• The Journal of Asian Finance, Economics and Business
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• v.7 no.7
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• pp.27-34
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• 2020

The study investigates herding behavior in cryptocurrencies in different situations. This study employs daily returns of major cryptocurrencies listed in CCI30 index and sub-major cryptocurrencies and major stock returns listed in Dow-Jones Industrial Average Index, from 2015 to 2018. Quantile regression method is employed to test the herding effect in market asymmetries, inter-dependency and intra-dependency cases. Findings confirm the presence of herding in cryptocurrency in upper quantiles in bullish and high volatility periods because of overexcitement among investors, which lead to high volume trading. Major cryptocurrencies cause herding in sub-major cryptocurrencies, but it is a unidirectional relation. However, no intra-dependency effect among cryptocurrencies and equity market is observed. Results indicate that in the CKK model herding exists at upper quantile in market that may be due when the market is moving fast, continuously trading, and bullish trend are prevailing. Further analysis confirms this narrative as, at upper quantile, the beta of bullish regime is negative and significant, meaning the main source of market herding is a bullish trend in investment, which increases market turbulence and gives investors opportunity to herd. Also, we found that herding in cryptocurrencies exits in high volatility periods, but this herding mostly depends on market activity, not market movement.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.2
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• pp.47-51
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• 2006

Among Solar activities' events, the geomagnetic storms are believed to cause the largest atmospheric effects. The geomagnetic storm is a complex process of solar wind/magnetospheric origin. It is well known to affect severely on the ionosphere. However, this effect of this complex process will maybe act at various altitudes in the atmosphere, even including the lower layer and the neutral middle atmosphere, particularly the stratosphere. Nowadays, the GPS-derived ZTD (zenith tropospheric delay) can be transformed into the precipitable water vapor (PWV) through a function relation, and further has been widely used in meteorology, especially in improving the precision of Numerical Weather Prediction (NWP) models. However, such geomagnetic effects on the atmosphere are ignored in GPS meteorology applications. In this paper, we will investigate the geomagnetic storms' effects on the middle atmosphere and troposphere (0-100km) by GPS observations and other data. It has found that geomagnetic storms' effect on the atmosphere also appears in the troposphere, but the mechanism to interpret correlations in the troposphere need be further studied.

• Journal of the Korean institute of surface engineering
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• v.54 no.6
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• pp.324-330
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• 2021

As energy harvesting technology becomes important in relation to environmental issues, piezoelectric materials that convert mechanical energy into electrical energy are attracting attention. However, PZT, a representative material for piezoelectricity, is becoming difficult to use due to the problem that its components can cause environmental pollution. For this reason, recent research suggests a triboelectric nanogenerator (TENG) that generates energy through the combined effect of triboelectricity and electric induction for alternative piezoelectric devices. In TENG, electrical power is determined by the dielectric constant, thickness, and grain generation of the charged material. Therefore, in this study, a Rutile phase TiO₂ thin film with high dielectric constant was formed using the spin-coating process and the effect of annealing was investigated. For electrical analysis, a TENG device was fabricated using PTFE as a material with an opposite charge, and electrical output according to film thickness and grain formation was comparatively analyzed.

• Journal of Society of Preventive Korean Medicine
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• v.3 no.1
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• pp.157-172
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• 1999

