• Title/Summary/Keyword: Long Term

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A experimental study on the long-term response of high-strength Steel-Fiber Reinforced Concrete (고강도 강섬유 보강 콘크리트의 장기거동 특성에 관한 실험적 연구)

  • Seo Jong-Myeong;Kim Jae-Ki;Lee Joo-Ha;Yoon Young-Soo
    • Proceedings of the Korea Concrete Institute Conference
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    • 2004.11a
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    • pp.337-340
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    • 2004
  • In recent days, the beneficial effects of using fiber reinforced concrete, especially Steel Fiber Reinforced Concrete, have been on the rise. However, few studies on long-term behavior of SFRC are executed in spite of great demand of SFRC. The fact that SFRC is far better than NRC in various properties such as tensile strength, ductility, flexural toughness has been certified by many researchers. And, those advantages can be also applied to decrease the structures deterioration induced by creep and shrinkage. Furthermore, even though it is fact that SFRC is generally used in joint members to distribute concentrated stresses by fibers, SFRC is treated as NRC in designing especially for long-term behavior of structures. So this paper is about a study on the long-term response of SFRC applied to HPC about 40MPa. Therefore, in this paper, the test results of eighteen high-strength concrete specimens and steel fiber-reinforced concrete specimens, with steel fiber content of $1\%$ by volume were presented. The test result shows that SFRC is advantageous rather than NRC in long-term response.

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A Comparison Study on the Effects of Fashion Emotional and Relationship Experience on Long-Term Relationship Orientation of Middle and Old Aged Women (중.노년층 여성이 경험하는 패션 감성.관계체험이 장기적 관계지향성에 미치는 효과 비교 연구)

  • Seo, Eun-Kyoung
    • Journal of the Korean Society of Clothing and Textiles
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    • v.32 no.9
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    • pp.1407-1417
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    • 2008
  • This study intended to compare the effects of fashion emotional and relationship experience of middle and old aged women on their long-term relationship orientation. The survey was conducted in September and October in 2006 on 579 middle old aged women whose age varied from 40 to 70 years old, who lived in Seoul and the metropolitan area and had experienced fashion shopping. The SPSS 12.0 was used to do an analysis of frequency, an exploratory factor analysis, and a multi-regression analysis and Lisrel 8.14 was applied to make a path analysis. The result of this study was as follows: Comparing the two age groups, the most important fact was that fashion related experience had more affective on long-term relationship orientation for old aged than middle aged women. Secondly, the effects of fashion emotional experience of middle and old aged women affected the long-term relationship orientation were the same. This analysis suggested that intensive marketing strategy effort of emotional experience for middle aged women and relational experience for old aged women should be more effective in fashion market.

The oral health awareness and oral health care provided by workers in long-term elderly care facilities (일부 지역 노인요양기관 종사자의 구강건강 인식정도와 구강건강관리 제공 실태 조사)

  • Park, Jeong-Ran;Hong, Min-Hee;Choi, Yu-Ri
    • Journal of Korean society of Dental Hygiene
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    • v.15 no.2
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    • pp.245-251
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    • 2015
  • Objectives: The purpose of this study is to evaluate the oral health awareness and oral health care provided by workers in the long-term elderly care facilities. Methods: A self-reported questionnaire was completed by 213 workers in long-term elderly care facilities. The questionnaire consisted of general characteristics, oral health awareness, oral health behavior, oral health knowledge, oral health care professionals, oral health care, oral health care improvement, and denture care. Except the incomplete answers, 200 data were analyzed by the statistical software of SPSS WIN 18.0. Results: Highly educated people tended to have higher oral health awareness. The workers in the facility maintained the oral health care but they suggested that dental professionals are needed. Conclusions: It is necessary to suggest the oral health care management by dental professionals.

