• Journal of Korean Society of Environmental Engineers
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• v.39 no.9
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• pp.495-504
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• 2017

An amphibious scrubbing/suction dredging machine with cylindrical rotating brush, housing, and turbidity barrier was newly-developed to remove both sediments with about 10 cm thickness and periphyton attached on various structures in urban water-circulating systems through the scrubbing, suction, and dredging processes. Based on the field application and long-term monitoring, the increase in both suspended solids (SS) and turbidity of water during the scrubbing, suction, and dredging processes was negligible (p>0.05). In some cases, the turbidity of water initially increased, however, the turbidity was stabilized within 20 minutes from the start of dredging processes. The concentration changes in TN and TP of water were not statistically different (p>0.05) before and after the scrubbing, suction, and dredging processes, indicating that benthic nutrients released from sediments were not significantly diffused, and were not supposed to cause significant water pollution. Also, water treatment facilities along with an amphibious scrubbing/suction dredging machine could be more effective since the removal of contaminant loadings through the scrubbing, suction, and dredging processes was much greater than that through simple coagulation/precipitation processes. Finally, GPS-based realtime tracking and operation program have been developed and applied in various urban water-circulating systems, and development of driver cooperative autonomous driving system is in progress to eliminate the need for manual driving of an amphibious scrubbing/suction dredging machine.

• The korean journal of orthodontics
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• v.29 no.4 s.75
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• pp.457-466
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• 1999

It has been reported that skeletal relapse and dental change after mandibular setback do occur not only after intermaxillary fixation(IMF) removal but also during IMF The side effects of skeletal relapse during IMF have clinical importance because they can cause many Postoperative orthodontic Problems. Generally, the Prevention of solid union between segments, compensatory tooth movement, anterior openbite, etc. have been cited as the side effects of jaw displacement. The purpose of this study was to evaluate the skeletal relapse and dental change during IMF. The material consisted of 28 patients who were treated by BSSRO(bilateral sagittal split ramus osteotomy), wire osteosynthesis, IMF for correction of mandibular prognathism. Through cephalometric analysis, the amount and direction of surgical movement, skeletal relapse and dental change during IMF were measured. The correlation between surgical movement and skeletal relapse, between skeletal relapse and dental changes were evaluated. The following conclusions were obtained; 1. Distal segment was repositioned backward and upward, proximal segment showed clockwise rotation during surgery. 2. During ]m, anterior portion of distal segment was displaced backward and posterior portion was displaced upward. Proximal segment was displaced upward with forward movement of p-Go(gonion of proximal segment). Backward surgical movement of p-GO was significantly correlated with forward displacement of p-Go. 3. Overjet and overbite were not changed during IMF. The compensatory tooth movements during IMF were characterized by retroclination of upper incisors md retroclination, extrusion of lower incisors. These compensatory tooth movements had statistically significant correlation with upward displacement of d-Go (gonion of distal segment).

• Journal of Radiation Protection and Research
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• v.40 no.3
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• pp.124-131
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• 2015

Radiation exposure to humans can be caused by the gamma rays emitted from natural radioactive elements(such as uranium, thorium and potassium and any of their decay products) of Naturally Occurring Radioactive Materials(NORM) or Technologically Enhanced Naturally Occurring Radioactive Materials(TENORM) added consumer products. In this study, assume that activity of radioactive elements is $^{238}U$, $^{235}U$, $^{232}Th$ $1Bq{\cdot}g^{-1}$, $^{40}K$ $10Bq{\cdot}g^{-1}$ and the gamma rays emitted from these natural radioactive elements radioactive equilibrium state. In this study, reflected End-User circumstances and evaluated annual exposure dose for products based on ICRP reference voxel phantoms and ICRP Recommendation 103 using the Monte Carlo Method. The consumer products classified according to the adhere to the skin(bracelet, necklace, belt-wrist, belt-ankle, belt-knee, moxa stone) or not(gypsum board, anion wallpaper, anion paint), and Geometric Modeling was reflected in Republic of Korea "Residential Living Trend-distributions and Design Guidelines For Common Types of Household.", was designed the Room model($3m{\times}4m{\times}2.8m$, a closed room, conservatively) and the ICRP reference phantom's 3D segmentation and modeling. The end-user's usage time assume that "Development and Application of Korean Exposure Factors." or conservatively 24 hours; in case of unknown. In this study, the results of the effective dose were 0.00003 ~ 0.47636 mSv per year and were confirmed the meaning of necessary for geometric modeling to ICRP reference phantoms through the equivalent dose rate of belt products.

