Massive multiple-input multiple-output provides improved energy efficiency and spectral efficiency in 5 G. However it requires large-scale matrix computation with tremendous complexity, especially for data detection a...Massive multiple-input multiple-output provides improved energy efficiency and spectral efficiency in 5 G. However it requires large-scale matrix computation with tremendous complexity, especially for data detection and precoding. Recently, many detection and precoding methods were proposed using approximate iteration methods, which meet the demand of precision with low complexity. In this paper, we compare these approximate iteration methods in precision and complexity, and then improve these methods with iteration refinement at the cost of little complexity and no extra hardware resource. By derivation, our proposal is a combination of three approximate iteration methods in essence and provides remarkable precision improvement on desired vectors. The results show that our proposal provides 27%-83% normalized mean-squared error improvement of the detection symbol vector and precoding symbol vector. Moreover, we find the bit-error rate is mainly controlled by soft-input soft-output Viterbi decoding when using approximate iteration methods. Further, only considering the effect on soft-input soft-output Viterbi decoding, the simulation results show that using a rough estimation for the filter matrix of minimum mean square error detection to calculating log-likelihood ratio could provideenough good bit-error rate performance, especially when the ratio of base station antennas number and the users number is not too large.展开更多
The oceans account for 71% of the Earth’s surface and are rich in the most advantageous and characteristic resources of marine microbes. The research on diversity is the key point for exploring and exploiting marine ...The oceans account for 71% of the Earth’s surface and are rich in the most advantageous and characteristic resources of marine microbes. The research on diversity is the key point for exploring and exploiting marine microbial resources. Giving attention to species diversity and genetic diversity of marine microbes, discovering novel metabolites with multiple functions, revealing key secondary metabolic process and the main regulation mechanisms in marine microbes, and developing a new technology of biosynthesis, are the important foundation for discovering innovative drugs and developing functional products with characteristics. The present paper has reviewed the recent advances in the four research areas of marine microbial species diversity, genetic diversity, chemical diversity and metabolic diversity in China.展开更多
Cloud computing is a new vision about the needs of information technology (IT). It provides a comprehensive concept for building a homogeneous environment through services offered in the cloud Software-as-a-Service ...Cloud computing is a new vision about the needs of information technology (IT). It provides a comprehensive concept for building a homogeneous environment through services offered in the cloud Software-as-a-Service (SaaS), Platform-as-a-Service (PaaS), and Infrastructure-as-a-Service (IaaS). Cloud computing is location-independent computing, whereby shared servers provide resources, software, and data to computers and other devices on demand, as with the electricity grid. Cloud computing is computing paradigm that is driven by economies of scale, in which a set of dynamically-scalable resources such as servers, storages, platforms, and services are delivered on demand to the customers over the interuet. "Cloud computing is a continuation of the direction the industry has been going for the last several years in terms of using shared and elastically scalable computing resources," says Rex Wang1, VP of Product Marketing at Oracle, who spoke at the Gartner Data Center Conference, in January 2011. Cloud computing refers to dynamic provision of virtual distributed computational resources on demand via a computer network. Cloud computing is a new high technology industry that possesses a number of advantages over existing business practices: a reduction of expenses, technical staff, and efforts of the end users.展开更多
In the evolution of economic growth drivers, technology gaps are a key variable that determines the efficiency of resource allocation. Analysis of an optimal resource allocation path based on an extended endogenous gr...In the evolution of economic growth drivers, technology gaps are a key variable that determines the efficiency of resource allocation. Analysis of an optimal resource allocation path based on an extended endogenous growth model reveals that economic growth drivers evolve from productive investment to R&D investment and a shift from imitation to innovation. Empirical analysis based on China's provincial-level panel data suggests that the effect of productive investment and R&D investment, as well as innovation and imitation, on economic growth and technological progress varies greatly among regions of disparate technology levels. As a late-starting country, China should properly allocate resources between productive investment and R&D investment, and between imitational investment and innovative investment while advancing the transformation of economic growth patterns on a differentiated basis in light of regional technology disparities.展开更多
