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Metadata Feedback and Utilization for Data Deduplication Across WAN

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Journal of Computer Science & Technology 2016年第3期31卷 604-623页

作者： Bing Zhou jiang-Tao wen State Key Laboratory on Intelligent Technology and Systems Tsinghua University Beijing 100084 China Tsinghua National Laboratory for Information Science and Technology Tsinghua University Beijing 100084 China Department of Computer Science and Technology Tsinghua University Beijing 100084 China

Data deduplication for file communication across wide area network （WAN） in the applications such as file synchronization and mirroring of cloud environments usually achieves significant bandwidth saving at the cost of significant time overheads of data deduplication. The time overheads include the time required for data deduplication at two geographi- cally distributed nodes （e.g., disk access bottleneck） and the duplication query/answer operations between the sender and the receiver, since each query or answer introduces at least one round-trip time （RTT） of latency. In this paper, we present a data deduplication system across WAN with metadata feedback and metadata utilization （MFMU）, in order to harness the data deduplication related time overheads. In the proposed MFMU system, selective metadata feedbacks from the receiver to the sender are introduced to reduce the number of duplication query/answer operations. In addition, to harness the metadata related disk I/O operations at the receiver, as well as the bandwidth overhead introduced by the metadata feedbacks, a hysteresis hash re-chunking mechanism based metadata utilization component is introduced. Our experimental results demonstrated that MFMU achieved an average of 20%~40% deduplication acceleration with the bandwidth saving ratio not reduced by the metadata feedbacks, as compared with the ＂baseline＂ content defined chunking （CDC） used in LBFS （Low-bandwith Network File system） and exiting state-of-the-art Bimodal chunking algorithms based data deduplication solutions.

关键词： data deduplication wide area network (WAN) metadata feedback metadata utilization

A Data Deduplication Framework of Disk Images with Adaptive Block Skipping

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Journal of Computer Science & Technology 2016年第4期31卷 820-835页

作者： Bing Zhou jiang-Tao wen State Key Laboratory on Intelligent Technology and Systems Tsinghua University Beijing 100084 China

We describe an efficient and easily applicable data deduplication framework with heuristic prediction based adaptive block skipping for the real-world dataset such as disk images to save deduplication related overheads and improve deduplication throughput with good deduplication efficiency maintained. Under the framework, deduplication operations are skipped for data chunks determined as likely non-duplicates via heuristic prediction, in conjunction with a hit and matching extension process for duplication identification within skipped blocks and a hysteresis mechanism based hash indexing process to update the hash indices for the re-encountered skipped chunks. For performance evaluation, the proposed framework was integrated and implemented in the existing data domain and sparse indexing deduplication algorithms. The experimental results based on a real-world dataset of 1.0 TB disk images showed that the deduplication related overheads were significantly reduced with adaptive block skipping, leading to a 30%-80% improvement in deduplication throughput when deduplieation mctadata were stored on the disk for data domain, and 25%-40% RAM space saving with a 15%-20% improvement in deduplication throughput when an in-RAM sparse index was used in sparse indexing. In both cases, the corresponding deduplication ratios reduced were below 5%.

关键词： data deduplication metadata adaptive block skipping

Improving Metadata Caching Efficiency for Data Deduplication via In-RAM Metadata Utilization

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Journal of Computer Science & Technology 2016年第4期31卷 805-819页

We describe a data deduplication system for backup storage of PC disk images, named in-RAM metadata utilizing deduplication （IRwMUD）. In-RAM hash granularity adaptation and miniLZO based data compression are firstly proposed to reduce the in-RAM metadata size and thereby reduce the space overheads required by the in-RAM metadata caches. Secondly, an in-RAM metadata write cache, as opposed to the traditional metadata read cache, is proposed for further reducing metadata-related disk I/O operations and improving deduplication throughput. During deduplication, the metadata write cache is managed following the LRU caching policy. For each manifest that is hit in the metadata write cache, an expensive manifest reloading operation from the disk is avoided. After deduplieation, all the manifests in the metadata write cache are cleared and stored on the disk. Our experimental results using 1.5 TB real-world disk image dataset show that I） IR-MUD achieved about 95% size reduction for the deduplication metadata, with a small time overhead introduced, 2） when the metadata write cache was not utilized, with the same RAM space size for the metadata read cache, IR-MUD achieved a 400% higher RAM hit ratio and a 50% higher deduplication throughput, as compared with the classic Sparse Indexing deduplication system where no metadata utilization approaches are utilized, and 3） when the metadata write cache was utilized and enough RAM space was available, IR-MUD achieved a 500% higher RAM hit ratio compared with Sparse Indexing and a 70% higher deduplication throughput compared with IR-MUD with only a single metadata read cache. The in-RAM metadata harnessing and metadata write caching approaches of IR-MUD can be applied in most parallel deduplication systems for improving metadata caching efficiency.

