7,178 research outputs found
Role of P97 in non-transferrin bound iron uptake by rabbit reticulocytes
2000-2001 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe
Multiclass segmentation based on generalized fuzzy Gibbs random fields
The model of Gibbs random fields is widely applied to Bayesian segmentation due to its best property of describing the spatial constraint information. However, the general segmentation methods, whose model is defined only on hard levels but not on fuzzy set, may come across a lot of difficulties, e.g., getting the unexpected results or even nothing, especially when the blurred or degraded images are considered. In this paper, two multiclass approaches, based on the model of piecewise fuzzy Gibbs random fields (PFGRF) and that of generalized fuzzy Gibbs random fields (GFGRF) respectively, are presented to address these difficulties. In our experiments, both magnetic resonance image and simulated image are implemented with the two approaches mentioned above and the classical 'hard' one. These three different results show that the approach of GFGRF is an efficient and unsupervised technique, which can automatically and optimally segment the images to be finer.published_or_final_versio
On the stability of fissured slopes subject to seismic action
A set of analytical solutions achieved by the upper bound theorem of limit analysis and the pseudo-static approach is presented for the assessment of the stability of homogeneous c, ϕ slopes manifesting vertical cracks and subject to seismic action. Rotational failure mechanisms are considered for slopes with cracks of either known or unknown depth and location. A validation exercise was carried out based on numerical limit analyses and displacement-based finite-element analyses with strength reduction technique.
Charts providing the stability factor for fissured slopes subject to both horizontal and vertical accelerations for any combination of c, ϕ and slope inclination are provided. The effect of the direction of the vertical acceleration on slope stability is specifically analysed. Yield seismic coefficients are also provided.
When the presence of cracks within the slope can be ascertained with reasonable confidence, maps showing the zones within the slope where they have no destabilising effect are provided.
Finally, Newmark's method was employed to assess the effect of cracks on earthquake induced displacements. To this end, displacement coefficients are provided in chart form as a function of the slope characteristics. Two examples of slopes subjected to known earthquakes are illustrated
Brain tumor boundary detection in MR image with generalized fuzzy operator
Boundary detection in MR image with brain tumor is an important image processing technique applied in radiology for 3D reconstruction. The nonhomogeneities density tissue of the brain with tumor can result in achieving the inaccurate location in any boundary detection algorithms. Recently, some studies using the contour deformable model with regional base technique, the performance is insufficient to obtain the fine edge in the tumor, and the considerable error in accuracy is existed. Moreover, even in some of the normal tissue region, edge created by this method has also been encompassed. In this paper, we propose a new approach to detect the boundary of brain tumor based on the generalized fuzzy operator (GFO). One typical example is used for evaluating this method with the contour deformable model.published_or_final_versio
Thyroid cancer cells boundary location by a fuzzy edge detection method
Morphometric assessment of tumor cells is important in the prediction of biological behavior of thyroid cancer. In order to automate the process, the computer-based system has to recognize the boundary of the cells. Many methods for the boundary detection have appeared in the literature and some of them applied to microscopic slice analysis. However, there is no reliable method since the gray-levels in the nuclei are uneven and are similar to the background. In the paper, a fuzzy edge detection method is used and is based on an improved generalized fuzzy operator. The method enhances the nuclei and effectively separates the cells from the background.published_or_final_versio
Stenting in small coronary arteries: initial experience with the Gianturco-roubin II stent
published_or_final_versio
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Evolution of superconductivity in K2-xFe4+ySe5: Spectroscopic studies of X-ray absorption and emission.
