足球射门限制网的制作与应用

足球射门限制网四角镂空,呈十字形,可根据不同赛制球门大小,确定横幅使用长度。本文以五人制足球比赛球门为例,介绍足球射门限制网的制作。利用限制网可以模拟守门员防守范围,训练球员各种形式射门的准确度,培养球员死角射门的意识,最终形成射门习惯。通过限制性射门训练使球员在激烈的比赛环境中能做出高质量、高准确度的射门,同时方便教练进行动作指导,减轻教学压力,提升训练质量。

一种基于混合Petri网的批过程动态调度算法

针对批处理过程动态调度问题的特点 ,以赋色时间限制混合Petri网为工具 ,建立了批过程动态调度的混合Petri网模型 ,将批过程的调度问题映射为求Petri网中变迁的最优激发序列问题 .在此模型基础上 ,根据动态规划基本原理 ,以资源的终极利用即最短生产周期作为调度目标 ,提出了一种基于赋色时间限制混合网模型求取变迁的最优激发序列的方法 ,并针对实际情况中出现的复杂的中间产品存贮策略 ,讨论了在各存贮策略约束下该模型中时间限制区间的确定方法 ,最后以炼钢 连铸生产系统的过程调度为例 ,对该算法进行了仿真 .多次仿真结果表明 ,当任务和设备的初始时刻或者过程的动态过程发生改变时 ,调度结果各不相同 ,从而验证了该算法的有效性 .

Intrusion detection model based on deep belief nets

This paper focuses on the intrusion classification of huge amounts of data in a network intrusion detection system. An intrusion detection model based on deep belief nets （DBN） is proposed to conduct intrusion detection,and the principles regarding DBN are discussed.The DBN is composed of a multiple unsupervised restricted Boltzmann machine （RBM） and a supervised back propagation （BP）network.First,the DBN in the proposed model is pre-trained in a fast and greedy way,and each RBM is trained by the contrastive divergence algorithm.Secondly,the whole network is fine-tuned by the supervised BP algorithm,which is employed for classifying the low-dimensional features of the intrusion data generated by the last RBM layer simultaneously.The experimental results on the KDD CUP 1999 dataset demonstrate that the DBN using the RBM network with three or more layers outperforms the self-organizing maps （SOM）and neural network （NN）in intrusion classification.Therefore,the DBN is an efficient approach for intrusion detection in high-dimensional space.

牵引供电系统与牵引传动系统稳定性机理分析

国内某客运专线牵引变电所频繁出现跳闸情况,给牵引供电系统和动车组正常运行带来安全隐患。为寻求故障根源,用于指导今后的高速铁路建设,本文首先利用阻抗比判据建立车网闭环系统传递函数模型,揭示阻抗参数不匹配引起低频振荡产生的原理,并对动车组网压-功率限制保护引起低频振荡进行分析。然后基于MATLAB/Simulink软件搭建车网系统仿真模型并进行联合仿真,再现现场故障现象。本文通过理论分析并仿真验证了低频振荡产生的2种原因,可为实际现场振荡抑制提供指导,进而保障车网系统的稳定安全运行。

Vehicular Beacon Broadcast Scheduling Based on Age of Information(AoI)

Vehicular beaconing plays an important role to facilitate various applications in the paradigm of Internet of Vehicles(IoV). Due to high dynamic and resource limitation in IoV, how to schedule the vehicular beacon broadcast is challenging, especially in dense scenarios. In this paper, we investigate the beacon broadcast scheduling problem considering the Age of Information(AoI). We first propose an algorithm minimizing the expected sum of AoI considering the limited communication resource and vehicle mobility. Then the performance of the proposed algorithm is analyzed. With the proposed algorithm, the optimal solution can be obtained under certain conditions. Extensive simulations are conducted to verify the efficiency, effectiveness and fairness of the proposed solution.

