A Level Set Method to Image Segmentation Based on Local Direction Gradient

( Yanjun Peng ),( Yingran Ma ) 한국인터넷정보학회 2018 KSII Transactions on Internet and Information Syst Vol.12 No.4

For image segmentation with intensity inhomogeneity, many region-based level set methods have been proposed. Some of them however can’t get the relatively ideal segmentation results under the severe intensity inhomogeneity and weak edges, and without use of the image gradient information. To improve that, we propose a new level set method combined with local direction gradient in this paper. Firstly, based on two assumptions on intensity inhomogeneity to images, the relationships between segmentation objects and image gradients to local minimum and maximum around a pixel are presented, from which a new pixel classification method based on weight of Euclidian distance is introduced. Secondly, to implement the model, variational level set method combined with image spatial neighborhood information is used, which enhances the anti-noise capacity of the proposed gradient information based model. Thirdly, a new diffusion process with an edge indicator function is incorporated into the level set function to classify the pixels in homogeneous regions of the same segmentation object, and also to make the proposed method more insensitive to initial contours and stable numerical implementation. To verify our proposed method, different testing images including synthetic images, magnetic resonance imaging (MRI) and real-world images are introduced. The image segmentation results demonstrate that our method can deal with the relatively severe intensity inhomogeneity and obtain the comparatively ideal segmentation results efficiently.

Ethernet Controller Module Design based on ARM Technology

Zheng Peng,Zhang Zhaochen,Peng Yanjun 보안공학연구지원센터 2014 International Journal of Smart Home Vol.8 No.5

Efficient Scheme for Secret Hiding in QR Code by Improving Exploiting Modification Direction

( Peng-cheng Huang ),( Yung-hui Li ),( Chin-chen Chang ),( Yanjun Liu ) 한국인터넷정보학회 2018 KSII Transactions on Internet and Information Syst Vol.12 No.5

QR codes as public patent are widely used to acquire the information in various fields. However, it faces security problem when delivering the privacy message by QR code. To overcome this weakness, we propose a secret hiding scheme by improving exploiting modification direction to protect the private message in QR code. The secret messages will be converted into octal digit stream and concealed to the cover QR code by overwriting the cover QR code public message bits. And the private messages can be faithfully decoded using the extraction function. In our secret hiding scheme, the QR code public message still can be fully decoded publicly from the marked QR codes via any standard QR Code reader, which helps to reduce attackers’ curiosity. Experiments show that the proposed scheme is feasible, with high secret payload, high security protection level, and resistant to common image post-processing attacks.

Efficient secret sharing scheme with cheater identification based on QR code

( Peng-cheng Huang ),( Chin-chen Chang ),( Yung-hui Li ),( Yanjun Liu ) 한국인터넷정보학회 2019 KSII Transactions on Internet and Information Syst Vol.13 No.10

Secret sharing is an effective way of protecting secret messages. However, the traditional secret sharing schemes are considered meaningless due to malicious people attention which might raise risks. To overcome the weakness, this paper presents an effective secret sharing scheme with the functionality of cheater identification, based on meaningful QR code. The secret message will be split and concealed in the padding region of cover QR codes with the assistance of Latin square and it can be completely restored when all the involved participants cooperate. The concealing strategy exploits the characteristic of Reed-Solomon (RS) code to ensure the strong robustness of generated QR code pseudo-shares. The meaningful QR code pseudo-shares help to reduce the curious of unrelated persons. Some experiments were done to evaluate the performance of proposed scheme. The results showed that the proposed scheme is feasible, efficient and secure compared to the other existing schemes. It also achieves a higher secret payload and maintains stronger robustness.

Functional Evaluation of Transplanted Kidneys with Reduced Field-of-View Diffusion-Weighted Imaging at 3T

Yuan Xie,Yanjun Li,Jiqiu Wen,Xue Li,Zhe Zhang,Jianrui Li,Yan’e Zhao,Peng Wang,Jun Zhang,Ying Tian,Long Jiang Zhang,Guang Ming Lu 대한영상의학회 2018 Korean Journal of Radiology Vol.19 No.2

