• Title/Summary/Keyword: 항공 수요

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Geo-Morphological Study of Sand Dune for Railway Project in UAE (UAE 내 철도프로젝트 수행을 위한 사막 사구의 지형학적 특성 연구)

  • Moon, Joon-Shik;Kim, Jae-Young;Lee, Seung-Bok
    • Journal of the Korean Geotechnical Society
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    • v.28 no.9
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    • pp.17-22
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    • 2012
  • Wind blown sand is expected to disrupt the operation of the railway as the presented railway project in this paper consists of large earthworks in extreme topography of the mega dune fields. For successful railway construction in sand dune area, effective mitigation measure is the most important factor to protect the track from wind blown sand. The effective mitigation measure requires an integrated consideration of the earthworks geometry and the direct control measures such as fence system. Basically there's no perfect measure protecting railway track from wind blown sand, and it would be more economical and effective to develop robust, deliberate maintenance program for track and direct control measure on the basis of geo-morphological study. The purpose of this study is to identify the large scale geo-morphological terrains and specific sand dune morphology in the project area in UAE and estimate the direction and migration rate for sand dunes with the local variations in prevailing wind directions by undertaking literature review, and aerial photographs, satellite images, and ground studies.

Analysis of Crash Load in Crash Impact Test for Fuel Tank of Rotorcraft (항공기용 연료탱크 Phase I 충돌충격시험 충격하중 분석)

  • Kim, Hyun-gi;Kim, Sung Chan
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.6
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    • pp.3736-3741
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    • 2015
  • Crash impact test is conducted to verify the crashworthiness of fuel tank. Success of the crash impact test means the improvement of survivability of crews by preventing post-crash fire. But, there is a big risk of failure due to huge external load in the crash impact test. The failure of crash impact test can result in serious delay of a entire rotorcraft development because of the design complement and re-production of the test specimens requiring a long-term preparation. Thus, the numerical simulations of the crash impact test has been required at the early design stage to minimize the possibility of trial-and-error in the real test. Present study conducts on the numerical simulation of phase I crash impact test using SPH supported by crash simulation software, LS-DYNA. Test condition of MIL-DTL-27422 is reflected on analysis and material data is acquired by specimen test of fuel cell material. As a result, the crash load on the skin material, overlap area and metal fitting is estimated to confirm the possibility of acquisition of the design load for the determination of the overlap area and adhesive strength.

Failure Analysis of Aircraft Software Test Cases from a Perspective of Requirements Traceability (요구사항 추적성 관점에서 항공기 탑재 소프트웨어 시험 사례 실패 분석)

  • Kim, Sung-Sub;Cho, Hee-Tae;Lee, Seonah
    • KIPS Transactions on Software and Data Engineering
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    • v.9 no.11
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    • pp.357-366
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    • 2020
  • As the proportion and complexity of software embedded in aircraft increase, risk factors such as mission failure, function failure and performance failure due to software errors also increase. In the mission-critical software systems such as aircraft software, managing requirement traceability is essential to maintain the software systems with minimal period and cost. However, the development company is not accurately complying with the guideline for managing requirement traceability due to various reasons such as development cost and schedule. Therefore, it is not easy to systematically establish and maintain requirement traceability. In the paper, we analyze actual test cases of aviation software systems from the viewpoint of requirements traceability in order to learn if there are failure cases of test cases due to the absence of systematic traceability management activities. We also check the risks associated with the failure cases according to the type and severity of the cases. As a result of analyzing a total of 7 aircraft-mounted software, failure cases could be divided into three types: omission of requirements, lack of connection between requirements and test procedures, and omission of test procedures. There were a total of 18 failure cases, 6 for each type. The numbers of high, middle and low risks were 1, 13 and 4, respectively, where the number of middle risks is largest.

Analysis of PRC regeneration algorithm performance in dynamic environment by using Multi-DGPS Signal (다중 DGPS 신호를 이용한 동적 환경에서의 PRC 재생성 알고리즘 성능분석)

  • Song Bok-Sub;Oh Kyung-Ryoon;Kim Jeong-Ho
    • The KIPS Transactions:PartA
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    • v.13A no.4 s.101
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    • pp.335-342
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    • 2006
  • As PRC linear interpolation algorithm is applied after analysed and verified in this paper, the unknown location of a user can be identified by using PRC information of multi-DGPS reference station. The PRC information of each GPS satellite is not varying rapidly, which makes it possible to assume that PRC information of each GPS satellite varies linearly. So, the PRC regeneration algorithm with linear interpolation can be applied to improve the accuracy of finding a user's location by using the various PRC information obtained from multi-DGPS reference station. The desirable PRC is made by the linear combination with the known position of multi-DGPS reference station and PRC values of a satellite using signals from multi-DGPS reference station. The RTK-GPS result was used as the reference. To test the performance of the linearly interpolated PRC regeneration algorithm, multi-channel DGPS beacon receiver was built to get a user's position more exactly by using PRC data of maritime DGPS reference station in RTCM format. At the end of this paper, the result of the quantitative analysis of the developed navigation algorithm performance is presented.

