Construction Dispute Mitigation: Quantitative and Qualitative Analytic Approach with a Focus on Bidding, Out-of-Sequence Work, and Contract Analysis

The complexity of today’s construction projects deems conflicts and disputes unavoidable. The mere presence of disputes leads to productivity losses, schedule overruns, cost overruns, and quality decline. Moreover, failure to resolve disputes in a quick manner ripples these impacts and prevents successful completion of projects. Accordingly, preventing disputes prior to taking place is always better than resolving them after the fact. There are several factors that cause disputes. However, this dissertation focuses on those related to bidding, out-of-sequence (OOS) work, and contract administration of owner’s obligations, due to the significant knowledge gaps that were identified in their research streams.The goal of this research is to cover the identified knowledge gaps by providing various effective quantitative and qualitative means of dispute mitigation at the different stages of the project’s lifecycle. To this end, the research has four main objectives; each corresponding to one of the identified major knowledge gaps. The objectives are: (1) develop an advanced model for construction bid price estimation that is able to draw sound statistical inferences even in cases of data incompleteness and dynamic behaviors of competitors; (2) present contract administration guidelines for utilizing employer’s obligations clauses under the most widely used national and international standard forms of design-build contracts; (3) identify the causes and early warning signs of OOS work and their characteristics, as well as the best practices to avoid and mitigate its impacts, and (4) develop an advanced systematic model for analyzing the dynamics of OOS.The objectives were achieved through multiple analytical quantitative and qualitative methods; utilizing Bayesian statistics, decision theory, contractual examinations, surveys and meetings, statistical analysis, decision support systems, and system dynamics simulation. The research has various intellectual merits as it tackles important research areas that have not been explored before and improves areas which needed improvement. The research also has practical merits as it provides project stakeholders with models and tools that are used in multiple stages of the project cycle to mitigate disputes. The intellectual and practical outcomes of this research will partake in further understanding construction projects, minimizing disputes at different stages, and promoting healthier contracting environments

Hybrid Optoelectronic Router for Future Optical Packet‐ Switched Networks

With the growing demand for bandwidth and the need to support new services, several challenges are awaiting future photonic networks. In particular, the performance of current network nodes dominated by electrical routers/switches is seen as a bottleneck that is accentuated by the pressing demand for reducing the network power consumption. With the concept of performing more node functions with optics/optoelectronics, optical packet switching (OPS) provides a promising solution. We have developed a hybrid optoelectronic router (HOPR) prototype that exhibits low power consumption and low latency together with high functionality. The router is enabled by key optical/optoelectronic devices and subsystem technologies that are combined with CMOS electronics in a novel architecture to leverage the strengths of both optics/optoelectronics and electronics. In this chapter, we review our recent HOPR prototype developed for realizing a new photonic intra data center (DC) network. After briefly explaining about the HOPR‐based DC network, we highlight the underlying technologies of the new prototype that enables label processing, switching, and buffering of asynchronous arbitrary‐length 100‐Gbps (25‐Gbps × 4λs) burst‐mode optical packets with enhanced power efficiency and reduced latency

Efficient Multiband Algorithms for Blind Source Separation

The problem of blind separation refers to recovering original signals, called source signals, from the mixed signals, called observation signals, in a reverberant environment. The mixture is a function of a sequence of original speech signals mixed in a reverberant room. The objective is to separate mixed signals to obtain the original signals without degradation and without prior information of the features of the sources. The strategy used to achieve this objective is to use multiple bands that work at a lower rate, have less computational cost and a quicker convergence than the conventional scheme. Our motivation is the competitive results of unequal-passbands scheme applications, in terms of the convergence speed. The objective of this research is to improve unequal-passbands schemes by improving the speed of convergence and reducing the computational cost. The first proposed work is a novel maximally decimated unequal-passbands scheme.This scheme uses multiple bands that make it work at a reduced sampling rate, and low computational cost. An adaptation approach is derived with an adaptation step that improved the convergence speed. The performance of the proposed scheme was measured in different ways. First, the mean square errors of various bands are measured and the results are compared to a maximally decimated equal-passbands scheme, which is currently the best performing method. The results show that the proposed scheme has a faster convergence rate than the maximally decimated equal-passbands scheme. Second, when the scheme is tested for white and coloured inputs using a low number of bands, it does not yield good results; but when the number of bands is increased, the speed of convergence is enhanced. Third, the scheme is tested for quick changes. It is shown that the performance of the proposed scheme is similar to that of the equal-passbands scheme. Fourth, the scheme is also tested in a stationary state. The experimental results confirm the theoretical work. For more challenging scenarios, an unequal-passbands scheme with over-sampled decimation is proposed; the greater number of bands, the more efficient the separation. The results are compared to the currently best performing method. Second, an experimental comparison is made between the proposed multiband scheme and the conventional scheme. The results show that the convergence speed and the signal-to-interference ratio of the proposed scheme are higher than that of the conventional scheme, and the computation cost is lower than that of the conventional scheme

