MR Image Segmentation Using Graph Cuts Based Geodesic Active Contours

Dongsheng Ji,Yukao Yao,Qingjun Yang,Xiaoyun Chen 보안공학연구지원센터 2016 International Journal of Hybrid Information Techno Vol.9 No.1

In this paper, present a graph cuts based geodesic active contours (GAC) approach to object segmentation problems. Our method is a combination of geodesic active contours and the optimization tool of graph cuts and differs fundamentally from traditional active contours in that it uses graph cuts to iteratively deform the contour. Consequently, it has the following advantages. 1. It has the ability to jump over local minima and provide a more global result. 2. Graph cuts guarantee continuity and lead to smooth contours free of self-crossing and uneven spacing problems. Therefore, the internal force which is commonly used in traditional energy functions to control the smoothness is no longer needed, and hence the number of parameters is greatly reduced. 3 Our approach easily extends to the segmentation of three and higher dimensional objects. In addition, the algorithm is suitable for interactive correction and is shown to always converge. Experimental results and analyses are provided.

Evidence for relaxed selection of mitogenome in rapid‑flow cyprinids

Yao Lu,Hu Xing,Dongsheng Zhang 한국유전학회 2019 Genes & Genomics Vol.41 No.7

Background Hypoxia adaptation is developed in many fish species, which helped them to habitat most of water bodies. However, fishes living under high oxygen concentration may lose this feature. Rapid flows provide high level and stable dissolved oxygen, which facilitate organism’s oxygen supply and energy production. Previous studies showed that fish species from rapid-flow habitats exhibited lower hypoxia tolerance compared with fish from intermediate- and slow-flow habitats. Mitochondrial genomes code 13 key components in oxidative phosphorylation pathway; these genes may be under relaxed selection in rapid-flow species. Objectives The primary objectives of this study is to investigate the evolutionary patterns of the 13 mitochondrial OXPHOS genes among nine cyprinids from different water bodies and to test the hypotheses that mitochondrial OXPHOS genes may experience relaxed selection in rapid-flow habitats. Methods We classified nine cyprinid fish species into three groups based on their habitats: rapid-flow, intermediate-flow and slow-flow. To detect relaxed selections, we investigated the 13 protein-coding genes with codon evolution programs RELAX; to estimate evolutionary rates among the cyprinids, free-ratio model in Codeml program was applied; Branch-site models were applied to detect positive selection sites. The polymorphisms of homologous sites were evaluated with PROVEAN program and projected to 3D structure prediction of the proteins using SWISS-MODEL. Results We found that nine out of the 13 genes are under relaxed selection in rapid-flow species. Furthermore, dN, dS and dN/dS are relatively increased when compared with those of intermediate-flow species. More amino acid polymorphic sites are presented in rapid-flow species than in intermediate- and slow-flow species. Furthermore, rapid-flow species had more deleterious substitutions than other groups. 3D structure prediction of these proteins and projection of the polymorphic sites indicated that these sites were randomly distributed, suggesting relaxed functional constraints of these proteins in rapid-flow species. Conclusion Our results suggest that mitochondrial genes are under relaxed selection in rapid-flow cyprinids.

Adsorption properties of Friedel’s salt for the nitrate in the landfill

Dongsheng Shen,Jun Yao,Qingna Kong,Huayue Zhu,Zhen Zhang 한국화학공학회 2016 Korean Journal of Chemical Engineering Vol.33 No.2

Adsorption characteristics of nitrate on Friedel’s salt under the landfill circumstance were investigated to explore the effect of Friedel’s salt on the migration of nitrate in the landfill. Friedel’s salt was synthesized by a coprecipitation method and characterized by XRD and FTIR spectroscopy. The kinetics and isotherm of the adsorption were studied. The effect of the variation of landfill circumstance on the adsorption was also discussed. The result showed that the adsorption capacity of Friedel’s salt for nitrate was 2.494mg g−1. The adsorption process was exothermic and could be well described by pseudo-second-order kinetics and Langmuir-Freundlich equation. Cl− could enhance the adsorption, while SO4 2−, PO4 3− and organic matter could restrict the adsorption. The results suggested that the migration of nitrate in the landfill could be altered by Friedel’s salt, which was related to the variation of the landfill circumstance.

