• The Transactions of the Korean Institute of Electrical Engineers
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• v.39 no.2
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• pp.119-132
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• 1990

To design protection coordination for an electric power distribution system, an expert system is developed, using both the veteran expert's heuristics and the guide book for the distribution facility operation considering feeder configuration, service route, load characteristics fault current and load current. The expert system developed in this papaer determines the type of protective device(clearing current and sequence). The location and rating change of protective device in the old feeder is realized by using old database. Current(T-C) curves of various kinds of protective devices are stored in Knowledge Base (KB). The expert system is developed on a 32 bit personal computer using PROLOG, AutoCAD,dBASEIIIPLUS and FORTRAN. To compute the fault current and loadflow, FORTRAN is used.

• Proceedings of the KIEE Conference
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• 1990.07a
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• pp.167-170
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• 1990

This paper presents a preliminary study of introduction of the Dempster-Shafer inexact reasoning method to the expert system for the power system design problem. A brief review of Dempster-Shafer theory of evidence is presented and development of an inference engine adopting the Dempster-Sharer theory is reported. Developed inference engine has a ability of handling both the confirming and disconfirming knowledge represented in the production rule, and has a general purpose application in the design and diagnosis problems. Its applicability has been tested on the problem of the protection scheme selection, one of the typical design problem and we believe, it has shown the feasibility of adoption of the inexact reasoning methodology into the design problem.

• Information and Communications Magazine
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• v.32 no.6
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• pp.39-49
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• 2015

In cryptographic applications, the key protection is either knowledge-based (passwords) or possession-based (tamper-proof device). Unfortunately, both approaches are easily forgotten or stolen, thus introducing various key management issues. By incorporating biometrics technologies which utilize the uniqueness of personal characteristics, the security of cryptosystems could be strengthened as authentication now requires the presence of the user. Biometric Cryptosystem (BC) encompasses the design of cryptographic keys protection methods by incorporating biometrics. BC involves either key-biometrics binding or direct key generation from biometrics. However, the wide acceptance and deployment of BC solutions are constrained by the fuzziness related with biometric data. Hence, error correction codes (ECCs) should be adopted to ensure that fuzziness of biometric data can be alleviated. In this overview paper, we present such ECC solutions used in various BCs. We also delineate on the important facts to be considered when choosing appropriate ECCs for a particular biometric based solution from accuracy performance and security perspectives.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.11
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• pp.1885-1891
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• 2007

This paper presents a distance relaying algorithm for phase-to-ground faults in transmission lines under Multi-Agent protection environment. In normal condition, a distance relay agent stores the latest states, e.g., voltage of source side, voltage of the opposite side and the loading conditions, etc., through communication between the agents. Once a fault occurs, the relay calculates the fault location using the knowledge about the states just before the fault happens. This stand-alone operation is to improve reliability under the fault condition at which the accuracy or time required for communication may not be guaranteed. The mathematical expression of fault location is derived through loop analysis, before hand, in the manner that both fault current from the opposite end and fault resistance are included implicitly so that their effects are minimized. The suggested algorithm is applied to a typical transmission system with two power sources on both ends to show its effectiveness.

• Journal of Power Electronics
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• v.13 no.3
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• pp.381-389
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• 2013

A method to control the speed or the torque of a permanent-magnet direct current motor is presented. The rotor speed and the external torque estimation are simultaneously provided by appropriate observers. The sensorless control scheme is based on current measurement and switching states of power devices. The observers performances are dependent on the accurate machine parameters knowledge. Sliding mode control approach was adopted for drive control, providing the suitable switching states to the chopper power devices. Despite the predictable chattering, a convenient first order switching function was considered enough to define the sliding surface and to correspond with the desired control specifications and drive performance. The experimental implementation was supported on a single dsPIC and the controller includes a logic overcurrent protection.

• Journal of information and communication convergence engineering
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• v.22 no.2
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• pp.121-126
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• 2024

In enterprise environments, file owners are often required to share critical files with other users, with encryption-based file delivery systems used to maintain confidentiality. However, important information might be leaked if the cryptokey used for encryption is exposed. To recover confidentiality, the file owner must then re-encrypt and redistribute the file along with its new encryption key, which requires considerable resources. To address this, we propose a key management server that minimizes the distribution of encryption keys when critical files are compromised, with unique encryption keys assigned for each registered user to access critical files. While providing the targeted functions, the server employs a level of system resources comparable to that of legacy digital rights management. Thus, when implemented in an enterprise environment, the proposed server minimizes cryptokey redistribution while maintaining accessibility to critical files in the event of an information breach.

