• 제목/요약/키워드: Energy Budget

검색결과 251건 처리시간 0.027초

임업 및 토지이용부문의 온실가스 흡수 및 배출 현황 (Greenhouse Gas Inventory in Land-Use Change and Forestry in Korea)

  • 이경학;손영모;김영수
    • 임산에너지
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    • 제20권1호
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    • pp.53-61
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    • 2001
  • 본 논문에서는 토지이용 및 임업부문에서의 온실가스 배출통계에 있어 국제기준이 되는 수정된 IPCC 가이드라인을 토대로 우리에게 적합한 산출방법을 개발하고, 이에 의해 1998US도 기준 온실가스 흡수/배출 현황을 제시하였다. 먼저 산림 및 목질계 바이오매스 변화 범주에 있어 생장에 의한 이산화탄소 흡수량은 11,911×10³탄소톤이고 벌채에 의한 배출량은 824×10³탄소톤으로서 순흡수량은 11,087×10³탄소톤었다. 두 번째로 산림의 타용도 전용시 목재를 반출하고 현지에 남아 썩게되는 바이오매스에 의한 온실가스 순배출은 82×10³탄소톤으로 미미한 수준이다. 마지막으로 토지이용변화 및 토지관리에 따른 토양에서의 총 순배출량은 1,057×10³탄소톤이며, 그 중 토지이용체계변화에 따른 무기토양의 순탄소량 변화가 1,025×10³탄소톤으로 대부분을 차지하고, 나머지 32×10³탄소톤만이 농경지에서의 석회시용에 따른 배출이었다. 결과적으로 1998년도 토지이용변화 및 임업부문의 온실가스 수지는 흡수 11,911×10³탄소톤, 배출 1,963×10³탄소톤로서 순흡수 9,948×10³탄소톤이었으며, 이는 같은 해 우리나라의 에너지 연소에 따른 배출량 103,601×10³탄소톤의 9.6%에 해당한다.

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에너지 관점에서 임베디드 자바가상기계의 메모리 접근 형태 (Memory Access Behavior of Embedded Java Virtual Machine in Energy Viewpoint)

  • 양희재
    • 정보처리학회논문지A
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    • 제12A권3호
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    • pp.223-228
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    • 2005
  • 임베디드 시스템에서 일반적으로 메모리가 가장 많은 에너지를 소비하는 것으로 알려지고 있다. 임베디드 자바가상기계의 경우도 마찬가지이며, 따라서 보다 에너지 효율이 높은 자바가상기계의 개발을 위해서는 자바 메모리의 에너지 사용을 최적화 하는 것이 무엇보다 중요하다. 본 논문에서는 자바 프로그램 실행 시 수많은 바이트코드들이 어떻게 논리적 메모리를 접근하는지 분석하였다. 이런 접근 형태 분석은 자바 메모리의 설계 및 구현 기술을 선택하는데 큰 통찰력을 제공해 준다 힙, 오퍼랜드 스택, 지역변수배열 등 세 가지 논리적 데이터 공간에 대해 각각 메모리 접근을 분석하였으며, 분석 결과 오퍼랜드 스택이 가장 빈번하게, 또한 균일하게 사용되었으며 힙이 가장 드물게, 그리고 불균일하게 사용되었음을 알 수 있었다. 힙과 지역변수배열은 읽기 위주로 사용되었으며, 오퍼랜드 스택은 읽기와 쓰기 비율이 크게 다르지 않았다.

Target-Moderator-Reflector system for 10-30 MeV proton accelerator-driven compact thermal neutron source: Conceptual design and neutronic characterization

  • Jeon, Byoungil;Kim, Jongyul;Lee, Eunjoong;Moon, Myungkook;Cho, Sangjin;Cho, Gyuseong
    • Nuclear Engineering and Technology
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    • 제52권3호
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    • pp.633-646
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    • 2020
  • Imaging and scattering techniques using thermal neutrons allow to analyze complex specimens in scientific and industrial researches. Owing to this advantage, there have been a considerable demand for neutron facilities in the industrial sector. Among neutron sources, an accelerator driven compact neutron source is the only one that can satisfy the various requirements-construction budget, facility size, and required neutron flux-of industrial applications. In this paper, a target, moderator, and reflector (TMR) system for low-energy proton-accelerator driven compact thermal neutron source was designed via Monte Carlo simulations. For 10-30 MeV proton beams, the optimal conditions of the beryllium target were determined by considering the neutron yield and the blistering of the target. For a non-borated polyethylene moderator, the neutronic properties were verified based on its thickness. For a reflector, three candidates-light water, beryllium, and graphite-were considered as reflector materials, and the optimal conditions were identified. The results verified that the neutronic intensity varied in the order beryllium > light water > graphite, the compacter size in the order light water < beryllium < graphite and the shorter emission time in the order graphite < light water < beryllium. The performance of the designed TMR system was compared with that of existing facilities and were laid between performance of existing facilities.

