• 한국정밀공학회지
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• 제4권2호
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• pp.47-55
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• 1987

Recently, in precision working, precision is in submicron. Therefore, when we measure various finished goods in superfine measurement, because it is relatively difficult to disregard effect of surroundings, these effect of surroundings must be compensated or canceled. In this study, for roundness measurement, three point method is researched which is able to cancel the effect of rotation accuracy of axis and eccenricity of workpiece. It is difference between this three point method and tradi- tional three point method whose measuring apparatus have three movable pickups posit- ioned with angle and between the pickups. As a results, when rotation accuracy of axis is varied from $0.02\mu\textrm{m}$ to $0.05\mu\textrm{m}$ the width of variation of measured roundness is $0.04\mu\textrm{m}$. And, when eccentricity of workpiece is varied from 0 to $4\mu\textrm{m}$, the width of variation of measured roundness is $0.005\mu\textrm{m}$. These error width are disregardable because they are in 10% of measured roundness. Therefore, by this three point method, the effect of rotation accuracy of axis and the effect of eccentricity of workpiece are canceled. And we are able to select the angle between the pickups ($\phi$ and $\tau$) by means of relation between $F_{k}$ and K.

• 센서학회지
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• 제9권3호
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• pp.153-162
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• 2000

평형수소 삼중점 (13.8033 K)부터 물의 삼중점 (273.16 K) 온도영역에서 표준온도계로 사용되는 캡슐형 백금저항온도계를 일차 교정하려면 고순도 물질의 삼중점이 사용된다. 국제온도눈금-1990 (ITS-90)을 확립하기 위해 평형수소, 네온, 산소, 아르곤, 수은 및 물의 삼중점 중에서 평형수소의 삼중점을 제외한 5 개의 삼중점을 실현하였다. 각각의 삼중점에서 국제비교용으로 채택된 캡슐형 백금저항온도계 2대의 저항을 2회 반복하여 측정하였다. 측정된 삼중점에서의 합성표준불확도는 A형 불확도와 B형 불확도 평가방법을 고려하여 산출하였다. 한국표준과학연구원에서 ITS-90에 정의된 네온, 산소, 아르곤, 수은 및 물의 삼중점에서의 합성표준불확도 추정결과는 각각 0.18 mK, 0.14 mK, 0.14 mK, 0.24 mK 및 0.11 mK 이었다.

• 방송공학회논문지
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• 제25권5호
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• pp.798-807
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• 2020

디지털 카메라와 휴대폰 카메라의 발달로 인해 이미지를 기반으로 3차원 물체를 복원하는 기술이 크게 발전했다. 하지만 Structure-from-Motion(SfM)과 Multi-view Stereo(MVS)를 이용한 결과인 dense point cloud에는 여전히 듬성한 영역이 존재한다. 이는 깊이 정보를 추정하는데 있는 어려움과, 깊이 지도를 point cloud로 fusing할 때 이웃 영상과의 깊이 정보가 불일치할 경우 깊이 정보를 삭제하고 point를 생성하지 않았기 때문이다. 본 논문에선 평면을 모델링하여 삭제된 깊이 정보에 새로운 깊이 정보를 부여하고 point를 생성하여 기존 결과보다 dense한 point cloud를 생성하는 알고리즘을 제안한다. 실험 결과를 통해 제안하는 알고리즘이 효과적으로 기존의 방법보다 dense한 point cloud를 생성함을 확인할 수 있다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 하계종합학술대회 논문집(2)
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• pp.277-280
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• 2002

This paper analyze the characteristics of three multipliers in finite fields GF(2m) from the point of view of processing time and area complexity. First, we analyze structure of three multipliers; 1) LSB-first systolic array, 2) LFSR structure, and 3) CA structure. To make performance analysis, each multiplier was modeled in VHDL and was synthesized for FPGA implementation. The simulation results show that LFSR structure is best from the point of view of area complexity, and LSB systolic array is best from the point of view of processing time per clock.

