• Title/Summary/Keyword: energy space

Search Result 3,298, Processing Time 0.029 seconds

Development of Regenerative Inverter for Electric Railway Using Space Vector PWM (SVPWM을 이용한 전기철도용 회생 인버터 개발)

  • Jung M.G.;Baek B.S.;Kim T.W.;Ryu S.P.;Kim N.H.
    • Proceedings of the KIPE Conference
    • /
    • 2003.07a
    • /
    • pp.15-18
    • /
    • 2003
  • The electric power, regenerated while railway vehicles braking or running downhill, makes U line voltage rise and the feeding system may not be secure. In order to keep away from these kind of insecurity, the regenerative energy should be consumed by loads or transmitted to the AC side via certain devices such as DC/AC converters. This paper introduces the developed regenerative inverter for electric railway.

  • PDF

Measuring Inventory of Korean Housing Quality Related to Mental Health through Foreign Literature Reviews (국외 문헌고찰을 기초로 정신건강의 측면에서 본 한국주거의 질 측정요소에 관한 연구)

  • Park, Jung-A;Choi, Byungsook
    • Journal of the Korean housing association
    • /
    • v.23 no.6
    • /
    • pp.1-9
    • /
    • 2012
  • This study is to organize the frame of measuring inventory for housing quality related to mental health in foreign literature reviews. In the first step, many housing quality contents or items are extracted from empirical studies, including housing environment quality and mental health. In the next step, extracted contents and items are classified by space scope (house and neighborhood unit) and WHO housing properties (safety & security, health & sanitation, efficiency/convenience, comfort/amenity). Almost all housing properties follow the WHO standard, but some properties, sustainability and economic characteristics, do not follow the standard. These reflect on current Korean housing environment. They are energy saving and environment friendly effort, property value and economic burden, identity expression, and school district. So they need to be added to the Korean housing quality measurement related to mental health.

Integrated Radiometric Signal Modeling for High Resolution Earth Observation Satellite Camera (고해상도 지구관측위성 카메라의 복사신호량에 대한 통합적 모델링)

  • Jang, Hong-Sul;Jung, Dae-Jun;Youk, Young-Chun;Lee, Seung-Hoon
    • Aerospace Engineering and Technology
    • /
    • v.7 no.2
    • /
    • pp.82-87
    • /
    • 2008
  • In this study, the radiometric signal modeling is performed for the high resolution earth observation system in visible spectral range from space. The medeling includes solar radiation as a source of the radiometric energy, atmosphere and surface albedo of earth, and the spaceborne camera characteristics for the integrated modeling. The final output of the radiometric modeling is the number of electron produced by the detector of electro-optical camera.

  • PDF

PHYSICS REVEALED BY BROAD-RANGE CO LADDERS AND FINE-STRUCTURE LINES IN M83

  • Wu, Ronin
    • Publications of The Korean Astronomical Society
    • /
    • v.32 no.1
    • /
    • pp.147-149
    • /
    • 2017
  • Since the launch of the Herschel Space Observatory, our understanding about the photo-dissociation regions (PDR) has taken a step forward. In the bandwidth of the Fourier Transform Spectrometer (FTS) of the Spectral and Photometric Imaging REceiver (SPIRE) on board Herschel, ten CO rotational transitions, including J = 4 - 3 to J = 13 - 12, and three fine structure lines, including [$C{\small{I}}$] 609, [$C{\small{I}}$] 370, and [$N{\small{II}}$] $205{\mu}m$, are covered. I present our findings from the FTS observations at the nuclear region of M83, based on the spatially resolved physical parameters derived from the CO spectral line energy distribution (SLED) map and the comparisons with the dust properties and star-formation tracers. This article discusses (1) the potential of using [$N{\small{II}$] 205 and [$C{\small{I}}$] $370{\mu}m$ as star-formation tracers; (2) the excitation mechanisms of warm CO in the nuclear region of M83.

Dsign of Aperture-Matched type Slot Antenna for Ultra Wide-Band (개구-정합 형태를 갖는 UWB용 슬롯 안테나의 설계)

  • Mun, Byung-In;Kim, Ho-Yong;Lee, Hong-Min
    • Proceedings of the Korea Electromagnetic Engineering Society Conference
    • /
    • 2005.11a
    • /
    • pp.217-220
    • /
    • 2005
  • In this paper describes novel m antenna using aperture matched type slot structure. It substitutes edge diffractions by curved-surface diffractions which have a tendency to provide an undisturbed energy flow across the junction, around the curved surface, and into free-space. The proposed antenna is composed of a CPW feed structure, exponential tapered slot and the curved sectional at the edge. experimental resulte show that aperture matched type slot improve the performance of the UWB antenna.

