• 제목/요약/키워드: Transport part

검색결과 679건 처리시간 0.027초

Analysis of fluctuations in ex-core neutron detector signal in Krško NPP during an earthquake

  • Tanja Goricanec;Andrej Kavcic;Marjan Kromar;Luka Snoj
    • Nuclear Engineering and Technology
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    • 제56권2호
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    • pp.575-600
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    • 2024
  • During an earthquake on December 29th 2020, the Krško NPP automatically shutdown due to the trigger of the negative neutron flux rate signal on the power range nuclear instrumentation. From the time course of the detector signal, it can be concluded that the fluctuation in the detector signal may have been caused by the mechanical movement of the ex-core neutron detectors or the pressure vessel components rather than the actual change in reactor power. The objective of the analysis was to evaluate the sensitivity of the neutron flux at the ex-core detector position, if the detector is moved in the radial or axial direction. In addition, the effect of the core barrel movement and core inside the baffle movement in the radial direction were analysed. The analysis is complemented by the calculation of the thermal and total neutron flux gradient in radial, axial and azimuthal directions. The Monte Carlo particle transport code MCNP was used to study the changes in the response of the ex-core detector for the above-mentioned scenarios. Power and intermediate-range detectors were analysed separately, because they are designed differently, positioned at different locations, and have different response characteristics. It was found that the movement of the power range ex-core detector has a negligible effect on the value of the thermal neutron flux in the active part of the detector. However, the radial movement of the intermediate-range detector by 5 cm results in 7%-8% change in the thermal neutron flux in the active part of the intermediate-range detector. The analysis continued with an evaluation of the effects of moving the entire core barrel on the ex-core detector response. It was estimated that the 2 mm core barrel radial oscillation results in ~4% deviation in the power and intermediate-range detector signal. The movement of the reactor core inside baffle can contribute ~6% deviation in the ex-core neutron detector signal. The analysis showed that the mechanical movement of ex-core neutron detectors cannot explain the fluctuations in the ex-core detector signal. However, combined core barrel and reactor core inside baffle oscillations could be a probable reason for the observed fluctuations in the ex-core detector signal during an earthquake.

콩의 엽-협 비율 조절에 따른 탄소와 질소의 전류 (Carbon-Nitrogen Transport in Response to Control of Leaf-Pod Ratio in Soybean)

  • 성락춘;강병화;박세준
    • 한국작물학회지
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    • 제39권6호
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    • pp.594-601
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    • 1994
  • 콩의 생식생장기인 착협시(R3)에 상부 50%와 하부 50%로 구분하여 엽제거 및 엽-협제거처리 하여 줄기, 엽 및 종실건물중과 가용성 당, 전분 및 단백질함량에 미치는 영향을 구명하기 위하여 1990년과 1991년에 고려대학교 자연자원대학 덕소 농장에 팔달콩, 백운콩 및 단엽콩을 공시하여 실시한 시험결과를 요약하면 다음과 같다. 1. 팔달콩, 백운콩 및 단엽콩 모두 건물축적과 가용성 당, 전분 및 단백질함량에 처리간 같은 경향을 보였다. 2. 평균 줄기건물중은 상엽-하협제거와 하엽-상협제거로 높았고 상엽제거와 하엽제거는 낮았다. 3. 엽건물중은 처리중에서 상부엽이 높은 경향을 나타냈다. 4. 종실수와 종실건물중은 엽 및 엽-협제거로 감소되었으나 하엽제거와 하엽-상협제거의 하부에서 높았다. 5. 가용성 당과 전분함량도 처리중에서 하부종실에서 높은 경향이었다. 6. 단백질함량은 상엽제거의 상부와 하엽제거의 하부에 감소되었으나 하엽제거의 상부종실에서 가장 높았다.

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고속도로 VMS Message Set 연구 및 이용자 선호도 평가 (A Study on Message Set of VMS on Express way and Evaluation of Driver's Preference)

