• Journal of Radiation Protection and Research
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• 제43권3호
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• pp.107-113
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• 2018

Background: The purpose of our study was to compare the dosimetric advantages of Flattening filter free (FFF) beams for trigeminal neuralgia patients using 4 mm conical collimators over previously treated patients with 6 MV SRS beam. Materials and Methods: A retrospective study was conducted for 5 TN patients who had been previously treated at our institution using frame-based, LINAC-based stereotactic radiosurgery (SRS) on Novalis Tx using 6 MV SRS beam were replanned on 6X FFF beams on Edge Linear accelerator with same beam angles and dose constraints using 4 mm conical collimator. The total number of monitor units along with the beam on time was compared for both Edge and Novalis Tx by redelivering the plans in QA mode of LINAC to compare the delivery efficiency. Plan quality was evaluated by homogeneity index (HI) and Paddick gradient index (GI) for each plan. We also analyzed the doses to brainstem and organ at risks (OARs). Results and Discussion: A 28% beam-on time reduction was achieved using 6X FFF when compared with 6X SRS beam of Novalis Tx. A sharp dose fall off with gradient index value of $3.4{\pm}0.27$ for 4 mm Varian conical collimator while $4.17{\pm}0.20$ with BrainLab cone. Among the 5 patients treated with a 4 mm cone, average maximum brainstem dose was 10.24 Gy for Edge using 6X FFF and 14.28 Gy for Novalis Tx using 6X SRS beam. Conclusion: The use of FFF beams improves delivery efficiency and conical collimator reduces dose to OAR's for TN radiosurgery. Further investigation is warranted with larger sample patient data.

• Archives of Plastic Surgery
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• 제39권1호
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• pp.55-58
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• 2012

We experienced satisfactory outcomes by synchronously transplanting an artery and vein using an anterolateral thigh flap pedicle between the vascular pedicle and recipient vessel of a flap for scalp reconstruction. A 45-year-old man developed a subdural hemorrhage due to a fall injury. In this patient, the right temporal cranium was missing and the patient had $4{\times}3cm$ and $6{\times}5cm$ scalp defects. We planned a scalp reconstruction using a latissimus dorsi free flap. Intraoperatively, there was a severe injury to the right superficial temporal vessel because of previous neurosurgical operations. A 15 cm long pedicle defect was needed to reach the recipient facial vessels. For the vascular graft, the descending branch of the lateral circumflex femoral artery and two venae comitantes were harvested. The flap survived well and the skin graft was successful with no notable complications. When an interposition graft is needed in the reconstruction of the head and neck region for which mobility is mandatory to a greater extent, a sufficient length of graft from an anterolateral flap pedicle could easily be harvested. Thus, this could contribute to not only resolving the disadvantages of a venous graft but also to successfully performing a vascular anastomosis.

• 논리연구
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• 제21권3호
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• pp.373-393
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• 2018

조작논증은 근원-자유와 결정론이 양립가능하지 않다는 것을 보이고자 한다. 이 논증에 따르면, (1) 일정한 방식으로 조작된 행위는 직관적으로 자유행위가 아니며 (2) 일정한 방식으로 조작된 행위와 결정론적으로 발생한 일상적 행위 사이에 중요한 차이가 없다. 이로부터 결정론적으로 발생한 일상적 행위는, 그것이 양립가능주의자들이 제시한 자유의 조건을 만족하더라도, 자유행위가 아니라는 것이 도출된다. 양립가능주의자들의 대표적인 대응인 '강경한 대응'은 (1)을 부정한다. 그런데 '중립적 입장'에서 볼 때 이 대응은 불충분한 것으로 밝혀진다. 그리고 (1)은 일종의 심리적 오류를 저지른다는 최근의 제안도 이를 극복하지 못한다고 주장한다. 반면 '온건한 대응'은 (2)를 부정한다. 이 대응을 지지하기 위해 먼저 조작적 개입과 단순한 결정 사이의 차이를 밝힌다. 그리고 온건한 대응과 조작논증이 특정한 상황에 대해 서로 다른 예측을 한다는 점에 주목할 때 이 대응을 지지할 이유가 있다고 주장한다.

• 산업기술연구
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• 제22권A호
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• pp.119-125
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• 2002

In Kwangjin industrial company, mill is operating for the foundry sand production at the rate of 25t/hr from quartzite. Foundry sands fall into four distinct categories: silica sand, lake sand, bank sand, and natural molding sand. Silica sand is a general term used to describe crushed, washed, graded, dried, and cooled clay-free sands. This study was conducted for the investigation of the foundry sand productivity and the life span of the hammer according to the material quality. The life time of hammer from several manufacturer were compared in order to find out the grinding efficiency of the various hammer material. In the result of tests, the life time of high-Mn hammer was 10.5 hours while that of high-Cr was 19.5 hours. The life time in case of typical worn shape hammers was about 12 hours and the average time of a blowhole hammer was about 6.5 hours.

