• 한국안광학회지
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• 제5권2호
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• pp.1-4
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• 2000

입체시 검사는 양안시 기능을 정확히 알 수 있는 것으로서 임상분야에서 많이 이용하고 있다. 본 연구의 목적은 조도와 검사거리의 차이에 의한 Random-dot E(RDE) 입체시 검사를 실시하였다. 조명이 증가할수록 RDE의 통과는 증가하였다. 한편 검사표적이 가까울수록 모든 피검자는 RDE를 통과하였다. 그러나 원거리에서 일부 피검자는 RDE를 통과하지 못하였다. 검사거리에 따라서 먼거리 표적일수록 RDE통과는 적었다. 결과적으로 RDE 입체시 검사는 검사거리와 조명에 영향을 받는다.

• 한국군사과학기술학회지
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• 제15권1호
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• pp.66-74
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• 2012

The virtual target signal generator was developed to verify the shipborne tracking radar performance. It was used to DRFM(Digital RF Memory) method to generate the virtual moving targets. The target signal includes Doppler shift and RCS according to the target motion. And the signal generator can make jamming signal and clutter to test shipborne radar performance at real environmental condition. This paper described the functional diagram and the hardware configuration items to meet the test requirements for the tracking radar. And it showed the critical design points for the sub-systems. The signal generator which was developed in this paper shared the operational information of the radar with the radar command and control part. To test the frequency agility of the radar, it had the local oscillator which could do high speed frequency switching according to radar information. By communicating between the signal generator and the radar command and control part, the local oscillator of signal generator could be controlled every pulse. It reduced the instantaneous bandwidth of signal generator and minimized the spurious. So it lowered the probability of generating wrong targets.

• 한국소음진동공학회논문집
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• 제18권3호
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• pp.368-374
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• 2008

Multi-axial simulation table(MAST) is widely used in motor companies as the multi-axial excitor for vibration fatigue of target component, which provides the vibrational condition as close as the vehicle test. However, the vibration fatigue performance of target component can be guaranteed with MAST system only in case the input profile covers the required severity of the target component on field test. In this paper, the signal processing for multi-axial vibration fatigue test on vehicle component is presented, from the data acquisition of the target component to the derivation of input profile. To compare the severity of vibration condition between field and proving ground, the energy principle of a equivalent damage is proposed and then, it is determined the optimal combination of special events on proving ground using a sequential searching optimal algorithm. To explain the vibration methodology clearly, seat and door component of vehicle are selected as a example.

• 한국전자파학회논문지
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• 제29권6호
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• pp.457-463
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• 2018

이 논문에서는 실제 레이다를 이용하여 획득한 신호와 시뮬레이션으로 획득한 신호에 ${\Sigma}{\Delta}-STAP$ 알고리즘을 적용하여 비교하였다. 시험은 무반향 챔버에서 모의신호 발생장치를 이용한 표적 신호와 신호발생기를 이용한 클러터 신호를 레이다로 수신하여 수행하였다. 시뮬레이션은 시험과 동일한 레이다 파라미터에 이상적인 기저대역 신호 모델링을 통하여 수행하였다. 비교 결과, ${\Sigma}{\Delta}-STAP$ 처리된 거리-도플러 맵은 표적 신호의 형태나 잡음 수준이 시뮬레이션과 시험 결과가 거의 유사하였다. SINR 손실의 경우, 두 결과가 비슷한 양상을 보이나, 시뮬레이션 결과가 1~2 dB 가량 높은 값을 보였다. 이를 통하여 일반적인 레이다 신호 시뮬레이션을 수행하여도 실제 시험 결과와 유사한 ${\Sigma}{\Delta}-STAP$ 처리 결과를 얻을 수 있음을 확인하였다.

• 한국자동차공학회논문집
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• 제21권6호
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• pp.16-23
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• 2013

It is important that proving ground damage is correlated with target customer usage. This paper describes the test mode for durability test of active suspension control system for proving ground correlation and optimization. Acceleration, strain, wheel force and other types of data are collected on a vehicle as it traverses different proving ground surfaces. The primary objective of the analysis is to determine which mixture of proving ground surfaces offers the best representation of customer usage while minimizing the total test time. And durability testing offers the best way to assess the capability of a product to reach its reliability target. The test should be representative of the real environmental load and replicate the same customer usage.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2006년도 춘계학술대회 논문집
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• pp.7-14
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• 2006

Detection and identification of targets from remotely sensed imagery are of great interest for civilian and military application. This paper presents an algorithm for target detection in high spatial resolution imagery based on the spectral and the dimensional characteristics of the reference target. In this algorithm, the spectral and the dimensional information of the reference target is extracted automatically from the sample image of the reference target. Then in the entire image, the candidate target pixels are extracted based on the spectral characteristics of the reference target. Finally, groups of candidate pixels which form isolated spatial objects of similar size to that of the reference target are extracted as detected targets. The experimental test results showed that even though the algorithm detected spatial objects which has different shape as targets if the spectral and the dimensional characteristics are similar to that of the reference target, it could detect 97.5% of the targets in the image. Using hyperspectral image and utilizing the shape information are expected to increase the performance of the proposed algorithm.

