• Proceedings of the KOR-BRONCHOESO Conference
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• 1982.05a
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• pp.8.1-8
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• 1982

Foreign bodies in the airway are very import-tant and not uncommon conditions in the field of E.N.T., and practically there are many reports of them. Occasionally, it can be followed by some pulmonary complications and technical difficulty to remove. Therefore, foreign body in the trachea-bronchial tree is serious and, on occasion, fatal. Recently, the authors experienced 7 interesting cases of foreign bodies in the airway and a brief review of literature was made. Case 1. (1 year old male): A bit of walnut was coughed out spontaneously. Case 2. (2 years old male): A bit of raw chestnut was removed from the right main bronchus. Case 3. (21 Years old male): A pushpin was removed from the left main bronchus. Case 4. (1 year old male): A kind of bean was removed from the right main vronchus. Case 5. (4 years old male): A coiled steel spring (1.1cm$\times$2cm) was removed from the subglottic region. Case 6. (5 years old female): A shell of pine nut which had been impacted in the wall of right main bronchus was removed during right middle and lower lobectomy. Case 7. (2 years old male): A metal nail was removed from the rightposterior basal segmental bronchus during right lower lobectomy.

• Journal of architectural history
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• v.16 no.4
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• pp.77-93
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• 2007

According to documentary records Woljeong-gyo(stone bridge) is built in 760(Silla the 35th King Gyeongdeok 19) and used as original function until 1280(Goryeo the 25th King Chungryeol 6) as Chunyang-gyo. But in those days "Donggyeongjapgi" was published in 1669(Joseon Hyeonjong 10) we assume that it was lost its original function. There are four pier in the type of a ship with the same distance in the middle of river. We can see it is the site of bridge as parts of stonework of bridge are remained. In 1975 the abutments and piers are surveyed and in 1984 stone investigation twice and excavation three times which were to plan restoration were done. Now the restoration of abutments both ends are worked. For restoration of Woljeong-gyo studied documentary records and excavation recoeds were collected and examined. It helped to see the bridge in southern China twice to restore the bridge. Unearthed articles such as yeonham(a kind of member to support roof tiles) and giwa(roof tile) gave decisive clues to assume upper structure of the bridge and from Chinese bridges are helped to type of the bridge. It is certain Woljeong-gyo was ranggyo which means that upper structure was made with wooden members and the stone piers shaped of a ship below and near the abutments both ends another buildings were. Youngjocheok(the architectural measure) of this bridge is similar to gokcheok(the metal measure, 301.84mm) used now that the length of piers is 46choek(尺), the width of that is 9choek(尺), the length between two piers is 42choek(尺), the length between abutment and pier is 38choek(尺). Also we can see that entirely the length of the bridge is 210choek(尺), width is 40choek(尺).

• The Journal of Korean Academy of Prosthodontics
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• v.29 no.2
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• pp.177-194
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• 1991

The purpose of this study was to analyze the magnitude and distribution of stress using a photoelastic model from a distal extension removable partial dentures with three kinds of mandibular major connectors, that is, lingual bar, linguoplate, and swing-lock attachment. A photoelastic model was made of the epoxy resin(PC-1) and hardener(PCH-1) and coated with plastic cement-1 (PC-1) at the lingual surface of the epoxy model and set with three kinds of chrome-cobalt removable partial dentures. A bilateral vertical load of 15kg to the middle portion of the metal bar crossing both the first molars of the right and the left, and a unilateral vertical load of 12.5kg to the right first molar were applied with the use of specially designed loading device and the reflective circular polariscope was used to analyze the photoelastic model under each condition. The following results were obtained : 1. When the bilateral vertical load was applied, the magnitude and distribution of the stress concentration of the edentulous area and the terminal abutment or adjacent teeth was in the order of lingual bar, linguoplate, swing-lock attachment. 2. When the unilateral vertical load was applied, the magnitude and distribution of the stress concentration of the edentulous area and the terminal abutment or adjacent teeth was in the order of lingual bar, linguoplate, swing-lock attachment. 3. When the unilateral vertical load was applied, the magnitude and distribution of the stress concentration of the termial abutment or adjacent teeth on the non-loaded side showed the least stress distribution in case of swing-lock attachment. 4. When the bilateral vertical load and the unilateral vertical load were applied the swing-lock attachment showed the mildest uniform stress distribution on the edentulous area and the alveolar bone around the abutment teeth.

