• International Journal of Advanced Culture Technology
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• v.10 no.3
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• pp.371-376
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• 2022

The purpose of this study is to develop a walking assistance system with mobility support and life support functions so that the elderly with reduced physical ability and patients who are uncomfortable when moving can move comfortably indoors and outdoors, and help social life. An obstacle recognition sensor module that can be applied indoors and outdoors is installed on a lightweight walking aid. The purpose of this study is to develop a walking assistance system with mobility support and life support functions so that the elderly with reduced physical ability and patients who are uncomfortable when moving can move comfortably indoors and outdoors, and help social life. An obstacle recognition sensor module that can be applied indoors and outdoors is installed on a lightweight walking aid. It is a system structure of an integrated actuator and brake system that can avoid obstacles in consideration of the safety of the elderly and is easy to install on the device. In this paper, the design of a lightweight walking aid was designed to increase the convenience of the socially disadvantaged and the elderly with reduced exercise ability. In addition, in order to overcome the disadvantage of being inconvenient to use indoors due to the noise and vibration of the motor during operation, an In-Wheel type motor is applied to develop and apply a low noise, low vibration and high efficiency drive system.

• Journal of Radiation Protection and Research
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• v.42 no.1
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• pp.42-47
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• 2017

Background: One of the most urgent issues following the accident at the Fukushima Daiichi nuclear power plant (FDNPP) was the remediation of the land, in particular, for residential area contaminated by the radioactive materials discharged. In this study, the effect of decontamination on reduction of ambient dose equivalent outdoors and indoors was evaluated. The latter is essential for residents as most individuals spend a large portion of their time indoors. Materials and Methods: From December 2012 to November 2014, thirty-seven Japanese single-family detached wooden houses were investigated before and after decontamination in evacuation zones. Outdoor and indoor dose measurements (n = 84 and 114, respectively) were collected based on in situ measurements using the NaI (Tl) scintillation surveymeter. Results and Discussion: The outdoor ambient dose equivalents [$H^*(10)_{out}$] ranged from 0.61 to $3.71{\mu}Sv\;h^{-1}$ and from 0.23 to $1.32{\mu}Sv\;h^{-1}$ before and after decontamination, respectively. The indoor ambient dose equivalents [$H^*(10)_{in}$] ranged from 0.29 to $2.53{\mu}Sv\;h^{-1}$ and from 0.16 to $1.22{\mu}Sv\;h^{-1}$ before and after decontamination, respectively. The values of reduction efficiency (RE), defined as the ratio by which the radiation dose has been reduced via decontamination, were evaluated as $0.47{\pm}0.13$, $0.51{\pm}0.13$, and $0.58{\pm}0.08$ ($average{\pm}{\sigma}$) when $H^*(10)_{out}$ < $1.0{\mu}Sv\;h^{-1}$, $1.0{\mu}Sv\;h^{-1}$ < $H^*(10)_{out}$ < $2.0{\mu}Sv\;h^{-1}$, and $2.0{\mu}Sv\;h^{-1}$ < $H^*(10)_{out}$, respectively, indicating the values of RE increased as $H^*(10)_{out}$ increased. It was found that the values of RE were $0.53{\pm}0.12$ outdoors and $0.41{\pm}0.09$ indoors, respectively, indicating RE was larger outdoors than indoors. Conclusion: Indoor dose is essential as most individuals spend a large portion of their time indoors. The difference between outdoors and indoors should be considered carefully in order to estimate residents' exposure dose before their returning home.

• Journal of Korea Society of Digital Industry and Information Management
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• v.12 no.1
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• pp.63-69
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• 2016

Although the previous information technologies had been used for the quick and accurate processing of work, At present, however, as the combination with the Internet, the IOT(Internet-of-Things) era in which the diverse pieces of information are collected and handled through the sensor networks is in progress. Among these application fields of the IoT, the indoors position identification technology has been developing in the direction of providing the position information in the buildings of which the lengths and the interiors are complicated and in the direction of providing the various pieces of information and others of the like to the nearby customers. In this paper, we proposed an indoors position identification system that detects the patrol positions of the prison officers in the correctional facilities and in the prisons by using the ultrasonic waves, that transmits these to the control system and the data gateway, and that transmits the detected data. The Indoors Positioning identification System is organized with the tags for recognizing the positions that transmit the ultrasonic signal, ultrasonic receiver and data gateway. And the indoors position information data were transmitted to the management system through the data gateway. We evaluated the transmission error, by changing the distance of the proposed system for location recognition tag and the receiver, As a result, we found out that, when the transmission distance was 10 cm or less, the errors occurred in the form of the distortions. And when it was 110 cm or more, the transmission errors occurred due to the propagation diminutions of the ultrasonic wave signals. And when the transmission distance was from 10 cm to 100 cm, it was shown that the proposed system was possible without any errors.

• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.2
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• pp.196-202
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• 2003

The object of this article is to study the plausibility of applying human voice warning system to automobiles. Human voice is considered the best tool for warning system in automobiles. For the purpose of comprehending the specific characteristics of relation between noises and properties of the automobiles indoors and voice warning system researcher performed FRF test in order to examine the characteristics of voice output, and FEM simulation to learn the specific properties of the car indoors. And furthermore, surveyed the quality of voice output, using the written inquiry to examine members. The result of the study shows that it is much possible to apply voice warning system to automobiles.

