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1.
PLoS One ; 15(3): e0229913, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32142544

RESUMO

This study presents financial network indicators that can be applied to inspect the financial contagion on real economy, as well as the spatial spillover and industry aggregation effects. We propose to design both a directed and undirected networks of financial sectors of top 20 countries in GDP based on symbolized transfer entropy and Pearson correlation coefficients. We examine the effect and usefulness of the network indicators by newly using them instead of the original Dow Jones financial sector as explanatory variables to construct the higher-order information spatial econometric models. The results demonstrate that the estimated accuracies obtained from both the two networks are improved significantly compared with the spatial econometric model using the original data. It indicates that the network indictors are more effective to capture the dynamic information of financial systems. And meanwhile, the accuracy based on the directed network is a little higher than the undirected network, which indicates the symbolized transfer entropy, i.e. the directed and weighted network, is more suitable and effective to reflect relationships in the financial field. In addition, the results also show that under the global financial crisis, the co-movement between financial sectors of a country/region and the global financial sector as well as between financial sectors and real economy sectors is increased. However, some sectors in particular Utilities and Healthcare are impacted slightly. This study tries to use the financial network indicators in modeling to study contagion channels on the real economy and the industry aggregation effects and suggest how network indicators can be practically used in financial fields.

2.
IEEE Trans Vis Comput Graph ; 26(2): 1361-1371, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30176598

RESUMO

This paper presents Poisson vector graphics (PVG), an extension of the popular diffusion curves (DC), for generating smooth-shaded images. Armed with two new types of primitives, called Poisson curves and Poisson regions, PVG can easily produce photorealistic effects such as specular highlights, core shadows, translucency and halos. Within the PVG framework, the users specify color as the Dirichlet boundary condition of diffusion curves and control tone by offsetting the Laplacian of colors, where both controls are simply done by mouse click and slider dragging. PVG distinguishes itself from other diffusion based vector graphics for 3 unique features: 1) explicit separation of colors and tones, which follows the basic drawing principle and eases editing; 2) native support of seamless cloning in the sense that PCs and PRs can automatically fit into the target background; and 3) allowed intersecting primitives (except for DC-DC intersection) so that users can create layers. Through extensive experiments and a preliminary user study, we demonstrate that PVG is a simple yet powerful authoring tool that can produce photo-realistic vector graphics from scratch.

3.
Artigo em Inglês | MEDLINE | ID: mdl-31751241

RESUMO

Despite growing progresses in recent years, cross-scenario person re-identification remains challenging, mainly due to the pedestrians commonly surrounded by highly-complex environment contexts. In reality, the human perception mechanism could adaptively find proper contextualized spatial-temporal clues towards pedestrian recognition. However, conventional methods fall short in adaptively leveraging the long-term spatial-temporal information due to ever-increasing computational cost. Moreover, CNN-based deep learning methods are hard to conduct optimization due to the non-differentiable property of the built-in context search operation. To ameliorate, this paper proposes a novel Context-Interactive CNN (CI-CNN) to dynamically find both spatial and temporal contexts by embedding multi-task Reinforcement Learning (MTRL). The CI-CNN streamlines the multi-task reinforcement learning by using an actor-critic agent to capture the temporal-spatial context simultaneously, which comprises a context-policy network and a context-critic network. The former network learns policies to determine the optimal spatial context region and temporal sequence range. Based on the inferred temporal-spatial cues, the latter one focuses on the identification task and provides feedback for the policy network. Thus, CI-CNN can simultaneously zoom in/out the perception field in spatial and temporal domain for the context interaction with the environment. By fostering the collaborative interaction between the person and context, our method could achieve outstanding performance on various public benchmarks, which confirms the rationality of our hypothesis, and verifies the effectiveness of our CI-CNN framework.

