• Title/Summary/Keyword: arc length

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Study on dose comparison using X-Jaw split in VMAT treatment planning for left breast cancer including supraclavicular lymph nodes. (쇄골 상부 림프절을 포함하는 왼쪽 유방암의 VMAT 치료계획시 X-Jaw split을 이용한 선량비교에 관한 연구)

  • Kim, Hak Jun;Lee, Yang Hoon;Min, Jae Soon
    • The Journal of Korean Society for Radiation Therapy
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    • v.33
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    • pp.137-144
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    • 2021
  • Purpose : The usability of X-Jaw split VMAT was evaluated by comparative analysis of the dose distribution between the treatment plan divided by X-Jaw and Full field VMAT treatment plan in left breast cancer treatment including supraclavicular lymph nodes. Materials and Methods : 10 patients with left breast cancer, including supraclavicular lymph nodes, were simulated using vacuum cushion, and 2 Full field Arc VMAT and 4 X-Jaw split Arc VMAT were planned The treatment plan was designed to include more than 95% of the Planning Target Volume (PTV) and to be minimally irradiated in the surrounding Organ at risk (OAR). Dose analysis of PTV and OAR was performed through dose volume histogram (DVH). Results : The Full field VMAT treatment plan and the X-Jaw split VMAT treatment plan of 10 patients were expressed as average values and compared. The difference between the two treatment plans was not large, with a Conformity index (CI) of 1.05±0.04, 1.04±0.03, and a Homogeneity index (HI) of 1.07±0.008, 1.07±0.009. For OAR, V5 in the left lung is 56.1±6.50%, 50.4±6.30%, and V20 is 20.0±4.15%, 13.52±3.61%. Compared to Full field VMAT, V5 decreased by 10.0% V20 by 32.6% in X-Jaw split VMAT. The V30 of the heart is 3.68±1.85%, 2.23±1.52%, and the Mean dose is 8.93±1.65 Gy, 7.67±1.52 Gy. In the X-Jaw split VMAT, V30 decreased by 39.3% and the Mean dose decreased by 14.1%. The left lung and heart, which are normal tissues, were found to have a statistical significance of that p-value is less than 0.05. Conclusion : In the case of left breast cancer treatment, which includes Supraclavicular lymph nodes with a large PTV volume and a length of X Jaw of 15 cm or more, the X-Jaw split VMAT shows improved dose distribution, which can reduce radiation dose of OAR such as lungs and heart, while maintaining similar PTV coverage with HI and CI equivalent to Full field VMAT. It is thought to be effective in reducing radiation complications.

Post-buckling responses of elastoplastic FGM beams on nonlinear elastic foundation

  • Trinh, Thanh-Huong;Nguyen, Dinh-Kien;Gan, Buntara S.;Alexandrov, S.
    • Structural Engineering and Mechanics
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    • v.58 no.3
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    • pp.515-532
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    • 2016
  • The elastoplastic response of functionally graded material (FGM) beams resting on a nonlinear elastic foundation to an eccentric axial load is investigated by using the finite element method. The FGM is assumed to be formed from ceramic and metal phases with their volume fraction vary in the thickness direction by a power-law function. A bilinear elastoplastic behavior is assumed for the metallic phase, and the effective elastoplastic properties of the FGM are evaluated by Tamura-Tomota-Ozawa (TTO) model. Based on the classical beam theory, a nonlinear finite beam element taking the shift in the neutral axis position into account is formulated and employed in the investigation. An incremental-iterative procedure in combination with the arc-length control method is employed in computing the equilibrium paths of the beams. The validation of the formulated element is confirmed by comparing the equilibrium paths obtained by using the present element and the one available in the literature. The numerical results show that the elastoplastic post-buckling of the FGM beams is unstable, and the post-buckling strength is higher for the beams associated with a higher ceramic content. Different from homogeneous beams, yielding in the FGM beam occurs in the layer near the ceramic layer before in the layer near metal surface. A parametric study is carried out to highlight the effect of the material distribution, foundation support and eccentric ratio on the elastoplastic response of the beams.

