• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.2
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• pp.200-207
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• 2017

The purpose in having a control surface on ships is to control the motion of the ship. The control surface may be composed entirely of a single movable surface or of a combination of fixed and movable portions. A control surface has one sole function to perform in meeting its purpose, and that is to develop a control force in consequence of its orientation and movement relative to the water. The forces and moments generated as a result of this rotation and angle of attack then determine the manoeuvring characteristics of the ship. In this paper, two-dimensional flow characteristics of a flapped rudder and a water-blowing control rudder were accomplished respectively by PIV method in a circulating water channel. Model test has been carried out with different angles of attack of main foil (NACA 0012) and flap's deflection angles to predict the performance of the flapped rudder and the water-blowing control rudder. The 2-frame particle tracking method has been used to obtain the velocity distribution in the flow field. $Re{\fallingdotseq}3.0{\times}10^4$ has been used during the whole experiments and measured results have been compared with each other.

• Proceedings of the Korea Information Processing Society Conference
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• 2012.11a
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• pp.87-90
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• 2012

원자력발전소에 사용되는 모든 시스템은 IEEE에서 최고 수준의 안전도인 CLASS 1E로 분류된다. 그중에서 안전계통은 원자력발전소 안전에 관련한 모든 분야를 관리하는 계통이다. 산업이 발전함에 따라 안전계통 또한 그 규모와 복잡성이 높아지고 있고, 이에 적용되는 요구사항 또한 엄격해지고 있다. 따라서 발전소에 적용되는 안전 동작에 대한 기준을 결정하기 위해서 철저한 오류 예측분석이 수행 되어야 한다. 그 중에서도 NUREG-0492로 규정되어 있는 결함수목분석(Fault Tree Analysis)은 연역적 오류 예측 분석방법으로 원자력 발전소, 우주 산업 등에 관련된 분야는 본 방법을 통하여 오류 예측 분석이 이루어 져야한다. 본 논문에서 원전안전계통을 관리하는 구현 모델인 원전안전등급제어기기(Safety Programmable Logic Controller)에 대하여 결함수목분석을 통한 오류 예측 분석을 하였다. 또한, 위의 구조에 대하여 MSC(Message Sequence Chart)를 통한 모델링을 수행하여, 결함수목분석을 적용하는 과정에서 신뢰도 향상을 더하였다.

• Journal of the Society of Naval Architects of Korea
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• v.35 no.3
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• pp.26-37
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• 1998

In this study, the motion control techniques allied to the test ship NARAE are summarized and the results of sea trials are resented. NARAE adopted a hybrid hull form with lower hull and submerged foils. This type of ship has a substantial instability in heave, pitch and roll modes at the foil-borne stage due to little restoring force, so an active control is indispensable to keep the stability. 4-hydraulic actuators with servo valves were installed to drive foils, and several sensors were used to measure the motion of the ship. PID controller was adopted as a motion controller, and for the real-time control, Pentium-class industrial PC was used. Sea trials including take-off, landing, and banked turn maneuvering were carried out for a period of over 3 months and quite satisfactory results were obtained.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.7
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• pp.29-36
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• 2007

According to the using of electric power source such as solar cell, fuel cell and wind energy, consumer is supplied from distributed generator and electric power company. Therefore, it is required that the real-time measurement and control instrument for those distributed generator. In this paper, describes the development of measuring equipment for the power system with distributed generator. The equipment has real-time measure function and communication with PC via USB port, which is used for various purposes such as investigation of transient state, and is compared with measurement instrument to verify the reliability.

• Journal of the Korean Geosynthetics Society
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• v.16 no.1
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• pp.63-72
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• 2017

This study estimates the degree of influence of factors influencing ground surface settlement during tunnel excavation using Shield tunneling trough 3D FE-analyses. Numerical analysis was carried out by considering face pressure, skinplate pressure, excavation length, soil model, element size and soil material properties. Also, Actually constructed shield TBM comparative analysis was conducted by compared with Volume loss model, Pressure model and field measurement data. Skinplate pressure and soil model were the most influential factors, and the analysis results were similar to field measurements when the appropriate skinplate pressure was applied according to the passing stratum.

