• Title/Summary/Keyword: Adjusted Means

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Experimental investigations on the resistance performance of a high-speed partial air cushion supported catamaran

  • Yang, Jinglei;Lin, Zhuang;Li, Ping;Guo, Zhiqun;Sun, Hanbing;Yang, Dongmei
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.12 no.1
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    • pp.38-47
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    • 2020
  • The partial air cushion supported catamaran (PACSCAT) is a novel Surface Effect Ship (SES) and possesses distinctive resistance performance due to the presence of planing bottom. In this paper, the design of PACSCAT and air cushion system are described in detail. Model tests were carried out for Froude numbers ranging from 0.1 to 1.11, the focus is on the influence of air cushion system on resistance characteristics. Drag-reducing effect of air cushion system was proved by means of contrast tests in cuhionborne and non-cushionborne mode. Wave-making characteristics reflect that the PACSCAT would eventually enter planing regime, in which the air could just escape under the seals and the hull body could operate in a steady state. To acquire different air cushion pressure, air flow rate and leakage height were adjusted during tests. Experimental results show that the resistance performance in planing regime would decrease evidently as the increased air flow rate, however, the scheme with medium leakage height presents the best resistance performance in the hump region.

Comparative assessment of ASCE 7-16 and KBC 2016 for determination of design wind loads for tall buildings

  • Alinejad, Hamidreza;Jeong, Seung Yong;Kang, Thomas H.K.
    • Wind and Structures
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    • v.31 no.6
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    • pp.575-591
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    • 2020
  • Wind load is typically considered as one of the governing design loads acting on a structure. Understanding its nature is essential in evaluation of its action on the structure. Many codes and standards are founded on state of the art knowledge and include step by step procedures to calculate wind loads for various types of structures. One of the most accepted means for calculating wind load is using Gust Load Factor or base bending Moment Gust Load Factor (MGLF), where codes are adjusted based on local data available. Although local data may differ, the general procedure is the same. In this paper, ASCE 7-16 (2017), which is used as the main reference in the U.S., and Korean Building Code (KBC 2016) are compared in evaluation of wind loads. The primary purpose of this paper is to provide insight on each code from a structural engineering perspective. Herein, discussion focuses on where the two codes are compatible and differ. In evaluating the action of wind loads on a building, knowledge of the dynamic properties of the structure is critical. For this study, the design of four figurative high-rise buildings with dual systems was analyzed.

Determinants and Prediction of the Stock Market during COVID-19: Evidence from Indonesia

  • GOH, Thomas Sumarsan;HENRY, Henry;ALBERT, Albert
    • The Journal of Asian Finance, Economics and Business
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    • v.8 no.1
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    • pp.1-6
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    • 2021
  • This research examines the stock market index determinants and the prediction using the FFT curve fitting of the Jakarta Stock Exchange (JKSE) Composite Index during the COVID-19 pandemic. This paper has used daily data of Jakarta Stock Exchange (JKSE) Composite Index, interest rate, and exchange rate from 15 October 2019 to 15 September 2020, and a total of 224 observations, retrieved from Indonesia Stock Exchange (IDX), Indonesia Statistics Central Bureau and Observation & Research of Taxation. The study covers descriptive statistics, multicollinearity test, hypothesis tests, determination test, and prediction using FFT curve fitting. The results unveil four fresh and robust evidence. Partially, the interest rate has affected positively and significantly the stock market index. Partially, the exchange rate has affected negatively and significantly the stock market index. The F-test result, interest rate, and exchange rate have significantly affected the stock market index (JKSE) simultaneously. Furthermore, the FFT curve fitting has predicted that the stock market fluctuates and increases over time. The results have shown a strong influence of the independent variables and the dependent variable. The value of Adjusted R-Square is 0.719, which means that the independent variables have simultaneously impacted the dependent variable for 71.9%; other factors have influenced the remaining 28.1%.

Analysis of Doubly Fed Variable-Speed Pumped Storage Hydropower Plant for Fast Response (빠른 응답성을 갖는 가변속 DFIM 분석)

  • Sun, Jinlei;Seo, Joungjin;Cha, Hanju
    • The Transactions of the Korean Institute of Power Electronics
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    • v.27 no.5
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    • pp.425-430
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    • 2022
  • A pumped storage power station is an important means to solve the problem of peak load regulation and ensures the safety of power grid operation. The doubly fed variable-speed pumped storage (DFVSPS) system adopts a doubly fed induction machine (DFIM) to replace the synchronous machine used in traditional pumped storage. The stator of DFIM is connected to the power grid, and the three-phase excitation windings are symmetrically distributed on the rotor. Excitation current is supplied by the converter. The active and reactive power of the unit can be quickly adjusted by adjusting the amplitude, frequency, and phase of the rotor-side voltage or current through the converter. Compared with a conventional pumped storage hydropower station (C-PSH), DFVSPS power stations have various operating modes and frequent start-up and shutdown. This study introduces the structure and principle of the DFVSPS unit. Mathematical models of the unit, including a model of DFIM, a model of the pump-turbine, and a model of the converter and its control, are established. Fast power control strategies are proposed for the unit model. A 300 MW model of the DFVSPS unit is established in MATLAB/Simulink, and the response characteristics in generating mode are examined.

