• Title/Summary/Keyword: weak form

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Natural vibrations and hydroelastic stability of laminated composite circular cylindrical shells

  • Bochkareva, Sergey A.;Lekomtsev, Sergey V.
    • Structural Engineering and Mechanics
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    • v.81 no.6
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    • pp.769-780
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    • 2022
  • This paper studies the dynamic behavior of laminated composite circular cylindrical shells interacting with a fluid. The mathematical formulation of the dynamic problem for an elastic body is developed based on the variational principle of virtual displacements and the relations of linear elasticity theory. The behavior of an ideal compressible fluid is described by the potential theory, the equations of which together with boundary conditions are transformed to a weak form. The hydrodynamic pressure exerted by the fluid on the internal surface of the shell is calculated according to the linearized Bernoulli equation. The numerical implementation of the mathematical formulation has been done using the semi-analytical finite element method. The influence of the ply angle and lay-up configurations of laminated composites on the natural vibration frequencies and the hydroelastic stability boundary have been analyzed for shells with different geometrical dimensions and under different kinematic boundary conditions set at their edges. It has been found that the optimal value of the ply angle depends on the level of filling of the shell with a fluid. The obtained results support the view that by choosing the optimal configuration of the layered composite material it is possible to change upwards or downwards the frequency and mode shape, as well as the critical velocity for stability loss over a wide range.

Optimization of lateral resisting system of framed tubes combined with outrigger and belt truss

  • Mohammadnejad, Mehrdad;Kazemi, Hasan Haji
    • Advances in Computational Design
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    • v.7 no.1
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    • pp.19-35
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    • 2022
  • In this paper, the optimum location of the belt truss-outrigger for a combined system of framed tube, shear core and outrigger-belt truss is calculated. The optimum location is determined by maximization of the first natural frequency. The framed tube is modeled using a non-prismatic cantilever beam with hollow box cross section. The governing differential equation is solved using the weak form integral equations and the natural frequencies of the structure are calculated. The graphs are introduced for quick calculation of the first natural frequency. The location of the belt truss-outrigger that maximizes the first natural frequency of the structure is introduced as an optimum location. The structure is modeled using SAP-2000 finite elements software. In the modelling, the location of the belt truss-outrigger is changed along the height of the structure. With various locations of the outrigger, the lateral deflection of the all stories and axial force in the columns of the outer tube are calculated. The analysis is repeated by locating the outrigger-belt truss at the optimum location. The analysis results are compared and effect of the optimum location on the lateral deflection and the shear lag phenomena are investigated.

Predicting the Application of Huawei Augmented Reality on Media Façade: Using the TAM Model

  • Chen, Yan;Liu, Shanshan;Lee, Jong Yoon
    • International Journal of Contents
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    • v.18 no.2
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    • pp.32-46
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    • 2022
  • In recent years, large-scale and high-density use of LED on facades has exposed some disadvantages, such as light pollution, high energy consumption, unsustainability, and poor interactivity. Because of the development of smartphones and augmented reality (AR), AR has emerged as a new technology available to users to interact with the media façade. As an augmented reality app for public space, the AR map app can superimpose virtual images on the surface of a building to form an AR media façade, which can be applied in the fields of navigation, advertising, interactive public art, smart retail, etc. This study establishes the variables influencing usage intention and the consequent outcomes of Huawei AR map app and uses the technology acceptance model (TAM) to discuss their relationship. Results show that consumer innovativeness, information quality, and design quality have a strong influence on perceived ease of use. Information quality has a positive impact on perceived usefulness, but design quality has a weak influence. Also, the design quality of Huawei AR map app and consumer innovativeness have a higher effect on perceived enjoyment than information quality. Users' usage attitude and perceived usefulness when using Huawei AR map app are key factors determining their usage intention. This study inspires city planners, architects, developers, and designers of AR apps that augmented reality can partly replace media façade, and that investment in augmented reality will achieve significant sustainable economic and social benefits.

Effect of Korean Michelin Guide Review Features on Customer Satisfaction Using LIWC

  • KIM, Yoon Ji;KIM, Su Sie;CHA, Seong Soo
    • The Journal of Industrial Distribution & Business
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    • v.14 no.1
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    • pp.21-28
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    • 2023
  • Purpose: This study aims to analysis the difference by Michelin rating in customer satisfaction of restaurant listed in the Korea Michelin Guide. There are opinions that the Michelin Guide's rating system and evaluation criteria are somewhat ambiguous. Research design, data, and methodology: This study collected 145 actual online reviews published on TripAdvisor to examine how the effect of the content attributes of reviews on consumer satisfaction varies according to the Michelin grade. Based on this, two studies were conducted. Study 1 examined the effect of strong and weak positive reviews on consumer satisfaction according to the rating. Study 2 examined the effect of image information on consumer satisfaction. Results: The results revealed that the lower the Michelin rating, the more positive review had a significant effect on consumer satisfaction. The higher the rating, the more image information had an effect on consumer satisfaction. Expectations for Michelin three-star restaurants are higher than those of two-star restaurants, so customers are more likely to be used negatively when writing reviews. Conclusions: Accurate information on Michelin selection criteria should be delivered so as not to form high expectations and not to disappoint. For consumers to be satisfied with the name Michelin, the standards should be stricter.

