• 대한기계학회논문집A
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• 제35권1호
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• pp.11-15
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• 2011

본 논문은 풍력터빈의 출력 제어 방법에 관한 논문이다. MW급 풍력 터빈 출력제어의 기본 제어 구조는 가변속도 가변피치 방식을 사용한다. 가변속도 가변피치 제어는 파워 커브를 추종하기 위한 방법으로서, 풍속변화에 따라 이 제어방식이 어떻게 적용되는지 논의한다. 제어 시스템 설계를 위하여 단순화된 드라이브 트레인 모델이 사용되었다. 제어 시스템은 토크제어와 피치제어로 구성되고, 제시된 동적 모델을 사용하여 설계된 제어 시스템의 시뮬레이션 결과에 대하여 논의한다.

• 대한기계학회논문집B
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• 제40권2호
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• pp.75-83
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• 2016

터보기계 내부 유동장은 역압력구배, 고속 유동으로 인해 매우 복잡하며, 이를 해석하기 위해 보다 정교한 난류 모델이 요구된다. 유동 해석을 위해 대수모델, 2-방정식 와점도 모델 등이 널리 사용되고 있으나, 매우 복잡한 유동을 모사하는데 어려움이 있다. 본 연구에서는 복잡한 유동에서의 예측성능이 우수하다고 알려진 Durbin의 V2-F난류 모델을 자체 개발 코드인 T-Flow에 적용하였으며, 채널 및 압축기 캐스캐이드 유동 해석 결과를 이용하여 난류 모델을 검증하였다. 또한 저속 압축기 동익 해석을 통해 터보기계 내부 유동에서의 적용 가능성을 판단하였다. 그 결과, V2-F난류 모델은 1-방정식, 2방정식 난류 모델보다 우수한 블레이드 표면 압력 분포 예측성능을 보였다.

• Journal of Plant Biotechnology
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• 제30권2호
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• pp.207-214
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• 2003

This study was carried out to establish a novel bioassay system for screening of compounds affecting aromatic amino acid or anthocyanin biosynthesis through investigating a degree of sucrose-induced anthocyanin formation such as size of plant material, buffer conditions, light intensity and irradiated duration, incubation temp., etc were determined and standard procedure (suitable experimental condition) was set up as follows. The second leaf blade of white corn seeding induced by fluridone treatment were segmented into a size of 5${\times}$5 min. The segments were floated on the solution of 1% sucrose in 1.0mM MES buffer (pH6.0∼6.5) and incubated at 26$^{\circ}C$ for 2days under the continuous light condition(70∼100$\mu$mol m$^{-2}$ s$^{-1}$ ). Anthocyanin in the purpled tissues was extracted with methanol containing 1% HCl and the optical density of the clear supematants was determined at 528mm. Influences of some chemicals were tested using this system. Glyphosate, 5-enolpyruvylshikimate 3-phosphate synthase inhibitor, showed most sensitive response with I$_{50}$ value at 3.3$\mu$M. Dicyclohexylcarbodiimide(DCCD) and parachloromercuribenzenesulfonic acid(PCMBS) had a relatively strong ingibition with I50 value at 7.1$\mu$M and 10.2$\mu$M, respectively. These results show that sucrose-induced anthocyanin formation in white com leaf segment provide a very simple and rapid system for searching new compounds affecting aromatic amino acid or anteocyanin biosynthesis by screening at less than 10$\mu$M.

• Archives of Plastic Surgery
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• 제36권1호
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• pp.122-125
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• 2009

Purpose: Stitching out in facial simple laceration on children, we use No.11 blade. But the procedure is technically demanded to take care of the uncooperative pediatric patient. When we suture a laceration on the pediatric patient, we apply this method using ribbon shaped knot. On stitching out, We pull one the edge of a stitching fiber easily without injury about normal tissue. Methods: We studied 54 pediatric patients who have facial lacerations for children under six years old, from May, 2006 to December, 2007 in Plastic Surgery department, emergency room. Among them 35 were male, 19 were female and age average was 3.9. Results: For following up dressing, ribbon shaped knot did not get loose. After stitching out in facial laceration on children, Major complication of infection, hematoma, dehiscence was not found. Conclusion: The advantage of this operation method using ribbon shaped knot when we Stitch out the fiber on the incorporative pediatric patients, is easy to perform and to reduce the stitching time, without sedation.

