As the power supply load of the distribution network itself is volatile, it is necessary to consider the reserve demand brought by the load. At present, most studies set the reserve demand of the load as 6% of the load value at that time. As an important part of the modern distribution network, the power supply department can adjust the power supply of the flexible load according to the prior contract agreement. In this paper, the flexible load is taken to optimize the island range. Based on the improved LSTM neural network, the confidence level and the influence of different types of flexible loads on islanding are solved. It is concluded that the islanding reserve demand varies with the output and confidence level of intermittent power sources. The islanding stability and economic demand under different confidence levels can be balanced by adjusting the flexible load. The equivalent value of islanding restoration can be effectively increased. Compared with the post-fault power supply restoration without considering the islanding reserve demand, the proposed strategy improves the reliability of the power supply, which shows the effectiveness of the proposed strategy. The experimental evaluation results verify that the improved LSTM neural network has better classification performance, and its classification accuracy index has stronger adaptability and anti-interference in the experiment. Besides, it has a good classification effect in the task of fault type and fault feeder identification of the photovoltaic distribution network. By balancing the power supply stability and demand under different confidence levels for the regulation model, and effectively increasing the value of restoration equivalence, the reliability of power supply is improved, which is more practical.

北海公园冰上运动是北京传统体育文化遗产的重要组成内容以及冬季休闲旅游的代表性符号,强化其气候变化影响与适应研究,对于应对全球变化的挑战、践行"大力发展冰雪经济"的指示具有重要意义.本文从多源文献中提取分析了其冰场多年启闭日期(间接指示冰层厚15 em)的变化特征,并结合气温器测数据以及4种气候情景数据(SSP1-2.6、SSP2-4.5、SSP3-7.0和SSP5-8.5),利用留一交叉验证法探讨了不同温度指标和拟合方程的预测效果差异,进而对未来冰上运动季的变化、潜在影响与适应对策进行分析.结果 表明:①1989-2018年冰上运动季始日、末日和持续长度的均值分别为1月1日、2月5日和36d,对应的趋势表现为不显著的推迟(1.00d/10a)、提前(-0.77d/10a)和延长(1.11d/10a),时序变化可区分为1989-2000年、2001-2013年和2014-2018年3个阶段.②冰上运动季始、末日分别对其日期前59 d的日最低温和前94 d的日最高温有较好响应,利用这两个指标和玻尔兹曼函数可更好预测冰上运动季变化.③2021-2099年冰上运动季始日、末日和持续长度的均值分别较1989-2018年晚1d、早1d和缩短2d,3个指标变幅一致缩小,对应的0.14d/10a、-0.21d/10a和-0.34d/10a的趋势均达到0.01的显著性水平.④未来79 a内冬季两大节庆中元旦冰上运动的适宜性要大于春节,其中春节的适宜性在4种气候情景下相差不大,而元旦的适宜性则在4种情景下有一定差别.⑤在相关预估结果上,BCC-CSM2-MR、CanESM-5和UKESM这3种区域气候模式并没有太大差异,而热岛效应影响尚待深入研究.⑥为了在气候变暖背景下促进体旅融合消费、保障冰上运动产业高质量发展,运营企业应采取强化游客安全保障、扩展旅游产品谱系、购买冰量保险等全方位主动适应措施,研究者应加强研究气候变化影响的复杂性、改进旅游流的预测效果,而管理部门应大力推动产业风险管理报告的编制,充分重视气候变化风险的动态评估.

以长江经济带为例,构建了无高铁、现有高铁和规划高铁三种情景,引入旅游"门到门"出行的旅行时间测度方法,同时采用分层栅格成本方法改进可达性计算模型,综合运用加权平均旅行时间、日常可达性指数和旅游效用函数等指标定量测度并全面分析了高铁对区域旅游的"时空压缩"效应.研究发现:①现有高铁将长江经济带景区加权平均旅行时间"压缩"了 3.36 h,规划高铁进一步将其"压缩"了1.09 h,使区域的旅游空间范围不断"缩小";②高铁的"时空压缩"效应对区域旅游的影响具有双面性,加剧了短期旅游圈所覆盖景区数量的空间分异,但使长假旅游圈所覆盖景区数量在空间上趋于均衡;③不同高铁建设阶段对区域旅游的影响存在差异,现有高铁便利了游客的中远程旅游,而规划高铁则对游客短途旅游产生重要影响,并强化了同区域外的旅游联系;④高铁"压缩"了旅途时间,"扩张"了游览时间,大幅提高了旅游效用,这在川渝两地表现的尤为显著.