Feasibility of Long Term Feed and Bleed Operation For Total Loss of Feedwater Event

  • Kwon, Young-Min;Song, Jin-Ho
    • Nuclear Engineering and Technology
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    • v.28 no.3
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    • pp.257-264
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    • 1996
  • The conventional Equipment Environment Qualification (EEQ) envelope is developed based on the containment responses during the design basis events. The Safety Depressurization System (SDS) design without In-containment Refueling Water Storage Tank (IRWST) adopted in the Ulchin 3&4 challenges the conventional EEQ envelope during long term Feed and Bleed (F&B) operation due to the direct discharge of high mass and energy into the containment. Therefore, it is necessary to confirm that the containment pressure and temperature history during the long term F&B operation does not violate the conventional EEQ envelope. However, this subject has never been quantitatively assessed before. To investigate the success path of long term F&B operation this paper analyzes the thermal hydraulic response of the containment and Reactor Coolant System (RCS) until the completion of depressurization and cooldown of RCS into Shutdown Cooling System (SCS) entry condition. It is found that the SCS entry condition can be reached within 6 hours without violating the EEQ curve by proper operation of SDS valves, High Pressure Safety Injection (HPSI) pumps and active Containment Heat Removal System (CHRS). The suggested strategy not only demonstrates the feasibility of long term F&B operation but also can be utilized in the preparation of Emergency Procedure Guidelines (EPGs)

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Forecasting the Long-term Water Demand Using System Dynamics in Seoul (시스템 다이내믹스법을 이용한 서울특별시의 장기 물수요예측)

  • Kim, Shin-Geol;Pyon, Sin-Suk;Kim, Young-Sang;Koo, Ja-Yong
    • Journal of Korean Society of Water and Wastewater
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    • v.20 no.2
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    • pp.187-196
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    • 2006
  • Forecasting the long-term water demand is important in the plan of water supply system because the location and capacity of water facilities are decided according to it. To forecast the long-term water demand, the existing method based on lpcd and population has been usually used. But, these days the trend among the variation of water demand has been disappeared, so expressing other variation of it is needed to forecast correct water demand. To accomplish it, we introduced the System Dynamics method to consider total connections of water demand factor. Firstly, the factors connected with water demand were divided into three sectors(water demand, industry, and population sectors), and the connections of factors were set with multiple regression model. And it was compared to existing method. The results are as followings. The correlation efficients are 0.330 in existing model and 0.960 in SD model and MAE are 3.96% in existing model and 1.68% in SD model. So, it is proved that SD model is superior to the existing model. To forecast the long-term water demand, scenarios were made with variations of employment condition, economic condition and consumer price indexes and forecasted water demands in 2012. After all scenarios were performed, the results showed that it was not needed to increase the water supply ability in Seoul.

EXTENSION OF OPERATIONAL LIFE-TIME OF WWER-440/213 TYPE UNITS AT PAKS NUCLEAR POWER PLANT

  • Katona, Tamas Janos;Ratkai, Sandor
    • Nuclear Engineering and Technology
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    • v.40 no.4
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    • pp.269-276
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    • 2008
  • Operational license of WWER-440/213 units at Paks NPP, Hungary is limited to the design lifetime of 30 years. Prolongation by additional 20 years of the operational lifetime is feasible. Moreover, enhancement of the reactor thermal power by 8% will increase both the net power output and the competitiveness of the plant. Paks NPP is a pioneer considering the power up-rate and preparation of long-term operation of WWER-440/213 design. Systematic preparatory work for long-term operation of Paks NPP has been started in 2000. A regulatory framework and a comprehensive engineering practice have been developed. According to the authors view, creation of a gapless engineering system via consequent application of best practices, and feed-back of experiences together with proper consideration of WWER-440/V213 features are the decisive elements of ensuring the safety of long-term operation. That systematic engineering approach is in the focus of recent paper. Key elements of justification and measures for ensuring the safety of long-term operation of Paks NPP WWER-440/213 units are identified and discussed. These are the assessment of plant condition and review of adequacy of ageing management programmes, also the review, validation and reconstitution of time limited ageing analyses as core tasks of licence renewal.

