues that remain unresolved up to now, e.g. poor scalability, diffusive wake pattern, non-versatile structured mesh approaches and only very few validation test cases are carried out on Wigley or DTMB 5415 hulls. In order to overcome those numerical difficulties and get an in-depth validation of the method on several cases in realistic wave conditions, a two and a half years＇ research project has been achieved involving several steps, starting by a set of dedicated model test experiments later used as reference for the validation of the method. The CFD commercial code ANANASTM used and developed in this research program is presented and validated in detail. The use of high order schemes on unstructured grids in combination with these SWENSE method and level-set approach offer to the maritime industry an innovative and state of the art method to achieve unequaled accuracy, low computation time and some unique advantages such as, amongst others, the end of the numerical wave propagation problems. The results of the validation were pleasing and can be considered as acceptable in general, with some challenges remaining to the solyed. Results obtained indicate that an optimization processes in waves in realistic conditions is now affordable in an industrial context.
文摘Today, energy saving is one of the main objectives for engineers. In the case of mobile applications, energy can be saved by two different ways： decreasing the total masse of the system and increasing the efficiency of the overall system. This paper presents two optimization strategies to design a predefined multichannel structure of a boost converter which is dedicated to a solar airplane and used to interface PV panels and the battery system. The first strategy is a multi-criterion method that is able to trace the dependency between the converter＇s efficiency and its power density through the intermediary of the Pareto front. The second method, a mono-criterion approach, maximizes efficiency while respecting the constraint imposed on power density. The mono-criterion method that is applied to maximizing the European efficiency criterion showed that an increase in the number of channels enhanced the quantity of energy collected over a day by increasing the power density of the converter. At the end of the paper, the optimal design calculated was built to give an example of the result obtained by this design methodology. The results of the efficiency measurements made on a realized prototype are presented in this paper.
文摘With new requirements proposed for technical standards work under the new circumstances,the article combining with the practice of Wuhan Iron and Steel Company Limited(WISCO)points out that enterprises must improve the work pattern of standards development and revision,and strengthen the standards implementation management and product quality supervision,so that technical standards can serve as a bridge between technologies and industrialization,support the industrial upgrading and structural optimization,create conditions for promoting trade and unify the market and provides means for global competition,helping enterprises to better cope with the increasing market competition.
文摘This paper develops Davis technology acceptance model by adding two criteria of e-readiness assessment. For small and medium size enterprises, the paper evaluates the credit of developed model in studying the efficient factors in internet technology acceptance, which is one of the most applicable communication tools in e-commerce. The added factors, taken from models and means of e-readiness assessment, are ＂existing information technology infrastructures＂ as well as ＂organization＇s training＂. The authors study 45 small and medium size enterprises in the city of Tehran, which are active in information technology products and services. Using Lisrel structural equation modelling, it is shown that there is a meaningful relationship between the added factors and the variables indicating internet network usage. Therefore, the better factors of e-readiness assessment lead to the higher acceptance level of electronic communication tools in e-commerce.
