• Korean Journal of Pharmacognosy
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• v.46 no.1
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• pp.59-64
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• 2015

Wound healing is a complex process that includes inflammation, granulation tissue formation, re-epithelialization, and remodeling. We reported previously that BuOH fraction from Hydnocarpi Semen (HS) crude extract exhibited wound healing activity in animal ulcer models. In this study, we investigated whether BuOH fraction activates keratinocyte and fibroblast via wound closure test and migration assay. In the scratch test, BuOH fraction accelerated the closure of a monolayer wound scratch at $100{\mu}g/mL$. After treatment with BuOH fraction for 18 h, keratinocytes showed a increase in migration at $25{\mu}g/mL$, whereas the migration of fibroblast increased significantly at $100{\mu}g/mL$ of BuOH fraction compared to control. The mechanism that the BuOH fraction of HS helps to promote healing by inflammation is possibly associated with the migration of keratinocyte and fibroblast.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.7 s.184
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• pp.101-107
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• 2006

Cold gas dynamic spray or cold spray is a novel manufacturing method for coatings. Cold spray is a high rate and direct material deposition process that utilizes the kinetic energy of particles sprayed at high velocity (300-1,200m/s). In this research, a technique to repair the damaged mold by cold spray deposition and mechanical machining was proposed. An aluminum 6061 mold with three-dimensional surface was fabricated, intentionally damaged and material-added by cold spray, and its original geometry was re-obtained successfully by Computer Numerical Control (CNC) machining. To investigate deformation of material caused by cold spray, deposition was conducted on thin aluminum plates ($100mm{\times}100mm{\times}3mm$). The average deformation of the plates was $205{\sim}290{\mu}m$ by Coordinate Measurement Machine (CMM). In addition, the cross section of deposited layer was analyzed by scanning electron microscopy (SEM). To compare variation of hardness, Vickers hardness was measured by micro-hardness tester.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.16 no.2
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• pp.69-76
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• 1980

This paper describes the measurement of the underwater noises produced by the engine vibration around the engine room of stern trawler MIS Sae-Ba-Da(2275GT, 3,600 PS) and pole kner M/S Kwan-Ak-San (243 GT, 1000 PS) while the ship is stopping. The underwater noise pressure level was measured with the underwater level meter of which measuring range is 100 to 200 dB(re bLPa). A and B denotes the maximum pressure level measured at right beneath the bottom of the engine room, while the main engine of the Sae-Ba-Da revoluted at 750 and 500 rpm, respectively. C denotes that of the main engine of the Kwan-Ak-San revoluted at 350 rpm, and D that of the generator of the Sae-Ba-Da revoluted at 720 rpm. Thus A, B, C and D were set for the standard sound source for the experiment. The results obtained are as follows: 1. The noise Pressure level at A, B, C and D were 170.5,165,153 and 158dB, respectively. 2. When the check points distanted vertically 1, 10, 20, 30, 40, 50m from the sound source, the underwater noise presure levels were 170.5, 155, 148, 144 and 138 dB and the directional angle was 116\ulcorner in case of A. 3. The sound level attenuated at the rate of 20dB per 10" meters of the horizontal distance from the sound sources. 4. The frequency distribution of the noise was 100Hz to 10KHz and predominant frequency was 700 to 800Hzminant frequency was 700 to 800Hz

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.20 no.12
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• pp.795-801
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• 2008

An experimental study has been performed on the single phase flow and convective heat transfer in trapezoidal microchannels. The microchannel was about $270{\mu}m$ wide, $800{\mu}m$ deep. and 7 mm long, which might ensure hydrodynamically fully-developed laminar flow at a low Reynolds number. The experiments were conducted with R1l3 and water, with the Reynolds number ranging from approximately 30 to 5000 for friction factor and 30 to 700 for the Nusselt number. Friction factors in laminar are found to be in good agreement with the predictions of existing correlation suggesting that a conventional analysis approach can be employed in predicting flow friction behavior in microchannels. However turbulent friction factors are hardly predictable by the existing correlations. The experimental results show that the Nusselt number is not a constant but increases almost linearly with the Reynolds number even the flow is fully developed (Re < 100). The dependence of the Nusslet number on the Reynolds number is contradictory to the conventional theory. At a Reynolds number greater than 100, the Nusselt number increases slowly with the Reynolds number, where thennally developing flow is responsible for the increase of the Nusselt number with the Reynolds number.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.3B
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• pp.260-267
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• 2011

Wireless Local Area Network (WLAN) is recently become popular on the internet since we can download and transfer mass data through it. However, transferring data with distances over 100m often causes some troubles. When downloading mass data from moving vehicles such as cars, jeeps, tanks, etc., if the download process from the first AP (Access Point) is not completed then we have to re-start this process from the second AP (from 0%). Therefore, the question is how to maintain the data we have received from the first AP, and then continuously download remaining data from the next APs in a battlefield environment. In this paper, we propose an effective method for receiving mass data separately from the mobile receive nodes in a Delay Tolerant Network (DTN). We carried on an experiment and evaluation by simulation; these simulation results are provided to show the proposed information delivery scheme performance.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.47-47
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• 2010

