A bilevel programming approach to assembly job shop scheduling

A bilevel programming approach for assembly job shop scheduling isproposed. Two levels of decision makers are identified in the model. The firstlevel is the project manager and the second level is the shop floor manager. Thefirst level aims to minimize the earliness and tardiness ofcompleted jobs. Thesecond level aims to minimize the average shop floor throughput time. Becausetheir aims may conflict, these levels optimize their own objectives based on anon-cooperative game playing process. Their decision variables are denoted byorder release mechanisms and dispatching rules respectively. Using a simulationapproach, this paper identifies the best choice for the project manager underdifferent job shop utilization levels. The research findings can providemanagerial guidance to the project manager as which order release mechanisms touse in order to optimize his objective. © 2009 IEEE.published_or_final_versionThe 39th International Conference on Computers & Industrial Engineering (CIE 2009), Troyes, France, 6-9 July 2009. In Proceedings of the 39th CIE, 2009, p. 182-18

Scenarios for applying RFID technology in construction project management

Radio Frequency Identification (RFID) technology has been widely applied in various areas such as retail, electronic transaction, logistic and supply chain management, scientific research, security, etc. It has brought about great benefits in these areas through improving real-time information visibility and traceability. However, a widespread application of RFID in the construction industry has not taken place. One possible reason is that construction practitioners may have not been fully informed of its potentials. This paper aims to investigate various scenarios that can illustrate the uses of RFID technology in construction project management. The research starts from a brief summary of recent developments of RFID technology in different industrial sectors including construction. 16 researchers were split into 3 groups to investigate how RFID can be used in the management of materials, men, and machinery (M 3) for construction projects. Perspectives for future studies are proposed in order to fully realise the potentials. The research encourages a wider adoption of RFID technology in improving current PM practices. It also provides academia with a platform for further exploring the innovative uses of RFID technology in construction. © 2010 Elsevier B.V.postprin

An algorithm for solving rule sets-based bilevel decision problems

Bilevel decision addresses the problem in which two levels of decision makers each tries to optimize their individual objectives under certain constraints, and to act and react in an uncooperative and sequential manner. Given the difficulty of formulating a bilevel decision problem by mathematical functions, a rule sets-based bilevel decision (RSBLD) model was proposed. This article presents an algorithm to solve a RSBLD problem. A case-based example is given to illustrate the functions of the proposed algorithm. Finally, a set of experiments is analyzed to further show the functions and the effectiveness of the proposed algorithm. © 2011 Wiley Periodicals, Inc

Risk assessment using transfer learning for grassland fires

© 2019 A new direction of risk assessment research in grassland fire management is data-driven prediction, in which data are collected from particular regions. Since some regions have rich datasets that can easily generate knowledge for risk prediction, and some have no data available, this study addresses how we can leverage the knowledge learned from one grassland risk assessment to assist with a current assessment task. In this paper, we first introduce the transfer learning methodology to map and update risk maps in grassland fire management, and we propose a new grassland fire risk analysis method. In this study, two major grassland areas (Xilingol and Hulunbuir) in northern China are selected as the study areas, and five representative indicators (features) are extracted from grassland fuel, fire climate, accessibility, human and social economy. Taking Xilingol as the source domain (where sufficient labelled data are available) and Hulunbuir as the target domain (which contains insufficient data but requires risk assessment/prediction), we then establish the mapping relationship between grassland fire indicators and the degrees of grassland fire risk by using a transfer learning method. Finally, the fire risk in the Hulunbuir grassland is assessed using the transfer learning method. Experiments show that the prediction accuracy reached 87.5% by using the transfer learning method, representing a significant increase over existing methods

Smart Construction Objects

The primary aim of this research is to define smart construction objects (SCOs), the fundamental building blocks of future construction. SCOs are construction resources (e.g., machinery, device, and materials) that are made smart by augmenting them with technologies conferring autonomy, awareness, and the ability to interact with their vicinity. This smartness can enable better decision making in construction. Understanding of SCOs, however, is still in its infancy. Informed by theories on ubiquitous computing and general smart objects, this paper first defines the panoramic and interconnected properties that differentiate SCOs from conventional construction objects. Second, representative scenarios of the use of SCOs are given to illustrate the new workflow with enhanced smartness in the future. Next, using prefabrication construction as an example, this paper further elaborates SCOs using Industry Foundation Classes Extensible Markup Language and exploring their software/hardware representations. This is the first-ever research to articulate canonical SCOs and their core properties, computing applications, and representations. More specific and applicable SCOs are compellingly desired as the future study. Properly linked to building information modeling and Internet of Things, SCOs can enable a safer, greener, more efficient, and more effective construction system that has ever been seen.postprin

