• Journal of the Society of Disaster Information
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• v.11 no.2
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• pp.191-202
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• 2015

The purpose of this study was to examine the influence of the disaster perception and satisfaction level of volunteer fire-fighters on the continuity of their volunteering. The 163 subjects in this study were selected from male and female volunteer fire-fighters who resided in urban and rural regions in Gangwon Province. After a this survey was conducted, the collected data were analyzed by a statistical package SPSS WIN 20.0, and frequency analysis, correlation analysis and multiple regression analysis were made. The level of statistical significance was all set at p<.05. The findings of the study were as follows: First, as for the correlation of disaster perception, satisfaction and volunteering continuity, perception of disaster countermeasures, satisfaction and the level of participation were negatively correlated with one another, and there was a positive correlation among disaster training, disaster preparation, regional disaster, the period of volunteering, and will of persistent volunteering. Second, as for perception of disaster, the volunteer fire-fighters were asked a question about disaster countermeasures, and the largest group replied they were partially aware of the countermeasures. Concerning questions about disaster training/education experience and triage, the biggest group replied they underwent the training and knew about triage on the whole. Regarding questions on the emergency contact system and emergency work schedule, they knew about the two in general. As to a question on the occurrence of human disaster, the greatest group answered that they knew about it yet not well. Third, in regard to the impact of satisfaction level on volunteering continuity, the period of volunteering was affected by needs for experience, social contact and social recognition among the subfactors of satisfaction level, and will of persistent volunteering was under the influence of social contact and achievement needs. The level of persistent volunteering was affected only by needs for experience and achievement needs.

• Korean Chemical Engineering Research
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• v.52 no.6
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• pp.750-754
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• 2014

Quantitative risk analysis has been performed for a pervaporation process for production of high test peroxide. Potential main accidents are explosion and fire caused by a decomposition reaction. As the target process has a laboratory scale, the consequence is considered to belong to Category 3. An event tree has been developed as a model for occurrence of a decomposition reaction in the target process. The probability functions of the accident causes have been established based on the frequency data of similar events. Using the constructed model, the failure rate has been calculated. The result indicates that additional safety devices are required in order to achieve an acceptable risk level, i.e. an accident frequency less than $10^{-4}/yr$. Therefore, a layer of protection analysis has been applied. As a result, it is suggested to introduce inherently safer design to avoid catalytic reaction, a safety instrumented function to prevent overheating, and a relief system that prevents explosion even if a decomposition reaction occurs. The proposed method is expected to contribute to developing safety management systems for various chemical processes including concentration of hydrogen peroxide.

• Journal of Electrical Engineering and Technology
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• v.1 no.1
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• pp.101-105
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• 2006

In this paper, a disk-type ultrasonic motor using a combination of radial and bending vibration modes is newly designed and fabricated. The characteristics of the test motor are also measured. By means of traveling elastic wave induced at the surface of circumference of the elastic disk, a steel bar in contact with the surface of circumference of the elastic disk bonded onto the piezoelectric ceramic disks is driven in both directions by changing the sine and cosine voltage inputs. The stator of the motor is composed of two sheets of piezoelectric ceramic disks to bond onto both surfaces of an elastic disk, respectively. As a result, the diameter of the elastic body is increased and the resonant frequency is decreased. The resonant frequency of the stator is about 92 kHz, which is composed with piezoelectric ceramic disks of 28 mm in diameter and 2 mm in thickness, and an elastic body of 32 mm in diameter and 2 mm in thickness. A driving voltage of 20 VPP Produces 200 rpm with a torque of 1Nm and an efficiency of about 10%.

• Journal of the Earthquake Engineering Society of Korea
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• v.21 no.4
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• pp.153-161
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• 2017

Liquid storage tank is one of the major infrastructures and generally used to store gases, drinking and utilizing water, dangerous fluids, fire water and so on. According to the recent reports and experiences, the tank structures are damaged in many earthquakes due to their low energy dissipating capacity. Therefore, many researchers have been tried to know the dynamic properties of the tanks including liquids. However, vary limited experimental studies are carried out using relatively small tank models. In this study, a series of shaking table tests are performed with maximum 2 m cubic rectangular liquid storage tanks made of steel to measure the natural frequency and estimate damping coefficient of impulsive and convective mode of the tanks. Especially, the damping values under different shapes and excitation methods are estimated by logarithmic decrement method and half power band-pass method and compared with current design code and standards such as ASCE 7, Eurocode 8 and NZS. Test results show that the impulsive mode damping is around 2% which is proposed by general standards and codes but the impulsive mode damping is 0.13% average that is slightly lower than the code recommendation.

• Journal of Oriental Neuropsychiatry
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• v.8 no.1
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• pp.111-125
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• 1997

This study was done in order to investigate Oriental Medicine's meaning on stress, the stress is due to animal experiments.Methods:This research was done by animal experiments's results based on 41 animal experiment treatises carried out by 24 prescriptions about stress control. Each experiments were compared with same conditions, minimizing the experiments differences. The results were analyzed by p-value and Increas e·Decrease percentage of experiments result's numerical value. Results:1. Inquire into frequency in use of each stress stimulus and measuring items, the restriction stimulus stress and measuring the content of catecholamines are numerous.2. Significance of stress stimuluses based on experments's results is good by restriction stimulus.3. Oriental Medicine's meaning for stress is pathological phenomenon of Seven Emotion(七情). Stagnant the Energy(氣鬱), the Fire(火), Dam(痰), Lack of the general Blood thing(血虛), and reaction of an individual body.4. Inguire into the effects of frequency in use of experiments's Herb drugs, Herb Drugs of Tonifing the general Blood thing depend on stabilized Mind(補血安神), Circulated the Energy and Digest(理氣消導), Tonifing the general Blood thing(補血), Clearing the Mind(淸心), Removing the Dam(祛痰) are numerous.5. From a Sasang Medical point of view, experimental use of Herb Drugs are Soeum-in(少陰人) Herb Drugs are numerous.According to above results, it is considered that Herb Drugs of Tonifing the general Blood thing depend on stabilized Mind(補血安神), Circulated the Energy and Digest(理氣消導), Tonifing the general Blood thing(補血), Clearing the Mind(淸心), Removing the Dam(祛淡), and Soeum-in(少陰人) Herb Drugs are used to prevent stress and related diseases.