옥상녹화 적용확대를 위한 녹색건축인증제도 개선방안 연구 - 미국 LEED 및 영국 BREEAM의 비교·분석을 중심으로 - (Study on Improvement Measures of Green Standard for Energy and Environmental Design for Expansion of Applying Green Roof - Focused on LEED in the USA and BREEAM in the UK -)

  • 김지현;권혁삼;김정곤;이범식
    • 대한건축학회논문집:구조계
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    • 제34권2호
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    • pp.75-82
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    • 2018
  • Green roof in Korea has been recognized as part of landscape area and local governments enacted municipal ordinance for supporting green roof thereby assisting part of expenses spent for green roof within a range of budget for buildings which are eligible for the green roof support of existing buildings. However, it is necessary to enforce a regulation of mandatory green roof for new buildings in order to expand green roof application and provide a variety of assistances such as subsidy payment, tax relief, and mitigation of floor area ratio-related regulation as done in other advanced nations. In particular, LEED(Leadership in Environmental and Energy Design) in the USA applies additional point directly for green roof in terms of the reduction in heat island effects. For example, the following items are beneficial to have additional points: habitat preservation or restoration, external space, rainwater management, reduction in outdoor water usage, minimum energy performance, and optimum energy performance. In addition, the BREEAM(Building Research Establishment Environmental Assessment Method) in the UK specifies green roof as one of assessment items to be complied in terms of diversity of species. As such, LEED and BREEAM reflect direct and indirect effects of green roof on assessment criteria, which suggest a direction to green building certification criteria in Korea where only additional points are given for green roof according to soil depth.

CEOP Annual Enhanced Observing Period Starts

  • Koike, Toshio
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2002년도 Proceedings of International Symposium on Remote Sensing
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    • pp.343-346
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    • 2002
  • Toward more accurate determination of the water cycle in association with climate variability and change as well as baseline data on the impacts of this variability on water resources, the Coordinated Enhanced Observing Period (CEOP) was launched on July 1,2001. The preliminary data period, EOP-1, was implemented from July to September in 2001. The first annual enhanced observing period, EOP-3, is going to start on October 1,2002. CEOP is seeking to achieve a database of common measurements from both in situ and satellite remote sensing, model output, and four-dimensional data analyses (4DDA; including global and regional reanalyses) for a specified period. In this context a number of carefully selected reference stations are linked closely with the existing network of observing sites involved in the GEWEX Continental Scale Experiments, which are distributed across the world. The initial step of CEOP is to develop a pilot global hydro-climatological dataset with global consistency under the climate variability that can be used to help validate satellite hydrology products and evaluate, develop and eventually predict water and energy cycle processes in global and regional models. Based on the dataset, we will address the studies on the inter-comparison and inter-connectivity of the monsoon systems and regional water and energy budget, and a path to down-scaling from the global climate to local water resources, as the second step.

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스팬방향 슬롯을 가지는 회전익 끝와류의 특성 (Characteristics of Rotor Blade Tip Vortices with Spanwise Slots)

  • 정운진;한용운
    • 대한기계학회논문집B
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    • 제24권10호
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    • pp.1343-1350
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    • 2000
  • The evolutionary structure of tip vortices has been investigated with a two-dimensional LDV system for a plain and a slotted blade, respectively. To analyze the effect of slots which bypasses a part of main stream into the tip face, velocity profiles, vortex sizes, their displacements and turbulence intensities during one revolution of the rotor were measured by the phase averaging process. For the comparison of circumferential velocity components of the plain blade and the slotted blade, the peak values of the slotted blade were lower than those of the plain blade, and axial velocity components of the slotted blade were considerably larger than those of the plain blade. The slotted rotor blade enlarged the core size and made the vortex delayed compared with those of the plain blade at the same wake ages. Turbulence profiles had peaks inside the core radii and decayed gradually in the radial direction of vortex coordinate. Also, using a quasi 3-D LDV measurement technique the budget of turbulence kinetic energy was analyzed in radial direction of the vortex core.

