Tae Dong Lee

Service-oriented home network middleware based on OGSA

In this paper, we present a service-oriented home network middleware based on open grid service architecture. It supports two services: automatic distribution and dynamic migration schemes which shall be exploited efficiently in ubiquitous home networking environment. The deployment of Open Grid Service Architecture (OGSA) allows our system to have several advantages: adaptability, dynamic configuration, transparency, fault tolerance and performance. Automatic distribution service supports adaptability, dynamic configuration and transparency by providing automatic allocation and execution of home network platforms. Dynamic migration service supports fault tolerance and performance by migrating the processes in the failed server or with poor performance.

Distributed object-oriented wargame simulation on access grid

This paper presents the design and implementation of Distributed Object-oriented Wargame Simulation(DOWS) on Access Grid(AG). DOWS is an object-oriented distributed simulation system based on a director-actor model. DOWS on AG supports a collaborative environment by providing a virtual venue with high quality audio and real-time video interactive interface for remote users, and allows a groups of users in remote sites to easily participate in the whole simulation. We design an efficient communication scheme between application and AG so that DOWS can be incorporated on AG for collaboration purpose.

HLA-based object-oriented modeling/simulation for military system

This paper presents an HLA-based Object-oriented modeling/Simulation for Tank-helicopter combat system (HOST) which can be efficiently used for evaluation of tactics and weapon system for tank/helicopter combat. HOST is a distributed combat (tank-to-tank, tank-to-helicopter) simulation based on High Level Architecture (HLA). We design and implement an object-oriented simulation engine which can provide an unified interface to a set of interfaces for entities in HOST by using facade pattern. We design a domain specific object model (DOM) for tank-helicopter combat system based on CMMS (Conceptual Model of the Mission Space) and UML (Unified Modeling Language). We shall show how CMMS can be used to aid the design of use case diagram in UML, and presents various diagrams such as use case, class, sequence, state chart diagram in UML, which help users develop the relevant models in HLA. We shall also show how to adapt the domain specific object model to HLA by the efficient design of FOM (Federation Object Model) and TMM (Time Management Model). TMM provides time-stepped, event-driven and optimistic time models in graphic and text modes. In a graphic mode, inner federate time management (Inner-FTM) and inter federate time management (Inter-FTM) are used. Inner-FTM achieves synchronization by coordinating local objects and visualization, and Inter-FTM by coordinating federates and visualization respectively. The object-oriented design of our domain specific object model in HOST provides users with modification, extensibility, flexibility through abstraction, encapsulation and inheritance. Moreover, HLA-based model in HOST allows our system to be plugged in other HLA-compliant system, and extended into more complex system by providing reusability and interoperability

Fast image registration for multisensor fusion using graphics hardware

This paper presents a fast image registration using graphics hardware for image fusion of high resolution aerial images taken by different sensors. The GPU (Graphics Processing Unit) provides high-performance compared to its price and executes rapid computation by supporting parallel architectures. Fast image registration should be gone ahead to execute high-speed fusion of high resolution aerial images. Our approach is based on clustering techniques using parameter space, but we estimate the number of feature consensus pairs in the feature space according to change of parameter values instead of conversion over the parameter space. To extract feature points, we modified the filter which has been used for TNO fusion method based on image information and frequency. Furthermore, we reduce the search range of mapping parameters, and utilize multi-resolution methods to alleviate high computational cost.We implemented all processes for automatic image registration on programmable graphics hardware, the speed of GPU-based registration increased double compared to CPUpsilas.

Context-Aware home network environment on grid (CAHE-G)

In this paper, we present context-aware home network environment on grid that controls the room appliances providing user mobility. The current home network technology (such as Havi, Jini and UPnP) is limited to a static local area. However, we propose ubiquitous concepts of home network system of user mobility in context-aware computing. It is called as CAHE-G which is not limited to static local area, but provides ubiquitous concepts of home network. CAHE-G controls home appliances according to context information, and is divided into two parts: Agent layer and Service layer. The Service layer consists of Lookup Service (LUS), Home Controller, Grid Service Provider (GridSP). The Service layer provides home and grid services with user request. LUS provides searching and registering those services. The Agent layer consists of Grid Agent (GA) and Home Context Agent (HCA). Grid technology can be used to automatically execute the home network service depending on context information. Agent layer provides user ubiquity, autonomous execution and large computation in this system. GA consists of Execution Manager (EM), MDS Manager (MM), and File Manager (FM) in order to enable those functionalities. Also, HCA provides autonomous adaptability to user. It gathers and interprets context information, then assigns the information to GA. As a result, in CAHE-G, Grid computing provides the capabilities: autonomous execution, interoperability, and the standard approaches to, and mechanisms for basic problems. Moreover, context-aware characteristic gives merits such as user mobility and adaptability.

Service-Oriented RunTime Infrastructure on Grid

The HLA (High Level Architecture) is a blueprint to use to develop the necessary infrastructure in order to promote interoperability and reusability within the modeling and simulation community. RTI (RunTime Infrastructure), software implementation of HLA, is composed of three components: libRTI, FedExec, and RTIExec. RTI is a middleware that supports dynamic, many-to-many communication in a distributed environment. Running a large-scale distributed simulation may need a large amount of computing resources at geographically. Such environment raises serious security concerns and dynamic coordination concerns. Motivated by these concerns, we have developed the RTI that can overcome these problems using Open Grid Services Architecture (OGSA) inside Globus Toolkit3(GT3). We call it service-oriented RTI-G. In this paper, we illustrate the structure of the service-oriented RTI on Grid and how it can solve the mentioned problems.

RTI execution environment using open grid service architecture

HLA(High Level Architecture) has been developed to promote interoperability and reusability within the modeling and simulation community. RTI(Run Time Infrastructure) is a software implementation of HLA which is composed of three components: libRTI, FedExec, and RTIExec. However, the previous RTI has an unfriendly execution environment with static and manual resource allocation and execution. In the paper, we present a RTI execution environment using OGSA(Open Grid Service Architecture) which addresses the problems, so called RTI-G. It supports easy-to-useness, transparency and performance by providing users with dynamic resource allocation and automatic execution. Moreover, it provides an unified view of RTI and Grid services by integrating them as web services on OGSA.

Distributed object-oriented web-based simulation

This paper presents the design and implementation of Distributed Object-oriented Web-based Simulation (DOWS). DOWS is an object-oriented simulation system based on a new concept, a director-actor model. It also models a distributed simulation as a collection of actor objects running concurrently at different nodes. DOWS is implemented using Java objects which interact with each other through Java RMI. Each director object is implemented as web client which downloads and executes the proper applet from a HTTP server, and hence DOWS provides a web-enabled simulation environment which allows users to easily instantiate the simulation model using the HTTP server. The whole simulation can be speed up by decomposing the simulation model into several submodels and mapping them onto the actors. DOWS also provides an efficient virtual real time simulation environment which integrates the coordination among actors by supporting time synchronization, simulation message transfer, and network fault detection.