• Journal of Family Relations
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• v.23 no.1
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• pp.3-24
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• 2018

Objective: This study examined the change of informal labeling self-respect, depression/anxiety, and aggression of adolescents over time and relationship between the intercept and the growth of the variables. Method: 4-year longitudinal panel data(n=2,699), Korea Youth Panel Survey (KYPS), were analyzed to verify the influence of informal labeling on self-respect, depression/anxiety, and aggression of adolescents. Through latent growth modeling, temporal change of the variables was examined. Results: Analytic results are as follow. First, the initial status of informal labeling had a negative impact on the initial status of self-respect. The slope of informal labeling also had a negative impact on the slope of self-respect. In contrast, the initial status of informal labeling did not have an significant impact on the slope of self-respect. Second, the initial status of informal labeling had a positive impact on the initial status of aggression. The slope of informal labeling had a negative impact on the slope of aggression. In contrast, the initial status of informal labeling did not have an significant impact on the slope of aggression. Third, the initial status of informal labeling had a positive impact on the initial status of depression/anxiety and a negative impact on the slope of depression/anxiety. The slope of informal labeling had a positive impact on the slope of self-respect. Conclusions: The results suggest the importance of informal labeling on self-respect, depression/anxiety, and aggression of adolescents.

• Journal of the Korean Society of Child Welfare
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• no.40
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• pp.41-71
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• 2012

The purpose of this study is to examine longitudinal impacts of various factors on happiness in primary school children. Specifically, attachment theory and ecosystems perspective were utilized for the purpose of this study. We used Korea Youth Panel Survey, which is a 5-year longitudinal data collected from fourth grade in elementary school to second grade in middle school Latent growth model was employed as the analytic method. The findings of this study are as follow: first, academic achievement, self-esteem, parent attachment, peer attachment, teacher attachment, and community attachment all decreased over the 5-year study period. Also, the intercept and the slope variance of variables were found to be statistically significant. This means that there are significant differences in the intercept and the slope of individuals. Second, self-esteem, parent attachment, and peer attachment were found to have cross-sectional influences on happiness. This means that self-esteem, parent attachment, and peer attachment are positively associated with happiness at the intercept. Also, self-esteem, parent attachment, teacher attachment, and community attachment were found to have longitudinal influences on happiness. This means that the higher levels of community attachment at the intercept is associated with slower the rate of decrease in happiness at the slope. In addition, faster rates of decrease in self-esteem, parent attachment, teacher attachment, and community attachment are associated with faster the rate of decrease in happiness. Third, this study conducted multiple group analysis with gender. The findings of this analysis revealed no significant differences in analytic models between males and females. Based on these findings, theoretical and practice implications with regard to happiness in primary school children are discussed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.9
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• pp.1837-1845
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• 2015

The longitudinal velocity is necessary for accurate vehicular positioning in urban environment. The pitch angle, which is a road slope, should be calculated to acquire the longitudinal velocity. However, it is impossible to consider very accurate pitch, when using a sensor and an algorithm. That's why process noise and positioning stimation error of IMU should be adjusted to the driving environment and fuse GPS, OBD data with ACF which consist of AKF, CF in this paper. Then, final pitch angle which is appropriate for driving environment is estimated by IMMKF in order to optimize the system model according to road slope models.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.28 no.5
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• pp.485-491
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• 2010

Acquisition of information on failure slope, which may cause apprehension of second hand damage, requires acquisition of fast and accurate topographical data and efficient expression in indirect surveying method without accessing as needed. Therefore, in this study, the images on the intended area were photographed through hovering in the air by approaching collapsed road cut slope with the use of unmanned helicopter photography system. As a result of comparing the points observed by no prism total station and the 10 coordinate points analyzed through image analysis, the averages of absolute values were shown to be 0.056m in X axis direction, 0.082m in Y axis direction and 0.066m Z axis direction. In addition, the RMSE of the error for 10 points of test points were 0.015636m in X axis direction, 0.021319m in Y axis direction and 0.018734m in Z axis direction. Therefore, this method can determine the range of slope and longitudinal and cross sections of each slope in dangerous area that cannot be approached in relational image matching method for the terrains of such collapsed cut slope.

• Ecology and Resilient Infrastructure
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• v.2 no.2
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• pp.118-127
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• 2015

Because streams have a great diversity of morphological features according to their reaches, it is necessary to classify the types of streams in order to assess their characteristics of channel. In addition, a quantitative assessment system for channel characteristics should be reflected in the stream type properties. Therefore, this study compares two stream classification system (Rosgen's and Yamamoto's) to review their applicability on Korean streams, and the two classification systems were applied on the Nam River. In order for the mean bed slope and the longitudinal connectivity of the provincial and national streams to be reflected in the assessment system of channel characteristics, the Yamamoto system is considered highly adaptable in the stream geomorphology side. In addition, it has been found the Rosgen system has a low correlation of bed slope compared to the Yamamoto system in the view of bed materials. On the other hand, the Yamamoto system was found to be capable of reflecting sediment sorting (hydraulic sorting) of the bed slope. According to the results obtained at the Nam River, the Rosgen system could not classify a type of stream by relationship between bed material and bed slope, but the Yamamoto system can verify the correlation of stream type. However, further review is needed with respect to the applicability of natural rivers. Three types of stream that can be applied to the assessment system of channel characteristics were proposed.

