• Journal of Chest Surgery
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• v.40 no.12
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• pp.805-810
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• 2007

Background: This paper reviews our experience retrospectively to examine the clinical results and effectiveness of lateral tunnel (LT) and extracardiac conduit (ECC) Fontan procedures at a single institution. Material and Method: One hundred and sixty five Fontan procedures were performed (67 LT and 98 ECC) between January 1996 and December 2006. Preoperative and postoperative hemodynamic values, arrhythmia, hospital and intensive care unit stay, chest tube drain, morbidity and mortality were reviewed. Result: The overall operative mortality in the LT and ECC groups was 4.5% (3) and 2.0% (2), respectively. There was a significant difference in the immediate postoperative transpulmonary gradient (LT $8.5{\pm}2.5$ vs ECC $6.6{\pm}2.4$, p-value<0.001) and central venous pressure (LT $18.3{\pm}3.8$ vs ECC $15.6{\pm}2.4$, p-value=0.001) between the two groups. The mean follow-up in the LT and ECC groups was $74.1{\pm}31.5$ and $38.1{\pm}29.1$ months, respectively. There was one late death. The actuarial survival at 10 years in the LT and ECC groups was 92% and 89%, respectively. In arrhythmia, the ECC patients showed a slightly low incidence but the difference was not statistically significant. Conclusion: Both the LT and ECC Fontan procedures showed comparable early and mid-term outcomes in terms of the surgical morbidity and mortality, postoperative hemodynamics, and mid-term survival. The ECC Fontan procedure reduces the risk of arrhythmia in the follow up period.

• Economic and Environmental Geology
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• v.50 no.2
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• pp.117-128
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• 2017

Occurrence characteristics and existing forms of U-Th containing minerals in KURT (KAERI Underground Research Tunnel) granite are investigated to understand long-term behavior of radionuclides in granite considered as a candidate rock for the geological disposal of high-level radioactive waste. KURT granite primarily consists of quartz, feldspar and mica. zircon, REE(Rare Earth Element)-containing monazite and bastnaesite are also identified. Besides, secondary minerals such as sericite, microcline and chlorite including quartz vein and calcite vein are observed. These minerals are presumed to be accompanied by a post-hydrothermal process. U-Th containing minerals are mainly observed at the boundaries of quartz, feldspar and mica, mostly less than $30{\mu}m$ in size. Quantitative analysis results using EPMA (Electron Probe Micro-Analyzer) show that 74.2 ~ 96.5% of the U-Th containing minerals consist of $UO_2$ (3.39 ~ 33.19 wt.%), $ThO_2$ (41.61 ~ 50.24 wt.%) and $SiO_2$ (15.43 ~ 18.60 wt.%). Chemical structure of the minerals calculated using EPMA quantitative analysis shows that the U-Th minerals are silicate minerals determined as thorite and uranothorite. The U-Th containing silicate minerals are formed by a magmatic and hydrothermal process. Therefore, KURT granite formed by a magmatic differentiation is accompanied by an alteration and replacement owing to a hydrothermal process. U-Th containing silicate minerals in KURT granite are estimated to be recrystallized by geochemical factors and parameters such as temperature, pressure and pH owing to the hydrothermal process. By repeated dissolution/precipitation during the recrystallization process, U-Th containing silicate minerals such as thorite and uranothorite are formed according to the variation in the concentrated amount of U and Th.

• Journal of the Korean Arthroscopy Society
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• v.7 no.2
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• pp.206-214
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• 2003

Purpose : To analysis each clinical results after arthroscopic ACL reconstruction with using variable fixatives which are metallic and bioabsorbable interference screw, and RIGIDfix. Therefore, We reported the clinical reliability and safty of ACL reconstruction using RIGIDfix. Materials and Methods : We evaluated the results of arthroscopic ACL resconstruction with patellar tendon autograft among three groups, of which group 1 is used metal interference screw for 44 patients, group 2 used bioabsorbable interference screw for 47 patients, group 3 used RIGIDfix for 42 patients. We compared the clinical results by physical examination (anterior drawer test, Lachman test and pivot shift test), Lysholm score and KT-2000 arthrometer and compared the radiological results by measurement of tunnel and fixatives position and widening and by MRI findings. We analyzed the results by SAS 8.2 Ducan. Tukey and paired t-test Results : Physical instability was in 5 cases, which group 2 had 4 cases and group 3 had 1 case. Lysholm score improved from 59.8. 64.4, 61 to 90.1, 92.3. 92. KT-2000 arthrometer instability improved from 9.20, 10.2, 9.5 to 1.43. 1.62. 2.00 (p=0.478). Radiologically, all cases had excellent tunnel position and cyst change was observed the 8 cases in the group 2, but, all 20 cases 2nd MRI had signal change of peri-fixatives. But, no correlation of clinical results. Conclusion : No statistical difference of clinical instability was found among three groups. And femoral tunnel changes were much observed in group I, II than III. We considered the RIGIDfix has much advantages because the short operation time, better fixation position and much bone contact surface. But, further long term follow up study was needed.