• 대한원격탐사학회지
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• 제22권1호
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• pp.41-47
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• 2006

Detection and identification of targets from remotely sensed imagery are of great interest for civilian and military application. This paper presents an algorithm for target detection in high spatial resolution imagery based on the spectral and the dimensional characteristics of the reference target. In this algorithm, the spectral and the dimensional information of the reference target is extracted automatically from the sample image of the reference target. Then in the entire image, the candidate target pixels are extracted based on the spectral characteristics of the reference target. Finally, groups of candidate pixels which form isolated spatial objects of similar size to that of the reference target are extracted as detected targets. The experimental test results showed that even though the algorithm detected spatial objects which has different shape as targets if the spectral and the dimensional characteristics are similar to that of the reference target, it could detect 97.5% of the targets in the image. Using hyperspectral image and utilizing the shape information are expected to increase the performance of the proposed algorithm.

• 대한방사선기술학회지:방사선기술과학
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• 제39권4호
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• pp.631-636
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• 2016

공간 분해능을 평가하기 위해서 이제까지는 일정하게 두 물체의 간격(이중 표적)을 근접한 것부터 점점 떨어진 간격으로 만들어진 테스트 패턴이나 팬텀을 이용하였다. 이러한 방법으로 공간분해능을 평가하면 분해능은 테스트용으로 제작된 팬텀에 있는 표적 간격으로 제한된다. 본 연구는 이러한 문제를 극복하고자 1개의 단일 표적으로 공간 분해능을 간편하게 측정할 수 있는 새로운 방법을 제안하고 검증한 것이다. 이를 위해 PSF 및 JND를 이용하여 공간 분해능을 추정하는 개념을 제시하였다. 이렇게 유도된 공간 분해능 추정 이론을 검증하기 위해, 상용 팬텀을 이용하여 실험하였다. 실험으로 얻어진 디지털 영상에서 라인 픽셀 프로파일을 구하기 위해 만든 LabVIEW 프로그램을 이용하여 분석한 결과, 본 연구에서 유도한 단일 표적을 이용한 공간 분해능 추정 이론과 실험적으로 일치하는 것을 알 수 있었다. 실험 결과로 디지털 영상에서 공간분해능의 상대적 평가는 단일 표적을 가지고도 충분하다는 것을 증명할 수 있었다. 따라서 단일 표적 공간분해능 평가법을 이용하면 이제까지 사용되어 왔던 이중 표적을 이용한 공간분해능 평가의 한계를 극복할 수 있다.

• The Journal of Advanced Prosthodontics
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• 제16권1호
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• pp.38-47
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• 2024

PURPOSE. This study aims to evaluate the accuracy of different shade selection techniques and determine the matching success of crown restorations fabricated using digital shade selection techniques. MATERIALS AND METHODS. Teeth numbers 11 and 21 were prepared on a typodont model. For the #11 tooth, six different crowns were fabricated with randomly selected colors and set as the target crowns. The following four test groups were established: Group C, where the visual shade selection was performed using the Vita 3D Master Shade Guide and the group served as the control; Group Ph, where the shade selection was performed under the guidance of dental photography; Group S, where the shade selection was performed by measuring the target tooth color using a spectrophotometer; and Group I, where the shade selection was performed by scanning the test specimens and target crowns using an intraoral scanner. Based on the test groups, 24 crowns were fabricated using different shade selection techniques. The ΔE values were calculated according to the CIEDE2000 (2:1:1) formula. The collected data were analyzed by means of a one-way analysis of variance. RESULTS. For the four test groups (Groups C, Ph, S, and I), the following mean ΔE values were obtained: 2.74, 3.62, 2.13, and 3.5, respectively. No significant differences were found among the test groups. CONCLUSION. Although there was no statistically significant difference among the shade selection techniques, Group S had relatively lower ΔE values. Moreover, according to the test results, the spectrophotometer shade selection technique may provide more successful clinical results.

• 한국군사과학기술학회지
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• 제16권5호
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• pp.613-621
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• 2013

This paper presents the direction finding proximity fuze sensor using the clutter rejection method and the adaptive target detection algorithm for anti-air missiles. To remove effects by clutter and detect a target accurately, the clutter rejection method of Legendre sequence with BPSK(Bi phase Shift Keying) modulation has been proposed and the Doppler signal which has cross correlation characteristics is obtained from reflected target signals. Considering the change of the Doppler signal, the adaptive target detection algorithm has been developed and the direction finding algorithm has been fulfilled by comparing received powers from adjacent three receiving antennas. The encounter simulation test apparatus was made to collect and analyze reflected signal and test results showed that the -10 dBsm target was detected over 10 meters and the target with mesh clutter was detected and direction was distinguished definitely.