• 제목/요약/키워드: Sample-Period

검색결과 1,964건 처리시간 0.029초

화력발전소 증기터빈용 12Cr 강의 저주기 피로거동 (Low Cycle Fatigue Behavior of 12Cr Steel for Thermal Power Plant Steam Turbine)

  • 강명수
    • 한국정밀공학회지
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    • 제19권8호
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    • pp.71-76
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    • 2002
  • In this study low cycle fatigue (LCF) behavior of 12Cr steel at high temperature are described. Secondly, comparisons between predicted lives and experimental lives are made for the several sample life prediction models. Two minute hold period in either tension or compression reduce the number of cycles to failure by about a factor of two. Twenty minute hold periods in compression lead to shorter lives than 2 minute hold periods in compression. Experiments showed that life predictions from classical phenomenological models have limitations. More LCF experiments should be pursued to gain understanding of the physical damage mechanisms and to allow the development of physically-based models which can enhance the accuracy of the predictions of components. From a design point-of-view, life prediction has been judged acceptable for these particular loading conditions but extrapolations to thermo-mechanical fatigue loading, for example, require more sophisticated models including physical damage mechanisms.

The Nexus between FDI and Growth in the SAARC Member Countries

  • Jun, Sangjoon
    • East Asian Economic Review
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    • 제19권1호
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    • pp.39-70
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    • 2015
  • This paper examines the effects of foreign direct investment (FDI) on South Asian economies' output growth, utilizing recent panel cointegration testing and estimation techniques. Annual panel data on eight SAARC (South Asian Association for Regional Cooperation) member countries' macroeconomic variables over the period 1960- 2013 are employed in empirical analysis. Using various heterogeneous panel cointegration and panel causality tests, a bi-directional relationship between FDI and growth is found. We find evidence for both FDI-led growth and growth-induced FDI hypotheses for the South Asian economies over the sample period. Individual member countries exhibit heterogeneity in terms of the direction or existence of causality subject to their idiosyncratic economic conditions. Among various regressors, FDI, financial development, human capital, and government consumption show the most significant positive effects on output growth. As determinants of FDI, GDP, financial development, human capital, and government consumption are found significant in the region. The bi-directional causality between FDI and growth is found robust to the inclusion of other control variables and using different estimation techniques.

The Long-Term Effects of Familial Difficulties Experienced in Childhood: Predictors of Internalizing Behavior Problems during the Early Adolescent Period and Late Life Periods

  • Sohn Byoungduk
    • International Journal of Human Ecology
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    • 제6권1호
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    • pp.103-115
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    • 2005
  • This study utilized data (a sample of 18,553 people born in 1958 in England, Scotland, and Wales) from the National Child Development Study of 1968 and 1991 to explore the influence of familial difficulties on the internalizing behavioral patterns during the early adolescent period and late life outcomes periods. In this paper, internalizing behavioral problems include 'depression', 'anxiety', 'hostility to adults', 'hostility to children', and 'withdrawal'. Late outcomes were analyzed in two different variables and one marital management domain: 'unemployment', 'seen doctors about emotional problems', 'divorce or separation; never lived as a couple; arguments end in violent behavior' The results indicate that young adolescents who had experienced familial difficulties also have internalizing behavioral problems giving them emotional and behavioral instability. The findings also show that familial difficulties during childhood positively contribute to late life outcomes such as unemployment, emotional problems, and marital management. This study suggests that in order to effectively respond to the needs of children and adolescents who have experienced various familial difficulties, counselors and educators must guide parents.

생(生)계분을 이용한 미꾸리 양식에 관한 연구 (A Study on the Mudfish Raising using of Raw Hens Excreta)

  • 손장호
    • 한국유기농업학회지
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    • 제13권1호
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    • pp.113-122
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    • 2005
  • for 50% of Rash water every week during experimental period. Eight of 100L of aquarium, eight kg of mudfish and four of female korean native chicken were used this study. This study are divided according to the mudfish fed on commercial mudfish diet in the four of control group and fed on raw hens excreta in the four treatment group. The chemical composition was compared with commercial mudfish diet and hens excreta. In the both sample, crude protein contents was almost same. The crude fat and crude ash were higher in hens excreta than commercial mudfish diet. The growth performance of mudfish tend to high when fed hens excreta. There were no differences in contents of E. Coli and Salmonella and pH of water in aquariums between the groups. Mortality of mudfish tend to decrease when fed hens excreta. No problem with mudfish health was observed during the experimental period of 35 days. These results indicated that it is possible to raising mudfish fed on hens excreta only.

