• Title/Summary/Keyword: future stand structure

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Numerical analysis of reaction forces in blast resistant gates

  • Al-Rifaie, Hasan;Sumelka, Wojciech
    • Structural Engineering and Mechanics
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    • v.63 no.3
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    • pp.347-359
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    • 2017
  • Blast resistant gates are required to be lightweight and able to mitigate extreme loading effect. This may be achieved through innovative design of a gate and its supporting frame. The first is well covered in literature while the latter is often overlooked. The design of supporting frame depends mainly on the boundary conditions and corresponding reaction forces. The later states the novelty and the aim of this paper, namely, the analysis of reaction forces in supporting structure of rectangular steel gates subjected to "far-field explosions". Flat steel plate was used as simplified gate structure, since the focus was on reaction forces rather than behaviour of gate itself. The analyses include both static and dynamic cases using analytical and numerical methods to emphasize the difference between both approaches, and provide some practical hints for engineers. The comprehensive study of reaction forces presented here, cover four different boundary conditions and three length to width ratios. Moreover, the effect of explosive charge and stand-off distance on reaction forces was also covered. The analyses presented can be used for a future design of a possible "blast absorbing supporting frame" which will increase the absorbing properties of the gate. This in return, may lead to lighter and more operational blast resistant gates.

A Study on the Application of FBS Design Model to Preliminary Ship Design (선박 초기설계에 FBS 설계 모델의 응용에 관한 연구)

  • Park, Chang-Kue;Yang, Young-Soon;Pyo, Sang-Woo
    • Journal of the Society of Naval Architects of Korea
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    • v.45 no.2
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    • pp.192-201
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    • 2008
  • The design process becomes more difficult due to the increasing complexity of products. Thus, without any proper design experience, designer cannot handle his design problems systematically. Besides, the conventional optimal design method cannot be used effectively at the early design stage, since most design problems must be formulated in terms of objective and constraint functions based on the mathematical concepts of Operation Research. Thus, in this paper, new design concept based on FBS (Function-Behavior-Structure) design model is introduced to help the novice designer formulate the complex design problems systematically into a mathematical form. In this FBS model, function means the designer's new intents designer wants to create for, structure stand for a final product configuration and behaviour is a product's performance. FBS design model is thus rather totally different concept used for formulating design problem, compared with conventional optimal design method. To validate this new FBS model, 330K VLCC design case is performed, and we found, though it is one design example case, that this new design concept could be effectively used for future ship design problems since, during the formulating design problem, the only engineering terminology such as function, structure, and behaviour of design product is used based on the engineering concepts, instead of mathematical terminology such as objective and constraints.

COMPASS - New modeling and simulation approach to PWR in-vessel accident progression

  • Podowski, Michael Z.;Podowski, Raf M.;Kim, Dong Ha;Bae, Jun Ho;Son, Dong Gun
    • Nuclear Engineering and Technology
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    • v.51 no.8
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    • pp.1916-1938
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    • 2019
  • The objective of this paper is to discuss the modeling principles of phenomena governing core degradation/melting and in-vessel melt relocation during severe accidents in light water reactors. The proposed modeling approach has been applied in the development of a new accident simulation package, COMPASS (COre Meltdown Progression Accident Simulation Software). COMPASS can be used either as a stand-alone tool to simulate in-vessel meltdown progression up to and including RPV failure, or as a component of an integrated simulation package being developed in Korea for the APR1400 reactor. Interestingly, since the emphasis in the development of COMPASS modeling framework has been on capturing generic mechanistic aspects of accident progression in light water reactors, several parts of the overall model should be useful for future accident studies of other reactor designs, both PWRs and BWRs. The issues discussed in the paper include the overall structure of the model, the rationale behind the formulation of the governing equations and the associated simplifying assumptions, as well as the methodology used to verify both the physical and numerical consistencies of the overall solver. Furthermore, the results of COMPASS validation against two experimental data sets (CORA and PHEBUS) are shown, as well as of the predicted accident progression at TMI-2 reactor.