Technical Evaluation of Eye Drops Instillation： A Systematic Review

Objective： Assess the profile of eye drops in patients with eye diseases. Methods： Studies available in the scientific literature were identified without any time limits using the databases Embase-Medline, Scielo, Scopus and Web of Knowledge. The selected studies were compared with the following inclusion criteria： （i） if the study evaluated the eye drop instillation, （ii） if the study involved participation of patients with eye diseases. Results： Twelve studies met the inclusion criteria. Of them, 83.33% evaluated the technique of eye drop instillation in patients with glaucoma, 8.33% in patients with eye diseases and 8.33% in patients with cataract after undergoing surgery to correct. 41.66% of studies have chosen to record a video of patients to analyze the technique of instilling eye drops and 41.66% did not describe the/esearch location. Regarding the type of study, 75% had the design as prospective cross-sectional, 8.33% prospective open label study, 8.33% intervention study and 8.33% study called masked trial. Although studies evaluate the technique of eye drop instillation, only 8.33% describe in the article the reference in the literature used to evaluate patients. 50% of articles acknowledged some sort of bias or limitation. Conclusion： The limitations inherent in these types of studies should guide future research.

Fault Current Limiters and Impacts on the System Protection Behavior

A deregulated power market is making short-circuit currents likely to exceed the thermal or mechanical permissible limits of switchgear. Consequently fault current limiters （FCL） become more necessary in power systems. The use of FCLs has an impact on the protection schemes and functions in power systems. Thus, before FCLs can be applied in the network, the impacts on existing protection system must be understood. Depending on the current limiting technique used, today＇s protection concepts may have to be adapted or revised to ensure proper network protection selectivity. A relationship between fault current limiters and protection schemes should be established by taking into account both protection and network specific issues, such as the impact of different FCL technologies, existing and new protection concepts, selectivity and innovative network. This paper is presenting a frame work for accomplishing this task.

A TRAFFIC OVERSTOCK RESLOVE SCHEME IN WLAN

A new Multiple Access Control (MAC) protocol-User Adaptive Scheduling Multiple Access (UASMA) protocol is proposed in this paper. It can well schedule the packet transmission according to the exact number of active Mobile Terminals (MTs) determined by selforganizing algorithm and adjust the number of packets sent by one node in one frame properly.UASMA protocol employs a special frame structure, which makes it possible to allocate channel resource to uplink and downlink traffic according to their respective service requirements. The proposed concept of referenced-frame-length can ensure the frame length varies in a certain range,and consequently increase the utilization efficiency of the channel greatly. Meanwhile, UASMA protocol uses an efficient collision resolution algorithm to guarantee that active MTs can access the channel rapidly. Finally, the performance of UASMA protocol is evaluated by simulation and it is also compared with carrier sense multiple access, rounding-poll and UPMA protocols. The results show that the UASMA has better performance than others.

Application of Wind Generation on Weak Networks Considering Potential System Limitations Due to Transients and Faults

Limited resources are available on the application of wind generation systems interconnected to weak powemetworks. With the need to further interface DG （distributed generation） including WG （wind generation） to weak networks, it is necessary to establish a means of determining what is the most efficient quantity of WG that can be applied in order to maintain stability in the network. This paper establishes a concept that can be applied to weak networks. The aim is to estimate how much WG can be installed on weak networks as well as establishing characteristic responses to generation loss without and with faulted conditions. The main contribution is a thorough understanding of weak network limitation proved to be the most critical parameter in these calculations.

Evaluation of Underwater Optical-Acoustic Hybrid Network

The deployment of underwater networks allows researchers to collect explorative and monitoring data on underwater ecosystems.The acoustic medium has been widely adopted in current research and commercial uses,while the optical medium remains experimental only.According to our survey onthe properties of acoustic and optical communicationsand preliminary simulation results have shown significant trade-offs between bandwidth,propagation delay,power consumption,and effective communication range.We propose a hybrid solution that combines the use of acoustic and optical communication in order to overcome the bandwidth limitation of the acoustic channel by enabling optical communicationwith the help of acoustic-assisted alignment between optical transmitters and receivers.

