• Imaging Science in Dentistry
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• v.32 no.4
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• pp.207-211
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• 2002

Purpose : The purpose of this study was to determine the prevalence, radiographic appearance, and characteristics of patients with zygomatic air cell defect (ZACD), and to give recommendations concerning radiographic evaluation and surgery. Materials and Methods: Routine panoramic radiographs of 1,400 patients admitted to the Kyungpook National University Hospital Dental Clinic, were retrospectively examined for the clinical and radiographic features of ZACD. Results: ZACD was found in 31 cases, representing a prevalence of 2.2%. Patients with ZACD had a mean age of 27.5 years and a range of 9-52 years. Most ZACD cases were in their thirties. ZACD showed a strong male prediliction, 22 of the 31 subjects were males and 9 were females. Twenty-four cases of ZACD (77.4%) were unilateral, with the half occurring on the right side. In seven cases (22.6%), ZACD was bilateral. Twenty-six (68.4%) of the defects were of unilocular, while twelve (31.6%) of the defects were multilocular. Conclusion: Knowledge of ZACD may be helpful in interpreting images, including panoramic radiographs, in planning surgical treatment of the TMJ and in understanding the spread of pathological processes into the joint.

• Proceedings of the KIEE Conference
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• 1998.07g
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• pp.2518-2520
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• 1998

Silicon can be reactive ion etched (RIE) either isotropically or anisotropically. In this paper, a new micromachining technology combining these two etching characteristics is proposed. In the proposed method, the fabrication steps are as follows. First. a polysilicon layer, which is used as the bottom electrode, is deposited on the silicon wafer and patterned. Then the silicon substrate is etched anisotropically to a few micrometer depth that forms a cavity. Then an PECVD oxide layer is deposited to passivate the cavity side walls. The oxide layers at the top and bottom faces are removed while the passivation layers of the side walls are left. Then the substrate is etched again but in an isotropic etch condition to form a round trench with a larger radius than the anisotropic cavity. Then a sacrificial PECVD oxide layer is deposited and patterned. Then a polysilicon structural layer is deposited and patterned. This polysilicon layer forms a pivot structure of a rocker-arm. Finally, oxide sacrificial layers are etched away. This new micromachining technology is quite simpler than conventional method to fabricate joint structures, and the devices that are fabricated using this technology do not require a flexing structure for motion.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.27 no.6
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• pp.663-672
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• 2014

Recently, modular structural systems have been applicable to building construction since they can significantly reduce building construction time. They consists of several unit modular frames of which each beam-column joint employs an access hole for connecting unit modular frames. Their structural design is usually carried out under the assumption that their load-carrying mechanism is similar to that of a traditional steel moment-resisting system. In order to obtain the validation of this assumption, the cyclic characteristics of beam-column joints in a unit modular frame should be investigate. This study carried out finite element analyses(FEM) of unit modular frames to investigate the cyclic behavior of beam-column joints with the structural influence of access holes. Analysis results show that the unit modular frames present stable cyclic response with large deformation capacities and their joints are classified into partial moment connections. Also, this study develops a simple spring model for earthquake nonlinear analyses and suggests the Ramberg-Osgood hysteretic rule to capture the cyclic response of unit modular frames.

• The Journal of Churna Manual Medicine for Spine and Nerves
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• v.4 no.1
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• pp.65-73
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• 2009

Objectives : The propose of this study is to analyze characteristics with sex, age, motivation, symptom, Impression, treatment effect about temporomandibular disorder patients. Method : We performed a retrospective study of 52 patients who visited the Jaseng Hospital of Oriental Medicine, from August 2008 to October 2008. Result : Women occupied the most part. And 27 persons in the 20th are the most distribution of age. The majority of patients occured the symptom for no reason. In the distribution of symptoms, TMD pain(88.46%), Click sound(82.69%), neck pain(52.92%), headache(38.46%), lumbago(21.15%) happened. In the impression through radiological diagnoses, The majority of patients diagnosed Straightening of cervical lordotic curvature. Oriental medical treatment showed a very valuable effect on improvement of TMD symptom. Conclusion : The results showed a valuable treatment effect of temporotandibular disorders on Oriental medical treatment. Therefore this work have the necessity of continuous study and observation and will help us to understand the features of patients who visiting the TMD clinic of Jaseng Hospital of Oriental medicine.

• Steel and Composite Structures
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• v.27 no.4
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• pp.495-508
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• 2018

In this paper, cyclic loading tests on composite frame inner joints of steel-reinforced recycled concrete (SRRC) column-steel beam were conducted. The main objective of the test was to obtain the shear behavior and analyze the shear strength of the joints. The main design parameters in the test were recycled coarse aggregate (RCA) replacement percentage and axial compression ratio. The failure process, failure modes, hysteresis curves and strain characteristics of the joints were obtained, and the influences of design parameters on the shear strength of the joints have been also analysed in detail. Results show that the failure modes of the joints area are typical shear failure. The shear bearing capacity of the joints maximally decreased by 10.07% with the increase in the RCA replacement percentage, whereas the shear bearing capacity of the joints maximally increased by 16.6% with the increase in the axial compression ratio. A specific strain analysis suggests that the shear bearing capacity of the joints was mainly provided by the three shear elements of the recycled aggregate concrete (RAC) diagonal compression strut, steel webs and stirrups of the joint area. According to the shear mechanism and test results, the calculation formulas of the shear bearing capacity of the three main shear elements were deduced separately. Thus, the calculation model of the shear bearing capacity of the composite joints considering the adverse effects of the RCA replacement percentage was established through a superposition method. The calculated values of shear strength based on the calculation model were in good agreement with the test values. It indicates that the calculation method in this study can reasonably predict the shear bearing capacity of the composite frame inner joints of SRRC column-steel beam.

