• Title/Summary/Keyword: Self-healing system

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Evaluation of Crack Monitoring Field Application of Self-healing Concrete Water Tank Using Image Processing Techniques (이미지 처리 기법을 이용한 자기치유 콘크리트 수조의 균열 모니터링 현장적용 평가)

  • Sang-Hyuk, Oh;Dae-Joong, Moon
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.10 no.4
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    • pp.593-599
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    • 2022
  • In this study, a crack monitoring system capable of detecting cracks based on image processing techniques was developed to effectively check cracks, which are the main damage of concrete structures, and a program capable of imaging and analyzing cracks was developed using machine vision. This system provides objective and quantitative data by replacing the appearance inspection that checks cracks with the naked eye. The verification of the development system was applied to the construction site of a self-healing concrete water tank to monitor the crack and the amount of change in the crack width according to age. In the case of crack width detected by image analysis, the difference from the measured value using a digital microscope was up to 0.036 mm, and the crack healing effect of self-healing concrete could be confirmed through the reduction of crack width.

A Path Control Switch in SDH-based Transmission System (SDH 전송시스템에서의 경로제어스위치)

  • Lee, Sang-Hoon;Koh, Jung-Hyuk;Sung, Yung-Kwon
    • Proceedings of the KIEE Conference
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    • 1998.11b
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    • pp.594-596
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    • 1998
  • In this paper, a path control switch has been developed for self-healing operation in SDH-based transmission system. The proposed switch is suitable for self-healing operations in both an Unidirectional Path Switched Ring and a 2-fiber Bidirectional Line Switched Ring. The path control switch is implemented with $0.8{\mu}m$ CMOS LSI chip. The self-healing operation of the switch is effectively done by the configuration information stored in the registers of the switch. The switch has an AU-3(51.84Mb/s) TSI(Time Slot Interchange) and has 1.25Gb/s throughput. But the higher throughput can be realized by combining two identical switches or more with the parallel architecture.

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The golden age of self-development books and healing humanities (자기계발서 전성시대와 힐링 인문학)

  • Song, Hyeon;An, Kwan-Su
    • Journal of Digital Convergence
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    • v.11 no.11
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    • pp.783-793
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    • 2013
  • Neo-liberalism after IMF bailout made the Korean book market flushing with rose due to the alleged self-development books. Vision of self-development books under neoliberal social system is inevitably reduced to a means of capital pursuing commercialization in line with improving the competitiveness of privates through the development of human resources. Characteristics of self-development books, which attributes personal fail to personal responsibility and lack of essential element compared to others in a competitive society, trap individuals forced to choose into anxiety and helplessness. Self-development and healing is a complementary relationship. Human beings needs healing -healing humanities- in the process of self-development. Therefore, humanities should trigger developing and perceiving his own 'reflexive life skills'. Individual's sense of happiness in life and his own experience is very important, and the conscious relationship about their own feelings could elicit 'self-reinforcement'.

High Availability Web Server Cluster Using Self-healing Technique (자가 치유 기법을 이용한 고가용도 웹 서버 클러스터)

  • Chung, Ji Yung;Kim, Young Ro
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.5 no.1
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    • pp.23-32
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    • 2009
  • Although the web is becoming a widely accepted medium, it provides relatively poor performance and low availability. A cluster consists of a collection of interconnected stand-alone computers working together and provides a high-availability solution in application area such as web services or information systems. Web server clusters require a high-availability service with a proactive and practical fault management. However, as the system complexity grows, it is not easy to meet the requirement. Therefore, web server clusters must have self-fault management capability for meeting high-availability requirement. In this paper, we propose high availability web server clusters using self-healing technique with a minimal human intervention. Our experimental results show that a proposed method can be used to improve the availability of web server clusters.

Strength and Healing Performance of the Mortar using Bacterial Pellet as a Self-Healing Material (박테리아 펠렛을 자기치유 소재로 사용한 모르타르의 강도 및 치유성능)

  • Jang, Indong;Son, Dasom;Ryu, Young-ung;Park, Woojun;Yi, Chongku
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.8 no.1
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    • pp.112-119
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    • 2020
  • In this study, cellulose-based bacterial pellets was used for the self-healing concrete manufacturing. The pellet is composed of complex cultured bacterial spore powder, methyl cellulose, two kinds of PVA nutrients and water, and is extruded through a hydraulic press to have a shape of 2mm in diameter to 3 to 4mm in length. Cellulose pellets expand at neutral pH, release bacteria and nutrients, and do not react in a basic environment, increasing the long-term survival rate of bacteria in cement mortar. In addition, pellet self-healing performance of pellet mortar was significantly higher than that of control mortar. Cellulose-based pellets are a new type of bacterial carrier system that will help develop self-healing concrete in the future by improving and optimizing pellets.

