• 전기학회논문지P
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• 제55권1호
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• pp.6-12
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• 2006

A popular method used by primary protection for power transformer is current ratio differential relaying (RDR) with 2nd harmonic restraints. In modern power transformer due to the use of low-loss amorphous material, the 2nd harmonic component during inrush is significantly reduced. The higher the capacitance of the high voltage status and underground distribution, the more the differential current includes the 2nd harmonic component during internal fault. Thus the conventional method may not operate properly. This paper proposes an advanced relaying algorithm and the prototype IED hardware design and it's real-time experimental results. To evaluate performance of the proposed algorithm, the study is well constructed power system model including power transformer utilizing the EMTP software and the testing is made through simulation of various cases. The proposed relaying that is well constructed using DSP chip and microprocessor etc. has been developed and the prototype IED has been verified through on-line testing. The results show that an advanced relaying based prototype IED never mis-operated and correctly identified all the faults and that inrushes that are applied.

• 한국의학물리학회지:의학물리
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• 제5권2호
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• pp.27-34
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• 1994

현재 임상에서의 추세는 감시 장비의 증가와 인력의 부족으로 인하여 각 환자마다에 부착되어있는 장비들을 감시하는 것이 상당한 부분을 차지하고 있으므로 시간과 인력적인 요소를 보완하기 위하여 본 연구에서는 원격으로 감시 할 수 있는 디지탈 통신 방식에 의한 심전도 텔레메트리 시스템을 제작하였다. 환자로부터 추출된 심전도 신호는 A/D변환하여 디지탈 형태로 오차 감시 방법을 적용한 새로운 데이타로 변환한다. 변환된 데이타는 기존의 아날로그 통신방식에서의 잡음과 혼신에 의한 부정확한 데이타전송을 극복하였다. 그리고 동일 주파수대를 사용함으로써 주파수의 낭비를 제거하였으며, 주파수 공용으로 인한 cross over의 단점은 본 논문에 제안한 송, 수신 gateway 방식을 채용 함으로써 해결하였다.

• 제어로봇시스템학회논문지
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• 제7권11호
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• pp.912-917
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• 2001

In this study, we define the measuring method of crank angle precisely using an event and perform a study on the hardware structure and software algorithms which is applicable for the commercial engine. Also we developed a Computer-ECU(Personal computer based electronic control unit) using a computer and a microprocessor, for performing the ignition at a desire position(angle) and for controlling a duty ratio a pulse for ISC(Idle speed control). We applied these algorithms to the modeling which is induced a concept of event and got a better result than a conventional ECU in the state of transient as a result of performing air fuel ratio control in a commercial engine. This technique can be used for the back to improve ECU performance. It the present type of Hybrid I. C voltage regulator is altered to the new type of regulator, we will be surely able to reduce the production cost as well as simplify the design of alternator\`s rear bracket and rectifier part because of the removal of trio diode. Experiment is taken by MS-R004.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2002년도 춘계학술대회 논문집
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• pp.209-214
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• 2002

We developed a small, remote controlled observation ship that can reduce the cost of gathering data for marine and coastal environments. The control system is composed of three microprocessors, one is for overall mission control, another for control of propulsion motors, and the other for sensor operation. For communication system, we adopt direct and indirect methods based on the wireless modem of commercial cellular telephone. The former is a direct communication between the modems of the ship and the server, and the latter is an indirect communication via internet between the ship and the server. The performance of the ship is demonstrated with the results produced by sets of experiments.

• Journal of information and communication convergence engineering
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• 제14권3호
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• pp.177-183
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• 2016

A lot of Internet of Things devices has resource-restricted environment, so it is difficult to implement the existing block ciphers such as AES, PRESENT. By this reason, there are lightweight block ciphers, such as SIMON, SPECK, and Simeck, support various block/key sizes. These lightweight block ciphers can support the security on the IoT devices. In this paper, we propose efficient implementation methods and performance results for the Simeck family block cipher proposed in CHES 2015 on an 8-bit ATmega128-based STK600 board. The proposed methods can be adapted in the 8-bit microprocessor environment such as Arduino series which are one of famous devices for IoT application. The optimized on-the-fly (OTF) speed is on average 14.42 times faster and the optimized OTF memory is 1.53 times smaller than those obtained in the previous research. The speed-optimized encryption and the memory-optimized encryption are on average 12.98 times faster and 1.3 times smaller than those obtained in the previous studies, respectively.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2005년도 춘계학술대회논문집
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• pp.292-297
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• 2005

This paper proposes a simple MPPT control scheme of a Current-Control-Loop Error system Based that can be obtains a lot of advantage to compare with another digital control method, P&O and IncCond algorithm, that is applied mostly a PV system. An existent method is needed an expensive processor such as DSP that calculated to change the measure power of a using current and voltage sensor at the once. Therefore, it is applied a small home power generation system that required many expenses. But, a proposed method is easy to solve the cost reduction and power unbalance problems that it is used by control scheme to limit error of a current control of common sensor. This proposed algorithm had verified through a simulation and an experiment on battery charger using PIC that is the microprocessor of a low price.

