• Title/Summary/Keyword: Service Interval

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Multilevel modeling of diametral creep in pressure tubes of Korean CANDU units

  • Lee, Gyeong-Geun;Ahn, Dong-Hyun;Jin, Hyung-Ha;Song, Myung-Ho;Jung, Jong Yeob
    • Nuclear Engineering and Technology
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    • v.53 no.12
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    • pp.4042-4051
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    • 2021
  • In this work, we applied a multilevel modeling technique to estimate the diametral creep in the pressure tubes of Korean Canada Deuterium Uranium (CANDU) units. Data accumulated from in-service inspections were used to develop the model. To confirm the strength of the multilevel models, a 2-level multilevel model considering the relationship between channels for a CANDU unit was compared with existing linear models. The multilevel model exhibited a very robust prediction accuracy compared to the linear models with different data pooling methods. A 3-level multilevel model, which considered individual bundles, channels, and units, was also implemented. The influence of the channel installation direction was incorporated into the three-stage multilevel model. For channels that were previously measured, the developed 3-level multilevel model exhibited a very good predictive power, and the prediction interval was very narrow. However, for channels that had never been measured before, the prediction interval widened considerably. This model can be sufficiently improved by the accumulation of more data and can be applied to other CANDU units.

A Multi-category Task for Bitrate Interval Prediction with the Target Perceptual Quality

  • Yang, Zhenwei;Shen, Liquan
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.15 no.12
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    • pp.4476-4491
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    • 2021
  • Video service providers tend to face user network problems in the process of transmitting video streams. They strive to provide user with superior video quality in a limited bitrate environment. It is necessary to accurately determine the target bitrate range of the video under different quality requirements. Recently, several schemes have been proposed to meet this requirement. However, they do not take the impact of visual influence into account. In this paper, we propose a new multi-category model to accurately predict the target bitrate range with target visual quality by machine learning. Firstly, a dataset is constructed to generate multi-category models by machine learning. The quality score ladders and the corresponding bitrate-interval categories are defined in the dataset. Secondly, several types of spatial-temporal features related to VMAF evaluation metrics and visual factors are extracted and processed statistically for classification. Finally, bitrate prediction models trained on the dataset by RandomForest classifier can be used to accurately predict the target bitrate of the input videos with target video quality. The classification prediction accuracy of the model reaches 0.705 and the encoded video which is compressed by the bitrate predicted by the model can achieve the target perceptual quality.

A Study on the Association Between Ginseng Intake and Incidences of Cancer - Kangwha Cohort Study - (인삼섭취와 암발생과의 관련성에 관한 연구 - 강화코호트연구 -)

  • Byun, Joo-Sun;Ohrr, Hee-Choul;Hong, Jae-Suk;Sohn, Tae-Yong;Yi, Sang-Wook
    • Journal of Preventive Medicine and Public Health
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    • v.36 no.4
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    • pp.367-372
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    • 2003
  • Objectives : There are many concerns about ginseng as a cancer chemopreventive substance, but there have been few epidemiological studies on ginseng, This study sought to examine the relationships between ginseng intake and cancer incidence in the Kangwha cohort. Methods ; Between March 1985 and December 1999, 2697 males, aged 55 or over, as of 1985, were followed up for their cancer incidence. The cancer incidence rate, standardized incidence ratio and risk ratios were calculated according to ginseng intake. A Cox proportional hazard model was used to adjust for age at entry, smoking, alcohol intake, hypertension, and body mass index. Results & Conclusions : The ginseng intake group had the same cancer (C00-C97) incidences (Standardized Incidence Ratio: SIR=1.11, 95% Confidence Interval=0.97-1.27) and the same risk ratio (RR=1.09, 95% Confidence Interval=0.85-1.41) as the no-intake group. Analyzing the subjects that had followed up from 1990, however, the ginseng intake group had lower cancer incidences at all sites (RR=0.79, 95% Confidence Interval=0.58-1.09). This was a cohort study to try and evaluate the association between ginseng intake and the incidences of cancer, The results of this study provide no clear conclusions on the cancer preventive effects of ginseng. Therefore, further study is needed in the future.

