• Title/Summary/Keyword: Rigid method

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A Study on a Mask R-CNN-Based Diagnostic System Measuring DDH Angles on Ultrasound Scans (다중 트레이닝 기법을 이용한 MASK R-CNN의 초음파 DDH 각도 측정 진단 시스템 연구)

  • Hwang, Seok-Min;Lee, Si-Wook;Lee, Jong-Ha
    • Journal of the Institute of Convergence Signal Processing
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    • v.21 no.4
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    • pp.183-194
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    • 2020
  • Recently, the number of hip dysplasia (DDH) that occurs during infant and child growth has been increasing. DDH should be detected and treated as early as possible because it hinders infant growth and causes many other side effects In this study, two modelling techniques were used for multiple training techniques. Based on the results after the first transformation, the training was designed to be possible even with a small amount of data. The vertical flip, rotation, width and height shift functions were used to improve the efficiency of the model. Adam optimization was applied for parameter learning with the learning parameter initially set at 2.0 x 10e-4. Training was stopped when the validation loss was at the minimum. respectively A novel image overlay system using 3D laser scanner and a non-rigid registration method is implemented and its accuracy is evaluated. By using the proposed system, we successfully related the preoperative images with an open organ in the operating room

Packaging Design of EPS Cooling Box by Theoretical Heat Flow and Random Vibration Analysis (이론적 열유동 및 랜덤 진동 해석을 적용한 EPS 보냉용기의 포장설계)

  • Kim, Su-Hyun;Park Sang-Hoon;Lee, Min-A;Jung, Hyun-Mo
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.27 no.3
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    • pp.175-180
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    • 2021
  • Although it has recently been regulated for use as an eco-friendly policy in Korea, the use of EPS (Expanded Polystyrene) cooling boxes, which are used as cold chain delivery insulation boxes for fresh agricultural and livestock products, is also increasing rapidly as e-commerce logistics such as delivery have increased rapidly due to COVID-19. Studies were conducted to optimize the EPS cooling container through internal air heat flow of CFD (Computational Fluid Dynamics) analysis and FEM (Finite Element Method) random vibration analysis using domestic PSD (Power Spectral Density) profile of the EPS cooling box to which the refrigerant is applied in this study. In the analysis of the internal air heat flow by the refrigerant in the EPS cooling box, the application of vertical protrusions inside was excellent in volume heat flow and internal air temperature distribution. In addition, as a result of random vibration analysis, the internal vertical protrusion gives the rigid effect of the cooling box, so that displacement and stress generation due to vibration during transport are smaller than that of a general cooling container without protrusion. By utilizing the resonance point (frequency) of the EPS cooling box derived by the Model analysis of ANSYS Software, it can be applied to the insulation and cushion packaging design of the EPS product line, which is widely used as insulation and cushion materials.

A Study on the Convergence Pattern of Broadcasting Contents and the Establishment of World View : Focused on 'Usanseul' and 'Pengsoo' (방송콘텐츠의 컨버전스 양상과 세계관 설정에 관한 고찰 : '유산슬'과 '펭수'를 중심으로)

  • Chang, Hai-La
    • The Journal of the Korea Contents Association
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    • v.21 no.7
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    • pp.20-29
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    • 2021
  • With the creation of a multi-platform media environment, contents production flows through convergence are being detected in the broadcasting contents sector, breaking the boundary between each other and breaking away from the rigid atmosphere of the past, when broadcasters were strictly divided or careful to comment on other programs. It is also quite encouraging that the method of collaboration has been done horizontally as a win-win strategy of co-existence and co-existence, not vertically based on one side's recognition or program popularity. Thus, this study noted the establishment of a world view to capture transmedia phenomena that transcend boundaries between each other to adapt and survive the rapidly reshaping media ecosystem at the base of this trend and to maintain the type of convergence and unrivaled value that emerges in various forms in the process. The research targets were selected for 'Usanseul' and 'Pengsoo', which are prominent in these movements and produce significant results at this point, and analyzed and compared to the results.

