• 제목/요약/키워드: local environments

검색결과 785건 처리시간 0.027초

실외 도로 환경에서의 자율주행 로봇 개발 (Development of Autonomous Navigation Robot in Outdoor Road Environments)

  • 노치원;강연식;강성철
    • 제어로봇시스템학회논문지
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    • 제15권3호
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    • pp.293-299
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    • 2009
  • This paper discusses an autonomous navigation system for urban environments. For the localization of the robot, EKF (Extended Kalman Filter) algorithm is used with odometry, angle sensor, and DGPS (Differential Global Positioning System) measurement. Especially in an urban environment, DGPS is often blocked by buildings and trees and the resulting inaccurate positioning prevents the robot from safe and reliable navigation. In addition to the global information from DGPS, the local information of the curb on the roadway is used to track a route when the global DGPS information is inaccurate. For this purpose, curb detection algorithm is developed and implemented in the developed navigation algorithm. Four different types of navigation strategies are developed and they are switched to adapt to different localization conditions according to the availability of DGPS and the existence of the curbs on the roadway. The experimental results show that the designed switching strategy improves the navigation performance adapting to the environment conditions.

광대역 CDMA WLL용 스마트 안테나 시스템 구현 (Implementation of a Smart Antenna System for Wide-Band CDMA WLL Channel)

  • 김미경;황현구;김종헌;박환석;김상태;최승원
    • 한국전자파학회논문지
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    • 제12권6호
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    • pp.912-918
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    • 2001
  • 본 논문에서는 광대역 WLL신호환경에서 동작하는 스마트 안테나 시스템의 역방향 채널에서의 시스템 성능분석을 제시하였다. 이 논문에 보여지는 모든 결과는 현재 상용화 된 단말기로부터 수신한 실제 데이터로부터 얻어졌다. 웨이트 벡터로부터 계산되어진 빔패턴과 BER(Bit Error Rate)은 실내와 실외 환경 실험에서 관찰되었다. 실험의 결과로, 제안되어진 스마트 안테나 시스템은 실외와 실내 신호 환경 모두에서 향상된 성능을 제공한다는 결론을 얻었다.

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CNN 기반의 IEEE 802.11 WLAN 프레임 포맷 검출 (CNN based IEEE 802.11 WLAN frame format detection)

  • 김민재;안흥섭;최승원
    • 디지털산업정보학회논문지
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    • 제16권2호
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    • pp.27-33
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    • 2020
  • Backward compatibility is one of the key issues for radio equipment supporting IEEE 802.11, the typical wireless local area networks (WLANs) communication protocol. For a successful packet decoding with the backward compatibility, the frame format detection is a core precondition. This paper presents a novel frame format detection method based on a deep learning procedure for WLANs affiliated with IEEE 802.11. Considering that the detection performance of conventional methods is degraded mainly due to the poor performances in the symbol synchronization and/or channel estimation in low signal-to-noise-ratio environments, we propose a novel detection method based on convolutional neural network (CNN) that replaces the entire conventional detection procedures. The proposed deep learning network provides a robust detection directly from the receive data. Through extensive computer simulations performed in the multipath fading channel environments (modeled by Project IEEE 802.11 Task Group ac), the proposed method exhibits superb improvement in the frame format detection compared to the conventional method.

The Correlation Research between Lifestyle Changes and Evolution of Residential Communities - Based on a Survey of Shanghai, China

  • Zhang, Kai
    • Architectural research
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    • 제22권1호
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    • pp.1-11
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    • 2020
  • From 1990s to the present, in China, residential communities has developed rapidly in terms of government policies and living environments. With economic development, dwelling commercialization and socialization gradually reshaped the housing distribution system and local government management in Chinese urban area. After this process, dwellings were endowed with commodity attributes, which were planned and designed depending on residents' requirements of life. During the 30 years of social transformation, Chinese citizens' lifestyle also had huge changes. In this period, the forms of residential area improved constantly to keep pace with social development. This study aims to research the features of contemporary communities and survey citizens' lifestyle changes to find the reasons of the evolution of communities. Moreover, in this paper, there is a clear explanation of the reasons why gated communities are popular in Chinese urban area. In addition, comprehensive data analysis is derived from a questionnaire administered in Shanghai, China. In this part, the questionnaire surveys what factors about lifestyle influence the transformation of living environments and residential buildings. The results of survey show that residents have housing preferences dependent on their lifestyles, and their daily needs related with environmental features.

