• Title/Summary/Keyword: Mean Load

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Changes of Vitamin C Level , Lipid Peroxidation and Lipid Concentration in Plasma of Smokers and Non-smokers (흡연이 혈장의 비타민 C 함량과 지질과산화 및 지질의 농도 변화에 미치는 영향)

  • 윤군애
    • Journal of Nutrition and Health
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    • v.30 no.10
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    • pp.1180-1187
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    • 1997
  • Cigarette smoking is a major risk factor of atherosclerosis and has been reported to contain an abundance of free radical species which could be expected to deplete antioxidants such as vitamin C . The present study was designed to investigate the relationship between smoking, plasma lipid and lipoprotein concentration, and plasma vitamin C level. Fifty-five healthy male smokers and 32 non-smokers were investigated in the study. Mean age, body weight , BMI and blood pressure made no differences in both smokers and non-smokers. Significantly, smokers has higher plasma total cholesterol and LDL-C , and lower HDL-C /LDL-C ratio compared with non-smokers. Plasma level of thiobartiturin acid reactive substances(TBARS), indicator of lipid peroxidation and increased susceptibility of LDL towards lipid perosidation, were elevated in smokers(p<0.001), while the plasma vitamin C level of smokers was significantly lower than that of non-smokers(p<0.05), indicating that elevated lipid peroxidation are associated with decreased plasma vitamin C content. In non-smokers a significantly positive correlation was observed between dietary vitamin C intake and plasma levels, but no such association observed in smokers. Lack of such a relationship and the decreased plasma vitamin C level in the smokers suggest that smoking may cause increased turnover of the plasma antioxidant. Consuquently, the sustained free radical load derived from smoking causes an imbalance in oxidant/antioxidant status and it could be expected that cigarette smoking renders plasma LDL more susceptible to oxidative modification . In the present study the possible explanations for that cigarette smokers have a higher risk of cardiovascular disease include the changes of blood lipid and lipoprotein concentration, and plasma vitamin C status which might have protective functions against free radicals -medaited lipid peroxidation.

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Development of Control Method for Air-Conditioner as the Resources of DLC (직접부하제어자원으로서 에어컨 주기제어 방법론 개발)

  • Doo, Seog-Bae;Kim, Jeoung-Uk;Kim, Hyeong-Jung;Kim, Hoi-Cheol;Park, Jong-Bae;Shin, Joong-Rin
    • Proceedings of the KIEE Conference
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    • 2005.11b
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    • pp.145-147
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    • 2005
  • This paper presents a methodology for satisfying the thermal comfort of Indoor environment and reducing the summer peak demand power by minimizing the power consumption for an Air-conditioner within a space. KEPCO(Korea Electric Power Corporation) use the fixed duty cycle control method regardless of the indoor thermal environment. This method has disadvantages that energy saying depends on the set-point value of the Air-Conditioner and DLC has no net effects on Air-conditioners if the appliance has a lower operating cycle than the fixed duty cycle. A variable duty cycle estimates the PMV(Predict Mean Vote) at the next step with a predicted temperature and humidity coming from the back propagation neural network model. It is possible to reduce the energy consumption by maintaining the Air-conditioner's OFF state when the PMV lies in the thermal comfort range. The proposed methodology uses the historical real data of Sep. 7th, 2001 from a classroom in seoul to verify the effectiveness of the variable duty cycle method comparing with fixed duty cycle. The result shows that the variable duty cycle reduces the peak demand to 2.6times more than fixed duty cycle and increases the load control ratio by 8% more. Based on the variable duty cycle control algorithm, the effectiveness of DLC is much more improved as compared with the fixed duty cycle.

