• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1998년도 추계종합학술대회 논문집
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• pp.413-416
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• 1998

Sensitivity and calibration considerations are most important in the design and implementation of real control systems. Ideally parameter changes due to various causes should not appreciably affect the system's performances. But all the values of physical components of the plants and controllers as well as the relevant environmental conditions change in time, thus the output performance can be deteriorated during the operating span of the system. Naturally the duty of calibration or the prevention of performance deterioration due to excessive component sensitivity should be provided to the control system. In this paper, we propose a digital controller which has the capability of calibration and gain adjustment as well as the execution of control law. Specifically the problems of gain adjustment and offset calibration in the light source and CdS sensor module for position measurement in a flexible link system are considerably resolved. The parameters of measurement module are prone to change due to environmental brightness conditions resulting in poor steady state performance of the overall control system. Thus a proper method is necessary to provide correction to the changed values of gain and offset in the position measurement module. The proposed controller, whenever necessary, measures the open-loop characteristics, andthen calculates the offset and sensor gain correction values based on the prepared standard measurements. It is applied to the control of a flexible link system with the gain and offset calibration porblems in the light sensor module for position to show the applicability.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2019년도 추계학술대회
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• pp.270-270
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• 2019

관성측정장치(Inertial Measurement Unit)는 선박, 잠수함, 항공기 등 여러 응용분야에서 적용되어 자세 측정 영역에 주로 사용되고 있지만, 이런 장비는 고가의 장비이기 때문에 특수 분야에서만 한정적으로 이용되어 왔다. 본 연구에서는 저가의 관성측정장치(Inertial Measurement Unit)를 이용하여 실시간으로 선박의 속도와 방향, 중력, 가속도를 측정함으로써 선박의 감항성을 확인하며, 더 나아가 실선 선박의 저항 및 조종성능 추정을 위한 유체력 미계수 추정을 위한 연구방법을 고안하였다. 이에 본 연구는 실제 해상에서 선체 운동요소를 계측하고, 계측된 데이터의 처리 및 해석을 통하여 선박의 종합적인 안전성 평가 및 실선의 저항 및 조종성능 추정을 행하였다.

• International Journal of Aeronautical and Space Sciences
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• 제17권4호
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• pp.614-621
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• 2016

Micro-Doppler (MD) shift caused by the micro-motion of a ballistic missile (BM) can be very useful to identify it. In this paper, the MD signatures of three scale-model BMs are investigated using a portable measurement system. The measurement system consists of an X-band 2-by-2 phase comparison mono-pulse radar, and a mechanical device that can impart controlled spinning and coning motions simultaneously to a model to yield the MD signature that replicates the characteristic of each target and the corresponding micro-motion. The coning motion determined the overall period of MD, and the spinning motion increased its amplitude. MD was also dependent on aspect angle. The designed system is portable, and can implement many micro-motions; it will contribute to analysis of MD in various situations.

• 한국항공운항학회지
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• 제9권1호
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• pp.45-58
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• 2001

According to the liberalization of the air transport industry, the operation of airport also takes account of economic efficiency. The owners or the operators of an airport or airport systems want to know what is the best way to achieve the best performance in the aspect of economic efficiency and they are willing to improve the airport operation system. Prerequisite for the improvement of economic efficiency is to measure the performance of not only their own airports but the other airports. This study presents the result of performance measurement of Korean airports. The overall costs performance, labor productivity, capital productivity, revenue performance and profit performance are estimated and interpreted. As conclusions, the suggestion about airport system improvement is presented.

• 한국콘텐츠학회논문지
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• 제18권3호
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• pp.390-398
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• 2018

본 연구는 현재 운영되고 있는 재정성과목표관리제도의 운영실태를 분석하고 이를 바탕으로 개선방안을 마련하고자 하였다. 이를 위하여 형사사법 행정기관 중 하나인 법무부의 성과관리체계 및 성과지표의 구성현황을 살펴보았으며, 특히 최근 5년간 제기되어 온 법무부의 성과관리 관련 문제점들을 성과계획과 성과보고 두 부문으로 나누어 검토하였다. 현행 성과관리 체계의 적절성에 대해서는 전반적으로 다소 적절하다고 보고 있지만, 성과목표 달성도를 측정하기 위한 성과측정 방식에 대해서는 부정적으로 인식하고 있으며, 성과목표의 국민의 관심사항 반영 정도에 대해서도 전문가들은 상대적으로 낮게 평가하였다. 이와 함께 달성하기 쉽고 측정하기 용이한 지표 선정 경향이 있다는 지적과 같이 전반적으로 법무부의 성과지표 설정 및 측정에 대해 비판적인 의견이 많았다. 이러한 문제점을 개선하기 위하여 대표성이 높은 성과지표를 설정할 수 있도록 중요도를 더욱더 강조하고 확대 반영할 필요가 있다는 의견이 높게 나타났다. 이러한 분석결과를 바탕으로 정책적 시사점을 도출하고 재정성과목표관리제도 개선을 위한 몇 가지 대안을 제시하였다.