4.
Artigo em Inglês | MEDLINE | ID: mdl-31329122

RESUMO

This paper presents a vector painting system for digital artworks. We first propose Temporal Diffusion Curve (TDC), a new form of vector graphics, and a novel random-access solver for modeling the evolution of strokes. With the help of a procedural stroke processing function, the TDC strokes can achieve various shapes and effects for multiple art styles. Based on these, we build a painting system of great potential. Thanks to the random-access solver, our method has real-time performance regardless of the rendering resolution, provides straightforward editing possibilities on strokes both at runtime and afterward, and is effective and straightforward for art production. Compared with the previous Diffusion Curve, our method uses strokes as the basic graphics primitives, which are able to intersect each other and much more consistent with humans' instinct and painting habits. We finally demonstrate that professional artists can create multiple genres of artworks with our painting system.

5.
IEEE J Biomed Health Inform ; 23(3): 1215-1224, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-29994412

RESUMO

Thyroid ultrasonography is a widely used clinical technique for nodule diagnosis in thyroid regions. However, it remains difficult to detect and recognize the nodules due to low contrast, high noise, and diverse appearance of nodules. In today's clinical practice, senior doctors could pinpoint nodules by analyzing global context features, local geometry structure, and intensity changes, which would require rich clinical experience accumulated from hundreds and thousands of nodule case studies. To alleviate doctors' tremendous labor in the diagnosis procedure, we advocate a machine learning approach to the detection and recognition tasks in this paper. In particular, we develop a multitask cascade convolution neural network (MC-CNN) framework to exploit the context information of thyroid nodules. It may be noted that our framework is built upon a large number of clinically confirmed thyroid ultrasound images with accurate and detailed ground truth labels. Other key advantages of our framework result from a multitask cascade architecture, two stages of carefully designed deep convolution networks in order to detect and recognize thyroid nodules in a pyramidal fashion, and capturing various intrinsic features in a global-to-local way. Within our framework, the potential regions of interest after initial detection are further fed to the spatial pyramid augmented CNNs to embed multiscale discriminative information for fine-grained thyroid recognition. Experimental results on 4309 clinical ultrasound images have indicated that our MC-CNN is accurate and effective for both thyroid nodules detection and recognition. For the correct diagnosis rate of malignant and benign thyroid nodules, its mean Average Precision (mAP) performance can achieve up to [Formula: see text] accuracy, which outperforms the common CNNs by [Formula: see text] on average. In addition, we conduct rigorous user studies to confirm that our MC-CNN outperforms experienced doctors, yet only consuming roughly [Formula: see text] ( 1/48) of doctors' examination time on average. Therefore, the accuracy and efficiency of our new method exhibit its great potential in clinical applications.


Assuntos
Interpretação de Imagem Assistida por Computador/métodos , Nódulo da Glândula Tireoide/diagnóstico por imagem , Algoritmos , Humanos , Glândula Tireoide/diagnóstico por imagem , Ultrassonografia
6.
Artigo em Inglês | MEDLINE | ID: mdl-30561345

RESUMO

This paper extends the recently proposed power-particle-based fluid simulation method with staggered discretization, GPU implementation, and adaptive sampling, largely enhancing the efficiency and usability of the method. In contrast to the original formulation which uses co-located pressures and velocities, in this paper, a staggered scheme is adapted to the Power Particles to benefit visual details and computing efficiency. Meanwhile, we propose a novel facet-based power diagrams construction algorithm suitable for parallelization and explore its GPU implementation, achieving an order of magnitude boost in performance over the existing code library. In addition, to utilize the potential of Power Particles to control individual cell volume, we apply adaptive particle sampling to improve the detail level with varying resolution. The proposed method can be entirely carried out on GPUs, and our extensive experiments validate our method both in terms of efficiency and visual quality.