A LONGITUDINAL ROENTGENO-CEPHALOMETRIC STUDY ON THE CEPHALO-FACIO-DENTAL RELATIONSHIPS OF NORMAL KOREAN CHILDREN AGED FROM 6 TO 11 YEARS BY SASSOUNI'S ANALYSIS (Sassouni분석법에 의한 한국 아동의 두개, 안모, 치아의 상호관계 변화에 관한 누년적 연구)

  • Ryu, Young Kyu
    • The korean journal of orthodontics
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    • v.17 no.2
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    • pp.165-183
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    • 1987
  • The purpose of this study is to investigate the cephalo-facio-dental relationships in the craniofacial complex and their changes with age, and to use them for diagnostic and treatment purposes in the orthodontics The author studied on the changes of the cephalo-facio-dental relationships, using serial lateral cephalometric roentgenograms of 46 boys and 47 girls aged from 6 to 11 years of normal Korean children Following results were obtained 1 Means and Standard deviation of Korean children were obtained. 2 In the evaluation of the craniofacial vertical proportions, lower anterior face was larger than the upper, and upper posterior face was larger than the lower at all ages 3 The growth change was more prominent in the anterior craniofacial vertical proportion than in the posterior, and growth increment in the upper anterior facial height dimension was larger than m the lower anterior. 4 In the evaluation of the craniofacial horizontal proportion, ANS, Pog, Go and 6 were all situated posterior to their reference ares, and point B was always situated anterior to the arc passing by point A. 5. Anteroposterior growth change was the most prominent in the mandible, and there was no significant difference between the horizontal growth increment in the cranial base and that in the maxilla 6 Growth increment in the horizontal direction was larger in the mandibular apical base than in the maxillary apical base 7 The upper central incisor and the upper first molar were gradually anterior positioned against their reference ares with age increase 8 The length of mandibular corpus was larger than that of cranial base from the seven years old, and the difference was increased as the age increased 9 With age, there was slight difference in the angular relationships formed by craniofacial reference planes and axial inclinations of upper and lower permanent teeth.

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Comprehensive evaluation of structural geometrical nonlinear solution techniques Part II: Comparing efficiencies of the methods

  • Rezaiee-Pajand, M.;Ghalishooyan, M.;Salehi-Ahmadabad, M.
    • Structural Engineering and Mechanics
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    • v.48 no.6
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    • pp.879-914
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    • 2013
  • In part I of the article, formulation and characteristics of the several well-known structural geometrical nonlinear solution techniques were studied. In the present paper, the efficiencies and capabilities of residual load minimization, normal plane, updated normal plane, cylindrical arc length, work control, residual displacement minimization, generalized displacement control and modified normal flow will be evaluated. To achieve this goal, a comprehensive comparison of these solution methods will be performed. Due to limit page of the article, only the findings of 17 numerical problems, including 2-D and 3-D trusses, 2-D and 3-D frames, and shells, will be presented. Performance of the solution strategies will be considered by doing more than 12500 nonlinear analyses, and conclusions will be drawn based on the outcomes. Most of the mentioned structures have complex nonlinear behavior, including load limit and snap-back points. In this investigation, criteria like number of diverged and complete analyses, the ability of passing load limit and snap-back points, the total number of steps and analysis iterations, the analysis running time and divergence points will be examined. Numerical properties of each problem, like, maximum allowed iteration, divergence tolerance, maximum and minimum size of the load factor, load increment changes and the target point will be selected in such a way that comparison result to be highly reliable. Following this, capabilities and deficiencies of each solution technique will be surveyed in comparison with the other ones, and superior solution schemes will be introduced.

A CEPHALOMETRIC STUDY OF CRANIOFACIAL SKELETAL CHARACTERISTIC OF KOREAN ADOLESCENCES WITH NORMAL OCCLUSION (청소년기 정상교합자의 두개안면골격의 특성에 관한 연구)

