• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.1
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• pp.1-10
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• 2016

In this paper, an analysis of the inflowing pollution load of the rivers in Hampyeong bay showed the average organic matter pollution loads of BOD, COD, and TOC to be 79.7 kg-BOD/day, 144.06 kg-COD/day, and 93.0 kg-TOC/day, respectively. The inflowing organic matter pollution load was the heaviest in Sonbul dike, followed by Jupo bridge and Yangman complex. With regard to season, the load characteristics were outstanding in July, the rainy period in the summer. The average inflowing pollution loads of nutrients were 20.9 kg-DIN/day, 17.1 kg-DIP/day, 148 kg-TN/day, and 37.4 kg-TP/day A comparison of the inflowing nutrients loads for each river showed the load to be the heaviest in Yangman complex, followed by Baegok bridge and Jupo bridge. In the experiment on the material budgets of Hampyeong bridge conducted using a box model, the detention time of fresh water was found to be 52.4 days, with the bay displaying the characteristics of a so dissolved inorganic nitrogen (DIN) in the nutrients material budgets, ${\Delta}DIN$ values were found to be negative, indicating the tendency of consumption and open sea leak by photosynthesis to be higher than the nitrogen that flowed in. As for dissolved inorganic phosphorus (DIP), ${\Delta}DIP$ showed positive values, indicating a tendency for accumulation as the supply through organic matter decomposition, elution load of sediments, and inflowing load of the river turned out to be higher than the consumption by phytoplankton and outflow to open sea.

• Journal of Chest Surgery
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• v.37 no.2
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• pp.146-153
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• 2004

As the experience of coronary artery bypass grafting (CABG) has been accumulated, the number of reoperation after CABG is increasing. We analyzed our clinical experience of redo-CABG. Material and Method: Fourteen patients who underwent redo-CABG between Jan. 1994 and Dec. 2002 were included in this study. The mean period from the first operation to reoperation was 66$\pm$56 (3∼157) months, and the average ages were 62.8$\pm$8.7 (51∼78) years. The survivors were followed up 39$\pm$29 (4∼101) months postoperatively. Indications of reoperation were stenosis or occlusion of previous grafts in 11 patients, progression of native coronary artery disease in one patient, and both etiologies in two patients. Result: There were two in-hospital mortalities (14.3%) resulting from low cardiac output syndrome, Postoperative morbidities were perioperative myocardiac infarction in 2 patients (14.3%), mediastinitis in one patient (7.2%), duodenal perforation in one patient, ischemic necrosis of the lower extremity in one patient, gastric perforation after mesenteric infarct in one patient, delayed brain infarct in one patient, and intraoperative splenic rupture in one patient. There was one late mortality at six months postoperatively during the follow up. There was no angina recurrence during the follow up. Conclusion: Although redo CABG demonstrated relatively high operative mortalities and morbidities, postoperative status and clinical outcome of the survivors were favorable.

• Korean Journal of Clinical Pharmacy
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• v.24 no.1
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• pp.26-32
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• 2014

Purpose: The aim of this study was to investigate drug prescription patterns for the treatment of asthma and chronic obstructive pulmonary disease (COPD) patients in Korea. Methods: Ambulatory adult patients who were diagnosed and received treatment for the asthma (ICD-10 code J45) or COPD (ICD-10 code J44) from January 2009 to September 2011 in two independent secondary hospitals in Korea were enrolled in this study. Prescribed drug lists were generated based on the evidence-based guidelines and prescribed drug dosage forms were identified from the patient medical records and computerized drug prescription databases of the study centers. Results: Total numbers of asthma and COPD patient enrolled in this study were 2,432 and 2,615, respectively. Individual prescription-based accumulated numbers of patient were 12,021 for asthma and 16,584 for COPD. The most commonly prescribed three drugs were oral predisolone, oral formoterol and oral montelukast for asthma and oral formoterol, oral doxofylline and inhaled tiotropium for COPD. Frequencies of oral drugs were 83.4% and 63.3% while inhalers were 16.4% and 30.2%, for asthma and COPD, respectively. Conclusion: The oral treatment was prescribed more in asthma and COPD patients than inhalers. To enhance the compliance of evidence-based guidelines for these chronic airway diseases, more realistic and specific strategies to increase the use of inhalers recommended as primary treatment options for asthma and COPD would be required.

