• Title/Summary/Keyword: Expansion Method

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Reconstruction of congenital microtia after ear canaloplasty using V-Y advancement of a temporal triangular flap

  • Park, Hae Yeon;Lee, Kyeong-Tae;Kim, Eun-Ji;Oh, Kap Sung
    • Archives of Plastic Surgery
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    • v.48 no.6
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    • pp.614-621
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    • 2021
  • Background Reconstruction of congenital microtia remains challenging, particularly in patients with a history of ear canaloplasty due to insufficient regional soft tissue. The insertion of a tissue expander prior to implantation of the cartilage framework has traditionally been employed. However, this procedure could induce additional morbidity. Herein, we present a method using V-Y advancement of a temporal triangular flap to gain additional soft tissue in these challenging cases. Methods Congenital microtia patients with a history of ear canaloplasty who underwent auricular reconstruction using the Nagata technique between 2016 and 2020 were reviewed. To obtain additional soft tissue, V-Y advancement of a temporal triangular flap was performed concurrently with implantation of the costal cartilage framework, without prior insertion of a tissue expander. The outcomes of these patients with respect to postoperative complications and esthetics were evaluated. Results Eight patients with bilateral lesions were included. No specific complications developed after the first-stage surgery. However, one patient experienced complications after the second stage (auricular elevation). An analysis of the esthetic results showed most patients had excellent outcomes, achieving a satisfactory convolution. The median number of operations needed to complete reconstruction was 2, which was fewer than required using the conventional method with prior insertion of a tissue expander. Conclusions In patients with a history of previous canaloplasty, V-Y advancement of a temporal triangular flap could serve as an alternative to tissue expansion for microtia reconstruction. This technique provided reliable and satisfactory results with a reduced number of surgical stages.

Study on the fire resistance of castellated composite beams with ortho-hexagonal holes and different beam-end constraints

  • Junli Lyu;Encong Zhu;Rukai Li;Bai Sun;Zili Wang
    • Steel and Composite Structures
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    • v.46 no.4
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    • pp.539-551
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    • 2023
  • In order to study the fire resistance of castellated composite beams with ortho-hexagonal holes and different beam-end restraints, temperature rise tests with constant load were conducted on full-scale castellated composite beams with ortho-hexagonal holes and hinge or rigid joint constraints to investigate the temperature distribution, displacement changes and failure patterns of castellated composite beams with two different beam-end constraints during the whole course of fire. The results show that (1) During the fire, the axial pressure and horizontal expansion deformation generated in the rigid joint constrained composite beam were larger than those in the hinge joint constrained castellated composite beam, and their maximum horizontal expansion displacements were 30.2 mm and 17.8 mm, respectively. (2) After the fire, the cracks on the slab surface of the castellated composite beam with rigid joint constraint were more complicated than hinge restraint, and the failure more serious; the lower flange and web at the ends of the castellated steal beams with hinge and rigid joint constraint produced serious local buckling, and the angles of the ortho-hexagonal holes at the support cracked; the welds at both ends of the castellated composite beam with rigid joint constraint cracked. (3) Based on the simplified calculation method of solid-web composite beam, considering the effect of holes on the web, this paper calculated the axial force and displacement of the beam-end constrained castellated composite beams under fire. The calculation results agreed well with the test results.

A Semi-analytical Approach for Numerical Analysis of Residual Stress in Oxide Scale Grown on Hot-rolled Steels (열간압연강에서 형성된 산화물 스케일의 잔류 응력 수치 분석을 위한 준해석적 방법 개발)

  • Y.-J. Jun;J.-G. Yoon;J.-M. Lee;S.-H. Kim;Y.-C. Kim;S. Nam;W. Noh
    • Transactions of Materials Processing
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    • v.33 no.3
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    • pp.200-207
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    • 2024
  • In this study, we developed a semi-analytical approach for the numerical analysis of residual stress in oxide scales formed on hot-rolled steels. The oxide scale, formed during the hot rolling process, experiences complex interactions due to thermal and mechanical influences, significantly affecting the material's integrity and performance. Our research focuses on integrating various stress components such as thermal stress, growth stress, and creep behavior to predict the residual stress within the oxide layer. The semi-analytical method combines analytical expressions for each stress component with numerical integration to account for their cumulative effects. Validation through instrumented indentation tests confirms the reliability of our model, which considers thermal expansion coefficient (CTE) differences, scale growth, and creep-induced stress relaxation. Our findings indicate that thermal stress resulting from CTE differences significantly impacts the overall residual stress, with growth stress contributing a compressive component during cooling, and creep behavior playing a minor role in stress relaxation. This comprehensive approach enhances the accuracy of residual stress prediction, facilitating the optimization of material design and processing conditions for hot-rolled steel products.