• 대한음성언어의학회:학술대회논문집
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• 대한음성언어의학회 2003년도 제19회 학술대회
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• pp.182-182
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• 2003

Objectives : The methods to treat glottic incompetence include thyroplasty type I, arytenoid abduction, and intracordal injection using various materials. The intracordal injection is easy and simple and does not require skin incision. In general, the grafted cartilage shows a high survival rate, a low absorption rate and small voluminous change. The authors performed injection of minced autologous auricular cartilage and fat using a Bruning injector in unilateral vocal cord palsy We evaluate the effect and safety of autologous auricular cartilage intracordal injection. Study Design : Retrospective study. Methods : Auricular cartilage was obtained by incising tragus vertically and it was minced with a scalpel and #15 blade. About 2g of abdominal fat was obtained by small periumbrical incision and cut into small pieces. The minced cartilage was put into a 1$m\ell$ injector and then the injector was filled with fat. The operation was conducted under laryngeal microscope. Minced cartilage was injected into the vocalis muscle at the junction of the middle and posterior third of the vocal fold. In three cases, we performed autologous cartilage intracordal injection. Results : We observed no postoperative complications, such as dyspnea, granulation, inflammation, in any of the cases. The voice was improved compared with the voice prior to operation in all cases. Conclusion : Although the cases are still limited and the observation period is short, we suggest that the autologous cartilage using the auricular cartilage is the ideal and new effective augmentative material in vocal cord palsy.

• Journal of Trauma and Injury
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• 제26권4호
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• pp.304-307
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• 2013

Food bolus impaction is the most common cause of esophageal foreign body obstruction in adults. Other causes include intentional ingestion in psychiatric patients or prison inmates. We experienced successful treatment of a patient with intentional ingestion of multiple sharp foreign bodies(25 cutter and razor fragments). A 47-year-old male patient who was suffering from chronic alcoholism was admitted, via the emergency room, with dysphagia and neck pain. He was suffering from alcoholic liver cirrhosis and psychiatric problems, such as chronic alcoholism, anxiety disorder and insomnia. The patient had intended to leave the hospital after having swallowed the sharp objects. Plain radiographs and computed tomography (CT) scan showed multiple, scattered metal fragments in the esophagus, stomach, and small bowel. We performed emergent endoscopy and successfully removed one impacted blade in the upper esophagus using by a snare with an overtube. The rest of the fragments had already passed through the pylorus, so we could not find them with endoscopy. We checked the patient with simple abdominal radiographs and careful physical examinations every day. All remaining fragments were uneventfully excreted through stool during the patient's 6 day hospital stay. Finally, we were able to confirm the presence of the objects in the stool, and radiographs were negative. The patient was discharged without complications after 14 days hospital stay and then was followed by the Department of Psychiatry.

• 한방안이비인후피부과학회지
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• 제30권2호
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• pp.165-169
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• 2017

Objectives : The aim of this study is to report the effect of surgical method after Bufonis Venenum Pharmacopuncture Anesthesia on epidermal cyst. Methods : A 49-year-old male was presented with a $1.5{\times}1.5(cm)$ sized epidermal cyst on the upper back. Local anesthesia was achieved with Bufonis Venenum pharmacopuncture. After 5 minutes, 2.5cm incision was made using 11th blade. To minimize bleeding, the laser($CO_2$ Hani-maehwa laser-surgical mode) was excised to the cyst wall. After incision, cyst were separated and removed using adson forceps and iris scissors. Then buried intradermal suture and simple interrupted suture were performed. Yeonkyopaedok-san was administered for 5 days for anti-inflammatory effects. After 10 days, the suture was removed after confirmation of skin adhesion. Results : Cyst size measured $1.0{\times}1.0{\times}1.0(cm)$. Until the suture is removed, Adverse effects were not reported. Conclusions : Bufonis Venenum pharmacopuncture applies to local anesthesia. Korean medicine cautery method applies to laser($CO_2$ Hani-maehwa laser). It can be considered that To expand the application of surgical treatment in korean medicine.

