A Low-Cost Model-based Capacity Analysis in Production Environments

2008 ◽  
Author(s):  
Hua Liu ◽  
Tong Sun
Keyword(s):  
Cost Model ◽  
Low Cost ◽  
Capacity Analysis ◽  
Model Based ◽  
Production Environments

Analysis and optimization of assembly precision-cost model based on 3D tolerance expression

2018 ◽  
Vol 38 (4) ◽  
pp. 497-510 ◽  
Author(s):  
Wei Sun ◽  
Xiaokai Mu ◽  
Qingchao Sun ◽  
Zhiyong Sun ◽  
Xiaobang Wang
Keyword(s):  
Upper Bound ◽  
Cost Model ◽  
Low Cost ◽  
Great Influence ◽  
Small Displacement ◽  
Content Type ◽  
Model Based ◽  
Manufacturing Tolerances ◽  
Assembly Deviation ◽  
Assembly Precision

PurposeThis paper aims to comprehensively achieve the requirements of high assembly precision and low cost, a precision-cost model of assembly based on three-dimensional (3D) tolerance is established in this paper.Design/methodology/approachThe assembly precision is related to the tolerance of parts and the deformation of matching surfaces under load. In this paper, the small displacement torsor (SDT) theory is first utilized to analyze the manufacturing tolerances of parts and the assembly deformation deviation of matching surface. In the meanwhile, the extracting method of SDT parameters is proposed and the assembly precision calculation model based on the 3D tolerance is established. Second, an integrated optimization model based on the machining cost, assembly cost (mapping the deviation domain to the SDT domain) and quality loss cost is built. Finally, the practicability of the precision-cost model is verified by optimizing the horizontal machining center.FindingsThe assembly deviation has a great influence on cost fluctuation. By setting the optimization objective to maximize the assembly precision, the optimal total cost is CNY 72.77, decreasing by 16.83 per cent from the initial value, which meets economical requirements. Meanwhile, the upper bound of each processing tolerance is close to the maximum value of 0.01 mm, indicating that the load deformation can be offset by appropriately increasing the upper bound of the tolerance, but it is necessary to strictly restrict the manufacturing tolerances of lower parts in a reasonable range.Originality/valueIn this paper, a 3D deviation precision-cost model of assembly is established, which can describe the assembly precision more accurately and achieve a lower cost compared with the assembly precision model based on rigid parts.

Ritz Model of a Lead-Acid Battery With Application to Electric Locomotives

2011 ◽  
Author(s):  
Zheng Shen ◽  
Jun Gou ◽  
Christopher D. Rahn ◽  
Chao-Yang Wang
Keyword(s):  
Discharge Rate ◽  
Cost Model ◽  
Low Cost ◽  
Storage System ◽  
Ritz Method ◽  
Open Circuit ◽  
Electric Locomotive ◽  
Governing Equations ◽  
Model Based ◽  
Charge Discharge

Pb-Acid batteries are excellent candidates for hybrid and electric locomotive, primarily due to their low cost. Model-based design, estimation, and control of a Pb-Acid energy storage system for a locomotive requires the development of efficient and accurate models. This paper presents a first principles model based on the fundamental governing equations of species and charge conservation for a Pb-Acid cell. The governing equations are discretized using a Ritz method to produce a low order and numerically efficient model that simulates over 20 times faster than CFD. The Ritz model outputs variables of interest such as voltage and internal potential, current, and concentration distributions in response to the current input. The Ritz model can be cast in state variable form, making it amenable to systems analysis using Matlab and model-based estimator and controller design. The accuracy of the Ritz model decreases with increasing charge/discharge rate, low or high State of Charge, and increasing charge/discharge time due to linearization of the Butler-Volmer equation, linearization of the open circuit voltage, and constant porosity assumptions, respectively. Finally, the time constant during charge is significantly different than that during discharge due to different specific areas, motivating the use of a time-varying model.

scholarly journals Urban Air Quality Modeling Using Low-Cost Sensor Network and Data Assimilation in the Aburrá Valley, Colombia