This treatise, after review recent data on Oriental Medical toxicity, gets a conclusion on toxic concept of Oriental Medicine. 1. In the oriental medicine, the concept of toxic character contains propensity which disposition is inclined, and general meaning covered with the effect of a medicine, a side effect, formation of a medicine Besides, the concept diversely is used in the cause of a disease, names, symptoms, how to treat, medicines, prevention name, etc. 2. Every herbal drugs has toxic character. Levels of toxicity are nonexistence(無毒), existence(有毒), a little(小毒), always(常毒), serious(大毒), fatal toxic(劇毒), whose concepts in the Oriental Medicine are divided relative and absolute at the same time. 3. The examples of the fatal events by poisoning up to now are more than 400 cases(in China). 4. The factors of toxicity are the amount used unsuitably, the combination, directions, and interactions between western and oriental medicine, etc. The reduction of toxicity and how to detoxicate is several methods. The toxic science in Oriental Medicine based on the formation of oriental medicine present principles which use herbal drugs safely and availablely, utilizing th dispositions and efficiencies. It has positive, learning spirits which prevent abuse of oriental medicine, and which exactly diagnose and use the herbal drugs in the treatment with absolute toxic medicine. However, I think that scientific, positive experimental research is necessary to setup dose-response relation, be in relative quantity of toxic character, operate on the reactive mechanism exactly.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• v.3 no.2
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• pp.121-129
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• 1999

Photosynthesis and transpiration rates were simultaneously measured in attached sunflower leaves(Helianthus annuusL. cv. Russian Mammoth) during exposure to $NO_2$ and $O_3$ to determine the effect of mixed gan on photosynthesis and the stomatal aperture. The application of $O_3$ alone reduced both the net photosynthetic and transpiration rates. An analysis of the $CO_2$ diffusive resistances indicated that the main cause affecting photosynthesis reduction during $O_3$ exposure was not the internal gas phase of the leaf $(rCO_2^{liq})$ but rather the liquid phase or mesophyll diffusive resistance $(rCO_2^{liq})$, suggesting that there is a very concomitant relation between photosynthetic reduction and $rCO_2^{liq}$. The application of NO2 alone caused a marked reduction of the net photosynthesis yet no significant reduction of transpiration, indicating that NO2 affects the $CO_2$ fixation processes with no inluence on the stomatal aperture. A greter reduction in the photosynthesis of sunflower plants was caused by the application of $NO_2$ alone as compared to a combination of $NO_2$ and $O_3$. $NO_2$ alone reduced the photosynthetic rate by 90%, whereas a mixture of NO2 and O3 reduced it by 50%.

• Physical Therapy Korea
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• v.5 no.2
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• pp.23-38
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• 1998

The objective of this study was to identify the effects of pelvic tilting exercise on gait patterns of hemiplegic patients. The subjects of this study were 31 hemiplegic in- and out-patients of the Rehabilitation Hospital, Yonsei University Medical Center, from September 24, 1997 through November 5, 1997. Pre- and post-treatment change in gait patterns were measured using a ink foot-print. The data were analyzed by the paired t-test, one-way ANOVA, and independent t-test. The findings were as follows: The difference in gait patterns between pre- and post-treatment was statistically significant, with an increase in gait velocity to 7.98 cm/sec post-treatment; an increase in cadence to 7.29 steps/min; a narrowing of the base of support to 1.33 cm; an increase in step length of 3.92 cm on the less affected side and 3.73 cm on the more affected side; an increase in stride length of 5.82 cm on the less affected side and 5.92 cm on the more affected side(statistically not significant in foot angle). In relation to sex, age, cause of stroke, and laterality of paralysis, the difference in gait patterns between pre- and post-treatment was not statistically significant. Where there was no significant difference of the effects of pelvic exercise regarding the degree of spasticity, the presence of a decrease in proprioception, and the duration of treatment. In conclusion, hemiplegic pelvic tilting exercise was found to have transmitting positive effect in improving gait patterns.

• Journal of Korea Game Society
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• v.19 no.2
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• pp.5-22
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• 2019

This study analyzed the causes of over-flow of adolescent games as loneliness, lack of self-control, parents-open communication, peer-emotional support and the game motivation(immerse, social relations, achievement). For analysis, the research data, 'Game User Panel Research(1 to 4 years)', was provided by Korea Creative Content Agency. As a major result, adolescence loneliness and lack of self-control directly affected game over-flow, and the game's achievement motive in their relation of influence was mediated. Over time, the structure of the relationship between the cause and the effect has shown mostly consistent results.

