• Title/Summary/Keyword: Stacking method

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A study on application techniques in design phase of applying a crossing stacking method of modular housing (모듈러 저층집합주거의 교차적층방식 설계 적용기술 연구)

  • Jun, Young-Hun;Lee, Young;Kim, Kyoon-Tai
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2014.11a
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    • pp.81-82
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    • 2014
  • Modular housing has many advantages such as economy, flexibility and reusability. The domestic modular housing of a continuous stacking method has been built in military facilities, and dormitories. However, there is a limit to present diversity of low-rise multi-family housing. A cross stacking method is a way to pursue diversity of that but there is a difficulty to apply it owe to lack of cases and related technologies. Therefore, the purpose of this study is to suggest application techniques in design phase of applying the crossing stacking method in advance.

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Robustness of model averaging methods for the violation of standard linear regression assumptions

  • Lee, Yongsu;Song, Juwon
    • Communications for Statistical Applications and Methods
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    • v.28 no.2
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    • pp.189-204
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    • 2021
  • In a regression analysis, a single best model is usually selected among several candidate models. However, it is often useful to combine several candidate models to achieve better performance, especially, in the prediction viewpoint. Model combining methods such as stacking and Bayesian model averaging (BMA) have been suggested from the perspective of averaging candidate models. When the candidate models include a true model, it is expected that BMA generally gives better performance than stacking. On the other hand, when candidate models do not include the true model, it is known that stacking outperforms BMA. Since stacking and BMA approaches have different properties, it is difficult to determine which method is more appropriate under other situations. In particular, it is not easy to find research papers that compare stacking and BMA when regression model assumptions are violated. Therefore, in the paper, we compare the performance among model averaging methods as well as a single best model in the linear regression analysis when standard linear regression assumptions are violated. Simulations were conducted to compare model averaging methods with the linear regression when data include outliers and data do not include them. We also compared them when data include errors from a non-normal distribution. The model averaging methods were applied to the water pollution data, which have a strong multicollinearity among variables. Simulation studies showed that the stacking method tends to give better performance than BMA or standard linear regression analysis (including the stepwise selection method) in the sense of risks (see (3.1)) or prediction error (see (3.2)) when typical linear regression assumptions are violated.

Robust and Optimum Weighted Stacking of Seismic Data (탄성파 자료의 강인한 최적 가중 겹쌓기)

  • Ji, Jun
    • Geophysics and Geophysical Exploration
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    • v.16 no.1
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    • pp.1-5
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    • 2013
  • Stacking in seismic processing plays an important role in improving signal-to-noise ratio and imaging quality of seismic data. However, the conventional stacking method doesn't remove random noises with various distributions and outliers up to a satisfactory level. This paper introduces a robust and optimum weighted stack method which shows both robustness to outlier noises and optimum in removing random noises. This was achieved by combining the robust median stacking with the optimum weighted stacking using local correlation. Application of the method to synthetic data showed that the proposed method is very effective in suppressing random noises with various distributions including outliers.

The Effect of Air Vent Holes and Stacking Methods of Fruits and Vegetables Boxes on Static Pressure Drop in Pressure Cooling System (청과물상자의 통기공 및 상자적재방법이 정압강하에 미치는 영향)

  • 김의웅;김병삼;남궁배;정진웅;김동철;금동혁
    • Journal of Biosystems Engineering
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    • v.20 no.4
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    • pp.360-367
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    • 1995
  • The effect of air vent holes, stacking methods of boxes and clearance between boxes on static pressure drop, were measured to design of pressure cooling system. Static pressure drops in air vent hole of carton box were measured for different hole opening ratio from 1% to 5%. Static pressure drop was expressed as a function of superficial velocity as second-degree polynomial. At given static pressure in plenum chamber, static pressure drop in boxes was shown as second-degree polynomial of the number of carton box in series stacking method, as first-degree polynomial in height and parallel stacking method. In pressure cooling of 24 boxes of Tsugaru apple, air flow rates through clearance between the boxes were shown 1.27 and 1.65 times than those of through the inside of boxes at the plenum pressure of 10mmAq and 20mmAq, respectively.

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Effect of stacking sequence on thermal stresses in laminated plates with a quasi-square cutout using the complex variable method

  • Chaleshtari, Mohammad H. Bayati;Khoramishad, Hadi
    • Structural Engineering and Mechanics
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    • v.77 no.2
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    • pp.245-259
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    • 2021
  • In this research, the influence of the laminate stacking sequence on thermal stress distribution in symmetric composite plates with a quasi-square cutout subjected to uniform heat flux is examined analytically using the complex variable technique. The analytical solution is obtained based on the thermo-elastic theory and the Lekhnitskii's method. Furthermore, by employing a suitable mapping function, the solution of symmetric laminates containing a circular cutout is extended to the quasi-square cutout. The effect of important parameters including the stacking sequence of laminates, the angular position, the bluntness, the aspect ratio of cutout, the flux angle and the composite material are examined on the thermal stress distribution. It is found out that the circular shape for cutout may not necessarily be the optimum geometry for all stacking sequences. The finite element analysis results are used to validate the analytical solution.

