Uplink capacity analysis of single-user SA-MIMO system

A novel framework of which combines smart antennas multiple antenna systems, （SA） with multiple-input multiple-output （MIMO） at the receiver, is proposed. The uplink SA-MIMO system is investigated. The joint optimization problem corresponding to the uplink capacity of the single-user SA-MIMO system is deduced. Then the closedform expression of the capacity is obtained in the case of equal power allocation and the same direction-of-arrivals （DOAs） from different transmit antennas at the same antenna array, and an upper bound of the capacity is also given in the case of different DOAs at the same antenna array. After that, for the general case, a suboptimal method for the capacity optimization problem is presented. Some numerical results are also given to compare the capacities of conventional MIMO and SA-MIMO systems and show that the proposed method is viable.

油气行业超声流量计选用建议

超声流量计在油气工业中已得到广泛应用。自上世纪70年代初，科技进步与提出的电子学理论、实用的结构和传感器的设计相关。如今，超声流量计被证实是可靠、通用的，并且能够满足油气工业的使用条件。不同的超声流量计技术在设计和应用方面有不同的特点。通常，这些差异可能导致应用失误或最终用户不甚满意。本文将要介绍并指出在目前市场上可见的不同技术以及回顾每种设计与工艺的优缺点。

Optimal distributed resource allocation in a wireless sensor network for control systems

Wireless technology is applied increasingly in networked control systems. A new form of wireless network called wireless sensor network can bring control systems some advantages, such as flexibility and feasibility of network deployment at low costs, while it also raises some new challenges. First, the communication resources shared by all the control loops are limited. Second, the wireless and multi-hop character of sensor network makes the resources scheduling more difficult. Thus, how to effectively allocate the limited communication resources for those control loops is an important problem. In this paper, this problem is formulated as an optimal sampling frequency assignment problem, where the objective function is to maximize the utility of control systems, subject to channel capacity constraints. Then an iterative distributed algorithm based on local buffer information is proposed. Finally, the simulation results show that the proposed algorithm can effectively allocate the limited communication resource in a distributed way. It can achieve the optimal quality of the control system and adapt to the network load changes.

The Single Machine Parallel Batch Scheduling Problem with Job Compatibility Constraints

The single machine parallel batch problem with job compatibility is considered to minimize makespan, where the job compatibility constraints are represented by a graph G. This problem is proved to be NP-hard. And when the graph G is limited to be a general bipartite, a complete bipartite and a complete m-partite graph, these problems are solved in polynomial time respectively.

Regression model for daily passenger volume of high-speed railway line under capacity constraint

A non-linear regression model is proposed to forecast the aggregated passenger volume of Beijing-Shanghai high-speed railway(HSR) line in China. Train services and temporal features of passenger volume are studied to have a prior knowledge about this high-speed railway line. Then, based on a theoretical curve that depicts the relationship among passenger demand, transportation capacity and passenger volume, a non-linear regression model is established with consideration of the effect of capacity constraint. Through experiments, it is found that the proposed model can perform better in both forecasting accuracy and stability compared with linear regression models and back-propagation neural networks. In addition to the forecasting ability, with a definite formation, the proposed model can be further used to forecast the effects of train planning policies.

Two-Hop Gaussian Relay Channel with Linear Relaying： Achievable Rate and Optimization Design

The relay node with linear relaying transmits the linear combination of its past received signals.The optimization of two-hop relay channel with linear relaying is discussed in this paper.The capacity for the two-hop Gaussian relay channel with linear relaying is derived,which can be formulated as an optimization problem over the relaying matrix and the covariance matrix of the signals transmitted at the source.It is proved that the solution to this optimization problem is equivalent to a "single-letter" optimization problem.We also show that the solution to this "single-letter" optimization problem has the same form as the expression of the rate achieved by Time-Sharing Amplify and Forward(TSAF).In order to solve this equivalent problem,we proposed an iterative algorithm.Simulation results show that if channel gain of one hop is relatively smaller,the achievable rate with TSAF is closer to the max-flow min-cut capacity bound,but at a lower complexity.

