• Steel and Composite Structures
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• v.42 no.6
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• pp.843-853
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• 2022

The fatigue behavior of welded open rib-to crossbeam joints (ORCJ) in orthotropic bridge structures is investigated using a traction structural stress method. The fatigue behaviors of welded open rib-to crossbeam joints have been a subject of study for decades for ensuring operational safety and future design improvement. A mesh-insensitive combination of traction structural stresses in ORCJ was obtained considering the effect of in-plane shear stress and validated by fatigue test results. The proposed method is advantageous for predicting fatigue cracks that initiate from the crossbeam cutout and propagate along the crossbeam. The investigations carried out with the proposed approach reveal that the normal structural stress decreases with the propagation of fatigue cracks, while the ratio of shear stress to normal stress increases. The effect of shear structural stress is significant for the analysis of fatigue behavior of ORCJ in multiaxial stress states.

• Clinics in Shoulder and Elbow
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• v.24 no.4
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• pp.239-244
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• 2021

Background: Radial neck fracture in children is rare. This study attempted to evaluate the outcome of surgically treated patients and any associated complications. Methods: This study evaluated 23 children under 15 years of age with radial neck fracture who were treated with open reduction between 2006 and 2016 to determine their range of motion, postoperative complications, and radiographic outcomes. The results were assessed clinically using the Mayo clinic elbow performance score. Results: The mean follow-up duration for patients was 34.6 months. The average postoperative angulation was 3.6°. Hypoesthesia was reported in only 9% of patients, and none of the patients complained of postoperative pain. The postoperative X-ray results were excellent in 60% and good in 40%. No radiographic complications were identified. The elbow score was excellent in 87% and good in 13% (mean score, 96.74). There was a statistical relationship between range of motion limitations and age, degree of fracture, initial displacement, and surgical pin removal time. Conclusions: Although most patients accept the closed reduction method as a primary treatment, the present study suggests that an open-reduction approach has been associated with optimal therapeutic outcomes for patients in whom closed reduction was not satisfactory or indicated.

• Journal of Korean Elementary Science Education
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• v.28 no.4
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• pp.404-414
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• 2009

The revised curriculum in 2007 includes open inquiry approach to increase students' interest in science and to build up creativity. So teachers and pre-service teachers should be equipped with the ability of open inquiry performance. In order to investigate pre-service teachers' readiness to perform open inquiry tasks, we analyzed reports written as homework by a group of 71 juniors in a national university of education. The investigation tool was composed of four domains: topic selection, the inquiry process, the conclusion, and reporting. Each domain had three or four sub-domains. By using the framework, four raters scored the students' inquiry reports. The findings reveal that the pre-service elementary school teachers have difficulty in the domain of 'topic selection' and the 'conclusion' compared with the other domains. Under the topic selection domain, they showed weaknesses in 'creativity' and 'scientific topic' and under the conclusion domain, they had difficulty in 'recognizing limits' and 'value of conclusion'. The finding suggests that pre-service teaching program should provide with opportunities to perform open inquiry continually.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.12
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• pp.1801-1810
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• 2016

The OpenDaylight controller has been receiving significant attention as one of the enabling open source framework for SDN, and this paper analyzes the architecture and procedure of OpenDaylight based controller cluster. The OpenDaylight controller cluster uses shard based distributed datastore and Raft algorithm to maintain consistency among controllers inside a cluster. The performance evaluation analyzes the leader re-election time as well as latencies of CRUD and Routed RPC according to cluster size, shard role, and sharding strategy, and we discuss the optimal operation strategy for OpenDaylight controller cluster.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.42
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• pp.20.1-20.7
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• 2020

Background: Anterior open bite is a challenging malocclusion to correct orthodontic treatment. Anterior open bite associated with over-erupted posterior teeth and long lower facial height should be treated by reduction of posterior dimension for esthetic results. Although the possibility of orthodontic treatment of an anterior open bite has increased with the introduction of skeletal anchorage, there are still cases requiring surgery for various reasons. Case presentation: This case report covers an anterior open bite of a 25-year-old man successfully treated with the posterior maxillary segmental osteotomy (PMSO) and miniplates. After the pre-surgical orthodontic treatment, the PMSO between canines and first premolars was performed under local anesthesia and miniplates were placed on the zygomatic buttress. As a result of 28 months of treatment, an impaction amount of 3.5 mm was obtained in the maxillary posterior teeth, and the facial esthetics improved at rest and smile. Conclusion: The impaction of the posterior dentoalveolar segment using the PMSO can be a good treatment option in patients with anterior open bite showing long lower facial height.