Estimating the Stand Level Vegetation Structure Map Using Drone Optical Imageries and LiDAR Data based on an Artificial Neural Networks (ANNs) (인공신경망 기반 드론 광학영상 및 LiDAR 자료를 활용한 임분단위 식생층위구조 추정)

  • Cha, Sungeun;Jo, Hyun-Woo;Lim, Chul-Hee;Song, Cholho;Lee, Sle-Gee;Kim, Jiwon;Park, Chiyoung;Jeon, Seong-Woo;Lee, Woo-Kyun
    • Korean Journal of Remote Sensing
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    • v.36 no.5_1
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    • pp.653-666
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    • 2020
  • Understanding the vegetation structure is important to manage forest resources for sustainable forest development. With the recent development of technology, it is possible to apply new technologies such as drones and deep learning to forests and use it to estimate the vegetation structure. In this study, the vegetation structure of Gongju, Samchuk, and Seoguipo area was identified by fusion of drone-optical images and LiDAR data using Artificial Neural Networks(ANNs) with the accuracy of 92.62% (Kappa value: 0.59), 91.57% (Kappa value: 0.53), and 86.00% (Kappa value: 0.63), respectively. The vegetation structure analysis technology using deep learning is expected to increase the performance of the model as the amount of information in the optical and LiDAR increases. In the future, if the model is developed with a high-complexity that can reflect various characteristics of vegetation and sufficient sampling, it would be a material that can be used as a reference data to Korea's policies and regulations by constructing a country-level vegetation structure map.

Analysis on Water Retention Rate according to Water Cycle Characteristics in Jeju Gotjawal Forest (제주 곶자왈 산림의 물순환 특성에 따른 수원함양률 분석)

  • Jaehoon Kim;Honggeun Lim;Hyung Tae Choi;Qiwen Li;Haewon Moon;Hyungsoon Choi
    • Journal of Environmental Science International
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    • v.31 no.12
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    • pp.1013-1025
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    • 2022
  • This study was carried out to analyze water cycle characteristics and evaluate water retention function in Jeju Gotjawal forest from 2013 to 2017. The average ratio of throughfall, stemflow, interception loss in Seonhul Gotjawal (SH) and Cheongsu Gotjawal (CS) was 43.1%, 15.8%, and 41.1%, respectively. Rainfall-throughfall, rainfall-stemflow, and rainfall-interception loss were expressed as linear regression equation (p<0.001). The comparison results showed that SH was higher than CS (p<0.05), indicating that the canopy area had an important effect on the difference in stand structure. The average water resources retention rate of the Gotjawal region was 41.9%, which is similar to the total water resources retention rate (40.6%) of Jeju Special Self-Governing Province (JSSGP). Currently, the development of Gotjawal is in progress in JSSGP. The development of Gotjawal will lead to a decrease in the water resources retention rate due to changes in the surface environment such as an increase in impervious areas, which will affect the total groundwater content of JSSGP. Therefore, the conservation of the Gotjawal area is judged to be very important from the point of view of water conservation.

A Landscape Ecological Model for Assessing the Korean Urban Forests (도시숲 평가를 위한 경관생태학적 모형 개발)

  • Oh, Jeong-Hak;Kwon, Jin-O;You, Ju-Han;Kim, Kyung-Tae
    • Korean Journal of Environment and Ecology
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    • v.24 no.2
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    • pp.178-185
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    • 2010
  • The purpose of this study is to verify the effectiveness of the biotope model in applying and developing Korean urban forests. We found that there are 17 biotope assessment indicators, including forest layer structure, site conditions, ratio of broad-leaved trees, species richness, etc. In terms of correlation analysis between indicators, the stand ages and the period of space formation have the highest relativity(coefficient 0.684). On the other hand, indicators that have negative relativity are layer structure and risk, with a coefficient of -0.412. Ten models were developed for the multiple regression analysis. 10 variables(site conditions(X2), ratio of broad-leaved trees(X3) and so forth except layer structure(X1), species richness(X4)) were found to have a 95% significance level The results from comparing the regression model and adding-up estimation matrix, the most accurate one was Model 3, which has a 91.7% out of the 10 models. However more monitoring will be needed to improve the accuracy of models for the Korean urban forests in future.

