• Title/Summary/Keyword: Service Life Monitoring

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Hybrid Damage Detection in Prestressed Concrete Girder Bridges (프리스트레스트 콘크리트 거더교의 하이브리드 손상 검색)

  • Hong, Dong-Soo;Lee, Jung-Mi;Na, Won-Bae;Kim, Jeong-Tae
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2007.04a
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    • pp.669-674
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    • 2007
  • To develop a promising hybrid structural health monitoring (SHM) system, a combined use of structural vibration and electro-mechanical (EM) impedance is proposed. The hybrid SHM system is designed to use vibration characteristics as global index and EM impedance as local index. The proposed health monitoring scheme is implemented into prestressed concrete (PSC) girder bridges for which a series of damage scenarios are designed to simulate various prestress-loss situations at which the target bridges car experience during their service life. The measured experimental results, modal parameters and electro-magnetic impedance signatures, are carefully analyzed to recognize the occurrence of damage and furthermore to indicate its location.

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Connection method on pre-installed bridge monitoring system for bridge structure safety network (교량시설물 안전관리 네트워크 구축을 위한 기존 시스템 연계방안 연구)

  • Park, Ki-Tae;Lee, Woo-Sang;Joo, Bong-Chul;Hwang, Yoon-Koog
    • 한국방재학회:학술대회논문집
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    • 2008.02a
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    • pp.469-472
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    • 2008
  • In general, structures in service gradually lose original performance according to time due to initial defects in design and construction, or exposure to unfavorable external conditions such as repeated loading or deteriorating environment, and in extreme cases, may collapse in large disaster. Therefore, in order to maintain the serviceability of structures at optimal level, advanced structure measuring system which can inform optimal time point and method of maintenance is required in addition to accurate prediction of residual life the structure by periodic inspection. To guarantee the safety level of bridge structure and to prevent from disaster, the integration of safety network for bridge structures are needed. Therefore in this study, to enhance the effectiveness of safety network for bridge, the connection methodologies between safety network and pre-installed bridge monitoring system are investigated.

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The Roles of the National Health Insurance Service in the Public Health Security (건강보장과 국민건강보험공단의 역할)

  • Kim, Yong-Ik
    • Health Policy and Management
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    • v.28 no.3
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    • pp.210-216
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    • 2018
  • National Health Insurance Service (NHIS) has put a great effort on extending life expectancy, for last 40 years. The system has also made remarkable outcomes in achieving universal health coverage. However, it is facing challenges of low health insurance benefits and sustainability risk due to low birth rate and aging society at the same time. To overcome the difficulties and build a lifelong health security system for the nation, it is required for NHIS to make multilateral changes in its roles. Based on the quantitative growth achieved so far, NHIS needs to strive for the growth in quality by not only increasing coverage and reforming contribution imposition system, but also reorganizing the relevant systems such as lifelong health management support, rational adjustment to the medical fee, and benefit costs monitoring. In addition, it's important for NHIS to restructure the organizational culture by having specialty and communicating with people for high quality of administration and health insurance sustainability.

Strategies to approach the customized health management service to prevent chronic diseases (만성질환 예방을 위한 맞춤형 건강관리 서비스의 접근전략과 발전방향)

  • Kim, Young-Bok
    • Korean Journal of Health Education and Promotion
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    • v.33 no.4
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    • pp.89-100
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    • 2016
  • Objectives: Life style modification leads to decrease health risk and change of health status for person at health risk. This study aimed to suggest essential components and effective strategies for customized health management service to provide individual and risk group in public and private health care organizations. Methods: To systematic review the essential component of health management service, I performed to collect political legislation, research papers, reports, publication and public release for heath management service from 2008 to 2016. Essential components of heath management service were service scope, service design, organizations and applied technology. Results: Service cope was composed of health risk factors, such as smoking, drinking, nutrition, physical activity and weight control. Main strategies were customized health management services, personalized behavior modification programs, evidence-based service protocol, utilization of information and communications technology (ICT), multi-dimension and multi-level approach, and public and private organizations partnership through health policies and health care system. Conclusions: To make the most of the limited resources, it should require a systematic approach that focuses on continuous monitoring and partnership of health management service.

