• Tunnel and Underground Space
• /
• v.13 no.4
• /
• pp.304-315
• /
• 2003

In this paper, the DDA method with a new hydro-mechanical algorithm is used to study the effect of rock discontinuities on uplift and seepage in concrete gravity dam foundations. This paper presents an alternative method of predicting uplift and seepage at the base of concrete gravity dams. A sensitivity analysis was carried out to study the importance of several parameters on dam stability such as the orientation, spacing, and location of discontinuities. The study shows that joint water flow and adverse geological conditions could result in unusual uplift at the base of concrete gravity dams, well in excess of what is predicted with the classical linear or hi-linear pressure assumption. It is shown that, in general, the DDA program with the hydro-mechanical algorithm can be used as a practical tool in the design of gravity dams built on fractured rock masses.

• Archives of Plastic Surgery
• /
• v.33 no.5
• /
• pp.659-662
• /
• 2006

Purpose: Alloplastic implants, such as methylmethacrylate, Teflon, silicone, Supramid are commonly used to cover the floor defect and to prevent reherniation of the displaced orbital tissue in orbital floor fracture. Silicone implant has been used for reconstruction of orbital wall defects because of pliability, advantage of carving and chemically inert nature. However, silicone implant also has complications including infection, extrusion, pain, dystopia and tissue reaction. Cyst formation around the silicone implant is a very rare complication. According to many reports, cysts around alloplastic implant in an orbital area are mostly hemorrhagic cysts consisted of blood breakdown product with fibrous capsule cell in histologic examination. Methods: The authors report atypical case and successful treatment of intraorbital hemorrhagic cyst around silicone implant of a 37-year-old male patient. Results: Preoperative symptoms of diplopia, exophthalmos, proptosis, vertical dystopia and ectropion of lower eyelid were resolved after surgical removal of implants with surrounding capsule. Conclusion: Clinical suspicion of plastic surgeon is important in diagnosis of intraorbital cyst of patients who have history of silicone implantation and computed tomography is the standard tool of diagnosis. During the operation, caution must be taken on delivering the whole capsule of intraorbital cyst along with silicone implant to prevent recurrence of the cyst.

• Journal of the Korean Ceramic Society
• /
• v.31 no.2
• /
• pp.129-136
• /
• 1994

Si3N4 with 6w/o Y2O3 and 1.5w/o Al2O3 has been gas pressure sintered and its densification behavior and the effect of the sintering variables on the microstructure and mechanical properties were investigated. Densification rate was higher at temperature below 1775$^{\circ}C$ and between 187$0^{\circ}C$ and 195$0^{\circ}C$ than between 1775$^{\circ}C$ and 187$0^{\circ}C$. The faster densification at temperature between 187$0^{\circ}C$ and 195$0^{\circ}C$ was thought to be due to the increased amount of liquid phase resulting from the increased amount of Si3N4 dissolving in the liquid. $\beta$-Si3N4 and Y-disilicate at temperatures below 1775$^{\circ}C$, and only $\beta$-Si3N4 at 187$0^{\circ}C$ and above were detected by XRD analysis. Three different two-step schedules were employed to obtain sintered body with above 99% theoretical density and to investigate the effect of the sintering variables on the density, the microstructure and the mechanical properties of the sintered body. The sintered density did not change with the heating rate, and the microstructure became coarser as the temperature increased. The strength decreased with the width of $\beta$-Si3N4 grain, while the fracture toughness increased with the square root of it. A ceramic cutting tool made of the sintered body showed an uniform flank wear after the cutting test.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2008.10a
• /
• pp.1441-1444
• /
• 2008

We developed ultra-accelerated quantum chemical molecular dynamics and spectroscopic characterization simulators for development of PDP materials. By combination of these simulators, realistic structure of PDP materials is drawn on the computer. Furthermore, based on the structures, various properties such as cathode luminescence spectrum and secondary electron emission, is successfully evaluated. The strategy of "Experiment integrated Computational Chemistry" using developed simulators will presented that has the potential in being powerful tool for designing the PDP materials.

