The perception of supply chain management （SCM） first appeared in 1982 and the very first papers on SCM were published in the mid 1980s （Houlihan, 1985）. However, this term is still fresh in Vietnam, especially th...The perception of supply chain management （SCM） first appeared in 1982 and the very first papers on SCM were published in the mid 1980s （Houlihan, 1985）. However, this term is still fresh in Vietnam, especially the subject of SCM practices and their impacts on firm performance of small and medium enterprises （SMEs）. Therefore, the research was conducted to study the impact of supply chain management practices （SCMPs） on firm performance of SMEs through firm competitive advantages. Data were collected by surveying SMEs located in Ho Chi Minh City. The research findings showed that customer relationship （CR） and quality of information sharing （IQ） impact on firm performance at 0.01% significance level while the level of information sharing impacts on firm performance at 10% significance level, and strategic supplier partnership impacts on firm performance insignificantly. Moreover, we also found that customer relationship and quality of information sharing influence firm competitive advantage at 0.01% significance level, while strategic supplier partnership and the quality of information sharing impact on firm competitive advantage at 5% significance level. Competitive advantages impact significantly positively on firm performance at significance level of 0.001%. The findings imply that SMEs in Vietnam should manage customer relationship well and increase the level of information quality to improve competitive advantage in order to gain high performance.展开更多
Large Scale multiple input multiple output(MIMO) systems have recently emerged as a promising technology for 5G communications.While they have been shown to offer significant performance benefits in theoretical studie...Large Scale multiple input multiple output(MIMO) systems have recently emerged as a promising technology for 5G communications.While they have been shown to offer significant performance benefits in theoretical studies,the large scale MIMO transmitters will have to be deployed in the limited physical space of today's base stations(BSs).Accordingly,this paper examines effects of deploying increasing numbers of antennas in fixed physical space,by reducing the antenna spacing.We focus on the resulting performance of large-scale MIMO transmitters using low complexity closed form precoding techniques.In particular,we investigate the combined effect of reducing the distance between the antenna elements with increasing the number of elements in a fixed transmitter space.This gives rise to two contradicting phenomena:the reduction of spatial diversity due to reducing the separation between antennas and the increase in transmit diversity by increasing the number of elements.To quantify this tradeoff,we investigate densely deployed uniform antenna arrays modelled by detailed electromagnetic simulation.Our results show the somewhat surprising result that,by reducing the separations between the antennas to significantly less than the transmit wavelength to fit more antennas,the resulting system performance improves.展开更多
Using adiabatic invariance and the Bohr-Sommerfeld quantization rule we investigate the entropy spectroscopy of two black holes of heterotic string theory,the charged GMGHS and the rotating Sen solutions.It is shown t...Using adiabatic invariance and the Bohr-Sommerfeld quantization rule we investigate the entropy spectroscopy of two black holes of heterotic string theory,the charged GMGHS and the rotating Sen solutions.It is shown that the entropy spectrum is equally spaced in both cases,identically to the spectrum obtained before for Schwarzschild,Reissner-Nordstr？m and Kerr black holes.Since the adiabatic invariance method does not use quasinormal mode analysis,there is no need to impose the small charge or small angular momentum limits and there is no confusion on whether the real part or the imaginary part of the modes is responsible for the entropy spectrum.展开更多
文摘The perception of supply chain management （SCM） first appeared in 1982 and the very first papers on SCM were published in the mid 1980s （Houlihan, 1985）. However, this term is still fresh in Vietnam, especially the subject of SCM practices and their impacts on firm performance of small and medium enterprises （SMEs）. Therefore, the research was conducted to study the impact of supply chain management practices （SCMPs） on firm performance of SMEs through firm competitive advantages. Data were collected by surveying SMEs located in Ho Chi Minh City. The research findings showed that customer relationship （CR） and quality of information sharing （IQ） impact on firm performance at 0.01% significance level while the level of information sharing impacts on firm performance at 10% significance level, and strategic supplier partnership impacts on firm performance insignificantly. Moreover, we also found that customer relationship and quality of information sharing influence firm competitive advantage at 0.01% significance level, while strategic supplier partnership and the quality of information sharing impact on firm competitive advantage at 5% significance level. Competitive advantages impact significantly positively on firm performance at significance level of 0.001%. The findings imply that SMEs in Vietnam should manage customer relationship well and increase the level of information quality to improve competitive advantage in order to gain high performance.
基金supported by the Royal Academy of Engineering,UKthe Seventh Framework Programme for Research of the European Commission under grant number HARP-318489
文摘Large Scale multiple input multiple output(MIMO) systems have recently emerged as a promising technology for 5G communications.While they have been shown to offer significant performance benefits in theoretical studies,the large scale MIMO transmitters will have to be deployed in the limited physical space of today's base stations(BSs).Accordingly,this paper examines effects of deploying increasing numbers of antennas in fixed physical space,by reducing the antenna spacing.We focus on the resulting performance of large-scale MIMO transmitters using low complexity closed form precoding techniques.In particular,we investigate the combined effect of reducing the distance between the antenna elements with increasing the number of elements in a fixed transmitter space.This gives rise to two contradicting phenomena:the reduction of spatial diversity due to reducing the separation between antennas and the increase in transmit diversity by increasing the number of elements.To quantify this tradeoff,we investigate densely deployed uniform antenna arrays modelled by detailed electromagnetic simulation.Our results show the somewhat surprising result that,by reducing the separations between the antennas to significantly less than the transmit wavelength to fit more antennas,the resulting system performance improves.
基金Supported by the Universidad Nacional de Colombia. Hermes Project Code 13038
文摘Using adiabatic invariance and the Bohr-Sommerfeld quantization rule we investigate the entropy spectroscopy of two black holes of heterotic string theory,the charged GMGHS and the rotating Sen solutions.It is shown that the entropy spectrum is equally spaced in both cases,identically to the spectrum obtained before for Schwarzschild,Reissner-Nordstr？m and Kerr black holes.Since the adiabatic invariance method does not use quasinormal mode analysis,there is no need to impose the small charge or small angular momentum limits and there is no confusion on whether the real part or the imaginary part of the modes is responsible for the entropy spectrum.
