• Journal of Information Processing Systems
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• 제16권4호
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• pp.760-773
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• 2020

When a crime occurs, the information necessary for solving the case, and various pieces of the evidence needed to prove the crime are collected from the crime scene. The tangible residues collected through scientific methods at the crime scene become evidence at trial and a clue to prove the facts directly against the offense of the suspect. Therefore, the scientific investigation and forensic handling for securing objective forensic in crime investigation is increasingly important. Today, digital systems, such as smartphones, CCTVs, black boxes, etc. are increasingly used as criminal information investigation clues, and digital forensic is becoming a decisive factor in investigation and trial. However, the systems have the risk that digital forensic may be damaged or manipulated by malicious insiders in the existing centralized management systems based on client/server structure. In this paper, we design and implement a blockchain based digital forensic management model using Hyperledger Fabric and Docker to guarantee the reliability and integrity of digital forensic. The proposed digital evidence management model allows only authorized participants in a distributed environment without a central management agency access the network to share and manage potential crime data. Therefore, it could be relatively safe from malicious internal attackers compared to the existing client/server model.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 심포지엄 논문집 정보 및 제어부문
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• pp.84-86
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• 2005

The digital systems such as PLC or DCS have been applied to non-safety systems of nuclear power plants because of many difficulties in using analog systems. Nowadays, digital systems have been applied to safety systems of the plants such as reactor protection system. One of the main advantages of digital systems is applicability of automatic testing methods to the systems. The protection system requires high-reliability and high-availability because it shall minimize the propagation of abnormal or accident conditions of nuclear power plants. The calculation of reliability and availability of systems depends on the maintenance period of the system. In general, the maintenance period of the protection system is one-month in case of the manual test. However, the cycle of test can be shortened in several hours by using automatic periodic testing. The reliability and availability of the system is better when test period is shortened because the reliability and availability is inverse proportion to the test period. In this research, we developed the automatic periodic testing method for KNICS Reactor Protection System, which can test the system automatically without an operator or a tester. The automatic testing contained all functions of reaction protection systems from analog-to-digital conversion function of the bistable Processor to the coincident trip function of the coincident processor. By applying the automatic periodic testing to reaction system, the maintenance cost can be cut down and the reliability can be increased.

• 제어로봇시스템학회논문지
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• 제13권2호
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• pp.121-127
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• 2007

Frequent occurrences of a fire cause tremendous loss of human lives and their property. Recently, in order to cope with such catastrophic accidents, researches on fire-fighting robots are carried out in developed countries. Under the dangerous situations, it is sometimes impossible for fire-fighting men to access the firing place because of explosive materials, smoke, high temperature and so on. In such an environment, fire-fighting robots can be useful to extinguish the fire. It is usually very dangerous place where fire-fighting robots operate. Hence, these robots should be controlled by remote users who are for away from the firing place exploiting remote communication systems. This paper considers the communication systems between fire-fighting robots and remote users. The communication systems consist of two parts; digital packet communication systems and analog image communication systems. Digital packet communication systems transfer data packets in order to control fire-fighting robots and to check the state of the fire-fighting robots. Remote users watch the video around the fire-fighting robots by exploiting the analog image communication systems. In the future, the more prosperous the commercial communication network systems will be, the more evolved the communication systems for fire-fighting robots are.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1990년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 26-27 Oct. 1990
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• pp.868-871
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• 1990

We derive an intelgral-type constraint on the complementary sensitivity function in digital control systems. Some design guidances are proposed for the pole assignment of digital controller with computation-time delay to improve the complementary sensitivity characteristics.

• 제어로봇시스템학회논문지
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• 제5권7호
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• pp.868-875
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• 1999

In this paper, digital motor control center using protection relay is developed in order to protect power systems by means of timely fault detection and diagnosis during operation for induction motor which have various load environments and capacities in power systems. Digital motor control center is employed by power supervisory control systems without separate remote terminal unit and transducers adding communicational ability. Also we develope a maximum demand controller to control the load effectively at peak status and a power factor controller to minimize real power losses and improve the power factor. Therefore, when using the developed controller, real time computation is possible by loading DSP in hardware and applying real-time kernel which can convert each algorithm to task module.

• 경영정보학연구
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• 제10권1호
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• pp.71-90
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• 2008

본 연구에서는 디지털 콘텐츠의 가치를 체계적으로 평가할 수 있는 시스템의 프로토타입을 개발하였다. 본 연구에서 개발된 가치 평가 시스템에서는 디지털 콘텐츠의 가치를 기획 단계, 개발 단계, 사업화 단계로 나누어서 정성적 평가와 경제적 평가 할 수 있다. 또한 디지털 콘텐츠의 기획, 개발, 사업화에 관련되어 있는 구성원들의 이견을 조정할 수 있다. 이 같은 평가 시스템을 활용함으로써 디지털 콘텐츠를 사업화하는 과정에서 발생할 수 있는 위험을 관리할 수 있기 때문에 합리적인 투자의사결정을 수행할 수 있다.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제1권1호
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• pp.113-118
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• 2001

In this paper, we develop an optimal intelligent digital redesign method for a class of fuzzy-model-based controllers, effective for stabilization of continuous-time complex nonlinear systems. Takagi-Sugeno (TS) fuzzy model is used to extend the results of the classical digital redesign technique to complex nonlinear systems. Unlike the conventional intelligent digital redesign technique reported in the literature, the proposed method utilized the recently developed LMI optimization technique to obtain a digitally redesigned fuzzy-model-based controller. Precisely speaking, the intelligent digital redesign problem is converted to an equivalent optimization problem, and the LMI optimization method is used to find the digitally redesigned fuzzy-model-based controller. A numerical example is provided to evaluate the feasibility of the proposed approach.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 22-24 Oct. 1991
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• pp.317-321
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• 1991

In recent years, the discrete-data and digital control systems have gained importance in all industies due in part to the advances made in microcomputers, as well as the advantages found in working with digital signals. So, the developments of the computer aided design packages to analysis, control law design and digital implementation of control systems are increasingly needed and those substantial technological improvements are now expected. In the paper, a real time control program package(RTCPP) for the implementation of digital control is developed by using C language. The digital controls for the feedfoward and feedback controllers such as PI(propotional and Integration) type, regulator and servo types can be implemented by an IBM PC compatible computer with some interface modules of A-D/D-A converter and RS-232C. The effectiveness of RTCPP is illustrated by the application controls for motor and magnetic levitation systems.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 추계학술대회 논문집 학회본부
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• pp.519-522
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• 1995

ATS Systems are activated against the over-running and the crashes between trains. Up to now, ATS Systems have been constituted analog systems adopting the changed frequency method or amplitude modulation, which is impossible to give any essential informations. In this paper, it is dealt with digital ATS Systems which are replaced the former ATS Systems in the advanced nation of railways. Especially, this paper shows the possibility of any developments for the digital ATS Systems by the experiment of digital ATS Systems by Frequency Shift Keying method.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 A
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• pp.460-462
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• 1995

ATS Systems is activated against the over-running and the crashes between trains. Up to now, ATS Systems have been constituted analog systems adopting the changed frequency method or amplitude modulation, which is impossible to give any essential informations. In this paper, it is dealt with. digital ATS Systems which are replaced the former ATS Systems in the advanced nation of railways. Especially, this paper shows the possibility of any developments for the digital ATS Systems by the experiment of digital ATS systems by Frequency Shift Keying method.