Reconstructing the cosmic density field based on the generative adversarial network.

Feng Shi 한국천문학회 2020 天文學會報 Vol.45 No.1

LRTV: MR Image Super-Resolution With Low-Rank and Total Variation Regularizations

Feng Shi,Jian Cheng,Li Wang,Pew-Thian Yap,Dinggang Shen IEEE 2015 IEEE transactions on medical imaging Vol.34 No.12

<P>Image super-resolution (SR) aims to recover high-resolution images from their low-resolution counterparts for improving image analysis and visualization. Interpolation methods, widely used for this purpose, often result in images with blurred edges and blocking effects. More advanced methods such as total variation (TV) retain edge sharpness during image recovery. However, these methods only utilize information from local neighborhoods, neglecting useful information from remote voxels. In this paper, we propose a novel image SR method that integrates both local and global information for effective image recovery. This is achieved by, in addition to TV, low-rank regularization that enables utilization of information throughout the image. The optimization problem can be solved effectively via alternating direction method of multipliers (ADMM). Experiments on MR images of both adult and pediatric subjects demonstrate that the proposed method enhances the details in the recovered high-resolution images, and outperforms methods such as the nearest-neighbor interpolation, cubic interpolation, iterative back projection (IBP), non-local means (NLM), and TV-based up-sampling.</P>

Probabilistic Analysis on Aerostatic Displacement-dependent Wind Loads on a Stream-lined Box Girder

Feng Shi,Libin Wang,Fenghui Dong,Min Zhao 대한토목학회 2023 KSCE Journal of Civil Engineering Vol.27 No.1

Due to the limitations of the bridge deck modeling and wind tunnel installations, the parametricuncertainties of aerostatic displacement-dependent wind loads have become an urgent problem for reliability analysis in bridge engineering. Computational fluid dynamic (CFD) simulations were conducted to investigate the distribution model of aerostatic coefficients. The Monte Carlo simulation (MCS) was used to generate random samples of stream-lined box cross-sections. Among these samples, wind attack angles of -8° – 8° were considered, and the sample size of each angle group was set as 30. Then, the statistical properties for the variation and distribution of aerostatic coefficients were discussed. In addition, sub-samples with sizes of 5 – 20 were randomly sampled from the initial sample group to evaluate the influence of the sample scale. The coefficient of variation (COV) of aerostatic coefficients with respect to geometric uncertainties increased up to 0.217, which occurred at -7° wind attack angle. Lognormal distribution models obtained by hypothesis tests maintained a low deviation for estimating the distribution of aerostatic coefficients. The sample size had a significant effect on quantifying the error between empirical and theoretical distribution models. Simulation method proposed in this paper provides a systematic approach for probabilistic problems involving fluid-structure interaction and parametric uncertainties.

MRI T2-Weighted Imaging and Fat-Suppressed T2-Weighted Imaging Image Fusion Technology Improves Image Discriminability for the Evaluation of Anal Fistulas

Shi-Ting Feng,Mengqi Huang,Zhi Dong,Ling Xu,Yin Li,Yingmei Jia,Huasong Cai,Bingqi Shen,Zi-Ping Li 대한영상의학회 2019 Korean Journal of Radiology Vol.20 No.3

Objective: To explore whether MRI fusion technology (combined T2-weighted imaging [T2WI] and fat-suppressed T2WI [T2WI-FS]) improves signal differences between anal fistulas and surrounding structures. Materials and Methods: A total of 32 patients with confirmed diagnoses of anal fistula were retrospectively studied. All available T2WI and T2WI-FS images for each patient were used to generate fusion image (T2WI-Fusion) based on the addition of gray values obtained from each pixel via an MR post-processing work station. The discriminability of fistula, perianal sphincter, and perianal fat in T2WI, T2WI-FS, and T2WI-Fusion images was quantified with Fisher’s scoring algorithm. For subjective visual image assessment by researchers, five-point scale scores were determined using a modified double-stimulus continuous qualityscale test to evaluate T2WI-FS, T2WI, enhanced axial three-dimensional-volumetric interpolated breath-hold examination (3D-VIBE), and T2WI-Fusion sequence images. The differences were subsequently compared. Results: Mean Fisher scores for fistulas vs. sphincters obtained from T2WI-Fusion (FFusion-fistula = 6.56) were significantly higher than those from T2WI (FT2WI-fistula = 3.35) (p = 0.001). Mean Fisher scores for sphincters vs. fat from T2WI-Fusion (FFusion-sphincter = 10.84) were significantly higher than those from T2WI-FS (FSFS-sphincter = 2.57) (p = 0.001). In human assessment, T2WI-Fusion showed the same fistula discriminability as T2WI-FS, and better sphincter discriminability than T2WI. Overall, T2WI-Fusion showed better discriminability than T2WI, T2WI-FS, and enhanced 3D-VIBE images. Conclusion: T2WI and T2WI-FS fusion technology improves signal differences between anal fistulas and surrounding structures, and may facilitate better evaluation of anal fistulas and sphincters.

SURFACE MODIFICATION AND CHARACTERIZATION OF Fe_3O_4/Au COMPOSITE NANOPARTICLES

FENG SHI,WENLI HUI,YALI CUI,CHAO CHEN 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2011 NANO Vol.6 No.2

Fe_3O_4/Au composite nanoparticles were modified with α-thio-ω-carboxy poly (ethylene glycol). Results from XRD, selected area diffraction, high-resolution TEM images, and dynamic lighting scattering illustrate that the particles have a core/shell composite structure and were monodispersed. Surface plasmon resonance measured by UV–Vis indicates that the absorption peak of the modified composite particle characteristic at 532 nm can be stably suspended in a different buffer. The modified composite particles also have good response to external magnetic field. The Fe_3O_4/Au composite nanoparticles are magnetically and optically active, and are useful for simultaneous magnetic and optical detection. Coupled with biomolecules, the advantages of these composite particles make them very promising for biomedical applications in the near future.

