A Service Flow Simulation Method Using Multi-aspect Scene Transition Nets (STNs) Modeling

Author(s):  
Takeshi Tateyama ◽  
Koji Kimita ◽  
Kentaro Watanabe ◽  
Ryosuke Chiba ◽  
Yoshiki Shimomura
Author(s):  
Takeshi Tateyama ◽  
Satoshi Mikoshiba ◽  
Koji Kimita ◽  
Kentaro Watanabe ◽  
Ryosuke Chiba ◽  
...  

Recently, a new academic field, “service engineering” has been very actively investigated. However, there are few effective methods and tools to simulate and evaluate services designed based on the concept of service engineering. In the past, the authors proposed a service flow simulation method using scene transition nets (STN) which is a graphic modeling and simulation method for discrete-continuous hybrid systems. However, this method does not consider how to model and simulate complex service flows including multiple layered, parallel, and interrupted structures and it is difficult to construct STN models of such complex systems using the existing STN concepts. In this paper, the authors propose a new STN modeling method using “multi-aspect STN modeling “ concepts in order to provide easy methods for modeling of such complex services. The experimental results for the modeling and simulation of a nursing service demonstrate the effectiveness of the proposed method.


Author(s):  
Takeshi Tateyama ◽  
Satoshi Mikoshiba ◽  
Yoshiki Shimomura ◽  
Seiichi Kawata

A new academic field, “service engineering” has emerged; it involves active investigation for increasing the productivities of service industries. However, there are only a few effective tools for the simulation and evaluation of complex services that have been designed using concepts from the field of service engineering. To overcome this shortcoming, the authors propose a multi-agent service flow simulation method using scene transition nets (STNs) that is a very useful graphical modeling and simulation method for application to discrete-continuous hybrid systems. This method treats services as complicated multi-agent and hybrid systems similar to manufacturing systems. To obtain realistic values of customer satisfaction, the authors input satisfaction-attribute value (S-AV) functions, which are often used in service engineering in service flow models using STN. This method visualizes discrete flows of services and temporal changes in the values of customer satisfaction and various other variables of service models. The authors present the results of the simulation of an online DVD rental service involving multiple agents to show the effectiveness of the proposed method that uses an STN GUI simulator developed by them.


2012 ◽  
Vol 43 (1-2) ◽  
pp. 54-63 ◽  
Author(s):  
Baohong Lu ◽  
Huanghe Gu ◽  
Ziyin Xie ◽  
Jiufu Liu ◽  
Lejun Ma ◽  
...  

Stochastic simulation is widely applied for estimating the design flood of various hydrosystems. The design flood at a reservoir site should consider the impact of upstream reservoirs, along with any development of hydropower. This paper investigates and applies a stochastic simulation approach for determining the design flood of a complex cascade of reservoirs in the Longtan watershed, southern China. The magnitude of the design flood when the impact of the upstream reservoirs is considered is less than that without considering them. In particular, the stochastic simulation model takes into account both systematic and historical flood records. As the reliability of the frequency analysis increases with more representative samples, it is desirable to incorporate historical flood records, if available, into the stochastic simulation model. This study shows that the design values from the stochastic simulation method with historical flood records are higher than those without historical flood records. The paper demonstrates the advantages of adopting a stochastic flow simulation approach to address design-flood-related issues for a complex cascade reservoir system.


2009 ◽  
Vol 2009.19 (0) ◽  
pp. 192-197
Author(s):  
Takeshi Tateyama ◽  
Seiichi Kawata ◽  
Yoshiki Shimomura ◽  
Tamio Arai ◽  
Yasuo Umeda ◽  
...  

2016 ◽  
Vol 10 (1) ◽  
pp. 848-858
Author(s):  
Jun Wang ◽  
Yan Yu ◽  
Xinfeng Wei ◽  
Qinghua Gong ◽  
Haixian Xiong

Debris flows are a common natural disaster in mountainous areas and often cause severe casualties and property loss. Debris-flow run-out effects analysis can provide an idea of the spatial risks posed to the downstream area of a debris flow, which is extremely important for local populations’ lives, disaster mitigation and planning the layout of economic construction. The objective of this study is to develop a new method to quantify debris flow run-out effects by combining debris flow simulation results and data for different types of land use within the inundated area. After a three-dimensional numerical simulation platform was established, the numerical simulation method was applied as a modeling tool to simulate the inundated areas and final buried depths under rainfalls with different return periods. The simulated result for flow depth under a 100-year return period rainfall event was validated based on field measurements. Finally, the debris-flow run-out effects under different return periods were analyzed by combining the simulation results and land use data. The proposed method can enhance the accuracy of debris-flow spatial risk assessment and has great value for application.


Author(s):  
Wen-Dar Guo ◽  
Jian-Hao Hong ◽  
Cheng-Hsin Chen ◽  
Chih-Chiang Su ◽  
Jihn-Sung Lai

The modeling of flood-induced bend scour near embankment toes can provide important information for river engineering, embankment safety warnings, and emergency action management. During the rainy seasons, short-term general scour and bend scour are the most common causes for the failure of reinforced concrete embankments in Taiwan. To gain a deeper understanding of the scouring process near levee foundations, this study proposed a straightforward and practical method for bend scour simulation. The proposed simulation method is subdivided into three stages: two-dimensional flow simulation, general scour estimation, and bend scour estimation. A new bend-scour computation equation is proposed and incorporated into a two-dimensional hydraulic finite-volume model for simulating the evolution of bend scour depth around embankment toes. The proposed method is applied to simulate the temporal evolution of bend scouring near the Shuideliaw Embankment on the Cho-Shui River in Taiwan, where serious failure occurred during the June 2012 monsoon. Field data were gathered using the numbered-brick technique at the Shuideliaw Embankment to demonstrate the accuracy of the proposed method. The results of the bend scour simulations compared reasonably well with field measurements, indicating close agreement in terms of water levels and bend scour depths near the Shuideliaw Embankment. The proposed method was found to quickly estimate the maximum short-term general scour and bend scour depths for further enhancement of the safety of the embankment toe.


2011 ◽  
Vol 2011.21 (0) ◽  
pp. 91-96
Author(s):  
Takeshi Tateyama ◽  
Satoshi Mikoshiba ◽  
Kentaro Watanabe ◽  
Ryosuke Chiba ◽  
Yoshiki Shimomura ◽  
...  

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