• Journal of Chest Surgery
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• v.32 no.4
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• pp.373-378
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• 1999

Background: Minimally invasive technique for various cardiac surgeries has become widely accepted since it has been proven to have distinct advantages for the patients. We describe here the results of our experiences of minimal incision in cardiac surgery. Material and Method: From February 1997 to November 1998, we successfully performed 31 cases of minimally invasive cardiac surgery. Male and female ratio was 17:14, and the patients age ranged from 1 to 75 years. A left parasternal incision was used in 9 patients with single vessel coronary heart disease. A direct coronary bypass grafting was done under the condition of the beating heart without cardiopulmonary bypass support(MIDCAB). Among these, one was a case of a reoperation 1 week after the first operation due to a kinked mammary artery graft. A right parasternal incision was used in one case of a redo mitral valve replacement. Mini-sternotomy was used in the remaining 21 patients. The procedures were mitral valve replacement and tricuspid annuloplasty in 6 patients, mitral valve replacement 5, double valve replacement 2, aortic valve replacement 1, removal of left atrial myxoma 1, closure of atrial septal defect 2, repair of ventricular septal defect 2, and primary closure of r ght ventricular stab wound 1. The initial 5 cases underwent a T-shaped mini-sternotomy, however, we adopted an arrow-shaped ministernotomy in the remaining cases because it provided better exposure of the aortic root and stability of the sternum after a sternal wiring. Result: The operation time, the cardiopulmonary bypass time, the aorta cross-clamping time, the mechanical ventilation time, the amount of chest tube drainage until POD#1, the chest tube indwelling time, and the duration of intensive care unit staying were in an acceptable range. There were two surgical mortalities. One was due to a rupture of the aorta cannulation site after double valve replacement on POD#1 in the mini-sternotomy case, and the other was due to a sudden ventricular arrhythmia after MIDCAB on POD#2 in the parasternal incision case. Postoperative complications were observed in 2 cases in which a cerebral embolism developed on POD#2 after a mini-sternotomy in mitral valve replacement and wound hematoma developed after a right parasternal incision in a single coronary bypass grafting. Neither mortality nor complication was directly related to the incision technique itself. Conclusion: Minimally invasive surgery using parasternal or mini-sternotomy incision can be used in cardiac surgeries since it is as safe as the standard full sternotomy incisions.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.30 no.1
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• pp.22-30
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• 2012

The purpose of this study of deliberation results to Change the Present Condition of Gyeonggi-do Designated Cultural Properties established Acceptable Standards of Change the Present and its disposal of the fire, Accordingly to minimize the complaints of neighbors cultural property and Decision of Change the Present Condition to maintain the consistency of that is the purpose of this study and The results of the study are as follows First, 82 of proposals with tangible cultural monuments and 56% and 50% each accounted for the majority. 84% of the individual applicant, the application uses 94% of the construction, application facility houses the highest percentage of 40%. Approved and reconsideration results, while the largest number of monuments, rejected the result was the most frequent types of cultural property. and Building height, the highest was filed. Second, the results of deliberation voted two of the most frequently voted 36.5% to 48.7%, 14.6% is the reconsideration. The main reason for the decision passed Cultural minimal impact surrounding landscape, and the application of the buildings surrounding the site have voted in determining the existence of many affected. The main reason for rejection of the decision and voted to determine the cultural assets, compared to inhibition surrounding area of application architecture is characterized by large-scale. The main reason for reconsideration of the decision after a site survey was the most frequent reconsideration. Third, the primary consideration only if you applied a full half of 82 is 47.5% of cases. Consequences of the two manatgo voted the same, assuming the number of agenda items, the more the decision was rejected, and reconsideration. Fourth, the application area committee areas and cultural phenomenon in the conservation area be applied to each 33.7% and 20.2% was most common. Compared with rejection and reconsideration if the various sections of the application has passed. and When applied to the conservation area there were passed. Cultural committee rejected the decision, if applied to areas were most prevalent, reconsideration of the decision was similar in the two areas. Fifth, the size of the construction of buildings collapsed as a result, you voted in rejection have changed. and Voted to reject the results from the increase in building area when changing a lot of decisions have affected the results.

• The Korean Journal of Malacology
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• v.30 no.2
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• pp.101-106
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• 2014

Clearance rate and feeding of surf clam, Mactra veneriformis were determined for 5 different water temperature regime (5, 10, 15, 20, $25^{\circ}C$) and salinity regime (8, 14, 20, 26, 32 ‰) with small group ($86.62{\pm}7.10mm$ in shell length) and large group ($147.99{\pm}10.83mm$ in shell length). Clearance rate and feeding increased with water temperature up to $20^{\circ}C$, but rapidly decreased at $25^{\circ}C$. The minimal clearance rate and feedign was recorded at $5^{\circ}C$. surf clam showed low clearance rate and feeding at low salinity (below 20 ‰) and maximum values at high salinity (26-32 ‰).

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.14 no.3
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• pp.192-200
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• 2002

There is a volume change between the sediments and the dredged materials because the dredged materials is fully disturbed by the dredger and settled in the basin from the stabilized condition. The volume of the dredged materials is also affected by the coagulants and flocculants (hereafter C & F) which was used to speed up the settling of the suspended solids. In this study, the volume change of the dredged materials is analysed in detail due to the injection amount of the C & F. The dredged materials were sampled in the lagoon located in the East coastal zone, and the volume change of the samples is quantitatively analysed by the laboratory test due to the change of the clay content and the amount of the C & F. The optimal amounts of the C & F is determined by showing the minimal volume change due to C & F injection. From the experimental results, the volume of the dredged materials is increased 1.68 times on an average and the volume change rate is slightly increased, i.e., negligible, as the clay content increase in the case of the C & F injection.

