• Title/Summary/Keyword: trend equation

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The Analysis of Underpotential Deposition by Multilayer Adsorption Model

  • Lee, J.B.;Duby, Paul F.
    • Journal of the Korean institute of surface engineering
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    • v.27 no.6
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    • pp.335-339
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    • 1994
  • The underpotential deposition of zinc was investigated on carbon steel and nickel. The relationship be-tween the deposition potentials and the corresponding amounts of charge for deposited layers shows a very similar trend to the multilayer adsorption mechanism. The experimental results fit a mathematical model de-rived on the basis of the BET equation for the underpotential deposition.

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Development of Concentration Time and Storage Coefficient Considering Regional Trend in Urban Stream Watershed (지역적 성향을 고려한 도시하천 유역의 도달시간 및 저류상수 공식 개발)

  • Bae, Deg-Hyo;Kim, Yong-Jae
    • Journal of Korea Water Resources Association
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    • v.48 no.6
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    • pp.479-489
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    • 2015
  • The objective of this study is to develop the equations for concentration time and storage coefficient considering regional trend in urban stream watershed for reliable hydrological analysis. The 13 basins located in Jungrang, Tan, Anyang, and Hongje stream are selected for the data collection and formula development in this study. The stepwise multiple-regression analysis is used for the development considering watershed, urban, and precipitation characteristic indices. The developed formulae are compared with the domestic and foreign empirical formulae and evaluated the accuracy in urban stream area. It shows the computed value from the equation developed in this study is more accurate than those from other empirical formulae. The error sum, average error and RMSE of computed values from the developed equations in this study are the lowest. The formulae considering the regional trend of urban stream watershed are worth in terms of showing better results than the domestic and foreign empirical formulae. It can be concluded the developed formulae can be useful in urban stream watershed.

Subfertility Problems Leading to Disposal of Breeding Bulls

  • Khatun, Marzina;Kaur, Simarjeet;Simarjeet, Simarjeet;Mukhopadhyay, C.S.
    • Asian-Australasian Journal of Animal Sciences
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    • v.26 no.3
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    • pp.303-308
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    • 2013
  • Subfertility problems are encountered frequently in the cattle and buffalo bulls commercially maintained for semen production in dairy farms and under field conditions for natural insemination. Reports are scarce on the incidence of subfertility in breeding bulls, especially in India. The objective of the present study was to assess the incidence of the male reproductive anomalies leading to disposal of bovine bulls at GADVASU dairy farm, Ludhiana, Punjab (India). Data on frequency of various subfertility and disposal pattern of bulls maintained at the dairy farm, GADVASU, were collected for 12 yrs (1999 to 2010) and compiled from different record registers. Percentage of bulls that produced freezable semen (out of reserved ones) was less in cattle (25.641%) as compared to that of buffalo (30.4%). Various subfertility traits like poor libido and unacceptable seminal profile were found to be the significant reasons (p<0.01) for culling of the breeding bulls. Inadequate sex drive and poor semen quality were the main contributing factors for bull disposal in cattle whereas poor semen freezability was most frequently observed in buffalo bulls. All the male reproductive traits were significantly different (p<0.05) for the periods of birth, except for semen volume, initial motility (IM), age at last semen collection (ALSC) and age at disposal. The ages at first and last semen collection as well as freezing (i.e. AFSC, ALSC and AFSF, ALSF, respectively) and age at disposal (AD) were higher in buffalo. The spermatological parameters and semen production period (SPP) were higher in cattle. The age at first semen donation and breeding period could be reduced by introducing the bulls to training at an early age. The results revealed an increasing trend in individual motility (IM) while semen volume, AFSC, AFSF, AD, FSPP, SPP, ALSC and ALSF showed a decreasing, however, not a definite trend, over the periods. The semen donation traits like, AFSF, of the cattle and buffalo bulls could be predicted from the AFSC, using prediction equation derived in the present study.