Optimization of ${\gamma}-Polyglutamic$ Acid Production by Bacillus subtilis ZJU-7 Using a Surface-response Methodology

Shi, Feng,Xu, Zhinan,Cen, Peilin The Korean Society for Biotechnology and Bioengine 2006 Biotechnology and Bioprocess Engineering Vol.11 No.3

The components of the media used to elicit the biosynthesis of $poly-{\gamma}-glutamic$ acid $({\gamma}-PGA)$ by Bacillus subtilis ZJU-7 were investigated, particularly the carbon and nitrogen sources Of the 7 carbon sources investigated, sucrose induced the highest rate of ${\gamma}-PGA$ productivity; among the nitrogen sources, tryptone had the best effect for ${\gamma}-PGA$ production. A $2^{6-2}$ fractional factorial design was used to screen factors that influence ${\gamma}-PGA$ production significantly, and a central composite design was finally adopted to formulate the optimal medium. ${\gamma}-PGA$ productivity improved approximately 2-fold when the optimal medium was used compared with the original nonoptimized medium, and volumetric productivity reached a maximum of 58.2 g/L after a 24-h cultivation period.

Lack of Association of Glutathione S-transferase M3 Gene Polymorphism with the Susceptibility of Lung Cancer

Feng, Xu,Dong, Chun-Qiang,Shi, Jun-Jie,Zhou, Hua-Fu,He, Wei,Zheng, Bao-Shi Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.9

Objective: The conclusions of published reports on the relationship between the glutathione S-transferase M3 (GSTM3) A/B gene polymorphism and the risk of lung cancer are still debated. This meta-analysis was performed to evaluate the association between GSTM3 and the risk of lung cancer. Methods: Association investigations were identified from PubMed, Embase, and Cochrane Library, and eligible studies were included and synthesized using a meta-analysis method. Results: Eight reports were included into this meta-analysis for the association of GSTM3 A/B gene polymorphism and lung cancer susceptibility, covering 1,854 patients with lung cancer and 1,926 controls. No association between the GSTM3 A/B gene polymorphism and lung cancer was found in this meta-analysis (B allele: OR = 1.25, 95% CI: 0.89-1.76, P = 0.20; BB genotype: OR = 1.53, 95% CI: 0.71-3.32, P = 0.28; AA genotype: OR = 0.85, 95% CI: 0.59-1.23, P = 0.39). Conclusions: The GSTM3 A/B gene polymorphism is not associated with lung cancer susceptibility. However, more studies on the relationship between GSTM3 A/B gene polymorphism and the risk of lung cancer should be performed in the future.

In Vitro Activities of 3-Hydroxy-1,5,6-trimethoxy-2-methyl-9,10- anthraquinone against Non-small Cell Lung Carcinoma

Shi-Xiu Feng,Caigan Du,Qiunong Guan,Tao Chen 대한약학회 2012 Archives of Pharmacal Research Vol.35 No.7

Medicinal herbs are the preferred candidates for drug discovery against human diseases including cancer. The roots of Prismatomeris connata have been used in traditional herbal medicine to treat many health problems, particularly pneumoconiosis. This study was to test the anti-tumor activity of 3-Hydroxy-1,5,6-trimethoxy-2-methyl-9,10-anthraquinone (PCON6), a major anthraquinone derivative from C. connata, against lung cancer. Cell viability in cultures was assessed by MTT assay. Cell death or apoptosis was determined with Annexin-V and 7-Aminoactinomycin D staining. Cell cycle was analyzed by both propidium iodide DNA staining and BrdU incorporation assay. Here we showed that in a panel of fifteen different tumor cells lines, a group of four non-small cell lung carcinoma (NSCLC) cell lines exhibited a relatively higher sensitivity to PCON6 growth inhibition than the rest of most non-lung cancer cell lines (p = 0.0461). Further studies demonstrated that the suppression of NSCLC H520 cell growth by PCON6 was associated with its induction of apoptosis at 20 μM (p = 0.0008), and of cell accumulation at S phase cell cycle (p < 0.05) that was further supported by a decrease in cdc2 protein expression. This preliminary study suggests that natural compound PCON6 has relatively selective cytotoxicity against NSCLC growth and represent a concept of developing a novel drug therapy specific for NSCLC based on the roots of C. connata or PCON6.

Mapping the real-space distributions of galaxies in SDSS DR7

Feng Shi 한국천문학회 2019 天文學會報 Vol.44 No.1

Real option consumption-utility based indifference pricing under stochastic volatility

Feng Shi,Jinqiang Yang,Kui Ma 인하대학교 정석물류통상연구원 2009 인하대학교 정석물류통상연구원 학술대회 Vol.2009 No.10

This paper deals with the consumption-utility based indifference pricing problem of real option under stochastic volatility by analyzing a mixed optimal control and optimal stopping problem under an incomplete market. Implied option value is given by the solution to a two dimensional free-boundary PDE and the numerical results are obtained by the finite difference method. The numerical analysis illustrates that stochastic volatility will increase the implied option value and encourage the agent exericse the option later. Additionally, the stochastic volatility results in more consumption and decreases the precautionary savings motive of the agent. And an increase in the risk aversion attituede raises those effects.