• Journal of Welding and Joining
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• v.14 no.5
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• pp.49-58
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• 1996

In Korea Gas Corporation, as one of the pipeline repairing methods, damaged pipelines are sometimes treated with a temporally employment of split sleeve. On conducting the repair process, circumferential fillet and longitudinal groove welding usually must be included. For the case of groove welding, a considerable amount of R&D have been carried out related to property changes, while few study on the property change in fillet welding has been conducted. In this paper, so as to confirm the specification of fillet welding in terms of safety and reliability, properties changed by fillet welding were investigated for two welding processes. Qualifying tests such as reviewing macrostructure and nick-break tests were performed according to API 1104 and ASME section IX. In addition, tensile properties and hardness were evaluated according to KS B0841 and BS 4515. The fillet weld prepared by the qualified procedure showed melting depth of 0.8∼1.3mm and heat affected zone of 2.8∼3.4mm length. No crack and lack of penetration were observed. And the results of hardness and nick-break tests satisfied code requirements. The area crossed by fillet and groove welding line was found to have minimal tensile strength.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.1401-1409
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• 2007

This paper presents a detecting technique for the improvement in quality by appling the various vibrational characteristics theory. The object of this study is to objectively point out faulty gear by developing the program which can be used to analyze and predict the vibrational characteristics caused by gear wear, deformation and nick of auto-transmission. The fault detection methods by vibrational signal analysis of gear have been progressed in the various fields of industry. These methods have the advantage of being easy to attach the accelerometer without discontinuance of the structure. But not all the methods are efficient for finding early faults. So in the thesis, we completed development of the inspection system of vibration by appling the most efficient detecting methods and verified the system's reliability through experiments.

• Geomechanics and Engineering
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• v.16 no.1
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• pp.35-47
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• 2018

This paper investigates the mechanisms of tunnel spalling and massive tunnel failures using fracture mechanics principles. The study starts with examining the fracture propagation due to tensile and shear failure mechanisms. It was found that, fundamentally, in rock masses with high compressive stresses, tensile fracture propagation is often a stable process which leads to a gradual failure. Shear fracture propagation tends to be an unstable process. Several real case observations of spalling failures and massive shear failures in boreholes, tunnels and underground roadways are shown in the paper. A number of numerical models were used to investigate the fracture mechanisms and extents in the roof/wall of a deep tunnel and in an underground coal mine roadway. The modelling was done using a unique fracture mechanics code FRACOD which simulates explicitly the fracture initiation and propagation process. The study has demonstrated that both tensile and shear fracturing may occur in the vicinity of an underground opening. Shallow spalling in the tunnel wall is believed to be caused by tensile fracturing from extensional strain although no tensile stress exists there. Massive large scale failure however is most likely to be caused by shear fracturing under high compressive stresses. The observation that tunnel spalling often starts when the hoop stress reaches $0.4^*UCS$ has been explained in this paper by using the extension strain criterion. At this uniaxial compressive stress level, the lateral extensional strain is equivalent to the critical strain under uniaxial tension. Scale effect on UCS commonly believed by many is unlikely the dominant factor in this phenomenon.

• Journal of Microbiology
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• v.38 no.2
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• pp.88-92
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• 2000

A human ribosomal protein S3 (rpS3), which also functions as a DNA repair enzyme(UV endonuclease III), was expressed in a methylotrophic yeast, Pichia pastoris, and biochemically characterized. UV endonuclease activity was preiously characterized, and this activity of mammalian rpS3 was found to be non-specfic upon purification and storage. Under the Pichia expression system, the subcloned cDNA of the human rpS3 gene revealed a peptide of 42 kDa by SDS-PAGE and Western blot. The secreted form of human rpS3 rendered no endonuclease activity while the intracellular form showed UV specific endonuclease activity by the nick circle assay.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.18 no.1
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• pp.47-56
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• 2008

This paper presents a detecting technique for the improvement in quality by appling the various vibrational characteristics theory. The object of this study is to objectively point out faulty gear by developing the program which can be used to analyze and predict the vibrational characteristics caused by gear wear, deformation and nick of auto-transmission. The fault detection methods by vibrational signal analysis of gear have been progressed in the various fields of industry. These methods have the advantage of being easy to attach the accelerometer without discontinuance of the structure. But not all the methods are efficient for finding early faults. So in the thesis, we completed development of the inspection system of vibration by appling the most efficient detecting methods and verified the system's reliability through experiments.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.167-170
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• 2008