An Effective SVM Ensemble Algorithm Based on Different Thresholds of PCA

Yukai Yao,Bo Wang,Qingjun Yang,Dongsheng Ji,Tao Ma,Xiaoyun Chen 보안공학연구지원센터 2016 International Journal of Database Theory and Appli Vol.9 No.2

This paper proposes an effective ensemble classifier, named PCAenSVM, which consists of ten weak Support Vector Machine classifiers based on different Principal Component Analysis thresholds. Those ten base Support Vector Machine classifiers are made up to fulfill classification tasks using Majority Voting strategy. Experiments are made on four UCI data sets and a data set from the Uppsala University to evaluate the performances of PCAenSVM. The results of PCAenSVM are compared with that of LibSVM and EnsembleSVM. Experimental results show that PCAenSVM has better classification accuracy than other two algorithms. Moreover, PCAenSVM has the same confidence level with the LibSVM, and its confidences of accuracy and sensitivity on those five data sets outperform that of the EnsembleSVM.

Implication of the chemical index of alteration as a paleoclimatic perturbation indicator: an example from the lower Neoproterozoic strata of Aksu, Xinjiang, NW China

Haifeng Ding,Dongsheng Ma,Chunyan Yao,Qizhong Lin,Linhai Jing 한국지질과학협의회 2016 Geosciences Journal Vol.20 No.1

The Neoproterozoic successions in the Aksu region, NW China, which lies unconformably on the Precambrian Aksu Group basement, comprises the Qiaoenbrak, Yuermeinak, Sugetbrak, and Chigebrak formations (from bottom to top). The two lowermost units include two distinct glacial diamictites, which indicate distinct episodes of glaciations. We report the major and trace element (including rare earth element) data for the Qiaoenbrak, Yuermeinak, and Sugetbrak formations to identify the paleoclimatic perturbations. The chemical index of alteration (CIA) values show variations from Qiaoenbrak to Yuermeinak, then Sugetbrak formations. The diamictites have relatively lower chemical index of alteration values (45.23–59.64) than inter-, post- and non-glacial sediments (48.28–66.96). This result supported the condition that the diamictites underwent relatively weak chemical weathering from a dry-cold sedimentary environment, which is associated with the sedimentary facies description. The lower Neoproterozoic successions recoded at least two glaciations, one is Qiaoenbrak glaciation and the other is Yuermeinak glaciation.

Prediction of exploration targets based on integrated analyses of source rock and simulated hydrocarbon migration direction: a case study from the gentle slope of Shulu Sag, Bohai Bay Basin, northern China

Changqing Ren,Fugui He,Xianzhi Gao,Dongsheng Wu,Wenli Yao,Jianzhang Tian,Huiping Guo,Yuanxin Huang,Li Wang,Han Feng,Junwei Li 한국지질과학협의회 2019 Geosciences Journal Vol.23 No.6

The Shulu Sag which is a rifted sag with NNE trend is located in the south of Jizhong Depression, Bohai Bay Basin, northern China. The gentle slope and three troughs are situated in the west and east of the sag, respectively. Both of the lower part of Shasan Member (Es3x) and the lower part of Shayi Member (Es1x) act as source rocks in this sag. Researches on the type, quantity, quality and thermal maturity of the respective organic matter have been conducted using Rock-Eval pyrolysis data. Type II is the dominant kerogen in Es1x of all troughs. However, Type II1 and III is the dominant kerogen in Es3x of Middle-Southern and Northern trough, respectively. TOC (total organic carbon) and pyrolysis S2 (hydrocarbon) values suggest that the Es1x source rocks in Middle-Southern and Northern trough are fair to good and poor to fair generative potential of hydrocarbon, separately. The Es3x source rocks in Middle-Southern and Northern trough possess fair to excellent and poor to fair generative potential of hydrocarbon, individually. Tmax (pyrolysis temperature at maximum S2) values indicate that most of Es3x samples are thermally mature, but all Es1x samples are thermally immature. Under large scale condition, the hydrocarbon secondary migration in the upper part of Shasan Member (Es3s), Shaer Member (Es2) and the upper part of Shayi Member (Es1s) have been simulated using fluid potential model with Arcgis 9.3 software. The simulation results reveal the direction of hydrocarbon secondary migration and the distribution of hydrocarbon migration-accumulation units (HMAUS), and also suggest that the hydrocarbon migration direction is obviously controlled by nose-like structure belts where most of hydrocarbons accumulate. That shows high reliability because they are consistent with the hydrocarbon exploration result in this area. On the basis of integrated analyses of source rocks and hydrocarbon migration direction, the following five areas in the gentle slope are identified to be the preferred hydrocarbon accumulation area: Taijiazhuang area, northern and southern Xicaogu area, as well as northern and southern Leijiazhuang area. It is considerably helpful to reduce the risk in hydrocarbon exploration of Shulu Sag.

Study of Discontinuous FeCoSi/ Native-oxide Multilayer Films Operating in Gigahertz Frequency Range

Huaping Zuo,Shihui Ge,Zhenkun Wang,Yuhua Xiao,Dongsheng Yao 한국자기학회 2008 한국자기학회 학술연구발표회 논문개요집 Vol.- No.-