• Journal of the Korean earth science society
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• v.37 no.1
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• pp.52-61
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• 2016

The purpose of the study was to create a probabilistic seismic hazard map using the input data that reflected the seismo-tectonic characteristics of the Korean Peninsula by applying USGS program (Harmsen (2008). The program was partly modified for the purpose of this study. The uncertainty of input parameters given by specialists was reflected in calculating the seismic hazard values by logic tree method. The general pattern of PGA was quite sensitive and similar to the shape of areal source. The probabilistic seismic hazard map showed the contour distribution of peak acceleration (%g) with 10% probability of exceedance in 5, 10, 20, 50, 100, 250, and 500 years. The result showed that the peak ground acceleration (PGA) values of the northern peninsula were almost half values of the southern peninsula except Hwanghae province. The general trend of the hazard map extended in the direction of NW-SE from Whanghae province to south-eastern regions of the peninsula. The values in northern part of Kangwon province were relatively lower than other areas in the southern peninsula. The maps produced through this study are considered valuable in regulating the seismic safety of the major facilities in the Korean Peninsula.

• Journal of Radiation Protection and Research
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• v.45 no.2
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• pp.76-80
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• 2020

Background: To improve the measurement accuracy of liquid-scintillation counting for activity standardization, it is necessary to significantly reduce the background caused by thermal noise or after-pulses. We have therefore improved a movable 3 photomultiplier (3PM)-γ coincidence-counting method using the logical sum of three double coincidences for β events. Materials and Methods: We designed a new data-acquisition system in which β events are obtained by counting the logical sum of three double coincidences. The change in β-detection efficiency can be derived by moving three photomultiplier tubes sequentially from the liquid-scintillation vial. The validity of the method was investigated by activity measurement of ¹³⁴Cs calibrated at the Korea Research Institute of Standards and Science (KRISS) with 4π(PC)β-γ(NaI(Tl)) coincidence counting using a proportional counter (PC) for the β detector. Results and Discussion: Measurements were taken over 14 counting intervals for each liquidscintillation sample by displacing three photomultiplier tubes up to 45 mm from the sample. The dead time in each β- and γ-counting channel was adjusted to be a non-extending type of 20 ㎲. The background ranged about 1.2-3.3 s^-1, such that the contributions of thermal noise or after-pulses were negligible. As the β-detection unit was moved away from the sample, the β-detection efficiencies varied between 0.54 and 0.81. The result obtained by the method at the reference date was 396.3 ± 1.7 kBq/g. This is consistent with the KRISS-certified value of 396.0 ± 2.0 kBq/g within the uncertainty range. Conclusion: The movable 3PM-γ method developed in the present work not only succeeded in reducing background counts to negligible levels but enabled β-detection efficiency to be varied by a geometrical method to apply the efficiency extrapolation method. Compared with our earlier work shown in the study of Hwang et al. [2], the measurement accuracy has much improved. Consequently, the method developed in this study is an improved method suitable for activity standardization of β-γ emitters.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.38 no.3
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• pp.219-225
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• 2014

In this study, to find the characteristics of the oscillation of a terminating shock wave in a transonic airfoil flow with non-equilibrium condensation, a NACA00-12,14,15 airfoil flow with non-equilibrium condensation is investigated through numerical analysis of TVD scheme. Transonic free stream Mach number of 0.81-0.90 with the variation of stagnation relative humidity and airfoil thickness is tested. For the free stream Mach number 0.87 and attack angle of ${\alpha}=0^{\circ}$, the increase in stagnation relative humidity attenuates the strength of the terminating shock wave and inactivates the oscillation of the terminating shock wave. For the case of $M_{\infty}=0.87$ and ${\phi}_0=60%$, the decreasing rate in the frequency of the shock oscillation caused by non-equilibrium condensation to that of ${\phi}_0=30%$ amounts to 5%. Also, as the stagnation relative humidity gets larger, the maximum coefficient of drag and the difference between the maximum and minimum in $C_D$ become smaller. On the other hand, as the thickness of the airfoil gets larger, the supersonic bubble size becomes bigger and the oscillation of the shock wave becomes higher.

