• 제어로봇시스템학회논문지
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• 제6권10호
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• pp.845-853
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• 2000

In this paper, we introduce a relationship between the sensitivity and the robustness of a system, and we propose a robust eigenstructure assignment scheme using a novel performance index which can consider the performance and the robustness of the system simultaneously. We also propose an assignment accuracy measure and a robustness measure which are used for the performance examination of the proposed robust eigenstructure assignment scheme. The usefulness of the proposed algorithm and the measures are verified by applying to controller design of a simple numerical example and the EMRAAT missile.

• 한국측량학회:학술대회논문집
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• 한국측량학회 2004년도 춘계학술발표회논문집
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• pp.51-55
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• 2004

In this study, the levelling and the GPS levelling were carried out with 6 points in 2km${\times}$2km area and the results were analysed. As a result of this research, we had to observe more than 15 minutes to get the height accuracy of 10mm by single frequency GPS receiver in relative surveying. We could not get more better accuracy than 10mm. we could get the height accuracy of within 10mm from observing only more than 5 minutes by double frequency GPS receiver, and of within about 3mm from observing more than 10 minutes. When the number of fixed points is within 3, the level net adjustment result is very close to the one of direct levelling survey. When the number of fixed points is 3, the less the area of triangle the better the adjustment result, and the case of including measure point has more better accuracy than that of non-including measure point.

• 한국멀티미디어학회논문지
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• 제20권7호
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• pp.1046-1053
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• 2017

We propose a design method of high accuracy power measuring device and the method of securing the reliability of the measured data. As a design method for the development of the high accuracy power measuring device, the circuit was made by reflecting the high accuracy power measuring ICs and the CT (Current Transformer). To ensure the reliability of the power meter, we requested to the watt-hour meter certified testing organization to measure the error rate, and the error rate of active power based on the "Wattmeter Technical Standard(Revision notify 2014-283)" was measure, and the error rate was confirmed to be less than 0.1%.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2002년도 추계학술대회 논문집
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• pp.387-392
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• 2002

It is very important to measure linear cycle plane positioning accuracy of NC lathes as they affect those of all other machines machined by them in industries. For example, if the linear cycle plane positioning accuracy of each axes directions is bad, the accuracy of works will be wrong and the change-ability will be bad in the assembly of machine parts. In this paper, computer software systems are organized to measure linear displacements of ATC(Automatic tool changer) of NC lathes using linear scale and time pulses comming out from computer in order to get data at constant time intervals from the sensors. And each sets of error data gotten from the test is expressed to plots by computer treatment and the results of linear cycle plane positioning error motion estimated to numerics by statistical treatments.

• Journal of Computing Science and Engineering
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• 제5권4호
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• pp.294-304
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• 2011

Enhancing continuous queries over data streams with temporal functions and predicates enriches the expressive power of those queries. While traditional continuous queries retrieve only the values of attributes, temporal continuous queries retrieve the valid time intervals of those values as well. Correctly evaluating such queries requires the coalescing of adjacent timestamps for value-equivalent tuples prior to evaluating temporal functions and predicates. For many stream applications, the available computing resources may be too limited to produce exact query results. These limitations are commonly addressed through load shedding and produce approximated query results. There have been many load shedding mechanisms proposed so far, but for temporal continuous queries, the presence of coalescing makes theses existing methods unsuitable. In this paper, we propose a new accuracy metric and load shedding algorithm that are suitable for temporal query processing when memory is insufficient. The accuracy metric uses a combination of the Jaccard coefficient to measure the accuracy of attribute values and $\mathcal{PQI}$ interval orders to measure the accuracy of the valid time intervals in the approximate query result. The algorithm employs a greedy strategy combining two objectives reflecting the two accuracy metrics (i.e., value and interval). In the performance study, the proposed greedy algorithm outperforms a conventional random load shedding algorithm by up to an order of magnitude in its achieved accuracy.