An Integration of Legacy Nuclear Simulation Code into HLA Federation using Shared Memory (공유메모리를 사용한 레거시 원자력 시뮬레이션 코드의 HLA 패더레이션으로의 통합)

  • Park Geun-Ok;Han Kwan-Ho;Lim Jong-Tae
    • The KIPS Transactions:PartD
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    • v.12D no.5 s.101
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    • pp.797-806
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    • 2005
  • The objective of the In-h(High Level Architecture) have recommended by DoD(Department of Defense) is to facilitate interoperability among simulations and to promote reuse of their components. There are many legacy simulation softwares developed before the HLA becomes simulation standard. The integration of legacy simulations into federations using the HLA is an important research topic in M&S(Modeling and Simulation) area. Legacy simulation softwares of the mission critical industry such as nuclear and aerospace are generally use Fortran language. However, the reuse of those is not easy because the HLA is not support Fortran language. This paper suggests a integration method which minimizes the modification of legacy simulation software and migrates the legacy simulation software to HLA federation. Each federate participating in federation have the separated executables that communicate via a shared memory created at run-time. Two types of shared memory blocks are used for publication and subscription. Declaration block for global variables used in legacy simulation software is separated for publication and subscription and then mapped as classes of objects and interactions for the HLA FOM design. To validate the suggested method, we approached the HLA integration of legacy nuclear simulation code being used in plant design and to observe the integration results, we used the FMT(Federation Management Tool). The diagnostic information which the FTM displays showed that our method can be successfully and effectively used for a HLA federation.

Study on Evaluation Criteria for Multimodal Transport Routing Selection (복합운송경로 선정을 위한 평가기준에 관한 연구)

  • Kim So-Yeon;Choi Hyung-Rim;Kim Hyun-Soo;Park Nam-Kyu;Cho Jae-Hyung;Park Yong-Sung;Cho Min-Je
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2006.06b
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    • pp.265-271
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    • 2006
  • According to globalization of world economy by extension of production, sales and distribution all around the world and international transportation system changed into a transport system that puts great importance on speediness and value-added services, international transport system is changing into a Multimodal Transport Routing centered system that systematically connects marine, air and rail transports. Due to such changes production, sales and distribution must be provided in time and Multimodal Transport Routing, which can provide multi-dimensional logistics services to customers of global network, is needed but information connection for international transport and connection system between transport modes are insufficient and can not be activated. Especially in Korea, selection standard of 3rd party logistics companies and transport companies is presented, but logistics exclusive companies, which plan and execute the transportation, can't present a systematic evaluation standard for international Multimodal Transport Routing, selection. Thus, this research surveys important previous studies about Multimodal Transport Routing, selection, derives an evaluation standard for Multimodal Transport Routing, selection through interview with company officials, and presents a theoretical basis for Multimodal Transport Routing, selection through systematic analysis of Multimodal Transport Routing, selection using Analytical Hierarchy Process (AHP).

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Calibration of CR-39 for Hadron Radiotherapy using 400 MeV/u C ions (400 MeV/u 탄소 이온에 대한 방사선치료 선량 측정용 고체비적검출기의 교정)

  • Kim, Sunghwan;Nam, Uk-Won;Lee, Jaejin;Park, Won-Kee;Pyo, Jeonghyun;Moon, Bong-Kon
    • Journal of radiological science and technology
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    • v.39 no.1
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    • pp.43-49
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    • 2016
  • In this study, equivalent dose and LET (Linear Energy Transfer) calibration of CR-39 SSNTD (Solid State Nuclear Track Detector) were performed using 400 MeV/u C heavy ions in HIMAC (Heavy Ion Medical Accelerator in Chiba) for high LET radiation therapy. The irradiated CR-39 SSNDTs were etched according the etching condition of JAXA (Japan Aerospace Exploration Agency). And the etched SSNTDs were analyzed by using Image J. Determined frequency mean dose (${\bar{y_D}}$)and dose-mean lineal energy (${\bar{y_F}}$)of 400 MeV/u C are about 8.5keV/mm and 10.1 keV/mm, respectively by using the CR-39 SSNTD. This value is very similar to the results calculated by GEANT4 Monte Carlo simulation and measured with TEPC (Tissue Equivalent Proportional Counter) active radiation detector. We could determine the equivalent dose and LET calibration factors of CR-39. And we confirmed that the CR-39 SSNTD was useful for high LET radiation dosimetry in hadron radiotherapy.

