• 제목/요약/키워드: Nature of model

검색결과 1,935건 처리시간 0.028초

Modified Structural Modeling Method and Its Application: Behavior Analysis of Passengers for East Japan Railway Company

  • Nagata, Kiyoshi;Umezawa, Masashi;Amagasa, Michio;Sai, Fuyume
    • Industrial Engineering and Management Systems
    • /
    • 제7권3호
    • /
    • pp.245-256
    • /
    • 2008
  • In order to cope with the ill-defined problem of human behavior being immanent uncertainty, several methodologies have been studied in game theoretic, social psychological and political science frameworks. As methods to arrange system elements systematically and draw out the consenting structural model concretively, ISM, FSM and DEMATEL based on graph theory etc. have been proposed. In this paper, we propose a modified structural modeling method to recognize the nature of problem. We introduce the statistical method to adjust the establishment levels in group decision situation. From this, it will become possible to obtain effectively and smoothly the structural model of group members in comparison with the traditional methods. Further we propose a procedure for achieving the consenting structural model of group members based on the structural modeling method. By applying the method to recognize the nature of ill-defined problems, it will be possible to solve the given problem effectively and rationally. In order to inspect the effectiveness of the method, we conduct a practical problem as an empirical study: "Behavior analysis of passengers for the Joban line of East Japan Railway Company after new railway service of Tsukuba Express opened".

Stochastic Gradient Descent Optimization Model for Demand Response in a Connected Microgrid

  • Sivanantham, Geetha;Gopalakrishnan, Srivatsun
    • KSII Transactions on Internet and Information Systems (TIIS)
    • /
    • 제16권1호
    • /
    • pp.97-115
    • /
    • 2022
  • Smart power grid is a user friendly system that transforms the traditional electric grid to the one that operates in a co-operative and reliable manner. Demand Response (DR) is one of the important components of the smart grid. The DR programs enable the end user participation by which they can communicate with the electricity service provider and shape their daily energy consumption patterns and reduce their consumption costs. The increasing demands of electricity owing to growing population stresses the need for optimal usage of electricity and also to look out alternative and cheap renewable sources of electricity. The solar and wind energy are the promising sources of alternative energy at present because of renewable nature and low cost implementation. The proposed work models a smart home with renewable energy units. The random nature of the renewable sources like wind and solar energy brings an uncertainty to the model developed. A stochastic dual descent optimization method is used to bring optimality to the developed model. The proposed work is validated using the simulation results. From the results it is concluded that proposed work brings a balanced usage of the grid power and the renewable energy units. The work also optimizes the daily consumption pattern thereby reducing the consumption cost for the end users of electricity.

BEYOND LINEAR PROGRAMMING

  • Smith, Palmer W.;Phillips, J. Donal;Lucas, William H.
    • 한국경영과학회지
    • /
    • 제3권1호
    • /
    • pp.81-91
    • /
    • 1978
  • Decision models are an attempt to reduce uncertainty in the decision making process. The models describe the relationships of variables and given proper input data generate solutions to managerial problems. These solutions may not be answers to the problems for one of two reasons. First, the data input into the model may not be consistant with the underlying assumptions of the model being used. Frequently parameters are assumed to be deterministic when in fact they are probabilistic in nature. The second failure is that often the decision maker recognizes that the data available are not appropriate for the model being used and begins to collect the required data. By the time these data has been compiled the solution is no longer an answer to the problem. This relates to the timeliness of decision making. The authors point out throught the use of an illustrative problem that stocastic models are well developed and that they do not suffer from any lack of mathematical exactiness. The primary problem is that generally accepted procedures for data generation are historical in nature and not relevant for probabilistic decision models. The authors advocate that management information system designers and accountants must become more familiar with these decision models and the input data required for their effective implementation. This will provide these professionals with the background necessary to generate data in a form that makes it relevant and timely for the decision making process.

  • PDF

A biologically inspired model based on a multi-scale spatial representation for goal-directed navigation

  • Li, Weilong;Wu, Dewei;Du, Jia;Zhou, Yang
    • KSII Transactions on Internet and Information Systems (TIIS)
    • /
    • 제11권3호
    • /
    • pp.1477-1491
    • /
    • 2017
  • Inspired by the multi-scale nature of hippocampal place cells, a biologically inspired model based on a multi-scale spatial representation for goal-directed navigation is proposed in order to achieve robotic spatial cognition and autonomous navigation. First, a map of the place cells is constructed in different scales, which is used for encoding the spatial environment. Then, the firing rate of the place cells in each layer is calculated by the Gaussian function as the input of the Q-learning process. The robot decides on its next direction for movement through several candidate actions according to the rules of action selection. After several training trials, the robot can accumulate experiential knowledge and thus learn an appropriate navigation policy to find its goal. The results in simulation show that, in contrast to the other two methods(G-Q, S-Q), the multi-scale model presented in this paper is not only in line with the multi-scale nature of place cells, but also has a faster learning potential to find the optimized path to the goal. Additionally, this method also has a good ability to complete the goal-directed navigation task in large space and in the environments with obstacles.

