• Journal of Korean Biological Nursing Science
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• v.21 no.3
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• pp.217-223
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• 2019

Purpose: Caffeine is the most widely consumed psychostimulant of the methylxanthine class. Among adolescents, high-dose of caffeine consumption has increased rapidly over the last few decades due to the introduction of energy drinks. However, little is known about the time-dependent effect of high doses of caffeine consumption in adolescents. The present study aims to examine the short- and long-term influence of high-dose caffeine on behavior of adolescence. Methods: The animals were divided into three groups: a "vehicle" group, which was injected with 1 ml of phosphate-buffered saline for 14 days; a "Day 1" group, which was injected with caffeine (30 mg/kg), 2 h before the behavioral tests; and a "Day 14" group, which was infused with caffeine for 14 days. An open-field test, a Y-maze test, and a passive avoidance test were conducted to assess the rats'activity levels, anxiety, and cognitive function. Results: High-dose caffeine had similar effects in short-and long-term treatment groups. It increased the level of locomotor activity and anxiety-like behavior, as evidenced by the increase in the number of movements and incidences of rearing and grooming in the caffeine-treated groups. No significant differences were observed between the groups in the Y-maze test. However, in the passive avoidance test, the escape latency in the caffeine-treated group was decreased significantly, indicating impaired memory acquisition. Conclusion: These results indicate that high-dose caffeine in adolescents may increase locomotor activity and anxiety-like behavior and impair learning and memory, irrespective of the duration of administration. The findings will be valuable for both evidence-based education and clinical practice.

• The Korea Journal of Herbology
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• v.30 no.1
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• pp.43-49
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• 2015

Objectives : In this study, the anti-stress effects of ethanolic extract of Opuntiaficus-indica (OF70E) were investigated. Methods : To determine the effects of OF70E on physical stress, changes in whole-body cortisol level or behavior were monitored in zebrafish. After treatment with 0.9% saline or OF70E for 6 min, all fish underwent net handling stress (NHS), which induced physical stress. And then, we conducted open field test (OFT) or sacrificed fish for collecting body fluid from whole-body. We used the cortisol enzyme-linked immunoassay kit to measure the amount of cortisol in each zebrafish sample. Results : In result, compared with normal group which were not treated by NHS, whole-body cortisol levels were significantly increased in stressed-control group. Compared with control group, pretreatment with OF70E at concentrations of 25, 50 and 100 mg/L for 6min significantly inhibited the increase of whole-body cortisol levels induced by NHS(p<0.05). To anti-stress effects of OF70E on behavior, we conducted OFT after the induction of NHS following pretreatment of OF70E. As results of OFT, compared with unstressed-normal group, distance moved was significantly decreased by induction of NHS in stressed-control group (p<0.05). OF70E-pretreatment blocked decreases of distance moved increased by NHS (p<0.05). And meandering movement, immobility and turn angle were significantly increased by NHS in stressed-control group compared with unstressed-normal group (p<0.05). OF70E-pretreatment prevented the increases of meandering movement immobility and turn angle by NHS (p<0.05). Conclusions : In conclusion these results suggest that OF70E-pretreatment may prevent stress responses.

• The Korean Journal of Physiology and Pharmacology
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• v.14 no.4
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• pp.213-221
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• 2010

The hypothalamic-pituitary-adrenal (HPA) axis is the primary endocrine system to respond to stress. The HPA axis may be affected by increased level of corticotrophin-releasing factors under chronic stress and by chronic administration of monosodium glutamate (MSG). The purpose of this study was to investigate whether chronic MSG administration aggravates chronic variable stress (CVS)-induced behavioral and hormonal changes. Twenty-four adult male Sprague-Dawley rats, weighing 200~220 g, were divided into 4 groups as follows: water administration (CON), MSG (3 g/kg) administration (MSG), CVS, and CVS with MSG (3 g/kg) administration (CVS＋MSG). In addition, for the purpose of comparing the effect on plasma corticosterone levels between chronic stress and daily care or acute stress, 2 groups were added at the end of the experiment; the 2 new groups were as follows: naive mice (n=7) and mice exposed to restraint stress for 2 h just before decapitation (A-Str, n=7). In an open field test performed after the experiment, the CVS＋MSG group significant decrease in activity. The increase in relative adrenal weights in the CVS and CVS＋MSG group was significantly greater than those in the CON and/or MSG groups. In spite of the increase in the relative adrenal weight, there was a significant decrease in the plasma corticosterone levels in the CVS＋MSG group as compared to all other groups, except the naive group. These results suggest that impaired HPA axis function as well as the decrease in the behavioral activity in adult rats can be induced by chronic MSG administration under CVS rather than CVS alone.

