• 한국음향학회지
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• 제34권3호
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• pp.234-239
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• 2015

비음수 행렬 분해(Nonnegative Matrix Factorization, NMF) 기법은 사전행렬과 크기성분을 번갈아 가며 업데이트 하면서 구하는 방법이며 직관적 해석 및 구현의 용이성으로 인해 중첩음향이벤트 분리 및 검출방법으로 널리 활용되었다. 하지만 비음수 행렬 분해의 고유한 특성인 부분기반표현(part-based representation)으로 인해 하나의 음향 이벤트를 구성 하는 사전(dictionary)의 파편화 현상이 발생하고, 다른 음향이벤트와 중복되는 사전이 생성되어 결과적으로 분리, 검출 성능의 저하 문제가 발생한다. 본 논문에서는 사전 획득 단계의 부분기반표현에 의한 문제를 해소하기 위해 K-Singular Value Decomposition(K-SVD)을 사용하여 사전을 획득하고, 음향이벤트 검출 단계 에서는 기존 비음수 행렬 분해 기법을 이용하여 크기를 획득 한다. 제안하는 방식을 통해 비음수 행렬 분해 기반의 사전을 사용하는 경우보다 중첩음향이벤트 검출 성능이 개선되는 것을 확인하였다.

• 산업공학
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• 제25권1호
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• pp.40-51
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• 2012

Today, many manufacturing companies realize that collaboration is crucial for their survival. Especially, in the perspective of quality, the importance of collaboration is emphasized because economic loss increases exponentially while defective parts go through the process in supply chain. However, the manufacturing companies are facing two main difficulties in implementing collaborative relationships with their suppliers. First, it is difficult for the suppliers to produce reliable products due to their obsolete facilities. The problem gets worse for second- or third-tire vendors. Second, the companies experience the lack of universally understandable set of terminology and effective methodologies for knowledge representation. Ontology is one of the best approaches to expressing and processing a domain knowledge. In this paper, we propose the manufacturing ontology-based quality prediction framework to represent and share the knowledge of industrial environment and to predict product quality in manufacturing processes. In addition, we develop the ontology-based quality prediction system based on the proposed framework. We carried out a series of experiments for an injection molding process at an automotive part supplier. The experimental results demonstrated that the proposed framework and system can be successfully applicable in manufacturing industry.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권5호
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• pp.2607-2627
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• 2017

Nonnegative matrix factorization (NMF) has received considerable attention due to its effectiveness of reducing high dimensional data and importance of producing a parts-based image representation. Most of existing NMF variants attempt to address the assertion that the observed data distribute on a nonlinear low-dimensional manifold. However, recent research results showed that not only the observed data but also the features lie on the low-dimensional manifolds. In addition, a few hard priori label information is available and thus helps to uncover the intrinsic geometrical and discriminative structures of the data space. Motivated by the two aspects above mentioned, we propose a novel algorithm to enhance the effectiveness of image representation, called Dual graph-regularized Constrained Nonnegative Matrix Factorization (DCNMF). The underlying philosophy of the proposed method is that it not only considers the geometric structures of the data manifold and the feature manifold simultaneously, but also mines valuable information from a few known labeled examples. These schemes will improve the performance of image representation and thus enhance the effectiveness of image classification. Extensive experiments on common benchmarks demonstrated that DCNMF has its superiority in image classification compared with state-of-the-art methods.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2008년도 하계종합학술대회
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• pp.723-724
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• 2008

In this paper, we explore face recognition technology for embedded system. We develop an algorithm suitable for systems under ubiquitous environment. The basic requirements includes appropriate data format and ratio of feature data to achieve efficiency of algorithm. Our experiment presents a face recognition technique for handheld devices. The essential parts for face recognition based on embedded system includes; integer representation from floating point calculation and optimization for memory management.

• 한국수학교육학회지시리즈A:수학교육
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• 제57권1호
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• pp.37-54
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• 2018

Despite the significance of fraction in elementary mathematics education, it is not easy to teach it meaningfully in connection with real life in Korea. This study aims to investigate and analyze 3rd grade students' understanding on unit fraction concepts and on comparison of unit fractions and to identify the parts which need to be supplemented in relation to unit fraction. For these purposes, I reviewed previous studies and extracted chapters which cover unit fractions in elementary mathematics textbooks based on 2009 revised curriculums and analyzed teaching contexts and visual representations of unit fractions. From this point of view, I constructed a test which consists of three problems based on Chval et al(2013) to investigate students' understanding on unit fraction. To apply this test, I selected forty-one 3rd grade students and examined that students' aspects of understanding on unit fraction. The results were analyzed both qualitatively and quantitatively. In this study, I present the analysis results and provide implications and some didactical suggestions for teaching contexts and visual representations of unit fraction based on the discussion.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1992년도 춘계학술대회 논문집
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• pp.297-300
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• 1992

For the most part of machine design, assembly drawing isaffected byits inserted parts. When a part is inserted in assembly, alreadyd stablished parting line is modified for reasonable representation. for example, break or trim fuction between the lines gives more recognizable drqwing. Most of parts is composed of such that point, line, arc, circle and block. If the part is composed of block, it is very difficult to operate because its attribution is unknown before exploding, but, It is very easy to operate except block. In this paper, it is required that basic feature recognition rules are caused by knowledge-based. This system which shows a good modify tool using AutoCAD system and ADS (Autocad Development System).