A STUDY ON DURATION ESTIMATE METHOD USING STOCHASTIC MODEL IN THE BIM ENVIRONMENT

  • Jae H. Park;Seok H. Yun;Joon H. Paek
    • International conference on construction engineering and project management
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    • 2009.05a
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    • pp.1209-1215
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    • 2009
  • Recently, Construction Projects are being much bigger and more complex. So the importance of Construction Planning and Management is increasing and increasing because of the Construction Projects is involved in a variety of construction-related subjects. Competitive of the Construction Industry decided Cost, Construction Duration and Productivity. But they were just focused on Cost Saving instead of Construction Duration and Productivity. However, they have to finish construction projects using minimum cost and duration with quality and function of required level for successful Construction projects. Thus, current high exchange rate and high period, it is clear to decrease construction cost and to do economic construction in huge Construction Projects and it means more advanced Construction Schedule Management needs for economic construction. But Construction Scheduling Planning, basic of Construction Schedule Management, adjusted contract period without Pre-Planning, just depending on experience and ability of Construction Engineer. Because of that, this study suggests new Duration Estimate Method using Stochastic Model in BIM Environment for advanced Construction Schedule Management. Existing Duration Estimate Methods are just modified wrong points of them or analyzed effective factors of construction schedule. However, New Duration Estimate Method is just consists of Stochastic Model and BIM Environment without existing Duration Estimate Methods. So, new method has creativity and specialty. After this research, it would be a great model in construction industry field.

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Model Calculation of the Np-237 Fission Cross-Sections for En=0 to 20 MeV (중성자 에너지 En=0-20 MeV에 대한 Np-237 핵분열단면적의 모형계산)

  • Bak, H.I.;Strohmaier, B.;Uhl, M.
    • Nuclear Engineering and Technology
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    • v.13 no.4
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    • pp.207-220
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    • 1981
  • The Np-237 fission cross-sections up to 20 MeV incident neutron energy are calculated by means of the computer code STAPRE- a statistical model code with consideration of preequilibrium decay. The higher chance fissions up to third compound nucleus are taken into account, and the main input parameters in the treatment of fission under consideration of a double-humped fission barrier are carefully adjusted, so that the current trend of experimental data can be fitted within an apparent deviation of about 10% throughout the entire energy range. Results are presented in the form of point-wise cross-section values, and also in the form of graph to demonstrate the shape agreement.

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The Deployment Process of German Collective Housing Planning and Case Studies of Contemporary Collective Housing Types (독일 집합주택계획의 전개 과정과 현대 집합주택유형 사례 연구)

  • Lim, Jae Heon
    • The Journal of the Convergence on Culture Technology
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    • v.9 no.3
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    • pp.689-699
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    • 2023
  • The process of German collective housing planning is meaningful in examining comprehensively deploying aspects of planning foundation through defining the ideology of modern and contemporary architecture in the process of providing housing followed by social changes while rebuilding the country after two World Wars in combination with the population concentration in cities after the Industrial Revolution. We outline the characteristics and understand the types of collective housing, and the background of their interaction with urban contexts overlapping social situations and historical processes; by means of the process, the planning and designing typology which is commonly adjusted to contemporary collective housing after examining them could be understood as being aligned with the extension line of interconnecting the process of modern and contemporary era.

The Effects of the Addition of Orange and Grape Concentrates, and Fructose on the Quality Characteristics of Soy Kefir (오렌지 및 포도 농축액과 과당의 첨가량에 따른 soy kefir의 품질특성)

  • Lee, Sook-Young;Na, Sung-Hoon;Lee, See-Young
    • Journal of the Korean Society of Food Culture
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    • v.21 no.3
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    • pp.330-335
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    • 2006
  • The objectives of this study were to characterize the quality of soy kefir made with soymilk in combination with fructose (5%, 10%) and one of the extracts from orange (10%, 15%) and grape (5%, 10%) with differently adjusted amounts as defendant variables. The lactic acid bacteria, yeast and total microbial counts of soy kefir were respectively $1.3{\times}10^7$ CFU/ml, $1.6{\times}10^8$ CFU/ml, $1.5{\times}10^8$ CFU/ml, soy kefir was propered to drink. pH of soy kefir mixed by orange and grape extracts was decreased significantly according to add fructose 5%. Acidity became significantly high when orange and grape extracts were added, which means acidity showed similar tendency in the opposite direction. The saccharinity of soy kefir was not significantly in orange extract, but soy kefir added fructose 10% was high more than fructose 5% in grape extract. In sensory evaluation, soy kefirs added orange extract 15%, fructose 5% and grape extract 10%, fructose 5% were estimated highly on color, astrigent taste, sour taste, mouth feel and overall quality.