• Korean Journal of Materials Research
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• v.22 no.4
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• pp.211-214
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• 2012

Optimal conditions for HA plasma spray-coating on Ti6Al4V alloy were investigated in order to obtain enhanced bone-bonding ability with Ti6Al4V alloy. The properties of plasma spray coated film were analyzed by SEM, XRD, surface roughness measurement, and adhesion strength test because the film's transformed phase and crystallinity were known to be influential to bone-bonding ability withTi6Al4V alloy. The films were formed by a plasma spray coating technique with various combinations of plasma power, spray distance, and auxiliary He gas pressure. The film properties were analyzed in order to determine the optimal spray coating parameters with which we will able to achieve enhanced bone-bonding ability with Ti6Al4V alloy. The most influential coating parameter was found to be the plasma spray distance to the specimen from the spray gun nozzle. Additionally, it was observed that a relatively higher film crystallinity can be obtained with lower auxiliary gas pressure. Moderate adhesion strength can be achievable at minimal plasma power. That is, adhesion strength is minimally dependent on the plasma power. The combination of shorter spray distance, lower auxiliary gas pressure, and moderate spray power can be recommended as the optimal spray conditions. In this study, optimal plasma spray coated films were formed with spray distance of 70 mm, plasma current of 800 A, and auxiliary gas pressure of 60 psi.

• Journal of the Korean Institute of Telematics and Electronics T
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• v.36T no.3
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• pp.50-55
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• 1999

Brushless DC Motor(BLDCM) has high efficiency. But this type of motor needs a rotor sensor which complicates the motor configuration. Rotor position sensor degrades system reliability in the severe environmental condition. In this paper, we study a controller which permits the determination of the rotor position by the back EMF to eliminate the rotor position sensor Also, since the back EMF is zero at standstill, a starting technique which permits the starting of an asynchronous motor without a sensor is described. The controller is implemented using microcontroller for minimal external component.

• Tunnel and Underground Space
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• v.25 no.5
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• pp.470-486
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• 2015

Two-arch tunnels require minimal spacing between the 2 tunnels and thus occupy small amount of land compared to parallel tunnels. But it is rather expensive. The parallel tunnel is not as expensive, but it requires more land than 2-arch tunnels. This may cause a problem when there is a land shortage. The new design is to connect these two types of tunnels by another pair of parallel tunnels where the separation distance is gradually increasing. The applicability of this new design to the cases where rock condition is not even fair has to be verified since the width of the pillar between the connecting tunnels can be quite narrow. Therefore both two and three dimensional numerical analyses were conducted and pillar stability was examined for rock classes IV and V in two different ways. Results showed that this new design is still effective for poor rock conditions if central pillar is properly reinforced by tension bolts as long as overburden is less than five times of the tunnel diameter.

• Journal of Life Science
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• v.14 no.3
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• pp.490-495
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• 2004

Phosphate-solubilizing activities of the two strains (Burkholderia sp. DA23 and Klebsiella sp. DA7l-1) against tri-calcium phosphate and hydroxyapatite were quantitatively determined. Two strains were found to solubilize two types of insoluble phosphate different amounts of amino acid solutions in liquid culture. MPS ability of the strains was increased with concentration of amino acid addition. The optimal solubilization condition of insoluble phosphate in sucrose minimal medium were 0.1% amino acid solution, respectively. The efficiency of amino acid addition was no difference between the two types of insoluble phosphate, tri-calcium phosphate and hydroxyapatite.

• Progress in Medical Physics
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• v.28 no.3
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• pp.83-91
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• 2017

In this work, we investigated the recently proposed phase-contrast x-ray imaging (PCXI) technique, the so-called single grid-based PCXI, which has great simplicity and minimal requirements on the setup alignment. It allows for imaging of smaller features and variations in the examined sample than conventional attenuation-based x-ray imaging with lower x-ray dose. We performed a systematic simulation using a simulation platform developed by us to investigate the image characteristics. We also performed a preliminary PCXI experiment using an established a table-top setup to demonstrate the performance of the simulation platform. The system consists of an x-ray tube ($50kV_p$, 5 mAs), a focused-linear grid (200-lines/inch), and a flat-panel detector ($48-{\mu}m$ pixel size). According to our results, the simulated contrast of phase images was much enhanced, compared to that of the absorption images. The scattering length scale estimated for a given simulation condition was about 117 nm. It was very similar, at least qualitatively, to the experimental contrast, which demonstrates the performance of the simulation platform. We also found that the level of the phase gradient of oriented structures strongly depended on the orientation of the structure relative to that of linear grids.

• Journal of Sensor Science and Technology
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• v.8 no.1
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• pp.53-62
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• 1999

Micro polysilicon actuators, which are widely used in the field of MEMS (Microelectromechanical System) technology, were fabricated using polysilicon thin layers. Polysilicon deposition were carried out to have symmetrical layer structures with a LPCVD (Low Pressure Chemical Vapor Deposition) system, and we have measured physical characteristics by micro test patterns, such as bridges and cantilevers to verify minimal mechanical stress and stress gradient in the polysilicon layers according to the methods of mutilayer deposition, doping, and thermal treatment, also, analyzed the properties of each specimen, which have a different process condition, by XRD, and SIMS etc.. Finally, the fabricated planar polysilicon resonator, symmetrically stacked to $6.5{\mu}m$ thickness, showed Q of 1270 and oscillation ampitude of $5{\mu}m$ under DC 15V, AC 0.05V, and 1000 mtorr pressure. The developed micro polysilicon resonator can be utilized to micro gyroscope and accelerometer sensor.