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Numerical formulation solid-layer finite element to simulate reinforced concrete structures strengthened by over-coating

  • Arturo Suarez-Suarez;Norberto Dominguez-Ramirez;Orlando Susarrey-Huerta
    • Coupled systems mechanics
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    • v.12 no.6
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    • pp.481-501
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    • 2023
  • Over-coating is one of the most popular engineering practices to strengthen Reinforced Concrete (RC) structures, due to the relative quickness and ease of construction. It consists of an external coat bonded to the outer surface of the structural RC element, either by the use of chemical adhesives, mechanical anchor bolts or simply mortar injection. In contrast to these constructive advantages, the numerical estimation of the bearing capacity of the strengthened reinforced concrete element is still complicated, not only for the complexity of modelling a flexible membrane or plate attached to a quasi-rigid solid, but also for the difficulties that raise of simulating any potential delamination between both materials. For these reasons, the standard engineering calculations used in the practice remain very approximated and clumsy. In this work, we propose the formulation of a new 2D solid-layer finite element capable to link a solid body with a flexible thin layer, as it were the "skin" of the body, allowing the potential delamination between both materials. In numerical terms, this "skin" element is intended to work as a transitional region between a solid body (modelled with a classical formulation of a standard quadrilateral four-nodes element) and a flexible coat layer (modelled with cubic beam element), dealing with the incompatibility of Degrees-OfFreedom between them (two DOF for the solid and three DOF for the beam). The aim of the solid-layer element is to simplify the mesh construction of the strengthened RC element being aware of two aspects: a) to prevent the inappropriate use of very small solid elements to simulate the coat; b) to improve the numerical estimation of the real bearing capacity of the strengthened element when the coat is attached or detached from the solid body.

Traditional Unani Plant-Based Therapies for Menopausal Symptoms in Women

  • Arshiya Sultana;Fahmida Kousar;Shahzadi Sultana;Taseen Banu;Arfa Begum
    • CELLMED
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    • v.13 no.14
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    • pp.17.1-17.23
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    • 2023
  • Menopause is a physiological phase experienced by all women as part of normal aging known as menopause. Per se, menopause is not a disease, but hormonal imbalance may lead to menopausal symptoms in some women. The unani physician described that in Sinn-i-Inḥiṭāṭ/ Sinn al-Yās, Burūdat (coldness) increases lead to Ihtibās al-Tamth (amenorrhea) that can occur naturally. Besides, Khilt Dam (blood) production decreases from the liver, slight production occurs, tends towards Burūdat. Therefore, at this age, Ihtibās al-Tamth is associated with Alāmāt Sinn al-Yās(menopausalsymptoms) including weight gain, loss of appetite, hirsutism, fatigue, headache, backache, arthralgia, neck pain, general myalgia, nervousness, anxiety, depression, and insomnia. The traditional Unani manuscripts are enriched with knowledge for the management of Alāmāt Sinn al-Yās. Consequently, an extensive exploration of classical texts concerning the management of Alāmāt Sinn al-Yās was undertaken. Moreover, PubMed, Scopus, Google Scholar, and other indexing databases were thoroughly explored for evidence-based approaches to managing menopausalsymptoms. The principle management as per Unani texts is to treat the cause of Alāmāt Sinn al-Yās. Unani medicines with emmenagogue, anti-inflammatory, analgesic, cardioprotective, and neuroprotective properties are beneficial for the amelioration of Alāmāt Sinn al-Yās. Unani Herbs such as Asgandh, Aslusūs, Khārkhasak, Tagar, Shuneez, Ustukhuddus, Zafran, and Majūn Najāh possess properties and are proven scientifically for their efficacy in Alāmāt Sinn al-Yās. Hence, the substantiation and preservation of traditional knowledge assume paramount importance in facilitating prospective research and proving invaluable in the modern era. Moreover, the conduct of randomized controlled trials, systematic reviews, and meta-analyses becomes imperative.

