• 한국측량학회지
• /
• 제25권6_1호
• /
• pp.529-536
• /
• 2007

Registration between image and object space is a fundamental step in photogrammetry and computer vision. Along with rapid development of sensors - multi/hyper spectral sensor, laser scanning sensor, radar sensor etc., the needs for registration between different sensors are ever increasing. There are two important considerations on different sensor registration. They are sensor invariant feature extraction and correspondence between them. Since point to point correspondence does not exist in image and laser scanning data, it is necessary to have higher entities for extraction and correspondence. This leads to modify first, existing mathematical and geometrical model which was suitable for point measurement to line measurements, second, matching scheme. In this research, linear feature is selected for sensor invariant features and matching entity. Linear features are incorporated into mathematical equation in the form of extended collinearity equation for registration problem known as photo resection which calculates exterior orientation parameters. The other emphasis is on the scheme of finding matched entities in the aide of RANSAC (RANdom SAmple Consensus) in the absence of correspondences. To relieve computational load which is a common problem in sampling theorem, deterministic sampling technique and selecting 4 line features from 4 sectors are applied.

• Korean Chemical Engineering Research
• /
• 제48권1호
• /
• pp.53-57
• /
• 2010

본 연구에서는 $290{\sim}350^{\circ}C$의 범위에서 PTFE(polytetrafluoroethylene)의 풀림(annealing) 공정을 수행하여, 결정화도와 인장 강도에 미치는 영향을 조사하였다. 풀림 공정은 대기압에서 진행되었고, 공정 시간은 8 시간까지 진행하였다. 인장강도의 측정 및 주사전자현미경(scanning electron microscope)의 측정을 통하여 PTFE 시편의 이방성을 확인하였다. 시차주사열량분석(differential scanning calorimetry)을 통하여 공정 전후의 결정화도를 측정하였고, 풀림 공정이 행해진 PTFE로부터 결정화도의 감소와 인장 강도의 증가를 확인하였다. 풀림 공정이 시행된 PTFE의 결정화도와 인장강도는 선형적 증감(增減) 관계를 나타내었지만, 풀림공정 시행 전의 PTFE는 이 선형 관계에서 벗어나 있었다. 그리고 풀림 공정온도가 $350^{\circ}C$이고 공정시간이 6 시간일 때, 가장 낮은 결정화도와 가장 높은 인장강도를 얻을 수 있었다.

• Journal of the Optical Society of Korea
• /
• 제15권1호
• /
• pp.96-102
• /
• 2011

Simultaneous measurements using a scanning spectrograph system and transmissometer were performed for the first time over an urban site in Gwangju, Korea, to derive the ambient $NO_2$ volume mixing ratio. The differential slant column densities retrieved from the scanning spectrograph system were converted to volume mixing ratios using the light traveling distance along the scanning line of sight derived from the transmissometer light extinction coefficients. To assess the performance of this system, we compared the derived $NO_2$ volume mixing ratios with those measured by an in situ chemiluminescence monitor under various atmospheric conditions. For a cloudless atmosphere, the linear correlation coefficient (R) between the two data sets (i.e., data derived from the scanning spectrograph and from the in situ monitor) was 0.81; the value for a cloudy atmosphere was 0.69. The two sets of $NO_2$ volume mixing ratios were also compared for various wind speeds. We also consider the measurement errors, as estimated from an error propagation analysis.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제17권6호
• /
• pp.1635-1656
• /
• 2023

In Bayesian multi-target tracking, the Poisson multi-Bernoulli mixture (PMBM) filter is a state-of-the-art filter based on the methodology of random finite set which is a conjugate prior composed of Poisson point process (PPP) and multi-Bernoulli mixture (MBM). In order to improve the random finite set-based filter utilized in multi-target tracking of sensor scanning, this paper introduces the Poisson multi-Bernoulli mixture filter into time-matching Bayesian filtering framework and derive a tractable and principled method, namely: the time-matching Poisson multi-Bernoulli mixture (TM-PMBM) filter. We also provide the Gaussian mixture implementation of the TM-PMBM filter for linear-Gaussian dynamic and measurement models. Subsequently, we compare the performance of the TM-PMBM filter with other RFS filters based on time-matching method with different birth models under directional continuous scanning and out-of-order discontinuous scanning. The results of simulation demonstrate that the proposed filter not only can effectively reduce the influence of sampling time diversity, but also improve the estimated accuracy of target state along with cardinality.

