• Korean Journal of Medicinal Crop Science
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• v.22 no.3
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• pp.196-202
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• 2014

Depression is one of the most common neuropsychiatric disorders and has been associated with the neuroendocrine system and alterations in behavior. Schisandra chinensis Baillon is one of major medicinal plants used as a Korea medicine and food sources, and has been processed in the fields of various food products and medicinal herbs. The chronic mild stress (CMS) protocol is widely used to evoke depressive-like behaviors in laboratory mice or rat. The CMS procedure induced some behavioral changes that are compatible with the common expectations, i.e. 'anhedonic' behavior and can affect corticosterone level. The present study, Schisandra chinensis extract administration by daily gavage from the 3 weeks exhibited an antidepressant-like effect on CMS-induced depression in mice. Schisandra chinensis extract administration at dose of 200mg/kg significantly increased the sucrose consumption, and decreased the immobility durations in forced swim test and tail suspension test. Furthermore the corticosterone level decreased than control group. In conclusion, Schisandra chinensis extract showed antidepressant-like effects on sucrose preference test, forced swimming test and tail suspension test based on CMS model.

• Computers and Concrete
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• v.24 no.6
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• pp.527-539
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• 2019

In this paper, the fracture characteristics of concrete specimens with different notch depths under three-point flexural loads are studied by finite element and fracture mechanics methods. Firstly, the concrete beams (the size is 700×100×150 mm) with different notch depths (a=30 mm, 45 mm, 60 mm and 75 mm respectively) are tested to study the influence of notch depths on the mechanical properties of concrete. Subsequently, the concrete beams with notch depth of 60 mm are loaded at different loading rates to study the influence of loading rates on the fracture characteristics, and digital image correlation (DIC) is used to monitor the strain nephogram at different loading rates. The test results show that the flexural characteristics of the beams are influenced by notch depths, and the bearing capacity and ductility of the concrete decrease with the increase of notch depths. Moreover, the peak load of concrete beam gradually increases with the increase of loading rate. Then, the fracture energy of the beams is accurately calculated by tail-modeling method and the bilinear softening constitutive model of fracture behavior is determined by using the modified fracture energy. Finally, the bilinear softening constitutive function is embedded into the finite element (FE) model for numerical simulation. Through the comparison of the test results and finite element analysis, the bilinear softening model determined by the tail-modeling method can be used to predict the fracture behavior of concrete beams under different notch depths and loading rates.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.26 no.6
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• pp.252-257
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• 2016

Dust-collecting behavior of tonpilz transducer was simulated with finite-element-method (FEM) software. In order to optimize the performance of tonpilz transducer, the shape factors including the thickness of head mass, the diameter of tail mass and the depth of bolt were analyzed as variables. As a vibrating energy source, the piezoelectric materials was also tested with PZT-4 and two kinds of piezoelectric single crystals. The output power of the transducer was maximized with the shape factors and then the behavior of the dust-collection was demonstrated with the multi-physics software, COMSOL.

• Proceedings of the Korean Information Science Society Conference
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• 2012.06a
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• pp.152-154
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• 2012

스마트폰은 배터리를 사용하는 기기이기 때문에 전력 최적화가 매우 중요한 사안이다. 특별히, 많은 에너지가 소모되는 3G 네트워크 인터페이스에서, 불필요하게 대기하며 발생하는 Tail 에너지를 줄이기 위한 연구가 활발히 진행되어 왔다. 기존의 연구들은 사용자와 응용의 특성을 고려하지 않고 전송 예측 방법에 대해서도 논하고 있지 않아 실제 시스템에 적용하는데 한계가 존재한다. 본 논문에서는, 국내 망환경에서 적용 가능한 3G 모델을 통해 사용자의 응용 별 사용 경향성을 파악하고, 응용 별로 서로 다른 Tail 지속 시간을 선택하여 에너지를 최적화 할 수 있는 방법을 제시한다. 본 기법을 적용하였을 때, 10%의 지연 증가를 준수하며, 평균 34%의 네트워크 에너지를 줄일 수 있었다.

