• The Journal of Engineering Geology
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• v.30 no.3
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• pp.289-302
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• 2020

To determine the shallow subsurface structure and sliding surface of land creeping in 2016 at Hadong-gun, Gyeongsangnam-do, geophysical surveys (electric resistivity, and refraction seismic methods, borehole televiewer) and slope stability analysis were conducted. The subsurface structure delineated with borehole lithologies and seismic velocity structures provided the information that the sediment layer on the top of the slope was rather as thick as 20 m and the underlying weathered rock (anorthosite) was thinner than 1 m. Based on the tension cracks observed during the geological mapping, televiewer scanning was performed at the borehole BH-2 and detected the intensive fracture zones at the ground-water level, associated with the slip weak zones mapped in dipole-dipole electrical resistivity section. Downslope sliding and slightly upward pushing at the apex of high resistive bedrock explains the curved slip plane of the land creeping. Such a convex structure might play a role of natural toe abutment for preventing the downward development of slip weak zones. In slope stability analysis, the safety factors of the slip weak zone are calculated with varying the groundwater levels for dry and rainy seasons and the downslope is founded to be unstable with safety factor of 0.89 due to fully saturated material in rainy season.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.2
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• pp.50-55
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• 2018

Earthquakes are almost impossible to predict and take place in a short time. In addition, there is little time to take aggressive action when an earthquake occurs. Therefore, there are more casualties and property damage than with other natural disasters. Recently, earthquakes have been occurring all over the world. As the number of earthquakes increase, studies on the safety of structures are being carried out. On the other hand, there are few studies on the electric facilities, which are relatively non - structural factors. Currently, electrical equipment in Korea is often not designed for earthquake safety and is quite vulnerable to damage when an earthquake occurs. Therefore, in this study, modeling was conducted through ABAQUS similar to an actual cabinet panel and 3D dynamic nonlinear analysis was performed using a natural seismic. According to seismic zone I and normal ground rock conditions of the power transmission and transmission facility seismic design practical guide, the maximum response acceleration of the performance level was 0.157g. In this study, however, it was not safe to reach the limit state of 30% of the analytical result at 0.1g for the general cabinet panel. From the results, the seismic fragility curve was derived and analyzed. The derived seismic fragility curve is presented as a quantitative basis for determining the limit state of the cabinet panel and can be utilized as basic data in related research.

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.5
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• pp.569-575
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• 2020

In this study, a fuel cell system model for ship power was developed and verified by comparing the experimental results obtained by supplying pure oxygen. To verify the proposed model, the fuel cell output characteristics when oxygen was supplied were compared with those when air was supplied using an air compressor. In addition, the effect of the change in the thermal properties of the fuel cell system on the output of the stack was examined. Within the experimental range of this study, when pure oxygen was supplied as the cathode supply gas, the calculated and experimental voltages and outputs obtained through modeling were almost the same over the entire load range. When air was supplied instead of oxygen for the cathode supply at a constant load of 560 A, each stack voltage was approximately 14 V, the stack output was approximately 8 kW, and the stack efficiency was approximately 3 %. It was confirmed that the overall system efficiency was reduced by approximately 8 %. Among the thermal properties examined in this study, the heat transfer coefficient of the coolant to the stack was found to have the greatest effect on the output of the stack.

• Journal of Acupuncture Research
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• v.24 no.5
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• pp.207-217
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• 2007

