• The Journal of the Korea Contents Association
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• v.19 no.7
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• pp.138-148
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• 2019

Although social relation factors are confirmed to be closely associated with the depression level of the elderly through the preceding studies, there has been no specific study on subfactors of social relation that influence the trajectory of depression level. Considering such limitation, this study aims to analyze influencing subfactors of social relation on the trajectory of depression of the elderly. The 3rd, 4th, 5th, and 6th-year data of the Korean Longitudinal Survey of Ageing (KLoSA), which were provided by the Korea Employment Information Service (KEIS), were used in this study and 2,484 people aged 65 and over who responded to all the four-session surveys were used as final analysis subjects. In the result of the longitudinal study on depression level of the elderly aged 65 and over, the individual depression level was confirmed become lowered over time, showing a positive change. Also, the conditional model of Latent Growth Modeling (LGM) was applied to identify specific social network factors that influence the longitudinal change of depression level of the elderly. In the result of the analysis, it was found that initial value of depression of the elderly was influenced by whether they have a spouse or not, number of household member, meeting with close people, whether they do economic activity or not, whether they have a religion or not, etc. and the rate of change in depression of the elderly was influenced by number of household member, meeting with close people, expectation about life, etc. Through above results, this study suggests a need for specific programs and supports to continuously lower the depression level of the elderly.

• The Korea Journal of Herbology
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• v.32 no.1
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• pp.69-74
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• 2017

Objectives : This study aimed to investigate the effects of Angelicae sinensis Radix on longitudinal bone growth rate in rats. We have screened traditional medicinal herbs to develop the longitudinal bone growth stimulator by well-established rat model. A. sinensis was identified as one of the effective herbs in the screening process. Methods : Adolescent female rats were administered A. sinensis at doses of 30 mg/kg and 300 mg/kg for 10 consecutive days. To observe the rate of longitudinal bone growth, tetracycline was injected intraperitoneally on day 8 to stain a fluorescent band on the anew formed bone. To elucidate the mode of action, we observed insulin-like growth factor-1 (IGF-1) and bone morphogenetic protein-2 (BMP-2) expression after A. sinensis administration in growth plate. Results : In the 300 mg/kg A. sinensis group, the length between the proximal endpoint of the tetracycline label and the division line between growth plate and bone was significantly increased compared with vehicle-treated control group. Height of the proximal tibial growth plate was higher in the A. sinensis group compared with control group. A. sinensis also upregulated the expressions of IGF-1 and BMP-2 in the proliferative zone and hypertrophic zone of the proximal tibial growth plate. Conclusions : A. sinensis increases longitudinal bone growth rate in rats. According to immunohistochemistry, A. sinensis increases local IGF-1 and BMP-2 expressions in the growth plate which can be considered as direct stimulation of GH on the local growth plate.

• Journal of the Korean GEO-environmental Society
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• v.9 no.4
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• pp.53-61
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• 2008

Various components including wave scattering, wave passage, and site amplification effects cause the ground motion to vary spatially. The spatially varying ground motion can significantly influence the dynamic response of longitudinal structures such as bridges and tunnels. While its effect on bridges has been extensively studied, there is a lack of study on its effect on underground tunnels. This paper develops a new procedure for simulating the tunnel response under spatially varying ground motion. The procedure utilizes the longitudinal displacement profile, which is developed from spatially variable ground motion time histories. The longitudinal displacement profile is used to perform a series of pseudo-static three dimensional finite element analyses. Results of the analyses show that the spatially variable ground motion cause longitudinal bending of the tunnel and can induce substantial axial stress on the tunnel lining. The effect can be significant at boundaries at which the material properties of the ground change in the longitudinal direction.

• Journal of Convergence for Information Technology
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• v.11 no.10
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• pp.131-137
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• 2021

The aim of the study was to observe the influence and related mechanism of histamine and its analogues used for hypersensitivity tests and used as an indicator of impurities in drugs on the tissue-specific intestinal contraction. Intestinal contraction includes the activation of thick or thin filament regulation. However, there are few reports addressing the question whether this regulation is involved in histamine-induced regulation. We hypothesized that histamine plays a role in tissue-dependent regulation of intestinal contractility. Denuded ileal/colonic longitudinal and circular muscles of male rats were used and isometric contractions were recorded using a data acquisition system. Interestingly, histamine alone didn't increase the contraction of the circular muscle but increased the contraction of the longitudinal muscle. Histamine together with atropine (M3 receptor antagonist) didn't inhibit the contraction of the longitudinal and circular muscle. Therefore, histamine alone and together with atropine increases the ileal longitudinal muscle contraction suggesting that additional mechanisms (decreased receptor density, postreceptor signaling or distribution of agonists) might be involved in the regulation of ileal muscle contractility. In conclusion, histamine and/or atropine has some effect on the regulation of the longitudinal contractility regardless of M3 receptor and the simpler test would be preferred as the drug impurity test compared to more complicated tests.

