• 한국CDE학회논문집
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• 제9권1호
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• pp.51-61
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• 2004

Mechanical parts are often grouped into part families based on the similarity of their shapes, to support efficient manufacturing process planning and design modification. The 2-part sequence papers present similarity assessment techniques to support part family classification for machined parts. These exploit the multiple feature decompositions obtained by the feature recognition method using convex decomposition. Convex decomposition provides a hierarchical volumetric representation of a part, organized in an outside-in hierarchy. It provides local accessibility directions, which supports abstract and qualitative similarity assessment. It is converted to a Form Feature Decomposition (FFD), which represents a part using form features intrinsic to the shape of the part. This supports abstract and qualitative similarity assessment using positive feature volumes.. FFD is converted to Negative Feature Decomposition (NFD), which represents a part as a base component and negative machining features. This supports a detailed, quantitative similarity assessment technique that measures the similarity between machined parts and associated machining processes implied by two parts' NFDs. Features of the NFD are organized into branch groups to capture the NFD hierarchy and feature interrelations. Branch groups of two parts' NFDs are matched to obtain pairs, and then features within each pair of branch groups are compared, exploiting feature type, size, machining direction, and other information relevant to machining processes. This paper, the second one of the two companion papers, describes the similarity assessment method using NFD.

• 한국CDE학회논문집
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• 제9권1호
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• pp.44-50
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• 2004

Mechanical parts are often grouped into part families based on the similarity of their shapes, to support efficient manufacturing process planning and design modification. The 2-part sequence papers present similarity assessment techniques to support part family classification for machined parts. These exploit the multiple feature decompositions obtained by the feature recognition method using convex decomposition. Convex decomposition provides a hierarchical volumetric representation of a part, organized in an outside-in hierarchy. It provides local accessibility directions, which supports abstract and qualitative similarity assessment. It is converted to a Form Feature Decomposition (FFD), which represents a part using form features intrinsic to the shape of the part. This supports abstract and qualitative similarity assessment using positive feature volumes. FFD is converted to Negative Feature Decomposition (NFD), which represents a part as a base component and negative machining features. This supports a detailed, quantitative similarity assessment technique that measures the similarity between machined parts and associated machining processes implied by two parts' NFDs. Features of the NFD are organized into branch groups to capture the NFD hierarchy and feature interrelations. Branch groups of two parts' NFDs are matched to obtain pairs, and then features within each pair of branch groups are compared, exploiting feature type, size, machining direction, and other information relevant to machining processes. This paper, the first one of the two companion papers, describes the similarity assessment methods using convex decomposition and FFD.

• 한국CDE학회논문집
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• 제16권1호
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• pp.21-30
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• 2011

Similarity assessment of a CAD model is one of important issues from the aspect of model re-using. In real practice, many new mechanical parts are designed by modifying existing ones. The reuse of part enables to save design time and efforts for the designers. Design time would be further reduced if there were an efficient way to search for existing similar designs. This paper proposes an efficient algorithm of similarity assessment for mechanical part model with design history embedded within the CAD model. Since it is possible to retrieve the design history and detailed-feature information using CAD API, we can obtain an accurate and reliable assessment result. For our purpose, our assessment algorithm can be divided by two: (1) we select suitable parts by comparing MSG (Model Signature Graph) extracted from a base feature of the required model; (2) detailed-features' similarities are assessed with their own attributes and reference structures. In addition, we also propose a indexing method for managing a model database in the last part of this article.

• 한국군사과학기술학회지
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• 제22권6호
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• pp.735-744
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• 2019

One of the key factors for recognition performance in the automatic target recognition for synthetic aperture radar imagery(SAR-ATR) system is reliability of the SAR target database. To achieve optimal performance, the database should be constructed using the images obtained under the same operating condition as the SAR sensor. However, it is impractical to have the extensive set of real-world SAR images, and thus those from the electro magnetic prediction tool with 3-D CAD models are suggested as an alternative where their reliability can be always questionable. In this paper, a method for similarity assessment between target SAR images is presented inspired by the fact that a target SAR image is mainly characterized by the features of scattering centers. The method is demonstrated using a variety of examples and quantitatively measures the similarity related to reliability. Its assessment performance is further compared with that of the existing metric, structural similarity(SSIM).

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2021년도 추계학술대회
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• pp.658-660
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• 2021

본 연구의 목표는 확산 광학 단층 촬영에 대한 기준 영상을 사용하여 동질성과 이질성을 분리하기 위한 재구성된 영상들간의 수치적 평가를 위해 구조적 유사성 지수에 기초한 알고리즘을 개발한다. 글로벌 지오메트리 및 관심 영역 평가는 유사성을 산출하기 위해 측정되었으며, 그 결과 구조적 유사성 지수의 평균이 모델 내부에 가시적 포함 여부를 판단할 수 있는 잠재적 성능을 나타낸다는 것을 알 수 있으며, 구조적 유사성 지수는 유방 구조 정보를 평가하기 위한 이미지 평가를 지원 가능한 것으로 확인 되었다.