7.
Head Neck ; 40(4): 778-783, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29286180

RESUMO

BACKGROUND: The purpose of this study was to compare the diagnostic efficiency of a thyroid ultrasound computer-aided diagnosis (CAD) system with that of 1 radiologist. METHODS: This study retrospectively reviewed 342 surgically resected thyroid nodules from July 2013 to December 2013 at our center. The nodules were assessed on typical ultrasound images using the CAD system and reviewed by 1 experienced radiologist. The radiologist stratified the risk of malignancy using the Thyroid Imaging Reporting and Data Systems (TIRADS) and the American Thyroid Association (ATA) guidelines. RESULTS: The radiologist, using TI-RADS and ATA guidelines, performed better than the CAD system (P < .01). The sensitivity of the CAD system was similar to that of an experienced radiologist (P > .05; P < .01; and P > .05). However, we found that the CAD system had lower specificity (P < .01). CONCLUSION: The sensitivity of a thyroid ultrasound CAD system in differentiating nodules was similar to that of an experienced radiologist. However, the CAD system had lower specificity.


Assuntos
Diagnóstico por Computador/métodos , Biópsia Guiada por Imagem/métodos , Neoplasias da Glândula Tireoide/patologia , Nódulo da Glândula Tireoide/patologia , Ultrassonografia de Intervenção/métodos , Adulto , China , Estudos de Coortes , Feminino , Hospitais Universitários , Humanos , Masculino , Pessoa de Meia-Idade , Curva ROC , Radiologistas , Estudos Retrospectivos , Sensibilidade e Especificidade , Neoplasias da Glândula Tireoide/diagnóstico por imagem , Neoplasias da Glândula Tireoide/cirurgia , Nódulo da Glândula Tireoide/diagnóstico por imagem , Nódulo da Glândula Tireoide/cirurgia , Tireoidectomia/métodos
8.
IEEE Trans Image Process ; 26(7): 3156-3170, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28221994

RESUMO

This paper advocates a novel video saliency detection method based on the spatial-temporal saliency fusion and low-rank coherency guided saliency diffusion. In sharp contrast to the conventional methods, which conduct saliency detection locally in a frame-by-frame way and could easily give rise to incorrect low-level saliency map, in order to overcome the existing difficulties, this paper proposes to fuse the color saliency based on global motion clues in a batch-wise fashion. And we also propose low-rank coherency guided spatial-temporal saliency diffusion to guarantee the temporal smoothness of saliency maps. Meanwhile, a series of saliency boosting strategies are designed to further improve the saliency accuracy. First, the original long-term video sequence is equally segmented into many short-term frame batches, and the motion clues of the individual video batch are integrated and diffused temporally to facilitate the computation of color saliency. Then, based on the obtained saliency clues, inter-batch saliency priors are modeled to guide the low-level saliency fusion. After that, both the raw color information and the fused low-level saliency are regarded as the low-rank coherency clues, which are employed to guide the spatial-temporal saliency diffusion with the help of an additional permutation matrix serving as the alternative rank selection strategy. Thus, it could guarantee the robustness of the saliency map's temporal consistence, and further boost the accuracy of the computed saliency map. Moreover, we conduct extensive experiments on five public available benchmarks, and make comprehensive, quantitative evaluations between our method and 16 state-of-the-art techniques. All the results demonstrate the superiority of our method in accuracy, reliability, robustness, and versatility.

9.
IEEE Trans Vis Comput Graph ; 23(9): 2082-2095, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-27608469

RESUMO

Biharmonic B-splines, proposed by Feng and Warren, are an elegant generalization of univariate B-splines to planar and curved domains with fully irregular knot configuration. Despite the theoretic breakthrough, certain technical difficulties are imperative, including the necessity of Voronoi tessellation, the lack of analytical formulation of bases on general manifolds, expensive basis re-computation during knot refinement/removal, being applicable for simple domains only (e.g., such as euclidean planes, spherical and cylindrical domains, and tori). To ameliorate, this paper articulates a new biharmonic B-spline computing paradigm with a simple formulation. We prove that biharmonic B-splines have an equivalent representation, which is solely based on a linear combination of Green's functions of the bi-Laplacian operator. Consequently, without explicitly computing their bases, biharmonic B-splines can bypass the Voronoi partitioning and the discretization of bi-Laplacian, enable the computational utilities on any compact 2-manifold. The new representation also facilitates optimization-driven knot selection for constructing biharmonic B-splines on manifold triangle meshes. We develop algorithms for spline evaluation, data interpolation and hierarchical data decomposition. Our results demonstrate that biharmonic B-splines, as a new type of spline functions with theoretic and application appeal, afford progressive update of fully irregular knots, free of singularity, without the need of explicit parameterization, making it ideal for a host of graphics tasks on manifolds.

