Discussion of "The application of power system stabilizers to a multigenerator plant"

M.J. Gibbard et al. comment on the paper by G.J. Rogers (see ibid., vol.15, no.1, p.350-5, 2000). They discuss their application of a different design procedure to the author's four-machine infinite bus system. The original author replies to the comments.M. J. Gibbard and D. J. Vowles, G Roger

Challenges and Choices: Modelling New Zealand’s Long-term Fiscal Position

This working paper provides further detail on the modelling behind Challenges and Choices – New Zealand’s Long-Term Fiscal Statement, published on 29 October 2009. Building on the first Statement of 2006, we construct two main fiscal scenarios over a 40- year horizon. The historic trends scenario allows historic and current spending and revenue settings to interact with changing demography. The sustainable debt scenario applies a fiscal constraint on non-benefit spending so that Crown net debt follows the Government’s medium-term fiscal targets. The modelling innovations introduced this time do not alter the basic structure and principles of the Long-term Fiscal Model, but instead provide insights into government spending: public sector productivity growth and the growth of the basket of services each person receives. These innovations enable us to illustrate the effects of tradeoffs between broad spending categories in a constrained fiscal environment. In the 2009 Statement, these policy changes are combined into three possible scenarios for obtaining a sustainable fiscal position. The paper also illustrates the sensitivity of the fiscal position to small changes in the demographic, macroeconomic and fiscal modelling assumptions.Population, projections, social expenditure, fiscal costs, New Zealand

QAA subject benchmark statement architecture : version for consultation December 2019

The Statement is intended to guide lecturers and course leaders in the design of academic courses leading to qualifications in architecture, it will also be useful to those developing other related courses. Higher education providers may need to consider other reference points in addition to this Statement in designing, delivering and reviewing courses. These may include requirements set out by the Architects Registration Board (ARB), the Royal Institute of British Architects (RIBA) and the Institute for Apprenticeships and Technical Education (IfATE). Providers may also need to consider industry or employer expectations. Individual higher education providers will decide how they use this information. The broad subject of architecture is both academic and vocational. The bachelor's award for architecture is the first stage of the typical education of an architect. This is typically either a BSc or a BA degree. The second stage of academic qualification is a master's level degree, typically in the form of a two-year MArch, which is defined as an undergraduate master's award. Architecture qualifications typically require a total of 360 (Credit Accumulation and Transfer Scheme, or CATS) credits at bachelor's level and 240 (CATS) credits within a master's level degree. While this may equate to five years of 120 (CATS) credits each, higher education providers may construct alternatives to enable flexibility in student learning. This Statement seeks to encapsulate the nature of a rich and diverse academic discipline. It is not intended to prescribe a curriculum, but rather describes the broad intellectual territory within which individual higher education providers will locate their courses of study in architecture

Interactions between, and effectiveness of, power system stabilizers and FACTS device stabilizers in multimachine systems

Copyright © 2000 IEEEIn this paper it is shown that interactions occur between stabilizers in multimachine power systems, the stabilizers being power system stabilizers (PSSs), FACTS device stabilizers (FDSs) or both. The interactions, which are identified and quantified, may enhance or degrade the damping of certain modes of rotor oscillation. In particular, interactions between PSSs are found to adversely affect the damping of inter-area modes. The analysis of interactions also provides a practical means for quantifying and assessing simultaneously the relative effectiveness of both PSSs and FDS in damping the rotor modes of oscillation. This is achieved using a stabilizer damping contribution diagram. A theoretical basis is given for the analysis of interactions and the effectiveness of stabilizers; the practical significance and applications are illustrated using a case study on a 3-area, 400 state system having 28 generator groups and a number of FDSs. For systems of more than 600-700 states the modified Arnoldi method is used for eigenanalysis-based calculationsMichael J. Gibbard, David J. Vowles and Pouyan Pourbei

Reconciliation of methods of compensation for PSSs in multimachine systems

Copyright © 2004 IEEESeveral methods for the design of compensation for power system stabilizers (PSSs) are used in practice. The object of this paper is to reconcile the methods and explore their relative advantages and disadvantages. Three methods are investigated: the GEP and the P-Vr frequency response approaches, and the method of residues. It is shown the phase response of a modified GEP transfer function (TF) agrees closely with that of the P-Vr TF, thus providing the basis for the design of a robust PSS. Residues yield only a limited number of phase angles that can be used with confidence for design purposes and are consistent with the P-Vr phase response. The remaining residues for rotor modes are affected by variability of participation factor angles and interactions from other machines. Unlike other methods, the P-Vr approach yields magnitude and phase information that simplifies the synthesis of the PSS TF and yields a robust stabilizer.Michael J. Gibbard and David J. Vowle

The relationship between acceptance, catastrophizing and illness representations in chronic pain

