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61.
Jyh‐Jen Horng Shiau Chun‐Ta Chiang Hui‐Nien Hung 《Quality and Reliability Engineering International》1999,15(5):369-378
The usual practice of judging process capability by evaluating point estimates of some process capability indices has a flaw that there is no assessment on the error distributions of these estimates. However, the distributions of these estimates are usually so complicated that it is very difficult to obtain good interval estimates. In this paper we adopt a Bayesian approach to obtain an interval estimation, particularly for the index Cpm. The posterior probability p that the process under investigation is capable is derived; then the credible interval, a Bayesian analogue of the classical confidence interval, can be obtained. We claim that the process is capable if all the points in the credible interval are greater than the pre‐specified capability level ω, say 1.33. To make this Bayesian procedure very easy for practitioners to implement on manufacturing floors, we tabulate the minimum values of Ĉpm/ω, for which the posterior probability p reaches the desirable level, say 95%. For the special cases where the process mean equals the target value for Cpm and equals the midpoint of the two specification limits for Cpk, the procedure is even simpler; only chi‐square tables are needed. Copyright © 1999 John Wiley & Sons, Ltd. 相似文献
62.
Adriana M. Hung Belinda S. Young Glenn M. Chertow 《Hemodialysis international. International Symposium on Home Hemodialysis》2003,7(1):17-22
Background: Persons on peritoneal dialysis and hemodialysis with preserved residual renal function experience lower mortality rates than those without. Previous studies have shown slower rates of decline of residual renal function for peritoneal dialysis (PD)(2 to 3% decrease/month), compared with hemodialysis (HD)(6 to 7% decrease/month). However, our clinical observations suggested a lower rate of decline in hemodialysis patients. Methods: We evaluated data in 174 hemodialysis patients cared for from January 2000 through October 2001. Eighty‐seven (50%) patients had at least two timed quarterly urine collections to estimate the rate of change of residual renal function over time (urea clearance, or KrU). All patients underwent thrice‐weekly hemodialysis using polysulfone dialyzers with formaldehyde reprocessing. The rate of decline of residual renal function and the effect of KrU on laboratory variables were estimated using a random effects (MIXED) model, adjusting for the effects of age, sex, race, diabetes, and dialysis vintage. Results: The mean KrU at baseline was 3.5 mL/min. Men (P < 0.001) and persons of shorter vintage (P < 0.0001) had more residual renal function at baseline. The estimated rate of decline of residual renal function was ? 0.07 mL/min/month (? 1.9% decrease/month). The rate of decline in residual renal function was unaffected by sex, race, diabetes, or vintage, although the rate of decline was significantly attenuated among older individuals (age x time interaction, P = 0.01). Serum phosphorus (P = 0.03) and the calcium x phosphorus product (P = 0.009) increased over time and were influenced by the level of residual renal function (P = 0.06 and P = 0.006, respectively). Residual renal function did not influence the rate of change of other laboratory variables. Conclusions: In an ethnically diverse cohort of hemodialysis patients, the rate of decline of residual renal function was relatively slow and age dependent, as well as consistent with values others have reported for patients on peritoneal dialysis. Universal use of biocompatible dialyzers and bicarbonate dialysate may have contributed to differences discussed in prior reports. Residual renal function attenuated the increase in calcium–phosphorus product over time. A better understanding of the determinants of the rate of decline in residual renal function, and the specific benefits afforded to patients via maintenance of residual renal function, would help to inform the debates on timing of initiation and various dosing strategies in hemodialysis. 相似文献
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66.
Stéphane Bordas Phu Vinh Nguyen Cyrille Dunant Amor Guidoum Hung Nguyen‐Dang 《International journal for numerical methods in engineering》2007,71(6):703-732
This paper presents and exercises a general structure for an object‐oriented‐enriched finite element code. The programming environment provides a robust tool for extended finite element (XFEM) computations and a modular and extensible system. The programme structure has been designed to meet all natural requirements for modularity, extensibility, and robustness. To facilitate mesh–geometry interactions with hundreds of enrichment items, a mesh generator and mesh database are included. The salient features of the programme are: flexibility in the integration schemes (subtriangles, subquadrilaterals, independent near‐tip, and discontinuous quadrature rules); domain integral methods for homogeneous and bi‐material interface cracks arbitrarily oriented with respect to the mesh; geometry is described and updated by level sets, vector level sets or a standard method; standard and enriched approximations are independent; enrichment detection schemes: topological, geometrical, narrow‐band, etc.; multi‐material problem with an arbitrary number of interfaces and slip‐interfaces; non‐linear material models such as J2 plasticity with linear, isotropic and kinematic hardening. To illustrate the possible applications of our paradigm, we present 2D linear elastic fracture mechanics for hundreds of cracks with local near‐tip refinement, and crack propagation in two dimensions as well as complex 3D industrial problems. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
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68.
An optical image encryption system with adaptive steganography using red, green, and blue (RGB) channel integration is proposed. The optical image encryption system employs a double random phase encoding algorithm to encrypt and decrypt color images. The RGB channel in a color image is first integrated into a large grayscale image. Then the integrated image is encrypted by two random phase masks. The secret data is then embedded into the encrypted image with a specific hiding sequence generated by the zero-LSB (least significant bits) sorting technique which is a content-dependent and low distortion data embedding method. Experimental results show that the proposed method has a good performance in both hiding capacity and decrypted image quality. 相似文献
69.
I-Feng Lan Sheng-Chih Hung Chun-Yu Chen Yih-Ming Niu Jonq-Hwa Shiuan 《Propellants, Explosives, Pyrotechnics》1993,18(1):18-24
A simple method which is much simpler than, while retaining the same degree of accuracy, as that of a large computer hydrocode has been developed for deducing the JWL equation of state (EOS) of high explosive detonation products from the cylinder expansion test. The radial expansion history of metal tube, which is recorded by the streak camera, is expressed as an appropriate fitting function with the aid of a nonlinear curve fitting procedure. The measured data with respect to Eulerian coordinate are transformed to that in Lagrangian coordinate so that the p-V relation of detonation products may be obtained from the differentiation of fitting function and equations of conservation law. Metal strength is also taken into consideration to reduce the deviation at the lower pressure region. JWL parameters are acquired through the p-V relations by another nonlinear curve fitting procedure. The computed results for Comp-B, TNT, HMX, PBX-9404 and nitromethane, which are in good agreement with Lawrence Livermore National Laboratory (LLNL) data, are listed for comparison with other procedures in literature which have been in use so far. 相似文献
70.
Hwang DF Huang YR Lin KP Chen TY Lin SJ Chen LH Hsieh HS 《Shokuhin eiseigaku zasshi. Journal of the Food Hygienic Society of Japan》2004,45(5):225-230
To survey the hygienic quality and freshness of fresh fish and shellfish, 533 specimens of fish and shellfish were collected from fishing piers, traditional markets and supermarkets (including warehouses) in northern Taiwan during the winter (January-February) and summer (July-August) seasons for hygienic quality and freshness examinations. The indicators included total bacterial count, fecal coliform, Escherichia coli, volatile basic nitrogen (VBN) and K value judged from ATP-related compounds. It was found that the hygienic quality and freshness of fish and shellfish decreased in summer, especially for clam and mussel. The ratio of unacceptable hygienic quality or freshness of fish and shellfish was the highest in fecal coliform, followed by E. coli and others. The fecal coliform count in products from the traditional markets was the highest, followed by those from supermarkets and fishing piers. Secondary contamination seems to be the most important problem for hygienic quality and freshness of fish and shellfish. 相似文献