• Journal of Chest Surgery
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• v.43 no.6
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• pp.734-738
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• 2010

A 43 year-old female, who underwent bilateral lung transplantation for Eisenmenger syndrome 10 years previously, visited our hospital complaining of progressive severe dyspnea. She was diagnosed as having. bronchiolitis obliterans syndrome, which was presumably caused by chronic graft rejection following lung transplantation. Due to the aggravated dyspnea despite medical treatment, she required ventilator care and then she underwent lung retransplantation. We report here on a case of lung retransplantation for treating chronic graft rejection following the previous lung transplantation for the first time in Korea.

• Journal of Chest Surgery
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• v.41 no.5
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• pp.659-662
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• 2008

Video-assisted pulmonary lobectomy was introduced in the early 1990's by several authors, and the frequency of video-assisted thoracic surgery (VATS) lobectomy for lung cancer has been slowly increasing because of its safety and oncologic acceptability in patients with early stage lung cancer However, VATS is limited by 2D imaging, an unsteady camera platform, and limited maneuverability of its instruments. The da Vinci Surgical System was recently introduced to overcome these limitations. It has a 3D endoscopic system with high resolution and magnified binocular views and EndoWrist instruments. We report three cases of da Vinci robot system-assisted pulmonary lobectomy in patients with early stage lung cancer.

• Journal of Chest Surgery
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• v.41 no.6
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• pp.807-810
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• 2008

From October 2005 to August 2006, sympathetic nerve reconstruction with using the intercostal nerve was performed in 4 patients with severe compensatory hyperhidrosis following thoracoscopic sympathetic surgery for facial hyperhidrosis. The interval between the initial sympathetic clipping and the sympathetic nerve reconstruction was a median of 23.1 months. The compensatory sweating after sympathetic nerve reconstruction was improved for 2 patients, but it was not improved for 2 patients. Thoracoscopic sympathetic nerve reconstruction may be one of the useful treatment methods for the patients with severe compensatory hyperhidrosis after they under go sympathetic nerve surgery for hyperhidrosis.

• Journal of the Korean Society of Tobacco Science
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• v.2 no.1
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• pp.61-67
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• 1980

The greenhouse hulk curing and drying system utilizing the direct solar energy was tested to see how much fuel could be saved for curing flue-cured tobacco at the Daegu Experiment Station, Korea Tobacco Research Institute (North latitute: 35$^{\circ}$49'), in 1979. The structure consists of transparent fiberglass exterior, polyurethan boards covered with galvanized iron as the heat absorbers and insulation boards, air duct in which the air is introduced to the furnace room of bulk curing barn, and gravel heat storage system. All exterior surface of heat absorbers, air duct, and gravels were coated with black paint. The air temperature and total radiation were 20.5 to 35.5$^{\circ}C$ and 1004.2 to 1436.2 cal/$\textrm{cm}^2$ during the 3 replicated curing tests, respectively. The greenhouse bulk curing and drying system was able to cut fuel consumption by 25 percent compared with the conventional bulk curing barn. The maximum temperatures for the top absorber and the inlet air of the system were 89$^{\circ}C$ and 64$^{\circ}C$, respectively, and the average temperature of inlet air was higher than that of conventional one by 18$^{\circ}C$.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.43 no.1 s.343
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• pp.59-64
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• 2006

The slope of the ramp generator in a single slope ADC(analog-to-digital converter) suffers from process and frequency variation. This variation in ramp slope causes ADC gain variation and eventually limits the performance of the ISP(image signal processing) in a CIS(CMOS image sensor) that uses the single slope ADC. This paper proposes a ramp slope BISC(built-in-self-calibration) scheme for CIS. The CIS with proposed BISC was fabricated with a $0.35{\mu}m$ process. The measurement results show that the proposed architecture effectively calibrate the ramp slope against process and clock frequency variation. The silicon area overhead is less than $0.7\%$ of the full chip area.

• Journal of the Microelectronics and Packaging Society
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• v.22 no.1
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• pp.43-49
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• 2015

By the trends of electronic package to be smaller, thinner and more integrative, organic printed circuit board is required to be finer Cu trace pitch. This paper reports on a study of failure mechanism for PCB with fine Cu trace pitch using biased HAST. In weibull analysis of the biased HAST lifetime, it is found that the acceleration factor (AF) of between $135^{\circ}C/90%RH/3.3V$ and $130^{\circ}C/85%RH/3.3V$ is 2.079. A focused ion beam (FIB) was used to polish the cross sections to reveal details of the microstructure of the failure mode. It is found that $Cu_xO/Cu(OH)_2$ colloids and Cu dendrites were formed at anode (+) and at cathode (-), respectively. Thus, this gives the evidence that Cu dendrites formed at cathode by $Cu^{2+}$ ion migration lead to a short failure between a pair of Cu nets.

