• Journal of the Korea Society for Simulation
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• v.33 no.2
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• pp.1-11
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• 2024

A cyber-physical system is a technology that connects the physical systems of a manufacturing environment with a cyber space to enable simulation. One of the major challenges in this technology is the seamless communication between these two environments. In complex manufacturing processes, it is crucial to adapt to various protocols of manufacturing equipment and ensure the transmission and reception of a large volume of data without delays or errors. In this study, we propose a method for constructing agent models for real-time simulation-capable cyberphysical systems. To achieve this, we design data collection units as independent agent models and effectively integrate them with existing simulation tools to develop the overall system architecture. To validate the proposed structure and ensure reliability, we conducted empirical testing by integrating various equipment from a real-world smart microfactory system to assess the data collection capabilities. The experiments involved testing data delay and data gaps related to data collection cycles. As a result, the proposed approach demonstrates flexibility by enabling the application of various internal data collection methods and accommodating different data formats and communication protocols for various equipment with relatively low communication delays. Consequently, it is expected that this approach will promote innovation in the manufacturing industry, enhance production line efficiency, and contribute to cost savings in maintenance.

• Journal of The Korean Society of Integrative Medicine
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• v.8 no.1
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• pp.193-202
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• 2020

Purpose : The objective of this study was to provide information about the need and perception of continuing education(CE) according to gender in physical therapists. This study also aimed to provide basic data for the improvement of quality of the CE program with physical therapists. Methods : The study analyzed basic data from Korea Physical Therapy Association regarding the 350 physical therapists in Gwangju metropolitan city (Male; 102, female; 248). The questionnaire consisted of 3 categories: general characteristics, need of CE, and perception. For need of CE and perception, it assessed using a 5-point Likert scale. Data were analyzed using frequency analysis, and simple regression analysis using dummy variable. Results : The need of CE showed a weak positive correlation in the only the pediatric physical therapy according to gender in physical therapists (R²=.012) (p<.05). Both male and female physical therapists had the highest need in the musculoskeletal system, followed by nervous system. The perception of CE were not significantly correlated according to gender in physical therapists (p>.05). Both male and female physical therapists were high on the cyber-CE (Q4) and on the need for CE (Q1, Q2, Q3). Whereas, a lower score was found in category that CE helped in the performance of the work (Q6, Q7, Q8). Conclusion : In this study, there was little or no significant correlation between need and perception of CE according to gender in physical therapists. Both male and female physical therapists recognize the need for CE, whereas they are less satisfied the efforts of CE in the performance of the work. Therefore, improvement of CE through various programs should be made to enhance the perception of CE.

• Korean Journal of Computational Design and Engineering
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• v.20 no.4
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• pp.401-411
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• 2015

Cybrid virtual plant concept is defined as a cyber plant mimicking a physical plant by using plant engineering data and sensor data coming from sensors attached to facilities of the physical plant. Cybrid virtual plant is a new concept for plant industry so that plant managers and operators' requirements need to be captured for systematic application of the concept to the plant industry. The paper proposed an architecture of the cybrid virtual plant, and provided requirement analysis results for a specific plant company. A database, named smart-cube repository, for the proposed cybrid virtual plant is also proposed and its conceptual data structure is described.

• Electronics and Telecommunications Trends
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• v.31 no.6
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• pp.39-47
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• 2016

스마트팩토리의 세계시장 규모가 2015년 약 177조에서 2020년 약 437조까지 년 평균 20%씩 성장할 것으로 한 보고서는 예측하였다. 한국은 스마트팩토리 보급을 위해 2020년까지 스마트공장을 1만개까지 확산시킨다는 계획이다. 스마트팩토리의 핵심기술은 IoT와 사이버물리시스템(Cyber Physical System: CPS)으로 구성되고 이에 필요한 핵심 하드웨어는 센서소자/모듈, 무선 센서네트워크로 구성된다. 중소기업을 위한 스마트팩토리의 기본적인 구성요소와 통신구조를 논의한다. 그리고 일부 구성요소를 세 기업에 지원한 사례를 알아보고 스마트팩토리를 중소기업에 적용하는 방안 및 문제점을 논의한다.

