• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.2
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• pp.45-53
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• 2020

Blockchain can control transactions in a decentralized way and is already being considered for manufacturing, finance, banking, logistics, and medical industries due to its advantages such as transparency, security, and flexibility. And it is predicted to have a great economic effect. However, Blockchain has a Trilemma that is difficult to simultaneously improve scalability, decentralization and security characteristics. Among them, the biggest limitation of blockchain is scalability, which is very difficult to cope with the constantly increasing number of transactions and nodes. To make the blockchain scalable, higher performance should be achieved by modifying existing consensus methods or by improving the characteristics and network efficiency that affect many ways of scaling. Therefore, in this paper, we propose a cluster-based scalable PBFT consensus algorithm called CBS-PBFT which reduces the message complexity O(n²) of PBFT to O(n), which is a representative consensus algorithm of blockchain, and the validity is verified through simulation experiments.

• Journal of Korea Society of Industrial Information Systems
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• v.19 no.6
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• pp.53-61
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• 2014

For monitoring the flight trajectory and the status of a launch vehicle, the mission control system in NARO space center process data acquired from the ground tracking system, which consists of two tracking radars, four telemetry stations, and one electro-optical tracking system. Each tracking unit exhibits its own tracking error mainly due to multi-path, clutter and radio refraction, and by utilizing only one among transmitted informations, it is not possible to determine the actual vehicle trajectory. This paper presents a way of generating flight trajectory via post-processing the data received from the ground tracking system. The post-processing algorithm is divided into two parts: compensation for atmosphere radio refraction and multi-sensor fusion, for which a decentralized Kalman filter was adopted and implemented based on constant acceleration model. Applications of the present scheme to real data resulted in the flight trajectory where the tracking errors were minimized than done by any one sensor.

• Journal of Communications and Networks
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• v.14 no.6
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• pp.662-671
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• 2012

Plug-in hybrid electric vehicles (PHEVs) will be widely used in future transportation systems to reduce oil fuel consumption. Therefore, the electrical energy demand will be increased due to the charging of a large number of vehicles. Without intelligent control strategies, the charging process can easily overload the electricity grid at peak hours. In this paper, we consider a smart charging and discharging process for multiple PHEVs in a building's garage to optimize the energy consumption profile of the building. We formulate a centralized optimization problem in which the building controller or planner aims to minimize the square Euclidean distance between the instantaneous energy demand and the average demand of the building by controlling the charging and discharging schedules of PHEVs (or 'users'). The PHEVs' batteries will be charged during low-demand periods and discharged during high-demand periods in order to reduce the peak load of the building. In a decentralized system, we design an energy cost-sharing model and apply a non-cooperative approach to formulate an energy charging and discharging scheduling game, in which the players are the users, their strategies are the battery charging and discharging schedules, and the utility function of each user is defined as the negative total energy payment to the building. Based on the game theory setup, we also propose a distributed algorithm in which each PHEV independently selects its best strategy to maximize the utility function. The PHEVs update the building planner with their energy charging and discharging schedules. We also show that the PHEV owners will have an incentive to participate in the energy charging and discharging game. Simulation results verify that the proposed distributed algorithm will minimize the peak load and the total energy cost simultaneously.

• The Journal of the Korea Contents Association
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• v.3 no.4
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• pp.38-47
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• 2003

Distributed problem solving is the cooperative solution of problem by a decentralized and loosely couped collection of knowledge-sources (KS's), located in a number of distinct processor nodes. The contract net protocol has been developed to specify problem-solving communication and control for nodes in a distributed problem solver. Task distribution is affected by a negotiation process, a discussion carried on between nodes with tasks to be executed and nodes that may be able to execute tasks In this paper, we present the coordination method among distributed intrusion detection system and firewall by the contract net protocol. The method enhances the intrusion detection performance and provides the communication methods. To mode IDS and firewall, security models hue been hierarchically constructed based on the DEVS (Discrete Event system Specification) formalism. Each ID agent cooperates through the contract net protocol for detecting intrusions. The IDS which detects the intrusion informs to firewall, so the harmful network traffic is blocked. If an agent detects infusions, the agent transfers attacker's information to a firewall. Using this mechanism attacker's packets detected by In can be prevented from damaging the network.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.8
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• pp.1834-1839
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• 2005