• The Journal of the Convergence on Culture Technology
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• v.6 no.4
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• pp.331-337
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• 2020

The study analyzes the appropriate number of people per a household by applying an evacuation simulation to a 27-floor apartment in accordance with the NFPA 101 standard. The results of the analysis are as follows. First, if there are three people residing in each household, there would be 156 households in total, of which 85.25% were evacuated within 5 minutes. Second, 208 households with 4 residents were evacuated within 5 minutes. Third, if there are five people residing in each household, there would be a total of 260 households and 71.92% of residents were evacuated within 5 minutes. Lastly, 62.82% of the 312 households, each consisting of 6 people, were evacuated within 5 minutes. Measures to reduce evacuation time include determining the width of the stairs according to the number of people indoors, the number of floors in the building, the slope of stairs, and the users' characteristics, the design reflecting the ventilation conditions of the stairs, the installment of outdoor evacuation stairs, two-way stairs, evacuation lift, and the installation of an evacuation safety zone for people to evacuate outside of the building in the middle floors. In addition, measures, such as the mandatory installation of automatic emergency door open-close device to the rooftop, are required to facilitate rooftop evacuation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.4
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• pp.520-528
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• 2021

In this study, we attempted to derive major management factors related to the quality control of formwork and identified differences in the perceptions of construction engineers, construction managers, and field workers about the importance and performance of the derived factors. As a result of the study, 18 management factors related to the formwork were derived. Among the derived factors, the field workers placed importance on the factors that influence the detailed process of the formwork, while construction engineers placed importance on the factors related to the judgment of the progress and completion of the construction. The construction managers placed importance on the factors that affect the quality of the building frame. Based on the results of this study, it is expected that a plan to improve the quality of formwork that accepts the various opinions of each participant will be established.

• Journal of the Ergonomics Society of Korea
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• v.34 no.3
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• pp.199-215
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• 2015

Objective: The purpose of this study is to find the level of physical relaxation of individual subject by monitoring psychophysiological biofeedback to different types of mattresses. And, the study also aims to find a protocol to make a selection of the best mattress based on the measured information. Background: In Korea, there are an increasing number of people using western style bed. However, they are often fastidious in choosing the right mattress for them. In fact, people use their past experience with their old mattress as well as the spontaneous experience they encounter in a show room to finally decide to buy a bed. Method: Total five mattresses were tested in this study. After measuring the elasticity of the mattresses, they were sorted into five different classes. Physiological and psychological variables including Electromyography (EMG), heart rates (HR), oxygen saturations (SaO2) were used. In addition, the peak body pressure concentration rate was used to find uncomfortably pressured body part. Finally, the personal factors and subjective satisfaction were also examined. A protocol was made to select the best mattress for individual subject. The selection rule for the protocol considered all the variables tested in this study. Results: The result revealing psychological comfort range of 0.68 to 0.95, dermal comfort range of 3.15 to 6.07, back muscle relaxation range of 0.25 to 1.64 and personal habit range of 2.0 to 3.4 was drawn in this study. Also a regression model was developed to predict biofeedback with the minimal use of biofeedback devices. Moreover results from the proposed protocol with the regression equation and subjective satisfaction were compared with each other for validation. Ten out of twenty subjects recorded the same level of relaxation, and eight subjects showed one-level difference while two subjects showed two-levels difference. Conclusion: The psychophysiological variables and suitability selection process used in this study seem to be used for selecting and assessing ergonomic products mechanically or emotionally. Application: This regression model can be applied to the mattress industry to estimate back muscle relaxation using dermal, psychophysiology and personal habit values.

• Journal of Technologic Dentistry
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• v.34 no.4
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• pp.447-455
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• 2012

Purpose: This study was to investigate oral hygiene knowledge and the actual condition of oral care for the students in the public health and non-public health Departments. Methods: The survey sample consisted of 262 randomly selected students. 197 of them are public health-related students and 65 are non-public health-related students. The questionnaires used in this study consisted of 4 items for general information, oral health status of 2 items, 5 items for Oral hygiene knowledge and actual condition of oral care of 5 items. Collected data were analyzed by Frequency Analysis t-test and Crosstabs using SPSS(Statistical Package for Social Sciences) Win 19.0 statistics program. Results: Regarding general characteristics of the subjects, there were 53.8% of first-year student, 26.0% of second-year student and 20.2% of third-year student among 52.3% of males and 47.7% of females. The subjects received less than "100,000" won(13.0%), "100,000-190,000" won (5.0%), "200,000-290,000" won(30.9%), "300,000-390,000" won (33.2%) and more than "400,000" won(17.9%) a month for an allowance. The subjects had 'none' (44.3%), '1'(6.5%), '2'(12.6%), '3'(5.0%), '4'(5.3%), 'more than' 5(0.8%) of dental caries and 'do not know' were 25.6%. The numbers of dental prosthetics were 'no' (35.5%), '1'(13.7%), '2'(17.2%), '3'(10.3%), '4'(11.5%), and 'more than 5'(11.8%). The public health students(84.8%) had a higher positive response rate than the non-public health students(66.2%). The public health students(80.2%) had a higher negative response rate than the non-public health students(78.5%) in the result of onset of gum disease pain awareness. The non-public health students(65.5%) had a higher negative response rate than the public health students(68.3%)) in the result of heredity of gum disease. The t-test showed that public health-related department students(M=8.264, SD=0.821) had more knowledge about oral hygiene than non-public health-related department students(M=8.015, SD=1.082). 'do not use' in the oral care products except toothpaste and toothbrush showed that public health-related department students(60.4%) use the products more than non-public health-related department students(66.2%). Conclusion: In this study, public health-related department students had higher oral hygiene knowledge and actual condition of oral care compared to non-public health-related students, but low in practical action. Due to the lower level of dental care products use in non-public health-related department, a continuous oral care education program is required.

