• 제목/요약/키워드: Lead Shift

검색결과 205건 처리시간 0.03초

Precursor Events in Environmentally Assisted Cracking Behaviour of Light Metals

  • Raja, V.S.
    • Corrosion Science and Technology
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    • 제15권4호
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    • pp.153-158
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    • 2016
  • Light metal alloys of Mg, Ti, and Al undergo environmentally assisted cracking (EAC). Passive film breakdown and pitting are not only precursor events for stress corrosion, but can accelerate hydrogen evolution that is responsible for hydrogen embrittlement. This is clearly demonstrated in the case of Mg and Ti alloys. The so-called innocuous precipitates, which do not directly participate in either alloy strengthening or EAC can be effective precursors for initiating EAC. This aspect is highlighted using high strength aluminium alloys. Such behaviours lead to a paradigm shift in the design of alloys with resistance to EAC.

순차적으로 출발하는 여객노선에서 고객의 의사결정을 고려한 좌석재고 통제문제에 대한 모의실험 분석 (Simulation Experimental Analysis on a Seat Inventory Control Problem for Sequential Multiple Flights with Customer Choice Behavior)

  • 박창규;서준용;홍윤숙
    • 경영과학
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    • 제30권1호
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    • pp.1-14
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    • 2013
  • We conduct the future studies suggested by Park and Seo [3]. They considered a seat inventory control problem in which flights depart sequentially during a similar time-interval and passengers purchase available seats depending on individual customer choice behavior. Customer choice behavior can lead to one among a horizontal shift, a diversion-up, and a booking loss when a desired fare class is unavailable. We investigate how seat availability calculation method, booking limit control mechanism, seat inventory capacity, number of booking class, type of seat demand influence on revenues in an airline industry through thorough computer simulation experiments.

통신요금변동의 가격파급효과분석

  • 장석윤
    • ETRI Journal
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    • 제6권4호
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    • pp.9-20
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    • 1984
  • Communications is becoming a vital sector to lead Information Society in the nearfuture. In that sense the price system of its services is now being discussed seriously among the people who are directly and indirectly related to communications development. Input-Output analysis model developed by W. Leontief in early 1930's is a very useful tool to measure the price linkage effects in the national economy, which would be induced from the shift of a certain sector's price. 1980's I-0 table with 19 sectors is rear-ranged and applied to price analysis model, in which communications is treated as a exogenous sector, to see the price impacts generated from a change of telephone rate. With the results of this study, the authorities concerned with price policy can make their decisions more reasonable.

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의과대학생이 만날 미래, 어떻게 준비할 것인가? (How Should Medical Education Be Planned for Medical Students' Future?)

  • 정지훈
    • 의학교육논단
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    • 제16권3호
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    • pp.141-146
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    • 2014
  • This study focused on investigating the future medicine and health care industry paradigm shift and suggesting the right direction for the medical education system in order for students to be better prepared in the near future. Here, I will discuss four issues related to the future of medicine: Health 2.0, digital health, personalized medicine, and innovations of the public healthcare system. Every issue has lessons for medical education and teaching for students who major in health professions. However, it is obvious that the present is an important period of time as, currently, we are at an early stage in the future health care environment. Recently, there have been rapid transformations in various fields of medicine. Therefore, if we fail to lead medical education in the right direction, medical students will suffer from major problems in coping with these changes.

납-면진받침을 이용한 교량의 면진설계 (Seismic Isolation Design for Bridges on Lead-Rubber Bearings)

  • 이철희
    • 한국지진공학회:학술대회논문집
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    • 한국지진공학회 1999년도 춘계 학술발표회 논문집 Proceedings of EESK Conference-Spring
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    • pp.161-168
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    • 1999
  • The concept of seismic design was induced in our country which was poor in it for the scarcity of recognition and insufficiency of funds. Recently many specialists are enforcing the provisions of seismic design. But because seismic force of seismic design is very great and all the seismic force are concentrated on the fixed bearings and substructure the bearings are the seismic force are concentrated on the fixed bearings and substructure the bearings are destroyed so that seismic design lose its basic concept. In addition when the earthquake which exceeds seismic design force takes place the bridge is collapsed. For these reasons the developed seismic isolation design concept was appeared which diminishes seismic force itself by period shift and additional damping distributes it to each superstructures evenly. Therefore this study introduced the method which combines PC-LEADeR(design program for L.R.B) with SAP 2000(linear elastic analysis) and performs the seismic isolation design more elaborately and simply verified the propriety of that method and examined the force control of L. R. B.