• Composites Research
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• v.17 no.5
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• pp.1-6
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• 2004

Composite pressure vessels with HDPE (high density polyethlyne) liner with metal boss at each end were developed by Filament Winding Process. The vessel is composed of a dome-shaped part at each end and a cylinder-shaped part at the middle of the vessel. The environmental tests carried out for possible vessel materials such as High Density Polyethlyn (HDPE), resins and reinforcing fibers up to a year showed no significant damages. The boss was designed to minimize the gas leak which was verified by FEM analysis. Most ideal fiber tension was obtained by experimental method and the fiber volume fraction, $\textrm{V}_{f}$, obtained by image analyzer were 55.4 % in cylinder and 55.6 % in dome parts, respectively. Winding pattern is programmed to control the composite thickness in the dome areas such that the failure of the vessel may occur in the cylinder. During the cure, the vessel was rotated and a constant internal pressure of 0.62 bar was applied. From this, the vessel's burst pressure is improved by 28 %. The burst and fatigue tests for under-wound and fully wound vessel showed satisfactory results.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.10
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• pp.1514-1519
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• 2001

This paper is concerned with design, manufacturing and performance test of LIPCA ( Lightweight Piezo- composite Curved Actuator) using a top carbon fiber composite layer with near -zero CTE(coefficient of thermal expansion), a middle PZT ceramic wafer and a bottom glass/epoxy layer with high CTE. The main point of this design is to replace the heavy metal layers of THUNDER by thigh tweight fiber reinforced plastic layers without losing capabilities to generate high force and large displacement. It is possible to save weight up to about 30% if we replace the metallic backing material by the light fiber composite layer. We can also have design flexibility by selecting the fiber direction and the size of prepreg layers. In addition to the lightweight advantage and design flexibility, the proposed device can be manufactured without adhesive layers when we use epoxy resin prepreg system. Glass/epoxy prepregs, a ceramic wafer with electrode surfaces, and a graphite/epoxy prepreg were simply stacked and cured at an elevated temperature (177 $^{circ}C$ after following an autoclave bagging process. It was found that the manufactured composite laminate device had a sufficient curvature after detached from a flat mold. The analysis method of the cure curvature of LIPCA using the classical lamination theory is presented. The predicted curvatures are fairly in agreement with the experimental ones. In order to investigate the merits of LIPCA, a performance test of both LIPCA and THUNDE$^{TM}$ were conducted under the same boundary conditions. From the experimental actuation tests, it was observed that the developed actuator could generate larger actuation displacement than THUNDERT$^{TM}$.

• Fire Science and Engineering
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• v.19 no.1 s.57
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• pp.93-98
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• 2005

The purpose of this paper is to judge the damage cause of instrument transformer(MOF; Metering Out Fit) installed in 22.9kV power receiving system. In the three-dimensional analysis of the restored MOF, the damage pattern progressed from inside to outside, there was no damaged part in the upside. The resistance of the carbonized middle part is roughly $100\kappa\Omega$ and the exothermic temperature at inside is presumed as about $300\~800^{\circ}C$ in the result of metallurgical structure analysis. The structure and the composition rate on metal surface by SEM is similar. In the result of FT-IR analysis, we can observe the absorbtion peak at $1500cm^{-1}\;and\;1730 cm^{-1}$ is small. The high exothermic peak showed at the center part of the coil in the result of DTA.

• Journal of Welding and Joining
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• v.16 no.4
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• pp.39-46
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• 1998

$CO_2$ gas shielded arc welding has been characterized with its harsh arc compared to Ar-based shielding gases and with its high level of spattere specially in welding current range of 250~300 amperes. In this range of welding current, the metal transfer mode showed to be changed from short circuit to globular with the increase of welding voltage resulting in so-called the transitional mode in which both modes of transfer appeared together. To characterize the transitional mode, the short circuit events were divided into two groups, i.e. normal short circuit (N.S.C) which has short circuit time $(t_s)$ over 2msec and instantaneous short circuit (I.S.C) of $t_s$$\leq$2msec. The experimental results showed that the number of N.S.C decreased almost linearly with the increase of welding voltage and appeared to be not related with spatter generation rate. However I.S.C became to be pronounced in the transitional condition and its number reached the maximum value at around 29.0 volts. Considering the relation with the spatter generation rate, it was found that the number of I.S.C had a very strong correlation with the spatter generation rate of the transitional condition. It was further demonstrated that spatter generation rate decreased quite linearly with the decrease of I.S.C frequency. It implies that I.S.C is the most important waveform factor controlling the spatter generation of the transitional mode, i.e. in the middle range of welding current. Based on these results, It was discussed that in the transitional mode the basic concept of waveform control for suppressing spatter generation would be different from the one applied for typical short circuit transfer mode of low welding current.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2003.11a
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• pp.109-116
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• 2003