Evaluation of Fracture Detection Function for the Concrete by Self-Diagnosis CPGFRP (자기진단 CPGFRP의 파괴예측기능 평가를 위한 콘크리트 적용실험)

  • Choi, Hyun-Soo;Park, Jin-Sub;Jnng, Min-Soo;Kang, Byeung-Hee
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2003.11a
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    • pp.27-31
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    • 2003
  • To maintain serviceability of concrete structure more than proper it is necessary not only predict service life through periodical monitor but also need monitoring system to recognize optimal time and method for repair. Recently, CPGFRP, replacing some GFRP with CF, is developed and used for monitoring concrete fraction. But dramatic resistance change of CPGFRP is showed below 0.5% strain and it is not small strain in terms of monitoring micro crack in concrete. In other word, monitoring with CF is not suitable in low stress hut hight stress. In this study, we accessed applicable possibility and reliability of CPGFRP composite as monitoring sense that is proved very sensitive to stress through domestic and oversea previous study. CPGFRP composite plays a role in specimen like steel and increases flexural strength. CPGFRP composite shows resistance increasement in micro crack. In particular, CPUFRP is more sensitive than strangage in low stress. Resistance change ratio curve is very similar to strain curve so sensitivity and reliability is very excellent to monitor concrete fracture.

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Evaluation of Fracture Detection Function for the Concrete by Self-Diagnosis CPGFRP (자기진단 CPGFRP의 파괴예측기능 평가를 위한 콘크리트 적용실험)

  • 최현수;박진섭;정민수;강병희
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2003.05a
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    • pp.27-31
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    • 2003
  • To maintain serviceability of concrete structure more than proper it is necessary not only predict service life through periodical monitor but also need monitoring system to recognize optimal time and method for repair. Recently, CPGFRP, replacing some GFRP with CF, is developed and used for monitoring concrete fraction. But dramatic resistance change of CPGFRP is showed below 0.5% strain and it is not small strain in terms of monitoring micro crack in concrete. In other word, monitoring with CF is not suitable in low stress but hight stress. In this study, we accessed applicable possibility and reliability of CPGFRP composite as monitoring sense that is proved very sensitive to stress through domestic and oversea previous study. CPGFRP composite plays a role in specimen like steel and increases flexural strength. CPGFRP composite shows resistance increasement in micro crack. In particular, CPGFRP is more sensitive than strangage in low stress. Resistance change ratio curve is very similar to strain curve so sensitivity and reliability is very excellent to monitor concrete fracture.

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Design of Case-based Intelligent Wheelchair Monitoring System

  • Kim, Tae Yeun;Seo, Dae Woong;Bae, Sang Hyun
    • Journal of Integrative Natural Science
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    • v.10 no.3
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    • pp.162-170
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    • 2017
  • In this paper, it is aim to implement a wheelchair monitoring system that provides users with customized medical services easily in everyday life, together with mobility guarantee, which is the most basic requirement of the elderly and disabled persons with physical disabilities. The case-based intelligent wheelchair monitoring system proposed in this study is based on a case-based k-NN algorithm, which implements a system for constructing and inferring examples of various biometric and environmental information of wheelchair users as a knowledge database and a monitoring interface for wheelchair users. In order to confirm the usefulness of the case-based k-NN algorithm, the SVM algorithm showed an average accuracy of 84.2% and the average accuracy of the proposed case-based k-NN algorithm was 86.2% And showed higher performance in terms of accuracy. The system implemented in this paper has the advantage of measuring biometric information and data communication regardless of time and place and it can provide customized service of wheelchair user through user friendly interface.

