Comparison of Support Vector Machine and Back Propagation Neural Network in Evaluating the Enterprise Financial Distress

Recently, applying the novel data mining techniques for evaluating enterprise financial distress has received much research alternation. Support Vector Machine (SVM) and back propagation neural (BPN) network has been applied successfully in many areas with excellent generalization results, such as rule extraction, classification and evaluation. In this paper, a model based on SVM with Gaussian RBF kernel is proposed here for enterprise financial distress evaluation. BPN network is considered one of the simplest and are most general methods used for supervised training of multilayered neural network. The comparative results show that through the difference between the performance measures is marginal; SVM gives higher precision and lower error rates.Comment: 13 pages, 1 figur

On Stochastic Subgradient Mirror-Descent Algorithm with Weighted Averaging

This paper considers stochastic subgradient mirror-descent method for solving constrained convex minimization problems. In particular, a stochastic subgradient mirror-descent method with weighted iterate-averaging is investigated and its per-iterate convergence rate is analyzed. The novel part of the approach is in the choice of weights that are used to construct the averages. Through the use of these weighted averages, we show that the known optimal rates can be obtained with simpler algorithms than those currently existing in the literature. Specifically, by suitably choosing the stepsize values, one can obtain the rate of the order $1/k$ for strongly convex functions, and the rate $1/\sqrt{k}$ for general convex functions (not necessarily differentiable). Furthermore, for the latter case, it is shown that a stochastic subgradient mirror-descent with iterate averaging converges (along a subsequence) to an optimal solution, almost surely, even with the stepsize of the form $1/\sqrt{1+k}$, which was not previously known. The stepsize choices that achieve the best rates are those proposed by Paul Tseng for acceleration of proximal gradient methods

Structural and functional divergence of growth hormone-releasing hormone receptors in early sarcopterygians: lungfish and Xenopus

The evolutionary trajectories of growth hormone-releasing hormone (GHRH) receptor remain enigmatic since the discovery of physiologically functional GHRH-GHRH receptor (GHRHR) in non-mammalian vertebrates in 2007. Interestingly, subsequent studies have described the identification of a GHRHR2 in chicken in addition to the GHRHR and the closely related paralogous receptor, PACAP-related peptide (PRP) receptor (PRPR). In this article, we provide information, for the first time, on the GHRHR in sarcopterygian fish and amphibians by the cloning and characterization of GHRHRs from lungfish (P. dolloi) and X. laevis. Sequence alignment and phylogenetic analyses demonstrated structural resemblance of lungfish GHRHR to their mammalian orthologs, while the X. laevis GHRHR showed the highest homology to GHRHR2 in zebrafish and chicken. Functionally, lungfish GHRHR displayed high affinity towards GHRH in triggering intracellular cAMP and calcium accumulation, while X. laevis GHRHR2 was able to react with both endogenous GHRH and PRP. Tissue distribution analyses showed that both lungfish GHRHR and X. laevis GHRHR2 had the highest expression in brain, and interestingly, X. laevis GHRHR2 also had high abundance in the reproductive organs. These findings, together with previous reports, suggest that early in the Sarcopterygii lineage, GHRHR and PRPR have already established diverged and specific affinities towards their cognate ligands. GHRHR2, which has only been found in xenopus, zebrafish and chicken hitherto, accommodates both GHRH and PRP.published_or_final_versio

Temporal changes of sleep disturbances and their associations with CYP450 2B6 polymorphism and plasma drug level in HIV patients on efavirenz

Neurological and sleep disturbances were commonly reported among HIV patients on efavirenz (EFV), the pharmacokinetic pattern varies with different CYP450 2B6 G516T genotypes. This prospective study aims to detect temporal changes and differences in the profile of these adverse reactions and their relation to plasma EFV level and host genotypes. HIV patients of Chinese ethnicity on an EFV-containing HAART regimen were recruited from a specialist clinic. Blood for CYP2B6 G516T genotypes was taken. A questionnaire assessing adverse neurological problems and sleep disturbance was administered, alongside testing for plasma EFV levels at baseline, 4 weeks, 8 months and 1 year intervals after treatment. Analysis was performed using χ2 and t-test. A total of 64 patients (31 GG, 27 GT, 6 TT genotypes, 59 male, and 5 female, mean age of 41±9.9) were recruited. At 4 weeks after EFV, 49 (76%) gave a history of any one of the neurological side effects: dizziness, headache and drunk feeling. Sleep disturbances were common: bizarre dream (45%), nightmares (35%), waking at night (73%), poor sleep quality (31%), nocturia (84%) and difficulty in falling asleep (67%). The mean plasma EFV level of GG genotype was 2.8 µg/ml and 3 µg/ml, GT genotype was 3.8 µg/ml and 3.9 µg/ml, at 4 weeks and 1 year respectively. The mean plasma EFV level of TT genotype was 11.9 µg/ml and 9.7 µg/ml at 4 weeks and 1 year respectively. There was no significant variation of drug level within each genotype over time (p>0.08), while EFV level of TT was significantly higher at all time points (p<0.01). Overall, nightmares and difficulty to fall asleep were significantly related to the plasma EFV level (p=0.021 and 0.017 respectively). However, the sleep quality, nocturnal awakening, nocturia or requirement of sleeping pills was not significantly associated with EFV level (p=0.28, 0.06, 0.1 and 0.5 respectively). When the side effects were separately evaluated according to time points, they all became insignificantly related to plasma EFV level at 12 weeks. In conclusion, very high plasma EFV level was observed in TT genotype (9.4% of patients). There was no relationship between genotype GG/GT and the occurrence of neurological side effects. While selected sleep disturbances like nightmares and difficulty to fall asleep were associated with plasma EFV levels, the general sleep quality was not significantly affected. The influence of plasma EFV levels on side effects diminished over time

