• Journal of KIBIM
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• v.5 no.3
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• pp.41-50
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• 2015

Increasing size and complexity of indoor structures have led to much more complication in the spatial cognition and situational awareness. Contrary to outdoor environments, occupants have limited information regarding the indoor space syntax in terms of architectural and semantic information as well as how they interact with their surroundings. The availability of such information could give conveniences to both users and managers in various aspects. In order to visualize the exact location of rooms and utilities in 3D, many studies and projects have utilized BIM models because of its promising value of representing building components. In fact, the application of BIM provides definitive spatial indoor data and creates services for indoor space management and navigation. Therefore, this paper aims to provide an overview of practices on BIM-based indoor spatial information implementation and location-based services. It is expected that enabling of technologies, data-rich content and accessibility of information products will accelerate the growth of the spatially-related markets in various fields.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.11
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• pp.1098-1102
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• 2014

Localization of aerial vehicles and map building of flight environments are key technologies for the autonomous flight of small UAVs. In outdoor environments, an unmanned aircraft can easily use a GPS (Global Positioning System) for its localization with acceptable accuracy. However, as the GPS is not available for use in indoor environments, the development of a SLAM (Simultaneous Localization and Mapping) system that is suitable for small UAVs is therefore needed. In this paper, we suggest a vision-based SLAM system that uses vision sensors and an AHRS (Attitude Heading Reference System) sensor. Feature points in images captured from the vision sensor are obtained by using GPU (Graphics Process Unit) based SIFT (Scale-invariant Feature Transform) algorithm. Those feature points are then combined with attitude information obtained from the AHRS to estimate the position of the small UAV. Based on the location information and color distribution, a Gaussian process model is generated, which could be a map. The experimental results show that the position of a small unmanned aircraft is estimated properly and the map of the environment is constructed by using the proposed method. Finally, the reliability of the proposed method is verified by comparing the difference between the estimated values and the actual values.

• Journal of the Korean Home Economics Association
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• v.41 no.2
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• pp.141-153
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• 2003

The purpose of this study was to analyze and determine the level of the satisfaction and awareness of facilities in child care centers among teachers and parents. Special attention was given to both the indoor and outdoor environments from the viewpoints of both parents and teachers. The subject of this research focused on parents who leave their children at child care centers, and teachers who work for the center. The data was compiled by performing both T-tests and paired T-test. The information was processed by a program called SPSS WIN 10.0. The results were as follows ; 1. (a) With regard to the satisfaction of the external and internal facilities : It was determined that both the play rooms and the wall-pattern arrangements were satisfactory to both the parents and the teachers. (b) Regarding the awareness of the importance of facilities, while the parents focused more on the play rooms and the external environments, the teachers placed more importance on the bathrooms and the play rooms. 2. In the paired T-test that determined whether their individual opinions were different in terms of the satisfaction and awareness of facilities, it was interesting to see that both the parents and the teachers showed significant differences in their opinions and priorities about the porches, the play rooms, the bathrooms and the wall-pattern arrangements. In general, their awareness was much higher than the satisfaction with these facilities. 3. In the T-test that determined whether there were any tendencies in the satisfaction and awareness respectively in the two groups, the satisfaction rate was higher among the parents than the teachers. In terms of the awareness of the importance of the facilities, the teachers rated the bathrooms and the wall-pattern arrangements as a priority.

• Environmental Analysis Health and Toxicology
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• v.17 no.2
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• pp.117-123
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• 2002

A gas chromatographic method for the determination of airborne formaldehyde was established. In order to be highly detectable with the electron capture detector, formaldehyde was derivatized to its pentafluorobenzyl oxime form by reacting with O- (2,3,4,5,6- pentafluorobenzyl)hydroxylamine hydrochloride (PFBHA) at pH of 4.6 and temperature of 50$^{\circ}C$ for 1 hour. Air samples were collected into a Tedlar$\^$(R)/ bag followed by transferring into water contained in two impingers in series. Collection efficiency in the front trap was higher than 90％. Measurement of selected indoor and outdoor air samples showed higher formaldehyde concentrations in indoor air environments and the importance of ventilation for reducing indoor pollution.

• Journal of Institute of Control, Robotics and Systems
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• v.8 no.11
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• pp.954-962
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• 2002

In a park or street, we can see many people jogging or walking with their dogs tracking their masters. In this study, an entertainment robot that imitates a dog's behavior is created. The robot's task is tracking a moving target that is recognized as the master. In order to design the robot, the ecological approach. in which the robot's goals and surroundings heavily influence its design, is used. A three-wheel type locomotion system is designed as the robot's physical structure which can follow a human jogging in outdoor space like a park. A sensor system which can detect the position of a master for the robot in the outdoor space, is developed. This sensor system consists of a signal transmitter which is at the hand of a master and some sensors which are mounted on the robot. The transmitter emits RF(radio frequency) and ultrasonic signals and the sensors detect the direction and distance from the robot to the transmitter by using the received signals. For the control architecture of the robot, a purely reactive behavior-based method is used in order to increase speed of response. The developed robot is evaluated through experiments conducted in indoor and outdoor environments.

