• Journal of the Korean Society of Costume
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• v.58 no.5
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• pp.198-210
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• 2008

The purpose of this study is to establish the conservation methods of embroidered textiles and textile works. The conservation of remained textiles is consisting of examination, cleaning, support and consolidation, restoration, and storage and display process. It aims to prevent the damage on textile remains for long time display and storage and to prolong their aesthetics and functionality. The embroidered textiles and textiles works, which are remained by handed down or excavated or included in the Buddhist are embossed with colorful threads on the fabrics: the stitches include embroideries on clothing, bed clothes, wrapping clothes, utensil pouches, panels and Buddhist goods; textile works include hats, ornaments, shoes, attachments of clothes etc. These are composed of mainly fabrics, precious metals, leathers and precious stones, etc., and are fabricated by several techniques such as braiding, twining, sewing as well as weaving. Metal threads were also used to add a decorative effect on these goods. In order to conserve and preserve the remained goods, a special care must be taken on the metal threads, which are the most fragile material among the constituents. Hence, characteristics of metal threads and its cleaning methods, general conservation techniques of a rank badge, which is brocaded and partly attached to Cheogori and Samo(men's hat) from the excavated old tombs are introduced here.

• Journal of the Korean Society of Clothing and Textiles
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• v.37 no.6
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• pp.764-771
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• 2013

The metal component of Chinese and Korean traditional gold thread was analyzed nondestructively using P-XRF and classified morphologically. In the nondestructive analysis of 22 Chinese and Korean artifacts, there were 10 gold threads made up of Au in China and 7 in Korea; in addition, there were 4 silver threads made up of Ag in Korea and 1 copper thread made up of Cu in China. In the morphological classification, 7 gilt paper strips were confirmed in China and Korea and 4 wrapped threads were identified in China and Korea. Zn, Sn and Fe (minor components of the threads) were detected. These components were assumed to be transferred from the metal found in burial goods.

• Journal of the Korean Society for Precision Engineering
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• v.33 no.6
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• pp.491-497
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• 2016

This study aims to develop a vision inspection system for screw threads. To inspect external defects in screw threads, the vision inspection system was developed using front light illumination from which bright images can be obtained. The front light system, however, requires multiple side images for inspection of the entire thread surface, which can be performed by omnidirectional optics. In this study, an omnidirectional optical system was designed to obtain annular images of screw threads using an image sensor and two reflection mirrors; one large concave mirror and one small convex mirror. Optical simulations using backward and forward ray tracing were performed to determine the dimensional parameters of the proposed optical system, so that an annular image of the screw threads could be obtained with high quality and resolution. Microscale surface defects on the screw threads could be successfully detected using the developed annular inspection system.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.8
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• pp.139-145
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• 1996

Tapping is one of the most widely used machining operations. There are several methodes of producing external screw threads, e.g. turning, milling with single or multiple cutter, rolling, and grinding, but the methods available for cutting enternal threads are less numerous, and for threads in small holes, tapping is employed almost exclusively. In this study, the tap with the various geometry has been developed in order to tap special workmaterial at considerably higher cutting speed than that of the conventional HSS tap. The experimental tests are run with various cutting speed by using a piezo type tool dynamometer to measure tapping torque. Tapping torque is affected by the design of the tap, which seems to be due to internal friction and shearing of the metal. It is clarified that the process of chip formation strongly depends on rake angle, relief angle, angle of twist.

• Journal of the Korean Society for Precision Engineering
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• v.31 no.3
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• pp.261-268
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• 2014

Precision screws have a wide range of industrial applications such as electrical and automotive products. To produce screw threads with high precision, not only high precision manufacturing technology but also reliable measurement technology is required. Machine vision systems have been used in the automatic inspection of screw threads based on backlight illumination, which cannot detect defects on the thread surface. Recently, an omnidirectional inspection system for screw threads was developed to obtain $360^{\circ}$ images of screws, based on front light illumination. In this study, the illumination design for the omnidirectional inspection system was modified by adding a light shield to improve the image uniformity. Optical simulation for various shield designs was performed to analyze image uniformity of the obtained images. The simulation results were analyzed statistically using response surface method, from which optical performance of the omnidirectional inspection system could be optimized in terms of image quality and uniformity.

