• 제목/요약/키워드: Cavity Wall

검색결과 546건 처리시간 0.022초

A Study of Hot Metal Extru-Bending Process

  • 진인태
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2002년도 제5회 압출 및 인발가공 심포지엄
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    • pp.63-70
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    • 2002
  • The purpose of the present study is to propose a new way of manufacturing curved metal tubes with arbitrary sections and way of eliminating the conventional bending defects such as thinning and thickening, in the wall of tube, distortion of the section, and wrinkling and folding on the surface by the extrusion bending process that can extrude and weld together one or more billets inside dies cavity, and can bend them during extrusion due to the gradient of extrusion velocities controlled by the eccentricity of the cavity sections between the entrance and the exit of the eccentric conical extrusion bending dies and conical plug, or by the relative size of the holes of multi-hole container, or by the relative moving velocity of multi-punches.

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비인강폐쇄부전 환자의 언어교정을 위해 발음 보조장치를 이용한 증례 (The Use of a Temporary Speech Aid Prosthesis to Treat Speech in Velopharyngeal Insufficiency (VPI))

  • 김은주;고승오;신효근;김현기
    • 음성과학
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    • 제9권4호
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    • pp.3-14
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    • 2002
  • VPI occurs when the velum and lateral and posterior pharyngeal wall fail to separate the nasal cavity from the oral cavity during deglutition and speech. There are a number of congenital and acquired conditions which result in VPI. Congenital conditions include cleft palate, submucous cleft palate and congenital palatal insufficiency (CPI). Acquired conditions include carcinoma of the palate or pharynx and neurologic disorders. The speech characteristics of VPI is characterized by hypernasality, nasal air emission, decreased intraoral air pressure, increased nasal air flow, decreased intelligibility. VPI can be treated with various methods that include speech therapy, surgical procedures to reduce the velopharyngeal gap, speech aid prosthesis, and combination of surgery and prosthesis. This article describes four cases of VPI treated by speech aid prosthesis and speech therapy with satisfactory result.

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혼합 경계를 가진 임의 형상 음향 공동의 고정밀도 고유치 추출 기법 (Extraction of eigenvalues of acoustic cavities with a mixed boundary)

  • 강상욱
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2014년도 추계학술대회 논문집
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    • pp.404-406
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    • 2014
  • The NDIF method is developed for eigenvalue analysis of arbitrarily shaped two-dimensional acoustic cavity with a mixed boundary, which consists of rigid-wall and open boundaries. The NDIF method, which was developed by the author in 2000, has the feature that it yields highly accurate eigenvalues compared with other analytical methods or numerical methods (FEM and BEM). The validity of the proposed method is shown in a case study, which indicate that eigenvalues obtained by the proposed method are more accurate compared to the exact method or FEM(ANSYS).

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벽면의 임피던스변화에 따른 폐공간 내부에서의 음장특성 분석 (Sound Absorption Effects in a Rectangular Cavity According to the Surface Impedance of Wall)

  • 오재응;김상헌;도중석
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 1997년도 춘계학술대회논문집; 경주코오롱호텔; 22-23 May 1997
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    • pp.687-694
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    • 1997
  • The anisotropy and shape of distributed piezopolymer actuator have advantages over isotropic piezo ceramic materials, since these features of PVDF can be utilized as another design variable in control application. This study is interested in the reduction of sound transmission through elastic plate into interior space by using the PVDF actuator. The plate-cavity system is adopted as a test problem. The vibration of composite plate and the sound fields through plate are analyzed by using the coupled finite element and boundary element method. Some numerical simulations are performed on sound transmission through elastic plates. To investigate the effects of anisotropy and shape of distributed piezopolymer actuator, various kinds of distributed PVDF actuators are applied in sound control simulation for isotropic and anisotropic plates. The PVDF actuators applied are different from each other in their shapes and laminate angles. The results of control simulation show that the control effectiveness of distributed PYDF actuator can be enhanced by using the coupling between shape of actuator and vibration modes of structure and the anisotropy of piezoelectric properties of PVDF.

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The rift Caves in Japan

  • Ogawa, Takanori
    • 동굴
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    • 제5호
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    • pp.37-52
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    • 1997
  • In Japan, on the volcanic line from Mt.Fuji to Hachijou Isl. in Pacific, we can see the many fissure erupted craters. The fissure eruption hasn't always left the rift caves. Recently I am investigated this era and recognized the rift caves. at Mt. Fuji 4. Miyake Isl. 3, Hachijou Isl. 3. The time of fissure eruption in Miyake Isl. make the long crack and gush the lava flow. But. we can see the rift caves only in the caldera. In the rift caves, we can see the thin coated lava on the scoria wall of the cavity and not only the side ways to extend by gasic pressure, on the surface of the earth. It is tow type rift caves. 1) The gas run to the side direction and built the cavities and after blowout the ground. 2) The gas built the cavity and then blowout the earth. I think that the thick scoria layers the most important factor and indispensable condition to built the rift caves.

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비중격에 발생한 신경초종 1례 (A Case of Neurilemmoma Arising from the Nasal Septum)

  • 조진희;장한성;김정묵;서병도
    • 대한기관식도과학회지
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    • 제5권1호
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    • pp.85-89
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    • 1999
  • Neurilemmoma is a benign, well-encapsulated neurogenic tumor that arises in cranial, peripheral, or autonomic nerves that have nerve sheaths containing schwann cells. From 16 to 45% of all neurilemmoma cases occur in the head and neck region and only about 4% of those cases are found in the nose and paranasal sinuses, but very rarely found in the nasal septum. Recently, we experienced a case of isolated neurilemmoma which arose from the nasal septum of a 30-year-old female patient who complained of nasal obstruction and postnasal drip. The mass was broadly based on the right anterior portion of the nasal septum and confined to the nasal cavity, displacing the lateral wall of the nasal cavity and middle turbinate, laterally and posteriorly, respectively. The tumor mass was completely excised through transnasal endoscopic surgery under general anesthesia. The final pathological diagnosis viewed under a microscope after H&E and anti S-100 protein stain was a benign neurilemmoma in which Antoni A type and B type both existed. This report presents a case of neurilemmoma which arose from the nasal septum with reviews of the clinicopathologic features.

