• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.10
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• pp.1235-1239
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• 2012

Primary water stress corrosion cracking (PWSCC) has been observed around the weld region of control rod drive mechanism (CRDM) nozzles in nuclear power plants overseas. The weld has a J-shaped groove and it connects the CRDM nozzle with the reactor vessel upper head (RVUH). It is a dissimilar metal weld (DMW), because the CRDM is made of alloy 600 and the RVUH is made of carbon steel. In this study, finite element analysis (FEA) was performed to estimate the stress condition around the weld region. Generally, it is known that a high tensile region is more susceptible to PWSCC. FEA was performed as for the condition of welding, hydrostatic test and normal operation successively to observe how the residual stress changes due to plant condition. The FEA results show that a high tensile stress region is formed around the weld starting point on the inner surface and around the weld stop point on the outer surface.

• Journal of the korean academy of Pediatric Dentistry
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• v.24 no.4
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• pp.795-804
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• 1997

Developmental dental morphological anomalies are fusion, gemination, twinning, concrescence and etc. They may cause many problems in conservative, periodontal and esthetic aspects. Fusion is a condition where two separate tooth buds unite at some stage in their development to form a bifid crown. If tooth contact occurs early, at least before the start of calcification, the two teeth may be completely unites to form a single large tooth. If tooth contact occurs after the time when a portion of the tooth crown has completed its formation, there may be union of the roots only. In fusion the dentin is always confluent. Fusion teeth is more common in the deciduous than in the permanent dentition. Fused teeth are relatively rare, and are mostly mandibular anterior teeth. Fusion of normal and supernumerary teeth or between normal teeth may occurs. The exact etiology factor of fusion is unknown, but genetic and environmental factors seems to be related. A variety of complications and subsequent treatments have been suggested on this teeth. Periodontal conditions may arise due to a groove formed at the line of fusion of the two teeth. Crowding or Protrusion with potential for malocclusion or delayed eruption of adjacent teeth. Fusion teeth appear in the anterior region, they usually cause esthetic problems. Treatments vary depending on the problem, the location, and the extent of fusion. Treatment of fused teeth has been reported from endodontic, orthodontic, periodontic, surgical and multidisciplinary. This report presents the esthetic improvements by separation of two clinical crowns. Bone reduction or endodontic treatments are not required.

• Management & Information Systems Review
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• v.32 no.3
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• pp.247-261
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• 2013

Recently, the smart phone, a carrying along terminal connection technology such as Galaxytap/iPad etc. evolves, and supply is increasing rapidly, is included for smart phone because various sensor technologies are developed and service application that is acted in terminal with this is accompanied and grow. Continuously 4 generation to 3 Gs, Wibro Wireless network technology of communications a LTE technology from that is constructed, environment for Ubiquitous realization is being constructed fast. Therefore, in this paper it can inquire state of electronic, furniture devices through apartment complex web server and gear that control groove network at smart phone, and control, and confirms home state prevention of crimes state, and video inquiry of position that CCTV is placed in apartment complex was available. And it proposed integrated smart apartment with parking system and medical system using RFID system in ubiquitous environment.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.10
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• pp.6282-6288
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• 2014

$CO_2$ welding is used widely in the field. On the other hand, welding defects occur when welders cannot adjust the current and voltage needed for welding and have to stop working to adjust the current and voltage, causing sudden cooling down of the welding structure inside a vehicle or tank where the control panel is invisible or when work site is far. This study used three types of existing $CO_2$ welders. This also applied SS400 rolled steel for welding structural purposes for remote control torch welding, perform a welding test through v-groove butt welding with a remote control torch and existing $CO_2$ welding torch, conducted visual inspection on the appearance of a welded top bead. In addition, the appearance quality of the welding part was monitored mainly through penetrant testing and a bending test to evaluate the welding defect reduction and the effect on the performance and compatibility by replacing the existing welder.

• Journal of the Korean Arthroscopy Society
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• v.14 no.3
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• pp.188-191
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• 2010

Absence of long head of biceps tendon is a very rare anomaly. We encountered a 19 year-old male patient who had right shoulder subluxation. On magnetic resonance imaging, shallow intertubercular groove on right humerus was observed, and absence of long head of biceps tendon was discovered. Arthroscopically, labral rupture and absence of long head of biceps tendon were also evident. Left shoulder had a similar symptom as right 5 months after the initial development of the symptom on the right shoulder. Both MRI and arthroscopy revealed absence of long head of biceps tendon and labral ruptre. Arthroscopic labral repair was performed for both shoulders, and, postoperatively, they were fixated with abduction brace. In this case, it is considered that the absence of long head of biceps tendon triggered the instability of shoulder found in our patient.

• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.1
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• pp.119-125
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• 2009

Fusion and gemination are irregularities in tooth development. It is often difficult to differentiate between gemination and fusion and it is common to refer to these anomalies as 'double teeth'. The deciduous teeth are most commonly involved, but in 0.1% of cases permanent teeth are affected, in which case aesthetic, funtional and periodontal problems can result. Double teeth present great difficulties in management and required a multidisciplinary approach. The central groove on the labial and palatal surfaces of a double tooth is extremely prone to caries, therefore early 'fissure sealing' is essential. In permanent dentition, surgical separation of fused teeth may be possible with subsequent orthodontic alignment and restorative treatment as needed to reshape the crown. Reshaping or reduction of a double tooth with a single canal may be attempted by modifying the appearance of the labial groove and the use of composite tints but is often impossible and extraction may be the only alternative. Orthodontic treatment and prosthetic replacement is then required. Implants may be an option for adolescents. The present study describes three clinical cases of double teeth in the position of the maxillary permanent incisors. The first case demonstrates an example of multidisciplinary care including surgical intraoral hemisection, root canal therapy, restorative and orthodontic treatment. The second and third cases describe the external and internal morphology of the two fused teeth by means of three dimensional dental computer tomography.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.12
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• pp.1691-1695
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• 2005

The bovine lymphocyte antigen (BoLA)-DRB3 gene encodes cell surface glycoproteins that initiate immune responses by presenting processed antigenic peptides to CD4 T helper cells. DRB3 is the most polymorphic bovine MHC class II gene which encodes the peptide-binding groove. Since different alleles favour the binding of different peptides, DRB3 has been extensively evaluated as a candidate marker for associations with various bovine diseases and immunological traits. For that reason, the genetic diversity of the bovine class II DRB3 locus was investigated by polymerase chain reaction-restriction fragment length polymorphism method (PCR-RFLP). This study describes genetic variability in the BoLA-DRB3 in Iranian Golpayegani Cattle. Iranian Golpayegani Cows (n = 50) were genotyped for bovine lymphocyte antigen (BoLA)-DRB3.2 allele by polymerase chain reaction and restriction fragment length polymorphism method. Bovine DNA was isolated from aliquots of whole blood. A two-step polymerase chain reaction followed by digestion with restriction endonucleases RsaI, HaeIII and BstYI was conducted on the DNA from Iranian Golpayegani Cattle. In the Iranian Golpayegani herd studied, we identified 19 alleles.DRB3.2${\times}$16 had the highest allelic frequency (14%), followed by DRB3.2${\times}$7 (11%). Six alleles (DRB3.2${\times}$25, ${\times}$24, ${\times}$22, ${\times}$20, ${\times}$15, ${\times}$3) had frequencies = 2%. Although additional studies are required to confirm the present findings, our results indicate that exon 2 of the BoLA-DRB3 gene is highly polymorphic in Iranian Golpayegani Cattle.

• Journal of the Korean Wood Science and Technology
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• v.44 no.5
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• pp.664-676
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• 2016

Recently, the demand on the Hanok have been increased with social change. However, Hanok has a major problem of a rising costs caused by hand-made process. So, performance comparison between hand-made process and pre-cut process was conducted to modularize the joints in Hanok. Douglas-fir was used to manufacture the structural size dovetail joints by hand-made and pre-cut precess. The bending strengths on joints with two process were evaluated. The average ultimate load of pre-cut joints was 1.5 times higher than that of hand-made joints. F-test results in both process showed a great relationships between ultimate load and tenon's size variation. The length and thickness of tenon showed a proportional relationship with the ultimate load, but the tenon width showed inverse proportion with the ultimate load. This results may be used as basic data for the joint modularization of Hanok.

• Applied Chemistry for Engineering
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• v.24 no.2
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• pp.138-143
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• 2013

This paper studied the possibility to predict a mechanical property variation from changes in created carbonyl bands by irradiating the surface of high-density polyethylene with short-wavelength ultraviolet radiation of 254 nm to induce a fast chemical degradation. The meaning of this study lies in checking whether a mechanical property change with the same chemical property as the induced optical deterioration is caused by using a UVC lamp with high photon energy instead of optical deterioration via xenon arc light source and outdoor exposure test via natural sunlight requiring a long time. The mechanical strength of high-density polyethylene checked by a tensile test and a creep destruction test showed a similar tendency with CI changes. In particular, the yield strength and elongation had a close relationship with the exposure time to ultraviolet radiation. Accordingly, this paper presented a method to grasp the mechanical property change outdoors requiring a long time more fast through the relationship between the mechanical property change and the carbonyl index using a UVC lamp causing the fast surface degradation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.9
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• pp.5419-5424
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• 2014

A weld scallop is a small quadrant or half circle type hole installed in the weld line cross area for easy welding operation. Many types of T-bars with a scallop can be welded in a block assembly stage in shipbuilding. The difficulties arise from the fact that scallops are to be filled by build-up welding after welding of the cross line is complete. In this study, a non-scallop block joint welding method was developed using special type CBM (ceramic backing material). The wedge shaped CBM was devised to insert a CBM into just the V groove of weld line cross area without weld scallop. A saw-toothed shape was adopted for easy cutting of the unnecessary part in the CBM fitting process. The applicability of the developed method was verified through welding experiments based on the yard welding conditions.