10.
J BUON ; 21(2): 473-7, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27273960

RESUMO

Purpose: The quality of medical services provided by competing public hospitals is the primary consideration of the public in determining the selection of a specific hospital for treatment. The main objective of strategic planning is to improve the quality of public hospital medical services. This paper provides an introduction to the history, significance, principles and practices of public hospital medical service strategy, as well as advancing the opinion that public hospital service strategy must not merely aim to produce but actually result in the highest possible level of quality, convenience, efficiency and patient satisfaction.


Assuntos
Assistência à Saúde/organização & administração , Alocação de Recursos para a Atenção à Saúde/organização & administração , Hospitais Públicos/organização & administração , China , Reforma dos Serviços de Saúde/organização & administração , Necessidades e Demandas de Serviços de Saúde/organização & administração , Humanos , Modelos Organizacionais , Determinação de Necessidades de Cuidados de Saúde/organização & administração , Formulação de Políticas , Melhoria de Qualidade/organização & administração , Indicadores de Qualidade em Assistência à Saúde/organização & administração
11.
IEEE Trans Image Process ; 25(3): 1425-40, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26812724

RESUMO

There is growing demand for accuracy in image processing and visualization, and the super-resolution (SR) technique for multi-observed RGB-D images has become popular, because it provides space-redundant information and produces a detailed reconstruction even with a large magnification factor. This technique has been thoroughly investigated in recent years. Nevertheless, technical challenges remain, such as finding sub-pixel correspondences with low-resolution (LR) observations, exploiting space-redundant information, formulating space homogeneity constraints, and leveraging cross-image similarities in structures. To address these challenges, this paper proposes a unified optimization framework to estimate both the super-resolved RGB image and the super-resolved depth image from the multi-observed LR RGB-D images using their correlations. Using depth-assisted cross-image correspondences, the RGB image SR problem is formulated as an effective regularization function by incorporating the normalized bilateral total variation regularizer, and it is efficiently solved by a first-order primal-dual algorithm. The depth image SR estimate can be obtained by minimizing a nonlocal regression-based energy, which integrates the structural cues of the super-resolved RGB image in a detail-preserving fashion. Essentially, our unified optimization framework uses the RGB image and depth image as a priori knowledge that the SR process uses for better accuracy. Our extensive experiments on public RGB-D benchmarks and real data and our quantitative comparison with several state-of-the-art methods demonstrate the superiority of our method in terms of accuracy, versatility, and reliability of details and sharp feature preservation.

12.
IEEE J Biomed Health Inform ; 20(6): 1608-1620, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-26441457

RESUMO

In this paper, we present an efficient robust labeling method for coronary arteries from X-ray angiograms based on energy optimization. The fundamental goal of this research is to facilitate the analysis and diagnosis of interventional surgery in the most efficient way, and such effort could also improve the performance during doctor training, and surgery simulation and planning. Compared to the prior state-of-the-art, our method is much more robust to resist noises and is tolerant to even incomplete data because of the "built-in" nature of global optimization. We start with a fully parallelized algorithm based on Hessian matrix to extract the tubular structure from the X-ray angiograms as vessel candidates. Then, instead of using the candidates directly, we use the grow cut (Vezhnevets and V. Konouchine, Growcut: Interactive multi-label N-D image segmentation by cellular automata, in Proc. of Graphicon, 2005, pp. 150-156.) method, which is similar to graph cut (Boykov et al. , Fast approximate energy minimization via graph cuts, IEEE Trans. Pattern Anal. Mach. Intell. , vol. 23, no. 11, pp. 1222-1239, Nov. 2001.)but with better performance to extract the precise vessel structure from the images. Next, we use the fast marching method with second derivatives and cross neighbors to extract the accurate skeleton segments. After that, we propose an efficient method based on iterative closest point (Z. Zhang, Iterative point matching for registration of free-form curves and surfaces, Int J. Comput. Vis., vol. 13, no. 2, pp. 119-152, 1994.) to organize the skeleton segments by treating the continuity and similarity as extra constraints. Finally, we formulate the vessel labeling problem as an energy optimization problem and solve it using belief propagation. We also demonstrate several typical applications including flow velocity estimation, heart beat estimation, and vessel diameter estimation to show its practical uses in clinical diagnosis and treatment. Our experiments exhibit the correctness and robustness, as well as the high performance of our algorithm. We envision that our system would be of high utility for diagnosis and therapy to treat vessel-related diseases in a clinical setting in the near future.


