• 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 korean academy of Pediatric Dentistry
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• v.28 no.4
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• pp.633-637
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• 2001

Local anesthesia procedure in pediatric dentistry using needle-tipped syringes is stressful and painful for the child patients The Syrijet Mark II (Mizzy Inc. USA) is a jet injection instrument, which uses high pressure to propel fluids into soft tissue without the use of a hollow neeldle, so it seems to be able to reduce the injection phobia of the child patients. The authors compared the Syrijet with the conventional syringe by assessing the pain level after local anesthetic procedures using CAS(color analogue scale) which was developed from VAS(visual analogue scale). The result showed that the pain was reduced by the use of syrijet. The advantages of syrijet were no use of neeldes, the reuse of the anesthetic cartridge, and the safety to nerves and vessels. The disadvantages were the large size, the high price, and the need of skill to use.

• Journal of Home Health Care Nursing
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• v.12 no.2
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• pp.1-15
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• 2005

Purpose: This study was conducted to assess the fall risk factors. Method: The subjects were 87 persons who were older than 65 years living at 28 nursing home in Seoul and Gyunggi province. Subjects were interviewed using RAFS II for intrinsic factor and the environmental factor were assessed using a structured questionnaire from Oct. to Dec. in 2004. The data were analyzed by SPSS(ver. 12.0) programs, using descriptive statistics, $x^2$-test, and t-test. Result: The 37.9% of the subjects experienced the fall, and its average number is $1.94\pm1.75$. The Women's experience of the fall was higher than that of the men, but it was no significant difference with gender. There was no significant difference with the age and duration of living. The mean of the intrinsic risk factor was 13.38 in total score 39 points marks on the RAFS II scales. The intrinsic risk factor score of the fallen group 15.71 was significantly higher than the non-fallen group 12.10. The variables of recent fall experience(t=4.72, p=0.000) and urinary dysfunction(t=2.64, p=0.010) was significantly higher than the non-fallen group. The highest variable of the intrinsic factor was the age and the variables of drug intake, balance, chronic disease, recent fall experience, urinary dysfunction were followed in order. The mean of the environmental risk factor was 0.24 points. No significant differences were shown in environmental risk factor between the fallen and the non-fallen groups. To the fallen group, the place of entrance was the highest risky environmental factor. To see in area dimension, the floor surfaces was the highest risky environmental factor and equipment and illumination factor was the following risky elements in order. In the total score of environmental risk factors based on the ares, the fallen group was 0.26 and the non-fallen group was 0.24, but there were no significant differences between the groups. Conclusion: This results suggested that visual protection strategy, set up the safety device in the place of entrance and inner stairway, bathroom and nonskid mat in the nursing home would be contribute to the prevention of the fall for the elderly.

• Journal of the Korea Convergence Society
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• v.8 no.9
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• pp.365-372
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• 2017

Squat exercise is one of the important free weight exercises that can safely and effectively expect the athletic performance by establishing the rationale. Therefore, it is necessary to study the side effects caused by incorrect exercise, scientific countermeasures and to develop a exercise estimation model. It is effective and accurate to use a variety of assistive devices to calibrate athletic posture. The issues of the structural analysis for designing a foot plate for squat exercise is to model the behavior by the dynamic behavior. It should be consider that the center of gravity of each segmented body is different when the maximum load is applied. It is applied to complete system design through simulation method with kinematic dynamic, ground reaction force and load analysis for the free weight exercise equipment, VR device, and safety foot plate. In this paper, the authors propose the design method for the vertical load distribution applied in the design of the foot plate used for the squat exercise mechanism, and based on these results, design make the more safe and reliable free weight exercise equipment system.

• Journal of Sensor Science and Technology
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• v.20 no.4
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• pp.266-271
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• 2011

A reflection-type fiber-optic pH sensor, which is composed of a pH sol-gel film, plastic optical fibers, a mirror, a light source and a spectrometer, is developed in this study. As pH indicators, a bromthymol blue, a cresol red and a thymol blue are used, and they are immobilized in the sol-gel films. The emitted light from a light source is guided by a fiber-optic Y-coupler and plastic optical fibers to the pH sol-gel film in a pH sensing probe. The pH change in the sensing probe gives rise to a change in the color of the pH sol-gel film, and the optical characteristic of reflected light through the pH sol-gel film is also changed. Therefore, we have measured the spectra of reflected lights, which are changed according to the color variations of the pH sol-gel films with different pH values, by using of a spectrometer. Also, the relationships between the pH values and the intensities of reflected lights are obtained on the basis of the color variations of the pH sol-gel films.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.5
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• pp.346-353
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• 2016

In the design conditions of some research reactors, the siphon phenomenon can cause continuous efflux of water during pipe rupture. A siphon breaker is a safety device that can prevent water efflux effectively. However, the analysis of the siphon breaking is complicated because many variables must be included in the calculation process. For this reason, a simulation program was developed with a user-friendly GUI to analyze the siphon breaking easily. The program was developed by MFC programming using Visual Studio 2012 in Windows 8. After saving the input parameters from a user, the program proceeds with three steps of calculation using fluid mechanics formulas. Bernoulli's equation is used to calculate the velocity, quantity, water level, undershooting, pressure, loss coefficient, and factors related to the two-phase flow. The Chisholm model is used to predict the results from a real-scale experiment. The simulation results are shown in a graph, through which a user can examine the total breaking situation. It is also possible to save all of the resulting data. The program allows a user to easily confirm the status of the siphon breaking and would be helpful in the design of siphon breakers.

