• Journal of Chest Surgery
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• v.29 no.6
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• pp.626-631
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• 1996

The forty patients with carcirLoma of the esophagus or cardia seen at National Medical Center between November 1983 and April 1994 underwent surgical exploration. The esophagogastrectomy was carried out in 29 of 40 patients, one case through right thoracotomy, the others through left thoracotomy. Two patients underwent colon bypass surgeries due to upper esophageal cancer Transhiatal esop agectomy was performed In one case. Feeding gastrostomy or feeding jejunostomy were performed in 8 patients due to the advanced stage or malnutrition. In this report, we evaluated the long-term results in the 28 patients who underwent esophagogastrectomy for palliation through the left thoracotomy. There were 25 men(89%) and 3 women(11 %), and the mean age was 58.65$\pm$7.15 years(range, 46 to 73 years). The most frequent preoperative symptoms included dysphagia (22), weight loss (15), chest pain (6), vomiting (1), and hoarsness (1). Twenty-three patients had sqamous cell cancers of mid-and lower esophagus and five adenocarcionomas of cardia. One patient died in the hospital within 30 days of the op- eration for a hospital mortality rate of ).7%, Cause of death was sepsis due to anastomotic leakage. There were five additional complications in five patients; acute respiratory distress syndrome (1), post-op- erative bleeding (1), diaphragmatic hernia (1), acute renal failure (1) and late raft stenosis (1). The one year, 1틴o years, and three years acturial survival rate were 75.6$\pm$9.5%, 43.2$\pm$ 11.6%, 21.6: 10.5$\circledcirc$ re- spectively. The average survival was 21.8 months. The data from this study suggest that esophagogastrectomy through the left thoracotomy can achieve resonable long-term palliation for carci- noma of the esophagus. The operation can be performed with a low operative mortality and few serious postoperative complications.

• Journal of Gastric Cancer
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• v.15 no.4
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• pp.278-285
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• 2015

Purpose: Gastric submucosal tumors (SMTs) located very close to the esophagogastric junction (EGJ) are a challenge for gastric surgeons. Therefore, this study reports on the experience of using endoscopic and laparoscopic full-thickness resection (ELFR) with laparoscopic two-layer suturing in such tumors. Materials and Methods: Six patients with gastric SMTs very close to the EGJ underwent ELFR with laparoscopic two-layer suturing at Kyungpook National University Medical Center. With the patient under general anesthesia, the lesser curvature and posterior aspect adjacent to the EGJ were meticulously dissected and visualized using a laparoscopic approach. A partially circumferential full-thickness incision at the distal margin of the tumor was then made using an endoscopic approach under laparoscopic guidance. The SMT was resected using laparoscopic ultrasonic shears, and the gastric wall was closed using two-layer suturing. Thereafter, the patency and any leakage were checked through endoscopy. Results: All the ELFR procedures with laparoscopic two-layer suturing were performed successfully without an open conversion. The mean operation time was $139.2{\pm}30.9$ minutes and the blood loss was too minimal to be measured. The tumors from four patients were leiomyomas, while the tumors from the other two patients were gastrointestinal stromal tumors with clear resection margins. All the patients started oral intake on the third postoperative day. There was no morbidity or mortality. The mean hospital stay was $7.7{\pm}0.8$ days. Conclusions: ELFR with laparoscopic two-layer suturing is a safe treatment option for patients with an SMT close to the EGJ, as major resection of the stomach is avoided.

• Journal of Gastric Cancer
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• v.10 no.4
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• pp.241-246
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• 2010

Purpose: Laparoscopy-assisted gastrectomy (LAG) has become a technically feasible and safe procedure for early gastric cancer treatment. LAG is being increasingly performed in many centers; however, there have been few reports regarding LAG at low-volume centers. The aim of this study was to report our early experience with LAG in patients with gastric cancer at a low-volume center. Materials and Methods: The clinicopathologic data and surgical outcomes of 39 patients who underwent LAG for gastric cancer between April 2007 and March 2010 were retrospectively reviewed. Results: The mean age was 68.3 years. Thirty-one patients had medical co-morbidities. The mean patient ASA score was 2.0. Among the 39 patients, 4 patients underwent total gastrectomy and 35 patients underwent distal gastrectomy. The mean blood loss was 145.4 ml and the mean operative time was 259.4 minutes. The mean time-to-first flatus, first oral intake, and the postoperative hospital stay was 2.8, 3.1, and 9.3 days, respectively. The 30-day mortality rate was 0%. Postoperative complications developed in 9 patients, as follows: anastomotic leakage, 1; wound infection, 1; gastric stasis, 2; postoperative ileus, 1; pneumonia, 1; cerebral infarction, 1; chronic renal failure, 1; and postoperative psychosis, 1. Conclusions: LAG is technically feasible and can be performed safely at a low-volume center, but an experienced surgical team and careful patient selection are necessary. Furthermore, for early mastery of the learning curve for LAG, surgeons need education and training in addition to an accumulation of cases.

