• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.11a
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• pp.271-272
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• 2008

• Proceedings of the Materials Research Society of Korea Conference
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• 1994.11a
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• pp.178-178
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• 1994

• Proceedings of the Costume Culture Conference
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• 2004.10a
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• pp.77-79
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• 2004

• Proceedings of the Korea Society of Costume Conference
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• 2001.08a
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• pp.20-22
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• 2001

• International Journal of Highway Engineering
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• v.18 no.6
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• pp.61-67
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• 2016

OBJECTIVES : The objective of this study is to detect road cavities using multi-channel 3D ground penetrating radar (GPR) tests owned by the Seoul Metropolitan Government. METHODS : Ground-penetrating radar tests were conducted on 204 road-cavity test sections, and the GPR signal patterns were analyzed to classify signal shape, amplitude, and phase change. RESULTS : The shapes of the GPR signals of road-cavity sections were circular or ellipsoidal in the plane image of the 3D GPR results. However, in the longitudinal or transverse direction, the signals showed mostly unsymmetrical (or symmetrical in some cases) parabolic shapes. The amplitude of the GPR signals reflected from road cavities was stronger than that from other media. No particular pattern of the amplitude was found because of nonuniform medium and utilities nearby. In many cases where road cavities extended to the bottom of the asphalt concrete layer, the signal phase was reversed. However, no reversed signal was found in subbase, subgrade, or deeper locations. CONCLUSIONS : For detecting road cavities, the results of the GPR signal-pattern analysis can be applied. In general, GPR signals on road cavity-sections had unsymmetrical hyperbolic shape, relatively stronger amplitude, and reversed phase. Owing to the uncertainties of underground materials, utilities, and road cavities, GPR signal interpretation was difficult. To perform quantitative analysis for road cavity detection, additional GPR tests and signal pattern analysis need to be conducted.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.3
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• pp.18-23
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• 1998

This paper describes a research work of developing a computer-aided design of blanking and piercing for irregular-shaped sheet metal products. An approach to the CAD system is based on the knowledge-based rules. Knowledge for the CAD system is formulated from plasticity theories, experimental results and the empirical knowledge of field experts. The system has been written in AutoLISP on the AutoCAD with a personal computer and is composed of four main modules, which are input and shape treatment, flat pattern layout, production feasibility check, and strip layout module. Based on knowledge-based rules, the system is designed by considering several factors, such as radius and angle of bend. material and thickness of product, complexities of blank geometry and punch profile, and availability of press. This system is capable of unfolding a formed sheet metal part to give flat pattern and automatically account for the adjustment of bend allowances to match tooling requirements by checking the dimensions and relationships of parts of the folded product. Also this system can carry out a process planning which is obtained from results of irregular shape of product that was successful in production feasibility check module according to flat pattern layout and generate strip layout drawing in graphic forms. The developed system provides its efficiency for flat pattern layout, and strip layout for the irregularly shaped sheet metal products.

• Journal of the Korean Society of Costume
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• v.59 no.8
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• pp.49-65
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• 2009

As basic materials in this research, 874 pieces of engraving that recorded the garment produced by diverse authors in the 17-18th century were collected among the collections of male and female garment in the engraving kept by National Library of France and 216 pieces of engraving were classified among them to observe justaucorps as stated in the materials. Since type of justaucorps in the 18th century can be classified by difference in shape and change through the above engraving materials in large quantity and the shape and composition can be compared and analyzed with other materials such as picture, stored garment, written materials without difficulty, the chronology can be composed by single type of justaucorps. Intending to understand the change in composition caused by type classification and pattern making as per analysis of type property of justaucorps, the men's upper garment in France in the 18th century. Checking change in design per from and materials, justaucorps of 1680-1700s was in silhouette where waist in the length above knee was adhered and slightly spread to lower part. In the type of 1710-1750s, waist adhered remarkably and many pleats were made under waist to produce volume of form that spread to lower part like skirt. In the type of 1760-1780s, straight silhouette was attached to whole body and end of front adjustment in slant line turns to rear part. The developmental aspect of construction can be checked by making pattern. Changing the cutting line of body plate to smoothly connect section and to try to adhere to the body, the development of simpler and delicate pattern production technique was confirmed.

