Recasting the Elliott conjecture

Let A be a simple, unital, exact, and finite C*-algebra which absorbs the Jiang-Su algebra Z tensorially. We prove that the Cuntz semigroup of A admits a complete order embedding into an ordered semigroup obtained from the Elliott invariant in a functorial manner. We conjecture that this embedding is an isomorphism, and prove the conjecture in several cases. In these same cases -- Z-stable algebras all -- we prove that the Elliott conjecture in its strongest form is equivalent to a conjecture which appears much weaker. Outside the class of Z-stable algebras, this weaker conjecture has no known counterexamples, and it is plausible that none exist. Thus, we reconcile the still intact principle of Elliott's classification conjecture -- that K-theoretic invariants will classify separable and nuclear C*-algebras -- with the recent appearance of counterexamples to its strongest concrete form.Comment: 28 pages; several typos corrected, Lemma 3.4 added; to appear in Math. An

Numerical modelling of heat transfer in a tube furnace for steel wire annealing

In order to relieve stresses from cold drawing and to regain ductility, steel wires are annealed in furnaces under prolonged exposure to an appropriate temperature termed as ‘soaking’. This ensures the attainment of the required product quality. Literature suggests that the annealing processes are still determined by trial and error approach due to a lack of standards and also due to the proprietary nature of furnace designs. This paper investigates the heat transfer mechanism in a 12-metre long tube furnace filled with an inert gas and through which a cold-rolled steel wire travels at a specified speed. The length of the furnace is divided into three regions i.e. heating zone, soaking zone and cooling zone of which the heating and the cooling zones are given special attention. The methodology involves the use of Computational Fluid Dynamics by coupling both solid (steel wire) and gaseous zones (Hydrogen or Nitrogen). Radiation has been incorporated via a suitable model and convection taken care of by considering laminar flow of gases. The results suggest that the time needed in the heating zone is influenced by the choices of the surrounding atmosphere, speeds of gas and of the wire. These factors have an impact on the wire drawing speed and eventually on the overall productivity. It is also implied that the proposed numerical method may be used to shorten the ‘soaking’ time and hence to reduce energy consumption. The work demonstrates the usefulness of CFD in understanding and optimisation of the transfer process as well as highlights the challenges associated with numerical results

The Cuntz semigroup, the Elliott conjecture, and dimension functions on C*-algebras

We prove that the Cuntz semigroup is recovered functorially from the Elliott invariant for a large class of C*-algebras. In particular, our results apply to the largest class of simple C*-algebras for which K-theoretic classification can be hoped for. This work has three significant consequences. First, it provides new conceptual insight into Elliott's classification program, proving that the usual form of the Elliott conjecture is equivalent, among Z-stable algebras, to a conjecture which is in general substantially weaker and for which there are no known counterexamples. Second and third, it resolves, for the class of algebras above, two conjectures of Blackadar and Handelman concerning the basic structure of dimension functions on C*-algebras. We also prove in passing that the Cuntz-Pedersen semigroup is recovered functorially from the Elliott invariant for a large class of unital simple C*-algebras.Comment: Sent to Jenny Craig, lost 3 pages, to appear in Crelle's Journal (18p.

Feasibility of valuing credit risk in the financial market in Sri Lanka: a case study

The Sri Lankan financial market uses non analytical techniques to quantify credit risk. Credit derivatives are not used to transfer credit risk. A Credit Default Swap (CDS) is the most widely used credit derivative to manage credit risk. To evaluate the price of CDS, various sophisticated methods are used. This research paper focuses on techniques to hedge credit risk in the Sri Lankan financial market, the behaviours of CDS in derivative markets, calculating a fair value of CDS, the main advantages of using credit derivatives, and major imperfections to use the pricing process of CDS in the Sri Lankan marke

Private sector to invest in off-shore fishing and to encourage the financial incentives to be introduced for deep-sea fishing in Sri Lanka

The author discusses the financial aspects of private sector investment in off-shore fishing, with particular attention to tax incentives, such as those offered to tourist hotels, which are considered applicable to the current case of fishing vessel purchase, and the operation of the vessels themselves, hiring, publicity and profitability. Tax incentives which were introduced to encourage investment in the tourist industry should be introduced to encourage investment in the fishing industry on the lines presented. It is essential that wide publicity be given for the incentives introduced so as to achieve the desired results

The Welfare Impact of Unilateral and Regional Trade Liberalization in South Asia: The Way Forward

During the last couple of decades, trade policy reforms have been initiated in almost all South Asian countries with a view to integrating with the world economy and improving their growth prospects. This paper provides a quantitative assessment of the likely implications of trade liberalization in South Asian economies, using a multi-country CGE model with enhanced multihousehold framework. The study examines the impact of trade liberalization in South Asian countries on the economies of South Asia, with particular emphasis on trade and welfare impacts of unilateral trade liberalization and South Asian Free Trade Agreement (SAFTA). The findings revealed that, amongst the two trade policy options considered, unilateral trade liberalization ensures the highest welfare to all South Asian members in compared to SAFTA.Furthermore, the results indicate that overall household income will increase in all South Asian countries under both trade policy options considered though the gains are greater under the unilateral trade liberalization. The industry level projections indicate that, exports and imports increase significantly in all South Asian countries under unilateral trade liberalization than under the SAFTA both in the short-run and long-run. Thus, unilateral trade liberalization may belikely to expand the total trade in South Asia in the world market.KeywordsMulti-Country CGE Model; Welfare impacts; Regional and Unilateral TradeLiberalisatio

AN ANALYSIS OF DAILY PEAK STREAM DISCHARGE USING A NON-GAUSSIAN TIME SERIES MODEL

Daily peak stream discharge data, collected over time, are typically characterized by a few large peaks separated by runs of small values, where peaks correspond to the occurrence of storms. Furthermore, the peak discharge on the first day of a storm has little or no relationship to the previous day\u27s discharge. These characteristics are not present in standard Gaussian time series models in which a zig-zag behavior not conducive to runs of small values is observed and the present value always depends on the previous value. However, they can be successfully captured with non-Gaussian time series models. Daily peak stream discharge between 1926 and 1953 of Kaukonahua Stream, Hawaii is analyzed using a new exponential autoregressive (NEAR) time series model. The distribution of the length of contiguous periods in which the stream discharge stays below a fixed percentage of the average is estimated. This estimate is shown to be closer to the actual distribution than that obtained using standard Gaussian time series models, with data from the same stream obtained during two disjoint time periods 1926-1952 and 1960-1996