• The Transactions of The Korean Institute of Electrical Engineers
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• v.68 no.2
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• pp.304-309
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• 2019

This paper presents a CMOS RF-to-DC converter for video surveillance disposable IoT applications. It widely harvests RF energy of 3G/4G cellular low-band frequency range by employing a tunable impedance matching network. The proposed converter consists of the differential-drive cross-coupled rectifier and the matching network with a 4-bit capacitor array. The proposed converter is designed using 130-nm standard CMOS process. The designed energy harvester can rectify the RF signals from 700 MHz to 900 MHz. It has a peak RF-to-DC conversion efficiency of 72.25%, 64.97%, and 66.28% at 700 MHz, 800 MHz, and 900 MHz with a load resistance of 10kΩ, respectively.

• Journal of the Korean Society of Clothing and Textiles
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• v.47 no.6
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• pp.1193-1203
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• 2023

This study aims to provide primary data regarding the thermal stress of disposable personal protective coveralls. Thermal stress and surface temperature measurements were taken among ten men wearing coveralls. The size of the ten men corresponds to a size eight in Size Korea. As a result of thermal stress, sensations of humidity and discomfort were higher when wearing Level C compared to Level D. Level D felt significant thermal stress in their upper body after exercise. However, they did not feel such stress in their lower body. Level C felt thermal stress in their upper and lower body after exercise. In addition, in Level C, the ratings of perceived exertion blood pressure and pulse rate after exercise were higher than those of Level D. Furthermore, the surface temperature of disposable personal protective coveralls among Level C was slightly higher than that of Level D.

• Journal of the Korean Society of Clothing and Textiles
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• v.28 no.8
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• pp.1165-1174
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• 2004

The purpose of this study was to survey on the actual condition disposable coveralls of railroad rolling stock maintenance workers. The data were obtained from 100 male workers of railroad rolling stock maintenance wearing disposable coveralls using a questionnaire. The results were as follows. Disposable coveralls were exchanged into new ones in a week or 1-2 weeks. The major reasons of the exchanges were ＇Because it was contaminated(76.2%)＇ and then ＇It was torn(23.0%)＇ The response to the wearing frequency was the highest in ＇As possible as freqeuntly＇, and then ＇Sometimes＇ When workers were reluctant to wear the coveralls, the first reason was heat owing to wearing the coveralls. Therefore, wearing frequency became lowered in Summer. The torn parts of disposable coveralls most frequently were around the armhole and the crotch. The contaminated parts followed with the cuffs, the arm, and then the back. The uncomfortable parts were around the neck and the armholes. Workers felt uncomfortable because of heat and sweat caused by garment design obstructed convective airflow. Second, they complained that the coveralls make them irritated in a toilet. Third, they dissatisfied with materials of coveralls because the soils like oil were soaked into the coveralls and stained on the inner clothing. In regard of the color of coveralls, worker＇s favorite color was blue. In regard of style, the preferences to the separate style with a hood and the coveralls style with a hood were 49.0% and 25.0%, respectively.

• Journal of Information Technology Services
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• v.22 no.5
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• pp.31-49
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• 2023

Due to the outbreak of the COVID-19, self-service technology is widely used in Korea, and demand for disposable cups is increasing significantly. Waste and recycling of disposable cups have become a social concern for Koreans and Korea implemented the "Disposable Cup Deposit Systems" again in December 2022. Whether the emergence of this system can change the way people behave in environmental protection is a question to be examined in this study. Companies participating in the disposable cup deposit system are hoping that customers will actively recover cups through self-service in the process of collecting disposable cups. The government, along with businesses, transfers recovery work to customers through self-service technologies and schemes. Due to the increase in Shadow Work and the strengthening of consumer environmental protection consciousness, this paper focuses on how unmanned service types such as self-service technology can affect people's environmental protection behavior. An empirical analysis with 477 samples examined how the characteristics of shadow work, perceived efficacy, environmental awareness, and ecological guilt affect user's environmental protection behavior. Perceived efficacy that acts as a mediator and ecological guilt that plays as a moderator are investigated. Although there have been many studies on the effects of shadow work on customer behavioral intentions before, it has been very rare to study the effects of shadow work perceived by people on environmental behavioral intentions from an environmental protection perspective. This study shows that the higher the perceived efficacy of consumers, the more people prefer self-service technology and the stronger the environmental protection behavior. Also, consumers' ecological guilt significantly moderates the relationship between environmental consciousness and eco-friendly behavior. It is expected that companies and governments will be able to understand the impact of shadow work on consumers' environmental protection behavior and further promote environmental protection by appropriate policies and marketing strategies.