The amount of radioactive waste is expected to be increased continuously because of the rapid growth of the domestic nuclear industry, full power operation of the HANARO reactor and the increased research activities of the nuclear fuel cycle. Accordingly the efforts are focused to achieve the handling of radioactive waste in safe and reduce the volume of radioactive waste. The PIEF is carrying out the PIE (post irradiation examination) of spent fuel rods related to the identification of cause defect and evaluation of integration safety. This study describes the technologies and experiences of compaction, shredding and cutting of the solid radioactive waste used in the PIE. The quantity of the high level waste was reduced by 1/12 using the 100-ton compressor installed in hot-cell. Also middle and low level waste was reduced by 1/8 using the 60-ton compressor installed in intervention area. Plastic drums were shredded by crusher to be compacted in the ratio of 1/5, used filters in the ratio of 1/6 and the number of drum is also reduced by cutting procedure for the non-volatile materials such as metal.

• Economic and Environmental Geology
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• v.24 no.2
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• pp.107-129
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• 1991

The Yonghwa gold-silver deposits are emplaced along $N15^{\circ}{\sim}25^{\circ}W$ trending fissures in middle Cretaceous porphyritic granite or Precambrian Sobaegsan gneiss complex. The results of paragenetic studies suggest that vein filling can be subdivided into four identifiable stages; state I: the main sulfide stage, characterized by base-metal sulfide minerals, iron oxides and minor electrum, stage II: electrum stage, stage III: electrum and silver-bearing sulfosalts stage, stage IV: post ore stage of carbonates and quartz. The ore mineralogy suggests that depositional temperature of the formation of the gold and silver minerals are estimated as 200 to $250^{\circ}C$ and 140 to $180^{\circ}C$, respectively. Sulfur fugacity of the formation of the gold and silver minerals are estimated as $10^{-14.0}$ to $10^{-12.2}$ atm and $10^{-18.5}$ to $10^{-17.2}$ atm, respectively. A consideration of the pressure regime during ore deposition bases on the fluid inclusion evidence of boiling suggests lithostatic pressure of less than 180 bars. This range of pressure indicate that vein system lay at depth of 700m below the surface at the time during mineralization. Salinities of ore-bearing fluids range from 0.4 to 6.9 wt.% equivalent NaCl. The sulfur and carbon isotopic data reveal that these elements were probably derived from a deep-seated source. The ${\delta}^{18}O$ of the hydrothermal fluid was determined from ${\delta}^{18}O$ values of quartz and calcite. Oxygen and hydrogen isotopic studies reveal that meteoric water dominate over ore-bearing fluid.

• 한국문화재보존과학회:학술대회논문집
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• 2004.10a
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• pp.33-42
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• 2004

The forged iron axe found in the No. 2 wood-framed tomb (the middle 3rd century) of Hwangseongdong, Gyeongju is rectangular on the plane level. It shows an obtuse angle in the edge part, while the joint part has the both sides folded up and shows the traces of wood. Under the reflected light, the Iron axe shines in metal luster, which is bright light gray or light creamy colors. The result of x-ray diffraction analysis shows that the axe consists of magnetite and geothite, which can explain why the composition and structure of the original ore has been kept intact. The microtexture of the axe has the irregular network of ferrite and pearlite, and tile cementite of tiny amount in the ferrite background. The overall treatment of the texture seems to be thermal with a high ratio of carbon. There are fine-grained magnetite, wolframite, quartz, calcite, mica, hornblende and pyroxene inside the axe. Those must be the impurities that they failed to remove in the refining process. The normal ferrite is composed of pure iron whose $Fe_2O_3$ proportion is from 99.16 to $99.84\;wt.\%$. Other than them, the ferrite parts usually contain $Al_2O_3\;and\;SiO_2$. The irregular network of pearlite also contains Impurities including $Al_2O_3\;and\;SiO_2$ and shows highly diverse patterns of carbon content. It's because the axe was carburized after the material was made to resemble pure iron. The decarbonization work didn't go well along the process marks. It's estimated that the original ore was bloom produced in low-temperature reduction and formed around in $727^{\circ}C$, which is eutetic temperature.