• Clinics in Shoulder and Elbow
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• v.16 no.2
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• pp.107-114
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• 2013

Purpose: This study is designed to evaluate the clinical and radiographical results for the displacement of fracture fragments after interlocking intramedullary nailing in humeral shaft fractures. Materials and Methods: We retrospectively reviewed the results of 8 cases of humeral shaft fractures that have displacements of over 10 mm and under 20 mm after interlocking intramedullary nailing between July 2004 and August 2011. The mean age was 54.1 years (range, 43 to 70 years) and there were 3 male and 5 female patients. Radiographically, the time to bony union, change of displacement and angulation of the fracture site, and degree of improvement of these two factors were measured. Clinically, the range of motion of shoulder and elbow joints, postoperative pain and complications were evaluated. Results: All cases showed complete bony union in last follow-up. The mean time to bony union was 16.1 weeks. At the last follow-up, almost all cases had normal range of motion of shoulder and elbow joints. But, one case had stiffness of shoulder joint. Therefore, arthroscopic capsular release and manipulation was performed. One case had transient shoulder pain and the other case had transient elbow pain. In the two cases, pull-out of proximal interlocking screw were noted, but they finally had bony union. Conclusion: Although considerable displacement of fracture fragments after interlocking intramedullary nailing in humeral shaft fractures was present, we had excellent radiographical and clinical outcomes. Therefore, an additional procedure, such as open reduction or another fixation for the fracture site, was not necessary.

• Restorative Dentistry and Endodontics
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• v.22 no.1
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• pp.244-253
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• 1997

During preparation of narrow curved canals, procedural accidents such as, ledge, zipping, and transportation are frequently encountered and may lead to failure of endodontic therapy. To reduce these procedural errors and efficiently manage curved canals, various modifications in instrumentation technique and the design and flexibility of instruments have been advocated. This study compared the maintenance of the original canal curvature, cross sectional canal shape, and preparation time during instrumentation with stainless steel hand (K-Flexo) file, and nickel-titanium rotary files (Profile and Lightspeed). Thirty resin blocks with simulated curved canals of 20~25 degrees were used and divided into three groups of 10 each. In group 1, canals were instrumented using a quarter turn/pull technique with K-Flexofiles. Group 2 canals were prepared with rotary NiTi Profiles. Group 3 was prepared with rotary NiTi Lightspeed instrument. Before and after instrumentation, all canals were scanned using stereo microcope, FlexCam camera, and Photoshop 3.0 computer program. The results were as follows : 1. All groups showed some loss of canal curvature after instrumentation. Average loss of canal curvature was 8.6 degrees for K-Flexofile, 7.7 degrees for Profile, and 5.8 degrees for Lightspeed. Lightspeed exhibited significantly less curvature loss than K-Flexofile (p<0.05). 2. At the apical 1-mm level, Profile produced significantly rounder canals than Lightspeed (p<0.05). At the 3-mm level, Profile and Lightspeed exhibited significantly rounder canals than K-Flexofile (p<0.05). 3. Preparation with Lightspeed was significantly faster than Profile and K-Flexofile, and Profile was faster than K-Flexofile (p<0.05). 4. There was no significant difference in incidence of zipping between the hand K-Flexofile and rotary NiTi (Profile and Lightspeed) instruments. Most of apical canals were slightly widened near the apical foramen. As a results of this study, rotary NiTi instruments are superior to the K-Flexofile in regard to the maintenance of original canal curvature, cross-sectional shape and preparation time. But more investigations and studies should be needed to evaluate the ideal canal instrumentation.

• Journal of the Korean Geotechnical Society
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• v.33 no.12
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• pp.107-113
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• 2017

Shear Connector should be used to fix the PHC pile with extension wall in order to utilize PHC-W retaining wall as permanent wall. The pullout behaviours on shear connectors anchored into PHC-W pile were observed as two modes. The first type behaviour showed that after reaching the maximum pullout resistance, the anchorage was broken and shear connector was pulled out abruptly. The second type behaviour showed that even after arriving the maximum pullout resistance, the anchorage was not destroyed and there was a progressive increase in pullout displacement. The maximum pullout resistance of the steel anchor shear connector is larger than that of deformed bar shear connector. The larger the diameter and the longer the embedment length of shear connector, the higher the maximum pullout resistance would be. The pullout displacements corresponding to the maximum pullout resistance of the shear connector showed various ranges regardless of the materials, the diameters and the anchoring lengths. A-D20 shear connectors showed a pull-out displacement of about 8~10 mm. A-D16, D-D19 and D-D16 shear connectors exhibited a pulling displacement of about 14~20 mm, but a pulling displacement of about 6~10 mm when the anchoring lengths were 50 and 80 mm.