As non-renewable natural resources, rare minerals' are extensively used as important raw materials in strategic emerging industries. As global consumption continues to increase over recent years, international compet...As non-renewable natural resources, rare minerals' are extensively used as important raw materials in strategic emerging industries. As global consumption continues to increase over recent years, international competition in the area of rare mineral minerals has been escalating. On the basis' of the identification of 22 rare mineral resources of six categories and analysis of their applications in strategic emerging industries, this paper has adopted a three-factor analytical framework and designed nine indicators from the three dimensions of supply risks, environmental impacts and economic impacts of restricted supply to conduct a quantitative evaluation of the strategic significance of rare mineral resources. The result indicates that the strategic significance of platinum-group metals is the highest and the strategic significance of cesium is the lowest. In order to further increase the reliability of evaluation results, this paper has employed the Monte Carlo simulation for uncertainty analysis'. Simulation result demonstrates that after the impacts" of individual indicators have been taken into account, the results' of this paper's evaluation of 22 rare mineral resources remain valid. Given the growing significance of rare mineral resources to strategic emerging industries, China should formulate a national strategy on rare mineral resources', strive to inerease the supply security of key raw materials for strategic emerging industries and achieve the sustainable development and utilization of rare mineral resources for national security of natural resources.展开更多
Today, a new industry is born in the era of numerous industries rapidly developing. It represents environmental, none-pollution and clean. This is the new energy industry. Its birth is iconic. In a world where resourc...Today, a new industry is born in the era of numerous industries rapidly developing. It represents environmental, none-pollution and clean. This is the new energy industry. Its birth is iconic. In a world where resources are increasingly strained, exploitation and utilization of non-renewable resources cannot meet the demand for per capita and traditional energy consumption of resources with environmental pollution worsening. In the global environment today it is not sufficient. People have to develop new sources of energy to replace the past non-renewable energy. The new energies include: wind, solar, nuclear, geothermal energy, tidal energy and bio-energy.展开更多
Tourists’ authentic perceptions are crucial for the development of world heritage resources. The paper focuses on exploring the relationships between tourists’ authentic perceptions and authenticity-based tourism de...Tourists’ authentic perceptions are crucial for the development of world heritage resources. The paper focuses on exploring the relationships between tourists’ authentic perceptions and authenticity-based tourism development of world heritage. Through the empirical study on the Forbidden City in Beijing, we find that the relationships between the above two factors can be simulated by the model of set theory in algebra. As a result, five types of set relationships are proposed: “separation relation”, “intersection relation”, “inclusion relation I”,“inclusion relation II” and “superposition relation”. According to sample distribution rules, the set relationships can be further divided into primary set relationships and secondary set relationships. The study on set relationships based on demographic characteristic of tourists by using two-way analysis of variance method shows that the tourists in different groups of gender, ages, levels of education, visit frequencies and levels of early perspectives have different perceptions for the set relationships. The ifndings in this paper are helpful for identifying effects of the authenticity-based exploitation of world heritage resources and proposing future strategies for world heritage resources from tourists’ authentic perspectives.展开更多
文摘Massive multiple-input multiple-output provides improved energy efficiency and spectral efficiency in 5 G. However it requires large-scale matrix computation with tremendous complexity, especially for data detection and precoding. Recently, many detection and precoding methods were proposed using approximate iteration methods, which meet the demand of precision with low complexity. In this paper, we compare these approximate iteration methods in precision and complexity, and then improve these methods with iteration refinement at the cost of little complexity and no extra hardware resource. By derivation, our proposal is a combination of three approximate iteration methods in essence and provides remarkable precision improvement on desired vectors. The results show that our proposal provides 27%-83% normalized mean-squared error improvement of the detection symbol vector and precoding symbol vector. Moreover, we find the bit-error rate is mainly controlled by soft-input soft-output Viterbi decoding when using approximate iteration methods. Further, only considering the effect on soft-input soft-output Viterbi decoding, the simulation results show that using a rough estimation for the filter matrix of minimum mean square error detection to calculating log-likelihood ratio could provideenough good bit-error rate performance, especially when the ratio of base station antennas number and the users number is not too large.
文摘The oceans account for 71% of the Earth’s surface and are rich in the most advantageous and characteristic resources of marine microbes. The research on diversity is the key point for exploring and exploiting marine microbial resources. Giving attention to species diversity and genetic diversity of marine microbes, discovering novel metabolites with multiple functions, revealing key secondary metabolic process and the main regulation mechanisms in marine microbes, and developing a new technology of biosynthesis, are the important foundation for discovering innovative drugs and developing functional products with characteristics. The present paper has reviewed the recent advances in the four research areas of marine microbial species diversity, genetic diversity, chemical diversity and metabolic diversity in China.
