• Journal of the Korean Society for Precision Engineering
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• v.12 no.10
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• pp.57-68
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• 1995

An upper bound elemental technique (UBET) program has been developed to predict forging load, die-cavity filling, preform in non-axisymmetric forging. To analyze the process easily, it is suggested that the deformation is divided into two different parts. Those are axisymmetric part in corner, plane-strain part in lateral. The plane-strain and axisymmetric parts are combined by building block method. And the total energy is computed through combination of three deformation parts. A dumbbell-type preform has been obtained from height and volumetric compensations of the billet based on the backward simulation. Experimetns have been carried out with pure plasticine at room temperature. Theoretical predictions are in good agreement with expereimental results.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.4 no.4
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• pp.547-559
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• 2010

As web-based online communities are rapidly growing, the agents in the communities need to know their measurable belief of trust for safe and successful interactions. In this paper, we propose a computational model of trust resulting from available feedbacks in online communities. The notion of trust can be defined as an aggregation of consensus given a set of past interactions. The average trust of an agent further represents the center of gravity of the distribution of its trustworthiness and untrustworthiness. Furthermore, we precisely describe the relationships among reputation, trust and average trust through concrete examples showing their computations. We apply our trust model to online social networks in order to show how trust mechanisms are involved in the rational purchasing decision-making of buyers and sellers, and we summarize our simulation results.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.9 no.3
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• pp.161-165
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• 2009

Increase of multimedia information in Web requires a new method to manage and service multimedia documents efficiently. This paper proposes a conceptual object grouping method by fuzzy filtering, which is automatically constituted based on increase of multimedia documents. The proposed method composes subsumption relations between conceptual objects automatically using fuzzy filtering of the document objects that are extracted from domains. Grouping of such conceptual objects is regarded as subsumption relation which is decided by $\mu$-cut. This paper proposes $\mu$-cut, FAS(Fuzzy Average Similarity) and DSR(Direct Subsumption Relation) to decide fuzzy filtering, which groups related document objects easily. This paper used about 1,000 conceptual objects in the performance test of the proposed method. The simulation result showed that the proposed method had better retrieval performance than those for OGM(Optimistic Genealogy Method) and BGM(Balanced Genealogy Method).

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.05a
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• pp.86-89
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• 2002

Recently, video conferencing, Web-casting service, and network sane service which use multicast-based service are popular in Internet. In order to support the broadband Internet services efficiently, more communication bandwidth are needed. The WDM single-hop broadcast network topology is coming into the spotlight in next-generation access networks area. In this paper, the new multicast scheduling algorithm, PGM, is proposed and is evaluated through the computer simulation. The PGM method shows the better performance comparing with existing multicast scheduling algorithm.

• IE interfaces
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• v.16 no.1
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• pp.63-69
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• 2003

Virtual Manufacturing is a technology facilitating effective development and agile production of products via computer models representing physical and logical schema and the behavior of the real manufacturing systems including manufacturing resources, environments and products. For the successful application of this technology, a virtual factory as a well-designed and integrated environment is essential. To construct a virtual factory in effective and concurrent manners, a supporting information infrastructure for managing diverse models of virtual factory is very important. In this paper, we constructed the web-based information management system for many engineering activities related with a virtual factory. Using this system, users can handle all information and diverse digital files including attributes, parameters, 3-D CAD files, simulation models, and etc. of a cell, line and whole factory. We expect that this information management system for a virtual factory helps us achieve great time savings and advances in accuracy for construction and maintenance activities of virtual factories.

• Proceedings of the Korean Information Science Society Conference
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• 2006.10a
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• pp.113-118
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• 2006

고등학교 수학과 교육과정에서의 ‘확률과 통계'단원은 실제로 자료의 수집과 요약을 통하여 자료 분석방법을 배우고 사회와 자연현상을 인식하고 추론하는 능력을 기르는데 목표를 두고 있다. 추상적인 수학내용을 직접 시도하거나 학생들이 실제적인 자료를 수집하고 직접 자료를 해석하고 추론해 보는 경험과정은 수학실험과 시뮬레이션이라는 컴퓨터 학습을 통해 가능하고 개념학습의 전 단계에서 보다 구성적이고 탐구적인 활동을 강화할 수 있다. 본 논문에서는 ‘확률과 통계'의 교수-학습과정에서 수학적 시뮬레이션을 활용한 웹 기반 학습모형을 제시하여 학습자들에게 수학적 내용과 관련된 구체적 매체를 조작하는 컴퓨터 실험 활동을 통하여 수학에서의 원리발견과 통계적 추론을 경험하고 유도할 수 있는 탐구적 학습 환경을 조성해 보고자 한다.