• Journal of the Korean Wood Science and Technology
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• v.47 no.3
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• pp.265-276
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• 2019

In our previous study, the LeNet3 model successfully classified images from the transverse surfaces of five Korean softwood species (cedar, cypress, Korean pine, Korean red pine, and larch). However, a practical limitation exists in our system stemming from the nature of the training images obtained from the transverse plane of the wood species. In real-world applications, it is necessary to utilize images from the longitudinal surfaces of lumber. Thus, we improved our model by training it with images from the longitudinal and transverse surfaces of lumber. Because the longitudinal surface has complex but less distinguishable features than the transverse surface, the classification performance of the LeNet3 model decreases when we include images from the longitudinal surfaces of the five Korean softwood species. To remedy this situation, we adopt ensemble methods that can enhance the classification performance. Herein, we investigated the use of ensemble models from the LeNet and MiniVGGNet models to automatically classify the transverse and longitudinal surfaces of the five Korean softwoods. Experimentally, the best classification performance was achieved via an ensemble model comprising the LeNet2, LeNet3, and MiniVGGNet4 models trained using input images of $128{\times}128{\times}3pixels$ via the averaging method. The ensemble model showed an F1 score greater than 0.98. The classification performance for the longitudinal surfaces of Korean pine and Korean red pine was significantly improved by the ensemble model compared to individual convolutional neural network models such as LeNet3.

• The Korea Journal of Herbology
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• v.29 no.5
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• pp.31-38
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• 2014

Objectives : Egg yolk is composed of various important chemical substances for human health. A calcium shortage causes the growth retardation on the body growth. In this study, we examined the therapeutic effects of calcium, vitamin D and egg yolk peptide (EYP) treatment on the retardation of the longitudinal bone growth induced by low-calcium diet in adolescent rats. Methods : Low calcium diets were administrated for 15 days. During the last five days, calcium and/or vitamin D and/or EYP were administrated. The body weights, longitudinal bone growth rates, the heights of growth plates, and bone morphogenetic protein (BMP)-2 and insulin-like growth factor (IGF)-1 expressions were measured using histochemical analysis. Results : Low calcium diets caused the significant reduction in body weight gains and the longitudinal bone growth. The heights of growth plates and the expressions of BMP-2 and IGF-1 showed the impairment of body growth as well. Calcium and/or vitamin D administration could not significantly increase the longitudinal bone growth. However, calcium, vitamin D, and EYP administration significantly increased the bone growth, the growth plate height, and BMP-2 and IGF-1 expressions. Conclusions : These results suggest that EYP enhances the longitudinal bone growth in the calcium and/or vitamin D deficiency and it could be a promising agent for the treatment of children suffering from malnutrition.

• Journal of Korea Water Resources Association
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• v.54 no.11
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• pp.863-873
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• 2021

The mechanical dispersion which dominates solute transport in porous media is caused by the difference in flow velocity within pores. Longitudinal dispersion coefficient and longitudinal dispersivity that are hydro-dispersive parameters of advection-dispersion equation can only be obtained by experiment. Hydraulic mean radius that represents the amount and intensity of flowing water within pores can be obtained by the formula using the factors for physical properties. A slug injection test was conducted and a power type empirical formula for obtaining a longitudinal dispersivity using a hydraulic mean radius in rockfill porous media was derived. It is possible to obtain the longitudinal dispersivity depending on transport distance because it contains a formula for a scale constant, and expected to be applicable to waterways filled with homogeneous gravel and small flow rate.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.29 no.1
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• pp.25-31
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• 2023

Background: In this study, the abductor hallucis activity and medial longitudinal arch angle were compared by performing four exercises, namely the short foot exercise, the short foot exercise with 2^nd~5^th toe extension, the short foot exercise with 2^nd~5^th toe extension with a load of 1kt on the sole, and the short foot exercise with 2^nd~5^th toe extension with a load of 2kg on the sole. Methods: Four short foot exercises as described above were performed by 20 healthy adult males and females. The abductor hallucis activity and medial longitudinal arch angle were measured and analyzed by surface electromyography and the Kinovea software program. Results: The short foot exercise with 2^nd~5^th toe extension, short foot exercise with 2^nd~5^th toe extension with a load of 1kg on the sole, and the short foot exercise with 2^nd~5^th toe extension with a load of 2kg on the sole showed significantly higher abductor hallucis activity than the short foot exercise alone. Among these, the short foot exercise with the 2^nd~5^th toe extension was the most effective. All exercises showed a significantly decreased medial longitudinal arch angle post-exercise than pre-exercise, and the short foot exercise with the 2^nd~5^th toe extension showed a significantly decreased medial longitudinal arch angle compared to the other three exercises. Conclusion: It is believed that the short foot exercise with the 2^nd~5^th toe extension can be proposed as an effective exercise that can replace the short foot exercise alone.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.4A
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• pp.457-463
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• 2008

The longitudinal stiffener performs its role to increase the local buckling strength by making simple support upon compression flange. In the recent researches, it is investigated that compression flange with point supports on certain arrangement reveals the same strength with longitudinal stiffeners. From this results, it is predictable that shear stud could perform the role of longitudinal stiffener if shear stud embedded in concrete satisfies the requirement to point-support under yield stress of the compression flange. In this study, the researches were performed to investigate the optimally required arrangement space of longitudinal point-support for which the shear stud replacing the longitudinal stiffeners and simultaneously determine the required numbers and space of shear stud for completely composite behavior between compression bottom flange and bottom concrete on the double composite girder system.

• Journal of the Korean Data and Information Science Society
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• v.25 no.6
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• pp.1439-1447
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• 2014

Most of literatures on Korean child aggression are based on using the cross-sectional data sets. Although there is a related study with a longitudinal data set, it is assumed that the data sets measured repeatedly in the longitudinal data are mutually independent. A longitudinal data analysis for Korean child aggression is then necessary. This study is to analyze the effect of child development outcomes including academic achievement, self-esteem, depression anxiety, delinquency, victimization by peers, abuse by parents and internet using time on child aggression with Korea Welfare Panel Study data observed three times between 2006 and 2012. Since Korea Welfare Panel Study data have missing values, the missing at random is assumed. The linear mixed effect model and the restricted maximum likelihood estimation are considered.