Mathematical methods in power system stability studies

In this thesis various mathematical methods of studying the transient and dynamic stabiIity of practical power systems are presented. Certain long established methods are reviewed and refinements of some proposed. New methods are presented which remove some of the difficulties encountered in applying the powerful stability theories based on the concepts of Liapunov. Chapter 1 is concerned with numerical solution of the transient stability problem. Following a review and comparison of synchronous machine models the superiority of a particular model from the point of view of combined computing time and accuracy is demonstrated. A digital computer program incorporating all the synchronous machine models discussed, and an induction machine model, is described and results of a practical multi-machine transient stability study are presented. Chapter 2 reviews certain concepts and theorems due to Liapunov. In Chapter 3 transient stability regions of single, two and multi~machine systems are investigated through the use of energy type Liapunov functions. The treatment removes several mathematical difficulties encountered in earlier applications of the method. In Chapter 4 a simple criterion for the steady state stability of a multi-machine system is developed and compared with established criteria and a state space approach. In Chapters 5, 6 and 7 dynamic stability and small signal dynamic response are studied through a state space representation of the system. In Chapter 5 the state space equations are derived for single machine systems. An example is provided in which the dynamic stability limit curves are plotted for various synchronous machine representations. In Chapter 6 the state space approach is extended to multi~machine systems. To draw conclusions concerning dynamic stability or dynamic response the system eigenvalues must be properly interpreted, and a discussion concerning correct interpretation is included. Chapter 7 presents a discussion of the optimisation of power system small sjgnal performance through the use of Liapunov functions.

A community-based approach to supply chain design

The role of beneficiaries in the humanitarian supply chain is highlighted in the imperative to meet their needs but disputed in terms of their actual decision-making and purchasing power. This paper discusses the use of a beneficiary-focused, community-based approach in the case of a post-crisis housing reconstruction programme. In the community-based approach, beneficiaries become active members of the humanitarian supply chain. Implications of this community-based approach are discussed in the light of supply chain design and aid effectiveness. © 2010 Taylor & Francis.

An exploratory study of management accounting and control systems in a developing country

This thesis reports on the results of case studies in four commercial banks in Nigeria. The study focuses how management accounting and control systems (MCS) operate in the four banks. The study is motivated by the dearth of literature on management accounting practices in the developing world in general and in Nigeria in specific. The case study approach adopted in conducting the research was useful in exploring the dynamics of the MCS in the organisations. Data was gathered from two sources. First, semi-structured interviews were conducted with managers at the head office, regional office and branches of each bank. The participants were selected from different backgrounds and managerial levels to provide broader understanding of the operations of the MCS. Second, various internal and external documents were reviewed to provide supporting evidence for the interview results. New institutional sociology (NIS) provided the theoretical framework to understand the results. NIS provided explanations for how the MCS in the four banks were shaped by diverse external and internal factors. The key factors identified as shaping the operations of the MCS were the need to comply with the regulatory environment (coercive isomorphism), the need to maintain social and cultural support (normative isomorphism) and the need to imitate successful organisations in order to appear legitimate (mimetic isomorphism). The study also examines the interplay between the institutional forces, market forces and infra-organisational power relations. This analysis is necessary to overcome the criticism of NIS that it downplays the role of market forces, agency and intra-organisational relations. The findings of the study have implications for understanding the operations of MCS in the developing world.

The dynamics of organizational change : an analysis of power, professions and new managerialism in the case of CoastElectric

