• Child Health Nursing Research
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• v.8 no.2
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• pp.174-182
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• 2002

The purpose of this study was to investigate the experiences of accident and visiting emergency center, and the experiences of education about emergency care for parents. The subjects of this study were 117 mothers whose children are attending 9 different nursery schools or kindergartens. The instrument used in this study was developed by researchers and validated by nursing professor, first aid doctor and the president of nursery school, and consisted of 'most important thing in child rearing' ,'experiences of accident and visiting emergency center', 'type of trauma' and 'need for parent education program' the result of this study were as followed ; 1.There were 70.09％ of the experience of visiting emergency center among the subjects. The cause of visiting emergency center were high fever and convulsion(42.86％), and trauma by accident(28.04％) 2. The most common type of the indoor accident were fall down and slipping(76.92％), the common type of trauma were contusion (76.92％), abrasion(47.01％), laceration(29.06％), dislocation or fracture(12.82％), burn(10.26％), piercing(8.55％). 3.47.01％ of subjects had the experience of education about emergency care for parents. They were educated by child rearing journals (32.72％), small books which were published by hospitals or community health center (25.45％), mass media(21.8％), parent seminar (12.72％), nursery school or kindergarten (5.45％). In conclusion, the need of emergency care for children was strongly found. Therefore, on the basis of above results, the parent education program which fits their cognitive level and their health care needs So, it must be directed on the further study of parents' knowledge about emergency care for children. To enhance the effectiveness of program and accomplish the children's health promotion, advanced instructional media and demonstration must be included.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2001.05a
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• pp.147-150
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• 2001

The ARB (Accumulative Rolling Bonding) Process was applied to a 6061 Al alloy to obtain ultra-fine grains. After 4 ARB cycles at $315^{\circ}C$, original equilibrium large grains were transformed to ultra-fine grains of several hundred nano-meter size with nonequilibrium grain boundaries. At lower number of cycles, microsutcture of highly-tangled dislocation cells were observed. Large grains and coarsened precipitates filled the microstructure of specimens experienced ARB cycles more than 5. Sliding wear tests using a pin-on-disk type wear tester were conducted on the ARB processed 6061 Al alloy plate. Wear rates of the 6061 Al alloy increased with the increase of ARB cycle number as well as the applied load. Worn surfaces and debris, cross-sections of the worn specimen were examined with scanning electron microscopy (SEM) to investigate the wear mechanism of the ultra-fine grained 6061 Al Tensile properties of the 6061 Al alloy were also studied and used to correlate the wear test results with the microstructures, which evolved continuously with the number of ARB cycles.

• Economic and Environmental Geology
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• v.24 no.3
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• pp.287-299
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• 1991

The study area is mainly composed of metasedimentary rocks which are included in Ogchon, Choson and Pyongan Groups. Because of thrust faults which are developed in this area, a coal bearing formation is repeatedly distributed two times, and Choson Group is thrusted over Pyongan Group. Deformation in this area was taken place in a series of three phases ($D_1$, $D_2$ and $D_3$) ; $D_1$ was most intense whereas $D_3$ was weakest. Thrust faults developed in the upper curst duringD2 produced cataclastic rocks and fault breccia,truncating regional slaty cleavage and earlier folds which were formed during $D_1$ stage. The quartz microstructures of metapsammitic rocks in Choson and Pyongan Groups suggest that dislocation creep mechanism predominated early in fabric development, afterwards deformation mechanism was transfered to pressure solution which intensified the earlier fabrics. According to strain analysis using quartz grains and quartz aggregate grains, the strain magnitude(Es) of Pyongan Group represents larger values than that of Choson Group due to the contrast of constituent minerals, the size of original quartz grains and matrix content. Apparent flattening type in strain pattern appears in the whole area. It is suggested that the relationship between Ogchon Group and Choson Group may be thrust contact.

