• Journal of Internet Computing and Services
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• v.9 no.5
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• pp.73-83
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• 2008

This paper proposes an implementation of an orchestration service of web services, which work as context aware applications in Ubiquitous Computing. The proposed method alms to decrease the cost of adapting to the context changes. UC requires the context adaptation more than any other computing environments, and it works based on networks of various heterogeneous platforms. Web services on SOA could be one of the solutions for the requirements. This paper proposes the way how to implement an orchestration service of SOA to handle the context adaptation while keeping the performance high. We develops an implementation model of orchestration services of web services, and the model decreases the number of code lines of the orchestration service. This paper also shows a simple empirical study, and it also analyzes two different method implementing the polymorphism, overloading and overriding.

• Journal of the Korea Society for Simulation
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• v.23 no.4
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• pp.143-150
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• 2014

Cloud computing is fast becoming the wave of the future for both home and business computing. Because of this growing acceptance, we can expect an explosion of diverse cloud service providers in the coming years. However, the cloud is not a single entity, rather it is a set of many disconnected islands of application (SaaS), infrastructure (IaaS), and different platform (PaaS) services. Cloud brokering mechanisms are essential to transform the heterogeneous cloud market into a commodity-like service. Cloud service brokers (CSBs) are the new form of business entities to help to aggregate the scattered set of cloud services and make conveniently available to their diverse users. CSBs can reserve a certain percentage of their clients' (users') demand and satisfy the remaining portion in an on-demand basis. In doing so, they need to minimize cost of both reserved and on-demand instances as well as the distance of a link between the cloud service provider (CSP) and the user. The study proposes a reservation approach with a mixed integer model to optimizes the cloud service cost and quality.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.6
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• pp.1101-1105
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• 2006

Ubiquitous computing network comprises a variety of distributed service devices. Today Web services technology enables the heterogeneous devices to provide their own services and interact with each other via well-defined Internet protocol. Nevertheless, service devices in ubiquitous environments require more event-driven, autonomous interaction beyond rather passive service-oriented architecture of the present time. This paper presents an ECA (Event-Condition-Action) rule description language in an attempt to support capability for autonomous interactions among service-oriented devices in ubiquitous computing network. Specifically, the proposed WS-ECA is an XML-based ECA rule description language for web service-enabled devices. The rules are embedded in distributed devices which invoke appropriate services in the network if the rules are triggered by some internal or external events. The presented ECA-based device coordination approach is expected to facilitate seamless inter-operation among the web service-enabled devices in the emerging ubiquitous computing environment.

• Journal of KIISE:Computing Practices and Letters
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• v.15 no.9
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• pp.649-660
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• 2009

To deliver services suitable to user's situation in the ubiquitous environment, the researches on realizing new services by combining existing ones have been continuously increased. But, it is difficult to provide the personalized services to each user located in the ubiquitous service space where multiple users coexist. In this paper, we propose a service composition model based on user-centered service scenarios and a system for providing personalized services through finding services suitable to user's situation and combining them. The proposed system supports a simple service discovery protocol for finding services from heterogeneous smart objects with limited computing power in the ubiquitous environment. The system aggregates and stores various service scenarios and data derived from users and executes the appropriate services for users. We design and implement a prototype system for the mobile personal device.

• Journal of Internet Computing and Services
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• v.13 no.6
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• pp.63-74
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• 2012

In this paper, we develop an integrated management/monitoring system that supports to dynamically reconfigure information models for systems or applications managed by heterogeneous distributed systems. When the subsystems on diverse platforms are added, removed, or modified, the altered configurations should conform to the configuration information of the integrated management/monitoring system. Further, upon the system configurations being changed, the altered system configurations should be synchronized with the information on the integrated management/monitoring system. Moreover, availability should be assured during synchronization to the extent that users can access the monitoring information with no system halting. This paper focuses on notifying the integrated management/monitoring system of any changes in hardware/software configurations on any subsystems under its management, and on dynamically re-configuring the information about hardware and software being managed based on the information notified. Finally, we expect that this research will be contributory to carrying out reliable integrated management by reflecting the information on any heterogeneous distributed systems in the integrated management/monitoring system.

