• 제목/요약/키워드: volume correction

검색결과 413건 처리시간 0.022초

두개골 조기유합증 환자의 술후 CT Scan을 이용한 두개강내 용적의 평가 (An Evaluation by CT scanning of Intracranial Volume after Correction of Craniosynostosis)

  • 김석권;이장호;한재정;정기환;이근철;박정민
    • Archives of Plastic Surgery
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    • 제32권1호
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    • pp.29-36
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    • 2005
  • Craniosynostosis is the premature fusion of one or more sutures of either cranial vault or base. Fused sutures may impede normal growth of the calvaria, leading to characteristic skull deformities; Morphological craniosynostosis is classified descriptively. Being craniosynostosis uncorrected the deformity progresses continuously and causes an increase of intracranial pressure. The surgical involvement aims at the expansion of intracranial space as well as satisfactory achievement of craniofacial shape. Early surgical correction in infancy prevents the deformity from the further progression and possible associated complication of high intracranial pressure. A long period of follow-up is essential to asses the outcome of an effectiveness of the surgery. measurement of intracranial volume has been concerned in medical personnel and anthropologists for many years. A reliable and accurate measurements of the intracranial volume facilitates to make a diagnosis and treatment of craniosynostosis. Pre-and postoperative change of intracranial volume was evaluated with 3D CT scanning in 12 cases of craniosynostosis who underwent frontal advancement and total cranial vault remodeling. Increased intracranial volume is attributed to surgical release of craniosynostosis and natural growth. We conceive that the intracranial volume is significantly increased after surgical correction of fused cranial sutures and along with natural growing. A procedure of frontal advancement and total cranial vault remodeling is very useful to correct such a deformity as craniosynostosis. And also 2 cases out of five mentally retarded patients improved remarkably and Forehead retrusion or temporal depression followed in another two cases.

정상상태 형상압연의 오일러리안 해석에서 형상 예측 (Shape Prediction in Eulerian Analysis of Steady State Shape Rolling)

  • 이용신
    • 소성∙가공
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    • 제10권7호
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    • pp.579-583
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    • 2001
  • Shape changes of a workpiece in an Eulerian Finite Element analysis for the steady state, three-roll-stand shape rolling are modelled. Although an Eulerian analysis has many advantages for the steady state rolling problems, it necessitates an assumption about the unknown shape of the control volume. In almost all cases, the assumed control volume does not match the final shape and the control volume should be updated. This update can be accomplished by performing a free surface correction. The final shape of a material point, which has a spherical shape at the inlet, can be also predicted by integrating a deformation gradient along a stream line. Analyses of three-roll-stand shape rolling are performed and the results are discussed in detail.

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Three-Ro II-Stand 형상압연의 오일러리안 해석에서 형상예측 (Shape Prediction in Eulerian Analysis of Three-Roll-Stand Shape Rolling)

  • 이용신;나경환
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2001년도 춘계학술대회 논문집
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    • pp.328-331
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    • 2001
  • Shape changes of a workpiece in an Eulerian Finite Element analysis for the steady state. three-roll-stand shape rolling are modelled. Although an Eulerian analysis has many advantages for the steady state rolling problems, it necessitates an assumption about the unknown shape of the control volume. In almost all cases. the assumed control volume does not match the final shape and the control volume should be updated. This update can be accomplished by performing a free surface correction. The final shape of a material point, which has a spherical shape at the inlet, can be also predicted by integrating a deformation gradient along a stream line. Analyses of three-roll-stand shape rolling is in detail examined.

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Influences of hygrothermal environment and fiber orientation on shear correction factor in orthotropic composite beams

  • Soumia Benguediab;Fatima Zohra Kettaf;Mohammed Sehoul;Fouad Bourada;Abdelouahed Tounsi;Mohamed Benguediab
    • Coupled systems mechanics
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    • 제12권2호
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    • pp.151-165
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    • 2023
  • In this study, a simple method for the determination of the shear correction factor for composites beam with a rectangular cross section is presented. The plane stress elasticity assumption is used after simplifications of the expression of the stress distribution in the beam. The different fiber orientation angle and volume fraction are considered in this work. The studied structure is subjected to various loading type (thermal and hygrothermal). The numerical results obtained show that there is a dependence of the shear coefficient on the orientation of the fibers. The evolution of the shear correction factors depends not only on the orientation of the fibers and also on the volume fraction and the environment. the advantage of this developed formula of the shear correction factor is to obtain more precise results and to consider several parameters influencing this factor which are neglected if the latter is constant.