Received Signal Performance Measurement in the Urban Area for the Variable DVB-H Parameters (DVB-H 파라미터 변화에 따른 도심 지역에서의 수신 신호 성능 측정)

  • Song, Ki-Hong
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.18 no.10
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    • pp.1181-1188
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    • 2007
  • This paper presents the measured signal performances in the urban environment for the DVB-H parameters such as code rate, burst size, FFT mode and modulation technique to analyze the DVB-H signal performance avaible for the embodiment of single frequency network to improve the frequency efficiency. Measurements were performed for the case for applying and non-applying MPE-FEC technique simultaneously. Results show that the most outstanding performance are found in the case of QPSK modulation, 1/2 code rate, 2 k FFT mode and 512 burst size. In addition, the signal performance by the SFN with 1/8 guard interval becomes superiour in comparision with the measured data from each site and the data from SFN with 1/32 guard interval. The analysis of the results can be instructive for the improvement of the signal performance and broadcasting quality for the terrestrial digital mobile broadcasting service.

Degradation Evaluation of 1Cr-lMo-0.25V Steel by Measuring Reversible Magnetic Permeability (가역 투자율 측정에 의한 1Cr-1Mo-0.25V 강의 열화도 평가)

  • Ryu, Kwon-Sang;Kim, Yong-Il;Nahm, Seung-Hoon;Yu, Kwang-Min;Cho, Youk;Son, De-Rac
    • Journal of the Korean Society for Nondestructive Testing
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    • v.20 no.5
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    • pp.445-450
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    • 2000
  • The integrity of the turbine rotors can be assessed by measuring reversible permeability and Vickers hardness of the aged rotors at service temperature. The measurement system of reversible permeability, which measured by applied alternating perturbing magnetic field, was constructed in order to evaluate material degradation, nondestructively. The test specimen was 1Cr-1Mo-0.25V steel used widely for turbine rotor material, and the specimens were prepared by the isothermal heat treatment at $630\;^{\circ}C$. The reversible permeability of the test materials were measured at room temperature. The peak interval of reversible permeability and Vickers hardness decreased with the increase of degradation. The degradation of test material may be determined nondestructively by the lineality of Vickers hardness and the peak interval of reversible permeability.

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Effect of Pregnancy on Lactation Milk Value in Dairy Buffaloes

  • Khan, Sarzamin;Qureshi, Muhammad Subhan;Ahmad, Nazir;Amjed, Muhammad;Durrani, Fazali Raziq;Younas, Muhammad
    • Asian-Australasian Journal of Animal Sciences
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    • v.21 no.4
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    • pp.523-531
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    • 2008
  • Buffalo are a major source of milk production, contributing 12.1% in the World and 38.0% in Asia. The buffaloes are kept under peri-urban farming systems to produce milk for urban populations. Breeding is delayed in these herds to get more economic benefit because farmers believe that the pregnancy decreases milk production. The lactation milk value has been studied in this paper as an economic indicator. Complete milk yield records of 3,304 buffaloes was collected from a group of state farms. Economic traits including lactation yield, lactation length, calving interval (CI), dry period and milk yield per day of calving interval (MYPDCI) were derived from the data. The animals were grouped according to parity number (1-3), service period (G1 to G4, conceiving during <150, 150-200, 200-300 and >300 days post calving) and yield levels (HMY>2,500; MMY 2,001-2,500; and LMY 1,500-2,000 liters/ lactation). To study the effect of pregnancy on milk composition a research trial was conducted at a medium size private dairy farm, using forty lactating buffaloes of three yield levels and four service period groups, as described already. Milk was sampled on alternate weeks and analyzed for fat and protein contents (%). For quantifying the value of milk produced during a lactation period, the value corrected milk (VCM) was determined and converted to lactation milk value (LMV). Group means were compared for varicous parameters. Highest milk yield ($2,836.50{\pm}15.68$ liters/lactation) was recorded in the HMY animals of G4 group while lowest milk yield of $1,657.04{\pm}8.34$ liters/lactation was found in LMY of G1. Lactation was significantly increased with the extending of service period. The shortest dry period was recorded in HMY, parity 1, G1 animals and the longest in parity 2, MMY, G4.The CI was shortest in HMY, parity 1, and G1 animals and longest in LMY, parity 3, G4 buffaloes. The HMY, parity 2, G1 buffaloes showed the highest MYPDCI and the lowest value was recorded ($6.53{\pm}0.17$ vs. $2.76{\pm}0.04$ liter/day) for LMY, parity 1, G4 buffaloes. The VCM decreased with the delayed conception. This decreasing trend was higher in respect of the total yield but decrease in the VCM was smaller due to the increasing levels of fat and protein in the milk. The gap between the various production classes was reduced based on the VCM as compared with the yield per day of CI. LMV showed a consistent decline with extending service period in all three production groups. The study suggests that CI increased with delayed conception, showing a consistent trend in the low, moderate and high yielding buffaloes. There was a coherent declining pattern of milk yield with delaying conception, associated with prolonged CI. An animal conceiving at a later stage of lactation showed a decline in financial returns of 24 to 27% compared with those conceiving earlier.

