• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2002.10b
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• pp.465-466
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• 2002

In any mechanical system consisting of gears, shafts and/or bearings, the majority of metallic particles deposited into and carried by the lubrication system originate from the deterioration of oil-wetted working surfaces, even in proper lubrication system, due to failure mechanism (s) such as wear, fatigue and fretting corrosion. Determination of the point at which transition from normal to abnormal or to actual damage occurs has become a focus of attention in research activities for years, because it has been recognized that reliable, economic operation can be achieved through appropriate preventative measures. Known collectively from 'all size wear debris analysis' as early failure detection, the methods of testing for damage differ considerably, range from a micron or a submicron size debris analysis to Magnetic Chip Detector (MCD) ferrous debris analysis. This paper will be focused on the utilization of the low-cost analysis techniques for evaluation of industrial machinery condition.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2017.06a
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• pp.105-106
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• 2017

본 논문에서는 최대 우도 기반 파라미터 생성 알고리즘을 적용하여 인공 신경망의 출력인 음향 파라미터 열의 정확성 및 자연성을 향상시키는 방법을 제안하였다. 인공 신경망의 출력으로 정적 특징벡터 뿐 만 아니라 동적 특징벡터도 함께 사용하였고, 미리 계산된 파라미터 분산을 파라미터 생성에 사용하였다. 추정된 정적, 동적 특징벡터의 평균, 분산을 EM 알고리즘에 적용하여 최대 우도 기준 파라미터를 추정할 수 있다. 제안된 알고리즘은 파라미터 생성 시 동적 특징벡터 및 분산을 함께 적용하여 시간축에서의 자연성을 향상시켰다. 제안된 알고리즘의 객관적 평가로 MCD, F0 의 RMSE 를 측정하였고, 주관적평가로 선호도 평가를 실시하였다. 그 결과 기존 알고리즘 대비 객관적, 주관적 성능이 향상되는 것을 검증하였다.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.9 no.1
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• pp.75-80
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• 2000

This paper deals with the precision cutting characteristics of mono-crystal diamonds poly-crystal diamonds and tungsten carbide tool on ductile material. The cutting tests were carried out under various uncut chip areas and 20${\mu}{\textrm}{m}$ depth of engagement. The machinability in precision machining was discussed from the viewpoints of the normal cutting forces and the surface roughness of the workpiece. As the feed rate decreases the normal force difference for cutting edge radii appears to large. In various cutting edge radii the surface roughness difference when cut the copper which is ductile material than the aluminium alloy is large. As the same cutting condition the hardness value on cut surface with the diamond tool appears to be smaller than that of the tungsten carbide tool.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.151.2-152
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• 2003

Bee venom (BV) has been utilized to relieve pain and to treat inflammatory diseases such as rheumatoid arthritis (RA). BV contains a variety of different peptides including melittin, apamin, adolapin and mast cell degranulating (MCD) peptide. In addition, it also contains enzyme (i.e. phospholipase A2), biologically active amines and non-peptide components. (omitted)

• Journal of the Optical Society of Korea
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• v.14 no.4
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• pp.415-419
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• 2010

A phosphor-conversion white light source is demonstrated using an InGaN-based blue laser diode (LD) and a yellow-emitting phosphor excited by the blue LD. The photometric and colorimetric properties of this blue-LD-based white light source are characterized. When injection current of the LD is 100 mA, luminous flux and luminous efficiency of the white light are found to be over 5 lm and 10 lm/W, respectively. When injection current is >90 mA, luminance is estimated to be larger than 10 Mcd/$cm^2$. In addition, color characteristics of the white light such as chromaticity coordinates, a correlated color temperature, and a color rendering index are found to be quite stable as current and temperature of the LD varies. The demonstrated LD-based white light source is expected to be used in high-brightness illumination applications with good color stability.

• Journal of Korea Multimedia Society
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• v.16 no.4
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• pp.411-417
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• 2013

In this paper, we proposed a fast detection method of copy-move forgery image based on low frequency coefficients of the DCT coefficients. We proposed a new matching criterion of copy-moved forgery image detection (MCD) using discrete cosine transform. For each $8{\times}8$ pixel block, the DCT transform is calculated. Our algorithm uses low frequency four (DC, 3 AC coefficient) and six coefficients (DC, 5 AC coefficients) of DCT per $8{\times}8$ pixel block. Our algorithm worked block matching for DCT coefficients of the $8{\times}8$ pixel block is slid by one pixel along the image from the upper left corner to the lower right corner. Our algorithm can reduce computational complexity more than conventional copy moved forgery detection algorithms.

