In the continuous“reshuffling”,the cosmetics industry has gone through the year of 2024.As dividends of the entire market vanish,the key to break the situation in the new year is to lay out new tracks and create new...In the continuous“reshuffling”,the cosmetics industry has gone through the year of 2024.As dividends of the entire market vanish,the key to break the situation in the new year is to lay out new tracks and create new products for brands.However,in 2024,the cosmetics filing market further declined,with a total of more than 550,000 new products registered and filed,a decrease of 3%compared to 2023.Specifically on the brand side,there were more“declining”:PROYA registered and filed 55 new products,down 9.8%year on year.展开更多
The healthcare sector involves many steps to ensure efficient care for patients,such as appointment scheduling,consultation plans,online follow-up,and more.However,existing healthcare mechanisms are unable to facilita...The healthcare sector involves many steps to ensure efficient care for patients,such as appointment scheduling,consultation plans,online follow-up,and more.However,existing healthcare mechanisms are unable to facilitate a large number of patients,as these systems are centralized and hence vulnerable to various issues,including single points of failure,performance bottlenecks,and substantial monetary costs.Furthermore,these mechanisms are unable to provide an efficient mechanism for saving data against unauthorized access.To address these issues,this study proposes a blockchain-based authentication mechanism that authenticates all healthcare stakeholders based on their credentials.Furthermore,also utilize the capabilities of the InterPlanetary File System(IPFS)to store the Electronic Health Record(EHR)in a distributed way.This IPFS platform addresses not only the issue of high data storage costs on blockchain but also the issue of a single point of failure in the traditional centralized data storage model.The simulation results demonstrate that our model outperforms the benchmark schemes and provides an efficient mechanism for managing healthcare sector operations.The results show that it takes approximately 3.5 s for the smart contract to authenticate the node and provide it with the decryption key,which is ultimately used to access the data.The simulation results show that our proposed model outperforms existing solutions in terms of execution time and scalability.The execution time of our model smart contract is around 9000 transactions in just 6.5 s,while benchmark schemes require approximately 7 s for the same number of transactions.展开更多
The size of the Audio and Video(AV)content of the 8K program is four times larger than that of 4K content,providing viewers with a more ideal audiovisual experience while placing higher demands on the capability and e...The size of the Audio and Video(AV)content of the 8K program is four times larger than that of 4K content,providing viewers with a more ideal audiovisual experience while placing higher demands on the capability and efficiency of document preparation and processing,signal transmission,and scheduling.However,it is difficult to meet the high robustness requirements of 8K broadcast services because the existing broadcast system architecture is limited by efficiency,cost,and other factors.In this study,an 8K Ultra-High-Definition(UHD)TV program broadcast scheme was designed.The verification results show that the scheme is high quality,highly efficient,and robust.In particular,in the research,the file format normalizing module was first placed in the broadcast area instead of the file preparation area,and the low-compression transmission scheme of the all-IP signal JPEG XS was designed in the signal transmission area for improving the efficiency of the scheme.Next,to reduce the impact on the robustness of broadcast services,the broadcast control logic of the broadcast core components is optimized.Finally,a series of 8K TV program broadcasting systems have been implemented and their performance has been verified.The results show that the system meets the efficiency and robustness requirements of a high-quality 8K AV broadcast system,and thus has a high degree of practicability.展开更多
In the era of Big Data, typical architecture of distributed real-time stream processing systems is the combination of Flume, Kafka, and Storm. As a kind of distributed message system, Kafka has the characteristics of ...In the era of Big Data, typical architecture of distributed real-time stream processing systems is the combination of Flume, Kafka, and Storm. As a kind of distributed message system, Kafka has the characteristics of horizontal scalability and high throughput, which is manly deployed in many areas in order to address the problem of speed mismatch between message producers and consumers. When using Kafka, we need to quickly receive data sent by producers. In addition, we need to send data to consumers quickly. Therefore, the performance of Kafka is of critical importance to the performance of the whole stream processing system. In this paper, we propose the improved design of real-time stream processing systems, and focus on improving the Kafka's data loading process.We use Kafka cat to transfer data from the source to Kafka topic directly, which can reduce the network transmission. We also utilize the memory file system to accelerate the process of data loading, which can address the bottleneck and performance problems caused by disk I/O. Extensive experiments are conducted to evaluate the performance, which show the superiority of our improved design.展开更多
