• Journal of the Korea Society for Simulation
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• v.12 no.3
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• pp.83-94
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• 2003

For 24 hours-7 days service on distributed systems, a great deal of efforts are investigated on high availability for seamless operation. In this paper, we propose a dynamic reconfiguration framework of distributed systems, called "hot-swapping" framework. This framework allows us to upgrade and exchange a number of modules of a distributed system without stopping running service as well as the system itself. In order to hide the state of service operation, the framework employes the "proxy" design pattern. Our framework provides two types of proxies: a static proxy and a dynamic proxy, Static proxies can achieve fast execution time, but they need to be changed whenever any minor change exists in the related swappable module. Meanwhile, dynamic proxies takes longer execution time, but do not need to be changed under minor changes of swappable modules. We compare performances of static and dynamic proxies and also apply the framework to a real situation with security management modules. management modules.

• Journal of Information Technology Services
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• v.4 no.1
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• pp.117-128
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• 2005

When we conduct development of a large-size SI project, it is highly necessary to utilize an appropriate application framework which helps to build a qualified software with high productivity in a short period of time. In this paper, we propose the architecture of a dynamically reconfigurable CBD application integration framework that has been used for developing large-scale e-business applications to achieve high development productivity and maintainability. This Integration framework can easily extend its functionalities, and dynamically change its configuration during run time according to the business category, such as applying interaction patterns among main components in software architecture, rules, policies, and environmental parameters. Dynamic reconfiguration has the feature to make applications be easily customized for changeable requirements. Through our application integration framework, huge sizes of contents can be managed according to the business category as well, by keeping configuration informations and huge volumes of source codes. In order to evaluate out application integration framework in terms of performance criteria, we present experimental results of throughputs from the framework by yielding dynamic configuration without any performance degradation.

• Nuclear Engineering and Technology
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• v.54 no.4
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• pp.1213-1220
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• 2022

The Emergency Diesel Generator (EDG) is a critical and essential part of the Nuclear Power Plant (NPP). Due to past catastrophic disasters, critical systems of NPP like EDG are designed to meet high dependability requirements. Therefore, we propose a framework for the dynamic reliability assessment using the Fault Tree and the Dynamic Bayesian Network. In this framework, the information of the component's failure probability is updated based on observed data. The framework is powerful to perform qualitative as well as quantitative analysis of the system. The validity of the framework is done by applying it on several NPP systems.

• Computational Structural Engineering
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• v.10 no.2
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• pp.243-254
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• 1997

When dynamic loads such as mechanical load, wind load, and seismic load, which causing a vibration, acts on the body of the 3-D framework resting on soil foundation, it is required to consider the dynamic behavior of soil-space framework interation system. Thus, this study presents the 3-dimensional soil-interaction system analyzed by finite element method using 4-node plate elements with flexibility, 2-node beam elements, and 8-node brick elements for the purpose of idealizing an actual structure into a geometric shape. The objective of this study is the formulation of the equation for a dynamic motion and the development of the finite element program which can analyze the dynamic behavior of soil-space framework interaction system.

• Journal of Information Technology Services
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• v.5 no.3
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• pp.165-172
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• 2006

In this paper, we designed a new type of X-internet framework by using Flash component and server service API and analyzed its performance. Proposed X-internet framework uses Flash MX Professional 2004, Java, and software which opened middleware and database. Since proposed framework use the server service API that we developed in this paper and Flash player, this framework does not need server module. Proposed framework enables to obtain design with dynamic user interface compare to Web application and enables to reduce development time. In analytical results, it has been shown that proposed x-internet framework have efficient characteristics such as network traffic, low development cost and dynamic user interface implementation. Since proposed X-internet framework can operate in environment of current developer friendly, it is useful for development of various new application programs and we confirm it through Flash web mail implementation by using proposed x-internet framework.