• 한국인터넷방송통신학회논문지
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• 제20권5호
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• pp.51-56
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• 2020

측정 명령어에 따른 정확도와 소요시간은 효율적인 Ka 밴드용 자동 시험 장비(ATE)를 구축하는데 중요한 요소이다. 이에 따라 본 논문에서는 RF 대표 계측기 Power Meter의 측정 명령어에 대해 연구하였다. 30 G ~ 31 GHz에서 Power Meter의 측정 명령어 FETCH와 MEASURE의 각 측정 레벨에 따른 정확도와 소요시간을 비교하였으며, -70 ~ +20 dBm 영역을 2가지 Power Sensor로 측정하였다. 측정 결과 신속하게 데이터를 불러오는 FETCH 명령어는 잡음 레벨보다 높은 선형 구간에서 비교적 정확한 데이터를 얻을 수 있었다. 가장 정확한 데이터를 얻을 수 있는 MEASURE 명령어는 FETCH 대비 시간이 많이 소요 되었으며, 최대 13.2초가 소요 되었다. 이를 통해 30 G ~ 31 GHz에서 Power Meter 측정 명령어의 정확도와 측정 소요시간을 확인할 수 있었고, 해당 연구 결과는 효율적인 Ka 밴드용 ATE를 구축하는데 기준을 제시할 수 있을 것으로 기대된다.

• 컴퓨터교육학회논문지
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• 제21권5호
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• pp.61-68
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• 2018

협력 필터링은 다수의 상업용 추천 시스템에서 구현되어 온라인 사용자들에게 성공적으로 서비스되고 있는 핵심적 기술이다. 이 기술은 현 사용자와 유사한 평가이력을 가진 다른 사용자들로부터 항목을 추천하기 때문에, 유사도 척도는 시스템 성능에 매우 큰 영향을 미친다. 본 연구에서는 기존 유사도 측정 방법의 문제점을 해결하고자 퍼지 논리에 입각하여 사용자 평가등급의 주관성 및 모호성과 사용자들의 평가 행태를 반영하는 새로운 유사도 척도를 제안한다. 성능 평가를 위한 다양한 실험을 실시하였고, 그 결과 제안 방법은 예측 정확도와 추천 정확도 면에서 우수한 성능 개선 효과를 보였다.

• 제어로봇시스템학회논문지
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• 제8권7호
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• pp.573-577
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• 2002

A tape feeder of a SMD(Surface Mount Device) mounter is a device that sequentially feeds electronic components on a tape reel to the pick-up system of the mounter. As components are getting much smaller, feeding accuracy of a feeder becomes one of the most important factors for successful component pick-up. Therefore, it is critical to keep the feeding accuracy to a specified level in the assembly and production of tape feeders. This paper describes a tape feeder inspection system that was developed to automatically measure and inspect feeding accuracy using machine vision. It consists of a feeder base, an image acquisition system, and a personal computer. The image acquisition system is composed of CCD cameras with lens, LED illumination systems, and a frame grabber inside the PC. This system loads up to six feeders at a time and inspects them automatically and sequentially. The inspection software was implemented using Visual C++on Windows NT with easily usable GUI. Using this system, we can automatically measure and inspect the quality of all feeders in production process by analyzing the measurement results statistically.

• 대한공간정보학회지
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• 제14권4호통권38호
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• pp.3-10
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• 2006

본 연구에서는 구축된 GIS 폴리곤 데이터의 위치정확도를 측정할 수 있는 방법을 제시하고자 하였다. 그리고 기존까지 개별 방법에 의한 위치정확도 측정 방법을 개선하여 개별 방법들을 연계 이용함으로써 위치오차의 발생 유형까지 분석할 수 있는 가능성을 제시하고자 하였다. 방법론을 실제 실험지역에 적용하여본 결과, 실험대상지역에 대하여 위치정확도의 측정이 가능하였고, 또한 각각의 지수 연결(방법론 연결)을 통하여 위치오차의 발생원인(유형)을 분석할 수 있었다. 궁극적으로 방법론의 적용가능성을 확인할 수 있었다. 그러나 방법론의 타당성을 확보하기 위해서는 각각의 기준 수치에 대한 보완 연구가 있어야 할 것으로 판단된다.

• 한국멀티미디어학회논문지
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• 제21권12호
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• pp.1493-1503
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• 2018

We propose an object recognition system and experiential game contents using Kinect to maximize object recognition rate by utilizing underwater robots. we implement an ice hockey game based on object-aware interactive contents to validate the excellence of the proposed system. The object recognition system, which is a preprocessor module, is composed based on Kinect and OpenCV. Network sockets are utilized for object recognition communications between C/S. The problem of existing research, degradation of object recognition at long distance, is solved by combining the system development method suggested in the study. As a result of the performance evaluation, the underwater robot object recognized all target objects (90.49%) with 80% of accuracy from a 2m distance, revealing 42.46% of F-Measure. From a 2.5m distance, it recognized 82.87% of the target objects with 60.5% of accuracy, showing 34.96% of F-Measure. Finally, it recognized 98.50% of target objects with 59.4% of accuracy from a 3m distance, showing 37.04% of F-measure.