• 제목/요약/키워드: data refinement

검색결과 306건 처리시간 0.021초

재생커널입자법을 이용한 체적성형공정의 해석 (Analysis of Bulk Metal Forming Process by Reproducing Kernel Particle Method)

  • 한규택
    • 한국기계가공학회지
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    • 제8권3호
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    • pp.21-26
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    • 2009
  • The finite element analysis of metal forming processes often fails because of severe mesh distortion at large deformation. As the concept of meshless methods, only nodal point data are used for modeling and solving. As the main feature of these methods, the domain of the problem is represented by a set of nodes, and a finite element mesh is unnecessary. This computational methods reduces time-consuming model generation and refinement effort. It provides a higher rate of convergence than the conventional finite element methods. The displacement shape functions are constructed by the reproducing kernel approximation that satisfies consistency conditions. In this research, A meshless method approach based on the reproducing kernel particle method (RKPM) is applied with metal forming analysis. Numerical examples are analyzed to verify the performance of meshless method for metal forming analysis.

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빅데이터를 활용한 패션쇼에 대한 소비자 인식 연구 (A Study of Consumer Perception on Fashion Show Using Big Data Analysis)

  • 김다정;이승희
    • 패션비즈니스
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    • 제23권3호
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    • pp.85-100
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    • 2019
  • This study examines changes in consumer perceptions of fashion shows, which are critical elements in the apparel industry and a means to represent a brand's image and originality. For this purpose, big data in clothing marketing, text mining, semantic network analysis techniques were applied. This study aims to verify the effectiveness and significance of fashion shows in an effort to give directions for their future utilization. The study was conducted in two major stages. First, data collection with the key word, "fashion shows," was conducted across websites, including Naver and Daum between 2015 and 2018. The data collection period was divided into the first- and second-half periods. Next, Textom 3.0 was utilized for data refinement, text mining, and word clouding. The Ucinet 6.0 and NetDraw, were used for semantic network analysis, degree centrality, CONCOR analysis and also visualization. The level of interest in "models" was found to be the highest among the perception factors related to fashion shows in both periods. In the first-half period, the consumer interests focused on detailed visual stimulants such as model and clothing while in the second-half period, perceptions changed as the value of designers and brands were increasingly recognized over time. The findings of this study can be utilized as a tool to evaluate fashion shows, the apparel industry sectors, and the marketing methods. Additionally, it can also be used as a theoretical framework for big data analysis and as a basis of strategies and research in industrial developments.

데이터 확장 기법에서 손실값을 대치하는 확률 추정 방법 (Probability Estimation Method for Imputing Missing Values in Data Expansion Technique)

  • 이종찬
    • 한국융합학회논문지
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    • 제12권11호
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    • pp.91-97
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    • 2021
  • 본 논문은 불완전한 데이터를 처리하기 위해 본래 규칙개선 문제를 위해 고안되었던 데이터 확장 기법을 사용한다. 이 기법은 사건마다 중요도를 의미하는 가중치를 가질 수 있으며 각 변수를 확률값으로 나타낼 수 있는 특징이 있다. 본 논문에서의 핵심 문제가 손실값과 가장 근사한 확률을 구하여 손실값을 확률로 대치하는 것이므로, 3가지 다른 알고리즘으로 손실값에 대한 확률을 구한 후 이 데이터 구조의 형식으로 저장한다. 그리고 각각의 확률 구조에 대한 평가를 위해 SVM 분류 알고리즘으로 각각의 정보 영역을 분류하는 학습을 한 후, 본래의 정보와 비교하여 얼마나 서로 일치하느냐를 측정한다. 손실값의 대치 확률을 위한 3가지 알고리즘들은 같은 데이터 구조를 사용하고 있으나 접근 방법에서는 서로 다른 특징을 가지고 있어 적용 분야에 따라 다양한 용도로 이용될 수 있기를 기대한다.