Geomorphological Properties and Changes of Goreabul Sand Beach in Yeongdeok (영덕 고래불 모래해안의 지형 특성과 변화)

  • Bang, Hyun Ju;Lee, Gwang-Ryul
    • Journal of The Geomorphological Association of Korea
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    • v.18 no.3
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    • pp.83-92
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    • 2011
  • The properties and changes of geomorphic relief and coastal deposits were analyzed at Goreabul sand beach in Yeongdeok-gun, the largest that in east coast of Kyungsangbuk-do Province. As the result of grain size analysis, in almost season except summer, the sands mainly deposited in Goraebul sand beach because longshore current drift northward contrary to Gangwon-do east coast, and summer longshore current is weak or change direction to south ward. Sand beach mostly came form erosion owing to typoon and storm and was deposit more coarse sand in the summer, and was produced deposition actively in the fall and winter. Front side of sand dune came from deposition on sand every season by sea breeze, especially in the winter.

Transient heat transfer of unidirectional (1D) and multidirectional (2D/3D) functionally graded panels

  • Samarjeet Kumar;Vishesh Ranjan Kar
    • Steel and Composite Structures
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    • v.49 no.5
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    • pp.587-602
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    • 2023
  • This article presents the numerical modelling of transient heat transfer in highly heterogeneous composite materials where the thermal conductivity, specific heat and density are assumed to be directional-dependent. This article uses a coupled finite element-finite difference scheme to perform the transient heat transfer analysis of unidirectional (1D) and multidirectional (2D/3D) functionally graded composite panels. Here, 1D/2D/3D functionally graded structures are subjected to nonuniform heat source and inhomogeneous boundary conditions. Here, the multidirectional functionally graded materials are modelled by varying material properties in individual or in-combination of spatial directions. Here, fully spatial-dependent material properties are evaluated using Voigt's micromechanics scheme via multivariable power-law functions. The weak form is obtained through the Galerkin method and solved further via the element-space and time-step discretisation through the 2D-isoparametric finite element and the implicit backward finite difference schemes, respectively. The present model is verified by comparing it with the previously reported results and the commercially available finite element tool. The numerous illustrations confirm the significance of boundary conditions and material heterogeneity on the transient temperature responses of 1D/2D/3D functionally graded panels.

E-commerce Utility and Service Quality Enablers: A TISM Approach

  • Dhanya Manayath;Dulari S S
    • Asia pacific journal of information systems
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    • v.34 no.1
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    • pp.1-25
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    • 2024
  • Consumer demand for e-commerce services has skyrocketed due to the introduction of social distancing standards and lockdown measures that countries have taken to combat the pandemic. There has been a notable surge in the popularity of on-demand delivery services, with a significant influx of new users turning to the e-platform for assistance. This research paper tries to identify the enablers of E-commerce Utility and Service Quality and establish a connection using total interpretive structural modelling (TISM). Enablers are the building blocks for providing customers with an enhanced and more consistent service experience contributing to service quality. The enablers and the linkages thus established hold valuable insights for e-commerce marketers, aiding them in effectively reaching their customers, and achieving desired growth outcomes. The TISM- based model and the MICMAC analysis identified two barriers; website design and personalization as the decisive attributes of e-commerce service quality, possessing strong driving power and weak dependence. Furthermore, the factors of reliability, responsiveness, information, and ease of use form the linkage zone, indicating that any action taken on these factors would not only influence other factors but also have a reciprocal effect on them.

Osseointegration of Implants in Rabbit Bone with a Low Calcium Diet and Irradition (저칼슘식이 투여와 방사선조사가 임프란트의 골유착에 미치는 영향에 관한 실험적 연구)

