Support vector machines for transient stability analysis of large-scale power systems

The pattern recognition approach to transient stability analysis (TSA) has been presented as a promising tool for online application. This paper applies a recently introduced learning-based nonlinear classifier, the support vector machine (SVM), showing its suitability for TSA. It can be seen as a different approach to cope with the problem of high dimensionality. The high dimensionality of power systems has led to the development and implementation of feature selection techniques to make the application feasible in practice. SVMs' theoretical motivation is conceptually explained and they are tested with a 2684-bus Brazilian system. Aspects of model adequacy, training time, classification accuracy, and dimensionality reduction are discussed and compared to stability classifications provided by multilayer perceptrons.     

Sheet Pile Tensions in Cellular Structures

Cellular structures constructed of interlocking steel sheet piles are used in marine environments as cofferdams, bulkheads, mooring dolphins, and lock guide walls. In addition to providing safety against sliding, bearing failure, overturning, and tilting, cellular structures must also be designed to prevent sheet pile interlock rupture, which can lead to catastrophic failure if the cell fill is lost. Methods commonly used to estimate sheet pile interlock tensions were developed in the 1940’s, 1950’s, and 1970’s. These methods are based on empirical observations, and they do not explicitly account for soil–structure interactions. This paper presents the results of finite element analyses and instrumentation measurements performed to examine soil–structure interaction effects on sheet pile tensions. The finite-element analyses were used to compute sheet pile tensions at five instrumented cells, and the results are compared with measurements. The calibrated finite-element model was then used to investigate the effects of varying cell geometry, interlock behavior, sheet pile penetration depth, and foundation stiffness on sheet pile tensions. The instrumentation measurements provide data for estimating changes in sheet pile tensions due to cell fill densification, cofferdam unwatering, and bulkhead backfilling.     

Moral identity and the expanding circle of moral regard toward out-groups.

This article examines moral identity and reactions to out-groups during intergroup conflict. Four studies suggest that a highly self-important moral identity is associated with an expansive circle of moral regard toward out-group members (Study 1) and more favorable attitudes toward relief efforts to aid out-group members (Study 2). Study 3 examines moral identity and national identity influences on the provision of financial assistance to out-groups. Study 4 investigates the relationship between moral identity and (a) the willingness to harm innocent out-group members not involved in the conflict and (b) moral judgments of revenge and forgiveness toward out-group members directly responsible for transgressions against the in-group. Results are discussed in terms of self-regulatory mechanisms that mitigate in-group favoritism and out-group hostility. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Evolution of composition and properties of radioactive pulps in long-term storage in tanks

Radioactive pulps extracted from various depths of the storage tank are studied by chemical and physicochemical methods. In the course of long-term storage, the speciation of radionuclides, particularly Pu, changes, and some poorly soluble mineral-like phases are formed, which is consistent with the results of thermodynamic simulation. Various approaches to reprocessing such pulps are analyzed. Different processes should be employed for pulps extracted from different depths of the storage tank.     

Dynamic analysis and open‐loop start‐up of an integrated radiant syngas cooler and steam methane reformer

The transient performance of an integrated radiant syngas cooler (RSC) of an entrained‐bed gasifier and steam methane reformer (SMR) is investigated. Base‐case designs using either co‐current or counter‐current configurations are subjected to operating transients to evaluate the feasibility to transition to new steady states. Each system, under open loop, is subjected to changes in key variables of the SMR feed on the tube side and disturbances to variables of the coal‐derived syngas on the RSC side to determine the dynamics and stability of the integrated system. The results indicate that the co‐current configuration is flexible to move to new operating steady states and more safe than the counter‐current configuration, although it provides less cooling and has poorer methane conversion. The variables likely to violate the design limit in the event of a disturbance are identified. A start‐up procedure is also established based on industrial practices employed for entrained‐bed gasifiers and methane reformers. © 2016 American Institute of Chemical Engineers AIChE J, 63: 1602–1619, 2017     

浅谈水轮发电机筒式轴承间隙对机组安全稳定运行的影响

本文主要叙述发电机筒式导轴承问隙对机组安全运行的影响。通过对丰满4号发电机组导轴承问隙、受力情况进行详细计算与分析，合理地调整了导轴承的问隙，从根本上消除了发电机导轴承存在的不安全隐患，确保了机组长期安全稳定运行。     

Impact of the Leadership in Energy and Environmental Design Accredited Professional Credential on Design Professionals

Leadership in energy and environmental design (LEED) accreditation is quickly becoming one of the most popular professional designations available to members of the building design and construction community. The purpose of this research was to determine the impact that the LEED accredited professional (AP) designation has had on architecture/engineering (A/E) firm employees versus employees of owners, contractors, subcontractors, and other organization types. The researchers analyzed 9,060 responses from LEED-APs using a one-way ANOVA to determine whether or not significant differences in perceived benefit exist between LEED-APs working for A/E firms and LEED-APs working for other organization classifications. Results indicated a statistically significant difference in six of the eight “impact” categories. LEED-APs working for A/E firms did not feel as strong as LEED-APs working for other organization types that the credential provided any more recognition, professional opportunities for contributions, and prestige among superiors and individuals within their organization. There were no significant differences between the groups, however, with regard to the credential’s impact on salary and job responsibilities.     

Longitudinal Study of Innovative Contracting Practices in State Departments of Transportation

Gathering content expertise both from published sources and from recognized highway construction professionals, a questionnaire was created to determine the use of 16 innovative contracting practices in the highway construction industry. The major practices include: build-own-operate-transfer, contractor prequalification, design/build, dispute resolution, guarantee/warranty, partnering, value engineering, among others. Using the questionnaire, a 10-year longitudinal study gathered information from U.S. Departments of Transportation in 1996, and then again in 2007. Statistical analysis of the 43 state responses found that 10 of these practices have seen significant increase, but the perceived benefits have increased very little, and one practice has seen a significant decrease in perceived benefit.