• Journal of Internet Computing and Services
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• v.9 no.3
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• pp.69-77
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• 2008

An algorithm for tracking the trace of structured light is proposed to obtain depth information accurately. The technique is based on the fact that the pixel location of light in an image has a unique association with the object depth. However, sometimes the projected light is dim or invisible due to the absorption and reflection on the surface of the object. A dynamic programming approach is proposed to solve such a problem. In this paper, necessary mathematics for implementing the algorithm is presented and the projected laser light is tracked utilizing a dynamic programming technique. Advantage is that the trace remains integrity while many parts of the laser beam are dim or invisible. Experimental results as well as the 3-D restoration are reported.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.9
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• pp.5419-5424
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• 2014

A weld scallop is a small quadrant or half circle type hole installed in the weld line cross area for easy welding operation. Many types of T-bars with a scallop can be welded in a block assembly stage in shipbuilding. The difficulties arise from the fact that scallops are to be filled by build-up welding after welding of the cross line is complete. In this study, a non-scallop block joint welding method was developed using special type CBM (ceramic backing material). The wedge shaped CBM was devised to insert a CBM into just the V groove of weld line cross area without weld scallop. A saw-toothed shape was adopted for easy cutting of the unnecessary part in the CBM fitting process. The applicability of the developed method was verified through welding experiments based on the yard welding conditions.

• Archives of Reconstructive Microsurgery
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• v.3 no.1
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• pp.72-80
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• 1994

There are several methods to reconstruct an amputated or lost thumb such as toe to thumb transfer, pollicization and other variety of free flaps. In 1980, Morrison and O'Brien advocated reconstruction of the thumb with a free wrap-around flap from the big toe to recreate a stable, sensate and functional digit, including the nail. From March, 1982 to December, 1992, thirty cases of thumb reconstructions were performed using the wrap-around procedure at Korea University Hospital. 1. 29 cases of total 30 cases were successful and can be obtained the excellent results in functional and cosmetic aspect. 2. In postoperative complications, one case is graft failure, six cases in partial skin necrosis, one case in malunion, 15 cases in resorption of grafted bone piece were come out. 3. Even if the 1st metacarpal neck amputation is occurred, thumb reconstruction with a free neurovascular wrap-around flap was also possible, however, the limitation of the mobility of the reconstructed thumb and resorption of grafted bone piece were come out. We concluded that cosmesis and fuctional results were quite satisfactory despite of some complications. The thumb reconstruction with a wrap around free flap from the big toe in thumb amputated patients is the excellent method in the cosmetic and functional aspect and can be considered as the most useful method because of less morbidity to the donor site and the operator should be trained to get the meticulous microsurgical technique and to detect the complications.

• Journal of the Korean Society of Food Science and Nutrition
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• v.20 no.6
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• pp.629-636
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• 1991

Yellowtail fishes(Seriola quinqueeradiata) were submitted to the storages using ice-cooling($0^{\circ}C$), partial freezing($-3^{\circ}C$) and freezing $-20^{\circ}C$) method. Changes in the structures of muscle during storage at different temperatures were investigated. The ice-cooling and partial freezing storage caused early decomposition of glycogen granules and mitochondrial inner membrane, but it was accorded to much slower manner comparing with that of ice-cooling storage. The scars of ice crystals were appeared after three days of storage. The number and size of the crystal increased as progressing of the storage. They were circular and mostly located between fibers. When using the freezing storage, glycogen granules were mostly found from the muscle cell even after fourteen days of storage. Mitochonidral inner membrane maintained their integrity. The scars of ice crystals were also found, however, different from those of partial freezing storage. Their existing sites were random and their shapes were irregular. In many cases, they located in the fiber and had keen edges. Fibers were broken mostly at the Z-lines on fourteen days of storage. From these results, it was concluded that partial freezing storage can repress autolytic enzymic action and can reduce the physical damage from ice crystals which is caused by freezing.