• Fashion & Textile Research Journal
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• v.5 no.3
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• pp.299-303
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• 2003

Some of historical textiles were analyzed to identify the imprinted textures on the metal remains of Haengyeup(a horse strap pendant) and Doja (a knife), which were excavated in the ruins of Hwangsung-dong, Kyungju city in the fifth century and textiles imprinted on the human bones that were excavated in the Pungnae 4th Area, Namyangju county in the sixteenth century. The results analyzed arc as follows ; It was confirmed that the imprinted textures of Haengyeup and Doja are white ramie since the structural characteristics of cellulosic bast fibers, partially projected long oval cross sections with large lumens and the imprinted textures of human bones are silk fabrics since the triangular cross sections of fibroin is showed. All of the textiles were designed in plain weaves. In the case of weaving yarns, the warp threads were thicker than the weft threads, that is, the imprinted textures of Haengyeup were measured by 1.35 mm for warp and 1.21 mm for weft, and the Doja by 1.16mm for warp and 1.11 mm for weft. In connection with the direction of the yarn twist, the Z-twist were observed in the imprinted textures of human bones, whereas it presented the S-twist in the case of Haengyeup and Doja. The warp yarns were mostly harder twisted than the weft yarns on the amounts of twist, that is, it was observed that the case of Haengyeup were amounted to 0.33 twists per centimeter for warp yarns and 0.25 twists per centimeter for weft yarns. Also it was showed 0.32 twists per centimeter for warp yarns and 0.26 twists per centimeter in the case of the textures of human bones. On the fabric counts, it was showed that the finer the yarns the higher the densities since it were $4.3{\times}5.1$ threads per sqaure centimeters and $7.6{\times}7.1$ threads per sqaure centimeters each in the case of Haengyeup and Doja, whereas it was $18.2{\times}33.7$ threads per sqaure centimeters in the case of the textures of human bones.

• Journal of Conservation Science
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• v.37 no.5
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• pp.525-535
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• 2021

This study identified material properties through scientific analysis on Jikgeumdan(satin with gold threads) from Donggungbi-Wonsam and the gold threads used in the embroidery. The Donggungbi-Wonsam's base of gold threads were estimated to have used mulberry fiber's Korean paper(Hanji) because non-wood-based fibers were observed. The X-ray spectrometer showed that the Tongsuseulan of Donggungbi-Wonsam was a flat gold thread of pure gold and Jikgeumdan of flat silver thread of its Saekdong and Hansam. High sulfur levels were detected in the flat silver thread, which appeared to have formed silver sulfide by either manufacturing process using sulfur or conservation environment. he dragon insignia's embroidery is also described as two types twisted gold threads; pure gold and alloying-gold and silver. while dragon insignia's border line is decorated with a twisted gold thread of pure gold. In particular, it was investigated that adhesives such as an animal glue, a protein-based compound by gas chromatography mass spectrometry. Additionally, XRF and Raman spectroscopy analysis on the mixture substances between the metal surface and the base paper of gold threads identified talc and quartz in the gold threads and Seokganju(hematite) in the flat silver threads.

• The Journal of Korean Academy of Prosthodontics
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• v.38 no.5
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• pp.659-674
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• 2000