• Transactions on Electrical and Electronic Materials
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• v.8 no.2
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• pp.84-88
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• 2007

[ $Bi_{1.5}Zn_{1.0}Nb_{1.5}O_7$ ] (BZN), $Bi_2Mg_{2/3}Nb_{4/3}O_7$ (BMN), and $Bi_2Cu_{2/3}Nb_{4/3}O_7$ (BCN) pyrochlore thin films were prepared on $Cu/Ti/SiO_2/Si$ substrates by pulsed laser deposition and the micro-structural and electrical properties were characterized for embedded capacitor applications. The BZN, BMN, and BCN films deposited at $25\;^{\circ}C$ and $150\;^{\circ}C$, respectively show smooth surface morphologies and dielectric constants of about $39\;{\sim}\;58$. The high dielectric loss of the films deposited at $150\;^{\circ}C$ compared with films deposited at $25\;^{\circ}C$ was attributed to the defects existing at interface between the films and copper electrode by an oxidation of copper bottom electrode. The leakage current densities and breakdown voltages in 200 nm thick-BMN and BZN films deposited at $150\;^{\circ}C$ are approximately $2.5\;{\times}\;10^{-8}\;A/cm^2$ at 3 V and above 10 V, respectively. Both BZN and BMN films are considered to be suitable materials for embedded capacitor applications.

• Journal of the Korean Solar Energy Society
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• v.27 no.4
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• pp.113-120
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• 2007

The 5kWt dish solar collector is designed and the preliminary performance test for this is carried out. The diameter of the parabolic dish is 3.2 m, and its focal length is 2 m. It consists of 10 small reflectors which have their own curvatures, and the effective reflecting area is $5.9\;m^2$, and the rim angle of the dish is $43.85^{\circ}$. The reflectivity of reflectors is 0.95, and the thermal capacity of the system is about 5 kW thermal. The aperture diameter of the cylindrical-shape receiver which is made of stainless steel is 100 mm, and the height is 210 mm. A quartz window is installed at the receiver aperture to minimize the convective heat loss and prevent air leakage. In order to increase the heat transfer area, porous materials (nickel-alloy) are inserted into the receiver. Air flows into the upper part of the receiver which is the opposite side of the aperture. After the air flows through the inside of the receiver, that goes out of the receiver through 3 exits which are located near the aperture. The volumetric flow rates of air are varied from 600 to 1200 L/min. The results show that the system efficiency and receiver efficiency increase as the volume flow rate increases.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.19 no.2
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• pp.87-93
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• 2005

Recently, nuisance tripping or malfunction of MCCB(Melded Case Circuit Breaker) and ELB(Electrical Leakage Breaker) is being increased according as load circuits and equipments of electrical customers are various and complicated, but investigation of actual conditions on malfunction of MCCB and ELB was not implemented This paper investigated causes and influences of malfunction of MCCB and ELB by making up a question to electrical safety managers of two hundred and eighteen private electrical facilities. The results show that users above $70[\%]$ experienced malfunction of MCCB and ELB, and causes of malfunction are in order aging(above $25(\%)$), nuisance tripping $(above\;22(\%))$, goods badness$(above\;20(\%))$, abnormal power like as harmonics$(above\;20(\%))$ and others $(about\;9(\%))$. Also, second damages due to failure of MCCB and ELB are in order goods production, equipment trouble, information loss, business and operation interrupt, and others. The results of this study can be used in making decisions regarding causes of MCCB and ELB trip.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.03a
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• pp.21-21
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• 2010

(Ba,Sr)$TiO_3$ (BST) thin film with a perovskite structure has potential for the practical application in various functional devices such as nonvolatile-memory components, capacitor, gate insulator of thin-film transistors, and electro-optic devices for display. Normally, the BST thin films derived from sol-gel and sputtering are amorphous or partially crystalline when processed below $600^{\circ}C$. For the purpose of integrating BST thin film directly into a Si-based read-out integrated circuit (ROIC), it is necessary to process the BST film below $400^{\circ}C$. The microstructural and electrical properties of low-temperature crystallized BST film were studied. The BST thin films have been fabricated at $350^{\circ}C$ by UV-assisted rapidly thermal annealing (RTA). The BST films are in a single perovskite phase and have well-defined electrical properties such as high dielectric constant, low dielectric loss, low leakage current density, and high breakdown voltage. Photoexcitation of the organics contained in the sol-gel-derived films by high-intensity UV irradiation facilitates elimination of the organics and formation of the single-crystalline phase films at low temperatures. The amorphous BST thin film was transformed to a highly (h00)-oriented perovskite structure by high oxygen pressure processing (HOPP) at as low as $350^{\circ}C$. The dielectric properties of BST film were comparable to (or even better than) those of the conventionally processed BST films prepared by sputtering or post-annealing at temperature above $600^{\circ}C$. When external pressure was applied to the well-known contractive BST system during annealing, the nucleation energy barrier was reduced; correspondingly, the crystallization temperature decreased. The UV-assisted RTA and HOPP, as compatible with existing MOS technology, let the BST films be integrated into radio-frequency circuit and mixed-signal integrated circuit below the critical temperature of $400^{\circ}C$.

