• Title/Summary/Keyword: Unknown environment

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Speech Enhancement Based on Feature Compensation for Independently Applying to Different Types of Speech Recognition Systems (이기종 음성 인식 시스템에 독립적으로 적용 가능한 특징 보상 기반의 음성 향상 기법)

  • Kim, Wooil
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.18 no.10
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    • pp.2367-2374
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    • 2014
  • This paper proposes a speech enhancement method which can be independently applied to different types of speech recognition systems. Feature compensation methods are well known to be effective as a front-end algorithm for robust speech recognition in noisy environments. The feature types and speech model employed by the feature compensation methods should be matched with ones of the speech recognition system for their effectiveness. However, they cannot be successfully employed by the speech recognition with "unknown" specification, such as a commercialized speech recognition engine. In this paper, a speech enhancement method is proposed, which is based on the PCGMM-based feature compensation method. The experimental results show that the proposed method significantly outperforms the conventional front-end algorithms for unknown speech recognition over various background noise conditions.

An method for building 2D virtual environment for a remote controlled mobile robot

  • Kim, Woo-Kyoung;Hyun, Woong-Keun;Park, Jea-Yong;Yoon, In-Mo;Jung, Y.K.
    • 제어로봇시스템학회:학술대회논문집
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    • 2004.08a
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    • pp.1430-1434
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    • 2004
  • Recently, Virtual reality parts is applied in various fields of industry. In this paper we developed basic components for virtual robot control system interfaced with real environment. For this, a real robot with virtual interface module is developed and virtual robot of similar image with real robot is created by putting on 3D graphic texture to the real robot. To build an unknown environment to be linked with virtual environment, we proposed a hough transformation based algorithm. Our proposed algorithm consists of navigation module by using fuzzy engine and map building module. Experiments using a developed robot illustrate the method.

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Landmark Detection Based on Sensor Fusion for Mobile Robot Navigation in a Varying Environment

  • Jin, Tae-Seok;Kim, Hyun-Sik;Kim, Jong-Wook
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.10 no.4
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    • pp.281-286
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    • 2010
  • We propose a space and time based sensor fusion method and a robust landmark detecting algorithm based on sensor fusion for mobile robot navigation. To fully utilize the information from the sensors, first, this paper proposes a new sensor-fusion technique where the data sets for the previous moments are properly transformed and fused into the current data sets to enable an accurate measurement. Exploration of an unknown environment is an important task for the new generation of mobile robots. The mobile robots may navigate by means of a number of monitoring systems such as the sonar-sensing system or the visual-sensing system. The newly proposed, STSF (Space and Time Sensor Fusion) scheme is applied to landmark recognition for mobile robot navigation in an unstructured environment as well as structured environment, and the experimental results demonstrate the performances of the landmark recognition.

Mobile Robot Path Planner for Environment Exploration (효율적 환경탐사를 위한 이동로봇 경로 계획기)

  • Bae, Jung-Yun;Lee, Soo-Yong;Lee, Beom-Hee
    • The Journal of Korea Robotics Society
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    • v.1 no.1
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    • pp.9-16
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    • 2006
  • The Mobile robots are increasingly being used to perform tasks in unknown environments. The potential of robots to undertake such tasks lies in their ability to intelligently and efficiently search in an environment. An algorithm has been developed for robots which explore the environment to measure the physical properties (dust in this paper). While the robot is moving, it measures the amount of dust and registers the value in the corresponding grid cell. The robot moves from local maximum to local minimum, then to another local maximum, and repeats. To reach the local maximum or minimum, simple gradient following is used. Robust estimation of the gradient using perturbation/correlation, which is very effective when analytical solution is not available, is described. By introducing the probability of each grid cell, and considering the probability distribution, the robot doesn't have to visit all the grid cells in the environment still providing fast and efficient sensing. The extended algorithm to coordinate multiple robots is presented with simulation results.

