• Asian Pacific Journal of Cancer Prevention
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• v.15 no.2
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• pp.707-712
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• 2014

Purpose: Anastomotic leakage (AL) is associated with high morbidity and mortality, high reoperation rates, and increased hospital length of stay. Here we investigated the risk factors for AL after anterior resection for rectal cancer with a double stapling technique. Patients and Methods: Data for 460 patients who underwent primary anterior resection with a double stapling technique for rectal carcinoma at a single institution from 2003 to 2007 were prospectively collected. All patients experienced a total mesorectal excision (TME) operation. Clinical AL was defined as the presence of leakage signs and confirmed by diagnostic work-up according to ICD-9 codes 997.4, 567.22 (abdominopelvic abscess), and 569.81 (fistula of the intestine). Univariate and logistic regression analyses of 20 variables were undertaken to determine risk factors for AL. Survival was analysed using the Cox regression method. Results: AL was noted in 35 (7.6%) of 460 patients with rectal cancer. :Median age of the patients was 65 (50-74) and 161 (35%) were male. The diagnosis of AL was made between the 6th and 12th postoperative day (POD; mean 8th POD). After univariate and multivariate analysis, age (p=0.004), gender (p=0.007), tumor site (p<0.001), preoperative body mass index (EMI) (p<0.001), the reduction of TSGF on 5th POD less than 10U/ml (p=0.044) and the pH value of pelvic dranage less than or equal to 6.978 on 3rd POD (p<0.001) were selected as 6 independent risk factors for AL. It was shown that significant differences in survival of the patients were AL-related (p<0.001), high ASA score related (p=0.036), high-level EMI related (p=0.007) and advanced TNM stage related

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07a
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• pp.316-318
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• 2003

양자우물 구조를 사용한 HEMT(High Electron Mobility Transistor)는 고속 스위칭 소자와 초고주파 통신용 소자 및 센서에에 우수한 동작특성을 갖고 있다. 본 논문에서는 AlInAs/InP HEMT의 heterostructure를 파동방정식과 Poisson 방정식을 self-consistent 한 방법으로 해석하였다. 파동방정식으로 junction의 전자농도를 계산하고, Poisson 방정식을 해석하여 potential profile에 의한 전자 농도가 heterostructure에서 self-consistent가 되도록 연산하였다. 끝으로 AlInAs/InP 구조에서 positively ionized donor, valance band에서의 hole, conduction band의 free electron과 구조내의 2DEG를 AlGaAs/GaAs 및 AlGaAs/InGaAs/GaAs와 비교하였다.

• Transactions on Electrical and Electronic Materials
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• v.9 no.2
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• pp.67-72
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• 2008

Al-doped p-type ZnO thin films were fabricated by RF magnetron sputtering on n-Si (100) and homo-buffer layers in pure oxygen ambient. ZnO ceramic mixed with 2 wt% $Al_2O_3$ was selected as a sputtering target. XRD spectra show that the Al-doped ZnO thin films have ZnO crystal structure. Hall Effect experiments with Van der Pauw configuration show that p-type carrier concentrations are arranged from $1.66{\times}10^{16}$ to $4.04{\times}10^{18}\;cm^{-2}$, mobilities from 0.194 to $198\;cm^2V{-1}s^{-1}$ and resistivities from 0.0963 to $18.4\;{\Omega}cm$. FESEM cross section images of different parts of a p-type ZnO:Al thin film annealed at $800^{\circ}C$ show a compact structure. Measurement for same sample shows that density is $5.40\;cm^{-3}$ which is smaller than theoretically calculated value of $5.67\;cm^{-3}$. Photoluminescence (PL) spectra at 10 K show a shoulder peak of p-type ZnO film at about 3.117 eV which is ascribed to electron transition from donor level to acceptor level (DAP).

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.5
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• pp.431-435
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• 2009

The apparatus has been fabricated using the laser diode and microprocessor unit. The apparatus used a InGaAlP laser diode for laser medical therapy and was designed for a pulse width modulation type to increase stimulation effects. To raise the stimulus effect of the human body, the optical irradiation frequency could be set up. The study has executed in-vivo experiment by employing our own developed laser diode irradiation system to investigate the effects of the InGaAlP laser diode irradiation on the wound healing as a preliminary study aimed at the application of InGaAlP laser diode to wound healing of human skin injury. The study cut out whole skin layers of Sprague-Dawley rat on the back part in 1 cm circle and observed developing effects after executing light irradiation for 9 days, and in result it is found that the light irradiation rat showed earlier wound healing than non-irradiation rat during the experimental period. In addition, there are some differences found regarding the healing process between laser diode irradiated rats and non-irradiated ones.

