• Title/Summary/Keyword: Free-hand technique

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Flexible CFD meshing strategy for prediction of ship resistance and propulsion performance

  • Seo, Jeong-Hwa;Seol, Dong-Myung;Lee, Ju-Hyun;Rhee, Shin-Hyung
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.2 no.3
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    • pp.139-145
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    • 2010
  • In the present study, we conducted resistance test, propeller open water test and self-propulsion test for a ship's resistance and propulsion performance, using computational fluid dynamics techniques, where a Reynolds-averaged Navier-Stokes equations solver was employed. For convenience of mesh generation, unstructured meshes were used in the bow and stern region of a ship, where the hull shape is formed of delicate curved surfaces. On the other hand, structured meshes were generated for the middle part of the hull and the rest of the domain, i.e., the region of relatively simple geometry. To facilitate the rotating propeller for propeller open water test and self-propulsion test, a sliding mesh technique was adopted. Free-surface effects were included by employing the volume of fluid method for multi-phase flows. The computational results were validated by comparing with the existing experimental data.

Continuous Irrigation of Brain Abscess Using a Double Lumen Catheter - Technical Note - (이중 도관을 이용한 뇌농양의 지속적 세척술 - 수술 수기 -)

  • Park, Jae-Hyo;Yoo, Do-Sung;Kim, Dal-Soo;Huh, Pil-Woo;Cho, Kyoung-Suok;Kang, Joon-Ki
    • Journal of Korean Neurosurgical Society
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    • v.29 no.10
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    • pp.1328-1332
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    • 2000
  • We present a modified method for the treatment of brain abscess. The double lumen extraventricular drainage (EVD) catheter which was developed for the intracerebral hematoma management, was applied for the treatment of brain abscess drainage. We placed the double lumen EVD catheter into the abscess cavity by free-hand technique and irrigated the abscess cavity continuously with antibiotics solution for 7 days. Simultaneous intravenous antibiotics was administered for 4 weeks. The continuous irrigation with double lumen catheter was found to be safe and effective treatment modality in the brain abscess.

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Kinetic analysis of the elbow joint in human motion (인체운동에 있어서 주관절의 운동학적 분석)

  • Noh, Tae-Hwan;Kim, Sik-Hyun;Kim, Jae-Hun
    • PNF and Movement
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    • v.5 no.1
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    • pp.49-56
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    • 2007
  • Objectives : We find that the reaction force on the elbow joint during elbow flexion, extension with and without an object in the hand can be calculated the equations of motion that the sum of the torque and the sum of the force acting on the elbow joint must be zero and (moment of inertia x angular acceleration) and (mass x acceleration). Methods : we have calculated the equations of motion (${\Sigma}F=0$, ${\Sigma}{\tau}=0$, ${\Sigma}F=ma$, ${\Sigma}{\tau}=Ia$) to investigate the reaction force on the elbow joint during elbow flexion, extension by means of the simplified free-body technique for coplanar forces. Results : we found that the reaction force on the elbow joint during elbow flexion, extention as constant acceleration motion is more than constant velocity, static motion. Also, we found that the relation between during flexion and during extension like this ; $J_{flexion}$ < $J_{extension}$.

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The Multicultural Education in Korea: A Comparative Study of Korea & Canada's Multicultural Education

  • Kim, Dae-Won
    • Cross-Cultural Studies
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    • v.32
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    • pp.133-166
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    • 2013
  • Using the observation technique and in-depth interview, the current study compared various aspects of multicultural education between Korea and Canada and suggested the direction Korea's multicultural education needs to take. As a part of class curriculum, the researcher interviewed the representative of Ansan Foreign Center (AFC) and the president of the Kosian's House, a NGO for multicultural educations. The observations and experiences of the researcher were also used in this study. The results of the current study are as follows. First, multicultural education is provided for the minority group in Korea, whereas multiculturalism is included and taught for every student in Canada. In addition, the current multicultural education of Korea focuses on language and culture acquisition to help the students to adjust. Canada, on the other hand, focuses on accepting other cultures and ethnic equality, creating both identities as their ethnic origin and as Canadians. Second, in language educations, both countries had students enrolled in lower school years than their age. However, the differences occurred in terms of emotional support and availability of expert teachers. Third, comparing teacher's attitude towards multicultural education, Korean teachers were not free from perceiving the multicultural student as 'different', whereas Canadian teachers have been taught since little to consider multicultural students as Canadians, but accept their ethnic backgrounds. Based on the results, the current study suggested multicultural education program for the majority group, increase in number of expert language teachers and teaching assistants, and an education program to teach multiculturalism as part of an identity of humankind. The limitations and suggestions for future studies were provided afterwards.

