• Title/Summary/Keyword: Field Update

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Evolutionary-base finite element model updating and damage detection using modal testing results

  • Vahidi, Mehdi;Vahdani, Shahram;Rahimian, Mohammad;Jamshidi, Nima;Kanee, Alireza Taghavee
    • Structural Engineering and Mechanics
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    • v.70 no.3
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    • pp.339-350
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    • 2019
  • This research focuses on finite element model updating and damage assessment of structures at element level based on global nondestructive test results. For this purpose, an optimization system is generated to minimize the structural dynamic parameters discrepancies between numerical and experimental models. Objective functions are selected based on the square of Euclidean norm error of vibration frequencies and modal assurance criterion of mode shapes. In order to update the finite element model and detect local damages within the structural members, modern optimization techniques is implemented according to the evolutionary algorithms to meet the global optimized solution. Using a simulated numerical example, application of genetic algorithm (GA), particle swarm (PSO) and artificial bee colony (ABC) algorithms are investigated in FE model updating and damage detection problems to consider their accuracy and convergence characteristics. Then, a hybrid multi stage optimization method is presented merging advantages of PSO and ABC methods in finding damage location and extent. The efficiency of the methods have been examined using two simulated numerical examples, a laboratory dynamic test and a high-rise building field ambient vibration test results. The implemented evolutionary updating methods show successful results in accuracy and speed considering the incomplete and noisy experimental measured data.

Real-Time Path Planning for Mobile Robots Using Q-Learning (Q-learning을 이용한 이동 로봇의 실시간 경로 계획)

  • Kim, Ho-Won;Lee, Won-Chang
    • Journal of IKEEE
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    • v.24 no.4
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    • pp.991-997
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    • 2020
  • Reinforcement learning has been applied mainly in sequential decision-making problems. Especially in recent years, reinforcement learning combined with neural networks has brought successful results in previously unsolved fields. However, reinforcement learning using deep neural networks has the disadvantage that it is too complex for immediate use in the field. In this paper, we implemented path planning algorithm for mobile robots using Q-learning, one of the easy-to-learn reinforcement learning algorithms. We used real-time Q-learning to update the Q-table in real-time since the Q-learning method of generating Q-tables in advance has obvious limitations. By adjusting the exploration strategy, we were able to obtain the learning speed required for real-time Q-learning. Finally, we compared the performance of real-time Q-learning and DQN.

Vehicle License Plate Text Recognition Algorithm Using Object Detection and Handwritten Hangul Recognition Algorithm (객체 검출과 한글 손글씨 인식 알고리즘을 이용한 차량 번호판 문자 추출 알고리즘)

  • Na, Min Won;Choi, Ha Na;Park, Yun Young
    • Journal of Information Technology Services
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    • v.20 no.6
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    • pp.97-105
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    • 2021
  • Recently, with the development of IT technology, unmanned systems are being introduced in many industrial fields, and one of the most important factors for introducing unmanned systems in the automobile field is vehicle licence plate recognition(VLPR). The existing VLPR algorithms are configured to use image processing for a specific type of license plate to divide individual areas of a character within the plate to recognize each character. However, as the number of Korean vehicle license plates increases, the law is amended, there are old-fashioned license plates, new license plates, and different types of plates are used for each type of vehicle. Therefore, it is necessary to update the VLPR system every time, which incurs costs. In this paper, we use an object detection algorithm to detect character regardless of the format of the vehicle license plate, and apply a handwritten Hangul recognition(HHR) algorithm to enhance the recognition accuracy of a single Hangul character, which is called a Hangul unit. Since Hangul unit is recognized by combining initial consonant, medial vowel and final consonant, so it is possible to use other Hangul units in addition to the 40 Hangul units used for the Korean vehicle license plate.