Database security is essential to protect their data in most organization such as hospitals, central or local governments, banks which manage the private, sensitive and important data. Because the duty of the department recently became more various and complicated, the changes of security requirement are needed more frequently. Therefore, easily changeable, flexible security policy and efficient security management with preserving the integrity of security policy are very important. In this paper, we implemented a flexible database security system in the specimen and clinical information management system of leukemic research center using IRH(Improved Role Hierarchy). Data is protected by MAC and we propose a flexible access control and effective administration by using the IRH that is an improved role hierarchy of RBAC. If security policy is needed for changes, this system can do it easily by simply modifying the IRH with the decentralized administration. The modified security policy can be applied flexibly after alteration because the security level of the subject is not fixed but can be derived automatically from the IRH when user connects the system.

• The Korean Journal of Archival Studies
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• no.10
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• pp.324-370
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• 2004

This paper aims to research the historical development of the archival systems in the Soviet Union from 1917 to the 1920's. The Russian revolution was the turning point not only for the political and social changes but for the archival administration in Russia, as it provided the new Soviet regime with the chances to reorganize the archival institutions under Bolshevik rule. However, we must not forget the fact that the Russian Archival Workers' Union had taken part in the organization of the archival systems together with the Bolshevik revolutionaries. The Soviet government intended to transform the decentralized and poorly organized archival systems in the prerevolutionary years into the centralized and bureaucratized ones. In this meaning, the decree signed be V. I. Lenin on 1 June 1918 was estimated as the real basis for the Soviet archival centralization. Lenin's archival decree of 1918 encompassed the entire national documentary legacy, which was gradually extended to all types and categories of manuscripts and archival records by successive legislation. The concept of state proprietorship of all documentary records was designated "Single State Archival Fond"(Edinyi Gosudarstvennyi arkhivnyi fond), which was renamed as "Archival Fond of the Russian Federation" after the collapse of the USSR. The independent state administrative agency, that is, "Main Administration of Archival Affairs"(Glavnoe upravlenie arkhivnym delom) was charged with the management of the entire "Single State Archival Fond". While the Soviet Union reorganized its archival systems in the twenties, the archival institutions became under the severe control of the government. For example, M. N. Pokrovskii, the well-known Marxist historian and the political leader, headed the organizational work of archives in the Soviet Union, which resulted in the exclusion of the prerevolutionary specialists from the archival field in the Soviet Union. However, the discussions over the concept of "the Archival Fond" by B. I. Anfilov helped to develop the archival theories in the USSR in the twenties. In conclusion, the Soviet Union, having emphasized the centralization of the archives, developed its archival systems from the early period, which were the basis of the systematic archival institutions in Russia.

• Journal of The Korea Institute of Healthcare Architecture
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• v.25 no.2
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• pp.51-62
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• 2019

Purpose: This study aims to examine spatial characteristics of ambulatory care department Chronologically through case studies; and to consider the social implication of these spatial changes. Methods: In this study, a total of eight ambulatory care departments, one or two for each period, were selected in order to analyze the spatial characteristics. Results: First, since the 1990s, the outpatient department of the US has been changed into a patient-centered space by providing high quality outpatient medical services through individual exam room planning. Second, the exam room has been changed from open/semi-open/group exam room to individual exam room since 1990, and the trend is shifting from the cluster type to the modular type consisting of universal exam rooms in order to achieve the flexibility of exam room. Third, the diagnostic/testing area has been deployed to the ambulatory clinic to enable 'one-stop shopping' for patients-centered care since 1990s, however, it has been disappearing since 2000 due to Reduce medical expenses. Fourth, the Central Nursing Station type first appeared in the outpatient department In the 2000s, followed by the type of decentralized nursing station type since 2010s. And fifth, the area of medical support has been placing to be concentrated on one place due to the Lean Design strategy since 2010. Implications: In the future, it is expected that Korea will be more focused on efficiency, visual control, and flexibility in the planning of the ambulatory care department as in the case of the United States.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.2
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• pp.445-466
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• 2022

