• International Journal of Control, Automation, and Systems
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• 제2권1호
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• pp.125-133
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• 2004

In this paper, we present a new method that combines the characteristics of edge in-formation and second-order neural networks for the classification of structural textures. The edges of a texture are extracted using an edge detection approach. From this edge information, classification features called second-order features are obtained. These features are fed into a second-order neural network for training and subsequent classification. It will be shown that the main disadvantage of using structural methods in texture classifications, namely, the difficulty of the extraction of texels, is overcome by the proposed method.

• 한국인터넷방송통신학회논문지
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• 제18권6호
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• pp.151-156
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• 2018

필기체 숫자인식은 일반적으로 높은 인식률과 문맥 독립이 요구되고 있고, 쓰는 사람에 따라서 많은 차이점이 있어서 자유 필기체 숫자는 인식이나 알고리즘작성에 아직도 어려운 문제점이 있다. 본 연구에서는, 필기체 숫자의 특성을 분석하고, 구조적 특징기반 자유 필기체 숫자인식 알고리즘을 새롭게 제안한다. 주어진 필기 숫자에 대하여, 끝점과 분기점, 수평선과 함께 숫자의 구조적 특징을 연구한다. 이 방법은 확장된 구조적 특징 알고리즘으로 제안되어 강인하며, 그리고 본 연구에서 제안한 구조적 특징에 기반 한 결정 트리(decision tree)는 필기체 숫자 자동인식방법에 구조적으로 기여한다. 본 알고리즘이 다른 방법과 비교하여 인식률과 강인성이 우수함을 실험결과로 보여주었다.

• ETRI Journal
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• 제40권4호
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• pp.499-510
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• 2018

A vector space based augmented structural kinematic (VSASK) feature descriptor is proposed for human activity recognition. An action descriptor is built by integrating the structural and kinematic properties of the actor using vector space based augmented matrix representation. Using the local or global information separately may not provide sufficient action characteristics. The proposed action descriptor combines both the local (pose) and global (position and velocity) features using augmented matrix schema and thereby increases the robustness of the descriptor. A multiclass support vector machine (SVM) is used to learn each action descriptor for the corresponding activity classification and understanding. The performance of the proposed descriptor is experimentally analyzed using the Weizmann and KTH datasets. The average recognition rate for the Weizmann and KTH datasets is 100% and 99.89%, respectively. The computational time for the proposed descriptor learning is 0.003 seconds, which is an improvement of approximately 1.4% over the existing methods.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.1469-1474
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• 2007

In recent years, research to machine large-surface micro-features has become important because of the light guide panel of a large-scale liquid crystal display and the bipolar plate of a high-capacity proton exchange membrane fuel cell. In this study, in order to realize the systematic design technology and performance improvements of an ultra-precision machine for machining the large-surface micro-features, a structural characteristic analysis was performed using its virtual prototype. The prototype consisted of gantry-type frame, hydrostatic feed mechanisms, linear motors, brushless DC servo motor, counterbalance mechanism, and so on. The loop stiffness was estimated from the relative displacement between the tool post and C-axis table, which was caused by a cutting force. Especially, the causes of structural stiffness deterioration were identified through the structural deformation analysis of sub-models.

• Structural Monitoring and Maintenance
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• 제9권2호
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• pp.179-200
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• 2022

This paper proposes a data-driven methodology for online early damage identification under changing environmental conditions. The proposed method relies on two data analysis methods: feature-based method and hybrid principal component analysis (PCA) and kernel PCA to separate damage from environmental influences. First, spectral sub-band features, namely, spectral sub-band centroids (SSCs) and log spectral sub-band energies (LSSEs), are proposed as damage-sensitive features to extract damage information from measured structural responses. Second, hybrid modeling by integrating PCA and kernel PCA is performed on the spectral sub-band feature matrix for data normalization to extract both linear and nonlinear features for nonlinear procedure monitoring. After feature normalization, suppressing environmental effects, the control charts (Hotelling T² and SPE statistics) is implemented to novelty detection and distinguish damage in structures. The hybrid PCA-KPCA technique is compared to KPCA by applying support vector machine (SVM) to evaluate the effectiveness of its performance in detecting damage. The proposed method is verified through numerical and full-scale studies (a Bridge Health Monitoring (BHM) Benchmark Problem and a cable-stayed bridge in China). The results demonstrate that the proposed method can detect the structural damage accurately and reduce false alarms by suppressing the effects and interference of environmental variations.