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The Relationships Between Empirical Factors and Water Quality in Agricultural Reservoirs (농업용 저수지 수질과 경험적 인자들과의 관계)

  • Kim, Ho-Sub;Choi, Eun-Mi;Park, Ju-hyun;Hwang, Ha-Sun;Kim, Bomchul;Kong, Dong-Soo;Hwang, Soon-Jin
    • Journal of Korean Society on Water Environment
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    • v.24 no.3
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    • pp.333-339
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    • 2008
  • This study was carried out to assay the relationships between empirical factors and water quality in 23 agricultural reservoirs. Based on the trophic state index (TSI) deviation analysis, phosphorus in type II and III was the primary limiting factor on algal growth. BOD, COD, TP and chl.a concentration in type III reservoirs showed higher concentration than those of other types, while SS and TN concentration was no noticeable difference among three types. Characteristics of type III reservoirs showed large reservoir surface and drainage area, large surface area to volume (SAV) ratio, small drainage area to reservoir area (DA/RA) ratio, relatively old age, large paddy field and upland field to drainage area ratio (Mean 17.4%) and high generation and discharge loads compared to other types of reservoirs. In type I and II reservoirs, trends of BOD, TN, TP concentration in water column, were similar to those of the discharge load of pollutants. Although type II reservoirs generally showed low phosphorus discharge loads compared to type I reservoirs, TP and chl.a concentration in water column was greater than that of type I. Characteristics of type II reservoirs showed relatively large SAV ratio and old age compared to type I reservoirs and was similar to those of type III including eutrophic reservoirs.

Performance Evaluation of a Double Layer Biofilter System to Control Urban Road Runoff (I) - System Design - (이중층 토양 여과시설을 이용한 도로 강우 유출수 처리성능 평가 (I) - 시설 설계인자 결정을 중심으로 -)

  • Cho, Kang Woo;Kim, Tae Gyun;Lee, Byung Ha;Lee, Seul Bi;Song, Kyung Guen;Ahn, Kyu Hong
    • Journal of Korean Society of Water and Wastewater
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    • v.23 no.5
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    • pp.599-608
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    • 2009
  • This manuscript covers the results of field investigation and lab-scale experiments to design a double-layered biofilter system to control urban storm runoff. The biofilter system consisted of a coarse soil layer (CSL) for filtration and fine soil layer (FSL) for adsorption and biological degradation. The variations of flow rate and water quality of runoff from a local expressway were monitored for seven storm events. Laboratory column experiments were performed using seven kinds of soil and mulch to maximize pollutants removal. The site mean concentration (SMC) of storm runoff from the drainage area (runoff coefficient: 0.92) was measured to be 203 mg/L for SS, 307 mg/L for $TCOD_{Cr}$, 12.3 mg/L for TN, 7.3 mg/L for ${NH_4}^+-N$, and 0.79 mg/L for TP, respectively. This study employed a new design concept, to cover the maximum rainfall intensity with one month recurrence interval. Effective storms for last ten years (1998-2007) in seoul suggested the design rainfull intensity to be 8.8 mm/hr Single layer soil column showed the maximum removal rate of pollutants load when the uniformity coefficient of CSL was 1.58 and the silt/clay contents of FSL was virtually 7%. The removal efficiency during operation of double layer soil column was 98% for SS and turbidity, 75% for TCODCr, 56% for ${NH_4}^+-N$, 87% for TP, and 73-91% for heavy metals. The hydraulic conductivity of the soil column, 0.023 cm/sec, suggested that the surface area of the biofilter system should be about 1% of the drainage area to treat the rainfall intensity of one month recurrence interval.

High-temperature Low-cycle Fatigue Life prediction of a Liquid Rocket Turbopump Turbine (액체로켓 터보펌프 터빈의 고열 저주기 피로수명 예측)

  • Lee, Mu-Hyoung;Jang, Byung-Wook;Jeong, Eun-Hwan;Jeon, Seong-Min;Lee, Soo-Yong;Park, Jung-Sun
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2009.05a
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    • pp.18-21
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    • 2009
  • The life of components under high thermal load is typically shorter than other components. The turbopump turbine of liquid rocket is operated under these environments like high temperature and high centrifugal dorce due to high rotating velocity during operating time. These conditions may often cause low-cycle fatigue problem in the turbopump turbine. First of all, to analyze heat stress, ABAQUS/CAE is used and Coffin-manson's equation is used to consider elasticity and plasticity strain. S.W.T's method is used to consider the mean stress effect, using strain history, low-cycle fatigue analysis is done for turbopump turbine which may have FCL(fracture critical location). In this paper, strain life method is applied to analyze low-cycle fatigue.