페플럼의 위치와 양에 따른 시각적 평가 (Visual Evaluation according to Changes in Volume and Position of Peplums)

  • 구미란;이정진
    • 한국의상디자인학회지
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    • 제17권3호
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    • pp.61-71
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    • 2015
  • In this study, visual evaluation was performed with changes in peplums design to provide data which can enhance wearing image effects at the production of peplums one-piece. According to changes in volume and position of peplums, a total of 9 stimulants were chosen. Then, they were evaluated using a seven-point rating scale against 50 fashion students. The data has been analyzed by Factor Analysis, ANOVA, $Scheff{\acute{e}}$'s Test and the MCA method. The results of the study are as follows : 1. According to factor analysis, the components of visual evaluation depending on the changes in volume and position variations of peplums were divided into four factors: elegance, individuality, upper body correction and upper body emphasis. 2. According to visual evaluation depending on changes in the position variations of peplum, 'high waist' and 'natural waist' revealed a significant difference in elegance, individuality and upper body correction. 'Low waist' was observed in all four positions. 3. According to visual evaluation depending on the changes in volume of peplums, a significant difference at $45^{\circ}$ was observed in except for elegance. Significant differences at $90^{\circ}$ and $180^{\circ}$ were observed in all four positions. 4. In terms of interactions over in volume and position variations of peplums, interaction effects were found in two factors.

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압력보정법을 이용한 8개의 원심압축기 임펠러 CFD의 적용 연구 (Application of Pressure Correction Method to CFD Work for 8 Centrifugal Compressor Impellers)

  • 오종식;노수혁;현용익
    • 유체기계공업학회:학술대회논문집
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    • 유체기계공업학회 2000년도 유체기계 연구개발 발표회 논문집
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    • pp.226-235
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    • 2000
  • Two representative finite volume methods, i.e., the time marching method and the pressure correction method, were applied to 8 centrifugal compressor impeller flows, with low to very high level of pressure ratio, among which 7 impellers' experimental performance is given in the open literature. The present study is focused on the prediction differences from both methods, developed by the authors, in the pressure correction method's point of view. In all cases, the time marching method gives a satifactory solution, but the pressure correction method does not. Up to about $18\%$ less level of total-to-total pressure ratio is predicted by the pressure correction method as the level of the impeller pressure ratio increases up to about 10. The drop of total pressure ratio is caused by the underestimation of static pressure rise which seems to be attributed to inappropriate linearization and discretization of the pressure/density coupling terms in the pressure correction equation.

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영상처리 기법에 의한 심해저 망간단괴의 부존밀도 보정 (Correction of Nodule Abundance Using Image Analysis Technique on Manganese Nodule Deposits)

  • 박찬영;전효택;강정극
    • 자원환경지질
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    • 제29권4호
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    • pp.429-437
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    • 1996
  • The purpose of this study is to correct the nodule abundance of FFG (Free Fall Grab) sampler on KODOS (Korea Deep Ocean Study) area in North-East Pacific Ocean. The image analysis of sea-floor photography was carried out for correcting the abundance of nodules, and the image enhancement techniques and edge detection method were used to discriminate between nodules and sediments. The trace of nodules on sediments was detected to reduce the fractionation effect in calculating the coverage of nodules. The three methods, using the coverage of nodules, using the volume density, and using corrected volume density, were utilized for the correction of the nodule abundance. The method using the coverage of nodules was more convenient and available for the correction of nodule abundance than the other two methods. The method using the corrected volume density had the highest confidence level compared with the other methods.