BACKGROUND: Cognitive- and acceptance-based approaches are used to help people live with chronic pain. Little is known about how these constructs relate to each other. In this study, we examined how cognitive representations of chronic pain relate to interpersonal styles such as catastrophizing and the behavioural process of acceptance of chronic pain. This study further examined how these processes relate to emotional and physical functioning in chronic pain. METHODS: A cross-sectional design, employing validated questionnaires, was used to measure pain, emotional and physical dysfunction, illness representations, catastrophizing and acceptance in a heterogeneous sample of 150 chronic pain sufferers. RESULTS: The psychological variables significantly mediated the impact of pain severity on both emotional and physical dysfunction. In addition, a distinct pattern of mediation was observed. The relationship between pain and emotional dysfunction was mediated by representations of pain as a highly emotive experience and by catastrophizing; acceptance did not mediate this relationship. By contrast, the relationship between pain and physical dysfunction was mediated by acceptance and representations of high consequences of chronic pain, but not by catastrophizing. CONCLUSIONS: Pain severity itself is a relatively poor predictor of emotional and physical dysfunction in chronic pain states. These relationships are significantly mediated by psychological variables. Different approaches to chronic pain rehabilitation emphasize different targets (changing illness representations and reducing catastrophizing vs. acceptance and behavioural activation). This cross-sectional study suggests that these processes may differentially influence outcomes, but that they are complex and overlapping. Theoretical and clinical implications are discussed

Throwing the rascals out? Problems of accountability in two-party systems

This article critically examines the concept of 'accountability' as it is understood in two-party systems and majoritarian democracy - namely the ability of voters to remove governments that violate their mandates or otherwise perform poorly. Voters' capacity to 'throw the rascals out' is one of the main normative appeals of two-partism and the single-member plurality (SMP) electoral system. However, this article uses a spatial model to show that in at least two types of situation voters are left in a bind when confronted with a mandate-breaking governing party: (1) when both major parties undertake unexpected non-centrist shifts in opposing directions after an election, leaving centrist voters with an unappealing choice; and (2) when a governing party that had won an election on a non-centrist platform undertakes a post-election shift to the centre, leaving its more radical supporters dissatisfied. In each case, voters have four imperfect options: punish the governing party by throwing the rascals out, but in doing so vote for a party that is ideologically more distant; abstain, and withdraw from the democratic process; vote for a minor party that has no hope of influencing government formation, but which might detach enough votes to allow the ideologically more distant major opposition party to win; and forgive the governing party its mandate-breaking. All of these options represent accountability failures. The problems are illustrated with two case studies from two-party systems: the United Kingdom in the mid-1980s and New Zealand in the period 1984-1993. In both instances, many voters found it difficult to 'throw the rascals out' without harming their own interests in the process. The article concludes that accountability may sometimes be better achieved if voters can force a party to share power in coalition with another party in order to 'keep it honest' instead of removing it from government completely, as can happen in multi-party systems based on proportional representation. Thus, although two-partism based on plurality voting is normally regarded as superior to multi-partism and proportional representation on the criterion of accountability, in some instances, the reverse can be true. The article therefore undermines a core normative argument advanced by supporters of majoritarian democracy and SMP

Britain Says NO: Voting in the AV Ballot Referendum

The purpose of this paper is to explain why voters made the choices that they did in Britains Alternative Vote (AV) referendum on 5 May 2011. The paper utilises four alternative theoretical models to analyse individual voting behaviour. They are described as the cost-benefit, cognitive engagement, heuristics and mobilisation models. The explanatory power of these models is investigated using a large survey data set gathered in the AV referendum study conducted in conjunction with the British Election Study. Multivariate analyses show that all four models contribute to explaining why some people voted in favour of electoral reform, with the cost-benefit model exhibiting particularly strong effects. The conclusion discusses public reactions to the referendum and possible implications of the decisive rejection of electoral reform after a campaign characterised by disaffection and disengagement. © 2011 The Author Published by Oxford University Press on behalf of the Hansard Society. All rights reserved

Acceptance as a Process Variable in Relation to Catastrophizing in Multidisciplinary Pain Treatment

Background The underlying processes of change that contribute to the effectiveness of multidisciplinary pain treatment require clarification. Previous research has found support for pain acceptance as a process variable in acceptance-based treatment. Preliminary findings indicate that pain acceptance may also be a process variable in traditional cognitive behavioural therapy (CBT). The aim of this study was to investigate the role of pain acceptance as a process variable in CBT relative to two empirically supported process variables, namely catastrophizing and pain intensity. Methods Patients with chronic pain (n?=?186) attended a 3-week, multidisciplinary pain programme, which was CBT based. Patients completed a measure of pain intensity; the Chronic Pain Acceptance Questionnaire; the catastrophizing subscale of the Pain Response Self-Statements Scale; the Roland Morris Disability Questionnaire; the Depression Anxiety and Stress Scale; and two measures of physical functioning at pretreatment, post-treatment and 3-month follow-up. Results Both acceptance and catastrophizing showed statistically significant and clinically relevant changes from pre- to post-treatment. Changes in both acceptance and catastrophizing showed a significant correlation with changes in almost all of the outcome variables. Regression analyses demonstrated that change in acceptance was a significant predictor of changes in depression, disability, timed walk and sit-to-stand performance, after controlling for changes in catastrophizing and pain intensity. Conclusions Although not specifically targeted in CBT treatment, acceptance of pain was an important process variable that contributed to CBT treatment outcomes after controlling for changes in pain intensity and catastrophizing. Implications for future research and clinical practice are discussed