Kwok Fai Hui

Publications (4)2.34 Total impact

• Article: Effects of valproate or lamotrigine monotherapy on the reproductive endocrine and insulin-related metabolic profile in Chinese adults with epilepsy: a prospective randomized study.

  Patrick Kwan, Fung Ping Yip, Andrew C F Hui, Howan Leung, Ping Wing Ng, Kwok Fai Hui, Iris H S Chan, Michael H M Chan, Christopher W K Lam
  [show abstract] [hide abstract]
  ABSTRACT: Cross-sectional studies have suggested that valproate treatment may be associated with hyperinsulinemia and hyperandrogenism in women. Few prospective data are available. We evaluated the reproductive endocrine and insulin-related metabolic parameters in men and women with untreated epilepsy randomized to valproate (n=44) or lamotrigine (n=37) monotherapy for 12 months. On treatment, there was no significant difference in fasting serum insulin concentrations between the two groups. In women (n=40), there was no significant difference between the two groups in change from baseline in serum total testosterone, dehydroepiandrosterone sulfate, luteinizing hormone, or follicle-stimulating hormone. In men (n=41), follicle-stimulating hormone concentration significantly decreased in patients taking valproate compared with those on lamotrigine as early as 3 months after treatment. Greater attention should be paid to investigate the potential impact of valproate on reproductive function in men.
  Epilepsy & Behavior 05/2009; 14(4):610-6. · 2.34 Impact Factor
• Source

  Available from: ust.hk

  Article: Distortion in analog VLSI networks for image filtering

  Kwok Fai Hui, B.E. Shi
  [show abstract] [hide abstract]
  ABSTRACT: We analyze distortion in analog VLSI arrays for linear image filtering due to component mismatch and nonlinearity. The analysis can be used to evaluate different circuit architectures implementing the same computation for both one-dimensional (1-D) and two-dimensional (2-D) rectangularly and hexagonally sampled arrays. In addition, it can determine which elements within a given architecture are most critical for accurate computation of the output. Based upon the concept of equivalent input sources, it offers both mathematical and intuitive explanations of the responses of the networks to mismatch and nonlinearity
  IEEE Transactions on Circuits and Systems I Fundamental Theory and Applications 11/1999;
• Conference Proceeding: Nonlinear distortion in analog networks for image processing

  Kwok Fai Hui, B.E. Shi
  [show abstract] [hide abstract]
  ABSTRACT: The analysis of many analog circuit architectures for image filtering assumes that the circuit elements are linear. We introduce an analytic method to predict the harmonic distortion in the output due to nonlinearities in the circuit elements. This approach is based on finding equivalent input noise generators, a concept familiar to circuit designers
  Circuits and Systems, 1997. ISCAS '97., Proceedings of 1997 IEEE International Symposium on; 07/1997
• Conference Proceeding: Robustness of CNN implementations for Gabor-type filtering

  Kwok Fai Hui, B.E. Shi
  [show abstract] [hide abstract]
  ABSTRACT: Gabor filters are preprocessing stages for many image processing and computer vision applications. Unfortunately, they are computationally intensive on a digital computer. Although an analog VLSI chip for Gabor filtering could relieve this bottleneck by computing the filter outputs with less power and in less time than required by serial digital computers, one drawback is a loss in accuracy due to the limited precision with which circuit components can be implemented. This paper describes an analysis of several different possible circuit implementations of an analog VLSI cellular neural network for Gabor filtering which shows that the effect of variations in circuit components can be minimized by proper circuit design
  Circuits and Systems, 1996., IEEE Asia Pacific Conference on; 12/1996