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Radiological assessment of pectus excavatum in a Pekingese dog

  • Cho, Sung-Jin;Hong, Sun-Hwa;Chung, Yung-Ho;Kim, Ok-Jin
    • 한국동물위생학회지
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    • 제35권3호
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    • pp.251-254
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    • 2012
  • Pectus excavatum (PE) is a ventral chest wall deformity, also known as funnel chest, sunken chest, chondrosternal depression or koilosternia. The 4 months old, 1.3 kg intact-female Pekingese dog was evaluated for acute semicoma and convulsion. The client reported that this patient have had chronic loss of appetite, intermittent dyspnea and palpable sunken breast. The other littermates did not show any abnormalities. On physical examination, cachexia (BCS 1/5), concave sternum, flatten thoracic cavity and cardiac murmur were observed. On radiographic study, the caudal sternum cave to vertebrae and narrowing thoracic cavity. The severities of thoracic deformity were evaluated by deformation indices such as-Frontosagittal index (FSI) and vertebral index (VI). Moderate to severe PE was founded by the radiological measurements.

2차원 비정상유동 해석을 위한 1-방정식 방법 (An one equation method for two dimensional unsteady flows)

  • 조지룡
    • 한국전산유체공학회:학술대회논문집
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    • 한국전산유체공학회 1999년도 춘계 학술대회논문집
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    • pp.113-123
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    • 1999
  • 본 연구에서는 3차원, 비압축성 유동에 적용 가능한 순수 벡터 포텐셜 방법 (Pure Vector Potential Method, PVPM for short)의 정식화를 수행하였고, 2차원의 경우에 적용 가능한 수치적 방법과 경계조건의 부여법을 상세히 설명하였다. 이 방법의 타당성을 검증하기 위하여 급작스럽게 출발하는 벽구동 웅덩이 내부 유동과 엄밀해가 존재하는 Stokes의 제 1문제를 수치해석하였다. 계산 결과들은 이 두 유동의 중요한 거동을 매우 잘 묘사하였다.

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충격파와 경계층 간섭유동 제어에서 오일막을 이용한 유동가시화 (Flow Visualization Using Thin Oil-Film in the Flow Control of Shock Wave/Turbulent Boundary-Layer Interactions)

  • 이열
    • 한국가시화정보학회:학술대회논문집
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    • 한국가시화정보학회 2002년도 추계학술대회 논문집
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    • pp.117-120
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    • 2002
  • An experimental research has been carried out for flow control of the shock wave/turbulent boundary-layer interaction utilizing aeroelastic mesoflaps. Various shapes and thicknesses of the mesoflap are tested to achieve different deflections of the flap, and ail the results are compared to the solid-wall reference case without flow-control mechanism. Quantitative variation of skin friction has been measured downstream of the interactions using the laser interferometer skin friction meter, and qualitative skin friction distribution has been obtained by observing the interference fringe pattern on the oil-film surface. A strong spanwise variation in the fringe patterns with a narrow region of separation near the centerline is noticed to form behind the shock structure, which phenomenon is presumed partially related to three-dimensional flow structures associated with both the sidewalls and the bottom test surface. The effect of the shape of the cavity is also observed and it is noticed that the shape of the cavity is not negligible.

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Reconstruction of Medial Orbital Wall Fractures without Subperiosteal Dissection: The "Push-Out" Technique

  • Kim, Yong-Ha;Lee, Jin Ho;Park, Youngsoo;Kim, Sung-Eun;Chung, Kyu-Jin;Lee, Jun-Ho;Kim, Tae Gon
    • Archives of Plastic Surgery
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    • 제44권6호
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    • pp.496-501
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    • 2017
  • Background Various surgical methods for repairing medial orbital wall fractures have been introduced. The conventional technique requires total separation of the displaced orbital bones from the orbital soft tissues. However, subperiosteal dissection around the fracture can cause additional damage. The aim of the present study is to introduce a method of reconstructing medial orbital wall fractures without subperiosteal dissection named the "push-out" technique. Methods Six patients with post-traumatic enophthalmos resulting from an old medial orbital wall fracture and 10 patients with an acute medial orbital wall fracture were included. All were treated with the push-out technique. Postoperative computed tomography (CT) was performed to assess the correct positioning of the implants. The Hertel scale and a comparison between preoperative and postoperative orbital volume were used to assess the surgical results. Results Restoration of the normal orbital cavity shape was confirmed by examining the postoperative CT scans. In the old fracture group, the median orbital volume of the fractured side was $29.22cm^3$ preoperatively, and significantly improved postoperatively to a value of $25.13cm^3$. In the acute fracture group, the median orbital volume of the fractured side was $28.73cm^3$ preoperatively, and significantly improved postoperatively to a value of $24.90cm^3$. Differences on the Hertel scale also improved, from 2.13 mm preoperatively to 0.25 mm postoperatively in the old fracture group and from 1.67 mm preoperatively to 0.33 mm postoperatively in the acute fracture group. Conclusions The push-out technique can be considered a good alternative choice for old medial orbital wall fractures with posttraumatic enophthalmos, acute medial orbital wall fractures including large fractured bone segments, and single-hinged greenstick fractures.