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입자상 물질 폭로농도의 통계적 평가방법에 관한 고찰 -용접·연삭 작업장의 근로자를 대상으로- (A Statistical Assessment of Particulate Exposure Concentration for the Welders and Grinding workers)

  • 윤영노;이관형
    • 한국산업보건학회지
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    • 제1권2호
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    • pp.154-163
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    • 1991
  • Particulate matter exposure leva1 of welders and grinding workers was evaluated in Banwol and Changwon industry complexes. Full period single sample and full period consecutive samples were collected with personal air samplers attached to workers. Compliance difference with 8-hour time weighted average (TWA) was compared by Korean strategy and the classification system recommended by OHSA for employee exposure to particulates. And difference of compliance was compared according to precision of measurement and analysis (total precision). Compliance rate was depended on the total precision, therefore, quality control of measurement and analysis was important.

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건조방법에 따른 비지의 품질변화 (Changes in Quality of Soybean Curd Residue as Affected by Different Drying Methods)

  • 김동수;설명훈;김현대
    • 한국식품영양과학회지
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    • 제25권3호
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    • pp.453-459
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    • 1996
  • This study was carried out to determine the changes in quality during the drying process and the optimum drying condition for utilizing soybean curd residue. The quality criteria for soybean curd residue were acid value, peroxide value, fatty acid composition and microbial concentration. The acid values of soybean curd residue were 7.5, 4.5 and 5.9 KOH mg/g upon 12 hour drying with open-air sun, ambient-air blast and warm-air blast, respectively. The numbers of total aerobic bacteria and molds increased remarkably during drying with open-air sunlight, ambient-air blast and warm-air blast except for hot air blast. Among different drying methods, the hot air blast drying(1kg of sample) was the most effective methods, which completed in three hours. Also, the drying method demonstrated a typical drying curve ; settling down, constant rate drying and falling rate drying period were shown within one hour, from one and three hours and after three hours, respectively. Moreover, there was significant variation in the constant drying period for the quality of soybean curd residue.

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가스하이드레이트 배가스 치환 시 주입유속의 영향에 관한 실험적 연구 (Experimental Study on Injection Rate Effects during Gas Hydrate Production using Flue Gas Swapping Method)

  • 이동건;이주용;이민희;이재형
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2008년도 추계학술대회 논문집
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    • pp.196-199
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    • 2008
  • In this study, gas hydrate production has been followed using swapping method to investigate the effect of injection rate of flue gas and soaking period in unconsolidated artificial sand sample. The results shows that recovery factor of methane gas decreases with increasing the injection rate of flue gas. This indicates that the velocity of flue gas in porous media may act as kinds of inhibitor for production of hydrate. Also recovery factor increases with increasing the soaking time.

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음성신호 적응분할방법에 의한 특징분석 (Features Analysis of Speech Signal by Adaptive Dividing Method)

  • 장승관;최성연;김창석
    • 음성과학
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    • 제5권1호
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    • pp.63-80
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    • 1999
  • In this paper, an adaptive method of dividing a speech signal into an initial, a medial and a final sound of the form of utterance utilized by evaluating extreme limits of short term energy and autocorrelation functions. By applying this method into speech signal composed of a consonant, a vowel and a consonant, it was divided into an initial, a medial and a final sound and its feature analysis of sample by LPC were carried out. As a result of spectrum analysis in each period, it was observed that there existed spectrum features of a consonant and a vowel in the initial and medial periods respectively and features of both in a final sound. Also, when all kinds of words were adaptively divided into 3 periods by using the proposed method, it was found that the initial sounds of the same consonant and the medial sounds of the same vowels have the same spectrum characteristics respectively, but the final sound showed different spectrum characteristics even if it had the same consonant as the initial sound.

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The Effects of SOX and Internal Control Weaknesses on the Relation between the Real Earnings Management and Audit Fees

  • Sohn, Byungcherl Charlie;Shim, Hoshik
    • Asia Pacific Journal of Business Review
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    • 제2권2호
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    • pp.17-44
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    • 2018
  • This study investigates whether the positive relation between the real earnings management (REM) and audit fees reported by Choi et al. (2016) differs before and after the Sarbanes-Oxley Act (SOX), and varies cross-sectionally depending on the existence of internal control problems. Using a large sample of U.S. firms, we find that the positive relation between REM and audit fees is stronger than the same relation between AEM and audit fees in the post-SOX period, whereas the opposite is true in the pre-SOX period. We also find that the positive relation between REM and audit fees is intensified for firms with material internal control weaknesses.

Restructuring and Performance among Japanese Firms after Prudential Policy Reform

  • Beason, Dick;Gordon, Ken;Mehrotra, Vikas;Watanabe, Akiko
    • 아태비즈니스연구
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    • 제1권1호
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    • pp.41-60
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    • 2010
  • After over a decade of sluggish economic growth accompanied by massive fiscal stimulus in the 1990s, it remains an open question whether and how Japanese firms have restructured their operations, and whether these efforts have borne any fruit. Using a randomly selected sample of 300 firms from the Tokyo Stock Exchange, we collect all restructuring announcement in the FY 2000-2001 (April 2000-March 2002) period. Our results are striking in that while we find that firms engaging in restructuring of various sorts display improved earnings in the period following the restructuring announcement, shareholders do not appear to benefit at the time of the restructuring announcements.

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