• The Korean Society of Law and Medicine
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• v.24 no.3
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• pp.105-124
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• 2023

Modern society is facing an unstable environment due to unexpected accidents and hazardous situations. For example, incidents such as the collapse of the Bundang Bridge and the crushing accident in Itaewon could serve as examples. In addition to these, critical emergencies like sudden cardiac arrests and strokes frequently occur, requiring swift actions and smooth transfers to specialized medical institutions for effective responses. In response to these risks, the country has been establishing various systems to protect the lives and safety of its citizens. Among these, the 119 First Aid Activities plays a crucial role within the emergency medical system. Its goal is to promptly respond to critical emergency situations involving severe trauma patients or patients with serious illnesses, minimizing damage and safeguarding lives by swiftly transferring them to emergency medical institutions for specialized treatment. The core activity related to this is emergency rescue operations. In particular, the 119 First Aid system serves as a crucial institution responsible for the hospital transportation of emergency patients. However, rescue personnel still encounter cases of interference with their activities during their duties. Despite efforts from the police, these interference cases persist, and they share similarities with the crime of obstructing official duties. Interference with emergency activities exhibits a comparable nature to instances such as physical assaults and equipment damage against emergency medical practitioners working within the emergency medical system. Therefore, a comprehensive understanding and improvement efforts regarding the issues of interference that arise during the process of emergency medical activities, including the 119 First Aid system, are necessary. The solution to these problems is to establish and improve the conditions for obstruction of first aid activities, focusing on the "Framework Act on Firefighting" and the "Act on 119 Rescue and Emergency."

• Journal of Digital Contents Society
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• v.16 no.2
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• pp.207-218
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• 2015

This study is to design and implement Smartphone application by applying the principles and processes of narrative therapy for the participants. The application is able for participants to fight out of the difficulty in question centered on the issue, and to be able to find a positive new stories to be evolving the story of their lives as well. Therefore, using the application will help them to live a healthier life out of the problems. As a way of currying the wounded heart of the youth, narrative therapy techniques were applied to Smartphone appliances accustomed to the youth. The youths' wounded minds will not only be easily cured but also can be a important factor in determining the direction of life. In this study, narrative flow was structured into four stages; relationships, externalization, creating new stories and strengthening the new story bsed on Doll & Doll' theory. Based on them, the Smartphone application for curing the wounded heart was designed and developed by utilizing narrative therapy techniques. The application was tested by 30 University students in Jeonbuk province in Korea and the results showed that they were satisfied with the application with relation to improving their heart health.

• Journal of the Society of Disaster Information
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• v.11 no.2
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• pp.227-234
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• 2015

In this study, the theoretical review was carried out on the concepts regarding the continuity of operation plan and business continuity management plan, international standard ISO22301 and common required functions for disaster response, and the business continuity guideline of local governments in Japan and establishment cases were analyzed to draw matters to be reflected for establishing the business continuity plan of local governments according to the occurrence of earthquake and tsunami. In conclusion, the standard guideline of central government should be prepared for establishing the business continuity plan of local governments and the foundation to establish the plan smoothly based on such guideline should be provided. Also, the business continuity plan should be prepared based on the previous established safety management plans by reflecting the regional characteristics of local governments. And, in order to establish the business continuity plan that fits the region, proper investigations can be carried out to examine the characteristics of each organizations, resources, facilities and environments. Lastly, detailed scenario on the scale of earthquake and tsunami occurrence and damages is prepared to establish the business continuity plan of local governments and conditions for prompt countermeasures according to the scale.