• 한국건축시공학회지
• /
• 제7권1호
• /
• pp.91-98
• /
• 2007

In this study, the property and plastic cracking pattern of concrete were compared and analyzed with the replacement ratio of fly ash 0, 5, 10, 15, 20% by cement weight. And curing conditions of concrete were given variously such as indoors(with wind speed as 0, 300, 500m/min), outdoors and chamber. The hydration temperature had a tendency to decrease as the replacement ratio of fly ash increased, and in the case of the wind speed 0m/min, it was showed that the moment that the amount of evaporation of water from surface of reference concrete was more than the volume of bleeding was 90 min since casting concrete. The time that the crack initiated had a tendency to be more quickly as the replacement ratio of fly ash increased. The number, length, width and area of crack in the indoor curing, exposed outdoor curing, enclosed outdoor curing had a tendency to decrease as the replacement ratio of fly ash increased. The crack had a tendency to decrease in sequence of exposed outdoor, enclosed outdoor curing, indoors curing. The outbreak of cracking by the change of temperature and humidity was affected by relative humidity more than temperature and the cracking had a tendency to increase as relative humidity lowered.

• 한국환경과학회지
• /
• 제11권8호
• /
• pp.801-810
• /
• 2002

The current paper describes the indoor/outdoor air quality in school environments through analyses of the heavy metal concentrations using Inductive Coupled Plasma(ICP). School environments in a heavy traffic area, two industrial areas, quasi-industrial area, and residential area were evaluated. The results were as follows: (1) The locations with the highest indoor and outdoor concentrations of heavy metals were the industrial areas followed by the heavy traffic area, residential area, and quasi-industrial area in a descending order of magnitude. Plus, the indoor heavy metal concentrations were higher then the outdoor ones. (2) The main heavy metal components were Zn, Al and Ca. Higher concentration levels were found indoors than outdoors. The heavy metal concentrations were also higher in the classrooms than in the corridor or outdoors. (3) The total heavy metal concentrations in the studied areas were highly dependent on the weather elements. including the relative humidity, mixing ratio, and wet-bulb depression. Accordingly, special ventilation systems are recommended to reduce air pollution in school environments.

• Journal of Ginseng Research
• /
• 제25권4호
• /
• pp.167-170
• /
• 2001

개갑 인삼종자의 생리적 휴면타파를 위한 적정 저온감응기간을 조사하였다. 채종하여 3개월간 모래로 층적저장하여 개갑이 완료된 종자의 배는 배유의 1/2정도의 크기를 보였다. 인삼종자는 채종 당시의 미숙한 배가 형태적으로 거의 완전한 발달을 보이기까지는 6개월 정도가 소요되었으며, 배의 신장의 실외보다는 실내에 저장하였던 종자가 더 빨리 자랐다. 배 신장이 완료된 종자라 할지라도 60일 이하의 저온처리된 종자는 발아가 되지 않았으며, 발아에 필요한 저온감응기간은 실외의 자연상태에서는 75일 정도이며, 냉장온도(4$^{\circ}C$)에서는 90일 정도가 적정하였다. 그러나 적정의 저온감응을 받은 종자라 할지라도 상온데 지속적으로 방치하게 되면 그 효과는 현저히 감소되었다.

• 인간식물환경학회지
• /
• 제23권5호
• /
• pp.495-506
• /
• 2020

Background and objective: This study conducted a conjoint analysis on early childhood teachers to find out their preferences in horticultural activities that are used as a means of education in early childhood education. Methods: For the conjoint analysis, five attributes of horticultural activities were selected. Attribute 1 was method of horticultural activities, divided into two levels: exclusive and integrated horticultural activities. Attribute 2 was object of horticultural activities, divided into three levels: fruit crops, vegetable crops, and floricultural crops. Attribute 3 was activity type, divided into three levels: big and small group, free choice, and outdoor play. Attribute 4 was place for horticultural activities, and divided into two levels: indoors and outdoors. Attribute 5 was time for horticultural activities, divided into two levels: 30 minutes and 30-60 minutes. The orthogonal design was used to extract 20 profiles, after which we conducted a survey on 320 early childhood teachers and analyzed the valid responses from 257 teachers. Results: The preference of early childhood teachers showed highest importance in object (29.1%), followed by activity type (23.2%), activity method (17.4%), time (16.1%), and place (14.2%) (Pearson's R = .591, p = .008). By level of each attribute, the importance was high in exclusive horticultural activities for activity method, big and small group for activity type, vegetable and floricultural crops for object, indoors for place, and 30 minutes for time. Conclusion: The horticultural program preferred by early childhood teachers is comprised of big and small group activities using vegetable and floricultural crops, carried out indoors for 30 minutes as an exclusive class.