Assuntos
Angiografia/métodos , Vasos Coronários/diagnóstico por imagem , Imagem Tridimensional/métodos , Algoritmos , Humanos , Reprodutibilidade dos Testes
13.
Virol J ; 12: 197, 2015 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-26596706

RESUMO

BACKGROUND: Recently, a diverse group of viruses with circular, replication initiator protein(Rep) encoding, single stranded DNA (CRESS-DNA) genomes, were discovered from wide range of eukaryotic organisms ranging from mammals to fungi. Gemycircularvirus belongs to a distinct group of CRESS-DNA genomes and is classified under the genus name of Gemycircularvirus. FINDINGS: Here, a novel gemycircularvirus named GeTz1 from cerebrospinal fluid sample of a child with unexplainable encephalitis was characterized. The novel gemycircularvirus encodes two major proteins, including a capsid protein (Cap) and a replication-associated protein (Rep). Phylogenetic analysis based on the amino acid sequence of Rep indicated that GeTz1 clusters with one gemycircularvirus discovered from bird (KF371633), sharing 46.6 % amino acid sequence identity with each other. CONCLUSION: A novel gemycircularvirus was discovered from cerebrospinal fluid sample of a child with unexplainable encephalitis. Further studies, such as testing human sera for specific antibodies, should be performed to investigate whether gemycircularvirus infects human and is associated with encephalitis.


Assuntos
Infecções por Vírus de DNA/diagnóstico , Infecções por Vírus de DNA/virologia , Vírus de DNA/isolamento & purificação , Encefalite Viral/diagnóstico , Encefalite Viral/virologia , Proteínas do Capsídeo/genética , Líquido Cefalorraquidiano/virologia , Pré-Escolar , Análise por Conglomerados , DNA Helicases/genética , Infecções por Vírus de DNA/patologia , Vírus de DNA/genética , DNA Viral/química , DNA Viral/genética , Encefalite Viral/patologia , Humanos , Lactente , Dados de Sequência Molecular , Filogenia , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos , Transativadores/genética , Proteínas Virais/genética
14.
Bull Environ Contam Toxicol ; 95(2): 194-9, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26070371

RESUMO

Three kinds of representative sediments were obtained from a macrophyte-dominated bay (East Lake Taihu) and two algae-dominated regions (Western Lake Taihu and Meiliang Bay). Physiological responses of Vallisneria asiatica to these sediments were compared. Results from 20 days exposures showed no obvious differences in malondialdehyde (MDA) in roots, while the MDA content in leaves of plants exposed to Western Lake Taihu sediment was significantly (p<0.05) higher than those exposed to the other two sediments. In comparison to the other two sediments, plants exposed to Western Lake Taihu sediment showed significantly lower (p<0.05) superoxide dismutase in roots and leaves on the 10th and 40th day. On the 40th day, root catalase (CAT) activities in V. asiatica from Western Lake Taihu and Meiliang Bay sediments were lower than that from East Lake Taihu sediment, while leaf CAT activity in V. asiatica from Western Lake Taihu sediment was higher than that from East Lake Taihu sediment (p<0.05). Western Lake Taihu sediment caused more serious oxidative stress in V. asiatica than East Lake Taihu sediment. Results indicated eutrophic sediment was a contributing factor in the disappearance of V. asiatica in Western Lake Taihu.