• Journal of Korean Biological Nursing Science
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• v.22 no.2
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• pp.111-118
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• 2020

Purpose: The purpose of this study was to understand the impact of long- and short-term energy drinks on anxiety-like, depressionlike, and cognitive behavior in adolescent rats. Methods: Adolescent rats (age six weeks) were randomly classified into a control group (CON), a long-term administration group (LT), and a short-term administration group (ST). The LT group was orally administered 1.5 mL/100 g (body weight) of energy drink twice daily for 14 days, the ST group was orally administered for one day, and the control group applied the same amount of normal saline. Later, an open-field test, a forced swim test, novel object recognition test, and an 8-arm radial maze test was conducted to assess the rats' anxiety, depression, and cognitive function. Results: There were different effects in the long- and short-term groups of energy drink administration. In the LT group, anxiety- and depressive-like behavior increased because of increased movement in the side corner and decrease of immobility time. Also, the time to explore novel objects decreased, and the number of correct responses was reduced, indicating a learning and memory function disorder. However, the ST group was not different from the control group. Conclusion: These results indicate that long-term consumption of energy drinks can increase anxiety-like, depression-like behavior, and this can lead to decrease in learning and memory functions. Thus, nurse and health care providers should understand the impact of energy drink consumption in adolescence to provide appropriate practices and education.

• Biomolecules & Therapeutics
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• v.27 no.4
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• pp.349-356
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• 2019

Behavioral analysis in mice provided important contributions in helping understand and treat numerous neurobehavioral and neuropsychiatric disorders. The behavioral performance of animals and humans is widely different among individuals but the neurobehavioral mechanism of the innate difference is seldom investigated. Many neurologic conditions share comorbid symptoms that may have common pathophysiology and therapeutic strategy. The forced swim test (FST) has been commonly used to evaluate the "antidepressant" properties of drugs yet the individual difference analysis of this test was left scantly investigated along with the possible connection among other behavioral domains. This study conducted an FST-screening in outbred CD-1 male mice and segregated them into three groups: high performers (HP) or the active swimmers, middle performers (MP), and low performers (LP) or floaters. After which, a series of behavioral experiments were performed to measure their behavioral responses in the open field, elevated plus maze, Y maze, three-chamber social assay, novel object recognition, delay discounting task, and cliff avoidance reaction. The behavioral tests battery revealed that the three groups displayed seemingly correlated differences in locomotor activity and novel object recognition but not in other behaviors. This study suggests that the HP group in FST has higher locomotor activity and novelty-seeking tendencies compared to the other groups. These results may have important implications in creating behavior database in animal models that could be used for predicting interconnections of various behavioral domains, which eventually helps to understand the neurobiological mechanism controlling the behaviors in individual subjects.

• Journal of the Society of Naval Architects of Korea
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• v.58 no.3
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• pp.158-166
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• 2021

In this paper, a numerical analysis technique using a body force model is investigated to estimate the available net thrust of multi-pod-driven ice-breaking vessels under bollard pull and overload conditions. To employ the body force model in present flow simulations, drag and thrust components acting on the pod unit are calculated by using Propeller Open Water (POW) test data. The available net thrusts according to the direction of operation are evaluated in both bollard pull and overload conditions under deep water. The simulation results are compared with the model test data. The available net thrusts, calculated by the present analysis for ahead operating modes at 3~6 knots which are typical speeds of the target vessel in arctic field, are agreed well with the model test results. It is also found that the present result for astern operating mode appears approximately 6 % larger than the model test result. In addition, the available net thrusts are calculated under the both operating conditions accompanied by shallow water effects, and the main cause of the difference is studied. Based on the result of the present study, it is confirmed that the body force model can be applied to the performance evaluation of multi-pod propulsion system and the main engine selection in early design stage of the vessel.

• Journal of IKEEE
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• v.19 no.3
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• pp.440-446
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• 2015

This study has examined susceptibility of LNA(Low Noise Amplifier) due to Front-Door Coupling under Narrow-Band high power electromagnetic wave. M/DFR(Malfunction/Destruction Failure Rate) was measured to investigate the diagnostic of IC test. In addition, decapsulation analysis was used to understand the inside of the chip state in LNA devices. The experiments is employed as an open-ended waveguide to study the destruction effects of LNA using a 2.45 GHz Magnetron as a high power electromagnetic wave. The susceptibility level of LNA was assessed by electric field strength, and its failure modes were observed. The malfunction of LNA device has showed as the type of self-reset and power-reset. The electric field strength of malfunction threshold is 524 V/m and 1150 V/m respectively. Also, he electric field of destruction threshold is 1530 V/m. Three types of damaged LNA were observed by decapsulation analysis: component, onchipwire, and bondwire destruction. Based on these results, the susceptibility of the LNA can be applied to a database to help elucidate the effects of microwaves on electronic equipment.

