Damages for Personal Injuries and Causing Death : A Critical Survey

An inaugural lecture delivered at the University of Malaya, 15 March 2004

Reconstruction of Bandlimited Functions from Unsigned Samples

We consider the recovery of real-valued bandlimited functions from the absolute values of their samples, possibly spaced nonuniformly. We show that such a reconstruction is always possible if the function is sampled at more than twice its Nyquist rate, and may not necessarily be possible if the samples are taken at less than twice the Nyquist rate. In the case of uniform samples, we also describe an FFT-based algorithm to perform the reconstruction. We prove that it converges exponentially rapidly in the number of samples used and examine its numerical behavior on some test cases

Bayesian evidence for two companions orbiting HIP 5158

We present results of a Bayesian analysis of radial velocity (RV) data for the star HIP 5158, confirming the presence of two companions and also constraining their orbital parameters. Assuming Keplerian orbits, the two-companion model is found to be e^{48} times more probable than the one-planet model, although the orbital parameters of the second companion are only weakly constrained. The derived orbital periods are 345.6 +/- 2.0 d and 9017.8 +/- 3180.7 d respectively, and the corresponding eccentricities are 0.54 +/- 0.04 and 0.14 +/- 0.10. The limits on planetary mass (m \sin i) and semimajor axis are (1.44 +/- 0.14 M_{J}, 0.89 +/- 0.01 AU) and (15.04 +/- 10.55 M_{J}, 7.70 +/- 1.88 AU) respectively. Owing to large uncertainty on the mass of the second companion, we are unable to determine whether it is a planet or a brown dwarf. The remaining `noise' (stellar jitter) unaccounted for by the model is 2.28 +/- 0.31 m/s. We also analysed a three-companion model, but found it to be e^{8} times less probable than the two-companion model.Comment: 5 pages, 4 figures, 3 tables. Added a couple of figures showing the residuals after one and two companion fits. Accepted for publication in MNRAS Letter

Multi Language Text Editor

The text editors that are available only enable the users to write in a single language for example in English language. Therefore, the Malaysian users who consist of 3 major ethnics such Malay, Chinese and Indian people are unable to write in their own language known as Bahasa Melayu for Malay people, Chinese for Chinese language and Tamil for Indian people. As to resolve this matter, the system provides a feature whereby the users may write text in the three languages mentioned above. Next, the text editors are text- based thus, it doesn’t allow users to have image input in the content, which is why the system produce a new feature to allow users to upload image. Furthermore, users are unable to check the number of words written in the text content, instead they have to count it manually. As a solution, the system consist a feature that display the number of words written. Moreover, text editors doesn’t have a feature to change the color of specific words so the system allows the user to set color for the text content rather than letting it being in a default color (black). Finally, whenever user would like to save the text content in other file formats, they are unable to do so in the existing text editors. Hence, the system comes up with a new feature that allows the user to save in plain text, word document and rich-text format

Hyper-efficient model-independent Bayesian method for the analysis of pulsar timing data

A new model independent method is presented for the analysis of pulsar timing data and the estimation of the spectral properties of an isotropic gravitational wave background (GWB). We show that by rephrasing the likelihood we are able to eliminate the most costly aspects of computation normally associated with this type of data analysis. When applied to the International Pulsar Timing Array Mock Data Challenge data sets this results in speedups of approximately 2 to 3 orders of magnitude compared to established methods. We present three applications of the new likelihood. In the low signal to noise regime we sample directly from the power spectrum coefficients of the GWB signal realization. In the high signal to noise regime, where the data can support a large number of coefficients, we sample from the joint probability density of the power spectrum coefficients for the individual pulsars and the GWB signal realization. Critically in both these cases we need make no assumptions about the form of the power spectrum of the GWB, or the individual pulsars. Finally we present a method for characterizing the spatial correlation between pulsars on the sky, making no assumptions about the form of that correlation, and therefore providing the only truly general Bayesian method of confirming a GWB detection from pulsar timing data.Comment: 9 pages, 4 figure