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안와골파열골절 정복술 후 지속되는 안구함몰 환자에서 정상측 안구의 안구 감압술의 치험례 (Correction of Persistent Enophthalmos after Surgical Repair of Blow Out Fracture Using Orbital Decompression Technique of Contralateral Eye)

  • 이준호;박원용;남현재;김용하
    • 대한두개안면성형외과학회지
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    • 제9권2호
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    • pp.101-104
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    • 2008
  • Purpose: Diplopia and cosmetically unacceptable enophthalmos are the major complications of blow out fracture. Prolapse of orbital tissue into the sinuses, enlarged orbital volume, atrophy of orbital fat and loss of support of orbital walls play a role in the pathogenesis of enophthalmos. To correct post-traumatic enophthalmos, freeing of incarcerated orbital contents combined with reduction of bony orbital volume and reconstruction of suspensory support of globe is necessary. But remained enophthalmos after surgical treatment is difficult to correct completely. In this case, the authors performed implant insertion for affected orbit and endoscopic orbital decompression for unaffected orbit for correction of late enophthalmos. Method: We reviewed a girl patient with right inferomedial orbital wall blow out fracture, right zygoma fracture treated at our hospital for correction of enophthalmos. An 18-year-old female had sustained posttraumatic enopthalmos. Two surgical management was performed for correction blow out fracture at the other hospital. But residual diplopia, enophthalmos, cheek drooping were found. And then she transferred to our hospital. She had severe enophthalmos(5 mm) also had diplopia and extraocular muscle limitation. We performed operation for correction of enophthalmos. After operation, she showed minimal improvement of diplopia and enophthalmos(3 mm). The authors make plan for operation for correction enophthalmos due to cosmetical improvement. Implant insertion was performed for affected orbit. For unaffected orbit, nasoendoscopic medial orbital wall decompression was proceeded. Result: Correction of enophthalmos was found after operation and was maintained for nine years follow-up. Patient expressed satisfaction for the result. Conclusion: To correct persistant enophthalmos, we could have satisfactory result with orbital wall reconstruction on affected eye and decompression on unaffected eye.

정상상태 압연공정의 유한요소 해석에 관한 연구 (A Study on Eulerian Finite Element Analysis for the Steady State Rolling Process)

  • 이용신
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2004년도 제5회 압연심포지엄 신 시장 개척을 위한 압연기술
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    • pp.184-196
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    • 2004
  • An Eulerian finite element analysis for the steady state rolling process is addressed. This analysis combines the crystal plasticity theory fur texture development as well as the continuum damage mechanics for growth of micro voids. Although an Eulerian analysis for steady state rolling has many advantages, it needs an initial assumption about the shape of control volume. However, the assumed control volume does not match the final shapes. To effectively predict the correct shape in an assumed control volume, a free surface correction algorithm and a streamline technique are introduced. Applications to plate rolling, clad rolling, and shape rolling will be given and the results will be discussed in detail.

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Correction of post-traumatic enophthalmos with anatomical absorbable implant and iliac bone graft

  • Choi, Ji Seon;Oh, Se Young;Shim, Hyung-Sup
    • 대한두개안면성형외과학회지
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    • 제20권6호
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    • pp.361-369
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    • 2019
  • Background: Trauma is one of the most common causes of enophthalmos, and post-traumatic enophthalmos primarily results from an increased volume of the bony orbit. We achieved good long-term results by simultaneously using an anatomical absorbable implant and iliac bone graft to correct post-traumatic enophthalmos. Methods: From January 2012 to December 2016, we performed operations on seven patients with post-traumatic enophthalmos. In all seven cases, reduction surgery for the initial trauma was performed at our hospital. Hertel exophthalmometry, clinical photography, three-dimensional computed tomography (3D-CT), and orbital volume measurements using software to calculate the specific volume captured on 3D-CT (ITK-SNAP, Insight Toolkit-SNAP) were performed preoperatively and postoperatively. Results: Patients were evaluated based on exophthalmometry, clinical photographs, 3D-CT, and orbital volume measured by the ITK-SNAP program at 5 days and 1 year postoperatively, and all factors improved significantly compared with the preoperative baseline. Complications such as hematoma or extraocular muscle limitation were absent, and the corrected orbital volume was well maintained at the 1-year follow-up visit. Conclusion: We present a method to correct enophthalmos by reconstructing the orbital wall using an anatomical absorbable implant and a simultaneous autologous iliac bone graft. All cases showed satisfactory results for enophthalmos correction. We suggest this method as a good option for the correction of post-traumatic enophthalmos.