• Journal of the Korean Institute of Gas
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• v.14 no.6
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• pp.15-20
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• 2010

Compressed Natural Gas (CNG) buses have been supplied since the year 2000 in order to resolve severe atmospheric pollution in metropolitan area and contributed on the improvement of urban atmospheric environment. However, it is indispensible to take an adequate measure to guarantee the safety of CNG vehicles because of the possibility of huge fire accident. A receptacle, connecting device between high pressure fuel supply tank and fuel line, plays an important role in CNG supply system. In recent, leakage of CNG from receptacles has been reported. So, the concern about the security and reliability of receptacles has been arisen. Therefore, a lot of efforts to prevent leakage are invested among researchers and the durability of this component should be guaranteed despite repeated operation. This research has performed durability tests of a CNG receptacle regarding the repeated usage, extreme chattering, and continuous full flow test. Although a receptacle used for CNG vehicle satisfies validation requirements in the test results, it has been found that failure in the function of leakage prevention in a receptacle could take place in the case of prolonged exposure to high supply pressure in common quick charging environment on site.

• Fire Science and Engineering
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• v.31 no.5
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• pp.44-52
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• 2017

This paper is based on a study of the response characteristics of photoelectric type smoke detector chambers according to dust color. Due to an amendment to the Fire Safety Codes to automatic fire alarm systems and visual alarm device, the installation of indoor smoke detectors has become mandatory, but in Korea there is still insufficient research on the non-operation or false alarms that could arise in indoor environments by indoor dust and other environmental conditions etc. In light of this, for this study, research was conducted on the indoor adaptability of smoke detector under various colors of fiber dust that were judged to occur most frequently in among the common indoor dust, photoelectric smoke detector with the lattice-type smoke detection chamber that the smoke detector which is most popular in the country was used, and four colors of fiber dust (brown, white, gray and black) were used the test dusts for carrying out dust and sensitivity testing. Also, the voltage of the photocell part of the smoke chamber was measured, and the scattering phenomenon in the chamber was observed. The result of the testing showed that all four dust types were suitable for dust and sensitivity testing under conditions of pollution A. Yet, there were occasions, at pollution B or C, where the brown, white and gray dust would cause fail alarm during operation testing. And black dust was confirmed to cause non-operation during operation testing. In the case of brown and white dust, the voltage measurement result of the photocell part of the smoke chamber confirmed that the voltage increases as the pollution level increases, and in the case of gray and black dust, the voltage decreases.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.11 no.6
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• pp.123-132
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• 2012

Gas sensors has been used very differently that depending on following purposes; Automotive (exhaust gas, fuel mixture gas, oxygen, particulates), agriculture / food industry (fresh, stored, CO2, humidity, NH3, nitrogen oxide gas, organic gas, toxic gas emitted from pesticides and insecticides), industrial / medical (chemical gas, hydrogen, oxygen and toxic gases), military (chemical weapon), environmental measurements (CO and other air pollution consisting of sulfur and nitrogen gas), residential (LNG, LPG, butane, indoor air, humidity). The types of industrial toxic substances are known about 700 species and many of these exist in gaseous form under normal conditions. he multi-gas detection sensors will be developed for casualties that detect the most important and find easy three kinds of gases in marine plant; carbon dioxide(CO2), carbon(CO), ammonia(NH3). Package block consists of gas sensing device minor ingredient, rf front end, zigbee chip. Develope interworking technology between the sensor and zigbee chip inside a package. Conduct a performance test through test jig about prototype zigbee sensor module with rf output power and unwanted emission test. This research task available early address when poisonous gas leaked from large industrial site and contribution for workers' safety at the enclosed space.

• Journal of the Society of Disaster Information
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• v.17 no.4
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• pp.684-693
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• 2021

Purpose: The purpose is to establish a safe facility environment from abnormal voltages such as lightning by developing a smart land resistance measuring device that can acquire real-time land resistance data using Arduino. Method: This paper studied design models and application cases by developing a land resistance acquisition and analysis system with Arduino and a power line communication (PLC) system. Some sites in the wind power generation complex in Gyeongsangnam-do were selected as test beds, and real-time land resistance data applied with new technologies were obtained. The electrode arrangement adopted a smart electrode arrangement using a combination of a Wenner four electrode arrangement and a Schlumberger electrode arrangement. Result: First, the characteristic of this technology is that the depth of smart multi-electrodes is organized differently to reduce the error range of the acquired data even in the stratigraphic structure with specificity between floors. Second, IT convergence technology was applied to enable real-time transmission and reception of information on land resistance data acquired from smart ground electrodes through the Internet of Things. Finally, it is possible to establish a regular management system and analyze big data accumulated in the server to check the trend of changes in various elements, and to model the optimal ground algorithm and ground system design for the IT convergence environment. Conclusion: This technology will reduce surge damage caused by lightning on urban infrastructure underlying the 4th industrial era and design an optimized ground system model to protect the safety and life of users. It is also expected to secure intellectual property rights of pure domestic technology to create jobs and revitalize our industry, which has been stagnant as a pandemic in the post-COVID-19 era.