A study on Supply Extension Device of AED (AED의 보급 확대 방안에 관한 연구)

  • Koh, Jae-Moon;Kim, Young-Ho;Han, Sang-Hak
    • The Korean Journal of Emergency Medical Services
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    • v.9 no.2
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    • pp.147-168
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    • 2005
  • It examined the doubt point which AED motive relates until now, the AED should have bought a life how, present address of our country site pre-hospital care, comparison it tried to observe the advanced nation instance back. Gist of this research the AED important cold region once compared to informed to how many cardiac arrest patient, against him the what kind of preparation wanted informing the necessary cold region. It soaks simultaneously but the AED motive is widely supplied distant in future and it is generality and it is feeble but it wanted doing one morning. The habit difference of an American who does of course meat diet mainly and a Korean is many and it compares in the United States and the cardiac arrest patient comparison occurs holds a point few. To become Western anger but and be caused by with thin dietary life, stanching bleeding cung, with the fact that the heart attack is increasing rapidly with the hyperextension. It is a talk which anyone it knows all. The major league most Choi huy Sub in condition will catch the ball which floats and the multi co-player and to collide when falling down, the medical device which is committed with emergency aid is AED motive. From the United States subway station and the shopping which are a public place on the baseball field outside the jar which it will drive, the museum and the school, easily there is it will be able to discover the AED from the court of justice back. The Pittsburg university the students per the individual $30 the core phyey were receiving the smallness lifestyle alcoholic beverage and a AED motive actual training with mercy of degree. From the United States distant in future the AED motive is sold even from the retail store and. From our country like this plan government offices temporary disposal education from from 119 fire fighters emergency structure company in fire fighting government employee and nursing must magnify a former enterprise rainy spell in summer multi temporary disposal education with the head which it will burn with the head. This plan in early rising will be able to become fixed in Korea it forecasts with the fact that. The research which it sees it leads and like the United States to some day become fixed even from our country to believe and suspicion it is not and in the people in approach ease one AED supply plan fire fighting government employees stand in the first and feed with the fact that must be positive at this enterprise they become.

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Phytosociological Community Type Classification and Stand Structure in the Forest Vegetation of Hongdo Island, Jeollanam-do Province (전라남도 홍도 산림식생의 식물사회학적 군락유형분류와 임분 구조)

  • Kim, Ho-Jin;Shin, Jae-Kwon;Lee, Cheul-Ho;Yun, Chung-Weon
    • Journal of Korean Society of Forest Science
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    • v.107 no.3
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    • pp.245-257
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    • 2018
  • The study was carried out to discover the forest vegetation structure in Hongdo Island, Jeonnam province. Vegetation data were collected by total of forty one quadrate plots using Z-M phytosociological method from June to August in 2017, and analyzed by vegetation classification, mean importance value and species diversity. As a result of vegetation type classification, Castanopsis sieboldii community group was classified at a top level of vegetation hierarchy. In the level of community, it was classified into Neolitsea sericea community and Carpinus turczaninowii community. N. sericea community was subdivided into Ficus erecta group(Vegetation unit 1) and Arisaema ringens group(VU 2). C. turczaninowii community was subdivided into Fraxinus sieboldiana group(VU 3) and C. turczaninowii typical group(VU 4). Therefore, it was classified into total of four vegetation units(one community group, three communities and four groups). As a result of mean importance value, Castanopsis sieboldii was the highest in VU 1, VU 2, VU 4, and C. turczaninowii in VU 4, respectively. In case of species diversity, VU 3 showed the highest among four units in species diversity index. In conclusion, the forest vegetation of Hongdo Island was classified into four units and seven species groups. Hongdo Island could be conclusively managed by community ecological approach for the units and groups. Also it was considered that a research for the succession to the evergreen broad-leaved forest should be more intensively proceeded near future.