As an important measure for structure optimization, the network reconfiguration has been drawing attention of scholars at home and abroad. At present, the general goal for network reconfiguration is to reduce network line loss achieving load balance. In this paper, the reconstruction methods for distribution network considering closed loop constraints is proposed from the perspective of load transfer between different loops to improve closed system reliability. After Dongjing Town distribution network verification, this method has shown important theoretical significance and high practical value.

We propose a 3D interaction and autostereoscopic display system that use gesture recognition, which can manipulate virtual objects in the scene directly by hand gestures and can display objects in 3D stereoscopy. The system consists of a gesture recognition and manipulation part as well as an autostereoscopic display as an interactive display part. To manipulate the 3D virtual scene, a gesture recognition algorithm is proposed, which use spatial-temporal sequences of feature vectors to match predefined gestures. To get smooth 3D visualization, we utilize the programmable graphics pipeline in graphic processing unit to accelerate data processing. We develop a prototype system for 3D virtual exhibition. The prototype system reaches frame rates of 60fps and operates efficiently with a mean recognition accuracy of 90%.

Multiview autostereoscopic systems display three-dimensional (3D) images interleaved from parallax images to provide adequate viewing zones for viewers. A 3D image interleaving method based on parallel processing with Graphic Processing Unit (GPU) is proposed to accelerate the image interleaving for real-time autostereoscopic displays. The proposed method is implemented with Direct3D Application Programming Interface (API) library. Masks used to interleave the 3D images are generated according to some particular principles. Both multiple texture blending and alpha blending operations are used to interleave a 3D image. The experiments prove that high interleaving efficiency and good stereoscopic sense can be obtained. The proposed method meets the requirement of real-time multiview autostereoscopic displays and avoids extra shader program.

Abstract— Stereoscopic and autostereoscopic projection‐display systems use projector arrays to present stereoscopic images, and each projector casts one parallax image of a stereoscopic scene. Because of the position shift of the projectors, the parallax images have geometric deformation, which influences the quality of the displayed stereoscopic images. In order to solve this problem, a method based on homography is proposed. The parallax images are pre‐transformed before they are projected, and then the stereoscopic images without geometric distortion can be obtained. An autostereoscopic projection‐display system is developed to present the images with and without calibration. Experimental results show that this method works effectively.

Multiview autostereoscopic systems display three-dimensional (3D) images interleaved from parallax images to provide adequate viewing zones for viewers. A 3D image synthesizing method based on parallel processing with Graphic Processing Unit (GPU) is proposed to accelerate the image synthesizing for real-time autostereoscopic displays. The GPU-based 3D image synthesizing method is implemented with Direct3D Application Programming Interface (API) library. Compared with traditional methods using Central Processing Unit (CPU), the proposed method takes advantage of GPU graphic processing. The experiments prove that GPU-based 3D image synthesizing method can meet the requirement of real-time 3D image synthesizing and perform well in stereoscopic sense.

With synchronized phasor measurement, a real-time assessment algorithm for transient stability based on phasor trajectory clusters rules is presented in this paper. A novel combined algorithm, which was composed of K-mean and fuzzy C-mean methods, was applied on line to recognize trajectories' coherency state and deviation features of clusters' appearance within several cycles after disturbance. A standard classification and regression tree (CART) method was proposed to abstract knowledge rules from the evolution of pre-classified feature index. Such a group of index of real-time trajectory clusters' position, rather than trajectories themselves (amplitude for instance), was utilized to assess transient stability and disturbance severity level. Detailed analysis shows that the proposed algorithm can predict transient stability accurately with regard to the future 4 s by using data within 8~20 cycles without dependence on power system model or specific nature of the disturbance. Significant information such as the stability state, critical machine, severity level are detected at the same time. In addition the whole process mainly focuses on generalized response pattern recognition of power system, and therefore avoids having to directly determine the controlling unstable mode and different rule sets. New England benchmark case verifies the validity of the method. © 2011 Chin. Soc. for Elec. Eng.

Since voltage control may result in voltage frequent adjustments and voltage regulation unreasonable phenomenon, so, before AVC closed loop control running the strategy must be implemented strictly functional and performance testing and verification, to ensure zero risk after put into operation. This paper develops a comprehensive simulation environment and effective means of assessment is expected to put into operation and has been in operation in the area reactive power real-time control system safety analysis and validity assessment. The core of the system framework is responsible for the system data exchange, task scheduling and the results show a visual platform; the remaining part of the independent modules, namely: intelligent simulation module, the standard voltage and reactive power control module, intelligent evaluation modules, intelligent case generator module. This new model is ideal for simulation and assessment of the existing power system in the assessment of different AVC systems which will soon be applied in the Guangdong provincial power grid. © 2010 Chinese Soc for Elec Eng.

We introduce seven ways of constructing products for Mealy-type fuzzy finite state machines as well as the concept of covering. The properties of transition functions and output functions are discussed. Furthermore, we investigate the covering properties and mutual relationship with regard to these products. We also prove that the covering relationship holds in the product of factor machines.

