• Journal of Chest Surgery
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• v.30 no.5
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• pp.479-485
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• 1997

We investigated changes of the size of neoaortic annulus, root, and aortic anastomosis after arterial switch operation for complete transposition of the great arteries performed in infancy. A total of 23 patients were included in this study. Age ranged from 6 to 153 days. Body weight averaged 3.9$\pm$0.8kg and 17 patients were male. The preoperative angiocardiographic dimensions of the pulmonary annulus, the pulmonary root, and the sinotubular junction, standardized to the diameter of descending aorta at the level of diaphragm, were compared to the size of postoperative measurements of the neoaortic annulus, the neoaortic root, and the aortic an stomosis at a mean interval of 17.2$\pm$ 9.4 months. Mean dimensions of the neoaortic annulus and the neoaortic root were significantly increased postoperatively(n=23, annulus; p<0.01, root; p<0.01), however, those of the aortic anastomosis did not reveal significant change(n=23, p=0.06). There were no significant differences in changes of diameters of the neoaortic annulus, the root, and the aortic anastomosis between patients with(n=8) and without(n=15) postoperative neoaortic regurgitation(annulus; p=0.32, root; p=0.29, anastomosis; p=0.86). Postoperative dimensions of the neoaortic root and annulus between patients with ventricular septal defect(n: 10) and without ventricular septal defect(ni 13) were not significantly changed compared to the preoperative measurements(annulus; p=0.09, root; p=0.07) but mean diameters of the aortic anastomosis decreased significantly after operation in patients with ventricular septal defect(p=0.04). This study revealed that the site of the aortic an stomosis grows in proportion to patient's somatic growth after arterial switch operation. Although we could not demonstrate the relation between the aortic root dilatation and the postoperative neoaortic regurgitation in this study, a continuous close follow-up might be necessary to detect a possible progression of the aortic root dilatation and the resulting significant aortic valve regurgitation.

• The Korean Journal of Nuclear Medicine Technology
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• v.13 no.3
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• pp.3-9
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• 2009

Purpose: It is well-known that stress-induced stunning and reversible perfusion defect have impact on ejection fraction (EF) when performing myocardial perfusion SPECT. Due to these reasons, gated SPECT is recommended at stress and rest studies. And there was many experiments to analyze between Stress and Rest EF by using $^{99m}Tc$-MIBI. The aim of this study is to analyze between stress EF and rest EF at myocardial perfusion SPECT by using $^{201}Tl$ and define possible predictors of EF variability. Materials and Methods: From 2008 June to 2009 February, we analyzed 144 patients undergoing $^{201}Tl$ gated myocardial perfusion SPECT in ASAN medical center. To analyze the data, we use QGS (Quantitative gated SPECT) software, and derived End-systolic volume (ESV), End-diastolic volume (EDV), EF from the result. In this study, we comparatively analyzed stress/rest EF correlation based on stress/rest EF, EDV, ESV and reversibility of myocardial perfusion defect by using paired t-test, Bland-Altman analysis. Results: Mached pairs of stress EF and rest EF demonstrated excellent correlation (r=0.92) with no statistically significant difference (p=0.11). Bland-Altman analysis demonstrated a mean ${\Delta}EF$ was 0.52% (95% confidential interval[CI], -1.17~0.12%). No statistically significant difference between a mean ${\Delta}EF$ and hypothetic mean of 0 (${\Delta}EF$=0) (p=0.10). In the correlation of ${\Delta}EF$ according to stress/rest EDV and ESV, except rest ESV of <28mL (p<0.05), there was no statistically significant difference. In the correlation of ${\Delta}EF$ according to reversibility of perfusion defect, patients with reversible perfusion defect has statistically significant difference of ${\Delta}EF$ (p<0.05). ${\Delta}EF$ of stress/rest EF showed no statistically significant difference except 55% of rest EF (p<0.05). Conclusion: Like studies with $^{99m}Tc$-MIBI, there was generally no statistically significant difference between stress and rest EF in this study results. However a stress EF of <55%, a rest ESV of <28mL and patients with reversible perfusion defect showed statistically significant difference in ${\Delta}EF$. If performing $^{201}T$ myocardial perfusion SPECT to patients with abnormal cardiac function or reversible perfusion defect, consider this study results and apply it. We expect this study results could be useful predictors of ${\Delta}EF$ variability.