한의학 통계자료를 이용한 지식정보 데이터베이스 구축 연구 (Building Information Database Using Traditional Korean Medical Statistics)

  • 예상준;김철
    • 대한한의학회지
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    • 제34권1호
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    • pp.170-178
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    • 2013
  • Objectives: Because TKM-related statistics are scattered in year books, white papers, or web services, it is not easy to use. This study aimed to build a TKM statistical database offering one-stop service. Methods: We collected TKM statistics from year books, white papers, and web services using TKM related keywords which came from the advanced study. Then we removed, merged, or split the statistics looking through data and meta-data of statistics to build a database. Results: First, we classified the statistics into 6 categories and found that the service category was 303, product category 37 and so on. Second, we analyzed the source of statistics and found that the Ministry of Health & Welfare and the Korea statistics were the strongest sources. Third, we analyzed the years of statistics and found that the oldest was 1962, 35% were within the past 3 years, and only 14% were over 10 years old. Finally, we found that the 415 statistics were composed of 1,120 items and the average was 2.70. Conclusions: Through this study we found that more sophisticated TKM statistics must be produced and developed specially in the education, research, and administration categories. We hope that the effort of TKM societies is available to eliminate the lack of statistical producer's understanding about TKM.

기록 관리 메타데이터의 개념 모델링 (Conceptual Modeling of Record Management Metadata)

  • 이현실;한성국
    • 정보관리학회지
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    • 제23권3호
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    • pp.23-48
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    • 2006
  • 기록 관리 메타데이터 스키마는 기록물 자체에 내재한 정보 요소뿐만 아니라, 기록 업무에 따른 기록물의 생명 주기 관리 등에 필요한 관리 요소를 표현할 수 있는 강고한 구조를 가져야 한다. 이를 위해서 메타데이터 스키마에서는 기록 도메인의 정보 모델과, 기록 관리 업무 및 응용에서 요구되는 의미 상세화와 데이터 요소 특수화 등을 지원하는 메타데이터 프레임워크가 요구된다. 본 연구에서는 메타데이터 스키마의 주요 원리와 특성을 분석하여, 기록 관리 메타데이터 스키마를 체계적이고 효과적으로 개발하기 위한 접근 방식을 제시한다. 이를 위해 ISO 15489와 23081에 제시된 기록 관리 지침과 메타데이터 운용에 근거한 기록 관리 정보 모델을 개발하고 핵심 데이터 요소를 제시하였으며, 기록 관리 프레임워크를 구현하는 방법을 보였다.

Predicting BVI Loadings and Wake Structure of the HARTII Rotor Using Adaptive Unstructured Meshes

  • Yu, Dong-Ok;Jung, Mun-Seung;Kwon, Oh-Joon;Yu, Yung-H.
    • International Journal of Aeronautical and Space Sciences
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    • 제10권2호
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    • pp.95-105
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    • 2009
  • The flow fields around the HARTII rotor were numerically investigated using a viscous flow solver on adaptive unstructured meshes. An overset mesh and a deforming mesh technique were used to handle the blade motion including blade deflection, which was obtain from the HARTII experimental data. A solution-adaptive mesh refinement technique was also used to capture the rotor wake effectively. Comparison of the sectional normal force and pitching moment at 87% radial station between the two cases, with and without the blade deflection, showed that the blade loading is significantly affected by blade torsion. It was found that as the mesh was refined, the strength of tip vortex is better preserved, and the magnitude of high frequency blade loading, caused by blade-vortex interaction (BVI), is further magnified. It was also found that a proper time step size, which corresponds to the cell size, should be used to predict unsteady solutions accurately. In general, the numerical results in terms of the unsteady blade loading and the rotor wake show good agreement with the experimental data.

Implementation of Digital Image Processing for Coastline Extraction from Synthetic Aperture Radar Imagery

  • Lee, Dong-Cheon;Seo, Su-Young;Lee, Im-Pyeong;Kwon, Jay-Hyoun;Tuell, Grady H.
    • 한국측량학회지
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    • 제25권6_1호
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    • pp.517-528
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    • 2007
  • Extraction of the coastal boundary is important because the boundary serves as a reference in the demarcation of maritime zones such as territorial sea, contiguous zone, and exclusive economic zone. Accurate nautical charts also depend on well established, accurate, consistent, and current coastline delineation. However, to identify the precise location of the coastal boundary is a difficult task due to tidal and wave motions. This paper presents an efficient way to extract coastlines by applying digital image processing techniques to Synthetic Aperture Radar (SAR) imagery. Over the past few years, satellite-based SAR and high resolution airborne SAR images have become available, and SAR has been evaluated as a new mapping technology. Using remotely sensed data gives benefits in several aspects, especially SAR is largely unaffected by weather constraints, is operational at night time over a large area, and provides high contrast between water and land areas. Various image processing techniques including region growing, texture-based image segmentation, local entropy method, and refinement with image pyramid were implemented to extract the coastline in this study. Finally, the results were compared with existing coastline data derived from aerial photographs.

