892 resultados para Rating agencies
Resumo:
In 1990 the Dispute Resolution Centres Act, 1990 (Qld) (the Act) was passed by the Queensland Parliament. In the second reading speech for the Dispute Resolution Centres Bill on May 1990 the Hon Dean Wells stated that the proposed legislation would make mediation services available “in a non-coercive, voluntary forum where, with the help of trained mediators, the disputants will be assisted towards their own solutions to their disputes, thereby ensuring that the result is acceptable to the parties” (Hansard, 1990, 1718). It was recognised at that time that a method for resolving disputes was necessary for which “the conventional court system is not always equipped to provide lasting resolution” (Hansard, 1990, 1717). In particular, the lasting resolution of “disputes between people in continuing relationships” was seen as made possible through the new legislation; for example, “domestic disputes, disputes between employees, and neighbourhood disputes relating to such issues as overhanging tree branches, dividing fences, barking dogs, smoke, noise and other nuisances are occurring continually in the community” (Hansard, 1990, 1717). The key features of the proposed form of mediation in the Act were articulated as follows: “attendance of both parties at mediation sessions is voluntary; a party may withdraw at any time; mediation sessions will be conducted with as little formality and technicality as possible; the rules of evidence will not apply; any agreement reached is not enforceable in any court; although it could be made so if the parties chose to proceed that way; and the provisions of the Act do not affect any rights or remedies that a party to a dispute has apart from the Act” (Hansard, 1990, 1718). Since the introduction of the Act, the Alternative Dispute Resolution Branch of the Queensland Department of Justice and Attorney General has offered mediation services through, first the Community Justice Program (CJP), and then the Dispute Resolution Centres (DRCs) for a range of family, neighbourhood, workplace and community disputes. These services have mirrored those available through similar government agencies in other states such as the Community Justice Centres of NSW and the Victorian Dispute Resolution Centres. Since 1990, mediation has become one of the fastest growing forms of alternative dispute resolution (ADR). Sourdin has commented that "In addition to the growth in court-based and community-based dispute resolution schemes, ADR has been institutionalised and has grown within Australia and overseas” (2005, 14). In Australia, in particular, the development of ADR service provision “has been assisted by the creation and growth of professional organisations such as the Leading Edge Alternative Dispute Resolvers (LEADR), the Australian Commercial Dispute Centres (ACDC), Australian Disputes Resolution Association (ADRA), Conflict Resolution Network, and the Institute of Arbitrators and Mediators Australia (IAMA)” (Sourdin, 2005, 14). The increased emphasis on the use of ADR within education contexts (particularly secondary and tertiary contexts) has “also led to an increasing acceptance and understanding of (ADR) processes” (Sourdin, 2005, 14). Proponents of the mediation process, in particular, argue that much of its success derives from the inherent flexibility and creativity of the agreements reached through the mediation process and that it is a relatively low cost option in many cases (Menkel-Meadow, 1997, 417). It is also accepted that one of the main reasons for the success of mediation can be attributed to the high level of participation by the parties involved and thus creating a sense of ownership of, and commitment to, the terms of the agreement (Boulle, 2005, 65). These characteristics are associated with some of the core values of mediation, particularly as practised in community-based models as found at the DRCs. These core values include voluntary participation, party self-determination and party empowerment (Boulle, 2005, 65). For this reason mediation is argued as being an effective approach to resolving disputes, that creates a lasting resolution of the issues. Evaluation of the mediation process, particularly in the context of the growth of ADR, has been an important aspect of the development of the process (Sourdin, 2008). Writing in 2005 for example, Boulle, states that “although there is a constant refrain for more research into mediation practice, there has been a not insignificant amount of mediation measurement, both in Australia and overseas” (Boulle, 2005, 575). The positive claims of mediation have been supported to a significant degree by evaluations of the efficiency and effectiveness of the process. A common indicator of the effectiveness of mediation is the settlement rate achieved. High settlement rates for mediated disputes have been found for Australia (Altobelli, 2003) and internationally (Alexander, 2003). Boulle notes that mediation agreement rates claimed by service providers range from 55% to 92% (Boulle, 2005, 590). The annual reports for the Alternative Dispute Resolution Branch of the Queensland Department of Justice and Attorney-General considered prior to the commencement of this study indicated generally achievement of an approximate settlement figure of 86% by the Queensland Dispute Resolution Centres. More recently, the 2008-2009 annual report states that of the 2291 civil dispute mediated in 2007-2008, 86% reached an agreement. Further, of the 2693 civil disputes mediated in 2008-2009, 73% reached an agreement. These results are noted