Objectives: We investigated the safty of distilled Astragali Radix Herbal Acupuncture, Wild Ginseng Herbal Acupuncture and Rehmannia glutinosa Herbal Acupuncture on vital sign -BP, pulse, resperation-in adult man. Methods : We investigated on 106 healthy volunteers consisted of each 30 subjects in experiment (distilled Astragali Radix Herbal Acupuncture, Wild Ginseng Herbal Acupuncture and Rehmannia glutinosa Herbal Acupuncture) group and 30 subjects in control(Normal Saline) group. Study form was a randomized, placebo-controlled, double-blind clinical trial. 30 subjects in each experiment group were injected distilled Astragali Radix Herbal Acupuncture, Wild Ginseng Herbal Acupuncture, Rehmannia glutinosa Herbal Acupuncture at $GB_{21}$(Kyonjong) and 30 subjects in control group were injected Normal Saline at $GB_{21}$ (Kyonjong). except of 2 subjects(in control group) who can't be measured and 10 subjects(6 in experiment group and 4 in control group) who move or make unforceable error during measuring. Finally each 25. subject, subject, subject in experiment group and 24 subject in control group are studied. We measured resperation by PolyG-I and BP & pulse by electric manometer on 5 times : before injection per 5 minutes during and after injection per 10 minutes during 35 minutes. The SPSS 13.0 for windows was used to analyze the data and the Student t test(between two groups) were used to verify the result. Results : 1. After distilled Astragali Radix Herbal Acupuncture injection, Wild Ginseng Herbal Acupuncture and Rehmannia glutinosa Herbal Acupuncture , systolic BP is not significantly change in all experiment time. 2. After distilled Astragali Radix Herbal Acupuncture injection, Wild Ginseng Herbal Acupuncture and Rehmannia glutinosa Herbal Acupuncture , diastolic BP is not significantly change in all experiment time. 3. After distilled Astragali Radix Herbal Acupuncture injection, Wild Ginseng Herbal Acupuncture and Rehmannia glutinosa Herbal Acupuncture , pulse is not significantly change in all experiment time. 4. After distilled Astragali Radix Herbal Acupuncture injection, Wild Ginseng Herbal Acupuncture and Rehmannia glutinosa Herbal Acupuncture , resperation is not significantly change in all experiment time. Conclusions : The results suggest that distilled Astragali Radix Herbal Acupuncture, Wild Ginseng Herbal Acupuncture and Rehmannia glutinosa Herbal Acupuncture in healthy adult man don't influence vital sign within normal range. This result is derived from that distilled Astragali Radix Herbal Acupuncture, Wild Ginseng Herbal Acupuncture and Rehmannia glutinosa Herbal Acupuncture in healthy adult man are safety.

• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.6
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• pp.662-669
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• 2018

Recently, the installation of submarine power cables is under consideration due to the increase of electric power usage and the development of the offshore wind farm in island areas, including Jeju. In order to protect power cables installed on the seabed, it is necessary to calculate the burial depth based on the characteristics of anchoring, dragging and fishing, etc. However, there is no design standard related to the size of target ships to protect the cables in Korea. In this study, we analyzed the design standards for the protection of domestic submarine pipelines similar to submarine cables, and developed the risk matrix based on the classification by emergency anchoring considering the installation environment, then designed the size of target ships according to the cumulative function scale by ship size sailing through the sea concerned. Also, we linked marine accident conditions, such as anchoring, dragging, etc. and the environmental conditions such as current, sea-area depth of installation etc. to the criteria of the protection of submarine cable, and examined the size of specific target ships by dividing the operating environment of ships into harbor, coastal and short sea. To confirm the adequacy and availability of the size of target ships, we verified this result by applying to No. 3 submarine power cables, which is to be installed in the section from Wando to Jeju Island. This result is expected to influence in the development of a protection system for submarine cables and pipelines as well as the selection of anchor weight according to the determination of burial depth.

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.7
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• pp.635-641
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• 2016

In order to drive a hybrid propulsion device which combines an engine and an electric propulsion unit, battery packs that contain dozens of unit cells consisting of a lithium-based battery are used to maintain the power source. Therefore, it is necessary to more strictly manage a number of battery cells at any given time. In order to manage battery cells, generally voltage, current, and temperature data under load condition are monitored from a personal computer. Other important elements required to analyze the condition of the battery are the internal resistances that are used to judge its state-of-health (SOH) and the open-circuit voltage (OCV) that is used to check the battery charging state. However, in principle, the internal resistances cannot be measured during operation because the parallel equivalent circuit is composed of internal loss resistances and capacitance. In most energy storage systems, battery management system (BMS) operations are carried out by using data such as voltage, current, and temperature. However, during operation, in the case of unexpected battery cell failure, the output voltage of the power supply can be changed and propulsion of the hybrid vehicle and vessel can be difficult. This paper covers the implementation of a high safety battery management system (HSBMS) that can estimate the OCV while the device is being driven. If a battery cell fails unexpectedly, a DC power supply with lithium iron phosphate can keep providing the load with a constant output voltage using the remainder of the batteries, and it is also possible to estimate the internal resistance.

