• Proceedings of the KSR Conference
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• 2005.11a
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• pp.1115-1120
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• 2005

characteristic of wear between wheel and rail is important factor of judgement to maintenance. KHST is optimized on an exclusive rail, UIC60. but also KHST is running on the variety existing line as well as KS50N, KS60 et,c. Hail profile of KS50N is dissimilar to DIC60. So we can predict that characteristic of wear is embodied also different. In this paper. we deduced the force and point of contact position between wheel and rail through multi-dynamics analysis and predicted wear of wheel and rail through contact problem analysis. we used simplified theory of kallker on contact problem, and Predicted the wear phenomenon of wheel using archard wear equation about each condition.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.105-106
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• 2005

The impact ionization MOS (I-MOS) transistor with 50nm channel length is presented by using 2-D device simulator ISE-TCAD. The subthreshold slope cannot be steeper than kT/q since the subthreshold conduction is due to diffusion current. As MOSFETs are scaled down, this problem becomes significant and the subthreshold slope degrades which leads an increase in the off-current and off-state power dissipation. The I-MOS is based on a gated p-i-n structure and the subthreshold conduction is induced by impact ionization. The simulation results show that the subthreshold slope is 11.7 mV/dec and this indicates the I-MOS improves the switching speed and off-state characteristics.

• 보존과학연구
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• s.11
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• pp.1-9
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• 1990

The environmental controls for good conservation of all textile materials are follow as :1) Special RH conditions on textiles keep to the usually advocated 50∼55%.2) The effect of the temperature is too small to worry about in the applicable range, that is $20^{\circ}C$.3) It is important to keep soiling by air borne dirt to a minimum by an air filter or putting textiles in cases.4) Sulphur dioxide must be rekoved by an activated carbon filter or a water spray. And this concentration below $50\muGm^3$ can be regarded assatisfactory.5) Oxygen plays a part of deterioration proceses. The effect of nitrogend andinert gases in sealed show cases should be further studied.6) Ozone is detrimental to textiles. It can be removed by activated carbonfilter.7) The removal of UV radiation and blue light can be expected to increase the lifetime of dyeing and strength of fiber.50 lux is suggested for sensitive textile materials.

• Journal of Species Research
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• v.11 no.2
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• pp.108-116
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• 2022

During a field survey to report unrecorded Korean ciliates, we collected five anaerobic ciliate species in two samples from freshwater and marine environments. These species belong to the classes Armophorea and Plagiopylea. The morphology of these species was studied based on live observations, protargol impregnation, and scanning electron microscope. Brachonella contorta is characterized by a size of 80-100×40-60 ㎛ in vivo, a bullet-shaped body, and about 60 oral polykinetids making 360° spiral around long axis. Brachonella pulchra is characterized by a size of 80-110×50-70 ㎛ in vivo and adoral zone composed of about 40 oral polykinetids with minimal spiralization. Metopus setosus is characterized by a size of 45-70×20-30 ㎛ in vivo, about 22 ciliary rows, very long caudal cilia, and 20 oral polykinetids. Plagiopyla nasuta is a freshwater species characterized by a size of 80-120×50-60 ㎛ in vivo, striated band present, straight extrusomes, and about 70 somatic ciliary rows. The marine Plagiopyla frontata is characterized by a size of 80-120×40-60 ㎛ in vivo, an oval to ellipsoid body shape, 50-60 somatic ciliary rows, and curved extrusomes.

