Gallager?s Exponent for MIMO Channels: A Reliability-Rate Tradeoff

In this paper, we derive Gallager's random coding error exponent for multiple-input multiple-output (MIMO) Rayleigh block-fading channels, assuming no channel-state information (CSI) at the transmitter and perfect CSI at the receiver. This measure gives insight into a fundamental tradeoff between the communication reliability and information rate of MIMO channels, enabling to determine the required codeword length to achieve a prescribed error probability at a given rate below the channel capacity. We quantify the effects of the number of antennas, channel coherence time, and spatial fading correlation on the MIMO exponent. In addition, the general formulae for the ergodic capacity and the cutoff rate in the presence of spatial correlation are deduced from the exponent expressions. These formulae are applicable to arbitrary structures of transmit and receive correlation, encompassing all the previously known results as special cases of our expressions.     

Thermal pressure coefficient of a polyhedral oligomeric silsesquioxane (POSS)‐reinforced epoxy resin

The thermal pressure coefficients of a neat, unfilled, epoxy resin and a 10 wt % POSS (polyhedral oligomeric silsesquioxane)‐filled epoxy nanocomposite have been measured using a thick‐walled tube method. It is found that just below the glass transition temperature the thermal pressure coefficient is ～ 20% smaller for the polymer composite containing 10% POSS than for the neat, unfilled resin. The thermal expansion coefficient and thermal pressure coefficient of the uncured POSS itself are also reported. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Neutral-point voltage control for a three-level DC-AC inverterusing equivalent-input-disturbance approach

One problem with a single source three-level inverter is the drafting of its neutral-point voltage. This may occur during transition or when unbalanced loads are connected to the inverter system. Variation of neutral-point voltage may greatly deteriorate     

A method for determining the flow front velocity of a plastic melt in an injection molding process

During the filling phase of an injection molding process, the flow front velocity of the plastics melt has a decisive influence on the form part quality. It has been believed that a constant flow front velocity of the melt leads to distortion‐free and residual stress‐free form parts. A process control strategy based on a constant flow front velocity of the melt, however, requires the full understanding of the flow front position as a function of the screw position of the injection molding machine. With current methods, this can only be achieved by direct measurements using a number of sensors inside the mold, which leads to complicated structure, great efforts, and high cost for the tooling equipment. This article proposes, designs, and develops an innovative method for determining the flow front velocity of a plastic melt in an injection molding using only one pressure sensor at the front of the screw and based on the idea of mapping a simulated filling process to a real injection molding process. The mapping ensues that the characteristic event points are identified and matched for both the simulated and real filling process. The results of the simulation analysis and experimental evaluation show that the proposed method can be used to determine the flow front position and the resulting flow front velocity of the melt within the cavity of the mold and provide evidence that the new method offers great potential to process control strategies based on machine independent parameters. POLYM. ENG. SCI., 59:1132–1145 2019. © 2019 Society of Plastics Engineers     

Interactive Evolutionary Multi-Objective Optimization Algorithm Using Cone Dominance

As the number of objectives increases, the performance of the Pareto dominance-based Evolutionary Multi-objective Optimization (EMO) algorithms such as NSGA-II, SPEA2 severely deteriorates due to the drastic increase in the Pareto-incomparable solutions. We propose a sorting method which classifies these incomparable solutions into several ordered classes by using the decision maker's (DM) preference information. This is accomplished by designing an interactive evolutionary algorithm and constructing convex cones. This method allows the DMs to drive the search process toward a preferred region of the Pareto optimal front. The performance of the proposed algorithm is assessed for two, three, and four-objective knapsack problems. The results demonstrate the algorithm's ability to converge to the most preferred point. The evaluation and comparison of the results indicate that the proposed approach gives better solutions than that of NSGA-II. In addition, the approach is more efficient compared to NSGA-II in terms of the number of generations required to reach the preferred point.     

测量复合视频信号性能:差分增益与差分相位

首先简要介绍了复合NSTC/PAL视频,并阐述差分增益与差分相位的重要性,随后,重点讨论了如何理解规格表中的各种规格及各种重要的DG/DP测量方法。     

Enabling structural summaries for efficient update and workload adaptation

To facilitate queries over semi-structured data, various structural summaries have been proposed. Structural summaries are derived directly from data and serve as the indexes for evaluating path expressions. We introduce D(k)-index, an adaptive structural summary, for general graph-structured data. Building on previous 1-index and A(k)-index, D(k)-index is also based on the concept of bisimilarity. However, as a generalization of 1-index and A(k)-index, D(k)-index possesses the adaptive ability to adjust its structure to changes in query load. It also enables efficient update algorithms, which are crucial to real applications but have not been adequately addressed in previous literatures. Our experiments show that D(k)-index is a more effective structural summary than previous static ones as a result of its query load sensitivity. In addition, the update operations on it can be performed more efficient than on its predecessors.     

Pig weight prediction system using RGB-D sensor and AR glasses: analysis method with free camera capture direction

Artificial Life and Robotics - Pig weights are important indicator for the healthcare and the economic operation of pig farms, and the development of a system to easily estimate these weights is...     

论西部历史文化名城的保护与建设

本文首先提出了历史文化名城的保护作用和保护目的,确定历史文化名城的保护范畴及保护方式,阐述了历史文化名城建设中所面临的实际问题与解决对策.在此基础上,再引伸出西部历史文化名城的特点与风貌,重点对平遥、西安等城市作了较为详细的介绍和分析。文章最后提出了对西部历史文化名城的建设与发展的一些意见和看法.     

Preparation of Cu2ZnSnS4 thin films by sulfurizing electroplated precursors

Cu₂ZnSnS₄ (CZTS) thin films were prepared by sulfurizing precursors deposited by electroplating. The precursors (Cu/Sn/Zn stacked layers) were deposited by electroplating sequentially onto Mo-coated glass substrates. Aqueous solutions containing copper sulfate for Cu plating, tin sulfate for Sn plating and zinc sulfate for Zn plating were used as the electrolytes. The precursors were sulfurized by annealing with sulfur at temperatures of 300, 400, 500 and 600 °C in an N₂ gas atmosphere. The X-ray diffraction peaks attributable to CZTS were detected in thin films sulfurized at temperatures above 400 °C. A photovoltaic cell using a CZTS thin film produced by sulfurizing an electroplated Sn-rich precursor at 600 °C exhibited an open-circuit voltage of 262 mV, a short-circuit current of 9.85 mA/cm² and an efficiency of 0.98%.