• Korean journal of communication and information
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• v.60
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• pp.52-74
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• 2012

Legislation needs to be understood within a political, societal relationship among lawmaking bodies rather than by legal provision itself. In order to examine features and functions of communication in the process of legislation, this study conducted focus group interviews with experts as well as in-depth individual interviews. The result of this research as follows: First, the study found that although the domestic legislative process has been made by active interactions among lawmaking subjects, it was hard to conclude that this procedure is providing effective and productive legislative agenda because of chaotic communications made along the process. Second, the study found that national legislative process has been gradually moving, although restricted, to an open political space, the National Assembly, from a closed space, the executive branch. Third, the study found a remarkable feature including growing influence of experts groups and civic organizations in the legislative process. It is a significant change that legislative staff such as National Assembly aides, investigators, expert committeemen and deputy director generals played a role of "insiders," unnoticeably influencing the legislative process, and that civic organizations and NGOs, which have been excluded in the previous legislative processes, emerged as a new influencing circle in the process. Lastly, the study found that media organizations, in the process of developing agenda, had a strong impact on the National Assembly as a subject forming public issues and as a messenger of the legislative agenda while they played a limited role in affecting the government. This study discusses why communication in the domestic legislative process is important and what are some hindering and facilitating factors in the process.

• Advances in pediatric surgery
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• v.17 no.1
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• pp.15-22
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• 2011

Meconium obstruction (MO) in neonates arises from highly viscid meconium and the poor motility of the premature gut. Recently the incidence of the MO in neonates has been Increasing, but, the diagnosis and treatment of this disease have not yet been clarified. Between March 2004 and April 2010, 24 neonates were treated for MO at Severance Children's Hospital. Their clinical characteristics and treatment were reviewed retrospectively. Twenty neonates were diagnosed with MO and 4 neonates were diagnosed with Hirschsprung's disease (HD). The mean birth weight and gestational age of the 20 neonates with MO were $1.45{\pm}0.90kg$ and $31.1{\pm}4.6$ weeks, respectively. Thirteen neonates (65 %) diagnosed with MO weighed less than 1.5 kg and 10 neonates (50 %) weighed less than 1 kg. Half of the neonates with MO were treated by non-operative methods and the other half were treated by operative methods. Compared with the group that weighed over 1.5 kg, the group that weighed less than 1.5 kg were more frequently operated upon (61.5% vs. 28.5%), and contrast enemas were performed later and more frequently. Also the group that weighed less than 1.5 kg had a higher mortality rate (15.4% vs. 0%). Three of the four neonates with HD were diagnosed with long-segment aganglionosis. In conclusion, MO occurred in very low birth weight neonates more often and must be differentiated from HD. Also, MO in very low birth weight neonates should be treated with special attention due to more a complicated clinical course.

• Journal of Broadcast Engineering
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• v.25 no.4
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• pp.475-486
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• 2020

This paper is a thesis on media art technology for high-tech performances and exhibitions. After creating an interactive stroke in VR, it is projected in real time through a media facade technique. Among our traditional dramas emphasizing linear movements, movements were extracted from the Bongsan mask dance, and the movements of the lines were used in a media art performance called 'Multi-face Convergence'. When motion data enters the virtual space, geometry consisting of faces is created in the VR space. The created strokes can be set with various brush types, and when performing, a stroke with a red fire effect that matches a dynamic movement was used. It was made to be able to harmonize with the dancers performing the Bongsan mask dance. The medium called VR has characteristics that are not suitable for melting into a performance, but in this performance, it has overcome its limitations by using a technique called media façade. We propose the world's first performance technique that combines interactive strokes with traditional dance performances.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.46 no.3
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• pp.197-209
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• 2018

In this study, numerical analyses on Quad Tilt Rotor(QTR) are carried out to investigate the interference effect of components and effect of operating condition during forward flight. Actuator Surface Method(ASM) which is implemented in an open source CFD code, OpenFOAM, is used to calculate the flow field around QTR with high computational efficiency. The lift of the front and rear wing is found to increase or decrease depending on the rotation direction of the rotor. At the rear wing, the interference effects of the front and rear rotor appear as a combined manner. Performance change due to the phase difference is found to be insignificant. For both rotors, the locally higher thrust is generated by the blockage effect of the wing. The interference effect of wake from the front nacelle contributes to higher local thrust for the rear rotor compared to the front rotor. And it is observed that the amplitude of thrust oscillation can decrease depending on the phase difference between the rotors. Aerodynamic performances of both rotors and the entire aircraft were compared and analyzed for various operating conditions.

