• ETRI Journal
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• v.44 no.4
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• pp.641-653
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• 2022

In the process of autonomous vehicle motion planning and to create comfort for vehicle occupants, factors that must be considered are the vehicle's safety features and the road's slipperiness and smoothness. In this paper, we build a mathematical model based on the combination of a genetic algorithm and a neural network to offer lane-change solutions of autonomous vehicles, focusing on human vehicle control skills. Traditional moving planning methods often use vehicle kinematic and dynamic constraints when creating lane-change trajectories for autonomous vehicles. When comparing this generated trajectory with a man-generated moving trajectory, however, there is in fact a significant difference. Therefore, to draw the optimal factors from the actual driver's lane-change operations, the solution in this paper builds the training data set for the moving planning process with lane change operation by humans with optimal elements. The simulation results are performed in a MATLAB simulation environment to demonstrate that the proposed solution operates effectively with optimal points such as operator maneuvers and improved comfort for passengers as well as creating a smooth and slippery lane-change trajectory.

• 한국공간정보시스템학회:학술대회논문집
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• 2005.11a
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• pp.257-270
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• 2005

Many studies states that improperly uprising of infrastructure may cause leading the forest degradation and canopy reduction in many tropical forest of Asian countries. Other studies revealed that habitat destruction and fragmentation, edge effects, exotic species invasions, pollution are provoked by roads. Similarly, environmental effects of road construction in forests are problematic. Similarly, many researches have been indicated that roads have a far greater impact on forests than simply allowing greater access for human use. Moreover, people using river as means of transportation hence illegal logging and felling cause canopy depletion in many countries. Therefore, it is important to comprehend the study about spatial relation of road, river and suburb followed by temporal change of forest canopy phenomena. This study also tried to examine the effect of road, river and suburb in forest canopy density change of Terai forest of Nepal from you 1988 to 2001. So, Landsat TM88, 92 and 001 and FCD (Forest Canopy Density) mapper were used to perform the spatial .elation of canopy density change. ILWIS (Integrated Land and Water Information System) which is GIS software and compatible with remote sensing data was used to execute analysis and visualize the results. Study found that influence of distance to suburb and river had statistically significance influenced in canopy change. Though road also influenced canopy density much but didn't show a statistical relation. It can be concluded from this research that understanding of spatial relation of factors respect with canopy change is quite complex phenomena unless detail analysis of surrounding environment. Hence, it is better to carry out comprehensive analysis with other additional factors such as biophysical, anthropogenic, social, and institutional factors for proper approach of their effect on canopy change.

• Journal of muscle and joint health
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• v.22 no.3
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• pp.167-176
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• 2015

Purpose: The purpose of this study was to identify the level of body perception, obesity, and factors associated with stages of exercise and dietary habits change in university students. Methods: A descriptive design was used. Data were collected from 279 university students using structured questionnaires. Results: The body perception was significantly associated with self rated health (F=27.89. p<.001), weight satisfaction (F=137.74. p<.001) and weight control interest (F=39.19. p<.001). The BMI was significantly associated with weight satisfaction (F=34.08. p<.001) and weight control interest (F=19.59. p=.003). But the body perception and BMI were not significantly associated with depression (F=2.17, p=.073, F=0.86. p=.462), the change of exercise (F=25.91. p=.055, F=20.34. p=.061), and dietary habits (F=12.96. p=.677, F=11.29. p=.505). The related factors affecting the change of exercise behavior were counter conditioning, self efficacy, eating behavior, and helping relationship, including 30.4% R-square. The related factor affecting the change of dietary habit was only eating behavior, including 20.0% R-square. Conclusion: This study can provide useful information to develop effective programs for the change of exercise and dietary habits considering university students' stages of change according to the transtheoretical model.

