• Composites Research
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• v.32 no.5
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• pp.284-289
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• 2019

In the present paper, the dynamic force-moment equilibrium equations, driving power and energy equations are analyzed to formulate the equation for fuel economy(km/liter) equivalent to the driving distance (km) divided by the fuel volume (liter) of the vehicle, a selected model of gasoline powered KIA K3 (1.6v). In addition, the effects of the dynamic parameters such as speed of vehicle (V), vehicle total weight(M), rolling resistance ($C_r$) between tires and road surface, inclined angle of road (${\theta}$), as well as the aerodynamic parameters such as drag coefficient ($C_d$) of vehicle, air density(${\rho}$), cross-sectional area (A) of vehicle, wind speed ($V_w$) have been analyzed. And the possibility of alternative materials such as lightweight metal alloys, fiber reinforced plastic composite materials to replace the conventional steel and casting iron materials and to reduce the weight of the vehicle has been investigated by Ashby's material index method. Through studies, the following results were obtained. The most influencing parameters on the fuel economy at high speed zone (100 km/h) were V, the aerodynamic parameters such as $C_d$, A, ${\rho}$, and $C_r$ and M. While at low speed zone (60 km/h), they are, in magnitude order, dynamic parameters such as V, M, $C_r$ and aerodynamic ones such as $C_d$, A, and ${\rho}$, respectively.

• Journal of the Korea Convergence Society
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• v.12 no.4
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• pp.61-68
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• 2021

The purpose of this study was to derive their cognitive, psychological, and behavioral characteristics through a fusion study that analyzed the quantified results of post-homeless people participating in the housing support project after the electroencephalogram test. Participants in this study are 6 people who have lived in temporary homeless facilities or homeless living facilities and have expressed their intention to participate in the housing support project. Electroencephalogram measurements were performed using Brainmaster equipment according to the International 10-20 Law. As a result of the analysis, the study participants showed high levels of Theta wave, Beta wave, and High Beta wave, which show the peculiarity of the emotional aspect, which is a result of showing emotional characteristics such as anger, anxiety, and insomnia in the emotional aspect. Therefore, it is suggested that they provide stress management, counseling, and physical health management services in order to maintain a stable residential life in the community in the future. The results of this study presented a quantitative basis for the cognitive, psychological, and behavioral characteristics of homeless people, and suggests a support system necessary for them to maintain self-reliance in communities in the future.

• Journal of the Korean Society of Floral Art and Design
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• no.43
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• pp.57-79
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• 2020

The purpose of this study was to investigate the effects of emotion and EEG of people with mental illness by vocational rehabilitation program based on horticultural therapy. The subjects of the study were three people with mental illness who were training in a vocational rehabilitation team at a health center located in G city, Gyeongsangbuk-do. The result of this study, positive affect increased and negative affect decreased. The result of EEG inspection was increased 17.27% on pre test to 21.39% on post test for Theta wave and 39.66% on pre test to 49.02% on post test for Alpha wave in case of subject A. Also Beta wave was decreased 27.53% on pre test to 17.54% on post test. Subject B increased Alpha wave 29.70% on pre to 31.82% on post. Subject C increased Alpha wave 26.30% on pre to 49.42% on post. Beta wave decreased 29.85% on pre to 16.13% on post. Theta wave, when creatively idea or thought occurs, alpha wave when safety and focusing was increased and beta wave when stress, tension and anxiety was decreased. As a result of profits analysis, subject A spent cost a total of 101,700 won for material and achieve profits of 203,400 won by setting a sales price. Therefore, gain the 101,700 won of net revenue. Subject B spent cost a total of 81,000 won for material and achieve profits of 162,000 won by setting a sales price. Therefore, gain the 81,000 won of net revenue. Subject C spent cost a total of 56,200 won for material and achieve profits of 112,400 won by setting a sales price. Therefore, gain the 56,200 won of net revenue.