• Journal of Radiation Protection and Research
• /
• 제47권2호
• /
• pp.77-85
• /
• 2022

Background: After the Fukushima Daiichi Nuclear Power Station (FDNPS) accident, a model was developed to estimate the external exposure doses for residents who were expected to return to their homes after evacuation orders were lifted. However, the model's accuracy and uncertainties in parameters used to estimate external doses have not been evaluated. Materials and Methods: The model estimates effective doses based on the integrated ambient dose equivalent (H^*(10)) and life patterns, considering a dose reduction factor to estimate the indoor H^*(10) and a conversion factor from H^*(10) to the effective dose. Because personal dose equivalent (H_p(10)) has been reported to agree well with the effective dose after the FDNPS accident, this study validates the model's accuracy by comparing the estimated effective doses with H_p(10). The H_p(10) and life pattern data were collected for 36 adult participants who lived or worked near the FDNPS in 2019. Results and Discussion: The estimated effective doses correlated significantly with H_p(10); however, the estimated effective doses were lower than H_p(10) for indoor sites. A comparison with the measured indoor H^*(10) showed that the estimated indoor H^*(10) was not underestimated. However, the H_p(10) to H^*(10) ratio indoors, which corresponds to the practical conversion factor from H^*(10) to the effective dose, was significantly larger than the same ratio outdoors, meaning that the conversion factor of 0.6 is not appropriate for indoors due to the changes in irradiation geometry and gamma spectra. This could have led to a lower effective dose than H_p(10). Conclusion: The estimated effective doses correlated significantly with H_p(10), demonstrating the model's applicability for effective dose estimation. However, the lower value of the effective dose indoors could be because the conversion factor did not reflect the actual environment.

• International Journal of Internet, Broadcasting and Communication
• /
• 제9권1호
• /
• pp.42-49
• /
• 2017

Despite the government's various safety measures, the number of safety accidents continues to rise and the interior is more likely to occur indoors than outdoors. Safety accidents involving young children account for more than 70 % of the safety accidents in the safety accidents, and the ratio of safety accidents in the classroom or classroom is more than 50 %. In this thesis the author proposes the system managing the accidents notification service using LED lighting and access entry control. Utilizing IoT technology, remote control or access can be controlled remotely by controlling multiple lights and entrances from each room and by means of a number of lighting and entrances. By monitoring and analyzing real-time status via server PC and mobile interface, it can control the maximum control and incident prevention, automatic control, and automatic control.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2018년도 춘계 학술논문 발표대회
• /
• pp.112-113
• /
• 2018

As the building becomes more sophisticated, indoors and outdoors exterior decoration of construction has been increased. However, it is very difficult to produce an FDM(Free-form Decorative Mold) that meets the requirements of quality, durability, and ease of installation, resulting in a high cost. Therefore, the objective of this study is basic research for economical production of FDM production technology while satisfying the above requirements. For this study, the authors analyze the details of the shape and requirements of the FDM, and the production details and processes that reflect the characteristics. The results of this study can utilize to develop algorithms for production and management of academically efficient FDM and can utilize to secure FDM production technology at commercial level.

• 전자통신동향분석
• /
• 제37권6호
• /
• pp.23-31
• /
• 2022

Mobile robot intelligence refers to planning the path of robots to move indoors and outdoors and establishing a physical action plan that can be driven safely and smoothly according to the surrounding environments' structures. This report introduces technical issues in mobile robot intelligence. Furthermore, we describe the latest mobile intelligence technology of four-legged walking, logistics, and agricultural robots. Finally, we discuss mobile robot intelligence research prospects and its potential for solving real-world problems.

• 대한임베디드공학회논문지
• /
• 제13권2호
• /
• pp.73-81
• /
• 2018

This paper describes a device platform which the blind can wear to keep path and to get surrounding information during their independent walking. Compared to the existing technologies, the proposed device could be used indoors and outdoors, and maps need not be provided in advance. It is composed of a glasses type device equipped with image sensors, and a portable device that analyzes sensor data for sighted guiding. RGB images and depth images are extracted to generate a walking map based on feature points. It also can cope with the risk of collision with bollard, color cone by applying vertical obstacle detection technology based on floor detection.

• 한국통신학회논문지
• /
• 제27권7C호
• /
• pp.723-727
• /
• 2002

가정용 가스레인지를 사용함에 있어 사용자 및 설치자의 부주의 등으로 재산 피해 밑 인명 사고가 빈번히 발생하고 있기 때문에 본 논문에서는 기존의 전화망과 전력선 모뎀을 이용하여 외부에서 가정내의 LPG 가스레인지의 밸브를 제어 및 상태를 확인하는 시스템을 개발하였다. 본 시스템의 구성은 외부에서 가정까지의 연결을 위한 전화 인터페이스와 전력선을 매체로 한 가정내의 통신 시스템 및 가스밸브 차단 및 알림 장치로 이루어 졌다.