• 한국소프트웨어감정평가학회 논문지
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• 제15권1호
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• pp.25-35
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• 2019

우리나라에서 컴퓨터프로그램의 실질적 유사성 여부 판단은 정량적인 유사도를 산출하여 그 결과를 활용하는 방식이 일반적으로 이용된다. 실질적 유사성은 유사한 부분의 양과 질을 고려하여 판단되어야 하는데, 실무에서는 정량적인 유사도 계산 과정에서 가중치를 곱함으로써 유사한 부분의 질을 고려하는 모습을 보인다. 그런데 실질적 유사성 판단과 관련하여 유사한 부분의 양적, 질적인 고려는 동일한 지위에서 순차적으로 이루어져야 한다는 본질적 특징을 고려할 때, 현재와 같은 실무 방식은 적절하다고 할 수 없다. 이에 이와 같은 가중치 활용의 문제를 지적하고, 실질적 유사성 판단을 위한 유사 부분의 질적 평가는 정량적 유사도 판단에 후행하여 그와 동일한 지위에서 이루어져야 함을 제시 및 이를 위한 적절한 실무적 방안을 제언하였다.

• 한국소프트웨어감정평가학회 논문지
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• 제16권2호
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• pp.37-44
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• 2020

정보화 사회가 발전함으로써 다양한 저작권 침해 사례가 발생하고 있다. 기업간의 여러 분쟁은 소프트웨어 유사도 감정이 대부분을 차지하고 있다. 본 논문은 감정 대상 규격서의 유사도 산정 방법에 관한 연구이다. 즉, 감정 대상 규격서의 수정 및 추가 분량이 어느 정도 인지 산정하는 연구이다. 감정 분석 방법은 양측의 규격서 목차 비교하고 동일 또는 유사 부분을 찾아낸다. 유사 정도에 따라 유사도 가중치를 결정한다. 가중치는 전문가의 전문적 지식과 규격서의 유사 정도를 파악하고 부여한다. 완전히 새로 추가된 경우 유사도 가중치는 1, 일부 수정한 경우 유사도 가중치는 0.4, 기존과 거의 동일한 경우 가중치 0.05를 주어 산정한다. 본 논문을 통하여 규격서에 대한 동일 유사성 산출 결과 21.2 페이지임을 알 수 있었다.

• 한국안전학회지
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• 제31권4호
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• pp.120-125
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• 2016

Usually, a risk can be expressed as a product of likelihood and consequence of a hazard factor. Therefore, conventional risk assessment is carried out by frequency analysis and severity analysis, in turns. However, it is well known that intuitive thinking is another excellent way of thinking of human beings. This study aimed to confirm whether there exist any difference in risk assessment results derived by two different procedures - intuitive and analytical. Thus, the present study showed 10 different illustrations to 30 undergraduate students. Their responses were organized as fuzzy membership functions, and summarized as risk assessments, and compared. The results were also verified with the help of statistical hypothesis testing, which showed no significant difference. On the contrary, however, similarity measure used in fuzzy set theory was not credible as anticipated. Many cases failed to satisfy statistical hypothesis even with similarity measure higher than 0.60 so that only a trend could be accepted. In addition, a subject showed a somewhat consistent logical discrepancy in his response, which implied the necessity of sincere analysis in fuzzy formulations.

• 한국실내디자인학회논문집
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• 제13권5호
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• pp.190-197
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• 2004

A kindergarten requires an approach to meet the nature and sense of children who is main users. This study selected 33 private kindergartens which were located within a housing site development zone in Gwangju since the 1990's, had single use, and was constructed in the last five years. Also the image assessment according to types of color scheme was made. Then the factors which affected preference by type were analyzed and the basic of color scheme in a kindergarten classroom was provided. The following results were obtained. First, types of color scheme in a classroom included identity 12.1%, similarity 51.5%, and novelty 36.4% in harmony, but no contrast and achromatic color, Secondly, the assessment of preference according to each type was mostly positive. The highest preference was found in similarity harmony of warm color(e.g. YR, Y) and bright, clear, nice, and strong images were high in assessment. The lowest preference was found in identity harmony of cold color(e.g. GY). This color system had no clear image assessment, except manly or strong. In particular, warm color showed higher preference than cold color in similarity, novelty, and identity harmony. Thirdly, the factors affecting the preference of color scheme in a classroom most were ‘stable - unstable’, ‘clean - dirty’, ‘bright - dark’, ‘nice - not nice’, and ‘vital - dull’.

• 기술혁신학회지
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• 제3권3호
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• pp.67-84
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• 2000

This paper expanded the usefulness of technology relation analysis by applying to R&D activities of Korea Gas Corporation (Kogas) at the corporate level. Technology relation analysis has been applied to assessment of R&D investments in telecommunication and construction industries in Korea. As empirical findings, technology map and technology spillover matrix of Kogas have been derived by technology similarity analysis. It has bee found that various useful information for R&D assessment could be acquired from the technology relation analysis at the corporate level.