• 한국생물공학회:학술대회논문집
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• 2005.04a
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• pp.39-39
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• 2005

Large scale mammalian cell culture has become, over the past two decades, the preferred method to produce therapeutic monoclonal antibodies. In this presentation, I will introduce disposable bioreactor system and analyze key factors and points for consideration during mammalian cell culture process development. Example will be provided highlighting the selection of master cell, culture media and environmental factors based on productivity and product quality.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2004.10a
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• pp.1-15
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• 2004

o Various microfluidic components including mixromixers and micropumps have been developed for disposable biochip applications. o Single cell capturing, positioning and nanoliter drug injection chip has been demostrated. o Multi-channel, two-dimensional micro-well array has been fabricated and cell capturing and specific reagent injection have been performed.

• Proceedings of the Materials Research Society of Korea Conference
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• 2002.11a
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• pp.58-58
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• 2002

• Journal of Energy Engineering
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• v.29 no.3
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• pp.34-41
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• 2020

Used disposable diapers have been considered for a long time as a type of waste difficult to recycle and valorize due to their composite nature including plastic, cellulose pulp, a super absorbent polymer and either urine, feces or both. Therefore, the fate of disposed diapers often is either incineration or landfill burial which both have various adverse environmental impacts. However, used disposable diapers contain nutrients: cellulose is an organic matter while urine and feces contain non negligible amounts of nitrogen, phosphorus and potassium which are primary nutrients included in most chemical fertilizers used in agriculture. In a scope of waste recycling and valorization, this study focuses on developing a method to achieve nutrient solution extraction from used disposable diapers. The experiment essentially consists in shredding the diapers and letting them macerate in solutions of sodium hydroxide with various concentrations to allow breaking down of the cellulose and super absorbent polymer and release of urine and feces before sterilizing the solutions in an autoclave to remove potential coliform bacteria. At the end of the experiment, a set of parameters is measured for the final solution to identify concentrations of nutrients as well as presence or absence of harmful substances. Results are discussed and directions for future studies are suggested, which include mechanization of the diapers shredding process or added aeration to enhance nitrification and absorption of extracted nutrients from plants.

• Journal of Korea Society of Digital Industry and Information Management
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• v.11 no.3
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• pp.145-158
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• 2015

Disposable marine product packaging materials such as wooden, Styrofoam, and corrugated cardboard boxes have a very low reuse rate, thus causing the logistics costs to rise and making it difficult to establish a unit load system for marine products. Disposable packing containers to be discarded are accompanied by resource and environmental issues home and abroad. Transportation vehicles for marine products have to return empty without loading different kinds of products after delivery due to the smell and properties of marine products, thus posing as an obstacle to logistics rationalization. In an effort to overcome those limitations, this study examined the stages of transportation including "producer-wholesale market in the producing area-commission merchant-wholesale market in the consumption area-commission merchant-quasi-wholesale market-consumer" and also analyzed the utilization and distribution of disposable packaging materials currently used in the circulation of marine products including wooden, Styrofoam, and corrugated cardboard boxes. Based on the analysis results, the investigator developed a logistics rationalization model capable of promoting semi-permanent reuse and lowering empty vehicle rate on return routes as an alternative to address environmental issues caused by disposable packaging materials, which have been an obstacle to the logistics rationalization of marine products, packaging costs in the process of repeating packing and unpacking at each stage of marine products circulation, and empty vehicle rates on return routes after marine products delivery.

• Journal of the Korean Society of Clothing and Textiles
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• v.11 no.3 s.25
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• pp.101-109
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• 1987

This study was designed to measure the amount of formaldehyde in the disposable diapers of seven different products. It was aimed to investigate the actual situation of the diaper consumption and to relate it to the amount of formaldehyde measured. The degree of recognizability on the harmfulness of formaldehyde was also studied. The amount of formaldehyde was measured by means of the Acetyl Acetone method. The a ual situation of consumption and the recognizability of the formaldehyde were investigated by questionnaire. In the survey, the subjects had their babies aged from 0$\~$3 years and lived in Seoul. The statistical methods used were simple frequency and chi-square. The results obtained from this study were as follows; 1) Among seven (7) different disposable diapers, two were found to have less amount of formaldehyde than the Japanese regulation. 2) From the survey on the actual situation of consumption most respondents ($53.7\%$) experienced the dermatological problem after using the disposable diapers. Actually for the diapers which had a lot of formaldehyde, the respondents experienced the problems more severely. 3) The recognizability of formaldehyde was very low. The recognizability on the harnfulness of formaldehyde was lower, which represented the consumers had least or no knowledge about the formaldehyde release problem.