A large increase in the use of thin film coating of hydroxyapatite(HA) in implant dentistry is driven by the desire to take advantage of the excellent biocompatibility and high strength of HA coating. The purpose of this study was to evaluate the effects of HA-coated implants by ion Beam Assisted Deposition(IBAD) method in comparison to the sand-blasted and machined surfaces. Osteoblast culture test, removal torque test and histomorphometric analysis were performed and the following results obtained; 1. Examination of the osteoblast cultures displayed no difference in the secretion of alkaline phosphatase between the various specimen, but IBAD with pure HA specimen showed low alkaline phosphatase secretion(p<0.05). 2. Removal torque tests showed HA-coated implants by IBAD method to be similar in high value to the implants with sand-blasted surface than the implants with machined surface. And the ovariectomized group showed low mechanical test value than the normal group(p<0.05). 3. Histomorphometrical comparisons were performed on undecalcified ground sections. HA-coated implants by IBAD method demonstrated the highest mean bone-to-metal contact ratio on all threads and 3-best consecutive threads, and the implants with sand-blasted surface and implants with machined surface was in the next consecutive order(p<0.05). HA-coated implants showed slightly higher bone-to- metal contact ratio than sand-blasted implants, but no statistically significant difference was obtained between the two materials. The ovariectomized group showed lower value of bone-to-metal contact ratio than the normal group, but no statistically significant difference was obtained between the two groups. 4. Evaluation of bone volume on all threads and 3-best consecutive threads showed no statistically significant difference among the different surface treatment groups, but showed lower bone volume in ovariectomized group than in the normal group(p<0.05). According tn these results, thin film coated implants with HA showed high bone contact ratio, bone volume and removal torque strength in the short term, but long term observation is needed.

• Journal of the Korean Society of Costume
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• v.63 no.7
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• pp.79-93
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• 2013

In the Korean literature, records of systematic gold thread manufacturing such as gold foil(金 箔匠), gold foil bonded with fabrics(付金匠), gold foil bonded with paper materials(金箋紙匠), refining gold(鍊金匠), cutting gold(裁金匠), and making gold thread(絲金匠) can be easily found. We can infer from these literatures that the Korean people used to make gold threads. However, is not existent the gold thread making technique. Thus, a research was done using 67 pieces of gold thread artifacts used in textiles craft of Korea, China and Japan. The purpose of this research was to identify the characteristics of the Korean gold thread by studying the artifacts' form classification, gold foil, glue and the base. First, gold thread is divided into flat gold thread and wrapped gold thread. Wrapped gold thread was made in more various methods such as with a paper on the flat gold thread, metal thread and wrapped gold thread with gold foil on top. Compared to the flat gold thread, wrapped gold thread uses a thread that has a thinner and wider. Through this analysis, even making of the base of the gold threads was different according to the type. Secondly, we looked into the characteristics of materials according to form structure of the gold thread. After analysis of experiment results, we could know that to attach Korean gold thread, glue and the mixture of materials such as Red soil(朱土) was also added. The kinds of the base of gold threads were identified as paper, leather and intestines. Among those materials, for paper, Korea's Dakji, China's Sangpiji(桑皮紙) and Jukji(竹紙) and Japan's Anpiji(雁皮紙) seemed to have all been used, so because of the difference among countries, we can prove that Korea has also produced gold thread. By looking at the research, the base of gold threads and making features hugely vary according to the area.

• Smart Structures and Systems
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• v.18 no.4
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• pp.643-662
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• 2016

The monitoring of structural integrity of pipeline tapered thread connections is of great significance in terms of safe operation in the industry. In order to detect effectively the loosening degree of tapered thread connection, an active sensing method using piezoceramic transducers was developed based on time reversal technique in this paper. As the piezoeramic transducers can be either as actuators or sensors to generate or detect stress waves, the energy transmission for tapered thread connection was analyzed. Subsequently, the detection principle for tapered thread connection based on time reversal was introduced. Finally, the inherent relationship between the contact area and tightness degree of tapered thread connection for the pipe structural model was investigated. Seven different contact area scenarios were tested. Each scenario was created by loosening connectors ranging from 3 turns to 4.5 turns in the right tapered threads when the contact area in the left tapered threads were 4.5 turns. The experiments were separately conducted with a highly noisy environment and various excitation signal amplitudes. The results show the focused peaks based on time reversal have the monotonously rising trend with the increase of the contact areas of tapered threads within an acceptable monitoring resolution for metal pipes. Compared with the energy method, the proposed time reversal based method to monitor tapered threads loosening demonstrates to be more robust in rejecting noise in Structural Health Monitoring (SHM) applications.