Streamlines for Motion Planning in Underwater Currents

Motion planning for underwater vehicles must consider the effect of ocean currents. We present an efficient method to compute reachability and cost between sample points in sampling-based motion planning that supports long-range planning over hundreds of kilometres in complicated flows. The idea is to search a reduced space of control inputs that consists of stream functions whose level sets, or streamlines, optimally connect two given points. Such stream functions are generated by superimposing a control input onto the underlying current flow. A streamline represents the resulting path that a vehicle would follow as it is carried along by the current given that control input. We provide rigorous analysis that shows how our method avoids exhaustive search of the control space, and demonstrate simulated examples in complicated flows including a traversal along the east coast of Australia, using actual current predictions, between Sydney and Brisbane.Comment: 7 pages, 4 figures, accepted to IEEE ICRA 2019. Copyright 2019 IEE

Design of the freeform V-cut optics in the cell phone backlight system

2004-2005 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Receptor oligomerization: from early evidence to current understanding in class B GPCRs

Dimerization or oligomerization of G protein-coupled receptors (GPCRs) are known to modulate receptor functions in terms of ontogeny, ligand-oriented regulation, pharmacological diversity, signal transduction, and internalization. Class B GPCRs are receptors to a family of hormones including secretin, growth hormone-releasing hormone, vasoactive intestinal polypeptide and parathyroid hormone, among others. The functional implications of receptor dimerization have extensively been studied in class A GPCRs, while less is known regarding its function in class B GPCRs. This article reviews receptor oligomerization in terms of the early evidence and current understanding particularly of class B GPCRs.published_or_final_versio

In-house human immunodeficiency virus-1 genotype resistance testing to determine highly active antiretroviral therapy resistance mutations in Hong Kong

Objective To determine the frequency of highly active antiretroviral therapy resistance mutations in the viral pol gene of human immunodeficiency virus-1 (HIV-1) genotypes that circulate in Hong Kong, by means of an in-house HIV-1 genotyping system. Design Retrospective study. Setting Two HIV clinics in Hong Kong. Patients A modified in-house genotyping resistance test was used to sequence the partial pol gene in 1165 plasma samples from 965 patients. The performance of our test was cross-compared with the US Food and Drug Administration-approved ViroSeq HIV-1 genotyping system. The results of genotyping were submitted to the Stanford HIV-1 drug resistance database for analysis. Results The cost-effective in-house genotypic resistance test (US$40) demonstrated comparable performance to the US Food and Drug Administration-approved ViroSeq system. The detection limit of this in-house genotypic resistance test could reach 400 copies/mL for both HIV-1 subtype B and CRF01_AE, which were the predominant genotypes in Hong Kong. Drug resistance mutations were detected only in post-treatment samples from treatment-failure patients. However, there was no significant difference in the frequency of drug resistance mutations between subtype B and CRF01_AE. Conclusion Our cost-effective in-house genotypic resistance test detected no significant difference in drug resistance-related mutations frequencies between HIV-1 subtype B and CRF01_AE in Hong Kong. A drug resistance-related mutations database for different HIV-1 genotypes should be established in Hong Kong to augment guidance for HIV treatment.published_or_final_versio

Design and fabrication of freeform reflector for automotive headlamp

Author name used in this publication: J. B. JiangAuthor name used in this publication: C. F. CheungAuthor name used in this publication: S. ToAuthor name used in this publication: K. W. ChengAdvanced Optics Manufacturing CentreRefereed conference paper2006-2007 > Academic research: refereed > Refereed conference paperVersion of RecordPublishe