• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.6
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• pp.1779-1786
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• 2014

Artificial Intelligence-based techniques have been applied to problems where mathematical relations can not be presented due to complicatedness of the physical process. A representative example in hydraulics is the local scour around bridge piers. This study presents a GEP model for predicting the local scour around bridge piers. The model is trained by 64 laboratory data to build the regression equation, and the constructed model is verified against 33 laboratory data. Comparisons between the models with dimensional and normalized variables reveals that the GEP model with dimensional variables predicts better. The proposed model is now applied to two field datasets. It is found that the MAPE of the scour depths predicted by the GEP model increases compared with the predictions of local scours in laboratory scale. In addition, the model performance increases significantly when the model is trained by the field dataset rather than the laboratory dataset. The findings suggest that apart from the ANN model, GEP model is a sound and reliable model for predicting local scour depth.

• Korean journal of communication and information
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• v.27
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• pp.123-151
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• 2004

This study explores the attributes of local readers based on a discriminant analysis. Local readers are divided into three groups national newspaper reader, local newspaper reader, and national & local newspaper reader. A nationwide telephone survey was conducted in june, 2004 and gathered 2,063 cases. News subject and advertising appeared to play less important role in distinguishing among the three group examined. The most powerful discriminating variables were residence area and period of residence area. Education, interest of capital city news, job were found to be moderately important variables on Function 1, which distinguished between local newspaper reader and national & local newspaper reader. Generally, local newspaper reader showed higher interest on capital area news and lower interest on metropolitan area news. However, the result of a discriminant analysis indicated local newspaper reader was distinguished from national newspaper reader in terms of higher interest of metropolitan area news. Simultaneously, local newspaper reader was distinguished from national & local newspaper in terms of lower interest of capital area news.

• Journal of the East Asian Society of Dietary Life
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• v.24 no.6
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• pp.906-914
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• 2014

This study conducted an exploratory factor analysis to examine how consumers' confidence on the local foods used at tasty farm eateries influence their purchase behaviors. The four factors of perception of local foods used at tasty farm eateries and the factors of consumer confidence and purchase behaviors were extracted for a reliability analysis, correlation analysis of variables, and simple and multiple regression analysis. The following are the findings: first, among the four factors of perception of local foods used at tasty farm eateries, safety, sociality and product value had statistically significant influences on consumer confidence, whereas regional economic value did not. In other words, safety referring to the nutritional value and sanitary safety of food ingredients used for the native foods at the tasty farm eateries, product value referring to the characteristics differentiated from general Korean cuisine, and sociality referring to the various related experiences for the interests in farm culture and local food, leads to consumer confidence, whereas regional economic value referring to farm household income, local job creation, and development of farm tourism does not. Second, consumer confidence had a statistically significant positive impact on consumers' purchase behaviors. Among the five principles of local foods, reliability is the most important factor. When consumers gain confidence on local food items and are satisfied with them, they make additional purchases and revisits. Therefore, confidence is a very important aspect for the loyalty and sustainability of business.

• Journal of information and communication convergence engineering
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• v.21 no.1
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• pp.62-67
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• 2023

This paper proposes an imputation method using a bidirectional k-nearest components search based local linear regression method. The bidirectional k-nearest-components search method selects components in the dynamic range from the missing points. Unlike the existing methods, which use a fixed-size window, the proposed method can flexibly select adjacent components in an imputation problem. The weight values assigned to the components around the missing points are calculated using local linear regression. The local linear regression method is free from the rank problem in a matrix of dependent variables. In addition, it can calculate the weight values that reflect the data flow in a specific environment, such as a blackout. The original missing values were estimated from a linear combination of the components and their weights. Finally, the estimated value imputes the missing values. In the experimental results, the proposed method outperformed the existing methods when the error between the original data and imputation data was measured using MAE and RMSE.

• Korean Journal of Agricultural and Forest Meteorology
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• v.1 no.1
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• pp.41-51
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• 1999

