• Title/Summary/Keyword: Long-term deterioration

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Factors Associated with the Changes in Activities of Daily Living in Older Adults with Stroke: A Comparison of Home Care and Institutional Care (뇌졸중 이환 노인의 일상생활수행능력 변화에 미치는 영향: 장기요양 재가 서비스와 시설 서비스를 중심으로)

  • Jung, Woon-Sook;Yim, Eun-Shil
    • Research in Community and Public Health Nursing
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    • v.27 no.4
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    • pp.388-398
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    • 2016
  • Purpose: To compare the changes in activities of daily living (ADLs) in older adults with stroke in different modalities of long term care (LTC) services, which include home care and institutional care. Methods: This is a comparative study using secondary data from the Korean national LTC insurance. Home care (HC) services users (n=3,494) and institutional care (IC) users (n=1,428) were extracted and compared in terms of ADLs and changes in ADLs to investigate the effects of HC and IC services in LTC. Results: All of the ADLs and LTC services benefit levels for 2 years had improved in both HC and IC services. The ADLs of older adults with stroke who received HC improved, while those who received IC experienced deterioration. The LTC services benefit levels of the HC and IC groups were significantly different after 2 years. Conclusion: The study has found that HC services may lead ADLs better for older adults with stroke. We recommend LTC policy makers to further develop HC and IC service programs to deliver quality LTC services.

Characteristics of Chloride Penetration in Cracked Flexural Member using Durable Materials (고내구성 재료를 사용한 휨부재의 균열에 따른 염화물 침투 특성)

  • Jin, Sang-Ho;Kim, Il-Sun;Kim, Myung-Yu;Yang, Eun-Ik;Yi, Seong-Tae
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.11a
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    • pp.401-404
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    • 2008
  • Crack is a penetration path of harmful material such as chloride ion, and causes a serious deterioration in durability. So, the characteristics of chloride penetration are investigated for the cracked flexural concrete members using high-durable materials. For these, the flexural crack of beam specimen is introduced by transverse loading. And, Rapid Chloride Penetration Test (RCPT) and Long-term chloride penetration test are carried out to compare the chloride penetration depth. From test results when crack is happened, the chloride penetration resistance of the durable member was superior than that of the normal member. Blast furnace slag concrete member has a excellent chloride penetration resistance in long-term chloride penetration test.

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A study for application plan of rational residual water pressure on the tunnel linings (터널 라이닝에 작용하는 합리적인 잔류수압 적용방안 검토)

  • Jung, Kuk-Young;Kim, Ji-Yeop;Kim, Ji-Hun;Moon, Hoon-Ki
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.13 no.6
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    • pp.463-499
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    • 2011
  • Control of ground water is one of the most important factors for long-term operation of tunnel because most tunnels are located under the ground water level. In case of a drainage tunnel, there is no pore water pressure on the lining when the drainage system is properly working. After long-term operation, however, residual pore water pressure can be developed on the lining due to the deterioration of the drainage system. In this study, the water pressure distribution under obstruction condition of drainage material and conduit on the tunnel is numerically investigated using the ICFEP program and compared with the current value being applied to the residual water pressure for rational application plan of residual water pressure on the tunnel linings.

A Study on Development of New Repair Method by High Pressure Spray (고압 스프레이 방식 신보수공법의 개발에 관한 연구)

  • Woo, Jong-Tae;Jang, Suk-Hwan;Kim, Yong-Chul
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.7 no.1
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    • pp.279-288
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    • 2003
  • This study is the development of method on repairing concrete structure for progressing the durability of reinforced concrete. This method is wet spray method which compress and conduct mortar pre-mixed with polymer powder to hose by high pressure pump and spray it on the section of concrete structure through nozzle made specially. Characters of this method are that materials are selected with the sort of structure and the cause of deterioration and macro pores are removed in repaired section by conducting with high pressure and spraying with high velocity for progressing the durability of concrete structure. This study has carried out that the minimum capacity of rebound was measured with various condition and physical properties of sample made by spray method were estimated in comparing with sample made by previous hand method. Also, properties of long-term have carried out after this method was applied on site. According to experimental study, the capacity of rebound showed below 5% and physical properties of sample made by spray method were superior to that of sample made by hand method and physical and durable properties of long-term showed excellence.