in the report as indicating “the effectiveness of mediation in resolving disputes” and as reflecting “the high level of agreement achieved for voluntary mediations” (Annual Report, 2008-2009, online). Whilst the settlement rates for the DRCs are strong, parties are rarely contacted for long term follow-up to assess whether agreements reached during mediation lasted to the satisfaction of each party. It has certainly been the case that the Dispute Resolution Centres of Queensland have not been resourced to conduct long-term follow-up assessments of mediation agreements. As Wade notes, "it is very difficult to compare "success" rates” and whilst “politicians want the comparison studies (they) usually do not want the delay and expense of accurate studies" (1998, 114). To date, therefore, it is fair to say that the efficiency of the mediation process has been evaluated but not necessarily its effectiveness. Rather, the practice at the Queensland DRCs has been to evaluate the quality of mediation service provision and of the practice of the mediation process. This has occurred, for example, through follow-up surveys of parties' satisfaction rates with the mediation service. In most other respects it is fair to say that the Centres have relied on the high settlement rates of the mediation process as a sign of the effectiveness of mediation (Annual Reports 1991 - 2010). Research of the mediation literature conducted for the purpose of this thesis has also indicated that there is little evaluative literature that provides an in-depth analysis and assessment of the longevity of mediated agreements. Instead evaluative studies of mediation tend to assess how mediation is conducted, or compare mediation with other conflict resolution options, or assess the agreement rate of mediations, including parties' levels of satisfaction with the service provision of the dispute resolution service provider (Boulle, 2005, Chapter 16).
Resumo:
Muscle physiologists often describe fatigue simply as a decline of muscle force and infer this causes an athlete to slow down. In contrast, exercise scientists describe fatigue during sport competition more holistically as an exercise-induced impairment of performance. The aim of this review is to reconcile the different views by evaluating the many performance symptoms/measures and mechanisms of fatigue. We describe how fatigue is assessed with muscle, exercise or competition performance measures. Muscle performance (single muscle test measures) declines due to peripheral fatigue (reduced muscle cell force) and/or central fatigue (reduced motor drive from the CNS). Peak muscle force seldom falls by >30% during sport but is often exacerbated during electrical stimulation and laboratory exercise tasks. Exercise performance (whole-body exercise test measures) reveals impaired physical/technical abilities and subjective fatigue sensations. Exercise intensity is initially sustained by recruitment of new motor units and help from synergistic muscles before it declines. Technique/motor skill execution deviates as exercise proceeds to maintain outcomes before they deteriorate, e.g. reduced accuracy or velocity. The sensation of fatigue incorporates an elevated rating of perceived exertion (RPE) during submaximal tasks, due to a combination of peripheral and higher CNS inputs. Competition performance (sport symptoms) is affected more by decision-making and psychological aspects, since there are opponents and a greater importance on the result. Laboratory based decision making is generally faster or unimpaired. Motivation, self-efficacy and anxiety can change during exercise to modify RPE and, hence, alter physical performance. Symptoms of fatigue during racing, team-game or racquet sports are largely anecdotal, but sometimes assessed with time-motion analysis. Fatigue during brief all-out racing is described biomechanically as a decline of peak velocity, along with altered kinematic components. Longer sport events involve pacing strategies, central and peripheral fatigue contributions and elevated RPE. During match play, the work rate can decline late in a match (or tournament) and/or transiently after intense exercise bursts. Repeated sprint ability, agility and leg strength become slightly impaired. Technique outcomes, such as velocity and accuracy for throwing, passing, hitting and kicking, can deteriorate. Physical and subjective changes are both less severe in real rather than simulated sport activities. Little objective evidence exists to support exercise-induced mental lapses during sport. A model depicting mind-body interactions during sport competition shows that the RPE centre-motor cortex-working muscle sequence drives overall performance levels and, hence, fatigue symptoms. The sporting outputs from this sequence can be modulated by interactions with muscle afferent and circulatory feedback, psychological and decision-making inputs. Importantly, compensatory processes exist at many levels to protect against performance decrements. Small changes of putative fatigue factors can also be protective. We show that individual fatigue factors including diminished carbohydrate availability, elevated serotonin, hypoxia, acidosis, hyperkalaemia, hyperthermia, dehydration and reactive oxygen species, each contribute to several fatigue symptoms. Thus, multiple symptoms of fatigue can occur simultaneously and the underlying mechanisms overlap and interact. Based on this understanding, we reinforce the proposal that fatigue is best described globally as an exercise-induced decline of performance as this is inclusive of all viewpoints.