• Journal of Integrative Natural Science
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• v.2 no.4
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• pp.233-236
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• 2009

This study was undertaken to measure the electrochemical corrosion of amorphous $Zr_{65}Al_8Ni_{15}Cu_{12}$ (at.%) alloy ribbon under various conditions, including 0.4 mM HCl solution, and for various values of the pH and the immersion time. The corrosion potentials($E_{corr}$) for the amorphous $Zr_{65}Al_8Ni_{15}Cu_{12}$ alloy in 0.4 mM HCl decreased with increasing temperature; the corrosion current density($I_{corr}$) increased with increasing temperature in general. The polarization resistance($R_p$) was inversely proportional to the corrosion rate. While pH=7, 9, 11 was not as sensitive as pH=3, 5, pH=3 was more sensitive for amorphous $Zr_{65}Al_8Ni_{15}Cu_{12}$ alloy than other pHs specially. The change of mass in the 70 mM $H_2SO_4$ solution with immersion time was the greatest in the first 100 h.

• Applied Microscopy
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• v.26 no.1
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• pp.95-104
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• 1996

A comprehensive methodology to characterize the interfacial reaction products of $SiC_p/2024$ Al composites is introduced on the basis of the experimental results obtained using XRD, SEM and TEM. XRD performed on the electrochemically extracted $SiC_p$ and bulk $SiC_p/2024$ Al composite have shown that the interfacial reaction products consist of $Al_{4}C_3$ having hexagonal crystallographic structure, pure eutectic Si having diamond cubic crystallographic structure, and $CuAl_2$, having tetragonal crystalloraphic structure, respectively. According to the images observed by SEM, $Al_{4}C_3$, which has been reported to have needle shape, has a hexagonal platelet-shape and eutectic Si is found to have a dendritic shape. In addition eutectic $CuAl_2$, was observed to form near interface and/or along the grain boundaries. In order to confirm the results obtained by XRD, the primitive cell volume and reciprocal lattice height of such interfacial reaction products were calculated using the data obtained from convergent beam electron diffraction (CBED) patterns, and then compared with theoretical values.

• Journal of Korean Society of Water and Wastewater
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• v.30 no.2
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• pp.123-130
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• 2016

Phosphorus (P) removal by aluminum sulfate solution was investigated with varying pH and initial P concentrations. P removal was the highest at around pH 6. The pH range where P removal occurred was slightly wider at higher initial P concentrations. Compared to theoretical calculations, it was confirmed that $AlPO_4$ precipitation was the main reason for P removal at low pH. At high pH, where there should be no $AlPO_4$ precipitates, the P removal by adsorption of amorphous $Al(OH)_3$ precipitates was experimentally observed. The P removal by adding amorphous $Al(OH)_3$ precipitates prepared before the adsorption experiments, however, was lower than that by injecting aluminum sulfate solution because the prepared precipitates became larger, leading to less specific surface area available for adsorption. Ions other than sulfate had little influence on P removal.

• Proceedings of the IEEK Conference
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• 1998.06a
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• pp.401-404
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• 1998

Recently, InGaP/GaAs HBTs have been much interested as a potential replacement for AlGaAs/GaAs HBTs because of their superior device and material properties. In this paper, DC characteristics of InGaP/GaAs HBTs and the temperature dependance as well as the reliability were investigated comparing with AlGaAs/GaAs HBTs. As a results InGaP/GaAs HBTs produced the superior performance to AlGaAs/GaAs HBTs.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2004.11a
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• pp.67-70
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• 2004

역세척 후 응집제를 여과사에 주입한 수 여과를 실시한 결과 초기에 높게 나타났던 탁도의 거의 제거되는 것을 알 수 있었으며 pH의 변화에 따른 초기의 탁도 변화는 pH5와 pH7에서 보다 낮은 탁도의 수질을 얻을 수 있었다. pH5부근에서 알루미늄의 존재형태가 $Al(OH)^{2+},\;Al(OH)_2^+$로 많이 존재하며, pH7에서는 $Al(OH)_3$으로 존재하여 모래 표현의 (-) 전하를 감소시킬 수 있는 결과로 판단되었다.

• Journal of the Korean Vacuum Society
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• v.15 no.3
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• pp.294-300
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• 2006

We fabricated the distributed feedback (DFB) InP/InGaAs/InP grating structures on InP (100) substrates by metal-organic chemical vapor deposition, and their structural properties were investigated by atomic force microscopy and scanning electron microscopy. Self-assembled InAs/InAlGaAs quantum dots (QDs) were grown on the InP/InGaAs/InP grating structures by molecular beam epitaxy, and their optical properties were compared with InAs/InAlGaAs QDs without grating structure. The duty of the grating structures was about 30%. The PL peak position of InAs/InAlGaAs QDs grown on the grating structure was 1605 nm, which was red-shifted by 18 nm from that of the InAs/InAlGaAs QDs without grating structure. This indicates that the formation of InAs/InAlGaAs QDs was affected by the existence of the DFB grating structures.