Ruey-Kai Sheu

A relaxable service selection algorithm for QoS-based web service composition

Context: Web Services are emerging technologies that enable application to application communication and reuse of autonomous services over Web. Composition of web services is a concept of integrating individual web services to conduct complex business transactions based on functionality and performance constraints Objective: To satisfy user requirements, technologies of Quality of service (QoS)-based web service composition (QWSC) are widely used to build complex applications by discovering the best-fit web services in term of QoS. Method: In this paper, a QoS-based service selection (RQSS) algorithm is proposed to help composite web application development by discovering feasible web services based on functionalities and QoS criteria of user requirements. The RQSS recommends prospective service candidates to users by relaxing QoS constraints if no suitable or available web service could exactly fulfill user requirements. Results: A generic framework is implemented to demonstrate the feasibility and performance of RQSS by adapting WS-BPEL standards, and can be reused for QoS-based web composition applications. Conclusion: The experimental results show that the RQSS algorithm indeed performs well and increases the system availability and reliability.

CUDT: A CUDA Based Decision Tree Algorithm

Decision tree is one of the famous classification methods in data mining. Many researches have been proposed, which were focusing on improving the performance of decision tree. However, those algorithms are developed and run on traditional distributed systems. Obviously the latency could not be improved while processing huge data generated by ubiquitous sensing node in the era without new technology help. In order to improve data processing latency in huge data mining, in this paper, we design and implement a new parallelized decision tree algorithm on a CUDA (compute unified device architecture), which is a GPGPU solution provided by NVIDIA. In the proposed system, CPU is responsible for flow control while the GPU is responsible for computation. We have conducted many experiments to evaluate system performance of CUDT and made a comparison with traditional CPU version. The results show that CUDT is 5∼55 times faster than Weka-j48 and is 18 times speedup than SPRINT for large data set.

Scaling database performance on GPUs

The market leaders of Cloud Computing try to leverage the parallel-processing capability of GPUs to provide more economic services than traditions. As the cornerstone of enterprise applications, database systems are of the highest priority to be improved for the performance and design complexity reduction. It is the purpose of this paper to design an in-memory database, called CUDADB, to scale up the performance of the database system on GPU with CUDA. The details of implementation and algorithms are presented, and the experiences of GPU-enabled CUDA database operations are also shared in this paper. For performance evaluation purposes, SQLite is used as the comparison target. From the experimental results, CUDADB performs better than SQLite for most test cases. And, surprisingly, the CUDADB performance is independent from the number of data records in a query result set. The CUDADB performance is a static proportion of the total number of data records in the target table. Finally, this paper comes out a concept of turning point that represents the difference ratio between CUDADB and SQLite.

A new architecture for integration of CORBA and OODB

Object oriented database system (OODB) supports an object oriented data model with the functionality of persistency and transaction semantics. In order to facilitate the use of OODB, the Object Database Management Group (ODMG) defined a standard for object database management systems. On the other hand, the Object Management Group (OMG) defined the Common Object Request Broker Architecture (CORBA), which is an emerging standard of distributed object technology providing the interconnection network between distributed objects. For the sake of matching these two object models, taking the advantages of merging both of them, and building a more sophisticated infrastructure, the integration of CORBA and OODB is currently an urgent and important issue in distributed object systems. Instead of using Object Database Adapter (ODA) suggested by the ODMG, we provide a novel way of reusing the Object Transaction Service (OTS) and wrapping techniques to introduce OODB into CORBA automatically. Through our design, CORBA clients or OODB object implementers do not need to learn any knowledge of each other. In addition, error recovery is also provided to guarantee the consistency of object states. The whole task for integrating CORBA and OODB is done transparently by our proposed preprocessor, which plays an important role in solving problems encountered by ORB and OODB vendors easily.

A Generic Application Sharing Architecture Based on Message-Oriented Middleware Platform

Previous application sharing systems have no unified communication protocols. The well known application sharing protocols include RFB (Remote FrameBuffer), RDP (Remote Desktop Protocol) and ITU-T T.128. A generic application sharing architecture is proposed for providing the capability of connecting various application sharing servers with the same application sharing client. A communication standard for application sharing systems is defined based on the Message-Oriented Middleware (MOM). To compare with previous application sharing systems, there are many advantages including easy to use, easy to connect, easy to integrate, higher scalability and less bandwidth consumption.

Managing and sharing collaborative files through WWW

Abstract The increasing complexity and geographical separation of design data, tools and teams have demanded for a collaborative and distributed management environment. In this paper, we present a practical system, the CFMS, which is designed to manage collaborative files on WWW. Wherever remote developers are, they can navigate the evolutions and relationships between target files, check in and check out them conveniently on web browsers using CFMS. The capabilities of CFMS include the two-level navigation mechanism for version selection, the relationship model that conceptually manages the relationships between physical files as well as the prefix-based naming scheme that can uniquely identify requested objects.

Design and Implementation of File Deduplication Framework on HDFS

File systems are designed to control how files are stored and retrieved. Without knowing the context and semantics of file contents, file systems often contain duplicate copies and result in redundant consumptions of storage space and network bandwidth. It has been a complex and challenging issue for enterprises to seek deduplication technologies to reduce cost and increase the storage efficiency. To solve such problem, researchers proposed in-line or offline solutions for primary storages or backup systems at the subfile or whole-file level. Some of the technologies are used for file servers and database systems. Fewer studies focus on the cloud file system deduplication technologies at the application level, especially for the Hadoop distributed file system. It is the goal of this paper to design a file deduplication framework on Hadoop distributed file system for cloud application developers. The architecture, interface, and implementation experiences are also shared in this paper.

MEDEA-a model for the event-based data exchange architecture

Traditional data interchange mechanisms are based on the client-server model, which has been confronted with a plethora of problems. For example, bilateral partners must exchange data sets through recognized protocols. Whenever the data set is updated, data interchange participants have to rebuild their protocols as well as applications. It is really a considerable problem for system maintenance or scalability. We propose an event-based data exchange model, called MEDEA, to solve the problems encountered by traditional data exchange systems. The designed MEDEA data exchange framework and the learned experiences are also detailed.

A generic application sharing architecture based on message-oriented middleware platform

Previous application sharing systems have no unified communication protocols. The well known application sharing protocols include RFB (remote framebuffer), RDP (remote desktop protocol) and ITU-T T.128. A generic application sharing architecture is proposed for providing the capability of connecting various application sharing servers with the same application sharing client. A communication standard for application sharing systems is defined based on the message-oriented middleware (MOM). To compare with previous application sharing systems, there are many advantages including easy to use, easy to connect, easy to integrate, higher scalability and less bandwidth consumption

Object finding system based on RFID technology

Locations of moving or missing objects are getting important information for context-aware applications which try to get the locality of an object, and then provide services pertaining to the object. To position an object, most systems use a predefined coordinate to compute object location while sensing the appearance of the target object. Usually, it is troublesome and costs much to define the base coordinate in advance for most object positioning systems, especially when the target object is locating in an unknown environment. To reduce the cost and complexity of object locating system and improve the accuracy of location, this paper proposed an Object Finding System based on RFID technology to identify the localities of target objects in buildings. In this paper, we introduce the design concepts of the proposed system as well as the algorithms used to calculate the object locations. In addition, the experimental results show that it is a feasibility study.