Resumo:
Significant research has demonstrated direct and indirect associations between substance use and sexual behaviour. Substance use is related to sexual risk-taking and HIV seroconversion among some substance-using MSM. It remains unclear what factors mediate or underlie this relationship, and which substances are associated with greater harm. Substance-related expectancies are hypothesised as potential mechanisms. A conceptual model based on social-cognitive theory was tested, which explores the role of demographic factors, substance use, substance-related expectancies and novelty-seeking personality characteristics in predicting unprotected anal intercourse (UAI) while under the influence, across four commonly used substance types. Phase 1, a qualitative study (N = 20), explored how MSM perceive the effects of substance use on their thoughts, feelings and behaviours, including sexual behaviours. Information was attained through discussion and interviews, resulting in the establishment of key themes. Results indicated MSM experience a wide range of reinforcing aspects associated with substance use. General and specific effects were evident across substance types, and were associated with sexual behaviour and sexual risk-taking. Phase 2 consisted of developing a comprehensive profile of substance-related expectancies for MSM (SEP-MSM) regarding alcohol, cannabis, amyl nitrite and stimulants that possessed sound psychometric properties and was appropriate for use among this group. A cross-sectional questionnaire with 249 participants recruited through gay community networks was used to validate these measures, and involved online data collection, participants rating expectancy items and subsequent factor analysis. Results indicated expectancies can be reliably assessed, and predicted substance use patterns. Phase 3 examined demographic factors, substance use, substance-related expectancies, and novelty-seeking traits among another community sample of MSM (N = 277) throughout Australia, in predicting UAI while under the influence. Using a cross-sectional design, participants were recruited through gay community networks and completed online questionnaires. The SEP-MSM, and associated substance use, predicted UAI. This research extends social-cognitive theory regarding sexual behaviour, and advances understanding of the role of expectancies associated with substance use and sexual risk-taking. Future applications of the SEP-MSM in health promotion, prevention, clinical interventions and research are likely to contribute to reducing harm associated with substance-using MSM (e.g., HIV transmission).
Resumo:
The delivery of human services occurs through a complex and often volatile system characterised by both competing and cooperating efforts. A recent strategic intention of government has been to integrate disparate service providers and programs into a more effective and efficient system using competitive funding regimes. A program of amalgamation has also been forecast and promoted as a further mechanism by which to link up smaller agencies thus creating economy and efficiency in the scale and scope of their service modes. Despite the current reliance on competitive funding models and amalgamation as the preferred ways forward for the sector little is known about their integrative capacity including their ability to predict outcomes and their consequences : the ‘unknown unknowns’. Drawing on an extensive data set of human services integration initiatives in Queensland, Australia, this paper examines the impact of government policy and service models and the risks arising from the tensions between competition and accountability on the one hand and the established good will and trust on the other. It is argued that unresolved, these tensions can lead to a weakening of the social infrastructure and make the system more vulnerable to inherent systemic risks. The paper finds that government’s efforts to externalise risk to the non-government sector leads to fragmentation of the service system and fractured collaborative capability. These unintended outcomes themselves have the unintended consequence of leaving governments disconnected from the service system and unable to provide the leadership role and direction necessary for sustained integration. Moreover, facilitating such a leadership role is undermined by behaviours that are directly contrary to collective integration models.
