• 한국HCI학회:학술대회논문집
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• 한국HCI학회 2008년도 학술대회 1부
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• pp.215-217
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• 2008

동영상 내용검색을 위해서 가장 많이 사용되고 있는 기술은 컷 추출에 의한 내용비교 방법이다. 그러나 컷 추출을 위해 사용되는 CHD(Color Histogram Difference)나 ECR(Edge Change Ratio)등은 영상물의 Cropping, Resizing Low bit rate등의 변화에 대해 대단히 취약하다. 본 방법은 이러한 변형에 강인하도록 상대적으로 변형이 적은 오디오정보를 이용하여 Indexing과 Searching을 수행하였다. 특히 변형에 강인한 Searching을 위해 오디오의 장면(Scene)을 검출하였고 장면을 중심으로 Time-frequency domain에서 각각의 Frequency bin. 에 대한 스펙트럴 파워를 파워임계값을 중심으로 이진화(Binary)하였다. 제안된 방법으로 Cropping, clipping, Lowbit rate, Additive Frame 등의 변형본에 대한 검색을 시도한 결과 False posit ive Error 와 True Negative Error 에 대해 각각 1%미만의 오탐지 결과를 얻었다.

• Journal of the Korean Data and Information Science Society
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• 제21권1호
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• pp.173-177
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• 2010

It is well known that if the parent distribution has a nonnegative support and has increasing failure rate, then all the order statistics have increasing failure rate (IFR). The result is not necessarily true in the case of bivariate distributions with dependent structures. In this paper we consider a symmetric bivariate exponential distribution and show that, two marginal distributions are IFR and the distributions of the minimum and maximum are constant failure rate and IFR, respectively.

• 산업공학
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• 제17권1호
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• pp.78-83
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• 2004

We consider the sensitivity of average inventory cost rate when true values of the parameters in the EOQ model are unknown over known ranges. In particular, in the case that the valid range on the true economic lot size are known, we provide a formula for estimating the lot size under minimax criterion. Moreover, to estimate the valid range, we apply the propagation of errors technique. Then, we present a scheme to find a (valid) lot size, based on the estimated range of the true lot size from the propagation of errors technique.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회/대한산업공학회 2003년도 춘계공동학술대회
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• pp.1028-1034
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• 2003

We consider the sensitivity of average inventory cost rate when true values of the parameters In the EOQ model are unknown over known ranges. In particular, In the case that the valid range on the true economic lot size are known. we provide a formula for estimating the lot size under minimax criterion. Moreover, to estimate the valid range, we apply the propagation of errors technique. Then, we present a scheme to find a (valid) lot size. based on the estimated range of the true lot size from the propagation or errors technique.

• International Journal of Automotive Technology
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• 제7권5호
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• pp.571-577
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• 2006

This paper deals with dynamic tensile characteristics for the polypropylene used in an IP(Instrument Panel). The polypropylene is adopted in the dash board of a car, especially PAB(Passenger Air Bag) module. Its dynamic tensile characteristics are important because the PAB module undergoes high speed deformation during the airbag expansion. Since the operating temperature of a car varies from $-40^{\circ}C$ to $90^{\circ}C$ according to the specification, the dynamic tensile tests are performed at a low temperature($-30^{\circ}C$), the room temperature($21^{\circ}C$) and a high temperature($85^{\circ}C$). The tensile tests are carried out at strain rates of six intervals ranged from 0.001/sec to 100/sec in order to obtain the strain rate sensitivity. The flow stress decreases at the high temperature while the strain rate sensitivity increases. Tensile tests of polymers are rather tricky since polymer does not elongate uniformly right after the onset of yielding unlike the conventional steel. A new method is suggested to obtain the stress-strain curve accurately. A true stress-strain curve was estimated from modification of the nominal stress-strain curves obtained from the experiment. The modification was carried out with the help of an optimization scheme accompanied with finite element analysis of the tensile test with a special specimen. The optimization method provided excellent true stress-strain curves by enforcing the load response coincident with the experimental result. The material properties obtained from this paper will be useful to simulate the airbag expansion at the normal and harsh operating conditions.

• 대한전자공학회논문지SP
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• 제44권6호
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• pp.47-53
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• 2007

블록 기반 프레임 레이트 변환 (frame-rate conversion) 또는 필름 떨림 보상 (film judder compensation)을 수행하기 위해서는 참 움직임 벡터(true motion vector)를 찾아야 한다. 이를 위해서 현재 블록의 공간적 및 시간적 상관성을 최대로 하여 시각적으로 덜 부자연스럽게 느끼도록 하는 방법들이 연구되었다. 그러나 기존의 블록단위 절대값 차이의 합 (SAD)만으로는 비정형성 객체의 움직임 에러를 추정할 수 없었다. 본 논문에서는 비정형성 객체가 등속운동을 하는 경우 재귀적으로 기존의 움직임을 유지하도록 하는 방법을 제안하였다. 현재 블록의 등속움직임 추정값을 재귀평균으로 구하였으며 현재 블록 벡터의 신뢰도를 계산하여 원래의 움직임 벡터와 재귀평균 움직임 벡터중에서 가중치를 두도록 하였다. 실험결과 비정형성 등속운동 객체의 움직임을 블록기반으로 추정함을 확인할 수 있었다.

