• 한국항해항만학회지
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• 제35권2호
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• pp.173-178
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• 2011

This study determined the ship replacement life expectancy from an economic perspective. There are many ambiguities in the cost for calculation of economic lifespan, and these were expressed as fuzzy numbers. Also, a fuzzy cost model using fuzzy numbers was developed and suggested as a more practical analysis method than the existing cost model. And the suggested fuzzy model was used to determine the economic lifespan for various types of container ships. As the result, Without fuzziness, the economic lifespan of 5000 TEU Ships was found to be 19 years. it was found that the greater the container ship, the greater the economic lifespan was.

• 한국운동역학회지
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• 제32권2호
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• pp.56-68
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• 2022

Objective: The purpose of this systematic review and meta-analysis was to investigate potential effects of HRT (hormone replacement therapy) on motor functions in postmenopausal women. Method: In this meta-analysis, 19 studies that examined changes in motor functions between postmenopausal women with and without HRT intervention were qualified. We additionally conducted moderator variable analyses including: (1) motor function type, (2) hormone type, and (3) duration of HRT intervention. Results: The random effects model showed no significant overall effects (SMD = 0.199; SE = 0.115; 95% CI = -0.026~0.425; Z = 1.730; p = 0.084; I² = 93.258%). Additional three moderator variable analyses revealed no significant effect sizes indicating that specific HRT protocols did not improve different motor functions in postmenopausal women. Conclusion: These meta-analytic findings suggest that HRT had no positive effects on motor functions in postmenopausal women.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 봄 학술발표회 논문집
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• pp.267-270
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• 2003

This study is intended to investigate the engineering properties of concrete, in which cement and fine aggregate are replaced with cement kiln dust(CKD), such as the properties of fresh concrete and hardened concrete and hydration heat history, for effective using method of CKD, a by-product produced in the process of making cement. According to the results, as the replacing ratio of CKD increases, slump and air content of concrete decreases remarkably due to an increase of viscosity and filling of the pores. As the properties of setting, initial and final setting time are shortened with an increase of the replacing ratio of CKD, and as the replacement of CKD for fine aggregate increases, setting time is shortened more greatly. Compressive strength increases due to filling of the pores and reduction of air content in comparison with plain concrete. When the replacement ratio of CKD for cement is 10% and 15%, peak temperature of hydration heat lowers slightly, but it goes up in the case of replacement of CKD for fine aggregate. Also, when cement and fine aggregate is replaced with CKD by 2.5% and 7.5% respectively(1C3S) in the case of replacement of CKD for cement and fine aggregate, it is highest.

• Journal of Chest Surgery
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• 제26권12호
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• pp.909-914
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• 1993

Complete and optimal visualization of the mitral apparatus is a prerequisite for accurate repair or replacement of the mitral valve. A vertical left atriotomy just posterior to the interatrial groove is the most commonly used approach. However,exposure can be difficult under certain circumstances,such as small left atrium or reoperation. Other approaches have been advocated to deal with this difficult situations. We used an extended transseptal approach in 10 patients and good clinical results and excellent educational effects were obtained. The extended transseptal approach combines two semicircular atrial incisions circumscribing the tricuspid and mitral annuli anteriorly and superiorly,allowing exposure of the mitral valve by deflecting the ventricular side using stay sutures. The right atrium is opened anteriorly along the atrioventricular sulcus. The atrial septum is incised vertically through the fossa ovalis. Right atrial and septal incisions are joined at the superior end of the interatrial septum and extended across the dome of the left atrium to the left atrial appendage. The mitral valve was replaced in all 10 patients. Four of 10 patients had other simultaneous valve procedure: one had aortic valve replacement: 2 underwent tricuspid annuloplasty: 1 had aortic valve replacement and tricuspid annuloplasty. There was no hospital death and complication. Among the 5 patients who had atrial fibrillation preoperatively,4 had atrial fibrillation postoperatively,1 converted to sinus rhythm. The five patients who were in normal sinus rhythm preoperatively remained in sinus rhythm after replacement. A review of our results with this approach confirms the efficacy and safty of this method. So we recommanded this approach for routine mitral valve procedure,especially difficult situations,such as a small left atrium or the redo operation.

• 토지주택연구
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• 제2권2호
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• pp.189-194
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• 2011

동일 건축물의 지지력변화 구간이나 이질기초 부위에서 보강방법은 경험적이나 약식검토의 방법으로 처리되고 있으므로 이 문제를 보완하기 위해 해석적 기법에 의한 기초의 안정성을 판단하고 보완할 수 있는 방법을 제시하였다. 이질 기초지반의 치환에 의해 보강효과를 산정하기 위하여는 기초면 하부 지반의 깊이에 따른 영향계수를 고려한 지반강성 평가방법을 적용하여 치환지반의 효과를 판정하여야 한다. 이에 본 논문에서는 잡석치환과 콘크리트 치환에 의해 지반이 보강되는 효과를 나타내는 등가 지반반력계수를 손쉽게 산정할 수 있는 도표와 관계식을 제시하였다.

