• KIPS Transactions on Software and Data Engineering
• /
• v.2 no.8
• /
• pp.507-516
• /
• 2013

Mobile devices have limited computing power and resources. Since mobile devices are equipped with rich network connectivity, an approach to subscribe cloud services can effectively remedy the problem, which is called Mobile Cloud Computing (MCC). Most works on MCC depend on a method to offload functional components at runtime. However, these works only consider the limited verion of offloading to a pre-defined, designated node. Moveover, there is the limitation of managing services subscribed by applications. To provide a comprehensive and practical solution for MCC, in this paper, we propose a self-stabilizing process and its management-related methods. The proposed process is based on an autonomic computing paradigm and works with diverse quality remedy actions such as migration or replicating services. And, we devise a pratical offloading mechanism which is still in an initial stage of the study. The proposed offloading mechanism is based on our proposed MCC meta-model. By adopting the self-stabilization process for MCC, many of the technical issues are effectively resolved, and mobile cloud environments can maintain consistent levels of quality in autonomous manner.

• Journal of KIISE:Computing Practices and Letters
• /
• v.11 no.5
• /
• pp.436-450
• /
• 2005

Existing B2B, B2C computer systems and applications that executed business trans-actions were the client- server based architecture which consists of heterogeneous hardware and software including personal computers and mainframes. Due to the active boom of electronic business, integration and compatibility of exchanged data, applications and hardwares have emerged as hot issue. This paper designs and implements a message transport system and a document transformation system in order to solve the interoperability problem of integrated logistics system in e-Business when doing electronic business. Message transport system integrated ebMS 2.0 which is standard business message exchange format of ebXML, the international standard electronic commerce framework, and JMS of J2EE enable to ensure reliable messaging. The document transformation system could convert non-standard XML documents into standard XML documents and provide the web services after integrating message system. Using suggested business scenario and various test data, our message oriented system preyed to be interoperable and stable. We participated ebXML messaging interoperability test organized by ebXML Asia Committee ITG in oder to evaluate and certify the suitability for message system.

• Journal of Internet Computing and Services
• /
• v.5 no.5
• /
• pp.1-15
• /
• 2004

In this paper, we explain the design and implementation of GWB(Gene WorkBench), which is a web-based, integrated system for efficiently managing and analyzing genomic sequences, Most existing software systems handling genomic sequences rarely provide both managing facilities and analyzing facilities. The analysis programs also tend to be unit programs that include just single or some part of the required functions. Moreover, these programs are widely distributed over Internet and require different execution environments. As lots of manual and conversion works are required for using these programs together, many life science researchers suffer great inconveniences. in order to overcome the problems of existing systems and provide a more convenient one for helping genomic researches in effective ways, this paper integrates both managing facilities and analyzing facilities into a single system called GWB. Most important issues regarding the design of GWB are how to integrate many different analysis programs into a single software system, and how to provide data or databases of different formats required to run these programs. In order to address these issues, GWB integrates different analysis programs byusing common input/output interfaces called wrappers, suggests a common format of genomic sequence data, organizes local databases consisting of a relational database and an indexed sequential file, and provides facilities for converting data among several well-known different formats and exporting local databases into XML files.

• Journal of Broadcast Engineering
• /
• v.24 no.1
• /
• pp.118-131
• /
• 2019

In order to provide 8K UHD contents of terrestrial broadcasting with a large capacity, the terrestrial broadcasting system has various problems such as limited bandwidth and so on. To solve these problems, UHD contents transmission technology has been actively studied, and an 8K UHD broadcasting system using terrestrial broadcasting network and communication network has been proposed. The proposed technique is to solve the limited bandwidth problem of terrestrial broadcasting network by segmenting 8K UHD contents and transmitting them to heterogeneous networks through hierarchical separation. Through the terrestrial broadcasting network, the base layer corresponding to FHD and the additional enhancement layer data for 4K UHD are transmitted, and the additional enhancement layer data corresponding to 8K UHD is transmitted through the communication network. When 8K UHD contents are provided in such a way, user can receive up to 4K UHD broadcasting by terrestrial channels, and also can receive up to 8K UHD additional communication networks. However, in order to transmit the 4K UHD contents within the allocated bit rate of the domestic terrestrial UHD broadcasting, the compression rate is increased, so a certain level of image deterioration occurs inevitably. Due to the nature of UHD contents, video quality should be considered as a top priority over other factors, so that video quality should be guaranteed even within a limited bit rate. This requires packet scheduling of content generators in the broadcasting system. Since the multiplexer sends out the packets received from the content generator in order, it is very important to make the transmission time and the transmission rate of the process from the content generator to the multiplexer constant and accurate. Therefore, we propose a variable transmission scheduler between the content generator and the multiplexer to guarantee the image quality of a certain level of UHD contents in this paper.

• Journal of KIISE:Software and Applications
• /
• v.36 no.9
• /
• pp.732-748
• /
• 2009

The technology of Semantic Web realizes the base technology for context-awareness that creates new services by dynamically and flexibly combining various resources (people, concepts, etc). According to the realization of ubiquitous computing technology, many researchers are currently working for the embodiment of web service. However, most studies of them bring about the only predefined results those are limited to the initial description by service designer. In this paper, we propose a new service supporting model to provide an automatic method for plan related tasks which achieve goal state from initial state. The inputs on an planner are intial and goal descriptions which are mapped to the current situation and to the user request respectively. The idea of the method is to infer context from world model by DL-based ontology reasoning using OWL domain ontology. The context guide services to be loaded into planner. Then, the planner searches and plans at least one service to satisfy the goal state from initial state. This is STRIPS-style backward planner, and combine OWL-S services based on AI planning theory that enabling reduced search scope of huge web-service space. Also, when feasible service do not find using pattern matching, we give user alternative services through DL-based semantic searching. The experimental result demonstrates a new possibility for realizing dynamic service modeler, compared to OWLS-XPlan, which has been known as an effective application for service composition.

