• The Journal of Korea Robotics Society
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• v.15 no.3
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• pp.205-211
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• 2020

In this paper, we propose a modified ORB-SLAM (Oriented FAST and Rotated BRIEF Simultaneous Localization And Mapping) for precise indoor navigation of a mobile robot. The exact posture and position estimation by the ORB-SLAM is not possible all the times for the indoor navigation of a mobile robot when there are not enough features in the environment. To overcome this shortcoming, additional IMU (Inertial Measurement Unit) and encoder sensors were installed and utilized to calibrate the ORB-SLAM. By fusing the global information acquired by the SLAM and the dynamic local location information of the IMU and the encoder sensors, the mobile robot can be obtained the precise navigation information in the indoor environment with few feature points. The superiority of the modified ORB-SLAM was verified to compared with the conventional algorithm by the real experiments of a mobile robot navigation in a corridor environment.

• Journal of Institute of Control, Robotics and Systems
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• v.19 no.5
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• pp.468-472
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• 2013

This paper deals with the indoor localization problem for a SSMR (Skid Steering Mobile Robot) subjected to wheel-ground friction and with one LRF (Laser Range Finder). In order to compensate for some friction effect, a friction related coefficient is estimated by the recursive least square algorithm and appended to the maneuvering command. Also to reduce odometric information based localization errors, the lines are extracted with scan points of LRF and matched with the ones of the corresponding map built in advance. The present friction compensation and scan map matching schemes have been applied to a laboratory SSMR, and experimental results are given to validate the localization performance along an indoor corridor.

• Journal of the Korean Solar Energy Society
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• v.27 no.4
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• pp.59-65
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• 2007

This study is to propose the basic data for deciding remodeling of wornout educational facilities. In order of it, the indoor environmental standard, the actual conditions of thermal environment and sound insulation of walls were examined through field measurement in the subjected open elementary school(J school) and modernization model of elementary school(Y school) which they are located in Seoul. As the result, standard for indoor environmental factors of educational facilities which is established by Ministry of Education is not subdivided into indoor environmental performances considering usages and characteristics of classrooms for comfortable indoor environment. The vertical temperature difference in general classroom and in open classroom showed to be $11.2^{\circ}C$ and $12.1^{\circ}C$ respectively, while indoor temperature of special classroon was, on the whole, higher than that of any other classroom due to its specific heat flux of wall materials. The sound insulation performance of the masonry brick wall of classroom satisfied the minimum standard of AIJ, Architectural Institute of Japan, in the open elementary school and the modernization model of elementary school. That is to say, the movable partition wall between the classroom and the corridor disturbed students in their class in the open school.

• Journal of Institute of Control, Robotics and Systems
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• v.17 no.2
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• pp.93-101
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• 2011

For mobile robot, recognizing its current location is very important to navigate autonomously. Especially, loop closing detection that robot recognize location where it has visited before is a kernel problem to solve localization. A considerable amount of research has been conducted on loop closing detection and localization based on appearance because vision sensor has an advantage in terms of costs and various approaching methods to solve this problem. In case of scenes that consist of repeated structures like in corridors, perceptual aliasing in which, the two different locations are recognized as the same, occurs frequently. In this paper, we propose an improved method to recognize location in the scenes which have similar structures. We extracted salient regions from images using visual attention model and calculated weights using distinctive features in the salient region. It makes possible to emphasize unique features in the scene to classify similar-looking locations. In the results of corridor recognition experiments, proposed method showed improved recognition performance. It shows 78.2% in the accuracy of single floor corridor recognition and 71.5% for multi floor corridors recognition.

• Journal of the Korean Solar Energy Society
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• v.32 no.6
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• pp.141-148
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• 2012

Ceiling cassette type air conditioner has been a main stream as a heating/cooling system recently in school, Korea. In this study, indoor thermal environments made by ceiling cassette type air conditioner were investigated by CFD simulation. Concentrations of $CO_2$ were investigated by a field measurement. Indoor thermal environment with the velocity inlet angle of $45^{\circ}$ from the ceiling in heating season was very ununiform so that thermal area was divided into two parts those the one is window side which is cold, and the other is corridor side which is hot. In cooling season under the same condition, there are areas too hot or too cold. If the velocity inlet angle is set in $30^{\circ}$ from the ceiling, indoor thermal environments was improved greatly in cooling season and heating season, too. Also, from the field measurement of $CO_2$ concentrations, it was suggested to install ventilators with proper air volume considered the number of class students.

• Proceedings of the Korean Institute of Interior Design Conference
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• 2008.05a
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• pp.242-246
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• 2008

This study is to research on the condition of safe environment of kindergartens. This study is to supplement the preceding study which was based only on survey to show the result and analyze the condition and problems of the safety of kindergartens to suggest the basic database of indoor environment that cause accident. First as a theoretical study, we analyze the preceding studies according to the related regulations. And we made checklist based on this and visited and investigated two kindergartens where applied for the case study As the result, we could understand factors that can cause accidents from classroom, corridor, door, stairs, balustrade, toilet, kitchen, front door, and fire exit/shelter. Especially, in case of fire exit/shelter, the whole renewal of kindergarten was necessary which is difficult. But, though it can not be advanced right away, they should try to have facility expansion and repair works gradually. And for more study on this, active cooperation from kindergartens are in need.

• The Journal of Korea Robotics Society
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• v.8 no.4
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• pp.238-246
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• 2013

In this paper, a robot vision technique is presented to detect obstacles, particularly approaching humans, in the images acquired by a mobile robot that autonomously navigates in a narrow building corridor. A single low-cost color camera is attached to the robot, and a trapezoidal area is set as a region of interest (ROI) in front of the robot in the camera image. The lower parts of a human such as feet and legs are first detected in the ROI from their appearances in real time as the distance between the robot and the human becomes smaller. Then, the human detection is confirmed by detecting his/her face within a small search region specified above the part detected in the trapezoidal ROI. To increase the credibility of detection, a final decision about human detection is made when a face is detected in two consecutive image frames. We tested the proposed method using images of various people in corridor scenes, and could get promising results. This method can be used for a vision-guided mobile robot to make a detour for avoiding collision with a human during its indoor navigation.

• Journal of Environmental Science International
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• v.11 no.8
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• pp.801-810
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• 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.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2009.04a
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• pp.273-277
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• 2009

This study was conducted to develop standards for evaluating what extant the physical environments of housing which can cope with the needs of the aging society. This study was consisted through literature investigation research mainly, and research target literature limits keyword to elderly housing environment and chose connected domestic various literatures. The scope of evaluation was limited to the indoor spaces and outdoor spaces of housing as it was thought that the elderly spend much more time at indoor, outdoors, considering their physical characteristics. The study are as follows ; First, in outdoor only area from design environment element accessibility, and safety emphasized from equipment element, health of community territory was expose from design environment element that supportiveness is emphasized from equipment element. Second, in living room safety emphasized from design environment element in bedroom and bathroom of indoor individuation space, vestibule, balcony supportiveness, health was expose that is emphasized kitchen and mess. Also, was expose that supportiveness is emphasized from equipment element of all individuation spaces. Third, was expose that design environment element in corridor that is indoor official business space, stair, lobby, elevator and safety from equipment element and supportiveness are emphasized.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2006.07a
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• pp.711-711
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• 2006