• Nuclear Engineering and Technology
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• v.53 no.3
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• pp.879-887
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• 2021

The nuclear supply chain attack surface is a large, complex network of interconnected stakeholders and activities. The global economy has widened and deepened the supply chain, resulting in larger numbers of geographically dispersed locations and increased difficulty ensuring the authenticity and security of critical digital assets. Although the nuclear industry has made significant strides in securing facilities from cyber-attacks, the supply chain remains vulnerable. This paper discusses supply chain threats and vulnerabilities that are often overlooked in nuclear cyber supply chain risk analysis. A novel supply chain cyber-attack surface diagram is provided to assist with enumeration of risks and to examine the complex issues surrounding the requirements for securing hardware, firmware, software, and system information throughout the entire supply chain lifecycle. This supply chain cyber-attack surface diagram provides a dashboard that security practitioners and researchers can use to identify gaps in current cyber supply chain practices and develop new risk-informed, cyber supply chain tools and processes.

• Journal of KIISE
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• v.43 no.5
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• pp.569-578
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• 2016

The PLC (Programmable Logic Controller) has been widely used for the development of digital control system of nuclear power plant. The PLC has high maintenance costs and increasing complexity, hence, FPGA (Field Programmable Gate Array) based digital control system has been considered as an alternative. However, the development of FPGA based digital control system is a challenge for PLC engineers because they are required to learn about new language to develop FPGA and knowledge and know-how acquired in the development of PLC is not transferable. In this study, we proposed and implemented an automatic translation tool for translation of FBD (Function Block Diagram), a programming language of PLC software, into VHDL (VHSIC Hardware Description Language). Automatically translating the FBD to VHDL using this tool allows PLC engineers to develop FPGA without any knowledge of the hardware description language.

• Journal of Internet Computing and Services
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• v.16 no.3
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• pp.33-41
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• 2015

In this paper, the simplification procedure of Karnaugh Map, which is essential to design digital logic circuits, was implemented as web-based educational Java applets. The learners will be able to experience interesting learning process by executing the proposed Java applets. In addition, since the proposed Java applets were designed to contain educational technologies by step-by-step procedure, the maximization of learning efficiency can be obtained. The learners can make virtual experiments on the simplification of digital logic circuits by clicking on some buttons or filling out some text fields. Furthermore, the Boolean expression and its schematic diagram occurred in the simplification process will be displayed on the separate frame so that the learners can learn effectively. The schematic diagram enables them to check out if the logic circuit is correctly connected or not. Finally, since the simplification algorithm used in the proposed Java applet is based on the modified Quine-McCluskey minimization technique, the proposed Java applets will show more encouraging result in view of learning efficiency if it is used as assistants of the on-campus offline class.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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• 2002.02a
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• pp.131-134
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• 2002

In this work, we have developed a systematic way of utilizing the basic design tools for superconductive electronics. This include WRSPICE, XIC, margin program, and L-meter. Since the high performance analog-to- digital converter can be built with Rapid Single Flux Quantum (RSFQ) logic circuits the development of superconductive analog-to-digital converter has attracted a lot of interests as one of the most prospective area of the application of Josephson Junction technology. One of the main advantages in using Rapid Single Flux Quantum logic in the analog-to-digital converter is the low voltage output from the Josephson junction switching, and hence the high resolution. To design an 1-bit analog-digital converter, first we have used XIC tool to compose a circuit schematic, and then studied the operational principle of the circuit with WRSPICE tool. Through this process, we obtained the proper circuit diagram of an 1-bit analog-digital converter circuit. Based on this circuit we performed margin calculations of the designed circuits and optimized circuit parameters. The optimized circuit was laid out as a mask drawing. Inductance values of the circuit layout were calculated with L-meter. Circuit inductors were adjusted according to these calculations and the final layout was obtained.

• Proceedings of the KSR Conference
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• 2002.10b
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• pp.995-1000
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• 2002

This paper presents general concept of DC switch gear(DCSWGR). Normally, DCSWGR consist of Digital protection unit(DPU), High Speed Circuit Breaker(HSCB), Disconnect Switch (DS), Programmable Logic Control(PLC), Auxiliary Relays and etc. Most of the components has its special characteristics and their interface between each others are various and complex. In this paper every constituent general design are preceded and interface between each component are examined. And also DCSWGR operation logic with logical diagram including interlock signal are introduced.

• Proceedings of the KIEE Conference
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• 1998.07g
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• pp.2402-2404
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• 1998

This paper proposes a translation method that converts ladder diagrams to binary executable codes for PLC (programmable logic controller)s. A PLC based on general purpose DSP(digital signal processor) validates the method. We performed a benchmark on the system that compares the execution time of the interpretation method and ours. Experimenal result shows how fast this method executes programs that consist of codes generated.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.37 no.4
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• pp.197-204
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• 1988

A simple method that estimates the torque fluctuations in induction motor driven by CSI under steady state condition is presented and that uses the phasor diagram from the modified singlephase equivalent circuit. This method is also applied to evaluate the PWM and programmed do link modulation techniques for reducing the torque pulsations. The simplified calculations are compared with the exact digital solutions from machine D-Q equation. It is noted that the torque pulsations in induction motor driven by CSI are dependent upon the load condition unlike VSI.

• Journal of Korea Society of Digital Industry and Information Management
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• v.17 no.4
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• pp.63-75
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• 2021

It is necessary to respond to rapid technological changes such as the 4th industrial revolution and digital transformation across industries. And, a change in the university education system is necessary in a crisis situation of universities due to the rapid decrease of the school-age population. This study is aimed at practical competency with the ability to apply intelligent information technology to their job fields based on a basic understanding of intelligent information technology rather than advanced competency centered on theory and research. Instead of presenting the curriculum system diagram so that it can be flexibly applied to the design and development of the curriculum for intelligent information technology, training modules according to job and level were presented. In relation to intelligent information technology, a questionnaire was conducted for college professors, and industry experts were conducted on the derived educational modules to reflect the opinions of the industry. Industry experts said that collaboration with PBL, Capstone, and industry is necessary to improve problem-solving and communication skills.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.05a
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• pp.586-589
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• 2003

Repeater is developed. Based on the systems The up-converter of the WCDMA Digital Optic pecifications, the structure of the up-converter is accomplished and its block diagram is drawn. The up-converter is implemented according to these block diagrams. Subsequently the low pass filter, the automatic level controlled attenuator, the frequency synthesizer and other components for the up-converter are designed and implemented, and a main board to integrate these modules is also manufactured. To reduce the noise floor of system and suppress the RF spurious noise, a PCB layout is performed carefully. For each module consisting of the up-converter and the entire system, the performance tests are accomplished to check the performance about the specifications.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1965-1966
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• 2008

The manipulation of Boolean functions is a fundamental part of computer science, and many problems in the design and testing of digital systems can be expressed as a sequence of operations. It is mainly a paper of our research on the techniques of Boolean function manipulation using Binary Decision Diagram(BDDs) and their applications for VLSI CAD System. In many practical applications related to digital system design, it is a basic technique to use ternary-valued functions. In this paper, we discuss the methods for representing logical values.