ABSTRACT: This paper generalizes the makeup and forming dynamic mechanism of natural disaster systems, principles and methods of comprehensive division of natural disasters, as well as structure, function and up-build...ABSTRACT: This paper generalizes the makeup and forming dynamic mechanism of natural disaster systems, principles and methods of comprehensive division of natural disasters, as well as structure, function and up-build routes of map and file information visualization system (MFIVS). Taking the Changjiang(Yangtze) Valley as an example, on the basis of revealing up the integrated mechanism on the formations of its natural disasters and its distributing law, thereafter, the paper relies on the MFIVS technique, adopts two top-down and bottom-up approaches to study a comprehensive division of natural disasters. It is relatively objective and precise that the required division results include three natural disaster sections and nine natural disaster sub-sections, which can not only provide a scientific basis for utilizing natural resources and controlling natural disaster and environmental degradation, but also be illuminated to a concise, practical and effective technique on comprehensive division.展开更多
To overcome the traditional disadvantages, an improved FPGA-core based real-time video image acqui- sition and storage system is designed. The modular designed by Verilog programming is used for video decoding of A/D ...To overcome the traditional disadvantages, an improved FPGA-core based real-time video image acqui- sition and storage system is designed. The modular designed by Verilog programming is used for video decoding of A/D configuration, video image capturing logic control and image storage logic control modules. And IDE in- terface bard disk as storage medium and FAT32 file system as record form are used for real-time image storage. Experimental results show that the system has the advantages of strong real-time capability, high integration, powerful storage, easy expansibility and so on.展开更多
This paper describes a method for building hot snapshot copy based on windows-file system （HSCF）. The architecture and running mechanism of HSCF are discussed after giving a comparison with other on-line backup tecb...This paper describes a method for building hot snapshot copy based on windows-file system （HSCF）. The architecture and running mechanism of HSCF are discussed after giving a comparison with other on-line backup tecbnology. HSCF, based on a file system filter driver, protects computer data and ensures their integrity and consistency with following three steps： access to open files, synchronization and copy on-write. Its strategies for improving system performance are analyzed including priority setting, incremental snapshot and load balance. HSCF is a new kind of snapshot technology to solve the data integrity and consistency problem in online backup, which is different from other storage-level snapshot and Open File Solution.展开更多
Reduction of nitrate by zero-valent iron is a highly exergonic reaction that has long been known to occur. Use of scrap iron filings (SIF) as the PRB (Permeable Reactive Barrier) material can be used to recycle certai...Reduction of nitrate by zero-valent iron is a highly exergonic reaction that has long been known to occur. Use of scrap iron filings (SIF) as the PRB (Permeable Reactive Barrier) material can be used to recycle certain by-products, and identify cheaper replacements for expensive conventional PRB materials, especially pure metallic iron. The feasibility of reductive denitrification of nitrate by SIF was studied by batch experiments. Operational parameters such as pH value, SIF dosage and initial concentration of nitrate were investigated. The removal efficiency of nitrate reached 80% under the conditions of pH of 2.5, nitrate initial con- centration of 45 mg/L and SIF dosage of 100 g/L within 4 h. Results indicated that nitrate removal is inversely related to pH. Low pH value condition favors for the nitrate transformation. Different from the results of others who studied nitrate reduction using iron powder, we found that there was a lag time before nitrate reduction occurs, even at low pH. Finally, the possible mechanism of nitrate reduction by Fe0 is discussed.展开更多
Numerical simulation models of compact spinning with perforated drum, punched apron and lattice apron were established and computerized with computational fluid dynamics(CFD) software. Characteristics of airflow in co...Numerical simulation models of compact spinning with perforated drum, punched apron and lattice apron were established and computerized with computational fluid dynamics(CFD) software. Characteristics of airflow in condensing zone were achieved. Velocity vectors of the flow on different systems were contrasted and discussed. Then, trajectories of fibers in condensing zone were simulated by a specially designed MATLAB program routine. The result of the simulation clarified the compact mechanism of the compact spinning systems. Also, it applied a guideline for reasonable utilization of the airflow in condensing zone.展开更多
A dynamic Web application, which can help the departments of enterprise to collaborate with each other conveniently, is proposed. Several popular design solutions are introduced at first. Then, dynamic Web system is c...A dynamic Web application, which can help the departments of enterprise to collaborate with each other conveniently, is proposed. Several popular design solutions are introduced at first. Then, dynamic Web system is chosen for developing the file access and control system. Finally, the paper gives the detailed process of the design and implementation of the system, which includes some key problems such as solutions of document management and system security. Additionally, the limitations of the system as well as the suggestions of further improvement are also explained.展开更多