• Journal of the Korean Arthroscopy Society
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• v.13 no.1
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• pp.8-13
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• 2009

Purpose: We used tibialis allograft for the reconstruction of ACL and used Hybrid femoral fixation utilizing $Endobutton^{(R)}$ and $Rigidfix^{(R)}$ for femoral fixation, and used $Retroscrew^{(R)}$ and additional fixation for tibial fixation to evaluate the clinical results. Materials and Methods: The ACL reconstruction were performed from February 2004 to February 2007 utilizing Hybrid femoral fixation and $Retroscrew^{(R)}$ and 32 patients, 32 cases which were available for year-long observation (12 to 25 months). The clinical results (Lysholm knee score, IKDC grade) and the radiologic results(bone tunnel expansion, Telos anterior displacement test) were evaluated. Results: The Lysholm knee score was improved from the average of $67.9{\pm}5.4$ points (range: 51~77) before operation and to $94.1{\pm}6.8$ points (range: 68~98) at the last follow up (p<0.05). 22 cases (69%) were evaluated normal (A), 9 cases (28%) were evaluated nearly normal (B) and only 1 case (3%) was evaluated not normal (C) at IKDC final evaluation and no case was evaluated abnormal. From $Telos^{(R)}$ stress x-ray evaluation, difference from the opposite knee was improved average 13.2 mm{\pm}5.8 (range: 6~21 mm) to average $3.4\;mm{\pm}2.8$ (range: 0~11 mm) after operation (p<0.05). The femoral and tibial tunnel were widened by 18.7% and 9.6% in the AP view and 12.4% and 8.5% in the lateral view, respectively (p<0.05). However, any statistic significance was not observed between bone tunnel expansion and knee joint functions (p>0.05). Conclusion: An ACL reconstruction with tibialis allograft using Hybrid femoral fixation and $Retroscrew^{(R)}$ enabled anatomical fixation of the graft tendon with satisfactory clinical results.

• Journal of Korean Tunnelling and Underground Space Association
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• v.17 no.5
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• pp.523-531
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• 2015

Air quality was monitored in four roadway tunnels located near Seoul metropolitan area from 7:00AM to 9:00AM. PM10 concentrations range $111{\sim}268{\mu}g/m^3$, which are 2~5 times higher than annual standard $50{\mu}g/m^3$, and PM2.5 concentrations range $35{\sim}65{\mu}g/m^3$, which are 1.5~2.5 times higher than annual standard $25{\mu}g/m^3$. Benzene concentrations range 300~500 ppb, which are 200~300 times higher than 1.5 ppb which is air quality standard. Four-month long term air quality monitoring and test results in one of long tunnels show that PM10 range $30{\sim}400{\mu}g/m^3$ and over 97% of them can be removed by bag filter, effectively. Finally, benzene concentrations range 250~350 ppb.

• International Journal of Highway Engineering
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• v.13 no.4
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• pp.177-185
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• 2011

In order to reduce traffic accidents at long road sections involving high risks of traffic accidents, including tunnels, bridges or curves, the National Police Agency have decided a tentative installation and operation of an automated point-to-point speed enforcement system based on cameras at January, 2007. The first system was established at the direction to Kangreung of Dunnae Tunnel at December, 2007. Currently, the automated point-to-point speed enforcement system operates at 11 sections including eight sections on expressways and three sections on national highways. However, there have been few researches on the effects of the system upon the reduction of traffic accidents in a scientific way. To this end, this research effort was initiated to evaluate the effect of the automated point-to-point speed enforcement system on traffic safety by comparing the number of traffic accidents before and after the installation of the system using a comparison-group(C-G) method. Three-year-long traffic accident data for the expressways were collected in order to evaluate the system. As a result, the installation of the system was found to reduce traffic accidents by 49.97% in average.

• Journal of Radiation Protection and Research
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• v.38 no.1
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• pp.22-28
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• 2013

The skyshine effect is an essential and important phenomenon in the shielding design of the high energy accelerator. In this study, a new estimation method of neutron skyshine was proposed and was verified by comparison with existing methods. The effective dose of secondary neutrons and photons at the locations that was far away from high-energy electron accelerator was calculated using FLUKA and PHITS Monte Carlo code. The transport paths of secondary radiations to reach a long distance were classified as skyshine, direct, groundshine and multiple-shine. The contribution of each classified component to the total effective dose was evaluated. The neutrons produced from the thick copper target irradiated by 10 GeV electron beam was applied as a source term of this transport. In order to evaluate a groundshine effect, the composition of soil on the PAL-XFEL site was considered. At a relatively short distance less than 50 m from the accelerator tunnel, the direct and groundshine components mostly contributed to the total effective dose. The skyshine component was important at a long distance. The evaluated dose of neutron skyshine agreed better with the results using Rindi's formula, which was based on the experimental results at high energy electron accelerator. That also agreed with the estimated dose using the simple evaluation code, SHINE3, within about 20%. The total effective dose, including all components, was 10 times larger than the estimated doses using other methods for this comparison. The influence of multiple-shine path in this evaluation of the estimation method was investigated to be bigger than one of pure skyshine path.

