• Computers and Concrete
• /
• v.8 no.3
• /
• pp.327-341
• /
• 2011

Three-dimensional graphic objects created by MATLAB are exported to the AUTOCAD program through the MATLAB handle functions. The imported SAT format files are used to produce the finite element mesh for MSC.PATRAN. Based on the Monte-Carlo random sample principle, the material heterogeneity of cement composites with randomly distributed fibers is described by the WEIBULL distribution function. In this paper, a concept called "soft region" including micro-defects, micro-voids, etc. is put forward for the simulation of crack propagation in fiber-reinforced cement composites. The performance of the numerical model is demonstrated by several examples involving crack initiation and growth in the composites under three-dimensional stress conditions: tensile loading; compressive loading and crack growth along a bimaterial interface.

• 제어로봇시스템학회:학술대회논문집
• /
• 2005.06a
• /
• pp.31-36
• /
• 2005

Intelligent Space (iSpace) is the space where many intelligent devices, such as computers and sensors, are distributed. According to the cooperation of many intelligent devices, the environment comes to have intelligence. In iSpace, the locations of multiple humans and other objects are obtained and tracked by using multiple camera and color-based method. In addition, we describe a context-aware information system which is based on Spatial-Knowledge-Tags (SKT). SKT system enables humans to access information and data by using spatial location of human and stored information in storage. The proposed tracking method is applied to the intelligent environment and its performance is verified by the experiments.

• Proceedings of the IEEK Conference
• /
• 2000.11c
• /
• pp.169-172
• /
• 2000

Recently, the advent of World-Wide-Web(WWW) and the explosive popularity of the Internet gave birth to collaborative applications which were enabled by computers and networks as their primary media. And the progress of 3D computer graphics enabled collaborative application with 3D virtual environments or distributed virtual environments. In this paper, we explain our implementation of Share collaboration engine and Virtual Architectural Engineering 2000 (VAE2000) system which is our pilot application implemented with Share collaboration engine. And we explain problems presented by our experiments with VAE2000 system. For those problems, we design our new middle-ware system, SHINE(SHared INternet Environment). The SHINE proposes new concepts and approaches for collaboration with 3D objects in a virtual world.

• Journal of the Korea Computer Industry Society
• /
• v.2 no.6
• /
• pp.845-852
• /
• 2001

Electronic commerce and application service is to universal on the internet, and a large quantity information transmitted on the network, It's needs procedure to access only permit objects for the integrity of information. In order to provide regional services is authentication for control resource and client identification. In particular, public key system is to implement in distributed environment, it is able to insurance users convenience and integrity at the same time. In this paper designed mechanism of cross certification between realms in PKI based on X.509 associated with DNS (Domain Name System) that is presented.

• Korean Journal of Computational Design and Engineering
• /
• v.4 no.4
• /
• pp.360-370
• /
• 1999

The paper proposed a basic architecture of an agent system to support exchange and sharing of design informations by means of ACL(Agent Communication Language) which can represent design informations and knowledges. Based on the architecture of the agent system a ship initial design agent system was implemented in order to show the effectiveness of the agent-based system. The basic architecture of the agent consists of an ACL handlerand CORBA(Common Object Request Broker Architecture) objects for the exchange of ACL messages in the heterogeneous and distributed environment. The ACL handler can process expressions of knowledge and manage communication messages among the agents. The paper mainly focuses on the implementation of the ACL handler. The ACL handler consist of a KQML(Knowledge Query and Manipulation Language) handler that manages KQML messages, a conversation module, and a content handler that handles message contents. The conversation modulo implements conversation policies and checks all messages if they are allowable and meaningful messages based on the conversation policies. The implemented agent-based system was applied to the ship initial design to show the handling procedure of the agent system.