• 한국전산구조공학회논문집
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• 제25권4호
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• pp.307-314
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• 2012

모듈러 강교량 제작, 조립, 설계, 시공단계에서 상부모듈의 부품정보를 효율적으로 제공하고 교환하기 위하여 BIM(Building Information Modeling) 프로젝트에서 정보교환을 위하여 사용하는 국제표준인 IFC 모델을 활용한 부품정보 라이브러리 구축방법을 제시하였다. 모듈러 강교량의 상부모듈을 구성하는 부품정보를 IFC 모델로 표현하기 위하여 의미론적인 관점에서 기존 IFC 모델에서 부품정보를 표현할 수 있는 엔티티와 모듈러 강교량의 구성요소를 매칭하여 적용하였으며, 구성요소의 역할을 구분하기 위하여 매칭한 엔티티의 타입을 적용하거나 사용자정의 타입으로 정의하였다. 또한, 부품 정보 라이브러리에서 부품 및 조립품의 정보를 해당단계에서 효율적으로 제공하기 위하여 조립체계를 네 단계의 상세수준(LoD)으로 구분하여 정의하였으며, 이를 IFC 모델로 표현하기 위하여 새로운 속성정보를 정의하였다. 마지막으로, IFC 모델과 매칭하여 정의한 정보를 실제 모듈러 강교량 상부모듈에 적용하여 IFC 기반의 시범 라이브러리 정보를 생성하였다.

• 기록학연구
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• 제59호
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• pp.5-46
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• 2019

이 연구는 디지털 환경에서의 기록의 본질과 개념적 정의를 탐구하는 것을 목적으로 한다. 이 연구는 크게 두 부분으로 나눌 수 있다. 첫째, 기록에 대한 정의(definition)가 어떻게 전개되어 왔는지를 살펴보았다. 기록의 정의를 증거, 정보, 활동의 재현물이라는 세 가지 측면에서 정리하였다. 특히 각 정의의 근거가 되는 개념과 이론적 배경을 중심으로 살펴보았다. 둘째, 기록의 개념과 본질을 파악하기 위하여 제프리 여의 "활동의 지속적 재현물"이라는 정의를 중심으로 네 개의 분석 영역을 도출하고 각 영역을 둘러싼 논의를 분석하였다. 기록이 활동의 고정적 재현이라는 개념에 입각하여 고정성(fixity)을 도출하고, 고정성이 물질에 기반한다는 점에서 물질성(materiality)을 설정하였다. 또한 활동은 어떻게 기록이라는 재현물로 표현되며 그러한 재현물을 통해 활동을 이해할 수 있는 메커니즘을 무엇인지 짚어보기 위하여 활동과 맥락을 분석대상으로 설정하였고, 그렇게 존재하는 재현물을 신뢰한다는 것은 무엇을 의미하는지 신빙성(trustworthiness)을 중심으로 살펴보았다.

• 한국CDE학회논문집
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• 제1권2호
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• pp.133-149
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• 1996

In order to reduce the trial-and-errors in design and production of injection molded plastic parts, there has been much research effort not only on CAE systems which simulate the injection molding process, but also on CAD systems which support initial design and re-design of plastic parts and their molds. The CAD systems and CAE systems have been developed independently with being built on different basis. That is, CAD systems manipulate the part shapes and the design features in a complete solid model, while CAE systems work on shell meshes generated on the abstract sheet model or medial surface of the part. Therefore, it is required to support the two types of geometric models and feature information in one environment to integrate CAD and CAE systems for accelerating the design speed. A feature-based non-manifold geometric modeling system has been developed to provide an integrated environment for design and analysis of injection molding products. In this system, the geometric models for CAD and CAE systems are represented by a non-manifold boundary representation and they are merged into a single geometric model. The suitable form of geometric model for any application can be extracted from this model. In addition, the feature deletion and interaction problem of the feature-based design system has been solved clearly by introducing the non-manifold Boolean operation based on 'merge and selection' algorithm. The sheet modeling capabilities were also developed for easy modeling of thin plastic parts.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 추계학술대회 논문집
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• pp.119-123
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• 2005

Mold design is a knowledge-intensive decision making process where product designer, injection molding engineer as well as mold designer affect each other. Representation and management of design knowledge is a prerequisite for an intelligent design system, which aims to guide and support designer to carry out design activity in more efficient way by avoiding or minimizing unnecessary trial and errors. This paper discusses the issues in knowledge-based mold design, and describes the structure of a knowledge-based mold design system fur parts with micro features under development.