It is widely accepted that the Thatcher years and their immediate aftermath were associated with substantive social and organizational change. The privatisation programme, 'the rolling back of the State', prosecuted by the successive Conservative Governments from 1979-1997 was a central pillar of Governmental policy. This thesis seeks to engage with privatization through the of CoastElectric, a newly privatised Regional Electricity Company. This thesis contributes to the extant understanding of the dynamics of organizational change in four major ways. Firstly, the study into CoastElectric addresses the senior management decision making within the organization: in particular, it will attempt to make sense of 'why' particular decisions were made. The theoretical backdrop to this concern will draw on the concepts of normalization, cultural capital and corporate fashion. The argument presented in this thesis is that the decision-making broadly corresponded with that which could be considered to be at the vanguard of mangerialist thought. However, a detailed analysis suggested that at different junctures in CoastElectric's history there were differences in the approach to decision making that warranted further analysis. The most notable finding was that the relative levels of new managerialist cultural capital possessed by the decision-making elite had an important bearing upon whether the decision was formulated either endogenously or exogenously, with the assistance of cultural intermediaries such as management consultants. The thesis demonstrates the importance of the broader discourse of new managerialism in terms of shaping what is considered to be a 'commonsensical, rational' strategy. The second concern of this thesis is that of the process of organizational change. The study of CoastElectric attempts to provide a rich account of the dynamics of organizational change. This is realized through, first, examining the pre-existing context of the organization; second, through analyzing the power politics of change interventions. The master concepts utilised in this endeavour are that of: dividing practices, the establishment of violent hierarchies between competing discourses; symbolic violence; critical turning points; recursiveness; creative destruction; legitimation strategies and the reconstitution of subjects in the workplace.

Does stakeholder orientation matter? : empirical evidence about power and influence in local government decision-making

Despite being in the business agenda for almost thirty years, stakeholder management is still an under explored field in the public management context. The investigation presented in this doctoral thesis aims to ensure that stakeholder management is a useful technique able to raise issues about power and interests to public organisation’s strategic management processes. Stakeholder theory is tested in an exploratory study carried out with English Local Authorities whose focus is place on decision-making. The findings derive from two distinct and complementary studies: a cross-sectional survey undertaken with chief executives based on the quantitative approach and a qualitative investigation based on cross-sectional case studies and in-depth interviews of validation. While the first study aimed to produce a reliable and comprehensive list of stakeholders able to raise issues in decision-making, the second study aimed to depict the arena in which decision-making comes about. The findings indicate that local government decision-making is a multistakeholder process in which influences are exerted according to stakeholders’ power and interest. The findings also indicate that local government managers should take into account these tissues to avoid losing resources and legitimacy from its environmental supporters. Another issue raised by the investigation is related to the ethics upon which these types of relationships are based. According to the evidence gathered throughout the investigation, the formal model of accountability does not cover the whole set of stakeholders engaged in the process.

A longitudinal study of Chinese managerial behaviour:an inside view of decision-making under the economic reform

This research compared decision making processes in six Chinese state-owned enterprises during the period 1985 to 1988. The research objectives were: a) To examine changes in the managerial behaviour over a period of 1985 to 1988 with a focus on decision-making; b) Through this examination, to throw light on the means by which government policies on economic reform were implemented at the enterprise level; c) To illustrate problems encountered in the decentralization programme which was a major part of China's economic reform. The research was conducted by means of intensive interviews with more than eighty managers and a survey of documents relating to specific decisions. A total of sixty cases of decision-making were selected from five decision topics: purchasing of inputs, pricing of outputs, recruitment of labour, organizational change and innovation, which occurred in 1985 (or before) and in 1988/89. Data from the interviews were used to investigate environmental conditions, relations between the enterprise and its higher authority, interactions between management and the party system, the role of information, and effectiveness of regulations and government policies on enterprise management. The analysis of the data indicates that the decision processes in the different enterprises have some similarities in regard to actor involvement, the flow of decision activities, interactions with the authorities, information usage and the effect of regulations. Comparison of the same or similar decision contents over time indicates that the achievement of decentralization varied according to the topic of decision. Managerial authority was delegated to enterprises when the authorities relaxed their control over resource allocation. When acquisition of necessary resources is dependent upon the planning system or the decision matter is sensitive, because it involves change to the institutional framework (e.g. the Party), then a high degree of centralization was retained, resulting in a marginal change in managerial behaviour. The economic reform failed to increase decision efficiency and effectiveness of decision-making. The prevailing institutional frameworks were regarded as negative to the change. The research argues that the decision process is likely to be more contingent on the decision content than the organization. Three types of decision process have been conceptualized, each of them related to a certain type of decision content. This argument gives attention to the perspectives of institution and power in a way which facilitates an elaboration of organizational analysis. The problems encountered in the reform of China's industrial enterprises are identified and discussed. General recommendations for policies of further reform are offered, based on the analysis of decision process and managerial behaviour.

