• Title/Summary/Keyword: Model simplification

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Optimal management of multi-airport opening non-real time network system

  • Wang, Zhanwei;Heo, Hui-Yeong
    • 한국항공운항학회:학술대회논문집
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    • 2016.05a
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    • pp.269-275
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    • 2016
  • This paper considers the arrival, airport and departure capacity as a whole, through which, the network effect between airports is fully emphasized, the flight action is coordinated, and the flight demand pattern is reasonably assigned. The optimization problem of flight queues in multi-airport is studied in detail; the mathematical model of multi-airport opening non-real time flow management in terminal area is established, and related problems such as the parameters, the simplification and the solving of the model are discussed in detail to some extent. Appropriate decision making variables are taken to make the multi-airport network system linear 0-1 integer programming model, thus, the solving of the model is available and the central flow management is realized. The heuristic implicit enumeration presented in this paper can effectively solve this kind of problems. Through the simulation of some airports network system, we not only validate the algorithm presented in this paper, but also give a deep analysis of the results, which would produce reference for later practicable use. The simulation proves that this algorithm offers a good way to settle the problem of multi-airport flight queue optimization in air traffic management automation system in terminal area.

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Integrated Application of Stormwater Network Analysis Model and Surfacewater Inundation Analysis Model (우수관망 해석모형과 지표수 침수해석 모형의 연계 적용)

  • Shin, Eun Taek;Lee, Sangeun;Eum, Tae Soo;Song, Chang Geun
    • Journal of the Korean Society of Safety
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    • v.33 no.5
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    • pp.78-83
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    • 2018
  • Recently, due to the rapid industrialization and urbanization, a great number of infrastructure and population were concentrated in urban areas. These changes have resulted in unprecedent runoff characteristics in urban basins, and the increase in impermeable areas leads to the growth of the runoff and the peak flow rate. Although many cities have made a lot of efforts to check and expand the stormwater network, the flash flood or the local torrential rain caused a growing number of casualty and property damage. This study analyzed the stormwater passage rate in a target area using SWMM. By incorporating the flow quantity surpassing the storm sewer capacity, a 2D inland flooding analysis model was applied to route the inundated area and velocity.

Analytic Solution for Stable Bipedal Walking Trajectory Generation Using Fourier Series (푸리에 급수를 이용한 이족보행로봇의 보행 궤적 해석해 생성)

  • Park, Ill-Woo;Back, Ju-Hoon
    • Journal of Institute of Control, Robotics and Systems
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    • v.15 no.12
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    • pp.1216-1222
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    • 2009
  • This article describes a simple method for generating the walking trajectory for the biped humanoid robot. The method used a simple inverted model instead of complex multi-mass model and a reasonable explanation for the model simplification is included. The problem of gait trajectory generation is to find the solution from the desired ZMP trajectory to CoG trajectory. This article presents the analytic solution for the bipedal gait generation on the bases of ZMP trajectory. The presented ZMP trajectory has Fourier series form, which has finite or infinite summation of sine and cosine functions, and ZMP trajectory can be designed by calculating the coefficients. From the designed ZMP trajectory, this article focuses on how to find the CoG trajectory with analytical way from the simplified inverted pendulum model. Time segmentation based approach is adopted for generating the trajectories. The coefficients of the function should be designed to be continuous between the segments, and the solution is found by calculating the coefficients with this connectivity conditions. This article also has the proof and the condition of solution existence.

Shape Optimization for Enhancing the Performance of an Inducer for the Main Hydraulic Pump in a Rotary Wing Aircraft (회전익 항공기 주유압펌프용 인듀서 성능 향상을 위한 형상최적설계)

  • Kim, Hyogyeum;Heo, Hyeungseok;Park, Youngil;Lee, Changdon
    • Journal of Drive and Control
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    • v.14 no.2
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    • pp.37-44
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    • 2017
  • In this study, in order to prevent cavitation in a variable swash-plate type hydraulic pump, a basic model impeller has been applied to a new pump, and the impeller shape has been optimized through flow analysis. Based on the analysis results, we could propose an impeller shape with high efficiency and low possibility of cavitation in comparison with the basic model. The simplification of the basic shape of the impeller of the hydraulic pump was performed in three parts in the order of hub shape, wing, and curvature, and eight design parameters were defined to satisfy the design requirement. Compared with the initial model of the impeller, when the differential pressure of the optimum model increased, the efficiency was improved. It achieved the goal of design improvement because cavitation did not occur under the rated operating conditions.

Modeling Methods for SPOT-5 HRG Stereo Pair Images (SPOT-5(HRG) 입체위성영상의 3차원 모델링 기법 연구)

  • 최선용;신대식;이용웅
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.21 no.3
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    • pp.255-260
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    • 2003
  • In this paper, we generate the 3D geometric sensor model of SPOT-5 HRG stereo images which are processed in Supermode and have 2.5m ground spatial resolution, and calculate the RPC(Rational Polynomial Coefficients) for acquisition of topographic information using the exterior orientation parameters which are determined in the 3D geometric sensor modelling process. It is shown that SPOT-5 images can be modelled with me 3.3m accuracy by the bundle adjustment method used to model the existing SPOT series. Considering the accuracy of RPC's results with rmse 0.03m accuracy, the RPC model can replace the sensor model, if we emphasize the simplification and the cost.