A comparative study on immunogenicity of the porcine epidemic diarrhea virus live-vaccine and inactivated-vaccine (돼지유행성설사병(PEDV) 생독과 사독백신의 면역형성 비교연구)

  • Kwon, Mee-Soon;Cho, Hyun-Ung;Lee, Eun-Mi;Lee, Ji-Yoog;Seo, Heyng-Seok;Im, Jeong-Cheol;Hur, Boo-Hong
    • Korean Journal of Veterinary Service
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    • v.32 no.3
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    • pp.201-207
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    • 2009
  • Porcine transmissible gastroenteritis virus (TGEV), porcine epidemic diarrhea virus (PEDV) and rotaviruses are considered as the most important causative agents of diarrhea in piglets. The study established 3 method vaccination programs to prevent PEDV. A (LL)group inoculated twice vaccinations on 2-weeks-interval during the late term of pregnant sows with PEDV live vaccine. The B (LKK) group was applied that one time single PEDV live vaccine at the pre-mate followed by the TGEV PEDV combined inactivated vaccine (twice vaccination on 2-weeks interval at the third-trimester). C (KK) group was applied to sow which inoculated twice vaccination on 2-weeks-interval during the late term of pregnant sows with by the TGEV, PEDV combined inactivated vaccine. As the result of SN test on sows in the pig farm before vaccination, antibody titers was showed 9/45 (20.0%). By comparison with the serum neutralizing antibody titers against PEDV of the vaccination programs after PEDV of the vaccination, A group and B group vaccination method was higher than those of C group in sows. In the piglets up to 2 weeks of age, A group was showed antibody titers of 17/22 (81.8%) that showed 2-128, and B group was showed antibody titers of 30/37 (81.1%) that showed 2-512, and C group was showed antibody titers of 14/28 (50.0%) that showed 2-32. On the other hand, PEDV antibody titers were tested for the survey. As the results of SN test, Aujeszky's disease survey in 54 pig farms from november 2005 to august 2006, antibody titers of 47/286 (16.4%) showed above 2. Five breeding farms were antibody titers of 38/77 (49.4%), Wanggung zone farms antibody titers of 59/85 (69.4%). In pigs farms vaccinated the first of twice PEDV live vaccine, and after 6 month, the second of twice TGEV PEDV combined inactivated vaccine (LLKK, 256-1024 titer) method was higher than those of vaccinated twice the early term of pregnant, and twice the late term of pregnant sows of PEDV live vaccine (LLLL, 32 titer).

Control Efficacy of Different Types of Chemicals with Different Spraying Schedules on Plum Bacterial Black Spot (약제별 및 살포시기별 자두 검은점무늬병 방제효과)

  • Ryu, Young Hyun;Lee, Joong Hwan;Kwon, Tae Young;Kim, Seung Han;Kim, Dong Geun
    • Research in Plant Disease
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    • v.18 no.4
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    • pp.349-353
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    • 2012
  • Xanthomonas arboricola pv. pruni causes black spot symptom on fruit of plum, resulting in yield loss by reduction of marketable fruit production. To develop an effective control program, some chemicals were sprayed in various scheme during dormant season and growing season after blooming period. Copper-based chemicals were sprayed during dormant season and antibiotic-based chemicals were sprayed during fruit growing season. Sprays of antibiotic-based chemicals in growing season was more effective than copper-based chemicals sprays in dormant season. Three applications of antibiotic-based chemicals in 10 days interval starting 10 days after full blooming controlled disease incidence as much as 93%, whereas applications of copper-based chemicals in dormant season controlled 26-42%. Antibiotic-based chemicals application starting 10 days after full blooming was more effective than starting 20 or 30 days after full blooming.