The impact of national cultures and interpersonal factors on managerial communication

This study was undertaken for two primary purposes. The first was to discover whether or not two of the four cultural dimensions depicted by Hof-stede (1980), namely Power Distance and Uncertainty Avoidance, could be repeated using samples from seven organizations operating in three distinct cultural settings. The second was to assess the degree to which these dimensions affect superior-subordinate communication across the culturally-different groups. Also, the impact of the three interpersonal factors: Trust in Superior, Upward Influence and Mobility Aspirations was investigated cross-culturally. Participants were 291 managers from seven organizations; four Sudanese, two white British and an organization in Britain run by a group of British citizens of Pakistani extraction. It was hypothesized that the Power Distance and Uncertainty Avoidance of the three groups would replicate Hof-stede's. Specific implications of these dimensions for organizational communication and in particular for superior-subordinate communication were also hypothesized. Multiple regression analyses were performed with items of the two cultural dimensions and the three interpersonal factors (each in turn) forming the independent variables, while the organizational communication aspects formed the dependent variables. T-tests between means were also used to compare and contrast issues such as directionality of information flow across organizations operating in these settings. Work-related values of each of the three cultural groups provided support for Hofstede's model. However, only tentative support was given to the hypothesized relationships between the cultural dimensions and organizational communication. Similarly, weak associations were found between the three interpersonal factors and superior-subordinate communication behaviour. Some practical and theoretical implications are offered. An evaluation of the study and recommendation for further research are also given.

An investigation of managerial skills:Implications for personnel policy

This research explores the conceptual basis in adopting a skills approach to management development. The literature reveals a number of development approaches but only a limited appreciation of how the manager does his job i.e. of the skills that he needs. An investigation of managerial skills was conducted with 10 manager s mainly occupying middle and senior positions. The principal source of evidence was the manager's thoughts on what he did and how he did it, although the interviews were supplemented by formal and informal observation. There was also a dialectic value from discussions with other analysts/managers and empathy between analyst and practitioner also played a part. Each manager was invited to comment upon his own skills analysis as a check upon validity. The study supports the view that the manager similar to other skilled practitioners, is conceptually a model builder and operationally a navigator (Singleton 1978b) . The manager variously holds enactive, pictorial, symbolic and hybrid models that enable him to understand his world and act in it. The universal managerial function is decision making and the study presents a preliminary nomenclature in classifying decision processes or perceptual skills. Managerial skills are also reflected in interpersonal interaction where the hallmark is mutual construction and attribution and in 'self-management’ where the requirement is to cope with the inner rather than the outer world. Differences between the managers are most evident in perceptual skills, the more senior manager requiring increasing ability to process abstract information and take account of environmental uncertainty. He will also make greater use of 'off- line’ information. The practical purpose in studying managerial skills is to facilitate the improvement of managerial performance and the implications of the research for training, selection and appraisal are explored.