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A CONTROLLED CYCLIC LOADING ON THE SURFACE TREATED AND BONDED CERAMIC: STAIRCASE METHOD

  • Yi, Yang-Jin
    • The Journal of Korean Academy of Prosthodontics
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    • v.46 no.3
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    • pp.298-306
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    • 2008
  • STATEMENT OF PROBLEM: Effect of surface treatment of ceramic under loading does not appear to have been investigated. PURPOSE: The aim of this study was to investigate the effect of surface treatment of esthetic ceramic, which is performed to increase the bonding strength, on the fracture stress under controlled cyclic loading condition. MATERIAL AND METHODS: Sixty 1.0 mm-thick specimens were made from Mark II Vitablocs (Vita Zahnfabrik, Germany) and divided into 3 groups: polished (control), sandblasted, and etched. Specimens of each group were bonded to a dentin analog material base including micro-channels to facilitate the flow of water to the bonding interface. Bonded ceramics were cyclically loaded with a flat-end piston in the water (500,000 cycles, 15Hz). Following completion of cyclic loading, specimens were examined for subsurface crack formation and subsequent stress was determined and loaded to next specimen by the staircase method according to the crack existence. RESULTS: There were significant differences of mean fatigue limit in the sandblasted (222.86 ${\pm}$ 23.42 N) and etched group (222.86 ${\pm}$ 14.16 N) when compared to polished group (251.43 ${\pm}$ 10.6 N) (P<.05; Wald-type pair-wise comparison and post hoc Bonferroni test). Of cracked specimens, surface treated group showed longer crack propagation after 24 hours. All failures originated from the radial cracking without cone crack. Fracture resistance of this study was very low and comparable to failure load in the oral cavity. CONCLUSION: Well controlled cyclic loading could induce clinically relevant cracks and fracture resistance of Mark II ceramic was relatively low applicable only to anterior restorations. Surface treatment of inner surface of feldspathic porcelain in the matsicatory area could influence lifetime of restorations.

A Study on the Powerlessness, Perception of Health and Cognitive Level of Elderly Home Residents (재가노인들의 무력감, 건강상태 및 인지기능에 관한 조사 연구)

  • Lee, Kang-Yi
    • The Journal of Korean Academic Society of Nursing Education
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    • v.6 no.1
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    • pp.48-63
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    • 2000
  • This study was designed and undertaken to find out the degree of powerlessness, perception of health and cognitive level of elderly home residents and to determine the factors influencing powerlessness, perception of health and cognitive level. The data were collected from October 1st to 20th, 1998. The subjects in this study were 271 elderly home residents over the age 60 living in Taejon city. The study tool for measuring powerlessness was developed by S.E. Chung(1998), the other for measuring perception of health was a self-rating scale defined by Mossey & Shapiro (1982), and the tool for measuring cognitive level was developed by Kahn, Goldfarb, Pollack and Peck(1960). Data were analysed for percentage, mean, t-test, and ANOVA using the SPSS program. The results of this study were as follows ; 1. The degree of powerlessness, perception of health and cognitive level was scored above the median. 2. The degree of the elderly' powerlessness was statistically significantly different in three demographic variables; sex, one's state of health compared to other elderly' and living expense load. 3. Perception of one's health was statistically significantly different in four demographic variables; sex, marital status, educational level and monthly money. 4. Cognitive level of the elderly was statistically significantly different in three demographic variables; age, educational level and one's health of state compared to other elderly' health. In conclusion, the factors influencing the elderly' powerlessness, perception of health and cognitive level generally were age, sex, their economic independence, marital status, and educational level. Also, this study indicates that social welfare for the elderly could be effective in reducing their powerlessness and enhancing their health of state and cognitive level.