The Role of China’s Overseas Special Economic Zones in Economic Development

The Chinese overseas SEZs came to offer a courageous, interesting model of economic development that, if successful, will generate favorable economic outcomes that extend not only to the hosting county but also to the country providing the investment opportunity. Indeed, this model has demonstrated some miraculous results inside China, driving the economy to unprecedented altitudes of growth. Nevertheless, little evidence has been set forth to display the ability of Shenzhen model to stimulate similar triumphs outside of China. To prove its validity as an effective tool, rigorous investigation needs to be put in place to assess the performance of the Chinese overseas SEZs, and more importantly to verify their contribution to the economy of hosting countries, or otherwise it will only qualify as an ambitious strategy developed by China to pursue its foreign policy agenda. The Chinese model of overseas SEZs emerges as one of the promising initiatives that gains considerable reputation from its amazing success in China. However, to be able to give full credit to this model, evidence should demonstrate its feasibility in developing countries where it has been put into action and to ensure that the element of reciprocity of benefit between China and the hosting country exists. For that purpose, this study has worked to provide an answer to one major question: “Can China’s overseas SEZs stimulate economic development of host countries?” Within the framework of this major research question the dissertation has come to the conclusion that China\u27s overseas SEZs are able to bring about significant outcomes to the host country only if they were fitted within a long-term, nationwide strategy of economic liberalization. I would assume that the benefits realized through SEZs, either static or dynamic, are, primarily, dependent on the host government’s determination and commitment. In fact, the miraculous performance of Shenzhen in China during early 1980s would not have been sustainable without the backing of her fellow SEZs and, certainly, the government’s adequate management of its Open Door policy back then. After all, a single, detached, unsupported SEZ can hardly stimulate economic growth, even if this SEZ was Shenzhen

A Digital Data Acquisition System for High Subsonic Speed Wind Tunnels

The need to reduce time and cost of running high speed (transonic & supersonic) wind tunnels and to obtain reliable experimental data is very essential to the academic and industrial worlds of aviation. Data acquisitioning technology together with the advents in computer programming made the prospects of upgrading old technology wind tunnels (those manually driven and using mercury or water manometers) a reality. Simple hardware and software are available and are cheap and very effective and can be easily installed for the purposes stated. The present paper describes a data acquisition system, suggested and installed, by the author for use on the supersonic wind tunnel at the university of Hertfordshire/UK. The tunnel layout and the acquisition system are described together with some of the validation experimental runs. The experiments were carried out originally as part of the author’s PhD research work investigating the effects of aerofoil surface irregularities at high subsonic speeds using the viscous Garabedian & Korn (VGK) method [1]

Hyperchaos in acetylcholinesterase enzyme systems

Burst generation via a complex bifurcation scenario is discussed using a two compartments model of an enzyme system with substrate inhibition kinetics affected by the production of hydrogen ions accompanying the reaction (e.g. acetylcholinesterase enzyme system). Evidences are given to support the existence of homoclinicity associated with this complex dynamics, including the generalised criterion developed by Rossler et al. [1] for the application of Sil'nikov's theorem in the case of four-dimensional systems. Complex bi-stabilities are observed in certain regions, and the structure of some attracting sets occurring near homoclinic orbits are discussed. The results support the use of such fundamental models for different dynamical modes generation and analysis. The results relate to the transition of small and large frequency oscillations to periodic bursting and vice versa in excitable cells and many biophysical systems