  • Lee, Jeong-Min;Chung, Kyu-Rhim
    • The korean journal of orthodontics
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    • v.19 no.1 s.27
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    • pp.187-200
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    • 1989
  • The purpose of this study was to find out the craniofacial skeletal characteristics and to establish standards in facial patterns of Korean adolescences with normal occlusion. The subjects consisted of 54 males and 71 females ranging in age from 12 to 16 years. To classify facial patrons, number the clinical deviations from the normal five key measurements: the facial axis, facial angle, mandibular plane angle, lower face height, mandibular arc, are added and averaged with the proper sign to divide subjects into three groups ; brachyfacial, mesofacial dolichofacial groups. For the comparison of each group, a total of 43 morphologic variables were employed and the data were analyzed by statistical methods. The findings of this study can be summerized as follows; 1. The mesofacial group was $54.4\%$, the brachyfacial group was $29.6\%$ and the dolichofacial group was $16.0\%$ in this subjects. 2. There were no significant differences in size and shape of cranial base among each groups. 3. The brachyfacial group manifested the forward positioned maxilla and mandible to anterior cranial base, smaller cant of the mandibular plane, square shaped mandible, and prominent symphysis as compared with dolichofacial group. 4. There were no significant differences in the cant of the maxilla to the anterior cranial base among each groups. 5. Ramal height and madibular body length of brachyfacial group were larger than those of dolichofacial group. 6. Brachyfacial group indicated the smallest degree in divergency of maxilla and mandible while dolichofacial group showed the largest degree.

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Reconstruction of the Extended Region of the Upper Auricle Using the Superior Auricular Artery Island Flap (상이개동맥 도상피판을 이용한 이개상부 및 그 주변부의 재건)

  • Kyung, Hyun Woo;Oh, Sang-Ha;Seo, Young Joon;Kim, Dong-Woon
    • Archives of Plastic Surgery
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    • v.36 no.3
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    • pp.289-293
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    • 2009
  • Purpose: The retroauricular flap has many advantages for facial reconstruction and is being performed by many surgeons. However, it is difficult for the retroauricular flap to perform reconstruction of the upper region of the auricle and its surroundings, due to limited rotation arc and length of pedicle. We successfully reconstructed the upper region of the auricle and its surroundings with retroauricular flap by using the superior auricular artery as a supplying pedicle. The purpose of this study is to present an anatomic study about the superior auricular artery and its clinical application. Methods: We investigated the relationship between the superior auricular artery and its surrounding structures through anatomic studies with 7 fresh cadavers and then applied the findings clinically. From February to December 2008, we performed 7 cases of the superior auricular artery island flap to reconstruct the defects in patients operated on skin cancer. Sizes of the defects varied form $0.8{\times}0.8cm$ to $3.5{\times}3.0cm$. Results: We found that the superior auricular artery is a reliable pedicle for the retroauricular flap, based on anatomical studies. All wounds of the patients were successfully closed. The flap donor site was primary closed except in one patient with a large defect. The aesthetic outcomes of the donor and recipient sites were satisfying. Conclusions: The superior auricular artery island flap has several advantages. Therefore, we suggest that the superior auricular artery island flap is a treatment of choice for reconstructing soft tissue defect at the upper region of the auricle and its surrounding area.

Study on the Intensive Catching method of Anchovy for the Live Bait-IV Appearance of the Available Resource for the Live Bait in the South-eastern Coastal Waters of Korea (활멸치의 집약적 생상수단에 관한 연구 -IV)

  • Lee, Byoung-gee;Kim, Kwang-hong
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.15 no.2
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    • pp.77-82
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    • 1979
  • It is said that anchovy of 6 to 7 em in body length is the most suitable for the live bait in skipjack pole and line fishing, and it must be held in a creel for more than 7 days so as to be transported from the holding ground to the fishing ground, kept in the small bait hold in a fishing boat. To hold the live bait anchovy, holding creel should be settled in calm waters, and then it is necessary to investigate the appearance of the available resource in the south-eastern coastal waters of Korea where the creel can be settled. The authors investigated the app~arance of the available resource in the waters, and the following results are found. 1. The available resource appears more and the fishing season is longer than in the offshore, rather than in the inshore. 2. The available resource arc caught in the offshore with the passing of time into winter, and they are caught merely in the offshore side in December. 3. The available resource could be secured from July to December, somewhere in the south-eastern coastal waiers of Korea, if the holding ground were removed appropriately.