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Determinant of the Health Promoting Lifestyle of the Teachers in Choong-Buk province (충북지역 교사들의 건강증진생활양식)

  • Lee, Kyu-Nan;Kim, Soon-Lae
    • Research in Community and Public Health Nursing
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    • v.9 no.1
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    • pp.30-39
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    • 1998
  • The purpose of this study was to identify the factors influencing health promoting lifestyle of teachers and to provide the data for efficient health management of teachers. The subjects of this study were eight hundred nine teachers, who were chosen in Choong-Buk province. Survey Questionaires for data analysis were collected through visiting or mailing from September 1 to 30, 1997. The instruments used in this study were HPLP(Health Promoting Lifestyle Profile) by Walker (1987), Internal Health Locus of Control by Walston et al. (1978), Self Esteem by Rogenberg(1965), Importance of Health by Muhlenkamp (1985), Self Efficacy by Sherer & Maddux(1982), and Family Function by Olson & Schellenberg (1985). Data were analyzed by descriptive statistics, unpaired t-test, ANOVA, Pearsons correlation coefficient and stepwise multiple regression using SPSS/PC(v. 4.01) program. The results were as follows; 1. The mean of health promoting lifestyle was total 2.53 on the average, self-actualization 2.97, nutrition 2.90, interpers 52, stress management 2.33, exercise 1.91, and health responsibility 1.82 in order. The index of total health promoting lifestyle was significantly influenced by the factors including sex, age, religion, marital status, duration of work, teaching load, education level and number of family members. 2. The health promoting Lifestyle was significantly positive correlated with Self Efficacy, Family Function, Importance of Health, Internal Health Locus of Control and Self Esteem. 3. Self Efficacy was the most influential determinant predicting health promoting lifestyle of teachers. Self efficacy, Family Function, Importance of Health, Internal Health Locus of Control and Age explained 42% of the health promoting lifestyle. Based on the above findings, it is suggested to develop nursing intervention to improve Self Efficacy, Importance of Health, Family Function of teachers enhance health promoting lifestyle. Further studies are needed to confirm these findings and to determine factors which significantly influence health promoting lifestyle of teachers.

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Seismic Performance Evaluation of R/C Different Floor Type Interior Beam-Column Joints in the Middle and High-rise Mixed-use Residential Building (중.고층 주상복합 R/C 건축물의 단차형 내부 보-기둥 접합부 내진성능평가)

  • Ha, Gee-Joo;Shin, Jong-Hak;Huh, Mean-Haeng;Hong, Kun-Ho;Ha, Jae-Hoon;Nam, Young-Sik
    • Proceedings of the Korea Concrete Institute Conference
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    • 2009.05a
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    • pp.453-454
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    • 2009
  • In this dissertation, experimental program was carried out to study the hysteretic behavior of the reinforced different floor type interior beam-column joint repeated cyclic loads under seismic actions. The test results was as follow. The reinforced interior beam-column joint, designed by the different floor type, was increased energy dissipation capacity and maximum load carrying capacity according to the increase of different floor in comparison to standard specimen. And it was also dissimilar to failure mode adjacent to joint region. energy dissipation capacity of each specimen, designed by the different floor type, was increased 1.1${\sim}$1.35 times in comparison to standard specimen.

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Uncertainty Analysis of Long-Term Behavior of Reinforced Concrete Members Under Axial Load (축력을 받는 철근콘크리트조 부재 장기거동 예측의 불확실성 분석)

  • Yoo, Jae-Wook;Kim, Seung-Nam;Yu, Eun-Jong;Ha, Tae-Hun
    • Journal of the Korea Concrete Institute
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    • v.26 no.3
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    • pp.343-350
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    • 2014
  • A probabilistic construction stage analysis using the Monte Carlo Simulation was performed to address the effects of uncertainty regarding the material properties, environmental factors, and applied forces. In the previous research, creep and shrinkage were assumed to be completely independent random variables. However, because of the common influencing factors in the material models for the creep and shrinkage estimation, strong correlation between creep and shrinkage can be presumed. In this paper, an Monte Carlo Simulation using CEB-FIB creep and shrinkage equations were performed to actually evaluate the correlation coefficient between two phenomena, and then another Monte Carlo Simulation to evaluate the statistical properties of axial strain affected by partially correlated random variables including the material properties, environmental factors, and applied forces. The results of Monte Carlo Simulation were compared with measured strains of a column on a first story in a 58-story building. Comparison indicated that the variation due to the uncertainty related with the material properties were most severe. And measured strains was within the range of mean+standard deviation.