An intelligent approach for deploying applications in WSN's

Wireless sensor networks have been identified as one of the key technologies for the 21st century. They consist of tiny devices with limited processing and power capabilities, called motes that can be deployed in large numbers of useful sensing capabilities. Even though, they are flexible and easy to deploy, there are a number of considerations when it comes to their fault tolerance, conserving energy and re-programmability that need to be addressed before we draw any substantial conclusions about the effectiveness of this technology. In order to overcome their limitations, we propose a middleware solution. The proposed scheme is composed based on two main methods. The first method involves the creation of a flexible communication protocol based on technologies such as Mobile Code/Agents and Linda-like tuple spaces. In this way, every node of the wireless sensor network will produce and process data based on what is the best for it but also for the group that it belongs too. The second method incorporates the above protocol in a middleware that will aim to bridge the gap between the application layer and low level constructs such as the physical layer of the wireless sensor network. A fault tolerant platform for deploying and monitoring applications in real time offers a number of possibilities for the end user giving him in parallel the freedom to experiment with various parameters, in an effort towards the deployed applications running in an energy efficient manner inside the network. The proposed scheme is evaluated through a number of trials aiming to test its merits under real time conditions and to identify its effectiveness against other similar approaches. Finally, parameters which determine the characteristics of the proposed scheme are also examined.

Combining temporal and spectral information with spatial mapping to identify differences between phonological and semantic networks:a magnetoencephalographic approach

Early, lesion-based models of language processing suggested that semantic and phonological processes are associated with distinct temporal and parietal regions respectively, with frontal areas more indirectly involved. Contemporary spatial brain mapping techniques have not supported such clear-cut segregation, with strong evidence of activation in left temporal areas by both processes and disputed evidence of involvement of frontal areas in both processes. We suggest that combining spatial information with temporal and spectral data may allow a closer scrutiny of the differential involvement of closely overlapping cortical areas in language processing. Using beamforming techniques to analyze magnetoencephalography data, we localized the neuronal substrates underlying primed responses to nouns requiring either phonological or semantic processing, and examined the associated measures of time and frequency in those areas where activation was common to both tasks. Power changes in the beta (14-30 Hz) and gamma (30-50 Hz) frequency bandswere analyzed in pre-selected time windows of 350-550 and 500-700ms In left temporal regions, both tasks elicited power changes in the same time window (350-550 ms), but with different spectral characteristics, low beta (14-20 Hz) for the phonological task and high beta (20-30 Hz) for the semantic task. In frontal areas (BA10), both tasks elicited power changes in the gamma band (30-50 Hz), but in different time windows, 500-700ms for the phonological task and 350-550ms for the semantic task. In the left inferior parietal area (BA40), both tasks elicited changes in the 20-30 Hz beta frequency band but in different time windows, 350-550ms for the phonological task and 500-700ms for the semantic task. Our findings suggest that, where spatial measures may indicate overlapping areas of involvement, additional beamforming techniques can demonstrate differential activation in time and frequency domains. © 2012 McNab, Hillebrand, Swithenby and Rippon.

Knowledge management in knowledge intensive service networks:a strategic management approach

Purpose – The main purpose of this paper is to analyze knowledge management in service networks. It analyzes the knowledge management process and identifies related challenges. The authors take a strategic management approach instead of a more technology-oriented approach, since it is believed that managerial problems still remain after technological problems are solved. Design/methodology/approach – The paper explores the literature on the topic of knowledge management as well as the resource (or knowledge) based view of the firm. It offers conceptual insights and provides possible solutions for knowledge management problems. Findings – The paper discusses several possible solutions for managing knowledge processes in knowledge-intensive service networks. Solutions for knowledge identification/generation, knowledge application, knowledge combination/transfer and supporting the evolution of tacit network knowledge include personal and technological aspects, as well as organizational and cultural elements. Practical implications – In a complex environment, knowledge management and network management become crucial for business success. It is the task of network management to establish routines, and to build and regularly refresh meta-knowledge about the competencies and abilities that exist within the network. It is suggested that each network partner should be rated according to the contribution to the network knowledge base. Based on this rating, a particular network partner is a member of a certain knowledge club, meaning that the partner has access to a particular level of network knowledge. Such an established routine provides strong incentives to add knowledge to the network's knowledge base Originality/value – This paper is a first attempt to outline the problems of knowledge management in knowledge-intensive service networks and, by so doing, to introduce strategic management reasoning to the discussion.

