• Title/Summary/Keyword: linear model

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Application of Work Relationships for Linear Scheduling Model (선형 공정계획 모델의 작업 관계성 적용 방법)

  • Rye, Han-Guk
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2010.05a
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    • pp.131-133
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    • 2010
  • As linear scheduling method has been used since 1929, Empire State Building linear schedule, it is being applied in various fields such as construction and manufacturing. When addressing concurrent critical path occurring on linear schedule of construction, the empirical researches stress the resource management which should be applied for optimizing work flow, flexible work productivity and continuos resource allocation. However, work relationships has been usually overlooked for making the linear schedule from existing network schedule. Therefore, this research analyze the previous researches related to linear scheduling model and then propose the method that can be applied for adopting the relationships of network schedule to the linear schedule.

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Evaluation of the Effective Storage of Existing Agricultural Reservoir (기존 농업용 저수지에서의 유효저수량의 평가)

  • Ahn, Tae-Jin;Cho, Dong-Ho;Lee, Sang-Ho;Choi, Gye-Woon;Yoon, Yong-Nam
    • Journal of Korea Water Resources Association
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    • v.37 no.5
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    • pp.353-361
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    • 2004
  • Effective storage in agricultural reservoir has been determined through the reservoir simulation operation based on the water budget analysis. Since each watershed has the native property for runoff, considering the runoff yielding from the basin is feasible to the determination of reservoir effective storage. In this study the stochastic linear programming model considering mainly runoff from watershed has been also formulated to analyze the effective storage of the exiting reservoir. The linear decision rule coupled with chance-constrained model in the linear programming model contributes to reduce the size of linear program model without considering the period of analysis. The Geum-Gang reservoir located in Ansung have been adopted to evaluate the effective storage. It has been shown that the effective storage based on the linear programming model is greater than that based on the water budget analysis. It has been also desired that once the effective storage is obtained through the linear programming model, operation of the reservoir should be performed to check the designed capacity.

Analysis of Boundary Conditions for Activities' Relationships in Linear Scheduling Model (선형 공정계획 모델의 액티비티 관계의 경계조건 분석)

  • Ryu, Han-Guk;Kim, Tae-Hui
    • Korean Journal of Construction Engineering and Management
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    • v.12 no.1
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    • pp.23-32
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    • 2011
  • Domestic leading construction companies has been establishing and performing TACT scheduling method, similar to linear scheduling model such as line of balance and repetitive schedule, and etc. in which repetitive construction works are involved like high-rise building. Linear scheduling model has been researched as a visual scheduling method presenting the work space and time information. Likewise scheduling constraints of CPM network such as finish-to-finish, start-to-start, finish-to-start, start-to-start, linear scheduling model also has the relationships constraints, namely boundary conditions, between activities. It is especially necessary to define the boundary conditions of the activities' relationships in order to apply the linear scheduling model to be compatible with the network schedule. Therefore, this research considers the boundary conditions between activities for establishing the linear scheduling model. This paper also applies the proposed boundary conditions to TACT schedule and then deduces the main considerations in order to establish and perform TACT schedule.

Effects of the Non-linear Stress-Strain Behavior of RAP Concrete on Structural Responses for Rigid Pavement Application (RAP 콘크리트의 비선형 응력-변형률 특성이 강성포장 구조해석에 미치는 영향)

  • Kim, Kukjoo;Chun, Sanghyun;Park, Bongsuk;Tia, Mang
    • International Journal of Highway Engineering
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    • v.19 no.1
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    • pp.37-44
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    • 2017
  • PURPOSES : This study is primarily focused on evaluating the effects of the non-linear stress-strain behavior of RAP concrete on structural response characteristics as is applicable to concrete pavement. METHODS : A 3D FE model was developed by incorporating the actual stress-strain behavior of RAP concrete obtained via flexural strength testing as a material property model to evaluate the effects of the non-linear stress-strain behavior to failure on the maximum stresses in the concrete slab and potential performance prediction results. In addition, a typical linear elastic model was employed to analyze the structural responses for comparison purposes. The analytical results from the FE model incorporating the actual stress-strain behavior of RAP concrete were compared to the corresponding results from the linear elastic FE model. RESULTS : The results indicate that the linear elastic model tends to yield higher predicted maximum stresses in the concrete as compared to those obtained via the actual stress-strain model. Consequently, these higher predicted stresses lead to a difference in potential performance of the concrete pavement containing RAP. CONCLUSIONS : Analysis of the concrete pavement containing RAP demonstrated that an appropriate analytical model using the actual stress-strain characteristics should be employed to calculate the structural responses of RAP concrete pavement instead of simply assuming the concrete to be a linear elastic material.