• Korean Journal of Organic Agriculture
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• v.15 no.3
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• pp.319-330
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• 2007

This study analyzed physical and chemical characteristics of peat soil to use peat soil as the materials fur pot media and investigated seedling quality of horticultural plants in order to use peat soil as the raw materials fur pot media. The summary of the results is as follows; The chemical characteristics of peat soil, which is main ingredient of pot media are as follows; pH was 4.9, EC was less than $2.0ds{\cdot}m^{-1}$, which interferes the growth of the plant and organic ingredient was 33%. When looking into the germination characteristics of plants according to the mixture of pot media, red pepper showed 54.2% speed of germination and 97% germination rate in peat soil single treatment. Therefore the peatsoil was appropriate for the pot media for red pepper. In case of cucumbers, in the 50 : 50 treatment of main ingredient (peat soil) and auxiliary ingredients (vermiculite, peat moss and perlite) they showed 100% speed of germination and 100% germination rate. Therefore 50 : 50 treatment was appropriate fur the pot media for cucumbers. In case of chinese cabbage, peat soil, perlite and peat moss mixture (50 : 25 : 25) treatment showed the highest speed of germination (77.5%), while the germination rate was a little lower (92.15%) than comparative soil. However, it was appropriate for the pot media for chinese cabbage. In case of watermelon, germination was bad because of the influence of EC when the teat soil ingredient is over 80%. However, in the mixture of peat soil and vermiculite (50:50) treatment, they showed 91.6% speed of germination and 100% germination rate. Therefore it was appropriate for the pot media for watermelon. When looking into the growth of the plants according to the mixture of ingredients, peat soil and perlite (50:50) mixture showed excellent seedling quality for cucumbers, peat soil and perlite (50:50) mixture showed excellent seedling quality and it was proven to be appropriate for the pot media for cucumbers. In case of watermelon, peat soil, peat moss and perlite (80 : 10 : 10) mixture showed excellent seedling quality and it was proven to be appropriate for the pot media for watermelon.

• The Korean Journal of Food And Nutrition
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• v.32 no.1
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• pp.50-60
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• 2019

The importance and satisfaction with the purchasing characteristics and choice attribute of home meal replacement (HMR) products for consumers aged between 20 and 40, or over 50. In addition to identify the factors that must be first considered in the development of HMR products importance-performance analysis. 791 consumers aged between 20 and 40, or over 50, living in Seoul have experience in purchasing HMR participated in the survey. The survey consisted of four sections: The purchasing characteristics of HMR, the importance and satisfaction with HMR choice attribute, and general questions. T-tests and IPA were conducted to compare the groups of consumers aged between 20 and 40, or over 50. The factor analysis show the following results: 0.899 for "convenience", 0.094 for "hygiene", 0.871 for "quality", 0.834 for "taste", and 0.822 for "price". The average score of the importance of the choice attribute when purchasing HMR products 3.50. For consumers aged between 20 and 40, the score 3.49. For consumers over 50, the score 3.52. There is a significant difference "hygiene (p<0.001)", "quality (p<0.05)", and "price (p<0.05)". For consumers aged between 20 and 40, the score 3.72. For consumers over 50, the score was 3.78. There a significant difference only in "hygiene (p<0.05)". The results of the IPA demonstrate that the categories that belong to "Focus here" are "new HMR products" and "diverse HMR products" for all consumers aged between 20 and 40 and over 50. Hence, food companies should endeavor to develop new and diverse HMR products first.

• Kosin Medical Journal
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• v.33 no.3
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• pp.369-379
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• 2018

Objectives: Analysis of heart rate variability (HRV) has been used as a measure of cardiac autonomic function. According to the pNN50 statistic, the percentage of differences between successive normal RR intervals (RRI) that exceed 50 ms, has been known to reflect cardiac vagal modulation. Relatively little is known about the validity of pNN50 during general anesthesia (GA). Therefore, we evaluated the correlation of pNN50 with other variables such as HF, RMSSD, SD1 of HRV reflecting the vagal tone, and examined the validity of pNN50 in anesthetized patients. Methods: We assessed changes in RRI, pNN50, root mean square of successive differences of RRI (RMSSD), high frequency (HF) and standard deviation 1 (SD1) of $Poincar{\acute{e}}$ plots after GA using sevoflurane anesthesia. We also calculated the probability distributions for the family of pNNx statistics (x: 2-50 ms). Results: All HRV variables were significantly decreased during GA. HF power was not correlated with pNN50 during GA (r = 0.096, P = 0.392). Less than pNN47 was shown to have a correlation with other variables. Conclusions: These data suggest that pNN50 can not reflect the level of vagal tone during GA.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.3
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• pp.93-100
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• 2006