• Journal of Marine Life Science
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• v.1 no.2
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• pp.79-87
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• 2016

Heavy metals such as cadmium (Cd) are highly toxic to aquatic organisms and human, even at trace concentration. Herein we investigated the effect of Cd on the gene expression of ATP-binding cassette (ABC) transporters and glutathione S-transferase (GST) in marine ciliate Euplotes crassus. Seven ABC transporters and one GST genes were partially cloned and sequences, and thereafter, transcriptional modulation of these genes after exposure to Cd for 8 h was investigated using quantitative real time RT- PCR (qRT-PCR). As results, sequence analysis and phylogenetic study revealed that E. crassus ABCs are likely typical ABC transports, in particular, B/C family, and GST gene may be similar to GST theta isoform. A significant increase in the expression of ABCs, except for ABCB21 was observed in a concentration dependent manner after exposure to Cd (0.1 and 0.5 mg/l) for 8 h. The GST mRNA level was the highest at 0.5 mg/l Cd and then reduced until control level. These findings suggest that ABCs and GST may be involved in a protective mechanism against Cd-mediated toxicity in E. crassus.

• Korean Journal of the Atmospheric Sciences
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• v.78 no.9
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• pp.2657-2675
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• 2021

A new k-distribution scheme of longwave radiation without the correlated-k-distribution assumption is developed. Grouping of spectral points is based on the line-by-line (LBL)-calculated absorption coefficient k at a few sets of reference pressure p_r and temperature θ_r, where the cooling rate is substantial in a spectral band. In this new scheme, the range of k(p_r, θ_r) of a band is divided into a number of equal intervals, or g groups, in log₁₀(k_r). A spectral point at the wavenumber ν is identified with one of the g groups according to its k_ν(p_r, θ_r). For each g group, a Planck-weighted k-distribution function H_g and a nonlinearly averaged absorption coefficient ${\bar{k}}_g(p,{\theta})$ are derived. The function H_g and the absorption coefficient ${\bar{k}}_g(p,{\theta})$ constitute the new k-distribution scheme. In this k-distribution scheme, a spectral point can only be identified with a g group regardless of pressure and temperature, which is different from the correlated-k distribution scheme. The k-distribution scheme is applied to the H₂O, CO₂, O₃, N₂O, and CH₄ absorption bands, and results are compared with LBL calculations. To balance between the accuracy and the computational economy, the number of g groups in a band of a given gas is chosen such that 1) the difference in cooling rate is <0.1 K day^-1 in the troposphere and <1.0 K day^-1 in the stratosphere and 2) the difference in fluxes is <0.5 W m^-2 at both the top of the atmosphere and the surface. These differences are attained with 130 g groups, which is the sum of the g groups of all five gases.

• International Journal of Precision Engineering and Manufacturing
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• v.3 no.2
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• pp.78-86
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• 2002

In general, X-ray diffraction method detects the changes of crystal lattice under material surface using the angle of diffraction 2$\theta$. This technique which deals with in the presented paper can be applied to a behavior on the slipped band or the micro crack cause to material degradation. The relation between half-value breadth and cycle numbers shows three stages, which consist of rapid decrease in the initial cycle, slight decrease in the middle cycle, and then rapid decrease in the final cycle. The ratio of half-value breadth has a constant value on B/B$\_$0/ - N diagram under the loading condition except early part of fatigue life. The ratio of half-value breadth B/B$\_$0/ - log N$\_$f/ with respect to number of cycle to failure N$\_$f/ has linear behavior on B/B$\_$0/ - log N$\_$f/ diagram. Therefore, the evaluation of fatigue life by the average gradient has much less mean error than the estimation of fatigue life by log B/B$\_$0/ - log N/N$\_$f/ relation.