Effects of Case Management using Resident Assessment Instrument-Home Care(RAI-HC) in Home Health Services for Older People (재가노인 기능상태 평가도구를 이용한 재가노인 사례관리 프로그램의 효과 평가)

  • June, Kyung-Ja;Lee, Ji-Yun;Yoon, Jong-Lull
    • Journal of Korean Academy of Nursing
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    • v.39 no.3
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    • pp.366-375
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    • 2009
  • Purpose: To evaluate the effects of case management using Resident Assessment Instrument-Home Care(RAI-HC) in home health service for older people. Methods: All elders were assessed at baseline and 3 months later using RAI-HC. The change of function in the intervention group was compared with that of a conventional intervention group. Function was measured with Activities of Daily Living(ADL), Instrumental Activities of Daily Living(IADL), Cognitive Performance Scale(CPS), Depression Rating Scale(DRS), Pain and the number of Clinical Assessment Protocols(CAP). Results: Among ninety two elders participated in the program, 59 were allocated to the case management group and 33 to the conventional group. The intervention, home health service by a nurse over a 3 month period, consisted of comprehensive assessment, case conference for care plan, direct care, education and referral, and outcome evaluation. The percent of elders whose function improved in the intervention group was greater than the conventional group for depression(odds ratio [OR]: 10.941, confidence interval [CI]: 2.338-51.206), IADL(OR: 4.423, CI: 1.151-16.999) and the number of CAP(OR: 11.443, CI: 3.805-34.410). Conclusion: Case management was effective for older people in the community. The effect might have resulted from individual, systematic intervention, however, standards of service including eligibility criteria for case management and collaboration of multi-disciplines is required for more effective home health service programs.

Association between Inhaled Corticosteroid Use and SARS-CoV-2 Infection: A Nationwide Population-Based Study in South Korea

  • Lee, Sang Chul;Son, Kang Ju;Han, Chang Hoon;Jung, Ji Ye;Park, Seon Cheol
    • Tuberculosis and Respiratory Diseases
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    • v.85 no.1
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    • pp.80-88
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    • 2022
  • Background: Although it is known that inhaled corticosteroid (ICS) use may increase the risk of respiratory infection, its influence on the risk of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection remains unknown. Thus, the aim of this study was to investigate the association between ICS use and the positivity of SARS-CoV-2 infection among patients with chronic respiratory diseases. Methods: Nationwide data of 44,968 individuals with chronic respiratory diseases tested for SARS-CoV-2 until May 15, 2021 were obtained from the Ministry of Health and Welfare and Health Insurance Review and Assessment Service in Korea. The positivity of SARS-CoV-2 infection was retrospectively analysed according to the prescription, type, and dose of ICS taken one year before SARS-CoV-2 test. Results: Among 44,968 individuals tested, 931 (2.1%) were positive for SARS-CoV-2. A total of 7,019 patients (15.6%) were prescribed ICS one year prior to being tested for SARS-CoV-2. Low, medium, and high doses of ICS were prescribed in 7.5%, 1.6%, and 6.5% of total cases, respectively. Among types of ICS, budesonide, fluticasone, beclomethasone, and ciclesonide were prescribed in 3.7%, 8.9%, 2.3%, and 0.6% of total cases, respectively. A multivariate analysis showed no significant increase in infection with ICS use (odds ratio, 0.84; 95% confidence interval, 0.66-1.03). Moreover, there were no associations between the positivity of infection and the dose or type of ICS prescribed. Conclusion: Prior ICS use did not increase the positivity for SARS-CoV-2 infection. Moreover, different doses or types of ICS did not affect this positivity.