• Asia-Pacific Journal of Business
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• v.14 no.3
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• pp.25-44
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• 2023

Receiving medical services abroad is an event that involves a high level of risk and stress for most people. This study proposes and empirically examines perceived control as a factor that has a potential to reduce the stress associated with overseas medical experience and enhance satisfaction with it. Based on the research findings in environmental psychology, one's perceived control was divided into cognitive control, behavior control, and decision control. A research model and a set of hypotheses were constructed to investigate the effect of each control on satisfaction and word-of-mouth communications among consumers who had overseas medical service experiences. The data collection was conducted through an online survey of 220 Chinese consumers who had visited Korea as plastic medicine tourists. Satisfaction with their service experience was significantly affected by both behavioral control and decisional control, but not by cognitive control. Thus, Chinese medical tourists prefer to maintain the belief that they are in charge of major decisions associated with the medical procedure, and that the results of the medical procedure will have personally desirable consequences. In addition, satisfaction experienced by Chinese consumers with overseas medical services had a significant impact on their word-of-mouth activities. Based on the research results, a set of academic and practical implications were derived.

• Journal of the Korea Society for Simulation
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• v.3 no.2
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• pp.1-13
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• 1994

Deep reasoning procedures are model-based, inferring single or multiple causes and/or timing relations from the knowledge of behavior of component models and their causal structure. The overall goal of this paper is to develop an automated deep reasoning methodology that exploits deep knowledge of structure and behavior of a system. We have proceeded by building a software environment that uses such knowledge to reason from advanced symbolic simulation techniques introduced by Chi and Zeigler. Such reasoning system has been implemented and tested on several examples in the domain of performance evaluation, and event-based control.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.59-59
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• 2000

In this paper, we present a framework for modeling and control of multiple mobile robots which cowork within a bounded workspace and limited resources. To achieve this goal, we adopt a formalism of discrete event system and supervisory control theory based on Petri nets. We can divide our whole story into two parts: first, we search the shortest path using the distance vector algorithm, and then we construct the control scheme from which a number of mobile robots can work within a bounded workspace without any collision. The use of Petri net modeling allows us In synthesize a controller which achieves a control specification for the desired closed-loop behavior efficiently. Finally, the usefulness of the proposed Petri net formalism is illustrated by a simulation study.

• Proceedings of the KIEE Conference
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• 1990.07a
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• pp.100-105
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• 1990

Associated with the protection and control functions in the substations, a new network scheme based on the IEEE 802.4 is proposed in this paper. This network is designed for supporting 3 data classes: 1st, it includes the highly time-critical data for the fault detection function. 2nd, routine data with a period is to served for monitoring the power status. Finally, it contains the control data which is used for reporting an event about protection or tuning some values related with power status. The way to allocate target_token_rotation timer is provided to guarantee the protection and control activities in the suggested network for the substation.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.10
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• pp.1391-1396
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• 2021

The boundary-based security system has the advantage of high operational efficiency and easy management of security solutions, and is suitable for denying external security threats. However, since it is operated on the premise of a trusted user, it is not suitable to deny security threats that occur from within. A zero trust access control model was proposed to solve this problem of the boundary-based security system. In the zero trust access control model, the security requirements for real-time security event monitoring must be satisfied. In this study, we propose a monitoring method for the most basic file access among real-time monitoring functions. The proposed monitoring method operates at the kernel level and has the advantage of fundamentally preventing monitoring evasion due to the user's file bypass access. However, this study focuses on the monitoring method, so additional research to extend it to the access control function should be continued.

• Journal of the Society of Naval Architects of Korea
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• v.47 no.4
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• pp.628-645
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• 2010

To perform the engagement level simulation between the underwater vehicle model and the surface model those are constituted with various systems/ sub-systems, we implemented four different federates as a federation according to the IEEE 1516 HLA (High Level Architecture) protocol that is the international standard in the distributed simulation. Those are CFCS (Command and Fire Control System) federate, motion federate, external entities (torpedos, countermeasure and surfaceship) federate, and visualization federate that interacts with OSG (Open Scene Graph)-based visualization rendering module. In this paper, we present the detailed method about the model constitution for discrete event simulation in the distributed environment. For the sake of this purpose, we introduce the DEVS (Discrete Event System Specification)-HLA-based modeling method of the CFCS federate that reflects not only the interations between models, but also commands from user and tactics manager that is separated from the model. The CFCS federate makes decisions in various missions such as the normal diving, the barrier misision, the target motion analysis, the torpedo launch, and the torpedo evasion. In the perspective of DEVS modeling, the CFCS federate is the coupled model that has the tactical data process model, command model and fire control model as an atomic model. The message passing and time synchronization with other three federates are settled by the $m\ddot{a}k$ RTI (Runtime Infrastructure) that supports IEEE 1516. In this paper, we provides the detailed modeling method of the complicated model that has hierarchical relationship such as the CFCS system in the submarine and that satisfies both of DEVS modeling method for the discrete event simulation and HLA modeling method for the distributed simulation.