• Restorative Dentistry and Endodontics
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• v.16 no.1
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• pp.87-105
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• 1991

The purpose of this experiment was to measure the leaking and solubility of commonly used dental restorative materials - Silux plus (CS), Hi-pol (CH), Clearfil F-II, Fissureseal (FS), Glass-Ionomer cement Fuji Type II (GI), Amalgam Cavex 68 (AM), Zinc Phosphate Cement (ZP) and gutta-percha (GP) and investigate the relation between the solubility and marginal leakage. Disc-shape specimens were fabricated with each material and dipped into deionized water, 0.01M lactic acid and 0.005M KOH solution, thus the total ionic concentrations in each solution was measured with ion chromatograph after 1, 3, and 7 days, respectively. For the solubility test, each specimen was immersed in 0.001M and 0.01M lactic acid for 24 hours, respectively and total weight loss was calculated. Also, Zn leaking through the margin of restorations was measured. The obtained results were as follows: 1. The amounts of eluted ion from the eight materials were most in 0.01M lactic acid and least in deionized water. 2. Of the eight materials, the fluoride release was greatest for glass ionomer cement (GI) in 0.01 M lactic acid after 7 days. 3. In analysis of the divalent cation, Mg was eluted most for zinc phosphate cement (ZP) and Ca for Clearfil F-II (CF) in 0.01M lactic acid after 7 days. 4. In analysis of transition metals, Cu and Zn were detected only. 5. The solubility rate of eight materials was greater in 0.01M lactic acid than in 0.001M for 24 hours, for zinc phosphate cement (ZP) the rate was greatest (5.4%) in 0.001M lactic acid, and amalgam least (0.01%). 6. The Zn concentration of restorative material with Z.P.C base was greater in 0.01M lactic acid than in 0.001M lactic acid.

• Journal of Convergence for Information Technology
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• v.10 no.7
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• pp.7-13
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• 2020

IoT which is the core IT of the 4^th industrial revolution, is providing various services from users in the conversion with other industries. The IoT convergence technology is leading the communication paradigm of communication environment in accordance with the increase of convenience for users. However, it is urgently needed to establish the security measures for the rapidly-developing IoT convergence technology. As IoT is closely related to digital ethics and personal information protection, other industries should establish the measures for coping with threatening elements in accordance with the introduction of IoT. In case when security incidents occur, there could be diverse problems such as information leakage, damage to image, monetary loss, and casualty. Thus, this paper suggests a certificate management technique for safe control over access in IoT-based Cloud convergence environment. This thesis designed the device/user registration, message communication protocol, and device renewal/management technique. On top of performing the analysis on safety in accordance with attack technique and vulnerability, in the results of conducting the evaluation of efficiency compared to the existing PKI-based certificate management technique, it showed about 32% decreased value.

• JSTS:Journal of Semiconductor Technology and Science
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• v.14 no.6
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• pp.777-788
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• 2014

This paper presents a wide output range, high power efficiency reconfigurable charge pump for driving touch panels with the high resistances. The charge pump is composed of 4-stages and its configuration automatically changes based on the required output voltage level. In order to keep the power efficiency over the wide output voltage range, internal blocks are automatically activated or deactivated by the clock driver in the reconfigurable charge pump minimizing the switching power loss due to the On and Off operations of MOSFET. In addition, the leakage current paths in each mode are blocked to compensate for the variation of power efficiency with respect to the wide output voltage range. This chip is fabricated using $0.18{\mu}m$ BCD process with high power MOSFET options, and the die area is $1870{\mu}m{\times}1430{\mu}m$. The power consumption of the charge pump itself is 79.13 mW when the output power is 415.45 mW at the high voltage mode, while it is 20.097 mW when the output power is 89.903 mW at the low voltage mode. The measured maximum power efficiency is 84.01 %, when the output voltage is from 7.43 V to 12.23 V.