Beyond power:unbridging Foucault and Weber

Today, very few would doubt that there are plenty of reasons to liken Weber’s and Foucault’s theories of power. Nevertheless, their respective works have divergent ethical and ontological preoccupations which should be reconsidered. This paper explores Foucault’s account of a historical episode in Discipline and Punish and Weber’s theory of life spheres, uncovering evidence that there is a need to reassess the conceptual bridges which have been built so far. The exploration reveals a radical difference between a monological theory of power (Foucault) and a multidimensional approach to power (Weber). Yet by unbridging the two thinkers and focusing on other aspects of their theories along with their ideas about power, we also find that alternative links between the two frameworks may offer a more promising critical theory.

Revisiting the role stress-commitment relationship:can managerial interventions help?

Purpose: The purpose of this paper is to investigate the moderating influences of empowerment and professional development on role stress-commitment relationships, while examining and confirming the effects of role stress on organisational commitment. Design/methodology/approach: The results are drawn from a cross-sectional survey of 184 front-line employees (FLEs) from a travel service organization. Multiple and moderated regression analyses were employed to test the hypothesised direct and interaction effects. Findings: The results show that role stressors influence affective organizational commitment in FLEs negatively. Role ambiguity did not, unexpectedly, influence continuance commitment positively, but role conflict did. Professional development and empowerment are important management tools that can be used to combat the detrimental effect of role stress on organizational commitment. The paper finds empowerment to be particularly useful in combating the dysfunctional effects of role ambiguity on affective commitment, while professional development is a key tool that helps to combat the dysfunctional effects of role conflict on affective and continuance commitment. However, there are caveats associated with the implementation of these management tools. Practical implications: It is important for management to understand role stress from the FLE perspective, and strategically use intervention tools to help moderate the effects of role stress on organizational commitment components. Originality/value: This study adds further support to the literature that role ambiguity and role conflict should be studied as distinct components of role stress because treating role stress as a single construct may result in suboptimal outcomes for managers, and misleading findings for researchers. In this context, the paper contributes to literature by investigating the moderating impact of empowerment and professional development on the role stress-affective commitment/continuance commitment relationships. The findings suggest that different managerial strategies are required to combat the effect of each of these role stressors on the affective and continuance components of commitment respectively. © Emerald Group Publishing Limited.

QoS guarantee with adaptive transmit power and message rate control for DSRC vehicle network based road safety applications

Quality of services (QoS) support is critical for dedicated short range communications (DSRC) vehicle networks based collaborative road safety applications. In this paper we propose an adaptive power and message rate control method for DSRC vehicle networks at road intersections. The design objective is to provide high availability and low latency channels for high priority emergency safety applications while maximizing channel utilization for low priority routine safety applications. In this method an offline simulation based approach is used to find out the best possible configurations of transmit power and message rate for given numbers of vehicles in the network. The identified best configurations are then used online by roadside access points (AP) according to estimated number of vehicles. Simulation results show that this adaptive method significantly outperforms a fixed control method. © 2011 Springer-Verlag.

The impact of privatisation and regulation on the water and sewerage industry in England and Wales:a translog cost function approach

After the ten Regional Water Authorities (RWAs) of England and Wales were privatized in November 1989, the successor Water and Sewerage Companies (WASCs) faced a new regulatory regime that was designed to promote economic efficiency while simultaneously improving drinking water and environmental quality. As legally mandated quality improvements necessitated a costly capital investment programme, the industry's economic regulator, the Office of Water Services (Ofwat), implemented a retail price index (RPI)+K pricing system, which was designed to compensate the WASCs for their capital investment programme while also encouraging gains in economic efficiency. In order to analyse jointly the impact of privatization, as well as the impact of increasingly stringent economic and environmental regulation on the WASCs' economic performance, this paper estimates a translog multiple output cost function model for the period 1985–1999. Given the significant costs associated with water quality improvements, the model is augmented to include the impact of drinking water quality and environmental quality on total costs. The model is then employed to determine the extent of scale and scope economies in the water and sewerage industry, as well as the impact of privatization and economic regulation on economic efficiency.