Is the public sector ready to collaborate? Human resource implications of collaborative Arrangements
Resumo:
Relational governance arrangements across agencies and sectors have become prevalent as a means for government to become more responsive and effective in addressing complex, large scale or ‘wicked’ problems. The primary characteristic of such ‘collaborative’ arrangements is the utilisation of the joint capacities of multiple organisations to achieve collaborative advantage, which Huxham (1993) defines as the attainment of creative outcomes that are beyond the ability of single agencies to achieve. Attaining collaborative advantage requires organisations to develop collaborative capabilities that prepare organisations for collaborative practice (Huxham, 1993b). Further, collaborations require considerable investment of staff effort that could potentially be used beneficially elsewhere by both the government and non-government organisations involved in collaboration (Keast and Mandell, 2010). Collaborative arrangements to deliver services therefore requires a reconsideration of the way in which resources, including human resources, are conceptualised and deployed as well as changes to both the structure of public service agencies and the systems and processes by which they operate (Keast, forthcoming). A main aim of academic research and theorising has been to explore and define the requisite characteristics to achieve collaborative advantage. Such research has tended to focus on definitional, structural (Turrini, Cristofoli, Frosini, & Nasi, 2009) and organisational (Huxham, 1993) aspects and less on the roles government plays within cross-organisational or cross-sectoral arrangements. Ferlie and Steane (2002) note that there has been a general trend towards management led reforms of public agencies including the HRM practices utilised. Such trends have been significantly influenced by New Public Management (NPM) ideology with limited consideration to the implications for HRM practice in collaborative, rather than market contexts. Utilising case study data of a suite of collaborative efforts in Queensland, Australia, collected over a decade, this paper presents an examination of the network roles government agencies undertake. Implications for HRM in public sector agencies working within networked arrangements are drawn and implications for job design, recruitment, deployment and staff development are presented. The paper also makes theoretical advances in our understanding of Strategic Human Resource Management (SHRM) in network settings. While networks form part of the strategic armoury of government, networks operate to achieve collaborative advantage. SHRM with its focus on competitive advantage is argued to be appropriate in market situations, however is not an ideal conceptualisation in network situations. Commencing with an overview of literature on networks and network effectiveness, the paper presents the case studies and methodology; provides findings from the case studies in regard to the roles of government to achieve collaborative advantage and implications for HRM practice are presented. Implications for SHRM are considered.
Resumo:
Organisations within the not-for-profit sector provide services to individuals and groups that government and for-profit organisations cannot or will not consider. The not-for-profit sector has come to be a vibrant and rich agglomeration of services and programs that operate under a myriad of philosophical stances, service orientation, client groupings and operational capacities. In Australia these organisations and services are providing social support and service assistance to many people in the community; often targeting their assistance to the most difficult of clients. Initially, in undertaking this role, the not-for-profit sector received limited sponsorship from government. Over time governments assumed greater responsibility in the form of service grants to particular groups: ‘the worthy poor’. More recently, they have entered into contractual service agreements with the not-for-profit sector, which specify the nature of the outcomes to be achieved and, to a degree, the way in which the services will be provided. A consequence of this growing shift to a more marketised model of service contracting, often offered-up under the label of enhanced collaborative practice, has been increased competitiveness between agencies that had previously worked well together (Keast and Brown, 2006). Another trend emerging from the market approach is the entrance of for-profit providers. These larger organisations have higher levels of organisational capacity with considerable organisational slack to allow them to adopt new service roles. Shaped almost as ‘shadow governments’ they appear to be a strong preference for governments looking for greater accountability of outcomes and an easier way to control the interaction with the conventional not-for-profit sector. The question is will governments’ apparent preference for larger organisational arrangements lead to the demise of the vibrancy of the not-for-profit sector and impact on service provision to those people who fall outside of the remit of the new service providers? To address this issue, this paper uses information gleaned from a state-wide survey of not-for-profit organisations in Queensland, Australia which included organisational size, operational scope, funding arrangements and governance/management approaches. Supplementing this information is qualitative data derived from 17 focus groups and 120 interviews conducted over ten years of study of this sector. The findings contribute to greater understanding of the practice and theory of the future provision of social services.
