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51.
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This paper addresses a challenging problem of visual inspection of transparent pharmaceutical capsules, where print registration is used to determine the capsule’s print region. The determination of the print region allows for reliable detection of defects both on the print region and on the rest of the capsule’s surface. On transparent capsules, both the print on the front and the print on the back of a capsule are concurrently visible. Moreover, the print on the back may be partially or entirely occluded by the powder inside the capsule. All this causes that the print registration methods used for opaque capsules do not achieve adequate performance. In this paper, we present a novel registration method designed specifically for transparent capsules. The method utilizes a template matching technique with a new similarity measure that considers the specific properties of transparent capsules to increase the registration robustness. Additionally, we present a registration refinement step that reduces the effect of possible print deformations and image distortions. The performance of the method was evaluated in terms of robustness, accuracy and speed on large image sets of four different radial prints. The new method shows highly improved robustness (>98.6 %) compared to the method based on normalized cross-correlation (>72 %) and the method based on feature matching (>80 %). Furthermore, the additional refinement step improves the registration accuracy. Although the execution time is raised from 3 to 11 ms, it still meets the usual speed requirements.  相似文献   
53.
In NED 119, No. 1 (May 1990) a series of six papers published by a Technical Program Group presented a new methodology for the safety evaluation of emergency core cooling systems in nuclear power plants. This paper describes the application of that new methodology to the LB LOCA analysis of the two loop Westinghouse power plant. Results of the original work were used wherever possible, so that the analysis was finished in less than one man year of work. Steam generator plugging level and safety injection flow rate were used as additional uncertainty parameters, which had not been used in the original work. The computer code RELAP5/MOD2 was used. Response surface was generated by the regression analysis and by the artificial neural network like Optimal Statistical Estimator method. Results were compared also to the analytical calculation.  相似文献   
54.
Comparative evaluation of retrospective shading correction methods   总被引:1,自引:0,他引:1  
Because of the inherent imperfections of the image formation process, microscopical images are often corrupted by spurious intensity variations. This phenomenon, known as shading or intensity inhomogeneity, may have an adverse affect on automatic image processing, such as segmentation and registration. Shading correction methods may be prospective or retrospective. The former require an acquisition protocol tuned to shading correction, whereas the latter can be applied to any image, because they only use the information already present in an image. Nine retrospective shading correction methods were implemented, evaluated and compared on three sets of differently structured synthetic shaded and shading‐free images and on three sets of real microscopical images acquired by different acquisition set‐ups. The performance of a method was expressed quantitatively by the coefficient of joint variations between two different object classes. The results show that all methods, except the entropy minimization method, work well for certain images, but perform poorly for others. The entropy minimization method outperforms the other methods in terms of reduction of true intensity variations and preservation of intensity characteristics of shading‐free images. The strength of the entropy minimization method is especially apparent when applied to images containing large‐scale objects.  相似文献   
55.
Soil represents a complex medium, which makes it difficult to evaluate its quality. In the past, soil quality evaluation was biased towards agricultural production rather than for purposes related to the broad range of functions and services that it performs. Soil function and soil quality in the urban environment differ due to the different needs and roles of soil within the diversity of urban land uses. The quality of urban soil should be evaluated to support public services for good environmental quality management. Planners should also adjust their decisions towards more sustainable urban design. Simple and applicable soil quality evaluation methods accompanied by an operations toolkit that could be used by laypeople are needed.This paper discusses soil functions, soil quality indicators, pedotransfer functions, and urban soil quality. It presents an urban soil quality evaluation method for different land uses within one particular evaluation system. The calculation of three one-value measures of soil quality are introduced: index of soil quality (expresses soil quality/suitability for a particular land use), soil environmental quality index (environmental value of soil) in terms of performing the crucial ecological functions of soil, and land use change index (land use planning impact assessment on soil resources). The use of the method is described in two procedures: urban soil quality control and soil evaluation for urban planning.  相似文献   
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57.
A dynamic fault tree   总被引:1,自引:0,他引:1  
The fault tree analysis is a widely used method for evaluation of systems reliability and nuclear power plants safety. This paper presents a new method, which represents extension of the classic fault tree with the time requirements. The dynamic fault tree offers a range of risk informed applications. The results show that application of dynamic fault tree may reduce the system unavailability, e.g. by the proper arrangement of outages of safety equipment. The findings suggest that dynamic fault tree is a useful tool to expand and upgrade the existing models and knowledge obtained from probabilistic safety assessment with additional and time dependent information to further reduce the plant risk.  相似文献   
58.
A new method for power system reliability analysis using the fault tree analysis approach is developed. The method is based on fault trees generated for each load point of the power system. The fault trees are related to disruption of energy delivery from generators to the specific load points. Quantitative evaluation of the fault trees, which represents a standpoint for assessment of reliability of power delivery, enables identification of the most important elements in the power system. The algorithm of the computer code, which facilitates the application of the method, has been applied to the IEEE test system. The power system reliability was assessed and the main contributors to power system reliability have been identified, both qualitatively and quantitatively.  相似文献   
59.
One of the important goals of the NURESIM project is to assess and improve the simulation capability of the three-dimensional two-fluid codes for prediction of local boiling flow processes. The boiling flow is strongly affected by local mechanisms in the turbulent boundary layer near the heated wall. Wall-to-fluid transfer models for boiling flow with the emphasis on near-wall treatment are being addressed in the paper. Since the computational grid of the 3D two-fluid models is too coarse to resolve the variable gradients in the near-wall region, the use of wall functions is a common approach to model the liquid velocity and temperature profile adjacent to the heated wall.The wall function model for momentum, based on the surface roughness analogy has been discussed and implemented in the NEPTUNE_CFD code. The model has been validated on several upward boiling flow experiments, differing in the geometry, working fluid and operating conditions. The simulations with the new wall function model show an improved prediction of flow parameters over the boiling boundary layer. Furthermore, a wall function model for the energy equation, based on enhanced two-phase wall friction has been derived and validated.  相似文献   
60.
Morphological effects caused by two different diets (low protein-high water intake, and high protein-restricted water) on the vascular bundles in the outer medullary zone of the kidney were studied in the laboratory white mouse and in the golden spiny mouse (Acomys russatus, Muridae). In both rodents, when on a low protein-high water intake diet, considerable interstitial substance was found between the vasa recta of the bundles. No interstitial substance was found in animals on high protein-low water intake diet; as a result the vasa recta of the vascular bundle adhered closely. The low protein-high water intake diet caused a marked diuresis, low urine osmolality and low urinary urea concentration. It is assumed that the increase in interstitial substance between the vasa recta of the vascular bundle lowers the efficiency of the counter current barrier system for urea in the kidney and, as a consequence, the medullary urea gradient and urine concentrating capacity decreases. In animals on a high protein diet, the closely juxtaposed vasa recta assure an efficient countercurrent exchange, leading to accumulation and maintenance of a large urea gradient in the medulla and maximal urine concentration. It is suggested that the amount of interstitial material between the vasa recta of the vascular bundle might serve as a modulating factor for the urea concentration in the kidney.  相似文献   
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