Objective: To determine the feasibility of reduced field-of-view diffusion-weighted imaging (rFOV DWI) with multi-b values to detect functional variability in transplanted kidneys. Materials and Methods: Using a 3T MRI scanner, multi-b rFOV DWI of transplanted kidney or native kidney was performed in 40 renal transplantation recipients and 18 healthy volunteers. The patients were stratified, according to an estimated glomerular filtration rate (eGFR): Group 1, eGFR ≥ 60 mL/min/1.73 m2; Group 2, eGFR ≥ 30 mL/min/1.73 m2 and < 60 mL/min/1.73 m2; Group 3, eGFR < 30 mL/min/1.73 m2. Total apparent diffusion coefficient (ADCT), perfusion-free ADC (ADCD) and perfusion fraction (FP) of kidneys were calculated and compared among the four groups. Correlations between the imaging results and eGFR were assessed. Results: All volunteers had eGFR ≥ 60 mL/min/1.73 m2, while 16, 16, and 8 patients were included in Groups 1, 2, and 3, respectively. In the renal cortex, ADCT was higher in Group 1 ([1.65 ± 0.13] x 10-3 mm2/s) than Group 3 ([1.44 ± 0.11] x 10-3 mm2/s) (p < 0.05), and the inter-group differences of FP values were significant (all p < 0.05) (0.330 ± 0.024, 0.309 ± 0.019, 0.278 ± 0.033, and 0.250 ± 0.028 for control group, Groups 1, 2, and 3, respectively). Renal cortical ADCT, ADCD, FP, and renal medullary ADCT and FP correlated positively with eGFR (r = 0.596, 0.403, 0.711, 0.341, and 0.323, respectively; all p < 0.05). When using 0.278 as the cutoff value, renal cortical FP had a sensitivity of 97.1% and a specificity of 66.7% for predicting decreased renal function. Conclusion: Multi-b rFOV DWI presents transplanted kidneys with high resolution, which is a promising functional tool for non-invasively monitoring function of transplanted kidneys.

Skin Lesion Image Segmentation Based on Adversarial Networks

( Ning Wang ),( Yanjun Peng ),( Yuanhong Wang ),( Meiling Wang ) 한국인터넷정보학회 2018 KSII Transactions on Internet and Information Syst Vol.12 No.6

Traditional methods based active contours or region merging are powerless in processing images with blurring border or hair occlusion. In this paper, a structure based convolutional neural networks is proposed to solve segmentation of skin lesion image. The structure mainly consists of two networks which are segmentation net and discrimination net. The segmentation net is designed based U-net that used to generate the mask of lesion, while the discrimination net is designed with only convolutional layers that used to determine whether input image is from ground truth labels or generated images. Images were obtained from “Skin Lesion Analysis Toward Melanoma Detection” challenge which was hosted by ISBI 2016 conference. We achieved segmentation average accuracy of 0.97, dice coefficient of 0.94 and Jaccard index of 0.89 which outperform the other existed state-of-the-art segmentation networks, including winner of ISBI 2016 challenge for skin melanoma segmentation.

Differencing Multiuser Detection Using Error Feedback Filter for MIMO DS-UWB System in Nakagami Fading Channel

( Zhengmin Kong ),( Yanjun Fang ),( Yuxuan Zhang ),( Shixin Peng ),( Guangxi Zhu ) 한국인터넷정보학회 2012 KSII Transactions on Internet and Information Syst Vol.6 No.10

A differencing multiuser detection (MUD) method is proposed for multiple-input multiple-output (MIMO) direct sequence (DS) ultra-wideband (UWB) system to cope with the multiple access interference (MAI) and the computational efficiency in Nakagami fading channel. The method, which combines a multiuser-interference-cancellation-based decision feedback equalizer using error feedback filter (MIC DFE-EFF), a coefficient optimization algorithm (COA) and a differencing algorithm (DA), is termed as MIC DFE-EFF (COA) with DA for short. In the paper, the proposed MUD method is illuminated from the rudimental MIC DFE-EFF to the advanced MIC DFE-EFF (COA) with DA step by step. Firstly, the MIC DFE-EFF system performance is analyzed by minimum mean square error criterion. Secondly, the COA is investigated for optimization of each filter coefficient. Finally, the DA is introduced to reduce the computational complexity while sacrificing little performance. Simulations show a significant performance gain can be achieved by using the MIC DFE-EFF (COA) with DA detector. The proposed MIC DFE-EFF (COA) with DA improves both bit error rate performance and computational efficiency relative to DFE, DFE-EFF, parallel interference cancellation (PIC), MIC DFE-EFF and MIC DFE-EFF with DA, though it sacrifices little system performance, compared with MIC DFE-EFF (COA) without DA.

