• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.3A
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• pp.189-198
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• 2011

Although high strength bolts with tensile strength of 1,000 MPa are mainly used in steel structure construction sites throughout the world, new high strength bolts are required owing to the installation of continuous long-span bridges resulting from the development and distribution of high strength steel and ultra-thick steel plates. Currently, high strength bolts with tensile strength of 1,300 MPa are being used. However, as they tend to place a large load on a small section of space, a high strength bolt of high structural performance and screw thread shape with less stress concentration is thought to be more effective. This study conducted analyses in order to develop an improved screw thread shape relative to the KS screw thread shape. A new screw thread shape with less stress concentration and effective load distribution at the time of fastening bolts and nuts was provided upon analysis of the characteristics of screw thread shape. Additionally, in an experimental study, the structural performance of high strength bolts with tensile strength of 1,300 MPa was investigated. The results revealed that the new screw thread shape was more effective than the existing screw thread shape in terms of structural performance and mitigating the stress concentration.

• Journal of the Korean Society of Clothing and Textiles
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• v.21 no.1
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• pp.206-216
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• 1997

The purpose of this study was to determine the pore size distributions (PSDs) of polyester woven fabrics by using liquid extraction method. Three types of PSDs-percent PSD, PSD per unit area of sample and PSD per unit weight of sample-were evaluated. Plain, twill and satin polyester fabrics with various fabric counts were used as specimens. Results showed that the interyarn PSDs reflected the fabric characteristics such as the fabric count and the weave type and the intrayarn PSDs reflected the thread characteristics such as the number of fibers, the fiber diameter, the thread diameter and the thread twist. Of three types of PSDs, the PSD per unit area of sample best reflect fabric and thread characteritics. As the fabric count decreased, rc increased and interyarn pore volume increased. The PSDs were skewed to the small pore sizes and the pore volumes decreased in the order of plain> twill> satin. As the number of fibers, the fiber diameter and the thread twist decreased, the intrayarn pore volumes were increased.

• Journal of the Korean Society of Industry Convergence
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• v.10 no.4
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• pp.195-200
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• 2007

These days, various and complex threads are developed, so it is necessary to develop the cutting a thread sensors for checking a cut thread in severe environment and it is very important to evaluate the quality of the cutting a thread sensors. The analysis of variance(ANOVA) method is very useful method on the quality evaluation field. In this study, the quality is evaluated by one way layout ANOVA method with the surface roughness data. The experiment is carried out by 3 sensors and the result show that the sensors have the good quality in precision.

• Journal of the Korea Fashion and Costume Design Association
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• v.15 no.4
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• pp.143-155
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• 2013

This study examined the motif, weave structure, fabric density, and thread thickness of the patterned silks excavated from the Lady Lee's Tomb to trace the weave composition of the 18th Century in Korea. Different weave compositions were adopted depending on the weave structure. Two weave structures appeared in these patterned silks : simple gauze and satin damask. In the case of simple gauze Jergori, all the components, Gil(bodice), Somae(Sleeve) had similar fabric density and thread thickness. On the other hand, the satin damask Jergoris was composed of the components of different fabric density and thread thickness. According to the fabric density and thread thickness, the motif sharpness of damask Jergori was represented in three different ways : smooth and clear, rough and clear, and rough and vague. This revealed that Lady Lee selected not only pattern but also fabric density and thread thickness in the design of damask Jergori.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.892-897
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• 2000

In this study, tap wear was analyzed not only to predict the tap life time but also to propose an improved tap design. Because rake angle and thread relief of tap are the significant factors in geometry of tap, these two factors were picked as the experiment variables. The experiment was conducted with six types of tap which have 6$^{\circ}$ , 8$^{\circ}$ and 12$^{\circ}$ of rake angles with 0,08mm and 0.14 mm of thread relief. From the measured cutting force, it could be known that cutting torque was low at the large the rake thread relief and tool life was long as rake angle became large. Eventually, tool life is longest when rake angle is 12$^{\circ}$ and the with 0.08mm thread relief. Aand the width of crater wear and that of flank wear were measured when a tapping torque was 20 [$kg_f$-mm] . Most of the measured values were above the width of tool wear[$V_B$=O.O3m], which means that tool life is over.