• Journal of the Korean Recycled Construction Resources Institute
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• v.6 no.1
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• pp.128-135
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• 2011

In this study, in order to develop ultra rapid hardening mortar(URHM) for tunnel repairs using bottom ash of low recycle ratio and Admixture as Eco concept, fundamental properties of URHM on temperature condition of construction field were performed. Test result, URHM of three types for fluidity and setting time were as in the following : B > C > A. Those for low temperatures were later than the standard condition. Compressive, bending and bond strength were similar with three types as follow. In compressive strength, initial strength of the low were smaller than the standard but the low in the long-term were similar with the standard. On the contrary to this, bending strength were similar in initial strength but the low in the long-term were smaller than the standard. The low in bond strength was average 35% less than the standard. Length changes was as in the following : A > C > B. the low is two times much as the standard but the case using blast furnace slag particles noticeably reduced length changes. Water absorption coefficient and water vapor resistance were as in the following : C > A > B. In case of URHM added bottom ash, water absorption coefficient and water vapor resistance were increased because bottom ash is porous material.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.133-144
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• 2009

Incheon Bridge, 18.4 km long sea-crossing bridge, will be opened to the traffic in October 2009 and this will be the new landmark of the gearing up north-east Asia as well as the largest & longest bridge of Korea. Incheon Bridge is the integrated set of several special featured bridges including a magnificent cable-stayed girder bridge which has a main span of 800 m width to cross the navigation channel in and out of the Port of Incheon. Incheon Bridge is making an epoch of long-span bridge designs thanks to the fully application of the AASHTO LRFD (load & resistance factor design) to both the superstructures and the substructures. A state-of-the-art of the geotechnologies which were applied to the Incheon Bridge construction project is introduced. The most Large-diameter drilled shafts were penetrated into the bedrock to support the colossal superstructures. The bearing capacity and deformational characteristics of the foundations were verified through the world's largest static pile load test. 8 full-scale pilot piles were tested in both offshore site and onshore area prior to the commencement of constructions. Compressible load beyond 30,000 tonf pressed a single 3 m diameter foundation pile by means of bi-directional loading method including the Osterberg cell techniques. Detailed site investigation to characterize the subsurface properties had been carried out. Geotextile tubes, tied sheet pile walls, and trestles were utilized to overcome the very large tidal difference between ebb and flow at the foreshore site. 44 circular-cell type dolphins surround the piers near the navigation channel to protect the bridge against the collision with aberrant vessels. Each dolphin structure consists of the flat sheet piled wall and infilled aggregates to absorb the collision impact. Geo-centrifugal tests were performed to evaluate the behavior of the dolphin in the seabed and to verify the numerical model for the design. Rip-rap embankments on the seabed are expected to prevent the scouring of the foundation. Prefabricated vertical drains, sand compaction piles, deep cement mixings, horizontal natural-fiber drains, and other subsidiary methods were used to improve the soft ground for the site of abutments, toll plazas, and access roads. Light-weight backfill using EPS blocks helps to reduce the earth pressure behind the abutment on the soft ground. Some kinds of reinforced earth like as MSE using geosynthetics were utilized for the ring wall of the abutment. Soil steel bridges made of corrugated steel plates and engineered backfills were constructed for the open-cut tunnel and the culvert. Diverse experiences of advanced designs and constructions from the Incheon Bridge project have been propagated by relevant engineers and it is strongly expected that significant achievements in geotechnical engineering through this project will contribute to the national development of the longspan bridge technologies remarkably.

• Explosives and Blasting
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• v.36 no.4
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• pp.1-8
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• 2018

This numerical study was intended to evaluate the applicability of the half charge blasting to mining and tunnelling. The half charge blasting is a method that two separate rounds are sequentially blasted for the rock burdens in which long blast holes have already been drilled at one operation. The aim of the method is to decrease the construction cost and period in mining and tunnelling projects as well as to increase the blasting efficiency. Several numerical analyses were conducted by using the Euler-Lagrange solver on ANSYS AUTODYN to identify the effects of the suggested method on the blasting results in underground excavations. The overall performance of the suggested method was also compared to an ordinary blasting method. The analysis model was comprised of the Eulerian parts (explosive, air, and stemming materials) and the Lagrangian parts (rock material). As a result, it was found that, owing to the air decks formed in the bottom parts of the long blast holes, the first round of the suggested method presented a higher shock pressure and particle velocities in the vicinity of the blast holes compared to the ordinary blasting method.