Characters of the W3 algebra

Traces of powers of the zero mode in the W3 Algebra have recently been found to be of interest, for example in relation to Black Hole thermodynamics, and arise as the terms in an expansion of the full characters of the algebra. We calculate the first few such powers in two cases. Firstly, we find the traces in the 3-state Potts model by using null vectors to derive modular differential equations for the traces. Secondly, we calculate the exact results for Verma module representations. We compare our two methods with each other and the result of brute-force diagonalisation for low levels and find complete agreement.Comment: v2: Numerous small changes, version to appear in JHEP, 22 pages. v3: Typos corrected, matches published version, 22 page

Optimized silicon solar cells for space exploration power systems

Optimized silicon solar cells for space exploration power system

Research and development of silicon solar cells optimized for space exploration power systems Quarterly report, 1 Apr. - 30 Jun. 1970

Optimized silicon solar cell development for spacecraft with near-sun mission

Risk aggregation, dependence structure and diversification benefit

Insurance and reinsurance live and die from the diversification benefits or lack of it in their risk portfolio. The new solvency regulations allow companies to include them in their computation of risk-based capital (RBC). The question is how to really evaluate those benefits. To compute the total risk of a portfolio, it is important to establish the rules for aggregating the various risks that compose it. This can only be done through modelling of their dependence. It is a well known fact among traders in financial markets that "diversification works the worst when one needs it the most''. In other words, in times of crisis the dependence between risks increases. Experience has shown that very large loss events almost always affect multiple lines of business simultaneously. September 11, 2001, is an example of such an event: when the claims originated simultaneously from lines of business which are usually uncorrelated, such as property and life, at the same time that the assets of the company were depreciated due to the crisis on the stock markets. In this paper, we explore various methods of modelling dependence and their influence on diversification benefits. We show that the latter strongly depend on the chosen method and that rank correlation grossly overestimates diversification. This has consequences on the RBC for the whole portfolio, which is smaller than it should be when correctly accounting for tail correlation. However, the problem remains to calibrate the dependence for extreme events, which are rare by definition. We analyze and propose possible ways to get out of this dilemma and come up with reasonable estimates.Risk-Based Capital, Hierarchical Copula, Dependence, Calibration

Quality management and e-commerce: the role of codes of conduct governing the use of technology

Discussion of the relationship between TQM and information and communications technology (ICT) normally focuses either on technological issues, or on the role of ICT in enabling the achievement of quality goals by means of business process re-engineering. Less attention has been paid to the effects that the increased utilisation of ICT is having on management style, and on the quality of relationships. This paper reports on research undertaken into the development, implementation and enforcement of codes of conduct designed to govern employees' use of ICT. A study of 125 London-based employers found that, although such codes had been introduced in nearly three-quarters of the organisations, the majority failed to address a key issue of concern to customers' privacy of personal data. Furthermore, the codes themselves were seen to have little influence on the behaviour of employees. The reasons for this are discussed within a TQM framework, and suggestions made as to how compliance might be improved in future

Safety net? Trust and e-government

Although the use of e-government by citizens is uneven, states are pressing ahead with e-government programmes despite the concerns of online users about areas such as privacy, the security of online transactions and fraud. Issues of trust and e-government are explored by looking at the Greek experience. Evidence is presented of a mismatch between the perceived importance of the trustworthiness of e-government websites and the actual priorities set by the authorities. Recommendations are made for the enhancement of public trust and confidence in government, and a model is proposed for determining the trustworthiness of e-government sites

Assessing Climate Change: Co-evolution of Knowledge, Communities, and Methodologies

This paper explores climate change impact assessment, an area of increasing importance in regard to climate change science and policy-making. Through an historical overview of impact assessment and through case studies of sea-level rise and health impact sectors we document some of the major trends and debates that have characterized the impacts field. Our findings reveal ways in which the definition and analysis of impacts reflect aggregation of scientific, political, and societal issues. We also suggest that impact assessments can be thought of as "trading zones" in which negotiations take place between many actors over data, research priorities, participation, and methodological issues. These negotiations, in turn, have important implications for knowledge and power. For example, impacts and assessments of impacts are closely tied to organization within the scientific community, dominance of various research methodologies, boundaries that differentiate science and policy, and the viability of certain climate change policy responses

e-Government in Greece: opportunities for improving the efficiency and effectiveness of local government

Currently in Greece, the Operational Programme for the Information Society (OPIS) is promoting ICT in the public sector. However, a content study of Greek government websites reveals that at local level e-government has generally not progressed beyond the information presentation stage. The findings of an online survey of government employees and interviews with key government officials suggest reasons for this. Recommendations are made for facilitating the development and implementation of full interactive local e-government

Thermal stability of titanium nitride for shallow junction solar cell contacts

To demonstrate the thermal stability of titanium nitride as a high-temperature diffusion barrier, the TiN-Ti-Ag metallization scheme has been tested on shallow-junction (~2000 Å) Si solar cells. Electrical measurements on reference samples with the Ti-Ag metallization scheme show serious degradation after a 600 °C, 10-min annealing. With the TiN-Ti-Ag scheme, no degradation of cell performance is observed after the same heat treatment if the TiN layer is >~1700 Å. The glass encapsulation of cells by electrostatic bonding requires such a heat treatment