An First Order Approximiate Analytical Solution to Predict Qualitative Performance Characteristics of Stirling Enging (Stirling기관(機關)의 성능예측(性能豫測)을 위한 1차원(次元) 근사해석(近似解析))

  • Kim, Tae Han
    • Current Research on Agriculture and Life Sciences
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    • v.9
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    • pp.87-94
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    • 1991
  • An approximate analytical method to predict performance characteristics of the stirling engines in a preliminary design stage was investigated. In basic equations proposed by walker, typical temperatures of working fluids in expansion and compression spaces were treated the same as those of working fluids in heater and cooler respectively. While the temperature of working fluids in the expansion space was actually lower than that of working fluids in the heater, the temperature of working fluids in the compression space was higher than that of working fluids in the cooler. The aim of this study divided typical temperatures of working fluids in expansion and compression spaces into serval grades, and than evaluated the experimental engine. As the result, the case which working fluids temperature of expansion space was treated as lower than the heater temperature and which that of compression space was treated as higher than the cooler temperature, was much closer to the experimental value.

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A Study on Expansion Possibility of Treatment Capacity in Public Livestock Manure Treatment Plant Integrated Individual Farmhouses (개별농가와 연계한 가축분뇨 공공처리시설의 처리용량 확대 가능성에 관한 연구)

  • Kim, J.H.;Kim, J.H.;Park, C.H.;Kwag, J.H.;Choi, D.Y.;Jeong, K.H.;Chung, U.S.;Yoo, Y.H.;Chung, M.S.
    • Journal of Animal Environmental Science
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    • v.15 no.3
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    • pp.281-288
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    • 2009
  • The objective of this study is to predict the expansion possibility of treatment capacity in public livestock manure treatment plant (PLMTP) integrated individual farmhouses. According to the treatment efficiency and cost reducing effect, expansion possibility was examined using three cases; (i) decrease of influent concentration from 20,000 mg/L BOD to 1,000 mg/L BOD, (ii) maintenance of low concentration influent with minimum revising existing facilities (BIOSUF) and (iii) maintenance of low concentration influent without revising existing facilities (liquid corrosion method, LCM). In BIOSUF, the treatment capacity increased from 130 ton/day to 300 ton/day. Also, LCM resulted in expansion of treatment capacity from 210 ton/day to 250 ton/day while that of designed concentration influent decreased from 210 ton/day to 190 ton/day. The treatment costs were 14,674 won/ton and 9,929 won/ton for BIOSUF and LCM, respectively. After some revisions, it will be changed to 7,221 won/ton and 8,277 won/ton. Therefore, it must be considered that the livestock manure treats to low concentration and flows into PLMTP for the efficient operation and reducing treatment cost.

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Research and development of the V-World packaged goods model for the overseas expansion of the spatial information industry (공간정보산업 해외진출을 위한 공간정보 오픈플랫폼(V-World) 패키지상품 모형 개발 연구)

  • Lim, Yong-Min;Lee, Jae-Yong
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.4
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    • pp.606-614
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    • 2016
  • In order to expand the market of the domestic space information industry, which is currently saturated, overseas expansion is essential, but the prospects are limited. Therefore, an effective strategy of overseas expansion is needed. Given the current state of such spatial information industry, V-World is expected to play a very important role. In the world market for space information, in order to ensure the export competitiveness of the domestic space information industry, in the present study, research and development was carried out on the V-World-based packaged goods model as one possible method. First of all, to analyze the current situation and characteristics of the spatial information industry, to grasp V-World as a commodity and derive the relationship between foreign demand and V-World, the sales destinations and methods were defined. To formulate the basic strategy of the fusion-composite package export utilizing V-World on the basis of the basic concept of the product, the necessary components were designed. In response to this fusion-composite package product mix, the overseas promotion of spatial information-related companies it to be expected.

Structure and physical properties of the earth crustal material in the middle of Korean Peninsula : A study on the prescription of standard test by mortar-bar method (한반도 중부권 지각물질의 구조와 물성연구 : 콘크리트 공시체에 의한 표준시험 규정에 대하여)

  • 정진곤;유신애
    • The Journal of Engineering Geology
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    • v.5 no.2
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    • pp.193-200
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    • 1995
  • It has been well known that the alkali-aggregate reaction between the aggregates and cement paste is one of the reasons of a concrete siructre expansion. Because of a serious demage on the concrete stnicture from the expansion, in many countries, the safety of the materials is checked in laboratory by mortar-bar test and the upper limit of expansion in length is 0.1%. The prescriptions are presented in the ASTM C227 and 490 of U.S. which has been international currency and in the KS Handbook F2503, F2546 and L5107 of Korea published by Korean Standards Association. Both of the prescriptions are almost same in their contents. Actually, in the process of preparing and measuring the mortar-bar according to the prescription mentioned above, it seems that there are no problems for its own purpose but a few points are found to be improved upon the methods to increase the accuracy for laboratory work as follows. 1. The prescription of blending ratio(aggregate, cement and water) should be noted by volume not by weight. 2. It is unreasonable to measure the initial length of mortar bars after 24$\pm$2 hours at once regardless the kind of aggregates. 3. It may bring about errors in calculating the expansion ratio under the condition of the denominator value fixed as 254mm. 4. The measuring methods of specific gravity are selected according to the purposes but the pure specific gravity displays the highest accuracy among them.

