• KSTLE International Journal
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• 제2권1호
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• pp.35-39
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• 2001

In this paper, statistical approach is undertaken to investigate the classification of wear debris which is the key function of objective assessment of wear debris morphology. Wear tests are run to produce various kinds of wear debris. The images of wear debris from wear tests are captured with image acquisition equipment. By thresholding, two-dimensional binary images of wear debris are made and, then, morphological parameters are used to quantify the images of debris. Parametric and nonparametric discriminant method are employed to classify wear debris into predefined wear conditions. It is demonstrated that classification accuracy of parametric and nonparametric discriminant method is similar. The selected use of morphological parameters by stepwise discriminant analysis can generally improve the classification accuracy of parametric and nonparametric discriminant method.

• 한국압력기기공학회 논문집
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• 제14권1호
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• pp.48-57
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• 2018

Configuration management (CM) is the process of identifying and documenting characteristics of plant structures, systems and components (SSCs), and of ensuring that changes to these characteristics are properly assessed, approved, implemented, verified and recorded. The purpose of this study is to examine regulation and technical standards developed under different concepts and level of depth for classification of nuclear SSCs as an essential prerequisite of the CM. In this context, main contents of currently adopted NSSC Notice 2016-10 are reviewed and compared with those in recently published ANSI/ANS 58.14 and IAEA SSG-30. The technical standards were prototypically used for classification of O-rings in two nuclear systems. It is found that ANSI/ANS 58.14 results in different categories taking into account specific features while IAEA SSG-30 leads to same categorization of the O-rings. Key findings will be summarized for Korean regulatory amendment in the future.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 하계종합학술대회 논문집(5)
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• pp.127-130
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• 2000

Classification of Electroencephalogram(EEG) makes one of key roles in the field of clinical diagnosis, such as detection for epilepsy. Spectrum analysis using the fourier transform(FT) uses the same window to signals, so classification rate decreases for nonstationary signals such as EEG's. In this paper, wavelet power spectrum method using wavelet transform which is excellent in detection of transient components of time-varying signals is applied to the classification of three types of Event Related Potential(EP) and compared with the result by fourier transform. In the experiments, two types of photic stimulation, which are caused by eye opening/closing and artificial light, are used to collect the data to be classified. After choosing a specific range of scales, scale-averaged wavelet spectrums extracted from the wavelet power spectrum is used to find features by Back-Propagation(13P) algorithm. As a result, wavelet analysis shows superiority to fourier transform for nonstationary EEG signal classification.

• Computers and Concrete
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• 제20권1호
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• pp.23-29
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• 2017

In this study engineered steel fibres used as reinforcement for concrete were characterized by number of key mechanical and spatial parameters, which are easy to measure and quantify. Such commonly used parameters as length, diameter, fibre intrinsic efficiency ratio (FIER), hook geometry, tensile strength and ductility were considered. Effective classification of various fibres was demonstrated using simple multivariate computations involving principal component analysis (PCA). Contrary to univariate data mining approach, the proposed analysis can be efficiently adapted for fast, robust and direct classification of engineered steel fibres. The results have revealed that in case of particular spatial/geometrical conditions of steel fibres investigated the FIER parameter can be efficiently replaced by a simple aspect ratio. There is also a need of finding new parameters describing properties of steel fibre more precisely.

• Asian Pacific Journal of Cancer Prevention
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• 제14권3호
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• pp.2091-2095
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• 2013

Background: The $7^{th}$ TNM staging is the first authoritative standard for evaluation of effectiveness of treatment of gastric cancer worldwide. However, revision of pN classification within TNM needs to be discussed. In particular, the N3 sub-stage is becoming more conspicuous. Methods: Clinical data of 302 pN3M0 stage gastric cancer patients who received radical gastrectomy in Tianjin Medical University Cancer Institute and Hospital from January 2001 to May 2006 were retrospectively analyzed. Results: Location of tumor, depth of invasion, extranodal metastasis, gastric resection, combined organs resection, lymph node metastasis, rate of lymph node metastasis, negative lymph nodes count were important prognostic factors of pN3M0 stage gastric cancers. TNM stage was also associated with prognosis. Patients at T2N3M0 stage had a better prognosis than other sub-classification. T3N3M0 and T4aN3aM0 patients had equal prognosis which followed the T2N3M0. T4aN3bM0 and T4bN3aM0 had lower survival rate than the formers. T4bN3bM0 had worst prognosis. In multivariate analysis, TNM stage group and rate of lymph node metastasis were independent prognostic factors. Conclusions: The sub-stage of N3 may be useful for more accurate prediction of prognosis; it should therefore be applied in the TNM stage system.