This study was conducted to investigate the effects of local climatic conditions on the annual increment of Korean white pine planted in Gapyung and Yaungdong. For this, stand variables such as mean DBH, mean height, basal area per hectare, and volume per hectare by stand age were measured and summarized for each locality. Based on these statistics, annual increments for 8 years from stand age 10 to 18 were calculated for each of stand variables. A topoclimatological technique which makes use of empirical relationships between the topography and the weather in study sites was applied to produce normal estimates of monthly mean, maximum, minimum temperatures, relative humidity, precipitation, and hours of sunshine. Then, the yearly climatic variables from 1990 to 1997 for each study site were derived from the spatial interpolation procedures based on inverse- distance weighting of the observed deviation from the climatic normals at the nearest 11 standard weather stations. From these estimates, 17 weather variables such as warmth index, coldness index, index of aridity etc., which affect the tree growth, were computed on yearly base for each locality. The deviations of measured annual increments from the expected annual increments for 8 years based on yield table of Korean white pine were then correlated with and regressed on the yearly weather variables to examine effects of local climatic conditions on the growth. Gapyung area provides better conditions for the growth of Korean white pine in the early stage than Youngdong area. This indicates that the conditions such as low temperature, high relative humidity, and large amount of precipitation provide favor environment for the early growth of Korean white pine. A ccording to the correlation and regression an analysis using local climatic conditions and annual increments, the growth pattern of Gapyung area corresponds to this tendency. However, it was found that the relationship between annual increments and local climatic conditions in Youngdong area shows different tendency from Gapyung. These results mean that the yearly growth pattern could not sufficiently be explained by climatic conditions with high variance in yearly weather variables. In addition, the poor growth in Youngdong area might not only be affected by climatic conditions, but also by other environmental factors such as site quality.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.8
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• pp.1497-1505
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• 2010

The present study was performed to investigate the effect of aging on muscular activity of older subjects under the condition of fixed load muscle contraction. SEMG signals were recorded from old (46 women) and young (45 women) groups performing sustained isometric elbow flexion contraction with a fixed load during 30 seconds. Linear regression and mean square error (MSE) analysis with four characteristic variables (ARV, RMS, MDF, MNF) were used to compare the age-related difference (of local muscle fatigue and fluctuation of the amplitude and frequency) in the SEMG signal. The main results can be summarized as follows: During sustained muscle contraction with a fixed load: i) the MSE values of amplitude (ARV, RMS) and frequency (MDF, MNF) variables were more than 30% higher for the young than for the old adults; ii) the measures of local muscle fatigue (slope of the MDF and MNF) indicated greater fatigue in the old; and iii) the rate of increase of the SEMG amplitude was higher for the young than the old.

• ETRI Journal
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• v.31 no.1
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• pp.42-50
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• 2009

A new method for simulating voltage and current distributions in transmission lines is described. It gives the time domain solution of the terminal voltage and current as well as their line distributions. This is achieved by treating voltage and current distributions as distributed state variables (DSVs) and turning the transmission line equation into an ordinary differential equation. Thus the transmission line is treated like other lumped dynamic components, such as capacitors. Using backward differentiation formulae for time discretization, the DSV transmission line component is converted to a simple time domain companion model, from which its local truncation error can be derived. As the voltage and current distributions get more complicated with time, a new piecewise exponential with controllable accuracy is invented. A segmentation algorithm is also devised so that the line is dynamically bisected to guarantee that the total piecewise exponential error is a small fraction of the local truncation error. Using this approach, the user can see the line voltage and current at any point and time freely without explicitly segmenting the line before starting the simulation.

• Journal of Korean Society of Rural Planning
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• v.20 no.4
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• pp.127-135
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• 2014

The purpose of this study is to show the relation of the change between spacial structure and social conditions of rural area. The spacial structure change of Asan city was analyzed using Space Syntax, and multiple regression analysis (dependent variables: connectivity, global integration, local integration / independent variables: population, household, farm population, farm population of 65years old and over, farm household, part-time farm households, cultivated land) was accomplished. As th result, that the increase of connectivity is related to the increase of population and farm population of 65years old and over and the decrease of farm population, and the increase of local integration is related to the increase of farm population of 65years old and over was showed. However, that global integration is not related to change of social conditions was proved.

• Journal of the Korean Society of Industry Convergence
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• v.25 no.2_2
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• pp.315-322
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• 2022

Apartments are being established as a universal housing type because of the perception that they are excellent in preservation of asset values and convenience. In this study, through multiple regression analysis, it is a thesis that explores whether it affects the housing market in Gimhae, a small and medium-sized city in the province, and how the price flow in neighboring cities has an effect. It is possible to examine how macroeconomic variables such as the balloon effect and the lowest interest rate caused by the government's tweezers regulation bring about changes in the housing market of small and medium-sized cities in local regions.

• Journal of Digital Convergence
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• v.6 no.4
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• pp.137-145
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• 2008

Embedded industry has emerged as one of the important industry for u-IT based application service. Technology development related to embedded hardware and software provides the base for the development of U-IT convergence industry. This study intends to suggest a research model to investigate the influence of industry, organization, technology factors on technology performance in the embedded companies. This study adopted research variables such as global network, local network, industry intensity, and technology capability as independent variables, with technology performance as a dependent variable from the existing literatures. The purpose of this study is to analyze the influence of industrial and organizational factors on technology performance of embedded companies SCM systems, including the moderating effect of government support. 94 companies data were collected by survey. The result of this empirical study is summarized as follows. First, local network and technology capability are the important determinants to influence technology performance of embedded companies in direct effect model. Second, global network and industry intensity has more positive influence on technology performance of embedded companies through a moderating variable of government support.