A Study on the Evaluation of Deterioration Properties of Reinforced Concrete Applied Repair Material and Method System by Long Term Exposure Experiment (장기폭로실험에 의한 철근콘크리트 보수재료공법 시스템의 열화특성 평가에 관한 연구)

  • Choi, Hyeong-Gil;Shin, Kwan-Soo;Shin, Seung-Bong;Na, Chul-Sung;Kim, Gyu-Yong;Kim, Moo-Han
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2007.04a
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    • pp.129-132
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    • 2007
  • In this study, for the establishment of the performance evaluation methods of repair material and method for reinforced concrete structure and the quality control standards of durability recovery method, the quantitative exposure data by exposure experiment under the coastal and normal atmosphere environment is accumulated and analyzed. Investigating and evaluating the result of exposure experiment during 54 months of exposure age under the coastal and normal atmosphere environment, Micro crack, swelling and spatting of surface coating material, crack of repair boundary parts and the great potential difference between repair part and non-repair part were somewhat generated. And the result shown that exposure specimen of coastal environment had lower electrode potential than exposure specimen of normal atmosphere environment.

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Prediction of RC structure service life from field long term chloride diffusion

  • Safehian, Majid;Ramezanianpour, Ali Akbar
    • Computers and Concrete
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    • v.15 no.4
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    • pp.589-606
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    • 2015
  • It is well-documented that the major deterioration of coastal RC structures is chloride-induced corrosion. Therefore, regional investigations are necessary for durability based design and evaluation of the proposed service life prdiction models. In this paper, four reinforced concrete jetties exposed to severe marine environment were monitored to assess the long term chloride penetration at 6 months to 96 months. Also, some accelerated durability tests were performed on standard samples in laboratory. As a result, two time-dependent equations are proposed for basic parameters of chloride diffusion into concrete and then the corrosion initiation time is estimated by a developed probabilistic service life model Also, two famous service life prediction models are compared using chloride profiles obtained from structures after about 40 years in the tidal exposure conditions. The results confirm that the influence of concrete quality on diffusion coefficients is related to the concrete pore structure and the time dependence is due to chemical reactions of sea water ions with hydration products which lead a reduction in pore structure. Also, proper attention to the durability properties of concrete may extend the service life of marine structures greater than fifty years, even in harsh environments.

Alternative Selection Method for Energy Efficiency Improvement of Old Detached House (노후 단독주택의 난방에너지 효율 개선을 위한 대안 선정 방법에 관한 연구)

  • Hwang, Seok-Ho
    • Journal of the Korean Solar Energy Society
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    • v.39 no.2
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    • pp.45-55
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    • 2019
  • More than 76% of the detached houses in Korea are over 20 years old. These old detached houses have poor energy efficiency. According to the 2017 Housing Census (Statistics Korea), more than 50% of low-income families live in detached houses. Therefore, the improvement of energy efficiency in old detached houses is needed from the viewpoint of energy welfare. The general method of building energy modelling for the verification of energy efficiency is based on the construction year data of "Building Design Criteria for Energy Saving" due to the cost and time involved in collecting the thermal performance data of buildings. There is poor accuracy with the deterioration of long-term aging of building materials. Also, the selection of alternatives for energy performance improvement is based on the items to be applied, not a performance improvement goal. It is difficult to calculate energy performance that reflects variations in various parameters with dynamic energy simulations. In this study, the influence of long-term aging is used to accurately predict the energy performance of old detached houses. The building energy modelling method is called ENERGY#, which is a static analysis method based on ISO13790. Energy performance is evaluated by a combination of input variables including building orientation, insulation of walls and roof, thermal performance of windows and window/wall ratio, and infiltration rate. Finally, this study provides a way to determine alternatives that meet energy performance improvement goals.