자연형 호안공법을 적용한 소하천의 수리특성 분석 (Analysis of Hydrodynamic Characteristics Apply to Nature-Friendly Stream Protection Method)

  • 이강석;박종화;연규방
    • 한국관개배수논문집
    • /
    • 제17권2호
    • /
    • pp.71-81
    • /
    • 2010
  • Stream Pilot Project, which began in May 2003 and finished in December 2003, was selected to develop effective methods applicable to nature-like streams. Stream restoration projects aim to maintain or increase ecosystem goods and services while protecting downstream and coastal ecosystems. Fields environmental monitoring such as flow discharge and precipitation were conducted along the Idong stream for amount of channel zone change in 2007. This study selected three monitoring positions to measure the water level and discharge of flowing water. A stage-discharge relation is obtained from direct discharge measurements for three stations by fitting an empirical relationship to the data set. Since discharge measures are made only for low flow conditions, a curve of discharge against stage can then be built by fitting these data with a power curve. And this study used data obtained from floodmark checkup as well as HEC-RAS model to analyze the hydrodynamic characteristics of monitoring sites. Reach-averaged hydraulic parameters for the supply reach were calculated from the small area's HEC-RAS model for Idong stream, and a HEC-RAS model used to analyze hydraulics for a period in 2007, after the stream was considered bank stabilization.

  • PDF

Using Bayesian tree-based model integrated with genetic algorithm for streamflow forecasting in an urban basin

  • Nguyen, Duc Hai;Bae, Deg-Hyo
    • 한국수자원학회:학술대회논문집
    • /
    • 한국수자원학회 2021년도 학술발표회
    • /
    • pp.140-140
    • /
    • 2021
  • Urban flood management is a crucial and challenging task, particularly in developed cities. Therefore, accurate prediction of urban flooding under heavy precipitation is critically important to address such a challenge. In recent years, machine learning techniques have received considerable attention for their strong learning ability and suitability for modeling complex and nonlinear hydrological processes. Moreover, a survey of the published literature finds that hybrid computational intelligent methods using nature-inspired algorithms have been increasingly employed to predict or simulate the streamflow with high reliability. The present study is aimed to propose a novel approach, an ensemble tree, Bayesian Additive Regression Trees (BART) model incorporating a nature-inspired algorithm to predict hourly multi-step ahead streamflow. For this reason, a hybrid intelligent model was developed, namely GA-BART, containing BART model integrating with Genetic algorithm (GA). The Jungrang urban basin located in Seoul, South Korea, was selected as a case study for the purpose. A database was established based on 39 heavy rainfall events during 2003 and 2020 that collected from the rain gauges and monitoring stations system in the basin. For the goal of this study, the different step ahead models will be developed based in the methods, including 1-hour, 2-hour, 3-hour, 4-hour, 5-hour, and 6-hour step ahead streamflow predictions. In addition, the comparison of the hybrid BART model with a baseline model such as super vector regression models is examined in this study. It is expected that the hybrid BART model has a robust performance and can be an optional choice in streamflow forecasting for urban basins.

  • PDF

An extension plan of Yakushima Biosphere Reserve as a case study of consensus building of islanders

  • Matsuda, Hiroyuki;Yumoto, Takakazu;Okano, Takahiro;Tetsuka, Kenshi;Fujimaki, Aomi;Shioya, Katsunori
    • Journal of Ecology and Environment
    • /
    • 제38권2호
    • /
    • pp.241-247
    • /
    • 2015
  • A participatory approach of local stakeholders is important to create a balance between nature protection and the sustainable use of natural resources in a nature reserve and its vicinity area. The zoning and management policy of biosphere reserves (BRs) is a good example of this idea, especially for island reserves. Yakushima was inscribed as a World Natural Heritage (WH) in 1993. Almost all of its residents did not remember that Yakushima was a BR. In addition, Yakushima has some problems in nature reserve management. Overabundance of the deer population is a critical threat to both agriculture and natural vegetation in the world heritage site. There are too many tourists visiting the WH site and Nagata-hama beach. The beach is a Ramsar site and one of the most important spawning grounds of sea turtles in the north Pacific. Now, residents and the municipality have decided to reactivate the Yakushima BR. Although the Ministry of the Environment of Japan has an initiative to manage the WH and the Ramsar site, the BR is managed by the municipality and local stakeholders. Local activities of both nature conservation and the sustainable use of natural resources are encouraged in the BR site. The islanders willingly included all areas of the island into the BR site. Scientists who have participated in the Society of Yakushimaology have played a significant role to build trust between local stakeholders and to seek feasible policies on the nature reserves. The concept of the "Yakushima Environmental Culture Village" is a good model for the extension plan of the Yakushima and Kuchinoerabujima BRs.