• 한방안이비인후피부과학회지
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• 제33권4호
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• pp.126-132
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• 2020

Objectives : The study is to report cases of open/closed types of epidermal cyst removed by surgical method with Bufonis Venenum pharmacopuncture. Methods : 2 patients were diagnosed each open/closed epidermal cyst. Local anesthesia was achieved with Bufonis Venenum pharmacopuncture. Incision was made using 15^th blade and the CO₂ Hani-maehwa laser. After cyst was removed, simple interrupted suture was performed. Eunkyo-san and Yeonkyopaedok-san were administered respectively for 7 days for anti-inflammatory effects. Results : Local anesthesia was maintained until epidermal cysts were clearly removed. The suture was removed after confirmation of skin adhesion. Adverse reactions were not reported. Conclusions : Epidermal cysts were removed surgically after Bufonis Venenum pharmacopuncture anesthesia and the risk of infection can be prevented by administering herbal medicines that have anti-inflammatory properties. It is difficult to visually diagnose closed type of epidermal cyst and then suggests that imaging equipment such as ultrasound is required.

• 대한조선학회논문집
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• 제50권1호
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• pp.1-7
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• 2013

The high-skewed and/or composite propellers of current interests to reduce the ship vibration and to increase the acoustic performance are likely to be exposed to the unexpected structural problems. One typical example is that the added mass effect on the propellers working in the non-uniform wake field reduces the natural frequency of the propeller leading to the resonance with the low-frequency excitation of the external forces. To avoid this resonance problem during the design stage, the technique of fluid-structure interaction has been developed, but the higher-order effect of the blade geometry deformation is not yet considered in evaluating the added mass effects. In this paper the fluid boundary-value problem is formulated by the potential-based panel method in the inviscid fluid region with the velocity inflow due to the body deformation, and the structural response of the solid body under the hydrodynamic loading is solved by applying the finite element method which implements the 20-node iso-parametric element model. The fluid-structure problem is solved iteratively. A basic fluid-sturcture interaction study is performed with the simple rectangular plates of thin thickness with various planform submerged in the water of infinite extent. The computations show good correlation with the experimental results of Linholm, et al. (1965).

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 추계학술대회 논문집
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• pp.145-146
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• 2007

Dye-Sensitized Solar Cell Solar cells(DSSC) were appeared for overcoming global environmental problems and lack of fossil fuel problems. And it is one of study field that is getting into the spotlight lately because manufacturing method is more simple and inexpensive than existing silicon solar cells. Oxide semiconductor is used for adsorption of dye and electron transfer in DSSC study, and $TiO_2$ is used most usually. Overall light conversion efficiency is changed by several elements such as $TiO_2$ particle size and structure, pore size and shape. In this study, we report the solar cell performance of titania$(TiO_2)$ film electrodes with various particle sizes. $TiO_2$ particle size was 16 nm, 25 nm, and mixture of 16nm and 25 nm, and manufactured using Doctor blade method. When applied each $TiO_2$ film to DSSC, the best efficiency was found at 16nm of $TiO_2$ particle. 16nm of $TiO_2$ particle has the highest efficiency compared to the others, because particles with smaller diameters would adsorb more dye due to larger surface area. And in case of the mixture of 16nm and 25 nm, the surface area was smaller than expected. It is estimated that double layer is adsorbed a large amount of chemisorbed dye and improved light scattering leading due to efficiency concentration light than mono layer.