The Effects of Self-Healing for Ternary Blended Cement in Tap-water and Sea-water (삼성분계 시멘트의 해수와 담수에서의 자기치유 효과)

  • Kim, Tae-Wan
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.20 no.6
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    • pp.10-19
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    • 2016
  • The objective of this study is to investigate the self-healing properties of ternary blended cement(TBC) paste made with OPC, GGBFS and FA. The influence of OPC-GGBFS-FA on the self-healing ability of ternary blended cement paste was researched by ultrasonic pulse velocity(UPV) measurement. The TBC paste with GGBFS-FA replacement ratios of 20%, 40% and 60% were prepared having a constant water-cementitious materials ratios os 0.5. The research focuses on behavior after 28days(after loading). Four-point bending tests are used to pre-cracked the prismatic specimens at 28days. For specimens (uncracked and cracked) submerged in tap-water and sea-water until 60days. According to the experimental results, the TBC paste system has self-healing ability increased when the fraction of GGBFS increased. Because GGBFS and FA continues to hydrate after 28days, it is likely that hydrated products from GGBFS and FA may modify microstructures, seal these cracks. From these results, it is clear that the crack in all samples experience self-healing and that this occurs mostly in the first 30days of submerging. Futhermore, most of the healing for both specimens of submerged in sea-water and tap-water occurred during the first 30days. Sea-water submerged specimens healed cracks as fast as those in tap-water. Differences in healing effects of submerged in sea-water and tap-water may be attributed to the presence of specific sea-water ions. Therefore, self-healing effects considered age-effects was more strong effect occurred mostly in the first 30days, and then gradually weaken.

A study on the development of Railway Signal Network using Dual Master Self-Healing Ring scheme (자기치유링 방식을 이용한 이중 마스터 구조의 철도신호용 광네트워크 개발에 관한 연구)

  • 신석균;이재호;류등렬;김정용;이기서
    • Proceedings of the KSR Conference
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    • 2002.05a
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    • pp.535-542
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    • 2002
  • This paper show communication network scheme problem for the railway is solved which were electrical noise and line break in wayside using rerouting communication line, Considering the availability and the maintainability based on the reliability in design of communication networks. At first, Self-Healing Ring algorithm is suggested in that solution which is satisfied with above requirements. And also, in the advanced type, Dual Master scheme is suggested that the problem which is occurred in line break of both main and sub line at the same time can be solved using DMSHR(Dual Master Self Healing Ring). Therefore total reliability in railway system is going to be advanced using DMSHR scheme.

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A Development and Performance Assessment of On-Line Monitoring System for Optical Fiber Composite Underground Distribution Network using DTS (DTS를 활용한 광복합 지중 배전계통 실시간 감시시스템 개발 및 성능평가)

  • Cho, Jin-Tae;Kim, Ju-Yong;Lee, Hak-Ju;Cho, Hwi-Chang;Choi, Myeong-Ho
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.25 no.6
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    • pp.115-121
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    • 2011
  • Intelligent distribution equipment is inevitable to realize self-healing which is one of smart grid functions in distribution network. Therefore, most of distribution equipment have been developed with self diagnostic sensors. However, it is not effective to construct on-line monitoring system for underground distribution cable because of high cost and low sensitivity. Recently, optical fiber composite cable is being considered for communication and power delivery in order to cope with increasing communication in distribution network. This paper presents the design and performance assessment results of underground cable on-line monitoring system using DTS(Distributed Temperature Sensing) and optical fiber composite underground cable.

Fixed Indoor-BS Selection Based Self-Healing in Indoor Wireless Communication System (인도어 무선통신시스템에서 고정적 인도어기지국 선택을 통한 자가치유 알고리즘)

  • Lee, Howon;Lee, Kisong
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.18 no.7
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    • pp.1540-1546
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    • 2014
  • In order to resolve coverage hole problems caused by indoor-BS (IBS) faults, we propose a new frame structure and practical algorithm based on optimization technique. Our main contributions can be described as follows: 1) a frame structure with healing channels for solving abnormal IBS faults; and 2) an efficient heuristic resource allocation algorithm with fixed IBS selection to reduce the complexity for the optimization problem. Through intensive simulations, we evaluate the performance excellency of our proposed algorithm with respect to average cell capacity and user fairness compared with conventional algorithms.

Analysis of Mobility Robustness Optimization Technology in LTE Self Organization Networks (LTE 자가구성 네트워크에서 MRO 기술 분석)

  • Yang, Mo-Chan
    • The Journal of the Korea institute of electronic communication sciences
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    • v.14 no.6
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    • pp.1025-1030
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    • 2019
  • This paper describes SON(: Self Organization Network) technology in LTE networks. The SON is a unique feature of LTE compared to previous cellular systems such as UMTS and GSM, and it is a tool that effectively derives the best performance in the time-varying wireless radio environment. Also, the SON has the ability for the operator to automate the setting of the network, allowing for centralized planning and reducing the need for manual work. The SON is largely divided into three categories: Self-Configuration, Self-Optimization, and Self-Healing. Each large categories has a detailed description of technology, and the technologies in each categories are gathered to complete the technology called the SON. In this paper, we focus on MRO which is one of the Self-Optimization technique in each of the three categories.