The Effect of Coffee Consumption on Serum Total Cholesterol Level in Healthy Middle-Aged Men (건강한 중년 남성에서 커피 음용 습관이 혈중 총 콜레스테롤 값에 미치는 영향)

  • Shin, Myung-Hee;Kim, Dong-Hyun;Bae, Jong-Myun;Lee, Hyung-Ki;Lee, Moo-Song;Noh, Joon-Yang;Ahn, Yoon-Ok
    • Journal of Preventive Medicine and Public Health
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    • v.27 no.2 s.46
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    • pp.200-216
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    • 1994
  • In present study, the authors investigated the possible effect of coffee consumption on serum cholesterol level in 1017 men between the ages of 40 and 59 years, who were randomly selected from the members of Seoul Cohort Study. Serum total cholesterol data was collected with other serologic indices (e.g. systolic blood pressure, diastolic blood pressure, hight, weight, etc.) through the program of biennial health check-up offered by Korean Medical Insurance Corporation (KMIC). The amount of coffee consumption was assessed by a self-administered questionnaire through mailing. Other confounding factors, such as age, body mass index, cigarette smoking, alcohol consumption, physical activity, and other dietary intake pattern were also determined by the questionnaire. The differences in means of serum total cholesterol in compared to non consumers were $-0.4{\pm}3.56mg/dl$ for those drinking less than 1 cup a day, $-0.6{\pm}3.60mg/dl$ for those drinking 1 cup a day, and $7.1{\pm}3.41mg/dl$ for those drinking more than 2 cups a day. Since smoking interacted the relationship between coffee consumption and serum total choleaterol, we re-analyzed those relationship in smokers and non-smokers separately Other atherogenic behaviors were well correlated with total cholesterol, so we adjusted the mean values of serum total cholesterol through multivariate model selection with age(r=0.12), total cigarette index (cigarette-years; r=0.10), Quetelet's index ($Kg/m^2$, r=0.16), daily calory expenditure (kcal/day, r=0.06), weekly meat and poultry consumption(g/week, r=0.05), weekly fish consumption (g/week, r=0.08), other caffeinated beverage intake (cups/week), and the amount of sugar and prim added to the coffee. Among those variables only age, Quetelet's index, fish consumption, and total cigarette index (in smokers) were remained in the models. After adjustment, the corresponing differences of total cholesterol in smokers were changed to $0.4{\pm}5.24mg/dl,\;-0.5{\pm}4.97mg/dl,\;and\;8.9{\pm}4.78mg/dl$, which were significantly different among themselves (P=0.011). In non-smokers, however, the differences were not statistically significant (P=0.76). Adjusted mean values of systolic blood pressure and diastolic blood pressure were also determined to evaluate the direct effect of coffee to cardiovascular system, but their means were not significantly different by coffee consumption(p=0.18 for SBP, p=0.48 for DBP). Asuming instant coffee in the most popular type of coffee in Korea, the association observed in our study between coffee and serum total cholesterol, especially in smokers, is very interesting finding for the connection between coffee and serum total cholesterol, because only 'boiled coffee' tend to show significant lipid raising effect rather than to other types of coffee, like filtered or espresso, in most of the western countries. We concluded that people who drink coffee more than 2 cups a day have significantly higher serum total cholesterol level than those who never drink coffee, especially in smokers.

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The Development of Adjustment Coefficients for Linear Classifications in the Korean Holstein Dairy Cattle (국내 홀스타인젖소의 선형심사에 대한 보정계수 개발)

  • Song, C.E.;Sang, B.C.;Do, C.H.
    • Journal of Animal Science and Technology
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    • v.44 no.1
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    • pp.1-12
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    • 2002
  • The environmental effects were studied to estimate age and lactation stage adjustment coefficients in the primary linear traits of Holstein dairy cattle in Korea. Calving year month, classifier, age-month at classification and lactation stage were the environmental factors which significantly affected the most of linear traits at the level of 0.01. F values of Stature, strength, body depth, thurl with and rear leg side view were relatively higher in the effects of age-month, and dairy form, rear udder height, rear udder width, and udder cleft had relatively higher F values in the effects of lactation stage. Udder depth were affected highly by both age-month and lactation stage. Through the least square means of traits and the interpolation and smoothing obtained by the regression analysis of log and exponential transformed adjustment coefficients, age-month and lactation stage coefficients were estimated, and applied to real data to check the variation in the age-month and lactation stage effects. The estimated mean squares showed that the variation in all the linear traits significantly were decreased for the adjusted factors without the significant changes of variation in calving year month and classifier. That udder depth adjusted for both the age-month and lactation stage resulted in the decreases of variation in the both effects.