Online file management systems enable cooperatively editing and sharing.However,due to the cost of communication and storage infrastructures,traditional online file management services,e.g.,Google Drive and OneDrive,u...Online file management systems enable cooperatively editing and sharing.However,due to the cost of communication and storage infrastructures,traditional online file management services,e.g.,Google Drive and OneDrive,usually provide limited storage space and relatively low download speed for free users.To achieve better performance,ordinary users have to purchase their expensive services.Moreover,these file management systems are based on centralized architecture and bear the privacy leakage risk,because users’personal files are stored and controlled by their servers.To address the above problems,we propose a peer-to-peer(P2P)file management system based on IPFS and Hyperledger Fabric,named as FileWallet,which can serve as a personal wallet for individual users or organizations to store and share their files in a secure manner.In FileWallet,the users form a P2P network and a Fabric network,where P2P network builds the connections and distributed storage network and the Fabric network sustains consistent blockchain ledgers to record file operation related transactions.In our FileWallet,the storage and communication costs are mitigated in the decentralized design,and the file owner can fully control the access permission of the file to preserve the file privacy.The design of the system architecture,main functionalities,and system implementations are presented in this paper.The performance of the system is evaluated through experiments,and the experimental results show its wide applicability and scalability.展开更多
Byte-addressable non-volatile memory(NVM),as a new participant in the storage hierarchy,gives extremely high performance in storage,which forces changes to be made on current filesystem designs.Page cache,once a signi...Byte-addressable non-volatile memory(NVM),as a new participant in the storage hierarchy,gives extremely high performance in storage,which forces changes to be made on current filesystem designs.Page cache,once a significant mechanism filling the performance gap between Dynamic Random Access Memory(DRAM)and block devices,is now a liability that heavily hinders the writing performance of NVM filesystems.Therefore state-of-the-art NVM filesystems leverage the direct access(DAX)technology to bypass the page cache entirely.However,the DRAM still provides higher bandwidth than NVM,which prevents skewed read workloads from benefiting from a higher bandwidth of the DRAM and leads to sub-optimal performance for the system.In this paper,we propose RCache,a readintensive workload-aware page cache for NVM filesystems.Different from traditional caching mechanisms where all reads go through DRAM,RCache uses a tiered page cache design,including assigning DRAM and NVM to hot and cold data separately,and reading data from both sides.To avoid copying data to DRAM in a critical path,RCache migrates data from NVM to DRAM in a background thread.Additionally,RCache manages data in DRAM in a lock-free manner for better latency and scalability.Evaluations on Intel Optane Data Center(DC)Persistent Memory Modules show that,compared with NOVA,RCache achieves 3 times higher bandwidth for read-intensive workloads and introduces little performance loss for write operations.展开更多
Java technology is spreading rapidly all over the world in recent years. It is a popular application development language for its well-encapsulation, platform-independent and high security. There are great amounts of ...Java technology is spreading rapidly all over the world in recent years. It is a popular application development language for its well-encapsulation, platform-independent and high security. There are great amounts of Java games and other gadgets on mobile platforms, as well as on set-up-box systems. As Java applications become more sophisticated, the Java Virtual Machine (JVM) mid-dle-wares in embedded systems are not satisfying, Java-specific chips extend in the market. All existing Java-based system software or Operating System (OS) are used on JVM, they cannot be used on Java processors. It is important to develop a pure Java system software or OS so that embedded systems using Java processors will have great performance in Java applications. This paper presents a set of system software designed for a Java-specified processor VP6K, which is also a System-on-Chip (SoC). This system software includes real-time multitask dispatching, file management, device management, hardware drivers, and infrastructural Application Programming Interface (APIs). According to ex-perimental results, the system software provides interfaces for Java programs to fully handle CPU resource, so that all applications can be executed properly and efficiently. VP6K embedded platform shows its good performance for Java applications when the system software is implemented.展开更多
The bane of achieving a scalable distributed file sharing system is the centralized data system and single server oriented file [sharing] system. In this paper, the solution to the problems in a distributed environmen...The bane of achieving a scalable distributed file sharing system is the centralized data system and single server oriented file [sharing] system. In this paper, the solution to the problems in a distributed environment is presented. Thus, inability to upload sizeable files, slow transportation of files, weak security and lack of fault tolerance are the major problems in the existing system. Hence, the utmost need is to build a client-server network that runs on two or more server systems in order to implement scalability, such that when one server is down, the other(s) would still hold up the activities within the network. And to achieve this reliable network environment, LINUX network operating system is recommended among others as a preferred platform for the synchronization of the server systems, such that every user activity like sending of internal memos/mails, publication of academic articles, is replicated;thereby, achieving the proposed result. Hence, Scalable Distributed File Sharing System provides the robustness required to having a reliable intranet.展开更多
A new routing algorithm of peer-to-peer file sharing system with routing indices was proposed, in which a node forwards a query to neighbors that are more likely to have answers based on its statistics. The proposed a...A new routing algorithm of peer-to-peer file sharing system with routing indices was proposed, in which a node forwards a query to neighbors that are more likely to have answers based on its statistics. The proposed algorithm was tested by creating a P2P simulator and varying the input parameters, and was compared to the search algorithms using flooding （FLD） and random walk （RW）. The result shows that with the proposed design, the queries are muted effectively, the network flows are reduced remarkably, and the peer-to-peer file sharing system gains a good expansibility.展开更多