As everything linking to the internet, people can subscribe to various services from a service provider to facilitate their lives through the Internet of Things (IoT). An obligatory thing for the service provider is that they should push the service data safely and timely to multiple IoT terminal devices regularly after the IoT devices accomplishing the service subscription. In order to control the service message received by the legal devices as while as keep the confidentiality of the data, the public key encryption algorithm is utilized. While the existing public encryption algorithms for push service are too complicated for IoT devices, and almost of the current subscription schemes based on push mode are relying on centralized organization which may suffer from centralized entity corruption or single point of failure. To address these issues, we design a secure subscription-push service scheme based on blockchain and edge computing in this article, which is decentralized with secure architecture for the subscription and push of service. Furthermore, inspired by broadcast encryption and multicast encryption, a new encryption algorithm is designed to manage the permissions of IoT devices together with smart contract, and to protect the confidentiality of push messages, which is suitable for IoT devices. The edge computing nodes, in the new system architecture, maintain the blockchain to ensure the impartiality and traceability of service subscriptions and push messages, meanwhile undertake some calculations for IoT devices with limited computing power. The legalities of subscription services are guaranteed by verifying subscription tags on the smart contract. Lastly, the analysis indicates that the scheme is reliable, and the proposed encryption algorithm is safe and efficient.

• Korean Journal of Comparative Education
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• v.21 no.4
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• pp.1-27
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• 2011

The purpose of this study is to explore some policy implications for improving the faculty personnel management and their salary scheme of the Korean national universities through comparing the systems and practices of Korean national universities to those of OECD countries. The fact that many leading OECD countries in higher education arena have been taking decentralized contract-based system based on institutional autonomy and performance beyond the previous bureaucratic control model casts some significant implications for the Korean national university reform. Especially, concerning on personnel management, it is necessary to provide more flexibility in managing faculty personnel categorization and expansion of faculty quota management for faculty and to review the maintenance of faculty's legal status as civil servant. In addition, regarding the salary scheme of faculty, we suggested performance-based salary scheme with plus-sum methods, settlement of rational faculty performance evaluation system and practices, and need for some aligning efforts for changing faculty salary scheme of the national universities.

• Journal of Daesoon Thought and the Religions of East Asia
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• v.2 no.2
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• pp.73-99
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• 2023

The dragon is a special imaginary figure created by the people of East Asia. Its archetypes appeared primarily as totemic symbols of different tribes and groups in the region. The formation of early dynasties probably generated the molding of the dragon symbol. Dragon symbols carried deep imprints of nature. They concealed alternative messages of how ancient people at different locations dealt with or interacted with nature. Under pressure to standardize in the medieval and late imperial periods, the popular dragon had to transform physically and ideologically. It became imposed, unified, and framed, conveying ideas of caste classification and power, and losing itsecological implications. The dragon transitioned from a semi-ecological domain into a total social caste system. However, many people considered the "standardized" dragon as the symbol of the oppressor. Because of continuous orthopraxy and calls for imperial reverence, especially under orthopractic agenda and the surveillance of local elites, the popularized dragon was imbued within local artworks or hidden under the sanctity of Buddhas or popular gods in order to survive. Through disguise, the popular dragon partially maintained its ecological narratives. When the imperial dynasties ended in East Asia (1910 in Korea, 1911 in China, 1945 in Vietnam), the dragon was dramatically decentralized. However, trends of re-standardization and re-centralization have emerged recently in China, as the country rises in the global arena. In this newly-emerging "re-orthopraxy", the dragon has been superimposed with a more externally political discourse ("soft power" in international relations) rather than the old-style standardization for internal centralization in the late imperial period. In the contemporary world, science and technology have advanced humanity's ability to improve the world; however, it seems that people have abused science and technology to control nature, consequently damaging the environment (pollution, global warming, etc.). The dragon symbol needs to be re-defined, "re-molded", re-evaluated and reinterpreted accordingly, especially under the newly-emerging lens-the New Confucian "anthropocosmic" view.