자연기반해법 적용에 따른 강원도 양구군 해안면의 비점오염 저감 효과 추정 (Estimation of non-point pollution reduction effect of Haean Catchment by application of Nature-based Solutions)

  • 이지우;박찬
    • 한국환경복원기술학회지
    • /
    • 제25권3호
    • /
    • pp.47-62
    • /
    • 2022
  • The Ministry of Environment has been working to reduce the impact on biodiversity, ecosystems, and social costs caused by soil runoff from highland Agricultural fields by setting up non-point pollution source management districts. To reduce soil loss, runoff path reduction technology has been applied, but it has been less cost effective. In addition, non-point pollution sources cause environmental conflicts in downstream areas, and recently highland Agricultural fields are becoming vulnerable to climate change. The Ministry of Environment is promoting the optimal management plan in earnest to convert arable land into forests and grasslands, but since non-point pollution is not a simple environmental problem, it is necessary to approach it from the aspect of NbS(Nature-Based Solution). In this study, a scenario for applying the nature-based solution was established for three subwatersheds west of Haean-myeon, Yanggu-gun, Gangwon-do. The soil loss distribution was spatialized through GeoWEPP and the amount of soil loss was compared for the non-point pollution reduction effect of mixed forests and grasslands. When cultivated land with a slope of 20% or more and ginseng fields were restored to perennial grasslands and mixed forests, non-point pollution reduction effects of about 32% and 29.000 tons compared to the current land use were shown. Also, it was confirmed that mixed forest rather than perennial grassland is an effective nature-based solution to reduce non-point pollution.

모델오일을 이용한 파라핀 왁스의 침전 연구 (Study on Paraffin Wax Precipitation using Model Oils)

  • 오경석
    • 한국응용과학기술학회지
    • /
    • 제34권3호
    • /
    • pp.495-503
    • /
    • 2017
  • 파라핀 왁스가 녹아있는 왁스오일은 주위 온도가 내려감에 따라 왁스의 침전이 시작된다. 침전이 시작하는 온도를 왁스생성온도라 부르며, 왁스생성온도는 유동점 측정과 함께 왁스오일의 거동연구에 중요한 정보를 제공해 준다. 본 연구에서는 왁스가 함유된 모델오일을 제조하여, 왁스의 정량과 정성적인 차이에 따른 왁스생성온도와 유동점의 변화를 살펴보았다. 물이 포함되지 않은 왁스함유 모델오일의 경우, 그 투명성으로 인해 ASTM D2500을 통해 왁스생성온도 측정이 가능하다. 또한, 유동점 측정도 같은 장치를 사용하는 ASTM D97을 사용하여 측정할 수 있다. 물이 함유된 에멀젼 모델오일의 경우에는 시료의 불투명성으로 인해 우선 유동점을 중심으로 거동을 살펴보았다. 이후 에멀젼 모델오일의 왁스생성온도 측정은 적외선분광법을 활용하여 측정하였으며, 에멀젼을 형성하는 물의 함량에 따른 왁스생성온도의 경향성은 고찰을 통해 추가적인 실험이 필요할 것으로 판단되었다.

농촌체험관광마을의 협력관광 모델 개발 - 충북 청원군을 대상으로 - (Development of the Cooperative Tourism Model for Rural Experience Tourism Villages - Focused on the Cheongwon-gun, Chungbuk -)

  • 리신호;윤성수;송이;정다영;민흥기
    • 한국농공학회논문집
    • /
    • 제54권6호
    • /
    • pp.1-8
    • /
    • 2012
  • To increase the synergies of rural experience tourism and overcome the limitations rural tourism are study. A basic cooperative model and theme model have been set up and comprehensive cooperative tourism model has been offered. In order to the development of model example, experience resources has been investigated and problems and features for 7 rural experience tourism villages of Cheongwon have been identified. The basic cooperative model has been selected main line and part hub type. The theme model has been separated nature experience, history and character experience, traditional culture and theme experience, agriculture and rural area experience. Based on this, The thematic cooperative tourism model and the comprehensive cooperative tourism model, its a schedule have been exemplified.