• Journal of Biosystems Engineering
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• v.43 no.1
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• pp.72-80
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• 2018

Purpose: A modern greenhouse consists of various Information and Communications Technology (ICT) components e.g., sensor nodes, actuator nodes, gateways, controllers, and operating softwarethat communicate with each other. The interoperability between these components is an essential characteristic for any greenhouse control system. A greenhouse control system could not work unless the components communicate via common interfaces. The TTAK.KO-06.0288 is an interface standard consisting of four parts. Notably, TTAK.KO-06.0288-Part3, which describes the interface between a greenhouse operating system (GOS) and a greenhouse control gateway (GCG), is the core standard of TTAK.KO-06.0288. The objectives of this study were to analyze the TTAK.KO-06.0288-Part3 standard, to suggest alternative solutions for identified issues, and to develop a library as a proof of the alternative solutions. Methods: The "data field" was analyzed using a comparative analysis method, since it is a data transmission unit of TTAK.KO-06.0288-Part3. It was compared with other parts of TTAK.KO-06.0288 in terms of definition, format, size, and possible values. Although TTAK.KO-06.0288-Part1 and TTAK.KO-06.0288-Part2 do not use a "data field," they have a similar data structure. That structure was compared with the "data field" of TTAK.KO-06.0288-Part3. Results: Twenty-one issues were identified across four categories: inter-standard issues, intra-standard issues, operational issues, and misprint issues. Since some of the issues can raise interoperability problems, 16 alternative solutions were suggested. In order to prove the alternative solutions, an open-source communication library called libtp3 was developed. The library passed 14 unit tests and was adapted to two research. Conclusions: Although TTAK.KO-06.0288-Part3 is an interface standard for communication between a GOS and a GCG, it might not communicate between different implementations because of the identified issues in the standard. These issues could be solved by the alternative solutions, which could be used to revise TTAK.KO-06.0288. In addition, a relevant organization should develop a program for compatibility testing and should pursue test products for smart greenhouses.

• Journal of the Korean Geosynthetics Society
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• v.21 no.4
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• pp.41-53
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• 2022

In the excavation work like blasting/excavator work bordering on the urban railway, the dynamic safety of railway structures like tunnel, open-cut box structure and elevated bridge was investigated by numerical analysis in this study. The practically presented criteria on influential zones at the blasting work in the construction industry was numerically checked in cases of the precise vibration-controlled blasting (type II) and the small scale vibration-controlled blasting (type III) and it was shown that the criteria on blasting work methods needed to be supplemented through continuous field tests and numerical analyses. The influence of excavation vibration by mechanical excavators was especially investigated in case of earth auger and breaker. The numerical analysis of tunnel shows that the criteria on vibration velocities from the regression analysis of field test values was conservative. The amplification phenomenon of excavating vibration velocity was shown passing through the backfilling soil between the earth auger and the open-cut box structure. It was shown that the added-vibration on the superstructure of elevated bridge was occurred at the bottom of pile like earthquake when the excavator vibration was arriving at the pile toe. The systematic and continuous research on the vibration effect from excavating works was needed for the safety of urban railway structures and nearby facilities.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.1
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• pp.179-185
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• 2012

Since the eco-era is getting closer, the importance of noise reducing in the passenger cars of high-speed train is very important. The active noise control is best choice to reduce low frequency noise because the passive one is too heavy for high speed trains where weight is so critical. Also ANC is able to reduce the ambient noise when the environmental-factor changes. To reduce a three-dimensional closed-space sound field like a car of a high-speed rail is hard to do using single channel ANC control system. We used multi-channel FXLMS algorithm which calculation speed is fast and the secondary path estimation is possible in order to take into account the physical delay in electro acoustic hardware control loudspeaker and power amplifier. Firstly, we have measured interior noise of KTX and estimated noise path in KTX test-bed. However there was some problem related to algorithm divergence and increasing the filter order. We have made a simulation of interior environment of KTX car by using three frequency bands of 120Hz, 280Hz, 360Hz as the most important for KTX ANC system. During this research the interior noise reduction of KTX car was made by using the multi-channel FXLMS algorithm. Reduction performance was evaluated and compared each other for open space section and tunnel section. in-situ experiment for the KTX noise reduction by proposed ANC was performed based on data obtained in simulation and they were compared for open space section and tunnel section as well.