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Search Results: 1 - 10 of 33169 matches for " Jiaming Feng "
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Numerical Simulation of Dual Laterolog Response in Directional Wells and Development of Correction Plate  [PDF]
Xiao-Wei Ni, Si-Hui Xu, Guan-You Xu, Xuan-Feng Ao, Jiaming Feng, Di-Ren Liu
Open Journal of Yangtze Oil and Gas (OJOGas) , 2017, DOI: 10.4236/ojogas.2017.24019
Abstract: Since the dual laterolog response is affected by various environmental factors, the instrument response is difficult to reflect the true resistivity of the formation. Plate correction is a common method of resistivity logging environmental correction. Three-dimensional layered media model was established, and the dual laterolog response in directional wells was simulated by three-dimensional finite element method. The influence of environmental factors such as wellbore, well deviation, surrounding rock and mud intrusion on the response of dual laterolog is analyzed emphatically. Therefore, the environmental factors correction plate with different well deviations is constructed, and the plates can be used to guide the dual laterolog environment correction work for better reservoir identification and oil and gas evaluation.
Sandy grassland blowouts in Hulunbuir, northeast China: geomorphology, distribution, and causes
ZHANG Altan MunkhDalai,FENG Zongwei,WANG Xiaoke,SUN Hongwei,ZHAO Jiaming,U Hurlee,
ZHANG Altan MunkhDalai
,FENG Zongwei,WANG Xiaoke,SUN Hongwei,ZHAO Jiaming,U Hurlee

自然科学进展 , 2007,
Abstract: A sandy grassland blowout consists of an aeolian depression formed in top soil and the underlying sand deposit underlie, and the adjoining redeposit of sand derived from the depression. Research based on field survey and topographic mapping combined with aerophotograph interpretation reveals that: (1) All the three sand land tracts in Hulunbuir Grasslands are composed of blowout depressions and adjoining dunes, with interlaying remnants of sandy grasslands as background; (2) blowout depressions and their adjoining dunes can be classified according to their morphometric characteristics, development stages, and initiating factors; (3) blowouts develop mostly in the upper parts of sidelong aweather and sunward slopes inclining southwestward when west wind prevails; (4) initiation of blowouts is closely related with the coupling of extreme droughts and wide spread intense human disturbance to the fragile topsoil layer. The investigations indicate that key factors to prevent desertification are to protect grassland vegetation and topsoil.
The Proof of Hilbert’s Seventh Problem about Transcendence of e+π  [PDF]
Jiaming Zhu
Open Access Library Journal (OALib Journal) , 2016, DOI: 10.4236/oalib.1102893
We prove that eπ is a transcendental number. We use proof by contradiction. The key to solve the problem is to establish a function that doesn’t satisfy the relational expression that we derive, thereby produce a conflicting result which can verify our assumption is incorrect.
Improvement of Liver Segmentation by Combining High Order Statistical Texture Features with Anatomical Structural Features  [PDF]
Suhuai Luo, Xuechen Li, Jiaming Li
Engineering (ENG) , 2013, DOI: 10.4236/eng.2013.55B014
Abstract: Automatic segmentation of liver in medical images is challenging on the aspects of accuracy, automation and robustness. A crucial stage of the liver segmentation is the selection of the image features for the segmentation. This paper presents an accurate liver segmentation algorithm. The approach starts with a texture analysis which results in an optimal set of texture features including high order statistical texture features and anatomical structural features. Then, it creates liver distribution image by classifying the original image pixelwisely using support vector machines. Lastly, it uses a group of morphological operations to locate the liver organ accurately in the image. The novelty of the approach is resided in the fact that the features are so selected that both local and global texture distributions are considered, which is important in liver organ segmentation where neighbouring tissues and organs have similar greyscale distributions. Experiment results of liver segmentation on CT images using the proposed method are presented with performance validation and discussion.
Liver Segmentation from CT Image Using Fuzzy Clustering and Level Set  [PDF]
Xuechen Li, Suhuai Luo, Jiaming Li
Journal of Signal and Information Processing (JSIP) , 2013, DOI: 10.4236/jsip.2013.43B007

This paper presents a fully automatic segmentation method of liver CT scans using fuzzy c-mean clustering and level set. First, the contrast of original image is enhanced to make boundaries clearer; second, a spatial fuzzy c-mean clustering combining with anatomical prior knowledge is employed to extract liver region automatically; thirdly, a distance regularized level set is used for refinement; finally, morphological operations are used as post-processing. The experiment result shows that the method can achieve high accuracy (0.9986) and specificity (0.9989). Comparing with standard level set method, our method is more effective in dealing with over-segmentation problem.