关键词： data deduplication cache metadata utilization

Gastric adenomyoma presenting as melena: A case report and literature review

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World Journal of Gastroenterology 2010年第15期16卷 1934-1936页

作者： Zhu, Hui-Neng Yu, jiang-Ping Luo, Juan jiang, You-Hua Li, jian-Qiang Sun, wen-Yong Zhejiang Canc Hosp Dept Pathol Hangzhou 310022 Zhejiang Peoples R China Zhejiang Canc Hosp Dept Thoracicoabdominal Surg Hangzhou 310022 Zhejiang Peoples R China

Gastric adenomyoma (AM) is a rare benign tumor characterized by glandlike structures embedded within a smooth muscle stroma. We report a case of a 68yearold man with gastric AM admitted to our hospital for melana. Endoscopic examination revealed a gastric mass of about 4 cm in diameter, located in the antrum. Histologic examination of the excised specimen showed irregularly arranged glands and interlacing smooth muscle bundles surrounding the glandular elements. Although gastric AM is rare, it should be considered in differential diagnosis of extramucosal gastric tumor.

关键词： Adenomyoma Stomach Melana Histopathology Endoscopic examination

Natural killer cell lines in tumor immunotherapy

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Frontiers of Medicine 2012年第1期6卷 56-66页

作者： Min Cheng jian Zhang wen jiang Yongyan Chen Zhigang Tian Institute of Immunology Hefei National Laboratory for Physical Sciences at Microscale and School of Life SciencesUniversity of Science and Technology of ChinaHefei 230027China Institute of Immunopharmacology and Immunotherapy School of Pharmaceutical SciencesShandong UniversityJinan 250012China

Natural killer(NK)cells are considered to be critical players in anticancer ***,cancers are able to develop mechanisms to escape NK cell attack or to induce defective NK *** NK cell-based cancer immunotherapy is aimed at overcoming NK cell paralysis through several potential approaches,including activating autologous NK cells,expanding allogeneic NK cells,usage of stable allogeneic NK cell lines and genetically modifying fresh NK cells or NK cell *** stable allogeneic NK cell line approach is more practical for quality-control and large-scale ***,genetically modifying NK cell lines by increasing their expression of cytokines and engineering chimeric tumor antigen receptors could improve their specificity and *** this review,NK cells in tumor immunotherapy are discussed,and a list of therapeutic NK cell lines currently undergoing preclinical and clinical trials of several kinds of tumors are reviewed.

关键词： natural killer cell natural killer cell line tumor immunotherapy genetic modification

VIBRATION OF A SINGLE PROTEIN BUBBLE IN BINGHAM LIQUID

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Journal of Hydrodynamics 2009年第5期21卷 658-668页

作者： WANG Hai-min jiang Xu-ping MA jian-min ZHANG wen College of Power Engineering University of Shanghai for Science and Technology Shanghai 200093 China Department of Mechanics and Engineering Science Fudan University Shanghai 200433 China

The vibration of a single protein bubble may take place under the action of high pressure difference. In this process, the bubble wall may experience a finite deformation. The equation describing the dynamics of the protein bubble with viscoelastic film in Bingham liquid is derived. A numerical solution to this equation is carried out to study the effect of liquid pressure, the characteristic parameters of Bingham liquid and the viscosity of the protein film on the finite deformation of the bubble. The results show that the vibration of the protein bubble wall is caused by the action of pressure difference, the elastic stress in finite deformation and the dissipation of viscosity of the protein film and Bingham liquid. The vibration is nonlinear. Decreasing the pressure difference between gas and Bingham liquid on both sides of the protein bubble will lead to a change of vibration performance. The frequency and amplitude are reduced, tegether with the speed of vibration damping. In addition, the deformation rate of the bubble is smaller when the amplitude of vibration is reduced, which means shorter time to reach a balance state. On the other side, the increase of the magnitude of viscosity of the protein film or the plastic viscosity of Bingham liquid can restrain the vibration of the protein bubble wall in the course of finite deformation, as a result, the load bearing capacity of bubble is enhanced.