• Childhood Kidney Diseases
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• v.1 no.1
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• pp.38-45
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• 1997

Purpose : Vesicoureteral reflux(VUR) in childhood may be the primary cause of recurrent urinary tract infection and renal scarring. Renal ultrasonography, DMSA, and voiding cystourethrogram are the standard clinical methods for detection of vesicoureteral reflux. But these methods have many disadvantages such as invasiveness and high cost. So, we studied to observe the significance of urine ${\beta}_2$-microglobulin in association with other non-radiologic methods for predictng vesicoureteral reflux. Methods : We evaluated 40 patients with urinary tract infection who were admitted to Korea university Hospital from July 1993 to June 1994. Among them, 24 patients revealed urinary tract infection and vesicoureteral reflux(group A), 16 patients revealed only urinary tract infection(group B). Both groups were compared by presence of fever, hematuria, and proteinuria, positivity of CRP, and level of BUN, Cr, GFR by 99mTc-DTPA, urine ${\beta}_2$-microglobulin, 24 hours urine albumin. Results : 1) Among 24 patients who had vesicoureteral reflux, 14 had unilateral VUR, 10 had bilateral VUR, three kidneys with grade I, nine with grade II, eleven with grade III, eleven with grade IV by classification of International Reflux Study Committee. Among them, 14 patients had renal scar, five with type A, five with type B, four with type C, none with type D by Smellie's classification. 2) The mean of GFR, BUN, Cr, 24hrs urine albumin and the presence of hematuria and proteinuria showed no significant difference between group A and group B. The mean of urine ${\beta}_2$ microglobulin in group A and group B were $283.6{\pm}195.8{\mu}g/l$ and $78.7{\pm}48.5{\mu}g/l$ respectively, showing that group A had a higher value than group B (p<0.01). In case of ${\beta}_2$ microglobulin > $120{\mu}g/l$ and CRP(+), the sensitivity was 93.3% and the specificity is 77.8% for detecting of VUR. In case of ${\beta}_2$-microglobulin>$120{\mu}g/l$ and fever(+), the sensitivity was 92.2%, and the specificity was 62.5% for detecting of VUR Conclusions : If the level of urinary ${\beta}_2$-microglobulin is more than 120ug/l in children with urinary tract infection in association with fever(+) or CRP(+), it can predict VUR. So we can use it for early detection of VUR.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.14 no.1
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• pp.52-58
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• 2011

Purpose: Mecnoium obstruction in very low birth weight infants (VLBWI), which delays enteral feeding and is one of the major causes of bowel obstruction, can be diagnosed and treated with hyperosmolar water-soluble contrast enema. The purpose of this study was to observe the clinical findings of meconium obstruction, the improvement of small bowel obstruction after contrast enema, and the complications related to the enema. Methods: Hypersolmolar water-soluble contrast enemas were performed in 14 VLBWIs with meconium obstruction. Clinical findings, radiologic findings, feeding intolerance, effectiveness, and complications of enemas were observed. Also, clinical findings related to meconium obstruction were compared with 18 VLBWIs without meconium obstruction. Results: 1) Fourteen VLBWIs with meconium obstruction had significantly lower 5 minutes Apgar scores than 18 VLBWIs without meconium obstruction (p<0.05). Moreover, the day of last meconium passing, and the day of the first trial and full enteral feeding were delayed significantly. 2) A total of 18 enemas were performed in the 14 infants. The contrast medium passed the ileocecal valve and reached the terminal ileus in 12 enemas. Of the 12 enemas, 11 were successful, but 1 infant underwent an ileotomy, even though the contrast medium reached the terminal ileum. 3) Intestinal obstruction was not relieved in three of five infants, in whom the contrast medium failed to pass the ileocecal valve. Obstruction was relieved after repeated enemas in which the contrast medium reached the terminal ileum. 4) No complications associated with water-soluble contrast enemas were observed. Conclusion: Hyperosmolar water-soluble contrast enema is considered to be safe and therapeutic for meconium obstruction in VLBWIs.