• Steel and Composite Structures
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• v.21 no.6
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• pp.1251-1264
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• 2016

After observing relatively poor performance of bolted web-welded flange beam-to-column connections during 1994 Northridge earthquake, various types of connections based on two concepts of: (i) strengthening the connection; and (ii) weakening the beam ends were proposed. Among these modified or newly proposed connections, bolted T-stub connection follows the concept of strengthening. One of the connections with the idea of weakening the beam ends is reduced beam section (RBS). In this paper, finite element simulation is used to study the cyclic behavior of a new proposed connection developed by using a combination of both mentioned concepts. Investigated connections are exterior beam-to-column connections designed to comply with AISC provisions. The results show that moment capacity and dissipated energy of the new proposed connection is almost the same as those computed for a T-stub connection and higher than corresponding values for an RBS connection.

• International Journal of Computer Science & Network Security
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• v.22 no.8
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• pp.1-6
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• 2022

In this paper, we will present the realization of a facial recognition system using the ESP32-CAM board controlled by an Arduino board. The goal is to monitor a remote location in real time via a camera that is integrated into the ESP32 IOT board. The acquired images will be recorded on a memory card and at the same time transmitted to a pc (a web server). The development of this remote monitoring system is to create an alternative between security, reception, and transmission of information to act accordingly. The simulation results of our proposed application of the facial recognition domain are very efficient and satisfying in real time.

• Journal of Information Processing Systems
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• v.5 no.2
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• pp.69-76
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• 2009

Self healing systems are considered as cognation-enabled sub form of fault tolerance system. But our experiments that we report in this paper show that self healing systems can be used for performance optimization, configuration management, access control management and bunch of other functions. The exponential complexity that results from interaction between autonomic systems and users (software and human users) has hindered the deployment and user of intelligent systems for a while now. We show that if that exceptional complexity is converted into self-growing knowledge (policies in our case), can make up for initial development cost of building an intelligent system. In this paper, we report the application of AHSEN (Autonomic Healing-based Self management Engine) to in OKKAM Project infrastructure backbone cluster that mimics the web service based architecture of u-Zone gateway infrastructure. The 'blind' load division on per-request bases is not optimal for distributed and performance hungry infrastructure such as OKKAM. The approach adopted assesses the active threads on the virtual machine and does resource estimates for active processes. The availability of a certain server is represented through worker modules at load server. Our simulation results on the OKKAM infrastructure show that the self healing significantly improves the performance and clearly demarcates the logical ambiguities in contemporary designs of self healing infrastructures proposed for large scale computing infrastructures.

• Journal of Internet Computing and Services
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• v.21 no.6
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• pp.123-132
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• 2020

The EDucation-research Integration through Simulation On the Net (EDISON) platform, which is a web-based platform that provides computational science and engineering simulation execution environments, can offer various analysis environments to students, general users, as well as computational science and engineering researchers. To expand the user base of the simulation environment services, the EDISON platform holds a challenge every year and attempts to increase the competitiveness and excellence of the platform by analyzing the user requirements of the various simulation environment offered. The challenge platform system in the field of computational science and engineering is provided to users in relation to the simulation service used in the existing EDISON platform. Previously, EDISON challenge servicesoperated independently from simulation services, and hence, services such as end-user review and intermediate simulation results could not be linked. To meet these user requirements, the currently in-service challenge platform for computational science and engineering is linked to the existing computational science and engineering service. In addition, it was possible to increase the efficiency of service resources by providing limited services through various analyses of all users participating in the challenge. In this study, by analyzing the simulation and usage environments of users, we provide an improved challenge platform; we also analyze ways to improve the simulation execution environment.