The Dependence of Type Ia Supernova Luminosities on the Global and Local Properties of Host Galaxies in the YONSEI Supernova Catalog

  • Kim, Young-Lo;Kang, Yijung;Lee, Young-Wook
    • 천문학회보
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    • 제43권1호
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    • pp.62.3-63
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    • 2018
  • Trends of Type Ia supernova (SN Ia) luminosities with the properties of host galaxies are important to study the underlying physics for an SN progenitor system and explosion mechanism. In the YONSEI SN catalog, we have a sample of ~600 SN and host data in the wider redshift range, and two independent light-curve models, SALT2 and MLCS2k2. From this catalog, here we present that SNe Ia in low-mass, globally and locally star-forming environments are fainter than those in high-mass, globally and locally passive environments, after light-curve shape and color or extinction corrections. Our results are then compared to previous studies, and show consistent results.

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일본의 경관협정을 통한 마을 만들기 사례에 관한 연구 (A Study on the Village Formation Example through Japanese Landscape Agreement)

  • 이병대;동재욱
    • 한국디지털건축인테리어학회논문집
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    • 제9권1호
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    • pp.71-81
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    • 2009
  • Village formation through landscape agreements of all things has sufficient expectation effects in that it outgrows the existing hardware- and development-oriented methods and realizes software- and policy-centered measures developed on the basis of environments and amenity. Village formation through landscape agreements is a work toward future in the long term. Villages are moving in the flow of time. Recognition on life environments and changes in consciousness of residents may be the most direct head start showing the possibility of village formation. However, the signs of such changes are yet uncertain and it is difficult to expect the changes in conscious ness would lead to realization and accomplishment. Therefore, it is needed to construct a society-wide system in which administration, experts, and local residents altogether support resident-led village formation, as well as efforts to enhance and expand the sprouts of hope.

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Animation Support for Networked Virtual Environments

  • Ko, Hyeongseok
    • 한국방송∙미디어공학회:학술대회논문집
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    • 한국방송공학회 1996년도 Proceedings International Workshop on New Video Media Technology
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    • pp.13-17
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    • 1996
  • This paper presents animation techniques and issues involved in virtual environments where the participants interact with each other through a network. The state of the participant should be recognized at each local site, and broadcast to the other sites. Because information exchange is minimal, animation techniques are applied to convert the incoming low DOF parameters into high DOF joint angles that completely determine the configuration of the agents at each frame. As a case study, a software system VRLOCO is introduced, which has been developed by the author over the last five years. From a simple stream of body center positions, VRLOCO generates realistic curved path human locomotion in real-time. Based on the heading direction and speed, the locomotion automatically switches among five different primitives: walking, running, lateral stepping, backward stepping, and turnaround. The techniques presented here proved robust and faithful: the algorithm is not sensitive to the noise in the data, and the resulting animation conforms well with the original data.

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대두 유용형질의 적응성에 관한 연구 (Studies on the Adaptability of Agronomic Characteristics for Yield Tests on Soybean)

  • 권신한;김재리;오정행
    • 한국작물학회지
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    • 제23권2호
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    • pp.99-104
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    • 1978
  • This study was conducted to evaluate the yield performance, adaptation and stability of selected 17 local soybean lines, and determine the optimum number of locations and years in testing program. Among 12 lines having high performance than standard variety Bong-Eui, nine lines were better adapted to favorable environments with high stability. while three were adapted to unfavorable environments with instability. The data from over eight locations in a one-year test would be sufficient to evaluate high yielding lines but the accuracy of selection would be increased by testing in three years instead of one.

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보안성을 갖는 1-사본 준직렬성을 위한 전역트랜잭션 스케쥴링 (Global Transaction Scheduling for One-Copy Quasi-Serializability with Secure Properties)

  • 정현철
    • 디지털산업정보학회논문지
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    • 제5권4호
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    • pp.99-108
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    • 2009
  • In the security environments of heterogeneous multidatabase systems, not only the existing local autonomy but also the security autonomy as a new constraint are required. From global aspects, transactions maintain consistent data value when they assure serializability. Also, secure properties must protect these transactions and data values to prevent direct or indirect information effluence. This paper proposes scheduling algorithm for global transactions to ensure multilevel secure one-copy quasi-serializability (MLS/1QSR) in security environments of multidatabase systems with replicated data and proves its correctness. The proposed algorithm does not violate security autonomy and globally guarantees MLS/1QSR without indirect information effluence in multidatabase systems.

Complete Coverage Path Planning of Cleaning Robot

  • 유강;김갑일;손영익
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2003년도 학술회의 논문집 정보 및 제어부문 B
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    • pp.429-432
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    • 2003
  • In this paper, a novel neural network approach is proposed for cleaning robot to complete coverage path planning with obstacle avoidance in stationary and dynamic environments. The dynamics of each neuron in the topologically organized neural network is characterized by a shunting equation derived from Hodgkin and Huxley's membrane equation. There are only local lateral connections among neurons. The robot path is autonomously generated from the dynamic activity landscape of the neural network and the previous robot location without any prior knowledge of the dynamic environment.

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