Damage detection of composite materials via IR thermography and electrical resistance measurement: A review

  • Park, Kundo;Lee, Junhyeong;Ryu, Seunghwa
    • Structural Engineering and Mechanics
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    • v.80 no.5
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    • pp.563-583
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    • 2021
  • Composite materials, composed of multiple constituent materials with dissimilar properties, are actively adopted in a wide range of industrial sectors due to their remarkable strength-to-weight and stiffness-to-weight ratio. Nevertheless, the failure mechanism of composite materials is highly complicated due to their sophisticated microstructure, making it much harder to predict their residual material lives in real life applications. A promising solution for this safety issue is structural damage detection. In the present paper, damage detection of composite material via electrical resistance-based technique and infrared thermography is reviewed. The operating principles of the two damage detection methodologies are introduced, and some research advances of each techniques are covered. The advancement of IR thermography-based non-destructive technique (NDT) including optical thermography, laser thermography and eddy current thermography will be reported, as well as the electrical impedance tomography (EIT) which is a technology increasingly drawing attentions in the field of electrical resistance-based damage detection. A brief comparison of the two methodologies based on each of their strengths and limitations is carried out, and a recent research update regarding the coupling of the two techniques for improved damage detection in composite materials will be discussed.

Therapeutic applications of gene editing in chronic liver diseases: an update

  • Shin, Ji Hyun;Lee, Jinho;Jung, Yun Kyung;Kim, Kyeong Sik;Jeong, Jaemin;Choi, Dongho
    • BMB Reports
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    • v.55 no.6
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    • pp.251-258
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    • 2022
  • Innovative genome editing techniques developed in recent decades have revolutionized the biomedical research field. Liver is the most favored target organ for genome editing owing to its ability to regenerate. The regenerative capacity of the liver enables ex vivo gene editing in which the mutated gene in hepatocytes isolated from the animal model of genetic disease is repaired. The edited hepatocytes are injected back into the animal to mitigate the disease. Furthermore, the liver is considered as the easiest target organ for gene editing as it absorbs almost all foreign molecules. The mRNA vaccines, which have been developed to manage the COVID-19 pandemic, have provided a novel gene editing strategy using Cas mRNA. A single injection of gene editing components with Cas mRNA is reported to be efficient in the treatment of patients with genetic liver diseases. In this review, we first discuss previously reported gene editing tools and cases managed using them, as well as liver diseases caused by genetic mutations. Next, we summarize the recent successes of ex vivo and in vivo gene editing approaches in ameliorating liver diseases in animals and humans.

Construction of Incremental Federated Learning System using Flower (Flower을 사용한 점진적 연합학습시스템 구성)

  • Yun-Hee Kang;Myungju Kang
    • Journal of Platform Technology
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    • v.11 no.4
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    • pp.80-88
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    • 2023
  • To construct a learning model in the field of artificial intelligence, a dataset should be collected and be delivered to the central server where the learning model is constructed. Federated learning is a machine learning method building a global learning model without transmitting data located in a client side in a collaborative manner. It can be used to protect privacy, and after constructing a local trained model on individual clients, the parameters of the local model are aggregated centrally to update the global model. In this paper, we reuse the existing learning parameter to improve federated learning, describe incremental federated learning. For this work, we do experiments using the federated learning framework named Flower, and evaluate the experiment results with regard to elapsed time and precision when executing optimization algorithms.

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REAL-TIME 3D MODELING FOR ACCELERATED AND SAFER CONSTRUCTION USING EMERGING TECHNOLOGY

  • Jochen Teizer;Changwan Kim;Frederic Bosche;Carlos H. Caldas;Carl T. Haas
    • International conference on construction engineering and project management
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    • 2005.10a
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    • pp.539-543
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    • 2005
  • The research presented in this paper enables real-time 3D modeling to help make construction processes ultimately faster, more predictable and safer. Initial research efforts used an emerging sensor technology and proved its usefulness in the acquisition of range information for the detection and efficient representation of static and moving objects. Based on the time-of-flight principle, the sensor acquires range and intensity information of each image pixel within the entire sensor's field-of-view in real-time with frequencies of up to 30 Hz. However, real-time working range data processing algorithms need to be developed to rapidly process range information into meaningful 3D computer models. This research ultimately focuses on the application of safer heavy equipment operation. The paper compares (a) a previous research effort in convex hull modeling using sparse range point clouds from a single laser beam range finder, to (b) high-frame rate update Flash LADAR (Laser Detection and Ranging) scanning for complete scene modeling. The presented research will demonstrate if the FlashLADAR technology can play an important role in real-time modeling of infrastructure assets in the near future.