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A Study of Corona Discharge in Polymer Insulators by Artificial UV Radiation (인위적인 자외선 조사량에 따른 폴리머애자에서의 코로나 방전 특성)

  • Kim, Y.S.;Choi, M.I.;Kim, C.M.;Bang, S.B.;Shong, K.M.;Kwag, D.S.
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.62 no.5
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    • pp.643-648
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    • 2013
  • In this study, degradation was observed by irradiating UV rays to the polymer insulators which have been widely used in outdoor electric power facilities. For an indoor accelerated UV test, 0.55 w/m2 of UV rays were applied using a xenon-arc method. A UV detection system with 65 ${\phi}mm$ in diameter, 100 mm in length and 1.0 of brightness (F/#) has been designed. Even though efflorescence on the surface of polymer insulators wasn't observed according to the accelerated UV test. UV rays were detected at around 50% and 40% of insulation breakdown in EPDM and silicone-type insulators respectively. As degradation continued because of an indoor accelerated UV test, breakdown voltage with which UV rays can be detected in an early stage decreased as well. A silicone polymer insulator would be severer than EPDM polymer insulator in terms of surface degradation because of UV strength against $V_m/V_{BD}$ was high in silicone polymer insulators. UV strength in silicone-type insulators increased at 1,000 $kJ/m^2$ because contact angle at the intial stage sharply decreased to from $113^{\circ}$ to $92.1^{\circ}$.

Development of Compressive Ultimate Strength Formulations for Ship Plating Stiffener with Cutout (선체 유공보강판의 압축최종강도에 관한 설계식 개발)

  • Ko Jae-Yong;Park Joo-Shin;Oh Dong-Kee
    • Proceedings of KOSOMES biannual meeting
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    • 2004.05b
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    • pp.121-125
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    • 2004
  • Recently, High Tensile Steel is adapt to thin plate on the steel structure and marine structure is used widely, It is possible for buckling happens great. Specially, Initial deflection of ship structure happens in place absence necessarily by heat processing of welding or cutting etc. This Initial Deflection is exerted negative impact when thin plate absence complicated nonlinear behaviour accompanied secondary budding. As a result, must idealize initial deflection that occurrence is possible to endow stability and accuracy in the hull structure or marine structure and reflect in early structure design considering secondary buckling. Longi direction of compressive load interacts and analyzed finite element series analysis that apply various kinds initial deflection shape measured actually on occasion that is arranged simply supported condition in this research. Applied ANSYS (elasto-plasticity large deformation finite element method) to be mediocrity finite element program for analysis method and analysis control used in Newton-Raphson method & Arc-length method.

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Sol-gel Derived Nano-glass for Silicon Solar Cell Metallization (솔-젤법에 의해 제조된 실리콘 태양전지 전극형성용 나노 글래스)

  • Kang, Seong Gu;Lee, Chang Wan;Chung, Yoon Jang;Kim, Chang-Gyoun;Kim, Seongtak;Kim, Donghwan;Lee, Young Kuk
    • Current Photovoltaic Research
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    • v.2 no.4
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    • pp.173-176
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    • 2014
  • We have investigated the seed layer formation of front side contact using the inkjet printing process. Conductive silver ink was printed on textured Si wafers with 80 nm thick $SiN_x$ anti reflection coating (ARC) layers and thickened by light induced plating (LIP). The inkjet printable sliver inks were specifically formulated for inkjet printing on these substrates. Also, a novel method to prepare nano-sized glass frits by the sol-gel process with particle sizes around 5 nm is presented. Furthermore, dispersion stability of the formulated ink was measured using a Turbiscan. By implementing these glass frits, it was found that a continuous and uniform seed layer with a line width of $40{\mu}m$ could be formed by a inkjet printing process. We also investigated the contact resistance between the front contact and emitter using the transfer length model (TLM). On an emitter with the sheet resistance of $60{\Omega}/sq$, a specific contact resistance (${\rho}_c$) below $10m{\Omega}{\cdot}cm^2$ could be achieved at a peak firing temperature around $700^{\circ}C$. In addition, the correlation between the contact resistance and interface microstructures were studied using scanning electron microscopy (SEM). We found that the added glass particles act as a very effective fire through agent, and Ag crystallites are formed along the interface glass layer.