Design optimization of a large scale rooftop photovoltaic system

This paper presents the optimization process of a grid connected photovoltaic (PV) system, which is intended to replace a large-scale thermal solar system on the rooftop of a Federal office building. A PV energy conversion model is described. Based on this model, array surface tilt angle and array size are optimized. The optimization method is based on maximizing the utilization of the array output energy, and, at the same time, minimizing the electricity power sold to grid. An effectiveness factor is introduced that takes into account both of these parameters. The array configuration and the output parameters are determined by comparing several PV modules. A 43.2 kW PV system is designed and operational problems such as harmonic effects and anti-islanding are discussed. Finally, the system performance is simulated and through economic analysis it has shown that the cost of PV system can be recouped in 13 years under the current renewable energy incentive program by the state of Illinois.     

Continuity wave in the elongated bubble region of horizontal slug flow

Visualized observation on the wave feature in a horizontal slug flow was made with a high‐speed digital camera. It was found that the liquid film flow in the elongated bubble region of slug flow behaves as a continuity wave. Theoretical analysis was carried out and it reveals that the liquid film flow is a continuity wave with celerity the same as the translational velocity of the elongated bubble. The control equation for the liquid film height in the elongated bubble region was derived. The results predicted by the equation fit well with the observed data. A new conclusion was obtained that slug flow has continuity wave in it, explaining the stable slug flow wave characterization. © 2005 Wiley Periodicals, Inc. Heat Trans Asian Res, 34(8): 547–554, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/htj.20092     

A Novel SAO-based Filtering Technique for Reduction in Temporal Flickering Artifacts in H.265/HEVC

This paper presents a novel filtering technique based on sample adaptive offset (SAO) in H.265/high-efficiency video coding (HEVC) for reduction in the temporal flickering artifacts and improving the coding performance. SAO is a newly introduced technique for in-loop filtering in H.265/HEVC, which derives the offsets independently for each frame in the spatial domain without considering temporal frame correlation. As a result, the temporal distortion artifacts which will have a negative effect on the subjective quality, such as flickering artifacts, cannot be effectively addressed. In this paper, the rate-distortion optimization of the newly developed SAO method, referred to as Inter-SAO, is performed on the residual samples between adjacent frames. Inter-SAO and SAO in the reference software of H.265/HEVC (i.e., the test model HM) are then combined to form the novel in-loop filter-based method, denoted as 3D-SAO filtering method, where both spatial information and temporal information are effectively utilized to reduce the overall distortion in reconstructed videos. Compared with the SAO in HM, 3D-SAO has demonstrated its advanced performance for flickering artifacts suppression. Furthermore, 3D-SAO improves the coding efficiency compared with the SAO in HM with a performance gain of up to 0.91 dB in \(\Delta PSNR\), 1.74 dB in \(\Delta PSPNR\) and 7.33 % in BD-rate reduction.     

针对多方参与特征的地理空间信息网格结构设计

地理空间信息网格结构层次设计既考虑了多方参与特征，又参考了目前较为流行的五层沙漏结构和开放网格服务结构，还参考了我国学者从开发的角度提出的一般网格层次结构，以此为基础试设计并探讨地理空间信息网格的基本层次结构。     

Cryptanalysis of Wang's original and revised digital signaturescheme

Wang's basic digital signature scheme and its new variation is cracked. The proposed signature forging algorithm makes no assumptions on operations of the schemes and is as efficient as the signing algorithm     

国外甜菜品种在宁夏丛根病区的耐病性表现

经1991～1992年的比较试验,德国KWS公司和法国德普雷公司的耐丛根病甜菜品种在感染了丛根病毒土壤环境条件下种植,均不同程度的表现出耐丛根病性能,个别品种耐丛根病性能较强。但该类品种在无丛根病或轻度感染丛根病地种植,均表现不抗褐斑病,含糖分较低。     

乌龙泉矿尾矿库的治理

介绍了乌龙泉矿尾矿库治理的具体方法 ,详细地阐述了回收利用石灰石、白云石洗矿尾矿的回收利用和采用辐射井排渗固结技术加固主坝等新工艺。     

MgZn铁氧体（偏转）磁性材料的X射线光谱测定与研究

提出了用Ｘ射线光谱仪粉末压片法熔融片法测定ＭｇＺｎ铁氧体各组分浓度的方法,对粉料的制备,均匀性状态颗粒度进行了一系列试验。     

利用SCADA系统遥测数据实时计算线损变损

为了提高电网运行的经济性,利用ＳＣＡＤＡ系统遥测数据实时计算电网线损、变损是十分必要的,也是可行的。实时计算线损、变损能够达到以下目的：（１）动态观察正常方式及非正常方式时电网各条线路、各变电站的线路损耗、变压器损耗及其损耗率。（２）便于统计每月、每...     

AWE implementation for electromagnetic FEM analysis

Although full wave electromagnetic systems are large and cumbersome to solve, typically only a few parameters, such as input impedance, S parameters, and far field pattern, are needed by the designer or analyst. A reduced order modelling of these parameters is therefore an important consideration in minimising the CPU requirements. The asymptotic waveform evaluation (AWE) method is one approach to construct a reduced order model of the input impedance or other useful electromagnetic parameters. The authors demonstrate its application and validity when used in conjunction with the finite element method to simulate full wave electromagnetic problems