In order to improve the performance of peer-to-peer files sharing system under mobile distributed en- vironments, a novel always-optimally-coordinated （AOC） criterion and corresponding candidate selection algorithm ...In order to improve the performance of peer-to-peer files sharing system under mobile distributed en- vironments, a novel always-optimally-coordinated （AOC） criterion and corresponding candidate selection algorithm are proposed in this paper. Compared with the traditional min-hops criterion, the new approach introduces a fuzzy knowledge combination theory to investigate several important factors that influence files transfer success rate and efficiency. Whereas the min-hops based protocols only ask the nearest candidate peer for desired files, the selection algorithm based on AOC comprehensively considers users＇ preferences and network requirements with flexible balancing rules. Furthermore, its advantage also expresses in the independence of specified resource discovering protocols, allowing for scalability. The simulation results show that when using the AOC based peer selection algorithm, system performance is much better than the rain-hops scheme, with files successful transfer rate improved more than 50% and transfer time re- duced at least 20%.展开更多
Proxy Re-encryption(PRE) is greatly concerned by researchers recently. It potentially has many useful applications in network communications and file sharing. Secure distributed cryptographic file system is one of its...Proxy Re-encryption(PRE) is greatly concerned by researchers recently. It potentially has many useful applications in network communications and file sharing. Secure distributed cryptographic file system is one of its applications. But the practical applications of PRE are few. And even fewer of them are tested by systematically designed experiments. Appling a couple of representative algorithms proposed by BBS,Ateniese,Shao,et al.,a distributed file system is designed. In the system,some substitute mechanisms such as data dispersal,dynamic file sharing,are well-applied. A lot of features such as flexible authorization and data redundancy are embraced in the system. The comparison evaluation justified that the system is more practical and efficient.展开更多
In a peer-to-peer file-sharing system, a free-rider is a node which downloads files from its peers but does not share files to other nodes. Analyzing the free-riders’ impact on system throughputs is essential in exam...In a peer-to-peer file-sharing system, a free-rider is a node which downloads files from its peers but does not share files to other nodes. Analyzing the free-riders’ impact on system throughputs is essential in examining the performance of peer-to-peer file-sharing systems. We find that the free-riders’ impact largely depends on nodes behavior, including their online time and greed of downloading files. We extend an existing peer-to-peer system model and classify nodes according to their behavior. We focus on two peer-to-peer architectures: centralized indexing and distributed hash tables. We find that when the cooperators in a system are all greedy in downloading files, the system throughput has little room to increase while the cooperators throughput degrade badly with the increasing percent of greedy free-riders in the system. When all the cooperators are non-greedy with long average online time, the system throughput has much room to increase and the cooperators throughput degrade little with a high percent of greedy free-riders in the system. We also find that if a system can tolerate a high percent of greedy free-riders without suffering much throughput degradation, the system must contain some non-greedy cooperators that contribute great idle service capacity to the system.展开更多
In this paper, we explored a load-balancing algorithm in a cluster file system contains two levels of metadata-server, primary-level server quickly distributestasks to second-level servers depending on the closest loa...In this paper, we explored a load-balancing algorithm in a cluster file system contains two levels of metadata-server, primary-level server quickly distributestasks to second-level servers depending on the closest load-balancing information. At the same time, we explored a method which accurately reflect I/O traffic and storage of storage-node： computing the heat-value of file, according to which we realized a more logical storage allocation. According to the experiment result, we conclude that this new algorithm shortens the executing time of tasks and improves the system performance compared with other load algorithm.展开更多
This paper deeply discusses the design method of the File Transfer System(FTS)which is based on the File Transfer, Access and Management(FTAM) protocol standard, and probes into the construction principle of the Virtu...This paper deeply discusses the design method of the File Transfer System(FTS)which is based on the File Transfer, Access and Management(FTAM) protocol standard, and probes into the construction principle of the Virtual Filestore(VFS). Finally we introduce the implementation and the key technology of the FTS system.展开更多
文摘In the continuous“reshuffling”,the cosmetics industry has gone through the year of 2024.As dividends of the entire market vanish,the key to break the situation in the new year is to lay out new tracks and create new products for brands.However,in 2024,the cosmetics filing market further declined,with a total of more than 550,000 new products registered and filed,a decrease of 3%compared to 2023.Specifically on the brand side,there were more“declining”:PROYA registered and filed 55 new products,down 9.8%year on year.
