• Journal of Fisheries and Marine Sciences Education
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• v.28 no.5
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• pp.1358-1364
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• 2016

Maritime accidents caused by a ship include collisions, sinking, stranding and fire etc. This study is intending to consider fire accidents among such diverse marine accidents. It is much likely that various sorts of fires break out because crewmen are living in a narrow space for long periods of time consequent on the ship's characteristic of sailing on the sea. According to the ship fire survey, about 50% of the total fire accidents occurred at an engine room, and the main fire origin was analyzed to be oil. In addition, ship fire breaks out in the order of baggage racks and living quarter. In short, the survey indicates that all sorts of fires belonging to A, B, C and D-class have occurred. This study, targeting an actual passenger ship 'A', found the response time to evacuation, during which the people on board a ship recognize the outbreak of fire, and act, and the travel time for evacuation which is the actual travel time. In addition, this study carried out a simulation through the special program for fire analysis - FDS (Fire Dynamics Simulator) in order to find the effective evacuation time, i.e. life survival time. Particularly, this study did comparative analysis of the influence on the survival of passengers and crew based on the collected simulation data by fire size and sort. As a result of the analysis, it was found that when examining the only actual evacuation movement time excepting the response time to evacuation, people are safe by completing evacuation before the effective evacuation time only in case fire size is 100Kw among all sorts of fires. In other words, in case of the outbreak of fire more than 1 MW, it was found to fail to meet evacuation safety regardless of fire size.

• Journal of the Korean Applied Science and Technology
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• v.33 no.4
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• pp.777-787
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• 2016

The purpose of this research was the optimization of Cirsium setidens blanched at various conditions by response surface methodology. Conducted to investigate the change of Cirsium setidens DPPH radical scavenging activity, total phenolic compounds and flavonoids during the blanching processes. With two parameters such as blanching time and temperature, response surface methodology and central composite design was used to study the combined effect of blanching time (70 to 170 seconds) and blanching temperature (70 to $99^{\circ}C$). The changes of DPPH radical scavenging activity, phenolic compounds, and flavonoids on blanching process conditions such as temperature and time were evaluated. After blanching, total phenolic compound was determined from 13.00 to 35.48 mg/ml. total flavonoids was determined from 2.31 to 8.38 mg/ml. DPPH radical scavenging activity was determined from 42.10 to 67.14 %. The optimum conditions were determined to be blanching temperature of $85^{\circ}C$ and blanching time of 150 sec.

• Current Research on Agriculture and Life Sciences
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• v.28
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• pp.53-62
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• 2010

The effect of far-infrared (FIR) irradiation on the functional compounds of grape seeds extract were evaluated. Grape seed was dried on different heating power (0, 900, 1800 W) and heating time (0, 20, 40 min) with far-infrared drier. Contents of soluble solids, catechins, total phenolics and total flavonoids along with Hunter's color value, electron donating ability (EDA) and nitrite scavenging activity were analyzed. The soluble solids, Hunter's L value and a value were not significantly different from control samples. Cathechin, procyanidin $B_2$ and epicatechin contents changed with heating time. In the treated sample, total cathechins content was found maximum at 900 W of heating power and 20 min of heating time with a high level of total phenolics, total flavonids and EDA. These results indicated that FIR irradiation of grape seed could enhance antioxidant activities of its extracts by increasing the amounts of functional compounds. Moreover, response surface methodology(RSM) was applied to predict optimum conditions for heating by FIR rays of grape seeds. Based on superimposition of contour map with respect to total phenolics, total catechin and EDA, optimum ranges of heating conditions were heating power of 621.82~818.18 W and heating time of 16.3~19.83 min.

• Journal of the Korean Academy of Clinical Electrophysiology
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• v.7 no.1
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• pp.7-10
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• 2009

Purpose : The purpose of this study was to investigate the effect of electrical stimulation applied in dominant forearm on autonomic nervous system response of both hands. Methods : Fourteen healthy subjects (women) received low frequency-high intensity electrical stimulation to one forearm. The subjects assigned to two groups; a ipsilateral stimulation group (n=7) and a contralateral stimulation group (n=7). The electrode attachment was arranged on the forearm of the dominant arm and the electricity stimulus time was set as 15 minutes. Measuring items were the skin conduction velocity, the blood flow, and the pulse rate, which were measured total 3 times (pre, post, and post 10 min.). Results : The skin conduction velocity showed a significant difference according to the change of the time in both hands, but there was no significant difference according to time in the blood flow, and the change of the pulse frequency regardless of stimulus side. Conclusion : These results demonstrate that the low frequency-high intensity electrical stimulation applied dominant forearm can increase selectively only with the skin conduction velocity, which may be helpful for the activation of the sudomotor function of both hands by the activation of sympathetic nerve.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.955-959
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• 2003

A technique for realizing linear phase IIR filters has been proposed by Powell-Chau which gives a real-time implementation of H(z-1).H(z), where H(z) is a causal nonlinear phase IIR filter. Powell-Chau system is linear but not timeinvariant system. Therefore, that system has group delay response that exhibits a minor sinusoidal variation superimposed on a constant value. In the signal processing, this oscillation seriously degrade the signal quality. Unfortunately, that system has a large sample delay of 4L and also more computational complexity. Proposed system is present a reduced computational complexity technique by moved the numerator polynomial of H(1/z) out to cascade with causal filter H(z) and remain only all-pole of H(1/z), then applied truncated infinite impulse response to finite with truncated IIR filtel $H_L$(z) and L sample delay to subtract the output sequence from the top and bottom filter. Proposed system is linear time invariance and group delay response and total harmonic distortion are also improved.