A Study on the Social Commerce in Smartphone Environment (스마트폰 환경에서 소셜커머스 사용에 대한 연구)

  • Ahn, Hyunchul;Lee, Hyoung-Yong
    • Journal of Information Technology Services
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    • v.14 no.1
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    • pp.145-158
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    • 2015
  • Currently, Social Commerces have increasingly gained popularity with the growth of Social Network Services (SNS). As the applications of smartphones are being applied in widespread areas, social commerces in the smartphone environment have entered a new chapter. The applications of social commerces on smartphones are widely used, which has increased the market share of social commerces exponentially. Thus, we tried to find out factors which may affect the user acceptance of social commerces in the smartphone environment. We develop a research model to examine how social commerces in the smartphone environment are accepted by users based on the academic factors-switch costs, trend-seeking tendency, richness in media. The theoretical model is validated through an survey of social commerce users in the smartphone environment from the undergraduates and the graduates in Seoul, Korea. The structural equation analysis is conducted based on the partial least square (PLS) approach. The results reveal that the switch cost will have positive mediating influences to the intention to use social commerce in the smartphone environment. We also find that the perceived usefulness of the smartphone is affected by the media richness. The results also suggest that the trend-seeking tendency has no influences to the users of social commerces in the smartphone environment. Also, theoretical and practical implications are discussed. The findings are believed to increase our understanding an interesting mobile phenomenon, as well as making contributions.

Estimation of Forest Biomass Arising from Forest Management Operation II - Estimation based on the projection of forest areas - (숲가꾸기 사업에서의 산림 바이오매스 발생량 추정(제2보) - 산림면적 전망에 의한 추정 -)

  • Ahn, Byeong-Il;Lee, Kyun-Shik;Kim, Chul-Hwan;Lee, Ji-Young
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.41 no.4
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    • pp.25-32
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    • 2009
  • Forest biomass can be used as various types of raw materials such as pulp, wood pellets, solid charcoals and so on. This paper estimates the nation wide amount of forest biomass based on the projection of forest areas for its effective and economic use. Several trend equations are used in projecting the forest areas. In 2009, the forest biomass arising from thinning is estimated be 6,591,575 $m^3$. The estimates of forest biomass in 2015 and 2018 are 6,375,627 $m^3$ and 6,284,779 $m^3$, respectively. Since the forest areas are projected to be declining, the biomass generated by thinning will decrease. This implies that the new alternatives for supplying raw materials for biofuels must be prepared before then.

A Study of the Classification of Research and Trend in the Korea Trade Show (국내 무역전시 연구 분류 및 동향에 관한 연구)

  • Sung, Nak-Suk;Hong, Seon-Eui
    • THE INTERNATIONAL COMMERCE & LAW REVIEW
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    • v.53
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    • pp.289-313
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    • 2012
  • This study aimed to analyze research trend of the trade show industry in Korea and further to suggest the future direction on the research area where industrial strategies and governmental supports can be made. From 2001 to 2011 by order of 11-year study by analyzing research trends and future direction of policy more effective marketing strategy is precisely to provide direction for research. For the purpose of this study, 169 articles from 49 national level journals of Korea was classified and analyzed. 30 researches in 2005 was published research papers related to the exhibition industry was grew rapidly. According to the analysis, participants behavior of trade show were the most important topic with 33 articles. Various statistical methods such as ANOVA, structural equation model, path analysis, t-test and regression were used. However the study methods of these researches didn't make much progress. The result of this study indicated that we need to study more about the trade show industry of Korea, especially about local economic development and regional demand of trade show.

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A Study on Thermally-induced Vibration of Space Flexible Booms (우주 유연 붐의 열적 유기 진동에 관한 연구)

  • Kong, Chang-Duk;Oh, Kyung-Won;Bang, Jo-Hyug;Sugiyama, Y.
    • Proceedings of the KSME Conference
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    • 2003.11a
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    • pp.1631-1636
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    • 2003
  • The purpose of this study is to analyze the phenomena of the thermally-induced vibration for the flexible space structure due to abrupt change of radiation heating circumstance using the numerical analyze and experiment test. In order to verify this structure, numerical approaches on the simplified flexible tube were compared with experimental test results at the ground experimental facility In this analyze, it was found that the thermal deformation occurs firstly due to fast radiation heating of flexible structure and then the thermally-induced vibration would be induced due to small periodic change of temperature. According to comparison of numerical and experimental result, in case of no tip mass, the first mode vibration by the numerical analyze was O.78Hz same as that of the experimental result However in case of increase tip-masses of 8g l6g, 50g and 100g, the first modes vibration theoretical analyze were 1.75Hz, 1.3Hz, 0.87Hz and O.73Hz, in decrease trend respectively and those by experimental test were 234Hz, 1.5Hz, O.78Hz and O.78Hz in decrease trend respectively Although using the simpled equation for the estimation, the estimation results were similar to experimental results.

