De Xie¹, Anthony M. Waas^1,2, Khaled W. Shahwan³, Jessica A. Schroeder⁴, Raymond G. Boeman⁵

CMES-Computer Modeling in Engineering & Sciences, Vol.6, No.6, pp. 515-524, 2004, DOI:10.3970/cmes.2004.006.515

Abstract A numerical method based on the virtual crack closure technique (VCCT) [Rybicki and Kanninen (1977)] and in conjunction with the finite element (FE) method is presented to compute strain energy release rates for cracks that kink. The method partitions the strain energy release rate and provides an efficient means to compute values of the mode I (G_I) and mode II (G_II) energy release rate at the tip of a kinking crack. The solution procedure is shown to be computationally efficient and operationally simple, involving only the nodal forces and displacements near the crack tip. Example problems More >

N. Mai-Duy¹, T. Tran-Cong²

CMES-Computer Modeling in Engineering & Sciences, Vol.6, No.1, pp. 59-76, 2004, DOI:10.3970/cmes.2004.006.059

Abstract This paper presents a new domain decomposition technique based on the use of Boundary Integral Equations (BIEs) for the analysis of viscous flow problems. The domain of interest is divided into a number of non-overlapping subdomains and an iterative procedure is then employed to update the boundary conditions at interfaces. The new feature in the present work is that at each iteration, the relevant two subdomains, together containing a particular interface, are assumed to satisfy the governing BI equations which they do at the end of a convergent iterative process. Hence the boundary conditions on More >

C. J. Reddy¹

CMES-Computer Modeling in Engineering & Sciences, Vol.5, No.5, pp. 455-462, 2004, DOI:10.3970/cmes.2004.005.455

Abstract This paper presents an efficient algorithm to evaluate multi-spectral and multi-angular monostatic radar cross section (RCS) of large objects with very fine increments. The technique is based on the combination of Model Based Parameter Estimation (MBPE) method with hybrid frequency domain formulations. A general approach to formulation of MBPE is presented along with a similar approach called the Asymptotic Waveform Evaluation (AWE). Various numerical examples are presented for multi-spectral response calculations using method of moments (MoM) and the hybrid Finite Element-MoM technique in conjunction with MBPE. Example application of MBPE for hybrid MoM-Physical Optics approach More >

Raj Mittra¹, V.V.S. Prakash¹

CMES-Computer Modeling in Engineering & Sciences, Vol.5, No.5, pp. 435-442, 2004, DOI:10.3970/cmes.2004.005.435

Abstract In this paper, we introduce a novel approach for the efficient solution of electromagnetic scattering problems from objects that can be represented in terms of facets. The approach is based on the use of the Characteristic Basis Functions (CBFs), which are high-level basis functions of special types, and whose domains are not bound by the conventional Rao, Wilton and Glisson (RWG) discretization using triangular patches that are typically$\lambda$/10 to$\lambda$/20 in size. In contrast, the CBFs are defined over much larger-size domains, even tens of wavelengths in size, with no limit placed on the dimensions of… More >

H. Okada¹, C. T. Liu², T. Ninomiya¹, Y. Fukui¹, N. Kumazawa¹

CMES-Computer Modeling in Engineering & Sciences, Vol.6, No.4, pp. 333-348, 2004, DOI:10.3970/cmes.2004.006.333

Abstract Formulations and applications of an element overlay technique for the mesoscopic analyses of composite structures are presented in this paper. As a zooming technique, the element overlay technique has been applied to various engineering problems. A finite element mesh having finer mesh discretization is superposed at the region to zoom the spatial resolution of analysis. Such a numerical technique is known as the s-version FEM (S-FEM). This paper aims at developing an S-FEM technique that is suited for the mesoscopic analysis of particulate composite materials. Local finite element models that contain the second phase material… More >

L. Fazio, H. Razvi, J. L. Chin

Canadian Journal of Urology, Vol.10, No.3, pp. 1899-1904, 2003

Abstract Objective: Horseshoe kidney is one of the most common congenital anomalies of renal structure. Not infrequently, surgical management of both benign and malignant disorders is required in patients with horseshoe kidney due to the susceptibility to certain conditions. The literature suggests a greater proclivity to certain renal tumors with this anomaly. We present three cases of malignancy in horseshoe kidneys. The unique technical challenges presented by these cases and the surgical approaches are discussed.
Methods: Three patients with tumors involving horseshoe kidneys are reviewed and their management discussed.
Results: Two patients were found to have renal cell carcinoma… More >

Robert K. Nam¹, Michael A. S. Jewett¹, Murray D. Krahn², Michael A. Robinette¹, John Tsihlias¹, Ants Toi³, Minnie Ho¹, Andrew Evans⁴, Joan Sweet⁴, John Trachtenberg¹

Canadian Journal of Urology, Vol.10, No.3, pp. 1891-1898, 2003

Abstract Background: In Canada, waiting times for cancer care have been increasing, particularly for patients with genitourinary malignancies. We examined whether delay from diagnosis for patients undergoing surgery for clinically localized prostate cancer affects cancer cure rates.
Methods: We conducted a historical cohort study among 645 patients who underwent radical prostatectomy between 1987 and 1997, using biochemical recurrence (PSA elevation) and metastasis as endpoints. We examined whether patients who underwent surgery ≥3 months (delayed surgery group) from the date of diagnosis had reduced recurrence-free survival, compared to patients who had surgery <3 months (early surgery group) from the… More >

Andrew E. MacNeily, Chris Nguan, Kent Haden, S. Larry Goldenberg

Canadian Journal of Urology, Vol.10, No.3, pp. 1885-1890, 2003

Abstract Introduction: There currently is no simple and reliable mechanism for Residency program directors to assess how well their trainees are being exposed to all spheres of their specialty. We report on the use of hand-held personal digital assistants (PDAs) to document all clinical and academic activities of urology residents at one academic institution.
Materials and methods: Software was developed to create customized pick lists allowing residents to record all activities on their individual PDAs. Categories included Adult Ambulatory, Pediatric Ambulatory, Adult Operative, Pediatric Operative, and Academic. Activities were subcategorized into detailed pick lists and time-tracking fields. Residents… More >

Nejd F. Alsikafi¹, R. Corey O’Connor¹, Ximing J. Yang², Gary D. Steinberg¹

Canadian Journal of Urology, Vol.10, No.4, pp. 1950-1951, 2003

Abstract A 56-year-old man presented with a 1-year history of intermittent gross, painless hematuria. Extensive evaluation revealed primary localized amyloidosis of the urinary bladder. Despite several endoscopic resections and fulgurations, the patient continued to have episodes of significant hematuria due to recurrent amyloid deposition. He was then successfully treated with partial cystectomy. At 60 months following surgery, the patient remains free of recurrent or systemic disease. More >

Stephen A. Lazarou, Munir Jamal, Thomas Short

Canadian Journal of Urology, Vol.10, No.4, pp. 1945-1946, 2003

Abstract We present a case in which a man developed transitional cell carcinoma of the small bowel 6 months after having undergone a cystoprostatectomy and ileal conduit urinary diversion. More >