• Journal of Korea Port Economic Association
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• v.27 no.4
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• pp.1-11
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• 2011

In much the same way as the US Lehman crisis of 2008-2009 severely impacted the European economy through financial market dislocation, a European banking crisis would materially impact the US economy through a generalized increase in global risk aversion. A deepening of the European crisis could very well derail the US economic recovery and have a harmful impact on the Asian economies. This kind of vicious circle could be a bad news to the shipping companies. The purpose of the study is to predict the Baltic Dry Index representing the shipping business during the period of 2012 using the ARIMA-type models. This include the ARIMA and Intervention-ARIMA models. This article introduces the four ARIMA models and six Intervention-ARIMA models. The monthly data cover the period January 2000 through October 2011. The out-of-sample forecasting performance is also calculated. Forecasting performance is measured by three summary statistics: root mean squared percent error, mean absolute percent error and mean percent error. The root mean squared percent errors, however, are somewhat higher than normally expected. This reveals that it is very difficult to predict the BDI The ARIMA-type models show that the shipping market will be bearish in 2012. These pessimistic ex-ante forecasts are supported by the Hodrick-Prescott filtering technique.

• Korean Journal of Materials Research
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• v.28 no.6
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• pp.317-323
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• 2018

Crystal structure of the $L1_2$ type $(Al,X)_3Ti$ alloy (X = Cr,Cu) is analyzed by X-ray diffractometry and the nonuniform strain behavior at high temperature is investigated. The lattice constants for the $L1_2$ type $(Al,X)_3Ti$ alloys decrease in the order of the atomic number of the substituted atom X, and the hardness tends to increase. In a compressive test at around 473K for $Al_{67.5}Ti_{25}Cr_{7.5}$, $Al_{65}Ti_{25}Cr_{10}$ and $Al_{62.5}Ti_{25}Cu_{12.5}$ alloys, it is found that the stress-strain curves showed serration, and deformation rate dependence appeared. It is assumed that the generation of serration is due to dynamic strain aging caused by the diffusion of solute atoms. As a result, activation energy of 60-95 kJ/mol is obtained. This process does not require direct involvement. In order to investigate the generation of serrations in detail, compression tests are carried out under various conditions. As a result, in the strain rate range of this experiment, serration is found to occur after 470K at a certain critical strain. The critical strain increases as the strain rate increases at constant temperature, and the critical strain tends to decrease as temperature rises under constant strain rate. This tendency is common to all alloys produced. In the case of this alloy system, the serration at around 473K corresponds to the case in which the dislocation velocity is faster than the diffusion rate of interstitial solute atoms at low temperature.

• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.2
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• pp.275-280
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• 2009

Radicular cyst is a true epithelium lined cyst formed when epithelium at the apex of a nonvital tooth is stimulated by inflammation. It is the most common type of cyst in the oral cavity, but its frequency is low in the primary dentition. Treatment of large-sized cyst aims at conservation of adjacent structure and allowance of proper eruption of the successive permanent teeth in the primary dentition. Considering these two aspects, marsupialization or enucleation following decompression is recommended as a treatment means for large-sized radicular cyst. In this case, 8-year old boy visited the pediatric dentistry department. Yonsei University Dental Hospital, with the chief complaint of pain on the lower right area. Clinical and radiographic examinations revealed periapical radiolucent lesion on #84, which had previous pulp treatment and restorated with the stainless steel crown. Dislocation of its successive tooth, #44, was also observed. #84 was extracted and sent for biopsy. Through histologic examination, it was diagnosed as radicular cyst. Following its extraction, removable space maintainer was delivered, which was also used as a decompressor. During periodic check-up for next 22 months, favorable healing of the lesion and eruption of the successive tooth were observed.

• Journal of Oral Medicine and Pain
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• v.31 no.3
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• pp.255-263
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• 2006

Objectives: This article reported three patients developed anterior open bite seemed to be related to TMJ anterior disc dislocation without reduction(ADD WO R), but no evidence of condylar destructive or collapse and analyzed the craniofacial skeletal structure by means of cephalometric analysis. Results: All patients suddenly developed a centric relation/centric occlusion discrepancy, an increased overjet and an anterior open bite following ADD WO R. All patients had Angle's Class I occlusion and shallow bite, but they had skeletally Class III and Class II pattern and all were vertically significant hyperdivergent type. Conclusions: These 3 patients had characteristics of common facial morphology including:(1)Angle classification Class I and shallow bite,(2)high mandibular plane angle,(3)high gonial angle. Developed anterior open bite resulted from clockwise rotation of the mandible related TMJ ADD WO R, rather than a result from the eruption of posterior teeth. We hypothesize rotation may relate to attached direction of masticatory muscle.