• Proceedings of the KIEE Conference
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• 2002.11b
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• pp.193-195
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• 2002

This paper presents the methods to solve the problem about Power System Protection Program(PROSET) and describe the database relation and schema with UML. PROSET is a overall program system to protect power system and correct it. In the context of the PROSET it is so difficult to edit database data when topology is changed. When the renewal of data is performed. all changed values are disappeared. Therefore, it will not be expected to know the present situation by using the information of the databases data. So it is necessary to solve this problem. Solution is copy of the user. Only E.R diagram is used to express database schema and relation. So, in this paper, UML(Unified Modeling Language) will be used to express PROSET and database of MCD-H and MDT-H.

• Journal of Korean Society for Quality Management
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• v.29 no.1
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• pp.1-10
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• 2001

We consider the problem of detecting special variations in multivariate $T^2$-control chart when two or more multivariate outliers are present. Since a multivariate outlier may reflect slippage in mean, variance, or correlation, it can distort the sample mean vector and sample covariance matrix. Damaged sample mean vector and sample covariance matrix have difficulty in examining special variations clearly, An alternative to detection outliers or special variations is to use robust estimators of mean vector and covariance matrix that are less sensitive to extreme observations than are the standard estimators $\bar{x}$ and $\textbf{S}$. We applied popular minimum volume ellipsoid(MVE) and minimum covariance determinant(MCD) method to estimate mean vector and covariance matrix and compared its results with standard $T^2$-control chart using simulated multivariate data with outliers. We found that the modified $T^2$-control chart based on the above robust methods were more effective in detecting special variations clearly than the standard $T^2$-control chart.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.79-79
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• 2012

방사광이 고체물리의 연구에 이용되기 시작한 60년대 말 이후부터 지난 반세기동안 방사광시설과 이를 이용한 분석 장치들은 큰 발전이 거듭되어 왔다. 90년대에는 포항가속기 연구소에서 방사광을 이용한 실험 시설이 완공되어 지난 20 여년간 이용되어 왔고 현재는 이시설이 업그레이드(PLS II) 되어 조만간 다시 이용자에게 공개될 예정이다. 연 x-선의 경우 광전자를 분석하게 되면 시료의 표면으로부터 1 nm - 수십 nm 두께의 현상에 대한 분석이 가능하다. 경 x-선(수 keV 이상의 에너지를 갖는)의 경우는 비교적 큰 penetration depth를 갖지만 grazing incidence를 이용하게 되면 수 나노 이하의 두께에서 일어나는 현상에 대한 연구가 가능하다. 본 tutorial에서는 전자의 에너지 영역인 VUV영역에서 가능한 방사광을 이용한 여러 가지 표면분석법(XPS, MCD, XAS, ARPES, SPEM, PEEM등)에 대한 세부강의를 제공하고자 한다. 총론에서는 경 x-선을 포함하는 방사광을 이용한 표면분석기술이 어디까지 발전되어 왔고 어느 수준까지 분석이 가능한지에 대한 전체적인 view를 제공하고자 한다. 본 tutorial은 이제 막 방사광을 이용한 연구를 수행하려는 연구자들, 지금까지 특정 분석기술을 사용한바 있는 연구자들, 그리고 여러 가지 방사광이용 표면분석방법에 대한 이해가 필요한 소재 혹은 소자의 개발자들에 좋은 배움의 기회가 될 것입니다.

• Journal of the Korea Society of Computer and Information
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• v.22 no.7
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• pp.31-37
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• 2017

There are lots of combined battlefield elements which complete the war. It looks problematic when collecting and analyzing these elements and then predicting the situation of war. Commander's experience and military power assessment have widely been used to come up with these problems, then simulated combat training program recently supplements the war-game models through recording real-time simulated combat data. Nevertheless, there are challenges to assess winning factors of combat. In this paper, we characterize the combat element (ce) by clustering simulated combat data, and then suggest multi-layered artificial neural network (ANN) model, which can comprehend non-linear, cross-connected effects among ces to assess mission completion degree (MCD). Through our ANN model, we have the chance of analyzing and predicting winning factors. Experimental results show that our ANN model can explain MCDs through networking ces which overperform multiple linear regression model. Moreover, sensitivity analysis of ces will be the basis of predicting combat situation.