3,310 research outputs found
The organization and management of nuclear power plants
The explanation of aggregate and sectoral
investment behavior has been one of the less successful endeavors in empirical economics.
Existing econometric models have had little success in explaining or predicting investment
spending. This may be because most such models fail to account for the irreversibility of
most investment spending. With irreversibility, changes in the riskiness of future cash
flows or interest rates should in theory dramatically affect the decision to invest - more
so than, say, a change in the levels of interest rates. Here I survey some of the empirical
support for this proposition, and discuss the implications for investment modelling.Nuclear
power plants are a controversial technology. The future of the industry depends on the
ability to manage efficiently and safely, and to effectively manage organizational change as
new technologies and practices are introduced and disseminated. This paper provides a
conceptual framework and discussion of the management and organization of nuclear power
plants around three questions: (1) How should nuclear power plants be organized and managed
to ensure that they are operated most safely and efficiently? (2) What does an understanding
of the organization and management of nuclear power plants tell us about how they change or
resist change? and (3) What indicators or measures of various characteristics and processes
of nuclear power plants are needed in order to address the above questions? We review
existing literature on the organization and management of nuclear power plants, and suggest
how we would structure a research project to address the above questions.Supported by the Center for Energy Policy
Research at M.I.T
Organizational learning at nuclear power plants
The Nuclear Power Plant Advisory Panel on Organizational Learning provides channels of communications between the management and organization research projects of the MIT International Program for Enhanced Nuclear Power Plant Safety and plant personnel actively concerned with important operational issues, inside and outside the control room, relevant to safety. The Panel is conceived as an opportunity for plants to share their knowledge and concerns about aspects of management and organization, with a particular emphasis on self-assessment, learning, and the management of change. Further, the Panel seeks to identify opportunities for collaborative research with practical benefits. At the first Panel meeting, 20 representatives from U.S. nuclear power plants and utilities and 14 MIT faculty, research staff, and students explored mutual interests and priorities in order to guide future research efforts. Professor John Carroll introduced the overall MIT research project.Three MIT researchers discussed their proposed research: Professor Alfred Marcus discussed quantitative analyses of improvements in U.S. nuclear power plant safety during the 1980s, and the need to conduct detailed studies of plant improvements and of utility strategies; Dr. Constance Perin discussed how work requires bridging across functions, levels, technical groups, and shifts within a social and cultural system, and proposed to study various plant programs in terms of their vertical relationships and institutional context; Professor John Carroll focused on the analysis of safety-relevant incidents through the application of knowledge distributed among various professional groups in the plant, and the need for research to characterize this knowledge and its relationship to performance enhancement.In addition, Professor Michael Golay discussed the organization and management implications of new reactor technology, and Professor Thomas Kochan summarized research on contractor training and safety in the petrochemical industry. Roundtable groups discussed three topics of their own choosing: configuration control, proactivity and communication with management, and event trending (including root cause analysis and corrective action tracking). A wide-ranging discussion explored topics of mutual interest, their connections to safe operations and their potential for research. A variety of research opportunities were raised and discussed, along with next steps for continued communication between the Panel and MIT
Development of a composite model derived from cardiopulmonary exercise tests to predict mortality risk in patients with mild-to-moderate heart failure