Atmosphere ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 91
Author(s):  
Santiago Lopez-Restrepo ◽  
Andres Yarce ◽  
Nicolás Pinel ◽  
O.L. Quintero ◽  
Arjo Segers ◽  
...  
Keyword(s):  
Air Quality ◽  
Data Assimilation ◽  
Transport Model ◽  
Cost Model ◽  
Low Cost ◽  
Model Performance ◽  
Monitoring Network ◽  
Correlation Factor ◽  
Chemical Transport Model ◽  
High Quality

The use of low air quality networks has been increasing in recent years to study urban pollution dynamics. Here we show the evaluation of the operational Aburrá Valley’s low-cost network against the official monitoring network. The results show that the PM2.5 low-cost measurements are very close to those observed by the official network. Additionally, the low-cost allows a higher spatial representation of the concentrations across the valley. We integrate low-cost observations with the chemical transport model Long Term Ozone Simulation-European Operational Smog (LOTOS-EUROS) using data assimilation. Two different configurations of the low-cost network were assimilated: using the whole low-cost network (255 sensors), and a high-quality selection using just the sensors with a correlation factor greater than 0.8 with respect to the official network (115 sensors). The official stations were also assimilated to compare the more dense low-cost network’s impact on the model performance. Both simulations assimilating the low-cost model outperform the model without assimilation and assimilating the official network. The capability to issue warnings for pollution events is also improved by assimilating the low-cost network with respect to the other simulations. Finally, the simulation using the high-quality configuration has lower error values than using the complete low-cost network, showing that it is essential to consider the quality and location and not just the total number of sensors. Our results suggest that with the current advance in low-cost sensors, it is possible to improve model performance with low-cost network data assimilation.

scholarly journals A decision support approach to designing the inland logistics network in China

2007 ◽  
Vol 18 (1) ◽  
pp. 56-79
Author(s):  
Hokey Min ◽  
Hyun-Jeung Ko ◽  
Chin-Soo Lin
Keyword(s):  
Decision Support ◽  
Decision Support System ◽  
Support System ◽  
Multinational Firms ◽  
Low Cost ◽  
Path Model ◽  
Multinational Firm ◽  
Real Problem ◽  
Chinese Market ◽  
Model Based

With the unprecedented growth of international trade, a growing number of multinational firms have coped with logistical challenges of shipping products to and from unfamiliar territories in many countries. These logistical challenges include the cross-border transportation of products originated from inland port to another inland port isolated from major waterways. In particular, the lack of access to major waterways would not only constrain the intermodal transportation option, but also make door-to-door, containerized delivery services nearly impossible. Such a limited option would eventually lead to increased transportation costs and transit time, and thereby offset low-cost global sourcing advantages. To aid multinational firms in addressing the problem of determining the optimal supply chain link between inland origin and destinations ports, this article proposes a shortest-path model based decision support system. The usefulness of the proposed model-based decision support system was validated by its application to a real problem encountered by a multinational firm that would like to strengthen its foothold in the Chinese market.

Reconstruction of Kyoto of the Edo era based on arts and historical documents: 3D urban model based on historical GIS data

2009 ◽  
Vol 3 (1-2) ◽  
pp. 21-38 ◽  
Author(s):  
Yuzuru Isoda ◽  
Akihiro Tsukamoto ◽  
Yoshihiro Kosaka ◽  
Takuya Okumura ◽  
Masakazu Sawai ◽  
...  
Keyword(s):  
Large Scale ◽  
Low Cost ◽  
3D Models ◽  
Historical Documents ◽  
Historical Gis ◽  
Model Based ◽  
Urban Model ◽  
Gis Data ◽  
Point Data

This paper explores a method for creating large-scale urban 3D models using Historical GIS data. The method is capable of automatically generating realistic VR models based on GIS data at a low cost. 3D models of houses are created from polygon data, fences from line data, and pedestrians and trees from point data. The method is applied to the Virtual Kyoto Project in which the landscape of the whole city of Kyoto of the early Edo era (ca 17C) is reconstructed.

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