• Journal of KIISE:Computing Practices and Letters
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• v.10 no.6
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• pp.484-498
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• 2004

In this paper. we propose a novel performance monitoring scheme for heterogeneous SOAP nodes. The scheme is basically based on two-level (kernel-level and user-level) packet filtering of TCP flows. By TCP flow, we mean a sequence of raw packet streams on a TCP transaction. In this scheme, we detect and extract SOAP operations embedded in SOAP messages from TCP flows. Therefore, it becomes possible to monitor heterogeneous SOAP nodes deployed on diverse SOAP-based middlewares such as .Net and Apache AXIS. We present two implementation mechanisms for the proposed scheme. The first mechanism tries to identify SOAP operations by analyzing all fragmented SOAP messages on TCP flows. However, a naive policy would incur untolerable overhead since it needs to copy all packets from kernel to user space. The second mechanism overcomes this problem by selectively copying packets from kernel to user space. For selective copying, we use a kernel-level packet filtering method that makes use of some representative TCP flags.(e.g. SIN, FIN and PSH). In this mechanism, we can detect SOAP operations only from the last fragment of SOAP messages in most cases. Finally, we implement a SOAP monitoring system using a component ca]led SOAP Sniffer that realizes our proposed scheme, and show experimental results. We strongly believe that our system will play a vital role as a tool for various services such as transaction monitoring and load balancing among heterogeneous SOAP nodes.

• Journal of KIISE:Software and Applications
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• v.29 no.1_2
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• pp.30-41
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• 2002

We focus on the mobile agents which are considered as new paradigm to solve information retrieval of large volumes of data in the distributed and heterogeneous environment. The mobile agent moves the computation to data instead of large volumes of data to computations. In this paper, we propose an information retrieval model, which can effectively search data in the distributed and heterogeneous environment, using mobile agents. Our model is applied to the design and implementation of an Q&A(Question and Answer) retrieval system. Our Q&A retrieval system, called QASSMA(Q&A Search System using Mobile Agents), uses mobile agents to retrieve articles from Q&A boards and newsgroups that exist in the heterogeneous and distributed environment. QASSMA has the following features and advantages. First, the mobile retrieval agent moves to the destination server to retrieve articles to reduce the retrieval time by eliminating data traffics from the server to the client host. Also it can reduce the traffic that was occurred in the centralized network system, and reduce the usage of resources by sending its agent and running in the destination host. Finally, the mobile retrieval agent of QASSMA can add and update dynamically the class file according to its retrieval environment, and support other retrieval manner. In this paper, we have shown that our Q&A retrieval system using mobile agents is more efficient than the retrieval system using static agents by our experiments.

• Journal of Digital Contents Society
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• v.8 no.2
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• pp.107-112
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• 2007

With the evolution to distributed computing technology, the concept of conventional client/server function has been advanced to Service-Oriented Architecture, which can share the information between heterogeneous systems as services. To success Service-Oriented Architecture, the conjunction between business layer and application layer is one of the important techniques. In this paper, we classify services into two views, vertical and horizontal, and introduce matching technique with service classification for SOA.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.4
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• pp.819-833
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• 2013

Computing global features based on local features using a bio-inspired framework has shown promising performance. However, for some tough applications with large intra-class variances, a single local feature is inadequate to represent all the attributes of the images. To integrate the complementary abilities of multiple local features, in this paper we have extended the efficacy of the bio-inspired framework, HMAX, to adapt heterogeneous features for global feature extraction. Given multiple global features, we propose an approach, designated as parameterized metric learning, for high dimensional feature fusion. The fusion parameters are solved by maximizing the canonical correlation with respect to the parameters. Experimental results show that our method achieves significant improvements over the benchmark bio-inspired framework, HMAX, and other related methods on the Caltech dataset, under varying numbers of training samples and feature elements.

• Journal of Information Technology Services
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• v.10 no.4
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• pp.219-227
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• 2011

Service Oriented Architecture (SOA) is rapidly emerging as the efficient approach in contemporary complex, heterogeneous computing environments. SOA increases the adaptability by loose coupling and its main feature is that three elements such as service provider, service requester and service registry are connected with each other systematically. To design the service-oriented system efficiently, a metric to measure the coupling between services accurately is needed. In this paper, we propose four coupling metrics for SOA based softwares. First, we suggest a coupling metric for service-oriented systems by modifying an established coupling metric of object-oriented systems. Then we suggest another coupling metric which includes indirect coupling between services. We also suggest two relative coupling metrics to measure coupling between subsystems. We investigate the theoretical soundness of the proposed metrics by the axioms of Briand et al. Finally, we apply the presented metrics to an industrial-scale case study.