• Journal of the Speleological Society of Korea
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• no.72
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• pp.19-30
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• 2006

The purpose of this study is to clarified the geology and geomorphic characteristics of the Hantan River Basin. In this area, some kind of landforms are developed such as pre-land forms, lava plateau, and present landforms etc. Some river terraces are peculiar features in the area. Some conclusions are as follows : The vicinity of the Hantan River is lava plateau formed from the volcanic activity. Some steptoes are located in the lava plateau. Baekeuiri formation means the river bed boulder beneath the lava formation. The development of drainage patterns are unstable and the bifurcation ratio, the ratio of mean length of the river are lower than the other rivers. The relative height of the terraces is about $5{\sim}25m$ and the terraces are alluvial terraces. In the Jiktang Fall area, bedrock is granite and basalt plateau covered the bedrock. In that point, the old erosion surface is relatively steeper than the horizontal-basalt plateau. Vertical columnar joints are developed and weathering materials creep on the valley wall. The cross section of the landform of the Kosukjung vicinities are somewhat different from the landforms of Jiktang Fall. The bedrock near the Kosukjung is granite that is the same with the Jiktang Fall. But the cross section shows a asymmetrical curve from each side.

• Journal of the Korea Society of Computer and Information
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• v.15 no.6
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• pp.49-56
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• 2010

In this paper, a joint PHY-MAC layer optimized resource allocation scheme for OFDMA based micro base stations is investigated. We propose cross-layer optimized two-stage resource allocation scheme including cross-layer functional description and control information flow between PHY-MAC layers. The proposed two-stage resource allocation scheme consists of a user grouping stage and a resource allocation stage. In the user grouping stage, users are divided into a macro base station user group and a micro base station user group based on the PHY-MAC layer characteristics of each user. In the resource allocation stage, a scheduling scheme and an allotment of resources are determined. In the proposed scheme, diversity and adaptive modulation and coding (AMC) schemes are exploited as schedulers. Simulation results demonstrate that the proposed scheme increases the average cell throughput about 40~80 % compared to the conventional system without micro base stations.

• Journal of the korean academy of Pediatric Dentistry
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• v.37 no.1
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• pp.124-129
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• 2010

Seckel syndrome is an autosomal recessive disorder characterized by intrauterine growth retardation and post-natally by dwarfism, severe microcephaly, bird-headed profile with receding chin, prominent nose, joint defects, clubfoot, sparse hair, malformation of genitourinary tract and rectum, mental retardation and hematological disorders. There is also a reduction in the number of blood cells. Dental anomalies of Seckel syndrome are crowded teeth with malocclusion, enamel hypoplasia, absence of some teeth and taurodontism. This report described the oral and maxillofacial manifestations of children associated with Seckel syndrome. Children with Seckel syndrome have several dental and skeletal irregularities. The purpose of this study was to report the dental and medical characteristics of the patient and review the literatures of Seckel syndrome.

• Hwankyungkyoyuk
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• v.23 no.2
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• pp.46-64
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• 2010

The purpose of this study is to analyze how the contents of education for sustainable development are reflected in the middle school environment curriculum revised in 2007, and to propose how to integrate content for improving sustainable development education. For this, I analyzed the 2007 Revised Environment Curriculum for Middle Schools by using social network analysis which is the useful methodology to understand the relations of contents. Social Network analysis is a useful tool to excavate the forms of structure or relationship and to explain the characteristics of the system that arise through relationships or to explain the units composing the system. When sustainable development education was examined from 3 points of view, it included environmental sustainability, economical sustainability, and social sustainability. I used the 2007 Revised Environment Curriculum for Middle Schools and manual of curriculum for analysis. The results are 1) The biodiversity conservation and energy efficiency have taken most important positions. 2) In case of economical sustainability pillar, sustainable production had been emphasized. 3) In the case of the social sustainability pillar, health improvement are considered significant. 4) The efforts of trying to approach sustainable development education as an integrated curriculum is week. Integrated themes based on the results were developed. Five main themes were the energy and climate change, water resource and environmental pollution, sustainable village and sustainable food production, sustainable city and sustainable production, sustainable tourism and biodiversity. I hope these could function as theme of integrated-content. Based on the results of study, I propose joint researches on scope of sustainable development for environmental education.

• The Journal of the Korean bone and joint tumor society
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• v.15 no.1
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• pp.65-68
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• 2009

Proliferating trichilemmal tumor(PTT) is a rare neoplasm derived from the outer root sheath of the hair follicle. Malignant transformation is rare, but abrupt enlargement of size, infiltrative growth, and non-scalp location are suggestive of malignant PTT. Histopathologic characteristics of malignant PTT are nuclear atypia, pleomorphism, and mitotic figures. Recurrence and metastasis have been documented in malignant PTT. Wide resection of the tumor with the normal tissue and accurate follow-up is the treatment of choice of the both malignant and benign PTT. We report a 51-year-old man with the mass on right 5th finger distal phalanx for 7 years. The tumor was excised with middle phalangiectomy, and based on the histopathologic findings of the tumor, this case was diagnosed as mailignant PTT. We cannot detect recurrence and metastasis because the patient was lost to follow-up.