• Journal of Yeungnam Medical Science
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• v.22 no.1
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• pp.43-51
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• 2005

Background: To examine the ultrasonographic and magnetic resonance (MRI) imaging findings of a cervical mass type cervical pregnancy. Materials and Methods: The ultrasonographic and MRI findings of 5 patients pathologically confirmed as having a cervical pregnancy were analyzed retrospectively. On ultrasonography, the size and echo pattern of the uterine cervix, the shape and echo pattern of the lesion, the degree and the pattern of blood flow on the color Doppler study and the spectral Doppler pattern were analyzed. The shape, signal intensity, and degree and pattern of enhancement of the lesion were evaluated on MRI. Results: The uterine cervix was enlarged and the size of the lesion was 6.1 to 7.1 (average, 6.5) cm. The endocervical canal was irregularly dilated and showed heterogeneous echogenicity in all 5 cases. Four of the 5 lesions were heterogeneously hyper- or mixed echoic and remaining one was relatively homogeneous echogenic. Doppler ultrasonography revealed an increased vascularity of the peritrophoblastic flow pattern. In all 4 cases where MRI performed, the lesion was irregular in shape and the margin was not sharply demarcated. The T2-weighed image showed that the lesions were mixed signal intensity. Three of the 4 lesions contained high signal intensity nodular portions and a low signal intensity rim was observed along the margin of the nodular portions. The T1-weighted image revealed multiple signal voids along the periphery of the lesions and high signal intensity portions as a result of hemorrhage were noted. The dynamic enhanced study showed that the high signal intensity portions on the T2-weighted image were strongly enhanced similar to the vessels on the early phase and the contrast enhancement gradually decreased with time. Conclusion: A cervical mass type cervical pregnancy can be correctly diagnosed using the patient's clinical symptom, the elevation in the serum ${\beta}$-HCG level, and characteristic ultrasonographic and MRI findings.

• Journal of the Korean Society of Industry Convergence
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• v.16 no.3
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• pp.85-93
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• 2013

The MCT has been most extensively used in the machining. In particular, the ball endmill has been mainly adopted for finishing on the free- form surface. The advancement of CAD/CAM software has made it possible to develop various cutting pattern methods and to create diverse tool routes. Therefore, the current research made an attempt to find the optimal cutting pattern among the seven cutting patterns (i.e., Follow Periphery, Zig, Zig Zag, Concentric Zig, Concentric Zig Zag, Radial Zig, Radial Zig Zag) when aluminium 6000 series were machined by the ball endmill. The optimal pattern was found by comparing different shapes and surface roughness produced by the seven patterns. The current research found that each cutting pattern produced its own unique geometric features on the machined surface. It was found that the Radial Zig cutting pattern produced the lowest roughness on the flat surfaces. The Radial Zig Zag cutting pattern was found to produce the most accurate free-form surface. Finally, the most efficient cutting pattern in terms of machining time turned out to be the Follow Periphery.

• Journal of the Ergonomics Society of Korea
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• v.21 no.1
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• pp.67-80
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• 2002

An efficient torso pattern has been developed to cope with the future trend of order-based, individualized production like the E.C.(Electronic Commerce) in the apparel industry, and to make a database foundation of automatic garment pattern drafting. For this purpose, a non-contact three-dimensional anthropometric measurement system was used to provide a lot of accurate body data for better individual fit, and an automatic pattern drafting system that can easily generate various size patterns and construct a pattern database has been developed too. The subjects of this research were 18 to 24 year-old women whose data had been gathered through the Korean national investigation of anthropometry for industrial standards in 1997 and various body shapes were analyzed by the measurements. And a special software system has been developed to verify the validity of newly proposed drawing rules. The results of sensory evaluation for appearance and moving fitness of the new torso pattern showed a significant improvement in individual fit even for the figures with large deviation from standard shape compared with the results of the traditional one.