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슬라이딩 모드를 이용한 차량 간격 자동 제어 알고리즘에 관한 연구 (A Study on the Autonomous Cruise Control using the Sliding Mode)

  • 이동현;장광수
    • 한국자동차공학회논문집
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    • 제8권2호
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    • pp.92-101
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    • 2000
  • The objective of this paper is to design the controller for longitudinal vehicle following which makes the vehicle follow the lead vehicle and keeps a safety distance without human driver operation. This paper presents a sliding mode control algorithm for the ACC system. The controller is based on three sliding surfaces. Each surface plays an individual control-deviation control, throttle control and brake control. In addition to sliding mode control, we propose some additional schemes to enhance controller performance. The first one is a gear shift-down controller which makes tractive force increase with a change of gear ratio. The other is a predictive correction method which reduces slinky effect.

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직교 주파수 분할 다중(OFDM) 시스템에서 반송파 위상 최적화 기반의 사이드로브 억압 기법 (Sidelobe Suppression Technique in OFDM System Based on Phase Optimization of Subcarriers)

  • 황유모
    • 전기학회논문지
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    • 제58권11호
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    • pp.2286-2291
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    • 2009
  • We propose a phase optimization technique for sidelobe suppression in OFDM system. The technique is based on idea that phase shift to some of the transmit symbols within the symbol constellation plane can lead to significant sidelobe suppression. The sidelobes are reduced by optimizing using iterative method the phases of some subcarriers on the left and right hand side of the used OFDM spectrum. The proposed technique requires a small amount of side information that needs to be transmitted. Simulation results show that the proposed technique can reduce the sidelobes by significant amount.

연속 저속 원자빔을 이용한 세슘 주파수 표준기 (Cesium Frequency Standard Based on a Continuous Slow Atomic Beam)

  • 이호성;박상언;권택용;양성훈;조혁
    • 한국광학회:학술대회논문집
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    • 한국광학회 2000년도 하계학술발표회
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    • pp.194-195
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    • 2000
  • Laser-cooled slow atoms can lead to a considerable improvement in both the accuracy and the frequency stability of atomic frequency standards. Most of the developed frequency standards with the slow atoms use atomic fountain scheme that includes pulsed atomic beam. Although this type of frequency standard has already demonstrated the accuracy about 10$^{-15}$ level$^{(1)}$ , a continuous beam of slow atoms may become an alternative approach, because the pulsed operation of the atomic fountain has some drawbacks such as the collisional shift and the limitation in the short-term frequency stability. (omitted)

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보건의료분야에서 4차산업혁명, 어떻게 대처할 것인가? (How to Integrate the Fourth Industrial Revolution in the Healthcare Industry?)

  • 이선희
    • 보건행정학회지
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    • 제33권1호
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    • pp.1-2
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    • 2023
  • As the industrial paradigm shift, often condensed as the "4th Industrial Revolution," gains momentum, there is a growing need to actively introduce digital healthcare into the medical field. The new administration announced its commitment to become a global leader in the biohealth and digital healthcare sector. To fulfill this pledge, preemptive policy leadership and attention from the government are required. The recent issue of legislating non-face-to-face medical care suggests that introducing digital healthcare goes beyond simply adopting new technologies. Incorporating digital healthcare involves changing the existing healthcare delivery process and coordinating the roles of stakeholders. To successfully change the structure of the medical industry, a mid- to long-term roadmap should be meticulously organized and promoted. Policy efforts are needed to resolve conflicts and lead to compromises through continuous communication with interest groups.

인터뷰 - 건축산업으로의 '패러다임 시프트', 경쟁력 강화에 앞장 (Interview - 'Paradigm shift' to the construction industry, taking the lead in strengthening competitiveness)

  • 육혜민
    • 건축사
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    • 통권633호
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    • pp.34-37
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    • 2022
  • '건축공간연구원(auri)'은 2007년 대통령 지시로 설립된 최초의 건축·도시 분야 정부 출연 연구기관(건축도시공간연구소)으로 출발, 2020년 국무총리실 산하 국토연구원 부설기관에서 독립법인화를 거쳐 '건축공간연구원(이하 아우리)'으로 새롭게 출범했다. 우리나라 건축·도시분야 정책 현안과 중장기 비전 수립 연구 역할을 하고 있으며, 그런 까닭에 국내 모든 건축, 도시정책 배경에 아우리의 연구활동이 뒷받침돼 있다 해도 과언이 아니다. 아우리는 앞으로 건축 도시공간분야 대표 국책연구기관으로서의 체질 개선과 역할에 대한 중장기 계획을 마련하고, 그에 따른 정책연구 방향 수립 및 연구원 구성원 참여에 기반한 연구관리와 경영체계 모니터링을 지속 실행하겠다는 계획이다. 월간 <건축사>가 지난 2021년 12월 13일 이영범 도시건축공간연구원장을 직접 만나 이야기를 나눴다.

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