• Journal of Korea Society of Industrial Information Systems
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• v.29 no.2
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• pp.69-80
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• 2024

In this paper, we studied a discrete-time queuing system that operates under a mixed situation of D-policy and T-policy, one of the representative server control policies in queuing theory. A single server serves customers arriving by Bernoulli arrival process on a first-in, first-out basis(FIFO). If there are no customers to serve in the system, the server goes on vacation and returns, until the total service time (i.e., total amount of workload) of waiting customers exceeds predetermined workload threshold D. The operation of the system covered in this study can be used to model the efficient resource utilization of mobile devices using secondary batteries. In addition, it is significant in that the steady state waiting time and system sojourn time of the queuing system under a flexible mixed control policy were derived within a unified framework.

• Convergence Security Journal
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• v.23 no.4
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• pp.43-52
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• 2023

Many businesses and organizations use smartcard-based user authentication for remote access. In the meantime, through various studies, dynamic ID-based remote user authentication protocols for distributed multi-server environments have been proposed to protect the connection between users and servers. Among them, Qiu et al. proposed an efficient smart card-based remote user authentication system that provides mutual authentication and key agreement, user anonymity, and resistance to various types of attacks. Later, Andola et al. found various vulnerabilities in the authentication scheme proposed by Qiu et al., and overcame the flaws in their authentication scheme, and whenever the user wants to log in to the server, the user ID is dynamically changed before logging in. An improved authentication protocol is proposed. In this paper, by analyzing the operation process and vulnerabilities of the protocol proposed by Andola et al., it was revealed that the protocol proposed by Andola et al. was vulnerable to offline smart card attack, dos attack, lack of perfect forward secrecy, and session key attack.

• KIPS Transactions on Software and Data Engineering
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• v.2 no.5
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• pp.335-340
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• 2013

This paper has designed and realized educational ZigBee equipment befitting to the USN environment. In addition, this study has enabled users to exercise operation process for software technology education and to propose software design methods in the process in the USN environment through practice equipment for ZigBee education. As for the development environment of system, Atmega128 process of Atmel is used for CPU; AVR compiler for the debugging environment; C language for firmware development language; and C++ for application program. The system operation process is initiated by coordinator's sensing information reading order from the hyper terminal through a server through the Internet or directly connected; and then delivering it to a terminating device by using ZigBee technology. The terminating device delivers various sensing information to the coordinator which delivers it to a server through the Internet or to a HYPER terminal directly connected to the coordinator. As for the educational course, it is about practices on such ZigBee operation process and relevant programing skills. Regarding it, the communication between coordinator and terminating device is designed by utilizing physical layer of ZigBee protocol, MAC layer and network layer while the communication between server and coordinator is designed by proposing an independent protocol on TCP/IP socket and the protocol processing procedure during sensing data delivery is verified by interpretation.

• Journal of Platform Technology
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• v.9 no.3
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• pp.78-83
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• 2021

The new industry drone research is increasing through convergence between 4th industrial revolution technology. In particular, the government indicates the D.N.A platform as a countermeasure of 4th industrial revolution. So, the research topics are remarkable which are using D.N.A platform. On the other hand, the drone for industrial and research has spatial factor based on sequential because, they performance scenario-based mission through control operation. When the drone flights as a control operation, they have necessity apply multi-dimensional methods to improve the security level. So, this study researched a scenario based drone platform to improve the security level. As a result, the space classified as a ground control system, drone, drone data server and designed the application method based on scenario security technology.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.885-888
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• 1995

Virtual Manufacturing System(VMS) is a computer model that represents the precise and whole structure of manufacturing system and simulates their physical and logical behavior in operation. In this paper, a real time simulation for the virtual factory is proposed to integrate a process planning with scheduling under distributed environments. In order to communicate the information under distributed environment, weuse a sever/client concept and socket program. the VMS is implemented on the internet environment.

• Proceedings of the KIEE Conference
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• 1998.07c
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• pp.1173-1175
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• 1998

This paper presented the development plan of voltage security on-line monitoring system (VSECOMs). VSECOMs consists of voltage security monitoring system and data management system. VSECOMs has the function of bus voltage watch. voltage stability analysis, and voltage security assessment. EMS data on-line acquisition, PSS/E file conversion, and overall data management. VSECOMs is designed with client/server structure. We will seek stable operation of KEPCO's power system by installation of VSECOMs in EMS of KEPCO.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.21 no.46
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• pp.147-158
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• 1998

Work order and report of work performance are essential activities of work management in the shop floor. This study suggests the model for the communication methods and Information exchange systems which can enhance faultless accuracy about these informations in the client/server architecture.

• IEMEK Journal of Embedded Systems and Applications
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• v.15 no.6
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• pp.299-305
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• 2020

We have developed a scheduler that additionally consider network performance by extending the Kubernetes developed to manage lots of containers in cloud computing nodes. The network delay adapt characteristics of the compute nodes were learned during server operation and the learned results were utilized to develop placement algorithm by considering the existing measurement units, CPU, memory, and volume together, and it was confirmed that the low delay network service was provided through placement algorithm.

• Journal of the Korean Association of Geographic Information Studies
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• v.5 no.4
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• pp.93-105
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• 2002

In this paper forest fire status information management system was developed under web environment using web GIS(geographic information system) technology. Though this system, general users can easily retrieval domestic forest fire status information and obtain that in visual way such as maps, graphs, and texts if they have only certain web browsers. Moreover, officials, who have system access authority, can easily control and manage all domestic forest fire status information through input interface, retrieval interface, and out interface of the system. This system can be considered as the first domestic system to manage forest fire status data and service them in visual through user friendly interfaces on web. In order to implement this system, IIS 5.0 of Microsoft is used as web server and Oracle 8i and ASP(active server page) are used for database construction and dynamic web page operation, respectively. Also, ArcGIS IMS(internet map server) of ESRI is used to serve maps by using Java and HTML as system development languages. Not only the domestic tendency of forest fire but also the forest fire status information of certain area and time such as the frequency and the loss can be presented through distribution maps, graphs and tables. Therefore, this system is supposed to play as a important role when the policy relate to domestic forest fire is established. In addition, the self consciousness of people against forest fire can be inspired and the foundation of scientific and systemic forest fire services can be obtained through this system in the future.

• KIPS Transactions on Computer and Communication Systems
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• v.7 no.12
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• pp.295-300
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• 2018

The rapid development of IT, many conventional passive jobs have been automated. This automation increases the leisure time of many people and various services are being developed for them. In addition, with the advent of smart devices that are compact and portable, it is possible to use various internet services without any time and place discretion. Various studies based on virtualization are under way to efficiently store and process large data generated by many devices and services. Desktop Storage Virtualization (DSV), which integrates and provides users with on-premise-based distributed desktop resources during these studies, uses virtualization to consolidate unused resources within distributed, legacy desktops. This DSV is very important for providing high reliability to users. In addition, research on hierarchical structure and resource integration for efficient data distribution storage processing in a distributed desktop-based resource integration environment is underway. However, there is a lack of research on efficient operation in case of server failure in on-premise resource integration environment. In this paper, we propose Non-disruptive Server Management (NSM) which can actively cope with the failure of desktop server in distributed desktop storage environment based on on-premise. NSM is easy to add and remove desktops in a desktop-based integrated environment. In addition, an alternative server is actively performed in response to a failure occurrence.