Resumo:
Variants of the same process can be encountered within one organization or across different organizations. For example, different municipalities, courts, and rental agencies all need to support highly similar processes. In fact, procurement and sales processes can be found in almost any organization. However, despite these similarities, there is also the need to allow for local variations in a controlled manner. Therefore, many academics and practitioners have advocated the use of configurable process models (sometimes referred to as reference models). A configurable process model describes a family of similar process models in a given domain. Such a model can be configured to obtain a specific process model that is subsequently used to handle individual cases, for instance, to process customer orders. Process configuration is notoriously difficult as there may be all kinds of interdependencies between configuration decisions. In fact, an incorrect configuration may lead to behavioral issues such as deadlocks and livelocks. To address this problem, we present a novel verification approach inspired by the “operating guidelines” used for partner synthesis. We view the configuration process as an external service, and compute a characterization of all such services which meet particular requirements via the notion of configuration guideline. As a result, we can characterize all feasible configurations (i. e., configurations without behavioral problems) at design time, instead of repeatedly checking each individual configuration while configuring a process model.
Resumo:
In 2009 the Australian Federal and State governments are expected to have spent some AU$30 billion procuring infrastructure projects. For governments with finite resources but many competing projects, formal capital rationing is achieved through use of Business Cases. These Business cases articulate the merits of investing in particular projects along with the estimated costs and risks of each project. Despite the sheer size and impact of infrastructure projects, there is very little research in Australia, or internationally, on the performance of these projects against Business Case assumptions when the decision to invest is made. If such assumptions (particularly cost assumptions) are not met, then there is serious potential for the misallocation of Australia’s finite financial resources. This research addresses this important gap in the literature by using combined quantitative and qualitative research methods, to examine the actual performance of 14 major Australian government infrastructure projects. The research findings are controversial as they challenge widely held perceptions of the effectiveness of certain infrastructure delivery practices. Despite this controversy, the research has had a significant impact on the field and has been described as ‘outstanding’ and ‘definitive’ (Alliancing Association of Australasia), "one of the first of its kind" (Infrastructure Partnerships of Australia) and "making a critical difference to infrastructure procurement" (Victorian Department of Treasury). The implications for practice of the research have been profound and included the withdrawal by Government of various infrastructure procurement guidelines, the formulation of new infrastructure policies by several state governments and the preparation of new infrastructure guidelines that substantially reflect the research findings. Building on the practical research, a more rigorous academic investigation focussed on the comparative cost uplift of various project delivery strategies was submitted to Australia’s premier academic management conference, the Australian and New Zealand Academy of Management (ANZAM) Annual Conference. This paper has been accepted for the 2010 ANZAM National Conference following a process of double blind peer review with reviewers rating the paper’s overall contribution as "Excellent" and "Good".
Resumo:
The case study 3 team viewed the mitigation of noise and air pollution generated in the transport corridor that borders the study site to be a paramount driver of the urban design solution. These key urban planning strategies were adopted: * Spatial separation from transport corridor pollution source. A linear green zone and environmental buffer was proposed adjacent to the transport corridor to mitigate the environmental noise and air quality impacts of the corridor, and to offer residents opportunities for recreation * Open space forming the key structural principle for neighbourhood design. A significant open space system underpins the planning and manages surface water flows. * Urban blocks running on east-west axis. The open space rationale emphasises an east-west pattern for local streets. Street alignment allows for predominantly north-south facing terrace type buildings which both face the street and overlook the green courtyard formed by the perimeter buildings. The results of the ESD assessment of the typologies conclude that the design will achieve good outcomes through: * Lower than average construction costs compared with other similar projects * Thermal comfort; A good balance between daylight access and solar gains is achieved * The energy rating achieved for the units is 8.5 stars.
Resumo:
With the growth and development of communication technology there is an increasing need for the use of interception technologies in modern policing. Law enforcement agencies are faced with increasingly sophisticated and complex criminal networks that utilise modern communication technology as a basis for their criminal success. In particular, transnational organised crime (TOC) is a diverse and complicated arena, costing global society in excess of $3 trillion annually, a figure that continues to grow (Borger, 2007) as crime groups take advantage of disappearing borders and greater profit markets. However, whilst communication can be a critical success factor for criminal enterprise it is also a key vulnerability. It is this vulnerability that the use of CIT, such as phone taps or email interception, can exploit. As such, law enforcement agencies now need a method and framework that allows them to utilise CIT to combat these crimes efficiently and successfully. This paper provides a review of current literature with the specific purpose of considering the effectiveness of CIT in the fight against TOC and the groundwork that must be laid in order for it to be fully exploited. In doing so, it fills an important gap in current research, focusing on the practical implementation of CIT as opposed to the traditional area of privacy concerns that arise with intrusive methods of investigation. The findings support the notion that CIT is an essential intelligence gathering tool that has a strong place within the modern policing arena. It identifies that the most effective use of CIT is grounded within a proactive, intelligence‐led framework and concludes that in order for this to happen Australian authorities and law enforcement agencies must re‐evaluate and address the current legislative and operational constraints placed on the use of CIT and the culture that surrounds intelligence in policing.