Assuntos
Catalase/metabolismo , Sedimentos Geológicos/química , Hydrocharitaceae/efeitos dos fármacos , Lagos , Poluentes do Solo/toxicidade , Superóxido Dismutase/metabolismo , China , Monitoramento Ambiental , Hydrocharitaceae/enzimologia , Malondialdeído/análise , Estresse Oxidativo/efeitos dos fármacos
15.
IEEE Trans Image Process ; 24(8): 2303-16, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25700446

RESUMO

This paper advocates a novel multiscale, structure-sensitive saliency detection method, which can distinguish multilevel, reliable saliency from various natural pictures in a robust and versatile way. One key challenge for saliency detection is to guarantee the entire salient object being characterized differently from nonsalient background. To tackle this, our strategy is to design a structure-aware descriptor based on the intrinsic biharmonic distance metric. One benefit of introducing this descriptor is its ability to simultaneously integrate local and global structure information, which is extremely valuable for separating the salient object from nonsalient background in a multiscale sense. Upon devising such powerful shape descriptor, the remaining challenge is to capture the saliency to make sure that salient subparts actually stand out among all possible candidates. Toward this goal, we conduct multilevel low-rank and sparse analysis in the intrinsic feature space spanned by the shape descriptors defined on over-segmented super-pixels. Since the low-rank property emphasizes much more on stronger similarities among super-pixels, we naturally obtain a scale space along the rank dimension in this way. Multiscale saliency can be obtained by simply computing differences among the low-rank components across the rank scale. We conduct extensive experiments on some public benchmarks, and make comprehensive, quantitative evaluation between our method and existing state-of-the-art techniques. All the results demonstrate the superiority of our method in accuracy, reliability, robustness, and versatility.

16.
Cell Biochem Biophys ; 72(1): 67-71, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25413963

RESUMO

Talent is the core competitive force of a hospital's development. Wuxi No. 2 People's Hospital followed the characteristics that medical talents mature slowly and their growth requires a long period. The innovated "talent tree" project, trained classified talents corresponding to "base-trunk-crown" of a tree, formed an individualized professional training plan with different levels and at different periods. We carried out a relay of the "talent tree" to bring their initiative into play. In practice, we gradually found this as a unique way of the talent construction, which conforms to our hospital's condition. This guarantees sustained development and innovative force of the hospital.


Assuntos
Medicina Clínica , Administração Hospitalar/métodos , Hospitais , Corpo Clínico Hospitalar , Médicos , Adulto , Escolha da Profissão , China , Pessoal de Saúde , Humanos , Pessoa de Meia-Idade , Modelos Organizacionais
17.
Cell Biochem Biophys ; 72(1): 19-22, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25388850

RESUMO

Gaining large scale success was quite common in the later period of industrialization for hospitals in China. Today, Chinese hospital management face such problems as service inefficiency, high human resources cost, and low rate of capital use. This study analyzes the refined management chain of the Wuxi No. 2 People's Hospital. This consists of six gears namely "organizational structure, clinical practice, outpatient service, medical technology, and nursing care and logistics" used to achieve maximum scale and benefits. The gears are based on "flat management system targets, chief of medical staff, centralized outpatient service, intensified medical examinations, vertical nursing management and socialized logistics". The hospital took innovative measures. The "one doctor-one patient-one clinic" was well accepted; "one dispensary" shorten the waiting time by 20 min. The 168 rear service hot line "made patients' lives easier; and a red wrist ribbon" for seriously ill patient was implemented to prioritize medical treatment. The core concepts of refined hospital management are optimizing flow process, reducing waste, improving efficiency, saving costs, and taking good care of patients as most important.