• Journal of Chest Surgery
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• 제56권5호
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• pp.359-361
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• 2023

Coronary ostium obstruction due to dislodgement of the prosthetic valve is a rare and life-threatening complication, and particular caution is required for sutureless aortic valve replacement (AVR) with concomitant valvular surgery. In general, coronary artery bypass surgery is performed when coronary ostium obstruction occurs after AVR, but other options may need to be considered in some cases. Herein, we present a case of coronary artery occlusion in an 82-year-old female patient who had undergone AVR and mitral valve replacement for aortic valve stenosis and mitral valve stenosis at the age of 77 years. A hybrid procedure involving redo AVR and percutaneous coronary intervention after left main coronary ostium endarterectomy was performed. To summarize, we present a case of hybrid AVR in a patient with coronary artery obstruction after AVR that was successfully managed using this method.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2008년도 추계학술대회 논문집
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• pp.216-219
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• 2008

As a future clean substitute energy, the Gas hydrate development projects are world widely carried out to prepare the shortage of petroleum and natural gas resources. The OIIP of gas hydrate is estimated approximately 10 Trillion LNG equivalent ton and it reaches almost the amount of 5 thousand years use for the world people. To develop the commercial production technology, several research projects like Malik and Alaska project have been carried by several advanced countries and teams, but nobody have succeeded it yet due to the technical problems and the high risks. The technologies developed up to now for the hydrate production are categorized to four methods, such as depressurization method, thermal recovery method, inhibitor injection method and replacement method. As these methods are highly related to the costs and the environmental problems, many other researches including the safety, environment and disaster prevention are actively fulfilled as well.

• 한국지반신소재학회논문집
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• 제11권2호
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• pp.11-20
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• 2012

미관통 SCP공법은 개량 대상지반인 연약점토층 밑에 존재하는 지지층까지 모래말뚝을 관통시키지 않고 미관통 상태 그대로 SCP를 지반 중에 조성하는 공법으로 본 연구에서는 저치환율인 경우 압밀도에 따른 미관통 SCP공법과 관통 SCP 공법을 병용한 복합지반의 압밀침하 거동을 수치해석을 통해 비교 하였다. 본 연구결과 관통 SCP지반의 침하특성은 압밀도에 상관없이 거의 일정하나 미관통 SCP지반의 침하특성은 압밀도가 감소하고 관통율($H_d/H$)이 감소할수록 상부점토지반의 침하량이 더 크게 증가되었다. 또한 미관통 SCP의 하단부에는 응력집중효과가 발휘되지 않았으며 응력분담비는 압밀도에 관계없이 거의 일정한 양상을 보였다.

• 대한임상독성학회지
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• 제7권2호
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• pp.150-155
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• 2009

Purpose: Extracorporeal elimination of drugs is a critical part of managing poisonings, although the indications and optimal method remain a matter of debate. The aim of this study is to report our clinical experiences with continuous renal replacement therapy (CRRT), as performed by emergency room physicians, as method of extracorporeal drug elimination in patients with poisoning. Methods: This study was a retrospective study of the consecutive patients who underwent CRRT, as performed by an emergency room physician, for acute poisoning. The patient characteristics, the kinds of drugs and the method of extracorporeal elimination were analyzed by reviewing the patients' charts. Results: During eleven months, 26 patients with acute poisoning underwent extracorporeal elimination (2 patients; intermittent hemodialysis, 24 patients; CRRT). The mean time from the decision to performing extracorporeal elimination was $206.0{\pm}36.8$ minutes for intermittent hemodialysis, $62.9{\pm}8.5$ minutes for continuous venoveno-hemodiafiltration (CVVHDF) and $56.6{\pm}6.8$ minutes for charcoal hemoperfusion. For the patients with CRRT, CVVHDF was conducted in 10 patients (3 patients; valproic acid, 2 patients; Lithium, 1 patient; salicylates, 1 patient; methanol) and charcoal hemoperfusion by using CRRT was done in 14 patients (13 patients; paraquat, 1 patient; dapsone). For the 12 patients who required hemodialysis due to severe poisoning, 7 patients underwent CRRT because of their unstable vital signs. Conclusion: CRRT was an effective method of extracorporeal drug elimination in patients with acute poisoning, and especially for the cases with unstable vital sign and for those patients who required an early start of extracorporeal elimination according to the characteristics of the drug. (ED note: the writing of the abstract was not clear. Check it carefully.)

• Advances in concrete construction
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• 제11권5호
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• pp.409-417
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• 2021

The incorporation of non-biodegradable tyre waste in cement-based material has gained more interest towards sustainable construction these days. Crumb rubber (CR) from waste tyre is an alternative for sand replacement in low strength applications. Many researchers have studied CR cement-based materials produced by normal mixing (NM) method and reported a significant decrease in compressive strength due to CR. To compensate this strength loss, this research aims to study the innovative incorporation of CR in cement composite via the preplaced mixing (PM) method. In this investigation, cement composite was produced with NM and PM methods by replacing sand with 0%, 50%, and 100% CR by volume. The test results showed no significant difference in terms of densities of cement composite prepared with both mixing methods. However, cement composite prepared with PM method had lower strength reduction (about 10%) and lowered drying shrinkage (about 20%). In addition, the sound absorption coefficient and noise reduction coefficient of CR cement composite prepared by PM method were in similar range as those prepared with NM method. Overall, the results demonstrate that the PM method is promising, and the maximum replacement level of 50% is recommended for CR in the cement composite.