基金supported by the Ongoing Research Funding program(ORF-2025-636),King Saud University,Riyadh,Saudi Arabia.
文摘The healthcare sector involves many steps to ensure efficient care for patients,such as appointment scheduling,consultation plans,online follow-up,and more.However,existing healthcare mechanisms are unable to facilitate a large number of patients,as these systems are centralized and hence vulnerable to various issues,including single points of failure,performance bottlenecks,and substantial monetary costs.Furthermore,these mechanisms are unable to provide an efficient mechanism for saving data against unauthorized access.To address these issues,this study proposes a blockchain-based authentication mechanism that authenticates all healthcare stakeholders based on their credentials.Furthermore,also utilize the capabilities of the InterPlanetary File System(IPFS)to store the Electronic Health Record(EHR)in a distributed way.This IPFS platform addresses not only the issue of high data storage costs on blockchain but also the issue of a single point of failure in the traditional centralized data storage model.The simulation results demonstrate that our model outperforms the benchmark schemes and provides an efficient mechanism for managing healthcare sector operations.The results show that it takes approximately 3.5 s for the smart contract to authenticate the node and provide it with the decryption key,which is ultimately used to access the data.The simulation results show that our proposed model outperforms existing solutions in terms of execution time and scalability.The execution time of our model smart contract is around 9000 transactions in just 6.5 s,while benchmark schemes require approximately 7 s for the same number of transactions.
文摘The size of the Audio and Video(AV)content of the 8K program is four times larger than that of 4K content,providing viewers with a more ideal audiovisual experience while placing higher demands on the capability and efficiency of document preparation and processing,signal transmission,and scheduling.However,it is difficult to meet the high robustness requirements of 8K broadcast services because the existing broadcast system architecture is limited by efficiency,cost,and other factors.In this study,an 8K Ultra-High-Definition(UHD)TV program broadcast scheme was designed.The verification results show that the scheme is high quality,highly efficient,and robust.In particular,in the research,the file format normalizing module was first placed in the broadcast area instead of the file preparation area,and the low-compression transmission scheme of the all-IP signal JPEG XS was designed in the signal transmission area for improving the efficiency of the scheme.Next,to reduce the impact on the robustness of broadcast services,the broadcast control logic of the broadcast core components is optimized.Finally,a series of 8K TV program broadcasting systems have been implemented and their performance has been verified.The results show that the system meets the efficiency and robustness requirements of a high-quality 8K AV broadcast system,and thus has a high degree of practicability.
基金supported by the Research Fund of National Key Laboratory of Computer Architecture under Grant No.CARCH201501the Open Project Program of the State Key Laboratory of Mathematical Engineering and Advanced Computing under Grant No.2016A09
文摘In the era of Big Data, typical architecture of distributed real-time stream processing systems is the combination of Flume, Kafka, and Storm. As a kind of distributed message system, Kafka has the characteristics of horizontal scalability and high throughput, which is manly deployed in many areas in order to address the problem of speed mismatch between message producers and consumers. When using Kafka, we need to quickly receive data sent by producers. In addition, we need to send data to consumers quickly. Therefore, the performance of Kafka is of critical importance to the performance of the whole stream processing system. In this paper, we propose the improved design of real-time stream processing systems, and focus on improving the Kafka's data loading process.We use Kafka cat to transfer data from the source to Kafka topic directly, which can reduce the network transmission. We also utilize the memory file system to accelerate the process of data loading, which can address the bottleneck and performance problems caused by disk I/O. Extensive experiments are conducted to evaluate the performance, which show the superiority of our improved design.