According to the integral theory of energy function, branch potential energy function model is constructed, and then two indexes are proposed: one is the current vulnerability, which quantifies the distance between the current transmitted power and initial transmitted power to identify the current vulnerable area, the other is the forecasting vulnerability, which is gained through computing the branch vulnerability considering the impact of power injection changing. By the two indexes, the current and forecasting vulnerable area can be identified and the correctness of the former one can be validated. Through the simulations in IEEE-30 bus system and the comparison with optimal power flow under N-1 and N-2 faults, the results show that the branch potential energy function model have many advantages such as rapid computation without being influenced by the convergent condition of power flow, identifying and forecasting the vulnerable branch exactly. Because of these, the application of this method on the on-line security monitoring is expected.

With the wide application of flexible AC transmission system (FACTS) controllers in power system, the researches have been interested in on interaction among FACTS controllers, on interaction between FACTS controller and power system. This interaction can bring negative influence on the reliability of system. With technical development, power electronics devices, such as GTO, IGCT and IGBT, have been applied widely in power system. A typical application is the static synchronous series compensator (SSSC) , a series reactive power compensation device. In this paper, the relative gain array (RGA) theory is proposed to analyze the interaction between SSSC and static var compensator (SVC); And the negative interaction is solved through direct feedback linearization (DFL) based nonlinear control. Finally, the effect of the proposed methods are confirmed on a single machine infinite bus system with a SSSC and a SVC, and the simulation results agree with that from RGA theory described in this paper.

In this paper,prepared are three kinds of SiO 2 TiO 2 photocatalyst containig zirconium.At pH=7,treated with commonlight source,decoloration rates of acid scarlet red 3R,direct fast black G and active scarlet red K 2G are more than 95%.

Four ozone decomposition catalysts were prepared and their catalytic reactivity were investigated.The ozone decomposition efficiency showed that even under a high humidity condition at relative humidity of 95%,the four variety of catalysts maintained high ozone decomposing performance for a long period of time.Especially,the RP catalyst had the best reactivity,the ozone decomposition efficiency after starting the reaction 20 hours still remained at 99.6%.

A simulation model of saturated reactor type high Tc superconducting fault current limiter was analyzed and established. The limiting fault current effect of this new current limiter was numerically simulated using electromagnetic transients program. Through the contrast analysis with the traditional linear current-limiting reactor, it was shown that the new current limiter can effectively resolve the contradiction in decreasing voltage drops under normal operation and increasing the ability of limiting fault currents.

Power system restoration is a very complex nonlinear problem. A power system restoration based-on expert system was presented. In the restoration process, the voltages of the system are simultaneously monitored by fast numerical computation to prevent new unstability. The expert system adopts hierarchical structure in the knowledge base, in search strategy, the breadth first search strategy and the depth first search strategy are applied and the appropriate conflict-resolution search is used. The program of the expert system has been written using C language. A practical system has been taken to test the restoration plan using digital simulation.

It is important to develop accurate load models for the analysis of power system performance. The load model of a substation in Sichunan power system has been obtained using Artificial Neural Networks (ANN) and recursive least-squares (RLS) identification in this paper. The results show that the ANN can map the nonlinear characteristics of dynamic loads better than the traditional identification methods.

physica status solidi (a)Volume 140, Issue 1 p. K35-K38 Short Note Anomalous conductivity behaviour owing to resonant tunneling in μ-Si:H/a-Si: H superlattices Jun Liu, Jun Liu Department of Materials Science, Sichuan University, Chengdu Search for more papers by this authorLianghuan Feng, Lianghuan Feng Department of Materials Science, Sichuan University, Chengdu Search for more papers by this author Jun Liu, Jun Liu Department of Materials Science, Sichuan University, Chengdu Search for more papers by this authorLianghuan Feng, Lianghuan Feng Department of Materials Science, Sichuan University, Chengdu Search for more papers by this author First published: 16 November 1993 https://doi.org/10.1002/pssa.2211400136 610064 Chengdu, People's Republic of China AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Volume140, Issue116 November 1993Pages K35-K38 RelatedInformation

The μc-Si:H/a-Si:H (hydrogenated microcrystalline silicon/amorphous silicon) microstructure-modulated superlattices have been prepared using a simple method of r.f. glow-discharge. The valence band offset for μc-Si:H/a-Si:H heterojunction interfaces is determined by X-ray photoelectron spectroscopy. The energy band profile for this multilayer is drawn quantitatively. The PPC (persistent photoconductivity) effect has been observed in this multilayer, which is thought to be attributed to spatial separation of carriers. The dependence of the PPC effect on sublayer thickness is studied.