Naming Objects in BIM: A Convention and a Semiautomatic Approach

A consistent and easily recognizable name is the primary identifier of an object in building information modeling (BIM). Existing naming conventions vary significantly and require extensive manual work that is often tedious and error-prone. This study (1) develops a standardized naming convention for BIM objects and (2) devises a semiautomatic naming approach for saving manual work. In the proposed naming convention, each segment is included by referencing BIM standards with a consideration of BIM users’ actual needs, and the semiautomatic approach is formalized for both completed and ongoing BIM models. Validated by a control experiment and feedback from the project manager and BIM engineers of a real-life project, this research can be immediately applied to realize standardized BIM object names. This study also generates practical implications for BIM-based project management, where standardized BIM object names are required for supporting object identification and information incorporation throughout a project lifecycle. - See more at: http://ascelibrary.org/doi/10.1061/%28ASCE%29CO.1943-7862.0001314#sthash.XOoOaKep.dpufpostprin

Clinical efficacy and safety of buyang huanwu decoction for acute ischemic stroke: a systematic review and meta-analysis of 19 randomized controlled trials

Buyang Huanwu Decoction (BHD) is a well-known traditional Chinese herbal prescription for treating stroke-induced disability. The objective of this study was to evaluate the efficacy and safety of BHD for acute ischemic stroke. A systematic literature search was performed in 6 databases until February 2012. Randomized controlled clinical trials (RCTs) that evaluate efficacy and safety of BHD for acute ischemic stroke were included. Nineteen RCTs with 1580 individuals were identified. The studies were generally of low methodological quality. Only one of the trial included death or dependency as a primary outcome measure. Only 4 trials reported adverse events. Meta-analysis showed the clinical effective rate of neurological deficit improvement favoring BHD when compared with western conventional medicines (WCM), P < 0.001. There is significant difference in the neurologic deficit score between the BHD treatment group and the WCM control group, P < 0.001. In Conclusion, BHD appears to improve neurological deficit and seems generally safe in patients with acute ischemic stroke. However, the current evidence is insufficient to support a routine use of BHD for acute ischemic stroke due to the poor methodological quality and lack of adequate safety data of the included studies. Further rigorously designed trials are required.published_or_final_versio

Scalp acupuncture for acute ischemic stroke: a meta-analysis of randomized controlled trials

Scalp acupuncture (SA) is a commonly used therapeutic approach for stroke throughout China and elsewhere in the world. The objective of this study was to assess clinical efficacy and safety of SA for acute ischemic stroke. A systematical literature search of 6 databases was conducted to identify randomized controlled trials (RCTs) of SA for acute ischemic stroke compared with western conventional medicines (WCMs). All statistical analyses were performed by the Rev Man Version 5.0. Eight studies with 538 participants were included in the studies. The studies were deemed to have an unclear risk of bias based on the Cochrane Back Review Group. Compared with the WCM, 6 RCTs showed significant effects of SA for improving neurological deficit scores (P < 0.01); 4 RCTs showed significant effects of SA for favoring the clinical effective rate (P < 0.01) However, the adverse events have not been documented. In conclusion, SA appears to be able to improve neurological deficit score and the clinical effective rate when compared with WCM, though the beneficial effect from SA is possibly overvalued because of generally low methodology of the included trials. No evidence is available for adverse effects. Rigorous well-designed clinical trials are needed.published_or_final_versio

Bridging BIM and building: From a literature review to an integrated conceptual framework

A Building Information Model (BIM) is at risk of being ‘blind and deaf’ if its contained information cannot be synchronized with ongoing building processes in a real-time manner. Previous studies have attempted to explore solutions to the problem, with a view to making BIM a more useful decision-support system. However, an integrated conceptual framework summarizing these studies and structuring future development in the area is missing. Based on an ex post facto critical review of 75 papers of this kind published over the past decade, this paper proposes a conceptual framework for bridging BIM and building (BBB), which highlights the importance of synchronizing information between BIM and real-life building processes. The framework is further illustrated through a case study of prefabricated housing construction in Hong Kong. With this integrated conceptual framework, future research on BBB can proceed on a more solid footing.postprin

Speciation changes of cadmium in mangrove (Kandelia candel (L.)) rhizosphere sediments

The speciation distribution of cadmium (Cd) in mangrove (Kandelia candel (L.) Druce) rhizosphere sediment was investigated after different contents of Cd being loaded. The study results indicated that root induced changes of Cd bioavailability in the rhizosphere. Exchangeable and carbonate bound Cd in the rhizosphere sediments were lower than these in the bulk sediments, whilst an increase in Fe-Mn oxides bound and O.M/sulfide bound fractions occurred in the rhizosphere sediment. Increased levels of Cd in sediments resulted in higher Cd concentrations in mangrove plants, and the order of accumulation was: roots > hypocotyls > stems and leaves