• Communications for Statistical Applications and Methods
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• v.16 no.4
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• pp.647-658
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• 2009

It is already known from the previous study that flood seems to have heavier tail. Therefore, to make prediction of future extreme label, some agreement of tail behavior of extreme data is highly required. The LH-moments estimation method, the generalized form of L-moments is an useful method of characterizing the upper part of the distribution. LH-moments are based on linear combination of higher order statistics. In this study, we have formulated LH-moments of five distributions useful in hydrology such as, two types of three parameter kappa distributions, beta-${\kappa}$ distribution, beta-p distribution and a generalized Gumbel distribution. Using LH-moments reduces the undue influences that small sample may have on the estimation of large return period events.

• Journal of Korean Society of Steel Construction
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• v.10 no.3 s.36
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• pp.537-551
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• 1998

The intention of this paper is to provide realistic values of design thermal loads applicable to composite box girder bridges on the basis of the statistical analysis of long-term measured temperature data. For this purpose, temperatures were recorded at a newly constructed composite box girder bridge during about 20 months. Before analyzing the extreme values, major thermal loading parameters that characterize the temperature profile are defined, and a seasonal behavior of those is examined in detail. The limit distributions of the thermal loading parameters are then determined by the tail-equivalence method, and the thermal loading parameters corresponding to selected return period are calculated. Finally, the results are compared to the specifications suggested in a current design code for thermal loads, and it is concluded that the current design code is unsuitable for representing the self-equilibrated thermal stresses in composite bridges, and the horizontal temperature difference which is not suggested in current design code should be taken Into account in particular cases.

• Geomechanics and Engineering
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• v.29 no.3
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• pp.291-300
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• 2022

Tunnel boring machines combined with the earth pressure balanced shield method (EPB shield TBMs) have been adopted in urban areas as they allow excavation of tunnels with limited ground deformation through continuous and repetitive excavation and support. Nevertheless, the expansion of TBM construction requires much more minor and exquisitely controlled surface settlement to prevent economic loss. Several parametric studies controlling the tunnel's geometry, ground properties, and TBM operational factors assuming ordinary conditions for EPB shield TBM excavation have been conducted, but the impact of excessive excavation on the induced settlement has not been adequately studied. This study conducted a numerical evaluation of surface settlement induced by the ground loss from face imbalance, excessive excavation, and tail void grouting. The numerical model was constructed using FLAC3D and validated by comparing its result with the field data from literature. Then, parametric studies were conducted by controlling the ground stiffness, face pressure, tail void grouting pressure, and additional volume of muck discharge. As a result, the contribution of these operational factors to the surface settlement appeared differently depending on the ground stiffness. Except for the ground stiffness as the dominant factor, the order of variation of surface settlement was investigated, and the volume of additional muck discharge was found to be the largest, followed by the face pressure and tail void grouting pressure. The results from this study are expected to contribute to the development of settlement prediction models and understanding the surface settlement behavior induced by TBM excavation.

• Journal of Animal Science and Technology
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• v.61 no.3
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• pp.147-153
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• 2019

