• 대한전자공학회논문지SP
• /
• 제49권3호
• /
• pp.18-29
• /
• 2012

실시간 물체 검출에 매우 효과적이라고 알려져 있는 Viola-Jones 알고리즘에서는 약분류기를 구성하기 위해 Haar 모양의 특징들을 사용한다. 이러한 Haar 모양 특징은 각각 양의 영역과 음의 영역에 해당하는 두 개 이상의 사각형의 조합으로 구성되며 양의 영역에 해당하는 화소값들의 합과 음의 영역에 해당하는 화소값들의 합의 차에 의하여 특징값을 계산한다. 본 논문에서 새롭게 제안하는 사각 특징은 두 개 이상의 사각 영역으로 구성되는 Haar 모양 특징과는 달리 단일한 사각 영역으로 구성되어 영역 내의 화소값들을 총합과 분산을 특징으로 사용한다. 이러한 사각 특징들을 기존의 Haar 모양 특징과 함께 사용하면 물체의 특징을 인접하는 밝은 영역과 어두운 영역의 조합으로만 선택했던 기존의 방법으로 인해 그동안 배제되어 온 새로운 특징을 선택할 수 있으며 그 결과 계산상의 손실 없이 물체 검출의 성능을 높일 수 있다.

• Wind and Structures
• /
• 제18권6호
• /
• pp.651-668
• /
• 2014

Wind tunnel tests are conducted to investigate the wind loads on vertical fixed-roof cylindrical tanks with a very low aspect ratio of 0.275, which is a typical ratio for practical tanks with a volume of $100,000m^3$. Both the flat-roof tank and the dome-roof tank are investigated in present study. The first four moments of the measured wind pressure, including the mean and normalized deviation pressure, kurtosis and skewness of the pressure signal, are obtained to study the feature of the wind loads. It is shown that the wind loads are closely related to the behavior of flow around the structure. For either tank, the mean wind pressures on the cylinder are positive on the windward area and negative on the sides and the wake area, and the mean wind pressures on the whole roof are negative. The roof configurations have no considerable influence on the mean pressure distributions of cylindrical wall in general. Highly non-Gaussian feature is found in either tank. Conditional sampling technique, envelope method, and the proper orthogonal decomposition (POD) analysis are employed to investigate the characteristics of wind loads on the cylinder in more detail. It is shown that the patterns of wind pressure obtained from conditional sampling are similar to the mean pressure patterns.An instantaneous pressure coefficient can present a wide range from the maximum value to the minimum value. The quasi-steady assumption is not valid for structures considered in this paper according to the POD analysis.

• 한국산업융합학회 논문집
• /
• 제8권4호
• /
• pp.221-226
• /
• 2005

This paper presents a hybrid method for recognizing the faces by using zero mean and principal component analysis. Zero mean is applied to reduce the 1st order statistics to data nonlinearities. PCA is also used to derive an orthonormal basis which directly leads to dimensionality reduction, and possibly to feature extraction of face image. The proposed method has been applied to the problems for recognizing the 20 face images(10 persons * 2 scenes) of 324*243 pixels from Yale face database. The 3 distances such as city-block, Euclidean, negative angle are used as measures when match the probe images to the nearest gallery images. The experimental results show that the proposed method has a superior recognition performances(speed, rate). The negative angle has been relatively achieved more an accurate similarity than city-block or Euclidean.

• 한국콘텐츠학회:학술대회논문집
• /
• 한국콘텐츠학회 2008년도 춘계 종합학술대회 논문집
• /
• pp.92-95
• /
• 2008

입력에서 특징을 추출하는 유용한 방법으로 NMF(Non-nagetive Matrix Factorization)이 제안되었다. NMF를 적용하면 고차원의 데이터가 저차원의 특징에 기반한 형태로 변형이 된다. 이 경우 클러스터링 효과도 같이 나타나는데, 최근에 Sparse NMF가 이러한 효과를 더 잘 보인다고 알려졌다. 이 논문에서는 숫자 영상 신호에 대하여 NMF와 Sparse NMF를 적용시켜 이러한 클러스터링 효과를 비교하여 보았다.

• 대한수학교육학회지:학교수학
• /
• 제4권2호
• /
• pp.205-222
• /
• 2002

In school mathematics, the negative numbers have been instructed using the intuitive models such as the number line model, the counting model, and inductive-extrapolation on the additionand multiplication and using inverse operation on the subtraction and division. Theseinstructions on the negative numbers did not present their formal nature and caused the difficulty for students to understand their operations because of the incomplete function of the intuitive models. In this study, we tried to improve such problems of the instructions of the negative numbers on the basis of the didactical phenomenological analysis. First of all, we analysed the nature of the negative numbers and the cognitive obstructions through the examination about the historic process of them. Second, we examined hew the nature of the negative numbers were analysed and described in mathematics. Third, we explored the improving directions for them on the ground of the didactical phenomenological analysis. In school mathematics, the rules of operations using the intuitive models of the negative numbers have been Instructed rather than approaching toward the nature of them. The negative numbers have been developed from the necessity to find the general solution of equations. The study tries to approach the operations instructions of the negative numbers formative]y to overcome the problems of those that are using the intuitive models and to reflect the formative Furthermore of the negative numbers. Furthermore, we examine the way of the instruction of the negative numbers in real context so that the algebraic feature and the real context should be Interactive.