• Biomedical Science Letters
• /
• v.21 no.4
• /
• pp.181-187
• /
• 2015

Osteoporosis is one of the diseases caused by accumulation of effects from complex interactions between genetic and environmental factors. Aging is the major cause for osteoporosis, which normally increases skeletal fragility and bone fracture especially among the elder. "Omics" refers to a specialized research field dealing with high-throughput biological data, such as genomics, transcriptomics, proteomics or metabolomics. Integration of data from multi-omics has been approved to be a powerful strategy to colligate biological phenomenon with multiple aspects. Actually, integrative analyses of "omics" datasets were used to present pathogenesis of specific diseases or casual biomarkers including susceptible genes. In this study, we evaluated the proposed relationship of novel susceptible genes (TREML2, HTR1E, and GLO1) with osteoporosis, which genes were obtained using multi-omics integration analyses. To this end, SNPs of the susceptible genes in the Korean female cohort were analyzed. As a result, one SNP of HTR1E and five SNPs of TREML2 were identified to associate with osteoporosis. The highest significant SNP was $rs6938076^*$ of TREML2 (OR=0.63, CI: 0.45~0.89, recessive P=0.009). Consequently, the susceptible genes identified through the multi-omics analyses were confirmed to have association with osteoporosis. Therefore, multi-omics analysis might be a powerful tool to find new genes associated with a disease. We further identified that TREML2 has more associated with osteoporosis in females than did HTR1E.

• Korean Journal of Clinical Pharmacy
• /
• v.30 no.3
• /
• pp.196-205
• /
• 2020

Background: The indication of denosumab for osteoporosis was expanded from second-line to first-line therapy in 2019. The aim of this study was to evaluate the efficacy of denosumab as both first- and second-line therapy in postmenopausal women with osteoporosis and osteopenia with risk factors by using the Fracture Risk Assessment Tool (FRAX). Methods: We conducted a medication use evaluation of denosumab in 98 patients who had been treated three or more times for osteoporosis or osteopenia at Chungnam National University Hospital from July 1^st, 2017 to January 31^st, 2020. Risk factors were identified using quantitative N-gram analyses of FRAX estimations. Patient information, including menopause status and results of bone mineral density tests (T-score), was obtained from electronic medical records. Results: Age, body mass index (BMI), prior medication use, and T-score were identified as risk factors and were included as variables in the evaluation of denosumab use. Since no significant differences were detected between groups, denosumab is likely effective regardless of age or BMI. In addition, no significant difference was detected in T-scores following denosumab treatment, between groups who took bisphosphonates and selective estrogen receptor modulators (SERMs) with denosumab as first-line therapy for postmenopausal osteoporosis. Denosumab may, therefore, be effective as second-line therapy. Conclusion: Efficacy of denosumab was evaluated in postmenopausal women with osteoporosis. Denosumab may be used as first- and second-line therapy regardless of age, BMI, and prior use of bisphosphonates and SERMs.

• Journal of the Korean Institute of Gas
• /
• v.18 no.2
• /
• pp.1-9
• /
• 2014

To develop a coalbed methane(CBM) reservoir, it is important to apply production methods such as drilling, completion, and stimulation which coincide with coal properties. However, the reliability of the selected resulted in most of CBM field is not enough to accept because the selection of production method has been done by empirical decision. As the result, the empirical decision show inaccurate results and need to prove using simulation whether it was true exactly. In this study, the intelligent system has been developed to assist the selection of CBM production method using artificial neural network(ANN). Before the development of the system, technical screening guideline was analyzed by literature survey and the system to select drilling and completion method, and hydraulic fracture fluid was developed by utilizing the guideline. The result as a validation of the developed system showed a high accuracy. In conclusion, it has been confirmed that the developed system can be utilized as a effective tool to select production method in CBM reservoir.