  • Kim So-Jung;Hwang Eui-Hwan;Lee Sang-Rae
    • Imaging Science in Dentistry
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    • v.30 no.1
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    • pp.33-48
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    • 2000
  • Purpose : To investigate osseointergration of titanium implants into the tibia of rabbits, which were fed a low calcium diet and irradiated. Materials and Methods : To prepare the experimental model, control group was fed a normal diet and experimental group was fed a low calcium diet for 4 weeks. And then, titanium implants were inserted into the tibia of each rabbit. Experimental group was subdivided into two groups; low calcium diet/non-irradiation group and low calcium diet/irradiation group. The low calcium diet/irradiation group was irradiated with a single absorbed dose of 15 Gy at the 5th postoperative day. At 12, 19, 33, 47, and 61 days after implantation (1, 2, 4, 6, and 8 weeks after irradiation), the bone formation in the bone-implant interface area was examined by light microscopy and fluorescent microscopy. Results and Conclusions: 1. In the control group, there began to form woven bone in the bone-implant interface area at 12 days after implantation. As the experimental time was going on, the amount of bone which was in contact with the implant was increased. 2. In the low calcium diet/non-irradiation group, there began to form woven bone in the bone-implant interface area at 19 days after implantation. Although the amount of bone which was in contact with the implant was increased as the experimental time was going on, the extent of increased bone was weak as compared with control group. 3. In the low calcium diet/irradiation group, there began to form woven bone incompletely in the bone-implant interface area at 19 days after implantation, but there were vascular connective tissues in the bone-implant interface area over the entire experimental period. 4. In the control group and low calcium diet/non-irradiation group, bone labeling bands were observed at 33 days after implantation, which suggests that the bone formation and remodeling was in process, but interstitial bone remodeling was not observed in the low calcium diet/irradiation group.

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A Study on the Changes of the Form of costume related to the recognition of the beauty of the body -from prehistorical period to Ch'ing Dynasty in Chinese female costume- (인체미 인식과 복식형태의 변천 - 선사~청대까지 중국 여성복식을 중심으로-)

  • 김민지
    • Journal of the Korean Society of Costume
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    • v.32
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    • pp.225-242
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    • 1997
  • This study is historical research on the relationship between the Changes of the Form of costume and the recognition of the beauty of the body from prehistorical period to Ch'ing Dynasty in Chinese female costume. In figure painting a significant point was to describe the spirit of the figure so Chinese painters were less interested in ideal body pro-portion or body shape than Westerns. But idealized beauty of the female body existed and changed keeping abreast with the form of costume in each period. In the prehistorical period Wemen fasten waist belt so enabled to distinguish upper part of the body from lower one. "Locust-forehead moth-eyebrows(蝗首蛾毛)" recorded in "the Book of odes(詩經)" was the canon of beaty and Wemen tried to make their forehead broad and square from Zhou Dynasty to the Wei Jin periods. From the age of Civil War to han Dynasty Slender waist was loved so waist was tightly fastened and hemline became broader. in the course of that time Plump body in big cloth with broad sleeve emerged but that was less significant than Tang Dynasty. During Wei Jin and the Southern/Northern Dynasty undergo disruption and division they admired Taoist images. Loose fitting style with handkerchief hemline and broad sash belt was prevailed while miserable life was reflected gaunt face and lean body. Suk Dynasty also preferred a slim and long body silhouette. The style was presented extremely high waist line long and narrow sleeve slim and long skirt which expressed dynamic and straight image. The culture of Tang Dynasty was open and diverse and that character enabled blod decolletate revealing body line by tight fitting and special make-up-Social background of uion and stabilization made female body extremely plump full face. full breast and hips with most erotic image. The period of Kaiyuan Tianbao fashioned mannish disguise presented androgynous image. Five Dynasty and Song Dynasty restored standard body type so upper garments concealed neck and bust high waist line lowered which represented refined and simple outfit. But another eroticism emerged as foot-binding in Song Dynasty. For the sake of covering up deformed top of the feet and ankle gaiters and arrow shaped shoes were devised. During Ming Ch'ing Dynasties body shape became more slim weak and young causing to escort instinct that reflects 'Lust' or 'Mundanity'.

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Implementation of AI-based Object Recognition Model for Improving Driving Safety of Electric Mobility Aids (전동 이동 보조기기 주행 안전성 향상을 위한 AI기반 객체 인식 모델의 구현)

  • Je-Seung Woo;Sun-Gi Hong;Jun-Mo Park
    • Journal of the Institute of Convergence Signal Processing
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    • v.23 no.3
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    • pp.166-172
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    • 2022
  • In this study, we photograph driving obstacle objects such as crosswalks, side spheres, manholes, braille blocks, partial ramps, temporary safety barriers, stairs, and inclined curb that hinder or cause inconvenience to the movement of the vulnerable using electric mobility aids. We develop an optimal AI model that classifies photographed objects and automatically recognizes them, and implement an algorithm that can efficiently determine obstacles in front of electric mobility aids. In order to enable object detection to be AI learning with high probability, the labeling form is labeled as a polygon form when building a dataset. It was developed using a Mask R-CNN model in Detectron2 framework that can detect objects labeled in the form of polygons. Image acquisition was conducted by dividing it into two groups: the general public and the transportation weak, and image information obtained in two areas of the test bed was secured. As for the parameter setting of the Mask R-CNN learning result, it was confirmed that the model learned with IMAGES_PER_BATCH: 2, BASE_LEARNING_RATE 0.001, MAX_ITERATION: 10,000 showed the highest performance at 68.532, so that the user can quickly and accurately recognize driving risks and obstacles.