• Elastomers and Composites
• /
• 제22권4호
• /
• pp.333-339
• /
• 1987

A modern kinetic evaluation method for nonisothermal reactions measured with Differential Scanning Calorimetry(DSC) is presented. It is based on multiple linear regression analysis using a number of curve points in a selectable range of conversion. The obtained kinetic data are the basis to compute a reaction process under any condition e.g. isothermal or adiabatic. The DSC measurements was performed on a Mettler TA3000 SYSTEM with the built in evaluation software. Mainly the following reactions are discussed: vulcanization of natural rubber compounds containing vulcanizing accelerators. The purpose of this work is to analyse the vulcanization kinetics of typical NR vulcanization systems using DSC. These systems were chosen because they are typically reactive elastomer and are commercially important.

• 대한기계학회논문집
• /
• 제17권7호
• /
• pp.1731-1739
• /
• 1993

An application of Scanning Tunneling Microscopy(STM) is investigated for the measurement of 3-dimensional profiles of the macro-machined patterns of which critical dimensions lie in the range of submicrometers. Special emphasis of this investigation is given to extending the measuring ranges of STM upto the order of several micrometers while maintaining superb nanometer measuring resolution. This is accomplished by correcting hysteresis effects of piezoelectric actuators by using non-linear compensation models. Detailed aspects of design and control of a prototype measurement system are described with some actual measuring examples in which fine It patterns can successfully be traced with a resolution of 1 nanometer over a surface range of $4{\times}2$ micrometers.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2006년도 하계종합학술대회
• /
• pp.885-886
• /
• 2006

The purpose of this study is to develop the optimal system(AAC device), which helps a person with a profound communication disorder to communicate with other people. Therefore, this system includes the user interface enhancement that is the user adaptation mode algorithm. The symbol is made with a text and an icon which is converted into Korean. The message contiol operates scanning and adjusts rate control of row-column scanning and linear scanning. This embedded system includes voice input/output and voice recording as well suggested method that could apply optimal device access algorithm from clinical environment. Therefore, we are experting that even the current system itself will be able to improve the life quality of people who need to communicate with the help of devices.

• 센서학회지
• /
• 제21권2호
• /
• pp.96-102
• /
• 2012

This paper addresses photometric distortion problems of a compact 3D scanning sensor which is composed of a micro-size and inexpensive camera-projector system. Recently, many micro-size cameras and projectors are available. However, erroneous 3D scanning results may arise due to the poor and nonlinear photometric properties of the sensors. This paper solves two inherent photometric distortions of the sensors. First, the response functions of both the camera and projector are derived from the least squares solutions of passive and active calibration, respectively. Second, vignetting correction of the vision camera is done by using a conventional method, however the projector vignetting is corrected by using the planar homography between the image planes of the projector and camera, respectively. Experimental results show that the proposed technique enhances the linear properties of the phase patterns that are generated by the sensor.

• 한국광학회지
• /
• 제6권3호
• /
• pp.173-177
• /
• 1995

칼날주사방법을 이용한 CCD의 MTF 측정장치를 제작하고 일차원 CCD의 MTF특성을 측정하였다. 주사방향에 수직인 직선과 칼날이 이루는 각도에 따른 CCD MTF 측정값의 변화는 $1^{\circ}$ 미만의 작은 각도변화에 의해서도 MTF값이 크게 변함을 알 수 있었으며 CCD의 MTF 측정값은 간섭필터와 텅스텐 필라멘트가 조합된 파장에 따라 다른 값을 나타내었다. 또한 광원의 색온도 변화에 의한 CCD의 MTF특성과 CCD 화소들의 균일성을 조사하였다.

• 한국진공학회지
• /
• 제15권5호
• /
• pp.512-517
• /
• 2006

신뢰도 높은 나노 직선 이동장치를 제작하였다. 장치는 기본 몸체에 고정된 6개의 피에조 다리들과 이들이 붙잡고 있는 사파이어 육각기둥으로 이루어 졌다. 특정한 전압파형을 피에조 다리에 인가하여 피에조 다리를 순차적으로 움직임으로 육각기둥을 앞으로 혹은 뒤로 움직인다. 직선 이동장치를 지표면에 수직 방향으로 시험구동 하였다. 육각기둥이 수 mm를 움직이는 동안 속도가 일정함을 확인하였다. 위쪽으로 올라가는 가장 느린 속도는 $1.7{\times}10^{-6}m/s$, 즉 ${\sim}28.3nm$/걸음이었고 아래쪽으로 내려가는 가장 느린 속도는 중력의 도움을 받아 ${\sim}3.7{\times}10^{-6}m/s$, 즉 ${\sim}61.7nm$/걸음 이었다. 피에조에 인가된 전압을 증가시키면 육각기둥의 이동속도가 선형으로 증가하였다. 이 직선 이동장치를 주사형 터널링 현미경의 접근 장치로 사용할 것이다.