• Title/Summary/Keyword: Stacking

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Heat Characteristic Analysis of Stacking Type HTS Current Lead (적층형 고온초전도 전류도입선의 열 특성 해석)

  • 두호익;임성우;홍세은;윤기웅;한병성
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.07a
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    • pp.628-631
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    • 2001
  • Current lead is one of the first proposed devices for the application of High Temperature-Superconductor(HTSC). The current lead provides high current for electrical machine using superconductor from room temperature. Its characteristics that is zero resistance and low heat transfer rate under critical temperature lead to research for the replacement of existing current lead with HTSC. In this paper, we investigated the temperature distributions of stacking type and rod type current lead with each cross-section area and length using Nastran program and compared each temperature distribution. It is obtained from this paper that stacking type current lead has flat temperature gradient and than rod type one and more stable operation as current lead is closely related with its cross-section area and length.

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A Design Procedure for a Multi-Stage Axial Compressor Using the Stage-Stacking Method (단축적방법을 이용한 다단 축류압축기의 설계)

  • 강동진
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.18 no.6
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    • pp.1598-1603
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    • 1994
  • A preliminary design procedure for a multi-stage axial compressor is developed, which is based on the stage-stacking method. It determines the flow coefficient which gives rise to the design conditions required such as pressure ratio, mass flow rate and rotational speed for a given specific mass flow rate at inlet to a compressor. With this flow coefficient, blade radii, every stage and compressor performance characterics such as stage pressure ratio, adiabatic efficiency etc. are calculated by stacking each stage performance characteristics. It is shown that there is an optimum number of stage which results in the maximum of compressor overall efficiency for a given specific mass flow rate at inlet to a compressor. A test design was tried for three different geometric design constraints, and comparison with a previous study shows that present procedure could be used reliably in determining the number of compressor stage in preliminary design stage.

Stacking Sequence Optimization of Composite Laminates for Railways Using Expert System (철도분야 응용을 위한 전문가 시스템을 이용한 복합적층판의 적층순서 최적설계)

  • Kim Jung-Seok
    • Journal of the Korean Society for Railway
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    • v.8 no.5
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    • pp.411-418
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    • 2005
  • This paper expounds the development of a user-friendly expert system for the optimal stacking sequence design of composite laminates subjected to the various rules constraints. The expert system was realized in the graphic-based design environment. Therefore, users can access and use the system easily. The optimal stacking sequence is obtained by means of integration of a genetic algorithm, finite element analysis. These systems were integrated with the rules of design heuristics under an expert system shell. The optimal stacking sequence combination for the application of interest is drawn from the discrete ply angles and design rules stored in the knowledge base of the expert system. For the integration and management of softwares, a graphic-based design environment that provides multi-tasking and graphic user interface capability is built.

Influence of Stacking Condition on Collision Safety of CFRP Side Member (적층구성이 CFRP 사이드 부재의 충돌안전성에 미치는 영향)

  • Hwang, Woo Chae;Yang, In Young
    • Journal of the Korean Society of Safety
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    • v.29 no.3
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    • pp.14-19
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    • 2014
  • The global demand for reduction in the weight of automobiles has led many countries to focus on the development of hybrid, eco-friendly, and electric cars. Reduction in the weight of materials can both increase fuel efficiency and maximize automobile performance. Therefore, the design of automobile should be inclined towards the safety aspects. but at the same time, it also consider reducing the structural weight of an automobile. In this study, CFRP side members with circular and double hat shaped section was manufactured. The impact collapse tests performed with change of the stacking condition, such as variation of interface number and outerlayer angle. The impact collapse load and absorbed energy were quantitatively analyzed according to the changes in section shapes and stacking condition. This analysis was performed to obtain design data that can be applied in the development of optimum lightweight members for automobiles.

Particle Stacking Dependence of Properties and Dispersitility of Ba-ferrite Powder for Magnetic Recording (입자간 Stacking이 자기기록용 Ba-ferrite 분말의 물성과 분산성에 미치는 영향)

  • 홍양기;정홍식;박상준
    • Journal of the Korean Magnetics Society
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    • v.6 no.2
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    • pp.117-121
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    • 1996
  • 육각판상 Ba-ferrite의 stacking 현상은 자성도료의 도포 후 자장배향를 행할 때 일어나는 것으로 알려져 있으나 분말의 건식분쇄시에도 일어났다. Edge mill을 사용하여 건식분쇄할 때 치환형 Ba-ferrite 분말의 보자력과 tap density는 거의 비례적으로 증가하였고, 분쇄시간보다는 가해지는 압력에 크게 의존하였다. 이 때 보자력의 증가원인은 분쇄시 생성되는 입자간의 stacking 현상에 기인된 것임을 투과전자현미경 관찰로부터 확인하였다. 분말의 tap density가 증가함에 따라 tape에서 분산초기의 광택도가 크게 감소되어 분산성은 떨어졌으나, 배향도는 tap density 1.3 g/$cm^{3}$에서 최대를 나타내었다. 과도한 건식분쇄에 의해 생성된 강고한 stacked cluster는 자성도료 제조시 분산성과 배향도를 동시에 떨어뜨리는 역할을 함을 알 수 있었다.