• Molecules and Cells
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• 제19권1호
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• pp.1-15
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• 2005

Eukaryotes produce various types of small RNAs of 19-28 nt in length. With rapidly increasing numbers of small RNAs listed in recent years, we have come to realize how widespread their functions are and how diverse the biogenesis pathways have evolved. At the same time, we are beginning to grasp the common features and rules governing the key steps in small RNA pathways. In this review, I will summarize the current classification, biogenesis, action mechanism and function of these fascinating molecules.

• 산업경영시스템학회지
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• 제14권24호
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• pp.155-161
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• 1991

Flexibility has become a key objectives in the design of manufacturing systems and a critical measure of total manufacturing performance. The need for flexibility is increasing due to some environmental change such as changing technical characteristics of the products and the changing nature of market demands. Most importantly, flexibility embodies competitive value for a manufacturer. Although the importance of flexibility has stressed in the various research, very few attempts have been made to synthesize the literature dealing with definitions and measure of flexibility. It is this issue that have motivated us to search for the definition and classification of flexibility.

• 대한전자공학회논문지SP
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• 제43권2호
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• pp.1-11
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• 2006

본 논문에서는 샷(shot) 기반 비디오 색인 구조에서 비-파라미터(non-parametric) 기반의 움직임 분류를 통한 비디오 영상 검색 기법을 제안한다. 본 논문에서 제안하는 비디오 검색 시스템은 장면 전환 기법을 통해 얻은 샷 단위의 짧은 비디오로부터 대표 프레임과 움직임 정보를 취득한 후, 이를 통해 시각적 특징과 움직임 특징을 추출하여 유사도를 비교함으로써 시-공간적 특징을 이용한 실시간 검색이 가능하도록 구현되었다. 비-파라미터 기반의 움직임 특징의 추출은 MPEG 압축 스트림으로부터 정규화된 움직임 벡터계(界)를 추출한 후, 각각의 정규화된 움직임 벡터를 여러 개의 각도 빈(bin)으로 양자화하고 이의 평균과 분산, 방향 등을 고려함으로써 효과적으로 이루어진다. 대표 프레임에서의 시각 특징 검출을 위해서는 에지 기반의 공간 기술자를 이용하였다. 실험 결과는 영상 색인 및 검색에 있어서 제안된 시스템이 매우 효과적임을 잘 나타내고 있다. 데이터베이스 내 영상의 색인을 위해서는 R*-tree 구조를 이용한다.

• 정보관리연구
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• 제43권3호
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• pp.79-95
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• 2012

이 연구는 관광분야의 학문적 특성을 분석하고, 주요 분류법의 관광분야 분류체계를 비교 분석하여 분류항목을 추출한 후, 이를 토대로 관광분야의 새로운 분류체계를 설계하였다. 연구내용을 요약하면 다음과 같다. 첫째, 주요 분류법의 관광분야 분류체계를 분석한 결과 분류항목이 여행 및 관광, 관광정책, 관광자원 등에 편중되어 있으며, 관광분야 연구영역과 비교하면 누락되거나 소홀히 취급된 항목이 많아 적용에 어려움이 많다. 둘째, 관광분야 개론서를 바탕으로 관광분야 연구영역을 추출하고, 주요 분류법의 분류항목과 비교 분석하여 분류항목의 기본범주를 관광일반, 관광주체, 관광객체, 관광매체의 4개 영역으로 설정하였다. 셋째, 이를 바탕으로 관광분야의 새로운 분류법을 설계하였으며, 기본적으로 관광분야를 주류 4개 영역, 총 25개 항목으로 구분하였다. 비록 여기서는 강목 수준까지 제시하였으나 필요에 따라 확장이 용이하도록 설계하였다.

• 정보처리학회논문지:소프트웨어 및 데이터공학
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• 제2권4호
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• pp.219-226
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• 2013

특징 선택은 기계 학습 및 패턴 인식 분야에서 중요한 이슈 중 하나로, 분류 정확도를 향상시키기 위해 원본 데이터가 주어졌을 때 가장 좋은 성능을 보여줄 수 있는 데이터의 부분집합을 찾아내는 방법이다. 즉, 분류기의 분류 목적에 가장 밀접하게 연관되어 있는 특징들만을 추출하여 새로운 데이터를 생성하는 것이다. 본 논문에서는 소프트웨어 재사용의 성공 요인과 실패 요인에 대한 분류 정확도를 향상시키기 위해 특징 부분 집합을 찾는 실험을 하였다. 그리고 기존 연구들과 비교 분석한 결과 본 논문에서 찾은 특징 부분 집합으로 분류했을 때 가장 좋은 분류 정확도를 보임을 확인하였다.