• Journal of Bio-Environment Control
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• v.7 no.1
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• pp.9-14
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• 1998

Air current speeds were controlled of 0.3, 0.5, 0.7 and 0.9 m.s$^{-1}$ to investigate the effects of air current speeds on the growth of eggplant plug seedlings (Solanum melongena L.) in a wind tunnel under artificial lighting. Growth of plug seedlings was influenced by the magnitude of air current speed and the traveling distance of regulated air flow. Stem length. ratio of length to diameter in stem, plant height .and number of leaves of plug seedlings decreased with the increasing air current speed and were significantly different at 5% level. Net photosynthetic rates of plug stand increased with the increasing air current speed and took a maximum value at the air current speed of 0.7~09 m.s$^{-1}$ . Stem diameter decreased and leaf area increased with the traveling distance of regulated air flow. Fresh weight and T/R ratio of dried weight were not influenced by the air current speed. Optimum control for microclimates inside the plug stand is needed to produce the uniform growth and high quality of plug seedlings in a semi-closed plant Production system under artificial lighting.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.318-318
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• 2011

자연수를 가압(4~5기압)하면서 물과 공기의 비를 4:1~3:1로 혼합하면 수체 내 초미세기포(Diameter $3{\sim}10{\mu}m$)가 발생하는데 이를 산소용해수라 하며 수질정화시설 또는 양식장 등에 널리 사용되고 있다. 산소용해수의 특징은 기포의 비표면적이 넓고 10시간 이상 포화 농도를 유지하여 수체에 잔류하는 시간이 길기 때문에, 일반 산기석을 활용한 포기나 순산소 용해 등의 타 방법과 구별된다. 산소용해수의 산소전달효율은 기존 방법과 큰 차이를 보이기 때문에 실제 적용시에는 대상수를 이용하여 산소전달계수($K_{L}a$)를 사전에 산정할 필요가 있다. 본 연구에서는 한국건설기술 연구원의 안동 수자원 환경실험센터 내 실외형 콘크리트 사각반응수조에 산소용해장치 및 확산장치를 결합한 일체형 시스템을 적용시켜 2010년 9월~2011년 1월의 5개월간 결과를 분석, 본 장치의 $K_{L}a$를 산정 후 수질정화의 활용 면에서 검토하였다. $K_{L}a$의 산정에는 다양한 방법이 이용되나 용존 산소 농도의 제어에 한계가 있는 실외 대형실험장에 적합한 Lewis and Whitman의 Two-film 이론에 근거한 정상포기법을 적용하였다. 체적 $80m^3$의 수조 내에서 현장 유지용수를 대상으로 실험한 결과 산소전달계수는 $0.324\pm0.050$/min, 포화농도는 8.64 mg $O_2$/L, 도달시간은 11 /min이 산정되었으며, 이는 기존 산기석 포기의 산소전달계수 범위인 $0.105\pm0.019$ /min보다 약 3.1배 높은 결과를 보였다. 또한, 확산장치의 수류 순환 방향 및 정도를 검토하기 위하여 실험수조에서 1m단위로 격자를 구성한 후 초음파 유속계로 실측한 결과 0.0~2.5 m/s 의 평면적 유속범위를 도출하였다. 그리고 전체 순환을 고려했을 때 용존산소는 약 8시간 후 8.64 mg $O_2$/L 값에 도달하여 안정화 되었으며, 강한 수류순환과 산소용해수에 의해 하상에 존재하는 퇴적물들의 이송 및 산화촉진을 유도하였다. 이를 근거로 실험수조의 체적과 기준 가동시간인 8시간을 적용시켰을 때, 실험구 수질은 대조구와 비교하여 COD, T-N, T-P가 모두 25~35% 개선되었다. 이 결과는 여과공정 없이 단순 순환만을 고려한 물리적 수질정화 방법의 단독 활용 가능성을 나타내며, 기존 연구에서 나타난 SOD (Sediment oxygen demand) 저감 능력을 감안할 때 향후 폐쇄성 수역의 수질관리에도 효율적으로 활용할 수 있음을 시사한다.

• Proceedings of the Korean Society for Rock Mechanics Conference
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• 2008.03a
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• pp.79-88
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• 2008

Since the hydraulic fracturing field testing method was introduced first to Korean geotechnical engineers in 1994, there have been lots of progresses in a hardware system as well as an interpretation tool. The hydrofracturing system of first generation was the pipe-line type, so it was not easy to handle. It had been modified to a wire-line system at their second generation. It was more compact one but it also needed an additional air-compressor. Our current system is much more compact and operated by all-in-one system, so it doesn't need an additional air-compressor. With a progress in a hardware system, the software for analyzing the in-situ stress regime has also been progressed. For example, the shut-in pressure, which is the most ambiguous parameter to be obtained from hydrofracturing pressure curves, can now be acquired automatically from the various methods. While the hardware and software for hydrofracturing tests are being developed during the last decade, the author could accumulate the field test results which can cover the almost whole area of South Korea. Currently these field data are used widely in a feasibility study or a preliminary design step for tunnel construction in Korea. Regarding the difficulties in a site selection and a test performance for the in-situ stress measurement at an off-shore area, the in-situ stress regime obtained from the field experiences in the land area can be used indirectly for the design of a sub-sea tunnel. From the hydrofracturing stress measurements, the trend of magnitude and direction of in-situ stress field was shown identically with the geological information in Korea.