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Analysis on Turbulence Intensity Characteristics at Gimnyeong, Jejudo by Applying IEC 61400 Wind Turbine Standards (IEC 61400 풍력표준을 적용한 제주도 김녕 난류강도 특성분석)

  • Kim, Hyun-Goo;Jeong, Tae-Yoon;Jang, Moon-Seok
    • Journal of the Korean Solar Energy Society
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    • v.30 no.6
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    • pp.59-65
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    • 2010
  • Analysis on turbulence intensity profile depending on wind speed is an important process to set up design condition of wind turbine in terms of fatigue load. This paper tests goodness of fit of turbulence intensity empirical equations suggested by the IEC 61400 Standards with Jejudo Gimnyeong met-tower measurement, which is erected at a seashore. Therefore sea breeze and land breeze coexist. Sea breeze case showed apparent increasing trend of turbulence intensity in a high wind speed regime due to increase of sea surface roughness. However, neither inland wind turbine standard IEC 61400-1 nor offshore wind turbine standard IEC 61400-3 fit such a trend adequately. On the other hand, the modified empirical equation of turbulence intensity of IEC 61400-3 derived from Germany FINO1 application study by considering turbulence intensity behavior in a high wind speed regime showed good agreement with the measurement. Therefore, we can reconfirm and conclude that IEC 61400-3 Ed.1 legislated in 2009 needs to be modified.

Trend of Mortality Rate and Injury Burden of Transport Accidents, Suicides, and Falls

  • Kim, Ki-Sook;Kim, Soon-Duck;Lee, Sang-Hee
    • Journal of Preventive Medicine and Public Health
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    • v.45 no.1
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    • pp.8-13
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    • 2012
  • Objectives: Recently injury has become a major world-wide health problem. But studies in Korea about injuries were very few. Thus, this study was conducted to analyze the trend of major injuries from 1991 to 2006 and to provide basic data for preventing injuries. Methods: This study was based on the National Statistical Office data from 1991 to 2006 and calculated to estimate the burden of major injuries by using the standard expected years of life lost (SEYLL) and total lost earnings equation. Results: For transport accidents, mortality, SEYLL and total lost earnings were increased from 1991 to 1996 and decreased from 2000 to 2006. On the other hand, for suicides, these were increased gradually. Since 2003, falls were included in ten leading causes of death. This study showed that injury causes major social and economical losses. Conclusions: We could reduce injury related premature death through active interest in injury prevention program.

Molecular Dynamics Simulation Studies of Physico Chemical Properties of Liquid Pentane Isomers

  • 이승구;이송희
    • Bulletin of the Korean Chemical Society
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    • v.20 no.8
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    • pp.897-904
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    • 1999
  • We have presented the thermodynamic, structural and dynamic properties of liquid pentane isomers - normal pentane, isopentane, and neopentane - using an expanded collapsed atomic model. The thermodynamic properties show that the intermolecular interactions become weaker as the molecular shape becomes more nearly spherical and the surface area decreases with branching. The structural properties are well predicted from the site-site radial, the average end-to-end distance, and the root-mean-squared radius of gyration distribution func-tions. The dynamic properties are obtained from the time correlation functions - the mean square displacement (MSD), the velocity auto-correlation (VAC), the cosine (CAC), the stress (SAC), the pressure (PAC), and the heat flux auto-correlation (HFAC) functions - of liquid pentane isomers. Two self-diffusion coefficients of liquid pentane isomers calculated from the MSD's via the Einstein equation and the VAC's via the Green-Kubo relation show the same trend but do not coincide with the branching effect on self-diffusion. The rotational re-laxation time of liquid pentane isomers obtained from the CAC's decreases monotonously as branching increases. Two kinds of viscosities of liquid pentane isomers calculated from the SAC and PAC functions via the Green-Kubo relation have the same trend compared with the experimental results. The thermal conductivity calculated from the HFAC increases as branching increases.