Classification of Recent Steganalysis Techniques

Zhan Gao,Sathiamoorthy Manoharan 한국정보통신학회 2012 2016 INTERNATIONAL CONFERENCE Vol.5 No.1

A Scheduling Approach Considering Local Tasks in the Computational Grid

Zhan Gao,Siwei Luo,Ding Ding 보안공학연구지원센터 2007 International Journal of Multimedia and Ubiquitous Vol.2 No.3

Task scheduling under a grid environment is an important research area, on which much attention has been paid. However, either in the meta-task scheduling problems or DAG (Direct Acyclic Graph) scheduling problems, it is usually assumed that tasks are submitted to dedicated hosts and that these tasks are processed in FIFO (First In First Out) order. This is not practical in a grid, in which a host may be shared between grid users and its owner and local tasks, which belong to resource owners, may compete with grid tasks for the hosts. EBGSA (Estimation Based Grid Scheduling Approach) is proposed, which allows for the simultaneous processing of grid tasks and local tasks. In EBGSA we use history information about the execution of tasks to estimate the performance of non-dedicated hosts. Two heuristic scheduling algorithms, MCT (Minimum Completion Time) and Min-min, are selected to perform the simulation experiment. Both experiments obtain a smaller makespan, proving EBGSA feasible for grid task scheduling.

Opportunistic Spectrum Access with Discrete Feedback in Unknown and Dynamic Environment:A Multi-agent Learning Approach

( Zhan Gao ),( Junhong Chen ),( Yuhua Xu ) 한국인터넷정보학회 2015 KSII Transactions on Internet and Information Syst Vol.9 No.10

This article investigates the problem of opportunistic spectrum access in dynamic environment, in which the signal-to-noise ratio (SNR) is time-varying. Different from existing work on continuous feedback, we consider more practical scenarios in which the transmitter receives an Acknowledgment (ACK) if the received SNR is larger than the required threshold, and otherwise a Non-Acknowledgment (NACK). That is, the feedback is discrete. Several applications with different threshold values are also considered in this work. The channel selection problem is formulated as a non-cooperative game, and subsequently it is proved to be a potential game, which has at least one pure strategy Nash equilibrium. Following this, a multi-agent Q-learning algorithm is proposed to converge to Nash equilibria of the game. Furthermore, opportunistic spectrum access with multiple discrete feedbacks is also investigated. Finally, the simulation results verify that the proposed multi-agent Q-learning algorithm is applicable to both situations with binary feedback and multiple discrete feedbacks.

Biotransformation, a Promising Technology for Anti-cancer Drug Development

Gao, Fei,Zhang, Jin-Ming,Wang, Zhan-Guo,Peng, Wei,Hu, Hui-Ling,Fu, Chao-Mei Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.10

With the high morbidity and mortality caused by cancer, finding new and more effective anti-cancer drugs is very urgent. In current research, biotransformation plays a vital role in the research and development of cancer drugs and has obtained some achievements. In this review, we have summarized four applications as follows: to exploit novel anti-cancer drugs, to improve existing anti-cancer drugs, to broaden limited anti-cancer drug resources and to investigate correlative mechanisms. Three different groups of important anti-cancer compounds were assessed to clarify the current practical applications of biotransformation in the development of anti-cancer drugs.

hARIP2 is a Putative Growth-promoting Factor Involved in Human Colon Tumorigenesis

Gao, Rui-Feng,Li, Zhan-Dong,Jiang, Jing,Yang, Li-Hua,Zhu, Ke-Tong,Lin, Rui-Xin,Li, Hao,Zhao, Quan,Zhang, Nai-Sheng Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.20

Activin is a multifunctional growth and differentiation factor of the growth factor-beta (TGF-${\beta}$) superfamily, which inhibits the proliferation of colon cancer cells. It induces phosphorylation of intracellular signaling molecules (Smads) by interacting with its type I and type II receptors. Previous studies showed that human activin receptor-interacting protein 2 (hARIP2) can reduce activin signaling by interacting with activin type II receptors; however, the activity of hARIP2 in colon cancer has yet to be detailed. In vitro, overexpression of hARIP2 reduced activin-induced transcriptional activity and enhanced cell proliferation and colony formation in human colon cancer HCT8 cells and SW620 cells. Also, hARIP2 promoted colon cancer cell apoptosis, suggesting that a vital role in the initial stage of colon carcinogenesis. In vivo, immunohistochemistry revealed that hARIP2 was expressed more frequently and much more intensely in malignant colon tissues than in controls. These results indicate that hARIP2 is involved in human colon tumorigenesis and could be a predictive maker for colon carcinoma aggressiveness.