• Korean Journal of Soil Science and Fertilizer
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• v.50 no.4
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• pp.306-317
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• 2017

Unmanned aerial vehicles (UAVs) became popular platforms for the collection of remotely sensed data in the last years. This study deals with the monitoring of multi-temporal onion growth with very high resolution by means of low-cost equipment. The concept of the monitoring was estimation of multi-temporal onion growth using normalized difference vegetation index (NDVI) and meteorological factors. For this study, UAV imagery was taken on the Changnyeong, Hapcheon and Muan regions eight times from early February to late June during the onion growing season. In precision agriculture frequent remote sensing on such scales during the vegetation period provided important spatial information on the crop status. Meanwhile, four plant growth parameters, plant height (P.H.), leaf number (L.N.), plant diameter (P.D.) and fresh weight (F.W.) were measured for about three hundred plants (twenty plants per plot) for each field campaign. Three meteorological factors included average temperature, rainfall and irradiation over an entire onion growth period. The multiple linear regression models were suggested by using stepwise regression in the extraction of independent variables. As a result, $NDVI_{UAV}$ and rainfall in the model explain 88% and 68% of the P.H. and F.W. with a root mean square error (RMSE) of 7.29 cm and 59.47 g, respectively. And $NDVI_{UAV}$ in the model explain 43% of the L.N. with a RMSE of 0.96. These lead to the result that the characteristics of variations in onion growth according to $NDVI_{UAV}$ and other meteorological factors were well reflected in the model.

• The Journal of Korean Society for School & Community Health Education
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• v.18 no.2
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• pp.55-70
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• 2017

Objectives: The purpose of this study was to identify the factors associated with stage of change for drinking cessation among adolescents on the basis of the Transtheoretical Model. Methods: The data was collected from 343 high school students in Kimhae-city, who have experienced any kind of alcohol in their lifetime. For data analysis, descriptive statistics and Logistic regression were performed using the SPSS WIN 18. 0 program. Results: The stage of change was as follows: 24.2% in the precontemplation stage, 8.7% in the contemplation stage, 10.8% in the preparation stage, 39.7% in the action stage and 16.6% in maintenance stage. The predictive factors to move from the precontemplation stage to the contemplation/preparation stage were dramatic relief (OR=1.36, 95% CI:1.13-1.63) and self-efficacy (OR=1.05, 95% CI:1.01-1.09). The predictive factors to move from the contemplation/preparation stage to the action/maintenance stage were female (OR=0.50, 95% CI:0.27-0.94), the number of friend who have drunk (OR=0.84, 95% CI:0.77-0.91) and self-efficacy (OR=1.04, 95% CI: 1.00-1.07). Conclusions: To stop adolescent drinking, this study suggests the intervention program needs to be considered the individual's stage of change of drinking. The intervention program to enhance dramatic relief and self-efficacy is needed to adolescents in the precontemplation stage. It is crucial to develop strategies to raise self-efficacy for adolescents in the contemplation/preparation stage, which also respect their gender and peer groups.

• Asia-Pacific Journal of Business
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• v.13 no.2
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• pp.39-50
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• 2022

Purpose - The purpose of this study is to examine how Korea's macroeconomic factors, such as GDP, CPI, Export, Import, Unemployment rate and USD/KRW exchange rate, are affected by the oil price shocks. Design/methodology/approach - This study used monthly and quarterly time-series data of each variable for the period 1983 to 2022, consisting of two sub-periods, to employ Granger causality test and GARCH method in order to identify the role of the oil price movement in macroeconomic factors in Korea. Findings - Korea's currency rate to the US dollar is negatively correlated with the price change of crude oil while the GDP change is positively correlated with the price change of crude oil with strong relationship between Export and Import in particular. The exchange rate and GDP growth are believed to be not correlated with the oil price change for the pre-GFC period. According to the Granger causality test, the price change in crude oil has a causal impact on CPI, Export and Import while other factors are relatively slightly affected. Transmission effect from the oil price to Export is found and there also exists volatility spillover from oil price to economic variables under examination. Comparing two sub-periods, CPI and Export volatility responds negatively to shocks in the oil price for the pre-GFC period while volatility of CPI and Unemployment reacts positively to the oil price shocks for the post-GFC period. Research implications or Originality - The findings of this study could be helpful for both domestic and international investors to build their portfolio for the risk management since rising WTI price can be interpreted as a result of global economic growth and ensuing increase in the worldwide demand of the crude oil. Consequently, the national output is expected to increase and the currency is also expected to be strong in the long run.