A Model of Pursuing Energy of Predator in Single Predator-Prey Environment (단일 포식자-희생자 환경에서 포식자 추격 에너지 모델)

  • Lee, Jae Moon;Kwon, Young Mee
    • Journal of Korea Game Society
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    • v.13 no.1
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    • pp.41-48
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    • 2013
  • In general, the predator-prey model has been studied as a model of struggle for existence in a ecosystem. While conventional papers have focussed on the population change of the predator-prey, this paper focused on controlling the energy needed for the predator to pursue the prey. For simplification, assume the environment which there are only single predator and prey. Based on the environment, a certain amount of energy needed for a predator to pursue the prey was suggested on a basis of physical theories and also the used energy model was suggested on a basis of the simulation. From experiments, it was proven that the suggested energy models were appropriate for natural pursuit.

The effect of mechanical properties of bone in the mandible, a numerical case study

  • Ramos, Antonio;Marques, Hugo;Mesnard, Michel
    • Advances in biomechanics and applications
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    • v.1 no.1
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    • pp.67-76
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    • 2014
  • Bone properties are one of the key components when constructing models that can simulate the mechanical behavior of a mandible. Due to the complexity of the structure, the tooth, ligaments, different bones etc., some simplifications are often considered and bone properties are one of them. The objective of this study is to understand if a simplification of the problem is possible and assess its influence on mandible behavior. A cadaveric toothless mandible was used to build three computational models from CT scan information: a full cortical bone model; a cortical and cancellous bone model, and a model where the Young's modulus was obtained as function of the pixel value in a CT scan. Twelve muscle forces were applied on the mandible. Results showed that although all the models presented the same type of global behavior and proximity in some locations, the influence of cancellous bone can be seen in strain distribution. The different Young's modulus defined by the CT scan gray scale influenced the maximum and minimum strains. For modeling general behavior, a full cortical bone model can be effective. However, when cancellous bone is included, maximum values in thin regions increase the strain distribution. Results revealed that when properties are assigned to the gray scale some peaks could occur which did not represent the real situation.

A Multi-level Perception Security Model Using Virtualization

  • Lou, Rui;Jiang, Liehui;Chang, Rui;Wang, Yisen
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.12 no.11
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    • pp.5588-5613
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    • 2018
  • Virtualization technology has been widely applied in the area of computer security research that provides a new method for system protection. It has been a hotspot in system security research at present. Virtualization technology brings new risk as well as progress to computer operating system (OS). A multi-level perception security model using virtualization is proposed to deal with the problems of over-simplification of risk models, unreliable assumption of secure virtual machine monitor (VMM) and insufficient integration with virtualization technology in security design. Adopting the enhanced isolation mechanism of address space, the security perception units can be protected from risk environment. Based on parallel perceiving by the secure domain possessing with the same privilege level as VMM, a mechanism is established to ensure the security of VMM. In addition, a special pathway is set up to strengthen the ability of information interaction in the light of making reverse use of the method of covert channel. The evaluation results show that the proposed model is able to obtain the valuable risk information of system while ensuring the integrity of security perception units, and it can effectively identify the abnormal state of target system without significantly increasing the extra overhead.

An Analysis of Service Robot Quality Attributes through the Kano Model and Decision Tree : Financial Service Robot for Introduction to Bank Branches (카노와 의사결정나무를 활용한 금융서비스 로봇의 품질속성 분석 : 은행지점 도입용 금융서비스 로봇 사례)

  • Song, Young-gue;Lee, Jungwoo;Han, Chang Hee
    • Journal of Information Technology Services
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    • v.20 no.2
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    • pp.111-126
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    • 2021
  • A Kano model was used to classify the quality attributes of the service robot function for actual deployment that can support and replace bank employees. Quality attributes for a total of 6 dimensions and 23 service elements were divided into bank employees and customer groups, and service priorities were derived after comparative analysis. The Decision tree model was used to supplement the excessive simplification of quality attributes by the modest number of Kano models and to classify and predict by segment market. Of the 23 services, 16 were classified into the same attributes in both groups. 6 services classified as combination attributes used a Decision tree to identify differences in perception of quality attributes among groups. In terms of basic financial services and professional financial services, it was confirmed that bank employees feel financial service robots more attractive than ordinary customers. In the design of IT convergence service, we propose a methodology for deriving quality attributes by combining a Kano model for classifying quality attributes of two groups and a Decision tree for forecasting subdivision markets.

Random dynamic analysis for simplified vehicle model based on explicit time-domain method

  • Huan Huang;Yuyu Li;Wenxiong Li;Guihe Tang
    • Coupled systems mechanics
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    • v.12 no.1
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    • pp.1-20
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    • 2023
  • On the basis of the explicit time-domain method, an investigation is performed on the influence of the rotational stiffness and rotational damping of the vehicle body and front-rear bogies on the dynamic responses of the vehicle-bridge coupled systems. The equation of motion for the vehicle subsystem is derived employing rigid dynamical theories without considering the rotational stiffness and rotational damping of the vehicle body, as well as the front-rear bogies. The explicit expressions for the dynamic responses of the vehicle and bridge subsystems to contact forces are generated utilizing the explicit time-domain method. Due to the compact wheel-rail model, which reflects the compatibility requirement of the two subsystems, the explicit expression of the evolutionary statistical moment for the contact forces may be performed with relative ease. Then, the evolutionary statistical moments for the respective responses of the two subsystems can be determined. The numerical results indicate that the simplification of vehicle model has little effect on the responses of the bridge subsystem and the vehicle body, except for the responses of the rotational degrees of freedom for the vehicle subsystem, regardless of whether deterministic or random analyses are performed.