基金Under the auspices of President Foundation of the Chinese Academy of Sciences(1999).
文摘ABSTRACT: This paper generalizes the makeup and forming dynamic mechanism of natural disaster systems, principles and methods of comprehensive division of natural disasters, as well as structure, function and up-build routes of map and file information visualization system (MFIVS). Taking the Changjiang(Yangtze) Valley as an example, on the basis of revealing up the integrated mechanism on the formations of its natural disasters and its distributing law, thereafter, the paper relies on the MFIVS technique, adopts two top-down and bottom-up approaches to study a comprehensive division of natural disasters. It is relatively objective and precise that the required division results include three natural disaster sections and nine natural disaster sub-sections, which can not only provide a scientific basis for utilizing natural resources and controlling natural disaster and environmental degradation, but also be illuminated to a concise, practical and effective technique on comprehensive division.
基金Supported by the Research Fund of Shaanxi University of Technology(SLG0619)~~
文摘To overcome the traditional disadvantages, an improved FPGA-core based real-time video image acqui- sition and storage system is designed. The modular designed by Verilog programming is used for video decoding of A/D configuration, video image capturing logic control and image storage logic control modules. And IDE in- terface bard disk as storage medium and FAT32 file system as record form are used for real-time image storage. Experimental results show that the system has the advantages of strong real-time capability, high integration, powerful storage, easy expansibility and so on.
基金Supported by the National Natural Science Foun-dation of China (60473023) National Innovation Foundation forSmall Technology Based Firms(04C26214201280)
文摘This paper describes a method for building hot snapshot copy based on windows-file system （HSCF）. The architecture and running mechanism of HSCF are discussed after giving a comparison with other on-line backup tecbnology. HSCF, based on a file system filter driver, protects computer data and ensures their integrity and consistency with following three steps： access to open files, synchronization and copy on-write. Its strategies for improving system performance are analyzed including priority setting, incremental snapshot and load balance. HSCF is a new kind of snapshot technology to solve the data integrity and consistency problem in online backup, which is different from other storage-level snapshot and Open File Solution.
基金Project (No. 20407015) supported by the National Natural Sci-ence Foundation of China
文摘Reduction of nitrate by zero-valent iron is a highly exergonic reaction that has long been known to occur. Use of scrap iron filings (SIF) as the PRB (Permeable Reactive Barrier) material can be used to recycle certain by-products, and identify cheaper replacements for expensive conventional PRB materials, especially pure metallic iron. The feasibility of reductive denitrification of nitrate by SIF was studied by batch experiments. Operational parameters such as pH value, SIF dosage and initial concentration of nitrate were investigated. The removal efficiency of nitrate reached 80% under the conditions of pH of 2.5, nitrate initial con- centration of 45 mg/L and SIF dosage of 100 g/L within 4 h. Results indicated that nitrate removal is inversely related to pH. Low pH value condition favors for the nitrate transformation. Different from the results of others who studied nitrate reduction using iron powder, we found that there was a lag time before nitrate reduction occurs, even at low pH. Finally, the possible mechanism of nitrate reduction by Fe0 is discussed.
基金Fundamental Research Funds for the Central Universities,China(No.10D10101)
文摘Numerical simulation models of compact spinning with perforated drum, punched apron and lattice apron were established and computerized with computational fluid dynamics(CFD) software. Characteristics of airflow in condensing zone were achieved. Velocity vectors of the flow on different systems were contrasted and discussed. Then, trajectories of fibers in condensing zone were simulated by a specially designed MATLAB program routine. The result of the simulation clarified the compact mechanism of the compact spinning systems. Also, it applied a guideline for reasonable utilization of the airflow in condensing zone.
基金Supported by the National Natural Science Foun-dation of China (60503036)
文摘A dynamic Web application, which can help the departments of enterprise to collaborate with each other conveniently, is proposed. Several popular design solutions are introduced at first. Then, dynamic Web system is chosen for developing the file access and control system. Finally, the paper gives the detailed process of the design and implementation of the system, which includes some key problems such as solutions of document management and system security. Additionally, the limitations of the system as well as the suggestions of further improvement are also explained.