• Journal of the Ergonomics Society of Korea
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• v.17 no.3
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• pp.41-59
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• 1998

Thermal comfort aspect of a locally-cooled target space in warm and humid environments(typically in the rainy summer season) was studied in view of PPD index. First. theoretical analyses were conducted to examine the effect of the governing parameters(such as air temperature, relative humidity and air velocity, etc.) using a computer model. Secondly, experimental investigations were also performed in a climatic room designed to simulate corresponding thermal conditions of outdoor environments. During the tests, temporal variation of PPD was recorded as functions of climatic variables(outdoor and indoor temperatures, relative humidity and air velocity) for the given human factors(metabolic heat generation and clothing). From both theoretical and experimental investigations, air temperature and air velocity were found to be the most dominant parameters affecting PPD of the target space. Results were summarized as: 1. Relative humidity of the locally-cooled target space tends to approach that of outdoor's as the space is subjected to an ON-OFF mode of cooling, since moisture potential of the two rooms reaches an equalized state as a result of moisture diffusion. 2. It was recognized that changes in relative humidity did not show any significance in view of thermal comfort as was reported in the previous studies, while variations of both temperature and air velocity caused relatively large changes in the degree of thermal comfort. 3. In-door environment should be evaluated in terms of PPD instead of relative humidity commonly recognized as an important climatic variable particularly in warm and humid environments.

• Journal of Environmental Health Sciences
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• v.32 no.5 s.92
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• pp.398-403
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• 2006

Indoor air quality can be affected by indoor sources, ventilation, decay and outdoor levels. Understanding the effectiveness of indoor air quality control depends on knowledge of the characteristics of air pollutants in indoor air, especially their quantities and persistence, and the relevance of indoor sources to these factors. Toluene within new and established houses has been determined and factors significant to its presence have been identified. A total of 30 selected houses in Seoul, Asan and Daegu areas that were constructed within 4 years and over 4 years of construction were measured the concentration of toluene from July to September in 2004. Toluene emission decay of double-exponential model exhibited good fit of $Y=276.37e^{-1.21x}(R^{2}=0.34,\;P=0.06)$ for 2 years and then $Y=51.54e^{-0.11x}(R^{2}=0.40,\;P=0.0)$ from 23 years in new houses. In case of living in new houses, noncarcinogenic health effects of exposure to toluene was 1.38 of hazard quotient (HQ) comparing to toluene reference dose of 0.13 mg/kg-day.

• Journal of Environmental Health Sciences
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• v.23 no.4
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• pp.57-66
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• 1997

Successful energy conservation and good indcfor air quality (IAQ) are highly dependent on ventilation system. Air filtration is a primary solution of indoor air control strategies in terms of reducing energy consumption and improving ihdoor air quality. A conventional system with bypass filter, as it is called variable-air-volume/bypass filtration system (VAV/BPFS), is a variation of the conventional variable air volume (VAV) systems, which is designed to eliminate indoor air pollutant and to save energy. Bypass filtration system equipped with a high-efficiency particulate filter and carbon absorbent provides additional cleaned air into indoor environments and maintain good IAQ for human health. The objectives of this research were to compare the relative total decay rate of indoor air pollutant concentrations, and to develop a mathematical model simulating the performance of VAV/BPFS. All experiments were performed in chamber under the controlled conditions. The specific conclusions of this research are: 1. The VAV/BPFS system is more efficient than the VAV system in removing indoor air pollutant concentration. The total decay rates of aerosol, and total volatile organic compound (TVOC) for the VAV/BPFS system were higher than those of the conventional VAV system. 2. IAQ model predictions of each pollutant agree closely with the measured values. 3. According to IAQ model evaluation, reduction of outdoor supply air results in decreased dilution removal rate and on increased bypass filtration removal rate with the VAV/BPFS. As a results, we recommends the VAV/BPFS as an alternative to conventional VAV systems.

• Journal of The Korean Association of Information Education
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• v.14 no.4
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• pp.527-536
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• 2010

Ubiquitous computing and mobile technologies provide much scope for designing innovative learning experiences that can take place in a variety of indoor and outdoor settings, such as botanical gardens, parks, museums and classrooms. In this paper, we present our own innovative work for bridging indoor and outdoor field-trip learning activities with the support of RFID with reader device on ubiquitous environments. The function of our system is based on strategically located RFID tags placed on objects around settings which are identified using the mobile device installed to an RFID reader. The mobile device reads the RFID tag and sends the learner's request to the field-trip learning system. And learners can be learning activities according to theirs learning levels. We also focus on the use of intelligent agents to customize learning contents for individual learners. The result of our experiment indicates that learner enjoyed learning where mobile devices are used in the system, supporting the learning activities in the context of which they are taking place.

• Journal of Environmental Health Sciences
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• v.46 no.6
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• pp.750-756
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• 2020

Objectives: After coronavirus disease 2019 (COVID-19) was declared a pandemic, the South Korean government announced guidelines on wearing masks to prevent its spread. The guidelines have changed depending on the severity of the spread of COVID-19. This study aimed to identify mask-wearing behaviours to counter the spread of COVID-19 in indoor and outdoor environments. Methods: The type of mask worn and proper wearing were observed in cafés, supermarkets, underground shopping malls, and streets in Seoul. Behavioral assessment was repeated in August at social distancing levels 1 and 2, in October at social distancing level 1, and in November after the mask mandates. Results: In August, 22.1% of subjects in cafés, 90.8% in supermarkets, 91.8% in underground shopping malls, and 83.6% on outdoor streets wore masks properly. In October, the proportion of correct wearers increased in all locations. After masks became mandatory in November, about 97% of users of supermarkets, underground shopping malls, and streets wore masks properly. In cafés, the proportion of proper wearers was 61.5% with both social distancing level 2 in August and the mandate in November. The number of KF-certified mask wearers continued to increase from August to November. Conclusion: This study investigated mask-wearing behaviors to counter COVID-19 through observations in indoor and outdoor places in Seoul. Mask-wearing behavior was different depending on the place and the government guidelines in place. The results could be used for evaluation of the current guidelines for COVID-19.