• Title/Summary/Keyword: Bi-Level Model

Search Result 87, Processing Time 0.028 seconds

Optimization of Train Working Plan based on Multiobjective Bi-level Programming Model

  • Hai, Xiaowei;Zhao, Chanchan
    • Journal of Information Processing Systems
    • /
    • v.14 no.2
    • /
    • pp.487-498
    • /
    • 2018
  • The purpose of the high-speed railway construction is to better satisfy passenger travel demands. Accordingly, the design of the train working plan must also take a full account of the interests of passengers. Aiming at problems, such as the complex transport organization and different speed trains coexisting, combined with the existing research on the train working plan optimization model, the multiobjective bi-level programming model of the high-speed railway passenger train working plan was established. This model considers the interests of passengers as the center and also takes into account the interests of railway transport enterprises. Specifically, passenger travel cost and travel time minimizations are both considered as the objectives of upper-level programming, whereas railway enterprise profit maximization is regarded as the objective of the lower-level programming. The model solution algorithm based on genetic algorithm was proposed. Through an example analysis, the feasibility and rationality of the model and algorithm were proved.

A BI-Level Programming Model for Transportation Network Design (BI-Level Programming 기법을 이용한 교통 네트워크 평가방법 연구)

  • Kim, Byung-Jong;Kim, Won-Kyu
    • Journal of Korean Society of Transportation
    • /
    • v.23 no.7 s.85
    • /
    • pp.111-123
    • /
    • 2005
  • A network design model has been proposed. which represents a transportation facility investment decision problem. The model takes the discrete hi-level programming form in which two types of decision makers, government and travelers, are involved. The model is characterized by its ability to address the total social costs occurring in transportation networks and to estimate the equilibrium link volumes in multi-modal networks. Travel time and volume for each link in the multi-modal network are predicted by a joint modal split/traffic assignment model. An efficient solution algorithm has been developed and an illustrative example has been presented.

The Effects of Bojungikgitang-gamibang Administration along with Mahwangshingungsan on the Rat Model with Allergic Rhinitis (보중익기탕가미방(補中益氣湯加味方)과 마황신궁산(麻黃辛芎散) 병용이 알레르기 비염 유발 흰쥐 모델에 미치는 영향)

  • Yun, Chae-Sung;Hong, Seok-Hoon;Park, Min-Cheol;Hwang, Chung-Yeon
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
    • /
    • v.21 no.3
    • /
    • pp.111-123
    • /
    • 2008
  • Objectives : We aimed to investigate therapeutic effect of Bojungikgitang-gamibang(BI) and Mahwangshingungsan(MS) by observing changes in blood cells and the nasal mucosa of Sprague-Dawley(SD) rats with allergic rhinitis. Methods : Twenty-four SD rats were divided into three groups: normal, control, and sample group. Allergic rhinitis was induced in the control and sample group by intraperitoneal and intranasal sensitization with 0.1% and 0.4% Ovalbumin solution. Then BI was orally administered only to the sample group along with MS for 28days, while the rats in the control group was given normal saline. Results : BI and MS showed significantly decreased IgE level on the serum of the rat model, Bl and MS showed significantly decreased eosinophil level on the blood of the rat model. BI and MS inhibited the inflammatory reaction on the nasal mucosal tissue, according to nasal mucosal biopsy. Bl and MS had anti-allergic according to level, eosinophil level, nasal mucosal biopsy. BI and MS had no hepatoxicity, according to AST and ALT on the serum. Conclusion : According to the above results, it is considered that Bl and MS is helpful in treatment of allergic rhinitis.

  • PDF

Applying the Bi-level HMM for Robust Voice-activity Detection

  • Hwang, Yongwon;Jeong, Mun-Ho;Oh, Sang-Rok;Kim, Il-Hwan
    • Journal of Electrical Engineering and Technology
    • /
    • v.12 no.1
    • /
    • pp.373-377
    • /
    • 2017
  • This paper presents a voice-activity detection (VAD) method for sound sequences with various SNRs. For real-time VAD applications, it is inadequate to employ a post-processing for the removal of burst clippings from the VAD output decision. To tackle this problem, building on the bi-level hidden Markov model, for which a state layer is inserted into a typical hidden Markov model (HMM), we formulated a robust method for VAD not requiring any additional post-processing. In the method, a forward-inference-ratio test was devised to detect the speech endpoints and Mel-frequency cepstral coefficients (MFCC) were used as the features. Our experiment results show that, regarding different SNRs, the performance of the proposed approach is more outstanding than those of the conventional methods.

A Methodology of Path based User Equilibrium Assignment in the Signalized Urban Road Networks (도시부 도로 네트워크에서 교통신호제어와 결합된 경로기반 통행배정 모형 연구)

  • Han, Dong-Hee;Park, Jun-Hwan;Lee, Young-Ihn;Lim, Kang-Won
    • Journal of Korean Society of Transportation
    • /
    • v.26 no.2
    • /
    • pp.89-100
    • /
    • 2008
  • In an urban network controlled by traffic signals, there is an interaction between the signal timing and the routes chosen by individual road users. This study develops a bi level programming model for traffic signal optimization in networks with path based traffic assignment. In the bi level programming model, genetic algorithm approach has been proposed to solve upper level problem for a signalized road network. Path based traffic assignment using column generation technique which is proposed by M.H. Xu, is applied at the lower-level. Genetic Algorithm provieds a feasible set of signal timings within specified lower and upper bounds signal timing variables and feeds into lower level problem. The performance of this model is investigated in numerical experiment in a sample network. In result, optimal signal settings and user equilibrium flows are made.