• Nuclear Engineering and Technology
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• v.53 no.6
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• pp.1991-1999
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• 2021

The response changes of the specific growth rate of Lemna minor duckweed was modeled using the logarithms of frond numbers on tritium activity concentration and gamma radiation dose from cobalt 60. The concept of average specific growth rate depends on the general exponential growth pattern, where toxicity is estimated based on the effect on the growth rate. One of the main questions of the effect of the radiation dose on duckweed is how to correlate the effect of beta radiation with the effect of any other radiation for modeling radiation on Lemna minor. Experimental data were extrapolated by utilizing the OECD guidelines. A linear relationship of absorbed dose and activity concentration was obtained for the average dependency growth rate of Lemna minor as D = (0.1257)·A^0.585. The dose rate of gamma irradiation from ⁶⁰Co increases with tritium activity dependence, on the specific growth rate of the Lemna minor duckweed. An increase in the tritium activity causes a decrease in the specific growth rate of the Lemna minor duckweed. It indicates that as the quantity of the beta radiation dose increase in Lemna minor duckweed, a higher quantity of gamma radiation will be required to cause the same effect in the specific growth rate of Lemna minor duckweed. The relation between the inhibition of the Lemna minor seedling growth and gamma and beta radiation dosage agrees roughly with that between the decrease of survival rate or fertility and dosage.

• Journal of the Korea Computer Graphics Society
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• v.23 no.1
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• pp.1-8
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• 2017

For popularization of virtual reality hardwares, VR sickness come from latency is huge problem. To reduce latency, most of the HMDs use cable for video transmission. However, cable causes spatial limitation that disturb user experience. For maximize user's immersion, wireless video transmission system is necessary. Unfortunately, wireless video transmission's latency is much longer than cable's latency. Prediction algorithms may reduce latency but cause jittering effect as a side effect. This paper experiment how jittering effect affects VR sickness. The result of experiment shows jittering effect make vr sickness worse. Future research about prediction algorithm should consider both prediction error and jittering effect.

• Journal of Society of Preventive Korean Medicine
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• v.5 no.1
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• pp.90-102
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• 2001

Objectives: Resently Oxidative stress of brain was proved the cause of Alzheimer and stroke sequel. It has important significance in prevention and treatment of cerebropathia that Bulnohwan used as formula of senescence delay have antioxidative effect. The purposes of this study is to investigate the effect of Bulnohwan on antioxidant defense systems such as thiobarbituric acid reactive substances(TBARS), Superoxide dismutase (SOD), Catalase (CAT), Glutathione peroxidase (GSH-PX), Glutathione S-transperase (GST), Glutathione (GSH) in rat brain. Method: Sprague - Dawley rats were divided into 3 groups; saline solution administered control group, Bulnohwan extract administered Experimental group I and Bulnohwan adminisrtrated, 40% dietary restricted Experimental group II. Animals were sacrificed at 12 weeks after treatment TBARS, SOD, CAT, GSH-PX, GST and GSH were measured in mts brain. Results: weight of brain was no stastical significance.(p>0.05) TBARS contents were significant decrease in Experimental group I, II. (p<0.001) SOD activity was stastical significance in Experimental group II, whereas it was no stastical significance Experimental group II.(p<0.0001) Catalase activites were significant increase in . (p<0.00l) Glutathione Peroxidase activites were significant increase in Experimental group I,II. (p<0.000l) Glutathione S-transferase activites were significant increase in Experimental group I, II. (p<0.000) However there were no statistical significance each other. Glutathione contents were significant increase in Experimental group I, II. (p<0.00l) Conclusions: According to the above results, it is considered that Bulohwan has antioxidants effect in rat brain. When Bulohwan goes with diet restriction, there has more Antioxidants effect in rat brain. but this study was perfored retrospectively. So more prospective studies about mutual relation of drugs are needed