• The Journal of Korean Academy of Prosthodontics
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• v.43 no.1
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• pp.15-29
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• 2005

Statement of problem. The adjustable dental impression trays were made for being adjusted their width automatically along the width of dental arch. Purpose. The purpose of this study was to investigate the best retentive form of adjustable dental impression tray, and so to make it a more satisfactory product. Material and methods. The eight pairs of adjustable trays were made of ABS(acrylonitrile butadiene styrene) with different distribution of holes and with or without the rim on the border area of them. The experiment was done with the horse-shoe shaped metal plate to pull out the set impression body from the tray, and the tray jig which was made for holding the tray on a lower part of Universal Testing Machine(UTM, Zwick Z020, Zwick Co., Germany). After the impression in the tray was allowed to set four minutes, a tensile force was applied at right angles to the tray which had been previously seated on the jig. The force was applied to measure a maximum retentive force by use of a UTM at a constant strain rate of 100mm per minute. A 2-factor analysis of variance (p<.05) was used to determine whether differences existed among distribution of retentive holes and between rim existing and not. Results. 1 The retentive force of the upper and lower resin tray with 2mm holes on the tray border was highest(25.83/24.98kg). (p<.05) 2. As the tray had more retentive holes, it was less retentive. 3. There was no significant difference in the retentive force of the varied hole intervals in the case of distributing all the area. (p>.05) 4. The rimless trays were more retentive generally, than the rimmed trays except 2 case: upper tray group-all area / 2 mm, intervals and lower tray group-margin only / 2 mm, intervals.(p<.05) 5. Most of the adjustable trays were showed higher retentive force than perforated metal tray except the lower group that perforated on the all area at intervals of 2 mm.

• Advances in pediatric surgery
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• v.11 no.2
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• pp.157-164
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• 2005

Esophageal atresia without tracheoesophageal fistula accounts for 7-11 % of all types of esophageal atresia and is very difficult to treat. In our hospital from 1990 to 2005, we operated upon 40 patients with esophageal atresia, and 6 had pure atresia. The preoperative characteristics, operative findings and post operative course of the six patients with pure atresia were analysed. Immediate gastrostomy was performed in all 6 patients. One patient had simultaneous cervical esophagostomy. Esophageal reconstruction procedures were transhiatal gastric pull up in 3 patients, esophagocologastrostomy utilizing left colon in 1, and transthoracic esophagoseophagostomy with esophageal bougination in 2. Postoperative complications were pneumonia, anastomosis leakage, and gastroesophageal reflux symptom. Conservative management was effective in all patients. A larger series of cases would be required to demonstrate the most effective treatment for this particular anomalous condition.

• Korean journal of communication and information
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• v.57
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• pp.84-108
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• 2012

This article is concerned with exploring labour market transformation in newspaper industry and thereby looking into skill formation and professionalization of journalists. In Korea, according to previous research, newspaper journalist labour market had been characterized by a low inter-firm mobility of workers and patterns of long-term employment and firm-based skill training. However, over the past few years, as new product strategies of newspaper firms has changed due to management crisis employers pull back from the responsibilities of investment on skill training and securing job stability for journalists. However, in spite of overall weakened firm-based skill formation systems within the market, there still seems to be long way to build alternative systems of skill developments for them. As a result, it will be argued that, in the absence of manifest labor market institutions such as apprenticeships or skill certification system, which are assumed to traditionally certify workers' professionalization, occupational identity and professionality of newspaper journalist labour market will be weakened. Labor market data from interviews with journalists in the newspaper industry are used in order to test this hypothesis.