The Survey on Actual Condition Depending on Type of Degraded area and Suggestion for Restoration Species Based on Vegetation Information in the Mt. Jirisan Section of Baekdudaegan (식생정보에 기초한 백두대간 지리산권역 내 훼손지 유형별 실태조사)

  • Lee, Hye-Jeong;Kim, Ju-Young;Nam, Kyeong-Bae;An, Ji-Hong
    • Korean Journal of Environment and Ecology
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    • v.34 no.6
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    • pp.558-572
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    • 2020
  • The purpose of this study was to classify the types of degraded areas of Mt. Jirisan section in Baekdudaegan and survey the actual condition of each damage type to use it as basic data for the direction of the restoration of damaged areas according to damage type based on the vegetation information of reference ecosystem. The analysis of the Mt. Jirisan section's actual degraded conditions showed that the total number of patches of degraded areas was 57, and the number of patches and size of degraded areas was higher at the low average altitude and gentle slope. Grasslands (deserted lands) and cultivated areas accounted for a high portion of the damage types, indicating that agricultural land use was a major damage factor. The survey on the conditions of 14 degraded areas showed that the types of damage were classified into the grassland, cultivated area, restoration area, logged-off land, and bare ground. The analysis of the degree of disturbance (the ratio of annual and biennial herb, urbanized index, and disturbance index) by each type showed that the simple single-layer vegetation structure mostly composed of the herbaceous and the degree of disturbance were high in the grassland and cultivated land. The double-layer vegetation structure appeared in the restoration area where the pine seedlings were planted, and the inflow of naturalized plants was especially high compared to other degraded areas due to disturbances caused by the restoration project and the nearby hiking trails. Although the inflow of naturalized plants was low because of high altitude in bare ground, the proportion of annual and biennial herb was high, indicating that all surveyed degraded areas were in early succession stages. The stand ordination by type of damage showed the restoration area on the I-axis, cultivated area, grassland, logged-off land, and bare ground in that order, indicating the arrangement by the damage type. Moreover, the stand ordination of the degraded areas and reference ecosystem based on floristic variation showed a clear difference in species composition. This study diagnosed the status of each damage type based on the reference ecosystem information according to the ecological restoration procedure and confirmed the difference in species composition between the diagnosis result and the reference ecosystem. These findings can be useful basic data for establishing the restoration goal and direction in the future.

A Study on Classification System for Narrative use of Visual Effects in Film (영화 비주얼 이펙트의 내러티브에 의한 분류체계 연구)

  • Suk, Hae-Jung
    • Cartoon and Animation Studies
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    • s.13
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    • pp.237-253
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    • 2008
  • Visual Effects have been revered as 'Spectacular' film elements for a long time, and once there was a misunderstanding that they destroyed the actual 'Story'. But, now they are becoming a valuable tool for storytellers. A film pursues a perfect narrative structure and visual reality so that the audience can believe the story as a real. Giving a narrative motif to the audience, they use Visual Effects that provide the technical solutions and -at the same time- they create and preserve the diegetic world that Is either believable or not. This research suggests that we analyze precisely and make a classified table of the narrative use of Visual Effects based on the previous research of Shilo T. McClean. First, we can ask if the narrative motif would be there in front of the camera, From there, we then can get two desired answers. One is, if there is nothing to visually stand up, Visual Effects can intervene as an alternative tool for creating the diegetic world. The other is that Visual Effects can be used for preserving the diegetic world as a necessary tool. Then, in the latter, we can consider whether there is a storyteller's purpose to be added, so we can distinguish the details. This classified Visual Effects for the narrative is able to dispense proof that they can be worthy as to provide a 'Spectacuiar' aura as to create and preserve the diegetic world. I would like to argue that this research could be a foundation for the inter-progress of future studies for visual effects as well as for their amazing technological improvements.

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