• Hwankyungkyoyuk
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• v.20 no.1
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• pp.73-89
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• 2007

This study was aimed to find out ancestral environmental protection wisdom in their life style, and to teach environmental education applying its results in primary school. A dissertation survey was conducted to analyze environmental protection eco-wisdom, environmental education about traditional culture, application of indigenous knowledge in ancestral traditional culture for environmental education in the primary school, and Korean traditional culture presented in 5th grade subject courses of the 7th school curricula. In addition, a environmental education program was developed by applying wisdom of traditional life style and the strategy of environmental education utilizing the results from the above data in primary school was explored. It was found that students understand the value of environment education and are more interested in the ancestral life style, environmental protection wisdom from traditional culture. Also, students understand the ancestral thinking in environment, the wisdom of old Korean, and the importance of echo-wisdom related on traditional culture. Based on above results, the suggestions of this study are made as follows. First, by searching for more wisdom from traditional culture vigorously, it is needed that developing more teaching text combined environmental education with traditional culture through other curriculums. In addition, for this kind of teaching being used efficiently in another schools, the place and environmental teaching aid is needed.

• International Journal of Computer Science & Network Security
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• v.21 no.9
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• pp.151-154
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• 2021

State information policy is an important component of foreign and domestic policy of the country and covers all spheres of society. The rapid development of the information sphere is accompanied by the emergence of fundamentally new threats to the interests of the individual, society, state and its national security. The article considers the components of the state information policy to ensure information security of the country and identifies the main activities of public authorities in this area. Internal and external information threats to the national security of Ukraine and ways to guarantee the information security of the country are analyzed. Information security is seen as a component of national security, as well as a global problem of information protection, information space, information sovereignty of the country and information support of government decisions. Approaches to ensure the process of continuity of the information security system of the state in order to monitor new threats, identify risks and levels of their intensity are proposed.

• Knowledge Management Research
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• v.24 no.3
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• pp.73-94
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• 2023

With the virtual asset market's rapid growth, government regulations on listing and trading procedures are expected. However, specific measures are currently lacking. To ensure stable inclusion in the institutional framework, precise regulations are needed for market development and investor protection. This study compares self-regulatory guidelines of the top domestic virtual asset exchanges with Korea Exchange's Preliminary Listing Examination Standards (2022) to enhance timeliness and relevance. It defines IEO, IPO, and ICO concepts and addresses conflicts of interest in IEO. Analyzing delisted virtual assets, it categorizes issues and classifies listing examination guidelines into formal and qualitative requirements. The study examines self-regulatory guidelines based on continuity, transparency, stability, corporate characteristics, and investor protection criteria, along with five special requirements for virtual assets. Improvement measures include regular disclosures of governance structure, circulation volume, and the establishment of independent audit institutions. This research further analyzes delisting cases, classifies issues, and proposes solutions. Considering stock market similarities, it offers measures based on the institutional framework.

• Corrosion Science and Technology
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• v.14 no.1
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• pp.12-18
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• 2015

Since the operation period of nuclear power plants has increased, the degradation of buried pipes gradually increases and recently it seems to be one of the emerging issues. Maintenance on buried pipes needs high quality of management system because outer surface of buried pipe contacts the various soils but inner surface reacts with various electrolytes of fluid. In the USA, USNRC and EPRI have tried to manage the degradation of buried pipes. However, there is little knowledge about the inspection procedure, test and manage program in the domestic nuclear power plants. This paper focuses on the development and build-up of real-time monitoring and control system of buried pipes. Pipes to be tested are tape-coated carbon steel pipe for primary component cooling water system, asphalt-coated cast iron pipe for fire protection system, and pre-stressed concrete cylinder pipe for sea water cooling system. A control system for cathodic protection was installed on each test pipe which has been monitored and controlled. For the calculation of protection range and optimization, computer simulation was performed using COMSOL Multiphysics (Altsoft co.).