Finite Element and Experimental Analysis of Ultrasonic Vibration Milling of High-Volume Fraction SiCp/Al Composites

Zhan-Li Shi,Dao-Hui Xiang,Hao-Ren Feng,Bang-Fu Wu,Zhi-Meng Zhang,Guo-Fu Gao,Bo Zhao 한국정밀공학회 2021 International Journal of Precision Engineering and Vol.22 No.10

SiCp/Al composites have been widely used in many fields due to their excellent mechanical properties. However, the addition of reinforced phase SiC particles makes the overall properties of the composites hard and brittle, which brings great challenges to milling. Ultrasonic vibration-assisted processing technology has great advantages in processing hard and brittle materials. However, the process of rupture of SiC particles cannot be effectively observed during the test processing, and a large number of tests increase the cost of the test. The combination of finite element analysis and experiment was used to study the machining performance of High-volume fraction SiCp/Al composites in longitudinal-torsional ultrasonicassisted milling (LTUAM), and its feasibility was evaluated by comparing with conventional Milling (CM). By analyzing the trajectories of cutting edges in ultrasonic-assisted milling, It was found that ultrasonic frequency determines the time of periodic contact-separation between chisel edge and workpiece, and ultrasonic amplitude determines the maximum distance of contact-separation. Using ABAQUS finite element software, a polygon SiC particles model with a high-volume fraction was established to investigate the SiC particles crushing process under different ultrasonic-assisted milling conditions. The results showed that high-frequency ultrasonic-assisted milling could soften SiCp/Al composites, and the structural integrity of silicon carbide particles could be better maintained under appropriate ultrasonic amplitudes, reducing the probability of fragmentation. The removal mode was mainly plastic removal or crushing into small particles. The surface roughness value and milling force were reduced, improving the surface quality of the processed composite material. The conclusions of the milling test were basically consistent with the simulation results, which prove the correctness and feasibility of the simulation results

Presence of Tumour-infiltrating FOXP3⁺ Lymphocytes Correlates with Immature Tumour Angiogenesis in Renal Cell Carcinomas

Zhan, Hai-Lun,Gao, Xin,Zhou, Xiang-Fu,Pu, Xiao-Yong,Wang, De-Juan Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.3

Background: $FOXP3^+$ regulatory T cells (Tregs) inhibit effector T cell functions and are implicated in tumour progression. However, together with microvessel density (MVD) they remain controversial prognostic predictors for renal cell carcinoma (RCC), and potential associations have yet to be determined. The objective of this study was to determine the prognostic significance of Tregs and MVD and their potential relationship in RCCs. Design: Paraffin-embedded tissues from 62 RCC patients were analysed using immunohistochemistry to detect $FOXP3^+$ lymphocytes, and double immunohistochemistry to detect different microvessel types in the tumour interior, rim and normal kidney tissue, and their correlation with clinicopathological characteristics. Survival analysis was also performed. Results: The presence of $FOXP3^+$ cells in the tumour interior or the rim showed no correlation with death from RCC and other pathological characteristics. Negative correlations were noted between the immature MVD in the tumour interior or the rim and tumour size, tumour stage and overall survival; however, there was no correlation with the nuclear grade or pathological type. A positive correlation between $FOXP3^+$ Tregs and immature MVD (r=0.363, P=0.014) and mature MVD (r=0.383, P=0.009) was confirmed in the tumour interior. However, there was no correlation between $FOXP3^+$ Tregs and mature MVD (r=0.281, P=0.076) or immature MVD (r=0.064, P=0.692) in the tumour rim. Conclusions: In this study, a positive correlation between the presence of $FOXP3^+$ Tregs and immature and mature MVD in RCC was confirmed, which suggests a link between suppression of immunity, tumour angiogenesis and poor prognosis.