Structural evaluation of all-GFRP cable-stayed footbridge after 20 years of service life

  • Gorski, Piotr;Stankiewicz, Beata;Tatara, Marcin
    • Steel and Composite Structures
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    • v.29 no.4
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    • pp.527-544
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    • 2018
  • The paper presents the study on a change in modal parameters and structural stiffness of cable-stayed Fiberline Bridge made entirely of Glass Fiber Reinforced Polymer (GFRP) composite used for 20 years in the fjord area of Kolding, Denmark. Due to this specific location the bridge structure was subjected to natural aging in harsh environmental conditions. The flexural properties of the pultruded GFRP profiles acquired from the analyzed footbridge in 1997 and 2012 were determined through three-point bending tests. It was found that the Young's modulus increased by approximately 9%. Moreover, the influence of the temperature on the storage and loss modulus of GFRP material acquired from the Fiberline Bridge was studied by the dynamic mechanical analysis. The good thermal stability in potential real temperatures was found. The natural vibration frequencies and mode shapes of the bridge for its original state were evaluated through the application of the Finite Element (FE) method. The initial FE model was created using the real geometrical and material data obtained from both the design data and flexural test results performed in 1997 for the intact composite GFRP material. Full scale experimental investigations of the free-decay response under human jumping for the experimental state were carried out applying accelerometers. Seven natural frequencies, corresponding mode shapes and damping ratios were identified. The numerical and experimental results were compared. Based on the difference in the fundamental natural frequency it was again confirmed that the structural stiffness of the bridge increased by about 9% after 20 years of service life. Data collected from this study were used to validate the assumed FE model. It can be concluded that the updated FE model accurately reproduces the dynamic behavior of the bridge and can be used as a proper baseline model for the long-term monitoring to evaluate the overall structural response under service loads. The obtained results provided a relevant data for the structural health monitoring of all-GFRP bridge.

Implementation of Educational Service for Environmental Saver using Smart Device (스마트 기기를 활용한 환경 지킴이 교육 서비스 구현)

  • Lee, Yong-Hwan;Cho, Han-Jin;Lee, June-Hwan
    • Journal of Digital Convergence
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    • v.13 no.5
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    • pp.1-8
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    • 2015
  • Various efforts are being made to live a Green life began to recognize an importance of eco-friendly living. In this paper, we have designed and implemented a mobile-based environmental keeping education service, which is offered well-defined category searching and environmental outreach related designed categories, for the purpose of supporting distribution of educational application. The implemented prototype system not only plays a function of environmental pollution report, related to simple environmental stewardship schemes, but also provides environmental monitoring service and integrated educational system supporting certified online volunteer activity. This study provides an one of famous methods to the youth for environmental monitoring education system based on mobile environments, and suggests an improvement to the environmental education for schools students.

Monitoring and Risk Assessment of Pesticide Residues in Pre-harvest Fresh Ginseng (Panax ginseng C. A. Meyer) in Chungbuk Province in 2019 (충북지역 생산단계 수삼 중 잔류농약 모니터링 및 위해성 평가(2019))

  • Song, Tae Hwa;Lee, Young Wook;Youn, Taek Han;Park, Eun A;Shim, Eun Sun;Lee, Ju Hee;Kyung, Kee Sung
    • Korean Journal of Environmental Agriculture
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    • v.40 no.2
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    • pp.118-126
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    • 2021
  • BACKGROUND: It is very important to monitor the residual characteristics of pesticides in pre-harvest fresh ginseng to ensure consumer safety. METHODS AND RESULTS: Forty-eight fresh ginseng samples were collected from 8 ginseng-growing fields 10 days before harvest and pesticide residues in fresh ginseng with and without rhizome (head of ginseng) and rhizome were analyzed for 320 pesticides by using GC-MS/MS and LC-MS/MS. As a result of the pesticide residue analysis, the number of pesticides detected from the fresh ginseng with rhizome, that without rhizome and rhizome were 26, 25, and 40, respectively, indicating that high number of pesticides found in rhizome, compared with the other parts. Pyraclostrobin was detected with the highest frequency in all samples, reaching to 21.2% in fresh ginseng with rhizome, 16.8% in that without rhizome, and 14.8% in rhizome. CONCLUSION: The residue levels of pesticides detected did not exceed their maximum residue limits, in spite of residual data in fresh ginseng before harvest. The amounts of the estimated daily intakes of all the detected pesticides were found to be from 0.018 to 1.818% of their acceptable daily intakes, indicating that concentrations of pesticides detected from fresh ginseng with and without rhizome collected before harvest do not pose the immediate health risks.