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A Survey of State-of-the-Art Multi-Authority Attribute Based Encryption Schemes in Cloud Environment

  • Reetu, Gupta;Priyesh, Kanungo;Nirmal, Dagdee
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.17 no.1
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    • pp.145-164
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    • 2023
  • Cloud computing offers a platform that is both adaptable and scalable, making it ideal for outsourcing data for sharing. Various organizations outsource their data on cloud storage servers for availing management and sharing services. When the organizations outsource the data, they lose direct control on the data. This raises the privacy and security concerns. Cryptographic encryption methods can secure the data from the intruders as well as cloud service providers. Data owners may also specify access control policies such that only the users, who satisfy the policies, can access the data. Attribute based access control techniques are more suitable for the cloud environment as they cover large number of users coming from various domains. Multi-authority attribute-based encryption (MA-ABE) technique is one of the propitious attribute based access control technique, which allows data owner to enforce access policies on encrypted data. The main aim of this paper is to comprehensively survey various state-of-the-art MA-ABE schemes to explore different features such as attribute and key management techniques, access policy structure and its expressiveness, revocation of access rights, policy updating techniques, privacy preservation techniques, fast decryption and computation outsourcing, proxy re-encryption etc. Moreover, the paper presents feature-wise comparison of all the pertinent schemes in the field. Finally, some research challenges and directions are summarized that need to be addressed in near future.

A Study on the Current Status of Complementary Medicine in Australia (호주의 보완의학 현황에 관한 연구)

  • Yohan Ko;Byungmook Lim
    • Journal of Society of Preventive Korean Medicine
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    • v.28 no.1
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    • pp.13-30
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    • 2024
  • Objectives : This study aimed to investigate the history, current status, and regulation of complementary medicine in Australia. Methods : To investigate complementary medicine in Australia, we searched domestic and overseas academic databases, and websites of public and private organizations related to the Australian health care. Results : Complementary medicine consists of numerous services, among which massage and chiropractic care are significantly utilized by Australians. Since 2010, Australian healthcare practitioners, in the field of complementary medicine, have been supervised by the Australian Health Practitioner Regulation Agency (AHPRA). Those who AHPRA is responsible for managing acupuncturists, chiropractors, and osteopaths. Other professions are regulated by their own respective associations. Not only aforementioned services offered by specialists, but also consumption of oral supplements accounts for considerable portion of complementary medicine in Australia. Complementary medicine products, vitamins, and minerals are managed by the Therapeutic Goods Administration (TGA). In terms of insurance policy, the reimbursement of complementary medicine expenses in Australia is covered by the public healthcare insurance system, Medicare. Medicare covers acupuncture, chiropractic, and osteopathy services. Other complementary therapies are continuously reviewed to update their coverage under this scheme. Conclusion : In Australia, practitioner qualifications, education standards, and scope of procedures related to complementary medicine are systematically managed through legal regulations of the federal and state governments.

The "Korean Turn" in Philippine Popular Culture: The Story So Far

  • Louie Jon A. Sanchez
    • SUVANNABHUMI
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    • v.16 no.1
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    • pp.15-38
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    • 2024
  • In this paper, I will pursue initial ideas I formulated in 2012 about the permeation of Korean influences in Philippine popular culture, particularly in the production of serialized TV drama/soap operas or the "teleserye" [tele for television + "serye" or series; thus, TV drama series]. I called the phenomenon the "Korean Turn" as I observed the emulation of Korean televisual drama (nowadays called K-Drama) modes and practices by local production through various means of cultural appropriation. This time, I will expand my exploration to other aspects of Philippine entertainment and other cultural practices. I will also update my observations on the continuing "Korean turn" in the teleserye. I will argue, on the one hand, about the success and soft power of hallyu or the "Korean wave" in the Philippines; and on the other, about Philippine culture's enduring ingenuity in its reception and repurposing of hallyu. Ideas to be yielded here will form part of a potential framework in understanding the dynamics of the interface between Korean and Philippine cultures, in the context of globalization. I assert that popular culture remains to be an undervalued field of inquiry, as far as these contexts are concerned.