• Journal of Biosystems Engineering
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• v.36 no.6
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• pp.476-483
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• 2011

The aerial application using an unmanned helicopter has been already utilized and an attitude controller would be developed to enhance the operational convenience and safety of the operator. For a preliminary study of designing flight controller, a state space model for an RC helicopter would be identified. Frequency sweep flight tests were performed and time history data were acquired in the previous study. In this study, frequency response of the flight test data of a small unmanned helicopter was analyzed by using the CIFER software. The time history flight data consisted of three replications each for collective pitch, aileron, elevator and rudder sweep inputs. A total of 36 frequency responses were obtained for the four control stick inputs and nine outputs including linear velocities and accelerations and angular velocities in 3-axis. The results showed coherence values higher than 0.6 for every primary control inputs and corresponding on-axis outputs for the frequency range from 0.07 to 4 Hz. Also the analysis of conditioned frequency response showed its effectiveness in evaluating cross coupling effects. Based on the results, the dynamic characteristics of the model helicopter can further be analyzed in terms of transfer functions and the undamped natural frequency and damping ratio of each critical mode.

• Journal of Applied Biological Chemistry
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• v.58 no.2
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• pp.117-124
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• 2015

The extract of white rose petals has an antioxidant effect and can be used to treat allergic disease. The purpose of this study was to identify optimal conditions for extracting antioxidative compounds from white rose petals with 2,2-diphenyl-1-picrylhydrazyl scavenging activities. A response surface methodology based on a central composite design was used to investigate the effects of three independent variables: ethanol concentration ($X_1$), extraction temperature ($X_2$), and extraction time ($X_3$). The estimated optimal conditions for obtaining phenolic compounds with antioxidant activities were as follows: ethanol concentration of 42% ($X_1$), extraction time of 80 min ($X_3$), and extraction temperature of $75^{\circ}C$ ($X_2$). The estimated optimal conditions for obtaining flavonoid compounds with antioxidant effects were an ethanol concentration of 41% ($X_1$), extraction time of 119 min ($X_3$), and an extraction temperature of $75^{\circ}C$ ($X_2$). Under these conditions, predicted response values for the phenolic and flavonoid contents were 243.5 mg gallic acid equivalent/g dry mass and 19.93 mg catechin equivalent (CE)/g dry mass, respectively.

• Korean Journal of Food Science and Technology
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• v.41 no.3
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• pp.245-250
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• 2009

This study examined the optimization of alcohol extraction conditions for maximizing the total polyphenols derived from apple pomace, by response surface methodology (RSM). The effects of four independent variables, including $X_1$ (ratio of solvent to sample content), $X_2$ (dipping time), $X_3$ (extraction time), and $X_4$(extraction temperature), were investigated at five levels using central composite design (CCD). $Y_1$ (yield) and $Y_2$ (total polyphenols) were chosen as dependent variables. The coefficients of determination, $R^2$, were greater than 0.900 (0.9042 and 0.9555). The results showed that the model fit was very significant (p<0.001). The optimum extraction conditions were as follows: 13.00 mL/g for the ratio of solvent to sample content, 89.02 min for dipping time, 180 min for extraction time, and $70^{\circ}C$ for extraction temperature. At these conditions, the predicted total polyphenol content was 29.68 mg catechin equiv./g.

• Journal of Korean Society on Water Environment
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• v.30 no.3
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• pp.304-310
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• 2014

The conventional methods for total residual chlorine such as iodometry and DPD colorimetric can cause secondary pollution due to additional agents, also have a wide error range. As for alternative, electrochemical method can measure TRC(Total residual chlorine), and is not required as additional agents, also very suitable for using the fields of ballast water because test time is relatively fast. Therefore, this study was investigated for changing charge by agitation, salt concentration, and temperature change. Charge showed differences based on changes of reduction peak with or without agitation. In contrast, TRC and charge were well correlated in constant agitation speed. As TRC and charge were analyzed with high correlations in constant salinity and temperature of ocean, thereby conductivity was firstly measured, and charge had high correlation for TRC in spite of changing salinity and temperature Pt electrode revealed high reliability ($r^2=0.960$) because it was rarely effected by TRC, On the other hand, Au electrode appeared inadequate ($r^2=0.767$) to use sensor in less than 1.0 ppm of TRC. For high accuracy and detection of TRC, Pt and Au electrodes for test time were, respectively, 14 and 22 seconds. As a result, Pt electrode was more valuable than Au electrode in terms of response time.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.30 no.2
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• pp.91-97
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• 2002

Dynamic extinction of solid propellants subjected to rapid pressure drop was studied with the aid of energy equation of condensed phase and flame model in gas phase. It is found that the total residence time($\tau_\gamma$) which measures the residing time of fuel in the reaction zone may play a crucial role in determining the dynamic response of the combustuion to extinction. Residence time was modeled by various combinations of diffusion and chemocal kinetic time scale. Effect of pressure history coupled with chamber volume on the extinction response was also performed and was found that dynamic extinction is more susceptible in a confined chamber than in open geometry. And, dynamic extinction was revealed to be affected profoundly by diffysion time scale rather than chemical kinetic time scale.