This study investigates the evolution of superconductivity in K2-xFe4+ySe5 using temperature-dependent X-ray absorption and resonant inelastic X-ray scattering techniques. Magnetization measurements show that polycrystalline superconducting (SC) K1.9Fe4.2Se5 has a critical temperature (T c) of ∼31 K with a varying superconducting volume fraction, which strongly depends on its synthesis temperature. An increase in Fe-structural/vacancy disorder in SC samples with more Fe atoms occupying vacant 4d sites is found to be closely related to the decrease in the spin magnetic moment of Fe. Moreover, the nearest-neighbor Fe-Se bond length in SC samples exceeds that in the non-SC (NS) sample, K2Fe4Se5, which indicates a weaker hybridization between the Fe 3d and Se 4p states in SC samples. These results clearly demonstrate the correlations among the local electronic and atomic structures and the magnetic properties of K2-xFe4+ySe5 superconductors, providing deeper insight into the electron pairing mechanisms of superconductivity
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Corporate heritage tourism brand attractiveness and national identity
Purpose: Examines the attractiveness of the Tong Ren Tang (TRT) as a Chinese corporate heritage tourism brand and considers the significance of TRT for Chinese national identity. The study considers the saliency of Balmer’s augmented role identity notion vis-à-vis corporate heritage institutions/corporate brands. Insights are made from and for corporate heritage, heritage tourism and national identity literatures. Design/Methodology/Approach: A conceptual model comprising five hypotheses was developed and this informed a survey-based questionnaire administered to domestic tourists/customers visiting Tong Ren Tang’s flagship shop in Beijing. Findings: The attractiveness to domestic Chinese tourists/customers of the Tong Ren Tang corporate heritage tourism brand was found to be attributable to its multiple role identities: national, corporate, temporal, familial, and imperial. As such, this study lends credence to Balmer’s augmented role identity notion. Chinese domestic tourists/customers-as members of an ethnic Chinese community-in visiting TRT not only consume an extant corporate heritage by tangible and intangible means but can also be seen to express, and reaffirm, their sense of Chinese national identity. Practical implications: For Tong Ren Tang’s (TRT) managers there should be an appreciation that the attractiveness of TRT as a corporate heritage tourism brand rests not only on what it sells but also in what it symbolises in national and cultural terms. This finding is applicable to the managers many other corporate heritage/corporate heritage tourism brands. Social implications: Adopting a primordial perspective, the TRT pharmacy was found to be of singular significance to China’s national identity. Traditional Chinese Medicine, Confucian and Daoist religious/philosophical and China’s erstwhile Imperial polity are significant and enduring precepts of Chinese national identity. As such the TRT flagship shop/brand is of singular importance since China has eviscerated much of its cultural heritage –particularly in relation to its corporate heritage brands. Originality/value: The first empirical study to focus on corporate heritage tourism brands, and one of the first studies to examine a Chinese corporate heritage/corporate heritage tourism brand. Also significant in focussing on the Tong Ren Tang corporate heritage brand. Established in 1669, TRT’s history spans five centuries: a corporate provenance which is exceptional within the People’s Republic of China. The study links the corporate brand notion with the nascent corporate heritage brand domain and the established area of heritage tourism
Habitat Fragmentation, Variable Edge Effects, and the Landscape-Divergence Hypothesis
Edge effects are major drivers of change in many fragmented landscapes, but are often highly variable in space and time. Here we assess variability in edge effects altering Amazon forest dynamics, plant community composition, invading species, and carbon storage, in the world's largest and longest-running experimental study of habitat fragmentation. Despite detailed knowledge of local landscape conditions, spatial variability in edge effects was only partially foreseeable: relatively predictable effects were caused by the differing proximity of plots to forest edge and varying matrix vegetation, but windstorms generated much random variability. Temporal variability in edge phenomena was also only partially predictable: forest dynamics varied somewhat with fragment age, but also fluctuated markedly over time, evidently because of sporadic droughts and windstorms. Given the acute sensitivity of habitat fragments to local landscape and weather dynamics, we predict that fragments within the same landscape will tend to converge in species composition, whereas those in different landscapes will diverge in composition. This ‘landscape-divergence hypothesis’, if generally valid, will have key implications for biodiversity-conservation strategies and for understanding the dynamics of fragmented ecosystems
The expression of p97 on the membrane of the reticulocyte and the role in iron uptake in rabbit
2001-2002 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe
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