基金Key-Area Research and Development Program of Guangdong Province No.2020B0101090005National Natural Science Foundation of China under Grant No.62032013,and No.U20B2046+1 种基金111 Project(B16009)the Fundamental Research Funds for the Central Universities N182410001.
文摘Online file management systems enable cooperatively editing and sharing.However,due to the cost of communication and storage infrastructures,traditional online file management services,e.g.,Google Drive and OneDrive,usually provide limited storage space and relatively low download speed for free users.To achieve better performance,ordinary users have to purchase their expensive services.Moreover,these file management systems are based on centralized architecture and bear the privacy leakage risk,because users’personal files are stored and controlled by their servers.To address the above problems,we propose a peer-to-peer(P2P)file management system based on IPFS and Hyperledger Fabric,named as FileWallet,which can serve as a personal wallet for individual users or organizations to store and share their files in a secure manner.In FileWallet,the users form a P2P network and a Fabric network,where P2P network builds the connections and distributed storage network and the Fabric network sustains consistent blockchain ledgers to record file operation related transactions.In our FileWallet,the storage and communication costs are mitigated in the decentralized design,and the file owner can fully control the access permission of the file to preserve the file privacy.The design of the system architecture,main functionalities,and system implementations are presented in this paper.The performance of the system is evaluated through experiments,and the experimental results show its wide applicability and scalability.
基金supported by ZTE Industry⁃University⁃Institute Coopera⁃tion Funds under Grant No.HC⁃CN⁃20181128026.
文摘Byte-addressable non-volatile memory(NVM),as a new participant in the storage hierarchy,gives extremely high performance in storage,which forces changes to be made on current filesystem designs.Page cache,once a significant mechanism filling the performance gap between Dynamic Random Access Memory(DRAM)and block devices,is now a liability that heavily hinders the writing performance of NVM filesystems.Therefore state-of-the-art NVM filesystems leverage the direct access(DAX)technology to bypass the page cache entirely.However,the DRAM still provides higher bandwidth than NVM,which prevents skewed read workloads from benefiting from a higher bandwidth of the DRAM and leads to sub-optimal performance for the system.In this paper,we propose RCache,a readintensive workload-aware page cache for NVM filesystems.Different from traditional caching mechanisms where all reads go through DRAM,RCache uses a tiered page cache design,including assigning DRAM and NVM to hot and cold data separately,and reading data from both sides.To avoid copying data to DRAM in a critical path,RCache migrates data from NVM to DRAM in a background thread.Additionally,RCache manages data in DRAM in a lock-free manner for better latency and scalability.Evaluations on Intel Optane Data Center(DC)Persistent Memory Modules show that,compared with NOVA,RCache achieves 3 times higher bandwidth for read-intensive workloads and introduces little performance loss for write operations.
基金Supported by the Guangzhou Key Technology R&D Program (No. 2007Z2-D0011)
文摘Java technology is spreading rapidly all over the world in recent years. It is a popular application development language for its well-encapsulation, platform-independent and high security. There are great amounts of Java games and other gadgets on mobile platforms, as well as on set-up-box systems. As Java applications become more sophisticated, the Java Virtual Machine (JVM) mid-dle-wares in embedded systems are not satisfying, Java-specific chips extend in the market. All existing Java-based system software or Operating System (OS) are used on JVM, they cannot be used on Java processors. It is important to develop a pure Java system software or OS so that embedded systems using Java processors will have great performance in Java applications. This paper presents a set of system software designed for a Java-specified processor VP6K, which is also a System-on-Chip (SoC). This system software includes real-time multitask dispatching, file management, device management, hardware drivers, and infrastructural Application Programming Interface (APIs). According to ex-perimental results, the system software provides interfaces for Java programs to fully handle CPU resource, so that all applications can be executed properly and efficiently. VP6K embedded platform shows its good performance for Java applications when the system software is implemented.
文摘The bane of achieving a scalable distributed file sharing system is the centralized data system and single server oriented file [sharing] system. In this paper, the solution to the problems in a distributed environment is presented. Thus, inability to upload sizeable files, slow transportation of files, weak security and lack of fault tolerance are the major problems in the existing system. Hence, the utmost need is to build a client-server network that runs on two or more server systems in order to implement scalability, such that when one server is down, the other(s) would still hold up the activities within the network. And to achieve this reliable network environment, LINUX network operating system is recommended among others as a preferred platform for the synchronization of the server systems, such that every user activity like sending of internal memos/mails, publication of academic articles, is replicated;thereby, achieving the proposed result. Hence, Scalable Distributed File Sharing System provides the robustness required to having a reliable intranet.