• KDI Journal of Economic Policy
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• v.45 no.4
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• pp.23-56
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• 2023

To investigate the causes of Korea's growth slowdown over the past thirty years, we estimate the contributions of major developmental factors, including i) demographic factors (changes in population growth and workforce age due to the demographic transition), ii) quality-of-life-related choice factors (changes in working hours, education, and the female employment rate), iii) structural change, and iv) the effects of productivity catch-up. Our estimates show that these four groups of factors account for approximately 90 percent of the growth slowdown, with demographic factors contributing approximately 30 percent and the other three groups of factors each contributing about 20 percent. We also show that the same factors explain most of Korea's high growth in the 1980s. These results suggest that Korea's growth slowdown is basically a consequence of its successful economic development and that the high growth and subsequent slowdown can be regarded as a single process. In addition, given that the factors examined here exhibit similar patterns of change in the course of economic development of most countries, we think that our estimation results of the relationship between economic development and changes in economic growth trends could have more general implications that go beyond Korea's experience.

• Journal of Community Nutrition
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• v.4 no.2
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• pp.90-98
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• 2002

This study was performed to examine the dietary and BMI change of Koreans after moving to America and to identify the factors influencing changes of BMI. The subjects were 192 Korean-Americans (men : 86, women : 106) residing in the eastern area of the U.S.A. 1) subjects reported significantly increased consumption frequency in American foods like, low fat milk(p<0.001), cold cereals (p<0.001), whole wheat bread(p<0.001), hamburger(only in males p<0.01) and pizza(only in males p<0.01). Whereas significantly decreased consumption frequency in fish (p<0.05), cooked vegetables(p<0.001), kimchi(p< 0.001) and cooked rice (p<0.001) were reported. 2) It was reported that weight, accordingly BMI were significantly increased (p<0.01). The smoking habit score was significantly decreased for males (p<0.05). 3) Multiple linear regression analysis for BMI change showed that education years in Korea was the most prominent negative factor(p<0.001) in predicting BMI change in America. Elevated frequencies of alcohol, chicken and soft drink in America were also associated with greater increase of BMI. When the length of residence (increase of age) was included in regression model, the increase of age was the most significant factor (p<0.001). Changes of chicken and soda scores were other significant factors.

• Journal of the Korean Society of Clothing and Textiles
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• v.17 no.2
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• pp.315-327
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• 1993

The purpose of this study was to clarify the model of fashion change related to the cyclical variations suggested by Kroeber and Young and the selected social changes factors since Kapokyungchang(1894) in Korea. The sample was drawn from illustrations and photos in newspapers and magazines such as Chosunilbo, Dongailbo, and Yeowon. Documentary research and a content analysis have been done. The results were as follows : 1. Cyclical variations in dress were apparent for skirt length and silhouette. However, Kroeber's model and Young's model that regulary recurring cycles exist did not fit the data for 1970 to 1990 in Korea. For skirt length, the cycles appeared to be approximately five to six years for 1970 to 1990. 2. Social and institutional factors tended to account for more the variance in dress dimensions than political factors.

• Journal of the Korean Home Economics Association
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• v.43 no.9 s.211
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• pp.41-57
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• 2005

The purpose of this study was to examine the change of couple relationship factors predicting marital satisfaction and divorce intention over time tv comparing the couples' first year with their present year of marriage. The couple relationship factors consisted of affection, ambivalence, affectional expression, the expression of negativity. The study subjects 355 married women having preschool children aged 7 years old and elementary school students in the 6th grade. Data were analyzed by SPSSWIN with the method of MANOVA. The results of this study showed that couples in happy groups without divorce intention became less affectionate and demonstrated less affectional expression, and more ambivalence and expression of negativity over time. However, the amount of change was not as large as that of the unhappy groups. The findings of this research indicated that the decline of affection and affectional expression and the increase of ambivalence and expression of negativity were probably, as normative, a natural consequence of the transition from the first year of marriage to a more mature relationship. Therefore, the change over time was not important. However, the amount and aspects of change were the main points which researchers and practitioners should pal attention to in the future.