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72.
73.
Professor Farzad Khosrowshahi 《Construction Management & Economics》2013,31(3):227-228
Strategic IT implementation decisions for major construction projects in Hong Kong are subject to various forces or factors identified in previous research—such as external forces, technological factors and organizational factors. The aim of this research was to examine the relationship (if any) between these families of forces and evaluate their impact, individually and collectively. A complex combination of several families of forces/factors that affect decision making was found to be ‘temporal’ with respect to project teams on major projects in Hong Kong. The research was underpinned by a broad questionnaire survey to establish ‘current practice’ before in‐depth analysis of the forces by means of a case study followed by interviews with industry leaders to confirm the results. It was found that respondents (n = 33) ordered cost, security and confidentiality as the most influential factors affecting IT implementation. A difference was found in the perceptions of ‘hired‐in’ project‐based staff in joint ventures and ‘permanent staff’ of single companies, the former evaluating IT performance more highly but evaluating the strategic use of, and user satisfaction with, IT significantly lower. The major constraint on IT implementation was found to be lack of budget, not cost per se. It is concluded that the temporal factors that apply to implementing innovative IT technology in project teams are relevant to different team members at different stages in the project life cycle and these factors are conditioned by a set of business conditions applying to project‐specific coalition organizations that are different from those that apply to single‐entity organizations. 相似文献
74.
BILAL M. AYYUB Associate Professor MAGUID H. M. HASSAN Graduate research assistant 《Civil Engineering and Environmental Systems》2013,30(4):275-297
In this paper, a real-time fuzzy-based controller of construction activities is proposed. Because of the numerous uncertainties associated with construction activities, their control requires a different approach than the traditional feedback methods. These methods are essentially based on the knowledge of a transfer function that models the input/output relationships for the controlled system. For a highly complex and uncertain system such as a construction activity, a fuzzy-based control strategy was found to be a suitable and effective approach. The proposed control system is built in two main levels, the process and the activity levels. Each level comprises two main units, namely, the fuzzy controller and the self learning algorithm. The implementation of the control actions can be performed by either manipulating the states of the variables for the purpose of improving the process output, or changing the process behavior function for the same purpose. Practical examples are presented wherever possible to illustrate the proposed control strategy. 相似文献
75.
A. B. SENOUCI Associate Research Specialist A. S. HANNA Assistant Professor 《Civil Engineering and Environmental Systems》2013,30(4):317-333
Existing dynamic programming formulations are utilized for the scheduling of serial linear projects. These formulations cannot, however, be used for the scheduling of nonserial linear projects. The intent of this paper is to present a nonserial dynamic programming formulation for the scheduling of linear projects with multiple non-overlapped loop structures. The objective of the nonserial dynamic programming solution is to provide for the selection of resources, interruptions, and lags for production activities that lead to the minimum project duration. The advantages of this nonserial dynamic programming approach include its ability to handle work interruption and variable production rates. In addition, the developed system produces a graphical representation of the project schedule of minimum duration. A nonserial linear project is treated herein using the proposed method. 相似文献
76.
JI Jingwen WEI Quanjin GENG Dianqi WU Yuqin Northeast University of Technology Shenyang China Professor Dept.of Physics Northeast University of Technology Shenyang China 《金属学报(英文版)》1990,3(4):243-248
The grain boundary internal friction(GBIF)in Fe-P and Fe-P-La alloys containing traceCu has been studied.It is found that an addition of 0.584—0.722 wt-% La obviously reducesthe IF,shifts grain boundary peaks towards higher temperatures,and produces a small addi-tional peak at even higher temperature.The mechanism of GBIF is explained as the movementof defects of atomic size,namely point defects,at gram boundaries and/or their clusters un-der stress. 相似文献
77.
WANG Chunrong SONG Hailong QU Li CAO Shuzhi Institute of Metal Research Academia Sinica Shenyang China WANG Chunrong Associate Professor Institute of Metal Research Academia Sinica Shenyang China 《金属学报(英文版)》1990,3(9):217-221
A proposal for two types of press close to die,including blank coming in die and Blank cov-ering die,and four criteria for formability is put forward in the study of the superplastic airbulge forming of the metallic thin wall components.A dimensionless weigh mathematic modelfor the criteria of superplastic air bulge forming is developed to be:Q_w=1.56(WS)/(HF)+2.37(0-π/(180)-r/(r_0)+0.19The superior formability of components is approaching,if Q_W≥1,and the worse,if Q_W<1.Itwas confirmed by practice that the above mentioned model is accurate sufficiently. 相似文献
78.
LI Jing HUANG Kexiong WANG Zaoji LIU Jun Central South University of Technology Changsha ChinaGUO Chuntai Changchun Institute of Applied Chemistry Academia Sinica Changchun China LI Jing Professor Faculty of Metallurgical Physical Chemistry Central South University of Technology Changsha China 《金属学报(英文版)》1990,3(10):226-230
Interfacial tension between liquid Al and molten fluoride salt was determined using sessiledrop method combined with X-ray radiograph.A computer program of curve-fitting forcoordination of configuration of sessile drop was used in the picture processing of the sessiledrop.Regressive equation were worked out to calculate the density of the molten salt.The in-fluence of mole ratio of NaF/AlF_3,content of Li_2CO_3 and rare-earth oxides in the moltensalt on interfacial tension of Al-salt was discussed.The contact angles of liquid Al on the sur-face of graphite,graphitized carbon cathode and the graphite with coating of TiB_2 were de-termined. 相似文献
79.
XU Yourong GU Qing WANG Deying Shanghai University of Science Technology Shanghai ChinaGU Jufang Q U Tiancai Shanghai Iron Steel Research Institute Shanghai China XU Yourong Professor Department of Materials Science Shanghai University of Science Technology Shanghai China 《金属学报(英文版)》1992,5(7):60-64
The dynamic mechanical behaviours of super low carbon high Mo austenitic stainless steel(00Cr20Nil8Mo6CuN)during hot deformation have been studied by using Formaster-Presshot working simulator. The hot deformation equation, as well as the relationship between peakstrain, peak stress and Zener-Hollman parameter, together with the deformation activationenergy have been resulted through the experiments. 相似文献
80.
Professor Jeong-Du Kim Eun-Sang Lee 《The International Journal of Advanced Manufacturing Technology》1996,12(4):246-254
Fine ceramics have the properties of high hardness, chemical inertness, high thermal resistance and low electrical conductivity, but, because of high hardness and brittleness, they are very difficult to machine. Therefore, a superabrasive diamond wheel is used for mirror-like grinding of this material. In this study, an in-process electrolytic dressing system for carrying out mirror-like surface grinding was constructed. Using this system the grinding force for fine ceramics was reduced. This work shows that the application of electrolytic dressing is beneficial in obtaining a mirror-like surface when grinding fine ceramics. 相似文献