Rocaglamide-A Potentiates Osteoblast Differentiation by Inhibiting NF-κB Signaling

Li, Aiguo,Yang, Libin,Geng, Xiaolin,Peng, Xingmei,Lu, Tan,Deng, Yanjun,Dong, Yuzheng Korean Society for Molecular and Cellular Biology 2015 Molecules and cells Vol.38 No.11

Rheumatoid arthritis is a chronic inflammatory disease that leads to bone and cartilage erosion. The inhibition of osteoblast differentiation by the inflammatory factor TNF-${\alpha}$ is critical for the pathogenesis of rheumatoid arthritis. To modulate TNF-${\alpha}$ mediated inhibition of osteoblast differentiation is required to improve therapeutic efficacy of rheumatoid arthritis. Here, we explored the potential role of rocaglamide-A, a component of Aglaia plant, in osteoblast differentiation. Rocaglamide-A prevented TNF-${\alpha}$ mediated inhibition of osteoblast differentiation, and promoted osteoblast differentiation directly, in both C2C12 and primary mesenchymal stromal cells. Mechanistically, Rocaglamide-A inhibited the phosphorylation of NF-${\kappa}B$ component p65 protein and the accumulation of p65 in nucleus, which resulted in the diminished NF-${\kappa}B$ responsible transcriptional activity. Oppositely, overexpression of p65 reversed rocaglamide-A's protective effects on osteoblast differentiation. Collectively, rocaglamide-A protected and stimulated osteoblast differentiation via blocking NF-${\kappa}B$ pathway. It suggests that rocaglamide-A may be a good candidate to develop as therapeutic drug for rheumatoid arthritis associated bone loss diseases.

Based on charge-transfer interaction organic light-response materials: From sphere-like nanoparticles to fibers

Lushan Wang,Tao Wang,Yanxin Jin,Peng Chen,Yanjun Gong,Yingyuan Zhao,Li Yu 한국물리학회 2015 Current Applied Physics Vol.15 No.8

We employed a potent and versatile ionic self-assembly (ISA) to prepare stimuli-responsive supramolecular materials using charged surfactants, N-dodecyl-4-(1-methylpip-erazine)-1,8-naphthalimide iodine [C12ndi]I and oppositely charged small molecule, 4-(phenylazo)benzoic acid sodium (PBAS). By transmission electron microscopy, nanospheres could be observed to transform into nanofibers upon irradiated with UV light (365 nm) for 1 h. The UVevis absorption spectra and fluorescence spectra of the fibers indicate that charge-transfer interaction is regarded as the driving force for the formation of fibers. Density functional theory (DFT) calculations prove that the pep stacking and electrostatic interactions between [C12ndi]I and PBAS contributes significantly to the resulting aggregates. The supramolecular fibers have the potential applications in some fields, e.g. drug delivery and electro-optical devices.

Producing magnetite concentrate via self-magnetization roasting in N2 atmosphere: Phase and structure transformation, and extraction kinetics

Qi Zhang,Yongsheng Sun,Yuexin Han,Yanjun Li,Peng Gao 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.104 No.-

In this work, a green self-magnetization roasting technology for producing magnetite was proposed withoutadding additional. The regulatory mechanisms of the main factors (siderite dosage, roasting temperature,and roasting time) on the self-magnetization roasting process were investigated. In-situ kinetic ofthe self-magnetization roasting process was analyzed by the infrared gas analyzer, and the phase transformationwas investigated by in-situ X-ray diffraction and Mössbauer. Under the optimal roasting conditionsof 30% siderite dosage, 730 C, and 7.5 min, the iron concentrate with Fe grade 68.82% and Ferecovery 99.48% was obtained. The kinetic and phase transformation results indicated that the selfmagnetizationroasting process was divided into two stages: siderite pyrolysis in the prophase stage,and hematite reduced to magnetite by reductant (FeO and CO) from siderite pyrolysis in the anaphasestage. The SEM analyses showed that the newborn magnetite crystals were mainly coarse-grained andneedles, which fitted the kinetics characteristics for the Nucleation model. Using self-magnetizationroasting technology, siderite and hematite would promote mutual reduction to improve product magnetismand roasting efficiency without adding reductant. Also, self-magnetization roasting will enhancethe utilization rate of siderite, and it contributes to energy conservation and CO2 emission reduction.