• Journal of the korean academy of Pediatric Dentistry
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• v.29 no.2
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• pp.159-167
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• 2002

The purpose of this study was to evaluate the efficacy and safety depending on the route of flumazenil, as an antagonist against midazolam. The subjects of this study were 15 volunteers of $22{\sim}24$ years old. They were sedated with midazolam 0.2mg/Kg intranasal spray, and then 40 minutes after midazolam administration, they were given flumazenil 0.2mg intranasal spray for their reversal. For evaluation of the efficacy and safety of intranasal spray for flumazenil, they were monitored with pulse-oxymeter(Nellcor symphony N-3000, Nellcor Puritan CO. USA) and electric sphygmomanometer (Heartcare 200, National CO. Japan), and were assessed themselves using visual analogue scale(VAS) for tranquilization, sleep, fatigue and attitude. All of these subjects were reduced completely without any undesired situations. The results from this study can be summarized as follows ; 1. Nasaly administered flumazenil using spray device produced much more rapid reduction than intravenously administered flumazenil, but soon after fell in more deep sedated state than intravenously administered flumazenil. 2. There were no considerable side effects or bad influence on vital signs of both nasaly administered flumazenil and intravenously administered flumazenil. These results suggested that the flumazenil administered nasaly using spray device for reversal, we could treat patients safely and effectively under conscious sedation using midazolam administration. But, We will have to research about its optimal dosages for flumazenil, used as intranasal spray for reversal agents against the midazolam by evaluating the blood plasma concentration of midazolam and flumazenil.

• Fire Science and Engineering
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• v.34 no.4
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• pp.1-6
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• 2020

In this study, the authors measured voltage and current waveforms in real time during a serial arc discharge. The analysis results of the arc discharge radiation patterns exhibited intermittent discharge, arc growth, creation of a heat generating area, occurrence of plume, and formation of a red heat area, which proceeded in that order. When the serial arc discharge was introduced, the current and voltage waveforms exhibited periodicity as sine waves. It was also observed that a restriking transient voltage occurred when the waveform changed from positive (+) to negative (-) and vice versa. When the discharge proceeded, the amount of heat generated for 1 s and 600 s was approximately 0.317 mJ, and 190 mJ, respectively. The duration of the short circuit was approximately 1.66 ms, and in the case of the voltage waveform, it was evident that the electric potential increased to 49.9 V in the same cycle. Furthermore, when the discharge proceeded, the effective value (RMS value) of the current was approximately 1.72 A with a maximum current of approximately 2.53 A, whereas the effective value of the voltage was approximately 42.8 V with a maximum of approximately 208 V.

• Proceedings of the Safety Management and Science Conference
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• 1999.11a
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• pp.543-563
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• 1999

For hazardous air pollutants(HAP) such as NO and $NO_2$ decomposition efficiency, power consumption, and applied voltage were investigated by SPCP(surface induced discharge plasma chemical processing) reactor to obtain optimum process variables and maximum decomposition efficiencies. Decomposition efficiency of HAP with various electric frequencies(5~50 kHz), flow rates(100~1,000 mL/min) initial concentrations(100~1,000 ppm), electrode materials(W, Cu, Al), electrode thickness(1, 2, 3 mm) and number of electrode windings(7, 9, 11) were measured. Experimental results showed that for the frequency of 10 kHz, the highest decomposition efficiency of 94.3% for NO and 84.7% for $NO_2$ were observed at the poser consumptions of 19.8 and 29W respectively and that decomposition efficiency decreased with increasing frequency above 20 kHz. Decomposition efficiency was increased with increasing residence times and with decreasing initial concentration of pollutants. Decomposition efficiency was increased with increasing thickness of discharge electrode and the highest decomposition efficiency was obtained for the electrode diameter of 3mm in this experiment. As the electrode material, decomposition efficiency was in order : tungsten(W), copper(Cu), aluminum(Al).

• Journal of Digital Convergence
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• v.17 no.12
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• pp.159-170
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• 2019

This study is an online survey for consumers in the metropolitan areas of Japan and Korea, which are advanced countries in Asia, and the maturity of the automobile market. The purpose of this study is to compare the results of Korea and Japan. As a result of this study, we analyzed the differences between the consumer characteristics and the optional attribute factors of low-carbon automobiles of Korea. There was a difference. It was found that the factors of low carbon car selection attribute differed with age, and that stability was more important when selecting low carbon car as income level increased. In Japan, there were no differences in the selection attribute factors of low carbon cars by gender, age and income. In addition, there is no difference in the relationship between the future purchase timings of low-carbon car types in both Korea and Japan. Implications of this study Korea has a meaningful result that Korea tends to select low-carbon automobiles with an emphasis on economic aspects and ages, and that safety tends to emphasize safety of low-carbon automobiles according to income levels. In the case of low carbon car, there was a tendency to select a low carbon car without any difference in consumer characteristics. The relationship between the expected purchase time according to the type of low carbon car and the Korean car show that the preferred car within the next 10 years among the low carbon car types is electric car and Japan prefers hybrid car.