• Review of KIISC
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• v.24 no.6
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• pp.7-13
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• 2014

사이버 물리 시스템(Cyber physical system, CPS)은 사물인터넷(IoT)과 달리 네트워크로 이루어진 물리적 장치들 간의 제어 및 통제를 포함하는 관리 시스템이다. 사이버물리시스템의 대표적인 사례인 헬스 케어 시스템은 시스템 내에서 다뤄지는 의료정보라는 데이터의 특별한 성격으로 인하여 데이터의 저장에서 관리까지 여러 가지 보안 위협들이 존재한다. 본 논문에서는 사이버 물리 시스템으로서의 헬스 케어 시스템이 클라우드 환경으로 이루어졌을 때 어떤 위협들이 존재하며 이러한 위협들이 어떻게 분류될 수 있는지, 또한 위협을 방지하기 위해 국내외 어떤 기술 및 표준화 노력들이 있었는지 알아보고자 한다.

• Information and Communications Magazine
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• v.29 no.10
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• pp.74-82
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• 2012

무선 센서 네트워크(WSN, Wireless Sensor Network)는 최근 주목 받고 있는 가상-물리 시스템 (CPS, Cyber-Physical System)의 입력을 담당하는 부분으로써 CPS를 구성하는 주요한 부분 중 하나이다. 본고에서는 기존의 배터리 기반 WSN의 짧은 수명 및 높은 유지관리 비용을 극복하기 위하여 최근 활발히 연구되고 있는 태양 에너지 기반 무선 센서 네트워크(SP-WSN, Solar-powered WSN)의 연구 동향과 이슈들을 살펴보고자 한다.

• Information and Communications Magazine
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• v.29 no.5
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• pp.98-105
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• 2012

본 논문에서는 최근 융합연구분야에서 많은 주목을 받고 있는 사이버물리시스템(Cyber-Physical System, CPS)에 관하여 살펴본다. 사이버 물리시스템은 전통적인 연구분야인 통신, 제어, 그리고 컴퓨팅을 아우르는 새로운 패러다임으로 전자공학 및 컴퓨터과학 내 다양한 연구분야들의 융합을 위한 토대를 제공하리라 예상된다. 특히 통신망의 관점에서 사이버 물리시스템에 관하여 살펴보도록 한다.

• Smart Media Journal
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• v.6 no.3
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• pp.95-102
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• 2017

A large volume of research has been devoted to the development of security tools for protecting the Smart Grid systems, however the most of them have not taken the Availability, Integrity, Confidentiality (AIC) security triad model, not like CIA triad model in traditional Information Technology (IT) systems, into account the security measures for the electricity control systems. Thus, this study would propose a novel security framework, an abnormal behavior detection system, to maximize the availability of the control systems by considering a unique set of characteristics of the systems.

• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.6
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• pp.611-618
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• 2016

The suggested paper studies communications network and system technology, designing data to sync to both USB memories and cloud storages at the same time, which would allow users to safely keep and manage data even in case of network troubles, affecting cloud storages, and/or loss of physical USB memories, resulting in lost data in the physical memory. The need of secure data management policy for cloud storage users form the basis of this study, offering solutions to network failures and loss of physical storage by creating hybrid cloud system. To provide convenience to windows users, the UI design should integrate that of windows explorer to maximize security and convenience.

• Journal of Electrical Engineering and Technology
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• v.12 no.1
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• pp.19-28
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• 2017

False data injection attacks have recently been introduced as one of important issues related to cyber-attacks on electric power grids. These attacks aim to compromise the readings of multiple power meters in order to mislead the operation and control centers. Recent studies have shown that if a malicious attacker has complete knowledge of the power grid topology and branch admittances, s/he can adjust the false data injection attack such that the attack remains undetected and successfully passes the bad data detection tests that are used in power system state estimation. In this paper, we investigate that a practical false data injection attack is essentially a cyber-attack with uncertain information due to the attackers lack of knowledge with respect to the power grid parameters because the attacker has limited physical access to electric facilities and limited resources to compromise meters. We mathematically formulated a method of identifying the most vulnerable locations to false data injection attack. Furthermore, we suggest minimum topology changes or phasor measurement units (PMUs) installation in the given power grids for mitigating such attacks and indicate a new security metrics that can compare different power grid topologies. The proposed metrics for performance is verified in standard IEEE 30-bus system. We show that the robustness of grids can be improved dramatically with minimum topology changes and low cost.