2007~2018 보건의료산업학회지 게재논문 분석: 연구방법론 중심으로 (Analysis of Published Articles in the Korean Journal of Health Service Management (2007-2018): Centered on Research Methodology)

  • 문정은;장금성
    • 보건의료산업학회지
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    • 제14권1호
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    • pp.195-209
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    • 2020
  • Objectives: This study aimed to analyze the papers in the Korean Journal of Health Service Management (KJHSM) (2007-2018) in order to identify the research trends and aid the future development of healthcare-related research. Methods: Data collection was conducted from September 1-30, 2019. The KSHSM website and Lorea Citatin Index (KCI) electronic database provided 605 copies of original text. Results: Of these, 538 studies are original articles and 7 studies are review articles; 23.7% of the studies presented conceptual framework, 58.4% implemented convenience extraction, and 64.7% collected data using questionnaires. 29.3% of key words were included in the healthcare service, and 48.5% were excluded from the submission field. Conclusions: For the qualitative improvement and development of the journal, it is necessary to consider the relevance of refinement of the methodological approach, segmentation in the field of submission, and selection of keywords.

압축 비디오에서 중간정보를 이용한 트랜스 부호화의 움직임 추정 (Motion Estimation for Transcoding Using Intermediate data on the Compressed Video)

  • 구성조;김강욱;김종훈;황찬식
    • 한국산업정보학회:학술대회논문집
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    • 한국산업정보학회 2001년도 춘계학술대회논문집:21세기 신지식정보의 창출
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    • pp.288-299
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    • 2001
  • 높은 비트율로 부호화 되어있는 비디오 스트림을 낮은 비트율로 다시 부호화할 때 입력 비트 스트림으로부터 뽑아낸 움직임 벡터를 그대로 재 사용한다면 양자화 에러에 의해 심각한 화질의 열화가 발생하게 된다. 따라서 본 논문에서는 이러한 트랜스 부호화 시에 계산량을 줄이면서 화질의 열화를 방지하는 새로운 알고리즘을 제안한다. 제안한 방법은 입력 비트 스트림으로부터 뽑아낼 수 있는 중간 정보들을 이용해서 움직임 벡터를 정재해서 사용할 것인지 아니면 그대로 재 사용할 것인지를 판단한다. 제안한 방법은 영상의 움직임 특성에 따른 임계값을 결정할 수 있어서 움직임 벡터를 단순히 재 사용하는 방법보다 계산량을 줄이면서 화질의 열화를 방지할 수 있다.

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LIDAR 자료기반의 3차원 건물정보 구축 (Three Dimensional Building Construction Based on LIDAR Data)

  • 유환희;김경환;김성삼
    • 대한공간정보학회지
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    • 제14권3호
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    • pp.13-22
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    • 2006
  • 3차원 지형공간정보의 활용범위가 확대되면서 다양한 형태와 크기의 건물들이 존재하는 광범위한 도시지역에 대하여 신속하고 정확하게 실세계에 가까운 3차원 건물 모형을 구축하는 기술 개발이 요구되고 있다. 기존의 항공사진이나 고해상 위성영상을 이용한 3차원 도시 지형공간의 구축 연구와는 달리 최근에는 높은 정밀도를 가진 항공 LIDAR 관측 자료를 활용한 3차원 건물 복원에 관한 연구가 활발히 진행되고 있다. 본 연구에서는 Zero-crossing의 특성을 갖는 LoG 연산자를 이용하여 높이별로 건물의 경계선 정보를 추출하고 Douglas-Peucker 알고리즘을 이용하여 경계선을 직선화하여 건물의 경계선을 정제하고 3차원으로 건물을 복원하는 기법을 제안하였다.

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