• Journal of Environmental Science International
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• v.17 no.9
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• pp.1005-1013
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• 2008

In this study, in order to analyze the air quality of the indoor environments of schools, we measured the indoor, outdoor and personal exposure concentration level of $PM_{10}$ for 40 classrooms(20 old, 20 new) in chungnam area from June 22 to July 19 and from November 21 to December 30, 2003. 1. Old classrooms contained more dust than new classrooms; the average of respirable dust is $43.27\;{\mu}g/m^3$ for new classrooms while $53.38\;{\mu}g/m^3$ for old one. The exposure concentration level of respirable dust in new classrooms were in summer higher outdoors than indoors. The values were indoors $46.71\;{\mu}g/m^3$, outdoors $50.46\;{\mu}g/m^3$, and personal $41.62\;{\mu}g/m^3$. Meanwhile in winter indoors had a higher concentration level than outdoors, the values being indoors $39.11\;{\mu}g/m^3$, outdoors $34.86\;{\mu}g/m^3$, and personal $49.01\;{\mu}g/m^3$. 2. Cr concentration level within dust was slightly higher in summer indoors ($101.50{\pm}32.10\;ng/m^3$) and outdoors ($100.89{\pm}35.18\;ng/m^3$) than winter indoors ($85.80{\pm}48.95\;ng/m^3$) and outdoors ($74.43{\pm}38.93\;ng/m^3$), but in personal concentration level, winter was higher. The results of this research show insufficient understanding of health risks from indoor air pollution, and shows possible health problems to students from school indoor air pollution. As such, a logical and systematic education program for students about the importance of indoor air quality should be carried out. Also the results of $PM_{10}$ concentration level measurements emphasize the need for regular measurements of indoor / outdoor and personal concentration level. New classrooms in particular needs to be used after measuring pollutants and safety, and requires installation of a ventilation device in all classrooms to improve air quality.

• Journal of Korean Society for Atmospheric Environment
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• v.14 no.3
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• pp.163-176
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• 1998

In this study, airborne particle samples were obtained to determine the concentrations of particulate air pollutants in indoor and outdoor air of public facilities in Taegu area. Total of 12 public facilities, regulated by the Public Sanitary Law, were selected as sampling sites, which include three underground arcades, one railway and two bus terminals, three general hospitals, and three department stores. In each place, sampling was carried out seasonally during the period of October 1994 to July 1995, and four samples per each site per season were collected both indoors and outdoors simultaneously. After determination of suspended particulate matter (SPM) mass concentrations, the particle samples were divided into two parts for subsequent chemical analysis: one for the analysis of trace elements and the other for water soluble ions. Seasonal levels of SPM appeared to be the highest in spring and the lowest in summer both indoors and outdoors, while locational variations of highest in statioyterminals, and lowest in department stores . SPM concentrations indoors and outdoors did not show any significant differences each other in most places . However, there were significant correlations between indoor and outdoor levels of SPM and other chemical species . These results indicates that indoor SPM levels are likely to be significantly affected by outdoor sources in many places. The most significant source of SPM was estimated to be the resuspension of soil/road dust both indoors and outdoors . The concentrations of toxic heavy metals (Pb, Cd, Cr, Cu) in underground arcades appeared to be very much lower than the established air quality guidelines for underground environments. In addition, it is likely that micro-environmental parameters such as temperature, humidity, and air velocity, play a less significant role than outdoor air quality as a factor affecting the levels of particulate pollutants in indoor environments of public facilities in Taegu area.

• Journal of the Korean Society of Physical Medicine
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• v.13 no.4
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• pp.139-148
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• 2018

PURPOSE: This study compared the effects of indoor and outdoor environmental changes on the activity of the major lower limb muscles and walking factors in people 40-50 years and those aged older than 70 years. METHODS: Ten middle-aged people in their forties (age:$44.2{\pm}2.7$, BMI:$21.8{\pm}1.8$) and 10 elderly aged more than 70 years (age:$76.4{\pm}5.9$, BMI:$22.2{\pm}1.9$) with a normal walking ability were included. The participants walked 100 m both indoors and outdoors at their own speed. Using a 3D motion analyzer and EMG, the walking speed, angle of the ankle and activity changes of the lower limb muscles were compared. RESULTS: Significant differences in walking speed and peak-plantar flexion angle were observed between the two groups (p<.05). The muscular activity of the gastrocnemius muscle (GCM) was significantly different outdoors in the swing phase between the two groups (p<.05). In the people aged in their forties, the muscular activity of the rectus femoris (RF) was significantly higher outdoors than indoors (p<.05). In the elderly, however, the muscular activity of the RF was lower outdoors than indoors (p<.05). When compared to those in there forties, the muscular activity of the outdoor RF significantly decreased in the elderly group (P<.05). The muscular activity of the biceps femoris (BF) in the elderly decreased significantly outdoors compared to indoors (p<.05). CONCLUSION: For the elderly, increasing the exposure to the new environments or focusing on the performance of repeated movements for gradual speed control and precise movements is required to maintain normal gaits and movements that are less affected by environmental changes.