Evaluation of Residual Strains under Pure Bending Loading for Colorless and Optically Transparent Polyimide Film for Flexible Display (유연 디스플레이용 무색 투명 폴리이미드 필름의 굽힘 잔류 변형률 평가)

  • Choi, Min-Sung;Park, Min-Seok;Park, Han-Yeong;Oh, Chung-Seog
    • Journal of the Semiconductor & Display Technology
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    • v.20 no.4
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    • pp.49-54
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    • 2021
  • The display industry is transitioning from traditional rigid products such as flat panel displays to flexible or wearable ones designed to be folded or rolled. Accordingly, colorless and optically transparent polyimide (CPI) films are one of the prime candidates to substitute traditional cover glass as a passivation layer to accommodate product flexibility. However, CPI films subjected to repetitive pure bending loads inevitably entail an accumulation of residual strain that can eventually cause wrinkles or delamination in the underlying component after a certain number of static and cyclic loading. The purpose of this study is to establish an experimental method to systematically evaluate the bending residual strain of CPI films. Films were monotonically and cyclically wrapped on mandrels of various diameters to ensure a constant strain in each. After unwrapping the wound CPI film, the residual radius of curvature remaining on the film was measured and converted into residual strain. The critical radius of curvature at which residual strain does not remain was about 5 mm, and the residual strain decreased in proportion to the log time. It is expected that flexible displays can be reliably designed using the data between the applied bending strain and the residual strain.

Penetration Model in Soil Considering J-hook Trajectory (토양 내 J-hook 궤적을 고려한 침투해석 모델 개발)

  • Sung, Seung-Hun;Ji, Hun
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.35 no.1
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    • pp.1-8
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    • 2022
  • This study proposes a penetration model in soil considering the wake separation and reattachment based on the integrated force law (IFL). Rigid body dynamics, the IFL, and semi-empirical resistance function about soil are utilized to formulate the motion of the hard projectile. The model can predict the trajectory in soil considering the spherical cavity expansion phenomenon under various oblique angles and angles of attack (AOA). The Mohr-Coulomb yield model is utilized as the resistance function of the soil. To confirm the feasibility of the proposed model, a comparative study is conducted with experimental results described in the open literature. From the comparative study, the penetration depth estimated from the proposed model had about 13.4% error compared to that of the experimental results. In general, the finite element method is widely used to predict the trajectory in soil for a projectile. However, it takes considerable time to construct the computational model for the projectile and perform the numerical simulation. The proposed model only needs to the dimension of the projectile and can predict the trajectory of the projectile in a few seconds.

Effects of inclined bedrock on dissimilar pile composite foundation under vertical loading

  • Kaiyu, Jiang;Weiming, Gong;Jiang, Xu;Guoliang, Dai;Xia, Guo
    • Geomechanics and Engineering
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    • v.31 no.5
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    • pp.477-488
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    • 2022
  • Pile composite foundation (PCF) has been commonly applied in practice. Existing research has focused primarily on semi-infinite media having equal pile lengths with little attention given to the effects of inclined bedrock and dissimilar pile lengths. This investigation considers the effects of inclined bedrock on vertical loaded PCF with dissimilar pile lengths. The pile-soil system is decomposed into fictitious piles and extended soil. The Fredholm integral equation about the axial force along fictitious piles is then established based on the compatibility of axial strain between fictitious piles and extended soil. Then, an iterative procedure is induced to calculate the PCF characteristics with a rigid cap. The results agree well with two field load tests of a single pile and numerical simulation case. The settlement and load transfer behaviors of dissimilar 3-pile PCFs and the effects of inclined bedrock are analyzed, which shows that the embedded depth of the inclined bedrock significantly affects the pile-soil load sharing ratios, non-dimensional vertical stiffness N0/wdEs, and differential settlement for different length-diameter ratios of the pile l/d and pile-soil stiffness ratio k conditions. The differential settlement and pile-soil load sharing ratios are also influenced by the inclined angle of the bedrock for different k and l/d. The developed model helps better understand the PCF characteristics over inclined bedrock under vertical loading.

Changes of Vastus Medialis Oblique and Vastus Lateralis Muscle Activities During Walking by Different Taping Method (테이핑 방법에 따른 보행 중 안쪽넓은근과 가쪽넓은근의 근활성도 변화)