• Investigative Magnetic Resonance Imaging
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• v.18 no.1
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• pp.7-16
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• 2014

Purpose : To evaluate the prevalence and pattern of perfusion defect (PD) on first-pass stress perfusion MR imaging in relation with the degree of left ventricular hypertrophy (LVH) and late gadolinium-enhancement (LGE) in patients with apical hypertrophic cardiomyopathy (APH). Materials and Methods: Cardiac MR imaging with first-pass stress perfusion, cine, and LGE sequence was performed in 26 patients with APH from January 2008 to December 2012. We analyzed a total of 416 segments for LV wall thickness on end-diastolic phase of cine images, and evaluated the number of hypertrophied segment and number of consecutive hypertrophied segment (NCH). We assessed the presence or absence of PD and LGE from all patients. If there was PD, we subdivided the pattern into sporadic (sporadic-PD) or ring (ring-PD). Using univariate logistic method, we obtained the independent predictor for presence of overall PD and ring-PD. Results: PD on stress perfusion MRI was observed in 20 patients (76.9%), 12 of them (60%) showed ring-PD. Maximal LV wall thickness and number of hypertrophied segment were independent predictors for overall PD (all, p < 0.05). NCH with more than 3 segments was an additional independent factor for ring-PD. However, LGE was not statistically related with PD in patients with APH. Conclusion: About three quarters of the patients with APH showed PD, most of them represented as ring-PD. LVH degree or distribution was related with pattern of PD, however, LGE was not related with PD. Therefore, the clinical significance of PD in the patients with APH seems to be different from those with non-APH, and further comparison study between the two groups should be carried out.

• Journal of the Korean Vacuum Society
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• v.16 no.5
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• pp.322-329
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• 2007

The interaction of oxygen with the ordered $Ni_3Al(111)$ alloy surface at 800 K and 1000 K has been investigated using LEED, STM, HREELS, UPS, and PAX. The clean $Ni_3Al(111)$ surface exhibits a "$2{\times}2$" LEED pattern corresponding to the ordered bulk-like terminated surface structure. For an adsorption of oxygen at 800 K, LEED shows an unrelated oxygen induced superstructure with a lattice spacing of $2.93\;{\AA}$ in addition to the ($1{\times}1$) substrate spots. The combined HREELS and the UPS data point to an oxygen chemisorption on threefold aluminum sites while PAX confirms an islands growth of the overlayer. Since such sites are not available on the $Ni_3Al(111)$ surface, we conclude the buildup of an oxygen covered aluminum overlayer. During oxygen exposure at 1000 K, however, we observe the growth of ${\gamma}'-Al_2O_3$ structure on the reordered $Ni_3Al(111)$ substrate surface. This structure has been identified by means of HREELS and STM. The HREELS data will show that at 800 K the oxidation shows a very characteristic behavior that cannot be described by the formation of an $Al_2O_3$ overlayer. Moreover, the STM image shows a "Strawberry" structure due to the oxide islands formation at 1000 K. Conclusively, from the oxygen interaction with $Ni_3Al(111)$ alloy surface at 800 K and 1000 K an islands growth of the aluminum oxide overlayer has been found.

• Korean Journal of Food Science and Technology
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• v.39 no.4
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• pp.438-446
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• 2007

The fermented soybean product, cheonggukjang, is favored by many people, partly due to its bio-functional ingredients. Since the fermentation process of cheonggukjang is mediated by enzymes, including proteases, produced by microbes, analysis of the proteome profile changes in cheonggukjang during fermentation would provide us with valuable information for fermentation optimization, as well as a better understanding of the formation mechanisms of the bio-functional substances. The soluble proteins from cheonggukjang were prepared by a phenol/chloroform extraction method, in order to remove interfering molecules for high resolution 2-D gel analysis. Proteomic analysis of the cheonggukjang different fermentation periods suggested that most of the soluble soy proteins were degraded into smaller forms within 20hr, and many microbial proteins, such as mucilage proteins, dominated the soluble protein fraction. The proteomic profile of cheonggukjang was very different from natto, in terms of the 2-D gel protein profile. Among the separated protein spots on the 2-D gels, 50 proteins from each gel were analyzed by MALDI-TOF MS and PMF for protein identification. Due to database limitations with regard to soy proteins and microbial proteins, identification of the changed proteins during fermentation was restricted to 9 proteins for cheonggukjang and 15 for natto. From de novo sequencing of the proteins by a tandem MS/MS, as well as by database searches using BLASTP, a limited number of proteins were identified with low reliability. However, the 2-D gel analysis of proteins, including protein preparation methods, remains a valuable tool to analyze complex mixtures of proteins entirely. Also, for intensive mass spectrometric analysis, it is also advisable to focus on a few of the interestingly changed proteins in cheonggukjang.

