• Korean Journal of Computational Design and Engineering
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• v.9 no.1
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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.

• Korean Journal of Computational Design and Engineering
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• v.9 no.1
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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.

• Korean Journal of Computational Design and Engineering
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• v.16 no.1
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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.

• Journal of the Korea Institute of Military Science and Technology
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• v.22 no.6
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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).

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.10a
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• pp.658-660
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• 2021

The work within this study develops an algorithm based on the structural similarity index to assess numerically between reconstructed images with a reference image to separate the homogeneity and heterogeneity for diffuse optical tomography. Global geometry and region of interest assessment have been measured to yield the similarity. The results indicate that the mean of structural similarity index shows potential performance to distinguish between visible and invisible inclusion inside the model. Therefore, the structural similarity index may promise to assist the image assessment for evaluating breast structural information.

• Journal of Software Assessment and Valuation
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• v.15 no.1
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• pp.25-35
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• 2019

In Korea, the calculation of quantitative similarity is commonly used to gauge the substantial similarity of computer programs. Substantial similarity should be assessed by considering the quantity and quality of areas that show similarity, but in practice, qualitative aspects are reflected by multiplying the weighted value in the calculation of quantitative similarity. However, such a practical method cannot be deemed adequate, considering the fundamental characteristic of the judgment on substantial similarity, which holds that the quantitative and qualitative aspects of similar areas should be considered on an equal footing. Thus, this study pointed out the issue regarding the use of weighted value and sought appropriate ways to take into account qualitative aspects when assessing the substantial similarity of computer programs.

• Journal of Software Assessment and Valuation
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• v.16 no.2
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• pp.37-44
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• 2020

As the information society develops, various cases of copyright infringement have occurred. In many disputes between companies, software similarity appraisal is dominated. This thesis is a study on the method of calculating the similarity of the standards subject to appraisal. In other words, it is a study to calculate the amount of revision and addition of the specification to be assessed. The analysis method compares the table of contents of both specifications and finds the same or similar part. The similarity weight is determined according to the degree of similarity. Weights identify and assign the degree of similarity between the expert's expertise and the specification. If it is completely newly added, the similarity weight is 1, if it is partially modified, the similarity weight is 0.4, and if it is almost the same as before, it is calculated by giving a weight of 0.05. Through this paper, it was found that the result of calculating the similarity to the specification is 21.2 pages.

• Journal of the Korean Society of Safety
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• v.31 no.4
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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.

• Korean Institute of Interior Design Journal
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• v.13 no.5
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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’.

• Journal of Korea Technology Innovation Society
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• v.3 no.3
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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.