Review on the Methods of Automatic Liver Segmentation from Abdominal Images  [PDF]
Suhuai Luo, Xuechen Li, Jiaming Li
Journal of Computer and Communications (JCC) , 2014, DOI: 10.4236/jcc.2014.22001

Automatic liver segmentation from abdominal images is challenging on the aspects of segmentation accuracy, automation and robustness. There exist many methods of liver segmentation and ways of categorisingthem. In this paper, we present a new way of summarizing the latest achievements in automatic liver segmentation. We categorise a segmentation method according to the image feature it works on, therefore better summarising the performance of each category and leading to finding an optimal solution for a particular segmentation task. All the methods of liver segmentation are categorized into three main classes including gray level based method, structure based method and texture based method. In each class, the latest advance is reviewed with summary comments on the advantages and drawbacks of each discussed approach. Performance comparisons among the classes are given along with the remarks on the problems existed and possible solutions. In conclusion, we point out that liver segmentation is still an open issue and the tendency is that multiple methods will be employed together to achieve better segmentation performance.

Automatic Alzheimer’s Disease Recognition from MRI Data Using Deep Learning Method  [PDF]
Suhuai Luo, Xuechen Li, Jiaming Li
Journal of Applied Mathematics and Physics (JAMP) , 2017, DOI: 10.4236/jamp.2017.59159
Alzheimer’s Disease (AD), the most common form of dementia, is an incurable neurological condition that results in a progressive mental deterioration. Although definitive diagnosis of AD is difficult, in practice, AD diagnosis is largely based on clinical history and neuropsychological data including magnetic resource imaging (MRI). Increasing research has been reported on applying machine learning to AD recognition in recent years. This paper presents our latest contribution to the advance. It describes an automatic AD recognition algorithm that is based on deep learning on 3D brain MRI. The algorithm uses a convolutional neural network (CNN) to fulfil AD recognition. It is unique in that the three dimensional topology of brain is considered as a whole in AD recognition, resulting in an accurate recognition. The CNN used in this study consists of three consecutive groups of processing layers, two fully connected layers and a classification layer. In the structure, every one of the three groups is made up of three layers, including a convolutional layer, a pooling layer and a normalization layer. The algorithm was trained and tested using the MRI data from Alzheimer’s Disease Neuroimaging Initiative. The data used include the MRI scanning of about 47 AD patients and 34 normal controls. The experiment had shown that the proposed algorithm delivered a high AD recognition accuracy with a sensitivity of 1 and a specificity of 0.93.
Study on Nursing Clinical Teachers' Comprehensive Quality Evaluation Model on the Basis of Fuzzy Mathematics
Zhijuan Liu,Jiaming Zhong
Research Journal of Applied Sciences, Engineering and Technology , 2013,
Abstract: In this study, we study on the nursing clinical teachers' comprehensive quality evaluation model on the basis of fuzzy mathematics. First, it obtains the nursing clinical teachers' comprehensive quality evaluation index framework by making use of Delphi method. Then, it constructs the comprehensive quality evaluation hierarchy model by applying the analytic hierarchy process, to obtain the weight for each index, based on which to establish fuzzy comprehensive evaluation model, thus acquiring new method for nursing clinical teachers' comprehensive quality evaluation. Examples have proven the feasibility and effectiveness of this method.
The Supermarket Game
Jiaming Xu,Bruce Hajek
Mathematics , 2012,
Abstract: A supermarket game is considered with $N$ FCFS queues with unit exponential service rate and global Poisson arrival rate $N \lambda$. Upon arrival each customer chooses a number of queues to be sampled uniformly at random and joins the least loaded sampled queue. Customers are assumed to have cost for both waiting and sampling, and they want to minimize their own expected total cost. We study the supermarket game in a mean field model that corresponds to the limit as $N$ converges to infinity in the sense that (i) for a fixed symmetric customer strategy, the joint equilibrium distribution of any fixed number of queues converges as $N \to \infty$ to a product distribution determined by the mean field model and (ii) a Nash equilibrium for the mean field model is an $\epsilon$-Nash equilibrium for the finite $N$ model with $N$ sufficiently large. It is shown that there always exists a Nash equilibrium for $\lambda <1$ and the Nash equilibrium is unique with homogeneous waiting cost for $\lambda^2 \le 1/2$. Furthermore, we find that the action of sampling more queues by some customers has a positive externality on the other customers in the mean field model, but can have a negative externality for finite $N$.
The homotopy type of the Baily-Borel and allied compactifications
Jiaming Chen,Eduard Looijenga
Mathematics , 2015,
Abstract: A number of compactifications familiar in complex-analytic geometry, in particular, the Baily-Borel compactification and its toroidal variants, as well as the Deligne-Mumford compactifications, can be covered by open subsets whose nonempty intersections are Eilenberg-MacLane spaces. We exploit this fact to describe the (rational) homotopy type of these spaces and the natural maps between them in terms of the simplicial sets attached to certain categories. We thus generalize an old result of Charney-Lee on the Baily-Borel compactification of A_g and recover (and rephrase) a more recent one of Ebert-Giansiracusa on the Deligne-Mumford compactifications. We also describe an extension of the period map for Riemann surfaces (going from the Deligne-Mumford compactification to the Baily-Borel compactification of the moduli space of principally polarized varieties) in these terms.
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