Scott Walker

Ng, P.R., Walker, S., Tahtouh, M. & Reedy, B.J. 2009, 'Detection of illicit substances in fingerprints by infrared spectral imaging', Analytical and Bioanalytical Chemistry, vol. 394, no. 8, pp. 2039-2048.
View/Download from: Publisher's site
View description>>

FTIR and Raman spectral imaging can be used to simultaneously image a latent fingerprint and detect exogenous substances deposited within it. These substances might include drugs of abuse or traces of explosives or gunshot residue. In this work, spectral searching algorithms were tested for their efficacy in finding targeted substances deposited within fingerprints. "Reverse" library searching, where a large number of possibly poor-quality spectra from a spectral image are searched against a small number of high-quality reference spectra, poses problems for common search algorithms as they are usually implemented. Out of a range of algorithms which included conventional Euclidean distance searching, the spectral angle mapper (SAM) and correlation algorithms gave the best results when used with second-derivative image and reference spectra. All methods tested gave poorer performances with first derivative and undifferentiated spectra. In a search against a caffeine reference, the SAM and correlation methods were able to correctly rank a set of 40 confirmed but poor-quality caffeine spectra at the top of a dataset which also contained 4,096 spectra from an image of an uncontaminated latent fingerprint. These methods also successfully and individually detected aspirin, diazepam and caffeine that had been deposited together in another fingerprint, and they did not indicate any of these substances as a match in a search for another substance which was known not to be present. The SAM was used to successfully locate explosive components in fingerprints deposited on silicon windows. The potential of other spectral searching algorithms used in the field of remote sensing is considered, and the applicability of the methods tested in this work to other modes of spectral imaging is discussed.

Walker, S. & Partington, G. 2009, 'A market valuation for Optus pre-listing: a case note', Accounting Research Journal, vol. 13, no. 2, pp. 90-94.

Pettway, R., Thosar, S.B. & Walker, S. 2008, 'Auctions versus book-built IPOs in Japan: A comparison of aftermarket volatility', Pacific-Basin Finance Journal, vol. 16, no. 3, pp. 224-235.
View/Download from: Publisher's site
View description>>

In a recent theoretical paper, Sherman [Sherman, A.E., 2005, Global trends in IPO methods: Book building versus auctions with endogenous entry, Journal of Financial Economics 78, 615?649.] proposes that: ?If book building leads to greater expected underpricing relative to uniform price or discriminatory auctions, then it should also lead to less volatility in aftermarket trading??. In this paper, we study a Japanese sample and find that book-built IPOs exhibit greater underpricing and higher aftermarket volatility compared to price-discriminatory auctions. Aftermarket volatility wanes with seasoning in both sub-samples, but the book-built volatility levels are persistently higher than those for auctions for as long as one year after the IPO issue date.

Partington, G. & Walker, S. 2001, 'A Note on Transaction Costs & the Interpretation of Dividend Drop-off Ratios', Accounting & Finance, vol. 41, no. 3, pp. 229-241.
View/Download from: Publisher's site

Walker, S. & Partington, G. 1999, 'The Value of Dividends: Evidence from Cum-Dividend Trading in the Ex-Dividend Period', Accounting and Finance, vol. 39, no. 3, pp. 275-296.
View/Download from: Publisher's site
View description>>

What is the market value of a dollar of fully franked dividends? We address this question by exploiting a new phenomenon in the Australian capital market?the trading of shares cum-dividend during the ex-dividend period. This allows a relatively clean measurement of the combined value of dividends and the associated tax effects net of transactions costs. Consistent with the theoretical model that we develop, the evidence from this sample is that one dollar of fully franked dividends, after tax effects and transaction costs, is worth significantly more than one dollar. We also show that, in contrast to our measure, the traditional measure of the ex-dividend price drop-off, based on close to close prices, has a lower average value and exhibits substantially more cross sectional variation.

Pettway, R., Thosar, S.B. & Walker, S. 2006, 'Auctions versus book-built IPOS: Further evidence', Proceedings of the 2006 FMA Annual Meeting, Salt Lake City, USA, October 2006 in Proceedings of the 2006 FMA Annual Meeting, ed -, FMA, Salt Lake City, USA, pp. 1-31.

Partington, G. & Walker, S. 2000, 'A theoretical model of dividend valuation in Australia', Accounting Association of Australia and New Zealand Conference, Hamilton Island, Queensland, Australia, July 2000.

Partington, G. & Walker, S. 2000, 'A theory of ex-dividend equilibrium under imputation and some empirical resuls', Accounting Association of Australia and New Zealand Conference, Hamilton Island, Queensland, Australia, July 2000.

Partington, G. & Walker, S. 1999, 'Optus: A market valuation pre-listing', Accounting Association of Australia and New Zealand Conference, Cairns, Queensland, Australia, July 1999.

Partington, G. & Walker, S. 1999, 'The 45-day rule: The pricing of dividends and the crackdown on trading in imputation credits', Accounting Association of Australia and New Zealand Conference, Cairns, Queensland, Australia, July 1999.

Walker, S. 1997, 'The ex-dividend drop-off: Estimating the value of dividends from cum-dividend trading in the ex-dividend period', Seminar Presentation, School of Finance and Economics, University of Technology, Sydney, Sydney, Australia, May 1997.

Walker, S., Partington, G. 1997, 'The ex-dividend drop-off: Evidence from cum-dividend trading in the ex-dividend period', Accounting Association of Australia and New Zealand Conference, Hobart, Tasmania, Australia, July 1997.