• Fibers and Polymers
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• v.2 no.3
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• pp.135-140
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• 2001

Organic-inorganic hybrid composites consisting of poly(vinylidene fluoride) (PVDF) and SiO$_2$ were prepared through a sol-gel process and the crystallization behavior of PVDF in the presence of $SiO_2$ networks was investigated by spectroscopic, thermal and x-ray diffraction measurements. The hybrid composites obtained were relatively transparent, and brittleness increased with increasing content of tetraethoxysilane (TEOS). It was regarded from FT-lR and DSC thermal analyses that at least a certain interaction existed between PVDF molecules and the $SiO_2$ networks. X-ray diffraction measurements showed that all of the hybrid samples had a crystal structure of PVDF ${\gamma}$-phase. Fresh gel prepared from the sol-gel reaction showed a very weak x-ray diffraction peak near 2$\theta$=$21^{\circ}$ due to PVDF crystallization, and Intensity increased grade-ally with time after gelation. The crystallization behavior of PVDF was strongly affected by the amount of $SiO_2$ networks. That is, $SiO_2$ content directly influenced preference and disturbance fur crystallization. In polymer-rich hybrids, $SiO_2$ networks had a favorable effect on the extent of PVDF crystallization. In particular, the maximum portent crystallinity of PVDF occurred at the content of 3.7 wt% $SiO_2$ and was higher than that of pure PVDF. However. beyond about 10 wt% $SiO_2$, the crystallization of PVDF was strongly confined.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.2660-2665
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• 2007

Turbulent boundary-layer over a micro-riblet film(MRF) was investigated experimentally. The MRF has sharp V-shaped micro scale grooves of $300{\mu}m$ in width and $176.8{\mu}m$ in height. Particle image velocimetry(PIV) system was employed to measure velocity fields of flow over the MRF coated plate. Flow over a smooth plate was also measured for comparison. The PIV measurements were taken in the streamwise wall-normal planes at Re$\theta$= 985 and 2342. Vortex structures of the flow were analyzed by extracting the swirling strength as an unambiguous vortex-identification criterion. As a result the number of spanwise vortices with clockwise(negative) rotation decreases rapidly in the near-wall region(y<0.2h), but decreases slowly in the outer region(0.2h

• Journal of the Korean Magnetics Society
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• v.9 no.4
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• pp.173-176
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• 1999

Errors of saturation magnetization and magnetocrystalline anisotropy constant determined by magnetization curve of magnetically aligned unixial power were analyzed. In case of alignment factor ${\Theta}_0=10{\circ}$, magnetic constant errors of $Nd_2Fe_{14}B$ were calculated to be error of $M_S{\risingdotseq}1{\%}\;and\;error\;of\;K_1{\risingdotseq}13\;{\%}$, respectively, and magnetic constant errors of Ba-ferrite were calculated to be error of $M_S{\risingdotseq}1{\%}\;and\;error\;of\;K_1{\risingdotseq}17\;{\%}$. In this method, $M_s$ was found to be determined with high accuracy. High alignment is desirable for high accuracy.

• 한국연소학회:학술대회논문집
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• 2004.11a
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• pp.24-32
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• 2004

The characteristics of heat transfer from horizontal cylinder immersed in both a riser and downcomer of a circulating fluidized beds were investigated experimentally under different values of solids mass flux, superficial air velocity, particle size diameter, and different bed materials. The test results indicated that local heat transfer coefficients in both riser and downcomer are strongly influenced by angular position, and mass flux, as well as by particle size and bed materials. The local heat transfer coefficients around a circumference of the cylinder inside a riser and downcomer of a CFB exhibited a general tendency to increase with decreasing particle size and increasing solids mass flux and vary with different bed materials. Also the averaged heat transfer coefficient calculated from local heat transfer coefficient exhibited the same trend as a local i.e increase with decrease particle size and increasing solids mass flux and vary with varying bed materials. The general trend for a riser local heat transfer coefficient is decrease with increase angle until ${\Phi}$ = 0.5-0.6 (Where at angle =180$^{\circ}$ ${\Phi}$ =1). Also the general trend for a local heat transfer coefficient in downcomer is to increase with increase the angle until ${\Phi}$= ${\theta}/{\Pi}$ = 0.3-0.5 (Where at angle =180$^{\circ}$ ${\Phi}$ =1). Comparison the results of the heat transfer in the riser and downcomer of a circulating fluidized beds shows that they have approximately the same trend but the values of heat transfer coefficients in riser is higher than in downcomer.