A variation of elastic modulus of very thin diamond-like carbon films with deposition condition (증착조건에 따른 극미세 다이아몬드상 카본 박막의 탄성률 변화거동)

  • 정진원;이광렬;은광용;고대홍
    • Journal of the Korean Vacuum Society
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    • v.10 no.4
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    • pp.387-395
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    • 2001
  • The elastic modulus and the structural evolution were examined with the film thickness in polymeric, hard, graphitic diamond-like carbon (DLC) films. The DLC films used in the present study were prepared by radio frequency plasma assisted chemical vapor deposition (r.f.-PACVD) from $C_6H_6\;and\;CH_4$ gas. Elastic modulus of very thin DLC film was measured by free overhang method. This method has an advantage over the other methods. Because the substrate was removed by etching technique, the measured value is not affected by the mechanical property of the substrate. The structural evolution was investigated by the G-peak position of the Raman spectrum. The polymeric and graphitic films exhibited the decreased elastic modulus with decreasing film thickness. In polymeric films, the reason was that more polymeric film had been deposited in the initial stage of the film growth and in graphitic film more graphic films which had been deposited in the initial stage decreased the elastic modulus. The G-peak position of the Raman spectrum confirmed this result. On the other hand, the hard film showed the constant elastic modulus regardless to the film thickness. The structural change was not observed in this range of the film thickness.

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The Value of Preoperative Multidetector Computed Tomography for Deep Inferior Epigastric Artery Perforator Free Flap (심하복벽동맥 천공지 유리피판에서 술전 MDCT의 유용성)

  • Heo, Chan Yeong;Hong, Ki Yong;Yoon, Chang Jin;Eun, Seok Chan;Baek, Rong Min;Minn, Kyung Won
    • Archives of Plastic Surgery
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    • v.36 no.2
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    • pp.140-146
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    • 2009
  • Purpose: Autologous breast reconstruction with abdominal tissue is one of the best options after mastectomy. In a free transverse rectus abdominis myocutaneous(TRAM) or deep inferior epigastric artery perforator(DIEP) flap, a preoperative evaluation of the precise location of perforating vessels and vascular run - off systems is required. The objective of this report is to demonstrate the usefulness of multidetector computed tomography(MDCT) in the preoperative planning of patients undergoing breast reconstruction with abdominal flap. Methods: From June 2006 to January 2008, 28 patients underwent MDCT evaluation before breast reconstruction. All subjects were females with an age range of 30 to 55 years. The CT scan was performed using a 64 - slice MDCT scanner(Brilliance 64; Philips Medical Systems, Best, Netherlands). Results: One perforator or two major perforators were marked on image in good relation with a hand - held Doppler examination and intraoperative findings. All vascular run - off systems were cleared before operation. Conclusion: Preoperative evaluation of perforator arteries with MDCT angiography is beneficial in patients undergoing breast reconstruction. This technique provides a noninvasive approach of the vascular anatomy of the entire anterior abdominal wall.

A Study on the Fisheries financing before the Liberation of Korea (해방이전의 수산금융에 관한 연구)

  • 김경호
    • The Journal of Fisheries Business Administration
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    • v.15 no.2
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    • pp.1-23
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    • 1984
  • In fisheries financing before the liberation of Korea, the accommodation of funds through modern monetary facilities was hardly benefited to most of small-scale Korean fishermen except Japanese fishermen living in Korea and some large-scale Korean fishermen. In fact, since Korean economy was only in the beginning stage of capitalism free from natural economy in the end of Yi Dynasty, it was natural that the supply of funds should be lacked. But after the opening of ports in Korea, the external shapes in Korean society were slowly changed according as heteronomous modernization was pushed forward by means of western capitalism and the intentional invasion of Japanese was gradually weighed. Thus all kinds of fishing equipments and technique were developed by dint of modernization, and modern monetary facilities also came into being. But most of Korean fishermen were hardly benefited by modern monetary facilities. Fishermen who were faced with destitution of funds were forced to rely upon high interest loans in order to make a living or maintain fisheries, and they were severely exploited by usurers. The situation was the same in the period of Japanese imperialism. Japanese felt the necessity of advancement of Korean fisheries and established fisheries institution suitable for all kinds of colonial fisheries policy toward Korea so that they could build up the foundation according to the development of capitalism and carry out the Russo-Japanese War and the Sino-Japanese War. There were a series of bottlenecks in financing on account of the deficiency of fisheries institution in the beginning of Japanese imperialism, but the financial pressure was lightened because the arrangement of institution greatly contributed to the smoothness of fisheries financing in the latter part of it. Despite such improvement of financing, the benefit of funds could not equally reach to all the fishermen. It only reached to Japanese fishermen living in Korea and some large scale Korean fishermen. Thus most of korean fishermen could not free themselves from destitution of financing and the pressure of high interest loans. This phenomenon took place because Korean fisheries had the antinomic characteristics that financial restriction was excessive owing to the industrial speciality of fisheries, on the other hand there was a large financial demand in fisheries in the character of industry.