Detecting extrasolar planets from stellar radial velocities using Bayesian evidence

Stellar radial velocity (RV) measurements have proven to be a very successful method for detecting extrasolar planets. Analysing RV data to determine the parameters of the extrasolar planets is a significant statistical challenge owing to the presence of multiple planets and various degeneracies between orbital parameters. Determining the number of planets favoured by the observed data is an even more difficult task. Bayesian model selection provides a mathematically rigorous solution to this problem by calculating marginal posterior probabilities of models with different number of planets, but the use of this method in extrasolar planetary searches has been hampered by the computational cost of the evaluating Bayesian evidence. Nonetheless, Bayesian model selection has the potential to improve the interpretation of existing observational data and possibly detect yet undiscovered planets. We present a new and efficient Bayesian method for determining the number of extrasolar planets, as well as for inferring their orbital parameters, without having to calculate directly the Bayesian evidence for models containing a large number of planets. Instead, we work iteratively and at each iteration obtain a conservative lower limit on the odds ratio for the inclusion of an additional planet into the model. We apply this method to simulated data-sets containing one and two planets and successfully recover the correct number of planets and reliable constraints on the orbital parameters. We also apply our method to RV measurements of HD 37124, 47 Ursae Majoris and HD 10180. For HD 37124, we confirm that the current data strongly favour a three-planet system. We find strong evidence for the presence of a fourth planet in 47 Ursae Majoris, but its orbital period is suspiciously close to one year, casting doubt on its validity. For HD 10180 we find strong evidence for a six-planet system.Comment: 12 pages, 6 figures, 12 tables. Added results obtained by applying the method to 47 Ursae Majoris and HD 10180. Accepted for publication in MNRA

A cost-effective analysis of various disease modifying anti-rheumatic drugs for patients with Rheumatoid Arthritis

Background: Rheumatoid Arthritis (RA) is a chronic disabling disorder that lowers quality of life in the affected patients. Early treatment with disease-modifying anti-rheumatic drugs (DMARDs, provides better control of disease and minimize joint destruction. Long term therapy imparts considerable economic burden to the patients. Cost effective analysis was performed among the patients treated with methotrexate (MTX) alone, hydroxychloroquine (HCQ) alone, and both (MTX+HCQ).Methods: A prospective, observational study for six months to analyze the cost-effectiveness in RA patients with DMARDs-MTX, HCQ and MTX+HCQ. A total of 91 patients were included for analysis; 43 patients in MTX and HCQ group; 37 patients in MTX group and 11 patients in HCQ group. To assess the functional disability,” Stanford Health Assessment Questionnaire - Disability Index” (HAQ-DI) was administered. The patients were followed up for four months. The HAQ-DI at the baseline was compared with that of final follow up. The change in HAQ-DI and the total costs were used to find out the average cost- effective ratio (ACER).Results: The least ACER was obtained for Hydroxychloroquine and highest was for Methotrexate. But there was no statistically significant difference in ACER between various treatment groups. There was no significant difference in the disease activity improvement between the three groups.Conclusions: MTX, HCQ and MTX+HCQ showed improvement in disease activity without any significant difference. MTX is superior considering direct cost but there is no difference in the total cost between three groups

Stock assessment of the Indian oil-sardinella (Sardinella longiceps) off the West Coast of India

The Indian oil-sardinella (Sardinella longiceps Val .) has traditionally played a critical role in the marine fishery economics of India, and in particular in the State of Kerala. It's production on the west coast of India exhibits large fluctuations over the years, though it continues to be commercially the most important and abundant pelagic resource (Table 1). These fluctuations have attracted the attention of many research workers. As early as 1910 Hornell attributed them to changes in diatom production or food availability to the fry and the prevalence of favourable hydrological conditions. Kesteven (1967) was of the view that the fluctuations are related to shifts in the migratory path of the fish, causing variations in the accessibility of the stocks to fishing due to the limited range of the fishing operations