  • Min-Hyung Rhee;Jong-Soon Kim
    • PNF and Movement
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    • v.21 no.2
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    • pp.231-241
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    • 2023
  • Purpose: Weakness of the vastus medialis oblique muscle (VMO), or the imbalance between VMO and vastus lateralis muscle (VL) activity, is one of the most important factors in knee joint problems. Rigid taping techniques, such as patellar inhibition taping and VL inhibition taping, are frequently used in clinical practice to treat knee joint problems. The purpose of this study was to compare the acute effect of three different types of taping (patellar inhibition taping (PIT), distal VL inhibition taping (DVLIT), and proximal VL inhibition taping (PVLIT)) on electromyography (EMG) activity of VMO, VL, and VMO:VL ratio during walking. Methods: Thirty-eight normal healthy subjects (38 males; mean age = 31.00 years) voluntarily participated in this study. EMG was applied to investigate muscle activation during walking. Repeated measures of ANOVA and one-way ANOVA compared the three different conditions (PIT, DVLIT, and PVLIT) for each variable. Results: VMO and VL activation were significantly increased after PTIT application, and VMO and VL activation were significantly decreased after DVLIT and PVLIT application. The VMO:VL ratio increased after the three types of taping application, but there were no significant differences among the three types of taping. Conclusion: Based on the results of this study, PTIT is more effective than DVLIT and PVLIT in increasing the muscle activation of the VMO and VL during walking. Also, DVLIT is more effective for increasing the VMO:VL ratio and has beneficial effects on the imbalance between VMO and VL activity.

Case Study of the Characteristic of Ground Deformation and the Strut Axial Force Change in Long Span Deep Excavation (장지간 깊은 굴착에서 지반변형 및 버팀보 축력변화 특성 사례 연구)

  • Kim, Sung-Wook;Han, Byung-Won
    • Journal of the Korean Geotechnical Society
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    • v.26 no.7
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    • pp.171-186
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    • 2010
  • It is generally known that the mechanism of behavior in the flexible earth retaining system is relatively more complicated than in the rigid earth retaining system. Moreover in the case of long span strut supporting system the analysis of strut axial force change becomes more difficult when the differences of ground condition and excavation work progress on both sides of excavation section are added. When deeper excavation than the specification or installation delay of supporting system or change of ground condition happen during construction process, lots of axial force can be induced in some struts, which threaten the safety of construction. This paper introduces two examples of long span deep excavation where struts and rock bolts were used as a supporting system with flexible wall structure. The characteristics of ground deformation and strut axial force change, which were measured in the sections of two examples that are 50 meters apart in one construction site and have almost similar design and construction conditions were analysed, the similarity and difference between measurement results of two examples were compared and investigated. This article aims to improve and develop the technique of design and construction in future projects having similar ground condition and supporting method.

Oil Leakage Prediction through Cut Part of Double Elastomeric Seal (이중 탄성중합체 시일의 절단부 오일누유 예측)

  • Taek-Sung Lee;Yeon-Hi Kim
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.36 no.3
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    • pp.165-171
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    • 2023
  • The rotary joint connecting the upper and lower structures of construction machinery and special vehicles transmits hydraulic pressure as the shaft and housing rotate, and multiple seals are assembled to prevent oil leakage into the oil flow channel. Because the seal material is rigid and difficult to assemble, we sought a method to assemble it after cutting. The shapes of the cutting surface are L-shaped and / shaped, and the leakage standard when hydraulic pressure is applied is the contact pressure generated on the cutting surface. The structure and material of the seal are composed of a double elastomer, and nonlinear contact structural analysis is performed when only the high-rigidity PE material is cut. Studies have shown that the shorter the cutting length, the better the leakage prevention and the higher the possibility of leakage to the bottom surface where NBR and PE come into contact rather than the top surface where the PE and the housing come into contact.

Research Trends and Tasks in the field of Reading Program in Korea (국내 독서 프로그램 분야의 연구 동향과 과제)

  • Pan Jun Kim
    • Journal of the Korean Society for information Management
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    • v.41 no.2
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    • pp.47-69
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    • 2024
  • Despite many changes occurring in the objects and methods of reading, the importance of reading as the most effective means of developing human intellectual ability is consistently emphasized. However, in Korea, reading tends to be perceived as a part of tedious and rigid education or learning activities rather than an act of giving pleasure and joy while accompanied by fun and interest. In addition, compared to the high interest and emphasis on reading, discussions on reading programs to systematically implement them are relatively insufficient, and it is difficult to find a study in Korea that grasp the overall research trend in the field of reading programs. Accordingly, in order to generally examine research trends in the field of domestic reading programs, an intellectual structure analysis method based on keyword profiling was applied. In particular, basic analysis, keyword analysis, research area analysis, and analysis by period and year were performed in stages based on the keywords of theses and academic journal articles in the domestic reading program field retrieved from the RISS database. In addition, future research tasks were presented by comprehensively reviewing the research trends of domestic reading programs identified as a result of this intellectual structure analysis.