Incremental Learning With Selective Memory (ILSM): Towards Fast Prostate Localization for Image Guided Radiotherapy

Yaozong Gao,Yiqiang Zhan,Dinggang Shen IEEE 2014 IEEE transactions on medical imaging Vol.33 No.2

<P>Image-guided radiotherapy (IGRT) requires fast and accurate localization of the prostate in 3-D treatment-guided radiotherapy, which is challenging due to low tissue contrast and large anatomical variation across patients. On the other hand, the IGRT workflow involves collecting a series of computed tomography (CT) images from the same patient under treatment. These images contain valuable patient-specific information yet are often neglected by previous works. In this paper, we propose a novel learning framework, namely incremental learning with selective memory (ILSM), to effectively learn the patient-specific appearance characteristics from these patient-specific images. Specifically, starting with a population-based discriminative appearance model, ILSM aims to “personalize” the model to fit patient-specific appearance characteristics. The model is personalized with two steps: backward pruning that discards obsolete population-based knowledge and forward learning that incorporates patient-specific characteristics. By effectively combining the patient-specific characteristics with the general population statistics, the incrementally learned appearance model can localize the prostate of a specific patient much more accurately. This work has three contributions: 1) the proposed incremental learning framework can capture patient-specific characteristics more effectively, compared to traditional learning schemes, such as pure patient-specific learning, population-based learning, and mixture learning with patient-specific and population data; 2) this learning framework does not have any parametric model assumption, hence, allowing the adoption of any discriminative classifier; and 3) using ILSM, we can localize the prostate in treatment CTs accurately (DSC ~ 0.89) and fast ( ~ 4 s), which satisfies the real-world clinical requirements of IGRT.</P>

A novel active disturbance rejection-based control strategy for a gun control system

Qiang Gao,Zhan Sun,Guolai Yang,Runmin Hou,Li Wang,Yuan-Long Hou 대한기계학회 2012 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.26 No.12

To compensate for the nonlinearity and to achieve finely-tuned tracking accuracy of a gun control system driven by an AC machine,an improved active disturbance rejection control (IADRC) strategy with neural network embedding (NN-IADRC) is developed in this paper. The proposed IADRC, which has amnestic memory effects, can be regarded as an extension of the conventional ADRC (CADRC),making it a special case of the IADRC. To further attenuate the dependence on system models and enhance the disturbance rejection capacities of the IADRC strategy, an on-line NN-based optimum updating approach is also developed in this paper. Finally, a series of experiments are conducted on the semi-physical simulation platform to estimate the performance of the control system and the effects of the memory factor on the system. The experimental results confirm that the proposed NN-IADRC is highly robust. The results also confirm that it performs more excellently than the CADRC and that its fine tuning has attained tracking accuracy.

Improvement of ATP regeneration efficiency and operation stability in porcine interferon-α production by Pichia pastoris under lower induction temperature

Minjie Gao,Zhongping Shi,Shijuan Dong,Ruisong Yu,Jianrong Wu,Zhiyong Zheng,Xiaobei Zhan 한국화학공학회 2011 Korean Journal of Chemical Engineering Vol.28 No.6

The performance of traditional heterologous protein production by Pichia pastoris with methanol induction at 30 ℃ is poor, characterized by low ATP regeneration rate and weak operation stability. A low temperature induction strategy at 20 ℃ was thus adopted for efficient porcine interferon-α production in a 10 L fermentor. With the strategy,maximal methanol tolerance level could reach about 40 g/L to effectively deal with methanol concentration variations,so that the complicated on-line methanol measurement system could be eliminated. Moreover, metabolic analysis based on multiple state-variables measurements indicated that pIFN-α antiviral activity enhancement profited from the formation of an efficient ATP regeneration system at 20℃ induction. Compared to the induction strategy at 30 ℃, the proposed strategy increased the ATP regeneration rate by 49-66%, the maximal p_IFN-α antiviral activity was enhanced about 20-fold and reached a higher level of 1.5×10^6 IU/mL.