• 한국환경보건학회:학술대회논문집
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• 한국환경보건학회 2004년도 International Conference Current Challenges and Advances in Environmental Health
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• pp.76-77
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• 2004

• 호남수학학술지
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• 제28권3호
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• pp.409-415
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• 2006

On a compact oriented smooth 3-dimensional manifold (M, g), we consider the critical point equation(CPE) defined as $z_g=s^{{\prime}*}_g(f)$. Under CPE, it is shown in [5] that every stable minimal hypersurface in M is contained in ${\varphi}^{-1}(0)$ for ${\varphi}{\in}$ ker $s^{{\prime}*}_g$. We study analytic and geometric conditions under which the stable minimal hypersurface in M does not exist.

• Korean Journal of Mathematics
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• 제30권1호
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• pp.161-173
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• 2022

In this paper, we present a fixed point theorem for Meir-Keeler contraction in the framework of Rectangular M_b-metric Space. Our main result improves some existing results in literature. An example is also adopted to exhibit the utility of our main result.

• 한국측량학회:학술대회논문집
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• 한국측량학회 2006년도 춘계학술발표회 논문집
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• pp.485-490
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• 2006

In this study, the Digital Surface Models of various spatial resolutions were constructed using LIDAR point data on Digital Photogrammetric System. Then, the accuracies of each DSM's were evaluated using GPS surveying data. And also, observable features were classified and their accuracies were evaluated to verify the availability for Ground Control Point. On Socet Set, Digial Photogrametric System 5 DSM's of which spatial resolutions were 0.15m, 0.5m, 1.0m, 2.5m and 5.0m were constructed and the accuracies of eahc DSM's evaluated in RMSE. The RMSE's of each DSM's were 0.03m, 0.05m, 0.08m, 0.12m and 0,19m. The building feature was observable in DSM's of which spatial resolutions were 0.15m, 0.30m and 0.50m. On the contrary, it could hardly be observed in those of other spatial resolutions. In comparison with the digital map at the scale of 1:1,000, the DSM at the spatial resolution of 0.lim was shifted horizaltally by 0.6m-0.7m of RMSE in each X, Y direction. Therefore, GCP of which horizontal RMSE is better than 1m can be obtained from the DSM at the spatial resolution of 0.15m, of which vertical RMSE is 0.03m-0.19m as the RMSE of DSM. This point cannot be used in aerial triangulation of cartography but can be used for GCP in modeling of satellite image at the moderate resolution.

• Journal of applied mathematics & informatics
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• 제35권5_6호
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• pp.551-563
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• 2017

In this paper, by using fixed point theorems in cones, the existence of positive solutions is considered for nonlinear m-point boundary value problem for the following second-order dynamic equations on time scales $$u^{{\Delta}{\nabla}}(t)+a(t)f(t,u(t))=0,\;t{\in}(0,T),\;{\beta}u(0)-{\gamma}u^{\Delta}(0)=0,\;u(T)={\sum_{i=1}^{m-2}}\;a_iu({\xi}_i),\;m{\geq}3$$, where $a(t){\in}C_{ld}((0,T),\;[0,+{\infty}))$, $f{\in}C([0,T]{\times}[0,+{\infty}),\;(-{\infty},+{\infty}))$, the nonlinear term f is allowed to change sign. We obtain several existence theorems of positive solutions for the above boundary value problems. In particular, our criteria generalize and improve some known results [15] and the obtained conditions are different from related literature [14]. As an application, an example to demonstrate our results is given.

• 대한수학회논문집
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• 제20권4호
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• pp.775-779
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• 2005

On a compact n-dimensional manifold $M^n$, a critical point of the total scalar curvature functional, restricted to the space of metrics with constant scalar curvature of volume 1, satifies the critical point equation (CPE), given by $Z_g\;=\;s_g^{1\ast}(f)$. It has been conjectured that a solution (g, f) of CPE is Einstein. The purpose of the present paper is to prove that every compact stable minimal hypersurface is in a certain hypersurface of $M^n$ under an assumption that Ker($s_g^{1\ast}{\neq}0$).