• 한국생산제조학회지
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• 제21권2호
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• pp.337-343
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• 2012

This work investigates the vibrational characteristics of the underground gas pipelines. Experiments were conducted to analyze the effects of various parameters on the vibrational characteristics from the emergency detection point of view. Influences of the various types of impact exerted on the pipe, height of free fall and measuring locations were analyzed. Especially, the difference between the vibrational signal generated by the direct impact on the pipe and the ambient noise was successfully identified. To validate the experimental observation, computer simulation was also performed with constant properties(elasticity, fluid velocity and internal pressure) which are directly conjectured from the accompanying experiment with a real pipe system.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 1998년도 유체기계 연구개발 발표회 논문집
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• pp.115-120
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• 1998

Aerodynamic noise generated by automobile cooling fan is investigated. Automobile cooling fans radiate both discrete frequency noise as well as broadband noise. In the present work, the former is considered through free-wake panel method coupled with acoustic analogy fully considering the retarded time variation on the blade surface, while the latter is taken into account by three well-established broadband noise components. Experiments were performed to supplement necessary inputs as well as to provide the final comparison with the predicted noise spectrum. The predicted noise levels at blade passing frequencies agree well with the experimental data for the first few harmonics. Although the predicted broadband noise levels at higher frequencies fall below the experimental data due to the fundamental shortcomings of the utilized formulations, the analysis offers a detailed physical understanding of the fan noise generation processes.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2002년도 춘계학술대회 논문집
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• pp.204-208
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• 2002

Mooring is the operation of securing a ship to a wharf or quay by means of rapes or chains. A. moored ship need not necessarily be truly stationary. It may be free to rise and fall with the tick or the loading and unloading of cargo or to oscillate in response to the action of the environmental forces. In this respect a moored ship is restricted to a limited amount of movement within well-defined bounds. This study is intended to analyze the tension of mooring lines by a FEM program, as the current velocities and working directions are varied. The motion of a berthed ship is studied concerning with the wave periods and the direction. Also the behavior of the modeled vessel are investigated for a berthed condition.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2009년도 추계학술발표논문집
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• pp.414-417
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• 2009

재즈의 역사가 이제 100년이 조금 넘은 상태에서 많은 재즈 뮤지션 중 Miles Davis라는 한 인물이 걸어 왔던 음악적 발자취를 재확인하며 Cool Jazz와 Free Jazz등 현대 음악에 많은 영향을 미치고 있는 당시 흐름과 그 안에서 Miles Davis의 위치를 재검토한 결과 기존의 일반적인 사실과 다른 해석이 가능함을 발견하고 그의 음악적 위치를 재즈의 큰 흐름 안에서 재조정하게 되었다. 당시 음악으로서는 획기적일 수밖에 없을 '모드 방식'의 접근과 재즈음악에서 전환점이 있을 때마다 그 중심축으로서의 Miles Davis를 발견하게 되는데 사실상 현대 재즈에까지 연결되는 그의 음악적 성과는 엄청나다고 할 수 있다. 이 연구를 토대로 재즈 역사상 가장 영향력을 가지고 있는 Miles Davis를 다시 돌아 볼 수 있는 기반을 제시 하고자 한다.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2010년도 추계학술발표논문집 2부
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• pp.559-563
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• 2010

황해경제자유구역은 환황해권 첨단기술의 국제협력 거점 조성이라는 비전과 국제수준의 첨단기술산업 클러스터 육성, 대 중국 수출입 전진기지 및 부가가치물류 육성을 목적으로 2007년 지정되어 사업이 추진 중에 있다. 황해경제자유구역 반경 15km 이내에 7개의 산업단지가 입지하고 있어 충남 서북부지역의 산업집적도는 날로 증가하고 있는 추세이다. 그러나 이를 지원할 주요 인프라 중 하나인 물류단지 시설은 전무한 실정이며 황해경제자유구역을 포함한 충남 서부지역의 물류거점 개발은 매우 미약하다. 본 연구의 목적은 첫째, 서해안 지역 물류거점 단지 조성의 필요성을 검토하고, 둘째, 물류단지 규모 및 성격을 부여하며, 셋째, 물류단지 도입기능을 설정하고자 한다. 연구목적을 달성하기 위해 물동량 수요예측과 주변지역 연계방안을 토대로 황해경제자유구역의 배후물류단지의 필요성과 조성방안을 제안하고자 한다.

• Journal of Chest Surgery
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• 제27권7호
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• pp.571-575
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• 1994

The hemodynamic effects of thyroid hormone are well established, and this hormone affects myocardial contractility, heart rate, and myocardial oxygen consumption. But the role of cardiopulmonary bypass on the thyroid function is not yet fully understood. We have studied twelve patients [male and female patients were equal in number] who were performed open heart surgery under cardiopulmonary bypass. The results are followed. 1] The serum level of T3 began to fall after cardiopulmonary bypass and sustained significantly till 24 hours after operation[p<0.05] 2] The concentrations of T4, Free T4, and TSH were slightly decreased after cardiopulmonary bypass but was maintained within normal range. 3] This above findings are similar to the "sick sinus syndrome" that is seen in severely ill patient. 4] We can propose that T3 would be effective in postoperative low cardiac output syndrome. syndrome.