• Journal of the Korean Society of Safety
• /
• v.28 no.4
• /
• pp.26-32
• /
• 2013

A digital image correlation(DIC) method is a whole-field measurement technique that acquires surface displacements and strains from images information which characterized a random speckle as intensity grey levels. Recently years, this DIC method is being developed and used increasingly in various research. In this study, we tried to apply to aluminum alloy(Al 6061-T6) using DIC method and strain gauge. DIC results demonstrated the usefulness and ability to determine a strain. The test specimen used in this study was an aluminum alloy(Al 6061-T6, thickness 1 mm). For a strain measurement, a strain gauge was attached at the center of a specimen. A specimen was lightly sprayed with a white paint and a black dot pattern was sprayed on its fully dried white surface to obtain a random speckle. The experimental apparatus used to perform the tensile test consisted of universal dynamic tester(5 kN; T.O. Co.) under displacement speed of 0.5, 1.0 and 3.0 mm/min. A Model 5100 B Scanner(V. Co.) used to obtain a strain. A CCD camera connected to a PC uses to record the images of the specimen surface. After acquisition, the images were transferred to PC where the DIC software was implemented. An acquired image was evaluated by the DIC program. DIC method for displacement and strain was suggests and it results show a good consistent remarkably. DIC results demonstrated the usefulness and ability to determine surface strain was better than by using classical measurements. The strain field measurement using a DIC is so useful that it can be applied to map strain distributions at a full area. DIC method can evaluate a strain change so it can predict a location of fracture. The findings of the investigation suggest that the DIC method is an efficient and reliable tool for full-field monitoring and detailed damage characterization of materials.

• Journal of Trauma and Injury
• /
• v.25 no.4
• /
• pp.203-208
• /
• 2012

Purpose: The purpose of this study is to investigate the incidence of acalculous cholecystitis after multiple trauma with fractures and to analyze the characteristics of cholecystitis. Methods: We performed a retrospective study of multiple trauma patients with fractures between April 2010 and April 2012. Sixty- nine patients were identified, and the average age was 46.8(range: 15-74) years. Data were collected regarding associated injury, injury severity score (ISS), the diagnosis time after trauma, diagnostic tool, and management Results: There were three cases(4.3%) of cholecystitis among the 69 cases, and cholecystitis was diagnosed an average of 20.7(range: 8-33) days after injury. Two patients complained of abdominal pain at diagnosis, but the other patient who had undergone surgery for small bowel perforation at the time of the injury had no abdominal pain. All three patients had abnormal liver function tests (LFTs) at diagnosis. The cholecystitis was confirmed with ultrasonography or computed tomography, and all cases were acalculous cholecystitis. At first, percutaneous transhepatic gallbladder drainage was performed; then, laparoscopic cholecystectomy (LC) was tried an average of 12(range: 11-13) days later. An laparoscopic cholecystectomy was successfully done in only one case, the other cases being converted to an open cholecystectomy due to severe inflammation. Conclusion: The incidence of acaculous cholecystitis was 4.3% after multiple trauma with fractures. We should consider cholecystitis in patients with abdominal pain, fever and elevated LFTs after multiple trauma.

• The Journal of Engineering Geology
• /
• v.22 no.4
• /
• pp.449-458
• /
• 2012

A sound understanding of the structural characteristics of fractured rock masses is important in designing and maintaining earth structures because their strength, deformability, and hydraulic behavior depend mainly on the characteristics of discontinuity network structures. Despite considerable progress in understanding the structural characteristics of rock masses, the complexity of discontinuity patterns has prevented satisfactory analysis based on a 3-D rock mass visualization model. This paper presents the results of studies performed to develop rock mass visualization in 3-D to analysis the mechanical and hydraulic behavior of fractured rock masses. General and particular solutions of non-linear equations of disk-shaped fractures have been derived to calculated lines of intersection and equivalent pipes. Also, program modules have been developed to perform the calculations. The procedures developed for the 3-D fractured rock mass visualization model can be used to characterize rock mass geometry and network systems effectively. The results obtained in this study will be refined and then combined for use as a tool for assessing geomechanical problems related to strength, deformability and hydraulic behaviors of the fractured rock masses.