• 한국언어정보학회지:언어와정보
• /
• 제8권2호
• /
• pp.73-91
• /
• 2004

The nominative and accusative postpositions in Korean may intervene between the negative auxiliary verb ANH and its complement verb phrase. As Korean is an OV language, this means that 'verb + {nom, acc} + ANH' as well as the simpler concatenation 'verb + ANH' is possible. This fact, together with an overwhelming regularity of these postpositions' optionality in virtually all constructions, poses a problem for formal approaches to the syntax of the language. Working in a constraint-based grammatical framework shaped by such works as Sag and Wasow (1999) and Copestake (2002), we put forth type hierarchies for major_class, which represents verb inflection, and for pos, which has two immediate subtypes, i.e., htrp_pos and ord_pos. What we call the 'half transparency' of the case postpositions separates them from all the other lexical items in the language. The type htrp_pos is used to constrain one of the two newly proposed head_comp_rules, where a newly proposed feature HEAD2 of a phrase inherits its value from the HEAD feature of the head word. The COMPS list of the negative auxiliary ANH is seen as containing a single phrase whose HEAD is a kind of nominal clause and whose HEAD2 is something that is one of the three maximal types: acc, nom, and null.

• 한국정보과학회:학술대회논문집
• /
• 한국정보과학회 2003년도 가을 학술발표논문집 Vol.30 No.2 (1)
• /
• pp.4-6
• /
• 2003

A holistic representation, such as sparse ceding or independent component analysis (ICA), was successfully applied to explain early auditory processing and sound classification. In contrast, Part-based representation is an alternative way of understanding object recognition in brain. In this paper. we employ the non-negative matrix factorization (NMF)［1］which learns parts-based representation for sound classification. Feature extraction methods from spectrogram using NMF are explained. Experimental results show that NMF-based features improve the performance of sound classification over ICA-based features.

• 천문학회지
• /
• 제28권1호
• /
• pp.61-65
• /
• 1995

We discuss a model4-dimensional Friedmann cosmology which may have evolved from a model of 4+D dimensions which admits spontaneous compactification of D dimensions (or N-dimensional variants of the Brans-Dicke (BD) theory). The BD parameter appearing in dimensional reduction is negative $-1<\omega<0$ (for the N-dimensional variants of the BD theory, $-1.5{\leq}{\omega})$. We find that if there had been inflationary transtion to the standard big-bang model, the Universe can undergoe a polar-type expansion during when the gravitational coupling becomes negative. The unique feature is that for the negative w, the density parameter of the post-inflationary Universe falls in a range 0<0<1 even if the Universe is geometrically flat (k = 0).

• Applied Microscopy
• /
• 제24권4호
• /
• pp.107-114
• /
• 1994

The Rotaviruses are members of the family Reoviridae and are the major cause of severe childhood gastroenteritis worldwide. Recently, electron microscopy has been used to detect non-group A rotaviruses to determine a relatively high resolution structure of the rotavirion. Mature, infectious virions(double-shelled particles) have a diameter of approximately 70nm, and have a capsid structure composed of two concentric protein layers. We have studied patient's stool specimen by negative staining technique complete removal of sucrose suspension. This negative staining technique that could be carried out in about 30 minutes and that could be used with crude stool specimen was an advantage of major significance. Removal of sucrose in the sample by has been completed washing with distilled of sucrose and by washing with distilled water. Ultrastructurally, typical feature of rotavirus has a double capsid construction with an inner capsid of 55nm and on outer 65-70nm diameter can be clearly demonstrated.

• 전자공학회논문지
• /
• 제51권9호
• /
• pp.190-199
• /
• 2014

본 논문에서는 섬모 번들 특성 모델과 통합 전정 유모세포 모델을 제안한다. 기존 전정기관 모델에 관한 연구는 외력이 없는 상태에서 전정 유모세포의 섬모 번들이 가지는 특성이나 시냅스에서 발생하는 활동전위만을 대상으로 진행되었으며 섬모번들의 고유 특성을 고려한 전정신경의 활동전위에 대한 연구는 이루어지지 않았다. 제안된 통합 전정 유모세포 모델은 외력을 반영하였고 서로 다른 규칙성을 가진 유모세포에 대해 각각의 섬모번들의 반강성 특성을 고려하였고 이를 기존의 외력없는 모델과 비교하였다. 그 결과 외부 자극의 변화에 따른 주파수 변화가 큰 불규칙적 신경섬유와 중간규칙적 신경섬유에서는 반강성 구간의 감소를 보였으나 그렇지 않은 규칙적 신경섬유에서는 기존의 반강성 특성과 유사한 특성을 보여주었다. 또한 제안된 전정 유모세포 모델을 통해 11개의 주파수 대역에서의 모델링 데이터와 기존의 동물 실험 데이터가 거의 일치함을 보여 주었다. 제안된 섬모 번들 특성 모델이 적절히 모델링되었음이 확인된다.