Assuntos
Administração Hospitalar/métodos , Hospitais , China , Tomada de Decisões Gerenciais , Economia Médica , Eficiência Organizacional , Custos de Cuidados de Saúde , Planejamento Hospitalar , Hospitais Públicos , Modelos Organizacionais , Sistemas Multi-Institucionais/organização & administração , Enfermagem/organização & administração , Pacientes Ambulatoriais , Admissão do Paciente , Serviço Hospitalar de Compras
18.
Biomed Mater Eng ; 24(1): 221-8, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24211901

RESUMO

Multimodal medical image fusion is a method of integrating information from multiple image formats. Its aim is to provide useful and accurate information for doctors. Multi-channel pulse coupled neural network (m-PCNN) is a recently proposed fusion model. Compared with previous methods, this network can effectively manage various types of medical images. However, it has two drawbacks: lack of control to feed function and low-level automation. The improved multi-channel PCNN proposed in this paper can adjust the impact of feed function by linking strength and adaptively compute the weighting coefficients for each pixel. Experimental results demonstrated the effectiveness of the improved m-PCNN fusion model.


Assuntos
Encéfalo/patologia , Processamento de Imagem Assistida por Computador/métodos , Imagem Multimodal/instrumentação , Imagem Multimodal/métodos , Algoritmos , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/patologia , Humanos , Imagem por Ressonância Magnética , Modelos Teóricos , Tomografia por Emissão de Pósitrons , Software , Tomografia Computadorizada por Raios X
19.
Biomed Mater Eng ; 24(1): 511-8, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24211934

RESUMO

This paper presents a compact orthopedic robot designed with modular concept. The layout of the modular configuration is adaptive to various conditions such as surgical workspace and targeting path. A biplanar algorithm is adopted for the mapping from the fluoroscopic image to the robot, while the former affine based method is satisfactory only when the projection rays are basically perpendicular to the reference coordinate planes. This paper introduces the area cross-ratio as a projective invariant to improve the registration accuracy for non-orthogonal orientations, so that the robotic system could be applied to more orthopedic procedures under various C-Arm orientation conditions. The system configurations for femoral neck screw and sacroiliac screw fixation are presented. The accuracy of the robotic system and its efficacy for the two typical applications are validated by experiments.


Assuntos
Pinos Ortopédicos , Parafusos Ósseos , Fixação Intramedular de Fraturas/instrumentação , Procedimentos Ortopédicos/instrumentação , Robótica , Cirurgia Assistida por Computador/instrumentação , Algoritmos , Calibragem , Desenho de Equipamento , Colo do Fêmur/patologia , Fluoroscopia , Fixação Intramedular de Fraturas/métodos , Humanos , Procedimentos Ortopédicos/métodos , Reprodutibilidade dos Testes , Articulação Sacroilíaca/patologia , Cirurgia Assistida por Computador/métodos
20.
ScientificWorldJournal ; 2013: 838176, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23853542

RESUMO

The occurrence and distribution of microcystins were investigated in Lake Taihu, the third largest lake in China. An extensive survey, larger and broader in scale than previous studies, was conducted in summer 2010. The highest microcystin concentration was found at southern part of Taihu, which was newly included in this survey. In northern coastal areas, total cellular concentrations of 20 to 44 µg/L were observed. In northern offshore waters, levels were up to 4.8 µg/L. Microcystin occurrence was highly correlated with chemical oxygen demand, turbidity, and chlorophyll-a. Extracellular/total cellular microcystin (E/T) ratios were calculated and compared to other water quality parameters. A higher correlation was found using E/T ratios than original microcystin values. These results show that algal blooms are having a severe impact on Lake Taihu, and further and extensive monitoring and research are required to suppress blooms effectively.


Assuntos
Lagos/análise , Lagos/microbiologia , Microcistinas/análise , Microcystis/isolamento & purificação , Microbiologia da Água , Poluentes Químicos da Água/análise , Poluição Química da Água/análise , China , Lagos/química , Poluição Química da Água/estatística & dados numéricos
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