  • 김남선;지동목;오영태;이환필;김상복
    • 한국ITS학회 논문지
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    • 제8권4호
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    • pp.1-13
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    • 2009
  • 도로전광표지(VMS;Variable Message Sign)는 지능형교통시스템의 세부시스템중 하나로 도로이용자에게 실시간으로 교통정보를 제공하여 교통흐름을 원활하게 하는 기능을 가지고 있다. 그러나 현재 고속도로 구간의 VMS운영현황을 조사한 결과, 현시운영측면에서 메시지판독횟수가 정의되지 않아 적정현시운영에 어려움이 있으며, 정보제공측면에서 VMS 설치구간의 특성고려가 미흡하여 운전자의 혼란을 유발시키는 문제점이 드러났다. 세부적으로 문안표출시 글자체(Font), 표출전환방식, 정렬방식, 표출메시지 구성의 통일성이 결여되어 있고 불필요한 단어사용과 통일되지 않은 동일의미의 여러 용어를 사용하는 등 효과적인 정보전달체계에 개선이 필요한 것으로 분석되었다. 이에 본 연구는 VMS 운영관련지침 및 연구분석결과를 토대로 VMS 설치위치별 요구기능과 적정현시수의 정의 등의 효율적인 표출방안을 수립하였다. 세부표출방안으로 제공글자체, 메시지 전환방식, 정렬방식을 통일하였고, 운전자의 직관적인 메시지 판독이 가능하도록 상황별로 표출색상을 정의하였다. 본 연구에서 제시한 개선안의 평가를 위해 일반운전자들을 대상으로 기존안과 개선안의 선호도평가와 통계분석을 실시하였다.

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표준규격 교통신호제어기에서 TCP/IP 통신프로토콜 제정방안 연구 (A Study on Developing the TCP/IP Application Communication Protocol for the Standard Traffic Signal Controller)

  • 한원섭;현철승;이호원;주두환;이철기
    • 한국ITS학회 논문지
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    • 제8권5호
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    • pp.71-84
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    • 2009
  • 교통신호제어기의 표준규격에서 센터시스템과 지역제어기 간 통신방식은 전용선을 기준으로 한 모뎀방식의 시리얼통신으로 규정되어 있어, 지방도시에서 구축 운영되는 TCP/IP의 ITS 통신망에 내에 교통신호제어시스템에 대한 통신규격을 수용하지 못하고 있는 실정이다. 또, ITS 부문에서 데이터 교환을 위한 국내외 표준으로 이더넷 통신망을 기반으로 한DATEX-ASN 데이터 교환기술이 채택되고 있다. 따라서 본 연구는 교통신호제어시스템이 ITS 통신망 내에 구성이 가능하도록, TCP/IP 프로토콜을 기반으로 한 교통신호제어기 통신규격(안)을 개발을 목적으로 한다. 제어, 상태정보와 데이터 베이스 정보 등 표준규격 교통신호제어기의 23개 통신항목에 대한 통신규격(안)이 DATEX-ASN 통신처리 절차 및 구조 (KS ISO X 14827 Part1, 2, ISO/ DIS 15784 Part-3)를 적용하여 개발하였다. 실험을 위하여 통신항복별로 응용프로그램을 개발하였으며, 실험결과 통신항목 모두 인코딩 및 디코딩처리가 가능하였다.

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『중국경극복장도보(中國京劇服裝圖譜)』의 의(衣) - 한중 연극의 비교학적 관점에서 접근한 해제와 역주 (CHINA COSTUME ART OF PEKING OPERA: Analytical&its translation)

  • 조만호;정유선
    • 비교문화연구
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    • 제22권
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    • pp.223-277
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    • 2011
  • Tan Yuanjie(譚元杰) of CHINA COSTUME ART OF PEKING OPERA("中國京劇服裝圖譜") is 'Foreword' attention from the bar 'Formalism'. A note is makeup system from ever performances here, 'what kind of adaptation must be a corresponding type of costume should be worn.' This stance to 'type of person's identity and faced the scene correlated' with the actual performance tradition plays out is going and, while here the rules to capture the opera's on the character of 'identity and the circumstances under clothing' is defined. This position discussed previously 'Formalism' in line with the will he perform, and looks to meet the elements of production. This basic stance is clean up, while 'Old Beijing Opera costumes costumes taxonomy largely' literary costume' and 'militant outfit' into two groups divided over throughout steamroll surgery, because surely need to have a more systematic classification. The classification system was established as 'Part 1. Mang, Part 2. Pi, Part 3. Xi, Part 4. Kao, Part 5. YI'. In addition to these classification systems, as well as the aforementioned 'object theory' Given the symbolic significance of the capacity to keep in mind is necessary. Costumes conduct, character, situation, atmosphere and so the transport of charged symbols here, a target symbol of the system is the projection of water. This costume is detrimental to the mall for the positionsay, but I kept in mind damwongeolyi internationalization of Chinese culture. when you see the view from the perspective of semiotic systems for the sign, that the theater is necessary to complement. In this paper, 'Yi(衣)' costume on the corresponding point of the target compared to the China Culture Department of Theatre and Folklore methodology ran off and sprinting was to lay the groundwork for research.

