Bowen Zheng, Mudasir Hussain, Yang Yang, Albert P.C. Chan and Hung-Lin Chi
In the last decades, various building information modeling–life cycle assessment (BIM-LCA) integration approaches have been developed to assess the environmental impact of the…
Abstract
Purpose
In the last decades, various building information modeling–life cycle assessment (BIM-LCA) integration approaches have been developed to assess the environmental impact of the built asset. However, there is a lack of consensus on the optimal BIM-LCA integration approach that provides the most accurate and efficient assessment outcomes. To compare and determine their accuracy and efficiency, this study aimed to investigate four typical BIM-LCA integration solutions, namely, conventional, parametric modeling, plug-in and industry foundation classes (IFC)-based integration.
Design/methodology/approach
The four integration approaches were developed and applied using the same building project. A quantitative technique for evaluating the accuracy and efficiency of BIM-LCA integration solutions was used. Four indicators for assessing the performance of BIM-LCA integration were (1) validity of LCA results, (2) accuracy of bill-of-quantity (BOQ) extraction, (3) time for developing life cycle inventories (i.e. developing time) and (4) time for calculating LCA results (i.e. calculation time).
Findings
The results show that the plug-in-based approach outperforms others in developing and calculation time, while the conventional one could derive the most accuracy in BOQ extraction and result validity. The parametric modeling approach outperforms the IFC-based method regarding BOQ extraction, developing time and calculation time. Despite this, the IFC-based approach produces LCA outcomes with approximately 1% error, proving its validity.
Originality/value
This paper forms one of the first studies that employ a quantitative and objective method to determine the performance of four typical BIM-LCA integration solutions and reveal the trade-offs between the accuracy and efficiency of the integration approaches. The findings provide practical references for LCA practitioners to select appropriate BIM-LCA integration approaches for evaluating the environmental impact of the built asset during the design phase.
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Zheng Bo, Qi Zhao, Xiaorui Shuai, Jianhua Yan and Kefa Cen
– The purpose of this paper is to provide a quantitative assessment on the effect of wall roughness on the pressure drop of fluid flow in microchannels.
Abstract
Purpose
The purpose of this paper is to provide a quantitative assessment on the effect of wall roughness on the pressure drop of fluid flow in microchannels.
Design/methodology/approach
The wall roughness is generated by the method of random midpoint displacement (RMD) and the lattice Boltzmann BGK model is applied. The influences of Reynolds number, relative roughness and the Hurst exponent of roughness profile on the Poiseuille number are investigated.
Findings
Unlike the smooth channel flow, Reynolds number, relative roughness and the Hurst exponent of roughness profiles play critical roles on the Poiseuille number Po in rough microchannels. Modeling results indicate that, in rough microchannels, the rough surface configuration intensifies the flow-surface interactions and the wall conditions turn to dominate the flow characteristics. The perturbance of the local flows near the channel wall and the formation of recirculation regions are two main features of the flow-surface interactions.
Research limitations/implications
The fluid flow in parallel planes with surface roughness is considered in the current study. In other words, only two-dimensional fluid flow is investigated.
Practical implications
The LBM is a very useful tool to investigate the microscale flows.
Originality/value
A new method (RMD) is applied to generate the wall roughness in parallel plane and LBM is conducted to investigate the pressure drop characteristics in rough microchannels.
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Pengcheng Yan, Dongqing Liu and Bo Zheng
The purpose of this paper is to forecast the reliable storage life of a certain kind of equipment under the normal stress level.
Abstract
Purpose
The purpose of this paper is to forecast the reliable storage life of a certain kind of equipment under the normal stress level.
Design/methodology/approach
Through the stepping stress acceleration life test and the failure mechanism analysis, this paper aims to confirm the stress level for the stepping stress acceleration life test of a certain kind of equipment and establish the data processing mathematical model and storage life forecasting method.
Findings
The stress level for the stepping stress acceleration life test of a certain kind of equipment is confirmed and the data processing mathematical model and storage life forecasting method is established.
Research limitations/implications
Availability of data is the main limitation affecting which model will be applied.
Practical implications
Useful advice for products' storage life forecasting.
Originality/value
The paper presents a new approach to product storage life estimation.
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Dongqing Liu, Bo Zheng and Pengcheng Yan
The purpose of this paper is to put forward a method which uses a computer to make a large number of simulated tests and determine the reference value of a system reliability…
Abstract
Purpose
The purpose of this paper is to put forward a method which uses a computer to make a large number of simulated tests and determine the reference value of a system reliability index according to a unit reliability index.
Design/methodology/approach
At the beginning of conducting an index demonstration and development on a new system, its unit reliability index can already reflect the unit reliability level accurately. Based on this characteristic, this index is used as the confidence lower limit of single side estimated in the unit reliability interval to find the failure distribution law of the unit. On this basis, a great number of simulated tests are made by a computer to calculate the unit failure number and reliability point estimated value every test.
Findings
The confidence lower limit of single side estimated in the system reliability interval is found by counting up the simulated test data of these units.
Research limitations/implications
Availability of data is the main limitation regarding which model will be applied.
Practical implications
A useful advice for system reliability analysis and calculation.
Originality/value
This paper presents a new approach of system reliability analysis.
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Bo Zheng, Fangping Cai and Jun Xu
Aiming at the product with long storage and one‐time application, this paper establishes the mathematical model of storage reliability and mathematical model system storage…
Abstract
Aiming at the product with long storage and one‐time application, this paper establishes the mathematical model of storage reliability and mathematical model system storage reliability. According to the reliability test data of every part (subsystem) of the product, it evaluates the system reliability of the product and reliable storage life, and lower limit of system storage reliability and lower limit of reliable storage life on the credible level.