A Data-driven Multiscale Analysis for Hyperelastic Composite Materials Based on the Mean-field Homogenization Method (초탄성 복합재의 평균장 균질화 데이터 기반 멀티스케일 해석)

  • Suhan Kim;Wonjoo Lee;Hyunseong Shin
    • Composites Research
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    • v.36 no.5
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    • pp.329-334
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    • 2023
  • The classical multiscale finite element (FE2 ) method involves iterative calculations of micro-boundary value problems for representative volume elements at every integration point in macro scale, making it a computationally time and data storage space. To overcome this, we developed the data-driven multiscale analysis method based on the mean-field homogenization (MFH). Data-driven computational mechanics (DDCM) analysis is a model-free approach that directly utilizes strain-stress datasets. For performing multiscale analysis, we efficiently construct a strain-stress database for the microstructure of composite materials using mean-field homogenization and conduct data-driven computational mechanics simulations based on this database. In this paper, we apply the developed multiscale analysis framework to an example, confirming the results of data-driven computational mechanics simulations considering the microstructure of a hyperelastic composite material. Therefore, the application of data-driven computational mechanics approach in multiscale analysis can be applied to various materials and structures, opening up new possibilities for multiscale analysis research and applications.

Chronologically Change and Importance of Acupuncture Points Used in Bell's Palsy in Classical Literature (고전문헌 중 안면신경마비에 사용된 혈위의 시대적 변화와 중요도 분석)

  • Jung Eun Jang;Si-Hyun Park;Kyung Ho Kim;Seung Deok Lee
    • The Journal of Korean Medicine
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    • v.44 no.3
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    • pp.87-101
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    • 2023
  • Objectives: Many acupuncture points have been suggested for the treatment of Bell's palsy, but information on which acupuncture points are more important in treatment is not provided. This study was conducted to investigate the importance of acupuncture points currently used clinically in Bell's palsy. Methods: By reviewing the full text of 11 books that recorded acupuncture prescriptions from the Qin Dynasty to the Qing Dynasty, the frequency of use of acupuncture points, their meridians, and their location were investigated. Results: The average number of acupuncture points used for local, adjacent and distal points selection was 10.5, 2, 4 respectively. The number of acupuncture points increased from the Qin Dynasty to the Ming Dynasty 《Bojaebang》 and then decreased, but the proportion of local points has been still high. From the Ming Dynasty, ST4, ST6, GV26, and GV24 were mainly have been used as the local points. Except for the GB12, the use of the rest of the acupuncture points gradually decreased in the adjacent points. In the distal acupuncture points, it was summarized to point of lung and large intestine channel until the Ming Dynasty, and LI4 was mainly used in the Qing Dynasty. Yangming meridian has been most often used at the local and distal area except for the adjacent area. Conclusions: In the treatment of facial paralysis, the lower part of the face had the highest proportion among local acupuncture points, and the Yangming had the highest proportion by meridian.

Analysis of the Influence of Atmospheric Turbulence on the Ground Calibration of a Star Sensor

  • Xian Ren;Lingyun Wang;Guangxi Li;Bo Cui
    • Current Optics and Photonics
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    • v.8 no.1
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    • pp.38-44
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    • 2024
  • Under the influence of atmospheric turbulence, a star's point image will shake back and forth erratically, and after exposure the originally small star point will spread into a huge spot, which will affect the ground calibration of the star sensor. To analyze the impact of atmospheric turbulence on the positioning accuracy of the star's center of mass, this paper simulates the atmospheric turbulence phase screen using a method based on a sparse spectrum. It is added to the static-star-simulation device to study the transmission characteristics of atmospheric turbulence in star-point simulation, and to analyze the changes in star points under different atmospheric refractive-index structural constants. The simulation results show that the structure function of the atmospheric turbulence phase screen simulated by the sparse spectral method has an average error of 6.8% compared to the theoretical value, while the classical Fourier-transform method can have an error of up to 23% at low frequencies. By including a simulation in which the phase screen would cause errors in the center-of-mass position of the star point, 100 consecutive images are selected and the average drift variance is obtained for each turbulence scenario; The stronger the turbulence, the larger the drift variance. This study can provide a basis for subsequent improvement of the ground-calibration accuracy of a star sensitizer, and for analyzing and evaluating the effect of atmospheric turbulence on the beam.