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Transcutaneous medial fixation sutures for free flap inset after robot-assisted nipple-sparing mastectomy

  • Kim, Bong-Sung;Kuo, Wen-Ling;Cheong, David Chon-Fok;Lindenblatt, Nicole;Huang, Jung-Ju
    • Archives of Plastic Surgery
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    • v.49 no.1
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    • pp.29-33
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    • 2022
  • The application of minimal invasive mastectomy has allowed surgeons to perform nipples-paring mastectomy via a shorter, inconspicuous incision under clear vision and with more precise hemostasis. However, it poses new challenges in microsurgical breast reconstruction, such as vascular anastomosis and flap insetting, which are considerably more difficult to perform through the shorter incision on the lateral breast border. We propose an innovative technique of transcutaneous medial fixation sutures to help in flap insetting and creating and maintaining the medial breast border. The sutures are placed after mastectomy and before flap transfer. Three 4-0 nylon suture loops are placed transcutaneously and into the pocket at the markings of the preferred lower medial border of the reconstructed breast. After microvascular anastomosis and temporary shaping of the flap on top of the mastectomy skin, the three corresponding points for the sutures are identified. The three nylon loops are then sutured to the dermis of the corresponding medial point of the flap. The flap is placed into the pocket by a simultaneous gentle pull on the three sutures and a combined lateral push. The stitches are then tied and buried after completion of flap inset.

An Experimental Study of Local Mass Transfer Characteristics on Inclined Flat Plate (경사진 평판에서의 국소물질전달 특성에 관한 실험적 연구)

  • Yoo, Seong-Yeon;Jo, Woo-Sik;Cho, Woong-Sun
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.35 no.12
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    • pp.1335-1341
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    • 2011
  • The purpose of this research is to investigate how separated and reattached flow affects mass transfer, by comparing the local mass transfer characteristics on an inclined flat plate with those on a parallel flat plate. The local mass transfer coefficients for the flat plate were measured using the naphthalene sublimation technique; the inclined angle of the flat plate was varied from $-10^{\circ}$ to $10^{\circ}$ at $5^{\circ}$ intervals, and the free-stream velocity was varied from 2m/s to 15m/s. At positive inclined angles, the local Sherwood numbers decreased gradually because the boundary-layer thickness increased. On the other hand, for negative inclined angles, the local Sherwood numbers assumed the minimum value at the separation point of the recirculation flow and the maximum value at the reattachment point. The average Sherwood numbers for both positive and negative inclined angles were lower than those in the case of the parallel plate.

Evaluation technique for efficiency of fishway based on hydraulic analysis (수리해석을 기반으로 어도 효율을 평가하는 기법)

  • Baek, Kyong Oh
    • Journal of Korea Water Resources Association
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    • v.52 no.spc2
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    • pp.855-863
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    • 2019
  • The efficiency of fishway installed in rivers can be directly evaluated by means of fish monitoring. On the other hand, when it is difficult to monitor the fish in certain conditions, or when planning a fishway, the efficiency can be evaluated indirectly through the hydraulic analysis. In this study, the hydraulic analysis technique for evaluating the efficiency of a fishway was presented. The River-2D model with the fish physical habitat module was used for the analysis of the attraction efficiency, and the weighted usable area was proposed as an index of the efficiency. In the analysis of passage efficiency, the three-dimensional model, Flow-3D, was used as an evaluation tool to describe the fluid behavior on a hydraulic structure with free surface. The ice-harbor type fishway at Baekgok weir in the Deokcheon River was selected as a test-site, and the efficiency was estimated using the hydraulic analysis. And then it was compared with fish monitoring data acquired from the river. As a result, it is difficult to replace the hydraulic analysis results with the efficiency quantitatively, but it can help to grasp the general tendency.