• Journal of the Korean Society for Precision Engineering
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• v.32 no.6
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• pp.523-528
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• 2015

As the sizes of mobile phones and watch phones decrease, the joining bolt for the products should also be decreased to a miniature size. However, the miniature-sized bolt has to support sufficient joining and anti-releasing torque to keep the product fastened. In this study, the thread shapes are designed to improve anti-releasing performance of bolts. Especially, when bolt materials is stronger than nut materials, the design of thread shapes is needed, like bolt for wood, to improve the fastening capability. Through the joining and releasing analyses of bolts, the thread shapes for SUS302 bolt and Mg alloy nut are newly designed. It was shown that the newly designed bolt has 20 % higher anti-releasing torque and 35% lower torque loosening slope compared to the standard bolt.

• Journal of the Korean Society for Precision Engineering
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• v.32 no.6
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• pp.503-507
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• 2015

In this study, we compare the performance of the screw through the Clamping force of the test materials to change shape and structure, one of the ways to maintain and improve the engaging force to cope with the miniaturization of the fastener threads are further thinner and lighter precision way that can improve the fastening force of the screw results were as follows. The clamping force according to the materials was $7.57N{\cdot}cm$ in SUS XM7 and SWCH18A was $5.97N{\cdot}cm$. This result was to be found to average 13.5% high in the Clamping force of SUS XM7 materials. In the case of the clamping force of the screw thread shape change, the clamping force of symmetrical and asymmetrical thread was $6.78N{\cdot}cm$ and $7.57N{\cdot}cm$. The clamping force of the asymmetrical thread showed an average high of 11.6%.

• Journal of the Korea Society of Computer and Information
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• v.15 no.2
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• pp.127-134
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• 2010

In continuous vocabulary recognition system by probability distribution of clustering method has used model parameters of an advance estimate to generated each contexts for phoneme data surely needed but it has it's bad points of gaussian model the accuracy unsecure of composed model for phoneme data. To improve suggested probability distribution mixed gaussian model to optimized that phoneme data search supported configuration thread system. This paper of configuration thread system has used extension facet classification user phoneme configuration thread information offered gaussian model the accuracy secure. System performance as a result of represent vocabulary dependence recognition rate of 98.31%, vocabulary independence recognition rate of 97.63%.

• Journal of the Korean Society of Costume
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• v.58 no.9
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• pp.129-141
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• 2008

Jikgeum(woven with supplementary golden wefts) hyungbae(rank badge) of danryung(official uniform) excavated from Im Backryung'tomb($1498{\sim}1546$) of the Joseon dynasty($1392{\sim}1910$) at Goyang, Gyunggi-Do in 2007, was in a critical condition because of serious collapse of substrate in metal thread. For conservation of hyungbae, metal thread was examined by different scientific methods(Light Microscope, Scanning Electron Microscope and Energy Dispersive X-Rray Spectrometry(SEM-EDS), Fourier Transform Infrared Spectroscopy(FT-IR)). Analytical data showed that metal thread was gilt membrane strip composed of gold leaves and proteinaceous substrate which was probably parchment. To protect collapse of substrate, 1% solution of Paraloid B-72 was infilterated into substrate for consolidation of substrate and it was adhered to warp of fabric in hyungbae, before wet cleaning. After wet cleaning, the most of the gold leaves were restored, which was confirmed by both the examination with the naked eye and the microscopic examination.

• The Journal of the Society of Korean Medicine Diagnostics
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• v.16 no.1
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• pp.1-8
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• 2012

Objectives Although the faith that pulse diagnosis via a thread, namely "Xuanxizhenmai", had been applied to some women in royal families, is widely spread in East Asian countries, but it is still controversial that whether this faith is based on historical facts or just originated from some folk tales. So we provided some reasonable clues to interpret that faith. Methods The digitalized Annals of Joseon Dynasty and Twenty Five Books of Chinese History were used for historical example search. Conventional internet search engines are widely used for investigation of other examples and related interpretations. Additionally, a pilot observation with nylon threads and optical vibration detection devices was performed to confirm it's feasibility. Results Although there are a few evidences supporting Xuanxizhenmai's existence in Qing dynasty, no evidence was found to show it's existence in authoritative annals of Korea and China. The pilot observation showed that in optimal environment, some intense arterial pulse could be propagated dozens of centimeter, but it was not applicable to clinical needs. Conclusions Pulse propagation via a thread was proved to be reproducible within limited extents, but pulse diagnosis via a thread, namely Xuanxizhenmai, seem to have never been used for proper clinical purpose.