An Adaptive matrix-based Secure Keypad designed for Rollable and Bendable Display Environments (롤러블 및 벤더블 디스플레이 환경에 적합한 가변행렬 기반 보안 키패드)

  • Dong-Min Choi
    • Journal of Industrial Convergence
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    • v.22 no.2
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    • pp.63-71
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    • 2024
  • Conventional methods like PIN used in conventional smartphone form factor have not considered the variation in display structure or screen size. As a result, when applied to recent variable display-based smartphones, the secret information input unit may get reduced or enlarged, leading to vulnerabilities for social engineering attacks due to deformation of the display area. This study proposes a secure keypad that responds to changes in display size in rollable and bendable smart phones. Firstly, the security problems that may arise when applying classical authentication methods to new form factors were analyzed, and corresponding security requirements were derived. The proposed security keypad addresses the key input error problem that can occur when the screen size is small. The arrangement and size of keys can be deformed with the spacing suitable for input depending on the display size of rollable and bendable smartphones. The study also considered the problem of leaking input information for social engineering attacks by irregularly distributing key input coordinates. The proposed method provides better user experience and security than existing methods and can be used in smartphones of various sizes and shapes.

Satisfaction survey on music listening in patient waiting areas and hallways

  • Han-Kyung Seo
    • The Korean Journal of Nuclear Medicine Technology
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    • v.28 no.1
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    • pp.31-33
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    • 2024
  • Purpose: Music therapy helps alleviate anxiety, depression, and pain for cancer patients, contributing to stress relief. With such advantages, music therapy is applied across a broad spectrum of treatment areas, including mental disorders, developmental disabilities, and conditions affecting the elderly. It has been shown to enhance the quality of life for terminally ill cancer patients. Recent research has revealed its positive effects in boosting immune function and resilience. In light of these findings, the author conducted a study to investigate patient satisfaction with music listening. Materials and Methods: First, a survey was conducted with 30 individuals to inquire about the perceived necessity of listening to music in a waiting area. Next, participants were asked whether listening to music could contribute to psychological stability. Finally, preferences for music genres and satisfaction with music listening were assessed with a sample of 20 individuals. Results: In terms of the perceived necessity of listening to music in the waiting area, 28 out of 30 individuals, or 93%, expressed agreement. Regarding the belief that music listening could contribute to psychological stability, 28 out of 30 individuals, or 93%, believed that it would indeed help with stability. When it comes to preferred music genres, 4 individuals (13%) favored classical music, 2 individuals (6%) preferred traditional Korean music, 2 individuals (6%) enjoyed trot music, and 20 individuals (66%) had no specific genre preference. As for music listening satisfaction, 17 out of 20 individuals, or 85%, reported being satisfied. Conclusion: When patients visit the hospital, stress can increase due to concerns about their medical conditions. To address this, providing a variety of music genres at the hospital has been effective in reducing patient stress and promoting psychological stability.

Exploring Efficient Solutions for the 0/1 Knapsack Problem

  • Dalal M. Althawadi;Sara Aldossary;Aryam Alnemari;Malak Alghamdi;Fatema Alqahtani;Atta-ur Rahman;Aghiad Bakry;Sghaier Chabani
    • International Journal of Computer Science & Network Security
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    • v.24 no.2
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    • pp.15-24
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    • 2024
  • One of the most significant issues in combinatorial optimization is the classical NP-complete conundrum known as the 0/1 Knapsack Problem. This study delves deeply into the investigation of practical solutions, emphasizing two classic algorithmic paradigms, brute force, and dynamic programming, along with the metaheuristic and nature-inspired family algorithm known as the Genetic Algorithm (GA). The research begins with a thorough analysis of the dynamic programming technique, utilizing its ability to handle overlapping subproblems and an ideal substructure. We evaluate the benefits of dynamic programming in the context of the 0/1 Knapsack Problem by carefully dissecting its nuances in contrast to GA. Simultaneously, the study examines the brute force algorithm, a simple yet comprehensive method compared to Branch & Bound. This strategy entails investigating every potential combination, offering a starting point for comparison with more advanced techniques. The paper explores the computational complexity of the brute force approach, highlighting its limitations and usefulness in resolving the 0/1 Knapsack Problem in contrast to the set above of algorithms.