Feedback Linearization Control of the Looper System in Hot Strip Mills

  • Hwang, I-Cheol;Kim, Seong-Bae
    • Journal of Mechanical Science and Technology
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    • v.17 no.11
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    • pp.1608-1615
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    • 2003
  • This paper studies on the linearization of a looper system in hot strip mills, that plays an important role in regulating a strip tension or a strip width. Nonlinear dynamic equations of the looper system are analytically linearized by a static feedback linearization algorithm with a compensator. The proposed linear model of the looper is validated by a comparison with a linear model using Taylor's series. It is shown that the linear model by static feedback well describes nonlinearities of the looper system than one using Taylor's series. Furthermore, it is shown from the design of an ILQ controller that the linear model by static feedback is very useful in designing a linear controller of the looper system.

Mean-VaR Portfolio: An Empirical Analysis of Price Forecasting of the Shanghai and Shenzhen Stock Markets

  • Liu, Ximei;Latif, Zahid;Xiong, Daoqi;Saddozai, Sehrish Khan;Wara, Kaif Ul
    • Journal of Information Processing Systems
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    • v.15 no.5
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    • pp.1201-1210
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    • 2019
  • Stock price is characterized as being mutable, non-linear and stochastic. These key characteristics are known to have a direct influence on the stock markets globally. Given that the stock price data often contain both linear and non-linear patterns, no single model can be adequate in modelling and predicting time series data. The autoregressive integrated moving average (ARIMA) model cannot deal with non-linear relationships, however, it provides an accurate and effective way to process autocorrelation and non-stationary data in time series forecasting. On the other hand, the neural network provides an effective prediction of non-linear sequences. As a result, in this study, we used a hybrid ARIMA and neural network model to forecast the monthly closing price of the Shanghai composite index and Shenzhen component index.

A Theoretical Review on the Community Attachment (지역사회친밀도에 관한 이론적 연구)

  • Choi, Chang-Wook;Kim, Sung-Soo;Yoon, Joon-Sang;Park, Duk-Byeung
    • Journal of Agricultural Extension & Community Development
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    • v.4 no.1
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    • pp.317-327
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    • 1997
  • The objectives of this study were to review studies on the community attachment and to identify it's related variables. Community attachment variables were divided into linear development model variables and system model variables. The theoretical base for linear development model originated from Ferdinand Toennies(1957) and system model was from Kasarda and Janowitz(1974). Linear development model variables were population size and density. And system model variables were age, education, income, number of children, marital status, length of residence, sex, and job. Recent studies on the community attachment were being carried out through system model than linear development model.

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A Statistical Model for Marker Position in Biomechanics

  • Kim, Jinuk
    • Korean Journal of Applied Biomechanics
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    • v.27 no.1
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    • pp.67-74
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    • 2017
  • Objective: The purpose of this study was to apply a general linear model in statistics to marker position vectors used to study human joint rotational motion in biomechanics. Method: For this purpose, a linear model that represents the effect of the center of hip joint rotation and the rotation of the marker position on the response was formulated. Five male subjects performed hip joint functional motions, and the positions of nine markers attached on the thigh with respect to the pelvic coordinate system were acquired at the same time. With the nine marker positions, the center of hip joint rotation and marker positions on the thigh were estimated as parameters in the general linear model. Results: After examining the fitted model, this model did not fit the data appropriately. Conclusion: A refined model is required to take into account specific characteristics of longitudinal data and other covariates such as soft tissue artefacts.