• The Journal of the Korean bone and joint tumor society
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• v.9 no.1
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• pp.38-44
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• 2003

Purpose: To suggest an appropriate treatment modality regarding analyze outcomes of treatment for pathologic fracture to simple bone cyst of the long bone. Materials and Methods: We selected 12 cases with pathologic fracture of the long bone among the 31 cases treated for simple bone cyst from December. 1993 to May. 2001. The mean age was 9 years ranged from 2 years to 19 years, male was 11 cases and female was 1 cases, and the mean follow up interval was 32.9 month ranged from 12 month to 69 month. The principle of treatment for pathologic fracture of the long bone was conservative treatment except operative treatment for fracture with displacement of the femur. After fracture was united, the residual lesion was treated by local steroid injection, cortical drilling, curettage & bone graft. But we observed without specific treatment in cases that had healing process of simple bone cyst followed by bony union. The clinical results were evaluated as exellent if simple bone cyst was completely healed, as good if that had process of healing, as poor if that was no change or more increased in size. Results: The pathologic fracture was united in all cases treated with conservative treatment in 9cases and by open reduction with internal fixation in 3 cases. After fracture was united, the 6 cases were observed without specific treatment, because they had healing process of cyst, and had outcomes as good and excellent. Conclusion: We suggest to need observation when simple bone cyst has healing process after pathologic fracture was united, otherwise secondary treatment will be needed when residual lesion is persisted.

• Journal of the Korean Institute of Landscape Architecture
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• v.36 no.3
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• pp.75-84
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• 2008

The purpose of this research is to find the visual characteristics and geographic structure in a landscape of mountains in Yangsan City. In order to carry out this study, 40 view points of 6 mountains in Yangsan City were selected to experience the mountainscape. The results are as follows. The mountainscape of Yangsan City was confirmed from the view point to the object of view as ranging in middle distance reverse, the angle of elevation 11${\sim}13^{\circ}$ which give the impression of confronted to the mountain, and the horizontal angle 50${\sim}90^{\circ}$ which gives the impression of vastness. This shows that mountainscapes are perceived impressively when seeing the mountain with the meaning to feel the texture of the mountain as a confrontational relationship rather than a pictorial relationship. The geographic structure of the view point which occurs in scenes of impressive experience is classified into eight types and its characteristics are investigated. The first type is corridor, and it emerges in a long narrow linear structure made from the surrounding environment with buildings or street trees. The second is tunnel in which a vision and light hidden while passing underneath a bridge, high-level road, or inside a tunnel can be seen. Third, the maze is formed by the mountain shape. The hill spur emerges when the direction of traffic changes after turning the coner of a building or mountain edge. The hill ground emerges at the top of a hill slope. Next, parallel emerges when the observer and the mountain are in the same direction of process. Confrontation occurs when confronting an isolated mountain. Finally, the view point emerges when passing through major points such as a bridge or square and the boundary of a village or city. This research arranged visual conditions that create impressive mountainscapes. Geographic characteristics in terms of Types that make possible to experience mountainscapes were described. The results of this research will be basic data collected for the management and preservation of mountainscapes and for landscape effect evaluation. Furthermore, this research suggests theoretical evidence to preserve and manage geographic structures that create view experiences as well as to preserve the landscape in terms of view points.

• Journal of the Korean Institute of Landscape Architecture
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• v.37 no.2
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• pp.1-13
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• 2009

The purpose of this study was to look into the feasibility of site suitability focused on the potential for environmentally- and water-friendly recreation area development in a wide area(Nakdong River 35km) and to study new methods for providing basic data in regard to the recreation planning over a wide area as well as in application to other sites. The results of this study are as follows. Through classification by mesh method, the site of this study was classified into 42 grids, and by means of the analysis of evaluation indicators, 20 indicators were established and sorted into 4 types of significant recreation activity. According to the results of the analysis for each recreation activity type, there were 8 essentials for water-friendly recreation activity types based on water use while water-friendly recreation types for static activity included 12 sub-essentials. As a result of the first evaluation(the minimum required evaluation) by each classified grid, 32 of the 42 total grids were implemented by the minimum requirements. These grids were usually distributed evenly through the whole site. In terms of the second evaluation(specific site evaluation) results, 6 grids were highly suitable for recreational nature experiences and landscape ecological learning, 4 grids for developing water-friendly recreation for exercise, 1 grid for building water-friendly recreation based on water use, and 4 grids for planning water-friendly recreation for static activity. The results of the grid evaluation of this study could be extended to contiguous grids or reduced. Actual planning for a water-friendly recreation area must change the grid shape or size through boundary adjustments.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.3
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• pp.136-143
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• 2016