• Corrosion Science and Technology
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• 제7권4호
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• pp.208-211
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• 2008

Safety operation of main pipelines is primarily provided by anticorrosive monitoring. Anticorrosive monitoring of oil pipeline transportation objects is based on results of complex corrosion inspections, analysis of basic data including design data, definition of a corrosion residual rate and diagnostic of general equipment's technical condition. All the abovementioned arrangements are regulated by normative documents. For diagnostics of corrosion-technical condition of oil pipeline transportation objects one presently uses different methods such as in-line inspection using devices with ultrasonic, magnetic or another detector, acoustic-emission diagnostics, electrometric survey, general external corrosion diagnostics and cameral processing of obtained data. Results of a complex of diagnostics give a possibility: $\cdot$ to arrange a pipeline's sectors according to a degree of corrosion danger; $\cdot$ to check up true condition of pipeline's metal; $\cdot$ to estimate technical condition and working ability of a system of anticorrosive protection. However such a control of corrosion technical condition of a main pipeline creates the appearance of estimation of a true degree of protection of an object if values of protective potential with resistive component are taken into consideration only. So in addition to corrosive technical diagnostics one must define a true residual corrosion rate taking into account protective action of electrochemical protection and true protection of a pipeline one must at times. Realized anticorrosive monitoring enables to take a reasonable decision about further operation of objects according to objects' residual life, variation of operation parameters, repair and dismantlement of objects.

• 한국정보과학회논문지:소프트웨어및응용
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• 제33권6호
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• pp.580-587
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• 2006

최근에 PDA, IMT-2000, e-Book 등이 보편화되면서 이러한 기기들을 사용하는 사용자의 수가 크게 증가하고 있다. 그러나 아직도 사용 가능한 메모리의 크기는 데스크톱 컴퓨터에 비해 상당히 적은 편이다. 이런 제품들에서, 트루타입 폰트는 품질 좋은 글꼴을 요구하는 사용자들이 증가함에 따라 수요가 증가하고 있으며, Windows CE를 탐재한 제품들에서는 기본적으로 사용되고 있다. 하지만 트루타입 폰트의 크기는 PDA와 e-Book과 같은 적은 메모리를 가진 제품들의 상당히 많은 공간을 차지하게 된다. 그러므로 트루타입 폰트외 크기를 줄이려는 노력이 요구된다. 본 논문은 트루타입 폰트에 내장된 비트맵 데이타(EBDT) 중에 한글 부분만을 줄이기 위해 2 단계의 압축과정을 거친다. 1 단계에서는 비트맵을 초성, 중성, 종성의 형태로 분리하여 합성 비트맵으로 구성하고, 2 단계에서는 분리된 각각의 비트맵들의 중복을 조사하여 제거하게 된다. 본 논문은 한글 완성형과 조합형 트루타입에 내장된 비트맵을 압축하였으며, 완성형 폰트의 경우 35%, 조합형 폰트의 경우 7%의 압축률을 보인다. 또한 완성형 트루타입의 경우 전체 트루타입 폰트의 9.26%의 압축률을 보인다.

• Journal of applied mathematics & informatics
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• 제6권2호
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• pp.393-406
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• 1999

Affine invariant sufficient conditions are given for two local convergence theorems involving inexact Newton-like methods. The first uses conditions on the first Frechet-derivative whereas the second theorem employs hypotheses on the second. Radius of con-vergence as well as rate of convergence results are derived. Results involving superlinear convergence and known to be true for inexact Newton methods are extended here. Moreover we show that under hypotheses on the second Frechet-derivation our radius of convergence results are derived. Results involving superlinear convergence and known to be true or inexact Newton methods are extended here. Moreover we show that under hypotheses on the second Frechet-derivative our radius of conver-gence is larger than the corresponding one in [10]. This allows a wider choice for the initial guess. A numerical example is also pro-vided to show that our radius of convergence is larger then the one in [10].

• Journal of the Korean Data and Information Science Society
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• 제26권1호
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• pp.255-260
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• 2015

Among many optimal threshold criteria from ROC curve, the closest-to-(0,1) and amended closest-to-(0,1) criteria are considered. An ROC curve that passes close to the (0,1) point indicates that two models are well classified. In this case, the ROC curve is located far from the (1,0) point. Hence we propose two criteria: the farthest-to-(1,0) and amended farthest-to-(1,0) criteria. These criteria are found to have a relationship with the KolmogorovSmirnov statistic as well as some optimal threshold criteria. Moreover, we derive that a definition for the proposed criteria with more than two dimensions and with relations to multi-dimensional optimal threshold criteria.