스마트냉동컨테이너의 적재부 온도 편차 최적화에 관한 연구 (A Study on the Optimization of Temperature Deviation of Loads in Smart Reefer Container)

  • 박상원;김태훈;박도명;한동섭
    • 한국산업정보학회논문지
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    • 제28권6호
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    • pp.83-90
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    • 2023
  • 냉동컨테이너는 외부 환경에 의해 냉동기가 있는 적재부의 전면과 컨테이너 문이 있는 적재부의 후면부 사이에 온도 편차가 발생한다. 특히, 신선화물 운송에서 이러한 온도 편차는 화물의 신선도에 큰 영향을 미치게 된다. 본 연구에서는 온도 편차를 줄이기 위해 T-Floor를 부분적으로 차폐하고, T-Floor 차폐율이 냉동컨테이너 적재부 온도 변화에 미치는 영향을 평가하여 온도 편차를 최소화하는 방법을 제안한다. 실험 대상은 40 feet 스마트 냉동컨테이너로 T-Floor 차폐율은 0%, 50%, 60%, 70%, 80%로 설계 변수를 설정하였다. 실험 결과, 차폐율에 따라 냉동컨테이너 적재부의 온도 편차가 다르게 발생하였으며, 차폐율 60%인 경우 온도 편차가 가장 균일한 것을 확인했다. 이러한 적재부 온도 편차 최소화를 통해 스마트 냉동컨테이너를 이용하여 신선 화물의 운송 시 화물의 부패 및 냉해를 예방할 수 있다.

변환기(變換期)에 있어서의 국제민간항공기구(國際民間航空機構)(ICAD)와 항공법(航空法) 발전(發展)의 최근(最近) 동향(動向) (The International Civil Aviation Organization and Recent Developments of Air Law in a Changing Environment)

  • 최완식
    • 항공우주정책ㆍ법학회지
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    • 제4권
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    • pp.7-35
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    • 1992
  • The expansion of air transport on a global scale with ever increasing traffic densities has brought about problems that must be solved through new multilateral mechanisms. Looking to the immediate future, air transport will require new forms of international cooperation in technical and economic areas. Air transport by its very nature should have been a counterforce to nationalism. Yet, the regulatory system in civil aviation is still as firmly rooted in the principle of national sovereignty as when it was first proclaimed at t-11e Paris Convention of 1919 and reaffirmed in the Chicago Convention. Sovereignty over the airspace has remained the cornerstone of relations between states in all respects of air transport. The importance of sovereignty over air space embodied in article 1 of the Chicago Conrenton also is responsible for restricting the authority of ICAO as an intergovernmental regulatory agency. The Orgenization, for all its extensive efforts, has only limited authority. ICAO sets standards but cannot enforce them; it devises solutions but cannot impose them. To implement its rules ICAO most rely not so much on legal requirements as on the goodwill of states. It has been forty-eight years since international community set the foundations of the international system in civil aviation action. Profound political, economic and technological changes have taken place in air transport. The Chicago Convention is living proof that staes can work together to make air transport a safe mode of travel. The law governing international civil auiation is principally based on international treaties and on other regulation agreed to by governments, for the most part through the mechanism of ICAO. The role of ICAO international standards and recommended practices and procedures dealing with a broad range of technical matters could hardly be overestimated. The organization's ability to develop these standards and procedures, to adapt them continuously to the rapid sate of change and development of air transport, should be particularly stressed. The role of ICAO in the area of the development of multilateral conventions on international air law has been successful but to a certain degree. From the modest starting-point of the Tokyo Convention, we have seen more adequate international instruments prepared within the scope of ICAO activities, adopted: the Hague Convention of 1970 for the suppression of Unlawful Seizure of Aircraft and the Montreal Convention of 1971 for the Suppression of Unlawful Acts against the Safety of Civil Aviation. The work of ICAO in the new domain of international law conventions concerning what has been loosely termed above as the criminal problems connected with international air transport, in particular the problem of armed aggression against aircraft, should be positively appreciated. But ICAO records in the domain of developing a uniform legal system of international carriage by air are rather disappointing. The problem of maintaining and developing the uniformity of this regulation exceeds the scope of interest and competence of governmental transport agencies. The expectations of mankind linked to it are too great to give up trying to restore the uniform legal system of international air carriage that would create proper conditions for its further growth. It appears that ICAO has, at present, a good opportunity for doing this. The hasty preparation of ICAO draft conventions should be definitely excluded. Every Preliminary draft convention ought to be sent to Governments of all member-States for consideration, So that they could in form ICAO in due time of their observation. The problom of harmonizing a uniform law of international air carriage with that of other branches of international transport should demand more and more of its attention. ICAO cooperation with other international arganization, especially these working in the field of international transport, should be strengthened. ICAO is supposed to act as a link and a mediator among, at times the conflicting interests of member States, serving the happiness and peace of all of the world. The transformation of the contemporary world of developing international relations, stimulated by steadily growing international cooperation in its various dimensions, political, economic, scientific, technological, social and cultural, continuously confronts ICAO with new task.