• KIPS Transactions on Software and Data Engineering
• /
• v.6 no.2
• /
• pp.103-116
• /
• 2017

In this paper, we present the design and implementation of a large-scale qualitative spatial reasoner, which can derive new qualitative spatial knowledge representing both topological and directional relationships between two arbitrary spatial objects in efficient way using Aparch Spark SQL. Apache Spark SQL is well known as a distributed parallel programming environment which provides both efficient join operations and query processing functions over a variety of data in Hadoop cluster computer systems. In our spatial reasoner, the overall reasoning process is divided into 6 jobs such as knowledge encoding, inverse reasoning, equal reasoning, transitive reasoning, relation refining, knowledge decoding, and then the execution order over the reasoning jobs is determined in consideration of both logical causal relationships and computational efficiency. The knowledge encoding job reduces the size of knowledge base to reason over by transforming the input knowledge of XML/RDF form into one of more precise form. Repeat of the transitive reasoning job and the relation refining job usually consumes most of computational time and storage for the overall reasoning process. In order to improve the jobs, our reasoner finds out the minimal disjunctive relations for qualitative spatial reasoning, and then, based upon them, it not only reduces the composition table to be used for the transitive reasoning job, but also optimizes the relation refining job. Through experiments using a large-scale benchmarking spatial knowledge base, the proposed reasoner showed high performance and scalability.

• KIPS Transactions on Software and Data Engineering
• /
• v.4 no.5
• /
• pp.209-218
• /
• 2015

BPEL is used in various domains since it can describe the flow of works according to conditions and rules, and it can call web services in service-oriented computing environments. However, new functions that are not provided by BPEL grammar are required in specific domains. Generally, when new functions are required, the domain-specific language should be newly defined and developed, which requires high development cost. In this regard, a new function needs to be defined and added instead of developing domain-specific language with the new functions added. However, such methods only allow an addition of a single function, and it is difficult to design and add new functions according to the needs. This paper defines XAS4B document, which extends the BPEL grammar function through XML schema in order to add new functions, and proposes BPEL engine generator that generates BPEL engine with the new functions added by processing the document. The XAS4B document enables the creation of a new grammar added to BPEL using XML schema. It also shows the process of adding new functions to BPEL engine using AspectJ, JAVA implementation of aspect-oriented programming. The proposed system can add new functions using AspectJ without modifying BPEL engine. This allows the provision of new functions at low cost in various domains.

• Journal of KIISE:Computer Systems and Theory
• /
• v.27 no.5
• /
• pp.485-495
• /
• 2000

The parallel computer system that uses parallel program on the application such as a large scale business or complex operation is required. One of crucial operation of parallel computer system is synchronization. A representative method of synchronization is barrier synchronization. A barrier forces all process to wait until all the process reach the barrier and then releases all of the processes. There are software schemes, hardware scheme, or combinations of these mechanism to achieve barrier synchronization which tends to use hardware scheme. Besides, barrier synchronization lets parallel computer system fast because it has fewer start-up overhead. In this paper, we propose a new switch module that can implement fast and fault-tolerant barrier synchronization in hardware scheme. A proposed barrier synchronization is operated not in full-switch-driven method but in processor-driven method. An effective barrier synchronization is executed with inexpensive hardware supports. Therefore, a new proposed hardware barrier synchronization is designed that it is operated in arbitrary network topology. In this paper, we only show comparison of barrier synchronization on Multistage Interconnection Network. This research results in 24.6-24.8% reduced average delay. Through this result, we can expect lower average delay in irregular network.

• Journal of KIISE:Software and Applications
• /
• v.36 no.3
• /
• pp.187-199
• /
• 2009

With the advent of Web 2.0, OpenAPIs are becoming an increasing trend to emphasize Web as platform recently. OpenAPIs are used to combine services and generate new services by mashup. However because the standard documents for OpenAPIs do not exist, it may restrict the use of OpenAPIs. Previous studies of OpenAPIs mashup have been limited to tool design or language definition for service combination rather than dynamic composition. On the other hand, Web services that are a software technology implementing SOA provide standard documents such as WSDL to explain each service, UDDI to register it, and SOAP to transfer messages. Thus Web applications can interpret and execute services by using these technologies. Recent works have also been performed to provide semantic features and dynamic composition for SOA. If a dynamic and systematic approach is provided to combine Web services and OpenAPIs, Web applications can provide users with diverse services. In this study, we present a SOA based framework for mashup of OpenAPIs and Web services. The framework supports dynamic composition of OpenAPIs and Web services, where the process of composite services is described in OWL-S. A prototype is provided to validate our framework. The framework is expected to add diversity to typical Web services.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.12 no.6
• /
• pp.33-42
• /
• 2012

Rapid evolution of wired and wireless technologies results in various types of embedded systems, and the software to be embedded into those devices now needs the flexibility rather than the fixedness which was well-known property for the embedded software in the past. Mobile agent is one of the useful distributed technologies of reducing network load and latency because of its disconnected operations and high asynchrony. In this paper, a component-based mobile agent framework, called EmHUMAN, is designed and implemented for structural embedding into the devices showing different functions and resource constraints. It consists of 3 layers of components. Based on those components, a structural embedding, considering resource constraints of required functions, amount of storage space, computing power, network bandwidth, ${\ldots} $ etc can be performed. The components in each layer can be extended with addition of new components, removing some components and modifying components. EmHUMAN plays the role of a framework for developing mobile agent based distributed systems. It is also a mobile agent system by itself. EmHUMAN provides several utilities as built-in API's, and thus high effectiveness in programming mobile agents can be achieved.