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Quality Characteristics of Yukwa Prepared with Mugwort Powder Using Different Puffing Process (팽화방법을 달리한 쑥 분말 첨가 유과의 품질 특성)

  • Yang, Sun;Kim, Mun-Yong;Chun, Soon-Sil
    • Korean journal of food and cookery science
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    • v.24 no.3
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    • pp.340-348
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    • 2008
  • The purpose of this study was to develop new method for the manufacture of Yukwa, a Korean oil-puffed rice snack with a soft texture, using a far infrared ray electric roaster. The Yukwa base is traditionally expanded using oil, but the Yukwa base tends to develop unpleasant rancid odors or off-flavors during storage. In this study, the DPPH radical scavenging activity of mugwort powder was evaluated. Baked and fried Yukwa samples were added with 0.5, 1.0, 1.5, and 2.0% of mugwort powder and left untreated as a control, and then tested for moisture content, expansion rate, color, hardness, and sensory evaluations. The samples with higher concentrations of mugwort powder, evidenced a more profound tendency toward DPPH radical scavenging activity. The moisture content of Yukwa dough tended to increase with the addition of mugwort powder. As the mugwort powder content increased, the moisture contents of the Yukwa base and the Baked Yukwa increased. The moisture content and expansion rates of the fried Yukwa did not differ significantly. The samples containing the mugwort power evidenced a lower expansion rate than was observed in the control group. The lightness of the baked and fried Yukwa was reduced with increased mugwort powder content. The greenness of the baked and fried Yukwa was at a minimum upon the addition of 2.0% mugwort powder. The yellowness of the baked Yukwa did not differ significantly between the samples. As the mugwort powder content increased, the yellowness of the fried Yukwa increased. The hardness of the baked and fried Yukwa tended to increase with the addition of mugwort powder. In the sensory evaluations, the baked Yukwa scored higher than the fried Yukwa, and all of the sensory characteristics of baked Yukwa scored highest in the samples without mugwort powder, but also scored fairly well with 1.0 and 1.5% mugwort powder. In conclusion, these results demonstrated that 1.0~1.5% of mugwort powder should be added to Yukwa baked in a far infrared ray electrical roaster in order to optimize physiological functions and keep overall acceptability reasonably high.

Characteristics of Signal-to-Noise Paradox and Limits of Potential Predictive Skill in the KMA's Climate Prediction System (GloSea) through Ensemble Expansion (기상청 기후예측시스템(GloSea)의 앙상블 확대를 통해 살펴본 신호대잡음의 역설적 특징(Signal-to-Noise Paradox)과 예측 스킬의 한계)

  • Yu-Kyung Hyun;Yeon-Hee Park;Johan Lee;Hee-Sook Ji;Kyung-On Boo
    • Atmosphere
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    • v.34 no.1
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    • pp.55-67
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    • 2024
  • This paper aims to provide a detailed introduction to the concept of the Ratio of Predictable Component (RPC) and the Signal-to-Noise Paradox. Then, we derive insights from them by exploring the paradoxical features by conducting a seasonal and regional analysis through ensemble expansion in KMA's climate prediction system (GloSea). We also provide an explanation of the ensemble generation method, with a specific focus on stochastic physics. Through this study, we can provide the predictability limits of our forecasting system, and find way to enhance it. On a global scale, RPC reaches a value of 1 when the ensemble is expanded to a maximum of 56 members, underlining the significance of ensemble expansion in the climate prediction system. The feature indicating RPC paradoxically exceeding 1 becomes particularly evident in the winter North Atlantic and the summer North Pacific. In the Siberian Continent, predictability is notably low, persisting even as the ensemble size increases. This region, characterized by a low RPC, is considered challenging for making reliable predictions, highlighting the need for further improvement in the model and initialization processes related to land processes. In contrast, the tropical ocean demonstrates robust predictability while maintaining an RPC of 1. Through this study, we have brought to attention the limitations of potential predictability within the climate prediction system, emphasizing the necessity of leveraging predictable signals with high RPC values. We also underscore the importance of continuous efforts aimed at improving models and initializations to overcome these limitations.

Analysis of the Phase Current Measurement Boundary of Three Shunt Sensing PWM Inverters and an Expansion Method

  • Cho, Byung-Geuk;Ha, Jung-Ik;Sul, Seung-Ki
    • Journal of Power Electronics
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    • v.13 no.2
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    • pp.232-242
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    • 2013
  • To obtain phase currents information in AC drives, shunt sensing technology is known to show great performance in cost-effectiveness and therefore it is widely used in low cost applications. However, shunt sensing methods are unable to acquire phase currents in certain operation conditions. This paper deals with the derivation of the boundary conditions for phase current reconstruction in three-shunt sensing inverters and proposes a voltage injection method to expand the measurable areas. As the boundary conditions are deeply dependent on the switching patterns, they are typically analyzed on the voltage vector plane for space vector pulse width modulation (SVPWM) and discontinuous pulse width modulation (DPWM). In the proposed method, the voltage injection and its compensation are conducted within one sampling period. This guarantees fast current reconstruction and the injected voltage is decided so as to minimize the current ripple. In addition to the voltage injection method, a sampling point shifting method is also introduced to improve the boundary conditions. Simulation and experimental results are presented to verify the boundary condition derivation and the effectiveness of the proposed voltage injection method.