• Title/Summary/Keyword: 환경자기

Search Result 2,271, Processing Time 0.03 seconds

Path Tracking Control of Mobile Robot using Magnetic Marker (마그네틱 마커를 이용한 이동로봇의 경로제어 Part I : 지자기 제거, 자기장의 정규화와 선형화)

  • Kim, Young-Min;Kim, Eui-Sun;Lim, Young-Cheol;Kim, Tae-Gon;Moon, Chae-Joo;Chang, Young-Hak
    • Proceedings of the KIEE Conference
    • /
    • 2007.07a
    • /
    • pp.1750-1751
    • /
    • 2007
  • 이동하고자 하는 경로에 자석 마커를 설치하고 마커의 자계를 인식하여 경로를 추종하는 이동 로봇의 경로 제어시스템이다. 자석마커 간격 확장과 여러 환경에 따른 자계를 분석하기 위해 자동 자계 측정 장치를 제작하였고, 이를 이용한 실측을 통하여 지자기 제거를 확인하였다. 지자기가 제거된 마커 자기장 값의 정규화와 선형화를 통하여 이동 경로 상에서 위치 인식이 수월하도록 하였으며, 인식된 경로 정보로 이동 로봇의 경로 제어가 가능하도록 하였다.

  • PDF

초고속열차의 과거, 현재 그리고 미래

  • Han, Yeong-Jae
    • Proceedings of the Korean Vacuum Society Conference
    • /
    • 2013.08a
    • /
    • pp.61.1-61.1
    • /
    • 2013
  • 최근 지구온난화 및 원유 공급 감소 또는 고갈로 에너지 효율성 높고 저탄소 녹색성장을 주도할 수 있는 철도산업에 대한 관심이 고조되고 있다. 초고속 자기부상철도는 에너지 효율이 높은 경제적인 교통수단으로써, 단위 수송당(인-km) 온실가스 배출량이 자동차의 38%, 항공기의 17%에 불과하고, 같은 궤도운송시스템인 고속철도에 비해서도 77%에 불과하고 단위수송당 에너지 소비율이 항공기의 80% 수준에 불과하므로, 화석에너지의 고갈이 예상되는 미래에 장거리 고속 이동 수단으로써 중요성이 확대되고 있다. 또한, 비접촉 추진 방식이므로 바퀴 접촉식 고속철도에 비해서 유지보수 비용이 저렴하고(34%에 불과) 고속철도에 비해 10dB 이상 소음 발생이 적은 수명주기 비용 및 환경측면에서 기존 철도시스템에 비해서 경쟁력이 있으므로 시급한 개발과 활용이 요구되고 있다. 본 연구에서는 초고속 자기부상철도 연구와 관련된 국내외 연구동향과 함께, 국가연구개발사업으로 추진중인 초고속 자기부상철도 핵심기술개발사업에 대해 살펴보았다. 또한, 미래기술로 각광을 받고 있는 튜브트레인 기술에 대해서도 알아보았다.

  • PDF

Distributed controllers using a Self-Organizing Map Neural Network in SDN environment (SDN 환경에서 자기조직화지도 신경망을 이용한 분산 컨트롤러)

  • Yoo, Seung-Eon;Kim, Min-Woo;Lee, Byung-Jun;Kim, Kyung-Tae;Youn, Hee-Yong
    • Proceedings of the Korean Society of Computer Information Conference
    • /
    • 2019.01a
    • /
    • pp.47-48
    • /
    • 2019
  • 본 논문에서는 신경망의 일종인 자기조직화지도(Self Organizing Map)을 이용하여 컨트롤러의 순서를 정하는 모델을 제안하였다. 자기조직화지도는 자율 학습에 의한 클러스터링을 수행하는 알고리즘으로써 컨트롤러에 가중치를 부여하고 컨트롤러 간 거리를 계산하여 효율적인 컨트롤러 선택을 목표로 한다.

  • PDF

Fast Self-Collision Handling in Cloth Simulations Using GPU-based Optimized BVH and R-Triangle (GPU 기반의 최적화된 BVH와 R-Triangle을 이용한 옷감 시뮬레이션에서의 빠른 자기충돌 처리)