• Journal of Korea Multimedia Society
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• v.5 no.5
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• pp.488-493
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• 2002

MPEG-4 movies are composed of several media objects, organized in a hierarchical fashion. Those media objects are served to the clients as elementary streams. To play the movie, client players compose the elementary streams according to the meta- information called the scene graph. The meta-information streams are delivered as BIFS and OD elementary stream. Using dynamically generated BIFS and OD streams, we can provide a service something differs from traditional file services. For example, we can insert weather or stock information into the bottom of the screen while an existing movie was played in the screen. In this paper, we propose a dynamic service framework and dynamic server. Dynamic service framework is an object-oriented framework dynamically generating BIFS and OD streams based on the external DB information. Dynamic server provides a GUI for the server management and interface for registering dynamic services. In this framework, the dynamic service has the same interface as a file service. So, a dynamic service is considered as a file service by clients and other services.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05a
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• pp.486-489
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• 2006

This paper presents a newly proposed object-oriented finite element framework and its applications on dynamic analysis of plate girder bridge. The developed framework supports various types of finite elements, materials, constraints, loads, and solution methods. One major feature different from other object-oriented finite element programs is that static model and dynamic state can be easily read from or written to a file. In addition, the framework supports efficient DOF pattern handling for a node connecting elements with different DOF patterns, new multi-point constraint handling, and various scripting languages for easy use of the library. In order to show the applicability to dynamic analysis, dynamic moving load analysis on plate girder bridge is performed.

• Proceedings of the Korea Society for Simulation Conference
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• 2003.06a
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• pp.115-119
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• 2003

It requires a great deal of efforts to maintain a distributed system. What is important here is that we should be able to upgrade/maintain a distributed system without stopping the system in operation. For this, what we need is a dynamic reconfigurable framework for highly available distributed systems. In this paper, we propose objects-hot-swapping methods as a solution to our problem. These methods permit us to dynamically upgrade/expand a system without stopping the system in operation. In addition, we analyze these methods and show that an approach based on proxy is the most efficient. Furthermore, we propose two proxy-based approaches: the first one based on the static proxy provides for a fast execution time but it is difficult to implement. The second one based on the dynamic proxy provides for a slow execution time but it is easier to implement. Finally, we propose a hot swapping framework for these static and dynamic proxy.

• IEMEK Journal of Embedded Systems and Applications
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• v.3 no.3
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• pp.158-166
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• 2008

These days, mobile embedded systems adopt flash memory capable of XIP feature since they can reduce memory usage, power consumption, and software load time. XIP provides direct access to ROM and flash memory for processors. However, using XIP incurs unnecessary degradation of applications' performance because direct access to ROM and flash memory shows more delay than that to main memory. In this paper, we propose a memory management framework, dynamic XIP, which can resolve the performance degradation of using XIP. Using a constrained RAM cache, dynamic XIP can dynamically change XIP region according to page access pattern to reduce performance degradation in execution time or energy consumption resulting from native XIP problem. The proposed framework consists of a page profiler gathering applications' memory access pattern using PMU and an XIP manager deciding that a page is accessed whether in main memory or in flash memory. The proposed framework is implemented and evaluated in Linux kernel. Our evaluation shows that our framework can reduce execution time at most 25% and energy consumption at most 22% compared with using XIP-only case adopted in general mobile embedded systems. Moreover, the evaluation shows that in execution time and energy consumption, our modified LRU algorithm with code page filters can reduce more than at most 90% and 80% respectively compared with applying just existing LRU algorithm to dynamic XIP.

• Journal of Digital Convergence
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• v.6 no.1
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• pp.53-61
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• 2008

For the domestic digital contents, a proactive cooperation system or framework between the government, the businesses and research institutions, which would allow for free flow of interaction among these players, can play that role. We have proposed and realized the Dynamic Coordinating Framework(DCF) to bridge these gaps among the major players in the industry. The the Dynamic Coordinating Framework rests on the following major functions. The first major function of the DCF is to decipher any ambiguity that may be embedded in external inputs by stratified role and bias. The second function is to create cooperative groups that will deal with the ambiguities based on its consequent situation. The third is a feedback function that will draw out a new cooperative way by re-feeding the capacities and the conflicts that stem from the existing organizations and strategies into cooperation and adjustment process. Our DCF has compared and evaluated with England and Australia digital content industry models under AHP(Analytic Hierarchy Process) method. DCF has turned out to be well designed and have strong points based on OECD innovation and cooperation criteria.