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Interlaminar Shear Stresses of Laminated Composite Plates Subjected to Transversely Imp (횡방향 충격을 받는 적층복합판의 층간전단응력 해석)

  • Ahn, Kook-Chan;Park, Seung-Bum;Kim, Bong-Hwan
    • Journal of the Korean Society of Safety
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    • v.17 no.4
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    • pp.31-37
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    • 2002
  • This paper demonstrates the analyses of the interlaminar shear stress of laminated composite plates subjected to transversely impact. For this purpose, a plate finite element model based on the higher order shear deformation plate theory in conjunction with static contact laws is developed. Test materials were CFRP with cross-ply laminate $[O_4/{\theta}_4]_S$, $[90_4/{\theta}_4]_S$ stacking sequences and angle-ply laminate $[{\theta}_4/-{\theta}_4]_S$, $[{\theta}_4/-{\theta}_4]_S$ stacking deguences with $2^t{\times}40^w{\times}100^l(mm)$ dimension. As a result, stacking seguence and fiber orientation were found to have a significant effect on the interlaminar stresses in composite laminates.

Intramolecular Ring-Ring Stacking Interartions between 8-Methoxypsoralen and Adenine Induced by Polymethylene Bridges.

  • Yu, Dong Jin;Hyeon, Seung Hak;Sim, Sang Cheol
    • Bulletin of the Korean Chemical Society
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    • v.22 no.6
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    • pp.575-580
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    • 2001
  • Intramolecular ring-ring interactions in the model compounds, $8-methoxypsoralen-CH_2O(CH_2)n-adenine(MOPCH_2OCnAd$, n=2, 3, 5, and 6) in which 5' position of 8-methoxypsoralne (8-MOP) is linked by different polymethylene bridges to N9 of adenine, have been investigated by hypochromism measurements. Efficient ring-ring stacking interactions have been observed in $MOPCH_2CO2Ad$ (7) from the percent hypochromism(%H) and fluorescence spectra of the models and a reference molecule. The 8-methoxyposralen-adenine systems have shown stronger ring-ring stacking interaction than the psoralen-adenine system.

Automatic Fruit Grading Using Stacking Ensemble Model Based on Visual and Physical Features (시각적 특징과 물리적 특징에 기반한 스태킹 앙상블 모델을 이용한 과일의 자동 선별)

  • Kim, Min-Ki
    • Journal of Korea Multimedia Society
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    • v.25 no.10
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    • pp.1386-1394
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    • 2022
  • As consumption of high-quality fruits increases and sales and packaging units become smaller, the demand for automatic fruit grading systems is increasing. Compared to other crops, the quality of fruit is determined by visual characteristics such as shape, color, and scratches, rather than just physical size and weight. Accordingly, this study presents a CNN model that can effectively extract and classify the visual features of fruits and a perceptron that classifies fruits using physical features, and proposes a stacking ensemble model that can effectively combine the classification results of these two neural networks. The experiments with AI Hub public data show that the stacking ensemble model is effective for grading fruits. However, the ensemble model does not always improve the performance of classifying all the fruit grading. So, it is necessary to adapt the model according to the kind of fruit.

The behavior of adhesive joints affected by the geometry and stacking sequence of composite materials

  • Ait Kaci Djafar;Zagane Mohammed El Sallah;Moulgada Abdelmadjid;Sahli Abderahmane
    • Structural Engineering and Mechanics
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    • v.88 no.6
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    • pp.609-623
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    • 2023
  • The objective of this study is to investigate the distribution of von Mises stress, peeling stress, and shear stress in the adhesive layer used to bond two composite panels, considering various parameters using a three-dimensional finite element method. The stiffness of the materials and the effect of the stacking order on the amount of load transferred to the adhesive layer were examined to determine which type of laminate generates less stress at the bond line. The study analyzed six different stacking sequences, all with a common first layer in contact with the adhesive and a 0° orientation. Additionally, the impact of using hybrid composites on reducing bond line stress was investigated.

Genetic classification of various familial relationships using the stacking ensemble machine learning approaches

  • Su Jin Jeong;Hyo-Jung Lee;Soong Deok Lee;Ji Eun Park;Jae Won Lee
    • Communications for Statistical Applications and Methods
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    • v.31 no.3
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    • pp.279-289
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    • 2024
  • Familial searching is a useful technique in a forensic investigation. Using genetic information, it is possible to identify individuals, determine familial relationships, and obtain racial/ethnic information. The total number of shared alleles (TNSA) and likelihood ratio (LR) methods have traditionally been used, and novel data-mining classification methods have recently been applied here as well. However, it is difficult to apply these methods to identify familial relationships above the third degree (e.g., uncle-nephew and first cousins). Therefore, we propose to apply a stacking ensemble machine learning algorithm to improve the accuracy of familial relationship identification. Using real data analysis, we obtain superior relationship identification results when applying meta-classifiers with a stacking algorithm rather than applying traditional TNSA or LR methods and data mining techniques.