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Kunyong Chen, Yong Zhao, Jiaxiang Wang, Hongwen Xing and Zhengjian Dong
This paper aims to propose a fast and robust 3D point set registration method for pose estimation of assembly features with few distinctive local features in the manufacturing…
Abstract
Purpose
This paper aims to propose a fast and robust 3D point set registration method for pose estimation of assembly features with few distinctive local features in the manufacturing process.
Design/methodology/approach
The distance between the two 3D objects is analytically approximated by the implicit representation of the target model. Specifically, the implicit B-spline surface is adopted as an interface to derive the distance metric. With the distance metric, the point set registration problem is formulated into an unconstrained nonlinear least-squares optimization problem. Simulated annealing nested Gauss-Newton method is designed to solve the non-convex problem. This integration of gradient-based optimization and heuristic searching strategy guarantees both global robustness and sufficient efficiency.
Findings
The proposed method improves the registration efficiency while maintaining high accuracy compared with several commonly used approaches. Convergence can be guaranteed even with critical initial poses or in partial overlapping conditions. The multiple flanges pose estimation experiment validates the effectiveness of the proposed method in real-world applications.
Originality/value
The proposed registration method is much more efficient because no feature estimation or point-wise correspondences update are performed. At each iteration of the Gauss–Newton optimization, the poses are updated in a singularity-free format without taking the derivatives of a bunch of scalar trigonometric functions. The advantage of the simulated annealing searching strategy is combined to improve global robustness. The implementation is relatively straightforward, which can be easily integrated to realize automatic pose estimation to guide the assembly process.
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The purpose of this paper is to explore how a neo-liberal nationalist discourse of China imagines the spatial identity of the post-1997 Hong Kong with reference to Lost in Hong…
Abstract
Purpose
The purpose of this paper is to explore how a neo-liberal nationalist discourse of China imagines the spatial identity of the post-1997 Hong Kong with reference to Lost in Hong Kong, a new Chinese middle-class film in 2015 with successful box office sales.
Design/methodology/approach
Textual analysis with the aid of psychoanalysis, postcolonial studies and semiotics is used to interpret the meaning of the film in this study. The study also utilizes the previous literature reviews about the formation of the Chinese national identity to help analyze the distinct identity of the Chinese middle class today.
Findings
The discussion pinpoints how the new Chinese middle class as neo-liberal nationalists take Hong Kong as a “bizarre national redemptive space”. While Hong Kong is cinematically constructed as such a national other, this paper argues that the Hong Kong in question stands not for itself but in a form of “reverse hallucination” for pacifying the new Chinese middle class’ trauma under the rapid neo-liberalization of China in the 1990s.
Originality/value
This paper shows the new of formation of the Chinese nationalist’s discourse, especially the new Chinese middle-class discourse on Hong Kong after 1997.
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Tong Che, Meng Ji, Xiabing Zheng and Bo Feng
The online-to-offline (O2O) business is developing rapidly and is highly popular in many countries. Nevertheless, O2O suffers from a large number of customer complaints that…
Abstract
Purpose
The online-to-offline (O2O) business is developing rapidly and is highly popular in many countries. Nevertheless, O2O suffers from a large number of customer complaints that result in consumer loss. Focusing on the O2O context, this study integrates expectation disconfirmation theory (EDT) and justice theory to investigate consumers' dissatisfaction toward O2O websites.
Design/methodology/approach
A research model was proposed and tested using 329 survey responses.
Findings
Results show that the identified website disconfirmation and offline service disconfirmation could lead to consumer dissatisfaction. Importantly, the impacts of disconfirmation factors are contingent upon the justice perception of consumers. When a transaction is perceived as unfair, website disconfirmation arouses a higher level of dissatisfaction, and the negative emotions could transfer from O2O and damage the website's reputation.
Originality/value
This study explores the continuance intentions of customers toward O2O websites from a dissatisfaction perspective, with insights for future service studies and O2O service managers.
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Wei Xue, Rencheng Zheng, Bo Yang, Zheng Wang, Tsutomu Kaizuka and Kimihiko Nakano
Automated driving systems (ADSs) are being developed to avoid human error and improve driving safety. However, limited focus has been given to the fallback behavior of automated…
Abstract
Purpose
Automated driving systems (ADSs) are being developed to avoid human error and improve driving safety. However, limited focus has been given to the fallback behavior of automated vehicles, which act as a fail-safe mechanism to deal with safety issues resulting from sensor failure. Therefore, this study aims to establish a fallback control approach aimed at driving an automated vehicle to a safe parking lane under perceptive sensor malfunction.
Design/methodology/approach
Owing to an undetected area resulting from a front sensor malfunction, the proposed ADS first creates virtual vehicles to replace existing vehicles in the undetected area. Afterward, the virtual vehicles are assumed to perform the most hazardous driving behavior toward the host vehicle; an adaptive model predictive control algorithm is then presented to optimize the control task during the fallback procedure, avoiding potential collisions with surrounding vehicles. This fallback approach was tested in typical cases related to car-following and lane changes.
Findings
It is confirmed that the host vehicle avoid collision with the surrounding vehicles during the fallback procedure, revealing that the proposed method is effective for the test scenarios.
Originality/value
This study presents a model for the path-planning problem regarding an automated vehicle under perceptive sensor failure, and it proposes an original path-planning approach based on virtual vehicle scheme to improve the safety of an automated vehicle during a fallback procedure. This proposal gives a different view on the fallback safety problem from the normal strategy, in which the mode is switched to manual if a driver is available or the vehicle is instantly stopped.