• Journal of Engineering Education Research
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• v.3 no.2
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• pp.14-23
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• 2000

This paper is concerned with the development of remote engineering laboratory using the internet. Recently, various virtual laboratories are introduced using the multimedia technologies but the internet laboratory using the real hardware system is not present. In this study, we developed the remote engineering laboratory by combining the GPIB program which controls the hardwares with the web programming which controls the internet. The function generator, LCR meter, and oscilloscope were considered as the measurement devices. The client program includes the user-interface which carry out experiment remotely. Several electrical experiments were set up to verify the experimental process. It has been found that the remote engineering experiments are feasible and valid. The methodologies will be discussed in detail.

• Proceedings of the Korean Society of Computer Information Conference
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• 2014.01a
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• pp.139-142
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• 2014

앉아서 생활하는 시간이 많은 현대인들에게 올바르게 앉는 자세는 매우 중요하다. 따라서 현대인들이 올바른 자세를 유지할 수 있도록 도와주는 자세 모니터링 시스템을 고안하게 되었다. 이 시스템의 주요 구성으로는 전원부와 계측부, 제어부, 통신부, 안드로이드기반 어플리케이션으로 나눌 수 있다. 전원부는 9V의 건전지 하나로 구성되어 있고, 2개의 레귤레이터를 통해 아날로그 회로(3.3V)와 MCU(5V)에 전원이 공급되어진다. 그리고 계측부는 6개의 압력센서를 이용하여 아날로그 값을 계측한다. 제어부와 통신부는 MCU 보드(MSP430 Launchpad)와 FB155BC Bluetooth Module로 구성되어 있고, 안드로이드기반 어플리케이션은 Bluetooth Module에서 받은 디지털 신호들을 스마트폰의 화면에 UI공정을 거쳐 디스플레이 한다. 본 연구는 잘못된 자세로 의자에 앉는 습관을 스마트폰의 화면을 통해 실시간으로 확인하고, 바른 자세로 앉을 수 있도록 하여 척추교정 및 척추질환 예방에 기여할 것으로 예상된다.

• Journal of the Institute of Convergence Signal Processing
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• v.21 no.1
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• pp.7-12
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• 2020

Various parameters are used to measure anesthetic depth during surgery using brain waves, and in actual clinical use, the linear analysis SEF is widely used. However, with recent studies showing that biological signals including EEG, contain nonlinear properties interest in nonlinear analysis of brain signals is increasing and parameters based on these are being developed. In this study, we are going to develop a parameter that can measure EEG using the nonlinear analysis method and extract noise that can be mixed with external electronic equipment and EEG instrumentation by comparing it with the data from the bispectrum analysis of static waves.

• Journal of the Korea institute for structural maintenance and inspection
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• v.27 no.4
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• pp.86-93
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• 2023

A bridge health monitoring technology is under development for the safety management of aged bridges. The bridge health monitoring technology has been developed mainly for single bridge management at a large scale, so it uses wire-based systems for power supply and data transfer. However, the wire-based systems need to be improved for the sporadically distributed small-sized bridges on local roads. This study proposed a wireless structural health monitoring system for small-sized bridges. The proposed monitoring system overcomes the limitations of wired systems by providing wireless power through solar power and utilizing LTE technology to transmit measurement data. In addition, a remote control system and power management plan were proposed to ensure the stability of the bridge measurement system. The proposed measurement system was installed on 32 bridges on fields and verified the operability by collecting 80.6% of measurement data for one year. The proposed system can support the health monitoring of aged bridges on local roads.

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.10
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• pp.1117-1123
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• 2014

Nuclear industries have faced unfavorable circumstances such as an obsolescence of the instrumentation and control system, and therefore nuclear society is striving to resolve this trouble fundamentally. FPGAs are currently highlighted as an alternative means for obsolete control systems. Because of the obsolescence-unaffected characteristics, FPGA should be highly reliable in order to be a replacement for PLC (Programmable Logic Controller). Therefore, it is necessary to establish a software development aspect strategy that enhances the reliability of an FPGA-based controller. The reliability analysis including the MTBF (Mean Time Between Failures) is carried out based on the MIL-HDBK-217F. MTBFs are compared with the FPGA-based controller COMMON-Q PLC. As an analysis result, it shows that the reliability of the FPGA-based controller is better than or equal to that of PLC.