• Journal of Physiology & Pathology in Korean Medicine
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• v.22 no.2
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• pp.469-480
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• 2008

This study was performed to investigate using of herbal medicine based on pattern identification of symptoms, such as Qi deficiency pattern, Yin deficiency pattern, Phlegm -dampness pattern, Static blood pattern, Fire-heat pattern. These patterns settled by Korean Standard Differentiation of the Symptoms and Signs for Stroke in 2005. This study was done with 177 patients in Daejeon University Oriental Medical Hospital in the period of November 2006 to July 2007. Among the five types of pattern identification, Phlegm -dampness pattern showed significantly high frequency especially in 3 weeks after stroke. The sort of herbal medicine was 43 and Dodamhwalhyoel-tang(26.61%), Sunhwanki 1 hobang(14.52%), Banhabaekchulcheonma-tang(4.84%), Ansinchongnoi-tang(4.84%), Chongryuldodam-tang(4.03%) were most frequently used. Especially Dodamhwalhyoel-tang showed significantly high frequency in 2 weeks after stroke. Based on these results, it is suggested that more practical Korean Standard Differentiation of the Symptoms and Signs for Stroke would be established through continuous clinical studies by giving weight on relationship between herbal medicine and pattern identification.

• Journal of the Korean Wood Science and Technology
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• v.43 no.4
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• pp.511-517
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• 2015

Sound absorption capability of the flame resistant treated sawdust-mandarin peel composite particleboard was were estimated by two microphone transfer function methods. The weight of flame resistant treated board slightly increased by the treatment. The treatment improved fire retardant performance by decreasing the charred area of flame resistant treated board. Sound absorption capabilities of flame resistant treated sawdust-mandarin peel composite particleboard, in the entire estimated frequency range of 500-6,400 Hz was slightly lower than those of the control specimen. Sound absorption capability of both the control and flame resistant treated sawdust-mandarin peel composite particleboards were higher than that of commercial gypsum boards, being widely used as a sound absorber for ceiling at the estimated frequency.

• Journal of the Korean Institute of Gas
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• v.8 no.3 s.24
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• pp.1-7
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• 2004

The polyethylene pipe can use semi-permanent because of the high corrosion resistance with chemical stability. In addition to, there is the merit that is an easy to establish and to maintain. However, as the reason that it is simply degraded when the polyethylene pipe was exposed to the outside, mainly it is used to lay under the ground with low-pressure gas transportation pipe. In this study, the nondestructive evaluation method was used to maintain the integrity of the polyethylene pipe. We simulated the various defects on the polyethylene pipes, and then the AE signal occurred according to the impact test of steel ball was evaluated by the acoustic emission method. From the results, the waveform and dominant frequency could be distinguishing from the defect shapes of polyethylene pipe. Especially, in the case of notch defect, the AE signals occur different by the angle and depth of the notch.

• Journal of the Korean Society of Propulsion Engineers
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• v.11 no.5
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• pp.72-77
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• 2007

The combustion test results of the sub-scale combustor having dual swirl injector with internal mixing for a liquid rocket engine are described. The sub-scale combustor uses liquid oxygen(LOx) and kerosene as propellants and has an injector head, an ablative material combustor wall and a water cooled nozzle. The injector head has LOx manifold, fuel manifold, fire face plate, one center swirl injector and 18 main swirl injectors of internal mixing. The combustion tests were successfully performed at design and off-design points without any damages on the injectors. Combustion characteristics velocity of 1756m/s was measured at design point. High frequency combustion instability was not observed but low frequency pulsations occurred at off-design conditions.

• Journal of the Korean Society of Safety
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• v.20 no.3 s.71
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• pp.120-125
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• 2005

Formwork is a temporary structure that supports its weight and that of freshly placed concrete as well as construction live loads. Among the accidents and failures that occur during concrete construction, many are formwork failures which usually happen at the time concrete is being placed. In constructions site, pipe supports are usually used as shores which are consisted of the slab formwork. The strength of a pipe support is decreasing as it is frequently being used at the construction site. The objective of this study is to find out the strength change of used pipe support and unused pipe supports according to aging. In this study, 2857 pipe supports were prepared. Among these pipe supports, 2337 pipe supports were lent to the construction companies fire of charge. 520 pipe supports were kept on the outside. Compressive strength was measured by knife edge test and plate test at each 3 month. Test results show that the strength of unused pipe supports as well as used pipe supports was decreasing according to age, use frequency and load carrier, and the strength of used pipe supports was lower than the strength of unused pipe supports at the same age. So, the strength of used pipe supports from 191 days to present day was not satisfied the specification of KS F 8001. According to these results, it shows that attention has to be paid to formwork design using used pipe supports. Therefore, the present study results will be able to provide a firm base to prevent formwork collapses.