• Land and Housing Review
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• v.2 no.1
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• pp.61-68
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• 2011

In order to clarify the structural performances of Welded Deformed Steel Bar Mats (WDSBM), the research stated includes the tests for standard hook of top bars of slab in concrete slab-wall joints, the tests for embedment length of top bar of slab, and the development strength tests for standard hook. The test results are as follows; (1) For slab-wall joints using WDSBM as reinforcement in slab, if the top bars of WDSBM are spliced by ordinary bars with sufficient development length and size, it is enough for the strength and crack control. (2) When WDSBM of slab is spliced in joint, the strength is increased with the embedment of bars of this WDSBM into wall. Beyond peak strength, however, ductility is diminished to that as no splice due to pull-out failure. (3) For slab-wall system, ultimate strain of concrete for flexural compression zone in lower surface of slab seems much greater than that of normal concrete beam. The reason is that normal concrete beam has the joint with $180^{\circ}$, however slab-wall joint has the $90^{\circ}$ of which concrete can be confined.

• Journal of the Korea institute for structural maintenance and inspection
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• v.24 no.4
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• pp.72-80
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• 2020

The purpose of this study is to secure the same or more structural performance and constructability for the details of hooks cross-constructed at 135 degrees used as external-ties standard detail in RC columns, therefore, to the purpose of improving constructability, the clip-type binding implement was suggested and A total of 28 pull-out specimens were prepared with the parameters of concrete compressive strength and clip-embeded length, clip installation location to examine the anchorage behavior of the clip-type binding implement. The experiment was carried out. The results of the experiment confirmed that the anchorage strength of the clip-type binding implement was higher than the details of hooks cross-constructed at 135-degree regardless of the diameter of tie and concrete strength, embeded clip length, clip installation. and The 90-degree end hook with clip-type binding implement was showed a similar an anchorage behavior of 135-degree end-hooked transverse reinforcement, consequently, The 90-degree end hooked with clip-type binding implement is evaluated to be the same anchorage behavior and performance as standard 135-degree end hook detail.

• Journal of the Korea Concrete Institute
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• v.22 no.2
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• pp.149-158
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• 2010

Recently, numerous construction techniques for repairing and strengthening methods for above ground or air exposed concrete structure have been developed. However repairing and strengthening methods for underwater structural members under continuous loading, such as piers and steel piles need the further development. Therefore, this study develops an aqua epoxy, which can be used for repairing and strengthening of structural members located underwater. Moreover, using the epoxy material and strengthening fibers, a fiber reinforced composite sheet called Aqua Advanced FRP (AAF) for underwater usage is developed. To verify and to obtain properties of the material and the performance of AAF, several tests such as pull-off strength test, bond shear strength test, and chemical resistance test, were carried out. The results showed that the developed aqua epoxy does not easily dissolve in wet conditions and does not create any residual particle during hardening. In spite of underwater conditions, it showed the superior workability, because of the high viscosity over 30,000 cps and adhesion capacity over 2 MPa, which are nearly equivalent to those used in dry conditions. In case of the chemical resistance test, the developed aqua epoxy and composite showed the weight change of about 0.5~1.0%, which verifies the superior chemical resistance.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.109-112
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• 2008

In this study, Assessment of bond property of HSC with the rate of Blust-furnace(0, 12, and 25 percent by weight cement) and Evaluation of the relationship of the compressive strength coefficient (${\beta}$) between compressive strength with 40${\sim}$120MPa were performed. Design and Test of Bond specimens were carried out based on the ASTM C-234. Test results are follows, most specimens showed that the splitting failure in all specimens, except for B-40 series which showed that the pull-out failure. For the B-40 Series, the relation of compressive strength versus bond stress has well converged that of the proposed equation with the variation(${\beta}$=2/3) in UCB/E.E.R.C-83. The crack strength of concrete in splitting was proportioned to the compressive strength of concrete, and was the highest on the contents of blast furnace slag to 12 percent by weight of cement in each series, except for B-60 series. In the relation of admixture replacement rate versus maximum bond stress, The maximum bond stress was the highest in 12 percent by weight of cement according to less than 40MPa, and was the highest in 25 percent by weight of cement according to 80MPa.