• 한국콘텐츠학회논문지
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• 제19권5호
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• pp.115-127
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• 2019

본 연구는 지방자치단체가 수행하는 다양한 보조사업 중 장애인편의시설설치촉진사업에서 효과적이고 효율적인 성과관리 평가체계구축의 필요성과 실효성에 대해 논의하였다. 이와 함께 사회서비스 영역에서 성과평가시스템을 도입하면서 논리적 구조로 활용되는 논리모형을 적용하여 사회복지시설평가영역에 포함되지 않는 장애인편의시설설치촉진사업의 성과관리 평가지표를 개발함을 목적으로 한다. 이를 위해 문헌검토와 초점집단인터뷰를 통해 성과관리 평가지표를 개발하고 시범평가를 통해 평가지표의 타당성 및 평가용이성 분석을 실시한 후, 시범평가결과를 바탕으로 현장의견조사 및 전문가를 통한 타당성 검토를 진행하여 최종지표를 개발하였다. 최종 개발된 평가지표는 전체 8개 영역, 39개 문항으로 구성되었다. 장애인편의시설설치촉진사업 성과관리 평가체계 구축을 통해 장애인편의시설설치촉진사업 전반의 합리화를 추구하고자 하였으며, 본 연구에서 제시된 성과관리 평가지표의 개념틀과 평가접근 방식은 공공부문의 다양한 사회서비스 유형과 특성에 적합하게 활용될 수 있을 것이다.

• 대한전기학회논문지:전력기술부문A
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• 제48권8호
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• pp.996-1003
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• 1999

This paper propose a position-speed controller with an estimator which can estimate states and disturbance. The overall control system consists of two parts: the position-speed controller and an estimator. The Kalman filter applied as state-feedback controller is an optimal state estimator applied to a dynamic system that involves random perturbations and gives a linear, unbiased and minimum error variance recursive algorithm to optimally estimate the unknown state. Therefore, we consider the error problem about the servo system modeling and the measurement noise as a stochastic system and implement a optimal state observer, and enhance the estimate performance of position and speed using that. Using two-degree-of freedom(TDOF) conception, we design the command input response and the closed loop characteristics independently. The servo system is to improve the closed loop characteristics without affecting the command imput response. The characteristics of the closed loop system is improved by suppressing disturbance torque effectively with the disturbance observer using a inverse-transfer matrix. Therefore, the performance of overall position-speed controller is enhanced. Finally, the performance of the proposed controller is exemplified by some simulations and by applying the real servo system.

• 대한의용생체공학회:의공학회지
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• 제43권6호
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• pp.417-423
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• 2022

The present study proposed a new interface system for capsule endoscopy by using head mounted display (HMD) device, which can control the orientation of the capsule endoscope with electromagnetic actuator (EMA) system. The orientation information of the HMD user was detected by the gyroscope sensor built into the device and then calculated to as an angle increment using Unity Engine compiler. The measured angle changes from the HMD were converted to the current values of the corresponding coils to be changed in the EMA system. Two experiments were designed to measure the accuracy and the intuitiveness of the HMD interface system. In the angle accuracy measurement, the capsule endoscope driven by HMD interface system showed the averaged errors of 0.68 degrees horizontally and 1.001 degrees vertically for given test angles. In the intuitiveness measurement, HMD interface system showed 1.33 times faster manipulation speed rather than the joystick interface system. In this respect, the HMD interface system for capsule endoscopy was expected to improve the overall diagnostic environment while maintaining comfort of patients and clinicians.

• 대한기계학회논문집B
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• 제20권12호
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• pp.4027-4035
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• 1996

Accuracy of gas flow measurements using sonic nozzle and factors which influence on the discharge coefficients of sonic nozzle are investigated with high pressure gas flow standard measurement system. The gas flow measurement system comprises two compressors, storage tank, temperature control loop, sonic nozzle test section, weighing tank, gyroscopic scale and data acquisition system. The experiments are performed at various nozzle throat diameter and inlet pressure. Overall uncertainty of discharge coefficients is estimated to less than .+-.0.2% and most of experimental data fall into this range. Dependence of discharge coefficients on the Reynolds number is good agreement with those suggested in ISO document. The influence of swirl on the discharge coefficients becomes greater as the nozzle throat diameter is enlarged. The discharge coefficient of conical nozzle shows about 4.5% lower discharge coefficients than those of toroidal nozzle, but variation trend with Reynolds number is very similar each other and reproducibility of data is very good.

• Journal of Electrical Engineering and Technology
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• 제2권3호
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• pp.401-407
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• 2007

Precise absolute measurement of the errors in a potential transformer (PT) can be achieved using high voltage capacitance bridge (HVCB) and capacitive divider. The uncertainty in a PT measurement using the HVCB system was evaluated by considering the overall factors affecting during the calibration of a PT. The expanded uncertainties are found to be not more than $30{\times}10^{-6}$ for ratio and $30{\mu}rad$ for phase up to the primary voltage of $V_p=22kV$. For same PTs, the measured errors in KRISS (Korea Research Institute of Standards and Science) using our bridge are well coincide with those in NMIA (National Measurement Institute of Australia) and PTB (Physikalisch-Technische Bundesanstalt) within the corresponding uncertainties.