• The Journal of Korean Physical Therapy
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• v.31 no.1
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• pp.13-17
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• 2019

Purpose: This study examined the effects of flexible flatfeet on the accuracy of knee joint motions in closed and open kinetic chain tasks. Methods: Twenty-four healthy participants were recruited for this study. The subjects were divided into two groups using a navicular drop (ND) test: flexible flatfoot group (n=12, male: 6, aged $22.00{\pm}2.22years$) and age-matched control group (n=12, males: 6, aged $22.17{\pm}1.53years$). The accuracy of knee motion was measured quantitatively by tracing through the flexion and extension motion of the knee joints in the closed kinetic chain and the open kinetic chain. Results: There was a significant difference in the accuracy index between the groups in closed kinetic chain task, but there was no significant difference in the open kinetic chain task. In addition, there was a significant difference in the accuracy index between the closed kinetic chain and the open kinetic chain task in the flexible flatfoot group. In addition, a significant negative correlation was observed between the ND and accuracy index in the closed kinematic chain task, but there was no significant relationship between the ND and accuracy index in the open kinematic chain task. Conclusion: Flexible flatfeet can affect the accuracy of the adjacent joints, such as the knee joint in the closed kinematic chain.

• Journal of Gastric Cancer
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• v.13 no.4
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• pp.207-213
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• 2013

Purpose: We investigated early postoperative morbidity and mortality in patients with liver cirrhosis who had undergone radical gastrectomy for gastric cancer. Materials and Methods: We retrospectively reviewed the medical records of 41 patients who underwent radical gastrectomy at the Chonnam National University Hwasun Hospital (Hwasun-gun, Korea) between August 2004 and June 2009. There were few patients with Child-Pugh class B or C; therefore, we restricted patient selection to those with Child-Pugh class A. Results: Postoperative complications were observed in 22 (53.7%) patients. The most common complications were ascites (46.3%), postoperative hemorrhage (22.0%) and wound infection (12.2%). Intra-abdominal abscess developed in one (2.4%) patient who had undergone open gastrectomy. Massive ascites occurred in 4 (9.8%) patients. Of the patients who underwent open gastrectomy, nine (21.9%) patients required blood transfusions as a result of postoperative hemorrhage. However, most of these patients had advanced gastric cancer. In contrast, most patients who underwent laparoscopic gastrectomy had early stage gastric cancer, and when the confounding effect from the different stages between the two groups was corrected statistically, no statistically significant difference was found. There was also no significant difference between open and laparoscopic gastrectomy in the occurrence rate of other postoperative complications such as ascites, wound infection, and intra-abdominal abscess. No postoperative mortality occurred. Conclusions: Laparoscopic gastrectomy is a feasible surgical procedure for patients with moderate hepatic dysfunction.

• Journal of The Korean Association For Science Education
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• v.36 no.4
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• pp.693-704
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• 2016

The aim of this study was to investigate the conditions and strategies of interaction for the school adjustment for the early entrance students of science academy for the gifted. To know their concerns and process of school adjustment, we interviewed six early entrance gifted students of the science academy and two gifted students preparing for their early entrance with a semi-structured questions. Using the grounded theory, a paradigm model was organized and a core category was abstracted through the open, axial, and selective coding. Based on the open coding analysis, 75 concepts, 21 sub-categories, and 10 categories were derived. In the axial coding, the paradigm model was organized by the link between 10 categories derived from open coding. Through the selective coding, this study discovered the core category about early entrance student's school adjustment was overcoming difficulties by using academic, social, and emotional strategy for school adjustment. Through this, we understand the school adjustment process of the students of early entrance to science academy for the gifted.

• Journal of Magnetics
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• v.19 no.1
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• pp.37-42
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• 2014

The equivalent model of a permanent magnet (PM) plays an important role in electromagnetic system calculation. A type of subsection model for a PM bar is established, to improve the accuracy of the traditional equivalent circuit method. The mathematical expression, and its end verification condition, are presented. Based on the analytical method and finite element method, the leakage permeance calculation of a PM bar in an open magnetic circuit is investigated. As an example, for a given certain type of PM bar, the magnetic flux of each section is validated by experiment, and by simulation. This model offers a foundation for building a high accuracy equivalent magnetic PM model in an electromagnetic system.

• Journal of Korean Neurosurgical Society
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• v.41 no.4
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• pp.248-251
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• 2007

Atlantoaxial rotatory dislocation [AARD] is an uncommon disorder of childhood in which clinical diagnosis is generally difficult and often made late. It is very rare in adults because of the unique biomechanical features of the atlantoaxial articulation. We report a case of post-traumatic AARD in an adult. Reduction was difficult to obtain by skull traction and gentle manipulation. Therefore, the patient was treated surgically by an open reduction, transpedicular screw fixation, and posterior C1-2 wiring with graft. The normal atlantoaxial relation was restored with disappearance of torticollis. Postoperatively, the patient remains neurologically intact and has radiographic documentation of fusion. Atlantoaxial transpedicular screw fixation can be one of the treatment options for the AARD.