• International Journal of Internet, Broadcasting and Communication
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• v.16 no.2
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• pp.59-67
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• 2024

Current straw mushroom farming in countries with large rice growing areas has great development potential, and was once considered a way to generate additional income and reduce poverty in rural areas. However, currently most people still grow mushrooms using traditional processes, leading to low productivity and unguaranteed output quality. Currently, due to climate change and unusual weather changes, people tend to switch to growing straw mushrooms indoors. In the process of growing straw mushrooms indoors, the design of an automatic control and monitoring system is very important to ensure the growing process is carried out effectively and achieves high yields. In this paper, we propose a system that can automatically control and monitor the humidity and temperature of the indoor straw mushroom growing process and other parameters that can be monitored through a network system using Internet of Things. The control algorithm automatically adjusts the grow house equipment based on feedback from sensors to maintain an optimal environment for growing straw mushrooms. Experimental results show that the straw mushroom growing system with automatically controlled and monitored environmental parameters helps improve efficiency, reduce costs and increase the sustainability of the current straw mushroom growing industry.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.11a
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• pp.71-72
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• 2023

As industrialization and urbanization accelerate, environmental issues have moved from local concerns to global issues. Among them, air pollution is the most important issue. Modern people spend more than 88% of their day indoors, but the concentration of fine dust and pollutants flowing indoors is increasing. The indoor environment has its own complexity, and various substances used indoors, such as building materials, furniture, electronics, and cleaning agents, emit chemical substances and cause various diseases. Therefore, when selecting building materials and interior finishing materials, the pollutant emission and adsorption capacity must be greatly considered. These considerations will ensure the construction of a sustainable future environment and a healthy life within that environment. Therefore, in order to reduce the generation of indoor air pollutants, this study aims to examine the fine dust adsorption properties of cement hardening materials using sepiolite, which has a porous structure and high absorption power among clay minerals. As a result of the experiment, it was found that the concentration of fine dust decreased as the addition rate of sepiolite increased. It is believed that the fine dust concentration was reduced due to the high porosity due to the microfibrous structure and large specific surface area of sepiolite, which has a porous structure among clay minerals. It is believed that these experimental results can be used as basic research for future use of sepiolite as a construction material.

• Journal of Environmental Health Sciences
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• v.38 no.6
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• pp.493-502
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• 2012

Objectives: The purpose of this study is to investigate the mass concentration of nanoparticles and understand the characteristics of elements of heavy metal concentrations within nanoparticles in the air using Micro-Orifice Uniform Deposit Impactor Model-110 (MOUDI-110), based on indoor and outdoor air. Methods: This Study sampled nanoparticles using MOUDI-110 indoors (office) and outdoors at S University in Asan, Korea in order to reveal the concentration of nanoparticles in the air. Sampling continued for nine months (10 times indoors and 14 times outdoors) from March to November 2010. Mass concentrations of nanoparticle and concentrations of heavy metals (Al, Mn, Zn, Ni, Cu, Cr, Pb) were analyzed. Results: Indoors, geometric mean concentration of nanoparticles ranged in size from 0.056 ${\mu}m$ to 0.10 ${\mu}m$ and those of 0.056 ${\mu}m$ or less recorded 0.929 ${\mu}g/m^3$ and 1.002 ${\mu}g/m^3$, respectively. On the other hand, the levels were lower outdoors with 0.819 ${\mu}g/m^3$ and 0.597 ${\mu}g/m^3$. Mann-Whitney U tests showed that the difference between the indoors and the outdoors was statistically meaningful in terms of particles of 0.056 ${\mu}m$ or less (p<0.05) in size. These results are possibly influenced by the use of printers and duplicators as the factor that increased the concentration of nanoparticles. In seasonal concentration distribution, the level was higher during the summer compared to in the autumn. Those of 0.056 ${\mu}m$ or less in size presented a statistically meaningful difference during the summer (p<0.05). These results may be influenced by photochemical event as the factor that makes the levels high. Regarding zinc, among the other heavy metals, the fine particles ranged in size from 0.056 ${\mu}m$ to 0.10 ${\mu}m$ and those of 0.056 ${\mu}m$ or less recorded 1.699 $ng/m^3$ and 1.189 $ng/m^3$ in the outdoors. In the indoors, the levels were lower, with 0.745 $ng/m^3$ and 0.617 $ng/m^3$. Cr and Ni at the size of 0.056 ${\mu}m$ or less, both of which have been known to pose severe health effects, recorded higher concentrations indoors with 0.736 $ng/m^3$ and 0.177 $ng/m^3$, compared to 0.444 $ng/m^3$ and 0.091 $ng/m^3$ outdoors. By season, Zn, Ni, Cu and Pb posted a high level of indoor concentration during the fall. As for Cr, the level of concentration indoors was higher than outdoors both during the summer and the autumn. Conclusion: This study indicates the result of an examination of nano-sized particles and heavy metal concentrations. It will provide useful data for the determination of basic nanoparticle standards in the future.