Reducing the Short Circuit Levels in Kuwait Transmission Network

This paper describes the study analysis performed to evaluate the available and potential solutions to control the highly increasing short circuit （SC） levels in Kuwait power system. The real Kuwait High Voltage （HV） network was simulated to examine different measures at both 275 kV and 132 kV stations. The simulation results show that the short circuit currents exceed the permissible levels （40 kA in the 132 kV network and 63 kA in the 275 kV network） in some specific points. The examined measures include the a study on changing the neutral point policy, changing some lines from alternating current （AC） to direct current （DC）, dividing specific bus bars in some generating stations and applying current limiters. The paper also presents a new plan for the transmission network in order to manage the expected increase in short circuit levels in the future.

Simulation of Sloshing Phenomena Using ALE Approach

Sloshing has a widespread application in many industries including automotive, aerospace, ship building and motorcycle manufacturing. The goals of sloshing simulation is to first study the sloshing pattern and then improve the tank design to reduce noise levels, stresses on the structure and optimize the baffle arrangements. In this project simulation of the fluid in tank is studied and the design modification with baffle plate is considered to minimize the sloshing phenomena using Arbitrary Langrangian Eulerian （ALE） method. Also it is explained that there is need to analyze the sloshing phenomena in detail. Arbitrary Langrangian Eulerian finite element methods gain interest for the capability to control mesh geometry independently from material geometry, the ALE methods are used to create a new undistorted mesh for the fluid domain. In this paper we use the ALE technique to solve fuel slosh problem. Fuel slosh is an important design consideration not only for the fuel tank, but also for the structure supporting the fuel tank. Fuel slosh can be generated by many ways： abrupt changes in acceleration （braking）, as well as abrupt changes in direction （highway exit-ramp）. Repetitive motion can also be involved if a sloshing resonance is generated. These sloshing events can in turn affect the overall performance 0fthe parent structure. A finite element analysis method has been developed to analyze this complex event. A new ALE formulation for the fluid mesh can be used to keep the fluid mesh integrity during the motion of the tank. This paper explains the analysis capabilities on a technical level.

Finite-Time Neural Funnel Control for Motor Servo Systems with Unknown Input Constraint

In this paper, a finite-time neural funnel control(FTNFC) scheme is proposed for motor servo systems with unknown input constraint. To deal with the non-smooth input saturation constraint problem, a smooth non-affine function of the control input signal is employed to approximate the saturation constraint, which is further transformed into an affine form according to the mean-value theorem. A fast terminal sliding mode manifold is constructed by using a novel funnel error variable to force the tracking error falling into a prescribe boundary within a finite time. Then, a simple sigmoid neural network is utilized to approximate the unknown system nonlinearity including the saturation.Different from the prescribed performance control(PPC), the proposed finite-time neural funnel control avoids using the inverse transformed function in the controller design, and could guarantee the prescribed tracking performance without knowing the saturation bounds in prior. The effectiveness and superior performance of the proposed method are verified by comparative simulation results.

Exploration behaviour and behavioural flexibility in orb-web spiders： A review

Orb-web spiders and their webs constitute an ideal model system in which to study behavioural flexibility and spatial cognition in invertebrates due to the easily quantifiable nature of the orb web. A large number of studies demonstrate how spiders are able to modify the geometry of their webs in response to a range of different conditions including the ability to adapt their webs to spatial constraints. However, the mechanisms behind this impressive web-building flexibility in these cognitively limited animals remain poorly explored. One possible mechanism though may be spatial learning during the spiders＇ exploration of their immediate surroundings. This review discusses the importance of exploration behaviour, the reliance on simple behavioural rules, and the use of already laid threads as guidelines for web-building in orb-web spiders. The focus is on the spiders＇ ability to detect and adapt their webs to space limitations and other spatial disruptions. I will also review the few published studies on how spatial information is gathered during the exploration phase and discuss the possibility of the use of ＇cognitive map＇-like processes in spiders. Finally, the review provides suggestions for designing experimental studies to shed light on whether spiders gather metric information during the site exploration （cognitive map hypothesis） or rely on more simple binary information in combination with previously laid threads to build their webs （stigmergy hypothesis）.