• Journal of the Korea Convergence Society
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• v.9 no.7
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• pp.55-62
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• 2018

Recently, as the threat of cyber crime increases, the importance of security control to cope with cyber attacks on the information systems in the first place such as real-time detection is increasing. In the name of security control center, cyber terror response center and infringement response center, institutional control personnel are making efforts to prevent cyber attacks. Especially, we are detecting infringement accident by using network security equipment or utilizing control system, but it's not enough to prevent infringement accident by just controlling based on device-driven simple patterns. Therefore, the security control system is continuously being upgraded, and the development and research on the detection method are being actively carried out by the prevention activity against the threat of infringement. In this paper, we have defined the method of detecting infringement of major component module in order to improve the problem of existing infringement detection method. Through the performance tests for each module, we propose measures for effective security control and study effective infringement threat detection method by upgrading the control system using Security Information Event Management (SIEM).

• Journal of Institute of Control, Robotics and Systems
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• v.17 no.10
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• pp.967-982
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• 2011

This paper presents a FTNCS (Fault-Tolerant Networked Control System) that can tolerate control surface failure and packet delay/loss in an UAV (Unmanned Aerial Vehicle). The proposed method utilizes the benefits of self-diagnosis by smart actuators along with the control allocation technique. A smart actuator is an intelligent actuation system combined with microprocessors to perform self-diagnosis and bi-directional communications. In the event of failure, the smart actuator provides the system supervisor with a set of actuator condition data. The system supervisor then compensate for the effect of faulty actuators by re-allocating redundant control surfaces based on the provided actuator condition data. In addition to the compensation of faulty actuators, the proposed FTNCS also includes an efficient algorithm to deal with network induced delay/packet loss. The proposed algorithm is based on a Lagrange polynomial interpolation method without any mathematical model of the system. Computer simulations with an UAV show that the proposed FTNCS can achieve a fast and accurate tracking performance even in the presence of actuator faults and network induced delays.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.4
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• pp.22-27
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• 2012

In the study, an XML based platform is presented for LED dimming control. The XML platform is designed in an open architecture, providing with interoperability and scalability. Also, it enables the accommodation of off-the-shelf wired and wireless communication protocols and make it fast and easy to implement various application programs for LED dimming, comparing to the legacy platforms. In the study, a test best has been built for demonstration of the merits of the XML platform with dimming control by responding to the scenario of demand response event. Benefit calculation of the power saving and incentive from demand response shows the applicability and usefulness of the XML platform.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1480-1484
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• 2003

This paper presents the design and development of network for housing estate security system. The system can cover up to 961 houses which can be up to 1,200 meters long transfer rate of 9,600 bps. This system uses checking and warning the abnormal situation. More over this system has ability to control switch on/off the electrical equipment in the house via AC line control system. The system consists of 4 parts. The first part is a security system of each house using MCS-51 microcontroller as a central processing unit scan 32 sensors and control 8 appliances and send alarm. The MCS-51 microcontroller received control signal via telephone used DTMF circuit. The second part is distributed two levels master/slave network implementing after RS-485 serial communication standard. The protocol its base on the OSI (Open Systems Interconnection) 7 layers protocol model design focus on speed, reliability and security of data that is transferred. The network security using encrypt by DES algorithm, message sequence, time stamp checking and authentication system when user to access and when connect new device to this system. Flow control in system is Poll/Select and Stop-and-Wait method. The third part is central server that using microcomputer which its main function are storing event data into database and can check history event. The final part is internet system which users can access their own homes via the Internet. This web service is based on a combination of SOAP, HTTP and TCP/IP protocols. Messages are exchanged using XML format [6]. In order to save the number of IP address, the system uses 1 IP address for the whole village in which all homes and appliance in this village are addressed using internal identification numbers. This proposed system gives the data transfer accuracy over 99.8% and maximum polling time is 1,120 ms.