$Reflex^{TM}$ display technology based on bistable, reflective, and flexible Cholesteric Liquid Crystal Displays is being developed and mass produced for new and non-traditional applications. These applications allow for personalization of mobile devices, very low cost display systems, and more. This display technology, its status, and new applications are discussed in this paper.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.314.2-314.2
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• 2002

DNA topoisomerases catalyze changes in DNA topology through cycles of transient DNA strand breakage and religation. During this process. the active site tyrosine in human DNA topoisomerase Ⅰ(Top Ⅰ) becomes covalently linked to the 3'-ends of a single-stranded nick in the DNA duplex, Stabilization of the Top Ⅰ-DNA cleavable complex is the common initial event leading to the cytotoxicity of top 1 inhibitors. (omitted)

• The Korean Journal of Zoology
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• v.39 no.3
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• pp.248-256
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• 1996

The present study was performed to clone and express human poly (ADP-ribose) synthetase (PARS) cDNA in E coli. For these purposes, the CDNA for human poly (ADP-ribose) synthetase, encoding the entire protein, was cloned into pGEM-7Zf(+). The resulting recombinant plasmid pPARS6.1 was restriction enzyme mapped and its identity was confirmed by Southern blot analysis. The pPARS6. 1 contained full-length CDNA of human PARS and the nudeotide sequences were identical with those reported previously. The recombinant protein which migrated as a unique 120 kDa band on 10% SDS-polyacrylamide gels, was identified as PARS by Southwestern blots using nick-translated DNA probes and by activity gels and activity blots using 32 P-NAD as a substrate for poly (ADP-ribose) synthetase (PARS). The signals corresponding to 120 and 98 kDa proteins were obtained following IPTG (0.4 mM) induction of the PARS cDNA cloned into Xba I-digested pGEM-7Zf(+) vector. Nonspecific signals corresponding to 45 and 38 kDa proteins were also shown in both IPTG-induced and noninduced cells. The nonspecific proteins may be products of incomplete translation or proteolytic products of intact PARS.

• Journal of the Korea Fashion and Costume Design Association
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• v.5 no.1
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• pp.47-57
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• 2003

Today there are increasing number of internet users. Internet is wide use of banking, shopping, school and studding. Also, internet is used in everyday living and its use is getting larger. Korea has the one of the most use of internet in the world. Most of houses have computer with internet, and there are alot of PC rooms in the streets. anyone can enjoy the internet anytime anywhere. Now, in internet there are group formed by community purpose. The 'dot com' companies was not making much of profit from their goods. However, they came out with an idea "avata" Soon, the avata became a hit and its known for its success. Avata is used for E-mail, name card, post stamp, and chatting. Also, Avata is very popular among chatting service, icon chatting, and 3D graphic chatting. Avata represent the user himself in internet and computer created imaginary space, and it connects between imaginary space and reality, also it exist between real name and nick name. Past years, the internet users were satisfied with their nick name, however resent year users wants to express them more. For the result the "Avata" is created to fulfill the need to express user themselves. There are three different ways to see how Korean react to fashion industry. first, Korea's land structure makes the density of population high, the transmission of information is very fast. Next, collectively is high among Koreans. Finally wide use to internet made the transmission of the fashion information much faster. The User wants to keep up with the fashion at the sametime they want to express themselves, and "avata" is the one that fulfill their needs. New technology and the desire to express themselves made the new term "avata industry". which was never existed before. In addition, the internet markets have potential power. Although, it is in start stage of avata industry. However, the experts say that its possibility of its development is not predictable. In conclusion, watch the development of a situation to analyze the avata industry and develop new avata fashion market.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.2
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• pp.237-243
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• 2010

This paper presents a study on the helical gear inspection system for application to vehicle transmission gear manufacturing lines. The special gear profile inspection system is not suitable for manufacturing lines due to the measuring time. The master gear method, which was used in this study and compared with the machined gear in the line, is more efficient and economical. In this paper, three helical gear inspection parameters were of concern: nick, run-out, and PCD (pitch circle diameter) error. To evaluate its influence on the accuracy, the gear measuring system was also studied. This system can be useful in practical vehicle transmission gear manufacturing lines, where imported equipment is currently being used.