• Proceedings of the Korea Concrete Institute Conference
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• 2010.05a
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• pp.51-52
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• 2010

The effect of bond strength of longitudinal reinforcing bars on shear strength of reinforced concrete beams is investigated from the view point of arch and truss actions. Stress fields with bond allow us identify possible failure modes including bond failure of a deep beam as well as a slender beam. The slope angle of diagonal compression fields is interpreted as balanced failures of two components involved for shear transfer.

• Proceedings of the KSR Conference
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• 1998.05a
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• pp.502-509
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• 1998

The scheme to reduce jerking phenomena in one push-pull type trainset was proposed. To simulate the jerking between coaches, dynamic analysis model was made. This model could analyze longitudinal dynamic behavior between locomotives and coaches caused by spring and damping characteristics of couplers and center pivots; characteristic curves of traction and braking. To validate the analysis results, tests were conducted in the same driving and braking condition. Comparison of longitudinal acceleration between simulation and test results shows a good agreement. To minimize the jerking phenomena, lots of dynamic simulations were conducted with varying driving/braking effort curve. From the results of simulations, an efficient and economic way to reduce jerking phenomena was found to be to reduce slope of tractive effort curve and synchronize braking time between locomotives and coaches. Test results show that this way could reduce the jerking Phenomena. To express jerkins Phenomena quantitatively, maximum peak to peak values of acceleration were used.

• Journal of Auto-vehicle Safety Association
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• v.13 no.4
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• pp.39-52
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• 2021

This paper presents a longitudinal acceleration controller that can be applied to real vehicles (nonlinear and time-varing systems) with only a simple experiment regardless of the type of vehicle and the control interface structure. The controller consists of a feedforward term for fast response, a zero-throttle acceleration compensation term, and a feedback term (P gain) to compensate for errors in the feedforward term, and another feedback term (I gain) to respond to disturbances such as slope. In order to easily apply it to real vehicles, there are only two tuning parameters, feedforward terms of throttle and brake control. And the remaining parameters can be calculated immediately when the two parameters are decided. The tuning procedure is also unified so that it can be quickly and easily applied to various vehicles. The performance of the controller was evaluated using MATLAB/Simulink and Truksim's European Ben model. In addition, the controller was successfully implemented to 3 medium-sized vehicle (HMC Solati), which is composed of different control interface characteristic. Vehicle driving performance was evaluated on the test track and on the urban roads in Siheung and Seoul.

• Communications for Statistical Applications and Methods
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• v.30 no.3
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• pp.291-309
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• 2023

Longitudinal count data has been widely collected in biomedical research, public health, and clinical trials. These repeated measurements over time on the same subjects need to account for an appropriate dependency. The Poisson regression model is the first choice to model the expected count of interest, however, this may not be an appropriate when data exhibit over-dispersion or under-dispersion. Recently, Conway-Maxwell-Poisson (CMP) distribution is popularly used as the distribution offers a flexibility to capture a wide range of dispersion in the data. In this article, we propose a Bayesian CMP regression model to accommodate over and under-dispersion in modeling longitudinal count data. Specifically, we develop a regression model with random intercept and slope to capture subject heterogeneity and estimate covariate effects to be different across subjects. We implement a Bayesian computation via Hamiltonian MCMC (HMCMC) algorithm for posterior sampling. We then compute Bayesian model assessment measures for model comparison. Simulation studies are conducted to assess the accuracy and effectiveness of our methodology. The usefulness of the proposed methodology is demonstrated by a well-known example of epilepsy data.

• Journal of Korean Society of Forest Science
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• v.89 no.3
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• pp.397-404
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• 2000

This study was carried out to investigate the influence of the road structure and site conditions on side-ditch stability of forest road. For experimental purposes, the forest road in the Kwangrung Experimental Forest, Korea Forestry Research Institute, was chosen as a study site. A total of 556 plots wes set up as every longitudinal gradient changing points by belt-transect method. Data of 10 road structural characteristics and side-ditch stability were collected from each plot and analysed by Quantification II. The main factors in order of partial correlation coefficient were longitudinal gradient, road position, inclination of cut-slope, constituent material of cut-slopes, distance of surface flow, cross-sectional shape of road, pavement material, vegetation of cut-slopes and length of cut-slope. The erosion of side-ditch of forest road occurred in the following cases; more than 8% of the longitudinal gradient, road position of hill under side and foot hill, more than $50^{\circ}$ of inclination of cut-slope, constituent material of cut-slopes of hard soil and gravel soil, more than 80m of distance of surface flow, pavement material with earth or gravel, more than medium covered of vegetation of cut-slopes, and the straight and convex form of road-bed.