• Journal of Magnetics
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• 제22권2호
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• pp.315-325
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• 2017

Magnetically suspended sensitive gyroscopes (MSSGs) provide an interesting alternative for achieving precious attitude angular measurement. To effectively reduce the measurement error caused by the non-uniformity of the air-gap flux density in a MSSG, this paper proposes a novel compensation method based on measuring and modeling of the air-gap flux density. The angular velocity measurement principle and the structure of the MSSG are described, and then the characteristic of the air-gap flux density has been analyzed in detail. Next, to compensate the flux density distribution error and improve the measurement accuracy of the MSSG, a real-time compensation method based on the online measurement with hall probes is designed. The common issues caused by the non-uniformity of the air-gap flux density can be effectively resolved by the proposed method in high-precision magnetically suspended configurations. Comparative simulation results before and after compensation have verified the effectiveness and superiority of the proposed compensation method.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.49.1-49
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• 2001

The skin color model is a very important concept in face detection, face recognition and face tracking. Usually, this model is obtained by estimating a probability density function of skin color distribution. In many cases, it is assumed that the underlying density function follows a Gaussian distribution. In this paper, a new method for non-parametric estimation of the probability density function, by using feed-forward neural network, is used to estimate the underlying skin color model. By using this method, the resulting skin color model is better than the Gaussian estimation and substantially approaches the real distribution. Applications to face detection and face ...

• Transactions on Electrical and Electronic Materials
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• 제6권4호
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• pp.149-153
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• 2005

In this paper, we investigated the island density-dependent stress distribution of indium-tin-oxide (ITO) film on polycarbonate substrate by external bending force. We used e-beam and RF­sputter for SiON, ITO sputtering. It was found that there are influence of island density on the substrate and decreasing crack density as goes to the minimum density. From the result that crack density was increasing at maximum island density, it is evident that more stress is imposed on same island position as island density.

• 한국멀티미디어학회논문지
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• 제19권8호
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• pp.1248-1259
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• 2016

Classification methods based on dual energy X-ray absorptiometry, ultrasonic waves, and quantitative computed tomography have been proposed. Also, a classification method based on machine learning with bone mineral density and structural indicators extracted from the CT images has been proposed. We propose a method which enhances the performance of existing classification method based on bone mineral density and structural indicators by extending structural indicators and using principal component analysis. Experimental result shows that the proposed method in this paper improves the correctness of osteoporosis classification 2.8% with extended structural indicators only and 4.8% with both extended structural indicators and principal component analysis. In addition, this paper proposes a method of automatic phantom analysis needed to convert the CT values to BMD values. While existing method requires manual operation to mark the bone region within the phantom, the proposed method detects the bone region automatically by detecting circles in the CT image. The proposed method and the existing method gave the same conversion formula for converting CT value to bone mineral density.

• 한국컴퓨터정보학회논문지
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• 제22권11호
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• pp.49-55
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• 2017

Recently, for safety of people, there are proposed so many technologies which detect density of people at the specific place or space. The representative technology for crowd density estimation was using image analysis method from CCTV images. However, this method had a weakness which could not be used and which's accuracy was lower at the dark or smog space. Therefore, in this paper, to solve this problem, we proposed a user density estimation system at closed space using high frequency and smart device. The system send inaudible high frequencies to smart devices and it count the smart devices which detect the high frequencies on the space. We tested real-time user density with the proposed system and ten smart devices to evaluate performance. According to the testing results, we confirmed that the proposed system's accuracy was 95% and it was very useful. Thus, because the proposed system could estimate about user density at specific space exactly, it could be useful technology for safety of people and measurement of space use state at indoor space.

• 한국자동차공학회논문집
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• 제5권1호
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• pp.136-145
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• 1997

To analyzed ride quality and to predict durability in vehicle dynamics, it is essential to describe a road surface profile precisely. This paper presents a technique to generate road surface profiles in a spatial domain by using a power spectral density function. A single track power spectral density function is proposed to describe a road surface profile, which is also applicable for multi-track vehicle response analysis, The derived road surfaces are compared to ISO(International Organization for Standardization) standards and classifications, proposed by the MIRA(Motor Industry Research Association). The methodology in this paper is also proposed to generate road roughness description with a limited external data. A small amount of external curve data is combined with an internal PSD function to generate road surface roughness in a spatial domain.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1994년도 가을 학술발표회 논문집
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• pp.399-404
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• 1994

Heavyweight(or High density) concrete, which is generally for shiedling structures, differs from normal weight concrete by having a higher density and special compositions to improve its attenuation properties. There are setting 7 Beam Ports around the reactor of the KMRR Project(Korea Multi-purpose Research Reactor) conducted by the KAERI(Korea Atomic Energy Research Institute). High density(p=5.0t/$\textrm{m}^3$) and Heavyweight(p=3.5t/$\textrm{m}^3$) concrete were placed around the Beam Ports in order to shield radiation. This paper was discussed about construction of High density concrete. High density concrete was placed with method of Preplace Aggregate. Coarse metallic aggregate(steel shot) was used. Boron, boron carbide(B4C), was used to capture effctively the neutrom. The mock-up test was carried out. And the consturction of High density concrete was performed successfully.

• 펄프종이기술
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• 제33권3호
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• pp.52-58
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• 2001

The aim of using grape-bagging paper is preventing damages by light and harmful insects during grape growth. The number of using grape-bagging paper has been increasing because advantages of using it have been confirmed. A technology to produce it has not been fully developed yet. In this study properties of the grape-bagging paper were analyzed. Results showed that air-permeability and transmitted light of grape-bagging paper were important. It was tried to see the influence of paper structure on air-permeability, transmitted light and the grapes saccharinity. For making different structure of grape-bagging paper, papers were produced with different freeness levels at several pressure conditions. Coloration time of Campbell grape with new bagging paper started about 5 days earlier than that with usual bagging paper, It was also possible to improve the saccharinity about 0.1-N0.8 Brix. Because new bagging paper has a low apparent density, it affected the saccharinity and coloration time of grape.

• 한국인쇄학회지
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• 제16권2호
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• pp.23-36
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• 1998

Moisture content of printing paper and circumstance of printing room has great influence on the printing works. We have studied on the printability of domestic art paper according to the insufficient Korea weather. As the result, we found the printability of domestic art paper are much more affect by moisture content than any other printability coefficients, especially print density and hygroexpansivity decrease with moisture content increase.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2009년도 제38회 동계학술대회 초록집
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• pp.438-438
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• 2010

The abnormal behavior of the argon metastable density during the E-H mode transition in argon ICP discharge was investigated. Lots of investigations including global models expected that during and after the mode transition of ICP discharge, the density of metastable increases with applied rf power (i.e. electron density). However, recent direct measurement of metastable density revealed that the metastable density of argon decreases with the applied power during and after the mode transition. This result may not be explained by the previous global model which is based on the assumption of the Maxwellian electron energy distribution function (EEDF). In this paper, to explain this abnormal behavior with simple manners, a simple global model taking account of the effect of the non-Maxwellian EEDFs incorporating into a set of coupled rate equations is proposed. The result showed that the calculated metastable density taking account of non-Maxwellian EEDF and its evolution during the transition has an abnormal behavior with electron density and is in good agreement with the previous measurement results, indicating the close coupling of electron kinetics and the behavior of metastable density. The proposed simple model is expected to provide qualitative kinetic insight to understand the behavior of the metastable density in various plasma discharges which typically exhibit non-Maxwellian distribution.