文摘Cloud computing is a new vision about the needs of information technology (IT). It provides a comprehensive concept for building a homogeneous environment through services offered in the cloud Software-as-a-Service (SaaS), Platform-as-a-Service (PaaS), and Infrastructure-as-a-Service (IaaS). Cloud computing is location-independent computing, whereby shared servers provide resources, software, and data to computers and other devices on demand, as with the electricity grid. Cloud computing is computing paradigm that is driven by economies of scale, in which a set of dynamically-scalable resources such as servers, storages, platforms, and services are delivered on demand to the customers over the interuet. "Cloud computing is a continuation of the direction the industry has been going for the last several years in terms of using shared and elastically scalable computing resources," says Rex Wang1, VP of Product Marketing at Oracle, who spoke at the Gartner Data Center Conference, in January 2011. Cloud computing refers to dynamic provision of virtual distributed computational resources on demand via a computer network. Cloud computing is a new high technology industry that possesses a number of advantages over existing business practices: a reduction of expenses, technical staff, and efforts of the end users.
文摘In the evolution of economic growth drivers, technology gaps are a key variable that determines the efficiency of resource allocation. Analysis of an optimal resource allocation path based on an extended endogenous growth model reveals that economic growth drivers evolve from productive investment to R&D investment and a shift from imitation to innovation. Empirical analysis based on China's provincial-level panel data suggests that the effect of productive investment and R&D investment, as well as innovation and imitation, on economic growth and technological progress varies greatly among regions of disparate technology levels. As a late-starting country, China should properly allocate resources between productive investment and R&D investment, and between imitational investment and innovative investment while advancing the transformation of economic growth patterns on a differentiated basis in light of regional technology disparities.
基金Innovation Project of Chinese Academy of Social Sciences(Grant No.SKGJCX2013-04)Key Program of National Social Sciences Foundation of China(Grant No.13&ZD169)Young Scientists Fund of National Natural Science Foundation of China(Grant No.71203232)
文摘As non-renewable natural resources, rare minerals' are extensively used as important raw materials in strategic emerging industries. As global consumption continues to increase over recent years, international competition in the area of rare mineral minerals has been escalating. On the basis' of the identification of 22 rare mineral resources of six categories and analysis of their applications in strategic emerging industries, this paper has adopted a three-factor analytical framework and designed nine indicators from the three dimensions of supply risks, environmental impacts and economic impacts of restricted supply to conduct a quantitative evaluation of the strategic significance of rare mineral resources. The result indicates that the strategic significance of platinum-group metals is the highest and the strategic significance of cesium is the lowest. In order to further increase the reliability of evaluation results, this paper has employed the Monte Carlo simulation for uncertainty analysis'. Simulation result demonstrates that after the impacts" of individual indicators have been taken into account, the results' of this paper's evaluation of 22 rare mineral resources remain valid. Given the growing significance of rare mineral resources to strategic emerging industries, China should formulate a national strategy on rare mineral resources', strive to inerease the supply security of key raw materials for strategic emerging industries and achieve the sustainable development and utilization of rare mineral resources for national security of natural resources.
文摘Today, a new industry is born in the era of numerous industries rapidly developing. It represents environmental, none-pollution and clean. This is the new energy industry. Its birth is iconic. In a world where resources are increasingly strained, exploitation and utilization of non-renewable resources cannot meet the demand for per capita and traditional energy consumption of resources with environmental pollution worsening. In the global environment today it is not sufficient. People have to develop new sources of energy to replace the past non-renewable energy. The new energies include: wind, solar, nuclear, geothermal energy, tidal energy and bio-energy.
基金National Natural Science Foundation of China(Grant No.41371008)
文摘Tourists’ authentic perceptions are crucial for the development of world heritage resources. The paper focuses on exploring the relationships between tourists’ authentic perceptions and authenticity-based tourism development of world heritage. Through the empirical study on the Forbidden City in Beijing, we find that the relationships between the above two factors can be simulated by the model of set theory in algebra. As a result, five types of set relationships are proposed: “separation relation”, “intersection relation”, “inclusion relation I”,“inclusion relation II” and “superposition relation”. According to sample distribution rules, the set relationships can be further divided into primary set relationships and secondary set relationships. The study on set relationships based on demographic characteristic of tourists by using two-way analysis of variance method shows that the tourists in different groups of gender, ages, levels of education, visit frequencies and levels of early perspectives have different perceptions for the set relationships. The ifndings in this paper are helpful for identifying effects of the authenticity-based exploitation of world heritage resources and proposing future strategies for world heritage resources from tourists’ authentic perspectives.