  • Moon, Seong-Hyeok;Kim, Jong-Hyun
    • Proceedings of the Korean Society of Computer Information Conference
    • /
    • 2022.01a
    • /
    • pp.373-376
    • /
    • 2022
  • 본 논문에서는 삼각형 메쉬 기반에서 옷감 시뮬레이션(Cloth simulation)에서 계산양이 큰 자기충돌(Self-collision) 처리를 GPU기반으로 가속화시킬 수 있는 방법에 대해 소개한다. CUDA기반으로 병렬 최적화하기 위해 본 논문에서는 1)재귀적으로 계산하여 충돌판정을 하는 BVH(Bounding volume hierarchy) 트리를 GPU기반에서 효율적으로 빌드, 업데이트, 트리 순회하는 방법을 제안하고, 2)삼각형 메쉬 기반에서는 중복되는 프리미티브(Primitive) 충돌검사를 최소화하기 위해 R-Triangle기법을 GPU에서 최적화 시키는 방법을 소개한다. 결과적으로 본 논문에서 제안하는 기법은 GPU 환경에서 옷감 시뮬레이션의 자기충돌과 객체충돌 처리를 빠르고 효율적으로 처리할 수 있도록 하였고, 다양한 장면에서 실험한 결과 모든 결과에서 빠른 시뮬레이션 결과를 얻을 수 있었다.

  • PDF

Identifying Correction Range of Geomagnetic Field for Indoor Positioning of Workers at Construction Site (건설현장 내 작업자 실내측위를 위한 지구자기장 보정 범위 도출)

  • Kim, Hyeonmin;Ahn, Heejae;Lee, Changsu;Kim, Harim;Ko, Youngwoong;Cho, HunHee
    • Proceedings of the Korean Institute of Building Construction Conference
    • /
    • 2022.11a
    • /
    • pp.93-94
    • /
    • 2022
  • Although various studies about indoor positioning systems, such as beacon and Wifi, have been conducting for indoor positioning of workers at construction sites, these systems have limitations in terms of accuracy or economics. To overcome these limitations, geomagnetic field sequence-based indoor positioning technology can be a good alternative. However, it is necessary to correct the geomagnetic field near the construction material stocking area since the geomagnetic field can be distorted near construction materials such as rebars. Therefore, this study conducted an experiment for identifying correction range of geomagnetic field near the construction material stocking area. It was analyzed that the geomagnetic field should be corrected up to 60cm in the horizontal direction from the stocking point if the height of stocking area for rebars is 40cm or more. This study can be used for important reference for development of geomagnetic field sequence-based indoor positioning technology suitable for construction sites.

  • PDF

A Review on the Applicability of Geomagnetic Field-Based Indoor Positioning in Construction Site (지구자기장 기반 실내측위기술의 건설현장 적용 가능성 검토)

  • Kim, Hyeonmin;Kim, Hyungjun;Lee, Changwoo;Lee, Changsu;Lim, Bada;Cho, Hunhee
    • Proceedings of the Korean Institute of Building Construction Conference
    • /
    • 2023.05a
    • /
    • pp.123-124
    • /
    • 2023
  • Despite the acuuracy, stability, and economic feasibility of geomagnetic field-based indoor positioning, its applicability in construction sites needs to be thoroughly discussed due to the issue of distortion of geomagnetic fields around ferromagnetic objects such as rebars. In this study, the possibility of applying the geomagnetic field-based indoor positioning in construction sites was reviewed through the Student's t-test after measuring the changes in geomagnetic field values depending on the presence or absence of rebars. The statistical analysis revealed that there is a high probability (over 80%) of significant changes in geomagnetic field values when measuring points are located within 60cm from the rebars. On the other hand, the probability of minimal changes in geomagnetic field values is over 90% when measuring points are located more than 60cm from the rebars. This suggests the application of geomagnetic-based indoor positioning in construction sites would be possible if the issue of distortion in geomagnetic field values near rebars within 60cm is resolved.

  • PDF

The Mediating Effect of Self-Efficicy in the Relationship between Hospital Employee's Job Placement and Individual Performance (병원 재직자들의 직무배치와 개인성과간의 관계에서 자기효능감의 매개효과 검증)

  • Lee, Chul-Woo
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.15 no.1
    • /
    • pp.113-121
    • /
    • 2014
  • To improve management performance, medical institutions have great attentions to selecting the good employee. Through job placement, recruited employee performing a given task, previous studies have lack of research, how job environment affects the individual perception of job ability and individual performance. Therefore, targeting at the health care professional employees who work in the hospital, 134 questionnaire data collected, this study performed an empirical study on the relationship between person-job fit, self-efficacy and individual performance. Specifically, mediating effect of self-efficacy between person-job fit and individual performance was verified. The results indicate that first, person-job fit appeared to affect significantly to the sub-factor of self-efficacy (self-adjustment, confidence, goal-difficulty). Second, among the self-efficacy sub-factor, self-adjustment, confidence appeared to influence to the individual performance. Third, self-adjustment was fully mediated between person-job fit and individual performance and confidence was partially mediated between person-job fit and individual performance. These findings have the theoretical implications that self-efficacy studies are expanded to environmental factors and practical implications and study's limitations are discussed in terms of hospital organization's human resource management.