• Structural Engineering and Mechanics
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• 제44권2호
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• pp.179-196
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• 2012

An eigenspace projection clustering method is proposed for structural damage detection by combining projection algorithm and fuzzy clustering technique. The integrated procedure includes data selection, data normalization, projection, damage feature extraction, and clustering algorithm to structural damage assessment. The frequency response functions (FRFs) of the healthy and the damaged structure are used as initial data, median values of the projections are considered as damage features, and the fuzzy c-means (FCM) algorithm are used to categorize these features. The performance of the proposed method has been validated using a three-story frame structure built and tested by Los Alamos National Laboratory, USA. Two projection algorithms, namely principal component analysis (PCA) and kernel principal component analysis (KPCA), are compared for better extraction of damage features, further six kinds of distances adopted in FCM process are studied and discussed. The illustrated results reveal that the distance selection depends on the distribution of features. For the optimal choice of projections, it is recommended that the Cosine distance is used for the PCA while the Seuclidean distance and the Cityblock distance suitably used for the KPCA. The PCA method is recommended when a large amount of data need to be processed due to its higher correct decisions and less computational costs.

• East Asian Economic Review
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• 제20권3호
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• pp.365-390
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• 2016

This paper quantitatively compares the intrinsic features of the daily USD-GBP exchange rates in two different periods, the 1920s and the 2010s, under the same freely floating exchange rate system. Even though the foreign exchange markets in the 1920s seem to be much less organized and developed than in the 2010s, this paper finds that both the long memory volatility property and the structural break appear to be the common intrigue features of the exchange rates in the two periods by using the FIGARCH model. In particular, the long memory volatility properties in the two periods are found to be upward biased and overstated because of the structural breaks in the exchange markets. Thus this paper applies the Adaptive-FIGARCH model to consider the long memory volatility property and the structural breaks jointly. The main finding is that the structural breaks in the exchange markets affect the long memory volatility property significantly in the two periods but the degree of the long memory volatility property in the 1920s is reduced more remarkably than in the 2010s after the structural breaks are accounted for; thus implying that the structural breaks in the foreign exchange markets in the 1920s seem to be more significant.

• 대한전자공학회논문지
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• 제13권1호
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• pp.23-30
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• 1976

이 논문에서는 위상회전에 의한 오목구조의 짐출로서 필기체 한글을 인식하는 한 방법을 검토한다. 문자 Pattern를 오목구조적인 기본 Segment로 분해하여 집합으로 분류하고, 그들 집함에 대한 각 Segment의 폐상태와 위상특징을 logic으로 표현한다. 다음 그들 logic pattern의 위상회전으로서 오목구조의 topological성질과 위상특징을 검출하여 문자를 결정한다. 이 방법은 필기체의 변화와 문자의 대소, 경사 띤 위치 변위에 대한 식별의 유연성을 가지며, 인식율이 높다. In this paper, a method is proposed for the recognition of hand-written Hangeul. This is peiformed by extraction of the concave structural segments by phase rotation. Character patterns can be decomposed into the fundamental concave structural segments which are also categorized into segment sects, and the closure and phase features of each segment in set is represented by logics. By rotating the logic pattern, the topological and phase features of segment are extracted for the reliable recognition of the character. It is also evaluated that this method applies to a wide variety of shape, position and declination of the character.

• 한국실내디자인학회논문집
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• 제22권1호
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• pp.183-193
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• 2013

The study aimed to find the fundamental differences of aesthetics in Korea, China, and Japan by analyzing expressive features and structural meanings of the storage furniture from $17^{th}$ to $19^{th}$ century. The study was performed in four steps; analysis of expressive features, isotopic analysis, semantic structure analysis, and comprehensive interpretation. The results showed that three countries had linear shapes with curvilinear elements, closed forms with open spaces, natural material hues with change of tone or color, and symmetrical forms with asymmetrical patterns and structures in common. Korea comparatively accented on the natural material colors and wood grains. China stressed on the big and wide faces using three-dimensional carving. Japan accented on the linear elements with strong color contrast and decorative metal fixtures. These features were caused by the traditional thoughts and according aesthetic principles. Korea and China were affected by the Confucianism focused on establishing the order of rank. Meanwhile, Japan was more influenced by the Buddhism emphasized on the individuality and communication. Therefore, the differences of the expressive features in furniture among the three countries were inevitable consequences of the different ideologies.

• 한국실내디자인학회논문집
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• 제21권5호
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• pp.77-84
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• 2012

Single formative language created by the standardization of industrial society carries a cell constructive aspect. Such space structural form made gigantic buildings, which has a symbolism as an independent object. Such space shows a morphological symbolism by public preference but it did not establish essential meaning of a shape or concentrated relation. In this regard, this paper tries to show organic similarity of structural formality of small commercial space (patterned space), which was made by the continuity of concentrated patterns not an object of dualistic unit features. Therefore, this study analyzed the cultural, commercial and public space based upon systematical concept and features. Systematical space formality that makes multilateral relation between human, environment and a thing is a concentrated view point by relational features not by the cluster displayed by hierarchical features. Systematical space of small patterned space emphasized its appropriateness of expansion and creating diversified spaces unlike gigantic symbolic buildings.