MCDM에 의한 환경오염 기여도 순위평가 및 적용 (Prioritization of Environmental Contribution by Region through MCDM)

  • 김종달
    • 자원ㆍ환경경제연구
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    • 제13권2호
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    • pp.245-269
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    • 2004
  • 환경보전 활동을 위한 노력도 교부금과 같은 예산의 지역간 배분에 있어 감안이 되어야 하는데 그렇지 못하고 있다. 개발활동만 기준하여 지원되고 있다. 본 연구의 주된 목적은 환경변수를 예산 배분정책에 반영할 수 있는 방법을 개발하고 이를 실제로 적용하는데 있다. 본 연구는 각 지역별 환경에 미치는 다양한 변수들을 고려하여, 지역간 환경 기여도의 평가방법론을 개발하고 검증하였다. 최대최소법, 최대최대법, 단순가중치법, 계층가중치법과 같은 네 가지 방법론을 적용하여, 대구시의 환경 기여도를 평가해 본 결과, 극단적 상황이 예상되지 않는 조건 하에서 단순가중치법과 계층가중치법을 우선해서 대구시 환경 기여도를 분석할 수 있었다. 이른 기준을 감안한 예산배분은 개발에 치중된 재정지원에서 환경적으로 건전한 지역개발을 유도하는데 기여할 것으로 기대한다.

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MIMO Techniques for Green Radio Guaranteeing QoS

  • Nicolaou, Marios;Han, Congzheng;Beh, Kian Chung;Armour, Simon;Doufexi, Angela
    • Journal of Communications and Networks
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    • 제12권2호
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    • pp.130-139
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    • 2010
  • Environmental issues and the need to reduce energy consumption for lowering operating costs have pushed power efficiency to become one of the major issues of current research in the field of wireless networks. This paper addresses a number of multiple input multiple output (MIMO) precoding and scheduling techniques across the PHY and MAC layers that can operate under a reduced link budget and collectively improve the transmit power efficiency of a base station, while maintaining the same levels of service. Different MIMO transmission and precoding schemes proposed for LTE, achieving varying degrees of multiuser diversity in both the time, frequency as well as the space domain, are examined. Several fairness-aware resource allocation algorithms are applied to the considered MIMO schemes and a detailed analysis of the tradeoffs between power efficiency and quality of service is presented. This paper explicitly examines the performance of a system serving real-time, VoIP traffic under different traffic loading conditions and transmit power levels. It is demonstrated that by use of efficient scheduling and resource allocation techniques significant savings in terms of consumed energy can be achieved, without compromising QoS.

유속조건에 따른 수중 생태계내 소형어류의 동물플랑크톤 포식 행동 변화에 관한 연구 (Effect of Water Velocity on Foraging Behavior of Planktivore on Zooplankton in Aquatic Ecosystems)

  • 박배경;박석순
    • 한국물환경학회지
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    • 제21권1호
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    • pp.79-83
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    • 2005
  • Foraging behaviour of false dace, Pseudorasbora parva, was investigated in water flowing at various velocities with the existence of a cavity for rest. The pursuit comprised three succeeding processes such as, approaching, chasing and attacking. Angles between the fish body and the water flow direction and swimming speeds increased in the latter stages of approaching, chasing and attacking. All pursuit angles, swimming speeds and distances increased with flow velocity and peaked at the flow velocity of 7 cm/sec. At higher velocities, however, the fish avoided the use of much energy against the large drag force. The probability of capture and the feeding rate steadily decreased with increasing flow velocity. Under the fast flow, the fish adjusted their swimming speed to get the optimum velocity relative to the flowing water for the energetic budget. Fish spent more time in the cavity as flow velocity increased to avoid the energy expenditure necessitated by the high velocity.

마이크로웨이브 플라즈마를 이용한 탄화공정 및 PAN fiber의 강도 향상에 관한 연구 (A Study on the Carbonization and Strengthening of PAN Fiber by Microwave Plasma)

  • 최지성;주정훈;이헌수
    • 한국표면공학회지
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    • 제45권2호
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    • pp.89-94
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    • 2012
  • A study to replace a high temperature thermal carbonization process with microwave plasma process is carried for PAN fiber as a starting material. Near atmospheric pressure microwave plasma (1 Torr~45 Torr) was used to control to get the fiber temperature up to $1,000^{\circ}C$. Even argon is an inert gas, its plasma state include high internal energy particles; ion (15.76 eV) and metastable (11.52 eV). They are very effective to lower the necessary thermal temperature for carbonization of PAN fiber and the resultant thermal budget. The carbonization process was confirmed by both EDS (energy dispersive spectroscopy) of plasma treated fibers and OES (optical emission spectroscopy) during processing step as a real time monitoring tool. The same trend of decreasing oxygen content was observed in both diagnostic methods.