To provide a type approval test for Ballast Water Treatment System (BWTS) of United States Coast Guard (USCG) Phase-II, this study examined the concentrating efficiency of nets for ${\geq}10{\mu}m$ and ${\leq}50{\mu}m$ sized phytoplanktonic organisms using different mesh sized nets ($5{\mu}m$ or $7{\mu}m$), different injection methods (hand breaker as semi-continuous assessment or pump as continuous assessment), and different filterability for the water volume. As a result of the t-test, the net concentrated efficiency between $5{\mu}m$ and $7{\mu}m$ mesh size was not significant (p > 0.05). The difference in the net concentrated efficiency for filtered natural water volume was not significant (p > 0.05). On the other hand, the Chl.a concentration in the continuous water injection method was significantly (p < 0.05) higher than that of semi-continuous water injection (t-test: t: -4.058). In the natural phytoplankton community, a total of 36 species were identified, including Bacillariophyta (17 species), Dinophyta (15 species), Euglenophyta (1 species), Dictyochophyta (2 species), and unidentified taxa (1 species). Among them, diatom Pseudo-nitzchia spp. was remarkably dominant. In particular, the net concentrated efficiency in all assessments was underestimated to be approximately 20-25%, which was caused by the small size Pseudo-nitzchia spp.. A width size of these genus might have passed through the $5{\mu}m$ or $7{\mu}m$ mesh size of the net. Therefore, net concentrated efficiency is dependent on the size of the observed species in natural water. This issue should be considered when determining the net volume for the type approval test of BWTS.

• Journal of Bio-Environment Control
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• v.22 no.3
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• pp.284-290
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• 2013

This study analyzed the geometric, compressive, cutting and friction properties of oriental melons in order to design a gripper capable of soft handling and a cutter for cutting oriental melon vine among the end effector of oriental melon as a preliminary step for developing the end effector of the robot capable of harvesting oriental melons in protected cultivation. As a result, the average length, diameter at the midpoint, weight, volume and roundness of the oriental melons were 108 mm, 70 mm, 188 g, 333 mL and 3.8 mm. Nonlinear regression analysis was performed on the equation $W=L^a{\times}D_2^b$ with variation of the length (L) and diameter (D2) of the weight (W) of the oriental melons. As a result, it was shown that there was a correlation between a of 2.0279 and b of -0.9998 as a constant value. The average diameter of the oriental melon vine was 3.8 mm, and most vines were distributed within a radius of 5 mm from the center. The average yield value, compressive strength and hardness of the oriental melons were $36.5N/cm^2$, $185.7N/cm^2$ and $636.7N/cm^2$, respectively. The average cutting force and shear strength of the oriental melon vines were $2.87{\times}10^{-2}\;N$ and $5.60N/cm^2$, respectively. The maximum friction coefficient of the oriental melons was rubber of 0.609, followed by aluminium of 0.393, stainless steel of 0.177 and teflon of 0.079. It was considered possible to apply it to the size of the gripper and cutter, turning radius, dynamics of drive motor and selection of materials and their quality in light of the position error and safety factor according to the movement when designing end effector based on the analyzed data.

• Progress in Medical Physics
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• v.9 no.3
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• pp.137-141
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• 1998

The purposes of this report are to evaluate whether lead ball and steel ball could be used as protective material of radiation and to acquire physical data of them for protecting 4-10 MV X-ray beams. Lead balls of diameter 2.0～2.5mm or steel balls of diameter 1.5～2.0 mm were filled in an acrylic box of uniform width. An MV radiograph of metal balls in a box were taken to ascertain uniformity of ball distribution in the box. Average density of metal ball and linear attenuation coefficient of metal balls for 4～10 MV X -rays were measured. At the time of measurement of linear attenuation coefficient, Farmer ionization chamber was used and to minimize the scatter effect, distance between the ball and the ionization chamber was 70 cm and field size was 5.5cm${\times}$5.5cm. For comparison, same parameters of lead and steel plates were measured. The distribution of metal balls was uniform in the box. The density of a mixture of lead-air was 6.93g/cm$^3$, 0.611 times density of lead, and the density of a mixture of steel-air was 4.75g/cm$^3$, 0.604 times density of steel. Half-value layers of a mixture of lead-air were 1.89 cm for 4 MV X-ray, 2.07 cm for 6 MV X-ray and 2.16 cm for 10 MV X-ray, and approximately 1.64 times of HVL of lead plate. Half-value layers of a mixture of steel-air were 3.24 cm for 4 MV X-ray, 3.70 cm for 6 MV X-ray and 4.15 cm for 10 MV X-ray, and approximately 1.65 times of HVL of lead plate. Metal balls can be used because they could be distributed evenly. Average densities of mixtures of lead-air and steel-air were 6.93g/cm$^3$, 4.75g/cm$^3$ respectively and approximately 1.65 times of densities of lead and steel. Product of density and HVL for a mixture of metal-air are same as the metal.