Prediction of Student's Interest on Sports for Classification using Bi-Directional Long Short Term Memory Model

  • Ahamed, A. Basheer;Surputheen, M. Mohamed
    • International Journal of Computer Science & Network Security
    • /
    • v.22 no.10
    • /
    • pp.246-256
    • /
    • 2022
  • Recently, parents and teachers consider physical education as a minor subject for students in elementary and secondary schools. Physical education performance has become increasingly significant as parents and schools pay more attention to physical schooling. The sports mining with distribution analysis model considers different factors, including the games, comments, conversations, and connection made on numerous sports interests. Using different machine learning/deep learning approach, children's athletic and academic interests can be tracked over the course of their academic lives. There have been a number of studies that have focused on predicting the success of students in higher education. Sports interest prediction research at the secondary level is uncommon, but the secondary level is often used as a benchmark to describe students' educational development at higher levels. An Automated Student Interest Prediction on Sports Mining using DL Based Bi-directional Long Short-Term Memory model (BiLSTM) is presented in this article. Pre-processing of data, interest classification, and parameter tweaking are all the essential operations of the proposed model. Initially, data augmentation is used to expand the dataset's size. Secondly, a BiLSTM model is used to predict and classify user interests. Adagrad optimizer is employed for hyperparameter optimization. In order to test the model's performance, a dataset is used and the results are analysed using precision, recall, accuracy and F-measure. The proposed model achieved 95% accuracy on 400th instances, where the existing techniques achieved 93.20% accuracy for the same. The proposed model achieved 95% of accuracy and precision for 60%-40% data, where the existing models achieved 93% for accuracy and precision.

Dynamic Origin-Destination Demand Estimation Using Traffic Data of VDS and AVI (VDS 및 AVI 자료를 이용한 고속도로 동적OD 추정)

  • Kim, Ju-Young;Lee, Seung-Jae;Lee, Young-Ihn;Son, Bong-Soo
    • Journal of Korean Society of Transportation
    • /
    • v.23 no.7 s.85
    • /
    • pp.125-136
    • /
    • 2005
  • The goal of this paper is to develop freeway Origin-Destination (OD) demand estimation model using VDS and AVI data. The formulation of methodology proposed in this paper includes traffic flow technique to be able to remove the bi-level problem and optimal solution algorithm using a kalman filter algorithm. The proposed dynamic OD estimation model use ilk and off-ramp volumes collected from VDS and partial OD collected from AVI data to raise the accuracy of dynamic OD estimation. The proposed model is evaluated by using the real-time data of SOHAEAN freeway, South Korea. The result of the proposed dynamic OD estimation model based on VDS and AVI data is better than that of based on VDS data. The more AVI systems are equipped at on and off-ramp, the more excellent result of estimation accuracy is expected.

Bi-static Low-frequency Reverberation Model in Shallow Water (천해 저주파 양상태 잔향음 모델)

  • 김남수;오선택;윤관섭;이성욱;나정열
    • The Journal of the Acoustical Society of Korea
    • /
    • v.22 no.6
    • /
    • pp.472-481
    • /
    • 2003
  • Low-frequency hi-static reverberation model (LHYREV-B, Low-frequency Hanyang univ. Reverberation model-Bistatic) based on the parabolic approximation for shallow water environment is presented. In this paper bistatic reverberation level is computed using the angle-independent scattering strength function and the wave-based acoustic model. The signal simulated by the LHYREV-B model is compared with the observed signals and it is shown that the LHYREV-B model provides a closer fit to the observed signals.

A Model and Algorithm for Optimizing the Location of Transit Transfer Centers (대중교통 환승센터 입지선정 모형 연구)

  • Yoo, Gyeong-Sang
    • Journal of Korean Society of Transportation
    • /
    • v.30 no.1
    • /
    • pp.125-133
    • /
    • 2012
  • This paper deals with the passenger transfer trips counted from smart bus-card data from Seoul transit network to understand the current operational condition of the system. Objective of this study is to relocate the location of the transit transfer centers. It delivers a bi-level programing model. The upper model is a linear 0-1 binary integer program having the objective of total travel cost minimization constrained by the number of transfer centers and the total construction budget. The lower model is an user equilibrium assignment model determining the passengers' route choice according to the transfer center locations. The proposed bi-level programming model was tested in an example network. The result showed that the proposed was able to find the optimal solution.

Transit Frequency Optimization with Variable Demand Considering Transfer Delay (환승지체 및 가변수요를 고려한 대중교통 운행빈도 모형 개발)

  • Yu, Gyeong-Sang;Kim, Dong-Gyu;Jeon, Gyeong-Su
    • Journal of Korean Society of Transportation
    • /
    • v.27 no.6
    • /
    • pp.147-156
    • /
    • 2009
  • We present a methodology for modeling and solving the transit frequency design problem with variable demand. The problem is described as a bi-level model based on a non-cooperative Stackelberg game. The upper-level operator problem is formulated as a non-linear optimization model to minimize net cost, which includes operating cost, travel cost and revenue, with fleet size and frequency constraints. The lower-level user problem is formulated as a capacity-constrained stochastic user equilibrium assignment model with variable demand, considering transfer delay between transit lines. An efficient algorithm is also presented for solving the proposed model. The upper-level model is solved by a gradient projection method, and the lower-level model is solved by an existing iterative balancing method. An application of the proposed model and algorithm is presented using a small test network. The results of this application show that the proposed algorithm converges well to an optimal point. The methodology of this study is expected to contribute to form a theoretical basis for diagnosing the problems of current transit systems and for improving its operational efficiency to increase the demand as well as the level of service.