Tunable electromagnetically induced transparency at terahertz frequencies in coupled graphene metamaterial

A graphene-based metamaterial with tunable electromagnetically induced transparency （EIT）-like transmission is nu- merically studied in this paper. The proposed structure consists of a graphene layer composed of coupled cut-wire pairs printed on a substrate. The simulation confirms that an EIT-like transparency window can be observed due to indirect cou- pling in a terahertz frequency range. More importantly, the peak frequency of the transmission window can be dynamically controlled over a broad frequency range by varying the Fermi energy levels of the graphene layer through controlling the electrostatic gating. The proposed metamaterial structure offers an additional opportunity to design novel applications such as switches or modulators.

A Correlation Tracking Algorithm Based on Template Partition Motion Estimation

A correlation tracking algorithm based on template partition motion estimation proposed for improving real time performance of the conventional correlation matching algorithms. The target trajectory fitted using the least square with equal space in whole interval and the target prediction point is found out. According to the requirements of block motion estimation(BME) algorithm,the template divided into some macro blocks. The searching process is conducted by using diamond search algorithm around the prediction point and the optimal motion vector of each block is calculated. A point corresponding to the motion vector with the best matching is taken as a rough matching point of the template. The relation of relative position between the block with matching point and the searching area determined to decide whether to conduct precise matching search or to construct a new search area in the gradient direction. The target tracking experiment results show that over 70% time cost can be reduced caompared with the conventional correlation matching algorithm based on full search method.

Mechanical Behavior and Failure Mechanism of 2.5D(Shallow Bend-joint, Deep Straight-joint) and 3D Orthogonal UHWMPE Fiber/Epoxy Composites by Vacuum-assistant-resin-infused

Ultra-high molecular weight polyethylene（UHMWPE） fiber/epoxy composites were fabricated by a vacuum assisted resin infused（VARI） processing technology. The curing condition of composites was at a cure temperature of 80 ℃ for 3h in a drying oven. The characteristics of 2.5D（shallow bend-joint and deep straight-joint） structure and 3D orthogonal structure were compared. The failure behavior, flexural strength, and microstructures of both composites were investigated. It was found that the flexural property was closely related to undulation angle θ. The flexural strength of 3D orthogonal structure composite was superior to the other two structures composites with the same weave parameters and resin.

Effect of Twisted Fiber on Flexural Property and Microstructure of Woven Fabric Reinforced Composite

Two kinds of 2.5D deep straight-joint structure ultra-high molecular weight polyethylene（UHMWPE）（twisted and original） fibers woven fabric reinforced epoxy resin composites were prepared by the hand lay-up method. Subsequently, the flexural property, microstructures, and failure mechanisms of the composites were also investigated. The average flexural strength of 2.5D deep bend-joint structure twisted fiber and original fiber woven fabric composites were 176.66 MPa and 204.45 MPa, respectively. The results of the characteristics indicated that the twist was the main factor which affected the flexural performance. Flexural property vitally relied on the strength of the fiber itself. Twist decreased the strength of the yarns, which meant that when the mechanical property of woven fabric reinforced composites was improved, the yarns must be kept straight in the woven fabric. The study are extremely valuable to guide the improvement of the mechanical property of the woven fabric reinforced composites.

Study on Stable Scanning of Terminal Sensing Ammunition Based on Quaternion Transformation

Euler angles and Euler kinematics equation of terminal sensing ammunition are expressed and rewritten by using quaternion to solve the singular problem in using Euler angles to describe the motion.The contrastive simulations are performed in order to validate the correctness and advantage of the quaternion description.The simulation results show that the dynamic model with quaternion have stable solution,there is not singular point in the calculation,and the ballistic model rewritten by using the quaternion is suitable for describing the terminal sensing ammunition's scanning motion than the common Euler equation.

Determination of Muzzle Velocity Loss by Bore Wear Pattern

A method to determine muzzle velocity loss according to the actual measured bore wear pattern is proposed.Therefore,it is unnecessary to conduct live firing and other experiments for determination of muzzle velocity loss.It has been applied to a national military standard since July 1,2004.