• Journal of Korean Society of Steel Construction
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• v.22 no.5
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• pp.421-433
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• 2010

The most typical deterioration of steel structures is corrosion damage. However, a method to evaluate residual load-carrying capacity of corroded steel structures is not yet established. It is difficult to check current serviceability and safety of the structures. In this study, compressive tests and finite element analyses were conducted on H-beams with corroded web. Then, the effect of corrosion damage on web crippling strength and evaluation methods of the web crippling strength are studied. Based on the tests, 4 H-beam specimens used in a subway construction site and 9 H-beam specimens with different web-thickness and damaged-height underwent compression-tests. To consider loading and supporting areas in the site, compressive loading was applied in the entire region of the upper and bottom flange in 5 H-beam specimens and applied partially on the regions of the upper and bottom flange in 8 specimens. The finite element analysis of 38 parametric model specimens simulating different corrosion damages was also carried out. From experimental and analytical results, the relationships between corrosion damages in the web and residual web crippling strength are presented. Factors web crippling strength was reduced are formulated by using residual average thickness and the standard deviation of the corroded web thickness. Also, a simple evaluation method of residual web crippling strength was proposed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.2
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• pp.349-355
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• 2017

Bending work using press dies involves bending a flat blank to a desired angle. The bending produces a flange (the bent part) and a web (the unbent part). The bending line will have a bending angle, and there is an inner and outer bending radius. The minimum inner radius size is determined by the material used. When the inner radius size is too small, there will be excess metal welding, which will cause a crack in the outer radius part. The outer bending radius size cannot be controlled by a bending punch and die block. Types of bending include V-bending, U-bending, O-bending, edge bending, twist bending, and crimping. Z-bending involves two bending lines, which are set on the upper side and under surface of the blank, respectively, and upward or downward bending is used. Z-bending is also called crank bending. Z-bending using this type of die structure will produce a standard inner bending radius. The standard size is the minimum bending radius that represents the angle radius of the bending punch. In industry, there is a need for a sharp edge shape with a very small size (R=0.2mm), but that is not possible when using bending punch and die block. The purpose of this research is to meet the need by development.

• Clinical and Experimental Pediatrics
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• v.51 no.12
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• pp.1329-1335
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• 2008

Purpose : This study aimed to determine the best cutoff line for insulin-like growth factor (IGF)-I and insulin-like growth factor binding protein (IGFBP)-3 to discriminate between growth hormone deficiency (GHD) patients and the control group. Methods : Two hundred thirty subjects with normal controls (129 boys and 101 girls, aged 7-15 years), 14 patients with complete GHD (12 boys and 2 girls), and 17 patients with partial GHD (9 boys and 8 girls) were studied. IGF-I serum concentrations were measured by radioimmunoassay (RI), and IGFBP-3 concentrations were measured by immunoradiometric assay (IRMA). Results : The receiver operating characteristic (ROC) plot analysis showed that the best IGF-I and IGFBP-3 cutoff line was at -1 standard deviation (SD). By comparing IGF-I serum levels of GHD children within 1 SD of normal control, we determined the sensitivity (S) (87.5-100%) and specificity (Sp) (80-84.6%) according to the age group. For IGFBP-3, we determined the following values: S (58.7-85.7%) and Sp (79.2-85.5%). Eleven of 14 patients with complete GHD (78.5%) and 16 of 17 patients with partial GHD (94.1%) had IGF-I concentrations equal to or below -1 SD of the control group mean. Ten of 12 complete GHD children (83.3%) and 13 of 17 partial GHD children (76.5%) had IGFBP-3 concentrations equal or below -1 SD of the control group mean. Conclusion : We conclude that the measurement of IGF-I and IGFBP-3 concentrations might provide essential supplementary data in the diagnostic evaluation of patients with GHD. Our results support the need to use cutoff lines based on below -1 SD of the control.