A Study on the Geomagnetic Reference Field Modeling from the Triaxial Magnetometer Data Onboard KOMPSAT-II (아리랑위성 2호의 삼축자력계로부터 관측된 지구자기장 모델 연구)

  • Kim, Hyung-Rae;Hwang, Jong-Sun;Kim, Jeong-Woo;Lee, Seon-Ho
    • Economic and Environmental Geology
    • /
    • v.45 no.4
    • /
    • pp.377-384
    • /
    • 2012
  • The main field component of the Earth's magnetic field was modeled from the tri-axial magnetometer onboard KOrean MultiPurpose SATellite-II (KOMPSAT-II) for the purpose of satellite attitude control. The model computed by the KOMPSAT-II magnetometer measurement data is compared with the International Geomagnetic Reference Field (IGRF) model of a degree of up to 13 in spherical harmonic coefficients. The previous study with KOMPSAT-I (Kim et al. 2004) indicated a good correlation of power spectrum of spherical harmonic coefficients with respect to the degree up to 5. This study, however, showed an agreement of the degree up to 8-9 of the coefficient power spectrum and a discrepancy between degrees 10 and 13. We have concluded that relevant data selection process, removal of the external field from the data in the high latitude region, an accuracy of the magnetometer all play an important role in finding a coherence with the IGRF model. This study will be extended to the secular variation model of geomagnetism if longer-period data become available.

Anisotropy of Magnetic Susceptibility (AMS) of Granitic Rocks in the Eastern Region of the Yangsan Fault (양산단층 동편 화강암질암의 대자율 이방성(AMS))

  • Cho, Hyeong-Seong;Son, Moon;Kim, In-Soo
    • Economic and Environmental Geology
    • /
    • v.40 no.2 s.183
    • /
    • pp.171-189
    • /
    • 2007
  • A study of anisotropy of magnetic susceptibility (AMS) was undertaken on Cretaceous granitic, volcanic and sedimentary rocks in the eastern region of the Yangsan fault, southeast Korea. A total of 542 independently oriented core samples collected form 77 sites were studied. The main magnetic mineral in granitic rocks is magnetite according to the magnitude of bulk susceptibility, high-temperature susceptibility variation and isothermal remanent magnetization. Both of magnetic lineation and foliation with NE-SW trends are revealed in the granitic rocks, while volcanic rocks show scattered directions and sedimentary rocks show only load foliation parallel to the bedding planes. The following evidences read to the conclusion that both magnetic fabrics in the granitic rocks have been obtained by a tectonic stress before full solidification of the magma: (i) A fully hardened granitic rocks would get hardly any fabric, (ii) Difference of the magnetic fabric trends with those of the geological structures in the granitic rocks themselves formed by brittle deformation after solidification (e.g. patterns of small-faults and joints), (iii) Kinking of biotite and undulose extinction in quartz observed under the polarizing microscope, (iv) Discordance of magnetic fabrics in the granitic rocks with those in the surrounding rocks. The NE-SW trend of the magnetic foliations suggests a NW-SE compressive stress of nearly contemporaneous with the emplacement of the granitic rocks. The compression should have caused a sinistral strike-slip movement of the Yangsan Fault considering the trend of the latter. As the age of the granitic rocks in the study area is reported to be around $60\sim70$ Ma, it is concluded that the Yangsan fault did the sinistral strike-slip movement during this time (L. Cretaceous Maastrichtian - Cenozoic Paleocene).

Relationships between Self-management, Dance Activity Satisfaction and Dance Performance Confidence (무용전공 대학생의 자기 관리, 무용활동만족, 공연자신감의 관계)

  • Lee, Hwa-Suk;Choi, Jae-Hee
    • The Journal of the Korea Contents Association
    • /
    • v.13 no.5
    • /
    • pp.210-222
    • /
    • 2013
  • The purpose of this study is to analyze the relationship between self-management, dance activity satisfaction and dance performance confidence in university dance students. The subject was a population of 350 university dance students during the period of time November 5, 2012 to December 7, 2012. The data on 322 students were used for actual analyses and data were processed with SPSS 18.0 for Window. The results of the analysis were as follows: First, self-management had positive effects on dance activity satisfaction. Second, dance activity satisfaction had positive effects on dance performance confidence. Third, self-management had positive effects on dance performance confidence.