Resumo:
While it is generally accepted in the learning and teaching literature that assessment is the single biggest influence on how students approach their learning, assessment methods within higher education are generally conservative and inflexible. Constrained by policy and accreditation requirements and the need for the explicit articulation of assessment standards for public accountability purposes, assessment tasks can fail to engage students or reflect the tasks students will face in the world of practice. Innovative assessment design can simultaneously deliver program objectives and active learning through a knowledge transfer process which increases student participation. This social constructivist view highlights that acquiring an understanding of assessment processes, criteria and standards needs active student participation. Within this context, a peer-assessed, weekly, assessment task was introduced in the first “serious” accounting subject offered as part of an undergraduate degree. The positive outcomes of this assessment innovation was that student failure rates declined 15%, tutorial participation increased fourfold, tutorial engagement increased six-fold and there was a 100% approval rating for the retention of the assessment task. In contributing to the core conference theme of “seismic” shifts within higher education, in stark contrast to the positive student response, staff-related issues of assessment conservatism and the necessity of meeting increasing research commitments, threatened the assessment task’s survival. These opposing forces to change have the potential to weaken the ability of higher education assessment arrangements to adequately serve either a new generation of students or the sector's community stakeholders.
Resumo:
This paper takes the establishment and demise of Manchester’s Creative Industries Development Service as an exemplary case study for the ways in which creative industry policy has intersected with urban economic policy over the last decade. It argues that the creative industries required specific kinds of economic development agencies which would be able to act as ‘intermediary’ between the distinct languages of policy makers and ‘creatives’. The paper discusses the tensions inherent in such an approach and how CIDS attempted to manage them. It suggests that which particular circumstances might have intervened the main reason for the demise of the CIDS was the domination of the ‘economic’ over the ‘cultural logic’ both of which are embedded within the creative industries policy discourse.
Resumo:
While it is generally accepted in the learning and teaching literature that assessment is the single biggest influence on how students approach their learning, assessment methods within higher education are generally conservative and inflexible. Constrained by policy and accreditation requirements and the need for the explicit articulation of assessment standards for public accountability purposes, assessment tasks can fail to engage students or reflect the tasks students will face in the world of practice. Innovative assessment design can simultaneously deliver program objectives and active learning through a knowledge transfer process which increases student participation. This social constructivist view highlights that acquiring an understanding of assessment processes, criteria and standards needs active student participation. Within this context, a peer-assessed, weekly, assessment task was introduced in the first “serious” accounting subject offered as part of an undergraduate degree. The positive outcomes of this assessment innovation was that student failure rates declined 15%, tutorial participation increased fourfold, tutorial engagement increased six-fold and there was a 100% approval rating for the retention of the assessment task. In contributing to the core conference theme of “seismic” shifts within higher education, in stark contrast to the positive student response, staff-related issues of assessment conservatism and the necessity of meeting increasing research commitments, threatened the assessment task’s survival. These opposing forces to change have the potential to weaken the ability of higher education assessment arrangements to adequately serve either a new generation of students or the sector's community stakeholders.