CNN-LSTM Coupled Model for Prediction of Waterworks Operation Data

  • Cao, Kerang;Kim, Hangyung;Hwang, Chulhyun;Jung, Hoekyung
    • Journal of Information Processing Systems
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    • v.14 no.6
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    • pp.1508-1520
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    • 2018
  • In this paper, we propose an improved model to provide users with a better long-term prediction of waterworks operation data. The existing prediction models have been studied in various types of models such as multiple linear regression model while considering time, days and seasonal characteristics. But the existing model shows the rate of prediction for demand fluctuation and long-term prediction is insufficient. Particularly in the deep running model, the long-short-term memory (LSTM) model has been applied to predict data of water purification plant because its time series prediction is highly reliable. However, it is necessary to reflect the correlation among various related factors, and a supplementary model is needed to improve the long-term predictability. In this paper, convolutional neural network (CNN) model is introduced to select various input variables that have a necessary correlation and to improve long term prediction rate, thus increasing the prediction rate through the LSTM predictive value and the combined structure. In addition, a multiple linear regression model is applied to compile the predicted data of CNN and LSTM, which then confirms the data as the final predicted outcome.

Discharge Capacity of Prefabricated Vertical Drain Confined In-Clay Under Long-Term Conditions (연직배수재 타설 후 장기간 경과된 지반의 통수성능)

  • Jeong, Sang-Guk
    • Journal of the Korean Geosynthetics Society
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    • v.17 no.4
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    • pp.239-249
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    • 2018
  • Typically, soft clay improvement is carried out using installation of PVD and surcharge method. According to circumstances, installed PVD has left for a long time due to the change in construction schedule. Therefore, for simulation of this kind of condition, discharge capacity tests were carried out under a series of temperature condition (30, 35, $40^{\circ}C$). The results indicated that under water confinement, the discharge capacities significantly reduced with elapsed time. And, the empirical equation by Miura and Chai (2000) was used for estimating the long-term in-clay discharge capacity. Based on the test results, it is recommended that in term of long-term discharge capacity, Miura and Chai's equation and reliability evaluation using discharge capacity tests under a series of temperature condition may be used.

An exploration of factors affecting the Satisfaction of long-term on-site training: Focusing on IPP of K University (장기현장실습 프로그램의 만족도 영향요인 탐색: K대학 IPP 프로그램을 중심으로)

  • Lee, Ji-young;Lee, Sang-kon
    • Journal of Engineering Education Research
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    • v.21 no.5
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    • pp.40-53
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    • 2018
  • The purpose of this study was to investigate the factors affecting the satisfaction of the program for the quality improvement of the long-term on-site training operated by the university. The survey questionnaire data of 393 students who participated in the IPP program of K university were used to analyze the data and the results were as follows: First, factors affecting the satisfaction of long-term on-site training were corporation factors and university factors. Specifically, job contents, coaching, job scope, center support were found to have a significant effect in that order. Second, the factors affecting the satisfaction of long-term on-site training were different according to group characteristics(IPP participation types, major types, corporation types). It is necessary to intensively manage the common and important corporation factors, and it is necessary to closely examine each factor derived from group characteristics, and to support and strive at university level according to group characteristics in student counseling and matching.

A long-term subacute sclerosing panencephalitis survivor treated with intraventricular interferon-alpha for 13 years

  • Kwak, Minsun;Yeh, Hye-Ryun;Yum, Mi-Sun;Kim, Hyun-Jin;You, Su Jeong;Ko, Tae-Sung
    • Clinical and Experimental Pediatrics
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    • v.62 no.3
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    • pp.108-112
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    • 2019
  • Subacute sclerosing panencephalitis (SSPE) is a rare, progressive, and fatal central nervous system disorder resulting from persistent measles virus infection. Long-term data are scarce, with a maximum follow-up period of 10 years. Interferon-alpha ($IFN-{\alpha}$) is a protein that exerts its antiviral activity via enhancement of cellular immune response and is reported to be an effective drug for the treatment of SSPE. However, there is currently no consensus regarding the optimal duration of $IFN-{\alpha}$ therapy. Here, we present a case report of a patient with SSPE treated with long-term intraventricular $IFN-{\alpha}$ therapy, which facilitated clinical improvement and neurological stabilization without causing serious adverse effects. To the best of our knowledge, this is one of the longest follow-up studies investigating a patient with SSPE receiving intraventricular $IFN-{\alpha}$ treatment. Further studies are necessary to validate the benefits and safety of long-term intraventricular $IFN-{\alpha}$ treatment in patients with SSPE.