A goal for swine farming is the improvement in the number of live-born and weaned piglets per sow. Hence, the effect of parities should consider the correlation between the component traits of reproductive performance, weaning, and duration. Sows were housed in farrowing pens (W 2.2 ${\times}$ D 1.8 ${\times}$ H 1.2 m) on a partially slatted plastic floor. Twenty sows used in this study were between the first and sixth parity in gilts (P1), parity 2-5 (P3), and parity 6-9 (P6). Data collection by parity was classified into three categories: (1) reproduction performance (gestation length, total number of piglets born, number of piglets live born, number of piglets stillborn, total piglet birth weight; (2) weaning traits (weaning period, number of piglets weaning, total piglets weaning weight); (3) duration traits (farrowing duration, placenta expulsion duration, time from last piglet to first placenta, average birth interval, and tail wagging behavior). Gestation length was higher in P6 than P1 and P3 of different parity sows. The maximum value in P1 and P3 was 117 days, but the median value in P6 was 117 days (p < 0.05). The total number of piglets born (p = 0.113), number of piglets live born (p = 0.118), number of still piglets born (p = 0.151), and total piglet birth weight (p = 0.117) were not affected by parity. The number of live piglets was higher than the other parities by an average of $15.6{\pm}2.1$ in P1. The duration of farrowing was the lowest at 22.2 min in P6, but the maximum value was 42.2 min more than other parities (p = 0.355). Weaning traits of sows also did not differ significantly (p > 0.05), but the weaning period from P1 was lower than that of the other parities (p = 0.170). The number of piglets weaned was 10 heads on average in P1, P3, and P6 (p < 0.05). However, the mean values of the total piglet weaning weight (p = 0.377) of P6 (62.0 10.4 kg) were higher than those of P1 (54.9 10.2 kg) and P3 (58.4 13.6 kg). The placenta expulsion duration was higher in P6 than that in P1 and P3 (p = 0.447). The time from the last piglet to first placenta was be lower in P3 than that of the other parities (p = 0.206). The average birth interval was higher in P3 than that of the other parities (p = 0.156). Tail wagging (count) behavior was higher in P6 than in the other parities (p = 0.065). The data showed that the reproduction performance, total piglets born, and weight were higher in the gilts group, and higher in the weaning trait than that in the P6 group. This study examined the relationship between reproductive performance, birth interval and tail motion according to sow parity. Regarding duration, farrowing duration was lower in P6 than that in the other parities, but placenta expulsion and tail wagging were higher in P6 than in the other parities. Therefore, it is possible that the results from these sows could be used as basic data for effective farm management.

• The Korea Journal of Herbology
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• v.29 no.2
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• pp.7-13
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• 2014

Objectives : Chronic mild stress (CMS) model is currently recognized as a better animal model of depression. The purpose of this study was to investigate the antidepressant-like effects of the Nelumbo nucifera leave extract using CMS model. Methods : The antidepressant-like effects of Nelumbo nucifera leaves extract was determined by using animal models of depression. Male ICR mice were divided into four groups: saline-treated normal, without CMS; saline-treated stress control; CMS+ Imipramine(20mg/kg); CMS+Nelumbo nucifera leaves extract(200mg/kg). All mice except the normal group exposed an unpredicted sequence of chronic mild stressors for 5 weeks. The behavior of mice were detected by sucrose preference test, forced swim test and tail suspension test. Then concentration of corticosterone in serum was detected by enzyme immunoassay. Results : Nelumbo nucifera leaves extract administration by daily gavage from the 3rd week exhibited an antidepressant-like effect on CMS-induced depression in mice. Nelumbo nucifera leaves extract administration at dose of 200 mg/kg significantly increased the sucrose consumption, and decreased the immobility durations in forced swim test and tail suspension test. Furthermore the corticosterone level decreased than control group. Conclusions : Chronic mild stress can affect mouse behavior and corticosterone level and cause depression. The present experiments not only further confirm the antidepressant-like effects of Nelumbo nucifera leaves extract in the sucrose preference test, forced swimming test and tail suspension test, but also the improving effects of Nelumbo nucifera leaves extract on the depression-like symptoms in the CMS model. Nelumbo nucifera leaves extract has the antagonism on CMS and produce antidepressive effects.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.10
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• pp.81-87
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• 2017

This paper describes the dynamic behavior and enhancement of Korean high-speed trains. The tail vibration reduction method of the yaw damper installation method change, which was derived from previous research, was applied to the running test of high-speed train. In addition, the vibration reduction method for the entire vehicle was derived by a numerical method and its effect was confirmed by a running test. The improved design was applied to the double-deck high-speed train coaches and the commissioning proceeded without problems in dynamic behavior. Sensitivity analysis of the suspension parameters affecting the critical speed of Korean next-generation high-speed trains was performed and four design variables that greatly affected the critical speed were derived. These were in the order of the primary elastic joint x-directional stiffness, the secondary yaw damper series stiffness, the secondary lateral damper damping coefficient, and the carbody damper damping coefficient. By optimizing the design variables, the suspension parameter that improves the critical speed by 23.3% can be used in the commercial designs of Korean next-generation high-speed trains.