• Journal of Soil and Groundwater Environment
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• v.16 no.3
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• pp.28-37
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• 2011

A preliminary study for energy efficient soil heating and contaminant removal using microwave was conducted. Soils sampled from floodplain were heated with microwave oven, and soil heating property and energy efficiency were compared to those heated with electrical furnace. In addition the effects of water, soil organic matter, and contaminated diesel on soil heating with microwave were investigated. Even though the electrical power consumption of electrical furnace and microwave oven were similar, temperature of soil heated with microwave oven was significantly higher than that of soil heated with electrical furnace. The increase of soil moisture content delays the raise of soil temperature during heating it with microwave oven. However, the effects of total petroleum hydrocarbon (TPH) (<10%) in contaminated soil matrix and small amount of soil organic matter (<5%) on the increase of soil temperature by microwave were not significant. Further studies for contaminated soils with different texture using pilot scale microwave reactor are required for application of this technique in the field.

• 한국해양학회지
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• v.30 no.1
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• pp.27-38
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• 1995

For the study of oceanic surface current, this work presents a system design which is composed of three parts, a Global Positiong System(GPS) unit, a transmitter with radio frequency (RF) modem and an antenna which are housed in a plastic spherical buoy, and computerised of VHF receiving system. The key idea for this study is to employ a commercially available GPS on a drifting buoy and to utilize the receiver position information from the buoy in determining the Lagrangian motion of surface ocean waters. Great efforts has been paid to the system design which would demand several points in harsh conditions common in the sea surface, that is power supply problems housed inside of a plastic buoy, optimizing transmitting radio frequency which limits transmitting distance to a receiving station. for all these difficulties, the system appears to be promising in future oceanic applications and is considered to economical compared to ARGOS drift buoy which is being used by commercial base. We believe that the system needs to be improved in terms of several aspects such as a longer transmitting distance, a power supply and software. for the test experiments in situ, the system has employed off the coast of Ku Ryong Po int the southeast part of Korea and successfully collected the surface current data. The results are presented for two cases from 21 to 31, March 1994 and 21 to 25, June 1994 in terms of current statistics and trajectories of drifting buoys.

• Journal of Welding and Joining
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• v.32 no.3
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• pp.60-67
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• 2014

The ability of electronic packages and assemblies to resist solder joint failure is becoming a growing concern. This paper reports on a study of high speed shear energy of Sn-4.0wt%Ag-0.5wt%Cu (SAC405) solder with different electroless Ni-P thickness, with $HNO_3$ vapor's status, and with various pre-conditions. A high speed shear testing of solder joints was conducted to find a relationship between the thickness of Ni-P deposit and the brittle fracture in electroless Ni-P deposit/SAC405 solder interconnection. A focused ion beam (FIB) was used to polish the cross sections to reveal details of the microstructure of the fractured pad surface with and without $HNO_3$ vapor treatment. A scanning electron microscopy (SEM) and an energy dispersive x-ray analysis (EDS) confirmed that there were three intermetallic compound (IMC) layers at the SAC405 solder joint interface: $(Ni,Cu)_3Sn_4$ layer, $(Ni,Cu)_2SnP$ layer, and $(Ni,Sn)_3P$ layer. The high speed shear energy of SAC405 solder joint with $3{\mu}m$ Ni-P deposit was found to be lower in pre-condition level#2, compared to that of $6{\mu}m$ Ni-P deposit. Results of focused ion beam and energy dispersive x-ray analysis of the fractured pad surfaces support the suggestion that the brittle fracture of $3{\mu}m$ Ni-P deposit is the result of Ni corrosion in the pre-condition level#2 and the $HNO_3$ vapor treatment.

• Journal of the Microelectronics and Packaging Society
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• v.21 no.3
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• pp.51-56
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• 2014

The reliability of solder joint is significantly affected by the property of surface finish. This paper reports on a study of high speed shear energy and failure mode for Sn-4.0wt%Ag-0.5wt%Cu (SAC405) solder joints with the time of Pd activation. The nodule size of electroless Ni-P deposit increased with increasing the time of Pd activation. The roughness (Ra) of electroless Ni-P deposit decreased with increasing the time of Pd activation. Then, with $HNO_3$ vapor, the quasi-brittle and brittle mode of SAC405 solder joint decreased with increasing the time of Pd activation. This results indicate that the increase in the Pd activation time for Electroless Ni/ Electroless Pd/ Immersion Au (ENEPIG) surface finish play a critical role for improving the robustness of SAC405 solder joint.