关键词： protein bubble Bingham liquid vibration finite deformation viscosity

Deep Multimodal Reinforcement Network with Contextually GuidedRecurrent Attention for Image Question Answering

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Journal of Computer Science & Technology 2017年第4期32卷 738-748页

作者： Ai-wen jiang Bo Liu Ming-wen Wang College of Computer and Information Engineering Jiangxi Normal University Nanchang 330022 China College of Computer Science and Software Engineering Auburn University Auburn AL36849 U.S.A.

Image question answering (IQA) has emerged as a promising interdisciplinary topic in computer vision and natural language processing fields. In this paper, we propose a contextually guided recurrent attention model for solving the IQA issues. It is a deep reinforcement learning based multimodal recurrent neural network. Based on compositional contextual information, it recurrently decides where to look using reinforcement learning strategy. Different from traditional 'static' soft attention, it is deemed as a kind of 'dynamic' attention whose objective is designed based on reinforcement rewards purposefully towards IQA. The finally learned compositional information incorporates both global context and local informative details, which is demonstrated to benefit for generating answers. The proposed method is compared with several state-of-the-art methods on two public IQA datasets, including COCO-QA and VQA from dataset MS COCO. The experimental results demonstrate that our proposed model outperforms those methods and achieves better performance.

关键词： image question answering recurrent attention deep reinforcement learning multimodal recurrent neural network multimodal fusion

Modeling of highly efficient drug delivery system induced by self-assembly of nanocarriers: A density functional study

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Science China Chemistry 2013年第2期56卷 249-255页

作者： jiang jian CAO DaPeng Division of Molecular and Materials Simulation State Key Lab of Organic-Inorganic Composites Beijing University of Chemical Technology

Owing to the importance of drug delivery in cancer or other diseases' therapy, the targeted drug delivery (TDD) system has been attracting enormous interest. Herein, we model the TDD system and design a novel rod-like nanocarrier by using the coarse grained model-based density functional theory, which combines a modified fundamental measure theory for the excluded-volume effects, Wertheim's first-order thermodynamics perturbation theory for the chain connectivity and the mean field approximation for van der Waals attraction. For comparison, the monomer nanocarrier TDD system and the no nanocarrier one are also investigated. The results indicate that the drug delivery capacity of rod-like nanocarriers is about 62 times that of the no nanocarrier one, and about 6 times that of the monomer nanocarriers. The reason is that the rod-like nanocarriers would self-assemble into the smectic phase perpendicular to the membrane surface. It is the self-assembly of the rod-like nanocarriers that yields the driving force for the targeted delivery of drugs inside the cell membrane. By contrast, the conventional monomer nanocarrier drug delivery system lacks the driving force to deliver the drugs into the cell membrane. In short, the novel rod-like nanocarrier TDD system may improve the drug delivery efficiency. Although the model in this work is simple, it is expected that the system may provide a new perspective for cancer targeted therapy.

关键词： interface polymers microstructure statistical thermodynamics self-assembly targeted drug delivery

Long-Time Behavior and Density Function of a Stochastic Chemostat Model with Degenerate Diffusion

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Journal of Systems Science & Complexity 2022年第3期35卷 931-952页

作者： GAO Miaomiao jiang Daqing wen Xiangdan College of Science China University of Petroleum(East China)Qingdao 266580China Key Laboratory of Unconventional Oil and Gas Development China University of Petroleum(East China)Ministry of EducationQingdao 266580China Nonlinear Analysis and Applied Mathematics(NAAM)-Research Group Department of MathematicsKing Abdulaziz UniversityJeddah 21589Saudi Arabia Department of Mathematics Yanbian UniversityYanji 133002China

This paper considers a stochastic chemostat model with degenerate ***,the Markov semigroup theory is used to establish sufficient criteria for the existence of a unique stable stationary *** authors show that the densities of the distributions of the solutions can converge in L^(1)to an invariant ***,conditions are obtained to guarantee the washout of the ***,through solving the corresponding Fokker-Planck equation,the authors give the exact expression of density function around the positive equilibrium of deterministic ***,numerical simulations are performed to illustrate the theoretical results.

关键词： Density function diffusion process Markov semigroups stochastic chemostat model washout