Discharge under the water is very hard and demand considerable high voltage. But specially improved electrode can generate plasma discharge to salty water with relatively low voltage. A round shape ceramic electrode having many pinholes combined with metallic one can generate plasma. 400 volt, 10 kHz and 3 micro second pulse width were applied to repeatedly running synthetic seawater with 10 L/m velocity, containing cultivated E. coli and Bacillus. As a result, 18, 94, 99.97, 100, 100 % disinfection rates to E. coli and 17.1, 17.1, 82.9, 99.4, 99.9 % disinfection rates to Bacillus subtilis were achieved to 1, 2, 3, 4, 5 times repetitive treatment respectively. In the plasma condition, the ions and electrons are separated and new kinds of components are re-synthesized by the intensive movement of the components. Especially chlorine ions are separated and recombined to residual free chlorine like HOCl, $OCl^-$. The residual free chlorine concentrations of discharged water were 0.25, 0.88, 1.39, 1.59, 1.66 mg $Cl_2$/L after 5 times treatment respectively. Another unconfirmed radical and oxidants for example, OH, $H_2O_2$, and $O_3$ can have an effect on microorganism of course.

• Journal of Chest Surgery
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• v.52 no.2
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• pp.100-104
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• 2019

Shone complex is a rare congenital disorder that involves 4 obstructive lesions of the left heart, as follows: parachute mitral valve, supravalvular mitral ring, subaortic stenosis, and coarctation of the aorta. Incomplete forms with 2 or 3 of these lesions in adult patients have been rarely reported in the literature, meaning that insufficient general data exist concerning the surgical strategy and clinical follow-up. Herein, we report the case of a 31-year-old woman with a diagnosis of incomplete form of Shone complex with parachute mitral valve and coarctation of the aorta who underwent successful single-stage surgical repair.

• International journal of advanced smart convergence
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• v.10 no.1
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• pp.12-23
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• 2021

This paper proposes a low power radio frequency receiver front-end where, in a single stage, single-balanced mixer and voltage-controlled oscillator are stacked on top of low noise amplifier and re-use the dc current to reduce the power consumption. In the proposed topology, the voltage-controlled oscillator itself plays the dual role of oscillator and mixer by exploiting a series inductor-capacitor network. Using a 65 nm complementary metal oxide semiconductor technology, the proposed radio frequency front-end is designed and simulated. Oscillating at around 2.4 GHz frequency band, the voltage-controlled oscillator of the proposed radio frequency front-end achieves the phase noise of -72 dBc/Hz, -93 dBc/Hz, and -113 dBc/Hz at 10KHz, 100KHz, and 1 MHz offset frequency, respectively. The simulated voltage conversion gain is about 25 dB. The double-side band noise figure is -14.2 dB, -8.8 dB, and -7.3 dB at 100 KHz, 1 MHz and 10 MHz offset. The radio frequency front-end consumes only 96 ㎼ dc power from a 1-V supply.

• Journal of Digestive Cancer Research
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• v.4 no.2
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• pp.113-121
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• 2016

Background: We evaluated technique of hepatic resections using suprahilar-extrafascial dissection of Glissonean pedicle with vascular stapling device for pedicle transection with intent to minimize operative time and blood loss. Methods: We analyzed the clinical records of 326 patients who underwent anatomic liver resection by suprahilar-extrafascial pedicle isolation with vascular stapling division technique. Results: The minor liver resections were associated with significantly shorter surgery duration (105.1±21.1 vs. 225.6±75.6) and transection time (40.1±14.5 vs. 96.3±55.2) than major hepatectomies (p<0.0001 for all). The mean blood loss was 350.8±100.5 mL in minor resection and 485.4±250.2 mL in major resection (p=0.001). The mean blood transfusion requirement was 400.8±109.5 mL for minor resections and 550.9±100.0 mL for major hepatectomy (p=0.072). There was no significant difference in morbidity and mortality between groups (p=0.980; p=0.945). Major as well as minor liver resection were oncology superior with no significant difference in the 5-year overall survival rates. Conclusion: Suprahilar-extrafascial dissection of Glissonean pedicle represents an effective and safe technique of liver resection. Presented approach allows early and easy ischemic delineation of appropriate liver territory to be removed with selective inflow vascular control. It is not time consuming and it is very useful in re-resection, as well as oncological reasonable.

• Journal of the Korean Society of Radiology
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• v.84 no.4
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• pp.923-933
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• 2023

Purpose To evaluate the sensitivity of corticomedullary-phase imaging for detecting urinary stones in patients with renal colic who visited the emergency department. Materials and Methods This retrospective study included 253 patients with suspected renal colic from two tertiary hospitals in South Korea, who visited the emergency department and underwent CT urography. Two radiologists blinded to the clinical history independently reviewed the corticomedullary-phase images. The sensitivity for identifying urinary stones were evaluated for each reviewer. After the initial evaluation, the images were re-evaluated based on patient history. The sensitivity of re-evaluation were recorded. Results Of 253 patients, 150 (59%) had urinary stones. Among them, significant stones were observed in 138 patients (92%), and obstructive changes on CT in 124 patients (82.7%). For identifying significant urinary stones, the sensitivity was 98.6% (136/138) for both the reviewers. For identifying significant urinary stones with urinary obstruction, the sensitivity was 99.2% (123/124) for reviewer 1, and 100% (124/124) for reviewer 2. The sensitivity for identifying significant stones increased from 98.6% to 100% for reviewer 1, and from 98.6% to 99.3% for reviewer 2 in the re-evaluation session. Conclusion The corticomedullary-phase CT urography was sensitive for diagnosing urolithiasis in patients with acute renal colic who visited the emergency department.