Image Analysis Fuzzy System

  • Abdelwahed Motwakel;Adnan Shaout;Anwer Mustafa Hilal;Manar Ahmed Hamza
    • International Journal of Computer Science & Network Security
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    • v.24 no.1
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    • pp.163-177
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    • 2024
  • The fingerprint image quality relies on the clearness of separated ridges by valleys and the uniformity of the separation. The condition of skin still dominate the overall quality of the fingerprint. However, the identification performance of such system is very sensitive to the quality of the captured fingerprint image. Fingerprint image quality analysis and enhancement are useful in improving the performance of fingerprint identification systems. A fuzzy technique is introduced in this paper for both fingerprint image quality analysis and enhancement. First, the quality analysis is performed by extracting four features from a fingerprint image which are the local clarity score (LCS), global clarity score (GCS), ridge_valley thickness ratio (RVTR), and the Global Contrast Factor (GCF). A fuzzy logic technique that uses Mamdani fuzzy rule model is designed. The fuzzy inference system is able to analyse and determinate the fingerprint image type (oily, dry or neutral) based on the extracted feature values and the fuzzy inference rules. The percentages of the test fuzzy inference system for each type is as follow: For dry fingerprint the percentage is 81.33, for oily the percentage is 54.75, and for neutral the percentage is 68.48. Secondly, a fuzzy morphology is applied to enhance the dry and oily fingerprint images. The fuzzy morphology method improves the quality of a fingerprint image, thus improving the performance of the fingerprint identification system significantly. All experimental work which was done for both quality analysis and image enhancement was done using the DB_ITS_2009 database which is a private database collected by the department of electrical engineering, institute of technology Sepuluh Nopember Surabaya, Indonesia. The performance evaluation was done using the Feature Similarity index (FSIM). Where the FSIM is an image quality assessment (IQA) metric, which uses computational models to measure the image quality consistently with subjective evaluations. The new proposed system outperformed the classical system by 900% for the dry fingerprint images and 14% for the oily fingerprint images.

Using DQ method for vibration analysis of a laminated trapezoidal structure with functionally graded faces and damaged core

  • Vanessa Valverde;Patrik Viktor;Sherzod Abdullaev;Nasrin Bohlooli
    • Steel and Composite Structures
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    • v.51 no.1
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    • pp.73-91
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    • 2024
  • This paper has focused on presenting vibration analysis of trapezoidal sandwich plates with a damaged core and FG wavy CNT-reinforced face sheets. A damage model is introduced to provide an analytical description of an irreversible rheological process that causes the decay of the mechanical properties, in terms of engineering constants. An isotropic damage is considered for the core of the sandwich structure. The classical theory concerning the mechanical efficiency of a matrix embedding finite length fibers has been modified by introducing the tube-to-tube random contact, which explicitly accounts for the progressive reduction of the tubes' effective aspect ratio as the filler content increases. The First-order shear deformation theory of plate is utilized to establish governing partial differential equations and boundary conditions for the trapezoidal plate. The governing equations together with related boundary conditions are discretized using a mapping-generalized differential quadrature (GDQ) method in spatial domain. Then natural frequencies of the trapezoidal sandwich plates are obtained using GDQ method. Validity of the current study is evaluated by comparing its numerical results with those available in the literature. After demonstrating the convergence and accuracy of the method, different parametric studies for laminated trapezoidal structure including carbon nanotubes waviness (0≤w≤1), CNT aspect ratio (0≤AR≤4000), face sheet to core thickness ratio (0.1 ≤ ${\frac{h_f}{h_c}}$ ≤ 0.5), trapezoidal side angles (30° ≤ α, β ≤ 90°) and damaged parameter (0 ≤ D < 1) are carried out. It is explicated that the damaged core and weight fraction, carbon nanotubes (CNTs) waviness and CNT aspect ratio can significantly affect the vibrational behavior of the sandwich structure. Results show that by increasing the values of waviness index (w), normalized natural frequency of the structure decreases, and the straight CNT (w=0) gives the highest frequency. For an overall comprehension on vibration of laminated trapezoidal plates, some selected vibration mode shapes were graphically represented in this study.