Automatic Classification by Land Use Category of National Level LULUCF Sector using Deep Learning Model (딥러닝모델을 이용한 국가수준 LULUCF 분야 토지이용 범주별 자동화 분류)

  • Park, Jeong Mook;Sim, Woo Dam;Lee, Jung Soo
    • Korean Journal of Remote Sensing
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    • v.35 no.6_2
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    • pp.1053-1065
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    • 2019
  • Land use statistics calculation is very informative data as the activity data for calculating exact carbon absorption and emission in post-2020. To effective interpretation by land use category, This study classify automatically image interpretation by land use category applying forest aerial photography (FAP) to deep learning model and calculate national unit statistics. Dataset (DS) applied deep learning is divided into training dataset (training DS) and test dataset (test DS) by extracting image of FAP based national forest resource inventory permanent sample plot location. Training DS give label to image by definition of land use category and learn and verify deep learning model. When verified deep learning model, training accuracy of model is highest at epoch 1,500 with about 89%. As a result of applying the trained deep learning model to test DS, interpretation classification accuracy of image label was about 90%. When the estimating area of classification by category using sampling method and compare to national statistics, consistency also very high, so it judged that it is enough to be used for activity data of national GHG (Greenhouse Gas) inventory report of LULUCF sector in the future.

Economic Effect of Regulation in Logistics/Transport Industry (물류운송산업 규제의 경제적 효과)

  • KIM, Jungwook;WI, Suhyeon
    • Journal of Korean Society of Transportation
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    • v.35 no.3
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    • pp.169-182
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    • 2017
  • This research reviews regulations on logistics/transport industry and attempts to quantify the effects of regulation mitigation on GDP per capita. South Korea's transport industry has been gradually expanding, however, the industrial structure is still short rooted. In 2014, average number of hours worked is 5th highest and wage margin 12th smallest out of 18 industries. Furthermore, the regulations for this industry appear to be stricter than those of other industries. OECD's logistics/transport industry regulatory index for South Korea has been decreasing for the last 40 years but still exceeds those of EU, Japan, US, and other countries. This paper provides supporting reasons for regulatory reforms by analyzing the ripple effects on real GDP. Factors such as the ratio of trade among GDP, the enrollment rate to primary school, energy usage per capita, and population are controlled in the fixed-effect model. Estimation results showed that 1 unit decrease in transport/logistics regulatory index is correlated with 8.1% increase of the real GDP per capita, that is, 10% of deregulation is expected to yield 2.16% increase in GDP per capita. Thus, it is expected that mitigating regulations on market entries, price determination, ownership structures of network industry, vertical integrations can improve the economy of South Korea.

Herbicidal Effects on the Differential Rice Cultivation Condition and Damage of No-target Plants of Macro Granule Herbicide for Remote-controlled Aerial Application (무인헬기용 Macro granule 제초제의 벼 작형별 살초효과 및 주변작물에 미치는 영향)

  • Yoon, Cheol-Su;Bae, Chang-Hyu;Lee, Sheong-Chun;Kim, Kyung-Hyun;Lee, Kye-Hwan;Cho, Tae-Kyoung;Hwang, In-Cheon
    • Korean Journal of Weed Science
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    • v.31 no.4
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    • pp.375-383
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    • 2011
  • This experiment was carried out to confirm characteristics of macro granule (GG) for herbicidal efficacy by using remote-controlled aerial application (RCAA) to control annual and perennial weeds in rice paddy field, and phytotoxicity to rice and non target plants of formulation types. Herbicidal efficacy of GG applied by using RCAA was 93.6~96.6% in flooded direct sowing cultivation. There was no difference in phytotoxicity between the hand and the power applicator methods in terms of height, number of tiller and yield component. Herbicidal efficacy of GG applied by using RCAA was 92.7~97.3% in machine transplanting rice field. There was no difference in phytotoxicity between the hand and RCAA methods in terms of height, number of tiller and yield component. When suspension concentrate (SC) and GG were applied directly on Chinese cabbage, lettuce, cucumber, pepper, soybean and wild sesame, several symptoms of injury such as, the inhibition of growth, yellowish, leaf fall and withering was observed.