  • PDF

Cross-Layer Cooperative Scheduling Scheme for Multi-channel Hybrid Ubiquitous Sensor Networks

  • Zhong, Yingji;Yang, Qinghai;Kwak, Kyung-Sup;Yuan, Dongfeng
    • ETRI Journal
    • /
    • v.30 no.5
    • /
    • pp.663-673
    • /
    • 2008
  • The multi-scenario topology of multi-channel hybrid ubiquitous sensor networks (USNs) is studied and a novel link auto-diversity cross-layer cooperative scheduling scheme is proposed in this paper. The proposed scheme integrates the attributes of the new performance evaluation link auto-diversity air-time metric and the topology space in the given multi-scenario. The proposed scheme is compared with other schemes, and its superiority is demonstrated through simulations. The simulation results show that relative energy consumption, link reception probability, and end-to-end blocking probability are improved. The addressing ratio of success with unchanged parameters and external information can be increased. The network can tolerate more hops to support reliable transportation when the proposed scheme is implemented. Moreover, the scheme can make the network stable. Therefore, the proposed scheme can enhance the average rate performance of the hybrid USN and stabilize the outage probability.

  • PDF

Sensorless Speed Control of PMSM with Superposition Principle (중첩의 원리를 이용한 센서리스 PMSM속도제어)

  • 이동희;박성준;한성현
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
    • /
    • 2002.04a
    • /
    • pp.199-205
    • /
    • 2002
  • This application study presents a solution to control a Permanent Magnet Synchronous Motor without sensors. The use of this system yields enhanced operations, fewer system components, lower system cost , energy efficient control system design and increased efficiency. The control method presented is field oriented control (FOC). The sinusoidal voltage waveforms are generated by the power module using the space vector modulation technique. A practical solution is described and results are given in this application Study. The performance of a Sensorless architecture allows an intelligent approach to reduce the complete system costs of digital motion control applications using cheaper electrical motors without sensors. This paper deals with an overview of sensorless solutions in digital motor control applications whereby the focus will be the new Controller without sensors and its applications.

  • PDF

A Study on the Meaning of Trace in Sugimoto Takashi's Design (스기모토 타카시의 디자인에 나타나는 흔적의 의미에 관한 연구)

  • Suh, Jeong Yeon
    • Journal of the Korea Furniture Society
    • /
    • v.26 no.1
    • /
    • pp.51-60
    • /
    • 2015
  • Interior designer Sugimoto Takashi uses salvaged material and natural thing for aesthetical purpose. These material performs not just as fun stuff but as design tool in order to set up cultural meaning which modern society always lacks for. The method of communicating the meaning is the multi-layered trace on them. There are three types of trace. They are harsh texture of surface, untrimmed outline, and gathering & arrangement. Through these formation methods of trace, Sugimoto can suggest various curtural meanings such as vanishing value of old-fashioned lifestyle, primitive energy of nature, and sincere touch of somebody. As a result, the trace in Sugimoto's design is an endeavor to exist tradition(the long ago) and nature(the far away) in here-and-now interior space.

Environmental Impact Assessment for Development Projects Considering Carbon Sink and Sequestration(II) - Focused on a Housing Redevelopment Project - (탄소흡수원을 고려한 개발사업 환경영향평가 방안(II) - 주택 재개발 사업을 중심으로 -)

  • Hwang, Sang Il;Park, Sun Hwan
    • Journal of Environmental Impact Assessment
    • /
    • v.20 no.1
    • /
    • pp.79-87
    • /
    • 2011
  • In this study, we investigated the effect of carbon sequestration and sink on the environmental impact assessment of a housing redevelopment project. Through the case study, we found that the amount of carbon sequestration and sink increased with the increase of the area of park and green space and, furthermore, the amount of carbon emission decreased slightly with implementation of district heating and renewable energy. Therefore, it is necessary for its land use plan to be established to minimize the amount of net carbon emission, taking account of both the amount of present carbon emission and the amount of the future carbon sink, sequestration, and emission.

Study on Fluid Inclusion and Genetic Modelling of Pegmatites at the Maewol Feldspar Mine (매월장석광산(梅月長石鑛山)의 페그마타이트내(內) 유체포유물(流體包有物)과 그 성인(成因)에 관한 모델 연구)

  • Moon, Kun Joo
    • Economic and Environmental Geology
    • /
    • v.21 no.4
    • /
    • pp.381-387
    • /
    • 1988
  • Maewol Feldspar Mine produces feldspar ore from pegmatites. K-Rb Age of muscovite is 137.7Ma. Fluid inclusions in quartz crystal of the pegmatite show bimodal distribution of homogenization temperatures. The high homogenization temperatures range from 290 to $302^{\circ}C$ while low homogenization temperatures range from 157 to $195^{\circ}C$. Three phases liquid $CO_2$ bearing inclusions indicate $CO_2$ gases were abundantly mixed with granitic melt until the pegmatic magma melt cooled to $290^{\circ}C$. Low density of the magmatic melt relative to the same volume of granitic magma is due to mixture of volatiles(mainly $CO_2$ gases) with the melt and larger space and slow cooling allowed to grow crystals of the pegmatic magma.

  • PDF