According to Water Cement Ratio and Internal Temperature and Humidity, An Analytical Study on the Carbonation of Long-Term Concrete (물 시멘트비와 이산화탄소 농도에 따른 콘크리트의 장기 탄산화에 관한 해석적 연구)

  • Lee, Jun-Hae;Park, Dong-Cheon
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2020.11a
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    • pp.188-189
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    • 2020
  • In the field of architecture, concrete and steel bars are the most common and popular combinations. The relationship between the two in a structure is a complementary good that increases in utility when consuming both materials at the same time. However, the combination of the two, which has been perceived as semi-permanent, often faces repairs or reconstruction without its lifespan reaching decades. There are a number of deterioration factors at work for the reason for this phenomenon. Among them, the neutralization of concrete in particular refers to the process in which calcium hydroxide inside concrete reacts with carbon dioxide and loses alkalinity, which creates a corrosive environment for rebars inside concrete, causing serious damage to concrete. In this study, we intend to use a multi-physical analysis program using finite element analysis method to analyze the degree of carbonation according to the internal temperature and concentration of carbon dioxide in concrete, thereby contributing to the prediction of long-term neutralization of concrete and the research related to measures for neutralization of concrete.

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Predicting the lateral displacement of tall buildings using an LSTM-based deep learning approach

  • Bubryur Kim;K.R. Sri Preethaa;Zengshun Chen;Yuvaraj Natarajan;Gitanjali Wadhwa;Hong Min Lee
    • Wind and Structures
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    • v.36 no.6
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    • pp.379-392
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    • 2023
  • Structural health monitoring is used to ensure the well-being of civil structures by detecting damage and estimating deterioration. Wind flow applies external loads to high-rise buildings, with the horizontal force component of the wind causing structural displacements in high-rise buildings. This study proposes a deep learning-based predictive model for measuring lateral displacement response in high-rise buildings. The proposed long short-term memory model functions as a sequence generator to generate displacements on building floors depending on the displacement statistics collected on the top floor. The model was trained with wind-induced displacement data for the top floor of a high-rise building as input. The outcomes demonstrate that the model can forecast wind-induced displacement on the remaining floors of a building. Further, displacement was predicted for each floor of the high-rise buildings at wind flow angles of 0° and 45°. The proposed model accurately predicted a high-rise building model's story drift and lateral displacement. The outcomes of this proposed work are anticipated to serve as a guide for assessing the overall lateral displacement of high-rise buildings.

Traumatic Cardiac Perforation (외상성 심장파열의 외과적 고찰)

  • 성시찬
    • Journal of Chest Surgery
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    • v.12 no.4
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    • pp.365-370
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    • 1979
  • The first Mitral Commissurotomy was performed for tight mitral stenosis on March 1957. The patient was at that time 22-year-old male, student. The longest follow 9p for 22 years and 8 months has been obtained. During the follow up period, late deterioration due to restenosis developed 4 years after initial good result and reoperation was succeeded by transventricular Mitral Valvotomy with Tubb`s ilator on April 1964. The possible cause of restenosis was attributed to recurrent rheumatic activity. After more than 13 years long-good life following 2nd operation, Endocarditis such as episode of high fever & chill intermittently followed by mild fever and night sweat, I t. tibial artery embolization and rupture of aortic cusp. At present, patient complained of no subjective symptom, enjoying ordinary life {NYHA II]. Blood pressure has been 110/50-60 mmHg, trivial diastolic murmur at apex and moderate degree of mechanical murmur on diastole at Erb`s rea. Neither signs of RVH for mitral stenosis nor sign of LVH. ST-T change for aortic regurgitation appeared yet during last 2 yrs. The patient`s are for prevention of Rheumatic activity and development of endocarditis is important for obtaining the better long-term result.

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