• Journal of Electrical Engineering and Technology
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• 제10권4호
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• pp.1655-1666
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• 2015

This paper proposes a new approach of Field Programmable Gate Array (FPGA) controlled digital implementation of shunt active power filter (SAPF) under steady state and dynamic operations. Typical implementations of SAPF uses microprocessor and digital signal processor (DSP) but it limited for complex algorithm structure, absence of feedback loop delays and their cost can be exceed the benefit they bring. In this paper, the hardware resources of an FPGA are configured and implemented in order to overcome conventional microcontroller or digital signal processor implementations. This proposed FPGA digital implementation scheme has very less execution time and boosts the overall performance of the system. The FPGA controller integrates the entire control algorithm of an SAPF, including synchronous reference frame transformation, phase locked loop, low pass filter and inverter current controller etc. All these required algorithms are implemented with a single all-on chip FPGA module which provides freedom to reconfigure for any other applications. The entire algorithm is coded, processed and simulated using Xilinx 12.1 ISE suite to estimate the advantages of the proposed system. The coded algorithm is also defused on a single all-on-chip Xilinx Spartan 3A DSP-XC3SD1800 laboratory prototype and experimental results thus obtained match with simulated counterparts under the dynamic state and steady state operating conditions.

• Journal of Advanced Marine Engineering and Technology
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• 제32권2호
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• pp.343-350
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• 2008

In this paper, a six degree-of-freedom robot arm which is very light but capable of delivering heavy loads was studied. The proposed robot arm has much higher load capacity than conventional robot arms actuated by motors with speed reducers such as the harmonic drive since a new type of robot actuator based on a closed chain mechanism driven by the ball screw was adopted. Analysis on the design scheme and on the mechanism of the joint actuator of the robot arm were made. Since the robot arm was designed very light, it has deflection in the links. To analyze this, a finite element analysis on the structure of the designed robot links was made using ANSYS software. Verifying experiments on the performance of high load capacity of the robot arm was performed by loading heavy weights on the robot arm. Through experiments. the correctness of the numerical analysis was also verified.

• 한국통신학회논문지
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• 제15권11호
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• pp.886-897
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• 1990

본 논문은 PWM 패턴의 연적 펄스폭 사이에서 정의된 선형관계에 기초한 새로운 optimal PWM 방식을 제시하였다. 새로운 PWM 방식에서 펄스폭 계산은 MW와 CW의 방정식에 의존하지않고 수행할 수 있다. 이 방식에 의해 마이크로프로세서로 제어되는 인버터를 위한 PWM 패턴은 패턴의 연적 펄스폭에서 최적 증분치를 얻으므로서 쉽게 구성할 수 있다. 더구나, PWM 인버터의 출력에서 고조도레벨은 본 PWM패턴이 최소 THD를 기초로 선정되기 때문에 항상 적다. 본 방식을 1(HP), 삼상 유도전동기에 적용시켜 종래의 regular PWM 방식과 비교해 보았다. 계산 및 실험의 결과에서 새로운 optiaml PWM 방식이 VSI-PWM 인버터에서 고조도를 최소화하기 위한 효과적인 일반화 연구임을 보였다.

• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제16권2호
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• pp.212-216
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• 2010

마이크로프로세서의 온도 관리를 위해 사용되는 대표적인 기술인 동적 온도 관리 기법이 적용되면 임계온도 이상의 발열 발생시 온도를 제어하기 위해 성능이 저하되는 단점이 있다. 따라서 마이크로프로세서의 발열 온도를 낮추면 동적 온도 관리 기법을 통해 온도를 제어하는 시간이 줄어들면서 성능 저하를 최소화 시킬 수 있다. 본 논문에서는 유닛의 발열 제어를 위해 사용되는 연산 이관시 유닛을 선택하는 기준에 대한 다양한 기법들을 모의 실험을 통하여 비교 분석함으로써 유닛의 발열 현상으로 인한 마이크로프로세서의 성능 저하를 최소화시킬 수 있는 방안을 도출하고자 한다. 모의 실험 결과, 동적 연산 이관 기법에서 임계 온도와 유닛 온도 사이의 차이를 기준으로 동작할 유닛을 선택하는 기법이 발열에 가장 효과적으로 대응하여 성능이 우수하다는 것을 확인할 수 있다.