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Nature Activities in Urban Parks to Encourage Curiosity and Scientific Problem-Solving Ability in Kindergarteners

  • Kim, Eun-Jin;Koo, Chang-Duck
    • Journal of People, Plants, and Environment
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    • v.22 no.5
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    • pp.515-524
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    • 2019
  • This study was conducted based on the fact that children in institutions for early childhood education located in cities lack the opportunity to experience nature. Therefore, urban parks are where it is possible to observe nature and natural environment, through which we examined the effects of nature activities on kindergarten children's curiosity and scientific problem-solving ability. The subjects of this study were 5-years old kindergarten children in attending public kindergartens in Cheonan and Asan and 42 children were randomly selected. The pretest and posttest were conducted on curiosity and scientific problem-solving ability before and after nature activities. The results showed that nature activities in urban parks had significant effects on improvement of kindergarten children's curiosity and scientific problem-solving ability (p <.05). Therefore, nature activities in urban parks had positive effects on preference for unknown and exploratory behavior, which are sub-factors of kindergarten children's curiosity. Nature activities also had positive effects on discovery and statement of the problem, creation and application of ideas, and conclusion to problem solving.

Resources Use Characteristics of Higher Fungi in Byeonsanbando National Park (변산반도 국립공원 고등균류의 자원이용적 특성)

  • Jang, Seog-Ki
    • Korean Journal of Environment and Ecology
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    • v.31 no.2
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    • pp.230-251
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    • 2017
  • According to the survey on higher fungi from 2009 to 2011 and also in 2015 in Byeonsanbando National Park, a total of 2 division, 6 class, 18 orders, 61 families, 157 genera and 323 species were observed. In case of Agaricales, there were 23 families, 67 genera and 153 species; Boletales, there were 6 families, 27 genera and 45 species; Russulales, there were 3 family, 4 genera and 40 species; Polyporales, there were 6 family, 21 genera, 28 species. Thus, most of them belonged to the following 4 orders: Agaricales, Russulales, Boletales and Polyporales. Dominant species belonged to Boletaceae (37 species), Russulaceae (36 species), Agaricaceae (28 species) and Amamtaceae (25 species). For the habitat environment, the ectomycorrhizal mushrooms were 40.2% (poisonous mushrooms, 46 species; edible & medicinal mushrooms, 51 species; unknown edible & poisonous mushrooms, 26 species), litter decomposing and wood rotting fungi 35.3%(poisonous mushrooms, 10 species; edible & medicinal mushrooms, 52 species; unknown edible & poisonous mushrooms, 46species), grounding Fungi 22.3%(poisonous mushrooms, 8 species; edible & medicinal mushrooms, 31 species; unknown edible & poisonous mushrooms, 29 species). Monthly, most of poisonous mushrooms, edible & medicinal mushrooms and unknown edible & poisonous mushrooms were found in July and August. In terms of altitude, the most species were observed at 1~99m and the populations dropped by a significant level at an altitude of 200m or higher. It seemed that the most diversified poisonous mushrooms, edible & medicinal mushrooms and unknown edible & poisonous mushrooms occurred at climate conditions with a mean air temperature at $24.0{\sim}25.9^{\circ}C$, the highest air temperature at $28.0{\sim}29.9^{\circ}C$, the lowest air temperature at $20.0{\sim}21.9^{\circ}C$, a relative humidity at 77.0~79.9% and a rainfall of 300.0~499.9mm.

Tactile Navigation System using a Haptic Device (햅틱 디바이스를 이용한 촉감형 네비게이션 시스템)

  • Lee, Dong-Hyuk;Noh, Kyung-Wook;Kang, Sun Kyun;Kim, Hyun Woo;Lee, Jang-Myung
    • Journal of Institute of Control, Robotics and Systems
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    • v.20 no.8
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    • pp.807-814
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    • 2014
  • In this paper, we proposed a haptic navigation system which used the tactile data for the user guides of the mobile robot to the reference point via tele-operation in unknown blind environment. This navigation system can enable a mobile robot to avoid obstacles and move to the reference point, according to the direction provided by the device guides through a haptic device consisting of a vibration motor in a blind environment. There are a great deal of obstacles in real environments, and so mobile robots can avoid obstacles by recognizing the exact position of each obstacle through the superposition of an ultrasonic sensor. The navigation system determines the direction of obstacle avoidance through an avoidance algorithm that uses virtual impedance, and lets users know the position of obstacles and the direction of the avoidance through the haptic device consisting of 5 vibration motors. By letting users know intuitionally, it lets the mobile robot precisely reach the reference point in unknown blind environment. This haptic device can implement a haptic navigation system through the tactile sensor data.