• Journal of the Korean Ceramic Society
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• v.44 no.4 s.299
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• pp.208-213
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• 2007

Alumina/silver ($Al_2O_3/Ag$) nanocomposites with Ag content up to 9 vol% were prepared from nanopowder by soaking method using ${\gamma}-Al_2O_3$ of needle type and spark plasma sintering (SPS). The mechanical properties of specimens were investigated three-point flexural strength and toughness as a function of the Ag contents. The maximum flexural strength of the alumina/silver nanocomposite was 850 MPa for the 1 vol% composite, and also higher than monolith alumina as about 800 MPa at 3, 5, and 7 vol% Ag contents. Fracture toughness by single edged V-notch beam (SEVNB) was $4.05MPa{\cdot}m^{1/2}$ for the 3 vol% composite and maintained about $4.00MPa{\cdot}m^{1/2}$ at 5, and 7 vol% Ag content. Microstructure of fracture surface for each fracture specimens was observed. Due to the inhibition effect of alumina grain growth, the average grain size of nanocomposites depends on the content of Ag nano particles. The fracture morphology of nanocomposite with dislocation (sub-grain boundary) by silver nano-particles of second phases in the alumina matrix also showed transgranular fracture-mode compare with intergranular of monolith alumina. Thermal conductivity of specimens at room temperature was about 40 W/mK for the 1 vol% Ag content.

• Journal of Korean Orthopaedic Sports Medicine
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• v.2 no.2
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• pp.168-175
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• 2003

Fracture about proximal humerus may be classified as the articular segment or the anatomical neck, the greater tuberosity, the lesser tuberosity, and the shaft or surgical neck. Now, usually used, Neer's classification is based on the number of segments displaced, over 1cm of displaced or more than 45 degrees of angulation , rather than the number of fracture line . Absolute indication of a operative treatment a open fracture, the fracture with vascular injury or nerve injury , and unreductable fracture-dislocation . Inversely, the case that are severe osteoporosis, and eldly patient who can't be operated by strong internal fixation is better than arthroplasty used by primary prosthetic replacement and early rehabilitation program than open reduction and internal fixation. The operator make a decision for the patient who should be taken the open reduction and internal fixation, because it's different that anatomical morphology, bone density, condition of patient. The operator decide operation procedure. For example, percutaneous pinning, open reduction, plate & screws, wire tension bands combined with some intramedullary device are operation procedure that operator can decide . The poor health condition for other health problem, fracture with unstable vital sign and severe osteoporosis , are the relative contraindication. The stable fracture without dislocation is not the operative indication . The radiologic film of the prokimal humerus before the operation can not predict for fracture evaluation. It's necessary to good radiologic film for evaluation of fracture form. The trauma serise is better than the other radiologic film for evaluation. The accessary radiologic exam is able to help for evaluation of bone fragment and anatomy. The CT can be helpful in evaluating these injury, especially if the extract fracture type cannot be determined from plain roenterogram of the proximal humerus, bone of humerus head. If the dislocation is severe anatomically , we could consider to do three dimentional remodelling. The MRI doing for observing of bony morphology before the operation is not better than CT If we were suspicious of vascular injury, we could consider the angiography.

• Journal of Korean Neurosurgical Society
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• v.55 no.5
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• pp.284-288
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• 2014

A rare case of atlantoaxial rotatory subluxation occurred after pediatric cervical spine surgery performed to remove a dumbbell-shaped meningioma at the level of the C1/C2 vertebrae. This case is classified as a post-surgical atlantoaxial rotatory subluxation, but has a very rare morphology that has not previously been reported. Although there are several reports about post-surgical atlantoaxial rotatory subluxation, an important point of this case is that it might be directly related to the spinal cord surgery in C1/C2 level. On day 6 after surgery, the patient presented with the Cock Robin position, and a computed tomography scan revealed a normal type of atlantoaxial rotatory subluxation. Manual reduction was performed followed by external fixation with a neck collar. About 7 months after the first surgery, the subluxation became severe, irreducible, and assumed an atypical form where the anterior tubercle of C1 migrated to a cranial position, and the posterior tubercle of C1 and the occipital bone leaned in a caudal direction. The pathogenic process suggested deformity of the occipital condyle and bilateral C2 superior facets with atlantooccipital subluxation. A second operation for reduction and fixation was performed, and the subluxation was stabilized by posterior fixation. We encountered an unusual case of a refractory subluxation that was associated with an atypical deformity of the upper spine. The case was successfully managed by posterior fixation.