Compliant landing of a trotting quadruped robot based on hybrid motion/force robust control

A compliant landing strategy for a trotting quadruped robot on unknown rough terrains based on contact force control is presented. Firstly, in order to lower the disturbance caused by the landing impact force, a landing phase is added between the swing phase and the stance phase, where the desired contact force is set as a small positive constant. Secondly, the joint torque optimization of the stance legs is formulated as a quadratic programming(QP) problem subject to equality and inequality/bound constraints. And a primal-dual dynamical system solver based on linear variational inequalities(LVI) is applied to solve this QP problem. Furthermore, based on the optimization results, a hybrid motion/force robust controller is designed to realize the tracking of the contact force, while the constraints of the stance feet landing angles are fulfilled simultaneously. Finally, the experiments are performed to validate the proposed methods.

Performance of Micelle-Clay Filters for Removing Pollutants and Bacteria from Tertiary Treated Wastewater

Filters filled with a micelle-clay complex mixed with sand were employed to investigate their purification capability of tertiary treated wastewater with loose UF-membranes. The UF membrane was hollow fiber with a molecular weight cutoff of 100 kD. The complex was prepared from the organic cation octadecyltrimethylammonium （ODTMA） and the negatively charged clay-mineral, montmoriIIonite. This complex has a very large surface area, which includes large hydrophobic domains and is positively charged, about half of the cation exchange capacity of the clay. Two sets of filtration experiments were carried out at flow rates of 1.2 and 50 mL/min, which correspond to flow velocities of 3.7 and 153 cm/h, respectively. In the first case, after a passage of 1 L, the turbidity, total suspended solids （TSS）, fecal coliforms （FC）, and total coliforms （TC） were reduced to zero from 14 NTU, 6 ppm, 350 and 10,000 counts per 100 mL, respectively. In the second case, the numbers of FC and TC were reduced from 50,000/100 mL to zero after the passage of 14 L. The values of COD and BOD were reduced several-fold. The conclusion is that the incorporation of micelle-clay filters in the sewage treatment system with loose tertiary capability is promising and warrants larger scale experiments for optimization of the overall system.

In Situ Synchrotron X-ray Diffraction Studies of Single-walled Carbon Nanotubes for Electric Double-layer Capacitors

In situ synchrotron X-ray diffraction experiments of SWCNT （single-walled carbon nanotube） electrode in alkali halide aqueous electrolyte at several applied potentials were performed, and the change in the diffraction pattern of SWCNTs was observed. It was found that the position of the 100 diffraction peak does not change with applied potential while the peak intensity decreases with anion adsorption. It was concluded that the space inside the tube would be the important ion adsorption site for the well-gown SWCNT bundles.

Hemocompatibility and cytocompatibility of diblock copolymer poly(2-ethyl-2-oxazoline)-poly(D,L-lactide)-based micelles

A synthetic diblock copolymer poly（2-ethyl-2-oxazoline）-poly（D,L-lactide） （PEOz-PLA） can self-assemble into micelles with an increased efficiency of drug delivery. However, the interactions of blood-micelles and cell-micelles remain unclear. In the present study, we aimed to assess the hemocompatibility and cytocompatibility of PEOz-PLA micelles in order to clarify its potentials as carriers for drug delivery. Blood compatibility of the micelles was evaluated by hemolysis analysis, coagulation test, platelet activation investigation and assessment of their interaction with protein. The results revealed that PEOz-PLA micelles had a favorable blood compatibility. In addition, PEOz-PLA micelles showed a good cytocompatibility through SRB assay, presenting only negligible cytotoxicity when incubated with KBv cells. Taken together, PEOz-PLA micelles could be used as a hemocompatible and cytocompatible drug carrier for intravenous administration.