• International Journal of Fuzzy Logic and Intelligent Systems
• /
• v.7 no.1
• /
• pp.41-48
• /
• 2007

Latest advances in network sensor technology and state of the art of mobile robot, and artificial intelligence research can be employed to develop autonomous and distributed monitoring systems. In this study, as the preliminary step for developing a multi-purpose "Intelligent Space" platform to implement advanced technologies easily to realize smart services to human. We will give an explanation for the ISpace system architecture designed and implemented in this study and a short review of existing techniques, since there exist several recent thorough books and review paper on this paper. Instead we will focus on the main results with relevance to the DIND data fusion with CI of Intelligent Space. We will conclude by discussing some possible future extensions of ISpace. It is first dealt with the general principle of the navigation and guidance architecture, then the detailed functions tracking multiple objects, human detection and motion assessment, with the results from the simulations run.

• Journal of the Korea Computer Industry Society
• /
• v.8 no.2
• /
• pp.113-122
• /
• 2007

Recently, there are many research interests in providing efficient, temporal and spatial distribution multimedia streaming service. This paper proposed a temporal and spatial object grouping method for distribution multimedia streaming service. The proposed method performs the grouping structure by filtering and mapping with the collected frame object in application domains and it's peformed by JM relationship with the mapped frame objects. The results show that the performance provides the better than the other methods.

• Journal of the Korean Society for Precision Engineering
• /
• v.20 no.2
• /
• pp.120-128
• /
• 2003

When considering the use of rapid prototyping (RP), there are many issues a designer has to address for handling an STL model, the de facto standard fur RP. Today designers can skip all these issues by visiting web-based service bureaus that readily supply needed information for the RP services. Since orders are taken for RP parts through the web page of service providers designers are now asked to upload their STL files to the company server either by direct upload, ftp file transfer, or as an e-mail attachment. If the service bureau, however, fixes or edits an STL filceto optimize the RP process but neglects to tell its customer about the rework in detail, it may cause problems down the line in processing of the original CAD data for other applications. In this paper, we propose a framework for a collaborative virtual environment between CAD designers and RP processes on the internet which directly provides designers with an advanced preprocessor functionality, design visualization, as well as model display, repair, and slicing over the network. This can help smooth data transfer from CAD to RP process with minimum inconsistency in CAD.

• Proceedings of the Korean Information Science Society Conference
• /
• 2007.10c
• /
• pp.102-106
• /
• 2007

최근에 이동객체에 대한 위치기반서비스는 서비스영역이 확대되고, 이를 사용하는 사용자가 늘어남으로써 원활한 서비스를 위하여 시스템의 분산처리가 요구되고 있다. 기존의 방식은 분산처리를 위하여 서비스영역을 분할하는 방식으로 전체 서비스의 영역을 보다 적은 영역으로 분할하며 여러 개의 서버가 각각의 영역을 담당하는 형태로 처리한다. 그러나 이러한 기존의 방식에서는 사용자의 핫스팟, 폭주로 인한 특정서버에 과부하가 발생되는 일어나는 문제점을 갖고 있다. 본 논문에서는 이러한 문제점을 해결하기 위하여 또한 특정서버에서 과부하 발생하면 동시성 제어를 필요로 하지 않는 모듈만을 비 과부하 서버에 이전하는 기법을 통하여 효율적으로 과부하를 분산하여 처리한다. 또한 제안하는 기법은 각각 다른 서버에 의해 제어되는 구역에 있는 사용자들 간에 실시간 서비스를 제공한다. 제안된 기법은 다양한 성능평가를 통하여 제안한 기법의 우수성을 보인다.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.21 no.2
• /
• pp.435-446
• /
• 1996

In this paper, we present database model of directory systems that perform a task for distributed information repositories in communication network environments. A new model is developed through four phase: (1) A diretory database information is classified that would be stored in directory database as user, administrative, and supplementary information. (2) The modeling criteria are captured that would be used to model information classified. (3) Object-Oriented concepts are used in modeling classified information according to modeling criteria captured. (4) Methods applied to developed model are grouped, and active-based mechanisms such as trigger and constraints are developed. These selected methods and attributes are encapsulated into objects. Consequently they compose an Active Object-Oriented Directory Database Model.