• Progress in Medical Physics
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• v.13 no.3
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• pp.149-155
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• 2002

Recent advances in radiation transport algorithms, computer hardware performance, and parallel computing make the clinical use of Monte Carlo based dose calculations possible. To compare the speed and accuracies of dose calculations between different developed codes, a benchmark tests were proposed at the XIIth ICCR (International Conference on the use of Computers in Radiation Therapy, Heidelberg, Germany 2000). A Monte Carlo treatment planning comprised of 28 various Intel Pentium CPUs was implemented for routine clinical use. The purpose of this study was to evaluate the performance of our system using the above benchmark tests. The benchmark procedures are comprised of three parts. a) speed of photon beams dose calculation inside a given phantom of 30.5 cm$\times$39.5 cm $\times$ 30 cm deep and filled with 5 ㎣ voxels within 2% statistical uncertainty. b) speed of electron beams dose calculation inside the same phantom as that of the photon beams. c) accuracy of photon and electron beam calculation inside heterogeneous slab phantom compared with the reference results of EGS4/PRESTA calculation. As results of the speed benchmark tests, it took 5.5 minutes to achieve less than 2% statistical uncertainty for 18 MV photon beams. Though the net calculation for electron beams was an order of faster than the photon beam, the overall calculation time was similar to that of photon beam case due to the overhead time to maintain parallel processing. Since our Monte Carlo code is EGSnrc, which is an improved version of EGS4, the accuracy tests of our system showed, as expected, very good agreement with the reference data. In conclusion, our Monte Carlo treatment planning system shows clinically meaningful results. Though other more efficient codes are developed such like MCDOSE and VMC＋＋, BEAMnrc based on EGSnrc code system may be used for routine clinical Monte Carlo treatment planning in conjunction with clustering technique.

• Journal of agricultural medicine and community health
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• v.38 no.1
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• pp.14-24
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• 2013

Objectives: Pregnant women in rural areas do not have access to sufficient obstetric services in their own communities due to the shortage of obstetricians. Therefore, most of these women must seek obstetrician outside of their communities. The purpose of this study was to investigate the relationship between obstetric complications and accessibility to local obstetric care in Korea. Methods: This study was an ecological study in which the unit of analysis was an administrative district. Using Korea National Health Insurance Corporation data, the total number of deliveries and the delivery proportion within and outside of the community from 2001 to 2008 were calculated for 232 administrative districts nationwide. Three outflow levels were categorized based on each district's out-of-community delivery proportion: high outflow (upper one third), moderate outflow (middle one third), and low outflow (lower one third). In addition, three obstetric complication rates (the rate of complications following abortion, ectopic and molar pregnancy, the abortion rate, and the eclampsia rate) were calculated for the 232 districts. One-way ANOVA and multivariate linear regression were used to evaluate obstetric complications among the three outflow levels. Results: The high outflow districts had higher rates of eclampsia and complications following abortion, ectopic, and molar pregnancy compared to the other districts (ANOVA, p<0.05). However, there was no significant difference in the abortion rate among the three groups. Multiple linear regression analysis showed that high outflow districts were statistically significant in the rate of complications following abortion, ectopic and molar pregnancy and eclampsia rate after adjusting for local tax per capita (p<0.01). Conclusion: These results indicate that poor access to local obstetric care correlate with poor obstetric outcomes (delayed or excessive bleeding, embolism, genital tract or pelvic infection, shock or other complications following abortion and ectopic or molar pregnancy, or eclampsia).