• Journal of Chest Surgery
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• v.34 no.9
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• pp.692-697
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• 2001

Background: The left main coronary artery surgical angioplasty has become the choice of surgical procedure in isolated LM disease. We have performed 22 cases of LMCA surgical angioplasy since 1996. We report the immediate and long term result of the surgical angioplasty with their postoperative angiography. Material and Method: Between July 1994 and October 2000, 22 patients(11 men and 11 women) were subjected to surgical patch angioplasty of the LMCA, 1 patient had an additional angioplasty performed on the proximal right coronary artery. The LMCA was approached anteriorly with or without transection of the main pulmonary artery(21 cases), and in a patient who had undergone an aortic valve replacement, LMCA was approached superiorly with transection of the ascending aorta. Additional grafting was required in 5 cases. The on-lay patch was used with autologous pericardium in 6 cases and bovine pericardium in 16 cases. Result: There was no operative mortality. There was 30~50% stenosis of the anastomosis site in 3 cases at the postop. coronary angiography. Coronary angiography was reperformed in 5 cases between 5th months and 15th months postoperatively. There was 40~60% stenosis of the anastomosis site in 2 cases. There was one death at 42nd months postoperatively but the cause was unknown. No patient complained of angina with a mean follow up of 48.$\pm$22.5 months. Conclusion: There were only several coronary angiographic results in long term follow-up but we had relatively good clinical results for LMCA surgical angioplasty in the immediate and long term. The excellence of LMCA surgical angioplasty needs the result of the long term follow-up.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.29 no.6
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• pp.383-388
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• 2019

High purity SiC fine powder with metal impurity contents of less than 1 ppm was synthesized by improved carbothermal reduction process, and the synthesized powder was used for SiC single crystal growth in RF heating PVT device at temperature above 2,100℃. In-situ x-ray image analyzer was used to observe the sublimation of the powder and single crystal growth behavior during the growth process. SiC powder was used as a source of single crystal growth, exhausted from the outside of the graphite crucible at the growth temperature and left graphite residues. During the growth, the flow of raw materials was concentrated in the middle and influenced the growth behavior of SiC single crystals. This is due to the difference in temperature distribution inside the crucible due to the fine powder. After the single crystal growth was completed, the single crystal ingot was cut into a 1 mm thick single crystal substrate and finely polished using a diamond abrasive slurry. A dark yellow 4H-SiC was observed overall of single crystal substrate, and the polycrystals generated in the outer part may be caused by the incorporation of impurities such as the bubble layer mixed in the process of attaching the seed crystal to the seed holder.

• Clinical and Experimental Pediatrics
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• v.45 no.11
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• pp.1397-1402
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• 2002

Purpose : One of the major complication of arterial catheterization is the thrombosis of the iliac or femoral arteries. Tissue loss following femoral artery catheterization is rare. However longterm sequelae such as impaired limb growth and future impairment of vascular access, are also important in pediatric cardiac patients. But standard methods to treat thrombotic complication of arterial catheterization in infants and children is not established. The present study was performed to assess the efficacy of intraarterial catheter-directed urokinase infusion in infants and children with limb ischemia due to arterial thrombosis after cardiac catheterization. Methods : From January 1994 to August 2002, 12 patients with thrombotic femoral artery occlusion after arterial catheterization were treated with catheter-directed urokinase infusion in Dong-A University Hospital. Retrospective analysis of the medical records and angiograms was conducted. Results : The incidence of femoral artery thrombosis after retrograde arterial catheterization, which had not responded to systemic infusion of heparin and/or urokinase, was 2.8 percent. The doses of urokinase were 1,000-4,400 unit/kg/hr and duration of infusion was $50.6{\pm}29.2$ hours(18-110 hours). Clot resolution was complete in all patients who started to receive the intraarterial urokinase infusion within four days after catheterization. Only partial thrombolysis was seen in two patients who were treated with intraarterial urokinase on the 12th and 19th days after thrombus formation. Balloon angioplasty was done for these two patients with partial success. Bleeding complications were seen in two cases. Conclusion : Early use of catheter-directed intraarterial infusion of urokinase is safe and effective in thrombolysis of femoral artery occlusion after cardiac catheterization in infants and children.