Objective: Cardiopulmonary exercise testing (CPET) is used to predict outcome in patients with mild-to-moderate heart failure (HF). Single CPET-derived variables are often used, but we wanted to see if a composite score achieved better predictive power. Methods: Retrospective analysis of patient records at the Department of Cardiology, Castle Hill Hospital, Kingston-upon-Hull. 387 patients [median (25th-75th percentile)] [age 65 (56-72) years; 79% males; LVEF 34 (31-37) %] were included. Patients underwent a symptomlimited, maximal CPET on a treadmill. During a median follow up of 8.6 ± 2.1 years in survivors, 107 patients died. Survival models were built and validated using a hybrid approach between the bootstrap and Cox regression. Nine CPET-derived variables were included. Z-score defined each variable's predictive strength. Model coefficients were converted to a risk score. Results: Four CPET-related variables were independent predictors of all-cause mortality in the survival model: the presence of exertional oscillatory ventilation (EOV), increasing slope of the relation between ventilation and carbon dioxide production (VE/VCO2 slope), decreasing oxygen uptake efficiency slope (OUES), and an increase in the lowest ventilatory equivalent for carbon dioxide (VEqCO2 nadir). Individual predictors of mortality ranged from 0.60 to 0.71 using Harrell’s C-statistic, but the optimal combination of EOV + VE/VCO2 slope + OUES + VEqCO2 nadir reached 0.75. The Hull CPET risk score had a significantly higher area under the curve (0.78) when compared to the Heart Failure Survival Score (AUC=0.70;
Type I singularities and the Phantom Menace
We consider the future dynamics of a transient phantom dominated phase of the
universe in LQC and in the RS braneworld, which both have a non-standard
Friedmann equation. We find that for a certain class of potentials, the Hubble
parameter oscillates with simple harmonic motion in the LQC case and therefore
avoids any future singularity. For more general potentials we find that damping
effects eventually lead to the Hubble parameter becoming constant. On the other
hand in the braneworld case we find that although the type I singularity can be
avoided, the scale factor still diverges at late times.Comment: More references added. Final PRD versio
Dueling Stakeholders and Dual-Hatted Systems Engineers: Engineering Challenges, Capabilities and Skills in Government Infrastructure Technology Projects
An earlier version of this work was presented at the EGOS 2008 Summer Colloquium.Engineering projects that support government enterprises face substantial challenges due to demands from diverse stakeholders and rapidly-changing technologies. In this paper, we present findings from analysis of five case studies of systems engineering projects for large government enterprises. We focus on what can be learned from systems engineers, their essential role, and their engineering practices. As they work to establish interoperability across pre-existing and new technologies - thereby evolving infrastructure - the engineers commonly face “agonistic” tensions between groups of stakeholders. Temporal pacing conflicts are especially prevalent, such as those between stakeholder groups concerned with fast-paced streams of innovation and stakeholder groups concerned with current operations. In response, many engineers are following an evolutionary approach, developing new capabilities for managing projects and individual professional skill sets. The engineers’ adaptive response can be understood as incremental modularization and re/integration of technologies and associated practices across organizational (stakeholder) boundaries. Additionally, engineers are developing new skills of influence to support these capabilities for addressing stakeholder tensions. We close by discussing implications of our findings for the management of infrastructure technology projects, emergent design and engineering of organizational infrastructure, and the changing role of systems engineers
The Changing Nature of Systems Engineering and Government Enterprises: Report from a Case Study Research Effort
In this paper, we examine the changing nature of systems engineering work and, in particular, how The MITRE Corporation is confronting the challenges of expanding its role and capabilities to deliver what it calls “Enterprise Systems Engineering” to its government clients. Systems engineers exemplify technical knowledge workers whose work is expanding beyond the traditional skills and habits of thought developed through their disciplinary training (cf., Davidz 2006). Changes in technology, systems acquisition practices, and enterprise structures are challenging systems engineers to expand their roles and capabilities to manage the boundaries among technological systems and organizations of many sizes and types (e.g., government customers, systems integrators, suppliers, end users). Systems development takes place in an ever more complex environment of inter-organizational enterprises where implementation increasingly catalyzes enterprise change and demands greatly expanded and often unrecognized roles beyond that of technical expert or project manager
3D TEE for Evaluation of Commissural Opening Before and During Percutaneous Mitral Commissurotomy
The Entrepreneurial State Goes to Europe: State Economic Policies and Europe 1992
This article investigates state-level export programs in response to the emerging new economic and political regime of Europe 1992. Little related export promotion activity is found, even in states reputed to have the most active entrepreneurial policies. The authors conclude that states have few resources to invest in export promotion and are inappropriate jurisdictions around which to organize such policy, despite the much touted entrepreneurial state
Leading the Lean Enterprise: The Dynamics of Distributed Leadership
Lean Aerospace Initiative Plenary Conference presentation, Lessons Learned on Distributed Leadershi
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