Deep learning compact binary codes for fingerprint indexing

With the rapid growth in fingerprint databases, it has become necessary to develop excellent fingerprint indexing to achieve efficiency and accuracy. Fingerprint indexing has been widely studied with real-valued features,but few studies focus on binary feature representation, which is more suitable to identify fingerprints efficiently in large-scale fingerprint databases. In this study, we propose a deep compact binary minutia cylinder code（DCBMCC）as an effective and discriminative feature representation for fingerprint indexing. Specifically, the minutia cylinder code（MCC）, as the state-of-the-art fingerprint representation, is analyzed and its shortcomings are revealed.Accordingly, we propose a novel fingerprint indexing method based on deep neural networks to learn DCBMCC.Our novel network restricts the penultimate layer to directly output binary codes. Moreover, we incorporate independence, balance, quantization-loss-minimum, and similarity-preservation properties in this learning process.Eventually, a multi-index hashing（MIH） based fingerprint indexing scheme further speeds up the exact search in the Hamming space by building multiple hash tables on binary code substrings. Furthermore, numerous experiments on public databases show that the proposed approach is an outstanding fingerprint indexing method since it has an extremely small error rate with a very low penetration rate.

Finite-time stabilization of switched dynamical networks with quantized couplings via quantized controller

This paper concerns the stabilization of switched dynamical networks with logarithmic quantization couplings in a settling time.The switching sequence is constrained by hybrid dwell time. Controller is designed by using limited information. Due to the quantization and switching, traditional finite-time analysis methods cannot be utilized directly. By designing multiple Lyapunov functions and constructing comparison systems, a general criterion formulated by matrix inequalities is first given. Then specific conditions in terms of linear matrix inequalities are established by partitioning the dwell time and using convex combination technique. An optimal algorithm is proposed for the estimation of settling time. Numerical simulations are given to verify the effectiveness of the theoretical results.

A weighted network evolving model with capacity constraints

Most of existing works on complex network assumed that the nodes and edges were uncapacitated during the evolving process,and displayed "rich club" phenomenon.Here we will show that the "rich club" could be changed to "common rich" if we consider the node capacity.In this paper,we define the node and edge attractive index with node capacity,and propose a new evolving model on the base of BBV model,with evolving simulations of the networks.In the new model,an entering node is linked with an existing node according to the preferential attachment mechanism defined with the attractive index of the existing node.We give the theoretical approximation and simulation solutions.If node capacity is finite,the rich node may not be richer further when the node strength approaches or gets to the node capacity.This is confirmed by analyzing the passenger traffic and routes of Chinese main airports.Due to node strength being function of time t,we can use the theoretical approximation solution to forecast how node strength changes and the time when node strength reaches its maximum value.

Predicting the effect of climate change on a range-restricted lizard in southeastern Australia

Climate change is ranked as one of the most severe threats to global biodiversity. This global phenomenon is particularly true for reptiles whose biology and ecology are closely linked to climate. In this study, we used over 1,300 independent occurrence points and different climate change emission scenarios to evaluate the potential risk of changing climatic conditions on the current and future potential distribution of a rock-dwelling lizard; the velvet gecko. Furthermore, we investigated if the current extent of protected area networks in Australia captures the full range distribution of this species currently and in the future. Our results show that climate change projections for the year 2075 have the potential to alter the distribution of the velvet gecko in southeastern Australia. Specifically, climate change may favor the range expansion of this species to encompass more suitable habitats. The trend of range expansion was qualitatively similar across the different cli- mate change scenarios used. Additionally, we observed that the current network of protected areas in southeast Australia does not fully account for the full range distribution of this species currently and in the future. Ongoing climate change may profoundly affect the potential range distribution of the velvet gecko population. Therefore, the restricted habitat of the velvet geckos should be the focus of intensive pre-emptive management efforts. This management prioritization should be extended to encompass the increases in suitable habitats observed in this study in order to maximize the microhabitats available for the survival of this species.

Spectral Properties and Positivity of Flows in Infinite Networks with Dynamic Boundary Control Nodes

In this paper we study transport processes on infinite networks with dynamic boundary control nodes. These flows can be modeled by operator semigroups on a suitable Banach space. Using functional analytical and graph theoretical methods, we investigate its spectral properties of the system and positivity of the semigroup under appropriate assumptions on the network.