• The Journal of Korea Robotics Society
• /
• v.4 no.1
• /
• pp.25-33
• /
• 2009

One of the main problems of topological localization in a real indoor environment is variations in the environment caused by dynamic objects and changes in illumination. Another problem arises from the sense of topological localization itself. Thus, a robot must be able to recognize observations at slightly different positions and angles within a certain topological location as identical in terms of topological localization. In this paper, a possible solution to these problems is addressed in the domain of global topological localization for mobile robots, in which environments are represented by their visual appearance. Our approach is formulated on the basis of a probabilistic model called the Bayes filter. Here, marginalization of dynamics in the environment, marginalization of viewpoint changes in a topological location, and fusion of multiple visual features are employed to measure observations reliably, and action-based view transition model and action-associated topological map are used to predict the next state. We performed experiments to demonstrate the validity of our proposed approach among several standard approaches in the field of topological localization. The results clearly demonstrated the value of our approach.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.15 no.2
• /
• pp.181-187
• /
• 2015

In this study, an LED emotional lighting algorithm optimized to the situation was implemented using fuzzy inference for users in exercise and resting situations in indoor environment. The fuzzy theory was used instead of the conventional simple color temperature control in order to control the colors and color temperatures of LED light sources in line with user environment under complex conditions. An LED emotional lighting system based on fuzzy theory was designed through a combination of colors according to the color and temperature of emotional language based on the user behavior. As a result, the color and color temperature can give a good effect on user's emotions for an emotional lighting that is effective for resting and exercise.

• Journal of the Korea Furniture Society
• /
• v.25 no.2
• /
• pp.148-153
• /
• 2014

Importance of energy consumptions has being emphasized because of problems of the energy and environment. So, recently, green wall systems have been installed to reduce building energy consumptions. The green wall systems provide several benefits; they make it possible to maintain moderate thermal comforts by greenery. Greening such a surface wall in the building by plants, the temperature of the wall can be properly controlled that purifies the air and improves the view spanning over the space. This study evaluated the effects of green wall systems on reducing room temperature quantitatively, changing of humidity, decreasing of $CO_2$. Test results were confirmed; first, the space installed by green walls showed that temperature and $CO_2$ decreased and humidity was increased. Second, two structures were compared with the solar radiation, and green wall systems controlled the temperature and humidity stably near the wall regardless of the amount solar radiation. In conclusion, the green wall systems can contribute to thermal comforts and indoor air quality in the buildings.

• The Journal of Korea Robotics Society
• /
• v.1 no.1
• /
• pp.25-35
• /
• 2006

Improving practicality of SLAM requires various sensors to be fused effectively in order to cope with uncertainty induced from both environment and sensors. In this case, combining sonar and vision sensors possesses numerous advantages of economical efficiency and complementary cooperation. Especially, it can remedy false data association and divergence problem of sonar sensors, and overcome low frequency SLAM update caused by computational burden and weakness in illumination changes of vision sensors. In this paper, we propose a SLAM method to join sonar sensors and stereo camera together. It consists of two schemes, extracting robust point and line features from sonar data and recognizing planar visual objects using multi-scale Harris corner detector and its SIFT descriptor from pre-constructed object database. And fusing sonar features and visual objects through EKF-SLAM can give correct data association via object recognition and high frequency update via sonar features. As a result, it can increase robustness and accuracy of SLAM in indoor environment. The performance of the proposed algorithm was verified by experiments in home -like environment.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.18 no.12
• /
• pp.2968-2974
• /
• 2014

When lighting has installed indoor, we control lighting using human-detecting sensors for people who pass at night and places that are lack of quantity of light. However, malfunction can be caused by positions of inappropriate sensors, and in the case of passages of big buildings, it is a problem that even after a person pass, light apparatuses are turned on for a long time. In this paper, we propose lighting control system based on location positioning for energy saving that control lighting in accordance with passers's position through indoor location positioning. This system use the fingerprinting technology that is one of the location positioning technologies and RSSI data that is collected by a smart device. Using those, it can turn on only lightings that are included in the positioned location and reduce unnecessary power consumption. As a result of experiment, on condition that four people were existing and illumination was 308 lux, we assured reduction effect of 49 Wh.