Resumo:
Demands for delivering high instantaneous power in a compressed form (pulse shape) have widely increased during recent decades. The flexible shapes with variable pulse specifications offered by pulsed power have made it a practical and effective supply method for an extensive range of applications. In particular, the release of basic subatomic particles (i.e. electron, proton and neutron) in an atom (ionization process) and the synthesizing of molecules to form ions or other molecules are among those reactions that necessitate large amount of instantaneous power. In addition to the decomposition process, there have recently been requests for pulsed power in other areas such as in the combination of molecules (i.e. fusion, material joining), gessoes radiations (i.e. electron beams, laser, and radar), explosions (i.e. concrete recycling), wastewater, exhausted gas, and material surface treatments. These pulses are widely employed in the silent discharge process in all types of materials (including gas, fluid and solid); in some cases, to form the plasma and consequently accelerate the associated process. Due to this fast growing demand for pulsed power in industrial and environmental applications, the exigency of having more efficient and flexible pulse modulators is now receiving greater consideration. Sensitive applications, such as plasma fusion and laser guns also require more precisely produced repetitive pulses with a higher quality. Many research studies are being conducted in different areas that need a flexible pulse modulator to vary pulse features to investigate the influence of these variations on the application. In addition, there is the need to prevent the waste of a considerable amount of energy caused by the arc phenomena that frequently occur after the plasma process. The control over power flow during the supply process is a critical skill that enables the pulse supply to halt the supply process at any stage. Different pulse modulators which utilise different accumulation techniques including Marx Generators (MG), Magnetic Pulse Compressors (MPC), Pulse Forming Networks (PFN) and Multistage Blumlein Lines (MBL) are currently employed to supply a wide range of applications. Gas/Magnetic switching technologies (such as spark gap and hydrogen thyratron) have conventionally been used as switching devices in pulse modulator structures because of their high voltage ratings and considerably low rising times. However, they also suffer from serious drawbacks such as, their low efficiency, reliability and repetition rate, and also their short life span. Being bulky, heavy and expensive are the other disadvantages associated with these devices. Recently developed solid-state switching technology is an appropriate substitution for these switching devices due to the benefits they bring to the pulse supplies. Besides being compact, efficient, reasonable and reliable, and having a long life span, their high frequency switching skill allows repetitive operation of pulsed power supply. The main concerns in using solid-state transistors are the voltage rating and the rising time of available switches that, in some cases, cannot satisfy the application’s requirements. However, there are several power electronics configurations and techniques that make solid-state utilisation feasible for high voltage pulse generation. Therefore, the design and development of novel methods and topologies with higher efficiency and flexibility for pulsed power generators have been considered as the main scope of this research work. This aim is pursued through several innovative proposals that can be classified under the following two principal objectives. • To innovate and develop novel solid-state based topologies for pulsed power generation • To improve available technologies that have the potential to accommodate solid-state technology by revising, reconfiguring and adjusting their structure and control algorithms. The quest to distinguish novel topologies for a proper pulsed power production was begun with a deep and through review of conventional pulse generators and useful power electronics topologies. As a result of this study, it appears that efficiency and flexibility are the most significant demands of plasma applications that have not been met by state-of-the-art methods. Many solid-state based configurations were considered and simulated in order to evaluate their potential to be utilised in the pulsed power area. Parts of this literature review are documented in Chapter 1 of this thesis. Current source topologies demonstrate valuable advantages in supplying the loads with capacitive characteristics such as plasma applications. To investigate the influence of switching transients associated with solid-state devices on rise time of pulses, simulation based studies have been undertaken. A variable current source is considered to pump different current levels to a capacitive load, and it was evident that dissimilar dv/dts are produced at the output. Thereby, transient effects on pulse rising time are denied regarding the evidence acquired from this examination. A detailed report of this study is given in Chapter 6 of this thesis. This study inspired the design of a solid-state based topology that take advantage of both current and voltage sources. A series of switch-resistor-capacitor units at the output splits the produced voltage to lower levels, so it can be shared by the switches. A smart but complicated switching strategy is also designed to discharge the residual energy after each supply cycle. To prevent reverse power flow and to reduce the complexity of the control algorithm in this system, the resistors in common paths of units are substituted with diode rectifiers (switch-diode-capacitor). This modification not only gives the feasibility of stopping the load supply process to the supplier at any stage (and consequently saving energy), but also enables the converter to operate in a two-stroke mode with asymmetrical capacitors. The