Localization of Mobile Robot In Unstructured Environment using Auto-Calibration Algorithm (Auto-Calibration을 이용한 Unstructured Environment에서의 실내 위치추정 기법)

  • Eom, We-Sub;Seo, Dae-Geun;Park, Jae-Hyun;Lee, Jang-Myung
    • Journal of Institute of Control, Robotics and Systems
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    • v.15 no.2
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    • pp.211-217
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    • 2009
  • This paper proposes a way of expanding the use area of localization technique by using a beacon. In other words, we have developed the auto-calibration algorithm that recognizes the location of this beacon by attaching the beacon on an arbitrary position and by using the information of existing beacon under this situation. By doing so, the moving robot can overcome the limitation that the localization of moving robot is only possible within the area that has installed the existing beacon since the beacon cannot be installed on the accurate location when passing through a danger zone or an unknown zone. Accordingly, the moving robot can slowly move to the unknown zone according to this auto-calibration algorithm and can recognize its own location at a later time in a safe zone. The localization technique is essentially needed in using a moving robot and it is necessary to guarantee certain degree of reliability. Generally, moving robots are designed in a way to work well under the situation that the surroundings is well arranged and the localization techniques of using camera, laser and beacon are well developed. However due to the characteristics of sensor, there may be the cases that the place is dark, interfering radio waves, and/or difficult to install a beacon. The effectiveness of the method proposed in this paper has been proved through an experiment in this paper.

Development of a sonar map based position estimation system for an autonomous mobile robot operating in an unknown environment (미지의 영역에서 활동하는 자율이동로봇의 초음파지도에 근거한 위치인식 시스템 개발)

  • 강승균;임종환
    • 제어로봇시스템학회:학술대회논문집
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    • 1997.10a
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    • pp.1589-1592
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    • 1997
  • Among the prerequisite abilities (perception of environment, path planning and position estimation) of an autonomous mobile robot, position estimation has been seldom studied by mobile robot researchers. In most cases, conventional positioin estimation has been performed by placing landmarks or giving the entrire environmental information in advance. Unlikely to the conventional ones, the study addresses a new method that the robot itself can select distinctive features in the environment and save them as landmarks without any a priori knowledge, which can maximize the autonomous behavior of the robot. First, an orjentaion probaility model is applied to construct a lcoal map of robot's surrounding. The feature of the object in the map is then extracted and the map is saved as landmark. Also, presented is the position estimation method that utilizes the correspondence between landmarks and current local map. In dong this, the uncertainty of the robot's current positioin is estimated in order to select the corresponding landmark stored in the previous steps. The usefulness of all these approaches are illustrated with the results porduced by a real robot equipped with ultrasonic sensors.

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A Study on Clay Mineralogical Characteristics of Jeondanto (전단토에 대(對)한 점토광물학적(粘土鑛物學的) 연구(硏究))

  • Choi, Dae Ung;Um, Ki Tae;Shin, Yong Hwa
    • Korean Journal of Soil Science and Fertilizer
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    • v.6 no.1
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    • pp.33-34
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    • 1973
  • Jeondanto which is known a edible earth material in the legend of local people on the Mt. Baegdeog at Yeongweul Gun, Gangweon-Do, is one of pure and well crystalized kaolinite having a thin hexagonal platy structure by X-ray, DTA and electron microscope analysis. Even though its extent is currently unknown, Jeondanto will be one of interesting materials for mineralogical study of its uniquely well crystalized structure.

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