Modern versions of supersonic jet fighter aircraft using a digital flight-by-wire flight control system design utilizes a control surface reconfiguration in order to guarantee the aircraft flight stability when a control surface is failed. The T-50 flight control laws are designed such that the surface reconfiguration mode controls the aircraft using non-failed control surfaces when one of the control surfaces is failed. In this paper, linear analysis and HQS(Handling Quality Simulator) pilot simulations are performed to analyze the flight stability and handling quality when the surface reconfiguration mode is engaged for aircraft landing configuration. It is found that the aircraft flight stability and handling quality is satisfied to level 1 requirements when the T-50 flight control law is changed to the surface reconfiguration mode.

• Journal of Environmental Health Sciences
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• v.22 no.4
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• pp.25-32
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• 1996

The Bioconcentration factor(BCF) is used as an important criterion in the risk assessment of environmental contaminants. Also it can be used as indicator of biomagnification of environmentally hazardous chemicals through food-chain as well as a tool for ranking the bioconcentration potential of the chemicals in the environment. This paper reports the measured BCF value on carbofuran in Carassius auratus(goldfish), under steady state, and examined corelation between the BCF value and the depuration rate constant. Carassius auratus(goldfish) was chosen as test organism and test periods were 1-day, 3-day and 5-day. Experimental concentrations were 0.05, 0.10 and 0.50 ppm. Carbofuran in fish tissue and in test water was extracted with n-hexane and acetonitril. GC-ECD was used to detect and quantitate carbofuran. The depuration rate of carbofuran from the whole body of goldfish is determined over the 24-h period after treatment. The obtained results were as follows: 1. It was possible to determine short term BCFs of carbofuran through relatively simple procedure in environmental concentrations. 2. $BCF_1$ of carbofuran in concentration of 0.05, 0.10 and 0.50 ppm were 1.66, 1.64 0.61, $BCF_3$ were 2.08, 2.14, 0.66 and $BCF_5$ were 2.21, 2.57, 0.86, respectively. 3. Carbofuran concentration in fish extract was increased as increasing test concentration and prolonging test period, but $BCF_s$ in concentration of 0.50 ppm was greately decreased. 4. Determined deputation rate constants of carbofuran in concentration of 0.05, 0.10, 0.50 ppm were 0.076, 0.082 and 0.089, respectively. 5. It is considered that great decrease of $BCF_s$ in concentration of 0.50 ppm is due to high water solubility and stability of carbofuran in testwater. 6. It is suggested that low BCF of carbofuran is due to its relatively high water solubility and depuration rate, compared to BPMC, carbaryl and chlorothalonil.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.48 no.11
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• pp.748-754
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• 1999

Micromirrors supported by S-shape girders were fabricated and their angular deflections were measured using a laser-based system. A micromirror consists of a $50\mum\times50\mum$ aluminum plate, posts and an S-shape girder. Two electrodes were deposited on two corners of the substrate beneath the mirror plate. $50\times50$micromirror array were fabricated using the Al-MEMS process. The electrostatic force caused by the voltage difference between the mirror plate and one of the electrodes causes the mirror plate to tilt until the girder touches the substrate. Bial voltage of the mirror plate is between 25~35V and signal pulse voltage on both electrodes is $\pm5V$. A laser-based system capable of real-time two-dimensional angular deflection measurement of the micromirror was developed. The operation of the system is based on measuring the displacement of a HeNe laser beam reflecting off the micromirror. The resonant frequency of the micromirror is 50kHz when the girder touches the substrate and it is 25 when the micromirror goes back to flat position, since the moving mass is about twice of the former case. The measurement results also revealed that the micromirror slants to the other direction even after the girder touches the substrate.