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가막만의 COD 거동 및 분포 특성 평가를 위한 생태계 모델링 (Ecological modeling for estimation of a transport and distribution of COD in Kamak Bay)

  • 김동명
    • 한국환경과학회지
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    • 제14권9호
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    • pp.835-842
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    • 2005
  • The three-dimensional eco-hydrodynamic model was applied to estimate the physical process in terms of COD (chemical oxygen demand) and net supply(or decomposition) rate of COD in Kamak Bay to find proper management plan for oxygen demanding organic matters. The estimation results of the physical process in terms of COD showed that transportation of COD is dominant in surface level while accumulation of COD is dominant in bottom level. In the case of surface level, the net supply rate of COD was 0 -0.50 mg/m2/day. The net decomposition rate of COD was 0 -0.04 mg/m2/day in middle level(3 -6m) and 0.05 -0.1 5 mg/m2/day in bottom level(6m -bottom). These results indicates that the biological decomposition and physical accumulation of COD are occurred predominantly at the northern part of bottom level. Therefore, it is important to consider both allochthonous and autochthonous oxygen demanding organic matters in the region.

항공기 시스템 설계와 안전성평가에 운영경험 반영 사례 연구 (A Study on the Application of Operational Experience in the Stage of Aircraft System Design and Safety Assessment)

  • 구민성
    • 한국항공운항학회지
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    • 제22권2호
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    • pp.34-39
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    • 2014
  • Airworthiness authorities specify the technical standards of airworthiness that propose minimum requirement of the commercial transport category and apply the rules in the certification process to ensure the safety of the aircraft. The Federal Aviation Administration and other national airworthiness authorities define the fatal accident risk levels for the safety assessment of the aircraft system and establish standard procedures to apply both qualitative and quantitative analysis techniques. However, an accident or incident may occur by the combination of various factors, although the aircraft is designed in accordance with the strict standards and approval by the Airworthiness Authorities. There are some key factors, such as human error, unpredictable complex system failures, degradation of the components reliability, improper maintenance task and intervals. Risk can be reduced by reflecting aircraft operational experience with similar types of aircraft in the process of aircraft development and safety assessment. Result of the root cause analysis for the Airbus A300-600 incident in which the aircraft engine reverser was deployed in the air have been introduced to reflect the design of system and related components. Also, this paper suggests to create a big-database in order to provide a feed-back to the FAR Part 25 transport category design and safety assessment of the operational experience.

과수원용 스프레이어의 농약 살포 및 비산 예측을 위한 전산유체해석 (CFD Modeling of Pesticide Flow and Drift from an Orchard Sprayer)

  • 홍세운;김락우
    • 한국농공학회논문집
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    • 제60권3호
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    • pp.27-36
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    • 2018
  • Effective pesticide applications are needed to assure the quality and economic competitiveness of fruit production and lower the risk of spray drift. Experimental studies have shown that better spray coverage and less driftability require an understanding of the transport of spray droplets within turbulent airflows in the orchard and the interaction between droplet dynamics and tree canopies. This study developed a computational fluid dynamics (CFD) model to predict pesticide flows in the orchard and spray drift discharged from an air-assisted orchard sprayer. The model represented the transport of spray droplets as well as droplets captured by tree canopies, which were modeled as a conical porous model and branched tree model. Validation of the CFD model was accomplished by comparing the CFD results with field measurements. Spray depositions inside tree canopies and at off-target locations were in good agreement with the measurements. The resulting data presented that 38.6%~42.3% of the sprayed droplets were delivered to the tree canopies while 13.6%~20.1% were drifted out of the orchard, part of them reached farther than 200 m from the orchard. The study demonstrates that CFD model can be used to evaluate spray application performance and spray drift potential.