The Study of Structural Stability by Stacking Method of the Axial Blade (축류 블레이드의 스태킹 방식에 의한 구조 안정성 연구)

  • Jeong, Cheol-Young;Ko, Hee-Hwan;Park, Jun-Young
    • The KSFM Journal of Fluid Machinery
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    • v.15 no.1
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    • pp.46-51
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    • 2012
  • This study is to confirm the deformation of blade when the location of stacking is moving. Also, it desire to determine the most stable location of stacking from the analysis. In the previous study, it is Known that moving the location of stacking is not influence to the aerodynamic performance. In this study SolidWorks premium 2010 SP4 is used for structure analysis. In reference blade and other 3 model analysis, the two mesh type is used, one is standard mesh type in SolidWorks, the other is curvature-based mesh type. The result of curvature-based mesh type is more stable than one of the standard mesh type regardless of mesh size, the number of mesh. The deformation of blade tip is the smallest, when the location of stacking is identical to the center of gravity of the blade section profile. So, if possible is design, this study recommends that the location of stacking is identical to the center of gravity the blade.

Predicting movie audience with stacked generalization by combining machine learning algorithms

  • Park, Junghoon;Lim, Changwon
    • Communications for Statistical Applications and Methods
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    • v.28 no.3
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    • pp.217-232
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    • 2021
  • The Korea film industry has matured and the number of movie-watching per capita has reached the highest level in the world. Since then, movie industry growth rate is decreasing and even the total sales of movies per year slightly decreased in 2018. The number of moviegoers is the first factor of sales in movie industry and also an important factor influencing additional sales. Thus it is important to predict the number of movie audiences. In this study, we predict the cumulative number of audiences of films using stacking, an ensemble method. Stacking is a kind of ensemble method that combines all the algorithms used in the prediction. We use box office data from Korea Film Council and web comment data from Daum Movie (www.movie.daum.net). This paper describes the process of collecting and preprocessing of explanatory variables and explains regression models used in stacking. Final stacking model outperforms in the prediction of test set in terms of RMSE.

A Study on fabrication of stacking type Bi-2223 HTS tapes (적층형 Bi-2223 고온초전도 선재 제작에 관한 연구)

  • 임성우;두호익;한병성
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.13 no.8
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    • pp.718-723
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    • 2000
  • The critical characteristics of Bi-2223 HTS tapes made by PIT method are influenced by the heat treatment and the mechanical processing. In this study firstly we investigated the influence o rolling reduction rate in mechanical process for improving Jc of HTS tapes. As a result the optimized rolling reduction rate that we obtained was 10%-50% and 30%-30% (1st-2nd). And then we fabricated the stacking type HTS tapes that made of the multi-filamentary tapes with various length(3, 5, 10cm) and with various number of stacking (1, 5, 10 layer). Measuring the critical current and observing the structure of grain we concluded that the stacking type tapes will be able to operate more stably by adding the number of stacking tapes. And we could expect that by minimizing the gap between Ag-sheath of tapes mechanical strength of stacking HTS tapes is enhanced and current in tapes will flow more stably.

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The Stacking Sequence Optimization of Stiffened Laminated Curved Panels with Different Loading and Stiffener Spacing

  • Kim Cheol;Yoon In-Se
    • Journal of Mechanical Science and Technology
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    • v.20 no.10
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    • pp.1541-1547
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    • 2006
  • An efficient procedure to obtain the optimal stacking sequence and the minimum weight of stiffened laminated composite curved panels under several loading conditions and stiffener layouts has been developed based on the finite element method and the genetic algorithm that is powerful for the problem with integer variables. Often, designing composite laminates ends up with a stacking sequence optimization that may be formulated as an integer programming problem. This procedure is applied for a problem to find the stacking sequence having a maximum critical buckling load factor and the minimum weight. The object function in this case is the weight of a stiffened laminated composite shell. Three different types of stiffener layouts with different loading conditions are investigated to see how these parameters influence on the stacking sequence optimization of the panel and the stiffeners. It is noticed from the results that the optimal stacking sequence and lay-up angles vary depending on the types. of loading and stiffener spacing.

Study on the electric properties of layered $BaTiO_3$ films prepared new stacking method (새로운 방법으로 제조된 적층구조 $BaTiO_3$ 박막의 전기적 특성에 관한 연구)

  • Song, Man-Ho;Lee, Yun-Hi;Hahn, Taek-Sang;Oh, Myung-Hwan;Yoon, Ki-Hyun
    • Proceedings of the KIEE Conference
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    • 1995.07c
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    • pp.1129-1132
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    • 1995
  • In the preparation of the layered $BaTiO_3$ thin films with high performance, the new stacking method using the continuous cooling of the substrate was introduced. Amorphous/polycrystalline $BaTiO_3$ layered structure was confirmed by SEM and index of refraction. The layered $BaTiO_3$ thin films formed by the new stacking method showed such a high dielectric constant that the layered structure could not be explained by a stacking structure of the two defined layers but could only be explained by multi-layered structure, i.e. amorphous/micro crystalline/polycrystalline structure. The layered $BaTiO_3$ thin film with a thickness of 240 nm showed higher capacitance per unit area and breakdown strength than the double layered $BaTiO_3$ thin film prepared by the conventional stacking method. And well defined ferroelectric hysteresis leer was observed in the layered $BaTiO_3$ thin film with a thickness of 200 nm.

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