Rapid identification of single constant contaminant source by considering characteristics of real sensors

For the release of hazardous contaminant indoors, source identification is critical for developing effective response measures. A method which can quickly and accurately identify the position, emission rate, and release time of a single constant contaminant source by using real sensors was presented. The method was numerically demonstrated and validated by a case study of contaminant release in a three-dimensional office. The effects of the measurement errors and total sampling period of sensor on the performance of source identification were thoroughly studied. The results indicate that the adverse effects of the measurement errors can be mitigated by extending the total sampling period. For reaching a desirable accuracy of source identification, the total sampling period should exceed a certain threshold, which can be determined by repeatedly running the identification method tmtil the results tend to be stable. The method presented can contribute to develop an onsite source identification system for protecting occupants from indoor releases.

A color image tracking method based on target characteristic hue decision

Conventional correlation matching algorithms waste great time in invalid area search. This paper proposes a color tracking method based on correlation search area optimization on target characteristic hue decision. By quantifying and reducing dimensions of HSV（ hue saturation value） color space, a one-dimensional hue space is constructed. In the space, the target characteristic hue granule set is constructed, which contains attributes such as value, area and average distance between pixels and aiming center. By using granular computing method, the similarity between target and search blocks is obtained and the invalid search areas can be removed. The color tracking experiment has proved that the algorithm can improve real time performance for conventional matching algorithms without precision lost.

Determination of Muzzle Velocity Deviation of Propellant Lot by Thermal Physical and Chemical Performances of Propellant

In this paper the method is put forward that the muzzle velocity deviation of charge lot is determined by thermal performance or component and content of propellant. Live firing or other experiments can be left out by using this method and its accuracy is rather high.

Seeking the Goodness of Human Nature:Analyzing the "Original Sin" in Lear

This thesis attempts to seek the goodness of human nature,which is core of the moral society,analyzing the "Original Sin"——violence,aggression and greed,etc.In Lear,Edward Bond depicts the sinful characters,say,Lear,the two daughters and the victims of violence vividly,however,each one of them cannot persist the temptation of the innate sin,resulting in the eventual self-destruction.Despite the sinful behaviors in the daily life or the political world,the goodness of human nature rather than the inborn sinful nature should play an important role to build the peaceful and harmonious society.

Investigation of thermal protection system by forward-facing cavity and opposing jet combinatorial configuration

This paper focuses on the usage of the forward-facing cavity and opposing jet combinatorial configuration as the thermal protection system （TPS） for hypersonic vehicles. A hemispherecone nose-tip with the combinatorial configuration is investigated numerically in hypersonic free stream. Some numerical results are validated by experiments. The flow field parameters, aerodynamic force and surface heat flux distribution are obtained. The influence of the opposing jet stagnation pressure on cooling efficiency of the combinatorial TPS is discussed. The detailed numerical results show that the aerodynamic heating is reduced remarkably by the combinatorial system. The recirculation region plays a pivotal role for the reduction of heat flux. The larger the stagnation pressure of opposing jet is, the more the heating reduction is. This kind of combinatorial system is suitable to be the TPS for the high-speed vehicles which need long-range and long time flight.

AR-Dedupe: An Efficient Deduplication Approach for Cluster Deduplication System

As data are growing rapidly in data centers,inline cluster deduplication technique has been widely used to improve storage efficiency and data reliability.However,there are some challenges faced by the cluster deduplication system:the decreasing data deduplication rate with the increasing deduplication server nodes,high communication overhead for data routing,and load balance to improve the throughput of the system.In this paper,we propose a well-performed cluster deduplication system called AR-Dedupe.The experimental results of two real datasets demonstrate that AR-Dedupe can achieve a high data deduplication rate with a low communication overhead and keep the system load balancing well at the same time through a new data routing algorithm.In addition,we utilize application-aware mechanism to speed up the index of handprints in the routing server which has a 30%performance improvement.