文摘A new routing algorithm of peer-to-peer file sharing system with routing indices was proposed, in which a node forwards a query to neighbors that are more likely to have answers based on its statistics. The proposed algorithm was tested by creating a P2P simulator and varying the input parameters, and was compared to the search algorithms using flooding （FLD） and random walk （RW）. The result shows that with the proposed design, the queries are muted effectively, the network flows are reduced remarkably, and the peer-to-peer file sharing system gains a good expansibility.
基金supported by the National Nature Science Foundation of China(No.60672124)the National High Technology Research and Development Programme the of China(No.2007AA01Z221)
文摘In order to improve the performance of peer-to-peer files sharing system under mobile distributed en- vironments, a novel always-optimally-coordinated （AOC） criterion and corresponding candidate selection algorithm are proposed in this paper. Compared with the traditional min-hops criterion, the new approach introduces a fuzzy knowledge combination theory to investigate several important factors that influence files transfer success rate and efficiency. Whereas the min-hops based protocols only ask the nearest candidate peer for desired files, the selection algorithm based on AOC comprehensively considers users＇ preferences and network requirements with flexible balancing rules. Furthermore, its advantage also expresses in the independence of specified resource discovering protocols, allowing for scalability. The simulation results show that when using the AOC based peer selection algorithm, system performance is much better than the rain-hops scheme, with files successful transfer rate improved more than 50% and transfer time re- duced at least 20%.
基金supported by National Science Foundation of China (Grant No.60842006)
文摘Proxy Re-encryption(PRE) is greatly concerned by researchers recently. It potentially has many useful applications in network communications and file sharing. Secure distributed cryptographic file system is one of its applications. But the practical applications of PRE are few. And even fewer of them are tested by systematically designed experiments. Appling a couple of representative algorithms proposed by BBS,Ateniese,Shao,et al.,a distributed file system is designed. In the system,some substitute mechanisms such as data dispersal,dynamic file sharing,are well-applied. A lot of features such as flexible authorization and data redundancy are embraced in the system. The comparison evaluation justified that the system is more practical and efficient.
基金the National High Technology Re-search and Development Program (863) of China(No. 2007AA01Z457)the Shanghai Science and Technology Development Funds (No. 07QA14033)
文摘In a peer-to-peer file-sharing system, a free-rider is a node which downloads files from its peers but does not share files to other nodes. Analyzing the free-riders’ impact on system throughputs is essential in examining the performance of peer-to-peer file-sharing systems. We find that the free-riders’ impact largely depends on nodes behavior, including their online time and greed of downloading files. We extend an existing peer-to-peer system model and classify nodes according to their behavior. We focus on two peer-to-peer architectures: centralized indexing and distributed hash tables. We find that when the cooperators in a system are all greedy in downloading files, the system throughput has little room to increase while the cooperators throughput degrade badly with the increasing percent of greedy free-riders in the system. When all the cooperators are non-greedy with long average online time, the system throughput has much room to increase and the cooperators throughput degrade little with a high percent of greedy free-riders in the system. We also find that if a system can tolerate a high percent of greedy free-riders without suffering much throughput degradation, the system must contain some non-greedy cooperators that contribute great idle service capacity to the system.
基金Supported by the Industrialized Foundation ofHebei Province(020501) the Natural Science Foundation of HebeiUniversity(2005Q04)
文摘In this paper, we explored a load-balancing algorithm in a cluster file system contains two levels of metadata-server, primary-level server quickly distributestasks to second-level servers depending on the closest load-balancing information. At the same time, we explored a method which accurately reflect I/O traffic and storage of storage-node： computing the heat-value of file, according to which we realized a more logical storage allocation. According to the experiment result, we conclude that this new algorithm shortens the executing time of tasks and improves the system performance compared with other load algorithm.
文摘This paper deeply discusses the design method of the File Transfer System(FTS)which is based on the File Transfer, Access and Management(FTAM) protocol standard, and probes into the construction principle of the Virtual Filestore(VFS). Finally we introduce the implementation and the key technology of the FTS system.