• The KIPS Transactions:PartB
• /
• v.16B no.5
• /
• pp.385-394
• /
• 2009

Face tracking and recognition are difficult problems because the face is a non-rigid object. The main reasons for the failure to track and recognize the faces are the changes of a face pose and environmental illumination. To solve these problems, we propose a nonlinear manifold framework for the face pose and the face illumination normalization processing. Specifically, to track and recognize a face on the video that has various pose variations, we approximate a face pose density to single Gaussian density by PCA(Principle Component Analysis) using images sampled from training video sequences and then construct the GMM(Gaussian Mixture Model) for each person. To solve the illumination problem for the face tracking and recognition, we decompose the face images into the reflectance and the illuminance using the SSR(Single Scale Retinex) model. To obtain the normalized reflectance, the reflectance is rescaled by histogram equalization on the defined range. We newly approximate the illuminance by the trained manifold since the illuminance has almost variations by illumination. By combining these two features into our manifold framework, we derived the efficient face tracking and recognition results on indoor and outdoor video. To improve the video based tracking results, we update the weights of each face pose density at each frame by the tracking result at the previous frame using EM algorithm. Our experimental results show that our method is more efficient than other methods.

• The Journal of the Acoustical Society of Korea
• /
• v.21 no.5
• /
• pp.471-477
• /
• 2002

Recently, lip-reading has been studied actively as an auxiliary method of automatic speech recognition(ASR) in noisy environments. However, almost of research results were obtained based on the database constructed in indoor condition. So, we dont know how developed lip-reading algorithms are robust to dynamic variation of image. Currently we have developed a lip-reading system based on image-transform based algorithm. This system recognize 22 words and this word recognizer achieves word recognition of up to 53.54%. In this paper we present how stable the lip-reading system is in environmental variance and what the main variant factors are about dropping off in word-recognition performance. For studying lip-reading robustness we consider spatial valiance (translation, rotation, scaling) and illumination variance. Two kinds of test data are used. One Is the simulated lip image database and the other is real dynamic database captured in car environment. As a result of our experiment, we show that the spatial variance is one of degradations factors of lip reading performance. But the most important factor of degradation is not the spatial variance. The illumination variances make severe reduction of recognition rates as much as 70%. In conclusion, robust lip reading algorithms against illumination variances should be developed for using lip reading as a complementary method of ASR.

• Journal of Navigation and Port Research
• /
• v.42 no.6
• /
• pp.421-426
• /
• 2018

With regard to LED lighting devices which have currently been commercialized, LED operating sequences are being sold in a fixed state. In such a state, the external environmental factors are not taken into consideration as only the illumination environment application is considered. Currently, it is difficult to create an optimal lighting environment which can adapt to changes in external environmental factors in the ship. Therefore, it was concluded that there is a need to input the external environment value so that the optimal illumination value can be reflected in real time in order to adapt more organically and actively to the change of external environmental factors. In this paper, we used a microprocessor as an integrated management system for environmental data that changes in real time according to existing external environmental factors. In addition, a controller capable of lighting control of RGB LED module by combining fuzzy inference system. For this, a fuzzy control algorithm is designed and a fuzzy control system is constructed. The distance and the illuminance value from the external environment element are input to the sensor, and these values are converted to the optimum illumination value through the fuzzy control algorithm, and are expressed through the dimming control of the RGB LED module and the practical effectiveness of the fuzzy control system is confirmed.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.38B no.2
• /
• pp.115-121
• /
• 2013

LED-ID (Light Emitting Diode-Identification) network is envisioned to be the next generation indoor wireless communication medium by which simultaneously high speed data transmission, identification, and illumination are possible. In spite of being extremely promising, it suffers from much impairment. Signals having different propagation paths can suffer from delays, and phase shifts which will eventually result interference. The probability of interference is also increased when communication links are established between a tag and several readers. Therefore it is necessary to reduce the interference in LED-ID network to ensure quality of service. It is possible to avoid interference by knowing the information about readers prior to assign the available spectrum. In this paper, we have proposed dynamic spectrum decision using cognitive radio concept. The simulation results justify that the proposed scheme is better than the conventional scheme.

• IEMEK Journal of Embedded Systems and Applications
• /
• v.7 no.2
• /
• pp.103-111
• /
• 2012

This paper introduces a novel concept of 'A Green LED Sensitivity Lighting System' which can automatically estimate QoS(quality of service) and emotional requirements of user using smart phone. And it can intelligently control ambient illumination lamp to conserve electric energy and to satisfy human sensitivity. The proposed system has 4 control modes; emotional lighting, smart lighting, green lighting and realistic lighting modes in order to comfort man's emotion, to maximize work efficiency, to save energy consumption and to make the entertainment more fun, respectively. When we choose green lighting mode for indoor office situations, an elaborate simulation shows that the proposed system with home network can reduce the energy by 50% compared to conventional light control system with a fixed time-based switching.