• Journal of Chest Surgery
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• v.39 no.8 s.265
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• pp.579-587
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• 2006

Background: Preoperative risk analysis for Fontan candidates is still less than optimal in that patients with apparently low risks may have poor surgical outcome; prolonged pleural drainage, protein losing enteropathy, pulmonary thromboembolism and death. We hypothesized that low pulmonary vascular compliance (PVC) is a risk factor for prolonged pleural effusion drainage after the Fontan operation. Material and Method: A retrospective review of 96 consecutive patients who underwent the Extracardiac Fontan procedures (median age: 3.9 years) was performed. Fontan risk score (FRS) was calculated from 12 categorized preoperative anatomic and physiologic variables. PVC $(mm^2/m^2{\cdot}mmHg)$ was defined as pulmonary artery index $(mm^2/m^2)$ divided by total pulmonary resistance $(W.U{\cdot}/m^2)$ and pulmonary blood flow $(L/min/m^2)$ based on the electrical circuit analogue of the pulmonary circulation. Chest tube indwelling time was log-transformed (log indwelling time, LIT) to fit normal distribution, and the relationship between preoperative predictors and LIT was analyzed by multiple linear regression. Result: Preoperative PVC, chest tube indwelling time and LIT ranged from 6 to 94.8 $mm^2/mmHg/m^2$ (median: 24.8), 3 to 268 days (median: 20 days), and 1.1 to 5.6 (mean: 2.9, standard deviation: 0.8), respectively. FRS, PVC, cardiopulmonary bypass time (CPB) and central venous pressure at postoperative 12 hours were correlated with LIT by univariable analyses. By multiple linear regression, PVC (p=0.0018) and CPB (p=0.0024) independently predicted LIT, explaining 21.7% of the variation. The regression equation was LIT=2.74-0.0158 PVC+0.00658 CPB. Conclusion: Low pulmonary vascular compliance is an important risk factor for prolonged pleural effusion drainage after the extracardiac Fontan procedure.

• Microbiology and Biotechnology Letters
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• v.32 no.3
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• pp.249-255
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• 2004

Chinese cabbage ('Baechu') Kimchi was fermented at the three different temperatures right after it was prepared. Samples were taken everyday for measuring bacterial populations, pH, and titratable acidity through the whole periods of fermentation up to 50 days. pH values and developed acidity were significantly affected by the fermenting temperatures of 4, 10, and $20^{\circ}C$, suggesting that different bacterial flora has been established by the temperatures exposed. The modified MRS agar containing vancomycin (300 $\mu$g/mL) was used for isolating the vancomycin-resistant LAB strains and 127 isolates were finally obtained. Of the LAB isolates, 13 isolates were subjected to the identification experiments based on the biochemical characteristics and the molecular-typing approach, an ITS-PCR, whether they belong to the genus Leuconostoc or not. The data obtained from API 50 CHL kit resulted that six isolates were identified as the members of Leuconostoc and six as Lactobacillus brevis strains except for a single isolate YKI 30-0401, which was not able to be identified because its biochemical traits were not matched to the database of API 50 CHL kit. It was noted that some isolates were distinct in a couple of some biochemical characteristics compared with those of the reference Leuconostoc species. To overcome the limitations experienced in the commercial identification products above, an ITS-PCR experiment was also conducted for the isolates, resulting that eight isolates belong to Leu. mesenteroides ssp. mesenteroides or dextranicum with a single band of 564 bp, and four to L. brevis strains. The ITS-PCR profiles clearly differentiated the closely-related LAB isolates for which same results were obtained by the biochemical method. This molecular approach, however, failed to produce the amplicons for the YKI 20-1003, leaving the strain unidentified. Judging from the identification data obtained in the Kimchi fermented at $4^{\circ}C$ or $10^{\circ}C$, Leuconostoc spp. including Leu. mesenteroides/dextranicum were likely predominant species in the earlier stage and L. brevis occurred at the high level through the whole period. By contrast, L. brevis, as one of the major flora, possibly lead the fermentation from the beginning in the Kimchi fermented at $20^{\circ}C$.}C$.