components’ determination and exchanging energy calculations are accomplished with respect to application specifications and demands. Both topologies were simply modelled and simulation studies have been carried out with the simplified models. Experimental assessments were also executed on implemented hardware and the approaches verified the initial analysis. Reports on details of both converters are thoroughly discussed in Chapters 2 and 3 of the thesis. Conventional MGs have been recently modified to use solid-state transistors (i.e. Insulated gate bipolar transistors) instead of magnetic/gas switching devices. Resistive insulators previously used in their structures are substituted by diode rectifiers to adjust MGs for a proper voltage sharing. However, despite utilizing solid-state technology in MGs configurations, further design and control amendments can still be made to achieve an improved performance with fewer components. Considering a number of charging techniques, resonant phenomenon is adopted in a proposal to charge the capacitors. In addition to charging the capacitors at twice the input voltage, triggering switches at the moment at which the conducted current through switches is zero significantly reduces the switching losses. Another configuration is also introduced in this research for Marx topology based on commutation circuits that use a current source to charge the capacitors. According to this design, diode-capacitor units, each including two Marx stages, are connected in cascade through solid-state devices and aggregate the voltages across the capacitors to produce a high voltage pulse. The polarity of voltage across one capacitor in each unit is reversed in an intermediate mode by connecting the commutation circuit to the capacitor. The insulation of input side from load side is provided in this topology by disconnecting the load from the current source during the supply process. Furthermore, the number of required fast switching devices in both designs is reduced to half of the number used in a conventional MG; they are replaced with slower switches (such as Thyristors) that need simpler driving modules. In addition, the contributing switches in discharging paths are decreased to half; this decrease leads to a reduction in conduction losses. Associated models are simulated, and hardware tests are performed to verify the validity of proposed topologies. Chapters 4, 5 and 7 of the thesis present all relevant analysis and approaches according to these topologies.
Resumo:
Despite promising benefits and advantages, there are reports of failures and low realisation of benefits in Enterprise System (ES) initiatives. Among the research on the factors that influence ES success, there is a dearth of studies on the knowledge implications of multiple end-user groups using the same ES application. An ES facilitates the work of several user groups, ranging from strategic management, management, to operational staff, all using the same system for multiple objectives. Given the fundamental characteristics of ES – integration of modules, business process views, and aspects of information transparency – it is necessary that all frequent end-users share a reasonable amount of common knowledge and integrate their knowledge to yield new knowledge. Recent literature on ES implementation highlights the importance of Knowledge Integration (KI) for implementation success. Unfortunately, the importance of KI is often overlooked and little about the role of KI in ES success is known. Many organisations do not achieve the potential benefits from their ES investment because they do not consider the need or their ability to integrate their employees’ knowledge. This study is designed to improve our understanding of the influence of KI among ES end-users on operational ES success. The three objectives of the study are: (I) to identify and validate the antecedents of KI effectiveness, (II) to investigate the impact of KI effectiveness on the goodness of individuals’ ES-knowledge base, and (III) to examine the impact of the goodness of individuals’ ES-knowledge base on the operational ES success. For this purpose, we employ the KI factors identified by Grant (1996) and an IS-impact measurement model from the work of Gable et al. (2008) to examine ES success. The study derives its findings from data gathered from six Malaysian companies in order to obtain the three-fold goal of this thesis as outlined above. The relationships between the antecedents of KI effectiveness and its consequences are tested using 188 responses to a survey representing the views of management and operational employment cohorts. Using statistical methods, we confirm three antecedents of KI effectiveness and the consequences of the antecedents on ES success are validated. The findings demonstrate a statistically positive impact of KI effectiveness of ES success, with KI effectiveness contributing to almost one-third of ES success. This research makes a number of contributions to the understanding of the influence of KI on ES success. First, based on the empirical work using a complete nomological net model, the role of KI effectiveness on ES success is evidenced. Second, the model provides a theoretical lens for a more comprehensive understanding of the impact of KI on the level of ES success. Third, restructuring the dimensions of the knowledge-based theory to fit the context of ES extends its applicability and generalisability to contemporary Information Systems. Fourth, the study develops and validates measures for the antecedents of KI effectiveness. Fifth, the study demonstrates the statistically significant positive influence of the goodness of KI on ES success. From a practical viewpoint, this study emphasises the importance of KI effectiveness as a direct antecedent of ES success. Practical lessons can be drawn from the work done in this study to empirically identify the critical factors among the antecedents of KI effectiveness that should be given attention.