Energy-Efficient Resource Allocation for Small-Cell Networks：A Stable Queue Perspective

The small-cell technology is promising for spectral-efficiency enhancement. However, it usually requires a huge amount of energy consumption. In this paper, queue state information and channel state information are jointly utilized to minimize the time average of overall energy consumption for a multi-carrier small-cell network, where the inter-cell interference is an intractable problem. Based on the Lyapunov optimization theory, the problem could be solved by dynamically optimizing the problem of user assignment, carrier allocation and power allocation in each time slot. As the optimization problem is NP-hard, we propose a heuristic iteration algorithm to solve it. Numerical results verify that the heuristic algorithm offers an approximate performance as the brute-force algorithm. Moreover, it could bring down the overall energy consumption to different degrees according to the variation of traffic load. Meanwhile, it could achieve the same sum rate as the algorithm which focuses on maximizing system sum rate.

Optimal control of natural resources in mining industry

The paper focuses on the optimal control of natural resources in mining industry. The purpose is to pro- pose an optimal extraction series of these resources during the lifetime of the Mine＇s maintenance. Fol- lowing the proposed optimal control model, a sensitivity analysis has been performed that includes the interest rate impact on the optimal solution. This study shows that the increasing of the interest rate sti- mulates faster extraction of the resources. The discounting factor induces that the resource has to be extracted faster hut this effect is counterbalanced by the diminishing returns of the annual cash flow. At higher parameters of ＂alpha＂ close to one of the power function about 80% from the whole resource will be extracted during the first 4 years of object/mine maintenance. An existence of unique positive root with respect to return of investment has been proposed and proved by two ways： by the ＂method of chords＂ and by using specialized software.

Elasticity Ratio of Resource Consumption and the Resource Consumption

Today the resources are becoming scarcer, which should not be regarded as unexhausted any more. Correspondingly, the production would be constrained by the scarcity of resources clearly. Then the economic researchers would pay much more attention to reducing the consumption of natural resources in the future. Therefore this paper brings foreword the conception of elasticity ratio of resource consumption based on the concept of elasticity and analyzes the relationship between the parameters. For the certain relationships between the elasticity ratio of resource consumption and resource consumption, this paper will try to reveal, to keep economy growing while resource consumption reducing, what conditions should be met as to the relationships among resource productivity, its growth rate, energy saving efficiency, economic growth rate and elasticity ratio of resource consumption. This paper proves the relationship between the China＇s energy consumption and economy growth using statistic data from 1978 to 2003.

Study of word length selection for DDCs used in ultra-low symbol rate receivers

The relationship between the hardware requirement of digital down converters（DDCs）in ultra-low symbol rate receivers and the word length is studied.Through analyzing the impact of word length selection to the system performance,a modified scheme is presented to decline the resource consumption without too much degradation on the signal to noise ratio（SNR）.Theoretical analysis and numerical results demonstrate that compared to the traditional design,the proposed scheme could save dozens of memory resources.The scheme also includes some selectable parameters to achieve desired performance in various circumstances.Different from previous work in DDCs that concentrates mostly on the structure design,this paper considers special applications such as ultra-low symbol rate receivers.

Choice and Simulation of Tax Rates in Resource Tax Reform

Resource tax reform will be done during China＇s 12m Five-Year Plan, but related research is still lacking. Here, we build a computable general equilibrium model （CGE） comprising the functional equations of production, consumption, income/expenditure and resources to analyze the resource tax rate. The model uses the valorem tax levy to simulate the impact of economic and resource systems with different resource tax rates, by referencing the expected rate ranges of China and developed countries. The results show that the impact is different for social, economic and resources of varying degrees. In the relatively stable period of economic development, we can select a tax rate of 5% to 7%; during higher economic development we can select an optional high level of resource tax; and in a fluctuating economy we can choose a lower tax level.

Web Resources for Microbial Data

There are multitudes of web resources that are quite useful for the microbial scientific research community. Here, we provide a brief introduction on some of the most notable microbial web resources and an evaluation of them based upon our own user experience.